Method for inhibiting ige production
FIELD OF THE INVENTION 
     This invention relates to a method for inhibiting IgE production by use of prostaglandins. 
     BACKGROUND 
     Mammals have evolved a defensive surveillance mechanism, known as the immune system, which protects them from a wide variety of environmental agents such as pathogenic microorganisms (e.g., viruses, bacteria and parasites). The immune system can specifically recognize, immobilize and eliminate environmental agents by way of a cellular-based or immunoglobulin-based response. However, certain human diseases are caused by either an over-reaction or under-reaction of the immune system. Such inappropriate or inopportune immune responses can lead to immunodeficiencies and can lead to autoimmune diseases. 
     When the immune system recognizes environmental agents as foreign, an undesirable immunopathological disorder can result (hypersensitivity disease), commonly referred to as an allergic reaction. Allergies in man are characterized by the appearance in serum and tissue of immunoglobulins of the immunoglobulin E (IgE) isotype directed against specific environmental agents. More formally, diseases in which the predominant cause can be attributed to the degranulation of tissue mast cells, stimulated by the cross-linking of the IgE receptor by antigen-bound immunoglobulins of the IgE isotype, are classified as atopic disorders (Atopy). Antigen crosslinking of surface-bound IgE molecules leads to an immediate degranulation of the mast cells and release of pre-formed inflammatory mediators, such as histamine and proteolytic enzymes, and subsequent synthesis and secretion of other arachidonic acid metabolites, such as platelet activating factor and leukotrienes, which act as chemoattractants, inflammatory activators and spasmogens for the tissue surrounding the site of allergen exposure (J. Morley et al., Mediators of Allergy. In Allergy: Immunological and Clinical Aspects, M. H. Lessof, ed. John Wiley &amp; Sons; Chichester, England: 45-72 (1984)). This combination of pharmacological mediators (whose activities also include vasodilation and bronchoconstriction) leads to irritability in nasal passageways resulting in sneezing, running noses, congestion, headaches and watery eyes, all of which are well known symptoms of allergic rhinitis (a sub-class of the disorders collectively called atopy). Atopy includes allergic rhinitis, asthma, food allergies, drug allergies, atopic dermatitis, hyper IgE syndrome and anaphylaxis (M. H. Lessof et al. Gastrointestinal reactions and food intolerance. In Allergy: Immunological and Clinical Aspects, M. H. Lessof, ed. John Wiley &amp; Sons; Chichester, England 175-218 (1984)). Atopic disorders and similar undesirable immune effects resulting from allergic type reactions cause tissue damage and life threatening conditions. 
     It is estimated that twenty percent of the North American populations and Western European populations is effected by allergies and asthma alone. Therefore, suppression of undesirable immune effects, such as those associated with the IgE isotype, is paramount to treating patients suffering from various immune related disorders. Current methods for treating patients with immune related disorders are non-specific (i.e., destroy both the desirable and undesirable effects of the immune response) and include dangerous side effects. 
     Current therapy in allergy is generally divided into three categories. The first category of therapy is directed toward preventing the action of inflammatory mediators, by symptomatic treatment via anti-histamines, systemic bronchodilators, aerosol bronchodilators, systemic corticosteroids, and nasal steroids. The second category of therapy is directed toward generalized immuno suppression with the use of topical or systemic corticosteroids. The third category of therapy is directed toward prophylactic desensitization (by repeated injection of impure allergen mixtures) directed toward the stimulation of blocking antibodies (most likely IgG) to neutralize or compete with an IgE response. None of these therapies are specific. 
     What is needed is a therapy that is specific (i.e., does not interfere with desirable functions of the immune response but hinders the life threatening or tissue damaging aspects of the immune response) for treating undesired immunologic effects. Such an immunosuppressive treatment would benefit patients suffering from the effects of autoimmunity, and hypersensitivity. 
     Immunosuppressive effects of prostaglandins in vitro has been demonstrated with natural prostaglandin E2 (PGE 2 ) (See J. Pene et al., Proc. Natl. Acad. Sci. USA. 85: 6880 (1988)). In addition, certain prostaglandins have been disclosed as useful for the treatment of skin diseases such as psoriasis, useful for the prevention of thrombus formation, and useful for stimulating the production of growth hormone and as regulators of the immune response (see U.S. Pat. Nos. 4,155,908 and 4,128,564). Likewise, U.S. Pat. Nos. 4,260,771 and 4,059,587 disclose compounds with prostaglandin-like biological activity that are useful as renal vasodilators, as platelet aggregation inhibitors, and as treatments of certain autoimmune diseases. None of the disclosures, however, teach a method of inhibiting production of IgE. 
     The present invention provides a highly specific method for treating undesirable effects of the immune response associated with the production of IgE. The method is highly specific in that the method inhibits the IgE response without inhibiting the response of other isotypes. 
     SUMMARY OF THE INVENTION 
     The invention is a method for inhibiting IgE production which comprises administering, in an amount effective to inhibit IgE production, a prostaglandin of the formula: ##STR2## or a pharmaceutically acceptable non-toxic salt thereof, in which R is hydrogen, C 1  -C 5  alkyl, C 3  -C 8  cycloalkyl, phenyl, or mono, di- or tri-substituted phenyl in which the substituents are selected from the group consisting of bromo, chloro, fluoro, iodo, C 1  -C 5  alkyl, hydroxy, nitro, acetyl, alkoxy, carboxy, acetoxy, amino, mono- or di- alkyl amino, amido and acetamido; R 1  and R 2  independently are hydrogen or C 1  -C 5  alkyl, n 3 , n 4 , n 5 , n 6 , n 7 , and n 8  independently are zero or one; when n&#39;s are zeros, R 3  and R 4  together, R 4  and R 5  together, R 5   and R 6  together, and R 7  and R 8  together are double bonds; when n&#39;s are ones, R 3 , R 5 , R 6 , R 7  and R 8  independently are hydrogen, R 4  is hydrogen or methyl, or R 3  and R 4  together, R 4  and R 5  together, or R 5  and R 6  together are methylene. 
     In preferred prostaglandins, R is hydrogen or alkyl, R 1  is alkyl, R 2  and R 4  are hydrogen, R 4  is hydrogen or methyl, n 3 , n 4 , n 5  and n 6  are one and R 3 , R 5  and R 6  are hydrogen, n 7  and n 8  are zero indicating a double bond between positions R 7  and R 8 . 
     Examples of suitable C 1  -C 5  alkyl radicals include methyl, ethyl, propyl, isopropyl, butyl, sec. butyl, isobutyl, tert. butyl and pentyl. Examples of suitable cycloalkyl radicals are cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and cyclooctyl. Examples of suitable substituted phenyl radicals are 4-chlorophenyl, 2,4-dichlorophenyl, 4-hydroxyphenyl, 4-aminophenyl, 2-methyl-aminophenyl, 3-dimethyl-aminophenyl, 4-carboxylphenyl, 2,4-dinitrophenyl, 4-methoxyphenyl, 4-methylphenyl, 2-propylphenyl, 3,4-diethylphenyl, 4-acetylphenyl, 2,3,4-trichlorophenyl, and 2,4-dihydroxyphenyl. 
     The prostaglandins of the invention are produced by known methods and are generally prepared as a mixture of steric isomers. Because of the difficulty of producing pure isomers or the difficulty of separating a mixture of isomers, the method of the invention may be carried out using a mixture of the α and β stereochemical configurations of the prostaglandins. It is appreciated, however, that one configuration is considerably more active than the other. 
     Examples of suitable prostaglandins include (±) phenyl 11α, 16-dihydroxy-16-methyl-9-oxoprosta-3,5Z,13E-trien-1-oate, (±) methylethyl 2-[2-[3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1.alpha.-cyclopentyl]ethylcyclopropanepropanoate, (±) ethyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate, (±) 4-methoxyphenyl 2-([3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1.alpha.-cyclopentyl]-methyl-1-cyclopropanebutanoate, (±) propyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate, (±) phenyl 11α, 16-dihydroxy-4,4,16-trimethyl-9-oxoprost-13E-en-1-oate, (±) phenyl 20-ethyl-11α, and 16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate, and (±) ethyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-4Z, 13E-dien-1-oate. 
     One embodiment of the invention is directed to (±) methyl 20-ethyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate which exhibits excellent IgE inhibition and is essentially free of detrimental diarrhea side effects. 
     As used herein, IgE production is indicated by and associated with those effects resulting from inappropriate or untimely production of IgE, which production leads to eczema, asthma, food allergies, drug allergies, and symptoms like sneezing, running noses, congestion, headaches, and watery eyes. Ig refers to Immunoglobulin, which is a globular protein that has antibody activity. The E, G, A, M or D that follows the Ig prefix refers to the class of immunoglobulin. Further, as used herein, an amount effective to inhibit IgE production is that amount which alleviates or prevents the undesired effects indicated by IgE production without causing greater undesirable effects than the IgE response. In addition, the &#34;(±)&#34; symbol before the compounds indicates the racemic forms and the wavy line represents the alternate α or β configuration, which α or β diastereoisomers are separable by high performance liquid chromatography (HPLC). The broken line indicates the substituent attached is behind the ring plane (i.e., α configuration). The wedge indicates the substituent attached is in front of the ring plane (i.e., β configuration). 
     Generally, the compounds for use in the method of the invention are well known and procedures for their synthesis are readily available. For example, U.S. Pat. Nos. 4,087,621; 4,322,543; 4,312,994; 3,965,143; and J. Med. Chem. volumes 20, 26 and 29 teach how to make the compounds of this invention. 
     It has been found that in vitro assays for prostaglandins for IgE inhibition is not predictive of biological activity in vivo. For example, natural prostaglandins E 1  and E 2  exhibit inhibition of IgE in vitro but exhibits only low inhibition in vivo. Thus, the method of the invention includes a class of synthetic prostaglandins which exhibits high IgE inhibition in vivo. 
     Biological testing in vivo demonstrates that the serum IgE response can be inhibited without suppression of serum IgG levels. The assay used to detect inhibition of IgE production by the method of the invention is as follows: 
     Mouse hybridoma cells expressing either FF1-4D5 antibody or H∂A1 antibody are thawed, established in culture, and incubated in mice as ascite tumors. FF1-4D5 antibody is a mouse IgG2a monoclonal antibody of the b allotype that binds the Fd fragment of the ∂ chain of the a allotype IgD which activates β cells through antigen internalization and processing, promoting cognate interactions with antigen-specific T cells (D. K. Goroff et al., J. Immunol. 136: 2382 (1986)). H∂A1 antibody is a mouse IgG2b of the b allotype that binds the Fc fragment of the ∂ chain of the a allotype IgD which activates β cells through crosslinking IgD (I. M. Zitron and B. L. Clevinger, J. Exp. Med. 152: 1135 (1980)). Each antibody is purified from their respective ascites tumor fluid. While each antibody alone does not stimulate immunoglobulin synthesis in vivo, Ig production increases when a mixture of FF1-4D5 antibody and H∂A1 antibody is injected into mice. Serum from the injected mice is recovered and the mean concentration of IgE determined. IgE determinations demonstrate that IgE concentration peaks between about 6 and 10 days after injection (about 8 to 40 fold increase). 
     To demonstrate inhibition of IgE production by the method of the invention, mice are injected with a mixture of FF1-4D5 antibody and H∂A1 antibody, and on days 3 and 4 after the injection, compounds are administered in accordance with the method of the invention. Serum levels of IgE are determined and IgE levels are shown to be inhibited in a dose dependent manner. 
     Sera from mice treated with compounds in accordance with the method of the invention are analyzed for levels of IgG1, IgG2a, IgG3, and IgM. Analysis shows that IgG1, IgG2a, IgG3, and IgM levels are not decreased while at the same time IgE levels are decreased. 
     Although a mouse model was used to measure IgE production and inhibition of IgE production, other models can be used. Examples of other models capable of measuring IgE production and inhibition of IgE production include the guinea pig model, the rabbit aspergillus model, and the helminthic parasite infected mouse model. More specifically, the Nippostrongulus model (F. Finkelman et al., Proc. Natl. Acad. Sci USA 83: 9675 (1986), rabbit alternaria tenuis model (G. Larson et al., Federation Proceedings 46: 105 (1987), rat antigen specific model (S. Blythe et al. Am. Rev. Respir. Dis. 134: 1246 (1986), and the guinea pig anaphylaxis model (J. Clausen et al., Allergy 40: 15 (1985) can be used. 
     The preferred time for practicing the method of the invention is prior to an IgE response. Therefore, the method of the invention is preferably used prophylactically. However, the method of the invention can be used after the effects of an IgE response are in progress. Prophylactic use also includes practicing the method of the invention several hours to several weeks prior to anticipated exposure to the IgE eliciting agent (e.g. hay fever season), preferably several weeks. The compounds can be administered by a variety of routes, depending on the circumstances. 
     The compounds for use in the method of the invention can be administered in the form of a pharmaceutical composition comprising one or more of the compounds or pharmaceutically acceptable non-toxic salts thereof in admixture with one or more pharmaceutically-acceptable non-toxic diluents or carriers. 
     Regardless of the route of administration selected, the compounds of the invention are formulated into pharmaceutically acceptable dosage forms by conventional methods known to those skilled in the art. 
     The compounds can be administered in such oral dosage forms as tablets, capsules, pills, powders, granules, suspensions, solutions, elixirs, or syrups. Such oral pharmaceutical dosage forms employ such ingredients as diluents and carriers, excipients and lubricants such as glucose, lactose, sucrose, corn and potato starch, sodium carboxymethylcellulose, ethyl cellulose, cellulose acetate, powdered gum carboxymethylcellulose, ethyl cellulose, cellulose acetate, powdered gum tragacanth, gelatin, alginic acid, agar, stearic acid, sodium, calcium and magnesium stearates, sodium lauryl sulfate, polyvinylpyrrolidone, sodium citrate, calcium carbonate, dicalcium phosphate; as well as various agents, surfactants, emulsifiers, dispersing agents, flavoring agents and the like. General texts in the field include Remington&#39;s Pharmaceutical Sciences, Ed. Arthur Osol, 16th edition, 1980, Mack Publishing Co., Easton, PA. 
     The compounds can also be administered intravascularly, intraperitoneally, subcutaneously, intramuscularly, or topically, using forms known to the pharmaceutical art. Pharmaceutical compositions adapted for parenteral administration employ diluents and carriers such as water and water-miscible organic solvents such as sesame oil, groundnut oil, aqueous propylene glycol, and N,N&#39;-dimethylformamide. Examples of such pharmaceutical compositions include sterile, isotonic, aqueous saline solutions of the compounds for use in the method of the invention which can be buffered with a pharmaceutically acceptable buffer. In general, the preferred form of administration is oral. 
     An effective but non-toxic quantity of the compound is employed in treatment. The dosage regimen for treatment with the compounds of this invention is selected in accordance with a variety of factors, including the type, age, weight, sex, and medical condition of the patient; and the severity of the condition; the route of administration and the particular compound employed. An ordinarily skilled physician can readily determine and prescribe the effective amount of the compound required to prevent or arrest the progress of the condition. In so proceeding, the physician could employ relatively low doses at first and subsequently increase the dose until a maximum response is obtained. Dosages of the compounds of the invention can be in the range of about 1 μg/kg to 100 μg/kg bodyweight, preferably in the range of about 10-80 μg/kg. 
     In the pharmaceutical compositions and methods of the present invention, the foregoing active ingredients will typically be administered in admixture with suitable pharmaceutical diluents, excipients, or carriers (collectively referred to herein as &#34;carrier&#34; materials) suitably selected with respect to the intended form of administration, that is, oral tablets, capsules, elixirs, syrups, and the like, and consistent with conventional pharmaceutical practices. For example, for oral administration in the form of tablets or capsules, the active drug components may be combined with any oral non-toxic pharmaceutically acceptable inert carrier including lactose, starch, sucrose, cellulose, magnesium stearate, dicalcium phosphate, calcium sulfate, and mannitol; for oral administration in liquid form, the active drug components may be combined with any oral non-toxic pharmaceutically acceptable inert carrier including ethanol and the like. Moreover, when desired or necessary, suitable binders, lubricants, disintegrating agents, and coloring agents can also be incorporated in the mixture. Suitable binders include starch, gelatin, natural sugars, corn sweeteners, natural and synthetic gums such as acacia, sodium alginate, carboxymethylcellulose, polyethylene glycol, and waxes. Lubricants for use in these dosage forms include boric acid, sodium benzoate, sodium acetate, and sodium chloride. Disintegrators include, without limitation, starch, methylcellulose, agar, bentonite, and guar gum. Sweetening and flavoring agents and preservatives are included where appropriate. 
     The following examples illustrate the specific embodiments of the invention described herein. As would be apparent to skilled artisans, various changes and modifications are possible and are contemplated within the scope of the invention described. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Preparation of Compounds for Use in the Method of the Invention 
     EXAMPLE 1 
     Preparation of ##STR3## (±) methyl 2-[2-(3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1.alpha.-cyclopentyl]ethyl]cyclopropanepropanoate is as follows: ##STR4## 
     The Δ 4 ,5 cis cyclopentenone (Collins et al., J. Med. Chem. 26:786 (1983)) (714 mg 3 mmol) is dissolved in 9 ml of dimethylformamide (DMF) and treated successively with 300 mg of imidazole and 540 mg (3.3 mmol) of t-butyl dimethyl chlorosilane. The reaction mixture is stirred at room temperature for 2 hours, diluted with ether, washed with H 2  O four times, dried (Na 2  SO 4 ) and evaporated to an oil which is purified by chromatography (silica gel 10% EtOAc in hexane) to give 928 mg (90% yield) of product as an oil. ##STR5## 
     The above cyclopentenone (725 mg, 2.12 mmol) is dissolved in 25 ml of benzene and treated with 3.2 ml of a 2M solution (6.4 mmol) of diethyl zinc (Et 2  Zn) and 2.7 g (10 mmol) of methylene iodide (CH 2  I 2 ). The reaction mixture is stirred at room temperature for 48 hours, poured into ether, washed once with a 1N HCl solution, then washed twice with water, dried (Na 2  SO 4 ) and evaporated. The residue is chromatographed on silica gel (10% EtOAc/hexane) to give 415 mg (55% yield) of product as an oil. ##STR6## 
     Substitution of the above compound into the procedure described for preparation of compound 1b (described in J. Med. Chem., 26:786 (1983)) provides (±) methyl 2-[2-[3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1.alpha.-cyclopentyl]ethyl]cyclopropanepropanoate as a viscous oil.  1  H NMR (CDCl 3 ): δ0.66 (m, cyclopropane protons); 0.93 (t, C-20); 1.19 (s, C-16 CH 3 ); 4.09 (q, C-11). 
     EXAMPLE 2 
     Preparation of ##STR7## (±) methyl 2-[2-[3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1.alpha.-cyclopentyl]methyl]cyclopropanebutanoate is as follows: 
     Substitution of Δ 5 ,6 cis cyclopentenone ##STR8## (preparation is described in P. Collins et al., J. Med. Chem. 20:1152 (1977)) into the procedures described above gives (±) methyl 2-[2-[3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1.alpha.-cyclopentyl]methyl]cyclopropanebutanoate as a viscous oil.  1  H NMR (CDCl 3 ): δ-0.25 (from TMS) (m, cyclopropane protons); 0.68 (m, cyclopropane protons); 0.93 (t, C-20); 1.18 (s, C-16-CH 3  ; 4.08 (q, C-11). 
     EXAMPLE 3 
     Preparation of ##STR9## (±) methyl 11α,16-dihydroxy-4,4,16-trimethyl-9-oxoprost-13E-en-1-oate is as follows: ##STR10## 
     Diethylamine (800 mg, 11 mmol) in 5 ml tetrahydrofuran (THF) is cooled to -60° C. and treated with n-butyl lithium (4.8 ml of a 2.3M solution in hexane, 11 mmol) followed by 2 g of hexamethylphosphoric triamide. The reaction mixture is stirred for 1 hour at -60° C. and then 1.53 g (10 mmol) of the imine (i) (Reference: Cuvigny and Normant, Bull. Soc. Chim. France 3976 (1970)) is added in 2 ml of THF. The reaction mixture is stirred for 2 hours at +10° C., cooled to -40° C. and treated with 2.1 g (9 mmol) of the ethylene ketal of 2-keto-6-bromohexane in 2 ml of THF. The reaction mixture is allowed to come to room temperature and to stand overnight. The reaction mixture is diluted with ether, washed twice with H 2  O, dried (Na 2  SO 4 ) and evaporated to give 3.2 g of product as an oil. ##STR11## 
     The imine (7 g, 27.7 mmol) is dissolved in 75 ml of THF containing 4.2 ml of glacial acetic acid and allowed to stand at room temperature overnight. The solution is diluted with ether, washed 3 times with H 2  O, dried (Na 2  SO 4 ) and evaporated to give 4.7 g (93%) of an oil. ##STR12## 
     The aldehyde (1.72 g, 10 mmol) and the commercially available phosphine (carboethoxymethylene triphenylphosphorane) (3.83 g, 11 mmol) are dissolved in 25 ml of toluene and refluxed for 24 hours. The solution is cooled, evaporated to a residue (which is taken up in hexane) and filtered (to remove triphenylphosphine oxide), evaporated and chromatographed on silica gel (15% EtOAc/hexane) to give an oil (2.06 g, 80%). ##STR13## 
     The keto ester (2.06 g, 8 mmol) is dissolved in 30 ml of THF and treated with 10 ml of 1N HCl solution and allowed to stand at room temperature overnight. The solution is diluted with H 2  O and extracted with ether twice. The ether extracts are combined, dried (Na 2  SO 4 ) and evaporated. The residue is taken up in 15 ml of methanol, treated with 6 ml of 2N NaOH and allowed to stand at room temperature for 48 hours. The solution is diluted with H 2  O and extracted with ether to remove neutral materials. The alkaline aqueous solution is acidified in HCl and extracted once with ether and twice with ethyl acetate (EtOAc). The extracts are combined, dried (Na 2  SO 4 ) and evaporated to give 1.6 g (92% yield) of a yellow oil. ##STR14## 
     The acid (214 mg, 1 mmol) is dissolved in 25 ml of ethanol and hydrogenated at room temperature and atmospheric pressure using 43 mg of 5% Pd/C as catalyst. The solution is filtered and evaporated to give the saturated acid as an oil. 
     Substitution of this acid into the procedures described in J. Med. Chem., 29:1198 (1986) for preparation of (±) methyl 7-(3-hydroxy-5-oxo-1-cyclopenten-1-yl)-5(E)-heptenoate provides the hydroxycyclopentenone ##STR15## which, when substituted into the procedures for conversion of (±) methyl 7-(3-hydroxy-5-oxo-1-cyclopenten-1-yl)-5(E)-heptenoate to the corresponding prostaglandin, gives (±) methyl 11α,16-dihydroxy-4,4,16-trimethyl-9-oxoprost-13E-en-1-oate as a viscous oil.  1  H NMR (CDCl 3 )δ0.82 (s CH 3  groups at C-4); 3.72, (s, OCH 3 );(4.05 (q, C-11); 5.50, (m, C-13,14). 
     EXAMPLE 4 
     Preparation of ##STR16## (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate is prepared in substantial accordance with the teachings in U.S. Pat. No. 4,087,621 and P. W. Collins et al., J. of Med. Chem. 20: 1152 (1977), both publications are incorporated herein by reference. 
     EXAMPLE 5 
     Preparation of ##STR17## (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-4Z,13E-dien-1-oate is prepared in substantial accordance with the teachings in U.S. Pat. No. 4,322,543 and P. W. Collins et al., J. of Med. Chem. 26: 786 (1983), both publications are incorporated herein by reference. 
     EXAMPLE 6 
     Preparation of ##STR18## (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-3,5Z,13-trien-1-oate is prepared in substantial accordance with the teachings in U.S. Pat. No. 4,312,994 and P. W. Collins et al, J. of Med. Chem. 29: 1195 (1986), both publications are incorporated herein by reference. 
     EXAMPLE 7 
     Preparation of ##STR19## (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate is in substantial accordance with the teachings in U.S. Pat. No. 3,965,143 and P. W. Collins et al., J. of Med. Chem. 20: 1152 (1977), both publications are incorporated herein by reference. 
     EXAMPLE 8 
     Preparation of ##STR20## (±) methyl-20-ethyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate is in substantial accordance with the teachings above for making (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate, with the appropriate omega side chain intermediate employed. 
     EXAMPLE 9 
     Preparation of (±) 11α,16-dihydroxy-16-methyl-9-oxo-prost-13E-en-1-oic acid: ##STR21## 
     To a stirred suspension of 3.1 g of (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate in 20 ml Tris buffer (pH 8.0) is added 50 ml porcine liver esterase (Sigma, St. Louis, Mo.). After 3 hours of stirring at room temperature, the reaction is extracted with 4 portions of ethyl acetate, the extracts combined, dried (Na 2  SO 4 ), evaporated and chromatographed on silica gel to give 2.8 g of (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oic acid. 
     EXAMPLE 10 
     Preparation of (±) 4-(acetylamino)phenyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate: ##STR22## 
     A mixture of 0.37 g (±) 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oic acid, 0.29 ml triethylamine, 0.27 ml isobutylchloroformate in 3.0 ml acetone is cooled to -5° C. A solution of p-acetamidophenol (0.38 g) in 12 ml pyridine is then added and the mixture stirred at room temperature overnight. The mixture is poured into ethyl acetate and washed with successive portions of 1N HCl, 5% NaHCO 3  and dried (Na 2  SO 4 ). After chromatography on silica gel, 65 mg of the desired product is obtained.  1  H NMR (CDCl 3 ): δ0.91 (t, CH 3 ); 1.13 (s, CH 3 ); 4.00 (q C.11 H, 6.85-7.6 (aromatic protons). 
     EXAMPLE 11 
     Preparation of (±) methylethyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate: ##STR23## (±) 11α,16-dihydroxy-16-methyl-9-oxoprost-3E-en-1-oic acid (55 mg) in 3 ml of methylene chloride is treated with 0.25 ml of pyridine, 1 ml of isopropanol and 75 mg of dicyclohexylcarbodiimide. The reaction mixture is stirred at room temperature under a nitrogen atmosphere for 48 hours, and then quenched by addition of 0.25 ml of acetic acid. The solvent is evaporated and the residue chromatographed on silica gel (65% ethyl acetate/35% hexane as eluent) to give 19 mg of desired product as a viscous oil.  1  H NMR (CDCl 3 ): δ1.27 (d, isopropyl CH 3  &#39;s); 4.08 (q, C.11 H), 5.03 (m, isopropyl CH). 
     EXAMPLE 12 
     Preparation of (±) methyl-11α,16-dihydroxy-16-methyl-9-oxoprostan-1-oate: ##STR24## 
     (±) methyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate (100 mg) in 15 ml of ethanol containing 100 mg of 4% palladium on carbon is hydrogenated at room temperature and atmospheric pressure for 24 minutes. The solution is filtered and evaporated. The residue is chromatographed on silica gel (60% ethyl acetate/40% hexane as eluent) to give 86 mg of desired product as a viscous oil. 1H NMR (CDCl 3 ): ∂0.93 (t, C.20 CH3); 1.18 (d, C.16 CH 3  ; 3.68 (s, OCH 3 ); 4.17 (q C.11 H). 
     Reagents and Assays 
     A frozen cell suspension of rat B lymphocyte hybridoma cells (B1E3) as described in A. D. Keegan et al., FASEB Journal V.2, 5541(1988), is rapidly thawed at about 37° C. and mixed drop by drop with 1 ml of supplemented mammalian tissue media containing 95% RPMI (Roswell Park Memorial Institute)1640 (Gibco, Grand Island, N.Y.), 5% Fetal Calf Serum (Gibco), 1 mM sodium pyruvate (Gibco), and 2 mM glutamine (Gibco). The diluted resuspended cells are collected by centrifugation at 1200 rpm for 5 minutes in a Sorvall RT6000 centrifuge. The spent media is removed by aspiration. The cells are resuspended in 10 ml of the media described above, plated in a CoStar T25 sterile tissue culture flask and incubated at 37° C. in 100% humidity and about 5% carbon dioxide (CO 2 ). When the cells reach a concentration of about 1×10 6  cells/ml, they are diluted into the same media to a concentration of about 1×10 5  cells/ml. After about 10×10 6  cells are available, an ascites tumor is grown in Lou-M rats. 
     Ten (10) Lou-M rats (Charles River, Wilmington, Mass.) are primed for ascites tumor growth by intraperitoneal injection with about 1 ml of Freunds Incomplete Adjuvant (Gibco, Grand Island, N.Y.). 7-10 days later about 1×10 6  B1E3  hybridoma cells are inoculated into the primed rats intraperitoneally. After 6-11 days a solid tumor is seen in the rats. The ascites fluid is removed with a 5 ml syringe affixed to a 18 gauge needle. Cells are removed by centrifugation. 
     Monoclonal antibodies are generally purified by chromatography over protein G Sepharose. Ascites fluid is stored frozen at -40° C. until needed. The ascites is thawed at 2°-8° C. and diluted with 9 volumes of 0.02M Na 2  HPO 4 , pH 8.5. The diluted ascites is stirred at 2°-8° C. for 1 hour. If a precipitate is visible, the solution is centrifuged at 23,000×g in a GSA (Sorval) rotor for 1 hour. The supernatant is decanted and filtered through a 0.2 micron cellulose acetate filter (Amicon, Lexington, Mass.). 
     The filtered column feed is then passed over a column of protein G Sepharose that has been equilibrated with 0.02M Na 2  HPO 4  buffer, pH 8.5. Capacity is approximately 5 ml of diluted ascites per ml of protein G Sepharose. After loading, the column is washed with 0.02M Na 2  HPO 4  buffer, pH 8.5 until absorbance at 280 nm returns to baseline. The antibody is eluted from the protein G Sepharose by washing the column with 0.1M glycine/HCl buffer, pH 2.7. Fractions showing absorbance at 280 nm are adjusted to pH 7 with 1M Tris base. Fractions are pooled and dialyzed against 50 mM phosphate buffered saline, pH 7.0. Purity of purified antibodies is checked by Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS PAGE). Protein is determined using absorbance at 280 nm, assuming an E 1  %=14. 
     Alternatively, monoclonal antibodies can be purified by chromatography over Baker ABx resin. ABx resin (40 micron particle size) is swelled in 1M potassium phosphate buffer, pH 7.0, packed into an Amicon 2.2 cm column to give a bed height of 10 cm. The column is then washed with 5 column volumes of 1  M potassium phosphate buffer, pH 7.0, 10 column volumes of distilled water, 10 column volumes 1M HOAc, and then washed exhaustively with 10 mM MES buffer, pH 5.6 (Sigma, St. Louis, Mo.). 
     Ascites is diluted with 9 volumes of 10 mM MES buffer, pH 5.6 and gently mixed at 2°-8° C. for 1 hour. Precipitate is removed by centrifugation in a GSA rotor at 23,000×g for 30 minutes and filtered through a 0.2 micron cellulose acetate filter. The filtered solution is applied to the equilibrated column of ABx resin. After loading, the column is washed with 10 mM MES, pH 5.6 until absorbance at 280 nm returns to baseline. 
     Elution of bound material is effected with a gradient of 100 mL 10 mM MES pH 5.6 to 100 mL NH 4  OAc. Flow rate is approximately 0.8 mL/min, and 12-15 ml fractions are collected during elution. Fractions are analyzed by SDS PAGE, and pooled based on qualitative assessment of antibody purity and dialyzed as described above. The antibody is concentrated to about 1 mg/ml in an Amicon stirred cell with a YM10 filter (Amicon, Lexington, Mass.) at 4° C. An absorbance of 1.4 at 280 nm in a 1 cm cell is equal to 1.0 mg/ml. 
     A murine IgE (known as anti-DNP-IgE, as described by Liu et al., J. Immunol. 124:2728 (1980)) is purified as described above. The IgE standard is stored in phosphate buffered saline (PBS) with 2% newborn Calf Serum (Gibco, Grand Island, N.Y.) at -80° C. at 25 μg/ml. 
     A frozen cell culture of rat B lymphocyte hybridoma cells (R1E4) (also referred to as 84-1c as described in M. Baniyash et al., Mol. Immunol. 25:705 (1988)) is thawed and expanded as described above. About 10×10 6  cells are injected into nude mice (Charles River, Wilmington, Mass.) as described above. The mice are primed seven days in advance with 1 ml intraperitoneal injection of pristane. R1E4 antibody is purified as described above. About 2 mg/ml solution of R1E4 antibody is added to a Spectra/por molecular porous tubing membrane (molecular weight cut-off 12,000-14,000) and sealed with Spectrum clips (Spectrum Medical Industries, Inc., Los Angeles, Calif.). The solution is changed to about 0.1M sodium carbonate (pH 8.6) by dialysis versus 1 L of this buffer at 4° C. for 18 hours with 3 changes. The R1E4 antibody is derivatized with biotin by mixing 2 ml dialyzed antibody at 2 mg/ml with 400 μl Sulfo-NHS-biotin (Pierce Chemical Co., Rockford, Ill.) dissolved at 1 mg/ml in water. The antibody plus NHS-biotin reacted at ambient temperature for 2 hours. The unreacted biotin is removed by placing the reaction mixture in a Spectra/Por dialysis bag (14,000 MW cutoff) and dialyzed against 1 liter phosphate buffered saline (PBS). The dialysis solution is changed 3 times over an 18 hour period at 4° C. Biotinylated R1E4 is stored at -80° C. at about 2.5 mg/ml. 
     ASSAY A 
     ELISA (enzyme linked immunosorbant assay) measurements of IgE are as follows. About 5 μg of B1E3 antibody in 100 μl borate buffered saline (pH8.5) is added to wells of a NuncImmulon II 96 well plate (DiRuscio &amp; Assoc., St. Louis, Mo.) at 37° C. for 90 minutes. The non-bound antibody is removed by flicking the plate. Unreacted sites on the plastic plate are blocked by adding about 200 μl of a 2% solution of newborn bovine serum (NBS) in PBS at 37° C. for 60 minutes. The standard IgE (or an unknown murine serum sample) is diluted to between about 4 ng/ml-256 ng/ml in Hanks-HS (20 mM Hepes, 2% NBS in Hanks Balanced Salt Solution, Gibco, Grand Island, N.Y.) or to 1/200 to 1/1000 in Hanks-HS respectively. 100 μl of standard (or unknown dilutions) are added in triplicate to the wells of the plate and allowed to absorb to B1E3 antibody at about 37° C. for 2-4 hours. The solution is removed by flicking the plate and each well is washed with about 0.5 ml 0.05% Tween 20-PBS 5 times. About 100 μl of biotinylated R1E4, called the primary antibody, diluted to 200 ng/ml is added to all wells and incubated at about 4° C. overnight. The solution is removed by flicking the plate and washed 5 times as described above. The developing reagent (Avidin and biotin-horse radish peroxidase) is incubated in 2% NBS in PBS at ambient temperature for 30 minutes, according to manufacturer&#39;s specifications (Vector Laboratories, Burlingame, Calif.). About 100 μl of developing reagent is added to each well and incubated at ambient temperature for 30 minutes. Colorimetric substrate for the developing reagent (ABTS peroxidase substrate system, KPL, Gaithersburg, Md.) is prepared by mixing equal volumes of solutions A and B and incubating at ambient temperature for  60 minutes. The developing reagent solution is removed by flicking the plate and washed 5 times as described above. About 100 μl of the mixture of substrates is added to each well and incubated at ambient temperature for 60 minutes. The optical density of each well is determined on a BioTek ELISA reader (Biotek Instruments, Inc., Burlington, Vermont) and the absorbance data transferred electronically to a DEC VAX mainframe computer. A standard curve is fitted to the IgE standard optical densities using straight line, linear regression statistical fits. IgE in the unknown serum samples is determined by comparing the optical density of the unknown to the standard curve and multiplying that number by the dilution of serum used in the assay. 
     ASSAY B 
     Mouse IgG1 measurement by a two site sandwich ELISA is as follows. About 5 μg of rabbit anti mouse IgG (Organon-Teknika-Cappel, Malvern, Pa.) is attached to the wells of a NuncImmulon 96 well plate and IgG1 levels are determined in substantial accordance with Assay A except with the following changes. The IgG1 standard is purchased from Southern BioTech, Birmingham, Ala., and stored at 10 μg/ml in 2% NBS in PBS at 4° C. The standard curve is prepared by diluting the mouse IgG1 standard in 0.05% Tween-80 in PBS, and is linear between 3.9 and 250 ng/ml. Serum containing IgG1 is diluted 1/10,000 to 1/1,000,000 in 0.05% Tween 80-PBS, to place the measurement within the standard curve. Standard IgG1 (or diluted serum) is incubated at about 37° C. for 1 hour and the plates are washed with 0.05% Tween 80-PBS as described in Assay A. About a 1/3,000 dilution of Goat anti mouse IgG1 (Southern Biotech, Birmingham, Ala.) conjugated to alkaline phosphatase in 0.05% Tween 80-PBS is added to each well and incubated at about 37° C. for 60 minutes. The plate is washed and colorimetric substrate, prepared as described by the manufacturer (Alkaline Phosphatase Substrate System, KPL, Gaithersburg, Md.), is added and optical density and data analysis is performed in the same manner as Assay A. 
     ASSAY C 
     Measurement of mouse IgG2a by a two site sandwich ELISA is performed in substantial accordance with the teaching of Assay B except with the following changes. NuncImmulon II plates are used in this assay. The IgG2a standard is purchased from Southern Biotech. The standard curve is linear between 4-250 ng/ml. Serum containing IgG2a is diluted 1/6400 to 1/1,000,000. About a 1/6,000 dilution of goat anti mouse IgG2a (Southern Biotech) conjugated to alkaline phosphatase is used. 
     ASSAY D 
     Measurement of mouse IgG3 by a two site sandwich ELISA is performed in substantial accordance with the teaching of Assay B except for the following changes. About 25 ng of rabbit anti mouse IgG3 (Zymed Laboratories, San Francisco, Calif.) is attached to NuncImmulon 96 well plates. The IgG3 standard is purchased from Southern Biotech. The standard curve is linear between 1-62 ng/ml. Serum containing IgG3 is diluted 1/60,000 to 1/1,000,000. About a 1/6000 dilution of goat anti mouse IgG3 (Southern Biotech) conjugated to horse radish peroxidase is used as a combined primary antibody and developing reagent. 100 μl is added to each well and the plate incubated for 60 minutes at 37° C. The colorimetric substrate is prepared and used as described in Assay A. 
     ASSAY E 
     Measurement of mouse IgM by a two site sandwich ELISA is performed in substantial accordance with the teachings of Assay B except for the following changes. About 250 ng of rabbit anti-mouse IgM (Zymed Laboratories) is used to coat a NuncImmulon 96 well plate. The IgM standard is purchased from Southern Biotech. The standard curve is linear between 8-500 ng/ml. Serum containing IgM is diluted 1/4,000 to 1/60,000. About a 1/10,000 dilution of goat anti mouse IgM conjugated to horse radish peroxidase is used as a combined primary antibody and developing reagent. 100 μl is added to each well and the plate is incubated at about 4° C. overnight. The colorimetric substrate is prepared and used as described in Assay A. 
     ASSAY F 
     Stimulation of a transient serum IgE response in mouse with two monoclonal antibodies directed against IgD is carried out as follows. 
     Mouse hybridoma cells expressing either FF1-4D5 antibody or H∂Al antibody are thawed, established in culture, and incubated in CB6 F1 female mice as an ascites tumor and each immunoglobulin is purified from the ascites fluid as described above. Both antibodies, stored separately, are dialyzed and concentrated at about 5 mg/ml in PBS. Antibodies are stored at -20° C. 
     A group of 4-5 Balb/c female mice (Charles River, Wilmington, Mass.) are maintained on water and chow ad librium. Individual mice between the age of 10-20 weeks are tagged with an ear label (National Band and Tag, Newport, Ky.). On day 0 each mouse receives about a 250-500 μl injection (mixture of 100 μg FF1-4D5 antibody and 100 μg H∂Al antibody dissolved in PBS) intravenously or subcutaneously. The mice are immobilized in a plastic shield with a slit for their tail to pass through. The tail vien is dilated with a swab of xylene and injected using a 281/2 gauge needle attached to a 1 cc syringe. 
     On days-1 (preimmune), 7, 8, 9 and 11, about 50-100 μl of serum is recovered separately from each mouse by puncturing the retroorbital venous sinus cavity. The mice are immobilized by tightly gripping the skin around the neck. Pressure is applied with a finger placed under the eye, causing the blood to pool in the retroorbital venus sinus cavity. An 18-22 gauge needle is used to puncture the vein. The drops of blood are collected by gravity into a 1.5 ml microtainer tube. The blood is permitted to coagulate at about 4° C. for 20 minutes to 4 hours. The clot is removed by centrifugation in an Eppendorf centrifuge at 500 rpm for about 20 minutes at 4° C. The serum in the supernatant is removed and transferred to a clean 1.5 ml polypropylene conical tube as described above. 
     Serum samples are stored, coded by mouse number from ear tag and day of bleed, at -20° C. Samples are diluted and IgE concentration determined by Assay A. Table 1 shows the mean IgE concentration of 4 treated mice on days -1 (Pre-treatment as background). The data indicate that IgE production peaks around eight days after injection of the immunostimulant. 
     
                       TABLE 1                                                     
______________________________________                                    
Day         IgE ± SD (ng/ml)                                           
______________________________________                                    
-1          1,135 ± 57                                                 
7           23,303 ± 2572                                              
8           38,717 ± 1814                                              
9           12,846 ± 4738                                              
11          3,570 ± 865                                                
______________________________________                                    
 
    
     EXAMPLE 13 
     Nine groups of 4 Balb/c female mice per group are injected with 100 μl FF1-4D5 antibody and 100 μl H∂Al antibody on day 0 in accordance with Assay F. On day 3 and 4 individual groups receive at 7 a.m., 1 p.m., 7 p.m. and 11 p.m. 250 μl of the indicated dose of (±)methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate dissolved in PBS injected peritoneally (IP) within 5 mm of the nipple with a 2811/2 gauge syringe. Group A is a control without any prostaglandin. Group B is a control which was injected by PBS alone. Group C is a control which was injected by 0.01% ethanol alone. Group D is a control which was injected by PBS on Day 0 and 20 μg of the prostaglandin on Day 3 and 4. 2 μg (Group E), 5 μg (Group F), 10 μg (Group G), 20 μg (Group H) or 40 μg (Group I) of the prostaglandin is injected into the respective groups. 
     On day -1 and 8, 50-100 μl of serum is recovered separately from each mouse in substantial accordance with Assay F. Serum IgE levels are determined in substantial accordance with Assay A. Inhibition of serum IgE synthesis by (±)methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate at different doses are shown in Table 2. The data show that the prostaglandin of this invention reduces IgE production in a dose dependent manner. The data further show that a dose of 2 μg is sufficient to cause a significant reduction (about 62% less) in IgE production and that a dose between 20 μg and 40 μg is sufficient to keep IgE production at normal levels. 
     
                       TABLE 2                                                     
______________________________________                                    
Mean IgE ± SD (ng/ml)                                                  
______________________________________                                    
Day of  Group A      Group B    Group C                                   
Bleed   0 μg      0 μg    0 μg                                   
______________________________________                                    
-1       1340 ± 217                                                    
                     1548 ± 762                                        
                                1343 ± 308                             
8       14083 ± 610                                                    
                     15890 ± 4241                                      
                                14478 ± 1345                           
______________________________________                                    
Day of  Group D      Group E    Group F                                   
Bleed   40 μg     2 μg    5 μg                                   
______________________________________                                    
-1      1289 ± 10 1294 ± 232                                        
                                1292 ± 185                             
8        1026 ± 387                                                    
                     5401 ± 883                                        
                                5076 ± 378                             
______________________________________                                    
Day of  Group G      Group H    Group I                                   
Bleed   10 μg     20 μg   40 μg                                  
______________________________________                                    
-1       1382 ± 135                                                    
                     1308 ± 204                                        
                                1114 ± 324                             
8        2661 ± 504                                                    
                     1608 ± 272                                        
                                1217 ± 344                             
______________________________________                                    
 
    
     EXAMPLE 14 
     Five groups of 4 Balb/c female mice per group are injected with 100 μg FF1-4D5 antibody and 100 μg H∂Al antibody on Day 0 as described in Assay F. On day 1 and 2 (Group A), day 2 and 3 (Group B), day 3 and 4 (Group C), day 4 and 5 (Group D) received IP injections of 5 μg (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate as described in Example 13. An untreated control is Group E. The results are shown in Table 3. IgE production is inhibited optimally when administered on day 3 and 4. The data show that regardless on what day the prostaglandin was administered IgE production (synthesis) was inhibited. The data also indicate that IgE production was still suppressed even after 11 days. 
     
                                           TABLE 3                                 
__________________________________________________________________________
Serum IgE ± SD (ng/ml)                                                 
     Day of                                                               
Group                                                                     
     Admin.*                                                              
           Day -1                                                         
                 Day 8   Day 9   Day 11                                   
__________________________________________________________________________
A    1,2   1344 ± 135                                                  
                 9753 ± 4566                                           
                         10678 ± 8402                                  
                                 2355 ± 709                            
B    2,3   1293 ± 88                                                   
                 6233 ± 1948                                           
                         5328 ± 1811                                   
                                 2139 ± 396                            
C    3,4   1517 ± 166                                                  
                 4683 ± 1247                                           
                         4505 ± 1155                                   
                                 1865 ± 361                            
D    4,5   1644 ± 560                                                  
                 7969 ± 1821                                           
                         7145 ± 1763                                   
                                 2316 ± 496                            
E    None  1363 ± 159                                                  
                 19549 ± 4166                                          
                         17498 ± 5076                                  
                                 5317 ± 831                            
__________________________________________________________________________
 *(±) methyl                                                           
 11α,16dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate           
 
    
     EXAMPLE 15 
     Ten groups of 4 Balb/c female mice per group are stimulated for IgE synthesis on day 0 by injection of FF1-4D5 antibody and H∂Al antibody as described in Assay F. On day 3 and 4 individual groups are injected IP with 1.0 μg (Group B), 2.0 μg (Group C), 10.0 μg (Group D), 40 μg (Group E) of (±)methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate at 7 a.m., 1 p.m. and 7 p.m. or 0.5 μg (Group F), 1.0 μg (Group G), 2.0 μg (Group H), 10.0 μg (Group I) or 40.0 μg (Group J) of (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate at 7 a.m, 1 p.m., 7 p.m. and 11 p.m. Group A is an untreated control. Individual mice are bled and serum IgE concentrations measured by Assay A. The results are shown in Table 4. The data indicate that (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate is equally effective at inhibiting IgE production in a dose dependent manner whether administered 3 times a day or 4 times a day. The data further indicated that some inhibition is obtained at the lowest dosage of 1.0 μg and that the maximum inhibition is obtained at the highest dosage of 40.0 μg. 
     
                                           TABLE 4                                 
__________________________________________________________________________
Serum IgE ± SD (ng/ml)                                                 
Group                                                                     
    Dose*                                                                 
        Day -1                                                            
              Day 7  Day 8 Day 9  Day 11                                  
__________________________________________________________________________
A   0.0 800 ± 10                                                       
              8850 ± 408                                               
                     7557 ± 305                                        
                           6458 ± 224                                  
                                  1466 ± 287                           
B   1.0 808 ± 17                                                       
              4974 ± 1232                                              
                     4595 ± 663                                        
                           4602 ± 771                                  
                                  1326 ± 241                           
C   2.0 800 ± 10                                                       
              5598 ± 1875                                              
                     3057 ± 331                                        
                            3644 ± 1179                                
                                  1279 ± 377                           
D   10.0                                                                  
        849 ± 77                                                       
              3223 ± 1717                                              
                     1705 ± 859                                        
                           1233 ± 601                                  
                                  1116 ± 276                           
E   40.0                                                                  
        822 ± 39                                                       
              998 ± 146                                                
                     1214 ± 181                                        
                           1119 ± 135                                  
                                  1110 ± 249                           
F   0.5 839 ± 44                                                       
              7813 ± 588                                               
                     5699 ± 322                                        
                           6097 ± 249                                  
                                   2049 ± 1201                         
G   1.0 1197 ± 272                                                     
              5549 ± 1044                                              
                     3051 ± 475                                        
                           4383 ± 832                                  
                                  1506 ± 794                           
H   2.0 1019 ± 206                                                     
              5483 ± 717                                               
                     3236 ± 599                                        
                           3987 ± 401                                  
                                  1925 ± 410                           
I   10.0                                                                  
        1040 ± 211                                                     
              2092 ± 605                                               
                     1884 ± 598                                        
                           1991 ± 834                                  
                                  1429 ± 361                           
J   40.0                                                                  
        929 ± 97                                                       
              1037 ± 237                                               
                     1152 ± 388                                        
                           870 ± 83                                    
                                  1028 ± 302                           
__________________________________________________________________________
 *(±) methyl                                                           
 11α,16dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate           
 
    
     EXAMPLE 16 
     Sera from the mice described in Example 13 are analyzed for the levels of IgG1, IgG2a, and IgG3 by Assays B, C, and D, respectively. The results are shown in Table 5. The data show that the prostaglandins of the invention have essentially no effect upon IgG1, IgG2a and IgG3 levels. 
     
                                           TABLE 5                                 
__________________________________________________________________________
Ig ± SD (μg/ml)                                                     
Group                                                                     
    Day -1                                                                
          Day 7  Day 8   Day 9   Day 11                                   
__________________________________________________________________________
IgG1                                                                      
A   222 ± 133                                                          
          4808 ± 1917                                                  
                 13818 ± 1281                                          
                         17700 ± 4149                                  
                                 17100 ± 3875                          
E   215 ± 124                                                          
          3220 ± 985                                                   
                 12947 ± 2195                                          
                         19938 ± 3279                                  
                                 17589 ± 1923                          
F   248 ± 189                                                          
          6902 ± 3604                                                  
                 18202 ± 5327                                          
                         27069 ± 3257                                  
                                 23205 ± 6506                          
G   166 ± 14                                                           
          6952 ± 3410                                                  
                 17649 ± 3158                                          
                         26978 ± 11752                                 
                                 26361 ± 6660                          
H   255 ± 66                                                           
          6816 ± 3349                                                  
                 16838 ± 4174                                          
                         23900 ± 11791                                 
                                 24998 ± 7169                          
I   175 ± 32                                                           
          5168 ± 2391                                                  
                 15666 ± 2300                                          
                         24337 ± 4729                                  
                                 25930 ± 4376                          
IgG2a                                                                     
A   23 ± 3                                                             
          139 ± 72                                                     
                 554 ±  247                                            
                         923 ± 69                                      
                                  951 ± 163                            
E   25 ± 25                                                            
          114 ± 61                                                     
                 277 ± 111                                             
                         1053 ± 256                                    
                                 1124 ± 219                            
F   58 ± 66                                                            
          133 ± 67                                                     
                 481 ± 192                                             
                         1093 ± 245                                    
                                 1540 ± 201                            
G   26 ± 7                                                             
          107 ± 45                                                     
                 276 ± 168                                             
                         855 ± 117                                     
                                 1097 ± 289                            
H   29 ± 9                                                             
          182 ± 105                                                    
                 493 ± 187                                             
                         1170 ± 285                                    
                                 2133 ± 862                            
I   23 ± 1                                                             
          81 ± 12                                                      
                 433 ± 314                                             
                         1177 ± 383                                    
                                 1667 ± 675                            
IgG3                                                                      
A    66 ± 3.6                                                          
          227 ± 61                                                     
                 519 ± 145                                             
                         510 ± 169                                     
                                  465 ± 118                            
E   70 ± 10                                                            
          370 ± 229                                                    
                 882 ± 310                                             
                         741 ± 475                                     
                                  687 ± 152                            
F   109 ± 44                                                           
          464 ± 161                                                    
                 640 ± 46                                              
                         649 ± 232                                     
                                  559 ± 162                            
G   68 ± 2                                                             
          494 ± 267                                                    
                 789 ± 264                                             
                         760 ± 340                                     
                                  802 ± 216                            
H   77 ± 10                                                            
          446 ± 266                                                    
                 1075 ± 453                                            
                         1636 ± 275                                    
                                 1288 ± 156                            
I    68 ± 6.5                                                          
          236 ± 84                                                     
                 639 ± 104                                             
                         1048 ± 167                                    
                                 1044 ± 115                            
__________________________________________________________________________
 
    
     Two groups of 4 Balb/c female mice per group are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂Al antibody. On day 3 and 4 the mice are injected with PBS (Group A) or 20 μg (±) methyl 11α,16-dihydroxy-16-ethyl-9-oxoprosta-5Z,13E-dien-1-oate (Group B) at 7 a.m., 1 p.m. and 7 p.m. in substantial accordance with the teaching of Example 13. On day -1, 7, 8, 9 and 11, 50-100 μl of serum is recovered and analyzed for IgE by Assay A and for IgM by Assay E. The results are shown in Table 6. The data show that IgE production is fully inhibited while IgM synthesis is not affected. 
     
                                           TABLE 6                                 
__________________________________________________________________________
Group                                                                     
    Day -1 Day 7 Day 8   Day 9  Day 11                                    
__________________________________________________________________________
IgE ± SD (ng/ml)                                                       
A   853 ± 101                                                          
           4545 ± 335                                                  
                 11398 ± 4689                                          
                          7114 ± 2317                                  
                                1064 ± 318                             
B   &lt;800   847 ± 67                                                    
                 1264 ± 173                                            
                         1064 ± 106                                    
                                808 ± 16                               
IgM ± SD (μg/ml)                                                    
A   234 ± 38                                                           
           1488 ± 314                                                  
                 1690 ± 338                                            
                         1396 ± 421                                    
                                548 ± 87                               
B   272 ± 19                                                           
           1858 ± 107                                                  
                 2569 ± 803                                            
                         2104 ± 276                                    
                                 725 ± 199                             
__________________________________________________________________________
 
    
     EXAMPLE 18 
     This example demonstrates that (±) methyl 11α,16-dihydroxy-16-methy-9-oxoprosta-5Z,13E-dien-1-oate does not effect basal cell surface density or distribution of leukocyte membrane proteins involved in immune recognition and regulation in unstimulated mice. One group of 4 unstimulated Balb/c female mice is injected with PBS (Group A). Another (Group B) is injected with 20 μg (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate as in Example 13. After 3 days, the mice are sacrificed by cervical dislocation. A 3 cm incision is made with a scalpel above the left hip, and the spleen is cut free from adjoining tissue and placed in a 100 mn plastic culture dish containing 10 ml PBS. The splenic cells are then made into a suspension, by rubbing the spleens between the rough, frosted ends of microscope slides repeatedly until the only remaining particulate matter is connective tissue. Cells are transferred to a 15 ml conical polystyrene tube and centrifuged in a centrifuge at 1200 rpm for 5 minutes. The supernatant is discarded by aspiration and the cell pellet is resuspended in 10 ml PBS, then centrifuged at 1200 rpm for 5 minutes. The supernatant is aspirated and the cell pellet is resuspended in 15 mM Tris, 140 mM Ammonium Chloride, to lyse red blood cells. After incubating at room temperature for 10 minutes the cell suspension is centrifuged at 1200 rpm for 10 minutes. The supernatant is discarded and the cell pellet is resuspended in 10 ml FACS Buffer (PBS containing 0.1% BSA and 0.1% Sodium Azide). The cell suspension is filtered through sterile glass wool plugged in the top of a pasteur pipet. Cells in the flow through are counted using a hemacytometer, then the cell suspension is centrifuged at 1200 rpm for 5 minutes. The supernatant is discarded and the cell pellet is resuspended in a volume of FACS Buffer that will yield 4×10 7  cells/ml. 10 μl (4×10 5  cells) is added to each well of a 96-well V-bottom plate. 25 μl of diluted monoclonal antibody directed against splenocyte cell surface proteins is added to each well: Major Histocompatability Complex (MHC) Class II (M5114, ATCC, Rockville Md.), MHC Class I (M1/42, ATCC), Anti-IgD (JA12.5, ATCC, Rockville, Md.), Thymocyte (Thy)-1 (JIJ, ATCC), B220 (14.8, ATCC), Kappa light chain (187, ATCC), IL-2 Receptor (7D4, ATCC), Lyt-1 (7.313, ATCC) and CD23 (biotinylated B3B4) and incubated on ice for 30 minutes. 100 μl 10% BSA 0.1% sodium azide is added to each well, then the plates are centrifuged at 1200 rpm for 10 minutes. The liquid is removed by aspiration and the cell pellets are resuspended in 100 μl FACS Buffer, and centrifuged at 1200 rpm for 5 minutes. The supernatant is removed by aspiration and the cells are resuspended in 25 μl secondary antibody as follows: For MHC Class II, MHC Class I, Anti-IgD, Thy-1, B220, Kappa light chain, IL-2 Receptor, Lyt-1 the secondary antibody is a mixture of FITC conjugated rat monoclonal antibodies, RG711.1 and RG9.1 (ATCC). For CD23, the secondary reagent is FITC labelled Avidin (Vector Laboratories, Burlingame, Calif.). After incubating the cells with the secondary antibody for 30 minutes on ice, 100 μl 10% BSA 0.1% sodium azide is added to each well, then centrifuged at 1200 rpm for 10  minutes. Cells are resuspended in 100 μl FACS buffer then centrifuged at 1200 rpm for 5 minutes. The supernatant is removed by aspiration and cells are resuspended in 50 μl FACS buffer. A FACScan Flow cytometer (Becton Dickinson, Mountain View, Calif.) is used. The instrument was equilibrated using an AutoComp program (Becton Dickinson, Mountain View, Calif.). Samples are transferred to individual tubes and 10,000 cells are analyzed. Using the Lysis software (Becton Dickinson, Mountain View, Calif.) the mean channel log fluorescence and percent positive cells are determined for the entire cell population. As shown in Table 7, the (±) methyl 11α,16-dihydroxy-16-ethyl-9-oxoprosta-5Z,13E-dien-1-oate treated group displayed identical cell surface density and distribution as the control group. 
     
                       TABLE 7                                                     
______________________________________                                    
         Mean Channel Log                                                 
                         Percentage                                       
Cell Surface                                                              
         Fluorescence    Positive Cells                                   
Protein  Group A   Group B   Group A Group B                              
______________________________________                                    
MHC      148 ± 3                                                       
                   149 ± 8                                             
                             56.2 ± 4                                  
                                     56.9 ± .4                         
Class II                                                                  
MHC Class I                                                               
         112 ± 3.5                                                     
                   113 ± 2                                             
                             57.8 ± 14.9                               
                                       79 ± 16                         
IgD      130 ± 4                                                       
                   132 ± 3.5                                           
                              1.4 ± 3                                  
                                     51.8 ± 3.7                        
Thy 1     91 ± 0                                                       
                    92 ± 3                                             
                              9.3 ± 2.6                                
                                     25.4 ± 3                          
B220     104 ± 43                                                      
                   105 ± 2.5                                           
                             49.6 ± 1.6                                
                                     50.6 ± 4.6                        
κ Light Chain                                                       
         135 ± 3.7                                                     
                   131 ± 4                                             
                             52.1 ± 3.9                                
                                     53.9 ± 2.1                        
Lyt 1    110 ± 3.2                                                     
                   117 ± 6                                             
                               31 ± 6.4                                
                                     44.5 ± 7                          
IL-2 receptor                                                             
          98 ± 1.7                                                     
                    96 ± 1                                             
                              2.4 ± 0.6                                
                                      2.7 ± 0.3                        
CD23      95 ±  5                                                      
                    94 ± 3.2                                           
                             46.6 ± 4.4                                
                                     44.2 ± 6.6                        
______________________________________                                    
 
    
     EXAMPLE 19 
     This example demonstrates that (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate does not effect cell surface density or distribution of leukocyte membrane proteins involved in immune recognition and regulation in mice stimulated with FF1-4D5 antibody and H∂Al antibody. Two (2) groups of 4 Balb/c female mice are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂Al antibody on day 0 in accordance with the procedure of Example 13. On day 3 and 4 the mice are injected with PBS (Group A) or injected with 20 μg (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate (Group B) as in Example 13. On day 7 the mice are sacrificed by cervical dislocation and the splenocytes harvested and stained for leukocyte proteins in substantial accordance with the teaching of Example 18. As shown in Table 8, the (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate treated group displayed identical cell surface density and distribution as the PBS treated group. 
     
                       TABLE 8                                                     
______________________________________                                    
         Mean Channel Log                                                 
                         Percentage                                       
Cell Surface                                                              
         Fluorescence    Positive Cells                                   
Protein  Group A   Group B   Group A Group B                              
______________________________________                                    
MHC      134 ± 8                                                       
                   137 ± 15                                            
                             59.8 ± 1.5                                
                                     68.6 ± 5.1                        
Class II                                                                  
MHC Class I                                                               
         113 ± 3.6                                                     
                   121 ± 15                                            
                             48.5 ± 12.3                               
                                     59.4 ± 5.4                        
IgD      107 ± 4.9                                                     
                    98 ± 0.5                                           
                             21.9 ± 8.4                                
                                     15.6 ± 8.4                        
Thy 1     97 ± 0.5                                                     
                    98 ± 0                                             
                             14.3 ± 2.5                                
                                       23 ± 10                         
B220     107 ± 1                                                       
                   112 ± 4                                             
                             49.3 ± 4.3                                
                                     61.2 ± .9                         
K Light  118 ± 3.5                                                     
                   119 ± 7                                             
                               50 ± 5.3                                
                                       58 ± 14.6                       
Chain                                                                     
Lyt 1    110 ± 1                                                       
                   109 ± 2                                             
                             31.3 ± 1.2                                
                                     30.4 ± 8.8                        
IL-2 receptor                                                             
         101 ± 1                                                       
                    97 ± 1.5                                           
                             18.4 ± 2.5                                
                                       23 ± 7.7                        
CD23      99 ±  1                                                      
                    95 ± 1.5                                           
                             20.4 ± 5.4                                
                                     11.6 ± 1.6                        
______________________________________                                    
 
    
     EXAMPLE 20 
     This example demonstrates that de nouo IgE synthesis is inhibited by (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate in vivo, but not by natural prostaglandin E 1  and prostaglandin E 2  in vivo. Four groups of 4 Balb/c female mice per group are injected with 100 μg FF1-4D5 antibody and 100 μg H∂Al antibody on Day 0. On day 3 and 4, Group B is injected with 20 μg (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate, Group C is injected with 20 μg prostaglandin E 1  (Biomol Research Laboratories, Inc., Plymouth Meeting, Pa.) and Group D is injected with 20 μg prostaglandin E 2  (Biomol Research Laboratories, Plymouth Meeting, PA) as described in Example 13. Group A is an untreated control. On day-1 and 8, 50-100 μg of serum is recovered and analyzed for IgE by Assay A. The results are shown in Table 9. The data shows the inhibition of IgE by (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13-dien-1-oate and the lack of inhibition by prostaglandin E 1  (PGE 1 ) and prostaglandin E 2  (PGE 2 ). 
     
                       TABLE 9                                                     
______________________________________                                    
IgE ± SD (ng/ml)                                                       
Group        Day -1     Day 8                                             
______________________________________                                    
A            &lt;800       3539 ± 499                                     
B            1015 ± 70                                                 
                        1206 ± 119                                     
C            &lt;800       2958 ± 717                                     
D             897 ± 194                                                
                        3340 ± 384                                     
______________________________________                                    
 
    
     EXAMPLE 21 
     This example demonstrates inhibition of de novo IgE synthesis by (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate when orally administered and that natural PGE 2  is ineffective. 
     Three groups of 4 Balb/c female mice per group are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂A1 antibody (Groups B, C, and D). Another group of 4 Balb/c female mice is injected with PBS alone, unstimulated control Group A. One of the stimulated group were not given any prostaglandin control Group B. On day 3 and 4, individual groups receive an intragastric feeding TID of 0.25 ml of 20 μg of (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate (Group C) or 20 μg of prostaglandin E 2  (Group D) dissolved in PBS. On day -1, 8, and 10, 50-100 μl of serum is recovered and analyzed for IgE by Assay A. The results are shown in Table 10. The data show that (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate significantly inhibits de novo IgE synthesis after oral administration, but that natural prostaglandin E 2  inhibits IgE synthesis slightly, if at all. 
     
                       TABLE 10                                                    
______________________________________                                    
IgE ± SD (ng/ml)                                                       
Group   Day -1       Day 8      Day 10                                    
______________________________________                                    
A       1053 ± 90 1015 ± 61                                         
                                1059 ± 143                             
B       1067 ± 18 5792 ± 1514                                       
                                1498 ± 124                             
C       1115 ± 201                                                     
                     1490 ± 525                                        
                                1131 ± 198                             
D       1094 ± 107                                                     
                     3724 ± 1361                                       
                                1496 ± 219                             
______________________________________                                    
 
    
     EXAMPLE 22 
     This example demonstrates that (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-4Z,13E-dien-1-oate inhibits de novo IgE synthesis but does not effect IgG1 or IgG2a. Two groups of 4 Balb/c female mice per group are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂A1 antibody. One of these groups is a stimulated control designated Group B. On day 3 and 4, the other group is injected with 40 μg (±) methyl 11α, 16-dihydroxy-1-methyl-9-oxoprosta-4Z,13E-dien-1-oate. Another group is injected with only PBS as an unstimulated control (Group A). On day -1 and 8, 50-100 μl of serum is recovered and analyzed for IgE, IgG1 and IgG2a by Assays A, B, and C, respectively. The results are shown in Table 11. The data show that (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-4Z,13E-dien-1-oate inhibits de novo IgE synthesis, but does not effect IgG1 or IgG2a. 
     
                       TABLE 11                                                    
______________________________________                                    
Group       Day -1     Day 8                                              
______________________________________                                    
IgE ± SD (ng/ml)                                                       
A           384 ± 242                                                  
                       1420 ± 156                                      
B           1548 ± 762                                                 
                       15890 ± 4241                                    
C           1717 ± 313                                                 
                       3973 ± 905                                      
______________________________________                                    
Group       Day -1     Day 9                                              
______________________________________                                    
IgG1 ± SD (μg/ml)                                                   
A           863 ± 743                                                  
                        767 ± 670                                      
B           344 ± 89                                                   
                       19800 ± 6139                                    
C           2331 ± 2212                                                
                       37728 ± 6913                                    
IgG2a ± SD (μg/ml)                                                  
A           61 ± 39  79 ± 74                                        
B           109 ± 97                                                   
                       1056 ± 116                                      
C           160 ± 130                                                  
                       1058 ± 202                                      
______________________________________                                    
 
    
     EXAMPLE 23 
     This example demonstrates that (±) methyl 2-[2-[3R-3a-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1α-cyclopentyl]-methyl]cyclopropanebutanoate and (±) methyl 2-[2-[3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1.alpha.-cyclopentyl]ethyl]cyclopropanepropanoate inhibit de novo IgE synthesis, but not IgG1, IgG2a or IgG3. 3 groups of 4 Balb/c female mice per group are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂A1 antibody on day 0. Group A is given no further treatment. On day 3 and 4, one group of mice is injected with 20 μg (±) methyl 2-[2-[3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl-5-oxo-1.alpha.-cyclopentyl]-methyl]cyclopropanebutanoate (Group B) and another group with 20 μg (±) methyl 2-[2-[3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1.alpha.-cyclopentyl]ethyl]cyclopropanepropanoate (Group C) as in Example 13. On day -1 and 8, 50-100 μl of serum is recovered and analyzed for IgE, IgG1, IgG2a and IgG3 by Assays A, B, C and D, respectively. The selectivity of inhibition of IgE is shown in Table 12. 
     
                       TABLE 12                                                    
______________________________________                                    
IgE ± SD  IgG1 ± SD                                                 
                        IgG2a ±                                        
                                  IgG3 ± SD                            
(ng/ml)      (μg/ml) (μg/ml)                                        
                                  (μg/ml)                              
______________________________________                                    
Day -1                                                                    
All    51 ± 82                                                         
                 180 ± 92                                              
                            43 ± 6                                     
                                    38 ± 21                            
Groups                                                                    
Day 8                                                                     
Group                                                                     
A     11398 ± 4689                                                     
                 10525 ± 949                                           
                            849 ± 304                                  
                                    584 ± 138                          
B*    2750 ± 318                                                       
                 14470 ± 2997                                          
                            834 ± 235                                  
                                    520 ± 39                           
C     3034 ± 878                                                       
                 22573 ± 5690                                          
                            840 ± 484                                  
                                    901 ± 213                          
______________________________________                                    
 *(±) methyl                                                           
 2[2[3R3hydroxy-2(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1cyclopentyl)methyl
cyclopropanebutanoate                                                     
  (±) methyl                                                           
 2[2(3R-3hydroxy-2(4-hydroxy-4-methyl-1E-octenyl)-5-oxo-1cyclopentyl)ethyl
yclopropanebutanoate                                                      
 
    
     EXAMPLE 24 
     This example demonstrates that (±) methyl 20-ethyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate inhibits de novo IgE synthesis. Two groups of 5 Balb/c female mice per group are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂A1 antibody on day 0. One group is stimulated control (Group A). On day 3 and 4, the other group is injected with 20 μg (±) methyl 20-ethyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate. On day -1 and 8, 50-100 μl of serum is recovered and analyzed for IgE by Assay A. The inhibition of IgE is shown in Table 13. 
     
                       TABLE 13                                                    
______________________________________                                    
IgE ± SD (ng/ml)                                                       
______________________________________                                    
Day -1                                                                    
All Groups    &lt;800 ng/ml                                                  
Day 8                                                                     
Group                                                                     
A             3653 ± 358                                               
B*            &lt;800                                                        
______________________________________                                    
 (±) methyl                                                            
 20ethyl-11α,16dihydroxy-1-methyl-9-oxoprost-13E-en-1-oate          
 
    
     EXAMPLE 25 
     This example demonstrates that (±) methyl 11α,16-dihydroxy-4,4,16-trimethyl-9-oxoprost-13E-en-1-oate and (±) methyl-11α,16-dihydroxy-16-methyl-9-oxoprost-3,5Z,13E-trien-1-oate inhibit de novo IgE synthesis, but not IgG1, IgG2a, IgG3 and IgM. Three groups of 5 Balb/c female mice per group are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂A1 antibody on day 0. Group A is a control with no further treatment. On day 3 and 4, the mice are injected with 20 μg (±) methyl 11α,16-dihydroxy-4,4,16-trimethyl-9-oxoprosta-13E-en-1-oate (Group B) or 20 μg (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-3,5Z,13E-trien-1-oate (Group C) as in Example 13. On day -1 and 8, 50-00 μl of serum is recovered and analyzed for IgE, IgG1, IgG2a, IgG3 and IgM by Assays A, B, C, D and E, respectively. The selective inhibition of IgE by the prostaglandins of the invention is shown in Table 14. 
     
                                           TABLE 14                                
__________________________________________________________________________
       IgE ± SD (ng/ml)                                                
                  IgG1 ± SD (μg/ml)                                 
                             IgG2a ± SD (μg/ml)                     
                                         IgG3 ± SD (μg/ml)          
                                                    IgM ± SD           
__________________________________________________________________________
                                                    (μg/ml)            
Day -1                                                                    
All Groups                                                                
       &lt;800        859 ± 379                                           
                              553 ± 364                                
                                         215 ± 80                      
                                                    1534 ± 433         
Day 8                                                                     
Group                                                                     
A      6071 ± 1700                                                     
                  21703 ± 3334                                         
                             1246 ± 168                                
                                         1538 ± 208                    
                                                    4147 ± 699         
B*     &lt;800       22555 ± 5821                                         
                             1019 ± 278                                
                                         2103 ± 616                    
                                                    9792 ± 984         
C      1176 ± 137                                                      
                  18320 ± 4695                                         
                             1202 ± 338                                
                                         1709 ± 429                    
                                                    7708                  
__________________________________________________________________________
                                                    ± 993              
 *(±) methyl                                                           
 11α,16dihydroxy-4,4,16-trimethyl-9-oxoprost-13E-en-1-oate          
  (±) methyl                                                           
 11α,16dihydroxy-16-methyl-9-oxoprosta-3,5Z,13E-trien-1-oate        
 
    
     EXAMPLE 26 
     This example demonstrates that (±) 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oic acid and (±) 4-(acetylamino)phenyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate inhibit de novo IgE synthesis. Three groups of 5 Balb/c female mice per group are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂A1 antibody on day 0. Group A is a control with no further treatment. On day 3 and 4, the mice are injected with 20 μg of (±) 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oic acid (Group B) and with 20 μg of (±) 4-(acetylamino)phenyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate (Group C). On day -1 and 8, 50-100 μl of serum is recovered and analyzed for IgE by Assay A. Inhibition of IgE by these compounds is shown in Table 15. 
     
                       TABLE 15                                                    
______________________________________                                    
IgE ± SD (ng/ml)                                                       
Group        Day -1    Day 8                                              
______________________________________                                    
A            1073 ± 391                                                
                       5090 ± 355                                      
B*           1029 ± 362                                                
                       1499 ± 132                                      
C            &lt;800      1880 ± 319                                      
______________________________________                                    
 *(±) 11α,16dihydroxy-16-methyl-9-oxoprost-13E-en-1-oic acid     
  (±) 4acetylamino)phenyl                                              
 11α,16dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate                 
 
    
     EXAMPLE 27 
     This example demonstrates that (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate, (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprostan-1-oate and (±) methyl ethyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate inhibit de novo IgE synthesis. Four groups of 5 Balb/c female mice per group are injected with both 100 μg FF1-4D5 antibody and 100 μg H∂A1 antibody on day 0. One group is control Group A. On day 3 and 4, the mice are injected with 10 μg of (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate (Group B), with 10 μg of (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprostan-1-oate (Group C), or with 10 μg of (±) methylethyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate (Group D). On day -1 and 8, 50-100 μl of serum is recovered and analyzed for IgE by Assay A. Inhibition of IgE by these compounds is shown in Table 16. 
     
                       TABLE 16                                                    
______________________________________                                    
IGE ± SD (ng/ml)                                                       
Group        Day -1   Day 8                                               
______________________________________                                    
A            &lt;1600     8548 ± 1117                                     
B*           &lt;1600    2123 ± 257                                       
C            &lt;1600    3844 ± 238                                       
D•     &lt;1600    2127 ± 149                                       
______________________________________                                    
 *(±) methyl 11α,16dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate  
  (±) methyl 11α,16dihydroxy-16-methyl-9-oxoprostan-1-oate       
 •(±) methyl ethyl                                               
 11α,16dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate                 
 
    
     EXAMPLE 28 
     From the data in the above examples, the effective dose of each prostaglandin to achieve 50% inhibition of IgE (ED 50 ) was calculated. The data show that eight of the compounds exhibit extraordinary high potency with dosages of only 1.0-1.5 μg/mouse to achieve 50% inhibition, whereas, natural prostaglandin E 2  requires a dosage of greater than 45 μg/mouse to achieve the same effect. 
     Since prostaglandins in general elicit diarrheal side effects in humans, some of these compounds were also evaluated for diarrheal effects in rats to determine their ability to cause this side effect. The data presented in Table 17 are ED 50  values defined as the dose required to produce diarrhea in 50% of the animals. The assay was performed as described in Collins et al., J. Med. Chem. 32, 1001(1989). Briefly, adult Charles River male rats weighing 210-230 g were individually housed and fasted with water available ad libitum for 24 hours prior to the test. The animals (N=6-12) received logarithmically graded prostaglandin doses orally. Immediately after administration, the animals were returned to their cages, and diarrhea, if any, was assessed on an all or none basis for 8 hours after drug treatment. The ED 50  and relative potency values were calculated by the logistic method of Berkson. The data show that (±) methyl-20-ethyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate is essentially free of the undesirable diarrhea side-effect. 
     
                                           TABLE 17                                
__________________________________________________________________________
                                      ED.sub.50                           
                                      IgE Inhibition                      
                                               Diarrhea                   
                                      (μg/mouse/TID)                   
                                               (μg/kg/Rat)             
__________________________________________________________________________
(±) 4-(acetylamino)phenyl 11α,16-dihydroxy-16-methyl-9-oxoprost-1
3E-en-1-oate                          1.0      --                         
(±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-4Z,13E-dien-1-o
ate                                   4.0       49                        
(±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-o
ate                                   1.0      173                        
(±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oate   
                                      1.5      360                        
(±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprostan-1-oate        
                                      4.8      --                         
(±) 1-methylethyl 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-
oate                                  1.5      --                         
(±) 11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-1-oic           
                                      1.0d     --                         
(±) methyl 2-[[3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-octen
yl)-5-oxo-1α-                   9.0      --                         
cyclopentyl]methyl]cyclopropanebutanoate                                  
(±) methyl 2-[2-(3R-3α-hydroxy-2β-(4-hydroxy-4-methyl-1E-oct
enyl)-5-oxo-1α-                 1.0      --                         
cyclopentyl]ethyl]cyclopropanepropanoate                                  
(±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-3,5Z,13E-trien-
1-oate.                               6.5      570                        
(±) methyl 11α,16-dihydroxy-4,4,16-trimethyl-9-oxoprost-13E-en-1-
oate                                  1.5      185                        
(±) methyl 20-ethyl-11α,16-dihydroxy-16-methyl-9-oxoprost-13E-en-
1-oate                                1.0      2700                       
Natural Prostaglandin E.sub.2 (PGE.sub.2)                                 
                                      &gt;45.0    --                         
__________________________________________________________________________
 
    
     EXAMPLE 29 
     Stimulation of a secondary antigen-specific IgE response in mouse with haptenated antigen absorbed on alum is inhibited by (±) methyl 11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate. Three groups of 7 Balb/c female mice were treated as follows. On day 0 all mice were injected IP, as in Example 13, with 1 μg of trinitrophenol-keyhole limpet hemocyanin (TNP-KLH) on 1 mg of alum, described in F. O. Finkelman et al., The Journal of Immunology, 141: 2335 (1988). On day 21, one group was given an intraperitoneal injection (IP) of PBS (Group A), and the other groups were given IP injections of 1 μg TNP-KLH on 1 mg alum. One of these groups was not given any further treatment (Group B). On days 24 and 25, the remaining group received an IP injection of 20 μg (±) methyl-11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate at 7 a.m., 1 p.m. and 7 p.m. (Group C). On day-1, 28 and 30, 50-100 μl of serum is recovered and analyzed for IgE by Assay A. The results are shown in Table 18. The data show a secondary IgE response in the boosted Group B mice, and no secondary IgE response in the control, non-boosted Group A mice. Mice that were boosted with antigen and treated with (±) methyl-11α,16-dihydroxy-16-methyl-9-oxoprosta-5Z,13E-dien-1-oate (Group C) were inhibited from the synthesis of a secondary IgE response. 
     
                       TABLE 18                                                    
______________________________________                                    
IgE ± SD (ng/ml)                                                       
Group Day -1      Day 28      Day 30                                      
______________________________________                                    
A     1472 ± 231                                                       
                  4696 ± 2068                                          
                              3245 ± 1635                              
B     1440 ± 88                                                        
                  28,568 ± 17,675                                      
                              22,564 ± 12,587                          
C     1487 ± 138                                                       
                  14,448 ± 4926                                        
                              7564 ± 1528                              
                  (p &lt; .02)   (p &lt; .016)                                  
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     Although the invention has been described with respect to specific modifications, the details thereof are not to be construed as limitations, for it will be apparent that various equivalents, changes and modifications may be resorted to without departing from the spirit and scope thereof and it is understood that such equivalent embodiments are to be included therein.