BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates to a new formulation of the oligonucleotide of SEQ ID NO:1.

2. The Relevant Technology

Mucosal surfaces represent the first interface between the internal environment of the host organism and the external environment. Mucosal surfaces are therefore enriched in a variety of cellular and acellular structures that protect the host from foreign pathogen or antigen exposure. These important surfaces are represented by the mucosal surfaces of the oral and nasal (sinus) cavity, the pulmonary and digestive systems and mucosal tissues surrounding the eye.

The cells comprising the mucosa are equipped to sense and respond to a variety of foreign substances. These cells also elaborate a variety of molecular pathways to communicate such invasion to the surrounding tissues and recruit an influx of additional inflammatory and immune cells to fight the infection, repair damage and if necessary induce specific immune responses in the form of antibodies. While these mechanisms serve an important and indeed life-saving function for the organism, their chronic and/or misguided activation can lead to considerable morbidity and mortality.

The chronic influx of inflammatory cells and the subsequent local activation of cells of the immune system are two primary loci where chronic mucosal inflammation can be controlled. These responses are part of the “innate immune system”. The first responding cells of the innate immune system, such as dendritic cells and macrophages, ingest pathogens and release cytokines drawing secondary, active and defensive cells from the blood. These secondary invading cells must be “drawn to” the site of inflammation by molecules on the surface of cells lining the local blood vessels (vascular endothelium). Such molecules are themselves expressed in response to cytokines released at the initial pathogen invasion site. These molecules bind to receptors on circulating blood cells and allow local adhesion and subsequent diapedesis into the invasion site. The adhesion molecules are known as intracellular adhesion molecules (ICAM) and a variety of these have been discovered. Blocking the expression and/or function of the various ICAM's has led to the development of several therapeutic products to suppress inflammatory diseases.

Cells of the innate immune system also have a well-developed repertoire of surface receptors that sense and bind microbial components expressed by bacteria, viruses, fungi and other pathogens. These receptors have been termed “toll-like receptors” (TLR's) and as many as 12 members of this family are now known in the human genome. Pathogen-encoded TLR ligands fall into three broad categories: lipids and lipopeptides (TLR2/1; TLR2/6 and TLR4), proteins (TLR5 and TLR11) and nucleic acids (TLR3, 7, 8 and 9). Therapeutic targeting of certain TLR's has been exploited as a means to stimulate the immune system (vaccine production) and agents targeting other TLR's are being developed to inhibit certain immune functions.

An ideal therapeutic agent to target and control mucosal inflammation would therefore be an agent with both acute and long-lasting effects on mucosa inflammation and may indeed be disease altering.

SUMMARY OF THE INVENTION

The present invention addresses this.

The present invention relates to, as a first aspect, a pharmaceutical composition comprising SEQ ID NO:1 with a cation optionally selected from the following list Na+, K+, Mg+, Ca++, Ba++, Mn++, Ni++, Zn++and Cr+++, preferably Na+, more preferably 40-200 mM Na+optionally including 2-20 mM Mg2+. The concentration range is preferably 40-200 mM for Na−or K−, and 2-20 mM for Mg++, Ca++, Ba++, Mn++, Ni++, Zn++or Cr+++. For example, the pharmaceutical composition may have a combination of 40-200 mM Na+and 2-20 mM Mg2+, or 40-200 mM Na+and 40-200 mM K+. For example the composition may comprise a combination of Na+and K+, or Na+and Mg++or Na+and Ca++or Na+and Ba++or Na+and Mn++or Na+and Ni++or Na+and Li++or Na+and Zn++or Na+and Cr++, or K+and Mg++or K+and Ca++or K+and Ba++or K+and Mn++or K+and Ni++or K+and Li++or K+and Zn++or K+and Cr+++.

The composition of the first aspect may also comprise one or more of hydroxymethyl cellulose, methyl paraben sodium, propylparaben sodium, monobasic sodium phosphate monohydrate, sodium hydroxide, hydrochloric acid and/or water.

The composition may be in the form of a liquid syrup, gel, film, cream, powder, tablet, enema and/or particulate, preferably which is suitable for inhalation.

The composition of the invention may be formulated as a gel, cream, lotion, solution, suspension, emulsion, ointment, powder or particulate which is suitable for inhalation, tablet, spray, aerosol, foam, salve, microparticle, nanoparticle, or bioadhesive, and may be prepared so as to contain liposomes, micelles and/or microspheres.

The composition may have the components in the following ranges

SEQ ID NO: 14mghydroxymethyl cellulose7-8 mg, optionally 7.5 mgmethylparaben sodium 16.6 mM2.8-3.0mgpropylparaben sodium 1.4 mM0.28-3mgmonobasic sodium phosphate4.4-4.6mgmonohydrate37.5 mM
wherein the ranges given are per ml with a total of 60 ml per dose. Thus, in a treatment of 240 mg in 60 ml, the treatment is 4 mg/ml. The above specific dose may be a liquid enema formulation.

A second aspect of the invention relates to the composition of the first aspect for use in medicine. The medicine may be human or veterinary. Veterinary medicine includes any animal including production and/or pet animals including, in particular dogs, cats and/or equine animals.

According to the second aspect of the invention, the medicine may be for the prevention or treatment of inflammatory bowel disease, rectal stump disease, radiation-induced proctitis, pouchitis, asthma, inflammation of the eye, dry eye, rhinitis or sinusitis or graft versus host disease.

A third aspect of the invention is the use of SEQ ID NO:1 in the manufacture of a medicament according to the first aspect of the invention for the prevention or treatment of inflammatory bowel disease, rectal stump disease, radiation-induced proctitis, pouchitis, asthma, inflammation of the eye, dry eye, graft versus host disease (GVHD), rhinitis or sinusitis.

All features of the first aspect of the invention also apply to the third aspect.

A fourth aspect of the invention relates to a method of treating inflammatory bowel disease, rectal stump disease, radiation-induced proctitis, pouchitis, asthma, inflammation of the eye, dry eye, rhinitis, sinusitis, or grant-versus host disease, the method comprising administration of a composition of the first aspect of the invention to a patient in need thereof.

All features of the first aspect of the invention also apply to the fourth aspect. The patient may be a human (adult or youth) or an animal.

A fifth aspect of the invention relates to a method of making a composition of the first aspect of the invention, the method comprising combining SEQ ID NO:1 with a cation, optionally selected from the following list Na+, Na+, Mg++, Ca++, Ba++, Mn++, Ni++, Li++, Zn++, and Cr+++, preferably Na+, more preferably 40-200 mM Na+, optionally including 2-20 mM Mg2+.

Methods for making this new composition are standard methods as known in the art.

The invention provides a composition, according to the first aspect of the invention, as claimed in any one of claims1to6, wherein the composition is in the form of an enema and wherein the composition is formulated in a dosage form to provide a concentration of SEQ ID NO:1 at 4 mg/ml per day.

The composition may be in the form of an enema and wherein the composition is formulated in a dosage form to provide a concentration of SEQ ID NO:1 at 0.25-4 mg/ml per day.

SEQ ID NO: 1 is as follows:5′-gcccaagctg gcatccgtca-3′.

The antisense oligonucleotide SEQ ID NO:1 is also known as alicaforsen.

Certain enhancements to the formulation containing the oligonucleotides of SEQ ID NO:1 may also be necessary to aid in the retention of the active ingredient at the site of application. For example, the formulation can be prepared using components that cause the formulation to be a liquid at room temperature, but solidify to a gel state at body temperature. In other instances, the formulation may be prepared as a liquid and applied to a mucosal surface, such as the nasal mucosa, followed by the application of an inert dry powder, such as methyl cellulose, to retain the formulation at the site of application. In other instances, a dry powder formulation of the composition may be mixed with the inert dry powder and applied together at the mucosa site.

The oligonucleotides SEQ ID NO:1 in accordance with this invention preferably comprises from about 20 to about 80 nucleic acid base units. It is more preferred that such oligonucleotides comprise from about 20 to 50 nucleic acid base units, still more preferred to have from about 20 to 30 nucleic acid base units, and most preferred to have from about 20 to 22 nucleic acid base units. As will be appreciated, a nucleic acid base unit is a base-sugar combination suitably bound to an adjacent nucleic acid base unit through phosphodiester or other bonds. One skilled in the art will understand that about 20 to about 80 nucleic acid base units includes 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79 or 80 nucleobase units.

In a further embodiment, the composition comprises a fragment of SEQ ID NO:1, wherein the fragment is at least 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 or 19 nucleotides in length. The fragment can hybridise to a sequence in the 3′-untranslated region of the human ICAM-1 mRNA. The fragment can hybridise under moderate or stringent conditions with nucleotides ‘cctgacg gatgccagct tgg’ (SEQ ID NO:2). Fragments include ‘cccaagctg gcatccgtca’ (SEQ ID NO:3), ‘gcccaagctg gcatccgtc’ (SEQ ID NO:4) and ‘gcccaagctg gca’ (SEQ ID NO:5).

“Stringency” of hybridization reactions is readily determinable by one of ordinary skill in the art, and generally is an empirical calculation dependent upon probe length, washing temperature, and salt concentration. In general, longer probes require higher temperatures for proper annealing, while shorter probes need lower temperatures. Hybridization generally depends on the ability of denatured DNA to reanneal when complementary strands are present in an environment below their melting temperature. The higher the degree of desired homology between the probe and hybridisable sequence, the higher the relative temperature which can be used. As a result, it follows that higher relative temperatures would tend to make the reaction conditions more stringent, while lower temperatures less so. For additional details and explanation of stringency of hybridization reactions, see Ausubel et al., Current Protocols in Molecular Biology, Wiley Interscience Publishers, (1995).

As herein defined, “Stringent conditions” or “highly stringent conditions”, may be identified by those that: (1) employ low ionic strength and high temperature for washing, for example 0.015 M sodium chloride/0.0015 M sodium citrate/0.1% sodium dodecyl sulphate at 50° C.; (2) employ during hybridization a denaturing agent, such as formamide, for example, 50% (v/v) formamide with 0.1% bovine serum albumin/0.1% Ficoll/0.1% polyvinylpyrrolidone/50 mM sodium phosphate buffer at pH 6.5 with 750 mM sodium chloride, 75 mM sodium citrate at 42° C.; or (3) employ 50% formamide, 5×SSC (0.75 M NaCl, 0.075 M sodium citrate), 50 mM sodium phosphate (pH 6.8), 0.1% sodium pyrophosphate, 5×Denhardt's solution, sonicated salmon sperm DNA (50 [mu]g/ml), 0.1% SDS, and 10% dextran sulphate at 42° C., with washes at 42° C. in 0.2×SSC (sodium chloride/sodium citrate) and 50% formamide at 55° C., followed by a high-stringency wash consisting of 0.1×SSC containing EDTA at 55° C.

“Moderately stringent conditions” may be identified as described by Sambrook et al., Molecular Cloning: A Laboratory Manual, New York: Cold Spring Harbor Press, 1989, and include the use of washing solution and hybridization conditions (e.g., temperature, ionic strength and % SDS) less stringent that those described above. An example of moderately stringent conditions is overnight incubation at 37° C. in a solution comprising: 20% formamide, 5×SSC (150 mM NaCl, 15 mM trisodium citrate), 50 mM sodium phosphate (pH 7.6), 5×Denhardt's solution, 10% dextran sulphate, and 20 mg/ml denatured sheared salmon sperm DNA, followed by washing the filters in 1×SSC at about 37-50° C. The skilled artisan will recognize how to adjust the temperature, ionic strength, etc. as necessary to accommodate factors such as probe length and the like.

As used herein, conditions of moderate or high stringency can be readily determined by those having ordinary skill in the art based on, for example, the length of the DNA. The basic conditions are set forth by Sambrook et al. Molecular Cloning: A Laboratory Manual, 2 ed. Vol. 1, pp. 1.101-104, Cold Spring Harbor Laboratory Press, (1989).

The oligonucleotide can be modified to comprise at least one phosphorothioate linkage. Phosphorothioate modification of the oligonucleotide, by substituting a sulfur molecule for a non-bridging oxygen molecule in each phosphodiester linkage, significantly increases exonuclease resistance relative to unmodified DNA and prolongs the drug half-life (Geary et al., Anti-Cancer Drug Design, 12:383-94, 1997). Phosphorothioate oligonucleotides are only minimally antigenic, non-cytotoxic and well tolerated, and their pharmacokinetic and pharmacodynamic properties are well characterized (see e.g., Butler et al., Lab. Invest, 77:379-88, 1997; Mirabelli et al., Anti-Cancer Drug Des., 6:647-61, 1991). In addition to phosphorothioate backbone modifications, a number of other possible backbone, sugar and other modifications are well known to those skilled in the art.

The actual amount administered, and rate and time-course of administration, will depend on the nature and severity of what is being treated. Prescription of treatment, e.g., decisions on dosage etc, is ultimately within the responsibility and at the discretion of general practitioners and other medical doctors, and typically takes account of the disorder to be treated, the condition of the individual patient, the site of delivery, the method of administration and other factors known to practitioners.

For example, in one embodiment, a suitable dose may be 2 mg/ml per day for example, per enema.

In another embodiment, a minimum dose would be 0.25 mg/mL per day for example, per enema.

The composition may be administered once, twice, three or four times a day or periodically.

The composition can be administered for 2, 3, 4, 5, 6, 7, 8 or more weeks.

For example, in one embodiment, a suitable dose per treatment may be 0.05 mg to 400 mg. A treatment can be administered from once to eight times per day.

A suitable dose concentration may be 0.5 mg/mL to 10 mg/mL. A suitable dose administered to asthma patients may be between 0.5 to 5 ml, in particular around 1 mL. A suitable dose administered to dry eye or inflammation of the eye patients may be between 1-100 ul, in particular around 50 ul. A suitable enema administered dose may be between 10 to 100 mL, in particular around 60 mL.

The composition may be administered once, twice, three, four, five, six, seven or eight times a day or periodically.

The composition can be administered for 1, 2, 3, 4, 5, 6, 7, 8 or more weeks.

The composition can be administered for 1, 2, 3, 4, 5 or 6 days.

The composition may be in respect of existing aggravation, inflammation, pain and/or discharge of the effected site or may be prophylactic (preventative treatment). Treatment may include curative, alleviation or prophylactic effects.

Specific examples of diseases treatable by the invention include the mucosal inflammatory conditions described below. Each disease requires the influx of certain blood borne inflammatory cells and activation of immune cells that have localized to the site of inflammation. Such diseases are therefore ideally treated by an agent that can block both the influx of inflammatory cells and the activation of the innate immune system, as provided by the present invention.

Inflammatory bowel diseases include ulcerative colitis (UC) and Crohn's disease (CD), both of which are inflammatory disorders of the intestinal mucosa. Ulcerative colitis is confined to the large intestine, while Crohn's disease can involve any region of the intestinal mucosa, including the oral cavity. Both UC and CD are characterized by the influx of inflammatory and immune cells in response to environmental and autoimmune stimuli. Although the histopathology of the two diseases differ, many therapeutic agents are used to treat both conditions, such as steroids, anti-TNF antibodies and mesalamine.

Pouchitis is inflammation of the distal intestinal mucosa remaining after surgical removal of the colon and formation of a J-pouch by ileal-anal anastomosis. Mucosal inflammation in pouchitis is similar to that observed in ulcerative colitis, although it may have microbial involvement to a greater extant. It is characterized by influx of activated inflammatory cells and activation of the local immune system.

Rectal stump disease is an inflammatory condition affecting the rectal mucosa remaining after colectomy.

Asthma is a complex and multifactorial disorder typified by episodes of breathlessness and wheezing in concert with airway hyper-reactivity (AHR) to a range of stimuli. Chronic inflammation mucosa of the airway wall is thought to be the primary factor driving asthmatic exacerbations. It is now well established that polarized CD4 T helper 2 (Th2) cells infiltrate and accumulate in the bronchial mucosa of allergic asthmatics, and that cytokines secreted from these cells (interleukin-(IL)-4, IL-5, IL-9 and IL-13) are largely responsible for acute exacerbations and promotion of the pathologic features of allergic asthma. Inhibiting the influx of inflammatory cells, through down-regulation of ICAM-1 and suppression of the innate immune response through inhibition of TLR-9 is an effective therapeutic approach provided by the present invention. This was a surprising discovery as several studies have identified TLR9 agonists as a potential therapy for asthma. Several clinical trials have explored the use of TLR9 agonists to treat asthma, for example, Astra Zeneca have a TLR9 agonist AZD1419, in-licensed from Dynavax, in Phase 2a for patients with eosinophilic, moderate to severe asthma via inhaled route. The TLR9 agonist suppresses Th2 (late phase) responses and enhanced Th1 responses. Cytos Biotechnology has run clinical trials using the TLR-9 agonist CYT003-QbG10 to treat allergic bronchial asthma. Other TLR9 agonists which have been evaluated in the clinic for treating asthma were AIC (Dynavax), AVE0675 and SAR-21609 (Sanofi-Aventis/Coley Pharmaceuticals); QAX-935 (Idera Pharmaceuticals/Novartis).

Eosinophilic sinusitis (ES) is an inflammation of the nasal mucosa characterized by the chronic influx of eosinophils and other monocytes and lymphocytes from the blood into the nasal mucosa in response to environmental antigens. This reaction leads to a variety of symptoms including nasal discharge (rhinorrea), congestion, nasal polyps. Eosinophilic sinusitis includes sinusitis and rhinitis. A paper by Licari A et al., (International Journal of Immunopathology Pharmacology, 2014 October-December; 27(4):499-508) explains how the upper and lower airways may be considered as a unique entity, interconnected by coexisting inflammatory processes that share common etiopathogenic mechanisms. The paper explains how previous studies have strongly demonstrated a relationship between rhinosinusitis and asthma. This has led to the introduction of the concept of ‘United Airways’, which has also been included in the WHO document Allergic Rhinitis and its Impact on Asthma (ARIA); this concept has important consequences also on the treatment of these disorders. The present invention is used to treat eosinophilic sinusitis.

Graft versus host disease occurs subsequent to bone marrow transplantation performed for treatment of blood cell cancers such as leukemia. During transplantation, the host blood-cell forming organs are eliminated by radiation treatment and the donor (graft) marrow transplanted to re-establish the organ's function. While this procedure can effectively treat the cancer, the transplanted immune system can begin to “reject” the host tissues. Sensitive tissues include the liver, skin, lungs and the GI tract. Systemic immunosuppression is used to control the rejection in most of these tissues, but the GI mucosa is particularly difficult to treat with systemic therapies. Inflammation occurring in the small intestine and colon is better treated with targeted therapy delivered directly to the gut lumen. The present invention in either an oral formulation or rectal enema formulation is used to suppress graft versus host disease.

In a paper by Calcaterra et al, in the Journal of Immunology, (2008, 181, 6132-6139) the authors demonstrate that inhibition of TLR9 may lead to the treatment of GVHD. The authors used C57BL/6 knockout mice to demonstrate that when TLR9 knockout mice were used as graft recipients, survival improved compared to wild type recipient mice. Mice were myeloablative-irradiated and injected with 107bone marrow cells and 4×107splenocytes obtained from full MHC major and minor Ag-disparate BALB/c donors. Recipient mice were monitored for clinical signs of GVHD, weight and survival. Interestingly those mice with a TLR4 knockout did not show an improved survival versus wild type recipient mice. All wild-type and TLR4−/− mice succumbed to severe acute GVHD within 60 days, while TLR9−/− mice showed a significantly higher survival rate, with four of eight mice still alive at the end of the experiment. The GVHD clinical score in TLR9−/− mice was also significantly lower than that in TLR 4−/− and C57B/6 mice and this correlated with reduced intestinal damage in the small intestine and to a lesser effect in the large bowel in TLR9−/− mice. Finally, at the end of the experiment, all TLR9−/− surviving mice achieved complete immune reconstitution, showed 100% donor peripheral blood lymphocyte cells. The results in this paper demonstrate the important role that TLR9 plays in the pathogenesis of GVHD.

Inflammation of the eye can also be treated with the present invention. Such conditions are dry eye or Sjogren's disease where reduction in the production of tear fluid results in local inflammation of the ocular mucosa. Dry eye disease is a common complaint of ophthalmic patients. Unaddressed conditions of dry eye can lead to erosion and abrasion of the epithelial cell surface of the cornea, raising susceptibility to infection. Progression of the disease can lead to ulceration of the cornea, even loss of sight. Disease and some physical conditions can predispose individuals to dry eye disorder, including; allergies, diabetes, lacrimal gland deficiency, lupus, Parkinson's disease, Sjogren's syndrome, rheumatoid arthritis, rosacea, and others. Medications for other diseases may cause or exacerbate dry eye disorders, including diuretics, antidepressants, allergy medications, birth control pills, decongestants and others. Age related changes may induce or exacerbate dry eye as well. Post-menopausal women experience changes in hormonal levels that can instigate or worsen dry eye and thyroid imbalances may cause similar changes. Finally aging itself can cause reduction in lipid production with resultant dry eye.

The present invention can be used for treating dry eyes, chronic dry eye (CDE) disease, or dry eye syndrome in a subject in need thereof. Subjects suffering from dry eyes, chronic dry eye (CDE) disease, or dry eye syndrome can be identified by any or a combination of diagnostic or prognostic assays known in the art. For example, typical symptoms of dry eyes, chronic dry eye (CDE) disease, or dry eye syndrome include, but are not limited to, symptoms such as, e.g., stinging, burning, or scratchy sensation in the eyes, stringy mucus in or around the eyes, increased eye irritation from smoke or wind, eye fatigue, sensitivity to light, eye redness, sensation of foreign object in the eyes, difficulty wearing contact lenses, periods of excessive tearing, swollen eyes, eye discomfort, eye pain, and blurred vision (which worsens at the end of the day or after focusing for a prolonged period).

In some embodiments, dry eyes is diagnosed by the tear osmolarity test. The tear osmolarity test measures the number of solid particles in a tear. The higher the tear osmolarity typically indicates that the tear has less water and more particles, e.g., salts, proteins, lipids, and mucin. A tear osmolarity score of below 308 mOsms/L is normal, 308-320 mOsms/L is mild dry eyes, 320-340 mOsms/L is moderate dry eyes, and above 340 mOsms/L is severe dry eye. The present invention can be used to treat mild dry eyes, moderate dry eyes, moderate to severe dry eyes and severe dry eyes.

Symptoms of severe dry eye may include, amongst others, conjunctival injection (hyperemia); such as bulbar conjunctival hyperemia, inferior tarsal conjunctival hyperemia, nasal bulbar conjunctival hyperemia; lid margin hyperemia, central corneal staining and redness of the eye.

More specifically, treatment includes “therapeutic” and “prophylactic” and these types of treatment are to be considered in their broadest context. The term “therapeutic” does not necessarily imply that a subject is treated until total recovery. Similarly, “prophylactic” does not necessarily mean that the subject will not eventually contract a disease condition.

Accordingly, therapeutic and prophylactic treatment includes amelioration of the symptoms of a particular condition or preventing or otherwise reducing the risk of developing a particular condition. The term “prophylactic” may be considered as reducing the severity or the onset of a particular condition. “Prophylactic” also includes preventing reoccurrence of a particular condition in a patient previously diagnosed with the condition. “Therapeutic” may also reduce the severity of an existing condition.

In summary, the present invention provides details describing that:Mucosal inflammation can be more effectively treated by agents that can target multiple pathways in the innate immune system.Blocking the influx of inflammatory/immune cells (ICAM-1) and blocking the activation of the innate immune response (TLR-9) together allows both an acute and durable response.The 20-base oligonucleotide SEQ ID NO:1 known to block ICAM-1, exerts both an acute and durable response because it also inhibits the activation of TLR-9.The primary sequence of SEQ ID NO:1 does not predict its action as a TLR-9 antagonist.The specific primary sequence of SEQ ID NO:1 suggests possible secondary structures that could influence TLR-9 activity, but does not predict the most stable or optimal structures.Conditions that influence the secondary structure of SEQ ID NO:1 also influence its activity as a TLR-9 antagonist.It has been discovered that an oligonucleotide, with the primary sequence of SEQ ID NO:1, when submitted to conditions that optimize its secondary structure, is a more potent treatment agent for mucosal inflammation than predicted by the primary sequence alone.

TLRs are a key means by which the host recognizes and mounts an immune response to foreign molecules. They also provide a mechanism by which the innate and adaptive immune responses are linked. Specifically, TLR-9 recognizes bacterial and viral DNA through certain unmethylated CpG motifs not present in mammalian DNA. Cells contained within the mucosa can therefore “sense” and respond to the presence of “foreign” DNA. Binding of such ligands activates the immune system to further respond to and remove the pathogen.

It is also known that synthetic oligonucleotides (ODN) containing CpG dinucleotide sequences can stimulate immune responses through the TLR-9 pathway. In addition, the use of synthetic oligonucleotides has shown utility as inhibitors of inflammatory cytokines and these actions are known to be mediated though inhibitory actions on TLR-9.

The published literature documenting the properties of DNA oligonucleotides required for binding to TLR-9 is extensive and has focused on both agonist and antagonist sequences. While the CpG motif is known to be required for stimulatory activity, there are no canonical sequences known to absolutely predict antagonist sequences. Certain inhibitors have been described previously in the art. In addition to these triplet-containing inhibitory ODNs, several groups have reported other specific DNA sequences that could inhibit TLR-9 mediated activation by CpG containing ODNs. These “inhibitory” or “suppressive” motifs are rich in poly “G” (e.g., “GGG”) or “GC” sequences, tend to be methylated and are present in the DNA of mammals and certain viruses. Other inhibitory sequences have been identified as containing a “GGGG” motif within the sequences. Certain repetitive TTAGGG elements, present at high frequency in mammalian telomeres, have been observed to down-regulate CpG-induced immune activation demonstrate that synthetic oligonucleotides containing the TTAGGG element mimic this activity and could be effective in the prevention/treatment of certain Th1-dependent autoimmune diseases.

The secondary structure of ODNs has also been studied as a basis for defining the DNA structure necessary for binding to TLR-9. However, there does not appear to be a secondary structure that absolutely specifies binding affinity, although sequence specific effects on structure are observed to alter the ODN agonist or antagonist activity.

The surprising finding is that SEQ ID NO:1 is an antagonist of TLR-9 and is devoid of agonist activity. Further, the invention defines specific conditions that contribute to the predicted secondary structure of SEQ ID NO:1 and relate the secondary structure to TLR-9 antagonism.

