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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, OBJECTIVE, METHODS, RESULTS. Meshes: Allergens, Animals, Antigens, Plant, Blotting, Southern, DNA, Plant, Injections, Subcutaneous, Latex, Latex Hypersensitivity, Lymph Nodes, Mice, Mice, Inbred BALB C, Plant Proteins, Plasmids, RNA, Plant, Reverse Transcriptase Polymerase Chain Reaction, Spleen, Vaccines, DNA.
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Is the latex allergen Hev b 5 transcript widely distributed after subcutaneous injection in BALB/c mice of its DNA vaccine? Context: DNA vaccines reduce IgE responses to selected allergens, but severe reactions to the expressed antigen may limit the usefulness of the technique in allergen immunotherapy. We sought to determine the extent of spread of an injected DNA vaccine in mice. We placed the gene encoding the potent Hevea latex allergen Hev b 5 in a mammalian expression vector and injected this DNA vaccine subcutaneously into BALB/c mice. At several times after injection, the presence of Hev b 5 transcript was determined in multiple tissues by RT-PCR. The identity of the amplification product was confirmed by Southern hybridization and restriction analyses. Hev b 5 RNA appeared at the injection site and in the lymph nodes, spleen, and lungs within 1 day after injection and persisted for at least 14 days. Hev b 5 RNA was also identified in the blood and tongue 14 days after injection. Antibody and cell-mediated responses to Hev b 5 were also noted in the immunized animals at later time points. As expected, animals injected with the identical plasmid containing the Hev b 5 DNA in the antisense orientation mounted no immune response to Hev b 5.
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The rapid and widespread appearance of the Hev b 5 transcript in the injected mice confirms that DNA is translocated from the injection site, transcribed, and expressed in immune and nonimmune tissues after injection. Controlling the extent and degree of expression in specific target tissues may allow therapeutic DNA vaccination with plasmids that encode potentially toxic allergens. Final Decision: yes