Allergy immune response is modulated by DNA vaccination for cockroach allergy in mice

RATIONALE: DNA Vaccination with the plasmid DNA encoding cockroach Blag2 in mice will protect immunized mice from specific cockroach allergen challenge by 1. inducing Th1 response (increase IFN-gamma production) 2. suppressing Th2 response (decrease IL-4, IL-5 production) and decrease inflammatory cell infiltrate in lung tissues.METHODS: C57/B6 mice were immunized either intramuscularly or intranasally. They were then subdivided into three groups: (1) blag-2, pCI-neo and Lipofectin (2) pCI-neo, Lipofectin, (3) Lipofectin only. They were immunized three times at weekly intervals. Two weeks after the last immunization, they were sensitized three times at 2 weeks intervals. Four weeks later, mice were challenged nasally with Blag-2. Four days later the mice were sacrificed. Sera and spleen cell culture supernatant were assayed for IL-10, IL-13 and INF-γ. Lung tissue, trachea, and nose tissue were taken for histologic examination. Thymidine update assay was done.RESULTS: Immunization with plasmid DNA with blag-2 gene induces increased antigen-specific IFN-γ (Th1 cytokine) mRNA/protein level. INF-γ levels in the culture supernatant of the lipofectin, Blag-2 and pc1-neo group were increased more than any other group. Also there was a marked decrease in the IL-13 level in this group compared to any other. The histologic and immunologic examination shows the lung tissue has less cell infiltration than control and CD8+ cells were more prominent than CD4 cells in the treated group.CONCLUSIONS: DNA vaccination is an excellent way of controlling cockroach allergy and furthermore Lipofectin treatment increased INF-γ levels, suggesting increased level of gene transfection of Blag-2. RATIONALE: DNA Vaccination with the plasmid DNA encoding cockroach Blag2 in mice will protect immunized mice from specific cockroach allergen challenge by 1. inducing Th1 response (increase IFN-gamma production) 2. suppressing Th2 response (decrease IL-4, IL-5 production) and decrease inflammatory cell infiltrate in lung tissues. METHODS: C57/B6 mice were immunized either intramuscularly or intranasally. They were then subdivided into three groups: (1) blag-2, pCI-neo and Lipofectin (2) pCI-neo, Lipofectin, (3) Lipofectin only. They were immunized three times at weekly intervals. Two weeks after the last immunization, they were sensitized three times at 2 weeks intervals. Four weeks later, mice were challenged nasally with Blag-2. Four days later the mice were sacrificed. Sera and spleen cell culture supernatant were assayed for IL-10, IL-13 and INF-γ. Lung tissue, trachea, and nose tissue were taken for histologic examination. Thymidine update assay was done. RESULTS: Immunization with plasmid DNA with blag-2 gene induces increased antigen-specific IFN-γ (Th1 cytokine) mRNA/protein level. INF-γ levels in the culture supernatant of the lipofectin, Blag-2 and pc1-neo group were increased more than any other group. Also there was a marked decrease in the IL-13 level in this group compared to any other. The histologic and immunologic examination shows the lung tissue has less cell infiltration than control and CD8+ cells were more prominent than CD4 cells in the treated group. CONCLUSIONS: DNA vaccination is an excellent way of controlling cockroach allergy and furthermore Lipofectin treatment increased INF-γ levels, suggesting increased level of gene transfection of Blag-2.