Objective: To assess the effects of DNA vaccine of mite major allergens on murine pulmonary allergic inflammation triggered by mite extract.
Methods: Two eukarycyte expression plasmids of Derp 1 and Derp 2 (pDerp 2-IRES-Derp 1 and pCMV-Derp 1) were constructed. BALB/c mice were divided into four groups: normal group, control group, mono-plasmid group and mixture immunization group. The latter three groups were immunized with blank plasmid, pDerp 2-IRES-Derp 1 and mixture of both pDerp 2-IRES-Derp 1 and pCMV-Derp 1, respectively. The mice were sensitized and challenged with mite extract 4 weeks later. Pathological scores, bronchoalveolar lavage (BAL) total cell count and differentiation were studied. IL-4 and IFN-gamma levels in BAL fluid (BALF) were detected by ELISA.
Results: Total cell count and eosinophil count in the mixture immunization group [(6 +/- 4) x 10(5)/ml], 0.05 +/- 0.04 were significantly lower than those in the control group [(21 +/- 13)10(5)/ml], 1.80 +/- 1.39, (P < 0.05). IL-4 in BALF in the mixture immunization [(168 +/- 233) g/L] group was significantly lower than that in the control group [(538 +/- 256) g/L], (P < 0.05). IFN-gamma showed no significant changes among different groups (P > 0.05).
Conclusions: DNA vaccine of mite major allergens showed inhibitory effect on pulmonary allergic inflammation induced by mite extract, and this effect was more prominent in the DNA vaccine expressing two allergens than that expressing only one allergen.