The DNA-induced protective immunity with chicken interferon gamma against poultry coccidiosis.

The immunogenicity of Eimeria acervulina cSZ-2 and chicken interferon gamma was observed against Eimeria tenella challenge. The chickens were randomly divided into six groups of 24 chicks each. Three groups of chickens were injected with DNA vaccines pVAX1-cSZ2, pVAX1-chIFN-gamma and pVAX1-cSZ2-chIFN-gamma two times (at days 14 and 21) at a dose of 100 microg intramuscularly. Three other groups were kept as control and injected with TE buffer (10 mM Tris-HCl pH 7.6 and 1 mM EDTA). One week following the booster dose, all chickens except the non-infected, non-vaccinated control group were inoculated orally with 5 x 10(4) sporulated oocysts of E. tenella. Seven days post challenge, all chickens were weighted and slaughtered for cecal lesion scoring and oocyst counts. The results demonstrated that cSZ-2 in combination with interferon gamma can protect chickens from coccidiosis by significantly decreasing body weight loss and oocyst excretion reflecting partial protection against E. tenella infection, and further studies are necessary to test for protection against other Eimeria species.