Immune Procedure, Cross-Immunity And Stability Of PEtK2-IL-2 DNA Vaccine Against E.tenella

Immunization prevention for avian coccidiosis is more and more important than traditional control in the past. The success of gene engineering vaccines and nucleic acid vaccine was mainly based on the discovery of novel antigens. Studies have proved that a powerful method of controlling the coccidiosis is to stimulate the response of host immune system. DNA vaccine, especially coadministrated with some immuno-regulating cytokines, could induce the special or/and nonspecial response of those immune cells. As we known, the inoculating procedures had a deep impact on the effect on immune response. At present, however, only few of the works were contributed to the research of immune methods of DNA vaccine. Here, the immunization procedures, the cross-protection and stability of the two DNA vaccines pcDNA4.0(c)-pEtK2-IL-2 and pVAX1-pEtK2-IL-2 were studied in this experiment. 1 Immunized dose of E. tenella pEtK2-IL-2 DNA vaccineFour groups were applied in the two immuno-regulating DNA vaccines: pcDNA4.0(c)-pEtK2-IL-2 and pVAX1-pEtK2-IL-2 respectively, 200μg, 100μg, 50μg, 25μg for pcDNA4.0(c)-pEtK2-IL-2 and 100μg, 80μg, 50μg, 25μg for pVAX1-pEtK2-IL-2 in the experiment. They were used to immunize chicken by injecting into the breast muscle at the age of two weeks, boosted at one week later. The chickens were challenged by E. tenella sporulated oocytes (5×10~4 per bird) at the age of four weeks. At the fifth week old, all chickens were killed. The follow parameters such as weight gain, oocytes production(OPG), the cecal lesion scores and anti-coccidial index (ACI) were surveyed. The results showed that both ACIs of the group 50μg pcDNA4.0(c)- pEtK2-IL-2 and that 80μg pVAX1-pEtK2-IL-2 were 189.90 and 184.87 respectively. They achieved a better...