Construction And Immunoprotection Of Recombinant Mycobacteirum Bovis BCG Expressing ADF Gene Against Eimeira Tenella Challenge

Eimeria tenella is an apicomplexan parasite which can result in coccidiosis. Thisdisease is considered to be a major problem for poultry industry. It can parasitize incecum of chicken, reduce body weight and even cause death of the chicker,and has a higheconomical impact in animal husbandry. Resently, the main way of prevention andtherapy of chicken coccidiosis anti-coccidiosis drug. However, the application of theanti-coccidiosis drug is limited because of government limitation and the side effect ofchemical medicines residue on human health. Attenuated live vaccines of several speciesare proved to be effective in preventing coccidial infection in the poultry industry. DNAvaccine and subunit vaccine are researched, but the effect is bad.The recombinant BCG is immunologic adjuvant, as a live vaccine. It has beenwidely researched. IL-2is a major cytokine of cell-mediated immunity, which isreleased by Th-1cell. IL-2can prevent E.tenella infection, which has been proved.In this study, we constructed two rBCG261–ADF,361-ADF of E.tenella ADFgene and immunize chicken.It was determined the effect of rBCG by pathologicalchanges of cecum, the content of oocyst,and ACI. At the same time, the level ofantibody was determined by ELISA and the change of CD4~+T cell and CD8~+T cellwas determined by flow cytometry. The result indicated that the ACI ofpMV261-ADF and pMV361-ADFrBCG increaesd. Compared with control group, thelevel of antibody and the number of CD4~+T cell are increased(P<0.01). At the sametime, rBCG co-expressing ADF and ChIL-2genes were constructed. By intranasalimmunized rBCG, the ACI of pMV261-ADF-IL-2and pMV361-ADF-IL-2group was176.08and172.89, the level of antibody and the change of CD4~+T、CD8~+T cell isdifferent significantly in comparation to controls(P<0.01). IL-2gene could providethe protection of rBCG strains against E. tenella challenge.