Shrikrishna, IsloorRathnamma, D.yathiraj, S.Sridhar, N.B.Byregowda, S.M.Chandrashekhara, N.--, --2017-11-032017-11-032009-07-15----http://krishikosh.egranth.ac.in/handle/1/5810034706P.G. ThesisThe study was carried out to evaluate T cell proliferative response in cattle by analyzing lymphocyte subpopulation with reference to CD4 and CD8 cells by flow cytometry and humoral immune response with reference to serum IgG level by indirect ELISA, in mastitis causing E.coli Biofilm vaccinated and Free cell vaccinated groups. In all, eighteen cattle in early lactation which were free from mastitis were subjected to trials. Bentonite clay (an adjuvant by itself) based E.coli BF and FC vaccines were administered at 0, 30 and 60 days. Freund’s incomplete adjuvant was incorporated in the first shot. In Flow cytometric analysis, vaccination based on the E.coli BF showed significant enhancement in CD4 and CD8 cells. The percentage of CD4 and CD8 increased significantly in the E.coli BF vaccinated groups than in the control group and further, in comparison with E.coli FC vaccine, the percentage of CD4 and CD8 cell population found to be marginally increased on days 60 and 90 and significantly increased on day 120 post vaccination. Further, serum IgG level detected by indirect ELISA was significantly higher in BF vaccinated than FC vaccinated groups. The increased levels of IgG in the BF vaccinated serum coincided with the CD4 levels determined by the flow cytometry, indicating the higher titres of IgG due to the presence of CD4 cells. Both BF and FC vaccinated groups showed significant difference with control group. T cell proliferative immunological response by analyzing lymphocyte subpopulation with reference to CD4 and CD8 cells and humoral immune responses indicated superiority of bovine mastitis causing E.coli BF vaccine over FC vaccine.ennull----Thesis