Impact of genetic background of cattle on immune responses to RB51 and BCG vaccination 9401

Abstract Description Bovine brucellosis and bovine tuberculosis (bTB) are two major bacterial zoonotic diseases of concern in the cattle industry. Brucella abortus strain RB51 is a commercially available live attenuated vaccine against bovine brucellosis. There is currently no approved vaccine for bTB, however, Bacillus Calmette-Guerin (BCG) is known to be protective against bTB. Results of previous studies conducted in our lab suggest that the genetic background in cattle may impact the adaptive immune responses induced following vaccination with RB51 and BCG. To further investigate the effect of genetic background on the immune response to RB51 and BCG in vitro, peripheral blood mononuclear cells were isolated from naïve Hereford and Holstein cattle. Cell cultures were enriched for monocytes via adherent cell selection and were then infected with RB51, BCG, or RB51+BCG. Transmission electron microscopy, RNA sequencing, and cytokine ELISAs were used to evaluate differences in bacterial colonization of monocytes, gene expression, and inflammatory and T helper 1 cytokine expression between beef and dairy backgrounds. Results of this study allowed for further description of the differences in the RB51- and BCG-specific immune responses in beef and dairy cattle, contributing the development of efficient vaccination and control strategies to prevent bovine brucellosis and bTB. Funding Sources Supported by USDA CRIS 5030–32000-234. Topic Categories Veterinary and Comparative Immunology (VET)