|GUERRA-MAUPOME, MARIANA - Kansas State University|
|LARSEN, MICHELLE - Albert Einstein College Of Medicine|
|MCGILL, JODI - Kansas State University|
Submitted to: American Association of Immunologists Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 1/20/2017
Publication Date: N/A
Technical Abstract: Bovine tuberculosis caused by Mycobacterium bovis is a globally significant veterinary health problem. Gamma delta T cells are known to participate in the immune control of mycobacterial infections. Data in human and non-human primates suggest that mycobacterial infection regulates memory/effector phenotype and adaptive immune functions of mycobacterium-responsive gamma delta T cells. To date, the impact of age or M. bovis infection on bovine gamma delta T cells memory/effector phenotype remains unknown. In this study, we addressed the age dependent changes of circulating gamma delta T cells, analyzed functional and phenotypic differences in memory and activation marker expression, and evaluated functional responses of M. bovis-specific gamma delta T cells following M. bovis Bacille Calmette-Guerin (BCG) vaccination or virulent M. bovis infection. As expected, aerosol vaccination and virulent infection induced robust mucosal and systemic M. bovis-specific gamma delta T cell proliferative responses. Analysis of peripheral blood gamma delta T cells indicated phenotypic differences based on the expression of CD27 and CD45R that could suggest distinct functional properties. Recall responses after in vitro stimulation with mycobacterial antigens showed that expression of CD27 is critical for the expansion of peripheral IFN-gamma-producing gamma delta T-cells and suggest that the CD27+ subset may compose the mycobacterium-responsive gamma delta T cell compartment in calves responding to M. bovis vaccination or infection. The ability of gamma delta T cells to mount a robust response during mycobacterial infections supports the notion that vaccine-elicited gamma delta T cell immunity might prove beneficial. Therefore, defining correlates of protection based on this population can accelerate the development of novel vaccines against TB.