Vaccination with BV8S2 protein amplifies TCR-specific regulation and protection against experimental autoimmune encephalomyelitis in TCR BV8S2 transgenic mice.

TCR determinants overexpressed by autopathogenic Th1 cells can naturally induce a second set of TCR-specific regulatory T cells. We addressed the question of whether immune regulation could be induced naturally in a genetically restricted model in which a major portion of TCR-specific regulatory T cells expressed the same target TCR BV8S2 chain as the pathogenic T cells specific for myelin basic protein (MBP). We found vigorous T cell responses to BV8S2 determinants in naive mice that could be further potentiated by vaccination with heterologous BV8S2 proteins, resulting in the selective inhibition of MBP-specific Th1 cells and protection against experimental encephalomyelitis. Moreover, coculture with BV8S2-specific T cells or their supernatants reduced proliferation, IFN-gamma secretion, and encephalitogenic activity of MBP-specific T cells. These results suggest that immune regulation occurs through a nondeletional cytokine-driven suppressive mechanism.