An increased ratio of CNS-localized CD8 T cells protects from demyelinating disease after LCMV Infection 3904

Abstract Description Myelin-specific CD4+ T cells can mediate autoimmune demyelinating disease. These cells traffic to the central nervous system (CNS) and promote neuroinflammation which leads to irreparable damage of the myelin sheath. Although, infections have been considered as a trigger for the development of autoimmune diseases, it is possible that infections can also have a potential protective role. Here we investigate the impact of microbes on demyelinating disease onset and severity. We found that infecting C57Bl/6 mice with lymphocytic choriomeningitis virus (LCMV) during experimental autoimmune encephalomyelitis (EAE) leads to protection from demyelinating disease onset and progressive paralysis compared to uninfected controls. The infected mice also exhibited decreased numbers and percentage of myelin-specific CD4+ T cells in the CNS. The CNS was instead populated with LCMV specific CD8+ T cells. LCMV infection also proved effective at limiting paralysis when 2D2 TCR Tg cells specific for myelin were used to induce EAE despite the CD4+ T cells being activated CD44+ and CD62l low. This data suggests that viral infection can prevent myelin specific T cells from entering the CNS. Thus, infections may play an important role in regulating trafficking of specific immune cells to prevent demyelination and paralysis. Funding Sources 5T32AI138945-07 Topic Categories Neuroimmunology (NEUR)