TRAIL NK Cells Control CD4 T Cell Responses during Chronic Viral Infection to Limit Autoimmunity

Abstract

Natural killer (NK) cells have been reported to control adaptive immune responses that occur in lymphoid organs at the early stages of immune challenge. Thephysiological purpose of such regulatory activity remains unclear, because it generally does not confera survival advantage. We found that NK cells specifically eliminated activated CD4+ Tcells in the salivary gland during chronic murine cytomegalovirus (MCMV) infection. This was dependent on TNF-related apoptosis inducing ligand (TRAIL) expression by NK cells. Although NK cell-mediated deletion of CD4+ Tcells prolonged the chronicity of infection, it also constrained viral-induced autoimmunity. In the absence of this activity, chronic in..