NK cells contribute to reovirus-induced IFN responses and loss of tolerance to dietary antigen.

Celiac disease is an immune-mediated intestinal disorder that results from loss of oral tolerance (LOT) to dietary gluten. Reovirus elicits inflammatory Th1 cells and suppresses Treg responses to dietary antigen in a strain-dependent manner. Strain type 1 Lang (T1L) breaks oral tolerance, while strain type 3 Dearing reassortant virus (T3D-RV) does not. We discovered that intestinal infection by T1L in mice leads to the recruitment and activation of NK cells in mesenteric lymph nodes (MLNs) in a type I IFN-dependent manner. Once activated following infection, NK cells produce type II IFN and contribute to IFN-stimulated gene expression in the MLNs, which in turn induces inflammatory DC and T cell responses. Immune depletion of NK cells impairs T1L-induced LOT to newly introduced food antigen. These studies indicate that NK cells modulate the response to dietary antigen in the presence of a viral infection.