Mucosal tissues are sites of frequent pathogen exposure and major routes for the transmission of infectious diseases. Migration of virus-specific memory CD8 T cells into mucosal tissues such as the small intestine and vaginal mucosa is highly restricted to non-circulating tissue resident memory CD8 T cells. Resident mucosal memory CD8 T cells are sufficient to protect against the establishment of mucosa-acquired viral infections, and thus it is essential to develop vaccine strategies that elicit long-lived mucosal CD8 T cells. CD8 T cells residing in mucosal tissues are phenotypically distinct from those in secondary lymphoid tissues and factors critical for their formation are poorly defined. It is also unclear whether mucosal CD8 T cells possess a unique requirement for their generation and maintenance from that of circulating memory CD8 T cells. We report that unlike in the secondary lymphoid tissues, the formation of virus-specific memory CD8 T cells in the small intestine and vaginal mucosa is dependent on mTOR signaling. In addition, we demonstrate using a CD8 T cell mediated model of intestinal autoimmune disease that inhibiting mTOR results in a loss of CD8 T cells in the small intestine and protects mice from lethality. Furthermore, we will discuss data that targets mTOR signaling intrinsically within the CD8 T cells to provide mechanistic insight into how the mTOR pathway specifically controls the generation of mucosal CD8 T cells in response to viral infections.
- Copyright © 2013 by The American Association of Immunologists, Inc.