Human Mucosal Associated Invariant T (MAIT) cells can be readily activated through their T cell receptor but additionally certain functions can be activated through combinatorial cytokine signals (e.g. IL-12 + IL-18) without T cell receptor engagement. Given that they are enriched at mucosal sites, such innate activation of MAIT cells could contribute to early local (and systemic) host defense against infection. This talk will address how such activation might occur in response to virus infections, in particular:

1) What is the evidence that virus infection leads to MAIT cell activation in vivo (in humans)?2) Does this activation correlate with disease activity? 3) What is the evidence that such activation can be reproduced using specific cell populations in vitro?4) What distinct signaling mechanisms underlie “non-TCR” MAIT cell activation for specific viruses?
The talk will focus mainly on RNA viruses - Dengue, HCV and Influenza, and I will discuss the likely consequences of such activation in these settings.