IFN-{gamma}-Producing {gamma}{delta} T Cells Help Control Murine West Nile Virus Infection

West Nile (WN) virus causes fatal meningoencephalitis in laboratory mice, thereby partially mimicking human disease. Using this model, we have demonstrated that mice deficient in [gamma][delta] T cells are more susceptible to WN virus infection. TCR[delta] super(-/-) mice have elevated viral loads and greater dissemination of the pathogen to the CNS. In wild-type mice, [gamma][delta] T cells expanded significantly during WN virus infection, produced IFN-[gamma] in ex vivo assays, and enhanced perforin expression by splenic T cells. Adoptive transfer of [gamma][delta] T cells to TCR[delta] super(-/-) mice reduced the susceptibility of these mice to WN virus, and this effect was primarily due to IFN-[gamma]-producing [gamma][delta] T cells. These data demonstrate a distinct role for [gamma][delta] T cells in the control of and prevention of mortality from murine WN virus infection.