Indirect CD4 + T cell protection against persistent MCMV infection by NK cells requires IFNγ

Host control of mouse cytomegalovirus (MCMV) infection of MHCII salivary gland acinar cells is mediated by CD4 T cells, but how they protect is unclear. Here, we show CD4 T cells control MCMV indirectly in the salivary gland, via IFNγ engagement with uninfected, but antigen MHCII APC and recruitment of NK cells to infected cell foci. This immune mechanism renders direct contact of CD4 T cells with infected cells unnecessary and may represent a host strategy to overcome viral immune evasion.