Self MHC class I licensed NK cells enhance adaptive CD8 T cell viral immunity (154.5)

Abstract MHC class I (MHC I) is essential to NK and T cell effector and surveillance functions. However, it is unknown if MHC I polymorphism influences adaptive immunity through NK cells. Previously, we found that MHC I Dk, a cognate ligand for the Ly49G2 inhibitory receptor, was essential to NK control of murine (M)CMV infection. Here we assessed the significance of NK inhibitory receptor recognition of MCMV on CD8 T cells in genetically defined MHC I Dk disparate mice. We observed that Dk-licensed Ly49G2+ NK cells stabilized and then enhanced conventional dendritic cells (cDC) recovery following infection. Further, licensed NK support of cDC recovery was essential to enhance the tempo, magnitude and effector activity of virus-specific CD8 T cells. Minimal cDC and CD8 T cell number differences after low dose MCMV in Dk disparate animals further implied that licensed NK recognition of MCMV imparted qualitative cDC changes to enhance CD8 T cell priming.