A role for plasmacytoid dendritic cells in the rapid IL-18-dependent activation of NK cells following HSV-1 infection

Abstract

Natural killer (NK) cells play a crucial role in the initial response to viral infections but the mechanisms controlling their activation are unclear. We show a rapid and transient activation of NK cells that results in the production of IFN-γ immediately following infection with herpes simplex virus type 1 (HSV-1). Activation of NK cells leading to synthesis of IFN-γ was not mediated by a direct interaction with virus but required the presence of additional cell types and was largely dependent on the cytokine IL-18, but not IL-12. HSV-1-induced IFN-γ expression by NK cells in vitro was impaired in spleen cultures depleted of CD11c+ cells. Conversely, coculture of NK cells with virus-exposed..