Herpes Simplex Virus Induces the Early Activation of NK Cell via MyD88- Dependent Signal

ABSTRACT

In the course of a Herpes Simples Virus type-1 (HSV-1) infection, the bidirectional cross-talk between Natural Killer (NK) cells and Dendritic Cells (DCs) is imperative in mounting an efficient immunological response. Enhanced DC maturation by Toll-Like Receptor (TLR) ligands is considered as a pivotal link between innate and adaptive immune responses, yet the impact of direct TLR signaling on NK:DC interaction during an HSV infection has yet to be examined. We demonstrate that HSV mediates the activation of NK cells and the induction of the cooperative relationship between NK cells and DCs via TLR. During the course of an HSV infection, the initial response required both types of innate cells and demonstrated phenotypic and functional activation much like that of TLR-stimulated cells. Using a MyD88 knock-out system diminished the early interaction between DCs and NK after HSV exposure. Our results indicate that HSV TLRligands modulate the early NK: DC interaction and may be a mechanism used by these innate immune cells to overcome virus mediated immune evasion and the initiation of a potent acquired immune response.