Role of Natural Killer and Gamma-Delta T cells in West Nile Virus Infection

Wang, Tian; Welte, Thomas

WNV has been studied in various animal models, including mice, hamsters, monkeys, and horses [12] [13] [14] [15] . The murine model is an effective in vivo experimental model to investigate viral pathogenesis and host immunity in humans. Following the initial subcutaneous or intraperitoneal inoculation in mice, WNV induces a systemic infection and eventually invades the CNS. Mice die rapidly when encephalitis develops, usually within one to two weeks. The severity and symptoms of lethal infection observed in the murine model mimic the symptoms caused by WNV infection in humans [13, 16, 17] . Studies from experimental animal models, in vitro cell culture, and/or WNV patient samples have provided important insights into host immunity to WNV infection. Natural killer (NK) cells and  T cells are two innate lymphocytes that respond rapidly and non-specifically to viral infection. They are also known to form a unique link between innate and adaptive immunity. Moreover, the characteristics of these two cell types in adaptive immunity have been described in several disease models [18] [19] [20] [21] . In this review, we will discuss recent studies on these two unique cell types in both protective immunity and viral pathogenesis during WNV infection.