Natural Killer Cells and Innate Immunity in HIV-2 Infection

Abstract

In contrast to the extensive efforts made to learn more about HIV-1 in the fields of epidemiology, geographical distribution, and viral pathogenesis, very little work has been carried out to understand the interactions between the HIV-2 and the host immune system. Although both cellular and humoral immune responses to HIV-1 have been shown to play a part during acute infection, these activities are impaired during chronic infection, leading to disease progression and eventually death (Zhang et al. 2003). Studies of HIV-2-infected individuals have shown that the majority experiences a slower and more prolonged disease course than seen in HIV-1 infection: therefore, a better understanding of the interactions between HIV-2 and the host immune response may be useful in providing insights for therapeutic and vaccine strategies. One way viruses are attacked early in infection is through the action of natural killer (NK) cells, which are one of the key components of the innate immune response to infections (Biron and Brossay 2001). These cells are naturally activated in response to infection without the requirement for prior sensitization and may play an important role in the outcome of viral infections. NK cells provide the first line of defense in the early stage of many infections, including HIV, and continue to render a critical service in nonspecific host defense mechanisms. However, little is known about NK cell function in HIV-2 infection.