γδ T cells in rhesus monkeys and their response to simian immunodeficiency virus (SIV) infection

This is the authors' abstract. We don't add key points for this paper.

Recent reports of the increase in peripheral blood gamma delta T cells in HIV+ patients prompted us to examine the gamma delta T cell system in rhesus monkeys (Macaca mulatta) and the responses of these cells to SIV infection. Our results reveal differences in the gamma delta T cell subset composition and their expression of CD8 in the peripheral blood of monkeys and humans. The outgrowth of simian gamma delta T cells in response to Daudi cells is similar to that in humans, but the exposure to IL-2 stimulates preferentially the simian V delta 1 subset rather than the V gamma 9/V delta 2 subset as found in humans. Upon SIV infection of the monkeys, we observed a transient increase of the percentage of total gamma delta T cell and the V gamma 9 subset. gamma delta T cells from infected animals also express more activation markers such as CD69, CD44 and the memory marker CD45RO. However, they respond to a lesser degree to Daudi or IL-2 stimulation in the outgrowth experiments compared with uninfected animals, although the subset composition of total gamma delta T cells is similar in infected and uninfected animals. The results clearly indicate that gamma delta T cells in rhesus monkeys are influenced by SIV infection. The detailed analysis of the gamma delta T cell response to SIV infection can serve as a model for understanding human gamma delta T cell responses to HIV infections.