[Altered expression of survival (CD127) and death (Fas) receptors in total, naïve and memory CD8 T lymphocytes from human immunodeficiency virus infected patients: possible implications for progression of infection].

We studied the ex vivo and in vitro expression of CD95/Fas and CD127 receptors in total, naive and memory CD8+ T cells from HIV infected patients with different blood counts of CD4+ T cells. In addition, spontaneous and induced apoptosis were determined in vitro using a viral antigen (Env), along with an evaluation of their specific proliferative capacity. The obtained results demonstrated that patients with low counts of CD4+ T cells (CD4 < 250/microL), showed ex vivo, a high expression of CD95/Fas and a low expression of CD127 in all CD8+ T cell subgroups, as compared with patients with bigger counts of CD4+ T cells in blood (CD4> 250/microL). In vitro analyses using Env antigen showed that CD8+ T cells displayed a similar expression of both receptors, with a higher incidence of spontaneous and induced apoptosis and a diminished proliferative capacity as compared with controls. Results indicate how the progression of VIH infection in non-treated patients is related to a decrease of CD8+ T cells in blood, characterized by failures in their proliferative capacity and apoptosis frequency, which is demonstrated by the altered expression of CD127 and CD95/Fas expression.