Study of activated T cells in man. II. Interleukin 2 receptor and transferrin receptor expression on T cells and production of interleukin 2 in patients with acquired immune deficiency syndrome (AIDS) and AIDS-related complex.

Because the expression of interleukin 2 (IL-2) receptor and transferrin receptor is essential for the proliferation of T cells to mitogens and antigens, we examined the expression of monoclonal antibody defined IL-2 receptor (Tac antigen) and transferrin receptor on unstimulated as well as on phytohemagglutinin (PHA)-activated highly enriched T cells from patients with acquired immune deficiency syndrome (AIDS) and AIDS-related complex (ARC). A trend of increased proportion of unstimulated T cells with Tac antigen and transferrin receptor was observed in patients with AIDS and ARC when compared to healthy heterosexual controls, but the differences were not significantly (P greater than 0.1). The proportions of Tac+ PHA-activated T cells were, however, significantly decreased in AIDS (P less than 0.001). ARC (P less than 0.001), and asymptomatic homosexuals (P less than 0.01) when compared to healthy heterosexuals. The proportions of transferrin receptor positive PHA-activated T cells were not significantly different among various groups. A significantly (P less than 0.01) decreased production of IL-2 was observed in AIDS. This study suggests that the poor proliferative responses of T cells may be due to several defects in lymphocyte-cytokine cascade and the deficiency of Tac antigen expression and of the production of IL-2 could be a few of several abnormalities contributing to poor T-cell functions in AIDS.