Increased interleukin-2 receptor expression after mitogen stimulation on CD4- and CD8-positive lymphocytes and decreased interleukin-2 production in HTLV-III antibody-positive symptomatic individuals.

We investigated the expression of the interleukin-2 (IL-2) receptor on phytohaemagglutin-stimulated peripheral blood lymphocytes from homosexual men with persistent generalized lymphadenopathy, the prodrome of the acquired immune deficiency syndrome. The subjects were positive for antibody against human T-cell lymphotropic virus III. Using two-colour fluorescence flow cytometry, IL-2 receptor expression was determined on both the CD4- and CD8-positive lymphocyte subpopulations. After 48 hr of stimulation, expression of the IL-2 receptor on both T-cell subsets was significantly increased in lymphadenopathy patients as compared to values in heterosexual age-matched controls; this difference was less after 72 hr of stimulation. Results from two AIDS patients were within the normal range. IL-2 production was significantly reduced in both lymphadenopathy and AIDS patients as compared to values in heterosexual controls. We conclude that a defect in IL-2 production is associated with human T-cell lymphotropic virus III infection, but that the expression of the IL-2 receptor on T cells is not greatly affected.