DYSREGULATION OF THE INTERLEUKIN-2 RECEPTOR ALPHA- AND BETA-CHAIN EXPRESSION IN CD4 AND CD8 T-CELLS IN HIV-INFECTION

Peripheral blood mononuclear cells were prepared from human immunodefi ciency virus-positive (HIV+) individuals (n = 46) to investigate the e xpression of both chains of the interleukin-2 receptor, Both qualitati ve and quantitative changes in expression were observed, Total lymphoc yte expression of the IL-2 alpha chain (CD25) was decreased compared w ith HIV-negative (HIV-) controls, This was due to the decrease in the CD4(+) population, which favored expression of this receptor, rather t han a decrease in expression, per se, CD8(+) lymphocytes expressed the beta chain (CD122) in the absence of the alpha chain. However, a sign ificant increase in the number of peripheral blood CD8(+) lymphocytes expressing mainly the beta subunit was observed in HIV+ patients (P = 0.02), This was observed to a similar extent in asymptomatic and sympt omatic patients and characterized a subpopulation of T lymphocytes exp ressing high levels of CD8, Lymphocytes from patients with advanced HI V disease failed to up-regulate both alpha and beta chains in response to mitogenic concentrations of phytohaemagglutanin. However, those ce lls that were able to up-regulate both of the IL-2 receptors were capa ble of effective signal transduction through the receptor, increasing the proliferative response to stimulation. (C) 1997 Wiley-Liss, Inc.