Interleukin 5 up-regulates high-affinity interleukin 2 receptor expression by human resting peripheral T cells: A comparison with the effect of interleukin 4 on B cells

Abstract

The separate regulation mechanisms of cytokines on two classes of interleukin 2 receptors (IL-2R) on human peripheral T and B cells were analyzed by a flow cytometer using a double stain with IL-2Rα (55 kilodalton Tac) and IL-2Rβ (75 kilodalton mikβ1, mikβ3). Although the expression of IL-2Rα by T cells was slightly enhanced by IL-2 and IL-4, expression of the β chain was diminished by both cytokines. IL-5 by itself did not alter the expression of either IL-2Rα or β, but preculturing with IL-2 for 24 h followed by IL-5 for another 24 h induced an increase in IL-2Rα expression and in simultaneous α/β chain expression. Increased numbers of high-affinity IL-2R were confirmed by 125I binding assays. On B cells, IL-4 increased α, β, and simultaneous α/β chain expression, but IL-4-treated B cells did not show an increased number of high-affinity IL-2R.