Anti-CD3 antibody-induced expression of both p55 and p75 chains of the high affinity interleukin-2 receptor on human T lymphocytes is inhibited by cyclosporin A

B. M.J. Foxwell, J. Simon, J. J. Herrero, D. Taylor, G. Woerly, D. Cantrell, B. Ryffel

Research output: Contribution to journalArticle

27 Citations (Scopus)


The inhibitory effect of cyclosporin (CsA) was investigated on human lymphocytes stimulated by anti-T-cell antibodies (anti-CD3 and -CD2) or mitogenic lectins. Whereas inhibition of cell proliferation (50%) occurred at 10 ng/ml CsA after cell activation via CD3 or CD2, higher CsA concentrations (300 ng/ml) were necessary to inhibit lectin-mediated cell activation (PHA, Con A). Exogenous recombinant interleukin-2 (rIL-2) partially reversed the inhibitory effect on antibody-stimulated cells only; however, at higher CsA concentrations (300 ng/ml) proliferation was again inhibited. Thus, CsA affected IL-2R expression and/or function at higher concentrations (300 ng/ml). CsA had no effect on receptor function as measured on IL-2-dependent cell growth of CTLL cells or preactivated lymphocytes. However, CsA inhibited both high and low affinity receptor expression as shown by [125I]IL-2 equilibrium binding studies on anti-CD3-stimulated cells. Cross-linking studies revealed that both p55 (TAC) and p75 chains of the IL-2R were not induced at low CsA concentrations (10 ng/ml). However, addition of rIL-2 reversed CsA inhibition of IL-2R expression. It is concluded that CsA, at least in anti-CD3-stimulated cells, inhibits IL-2R expression and cell proliferation with similar potency. Exogenous rIL-2 reverses CsA inhibition of Il-2R expression. This might be due to binding of rIL-2 to receptors which escape CsA inhibition, thereby up-regulating receptor expression which is drug resistant.

Original languageEnglish
Pages (from-to)104-109
Number of pages6
Issue number1
Publication statusPublished - 1 Jan 1990


Cite this