Presence of an IL-3-producing suppressor T cell resistant to cyclosporin A in the peripheral blood of patients with systemic lupus erythematosus.

We studied the effects of cyclosporin A (CYA) on the production of various lymphokines and on the suppressor functions of peripheral blood mononuclear cells (MNC) of ten untreated SLE patients. CYA was found to inhibit the production of IL-2 and of B cell stimulating factor (BSF) by both normal and SLE MNC but it did not alter the LPS-driven production of IL-1 by either of them. However, it did abrogate the spontaneous release of IL-1 by SLE monocytes. CYA strongly inhibited the production of IL-3-like activity by normal T cells, an effect noticed only on cells from 4 SLE patients, three of whom were in remission. Addition of CYA significantly increased suppressor cell function by cells from all SLE patients. T cell clones could be obtained from two of them by using CYA-conditioned medium containing IL-3. These clones were found to have strong suppressor capacity.