RESPONSIVENESS OF T-LYMPHOCYTES FROM SYSTEMIC LUPUS-ERYTHEMATOSUS TO SIGNALS PROVIDED THROUGH CD26 ANTIGEN

To investigate whether the T cell defective capacity to proliferate ob served in systemic lupus erythematosus (SLE) T cells is a possible con sequence of an intrinsic T cell disorder, the integrity of the accesso ry activation pathway mediated through CD26 antigen in SLE T cells was studied. Hyporesponsiveness of peripheral blood mononuclear cells (PB MC) from SLE to PHA and CD26 Mab was observed and no differences were found when the responsiveness of highly purified T cells to IL-2, IL-2 plus CD26 Mab, phorbol 12-myristate 13-acetate (PMA), or when PMA plu s CD26 Mab was analyzed. Findings suggest that signals induced by trig gering CD26 are not intrinsically altered in SLE T cells. However, som e alteration of the regulatory involvement of monocytes or B cell over T cell function may be involved. (C) 1994 Academic Press, Inc.