Failure of autologous mixed lymphocyte reactions between T and non-T cells in patients with systemic lupus erythematosus.

Abstract

Normal human T [thymus-derived] cells proliferate vigorously when stimulated with autologous non-T cells. This autologous mixed lymphocyte reaction (MLR) between T and non-T cells was defective in patients with active systemic lupus erythematosus (SLE). T cells and non-T cells from active SLE patients behaved normally as responding and stimulating cells, respectively, in the allogeneic MLR. The etiology of the impaired autologous MLR was further examined by studying the functional capacity of subsets of stimulating or responding cells. B [bone marroW-derived] cells, L cells [cells with Fc receptors but lacking surface immunoglobulin (Ig)] and monocytes from active SLE patients failed to stimulate autologous T cells but these cells effectively stimulated allogeneic T cells. Fc(IgG)+T cells from active patients were unable to respond in the autologous and allogeneic MLR; their Fc(IgG)-T cells responded well in the allogeneic but not in the autologous MLR. The Fc(IgG)+T cells, but not the Fc(IgG)-T cells, from inactive SLE patients also failed to respond in the autologous and allogeneic MLR. Patients with SLE apparently have functionally defective Fc(IgG)+T cells and a defective autologous MLR, both of which may contribute to impaired regulation of immune functions.