STAPHYLOCOCCAL-ENTEROTOXIN-B INDUCES ARTHRITIS IN FEMALE DBA 1 MICE BUT FAILS TO INDUCE ACTIVATION OF TYPE-II COLLAGEN-REACTIVE LYMPHOCYTES/

It has been proposed that superantigens are involved in the pathogenes is of autoimmune diseases. To test the possibility of superantigens in ducing arthritis in naive mice, V beta(8)-reactive superantigen staphy lococcal enterotoxin B (SEB) was injected into naive mice. We used fem ale DBA/1 mice, because they were susceptible to collagen-induced arth ritis (CIA), in which the pathogenic T cells were supposed to preferen tially use limited V(beta)s of T cell receptors including V(beta)8. Mi ld monoarthritis developed in uninjected hindlimbs of mice administere d with SEB in higher frequency (an average incidence of 24%) than the control phosphate-buffered saline-injected mice (4.2%). Autoimmune res ponses in mice administered with SEB were compared with those in mice developing CIA. However, activation of type II collagen (IIC)-reactive T cells was not detected in SEB-injected mice. Production of auto-ant ibodies, anti-IIC antibody and rheumatoid factor was also undetected. Although exact mechanisms of pathogenesis of this arthritis remain to be known, V(beta)8(+) T cells were activated for a long period and the unresponsiveness of V(beta)8(+) T cells was not detected in this stra in. From these results, we discuss the pathogenesis of arthritis induc ed by SEB and the possibility that superantigen may play a role in the induction of autoimmune diseases. (C) 1997 Academic Press.