HLA DEPENDENT HETEROGENEOUS T-CELL RESPONSE TO MYCOPLASMA ARTHRITIDIS-DERIVED SUPERANTIGEN (MAS)

Mycoplasma arthritidis induces a chronic arthritis in rodents. The rol e of M. arthritidis-derived superantigen (MAS) in the arthritis is sti ll a subject of controversy. MAS stimulates mouse and human T cells in a V beta-restricted manner with the subsequent liberation of cytokine s. The presence of the major histocompatibility complex class II molec ule is required for such a stimulation. In this study we assessed MAS- induced cytokine production in peripheral blood from patients with dif ferent rheumatic diseases and controls using an enzyme-linked immunoso rbent assay. Statistically significant differences in cytokine product ion in response to MAS stimulation allowed the distinction of high res ponders and low responders within groups of patients and controls. Hig her cytokine induction was statistically correlated with the HLA-DR sp ecificities DR4, DR7 and DR12. To confirm these results, murine V beta 8.1 cytotoxic T lymphocytes (CTL) were stimulated with MAS in the pre sence of different HLA-DR lymphoblastoid B cells. CTL proliferation wa s only observed in presence of DR4 and DR7. In conclusion, MAS T cell stimulation and its subsequently cytokine production depends on the pr esence of certain HLA-DR specificities.