T-CELL ACTIVATION BY AUTOANTIGENS IN MULTIPLE-SCLEROSIS

A panel of autoantigens (myosin, actin, myelin basic protein MBP, and thyroglobulin) was used to analyze antigen recognition by the peripher al blood leukocytes (PBL) of patients with active and stable multiple sclerosis (MS), patients with other neurological diseases (OND) and he althy individuals. The immune responsiveness was studied by examining the in vitro cell proliferation and the increase in the expression of two T-cell-surface activation markers (the interleukin-2 receptor IL-2 R, and a late activation antigen recognized by the 19.2 monoclonal ant ibody). In MS, autoantigen recognition occured more frequently than in the other groups and it was manifested by moderate proliferation or m arked elevation of the expression of the IL-2R, whereas autoantigen re cognition in the other groups concerned essentially the expression of the late activation antigen. Results similar to those described above were obtained with enriched T lymphocytes either in the presence or ab sence of IL-2. Our results suggest that the peripheral immune system i n MS patients may recognize and can be activated by different autoanti gens and not only by MBP, and that this response is quantitatively and qualitatively different from that of PBL from OND patients and health y individuals.