T CELL-T CELL ACTIVATION IN MULTIPLE-SCLEROSIS

Activated T cells ore able to stimulate proliferation in resting T cel ls through on antigen non-specific mechanism. The in vivo usefulness o f this T cell-T cell activation is unclear but it may serve to amplify immune responses. T cell-T cell activation could be involved in the w ell-documented occurrence of multiple sclerosis (MS) exacerbations fol lowing viral infections. Excessive activation via this pathway could a lso be a factor in the etiology of MS. We tested the hypothesis that e xcessive T cell-T cell activation occurs in MS patients using in vitro proliferation assays comparing T cells from MS patients to T cells fr om controls. When tested as responder cells, T cells from MS Patients proliferated slightly less after stimulation with previously activated cells then T cells from controls. When tested as stimulator cells, ac tivated cells from MS patients stimulated slightly more non-specific p roliferation than activated cells from controls. Neither of these diff erences were statistically significant We conclude that T cell prolife ration in response to activated T cells is similar in MS and controls.