Polyspecific immunoglobulins (IVIg) suppress proliferation of human (auto)antigen-specific T cells without inducing apoptosis

Polyspecific immunoglobulins (IVIg) have been shown to reduce disease activity in multiple sclerosis (MS). To investigate the mechanisms of action of IVIg, we studied the impact of IVIg on growth and death (apoptosis) of human (auto)antigen-specific T cells. We observed a substantial suppression of proliferation of specifically activated T cells, in absence of caspase activation or DNA fragmentation. Further, neither susceptibility of T cells to undergo CD95-mediated apoptosis nor expression of,apoptosis-blocking bcl-2 was modulated by Mg. We conclude that IVIg may inhibit the reactivity of antigen-specific T cells in MS through suppression of proliferation rather than modulation of apoptosis. (C) 2001 Elsevier Science B.V. All rights reserved.