Characterization of T cell lines derived from glatiramer-acetate-treated multiple sclerosis patients

We analyzed the effects of glatiramer acetate (GA) therapy on in vitro prol iferative responses and cytokine production by lymphocytes derived from mul tiple sclerosis patients receiving this therapy. We confirmed that lymphocy tes derived from GA naive patients show a high frequency of response when i nitially exposed to GA in vitro; this frequency decreased following GA ther apy. The frequency of lymphocytes responding to whole MBP stimulation did n ot change with GA therapy. GA- and MBP-specific T cell lines generated from these patients by repeated cycles of in vitro stimulation did not cross re act. Some (23%) whole MBP-reactive T cell lines did cross react with MBP pe ptide 83-99. The mean levels of interferon (IFN) gamma secretion and the me an ratio of IFN-gamma/lL-5 were lower for GA-reactive cell lines, derived f rom patients both prior to and during GA therapy, compared to MBP-reactive T cell lines. The proportion of IFN-gamma(+) cells in unfractionated lympho cyte preparations derived from the GA-treated patients did not differ from that found for healthy controls. Our findings indicate that GA-reactive T c ell lines derived from GA-treated MS patients continue to show a relative T h2 cytokine bias consistent with a bystander suppressor function. GA treatm ent is not associated with a cytokine phenotype shift in the total T cell o r MBP-reactive T cell populations. (C) 2000 Elsevier Science B.V. All right s reserved.