Glatiramer acetate immune modulates B-cell antigen presentation in treatment of MS

OBJECTIVE: We examined the effect of glatiramer acetate (GA) on B-cell maturation, differentiation, and antigen presentation in MS and experimental autoimmune encephalomyelitis (EAE). METHODS: A cross-sectional study of blood samples from 20 GA-treated and 18 untreated patients with MS was performed by flow cytometry; 6 GA-treated patients with MS were analyzed longitudinally. GA-mediated effects on B-cell antigen-presenting function were investigated in EAE, or, alternatively, B cells were treated with GA in vitro using vehicle as a control. RESULTS: In MS, GA diminished transitional B-cell and plasmablast frequency, downregulated CD69, CD25, and CD95 expression, and decreased TNF-α production, whereas IL-10 secretion and MHC Class II expression were increased. In EAE, we observed an equivalent dampening of proinflammatory B-cell properties and an enhanced expression of MHC Class II. When used as antigen-presenting cells for activation of naive T cells, GA-treated B cells promoted development of regulatory T cells, whereas proinflammatory T-cell differentiation was diminished. CONCLUSIONS: GA immune modulates B-cell function in EAE and MS and efficiently interferes with pathogenic B cell–T cell interaction.