Interferon beta-1a therapy enhances CD4(+) regulatory T-cell function: An ex vivo and in vitro longitudinal study in relapsing-remitting multiple sclerosis

Interferon beta-1a (IFNa-1a) has demonstrated efficacy in multiple sclerosis (MS), although its mechanism of action remains only partly understood. We evaluated the ex vivo and in vitro effects of IFNa-1a (Rebif((R))) on regulatory T-cell (T-Reg) function in 22 relapsing-remitting MS patients and 16 healthy controls. T-Reg function was significantly enhanced after 3 and 6 months of IFN beta-1a therapy. Furthermore, there was a trend towards increasing proportions of total CD4(+)CD25(+) and CD4(+)CD25(+)GITR(+) T-Reg after 6 months of IFN beta-1a therapy when compared with baseline. In conclusion, IFN beta-1a therapy enhances T-Reg function, and this may be relevant in the inflammatory environment of MS lesions. (c) 2006 Elsevier B.V. All rights reserved.