Pathogenic functions of B cells in autoimmune diseases: IFN-γ production joins the criminal gang.
B-cell depletion therapy has emerged as a powerful strategy to intercept the progression of T-cell-mediated autoimmune diseases such as rheumatoid arthritis, type 1 diabetes, or relapsing remitting multiple sclerosis. However, its mode of action remains incompletely defined, reflecting our incomplete understanding of the pathogenic functions of B cells in such pathologies. B cells can contribute to immune responses through the production of antibodies, presentation of antigen to T cells, and production of cytokines. In this issue of the European Journal of Immunology [Eur. J. Immunol. 2015. 45: 988-998], Olalekan et al. demonstrate that IFN-γ production by B cells is essential for the development of arthritis in mice. Lack of IFN-γ expression in B cells results in reduced autoimmune T-cell responses and autoantibody levels, impacting the arthritogenic reaction akin to that in B-cell depletion therapy. Together with other reports, the article by Olalekan et al. emphasizes the importance of cytokine-producing B cells in the pathogenesis of autoimmune diseases. In this commentary, I discuss how these findings shed new light on the roles of B cells as drivers of autoimmune pathogenesis, and how they more generally contribute to our understanding of the role of B cells in immunity.
Deutsches Rheuma-Forschungszentrum, a Leibniz Institute, Berlin, Germany.
Simon
S
Fillatreau
D000818:Animals; D001172:Arthritis, Rheumatoid / Q000276:immunology / Q000628:therapy; D001327:Autoimmune Diseases / Q000276:immunology* / Q000628:therapy; D015551:Autoimmunity / Q000276:immunology; D001402:B-Lymphocytes / Q000276:immunology*; D016207:Cytokines / Q000096:biosynthesis / Q000276:immunology; D003922:Diabetes Mellitus, Type 1 / Q000276:immunology / Q000628:therapy; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D008212:Lymphocyte Depletion; D051379:Mice; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000276:immunology / Q000628:therapy; D013601:T-Lymphocytes / Q000276:immunology*
D016207:Cytokines; D007371:Interferon-gamma
Arthritis; Autoimmunity; B cells; IFN-γ; T cells