Evidence for the role of Th-17 cell inhibition in the prevention of autoimmune diseases by anti-interluekin-6 receptor antibody

Deregulated production of interleukin-6 (IL-6) has been found in several chronic inflammatory autoimmune disorders, including rheumatoid arthritis (RA) and inflammatory bowel diseases. Treatment with tocilizumab, a humanized antihuman IL-6 receptor (IL-6R) antibody, significantly proved disease activity and inhibited the progression of joint destruction in RA patients, but the reason why IL-6 blockade causes improvement of RA is still unclear. In this review, we discuss the influence of anti-IL-6R antibody treatment on the differentiation of Th-17 cells, which are thought to be involved in the pathogenesis of autoimmune diseases in animal models, present new results for the effect of anti-IL-6R antibody on the induction of Th-17 cells in a mouse collagen-induced arthritis model, and come to the conclusion that anti-IL-6R antibody inhibited the differentiation of Th-17 cells in mouse models. It is thought that this inhibitory action may contribute to the therapeutic effects of anti-IL-6R antibody in human autoimmune diseases. (C) 2009 international Union of Biochemistry and Molecular Biology, Inc. Volume 35, Number 1, January/February 2009, Pages 47-51. E-mail: miharamsh@chugai-pharm.co.jp