Th17 cells, CD4⁺ T cells that secrete interleukin-17 (IL-17), are pathogenic in autoimmune diseases and their development and expansion is driven by the cytokines IL-6, TGF-β, IL-21, IL-1, and IL-23. [1]

We have demonstrated that stimulated PBMCs from DM and PM patients produce increased levels of IL-23 as compared to HC. IL-17 and IL-23 levels are increased in early as compared to established disease. This provides further evidence that IL-17/IL-23 may play a crucial role in autoimmune diseases. [2]

"Compared to non-inflammatory myopathy, IL-17 positively expresses in patients with polymyositis which is mainly in cells,and the number of Th17 cells is positively related to the severity of inflammation." [3]

The presence in inflamed muscle tissue of myositis of IL-17–producing cells, in association with activated dendritic cells, suggests a local activation of the IL-23–Th17 pathway. IL-17 can act on muscle cells together with proinflammatory cytokines produced by monocytes and innate immunity to amplify the immune response that could lead to muscle destruction. Evidence for activation of the Th17 pathway in myositis lesions and in vitro effects of IL-17 on muscle cells suggest IL-17 as a therapeutic target.[4]

 

 

 

1. Bruno Martin, Keiji Hirota, Daniel J. Cua, Brigitta Stockinger, Marc Veldhoen Interleukin-17-Producing γδ T Cells Selectively Expand in Response to Pathogen Products and Environmental Signals, Immunity, Volume 31, Issue 2, 21 August 2009, Pages 321-330

2. Shen, H (Shen, H.)^{[ 1 ]} ; Xia, L, Interleukin-17 and interleukin-23 in patients with polymyositis and dermatomyositis, Scandinavian Journal of Rheumatology, Volume 40, Issue 3, 2011

3. HAN Wen-juan,ZHANG Hong-ya, et al, The Infiltration of Th17 Cells in Muscle Tissues of Polymyositis, 《Progress in Modern Biomedicine》 2012-07 as found at http://en.cnki.com.cn/Article_en/CJFDTotal-SWCX201207023.htm

4. Anne Tournadre, Pierre Miossec, Interleukin-17 in Inflammatory Myopathies, Current Rheumatology Reports June 2012, Volume 14, Issue 3, pp 252–256