Review
Copyright ©2009 The WJG Press and Baishideng. All rights reserved.
World J Gastroenterol. Dec 14, 2009; 15(46): 5784-5788
Published online Dec 14, 2009. doi: 10.3748/wjg.15.5784
Potential role of Th17 cells in the pathogenesis of inflammatory bowel disease
Zhan-Ju Liu, Praveen K Yadav, Jing-Ling Su, Jun-Shan Wang, Ke Fei
Zhan-Ju Liu, Praveen K Yadav, Jing-Ling Su, Jun-Shan Wang, Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University, Shanghai 200072, China
Ke Fei, Department of Thoracic Surgery, Shanghai Tenth People’s Hospital, Tongji University, Shanghai 200072, China
Author contributions: Liu ZJ and Fei K designed and supervised this work; Liu ZJ and Yadav PK wrote the manuscript; Su JL and Wang JS provided the collection of materials.
Supported by Grants From the National Natural Science Foundation of China, No. 30770988 and No. 30971358
Correspondence to: Dr. Zhan-Ju Liu, Professor, Department of Gastroenterology, Shanghai Tenth People’s Hospital, Tongji University, Shanghai 200072, China. zhanjuliu@yahoo.com
Telephone: +86-21-66301164 Fax: +86-21-66303893
Received: August 17, 2009
Revised: November 3, 2009
Accepted: November 10, 2009
Published online: December 14, 2009
Abstract

The etiopathology of inflammatory bowel disease (IBD) remains elusive. Accumulating evidence suggests that the abnormality of innate and adaptive immunity responses plays an important role in intestinal inflammation. IBD including Crohn’s disease (CD) and ulcerative colitis (UC) is a chronic inflammatory disease of the gastrointestinal tract, which is implicated in an inappropriate and overactive mucosal immune response to luminal flora. Traditionally, CD is regarded as a Th1-mediated inflammatory disorder while UC is regarded as a Th2-like disease. Recently, Th17 cells were identified as a new subset of T helper cells unrelated to Th1 or Th2 cells, and several cytokines [e.g. interleukin (IL)-21, IL-23] are involved in regulating their activation and differentiation. They not only play an important role in host defense against extracellular pathogens, but are also associated with the development of autoimmunity and inflammatory response such as IBD. The identification of Th17 cells helps us to explain some of the anomalies seen in the Th1/Th2 axis and has broadened our understanding of the immunopathological effects of Th17 cells in the development of IBD.

Keywords: Crohn’s disease; Inflammatory bowel disease; Interleukin-17; Interleukin-23; Th17 cells; Ulcerative colitis