Review
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World J Gastroenterol. Dec 28, 2014; 20(48): 18177-18188
Published online Dec 28, 2014. doi: 10.3748/wjg.v20.i48.18177
Role of interleukin-22 in inflammatory bowel disease
Lin-Jing Li, Chen Gong, Mei-Hua Zhao, Bai-Sui Feng
Lin-Jing Li, Chen Gong, Mei-Hua Zhao, Bai-Sui Feng, Department of Gastroenterology, the Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou 450000, Henan Province, China
Author contributions: Li LJ, Gong C and Zhao MH collected the materials and wrote the manuscript; and Feng BS reviewed the manuscript and supervised the research work.
Supported by National Natural Science Foundation of China, No. 81070288 and No. 81270452; Medical Science and Technology Foundation of Henan Province, No. 201001004; and Science and Technology Leader Overseas Training Foundation of Henan Province, No. 201201013
Correspondence to: Bai-Sui Feng, MD, PhD, Professor, Department of Gastroenterology, the Fifth Affiliated Hospital of Zhengzhou University, 3 Kangfu Front Street, Erqi District, Zhengzhou 450000, Henan Province, China. fbs163@163.com
Telephone: +86-371-66916927 Fax: +86-371-66902232
Received: May 5, 2014
Revised: June 21, 2014
Accepted: September 5, 2014
Published online: December 28, 2014
Processing time: 245 Days and 16 Hours
Abstract

Inflammatory bowel disease (IBD) is a chronic inflammatory disease thought to be mediated by the microbiota of the intestinal lumen and inappropriate immune responses. Aberrant immune responses can cause secretion of harmful cytokines that destroy the epithelium of the gastrointestinal tract, leading to further inflammation. Interleukin (IL)-22 is a member of the IL-10 family of cytokines that was recently discovered to be mainly produced by both adaptive and innate immune cells. Several cytokines and many of the transcriptional factors and T regulatory cells are known to regulate IL-22 expression through activation of signal transducer and activator of transcription 3 signaling cascades. This cytokine induces antimicrobial molecules and proliferative and antiapoptotic pathways, which help prevent tissue damage and aid in its repair. All of these processes play a beneficial role in IBD by enhancing intestinal barrier integrity and epithelial innate immunity. In this review, we discuss recent progress in the involvement of IL-22 in the pathogenesis of IBD, as well as its therapeutic potential.

Keywords: Inflammatory bowel disease; Interleukin-22; Signal transducer and activator of transcription 3

Core tip: Interleukin (IL)-22 is expressed by adaptive immune system cells and innate lymphocytes. Several cytokines and many transcriptional factors and T regulatory cells can regulate IL-22 expression. Through activation of signal transducer and activator of transcription 3 signaling cascades, IL-22 induces antimicrobial, proliferative and antiapoptotic pathways, which can help fix damaged tissue and promote tissue repair mechanisms. IL-22 is also associated with inflammatory bowel disease (IBD) susceptibility genes that regulate inflammatory responses in tissues. All of these processes play crucial roles in IBD pathogenesis and collectively provide an important rationale for the development of novel therapeutic measures for this disease.