Published online May 21, 2015. doi: 10.3748/wjg.v21.i19.5823
Peer-review started: October 13, 2014
First decision: November 14, 2014
Revised: December 4, 2014
Accepted: January 21, 2015
Article in press: January 21, 2015
Published online: May 21, 2015
Processing time: 219 Days and 21.2 Hours
Inflammatory bowel diseases (IBDs) are chronic disorders of modern society, requiring management strategies aimed at prolonging an active life and establishing the exact etiology and pathogenesis. These idiopathic diseases have environmental, genetic, immunologic, inflammatory, and oxidative stress components. On the one hand, recent advances have shown that abnormal immune reactions against the microorganisms of the intestinal flora are responsible for the inflammation in genetically susceptible individuals. On the other hand, in addition to T helper cell-type (Th) 1 and Th2 immune responses, other subsets of T cells, namely regulatory T cells and Th17 maintained by IL-23 are likely to develop IBD. IL-23 acts on innate immune system members and also facilitates the expansion and maintenance of Th17 cells. The IL-17/IL-23 axis is relevant in IBD pathogenesis both in human and experimental studies. Novel biomarkers of IBD could be calprotectin, microRNAs, and serum proinflammatory cytokines. An efficient strategy for IBD therapy is represented by the combination of IL-17A and IL-17F in acute IL-17A knockout TNBS-induced colitis, and also definite decrease of the inflammatory process in IL-17F knockout, DSS-induced colitis have been observed. Studying the correlation between innate and adaptive immune systems, we hope to obtain a focused review in order to facilitate future approaches aimed at elucidating the immunological mechanisms that control gut inflammation.
Core tip: The pathogenesis of inflammatory bowel diseases (Crohn’s disease and ulcerative colitis) is multifactorial and still not completely understood. There is a need to identify new diagnostic biomarkers as well as an efficient therapy for these diseases. A better understanding of the immunological mechanisms that control gut inflammation, is of high clinical importance because it offers the possibility to develop new drugs, which attack the key pro-inflammatory pathways in chronic intestinal inflammation.