Role of interleukin-22 in inflammatory bowel disease

Figure 1 Interleukin-22 signaling pathway. IL-22 binds to a heterodimeric receptor composed of IL-10R2 and IL-22R1, activating JAK1 and TYK2, which self-phosphorylate, resulting in binding and phosphorylation of STAT3. Then, STAT3 translocates to the nucleus and induces target genes. IL: Interleukin; JAK: Janus kinase; TYK: Tyrosine protein kinase; STAT: Signal transducer and activator of transcription.

Figure 2 Protective function of interleukin-22 in inflammatory bowel disease. In the intestine, innate and adaptive immune cells, cytokines and many of the transcriptional factors can induce and regulate expression of IL-22. Through activation of STAT3 signaling cascades, IL-22 induces antimicrobial molecules and proliferative and antiapoptotic pathways, and helps regenerate goblet cells and produce mucin proteins, which could prevent tissue damage and aid in its repair. IL: Interleukin; STAT: Signal transducer and activator of transcription.