Application of single-cell sequencing in the study of immune cell infiltration in inflammatory bowel disease and colorectal cancer

Figure 3 Interleukin 22 signaling pathways and immune cell interactions. Interleukin 22 (IL-22) is secreted by various immune cells, including group 3 innate lymphoid cells (ICL3s), gamma delta (γδ) T cells, T helper 17 cells (Th17) cells, Th22 cells, and cluster of differentiation 4-positive (CD4+) T cells. Upon binding to its receptor, interleukin 22 receptor (IL-22R), IL-22 activates several intracellular signaling pathways. These pathways include the signal transducer and activator of transcription 3 (STAT3) pathway, which promotes immune responses and cell survival; the phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin pathway (mTOR), which regulates cell metabolism and growth; and the mitogen-activated protein kinase (MAPK) and p38 pathways, which are involved in cellular stress responses and inflammation regulation. IL-22 plays a crucial role in maintaining epithelial barrier integrity, stimulating the secretion of antimicrobial peptides and promoting tissue repair, especially in mucosal immunity and inflammatory responses.