IL-10 Beyond Immunosuppression: Unraveling Spatial, Cellular, and Metabolic Mechanisms of Gut Protection
Yuchen Zhang, Xiaohui Liu, Boya Wang, Haoyuan Yin, Xiang Tian, Jiatong Zhao, Shuzi Xin, Hongli Wang, Yushuo Ren, Xinyue Liu, Jingyu Liu, Yuhang Bian, Sijin Gu, Haoxuan Zhang, Tong Wei, Lei Gao, Xin Lu, Hongwei Shang, Jingdong XuIntestinal homeostasis requires immune tolerance, barrier integrity, tissue repair, and microbiota mutualism. Interleukin-10 (IL-10) is essential, but not merely as an immunosuppressant. Although IL-10 signals via the IL-10R—JAK1/TYK2—STAT3 axis, its outputs are cell-type and context dependent. In macrophages, IL-10 restrains IL-23 production, inflammasome activation, IL-1β release, and metabolic reprogramming. In T cells, it limits pathogenic T helper 17 cell (Th17) responses while stabilizing regulatory cells and promoting metabolically driven IL-10 production. In the epithelium, IL-10 maintains barrier integrity by limiting apoptosis, endoplasmic reticulum (ER) stress, and mucus defects. IL-10 and the gut microbiota engage in reciprocal regulation: microbial metabolites and structural components enhance IL-10 production and receptor responsiveness, whereas IL-10 signaling preserves microbial diversity and ecological resilience. This may help to explain why systemic recombinant IL-10 failed in Crohn’s disease (CD)—increasing ligand abundance alone is unlikely to recapitulate endogenous localization or restore refractory target cells. Emerging strategies aim to tune IL-10 signaling through gut-selective delivery, engineered cytokines, conditionally activated prodrugs, regulatory cell approaches, and microbiome or metabolic interventions. Clinical translation requires biomarkers of IL-10R expression, STAT3 responsiveness, macrophage metabolic state, microbial signatures, and acquired IL-10 hyporesponsiveness. Despite the established role of IL-10 in intestinal homeostasis, systemic IL-10 therapy has failed in clinical trials, and there is a lack of effective strategies to restore IL-10 signaling in a spatially and cell-specific manner. The spatially organized, metabolically conditioned homeostatic IL-10 signaling—largely inferred from model systems and awaiting direct spatial validation in human intestine—offers a roadmap for more precise therapy in inflammatory bowel disease and related intestinal disorders.