Figures & data
Figure 1. Intestinal epithelium in homeostasis and GVHD. a. The intestinal epithelium comprises crypts and villus. A mucous layer separates epithelial cells and intestinal bacteria, which is indispensable to intestinal homeostasis. ISCs give rise to all kinds of epithelial cells, and the activities of ISCs are tightly regulated by various cells and signals; b. Conditioning regimens induce epithelial damage and dysbiosis. Antibiotics and diet further affect the microbiome components and metabolites. Accumulated DAMPs and PAMPs activate the innate immune system and trigger donor lymphocyte infiltration, leading to impaired ISC niche and sustained tissue damage.(ISC, intestinal stem cell; EP, enterocyte progenitor; SP, secretory progenitor; EC, enterocyte; PC, Paneth cell; GC, goblet cell; EEC, enteroendocrine cell; TC, tuft cell; Mø, macrophage; Neu, neutrophil; Lym, lymphocyte; APC, antigen-presenting cell; SCFA, short-chain fatty acid; BA, bile acid; TMAO, trimethylamine N-oxide; DAMPs, damage-associated molecular patterns; PAMPs, pathogen-associated molecular patterns.).
Figure 2. Outstanding issues and treatment strategies for GVHD.
