RNA-seq of colon

Objective: Inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn’s disease (CD), represents a challenging group of chronic gastrointestinal inflammatory disorders. While trained immunity, a form of innate immune memory, has shown promise in combating infection and cancer, its role in chronic inflammatory diseases, particularly inflammatory bowel disease (IBD), remains relatively underexplored. This study aims to investigate the potential of trained immunity to ameliorate IBD. Results: BG induced trained immunity significantly ameliorates DSS-induced colitis. Mechanistically, β-glucan primed the hematopoietic compartment, leading to a profound shift in monocyte fuction. Both bone marrow transplantation from trained donors to naïve recipients and adoptive transfer of trained peripheral monocytes provided protection against DSS colitis. Notably, trained mice displayed enhanced bactericidal activity against intestinal bacterial infections. Furthermore, single-cell RNA sequencing revealed that β-glucan-induced trained immunity resulted in an expansion of reparative Cx3cr1 intestinal macrophages originating from Ly6Chi monocytes, facilitating faster recovery of the colon epithelium. Conclusion: Our findings demonstrate that β-glucan effectively induces trained immunity, leading to a multifaceted protective response against experimental colitis. These findings provide compelling evidence for the therapeutic potential of harnessing trained immunity to treat IBD and offer a novel approach to modulating intestinal inflammation and restoring gut homeostasis.