MSC-derived SIRPα-engineered extracellular vesicles enable targeted NLRP3 ASO delivery and mucosal regeneration in experimental colitis

초록

Introduction Inflammatory bowel disease (IBD) is driven by dysregulated macrophage activation, yet effective targeted delivery of therapeutics to pathological immune cells remains elusive. NLRP3 inflammasome is a key driver of IL-1β/IL-18-mediated intestinal inflammation, but systemic inhibition risks impairing protective immunity. Here we identify CD47 and NLRP3 as co-expressed therapeutic targets in IBD macrophages and develop MSC-derived SIRPαengineered extracellular vesicles (SIRP-EV) for targeted NLRP3 ASO delivery to inflamed colon. Methods We analyzed single-cell RNA sequencing data from IBD patients (UC and CD; n=6 each) and cross-validated findings in DSS-induced colitis mice. CD47 and NLRP3 co-expression was mapped across immune cell populations. SIRP-EVs were generated from human bone marrow MSCs expressing high-affinity SIRPα variant and loaded with NLRP3 ASO via cholesterol conjugation. Biodistribution was assessed by IVIS imaging. Therapeutic efficacy was evaluated by disease activity index (DAI), colon length, histopathology, cytokine profiling, and epithelial regeneration markers. Results scRNA-seq analysis revealed a disease-associated shift in macrophage composition in IBD, showing an increased proportion of inflammatory macrophages and a relative reduction of tissue-resident macrophages. Notably, CD47 and NLRP3 expression displayed a significant positive correlation specifically within inflammatory macrophages, accompanied by upregulation of pro-inflammatory mediators such as IL1β and TNF. Furthermore, among inflammatory macrophage subsets, neutrophil-recruiting macrophages were selectively enriched in both UC and CD patients. Compared to unloaded SIRP-EV, SIRP-EV-NLRP3 ASO achieved superior therapeutic outcomes: improved DAI, preserved colon length, reduced inflammatory cytokines (IL-6), and restored mucosal architecture. Notably, MSC-derived SIRP-EV-NLRP3 ASO promoted epithelial regeneration, evidenced by preserved crypt structure and increased Lgr5+ stem cell markers. Conclusion MSC-derived SIRP-EV enables targeted NLRP3 ASO delivery to pathological macrophages in inflamed colon, combining inflammasome inhibition with MSC-mediated regenerative effects. This dual-action platform—precise targeting plus mucosal repair— offers a differentiated therapeutic strategy for IBD.