Immunotherapy of inflammatory bowel disease (IBD) through mesenchymal stem cells

Many pathophysiologic pathways and immune-pathologic etiologies are addressed as Inflammatory bowel disease (IBD) causes. Moreover, dysfunction of the immune system leads to inflammatory responses against intestinal components that boost disease severity. The use of routine treatments has limitations. Besides, patients may experience drug resistance. Therefore, the use of novel and effective therapies is essential. Relying on the immune regulatory functions of Mesenchymal Stem Cells (MSCs), researchers have suggested possible benefits of MSCs administration for IBD, both in experimental and clinical studies. Experimental animal models of IBD have shown effects of MSCs, MSC-derived exosomal micro RNAs, and MSC-based drug delivery systems on the regulation of the immune system (Th17 suppression versus T-regular cell biased responses). These studies have suggested MSCs' benefits on intestinal integrity, improved smooth cell function, and tissue repair. On the other hand, various clinical trials have been registered for MSCs application in IBD patients that show reliable safety in humans. Most clinical trials have used MSCs of bone marrow, umbilical cord, and adipose tissue that have been administered by intravenous or intra-tissue injection. Studies have evaluated clinical outcomes, patient symptoms, or healing processes; while immunological studies in the clinical era are missing. As we reviewed, huge shreds of experimental shreds of evidence have led to the inception of multiple clinical trials in phase I/II, showing promising results for IBD treatment. We suggest that further clinical investigation should be more focused on in-vitro/in-vivo assessed outcomes as well as the immunological endpoints to have more reliable results with more support for laboratory evidence.