Granulocytic myeloid derived suppressor cells derived extracellular vesicles ameliorate DSS-induced colitis via modulation of Th17/Treg balance.

Colitis is closely associated with immune system dysregulation in the gastrointestinal tract. The present study aimed to evaluate the impact of Granulocytic Myeloid-Derived Suppressor Cells (G-MDSCs)-derived extracellular vesicles (EVs) on disease activity and the immunologic profile in a murine model of colitis. G-MDSCs-EVs were administered to colitis-bearing mice and were evaluated for changes in body weight, disease activity index, colon histopathology, frequencies of Th17 and Tregs, and cytokine release from lymphocytes. The impact of G-MDSCs-EVs was also evaluated on the expression of immune-response-related genes and the intestinal microbiome. G-MDSCs-EVs prevented body weight loss and controlled the disease activity index on day 10. This treatment improved the Treg population along with a decrease in the release of IL-6, IL-17A, and IFN-γ from lymphocytes. Treatment with G-MDSCs-EVs modulated immune-response-related gene expression and influenced the gut microbiota and colon histopathology. G-MDSCs-EVs demonstrated a preliminary potential in expanding the Treg population and upregulating immunoregulatory cytokines, which contributed to improvements in disease activity index and histopathology of the affected tissue.