Intestine epithelial cell-Derived Extracellular Vesicles alleviate Inflammation Induced by Clostridioides Difficile TcdB through the Activity of TGF- β1

Background: Clostridioides difficile infection (CDI) has been primarily associated with the toxin B (TcdB), which can activate the intestinal immune system and lead to pathological damage. Even though the biological functions of intestine epithelial cell- derived extracellular vesicles (I-Evs) have been well documented, the role of I-Evs in the process of CDI is still unknown. Results: We isolated I-Evs ranging from 100–200 nm in mean diameter, with a density of 1.09-1.17 g/mL. These I-Evs expressed the extracellular vesicle-associated specific surface markers, CD63 and TSG101. In vitro, 50 µg I-Evs decreased the expression of IL-6, TNF- β, IL-1β, and IL-22 in MC38 induced by 0.8 ng/mL C. difficile TcdB, and increased expression of TGF- β1. In vivo, I-Evs also promoted regulatory T cell induction, which improved inflammation of mice up to 80% relative to C. difficile TcdB infected mice, depending on the TGF- β1 signal pathway. Conclusion: Our study firstly demonstrated that I-Evs originated from intestine epithelial cells is potentially a novel treatment endogenous candidate to effectively reduce the local infection induced by C. difficile TcdB.