Intestine epithelial cell-derived extracellular vesicles alleviate inflammation induced by Clostridioides difficile TcdB through the activity of TGF-β1

Shuangshuang Wan; Guangzhong Song; Hui Hu; Yaqing Xu; Peng Zeng; Shan Lin; Jun Yang; Jinqin Jiang; Xiaojun Song; Yongneng Luo; Dazhi Jin

doi:10.1007/s13273-022-00280-8

Intestine epithelial cell-derived extracellular vesicles alleviate inflammation induced by Clostridioides difficile TcdB through the activity of TGF-β1

Mol Cell Toxicol. 2022 Jul 30:1-11. doi: 10.1007/s13273-022-00280-8. Online ahead of print.

Authors

Shuangshuang Wan^{1

2}, Guangzhong Song^{1

2}, Hui Hu^{1

2}, Yaqing Xu^{1

2}, Peng Zeng^{1

2}, Shan Lin^{1

2}, Jun Yang^{1

2}, Jinqin Jiang^{1

2}, Xiaojun Song³, Yongneng Luo^{1

2}, Dazhi Jin^{1

2}

Affiliations

¹ School of Laboratory Medicine and Bioengineering, Hangzhou Medical College, No. 481 Binwen Rd., Hangzhou, 310053 Zhejiang China.
² Key Laboratory of Biomarkers and In Vitro Diagnosis Translation of Zhejiang Province, Hangzhou, 310063 Zhejiang China.
³ Centre of Laboratory Medicine, People's Hospital of Hangzhou Medical College, Zhejiang Provincial People's Hospital, Hangzhou, 310014 Zhejiang China.

Abstract

Background: Clostridioides difficile infection (CDI) has been primarily associated with the toxin B (TcdB), one of the three known protein toxins secreted by C. difficile, 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.

Objectives: The protective effect of I-Evs against C. difficile TcdB was investigated both in cultured murine colon carcinoma MC38 cells and a mouse model used in this study.

Results: Mouse I-Evs with mean diameter ranging from 100 to 200 nm and a density of 1.09-1.17 g/mL were obtained and confirmed containing the Ev-associated specific surface markers CD63 and TSG101 as well as high level of TGF-β1. In MC38 cells, I-Evs were able to decrease the gene expression of IL-6, TNF-α, IL-1β, and IL-22 induced by C. difficile TcdB, but to increase both the gene expression and protein levels of TGF-β1. I-Evs treatment via intraperitoneal administration alleviates C. difficile TcdB-induced local colon inflammation in mice and increased their survival rate from 50% up to 80%. Furthermore, I-Evs induced an increase in the proportion of CD4⁺Foxp3⁺Tregs in vitro and in vivo through a TGF-β1-dependent mechanism by activating the TGF-β1 pathway and prompting phosphorylation of the downstream proteins Smad 2/3.

Conclusion: For the first time, our study demonstrated that I-Evs originated from intestine epithelial cells can alleviate inflammation induced by C. difficile TcdB both in vitro and in vivo. Therefore, I-Evs might be potentially a novel endogenous candidate for effective treatment of CDI.

Keywords: Clostridioides difficile; Extracellular vesicles; Immunotherapy; Inflammatory cytokines; Regulatory T cells; TGF-β1; TcdB.