Exosomes Derived from Dendritic Cells Attenuate Liver Injury by Modulating the Balance of Treg and Th17 Cells After Ischemia Reperfusion

Abstract

Background/Aims: The present study aimed to evaluate the effects as well as the underlying mechanisms of bone marrow-derived dendritic cells (BMDCs) and exosomes produced by BMDCs (DEXs) on hepatic ischemia-reperfusion (I/R) injury (IRI). Methods: Primary hepatocytes were isolated and used to mimic the liver IR microenvironment. BMDCs were induced and characterized both biochemically with a flow cytometer (FCM) and biophysically with a microscope. Then, we exposed BMDCs to the supernatants from primary hepatocytes and evaluated the maturation of BMDCs by FCM. BMDCs were systemically injected into mice before liver IR via the tail vein, and the therapeutic effects were evaluated. The serum levels of transaminases (aspartate aminotransferase (AST) and alanine aminotransferase (ALT), inflammatory cytokines, and histological changes were respectively examined by ELISA, RT-qPCR and microscopy. Furthermore, we isolated DEXs by ultracentrifugation, characterized DEXs by transmission electron microscopy (TEM) and nanosight tracking analysis (NTA) and western blotting (WB), and then we co-cultured BMDCs/DEXs and naïve T cells and performed FCM, ELISA and confocal imaging. Moreover, we injected DEXs into mice prior to liver IR via the tail vein and examined its therapeutic effects by microscopy and ELISA. Finally, inhibitors of HSP70 (cmHSP70.1), PI3K (BKM120) and mTOR (Rapamycin) were used to investigate the role of HSP70 and the PI3K/mTOR axis in the effects of DEXs on naïve T cells by WB and FCM. Results: Bone marrow cells were efficiently induced into dendritic cells (DCs) with typical DC characteristics. The supernatants from primary hepatocytes exposed to H/R upregulated DC maturation markers. After DC administration, liver IR injury was improved with histopathological scores and serum transaminases. Additionally, we found that the anti-inflammatory cytokines TGF-β, Foxp3 and interleukin (IL)-10 were upregulated and that IL-17 was downregulated. Furthermore, confocal imaging revealed that the uptake of H/R-DEXs by naïve T cells was greater than that of DEXs derived from the control or negative group of BMDCs, and this increase was correlated with a significantly greater degree of differentiation of Tregs and Th17 cells. Moreover, H/R-DEXs administration improved liver function in mice after IR. Finally, the inhibition of HSP70, PI3K and mTOR completely abolished the effect of DEXs on naïve T cells. Conclusion: These results demonstrated that BMDCs and DEXs could alleviate hepatic I/R injury via modulating the balance between Tregs and Th17 cells. DEXs transported HSP70 into naïve T cells and stimulated the PI3K/mTOR axis to modulate the balance between Tregs and Th17 cells and protect the liver from IR injury.

Exosomal miR‐1246 derived from human umbilical cord blood mesenchymal stem cells attenuates hepatic ischemia reperfusion injury by modulating T helper 17/regulatory T balance

“…Besides, the exogenous exosomes could modulate the numbers of Treg and Th17 cells. Zheng et al found that exosomes produced by bone marrow‐derived dendritic cells alleviated liver I/R injury via upregulating the differentiation of Treg cells and inhibiting the differentiation of Th17 cells . In the present study, hUCB‐MSCs‐derived exosomes in the post‐I/R hepatocyte microenvironment activated naïve T cells and accelerated differentiation of Treg cells and inhibited the differentiation of Th17 cells, thereby regulating ROR‐γt, Foxp3, and Th17/Treg‐related cytokines.…”

Acidic Microenvironment Regulates the Severity of Hepatic Ischemia/Reperfusion Injury by Modulating the Generation and Function of Tregs via the PI3K-mTOR Pathway

“…In our previous studies, pretreatment with iTregs ameliorated HIRI and decreased IFN-γ and IL-17 in the liver after reperfusion. Recently, Zheng et al found that exosomes produced by bone marrow-derived dendritic cells alleviate HIRI via regulating the balance between Tregs and Th17 cells (30).…”

Netrin-1 reduces lung ischemia-reperfusion injury by increasing the proportion of regulatory T cells

“…22 Tregs are the most important immune regulatory cells in peripheral blood, and suppress immune responses through two mechanisms: (i) Tregs express immunosuppressive molecules (HLA-G and CTLA-4) that can inhibit inflammatory cells through direct cell contact, and (ii) Tregs can secrete large amounts of IL-10 and TGF-b to inhibit inflammation and promote the proliferation the activities of other types of regulatory immune cells. 23,24 Our study found that the immunoregulatory functions of Tregs in control and LIRI mice were similar, suggesting that LIRI had no significant effect on Treg function.…”