Interleukin 10 Gene-Modified Bone Marrow-Derived Dendritic Cells Attenuate Liver Fibrosis in Mice by Inducing Regulatory T Cells and Inhibiting the TGF-β/Smad Signaling Pathway

Abstract

Aim To explore the therapeutic effects and mechanisms of interleukin 10 gene-modified bone marrow-derived dendritic cells (DC-IL10) on liver fibrosis. Methods In vitro, BMDCs were transfected with lentiviral-interleukin 10-GFP (LV-IL10-GFP) at the MOI of 1 : 40. Then, the phenotype (MHCII, CD80, and CD86) and allo-stimulatory ability of DC-IL10 were identified by flow cytometry, and the levels of IL-10 and IL-12 (p70) secreted into the culture supernatants were quantified by ELISA. In vivo, DC-IL10 was injected into mice with CCl4-induced liver fibrosis through the tail vein. Lymphocytes were isolated to investigate the differentiation of T cells, and serum and liver tissue were collected for biochemical, cytokine, histopathologic, immune-histochemical, and Western blot analyzes. Results In vitro, the expressions of MHCII, CD80, and CD86 in DC-IL10 were significantly suppressed, allogeneic CD4+T cells incubated with DC-IL10 showed a lower proliferative response, and the levels of IL-10 and IL-12 (p70) secreted into the DC-IL10 culture supernatants were significantly increased and decreased, respectively. In vivo, regulatory T cells (Tregs) were significantly increased, while ALT, AST, and inflammatory cytokines were significantly reduced in the DC-IL10 treatment group, and the degree of hepatic fibrosis was obviously reversed. The TGF-β/smad pathway was inhibited following DC-IL10 treatment compared to the liver fibrosis group. Conclusion IL-10 genetic modification of BMDCs may maintain DC in the state of tolerance and allow DC to induce T cell hyporesponsiveness or tolerance. DC-IL10 suppressed liver fibrosis by inducing Treg production and inhibiting the TGF-β/smad signaling pathway.

Dendritic Cells Transfected with MHC Antigenic Determinants of CBA Mice Induce Antigen-Specific Tolerance in C57Bl/6 Mice

“…However, despite the more mature phenotype, the DCs transfected with pIL-10 as well as with pMHC induced FoxP3 + Tregs and IL-10 + CD4 + cells in cocultures with autologous splenocytes at similar levels to immature nonelectroporated DCs ( Figure 3 ). These findings correspond to the researches showing that immature DCs [ 17 , 18 ], IL-10-producing DCs [ 5 , 6 , 21 – 23 ], and antigen-loaded DCs [ 8 , 17 , 18 ] are able to induce CD4 + IL-10 + cells and FoxP3 + Tregs. In our opinion, the level of suppression which corresponds to that of nonelectroporated immature DCs is enough and expected, as the effect of this group, in fact, more closely reflects that of the immature DCs taking part in immunoregulatory processes in vivo than other groups.…”

“…Interestingly, increased FoxP3 + Treg frequencies were observed only in the DCpMHC and the DCpIL-10 + pMHC groups 3 weeks post-GVHD induction despite the fact that DCs transfected with IL-10 were capable of Treg induction in MLCs. According to the previous findings, in vivo Treg generation by IL-10-producing DCs requires allogeneic [ 21 ] or antigen-loaded [ 27 ] DCs. By contrast, Tregs can be generated in vitro with syngeneic non-antigen-loaded IL-10 producing DCs [ 22 ].…”

Melatonin Inhibits Transforming Growth Factor-β1-Induced Epithelial–Mesenchymal Transition in AML12 Hepatocytes

“…We found that TGF-β1-stimulated activation of ERK1/2 and p38 was also dose-dependently inhibited by melatonin, whereas JNK1/2 phosphorylation was not affected. Previous studies have shown that Smad and MAPK signaling pathways play an important role in EMT stimulated by TGF-β1 [31][32][33] and the development of liver fibrosis [34][35][36][37]. Taken together, these results suggest that melatonin prevents EMT stimulated by TGF-β1 in AML12 hepatocytes through suppression of Smad and MAPK signaling cascades.…”

Tolerogenic Dendritic Cells: The Pearl of Immunotherapy in Organ Transplantation

“…For example, promoting the expression of IL-10-related genes in DC could attenuate liver fibrosis in mice via increasing Treg induction. This kind of IL-10 + DC is characterized by low expression of costimulatory molecules ( 69 ). Nuclear paraspeckle assembly transcript 1 (NEAT1) is proven to use NACHT, LRR, and PYD domain-containing protein 3 (NLRP3) inflammasomes as molecular decoys for miR-3076-3p, so knockdown NEAT1 could facilitate the tolerogenic phenotype in DC, which prevents progression of experimental autoimmune myocarditis and induces immune tolerance in a heart transplantation model ( 70 ).…”