Interleukin 35 (IL-35) is a relatively newly identified cytokine required for the regulatory and suppressive functions of regulatory T cells (Treg), playing an important role in the prevention of autoimmune diseases. This study used mesenchymal stem cells (MSCs) as the gene-delivery vehicles for IL-35 gene therapy and investigated their protective effects in Concanavalin A (Con A)-induced autoimmune hepatitis. Results showed that IL-35 gene modified MSCs (IL-35-MSCs) can specifically migrate to the injured liver tissues and significantly narrow the necrosis areas of injured livers. IL-35-MSCs prevented hepatocyte apoptosis by reducing the FASL expression by mononuclear cells. Although MSC treatment can alleviate liver injury to some extent, IL-35-MSCs showed a stronger protective effect, which means some novel mechanisms exist. The results show that IL-35-MSCs could decrease the level of interferon gamma secreted by liver mononuclear cells through the JAK1-STAT1/STAT4 signal pathway. In summary, this study thus demonstrates a novel and efficient treatment for Con A-induced fulminant hepatitis through negatively regulating the secretion of interferon gamma, thus providing a novel therapeutic approach for this devastating liver disease.

Alpha-fetoprotein (AFP) is overexpressed in hepatocellular carcinoma (HCC) and could serve as a tumor-associated antigen (TAA) and potential target for adoptive immunotherapy. However, low frequency and severe functional impairment of AFP-specific T cells in vivo hamper adoptive infusion. TAA-specific T cell receptor (TCR) gene transfer could be an efficient and reliable alternation to generate AFP-specific cytotoxic T lymphocytes (CTLs). Autologous dendritic cells (DC) pulsed with AFP158-166 peptides were used to stimulate AFP-specific CTLs. TCR α/β chain genes of AFP-specific CTLs were cloned and linked by 2A peptide to form full-length TCR coding sequence synthesized into a lentiviral vector. Nonspecific activated T cells were engineered by lentivirus infection. Transgenetic CTLs were evaluated for transfection efficiency, expression of AFP158-166-specific TCR, interferon (IFN)-γ secretion, and specific cytotoxicity toward AFP+ HCC cells in vitro and in vivo. Flow cytometry revealed the AFP158-166-MHC-Pentamer positive transgenetic CTLs was 9.86 %. The number of IFN-γ secretion T cells and the specific cytotoxicity toward HpeG2 in vitro and in tumor-bearing NOD/SCID mice were significantly raised in transgenetic CTLs than that of AFP158-166-specific CTLs obtained by peptide-pulsed DCs or control group. TCR gene transfer is a promising strategy to generate AFP158-166-specific CTLs for the treatment of HCC.

To explore generation of interleukin (IL)-35-expressing mouse adipocyte-derived mesenchymal stem cells (Ad-MSCs) using lentiviral vector and their potential immunosuppressive effects in mice. Ad-MSCs were isolated and cultured in vitro and transfected with a lentivirus vector for overexpression of the therapeutic murine IL-35 gene. IL-35 expression in transfected MSCs (IL-35-MSCs) was quantified by enzyme-linked immunosorbent assay (ELISA). The lymphocytes subsets after one-way mixed lymphocyte culture and in vivo intravenous transplantation were analysed by flow cytometry to evaluate the immunosuppressive effects of IL-35-MSCs. ELISA was performed to examine IL-10, IL-17A and IL-35 expression in lymphocyte culture. Mouse Ad-MSCs were isolated and cultured. IL-35 was expressed in the MSC supernatant and serum after IL-35 transduction into Ad-MSCs by lentiviral vector transfection in vitro and in vivo. The percentage of CD4 CD25 T regulatory (Treg) cells in mice treated with IL-35-MSCs significantly increased. IL-35-MSCs upregulated the CD4 CD25 Treg cells in the allogeneic mixed lymphocyte reaction system, and lowered the percentage of CD4 T cells compared with the other two control groups (P < 0.01). IL-17A expression significantly decreased and IL-10 expression significantly increased in IL-35-MSCs and MSCs when compared by ELISA to the control groups (P < 0.01). IL-35-transduced Ad-MSCs in vivo can enhance proliferation of CD4 CD25 Treg cells and suppress the function of effector T cells such as T helper (Th) 1, Th2 and Th17 cells and may reduce the development of allograft rejection. Our data suggest that transduced Ad-MSCs overexpressing IL-35 may provide a useful approach for basic research on cell-based immunotolerance therapy for inducing transplantation tolerance.

No abstract

No abstract