Myeloid dendritic cells loaded with dendritic tandem multiple antigenic telomerase reverse transcriptase (hTERT) epitope peptides: a potentially promising tumor vaccine.

Human telomerase reverse transcriptase (hTERT) has been identified as an ideal tumor-associated antigen (TAA). Use of a synthetic hTERT epitope peptide to pulse dendritic cells can induce autologous T cell anti-tumor immune responses, but such responses induced by a single epitope peptide have been shown to be weak and a narrow-spectrum. Here, we designed dendritic tandem multiple antigenic peptides (MAPs) containing the following three hTERT epitope peptides: I540, V461 and L766, which are HLA-A*02-, HLA-A*24- and HLA-RDB1*04/11/15-restricted, respectively. The MAPs and their three single-epitope peptides were obtained through solid-phase synthesis. Healthy volunteers that were HLA-A*02(+)/HLA-DRB1*04(+) and HLA-A*24(+)/HLA-DRB1*15(+) were recruited. Myeloid dendritic cells were isolated by magnetic activated cell sorting and were divided into a MAP-stimulated group (MAP-DC), a group in which the three epitope peptides were mixed and used to stimulate the DCs (MixP-DC) and a no peptide-stimulated group (NoP-DC, control group). All of the DCs were cultured in serum-free medium, pulsed with the corresponding peptides on the 3rd, 5th and 7th days, and co-cultured with autologous lymphocytes when they were mature. The related cytokines were measured via ELISA. The killing effects of cytotoxic T lymphocytes (CTLs) on SW480/A549 tumor cells expressing HLA-A*02(+), HepG2/SMMC-7721 cells expressing HLA-A*24(+) and SKOV3 cells negative for HLA-A*02/A*24 were detected by flow cytometry. Our results indicated that the CTLs induced by the MAP-DCs had the greatest anti-tumor effect. Therefore, the dendritic tandem multiple antigenic hTERT epitope peptides combined with MDCs may represent a powerful, broad-spectrum anti-tumor vaccine.

Suppression of histone deacetylase 11 promotes expression of IL-10 in Kupffer cells and induces tolerance following orthotopic liver transplantation in rats.

BACKGROUND: Suppression of histone deacetylase 11 (HDAC11) can promote IL-10 expression in mouse macrophages RAW264.7 and induce immune tolerance. This study is to further investigate the role of HDAC11 in tolerance induction via Kupffer cells (KCs) following orthotopic liver transplantation (OLT) in rats. MATERIALS AND METHODS: KCs isolated from BALB/c mice were divided into pHDAC11, adHDAC11, and pCV group (treated with HADC11-shRNA, adenovirus encoding HDAC11, and control vector, respectively). IL-10 expression was determined after lipopolysaccharide treatment. The expression of MHC-II and co-stimulatory molecules on KCs surface was evaluated by flow cytometry. T cell proliferation was measured by [(3)H]-thymidine incorporation after culturing with aforementioned three groups, treated KCs, respectively. OLT was performed in rats after Ad-HDAC11 and pHDAC11 treatment. Blood samples were collected for biochemical studies, and postoperative survival was examined. RESULTS: IL-10 expression was inhibited and promoted by Ad-HDAC11 and HDAC11-shRNA in KCs, respectively. MHC-II and co-stimulatory molecules on KCs surface as well as T cell proliferation were significantly inhibited and induced in pHDAC11 and Ad-HDAC11 compared with pCV, respectively. Serum IL-2, TNF-α, and IFN-γ levels were significantly lower in pHDAC11 and higher in Ad-HDAC11 compared with pCV, respectively, while IL-4 and IL-10 were the reverse. Postoperative survival, liver function, and histology were different among the three groups. CONCLUSIONS: Suppression of HDAC11 can promote IL-10 expression in KCs and induce tolerance following OLT in rats. Consequently, HDAC11 may be a key component of this immune regulation system and a promising target for development of novel drugs of gene therapy for inducing tolerance in clinical liver transplantation.