Silencing of the TGF-?1 gene increases the immunogenicity of cells from human ovarian carcinoma.

ABSTRACT: Cells from many tumors produce transforming growth factor (TGF)-? which facilitates their escape from control by the immune system. We previously reported that nonimmunogenic cells from either of 2 transplantable mouse tumors became effective as therapeutic tumor vaccines after lentivirus-mediated shRNA interference to "silence" the TGF-?1 gene. We now show that cells from in vitro cultured human ovarian carcinomas (OvC) make large amounts of TGF-?1 and that this can be prevented by "silencing" the TGF-?1 gene. We further show that in vitro sensitization of peripheral blood mononuclear cells in the presence of either mitomycin-treated OvC cells whose TGF-?1 gene was silenced or in vitro matured dendritic cells that had been pulsed with homogenates from OvC cells with silenced TGF-?1 generated a stronger Th1/Tc1 immune response to the respective wild-type OvC and also to the OvC antigens mesothelin and HE4 as measured by ELIspot assays. The percentage of interferon-? and tumor necrosis factor-?-producing CD4+ and CD8+ T cells increased while there were fewer cells expressing markers characteristic for regulatory T cells or myeloid-derived suppressor cells. Similar results were obtained when peripheral blood mononuclear cells from a patient with OvC were sensitized to dendritic cells pulsed with homogenate from autologous TGF-?1-silenced tumor cells, and a cytolytic lymphocyte response was generated to autologous OvC cells. Our results support clinical evaluation of TGF-?1-silenced tumor vaccines for immunotherapy of OvC.

SUBMITTER: Wei H 

PROVIDER: S-EPMC3327124 | biostudies-other | 2012 Apr

REPOSITORIES: biostudies-other