Dendritic cell vaccines based on immunogenic cell death elicit danger signals and T cell–driven rejection of high-grade glioma

AD Garg, L Vandenberk, C Koks… - Science translational …, 2016 - science.org
AD Garg, L Vandenberk, C Koks, T Verschuere, L Boon, SW Van Gool, P Agostinis
Science translational medicine, 2016science.org
The promise of dendritic cell (DC)–based immunotherapy has been established by two
decades of translational research. Of the four malignancies most targeted with clinical DC
immunotherapy, high-grade glioma (HGG) has shown the highest susceptibility. HGG-
induced immunosuppression is a roadblock to immunotherapy, but may be overcome by the
application of T helper 1 (TH1) immunity–biased, next-generation, DC immunotherapy. To
this end, we combined DC immunotherapy with immunogenic cell death (ICD; a modality …
The promise of dendritic cell (DC)–based immunotherapy has been established by two decades of translational research. Of the four malignancies most targeted with clinical DC immunotherapy, high-grade glioma (HGG) has shown the highest susceptibility. HGG-induced immunosuppression is a roadblock to immunotherapy, but may be overcome by the application of T helper 1 (TH1) immunity–biased, next-generation, DC immunotherapy. To this end, we combined DC immunotherapy with immunogenic cell death (ICD; a modality shown to induce TH1 immunity) induced by hypericin-based photodynamic therapy. In an orthotopic HGG mouse model involving prophylactic/curative setups, both biologically and clinically relevant versions of ICD-based DC vaccines provided strong anti-HGG survival benefit. We found that the ability of DC vaccines to elicit HGG rejection was significantly blunted if cancer cell–associated reactive oxygen species and emanating danger signals were blocked either singly or concomitantly, showing hierarchical effect on immunogenicity, or if DCs, DC-associated MyD88 signal, or the adaptive immune system (especially CD8+ T cells) were depleted. In a curative setting, ICD-based DC vaccines synergized with standard-of-care chemotherapy (temozolomide) to increase survival of HGG-bearing mice by ~300%, resulting in ~50% long-term survivors. Additionally, DC vaccines also induced an immunostimulatory shift in the brain immune contexture from regulatory T cells to TH1/cytotoxic T lymphocyte/TH17 cells. Analysis of the The Cancer Genome Atlas glioblastoma cohort confirmed that increased intratumor prevalence of TH1/cytotoxic T lymphocyte/TH17 cells linked genetic signatures was associated with good patient prognosis. Therefore, pending final preclinical checks, ICD-based vaccines can be clinically translated for glioma treatment.
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