Cancer Stem Cell Vaccination With PD-L1 and CTLA-4 Blockades Enhances the Eradication of Melanoma Stem Cells in a Mouse Tumor Model. Issue 8 (October 2018)

• Record Type: Journal Article
• Authors: Zheng, Fang; Dang, Jianzhong; Zhang, Hongyu; Xu, Fangzhou; Ba, Diandian; Zhang, Bingyu; Cheng, Fanjun; Chang, Alfred E.; Wicha, Max S.; Li, Qiao
• Is Part Of: Journal of immunotherapy. Volume 41:Issue 8(2018:Oct.)
• Publication Date: 2018-10
• Subjects: cancer stem cells -- vaccine -- PD-L1 -- CTLA-4 -- immunotherapy; Immunotherapy -- Periodicals; Immunotherapy -- Periodicals; Neoplasms -- therapy -- Periodicals; Electronic journals; Electronic journals; 615.37
• DOI: 10.1097/CJI.0000000000000242
• Languages: English
• ISSNs: 1524-9557

Abstract

Abstract : Immune checkpoint inhibitors and monoclonal antibodies reinvigorate cancer immunotherapy. However, these immunotherapies only benefit a subset of patients. We previously reported that ALDH high tumor cells were highly enriched for cancer stem cells (CSCs), and ALDH high CSC lysate-pulsed dendritic cell (CSC-DC) vaccine was shown to induce CSC-specific cytotoxic T lymphocytes. In this study, we investigated the CSC targeting effect of the CSC-DC vaccine combined with a dual blockade of programmed death-ligand 1 and cytotoxic T-lymphocyte-associated protein (CTLA-4) in B16-F10 murine melanoma tumor model. Our data showed that animals treated with the dual blockade of programmed death-ligand 1 and CTLA-4 and CSC-DC vaccine conferred significantly more tumor regression than the CSC-DC vaccine alone. Importantly, the triple combination treatment dramatically eliminated ALDH high CSCs in vivo. We observed that CSC-DC vaccine in combination with anti-PD-L1 and anti-CTLA-4 administration resulted in ∼1.7-fold fewer PD-1 + CD8 + T cells and ∼2.5-fold fewer CTLA-4 + CD8 + T cells than the populations observed following the CSC-DC vaccination alone. Moreover, significant antitumor effects and dramatically eliminated ALDH high CSCs following the triple combination treatment were accompanied by significantly enhanced T-cell expansion, suppressed transforming growth factor β secretion, enhanced IFN-γ secretion, and significantly enhanced host specific CD8 + T-cell response against CSCs. Collectively, these data showed that administration of a-PD-L1 and a-CTLA-4 combined with CSC-DC vaccine may represent an effective immunotherapeutic strategy for cancer patients in clinical.