MHC class II molecules on pancreatic cancer cells indicate a potential for neo-antigen-based immunotherapy. (31st December 2022)

• Record Type: Journal Article
• Authors: Baleeiro, Renato B.; Bouwens, Christian J.; Liu, Peng; Di Gioia, Carmela; Dunmall, Louisa S. Chard; Nagano, Ai; Gangeswaran, Rathistevy; Chelala, Claude; Kocher, Hemant M.; Lemoine, Nicholas R.; Wang, Yaohe
• Is Part Of: Oncoimmunology. Volume 11:Number 1(2022)
• Publication Date: 2022-12-31
• Subjects: Neo-antigens -- cancer immunotherapy -- MHC-II-positive tumors -- cytotoxic CD4+ T-cells -- pancreatic cancer; Tumors -- Immunological aspects -- Periodicals; Neoplasms -- therapy -- Periodicals; Immunotherapy -- Periodicals; 616.994
• DOI: 10.1080/2162402X.2022.2080329
• Languages: English
• ISSNs: 2162-402X

Abstract

ABSTRACT: MHC class II expression is a hallmark of professional antigen-presenting cells and key to the induction of CD4+ T helper cells. We found that these molecules are ectopically expressed on tumor cells in a large proportion of patients with pancreatic ductal adenocarcinoma (PDAC) and on several PDAC cell lines. In contrast to the previous reports that tumoral expression of MHC-II in melanoma enabled tumor cells to evade immunosurveillance, the expression of MHC-II on PDAC cells neither protected cancer cells from Fas-mediated cell death nor caused T-cell suppression by engagement with its ligand LAG-3 on activated T-cells. In fact and surprisingly, the MHC-II/LAG-3 pathway contributed to CD4+ and CD8+ T-cell cytotoxicity toward MHC-II-positive PDAC cells. By combining bioinformatic tools and cell-based assays, we identified a number of immunogenic neo-antigens that can be presented by the patients' HLA class II alleles. Furthermore, CD4+ T-cells stimulated with neo-antigens were capable of recognizing and killing a human PDAC cell line expressing the mutated genes. To expand this approach to a larger number of PDAC patients, we show that co-treatment with IFN-γ and/or MEK/HDAC inhibitors induced tumoral MHC-II expression on MHC-II-negative tumors that are IFN-γ-resistant. Taken together, our data point to the possibility of harnessing MHC-II expression on PDAC cells for neo-antigen-based immunotherapy.