MHC class II molecules on pancreatic cancer cells indicate a potential for neo-antigen-based immunotherapy

Oncoimmunology. 2022 May 27;11(1):2080329. doi: 10.1080/2162402X.2022.2080329. eCollection 2022.


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.

Keywords: MHC-II-positive tumors; Neo-antigens; cancer immunotherapy; cytotoxic CD4+ T-cells; pancreatic cancer.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carcinoma, Pancreatic Ductal* / genetics
  • Carcinoma, Pancreatic Ductal* / therapy
  • Histocompatibility Antigens Class II / genetics
  • Histocompatibility Antigens Class II / metabolism
  • Humans
  • Immunologic Factors
  • Immunotherapy
  • Pancreas / metabolism
  • Pancreatic Hormones
  • Pancreatic Neoplasms* / genetics
  • Pancreatic Neoplasms* / therapy


  • Histocompatibility Antigens Class II
  • Immunologic Factors
  • Pancreatic Hormones

Supplementary concepts

  • Pancreatic Carcinoma