HLA-A0201 positive pancreatic cell lines: new findings and discrepancies

Pancreatic cancer is being pursued as an immunotherapy target using antigen-specific vaccine approaches activating CD8⁺ CTL and CD4⁺ T-helper cells. CD8⁺ CTL exert their anti-tumor effects in an HLA-restricted manner and only tumor cells carrying a matched HLA class I sub-type are targets for antigen-specific CTL. In the process of characterizing CD8⁺ T cell responses against pancreatic cancer, we screened a number of human pancreatic tumor cell lines for HLA-A0201 positive (HLA-A2⁺) cell lines to be used in the evaluation of CTL function. This analysis revealed some new findings and discrepancies in the literature on the HLA sub-type of some commonly used pancreatic cell lines. We found that Capan-1 cells, originally reported to be HLA-A0201⁺, actually only express HLA-A010101 and HLA-A300101 and were targets for HLA-A0201-restricted CTL only after transduction with an HLA-A0201-expressing lentivirus. Panc-1 cells were found to be HLA-A0201 positive, in agreement with published reports, while CF-Pac-1 cells were found to express both HLA-A020101 and HLA-A030101. We also found a normal human pancreatic ductal epithelial cell line, HPDE, to be HLA-A0201 positive. Our findings were verified with two different sequence-based typing methods, antibody staining followed by flow cytometry analysis, and functional analysis using an HLA-A0201-restricted peptide-specific T cell response.