Histocompatibility leukocyte antigen-A2402-restricted cytotoxic T lymphocytes recognizing adenocarcinoma in tumor-infiltrating lymphocytes of patients with colon cancer

To cast light on T cell-mediated specific immunity at the tumor site of colon cancer, we investigated whether interleukin-3 (IL-2)-activated tumor-infiltrating lymphocytes (TIL) from colon cancer show histocompatibility leukocyte antigen (HLA)-class I-restricted cytotoxicity against adenocarcinoma. IL 2-activated TIL from all four HLA-A24 patients examined lysed HLA-A2402(+) adenocarcinomas, but not HLA-A2402(-) tumors. Those of two of the four cases also lysed HLA-A2402(+) squamous cell carcinomas. CD8(+) cytotoxic T lymphocyte (CTL) clones recognizing HLA-A2402(+) adenocarcinomas were established from one CTL line. This CTL line produced IFN-gamma upon recognition of an HLA-A2402(-) adenocarcinoma transfected with HLA-A2402 cDNA. These results suggest the presence of HLA-A2402-restricted CTL recognizing adenocarcinoma at the tumor site of colon canter. Furthermore, HLA-A31-restricted CTL activity was found in IL-2-activated TIL from one of two HLA-A31(+) patients, suggesting the existence of HLA-class I restricted CTL involving an allele other than A24.