CD4+Hepatic Cancer-Specific Cytotoxic T Lymphocytes in Patients with Hepatocellular Carcinoma

We investigated T cell immunity against hepatocellular carcinoma (HCC), and showed that both peripheral blood mononuclear cells and tumor-infiltrating lymphocytes incubated with interleukin-2 alone displayed HLA-nonrestricted but hepatic cancer-specific cytotoxicity in a majority of patients with HCC. Namely, they lysed both HCC and cholangiocellular carcinomas in an HLA-nonrestricted manner, but they did not lyse any tumors with the other histological types tested, normal hepatocytes, or the cells transfected with hepatitis C virus orMUC1gene. These CTL lines and clones were phenotypically CD3+CD4+CD8−. These unique CTL could play important roles in T cell immunity against HCC.