Analysis of immune response to tumor specific antigen restricted to HLA class II on renal cell carcinoma and its recognition mechanism

PURPOSE: In this study, we studied the immune response against to human renal cell carcinoma and its antigensity. METHODS: Mixed lymphocyte tumor culture test was performed using tumor cells as stimulator cells, peripheral blood lymphocytes from tumor patient (autologous) or healthy volunteer (allogeneic) as responder cells, and tumor cells or peripheral blood lymphocytes from tumor patient as target cells. The cytotoxic activity of mixed lymphocyte tumor culture test was assayed by 51Cr-relase test, and cell surface antigens presented on tumor cells or peripheral blood lymphocytes were assayed by antibody block test. RESULTS: The cytotoxic activity against to tumor cells was induced from allogeneic peripheral blood lymphocytes by mixed lymphocyte tumor culture test. Its cytotoxic activity was inhibited by anti-CD8 antibody treatment of peripheral blood lymphocytes and anti-HLA class II antibody treatment of tumor cells. Furthermore, allogeneic peripheral blood lymphocytes induced to tumor cells did not damage peripheral blood lymphocyte of the tumor patient derivation. CONCLUSION: Renal cell carcinoma may express tumor specific antigen restricted to HLA class II antigens that could be recognized by allogeneic CD8 positive T lymphocytes.