DEFINITION OF UNIQUE AND SHARED T-CELL DEFINED TUMOR-ANTIGENS IN HUMAN RENAL-CELL CARCINOMA

From peripheral blood mononuclear cells of a patient with renal cell c arcinoma (RCC), we isolated several T-cell clones, which efficiently l yse the autologous RCC cell line (LE-8915-RCC), but not the autologous Epstein Barr virus-transformed lymphoblastoid cell line. Most of the cytotoxic T lymphocyte (CTL) clones recognize HLA-Al-positive allogene ic RCC cell lines, indicating that HLA-A1 is the restricting element f or these T cells. One CTL clone exclusively recognizes the autologous tumor cells. The HLA-Al-restricted CTL clones can be divided further i nto two subsets of T-cell clones, one blocked by an HLA-Al-specific mo noclonal antibody, the other not. The reactivity of HLA-Al-restricted T-cell done 6/135 was studied in greater detail. This T-cell clone als o recognizes a number of melanoma cell lines, indicating that expressi on of the antigen seen by this CTL clone is not restricted to RCC. Str ikingly, the antigen is not exclusively expressed by tumor cell lines: because primary cultures of proximal tubulus epithelium cells, adult mesangial cells, and normal breast epithelium cells are also lysed. Th ese results corroborate the notion that renal carcinoma cells are immu nogenic by virtue of a broadly distributed antigenic structure that ma y serve as a target for cytotoxic T cells and may be a potential candi date for tumor vaccine development.