Lymphoid cells mediating tumor-specific cytotoxicity to carcinoma of the urinary bladder. Separation of the effector population using a surface marker.

Peripheral lymphocytes from patients with urinary bladder carcinoma and controls have been separated on the basis of rosette formation with sheep erythrocytes. The fractions were tested for tumor-specific cytotoxicity. The E rosette-forming cells of purity 90% respond well in PHA-induced cytotoxicity but are totally inactive in the tumor assay. The non-E rosette-forming cells (purity 91%) give enhanced activity in the tumor-specific cytotoxicity as well as in antibody-mediated target cell lysis in a model system. These data support the notion that the effector cells in cell-mediated immunity to carcinoma of the urinary bladder are members of the nonthymus-derived population of peripheral lymphocytes.