Human urinary bladder carcinoma cell line (T24): immunological studies and search for oncornavirus in T24 cell population and derived clones.

Cytotoxicity of mononuclear cell (MNC) preparations isolated from peripheral blood of patients with urinary bladder carcinomas of a transitional (BTCC) or squamous (BSCC) type and from blood of control subjects was examined on the target cells of T24 cell line. In pilot experiments the percentage of cytotoxic MNC preparations was found to be similar in patients with tumors of BTCC (European, 56%;African, 60%) and BSCC (54%) type. Cytotoxicity of MNC prepared from control subjects was detected in 10% of cases or less. These data suggest an antigenic cross-reactivity between urinary bladder carcinomas of transitional and squamous cell type. The cytotoxic MNC from peripheral blood of patients with BTCC and control subjects were fractionated by adherence in nylon wool columns, and the cytotoxicity of adherent and nonadherent MNC subpopulations was examined. In the majority of cytotoxic MNC preparations from both donors with and without BTCC, the cytotoxic activity was associated with nonadherent MNC. Comparison of immunosensitivity of T24 cell population with the cloned T24 subpopulations indicated that clones with various digrees of immunosensitivity are present in the T24 cell population. However, immunosensitivity of the clones was never higher than the immunosensitivity of the T24 cell population. A search for oncornavirus particles produced spontaneously or after treatment with virus production activators performed with regard to the possible association of oncornaviruses and antigens responsible for cell-mediated cytotoxicity gave thus far negative results.