Clonal analysis of T lymphocytes isolated from ovarian carcinoma ascitic fluid. Phenotypic and functional characterization of T-cell clones capable of lysing autologous carcinoma cells.

T lymphocytes isolated from ascitic fluid of patients with stage III-IV ovarian carcinoma were cloned by means of a microculture system that allows cloning of virtually all peripheral blood human T lymphocytes. Under these experimental conditions, 15% to 42% of ascitic T cells gave rise to clonal progenies that were analyzed for different functional capabilities. Of the clones obtained, 36%-70% had cytolytic activity in a PHA-dependent assay (using P815 as target cells) that allowed detection of cytolytic cells of any specificity. About one-half of the cytolytic clones lysed the NK-sensitive K562 target cells as well. In addition, 30%-50% of the total clones released IL-2 upon stimulation with PHA for 24 hr. In all patients analyzed a variable proportion (11%-56% of all cytolytic clones) had cytolytic activity against autologous tumor cells. Some of these clones have been analyzed in more detail: 18/21 expressed the T4-T8+ phenotype, whereas the remaining 3 were T4+ T8-. Only one out of 6 clones tested lysed allogeneic ovarian carcinoma cells as well, while 5/8 had a definite NK-like activity. Finally, all 8 clones tested were inhibited by anti-T11 and 7/8 by anti-T8 monoclonal antibody.