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

Abstract

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.