HUMAN T LYMPHOCYTE COLONIES IN AGAR: A COMPARISON WITH OTHER T CELL ASSAYS IN HEALTHY SUBJECTS AND CANCER PATIENTS

Abstract

Colonies of human lymphocytes with T cell characteristics will grow in agar from repeated mitotic divisions with phytohaemagglutinin (PHA) stimulation. The colonies comprise spheres of tightly-packed cells with up to 500–1,000 blast-like cells in each colony. 65% of cells from pooled colonies bound AET-treated sheep red cells. 1,100–2,500 colonies/10⁶ peripheral blood lymphocytes developed when cell donors were healthy but lower numbers (350–1,000 colonies/10⁶ lymphocytes) were detected in blood from cancer patients. Comparison with other non-specific assays of cell-mediated immunity showed that, while 66% of cancer patients were anergic (to five recall antigens) and 78% exhibited depressed mitotic activity in standard cultures with low dose PHA, 100% of these patients revealed T cell colony formation below normal. It is suggested that further studies of T lymphocyte colony-forming cells in healthy people and in a number of disease states may significantly advance our understanding of mechanisms of cell-mediated immunity.