Morphological, immunophenotypical and isoenzymatic profiles of human leukemia cells and derived T-cell lines

Six monoclonal leukemia cell lines (MOLT 12-17) were established from three patients with acute leukemia. Two of the patients' samples were of the T-ALL type, the third had morphological, isoenzymatic and immunological features of AMoL. The cell lines resulting from these original cells displayed distinct, but stable marker profiles. A comparison between primary cells and resulting cell lines showed that the cell lines established from patients with T-ALL (MOLT 12, 13, 14 and MOLT 16, 17) expressed similar phenotypes and isoenzyme patterns, but were different in a few specific aspects. The changes suggest a modulation of marker expression in vitro or an arrest at a more immature stage of differentiation than the original cells. The cell line MOLT 15 established from the case of AMoL exhibited a quite discordant profile when compared to the primary sample: the cells lacked all previously found myelomonocytic antigens and a monocyte-specific esterase isoenzyme, but expressed the T-cell associated CD7 antigen and had rearrangements and RNA transcripts of the T-cell receptor beta and gamma chain genes. This striking discrepancy between the patient's malignant cells and the corresponding cell line suggests that subpopulation selection had occurred in culture.