[Induction of the traits of the T-cell differentiated phenotype in a blast cell population from patients with acute lymphoblastic leukemia. II. Parallel changes in the antigenic characteristics and functional properties of blast cells as affected by inducers].

Data are provided which allow to assume that the appearance of T-cell markers on blast cells of patients with non T-, non B- and pre-T-cell acute lymphoblastic leukaemia may reflect the process of differentiation in leukaemic lymphoblasts in T-cells under the action of phytohaemagglutinin (PHA) combined with phorbol ether (TPA) or ouabain. As result of the induction, in the lymphoblast population the number of cells carrying the markers of non-differentiated phenotype decreased, which was proportional to the increase in the number of cells with differentiated T-lymphocytic phenotype. The expression of T-cell markers was suppressed by the inhibitors of transcription and protein synthesis. As a result of induction the leukaemic cells acquire the ability to form T-cell colonies in semisolid agar which reflects their functional changes under the action of inducers. Possible mechanisms of PHA inducing action are discussed.