IMMUNE PHENOTYPE AND SOME ENZYME PATTERNS IN PHORBOL ESTER-INDUCED CHRONIC LYMPHOCYTIC-LEUKEMIA CELLS

Leukemic cells from 10 patients with B-chronic lymphocytic leukemia (B -CLL) were isolated and cultured in the presence of 12-0-tetradecanoyl phorbol 13-acetate (TPA) at a concentration of 8 x 10(-7) mol for 72 h ours. Cells were analyzed before cultivation and after 72 h of cultiva tion with and without TPA for changes in surface membrane (Sm) and cyt oplasmic (cyt) markers expression, presence of receptor for mouse rose tte forming cells (MRFC) and some enzyme profiles. All B-CLL cases stu died showed typical B-cell phenotype. TPA treatment induced hairy cell leukemia (HCL) characteristics, given by the membrane CD22 and CD25 e xpression and TRAP positivity in the majority of the cases tested. Cel ls had hairy cell-like morphology with more intensive cytoplasmic immu noglobulin (CIg) fluorescence staining, absent receptor for MRFC and i ncreased activity of purine nucleosidephosphorylase. In common these c hanges indicate that TPA can induce hairy cell characteristics on B-CL L cells in vitro suggesting the more mature differentiation stage of H CL compared with CLL. Furthermore, we originally demonstrated that the CD22, present in the cell membrane after TPA, could be detected in th e majority of unaffected B-CLL cells in their cytoplasm. From the tech nical point of view some intracellular CD markers and Igs of B-CLL cel ls in viable cells in suspension assayed by flow cytometry are describ ed in this study.