EXPRESSION AND DETECTION OF FUNCTIONAL-AC TIVITY OF FAS APO-1/CD95 ANTIGEN, MEDIATING APOPTOSIS IN HUMAN HEMOBLASTOSES/

Fas/APO-1/CD95 antigen expression was studied using indirect immunoflu orescent technique on flow cytofluorimeter on peripheral blood cells o f 14 patients with CML chronic stage, 14 cases with CML blastic phase, 21 with acute leukemias (8 - ALL, 13 - ANLL), 10 with CLL and 4 patie nts with leukemic phase of lymphoblastic lymphoma. Fas-antigen was rev ealed on periferal blood cells in 50% of CML BP, 23.1% of ANLL, 12.5% of ALL, 50% of CLL and 25% of lymphoma patients. We did not reveal Fas -antigen in CML chronic stage. We detected triggering of apoptosis in cultured blast cells with anti-fas antibodies IPO-4 in 2 patients with CML BP and 1 with lymphoma. in all 3 cases we have revealed pound nuc leosomic ladder'' on agarose gel electrophoresis at 25 hrs in CML pati ents and at 72 hrs in lymphoma patient. Taking into account our data, evidence reported earlier on co-expression of Fas and CD34 antigens, t hese results suggest that Fas-antigen can play an important role in he mopoietic stem cell differentiation.