Expression of myeloid differentiation antigens on normal and chronic granulocytic leukemia erythroid progenitor cells identified by monoclonal antibodies.
The antigenic phenotype of erythroid progenitor cells (BFU-E and CFU-E) in bone marrow and peripheral blood from normal individuals and patients with chronic granulocytic leukaemia (CGL) was studied using 14 myeloid monoclonal antibodies (Mc Abs) in a complement dependent cytotoxicity assay followed by culture in methylcellulose. Mc Abs which reacted with normal CFU-GEMM and CFU-GM antigens usually reacted strongly with normal and CGL-BFU-E. In contrast, the majority of myeloid Mc Abs used in the study reacted poorly or did not recognize the antigens on normal and CGL CFU-E. HLA-DR antigens recognized by L243 Mc Ab were expressed on the majority of BFU-E from blood and bone marrow of normal individuals and CGL patients. On the other hand, those antigens were not expressed on normal and leukaemic CFU-E. Two Mc Abs, R1.B19 and WGHS29.1, which recognised the antigens on "late" CFU-GM and not on "early" CFU-GM reacted with a higher proportion of BFU-E from the marrow and blood of CGL patients than of normal subjects. These results indicate that BFU-E in CGL are more differentiated than their normal counterparts. The Mc Ab 54/39, frequently expressed on platelets, recognized a higher percentage of BFU-E and CFU-E from CGL patients than from normal individuals. This may suggest that in CGL there exists a tendency for the expression of megakaryocytic markers on erythroid progenitor cells.
D000911:Antibodies, Monoclonal / Q000276:immunology; D000943:Antigens, Differentiation; D003114:Colony-Forming Units Assay; D003165:Complement System Proteins / Q000276:immunology; D003601:Cytotoxicity Tests, Immunologic; D004912:Erythrocytes / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000276:immunology*; D006801:Humans; D007951:Leukemia, Myeloid / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000943:Antigens, Differentiation; D003165:Complement System Proteins