Distribution of a Hematopoietic-speciflc Differentiation Antigen of K562 Cells in the Human Myeloid and Lymphoid Cell Lineages1

BALB/c mice were immunized with uninduced K562 erythroleukemia cells and hybridomas were isolated after fusion of immune spleen cells to P3/NS1 murine myeloma cells. One selected hybrid, designated 101,30, secreted an antibody of subclass immunoglobulin G2a which was specific for hematopoietic cells. Analysis of 10L-30 binding by comple ment-mediated cytotoxicity, indirect immunofluorescence, solid-phase radioimmummssay, and mixed hemadsorption assay indicated that the 10L-30 antigen was expressed on the myeloid cell lines K562, KG-1A, KG-1, some Band T-lymphoid cell lines, and all normal human periph eral blood T-Iymphocyte samples tested, but was absent on the more differentiated myeloid cell lines III -60, ML-2, ML-3, and normal blood granulocytes. Induction of erythroid differentiation in hemin-treated KS62 cells caused a 10-fold reduction in 101-30 binding. Human erythroid and granulocytic progenitor cells, platelets, erythrocytes, and reticulocytes were nonreactive, as were a variety of nonhematopoietic human tumor cell lines. Freshly isolated leukemic bone marrow samples from patients with MS (2 of 5), M6 (2 of 2), acute lymphoid leukemia (9 of 14), and chronic myeloid leukemia in lymphoid blast crisis (1 of 1) were 10L-30 positive. The combined evidence indicates that the 101-30 antigen is a normal, hematopoietic-specific differentiation antigen which is strongly expressed on both immature cells of the myeloid lineage and more generally in lymphoid ontogeny. The 101,-30 antigen may be a useful marker of both normal and leukemic hematopoietic differentiation.