MY-1, A NEW MYELOID-SPECIFIC ANTIGEN IDENTIFIED BY A MOUSE MONOCLONAL-ANTIBODY

Abstract

Antibody-secreting hybridomas were produced by fusion of P3-NS1/1Ag-4-1 mouse plasmacytoma cells with splenocytes from a mouse immunized with HL-60 human promyelocytic leukemia cells. A cloned hybridoma cell line was identified that secreted antibody against a cell surface antigen expressed on all normal human peripheral blood granulocytes, on bone marrow granulocytic precursor cells, and on blast cells from 3 of 15 patients with nonlymphoid leukemia. The antibody did not react with normal peripheral blood lymphocytes, monocytes, platelets, red cells or blast cells from 20 patients with acute lymphoblastic leukemia of from 5 patients with lymphoma. This monoclonal antibody identified a granulopoietic differentiation antigen (designated My-1) and may prove useful in the subclassification of nonlymphoid leukemia and in hematopoiesis investigation.