Human acute myelogenous leukemia-associated antigens defined by a monkey antiserum to glycoproteins shed from leukemia myeloblasts

Abstract

A human leukemic myeloblast-associated cell surface antigen(s) was defined by a monkey antiserum as a glycoprotein antigen released from leukemic myeloblasts in short-term culture. The antiserum, after a single absorption with normal human red blood cells and platelets, is preferentially reactive with human leukemic cells by cytotoxicity and immunofluorescence and immunoprecipitated a 75,000–80,000 daltons glycoprotein component. Erythroid and myeloid precursor cells prepared by density gradient centrifugation from normal human bone marrow aspirations did not show any significant reaction with the antiserum. Blast cells prepared from an acute myelogenous leukemia patient consistently reacted with the monkey antiserum by microcytotoxicity and immunofluorescence, whereas B-lymphocyte populations from the patient's normal identical twin in no instance reacted. In addition, the monkey antiserum retained its antimyeloblast activity following absorptions with Ia-positive cells, leukemic lymphoblasts and various non-leukemic cell populations. Thus, an antiserum that is selectively reactive with human leukemic myeloblasts has been prepared which no longer requires extensive absorption procedures to make it specific and will be a useful reagent in the definition of human acute myelogenous leukemia-associated antigens.