Expression of an Antigen Associated With Acute Lymphoblastic Leukemia in Human Leukemia-Lymphoma Cell Lines

Thirty human hematopoietic cell lines were studied for the presence of a cell-surface antigen on the non-T-, non-B-cells of acute lymphoblastic leukemia (ALL), which is a major subclass leukemia of ALL. This cell-surface antigen is referred to as common ALL (cALL). Whereas 9 or 20 proved leukemia-lymphoma cell lines studied were positive for cALL antigen, all 10 normal Epstein-Barr virus-positive, B-lymphoblastoid cell lines were negative. On the basis of cell markers, the nine cALL antigen-positive cell lines could be classified as two non-T-, non-B-cell ALL's, one lymphoid-type blast crisis of chronic myelocytic leukemia, four (of a total of six) T-cell leukemia-lymphomas, and two (of a total of 10) B-cell lymphomas. Cross-absorption studies established the complete antigenic cross-reactivity of the cALL antigen on these various cell lines and fresh cALL antigenpositive leukemia cells. Although ALL's with T-cell phenotype (T-cell ALL's) were previously shown not to express the cALL antigen, we found the leukemias of 7 patients (of 89 patients with leukemias with a T-cell phenotype: positive human thymus leukemia antigen and negative B-cell-associated membrane structures detected by rabbit antisera made against human p24, 31 antigen) that resembled those four T-cell leukemia-lymphoma lines in weakly expressing the cALL antigen. Serial studies on the cell cultures demonstrated stable expression of the cALL antigen. We interpreted these results in terms of a pluripotential stem cell and/or lymphoid precursor cell association of the cALL antigen.