Immunocytological and Immunochemical Analysis on the Common Acute Lymphoblastic Leukemia Antigen (CALLA): Evidence that CALLA on ALL Cells and Granulocytes Are Structurally Related

The common acute lymphoblastic leukemia antigen(CALLA) on acute lymphoblastic leukemia(ALL) cells and granulocytes were compared by newly developed and other anti-CALLA monoclonal antibodies(anti-CALLA). New anti-CALLA(IF-3 through IF-7) were effectively selected by immunostaining on kidney sections. By competitive binding three antigenic determinants were separated on ALL cells by IF and other anti-CALLA. All three determinants existed on granulocytes although the reactivity of each anti-CALLA was variable. Such a variability was partly due to the heterogeneous terminal sialic acid compositions. Although CALLA from granulocytes and ALL cells differed in molecular weight they showed identical peptide mapping patterns. These results strongly suggest that CALLA on ALL cells and granulocytes are structurally related although they are different in posttransulational modification.