cdw17-antigen and Leukemia--Myeloid--Acute

LacCer/CDw17 is the most abundant GSL in neutrophils. The cell-surface and intracellular presence of LacCer was determined quantitatively using anti-CDw17 mAbs in a flow cytometry assay. The quantified alterations in the level of CDw17 antigen expression are consistent with alterations in LacCer content, determined chemically. Our results show that CDw17 antigen expression defines successive stages in the maturation of the myeloid cell. The assessment of cell-surface and intracellular CDw17 expression may be useful in evaluating neutrophil physiological status.

Topics: Antigens, CD; Cell Membrane; Flow Cytometry; Humans; Lactosylceramides; Leukemia, Myelogenous, Chronic, BCR-ABL Positive; Leukemia, Myeloid, Acute; Neutrophils

The mouse hybridoma line T5A7 was derived during studies aimed at mapping human myeloid differentiation antigens. The IgM antibody secreted by this line recognizes an antigen richly expressed on mature myelomonocytic cells and on a subpopulation of lectin-activated human T-lymphocytes (Andrews, R. G., Torok-Storb, B., and Bernstein, I. D. (1983) Blood 62, 124-132). In the present study, we have determined the specificity of T5A7 antibody to be directed to lactosylceramide (Gal beta 1----4Glc beta 1----1 Cer) based on direct and indirect binding assays using a variety of glycolipids with known structures. The antibody did not cross-react with glycolipids having an N-acetyllactosamine terminus, including lactoneotetraosylceramide lactonorhexaosylceramide (i antigen), and lactoisooctaosylceramide (I antigen). The possible contribution of ceramide to the reactivity of lactosylceramide with this antibody was also studied using lactosylceramide preparations having different fatty acid composition.

Topics: Animals; Antibodies, Monoclonal; Antigen-Antibody Complex; Antigens, CD; Carbohydrates; Cell Line; Glycolipids; Glycosphingolipids; Humans; Hybridomas; Lactosylceramides; Leukemia, Myeloid, Acute; Mice; Radioimmunoassay