Myeloglycan, a Series of E-Selectin-Binding Polylactosaminolipids Found in Normal Human Leukocytes and Myelocytic Leukemia HL60 Cells

Abstract

Sialosyl-LeX (SLeX) is assumed to be the binding epitope of E- and P-selectin in normal human neutrophils and myelocytic leukemia HL60 cells. Glycosphingolipid (GSL) fractions from large quantities of normal human neutrophils and HL60 cell extract did not contain SLeX GSLs having 6-10 sugar residues, as commonly found in solid tumor cells and tissues. Instead, the binding target of E-selectin was revealed to be a series of long-chain, unbranched polylactosamine GSLs with terminally sialylated, internally α1→3 polyfucosylated structure as the major component, or having SLeX at the terminus and internally polyfucosylated structure as a minor component. These GSLs are hereby collectively termed "myeloglycan." Regardless of the site of fucosylation, all myeloglycans cross-react strongly with "anti-SLeX" monoclonal antibodies such as CSLEX, FH6, SNH3, and SNH4.