title: Sialoadhesin binds preferentially to cells of the granulocytic lineage.
abstract: Sialoadhesin is a macrophage-restricted, sialic acid-dependent receptor of 185 kD that binds to the oligosaccharide sequence NeuAc alpha 2,3Gal on cell surface glycoconjugates. Recent cDNA cloning has shown that sialoadhesin is a new member of the immunoglobulin superfamily with sequence similarity to CD22, a sialic acid-dependent receptor of B lymphocytes. Sialoadhesin has been implicated in cellular interactions of stromal macrophages with developing myeloid cells. In this study, direct evidence for this interaction was obtained in cell-cell binding assays using both native and recombinant forms of the protein. In all assays, sialoadhesin exhibited specific, differential binding to various murine cell populations of hemopoietic origin. In rank order, sialoadhesin bound neutrophils > bone marrow cells = blood leukocytes > lymphocytes > thymocytes. Single-cell analyses confirmed that sialoadhesin selectively bound myeloid cells in complex cell mixtures obtained from the bone marrow and blood. In comparison, a recombinant Fc-chimeric form of murine CD22 showed high binding to B and T lymphocytes, but very low binding to immature and mature myeloid cells. These results are consistent with the notion that sialoadhesin in involved in interactions with granulocytes at different stages of their life histories.
authors.affiliation: Imperial Cancer Research Fund Laboratories, University of Oxford, John Radcliffe Hospital, United Kingdom.
authors.forename: P R
authors.initials: PR
authors.lastname: Crocker
authors.forename: S
authors.initials: S
authors.lastname: Freeman
authors.forename: S
authors.initials: S
authors.lastname: Gordon
authors.forename: S
authors.initials: S
authors.lastname: Kelm
mesh_terms: D000818:Animals; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D015815:Cell Adhesion Molecules / Q000276:immunology / Q000378:metabolism; D002460:Cell Line; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D018076:DNA, Complementary; D000939:Epitopes / Q000032:analysis; D004912:Erythrocytes / Q000276:immunology* / Q000378:metabolism; D005260:Female; D006001:Glycoconjugates / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D006098:Granulocytes / Q000276:immunology* / Q000378:metabolism; D007140:Immunoglobulin Fab Fragments / Q000494:pharmacology; D007074:Immunoglobulin G / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D008562:Membrane Glycoproteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D011971:Receptors, Immunologic / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D063267:Sialic Acid Binding Ig-like Lectin 1; D014162:Transfection
chemical_list: D015815:Cell Adhesion Molecules; D018076:DNA, Complementary; D000939:Epitopes; D006001:Glycoconjugates; D007140:Immunoglobulin Fab Fragments; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D011971:Receptors, Immunologic; D011994:Recombinant Proteins; D063267:Sialic Acid Binding Ig-like Lectin 1; C571167:Siglec1 protein, mouse