Purification and properties of sialoadhesin, a sialic acid-binding receptor of murine tissue macrophages.

Abstract

Macrophage subpopulations in the mouse express a lectin‐like receptor, sialoadhesin (originally named sheep erythrocyte receptor, SER), which selectively recognizes sialoglycoconjugates and is likely to be involved in cellular interactions of stromal macrophages in haematopoietic and lymphoid tissues. In this report we describe the purification and ligand specificity of sialoadhesin isolated from mouse spleen. Purified sialoadhesin, a glycoprotein of 185 kd apparent Mr, agglutinated sheep or human erythrocytes at nanomolar concentrations in a sialic acid‐dependent manner. Low angle shadowing and electron microscopy showed that sialoadhesin consisted of a globular head region of approximately 9 nm and an extended tail of approximately 35 nm. To investigate the specificity for sialic acid, we studied the interaction of sialoadhesin with derivatized human erythrocytes, glycoproteins, and glycolipids. In conclusion, sialoadhesin specifically recognizes the oligosaccharide sequence Neu5Ac alpha 2‐‐‐‐3Gal beta 1‐‐‐‐3GalNAc in either sialoglycoproteins or gangliosides. These findings imply that specific sialoglycoconjugates carrying this structure may be involved in cellular interactions between stromal macrophages and subpopulations of haematopoietic cells and lymphocytes.

Intracellular replication ofSalmonella typhimuriumstrains in specific subsets of splenic macrophagesin vivo

“…Both of these markers are expressed by, but are not restricted to, macrophages. The scavenger receptor and sialoadhesin markers detected here are apparently restricted to macrophages (Hughes et al, 1995;Crocker et al, 1991), but immature splenic dendritic cells can also express F4/80 (Leenen et al, 1998). Our work provides direct evidence showing that the majority of S. typhimurium bacteria reside within splenic macrophages, but it is also possible that a proportion of dendritic cells may be colonized.…”

“…Three monoclonal antibodies raised in the same host (F4/80, anti-scavenger receptor/ 2F8 and anti-sialoadhesin/CD169) were pooled to provide a pan-macrophage marker. The F4/80 antibody recognizes mature macrophages mainly in the red pulp of the spleen (Austyn and Gordon, 1981;Hume et al, 1983), whereas the 2F8 and anti-sialoadhesin antibodies recognize different subsets of spleen marginal zone macrophages (Crocker and Gordon, 1989;Crocker et al, 1991;Fraser et al, 1993;Hughes et al, 1995). In all experiments, appropriate isotype controls were included for gate setting.…”

Recombinant human lactoferrin expressed in glycoengineered Pichia pastoris: effect of terminal N-acetylneuraminic acid on in vitro secondary humoral immune response

“…This would suggest that reconstruction of MTX-inhibited secondary humoral immune response requires interaction of LF with cells expressing neuraminic dependent receptors. The prime candidate for such a receptor is sialoadhesin, a sialic acid-binding receptor, found on murine tissue macrophages [10,14,28] and dendritic cells [4], and perhaps the CD22 marker on B cells that bears sequence similarity to sialoadhesin [20]. Nevertheless, the use of specific anti-sialoadhesin antibody, with no apparent crossreactivity with CD22, makes such a possibility very unlikely.…”

True

“…44 Changes in the sialylation pattern of cell surface structures during malignancies are also reported. 1,[10][11][12][13][14]17,18 The present study identifies two biomarkers, 9-OAcSGs, appearing exclusively on leukemic blasts of ALL patients employing ATN H as an analytical probe. ATN H selectively binds to leukemic blasts (Figure 2a) inducing their 11-fold increased agglutination as compared to PBMC of normal donors (Table 2).…”

“…9 Lectins or lectin-like proteins endowed with the ability to bind sialoglycoconjugates have been used as recognition molecules to predict changes in the pattern of sialylation and the degree of O-acetylation during malignant transformation. [10][11][12][13] Binding studies with Sambuccus nigra agglutinin (SNA) state de novo expression of specific sialic acids on selected glycoproteins in colon carcinoma. 14 Employing Ricinus cummunis agglutinin, the granulocytes of patients with chronic myelogenous leukemia (CML) are reported to contain more sialylated glycopeptides than normal granulocytes.…”