|Detection of Human Siglec‑1 by Western Blot. Western blot shows lysates of SH‑SY5Y human neuroblastoma cell line and mouse lymph node tissue. PVDF membrane was probed with 1 µg/mL of Sheep Anti-Human Siglec‑1 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF5197) followed by HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). A specific band was detected for Siglec‑1 at approximately 180 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 8.|
Cell Adhesion Mediated by Siglec‑1/CD169 and Neutralization by Human Siglec‑1/CD169 Antibody. |
Recombinant Human Siglec‑1/CD169 Fc Chimera (Catalog # 5197-SL), immobilized onto a microplate, supports the adhesion of human red blood cells in a dose-dependent manner (orange line). Adhesion elicited by Recombinant Human Siglec‑1/CD169 Fc Chimera (5 µg/mL) is neutralized (green line) by increasing concentrations of Sheep Anti-Human Siglec‑1/CD169 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF5197). The ND50 is typically 1.5-7.5 µg/mL.
Siglecs are sialic acid specific I-type lectins that belong to the immunoglobulin superfamily. Structurally, they are transmembrane proteins with an N-terminal Ig-like V‑set domain followed by varying numbers of Ig-like C2-set domains (1, 2). Human Siglec-1, also known as sialoadhesin and CD169, is a 175‑185 kDa glycoprotein. It contains a 1622 amino acid (aa) extracellular domain (ECD) with one Ig-like V‑set domain and 16 Ig-like C2-set domains, a 21 aa transmembrane segment, and a 44 aa cytoplasmic domain (3). Within the ECD, human Siglec-1 shares approximately 70% aa sequence identity with mouse and rat Siglec-1. Alternate splicing generates a potentially soluble form of the ECD, and a second isoform with a substituted cytoplasmic domain. Siglec-1 expression is restricted to lymph node and splenic macrophages, plus some tissue macrophages (3). The adhesive function of Siglec-1 is supported by the N-terminal Ig-like domain which shows a selectivity for alpha 2,3‑linked sialic acid residues (3‑5). Siglec-1 binds a number of sialylated molecules including the mannose receptor, MGL1, MUC1, PSGL-1, and different glycoforms of CD43 (6‑9). Its binding capacity can be masked by endogenous sialylated molecules (10, 11). The sialylated and sulfated N-linked carbohydrates that modify Siglec-1 itself are required for ligand binding (6, 7). Siglec-1 is expressed on dendritic cells following rhinovirus exposure, and these DC promote T cell anergy (12). It is also induced on circulating monocytes during systemic sclerosis and HIV-1 infection (13‑15). Siglec-1 can trap HIV-1 particles for trans infection of permissive cells (14).
R&D Systems personnel manually curate a database that contains references using R&D Systems products. The data collected includes not only links to publications in PubMed, but also provides information about sample types, species, and experimental conditions.
2 Citations: Showing 1 - 2
Filter your results: