VSIG4 Antibody (528912) [Unconjugated]

Recombinant Human Siglec-7/Fc protein (1138-SL) binds to HEK293 human embryonic kidney cell line transfected with recombinant human VSIG4 and eGFP. (A) Binding is completely blocked by 50 µg/mL of Mouse Anti-Human VSIG4 Monoclonal Antibody (Catalog # MAB46462) but not by (B) Mouse IgG2A Isotype Control (MAB003). Protein binding was detected with Mouse Anti-Human IgG Fc APC-conjugated Monoclonal Antibody (FAB110A). Staining was performed using our Staining Membrane-Associated Proteins protocol.

VSIG4 blockade impairs C3b induced macrophages polarization. A Uniform manifold approximation and projection (UMAP) of single-cell RNA-seq from human decidual immune cells isolated from patients with RSA and healthy controls. The single-cell RNA sequencing data used in this study were previously published by Guo [9]. B Feature plot showed ICAM1 and VSIG4 expression in the different clusters between Ctrl vs. RSA as defined in (A). C Gene expression levels of VSIG4 and ICAM1 in decidual macrophages from normal pregnancies and RSA patients. D CLSM images showing the expression of VSIG4 protein in decidual macrophages from normal pregnancies and RSA patients. Scale bars = 5 μm. E Statistical histogram of VSIG4 mean fluorescence intensity of each decidual macrophages from normal pregnancies (n = 3) and RSA patients (n = 3). F Gene expression levels of IL1B, IL6 and TNF in macrophages with or without the addition of VSIG4 blocking antibody during co-culture with dNK. G Representative mean fluorescence intensity of CD80 (upper panel) or CD206 (lower panel) in macrophages with or without the addition of VSIG4 blocking antibody during co-culture with dNK. Experiments were repeated for 3 independent times. P values have been determined by two-tailed paired t-test Image collected and cropped by CiteAb from the following open publication (//translational-medicine.biomedcentral.com/articles/10.1186/s12967-024-05829-w), licensed under a CC-BY license. Not internally tested by R&D Systems.

dNK cells from normal pregnancy express the natural ligand of VSIG4. A Gene expression levels of VSIG4 in peripheral blood NK cells (pNK), peripheral blood monocytes (pM), decidual macrophages (dM), and decidual NK cells (dNK). B Fluorescence image depicting the expression of VSIG4 protein on decidual macrophages. C Biological processes that are significantly enriched in Sankey dot pathway enrichment analysis of the upregulated genes of dNK relative to pNK. D Heat map of differential genes in complement and coagulation cascade pathways, n = 3 per group. E Gene set enrichment analysis (GSEA) revealed an increase in complement and coagulation cascade pathways (enrichment plot: COMPLEMENT AND COAGULATION CASCADES PATHWAYS, HSA04610) in dNK cells compared with pNK cells, n = 3 per group. F qPCR validation of the differential expression of the C3 gene in dNK cells and pNK cells. G CLSM images showing the secretion of C3b in pNKs and dNKs. The images were captured using the same parameters. Scale bars = 5 μm. H Statistical histogram of C3b mean fluorescence intensity of each decidual or peripheral NK cell. P values have been determined by two-tailed unpaired t-test Image collected and cropped by CiteAb from the following open publication (//translational-medicine.biomedcentral.com/articles/10.1186/s12967-024-05829-w), licensed under a CC-BY license. Not internally tested by R&D Systems.

• Reactivity: Hu
• Applications: B/N
• Clone: 528912
• Clonality: Monoclonal
• Host: Mouse
• Conjugate: Unconjugated

VSIG4 Antibody (528912) [Unconjugated] Summary

• Immunogen: Mouse myeloma cell line NS0-derived human VSIG4
  Arg20-Pro283
  Accession # Q9Y279
• Specificity: Detects human VSIG4 in direct ELISAs.
• Source: N/A
• Isotype: IgG2a
• Clonality: Monoclonal
• Host: Mouse
• Purity Statement: Protein A or G purified from hybridoma culture supernatant

Applications/Dilutions

• Dilutions:
  • Blockade of Receptor-ligand Interaction 50 ug/mL

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 6 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied either lyophilized or as a 0.2 µm filtered solution in PBS.
• Reconstitution Instructions: Reconstitute at 0.5 mg/mL in sterile PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for VSIG4 Antibody (528912) [Unconjugated]

• CRIg
• Ig superfamily protein
• Protein Z39Ig
• V-set and immunoglobulin domain containing 4
• V-set and immunoglobulin domain-containing protein 4
• VSIG4
• Z39IG
• Z39IGcomplement receptor of the immunoglobulin superfamily

Background

VSIG4 (Vset and immunoglobulin domain containing 4), also known as complement receptor immunoglobulin (CRIg) and Z39IG, is a 45 kDa, type I transmembrane protein of the B7 family within the Ig superfamily that is expressed only in tissue resident macrophages (1-4). The gene is located on the X chromosome (2). The human VSIG4 cDNA encodes 399 amino acids (aa) including a 19 aa signal sequence, a 264 aa extracellular domain (ECD) containing a V-type and a C2-type Ig domain, a 21 aa transmembrane domain and a 95 aa cytoplasmic domain (3). The human VSIG4 ECD shares 84% aa identity with canine VSIG4. Within the IgV domain, it shares 90%, 80% and 78% aa identity with bovine, mouse and rat VSIG4, respectively; these animals lack the C2-type domain. Splice isoforms of 321, 305, 272, 201 and 199 aa lack all or part of the cytoplasmic domain, the C2-type Ig domain and/or the transmembrane domain (5). VSIG4 is specifically expressed on macrophages in the thymic medulla, peritoneum, alveoli, synovia, adipose and heart, liver Kupffer cells, placental Hofbauer cells, and atherosclerotic foam cells (1-4, 6-9). It is absent on infiltrating macrophages (8). VSIG4 is a complement receptor that binds C3b and iC3b fragments, internalizes them to recycling endosomes, and is recycled to the cell surface (4, 6). It contributes significantly to innate immunity by binding and phagocytosis of complement opsonized invading pathogens (4, 8, 10). Binding of either native or recombinant soluble VSIG4 to C3b inhibits complement amplification through the alternative, but not classical, pathway (10, 11). VSIG4 is also a negative regulator of mouse and human T cell activation (2). Although VSIG4 engagement may activate NF kappa B and thus be proinflammatory in some cases, many of its activities are important in resolving, rather than initiating, inflammation (1, 2, 7, 10, 11). There is emerging evidence in human conditions that VSIG4 may be a valuable biomarker in infection and immunity, inflammatory conditions and cancer prognosis (12, 13, 14).

1. He, J.Q. et al. (2008) Mol. Immunol. 4041.
2. Vogt, L. et al. (2006) J. Clin. Invest. 116:2817.
3. Langnaese, K. et al. (2000) Biochim. Biophys. Acta 1492:522.
4. Helmy, K. et al. (2006) Cell 124:915.
5. Entrez protein Accession # EAX05393, NP_001093901, CAI42052, CAI4205, EAX05394.
6. Tanaka, M. et al. (2008) Clin. Exp. Immunol. 154:38.
7. Lee, M.Y. et al. (2006) J. Leukoc. Biol. 80:922.
8. Gorgani, N.N. et al. (2008) J. Immunol. 181:7902.
9. Walker, M.G. (2002) Biochim. Biophys. Acta 1574:387.
10. Wiesmann, C. et al. (2006) Nature 444:217.
11. Katschke, K.J. et al. (2007) J. Exp. Med. 204:1319.
12. Small, A.G. et al. (2016) Swiss Med Wkly. 5:146.
13. Roh J. et al. (2017) Oncotarget. 8:58122.
14. Kim K.H. et al. (2016) Autophagy. 12:1647.

Limitations

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Primary Antibodies are guaranteed for 1 year from date of receipt.

Bioinformatics

• Uniprot:
  • Q9Y279()