Recombinant Mouse VSIG4 Fc Chimera Protein, CF

Recombinant Mouse VSIG4 Fc Chimera (Catalog # 4674-VS) inhibits anti-CD3-induced proliferation of mouse splenicT lymphocytes. The presence of immobilized Recombinant Mouse VSIG4Fc Chimera inhibits the anti-CD3 response by ≥50%. The ED50for this effect is 1.25‑5 µg/mL.

• Reactivity: Mu
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant Mouse VSIG4 Fc Chimera Protein, CF Summary

• Details of Functionality: Measured by its ability to inhibit anti-CD3-induced proliferation of splenic T lymphocytes. Vogt, L. et al. (2006) J. Clin. Invest. 116:2817. The presence of immobilized Recombinant Mouse VSIG4 Fc Chimera inhibited the anti-CD3 response by ≥50%. The ED₅₀ for this effect is 1.25‑5 µg/mL.
• Source: Mouse myeloma cell line, NS0-derived mouse VSIG4 protein
  

  Mouse VSIG4 (His20-Pro187) Accession # NP_808457	IEGRMDP	Mouse IgG2A (Glu98-Lys330)
  N-terminus		C-terminus

• Accession #: NP_808457
• N-terminal Sequence: His20
• Structure / Form: Disulfide-linked homodimer
• Protein/Peptide Type: Recombinant Proteins
• Gene: Vsig4
• Purity: >90%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <1.0 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 46 kDa (monomer).
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 60-65 kDa, reducing conditions

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.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS.
• Purity: >90%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 200 μg/mL in sterile PBS.

Notes

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

Alternate Names for Recombinant Mouse VSIG4 Fc Chimera Protein, CF

• 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

Mouse VSIG4 (V-set and immunoglobulin domain containing 4), also known as CRIg and Z39IG, is a 45 kDa, type I transmembrane glycoprotein that is a B7 family-related protein and an Ig superfamily member (1, 2). Mouse VSIG4 is synthesized as a 280 amino acid (aa) precursor that contains a signal sequence, an IgV-type immunological domain (aa 36-115), one potential N-linked glycosylation site, and a single transmembrane domain (2). The IgV domain of mouse VSIG4 shares 86% and 80% aa sequence identity with the IgV domains of rat and human VSIG4, respectively. Quantitative PCR reveals that VSIG4 mRNA is expressed at high levels in the liver, dendritic cells, neutrophils, and macrophages, and at lower levels in the lung, heart, spleen, and lymph nodes (1). No VSIG4 expression appears to be present in T and B cells (1). The use of polyclonal rabbit serum against the extracellular domain of VSIG4 demonstrates that VSIG4 is specifically expressed on naïve resting tissue macrophages, and that the expression is downregulated or lost upon activation (1). Furthermore, histological analysis shows expression of VSIG4⁺ macrophages only in the liver, thymic medulla, and heart (1). VSIG4 macrophages are not detected in the intestines, kidney, skeletal muscle, lymph node, splenic white pulp, lung, or brain (1). Studies show that VSIG4/Fc Chimera strongly inhibits proliferation of anti-CD3 as well as anti-CD3/anti-CD28-stimulated T cells (1). Indeed, VSIG4 functions as a negative regulator of mouse as well as human T cell activation, and may be involved in the maintenance of peripheral T cell tolerance and/or unresponsiveness (1). In addition, VSIG4’s expression on Kupffer cells is required for efficient binding and phagocytosis of complement C3 opsonized particles (2). VSIG4 acts as a macrophage complement receptor by binding complement fragments C3b and iC3b (2). VSIG4 binding to C3b inhibits complement activation through the alternative pathway, making it a potent suppressor of established inflammation (3, 4).

1. Vogt, L. et al. (2006) J. Clin. Invest. 116:2817.
2. Helmy, K. et al. (2006) Cell 124:915.
3. Katschke, K.J. et al. (2007) J. Exp. Med. 204:1319.
4. Wiesmann, C. et al. (2006) Nature 444:217.

Bioinformatics

• Gene Symbol: Vsig4
• Uniprot:
  • NP_808457()