Recombinant Rat B7-H3 Fc Chimera Protein, CF

Recombinant Rat B7-H3 Fc Chimera (Catalog # 10610-B3) inhibits Mouse CD3 epsilon Antibody (Clone # 145-2C11, MAB484) induced proliferation of Mouse T cells. The ED50 for this effect is 0.06-0.54 µg/mL.

2 μg/lane of Recombinant Rat B7-H3 Fc Chimera Protein (Catalog # 10610-B3) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 66-76 kDa and 132-152 kDa, respectively.

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

Recombinant Rat B7-H3 Fc Chimera Protein, CF Summary

• Details of Functionality:

  Measured by its ability to inhibit Mouse CD3 epsilon Antibody induced proliferation of Mouse T cells. The ED₅₀ for this effect is 0.06-0.54 µg/mL.

• Source: Mouse myeloma cell line, NS0-derived rat B7-H3 protein
  

  Rat B7-H3 (Val29-Phe244) Accession # Q7TPB4.1	IEGRMD	Human IgG1 (Pro100-Lys330)
  N-terminus		C-terminus

• Accession #: Q7TPB4.1
• N-terminal Sequence: Val29
• Structure / Form: Disulfide-linked homodimer
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 50 kDa.
  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: 66-76 kDa, under 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: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 500 μg/mL in PBS.

Notes

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

Alternate Names for Recombinant Rat B7-H3 Fc Chimera Protein, CF

• B7H3
• B7-H3
• B7H34Ig-B7-H3
• B7-H3B7 homolog 3
• CD276 antigen
• CD276 molecule
• CD276
• Costimulatory molecule

Background

B7 homolog 3 (B7-H3), also known as CD276 antigen (CD276), is one member among at least 10 members of the B7 family of immune regulatory proteins within the immunoglobulin superfamily (1-3). The B7 family members all display a conserved extracellular fold but share only about 20-40 % amino acid (aa) sequence identity. Rat B7-H3 consists of an extracellular domain (ECD) containing one V-like and one C-like Ig domain, a helical single-pass type I transmembrane domain, and a cytoplasmic domain. Two isoforms in the ECD of B7-H3 resulting from gene duplication and differential splicing have been identified: one containing four-Ig-like domains (main isoform in humans) and one containing two-Ig-like domains (only isoform in mice) (4, 5). Soluble forms of B7-H3 can result from proteinase cleavage of the isoform with two-Ig-like domains (3). Within the ECD, mature rat B7-H3 shares 92% and 98% aa sequence identity with human and mouse B7-H3, respectively. Human B7-H3 is not expressed on resting B cells, T cells, monocytes or dendritic cells, but is induced on dendritic cells and monocytes by inflammatory cytokines (6, 8). B7-H3 is also overexpressed in numerous cancers including bladder, breast and melanoma (9). Unlike other B7 family members, human B7-H3 does not bind any known members of the CD28 family of immunoreceptors and its receptor has yet to be identified. However, B7-H3 has been shown to bind an unidentified counter-receptor on activated T cells to costimulate the proliferation of CD4+ or CD8+ T cells (10). B7-H3 has also been found to enhance the induction of primary cytotoxic T lymphocytes and stimulate IFN-gamma production (6-8, 10).

1. Dong, P. et al. (2018) Front. Oncol. 8:264.
2. Castellanos, J. et al. (2017) Am. J. Clin. Exp. Immunol. 6:66.
3. Ni, L. and Dong, C. (2017) Mol. Cancer. Ther. 16:1203.
4. Shi, T. et al. (2019) Cell Death and Disease. 10: 308.
5. Tang, X. et al. (2019) Mol. Ther. Oncolytics. 14:279.
6. Chapoval, A.I. et al. (2001) Nat. Immunol. 2:269.
7. Coyle, A. and J. Gutierrez-Ramos (2001) Nat. Immunol. 2:203.
8. Prasad, D.V. et al. (2004) J Immunol. 173:2500.
9. Dong, P. et al. (2018) Front Oncol. 8:264.
10. Suh, W.K. et al. (2003) Nat Immunol. 4:899.

Bioinformatics

• Uniprot:
  • Q7TPB4.1()