Recombinant Human B7-H3 (4Ig)/B7-H3b Fc Avi-tag Protein, CF

Recombinant Human B7-H3 (4Ig)/B7-H3b Fc Avi-tag Protein, CF Summary

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: B7-H3

Human B7 homolog 3 (B7-H3), also known as CD276, is a member of the B7 family of immune checkpoint molecules, responsible for regulating immune responses (1‑3). There are at least seven structurally related B7 family members, all sharing about 20-40% amino acid (aa) sequence identity (4). The B7 protein family are immunoglobulin (Ig) superfamily members with varying numbers of Ig-V-like and Ig-C-like regions in the extracellular domain (ECD) and they can either be glycosylphosphatidylinositol (GPI)-linked or transmembrane (4). The mature ECD of B7-H3 contains two V-like and two C-like Ig domains, a transmembrane region, and a short cytoplasmic domain. An isoform of human B7-H3 containing only a single set of V-like and C-like Ig domains in the ECD has also been identified (1, 5). The ECD of both mouse and rat B7-H3 only contain a single set of V-like and C-like Ig domains. 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 (1, 6). B7-H3 is also overexpressed in numerous cancers including bladder, breast and melanoma (7). 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 co-stimulate the proliferation of CD4+ or CD8+ T cells (8). B7-H3 has also been found to enhance the induction of primary cytotoxic T lymphocytes and stimulate IFN-gamma production (1-3, 8).

Related Research Areas

• B Cell Activation
• Co-stimulatory and Co-inhibitory Molecules
• Dendritic Cell Co-stimulatory Molecules
• Epithelial Cell Markers and Intracellular Molecules
• Search Immune Checkpoint Targets
• Surface Ectodermal Cells