Recombinant Human B7-H2 Isoform 3 Fc Avi-tag Protein, CF

Recombinant Human B7-H2 Isoform 3 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-H2

B7-H2, also known as B7-related protein (B7RP1), ICOS Ligand, and CD275, is an approximately 60 kDa transmembrane glycoprotein in the B7 family of immune regulatory molecules (1). Mature human B7-H2 consists of a 238 amino acid (aa) extracellular domain (ECD) with two immunoglobulin-like (Ig-like) domains, a 21 aa transmembrane segment, and a 25 aa cytoplasmic domain (2, 3). Within the ECD, human B7-H2 shares 50% and 54% aa sequence identity with mouse and rat B7‑H2, respectively. Alternative splicing generates a long isoform (Isoform 2),  which carries a 10 aa substitution for the C-terminal 3 residues, and a short isoform (Isoform 3; this product), which lacks the first Ig-like domain (aa 18 - 134 is missing). B7-H2 is expressed on antigen presenting cells such as B cells, macrophages, monocytes, and dendritic cells (2-6). It binds to ICOS on activated T cells, leading to both positive and negative effects on immune responses including its own down-regulation (2, 4, 7). Mouse and human B7-H2 exhibit cross-species binding to ICOS (3, 6). The B7-H2 interaction with ICOS is costimulatory for T cell proliferation as well as the development of B cells, plasma cells, follicular helper T cells (T^FH) and germinal centers (2-4, 8, 9). In human but not in mouse, B7-H2 additionally binds to CD28 and CTLA4, and its interaction with CD28 can costimulate both human and mouse naïve T cells and regulatory T cells (Treg) (6). B7-H2 contributes to the development of allergic asthma by enhancing Th2 biased immune responses, limiting Th17 responses, and promoting eosinophilic infiltration into the lung (8, 10, 11). Its activation of ICOS on Treg limits pulmonary inflammation and airway hyperresponsiveness, promotes the development of inhalational tolerance, and impairs anti-tumor immunity (5, 12, 13). In contrast, its ligation of ICOS on T^FH cells can increase the severity of autoimmune symptoms (9). A soluble form of human B7-H2 is elevated in the circulation of patients with active systemic lupus erythematosus (14). In the thyroid, B7-H2 is up-regulated on thyrocytes during inflammation and promotes their proliferation and production of thryoid hormones (15).

Related Research Areas

• B Cell Activation
• Co-stimulatory and Co-inhibitory Molecules
• Co-stimulatory Molecules Associated with Tfh Cells
• Epithelial Cell Markers and Intracellular Molecules
• Regulatory T Cells (Tregs)
• Search Immune Checkpoint Targets
• Surface Ectodermal Cells