Biolegend, 798704, Biotinylated Recombinant Human B7-H2 (ICOSL)-Fc Chimera (carrier-free), 25μg

ICOSL (B7-H2) belongs to the B7 family of immunoregulatory molecules and is a transmembrane glycoprotein of approximately 60 kD. Mature human B7-H2 consists of a 238 amino acid extracellular domain (ECD), two immunoglobulin-like domains, a 21 amino acid transmembrane segment, and a 25 residue cytoplasmic domain. Within the ECD, human B7-H2 shares 50% and 54% amino acid sequence identity with mouse and rat B7-H2, respectively. B7-H2 is expressed on antigen presenting cells such as B cells, macrophages, dendritic cells, and also in monocytes. It binds to ICOS and is expressed on activated T cells, which leads to both positive and negative effects on immune responses including its own downregulation. Mouse and human B7-H2 exhibit cross species binding to ICOS. 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, and germinal centers. In addition, human B7-H2 binds to CD28 and CTLA4.  The interaction of human B7-H2 and CD28 can costimulate both human and mouse naïve T cells and regulatory T cells (Treg). B7-H2 plays a role in the development of allergic asthma by enhancing Th2 biased immune responses, limiting Th17 responses, and promoting eosinophilic infiltration into the lungs. B7-H2 activation of ICOS on Tregs limits pulmonary inflammation and airway hyper-responsiveness, promotes the development of inhalational tolerance, and impairs anti-tumor immunity.
25μg
Source: Human B7-H2, amino acids (Asp19-Ser258) (Accession# O75144.2), with a linker (GS), a C-terminal human IgG1 (Pro100-Lys330) and an Avi-tag, was expressed in CHO cells. Human ICOSL-Avi tag was site-specifically biotinylated by enzyme BirA.
Molecular Mass: The 488 amino acid recombinant protein has a predicted molecular mass of approximately 54.58 kD. The DTT-reduced and non-reduced protein migrates at approximately 80 kD and 150 kD by SDS-PAGE, respectively. The predicted N-terminal amino acid is Asp.
Purity: > 95%, as determined by Coomassie stained SDS-PAGE.
Formulation: 0.22 µm filtered protein solution is in PBS, 5% glycerol.
Endotoxin Level: Less than 0.1 EU per µg cytokine as determined by the LAL method.
Concentration: 25 µg size is bottled at 200 µg/mL. 100 µg size and larger sizes are lot-specific and bottled at the concentration indicated on the vial. To obtain lot-specific concentration and expiration, please enter the lot number in our Certificate of Analysis online tool.
Storage & Handling: Unopened vial can be stored between 2°C and 8°C for up to 2 weeks, at -20°C for up to six months, or at -70°C or colder until the expiration date. For maximum results, quick spin vial prior to opening. The protein can be aliquoted and stored at -20°C or colder. Stock solutions can also be prepared at 50 – 100 µg/mL in appropriate sterile buffer, carrier protein such as 0.2 – 1% BSA or HSA can be added when preparing the stock solution. Aliquots can be stored between 2°C and 8°C for up to one week and stored at -20°C or colder for up to 3 months. Avoid repeated freeze/thaw cycles.
Activity: Biotinylated recombinant human B7-H2 (ICOSL)-Fc binds to immobilized human ICOS in a dose dependent manner. HRP Avidin (Cat. No. 405103) was used to detect the binding). The ED50 for this effect is 2 – 10 ng/mL.
Application: Bioassay
Application Notes: BioLegend carrier-free recombinant proteins provided in liquid format are shipped on blue-ice. Our comparison testing data indicates that when handled and stored as recommended, the liquid format has equal or better stability and shelf-life compared to commercially available lyophilized proteins after reconstitution. Our liquid proteins are validated in-house to maintain activity after shipping on blue ice and are backed by our 100% satisfaction guarantee. If you have any concerns, contact us at [email protected].
Structure: Homodimer
Distribution: B cells, macrophages, monocytes, and dendritic cells
Function: The B7-H2/ICOS signal transduction induces T cell proliferation and secretion of both Th1 and Th2 cytokines, such as IL-4 and IFN-γ, but not IL-2 ( it also induces IL-5 and TNF-α production). B7-H2/ICOS signal may favor the induction of Th2-type responses and thus may be involved in the negative regulation of cell-mediated immune responses against tumors. B7-H2 is induced by TNF-α in B cells and monocytes and downregulated in dendritic cells.
Ligand/Receptor: ICOS (CD278)
Bioactivity: Measured by its ability to bind recombinant human ICOS
Cell Type: Dendritic cells, Tregs
Biology Area: Cell Adhesion, Cell Biology, Costimulatory Molecules, Immunology, Signal Transduction
Molecular Family: Soluble Receptors, TCRs
Antigen References: Ishikawa K, et al. 1998. DNA Res. 5:169-76. Yoshinaga SK, et al. 2000. Int. Immunol. 12:1439-47. Flesch IE, 2003. J Biol Regul Homeost Agents. 16:217-9. Akbari O, et al. 2002. Nat. Med. 8:1024-32. Yao S, et al. 2011. Immunity. 34:29-40.
Gene ID: 23308
UniProt: View information about B7-H2 on UniProt.org
Regulatory Status: RUO
Other Names: B7 homolog 2 (B7H2), GL50, B7 related protein 1 (B7RP1), CD275, inducible T cell costimulator ligand ICOS Ligand), LICOS, ICOSLG