CD278, also known as ICOS (inducible co-stimulator), is a single-pass type I transmembrane glycoprotein that belongs to the CD28/CTLA4 (cytotoxic T lymphocyte-associated antigen 4, or CD152) family of the immunoglobulin (Ig) superfamily.  Like other family members, CD28, CTLA4 and PD-1, CD278/ICOS contains one Ig-like V-type domain in the extracellular region and shares 39% amino acid similarity with CD28 and CTLA­4. ICOS is expressed on most CD45RO+ cells and is up­regulated after the activation on Th primed cells. B7­H2, a member of the B7 family of co-stimulatory ligands, has been identified as the ICOS ligand (ICOSL). Optimal T cell activation and expansion are regulated by signals delivered not only through the T cell receptor (TCR), but also a number of co-stimulatory molecules, including ICOS and ICOSL. ICOS is expressed on antigen-primed T cells, and ICOSL is expressed mainly on B cells and macrophages. The interaction of B7-H2/ICOS plays critical roles in T cell dependent B cell activation and in Th cell differentiation. These T−B cell interactions are essential for germinal center formation, and humoral immune responses, and as well as the production of cytokine IL-4. In addition, ICOS also regulates TH2-mediated mucosal inflammatory responses, and aberrant expression of ICOS has been implicated in allergic inflammatory responses and other immune disorders.

CD278, also known as ICOS (inducible co-stimulator), is a single-pass type I transmembrane glycoprotein that belongs to the CD28/CTLA4 (cytotoxic T lymphocyte-associated antigen 4, or CD152) family of the immunoglobulin (Ig) superfamily.  Like other family members, CD28, CTLA4 and PD-1, CD278/ICOS contains one Ig-like V-type domain in the extracellular region and shares 39% amino acid similarity with CD28 and CTLA­4. ICOS is expressed on most CD45RO+ cells and is up­regulated after the activation on Th primed cells. B7­H2, a member of the B7 family of co-stimulatory ligands, has been identified as the ICOS ligand (ICOSL). Optimal T cell activation and expansion are regulated by signals delivered not only through the T cell receptor (TCR), but also a number of co-stimulatory molecules, including ICOS and ICOSL. ICOS is expressed on antigen-primed T cells, and ICOSL is expressed mainly on B cells and macrophages. The interaction of B7-H2/ICOS plays critical roles in T cell dependent B cell activation and in Th cell differentiation. These T−B cell interactions are essential for germinal center formation, and humoral immune responses, and as well as the production of cytokine IL-4. In addition, ICOS also regulates TH2-mediated mucosal inflammatory responses, and aberrant expression of ICOS has been implicated in allergic inflammatory responses and other immune disorders.

 

Product Details

 

Gene Symbol: ICOS; CD278; AILIM; CVID1

 

NCBI Gene ID: 29851

 

Uniprot Entry: Q9Y6W8

 

Construct Details: The recombinant human ICOS-Fc fusion protein is expressed as a 348-amino acid protein consisting of Glu21 - Lys140 region of ICOS (UniProt accession #Q9Y6W8) and a C-terminal Fc from human IgG1, which exists as a dimer under non-reducing conditions.  

 

Source:  Human cells stably expressing ICOS-Fc and growing in chemical-defined media with no animal components or antibiotics

 

Deduced Amino Acid Sequence:

EINGSANYEMFIFHNGGVQILCKYPDIVQQFKMQLLKGGQILCDLTKTKGSGNTVSIKSLKFCHSQLSNNSVSF

FLYNLDHSHANYYFCNLSIFDPPPFKVTLTGGYLHIYESQLCCQLKSTGTHTCPPCPAPELLGGPSVFLFPPKP

KDTLMISRTPEVTCVVVDVSHEDPEVKFNWYVDGVEVHNAKTKPREEQYNSTYRVVSVLTVLHQDWLNGKEYKC

KVSNKALPAPIEKTISKAKGQPREPQVYTLPPSREEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTP

PVLDSDGSFFLYSKLTVDKSRWQQGNVFSCSVMHEALHNHYTQKSLSLSPGK

M.W.: Calculated molecular mass 39.2 kDa; estimated by SDS-PAGE under reducing condition ~55 kDa probably due to glycosylation

 

Calculated PI: 7.98

 

Calculated Extinction Coefficients (M-1 cm-1, at 280nm):  46590

 

Purity: >95% judged by SDS-PAGE under reducing condition (see the gel image above)

 

Formulation: Supplied at 0.5 mg/ml in sterile PBSpH7.4 (carrier and preservative free). The purified recombinant protein was labeled with Biotin (3-5 Biotin per molecule) using the standard procedure.

 

Endotoxin Level: <0.1 EU per 1 μg of purified recombinant protein determined by the LAL method

 

Biological Activity: Binds to its ligand ICOSL/B7-H2/CD275 and inhibits human T cell proliferation induced by ICOSL in the presence of anti-CD3e antibody.

 

 

 

 

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

Restriction: This product is not transferable or re-sellable.  Customer obtain no right to transfer, assign, or sublicense its use rights, or to transfer, resell, package, or otherwise distribute the product, or to use the product for the benefit of any third party or for any commercial purpose.  Customer may only use the product in compliance with applicable local, state and federal laws, regulations and rules.  Customer may not directly or indirectly use the product or allow the transfer, transmission, export or re-export of all or any part of the product in violation of any export control law or regulation of the united states or any other relevant jurisdiction.  Your use of this product constitutes acceptance of the terms of this limited use agreement.  Please refer to our “terms & conditions” for details.  If you are not willing to accept the limitation of this agreement, G&P Biosciences will accept return of the product for a full/partial refund.

 

Storage

 

The product is shipped at 4°C. Upon receipt, centrifuge the product briefly before opening the vial. It is recommended to store small aliquots at the temperature below –20°C for long-term storage and the product is stable for at least 3 months. The undiluted protein can be stored at 4°C for no more than 2 weeks.

 

 

Use a manual defrost freezer and avoid repeated freeze-thaw cycles.

 

 

 

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

 

References

 

1. Nature 397:263 (1999).  

2. Nature 402:827 (1999). 

3. J. Immunol. 164:4689 (2000).  

4. Immunity 13:95 (2000).  

5. Nature. 409: 97 (2001).

 

 

 

Documentation

 

Product datasheet (pdf) can be downloaded here: FCL0731B-PDS.pdf

 

 

 

Additional supporting documents, including COA and MSDS are available upon request.

 

 

 

FOR RESEARCH USE ONLY. NOT FOR DIAGNOSTIC OR THERAPEUTIC USE IN HUMAN.

Restriction: This product is not transferable or re-sellable.  Customer obtain no right to transfer, assign, or sublicense its use rights, or to transfer, resell, package, or otherwise distribute the product, or to use the product for the benefit of any third party or for any commercial purpose.  Customer may only use the product in compliance with applicable local, state and federal laws, regulations and rules.  Customer may not directly or indirectly use the product or allow the transfer, transmission, export or re-export of all or any part of the product in violation of any export control law or regulation of the united states or any other relevant jurisdiction.  Your use of this product constitutes acceptance of the terms of this limited use agreement.  Please refer to our “terms & conditions” for details.  If you are not willing to accept the limitation of this agreement, G&P Biosciences will accept return of the product for a full/partial refund.