• Purity

  >95%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.1 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its binding ability in a functional ELISA. Immobilized rmICOS/Fc Chimera at 1 µg/mL (100 µL/well) can bind biotinylated rhB7-H2/Fc Chimera with a linear range of 0.156-10 ng/mL.    
     Optimal dilutions should be determined by each laboratory for each application.  

• Source

  Spodoptera frugiperda,     Sf 21 (baculovirus)-derived

  Mouse ICOS (Glu21-Leu142) Accession # NP_059508	IEGRMD	Human IgG1 (Pro100-Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Glu21

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  44 kDa (monomer)

• SDS-PAGE

  47 kDa, reducing conditions

Background: ICOS

Mouse ICOS (inducible co-stimulator), also called AILIM (activiation-inducible lymphocyte immunomediatory molecule) and CRP-1 (CD28-related protein-1), is a member of the growing CD28 family of immune costimulatory receptors. Other family members are CD28, CTLA-4 and PD-1. Mouse ICOS is a homodimeric type I transmembrane protein consisting of 200 amino acids (aa) with a putative 20 aa signal sequence, a 122 aa extracellular domain, a 23 aa transmembrane region, and a 35 aa cytoplasmic domain. ICOS shares approximately 39% amino acid similarity with CD 28 and CTLA-4. Mouse and human ICOS share approximately 72% amino acid identity. ICOS is expressed on most CD45RO⁺ cells. ICOS expression is up-regulated within approximately 24 - 48 hours of activation on T_h primed cells. B7-H2, a member of the B7 family of costimulatory ligands, has been identified as the ICOS ligand. The B7-H2/ICOS interaction appears to play roles in T cell dependent B cell activation and T_h differentiation.

• References:

1. Coyle, A.J. and J.C. Gutierrez-Ramos (2001) Nat. Immunol. 2:203.

2. Mages, H.W. et al. (2000) Eur. J. Immunol. 30:1040.

3. Yoshinaga, S.K. et al. (1999) Nature 402:827.

4. Hutloff, A. et al. (1999) Nature 397:263.

5. Aicher, A. et al. (2000) J. Immunol. 164:4689.

6. Coyle, A.J. et al. (2000) Immunity 13:95.

7. Gonzalo, J.A. et al. (2001) J. Immunol. 166:1.

• Long Name:

  Inducible Co-stimulator

• Entrez Gene IDs:

  29851 (Human); 54167 (Mouse); 102116512 (Cynomolgus Monkey)

• Alternate Names:

  Activation-inducible lymphocyte immunomediatory molecule; AILIM; AILIMCD278; CD278 antigen; CD278; CRP-1; CVID1; ICOS; inducible costimulator; inducible T-cell costimulator; inducible T-cell co-stimulator; MGC39850