The inducible costimulator CD278 (ICOS, T cell activation molecule H4) is similar to human CD28 (24% homology), and plays an analogous role in the T cell activation process. Each secondary signal from CD28 or ICOS results in a discrete cytokine secretion profile displayed by the activated T cell.¹ Both activation processes are effectively down regulated by CD152 (CTLA-4) engagement.² Human CD275 (ICOSL, GL50, B7-H2) is a member of the B7 family sharing ~20% homology with CD80 (B7-1) and CD86 (B7-2), and has been shown to be a ligand for CD278.³ CD278-muIg recombinant protein binds to recombinant CD275-muIg in EIA.

Molecular Structure:A soluble fusion protein consisting of the extracellular (121aa) domain of mature human CD278(ICOS): eingsanyemfifhnggvqilckypdivqqfkmqllkggqilcdltktkgsgntvsikslkfchsqlsnnsvsfflynldhshanyyfcnlsifdpppfkvtltggylhiyesqlccqlkf

linker amino acids: gt

fused to murine IgG2a Fc (233 aa): eprgptikpcppckcpapnllggpsvfifppkikdvlmislspivtcvvvdvseddpdvqiswfvnnvevhtaqtqthredynstlrvvsalpiqhqdwmsgkefkckvnnkdlpapiertiskpkgsvrapqvyvlpppeeemtkkqvtltcmvtdfmpediyvewtnngktelnykntepvldsdgsyfmysklrvekknwvernsyscsvvheglhnhhttksfsrtpgk

predicted nonglycosylated monomeric molecular weight: 40.4 kd.

Transfectant Cell Line: CHO

Functional Application:CD278-muIg binds to recombinant CD275(ICOSL, GL50)-muIg in EIA.

References:

^{1Beier, K.C., R.A. Kroczek, et al. 2000, Eur J Immunol. 30(12):3707-3717.}

^{2 Riley, J.L., C.H. June, et al. 2001, J. Immunol. 166: 4943-4948.}

^{3 Ling, V., M. Collins, et al. 2000, J. Immunol. 164: 1653-1657.}

^{4 Ling, V., M. Collins, et al. 2001, J. Immunol. 166: 7300-7308.}

^{5 A.J. McAdam, et al, (2000) J Immunol 165: 5035-5040.}