Inducible T Cell Costimulator, Activation-Inducible Lymphocyte Immunomediatory Molecule, Inducible T-Cell Costimulator, AILIM, Inducible T-Cell Co-Stimulator, Inducible Costimulator, CD278 Antigen, CD278, CVID1.
ICOS (inducible T-cell costimulatory) belongs to the CD28 family of immune-assisted stimulatory receptors. ICOS forms homodimers and takes a significant part in immune responses, cell-cell signaling, as well as regulation of cell proliferation. The interaction of B7-H2 / ICOS takes a vital role in T-cell differentiation, T-B cell interaction in addition to humoral immune response is essential for the formation of reproductive centers as well as the production of cytokine IL-4. Moreover, ICOS is more effective in inducing IL-10 production, a cytokine which is important for the inhibitory function of T regulatory cells. The ICOS-B7RP-1 and B7-1 / B7-2-CD28 / CTLA-4 pathways offer a significant second signal which can regulate the inhibition, activation and fine regulation of T-lymphocyte responses. ICOS stimulates the production of Th1 and Th2 cytokines, however it can also participate in the generation of Th2 cells.
ICOS produced in Sf9 Baculovirus cells is a single, glycosylated polypeptide chain containing 362 amino acids (21-140a.a.) and having a molecular mass of 40.8kDa. (Molecular size on SDS-PAGE will appear at approximately 40-57kDa). ICOS is expressed with an 242 amino acid His tag at C-Terminus and purified by proprietary chromatographic techniques.
ICOS protein solution (0.25mg/ml) contains 20mM MES buffer (pH 5.5), 40% glycerol, 2mM DTT and 1mM EDTA 0.1M NaCl.
Greater than 90.0% as determined by SDS-PAGE.
Amino acid sequence
ADPEINGSAN YEMFIFHNGG VQILCKYPDI VQQFKMQLLK GGQILCDLTK TKGSGNTVSI KSLKFCHSQL SNNSVSFFLY NLDHSHANYY FCNLSIFDPP PFKVTLTGGY LHIYESQLCC QLKLEPKSCD KTHTCPPCPA PELLGGPSVF LFPPKPKDTL MISRTPEVTC VVVDVSHEDP EVKFNWYVDG VEVHNAKTKP REEQYNSTYR VVSVLTVLHQ DWLNGKEYKC KVSNKALPAP IEKTISKAKG QPREPQVYTL PPSRDELTKN QVSLTCLVKG FYPSDIAVEW ESNGQPENNY KTTPPVLDSD GSFFLYSKLT VDKSRWQQGN VFSCSVMHEA LHNHYTQKSL SLSPGKHHHH