Source

Human ICOS, Fc Tag (H-ICOS-1) is expressed from human 293 cells (HEK293). It contains AA Glu 21 - Phe 141 (Accession # NP_036224).

Predicted N-terminus: Glu 21

Molecular Characterization

This protein carries a human IgG1 Fc tag at the C-terminus.

Endotoxin

Less than 0.01 EU/mg by the LAL method.

Purity

>95% as determined by SDS-PAGE.

Bioactivity

ELISA ；

BIACORE (With our Research Grade Biosimilar Antibody products);

Formulation

Lyophilized from 0.22 μm filtered solution in 50 mM Tris, 100 mM Glycine, pH7.5. Normally trehalose is added as protectant before lyophilization.

Reconstitution

Please see Certificate of Analysis for specific instructions.

For best performance, we strongly recommend you to follow the reconstitution protocol provided in the CoA.

Storage

For long term storage, the product should be stored at lyophilized state at -20°C or lower.

Please avoid repeated freeze-thaw cycles.

No activity loss was observed after storage at:

4-8°C for 12 months in lyophilized state;

-70°C for 3 months under sterile conditions after reconstitution.

Background

Inducible T-cell costimulator (ICOS) is also known as Activation-inducible lymphocyte immunomediatory molecule (AILIM), CD278, which belongs to the CD28 family of immune costimulatory receptors consisting of CD28, CTLA-4 and PD-1. ICOS enhances all basic T-cell responses to a foreign antigen, namely proliferation, secretion of lymphokines, up-regulation of molecules that mediate cell-cell interaction, and effective help for antibody secretion by B-cells. CD278 / ICOS prevents the apoptosis of pre-activated T-cells and also plays a critical role in CD40-mediated class switching of immunoglobin isotypes.

Reference

(1) Hutloff A., et al., 1999, Nature 397:263-266.

(2) Tezuka K., et al., 2000, Biochem. Biophys. Res. Commun. 276:335-345.

(3) Beier K.C., et al., 2000, Eur. J. Immunol. 30:3707-3717.