• Purity

  >97%, by SDS-PAGE under reducing conditions and visualized by silver stain

• Endotoxin Level

  <0.10 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to compete with biotinylated recombinant human GITR Ligand for binding to immobilized recombinant human GITR Fc Chimera.

• Source

  Spodoptera frugiperda,     Sf 21 (baculovirus)-derived Glu74-Ser199, with an N-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  His

• Predicted Molecular Mass

  15 kDa

• SDS-PAGE

  14 kDa-16 kDa, reducing conditions

Carrier Free

What does CF mean?

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

What formulation is right for me?

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: GITR Ligand/TNFSF18

GITR Ligand, also known as TNFSF18 and TL6, is an approximately 30 kDa type II transmembrane glycoprotein in the TNF superfamily (1). Human GITR Ligand consists of a 50 amino acid (aa) cytoplasmic domain, a 21 aa transmembrane segment, and a 128 aa extracellular domain (ECD) (2, 3). Within the ECD, human GITR Ligand shares 56% and 60% aa sequence identity with mouse and rat GITR Ligand, respectively. GITR Ligand is expressed on antigen presenting cells, CD4^-CD8^- double negative thymic precursors, vascular endothelial cells, neurons, and in the eye (4 ‑ 11). Its expression is transiently up‑regulated by proinflammatory stimulation (4, 8, 11). The binding of GITR Ligand to GITR on mouse CD25⁺ Treg cells permits the reactivation of T cells from Treg-induced suppression, although this does not appear to occur in humans (5, 9, 12 - 14). GITR Ligand binding to GITR additionally provides a costimulatory signal to activated CD4⁺  and CD8⁺ T cells and NK cells (5, 6, 15, 16). This interaction also induces reverse signaling in GITR Ligand expressing dendritic cells to suppress cellular activation through the same pathway induced by the immunosuppressant dexamethasone (17). In the brain, GITR Ligand/GITR interactions enhance NGF-mediated neurite outgrowth from sympathetic neurons (10).

• References:

1. Azuma, M. (2010) Crit. Rev. Immunol. 30:547.

2. Kwon, B. et al. (1999) J. Biol. Chem. 274:6056.

3. Gurney, A.L. et al. (1999) Curr. Biol. 9:215.

4. Stephens, G.L. et al. (2004) J. Immunol. 173:5008.

5. Tone, M. et al. (2003) Proc. Natl. Acad. Sci. 100:15059.

6. Hanabuchi, S. et al. (2006) Blood 107:3617.

7. Kamimura, Y. et al. (2009) J. Immunol. 182:2708.

8. Hwang, H. et al. (2010) J. Neurosci. Res. 88:2188.

9. Tuyaerts, S. et al. (2007) J. Leukoc. Biol. 82:93.

10. O’Keefe, G.W. et al. (2008) Nat. Neurosci. 11:135.

11. Kim, B.J. et al. (2004) Invest. Ophthalmol. Vis. Sci. 45:3170.

12. Shimizu, J. et al. (2002) Nat. Immunol. 3:135.

13. Ji, H. et al. (2004) J. Immunol. 172:5823.

14. McHugh, R.S. et al. (2002) Immunity 16:311.

15. Kanamaru, F. et al. (2004) J. Immunol. 172:7306.

16. Ronchetti, S. et al. (2004) Eur. J. Immunol. 34:613.

17. Grohmann, U. et al. (2007) Nat. Med. 13:579.

• Long Name:

  Glucocorticoid Induced TNF Receptor Family Related Gene Ligand

• Entrez Gene IDs:

  8995 (Human); 240873 (Mouse)

• Alternate Names:

  Activation-inducible TNF-related ligand; AITRLMGC138237; GITR Ligand; GITRLglucocorticoid-induced TNFR-related protein ligand; Glucocorticoid-induced TNF-related ligand; hGITRLGITR ligand; TL6AITR ligand; TNFSF18; tumor necrosis factor (ligand) superfamily, member 18; tumor necrosis factor ligand superfamily member 18