• Purity

  >97%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.

• Endotoxin Level

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

• Activity

  Measured by its binding ability in a functional ELISA. When Recombinant Human (rh) 4-1BB/TNFRSF9/CD137 Fc Chimera (Catalog # ) is Immobilized at 10 ng/mL (100 µL/well), the concentration of rh4-1BB Ligand that produces 50% optimal binding response is found to be approximately 0.5‑2.5 ng/mL.

• Source

  E. coli-derived Arg71-Glu254, with an N-terminal Met and a 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Met

• Predicted Molecular Mass

  20.4 kDa

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: 4-1BB Ligand/TNFSF9

4-1BB Ligand (4-1BBL), also known as CD137L, is a type II transmembrane protein that belongs to the TNF superfamily of molecules and plays an important role in immune response activation (1). The 38 kDa human 4-1BB Ligand consists of an 25 aa cytoplasmic domain, a 23 aa transmembrane segment, and a 206 aa extracellular domain (ECD) (2). Within the ECD, human 4-1BB Ligand shares 34% aa sequence identity with mouse and rat 4-1BB Ligand. 4-1BB Ligand is expressed by activated B cells, monocytes, macrophages, dendritic cells (DC), T cells, lymphoma and multiple myeloma cells, hematopoietic stem cells, early myeloid progenitors, neurons, and astrocytes (3-9). A 26 kDa soluble form of 4-1BB Ligand can be released from the surface of activated cells and retains bioactivity (10).  
4-1BB Ligand binds to 4-1BB/TNFRSF9/CD137 on activated CD4  ⁺ and CD8  ⁺ T cells, thymocytes, and NK cells as well as on monocytes, neutrophils, DC, and eosinophils. In response to 4-1BB Ligand binding, 4-1BB transduces a co-stimulatory signal that promotes the proliferation, activation, and survival of CD4  ⁺ and CD8  ⁺ T cells (4, 11, 12). T cell co-stimulation through CD28 is important for the initial T cell expansion, while 4-1BB acts later in the response (12, 13). 4-1BB Ligand function supports the survival and responsiveness of memory T cells during viral infection (13-15). Reverse signaling through 4-1BB Ligand on monocytes induces the production of inflammatory cytokines (5). On macrophages, 4-1BB Ligand associates in cis with TLR4 and enhances inflammatory cytokine production in response to TLR4 ligation (6). Its expression on early myeloid progenitor cells limits the development of dendritic cells, monocytes, and B cells (9).

• References:

1. Wang, C. et al. (2009) Immunol. Rev. 229:192.

2. Alderson, M.R. et al. (1994) Eur. J. Immunol. 24:2219.

3. Reali, C. et al. (2003) J. Neurosci. Res. 74:67.

4. DeBenedette, M.A. et al. (1997) J. Immunol. 158:551.

5. Langstein, J. et al. (1998) J. Immunol. 160:2488.

6. Kang, Y.J. et al. (2007) Nat. Immunol. 8:601.

7. Baessler, T. et al. (2010) Blood 115:3058.

8. Gullo, C. et al. (2010) PLoS One 5:e10845.

9. Lee, S.-W. et al. (2008) Nat. Immunol. 9:917.

10. Salih, H.R. et al. (2001) J. Immunol. 167:4059.

11. Wen, T. et al. (2002) J. Immunol. 168:4897.

12. Cannons, J.L. et al. (2001) J. Immunol. 167:1313.

13. Bertram, E.M. et al. (2002) J. Immunol. 168:3777.

14. Bukczynski, J. et al. (2004) Proc. Natl. Acad. Sci. USA 101:1291.

15. Lin, G.H.Y. et al. (2009) J. Immunol. 182:934.

• Entrez Gene IDs:

  8744 (Human); 21950 (Mouse); 353218 (Rat)

• Alternate Names:

  41BB Ligand; 4-1BB Ligand; 4-1BBL; 4-1BB-L; CD137L; homolog of mouse 4-1BB-L; receptor 4-1BB ligand; TNFSF9; tumor necrosis factor (ligand) superfamily, member 9; tumor necrosis factor ligand superfamily member 9