Anti-mouse CD137L (4-1BBL) – PE

BALB/c mouse B lymphoma line 2PK-3

This R-phycoerythrin (R-PE) conjugate is formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.4, 1% BSA and 0.09% sodium azide as a preservative.

This R-phycoerythrin (R-PE) conjugate is stable when stored at 2-8°C. Do not freeze.

Next Day Ambient

Blue Laser (488 nm) and/or Green Laser (532 nm)/Yellow-Green Laser (561 nm)

TKS-1 activity is directed against 4-1BBL (CD137L).

4-1BBL is expressed by activated B cells, macrophages, and dendritic cells.

4-1BBL (CD137L) and 4-1BB (CD137) are a receptor ligand pair belonging to the tumor necrosis factor (TNF) receptor/TNF superfamily^1,2. 4-1BBL is a type II transmembrane protein expressed by splenic B and T cells, macrophages, and dendritic cells^1-5. Members of the TNF-TNF receptor superfamily play critical roles in regulating cellular activation, differentiation, and apoptosis⁶ and the 4-1BBL-4-1BB interaction is important in cellular immune responses⁵. 4-1BBL-4-1BB interaction provides a co-stimulatory signal to T cells, resulting in increased proliferation and cytokine production⁵.

A TKS-1-producing hybridoma was generated by immunizing a SD rat with 4-1BBL-transfected NRK cells (rat IgG2a,κ)⁵. Splenocytes were fused with P3U1 cells and hypoxanthine–aminopterin–thymidine selection was performed. The monoclonal antibody was identified by its strong reactivity with 4-1BBL-transfected L5178Y cells, cloned by limiting diffusion, purified from ascites, and found to bind to 4-1BBL/NRK and 4-1BBL/P815 cells⁵.

Pre-incubation with TKS-1 blocks 4-1BB–Ig binding to 4-1BBL/L5178Y cells, indicating TKS-1 is specific to mouse 4-1BBL and can interrupt the interaction between 4-1BBL and 4-1BB⁵. Additionally, TKS-1 can block anti-CD3-stimulated T cell proliferation co-stimulated by 4-1BBL /P815 cells. The monoclonal antibodies 19H3 and TKS-1 bind to different sites on murine 4-1BBL, with TKS-1 binding to a site that overlaps with the receptor binding site⁷. Additionally, TKS-1 and 4-1BB bind to a similar site, making TKS-1 especially useful for blocking studies.

4-1BB (CDw137)

1. Goodwin RG, Din WS, Davis-Smith T, et al. Eur. J. Immunol. 23:2631-2641. 1993.
2. Alderson MR, Smith CA, Tough TW, et al. Eur. J. Immunol. 24:2219-2227. 1994.
3. Pollok KE, Kim YJ, Hurtado J, et al. Eur J Immunol. 24(2):367-374. 1994.
4. DeBenedette MA, Shahinian A, Mak TW, et al. J. Immunol. 158:551-559. 1997.
5. Futagawa T, Akiba H, Kodama T, et al. Int Immunol. 14(3):275-286. 2002.
6. Smith CA, Farrah T, Goodwin RG. Cell 76:959-962. 1994.
7. Mbanwi AN, Lin GHY, Wang KC, et al. J Immunol Methods. 450:81-89. 2017.
8. Zheng G, Wang B, Chen A. J Immunol. 173(4):2428-2434. 2004.
9. Madireddi S, Eun SY, Lee SW, et al. J Exp Med. 211(7):1433-1448. 2014.
10. Shrestha S, Noh JM, Kim SY, et al. Oncoimmunology. 5(1):e1067744. 2015.
11. Kang SW, Lee SC, Park SH, et al. Cancer Res. 77(21):5989-6000. 2017.