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 (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.

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

4-1BB (CDw137)

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