4-1BB Ligand (4-1BBL) is a transmembrane cytokine that belongs to the tumor necrosis factor (TNF) ligand family. 4-1BBL is a bidirectional signal transducer that acts as a ligand for TNFRSF9, a costimulatory receptor in T lymphocytes. TNFSF9 and its TNFRSF9 participate in the antigen presentation development and the generation of cytotoxic T cells. 4-1BBR is absent from resting T lymphocytes but rapidly expressed upon antigenic stimulation. TNFSF9 reactivates anergic T lymphocytes as well as promoting T lymphocyte proliferation. 4-1BB Ligand is necessary for the optimal CD8 responses in CD8 T cells. 4-1BBL is expressed in carcinoma cell lines and is considered to be involved in T cell-tumor cell interaction. 4-1BBL is expressed by activated B cells, macrophages, dendritic cells, activated T cells, neurons and astrocytes. The binding of 4-1BB with TNFRSF9 strongly regulates immunity and has been proposed to preferentially control T cell responses based on studies in various murine.

Expression System
Escherichia coli

Sequence
MREGPELSPDDPAGLLDLRQGMFAQLVAQNVLLIDGPLSWYSDPGLAGVSLTGGLSYKEDTKELVVAKAGVYYVFFQLELRRVVAGEGSGSVSLALHLQPLRSAAGAAALALTVDLPPASSEARNSAFGFQGRLLHLSAGQRLGVHLHTEARARHAWQLTQGATVLGLFRVTPEIPAGLPSPRSE with polyhistidine tag at the C-terminus.

Species
Human

Tag
polyhistidine tag at the C-terminus

Endotoxin Level
<0.1 EU per 1 μg of the protein by the LAL method.

Activity
Measure by its ability to induce IL-8 secretion in human PBMCs.
The ED₅₀ for this effect is 1-5 ng/mL.

Purity
>95% as determined by SDS-PAGE. Ni-NTA chromatography

Formulation
The protein was lyophilized from a solution containing 1X PBS containing, pH 7.4.

Reconstitution

• Unopened ampoules can be stored at -20°C or -80°C.
• Need not spin the ampoule. Open the cap carefully, then dissolve the lyophilized protein with sterile water for a 100 μg/mL concentration or acc ording to the product’s Certificate of
• Analysis (CoA). (Note: Need not add carrier* to the initial reconstitution solution).
• Rinse the inner side of the ampoule gently and stand for at least 20 minutes at room temperature. (Important Note: Do Not Vortex!)
• Use the reconstituted solution immediately or store it by distributing it to aliquots and store at -20 °C. (Important Note: Avoid repeated freeze-thaw cycles)
• We recommend diluting the solution to working concentration by using buffers or medium containing a carrier*. (Important Note: Do not dilute the working solution with water, which may cause protein degradation.)

*Carriers: 0.1% BSA or 5% HSA or 10% FBS.

SDS-PAGE analysis of recombinant 4-1BBL