Recombinant Human Fas Ligand (FasL)

Fas ligand (FasL), also known as TNFSF6, is a type II transmembrane protein that belongs to the tumor necrosis factor (TNF) family and is involved in membrane mediated apoptosis. The specific receptor for FasL is Fas (CD95, Apo-1). FasL is primarily expressed on activated T cells and NK cells, while Fas is expressed on various types of cells. Ligation of Fas by FasL triggers activation of the caspase cascade. Functional impairment of the Fas/FasL system is associated with the development and progression of malignancies. Tumor cells frequently exhibit de novo expression of FasL, which plays a significant role in local tissue destruction, metastatic spread and immune escape of the tumor cells.¹ The apoptosis of lymphocytes, which occurs in autoimmune diseases, is usually induced by the Fas/FasLsystem, therefore, FasL is regarded as a potential target for immunotherapy.² One study has suggested a correlation between high levels of FasL expression in the cornea and successful corneal transplantation.³

The biological activity of Human Soluble Fas Ligand is determined by its ability to induce cytotoxicity in Jurkat cells. The expected ED₅₀ for this effect is <1.0 - 3.0 ng/ml, in the presence of 10 µg/ml of a cross-linking antibody.

Histidine Tag

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Met

Lyophilized

The predicted molecular weight of Recombinant Human Fas Ligand is Mr 18 kDa. However, the actual molecular weight as observed by migration on SDS-PAGE is Mr 19 - 32 kDa (reducing conditions).

18

This recombinant protein was 0.2 µm filtered and lyophilized from modified Dulbecco’s phosphate buffered saline (1X PBS) pH 7.2 – 7.3 with no calcium, magnesium, or preservatives.

This lyophilized protein is stable for six to twelve months when stored desiccated at -20°C to -70°C. After aseptic reconstitution, this protein may be stored at 2°C to 8°C for one month or at -20°C to -70°C in a manual defrost freezer. Avoid Repeated Freeze Thaw Cycles. See Product Insert for exact lot specific storage instructions.

Next Day Ambient

1. Igney, FH. et al. (2005) Cancer Immunol. Immunother. 54:1127
2. Ottmar, J. et al. (2008) Cell Communication and Signaling 6:11
3. Stuart, P. et al. (1997) J. Clin. Investigation 99:396