Fas-Ligand ELISA

Formerly sold as BE51921. Fas (Apo 1; CD95) is a type I membrane protein that belongs to the TNF/nerve growth factor receptor family. Fas mediates apoptosis, the programmed cell death, when it is cross-linked with specific binding partners. The natural binding partner of Fas is its ligand, FasL, which is a 37 kDa type II-membrane protein that belongs to the TNF family which includes TNF, lymphotoxin, TNF-related apoptosis-inducing ligand (TRAIL), CD40 ligand, CD27 ligand, CD30 ligand, and OX40 ligand. FasL is predominantly expressed on activated T-cells and NK cells, thus FasL-mediated cell death is involved in the T or NK cell-mediated cytotoxicity, some pathologic tissue damages, and the regulation of lymphocyte homeostasis. A soluble form of FasL (sFasL) is naturally produced by metalloproteinase- mediated processing. The soluble form resulting from this cleavage was shown to induce apoptosis in susceptible. Several lines of evidence suggest that sFasL may be involved in the pathogenesis of tissue injury. Circulating sFasL is elevated in the serum of patients with various diseases. Markedly elevated levels of sFasL have been shown in TEN (Toxic Epidermal Necrolysis, Lyell’s Syndrom) patients’ sera. FasL furthermore turned out to be a sensor for DNA damage in skin cancer. Elevated expression levels of FasL have been measured in various proliferative disorders and cancers like esophageal carcinomas metastasizing colorectal tumors, hepatocellular carcinoma, multiple myeloma, sarcoma, Non-Hodgkin’s lymphoma and nasal lymphoma. Liver dysfunction was shown to be paralleled by increased sFasL levels as well as kidney damage. FasL is discussed to be involved in the pathogenesis of autoimmune diseases, especially the concentrations of sFasL are remarkably higher in the sera and synovial fluids of patients with severe rheumatoid arthritis as compared to normal controls. Increased levels of soluble FasL in the serum of graft-versus-hostdisease patients make it a good marker for treatment of the disease. Levels of soluble Fas Ligand in bronchoalveolar lavage (BAL) fluid of humans with acute lung injury (ARDS) and serum levels in congestive heart failure and Multiple organ failure were significantly higher than in healthy controls. Cerebrospinal fluid from patients with severe brain injury contains high concentrations of FasL. Elevations of serum FasL levels in hematological disorders and HIV infections are furthermore described. Synonyms: TNF ligand superfamily member 6, Fas antigen ligand, CD178 antigen, Apoptosis antigen ligand, CD95 ligand