The CD95 antibody in the news
CD95, also known as FAS or APO1, is a member of the tumor necrosis factor (TNF) superfamily. Early experiments with monoclonal antibodies identified it as a death receptor expressed on the membrane of a number of cell types, including tumor cells and lymphocytes. In a recent FAS antibody study, a single nucleotide variant of FAS was shown to have a possible protective role against malaria in children. We at Novus Biologicals have an extensive range of CD95/Fas antibodies on our antibody database.
CD95 initiates apoptosis following Fas-ligand (FasL/CD95L) binding, forming the death-inducing signaling complex (DISC ) via recruitment of caspase 8 and FADD. Cross-linking of CD95 using monoclonal antibodies has been shown to cause apoptosis of cells expressing CD95, in the same way that ligand-receptor binding does.
While the Fas ligand is primarily expressed on activated T cells and natural killer cells, the receptor protein is highly expressed in a number of other areas, including white blood cell types, and epithelial cells. In mice, it has been identified in heart, thymus, lung, liver, kidney and ovarian tissue. Alternatively spliced cDNAs, encoding a number of Fas isoforms, have been identified, and the Fas antibody is widely used in cancer research.
In normal cells, cell-specific apoptosis induced by the CD95/CD95 Ligand-binding mechanism plays a critical role in modulating the immune response. Defects in this pathway can be a cause of autoimmune disorders.
However, it appears that genetically altered variants may also have a beneficial role. In a joint study by Kumasi University, Ghana and the Bernhard Nocht Institute for Tropical Medicine in Hamburg, a variant at the human FAS locus was shown to prevent a potentially fatal immune response to malaria in children. Malaria is a major killer of children under the age of five in Africa, as unlike adults they do not have the immunity which prevents severe reactions to the parasite. CD95 antibodies revealed a genetic disposition in some children to overexpress CD95 on certain white blood cells, increasing apoptosis of these cells and muting the immune response.