FAS Ligand Protein

Background

Fas Ligand (FASLG), also referred to as CD95L, is a type-II transmembrane protein belonging to the tumor necrosis factor (TNF) family. FASLG plays a pivotal role in regulating apoptosis, particularly in immune system homeostasis and cytotoxic T-cell-mediated killing. It binds to its receptor, Fas (CD95), triggering the formation of the death-inducing signaling complex (DISC) and initiating the caspase cascade, ultimately leading to programmed cell death. This pathway is crucial for eliminating autoreactive lymphocytes, maintaining immune tolerance, and resolving immune responses after infections. Dysregulation of FASLG-Fas signaling has been implicated in various pathological conditions, including autoimmune disorders, cancer, and chronic inflammatory diseases. In cancer, tumor cells often evade apoptosis by downregulating Fas or mutating components of the pathway. Conversely, overexpression of FASLG in the tumor microenvironment can contribute to immune evasion by inducing apoptosis in Fas-expressing tumor-infiltrating lymphocytes. Therapeutic strategies targeting FASLG or its signaling pathway are being explored for their potential in cancer immunotherapy, autoimmune disease modulation, and transplantation tolerance. Additionally, genetic polymorphisms in the FASLG gene have been associated with altered susceptibility to diseases, further highlighting its importance in immune regulation and disease pathology.