Recombinant Human FASL protein

FASL (Fas ligand), a transmembrane protein belonging to the tumor necrosis factor (TNF) superfamily, plays a critical role in regulating apoptosis and immune homeostasis. It binds to the Fas receptor (CD95), triggering caspase-dependent programmed cell death, a mechanism essential for maintaining immune tolerance, eliminating damaged cells, and controlling lymphocyte populations. FASL is predominantly expressed by activated T cells, natural killer (NK) cells, and immune-privileged tissues (e.g., eyes, testes), where it enforces immune tolerance by inducing apoptosis in infiltrating inflammatory cells.

Recombinant FASL (rFASL) is engineered using genetic recombination techniques, typically produced in mammalian cell systems (e.g., HEK293) or bacteria (e.g., E. coli) to ensure proper folding and post-translational modifications. Soluble isoforms, generated by metalloproteinase-mediated cleavage or alternative splicing, are often utilized in research to study apoptotic signaling without membrane anchoring. rFASL retains bioactivity in activating Fas receptors, making it a valuable tool for investigating immune regulation, cancer biology, and autoimmune diseases. Studies explore its therapeutic potential in targeting Fas-overexpressing cancer cells or modulating hyperactive immune responses. However, systemic toxicity due to off-target apoptosis remains a challenge, prompting research into engineered variants with improved specificity or localized delivery systems. Current applications extend to in vitro models of immune cell interactions, drug screening, and mechanistic studies of apoptosis pathways. Ongoing efforts focus on optimizing rFASL stability, receptor-binding affinity, and tissue targeting to enhance its translational utility in immunotherapy and precision medicine.