Traditionally researchers have studied the interactions between Fas and FasL using soluble FasL (sFasL) or anti-Fas monoclonal antibodies (mAbs). Now Lake Placid, N.Y.-based Upstate Biotechnology Inc. offers a less expensive and more potent research tool-a bioactive, lyophilized form of FasL on membranous vesicles.
FasL, a TNF superfamily member, is a mediator of immune responses, and the Fas/FasL system plays a pivotal role in T-cell development and clonal deletion of self-reactive T cells. Binding of FasL to its receptor activates death domain proteins, which in turn activate various caspase family members.1 The caspases, which are cysteine-dependent, aspartate-specific proteases, target specific enzymes involved in cell function, leading to cell death.
Upstate Biotechnology's preparation of FasL-expressing membranous vesicles, developed from recombinant human full-length FasL, exerts a much higher cytotoxic and apoptotic activity than that of other FasL tools.2 According to Upstate Biotechnology's John Ficele, this makes membrane-bound FasL more cost-effective than other FasL ...
