Figure 5
Kinetic explanation of Fas agonist activity. Jurkat cells were incubated with the selected antibodies or FasL for the indicated time points. Agonistic activity was monitored by caspase substrate z-DEVD cleavage. (a) Experiment performed without cross-linking the antibodies, showing the rate of caspase induction over time. Also labelled next to the relevant curve is the rate of koff (s−1) for each antibody, as determined by SPR. (b) The same experiment was performed following cross-linking of the antibodies with protein A. These experiments were performed in triplicate and error bars indicate the S.D. between replicates. (c) Schematic illustration of the difference in agonism between an antibody with relatively fast dissociation from Fas (above) and an antibody with relatively slow dissociation (below). The antibody with the faster rate of koff (above) is better able to recruit new Fas monomers and create an active signalling complex
