Table 1. Summary of binding affinity, epitope competition and in vitro cell-killing data for Fas agonists.
|
Competition with FasL |
Competition with E09 IgG |
Jurkat cell killing |
|||||
|---|---|---|---|---|---|---|---|
| Ligand | Fas Kd, nM | IC50, nM | Max. Inh., % | IC50, nM | Max. Inh., % | EC50, nM | Efficiency, % |
| FasL | 14.0 | ND | ND | ND | ND | 7.1 | 94.0 |
| E09 | 17.0 | 1.4 | 100.0 | 0.9 | 100.0 | 0.9 | 80.0 |
| DX2 | 7.3 | 2.4 | 98.0 | 1.6 | 34.0 | 1.4 | 16.0 |
| SM1.1 | 5.2 | 5.5 | 86.0 | 1.8 | 100.0 | 4.0 | 26.0 |
The Kd values were determined by SPR analysis of binding to recombinant Fas. Each antibody was also tested for their ability to compete the Fas:FasL and the Fas:E09 interactions in biochemical competition assays to calculate an IC50 value (nM) and maximum inhibition value (%). Cell viability assays were performed on Jurkat cells using a titration of anti-Fas molecules to determine the maximal killing efficiency (%) and EC50 (nM)