Figure 4. Evaluating agonist activity of c-Met antibodies. (A) Epitope class 2 but not epitope class 1 antibodies display partial agonist activity in the cellular c-Met activation assay. Various concentrations of HGF, c-Met antibodies (including those from epitope classes 1 and 2 and AF276) or KLH antibodies were added to A549 cells for 15 min and induction of phosphoMet was determined by capture ELISA with PY20 as the detection antibody. Each group represents triplicate samples, and values are means ± SD (B and C) CE-310083 does not promote c-Met-dependent tubular morphogenesis of HepG2 cells. HepG2 cells were treated with HGF, epitope class 2 antibody CE-310083, AF276 or KLH antibodies for 4 d and tubule length (B, dLength/cArea) and number (C, dCount/cArea) were determined. Values are means ± SD of 5 sample groups per treatment condition.