Figure 4.

CEP-37247 mediates antibody-dependent cellular cytotoxicity. CEP-37247 was able to mediate ADCC of a membrane associated TNFα expressing target cell line in response to incubation with human peripheral blood mononuclear cells (PBMCs). (A) The target cells, stably transfected NS0 cells expressing membrane-associated TNFα were incubated with CEP-37247 (red line), etanercept (blue line) or IgG1 isotype control (black line) followed by fluorescein-conjugated anti-human IgG, Fc specific antibody. Following incubation, the cells were analyzed by flow cytometry. The population exhibited homogeneous fluorescence of similar intensities with both CEP-37247 and etanercept. The isotype control exhibited fluorescence comparable to background levels that were also seen for the incubation of CEP-37247, etanercept and the isotype control with untransfected NS0 host cells (data not shown). (B) The membrane associated TNFα expressing NS0 cells target cells (2 × 104 cells) were incubated with 5 × 105 PBMCs (effector cells) and increasing concentrations of either CEP-37247 (solid red circle), etanercept (solid blue square) or IgG1 isotype control (unfilled square). This is a representative dataset of three experiments using PBMCs from three different individual donors.