Figure 6. Enhanced ADCC activity of λdS relative to λ in A431 cells overexpressing receptor X (A431x). An LDH release based ADCC assay was performed to assess the difference in percent of target A431x cell lysis by PBMCs effector cells in the presence of either λ or λdS antibody. (A) ADCC activities of λ and λdS antibodies with an effector to target (E:T) ratio = 25:1. (B) ADCC activities of λ and λdS antibodies with an E:T = 100:1. A luminescence reporter assay was used to compare the Jurkat effector cell activation by λ and λdS upon binding to A431x (E:T = 20:1). (C) Effector cell activation was measured in luminescence relative light unit (RLU) by λ or λdS antibody in the presence of the target A431x cells. (D) Effector cell activation fold increase in RLU (calculated from dividing the maximal RLU by the background RLU) of λ and λdS antibodies. All measurements were done in duplicate or triplicate. SD are indicated by error bars.