FIGURE 4.

Binding properties of Fc-engineered hIgG1 variants toward classical hFcγRs. ELISA binding of titrated amounts (1000.0–0.5 ng/ml) of WT hIgG1 and the Fc-engineered variants to (A) hFcγRI, and calculation of relative binding of WT hIgG1 and the Fc-engineered variants to (B) hFcγRI, (C) hFcγRIIa-R131, (D) hFcγRIIa-H131, (E) hFcγRIIb, (F) hFcγRIIIa-V158, (G) hFcγRIIIa-F158, and (H) hFcγRIIIb. The experiments were performed at pH 7.4, and obtained data are shown as mean ± SEM of one experiment performed in triplicate (A), and as mean ± SEM of three independent experiments performed in triplicate (B–H). *p < 0.05, **p < 0.01, ***p < 0.001 by one-way ANOVA test.