FIGURE 5.

In vitro binding of recombinant IgG2/4 hybrid Abs to complement and Fc-receptors. Increasing concentrations of rMil2 (○), r18D11 (△) or raNIP (□) were incubated with (A) immobilized human C1q, (B) the human Fcγ receptors FcγRI, (C) FcγRIIa (allotype His131), (D) FcγRIIb, (E) FcγRIIIa (allotype Val158), (F) FcγRIIIb, and (G, H) human (hFcRn) or (I, J) porcine FcRn (pFcRn) at acidic (pH 6.0) and neutral pH (pH 7.4). Human IgG1 (◇) (A–H) or porcine IgG (pIgG; ♦) (I, J) served as positive controls. Binding was measured as absorbance at 450 nm. Data are given as mean and SD (n = 3 independent experiments).