Figure 5.

Fab arm exchange reduces antibody-mediated C3b deposition. Bispecific IgG1 and IgG4 variants were generated by half molecule exchanging anti-biotin and anti-trinitrophenyl (TNP) clones (both normal galactosylation) with IgG1 K409R adalimumab and IgG4 natalizumab respectively under mild reduction conditions. C3b deposition by (A) anti-biotin and (B) anti-TNP monospecific (full dots) and bispecific (empty dots) IgG1 and IgG4 in the presence of either TNPlated (1 mM 2,4,6-trinitrobenzenesulfonic acid) or biotinylated (240 μM biotin) human serum albumin and 2.5% human serum was tested. Binding to either biotin or TNP was measured for all variants (right panel). All experiments were performed at least three times, shown are representative figures.