The Effects of Somatic Hypermutation on Neutralization and Binding in the PGT121 Family of Broadly Neutralizing HIV Antibodies
Figure 10
Antibody 3H+3L likely crosslinks between trimers.
(A) 3H+3L binds an epitope overlapping with those of PGT121, PGT128, and 2G12 as shown by competition of biotinylated antibody 3H+3L with an antibody panel. Binding assays were performed by flow cytometry on JR-FLΔCT isolate transfected in 293T cells. (B) IgG and Fab fragments were tested for binding on JR-FLΔCT isolate expressed on transfected 293T cells and no substantial differences in avidity were observed. Solid lines represent IgG and dashed lines represent Fab fragments. (C) Purified IgGs of 3H+3L and PGT121 were digested into Fab fragments using Lys-C, purified, and tested for neutralization on a cross-clade panel. Loss of neutralization was found for 3H+3L Fab, but not for PGT121 Fab. Reported values are IC50 ratios of Fab compared to IgG using the equation: (IC50 Fab)∶(IC50 IgG).