Fig. 7

Effect of escape mutations on the neutralization and binding properties of mAb 17b. A–B Neutralization activity of 17b IgG against HIV-1 pseudotyped with wild type and resistant Envs from strains NL4-3 (A) and HxBc2 (B). Data reflect the mean and standard deviation of five independent experiments. C Binding isotherms of 17b to wild type, V255I and V255I/S143N monomeric gp120 variants obtained by ITC. Solid lines represent fits to a single-site binding model. Data represent mean and range of mean of two independent experiments performed. D Thermodynamic parameters free energy, enthalpy and entropy extracted from the fits in C. The data in C and D are derived from a single binding experiment for each condition. The titrations were repeated with quantitatively similar results. E–G Biacore 3000 sensorgrams depicting 17b interaction with immobilized monomeric gp120: WT (E), V255I (F) and V255I/S143N (G). The global fits to two replicates, as defined in Materials and Methods, are shown as red lines. The binding parameters derived are summarized in Table 5