Fig 7. HFWR somatic mutations encode proline amino acids that are critical for antibody function.

(A) High mannose glycan reactivity for DH501 IgG variants where framework region prolines were reverted to their germline-encoded amino acid. Prolines selected for reversion are indicated with diamonds in Fig 6A. Prolines were reverted individually, or all four prolines were reverted in the same antibody (4 prolines). Positive glycan binding based on negative control antibody binding is shown as a filled bar. Open bars indicate negative binding values. Positivity threshold for 7, 8a, 8b, and 9 was 0.18x10⁴ for each glycan. DH501 H/UCA L which includes all four prolines was used as a positive control as shown in Fig 4. (B) CON-S SOSIP binding by SPR for each of the DH501 proline revertants. Antibody binding to buffer without envelope is shown by a dotted line (No Env). (C) DH501 proline-revertant antibody neutralization of Man₉GlcNAc₂-enriched HIV-1 JR-FL infection of TZM-bl cells.