Fig. 1

Continual advances in identifying bnAb epitopes on HIV Env following the identification of new bnAbs. Each panel represents a key advance in the identification of new epitopes/refinement of epitopes bound by bnAbs. The Env figure is adapted from the crystal structure of the BG505 SOSIP.664 trimer (PDB: 5cez), gp120 is coloured light grey, gp41 is coloured dark grey. Approximate epitope locations are indicated by red arrows/lines and circles are color-coded for each year as shown in the key given in each panel heading. Epitopes are highlighted only once per protomer. a Pre 2009 knowledge of CD4bs, glycan and MPER epitopes gained from studying predominantly by b12, 2G12, 2F5 and 4E10 respectively. b By 2010 the trimer apex epitope had been described following discovery of PG9/16 in 2009 and the importance of angle of approach to the CD4bs highlighted by the discovery of VRC01 in 2010. c The glycan patch epitope was redefined as supersite of vulnerability by the isolation of the PGT121 and 128 families of bnAbs in 2011. d From 2014 onwards the discovery of additional bnAbs, including PGT151, 35O22 and 8ANC195, revealed a new area of bnAbs which span the gp120–gp41 interface. e In 2016 subunit interface targeting antibodies were found that also bind the gp41 fusion peptide, VRC34 and ACS202. f 2018 saw the description of bnAbs binding the highly glycosylated “silent” face of gp120 and targeting CD4bs via novel contacts with the gp120 inner domain after bypassing the Phe43 cavity