HIV envelope V3 region mimic embodies key features of a broadly neutralizing antibody lineage epitope.

Fera, Daniela; Lee, Matthew S; Wiehe, Kevin; Meyerhoff, R Ryan; Piai, Alessandro; Bonsignori, Mattia; Aussedat, Baptiste; Walkowicz, William E et al. · Nat Commun · 2018

basic_science · Level V

Where this comes from

Abstract

HIV-1 envelope (Env) mimetics are candidate components of prophylactic vaccines and potential therapeutics. Here we use a synthetic V3-glycopeptide ("Man<sub>9</sub>-V3") for structural studies of an HIV Env third variable loop (V3)-glycan directed, broadly neutralizing antibody (bnAb) lineage ("DH270"), to visualize the epitope on Env and to study how affinity maturation of the lineage proceeded. Unlike many previous V3 mimetics, Man<sub>9</sub>-V3 encompasses two key features of the V3 region recognized by V3-glycan bnAbs-the conserved GDIR motif and the N332 glycan. In our structure of an antibody fragment of a lineage member, DH270.6, in complex with the V3 glycopeptide, the conformation of the antibody-bound glycopeptide conforms closely to that of the corresponding segment in an intact HIV-1 Env trimer. An additional structure identifies roles for two critical mutations in the development of breadth. The results suggest a strategy for use of a V3 glycopeptide as a vaccine immunogen.

Medical subject headings