PMID: 21998254

Authors:

Pejchal R, Doores KJ, Walker LM, Khayat R, Huang PS, Wang SK, Stanfield RL, Julien JP, Ramos A, Crispin M, Depetris R, Katpally U, Marozsan A, Cupo A, Maloveste S, Liu Y, McBride R, Ito Y, Sanders RW, Ogohara C, Paulson JC, Feizi T, Scanlan CN, Wong CH, Moore JP, Olson WC, Ward AB, Poignard P, Schief WR, Burton DR, Wilson IA

Title:

A Potent and Broad Neutralizing Antibody Recognizes and Penetrates the HIV Glycan Shield.

Journal:

Science. 2011 Oct 13.

Abstract:

The HIV envelope (Env) protein gp120 is protected from antibody recognition by a dense glycan shield. However, several of the recently identified PGT broadly neutralizing antibodies appear to interact directly with the HIV glycan coat. Crystal structures of Fabs PGT 127 and 128 with Man(9) at 1.65 and 1.29 A resolution, respectively, and glycan binding data delineate a specific high mannose binding site. Fab PGT 128 complexed with a fully glycosylated gp120 outer domain at 3.25 A reveals that the antibody penetrates the glycan shield and recognizes two conserved glycans as well as a short beta-strand segment of the gp120 V3 loop, accounting for its high binding affinity and broad specificify. Furthermore, our data suggest that the high neutralization potency of PGT 127 and 128 IgGs may be mediated by cross-linking Env trimers on the viral surface.