Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41

Charles Sabin, Davide Corti, Victor Buzon, Mike S. Seaman, David Lutje Hulsik, Andreas Hinz, Fabrizia Vanzetta, Gloria Agatic, Chiara Silacci, Lara Mainetti, Gabriella Scarlatti, Federica Sallusto, Robin Weiss, Antonio Lanzavecchia, Winfried Weissenhorn

Research output: Contribution to journalArticle

58 Citations (Scopus)

Abstract

The human monoclonal antibody (mAb) HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1) of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for Cclade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

Original languageEnglish
Article numbere1001195
JournalPLoS Pathogens
Volume6
Issue number11
DOIs
Publication statusPublished - Nov 2010

Fingerprint

HIV-1
Monoclonal Antibodies
Epitopes
Immunoglobulin G
Antibodies
Viruses
Serum
Therapeutics

ASJC Scopus subject areas

  • Microbiology
  • Parasitology
  • Virology
  • Immunology
  • Genetics
  • Molecular Biology

Cite this

Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41. / Sabin, Charles; Corti, Davide; Buzon, Victor; Seaman, Mike S.; Hulsik, David Lutje; Hinz, Andreas; Vanzetta, Fabrizia; Agatic, Gloria; Silacci, Chiara; Mainetti, Lara; Scarlatti, Gabriella; Sallusto, Federica; Weiss, Robin; Lanzavecchia, Antonio; Weissenhorn, Winfried.

In: PLoS Pathogens, Vol. 6, No. 11, e1001195, 11.2010.

Research output: Contribution to journalArticle

Sabin, C, Corti, D, Buzon, V, Seaman, MS, Hulsik, DL, Hinz, A, Vanzetta, F, Agatic, G, Silacci, C, Mainetti, L, Scarlatti, G, Sallusto, F, Weiss, R, Lanzavecchia, A & Weissenhorn, W 2010, 'Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41', PLoS Pathogens, vol. 6, no. 11, e1001195. https://doi.org/10.1371/journal.ppat.1001195
Sabin, Charles ; Corti, Davide ; Buzon, Victor ; Seaman, Mike S. ; Hulsik, David Lutje ; Hinz, Andreas ; Vanzetta, Fabrizia ; Agatic, Gloria ; Silacci, Chiara ; Mainetti, Lara ; Scarlatti, Gabriella ; Sallusto, Federica ; Weiss, Robin ; Lanzavecchia, Antonio ; Weissenhorn, Winfried. / Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41. In: PLoS Pathogens. 2010 ; Vol. 6, No. 11.
@article{375be78b23414632bc5aeef54968de8e,
title = "Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41",
abstract = "The human monoclonal antibody (mAb) HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1) of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 {\AA} resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for Cclade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.",
author = "Charles Sabin and Davide Corti and Victor Buzon and Seaman, {Mike S.} and Hulsik, {David Lutje} and Andreas Hinz and Fabrizia Vanzetta and Gloria Agatic and Chiara Silacci and Lara Mainetti and Gabriella Scarlatti and Federica Sallusto and Robin Weiss and Antonio Lanzavecchia and Winfried Weissenhorn",
year = "2010",
month = "11",
doi = "10.1371/journal.ppat.1001195",
language = "English",
volume = "6",
journal = "PLoS Pathogens",
issn = "1553-7366",
publisher = "Public Library of Science",
number = "11",

}

TY - JOUR

T1 - Crystal structure and size-dependent neutralization properties of HK20, a human monoclonal antibody binding to the highly conserved heptad repeat 1 of gp41

AU - Sabin, Charles

AU - Corti, Davide

AU - Buzon, Victor

AU - Seaman, Mike S.

AU - Hulsik, David Lutje

AU - Hinz, Andreas

AU - Vanzetta, Fabrizia

AU - Agatic, Gloria

AU - Silacci, Chiara

AU - Mainetti, Lara

AU - Scarlatti, Gabriella

AU - Sallusto, Federica

AU - Weiss, Robin

AU - Lanzavecchia, Antonio

AU - Weissenhorn, Winfried

PY - 2010/11

Y1 - 2010/11

N2 - The human monoclonal antibody (mAb) HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1) of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for Cclade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

AB - The human monoclonal antibody (mAb) HK20 neutralizes a broad spectrum of primary HIV-1 isolates by targeting the highly conserved heptad repeat 1 (HR1) of gp41, which is transiently exposed during HIV-1 entry. Here we present the crystal structure of the HK20 Fab in complex with a gp41 mimetic 5-Helix at 2.3 Å resolution. HK20 employs its heavy chain CDR H2 and H3 loops to bind into a conserved hydrophobic HR1 pocket that is occupied by HR2 residues in the gp41 post fusion conformation. Compared to the previously described HR1-specific mAb D5, HK20 approaches its epitope with a different angle which might favor epitope access and thus contribute to its higher neutralization breadth and potency. Comparison of the neutralization activities of HK20 IgG, Fab and scFv employing both single cycle and multiple cycle neutralization assays revealed much higher potencies for the smaller Fab and scFv over IgG, implying that the target site is difficult to access for complete antibodies. Nevertheless, two thirds of sera from HIV-1 infected individuals contain significant titers of HK20-inhibiting antibodies. The breadth of neutralization of primary isolates across all clades, the higher potencies for Cclade viruses and the targeting of a distinct site as compared to the fusion inhibitor T-20 demonstrate the potential of HK20 scFv as a therapeutic tool.

UR - http://www.scopus.com/inward/record.url?scp=79251506314&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79251506314&partnerID=8YFLogxK

U2 - 10.1371/journal.ppat.1001195

DO - 10.1371/journal.ppat.1001195

M3 - Article

C2 - 21124990

AN - SCOPUS:79251506314

VL - 6

JO - PLoS Pathogens

JF - PLoS Pathogens

SN - 1553-7366

IS - 11

M1 - e1001195

ER -