title: Global mapping of antibody recognition of the hepatitis C virus E2 glycoprotein: Implications for vaccine design.
abstract: The E2 envelope glycoprotein is the primary target of human neutralizing antibody response against hepatitis C virus (HCV), and is thus a major focus of vaccine and immunotherapeutics efforts. There is emerging evidence that E2 is a highly complex, dynamic protein with residues across the protein that are modulating antibody recognition, local and global E2 stability, and viral escape. To comprehensively map these determinants, we performed global E2 alanine scanning with a panel of 16 human monoclonal antibodies (hmAbs), resulting in an unprecedented dataset of the effects of individual alanine substitutions across the E2 protein (355 positions) on antibody recognition. Analysis of shared energetic effects across the antibody panel identified networks of E2 residues involved in antibody recognition and local and global E2 stability, as well as predicted contacts between residues across the entire E2 protein. Further analysis of antibody binding hotspot residues defined groups of residues essential for E2 conformation and recognition for all 14 conformationally dependent E2 antibodies and subsets thereof, as well as residues that enhance antibody recognition when mutated to alanine, providing a potential route to engineer E2 vaccine immunogens. By incorporating E2 sequence variability, we found a number of E2 polymorphic sites that are responsible for loss of neutralizing antibody binding. These data and analyses provide fundamental insights into antibody recognition of E2, highlighting the dynamic and complex nature of this viral envelope glycoprotein, and can serve as a reference for development and rational design of E2-targeting vaccines and immunotherapeutics.
authors: Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850; pierce@umd.edu sfoung@stanford.edu.
authors: Brian G
authors: BG
authors: Pierce
authors: Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305.
authors: Zhen-Yong
authors: ZY
authors: Keck
authors: Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305.
authors: Patrick
authors: P
authors: Lau
authors: INSERM, U1110, Institute de Recherche sur les Maladies Virales et Hépatiques, 67000 Strasbourg, France.|Université de Strasbourg, 67000 Strasbourg, France.
authors: Catherine
authors: C
authors: Fauvelle
authors: Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850.
authors: Ragul
authors: R
authors: Gowthaman
authors: INSERM, U1110, Institute de Recherche sur les Maladies Virales et Hépatiques, 67000 Strasbourg, France.|Université de Strasbourg, 67000 Strasbourg, France.|Institut Hopitalo-Universitaire, Pôle Hépato-Digestif, Hôpitaux Universitaires de Strasbourg, 67000 Strasbourg, France.
authors: Thomas F
authors: TF
authors: Baumert
authors: Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850.
authors: Thomas R
authors: TR
authors: Fuerst
authors: Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850.
authors: Roy A
authors: RA
authors: Mariuzza
authors: Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305; pierce@umd.edu sfoung@stanford.edu.
authors: Steven K H
authors: SKH
authors: Foung
keywords: HCV; alanine scanning; clustering; hotspots; immune recognition