@article{791601d6b050401c996d8e670f51cec6,
title = "HCV Broadly Neutralizing Antibodies Use a CDRH3 Disulfide Motif to Recognize an E2 Glycoprotein Site that Can Be Targeted for Vaccine Design",
abstract = "Hepatitis C virus (HCV) vaccine efforts are hampered by the extensive genetic diversity of HCV envelope glycoproteins E1 and E2. Structures of broadly neutralizing antibodies (bNAbs) (e.g., HEPC3, HEPC74) isolated from individuals who spontaneously cleared HCV infection facilitate immunogen design to elicit antibodies against multiple HCV variants. However, challenges in expressing HCV glycoproteins previously limited bNAb-HCV structures to complexes with truncated E2 cores. Here we describe crystal structures of full-length E2 ectodomain complexes with HEPC3 and HEPC74, revealing lock-and-key antibody-antigen interactions, E2 regions (including a target of immunogen design) that were truncated or disordered in E2 cores, and an antibody CDRH3 disulfide motif that exhibits common interactions with a conserved epitope despite different bNAb-E2 binding orientations. The structures display unusual features relevant to common genetic signatures of HCV bNAbs and demonstrate extraordinary plasticity in antibody-antigen interactions. In addition, E2 variants that bind HEPC3/HEPC74-like germline precursors may represent candidate vaccine immunogens. Flyak et al. present the structures of full-length E2 ectodomains of HCV bound to two broadly neutralizing antibodies isolated from individuals who spontaneously cleared infection. The structures illustrate shared genetic signatures and a common mode of antigen recognition using CDRH3s. These results demonstrate antibody plasticity and inform lineage-targeted immunogen design.",
keywords = "E2, HCV, broadly neutralizing antibodies, disulfide bond, epitope, glycoprotein, structure",
author = "Flyak, {Andrew I.} and Stormy Ruiz and Colbert, {Michelle D.} and Tiffany Luong and Crowe, {James E.} and Bailey, {Justin R.} and Bjorkman, {Pamela J.}",
note = "Funding Information: We thank the Caltech Protein Expression Center for help with protein expression and Jens Kaiser, Christopher Barnes, Beth Stadtmueller, and Harry Gristick for training in crystallography. This research was supported by National Institutes of Health grant R01 AI127469 (to J.R.B. and P.J.B.), U19 AI088791 (to J.R.B.) (content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH) and the Molecular Observatory at Caltech supported by the Gordon and Betty Moore Foundation . A.I.F. is a Cancer Research Institute Irvington Fellow supported by the Cancer Research Institute . This research used resources of the Advanced Photon Source, Advanced Light Source, and Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory. Use of the Advanced Photon Source was supported by the U.S. Department of Energy , Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357 . The Advanced Light Source is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231 . Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515 . The SSRL Structural Molecular Biology Program is supported by the DOE Office of Biological and Environmental Research and by NIHGMS P41GM103393 . Funding Information: We thank the Caltech Protein Expression Center for help with protein expression and Jens Kaiser, Christopher Barnes, Beth Stadtmueller, and Harry Gristick for training in crystallography. This research was supported by National Institutes of Health grant R01 AI127469 (to J.R.B. and P.J.B.), U19 AI088791 (to J.R.B.) (content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH) and the Molecular Observatory at Caltech supported by the Gordon and Betty Moore Foundation. A.I.F. is a Cancer Research Institute Irvington Fellow supported by the Cancer Research Institute. This research used resources of the Advanced Photon Source, Advanced Light Source, and Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory. Use of the Advanced Photon Source was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The Advanced Light Source is a DOE Office of Science User Facility under contract no. DE-AC02-05CH11231. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, is supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Contract No. DE-AC02-76SF00515. The SSRL Structural Molecular Biology Program is supported by the DOE Office of Biological and Environmental Research and by NIHGMS P41GM103393. Publisher Copyright: {\textcopyright} 2018 Elsevier Inc.",
year = "2018",
month = nov,
day = "14",
doi = "10.1016/j.chom.2018.10.009",
language = "English (US)",
volume = "24",
pages = "703--716.e3",
journal = "Cell Host and Microbe",
issn = "1931-3128",
publisher = "Cell Press",
number = "5",
}