Antigenic Characterization of the HCMV gH/gL/gO and Pentamer Cell Entry Complexes Reveals Binding Sites for Potently Neutralizing Human Antibodies

PLoS Pathogens

Nathalie Norais¹  Alexander Leitner¹  Ethan C. Settembre²  Rachel Gerrein³  Michael A. Cianfrocco⁴  Ruedi Aebersold⁵  Yukti Aggarwal⁵  Claudio Ciferri⁵  Kristian Friedrich⁵  Sumana Chandramouli⁵  Giuseppe Palladino⁵  Danilo Donnarumma⁶  Andrea Carfi⁶ 

[1]ETH Zürich, Department of Biology, Institute of Molecular Systems Biology, Zürich, Switzerland

[2]Faculty of Science, University of Zurich, Zurich, Switzerland

[3]Harvard Medical School, Department of Cell Biology, Boston, Massachusetts, United States of America

[4]Harvard University, Department of Molecular and Cellular Biology, Cambridge, Massachusetts, United States of America

[5]Novartis Vaccines (a GSK company), Cambridge, Massachusetts, United States of America

[6]Novartis Vaccines (a GSK company), Siena, Italy

关键词: Antibodies;    Monoclonal antibodies;    Enzyme-linked immunoassays;    Human cytomegalovirus;    Binding analysis;    Cross-linking;    Cytomegalovirus infection;    Lysine;   

DOI  :  10.1371/journal.ppat.1005230

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Human Cytomegalovirus (HCMV) is a major cause of morbidity and mortality in transplant patients and in fetuses following congenital infection. The glycoprotein complexes gH/gL/gO and gH/gL/UL128/UL130/UL131A (Pentamer) are required for HCMV entry in fibroblasts and endothelial/epithelial cells, respectively, and are targeted by potently neutralizing antibodies in the infected host. Using purified soluble forms of gH/gL/gO and Pentamer as well as a panel of naturally elicited human monoclonal antibodies, we determined the location of key neutralizing epitopes on the gH/gL/gO and Pentamer surfaces. Mass Spectrometry (MS) coupled to Chemical Crosslinking or to Hydrogen Deuterium Exchange was used to define residues that are either in proximity or part of neutralizing epitopes on the glycoprotein complexes. We also determined the molecular architecture of the gH/gL/gO- and Pentamer-antibody complexes by Electron Microscopy (EM) and 3D reconstructions. The EM analysis revealed that the Pentamer specific neutralizing antibodies bind to two opposite surfaces of the complex, suggesting that they may neutralize infection by different mechanisms. Together, our data identify the location of neutralizing antibodies binding sites on the gH/gL/gO and Pentamer complexes and provide a framework for the development of antibodies and vaccines against HCMV.

【 授权许可】

CC BY