Ciferri, Claudio, Chandramouli, Sumana, Danilo, Donnaruma, Nikitin, Pavel, Michael A., Cianfrocco, Gerrein, Rachel, Feire, Adam, Barnett, Susan, Lilja, Anders, Rappuoli, Rino, Nathalie , Norais, Settembre, Ethan and Carfi, Andrea (2015) Structural and biochemical studies of HCMV gH/gL/gO and pentamer reveal mutually exclusive cell entry complexes. Proceedings of the National Academy of Sciences of the United States of America, 112 (6). pp. 1767-1772. ISSN 1091-6490

Abstract

Human cytomegalovirus (HCMV) is a major cause of morbidity and mortality in transplant patients and the leading viral cause of birth defects after congenital infection. The glycoprotein complexes gH/gL/gO and gH/gL/UL128/UL130/UL131A (Pentamer) are key targets of the human humoral response against HCMV and are required for HCMV entry into fibroblasts and endothelial/epithelial cells, respectively. We expressed and characterized soluble forms of gH/gL, gH/gL/gO, and Pentamer. Mass spectrometry and mutagenesis analysis revealed that gL-Cys144 forms disulfide bonds with gO-Cys351 in gH/gL/gO and with UL128-Cys162 in the Pentamer. Notably, Pentamer harboring the UL128-Cys162Ser/gL-Cys144Ser mutations had impaired syncytia formation and reduced interference of HCMV entry into epithelial cells. Electron microscopy analysis showed that HCMV gH/gL resembles HSV gH/gL and that gO and UL128/UL130/UL131A bind to the same site at the gH/gL N terminus. These data are consistent with gH/gL/gO and Pentamer forming mutually exclusive cell entry complexes and reveal the overall location of gH/gL-, gH/gL/ gO-, and Pentamer-specific neutralizing antibody binding sites. Our results provide, to our knowledge, the first structural view of gH/gL/ gO and Pentamer supporting the development of vaccines and antibody therapeutics against HCMV.

Item Type:	Article
Keywords:	GH/gL/gO HCMV Human cytomegalovirus Pentamer complex Virus entry
Date Deposited:	25 Nov 2017 00:45
Last Modified:	25 Jan 2019 00:45
URI:	https://oak.novartis.com/id/eprint/24740