Effects of herpes simplex virus on structure and function of nectin-1/HveC.
Herpes simplex virus (HSV) entry requires the interaction between the envelope glycoprotein D (gD) and a cellular receptor such as nectin-1 (also named herpesvirus entry mediator C [HveC]) or HveA/HVEM. Nectin-1 is a cell adhesion molecule found at adherens junctions associated with the cytoplasmic actin-binding protein afadin. Nectin-1 can act as its own ligand in a homotypic interaction to bridge cells together. We used a cell aggregation assay to map an adhesive functional site on nectin-1 and identify the effects of gD binding and HSV early infection on nectin-1 function. Soluble forms of nectin-1 and anti-nectin-1 monoclonal antibodies were used to map a functional adhesive site within the first immunoglobulin-like domain (V domain) of nectin-1. This domain also contains the gD-binding site, which appeared to overlap the adhesive site. Thus, soluble forms of gD were able to prevent nectin-1-mediated cell aggregation and to disrupt cell clumps in an affinity-dependent manner. HSV also prevented nectin-1-mediated cell aggregation by occupying the receptor. Early in infection, nectin-1 was not downregulated from the cell surface. Rather, detection of nectin-1 changed gradually over a 30-min period of infection, as reflected by a decrease in the CK41 epitope and an increase in the CK35 epitope. The level of detection of virion gD on the cell surface increased within 5 min of infection in a receptor-dependent manner. These observations suggest that cell surface nectin-1 and gD may undergo conformational changes during HSV entry as part of an evolving interaction between the viral envelope and the cell plasma membrane.
Krummenacher
Claude
C
Department of Microbiology, School of Dental Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA. krumm@biochem.dental.upenn.edu
Baribaud
Isabelle
I
Sanzo
James F
JF
Cohen
Gary H
GH
Eisenberg
Roselyn J
RJ
D000818:Animals; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002449:Cell Aggregation; D005434:Flow Cytometry; D006561:Herpes Simplex / Q000821:virology; D006801:Humans; D051379:Mice; D000075983:Nectins; D018139:Simplexvirus / Q000378:metabolism* / Q000472:pathogenicity; D014407:Tumor Cells, Cultured; D014759:Viral Envelope Proteins
D015815:Cell Adhesion Molecules; C000619010:NECTIN1 protein, human; C000619015:Nectin1 protein, mouse; D000075983:Nectins; D014759:Viral Envelope Proteins; C039447:glycoprotein D, Human herpesvirus 1