Multiple Correspondence Analysis on Amino Acid Properties within the Variable Region of the Capsid Protein Shows Differences between Classical and Virulent Systemic Feline Calicivirus Strains.

Sylvie Brunet,Daniel Pialot,Hervé Poulet,Cécile Sigoillot-Claude

doi:10.3390/v11121090

Sylvie Brunet, Daniel Pialot + Show 2 more

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https://doi.org/10.3390/v11121090

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Abstract

Feline calicivirus (FCV) is a widespread and highly prevalent pathogen of domestic cats, responsible for mild upper respiratory tract disease. Outbreaks of severe virulent systemic disease (VSD) associated with FCV infection have been reported worldwide. VSD FCV strains have a broader tropism and cause a systemic vascular compromise. Despite clear differences in the pathogenesis of VSD and oral respiratory infections, attempts to identify specific molecular markers of VSD strains on the major capsid protein VP1 have failed. Region E of VP1 is responsible for the interaction with the cell receptor Junctional Adhesion Molecule JAM-1 (FeJAM-1) and with VP2 minor capsid protein during the entry of the virus. We carried out an original analysis on the sequences from region E of VSD and classical strains. A Multiple Correspondence Analysis was performed on a Boolean matrix built by coding sequences on the basis of their amino acid properties. For the first time, this approach was able to differentiate VSD and classical FCV. Seven remarkable residue positions were shown to be statistically significant for pathotype differentiation, mainly located in the N-terminal hypervariable part of region E. As structural analysis suggested an interaction of these residues with FeJAM-1 or VP2, post-binding events, and specific conformational changes may explain the difference of pathogenesis between pathotypes.

Highlights

Feline Calicivirus (FCV) is a small RNA non-enveloped virus belonging to the Caliciviridae family.The single strand RNA genome contains three open reading frames (ORF) coding for non-structural proteins (ORF1), VP1 major capsid protein (ORF2), and VP2 minor capsid protein (ORF3) respectively.The T = 3 icosahedral capsid is made of 90 dimers of VP1 [1]
11.8 software and sur-impressed in order to localize the amino acids highlighted by Multiple Correspondence Analysis (MCA) analysis and Thetheir alignment of interactions region E of the Feline calicivirus (FCV) residues strains isinshown
Strains reported to be isolated from a cat with upper-respiratory tract disease may be found to be hypervirulent when inoculated to cats, like strain 393 used in a vaccine efficacy study [48]. Another possible cause of unsuccessful clustering might be mutations of the isolate during passages in cell culture before sequencing. This is the first study describing a method to discriminate between virulent systemic disease (VSD) and ORD FCV isolates

Summary

Introduction

Feline Calicivirus (FCV) is a small RNA non-enveloped virus belonging to the Caliciviridae family. The single strand RNA genome contains three open reading frames (ORF) coding for non-structural proteins (ORF1), VP1 major capsid protein (ORF2), and VP2 minor capsid protein (ORF3) respectively. The T = 3 icosahedral capsid is made of 90 dimers of VP1 [1]. VP2 is incorporated into the virion at a lower copy-number [2]. FCV displays a remarkable genetic and antigenic diversity [3,4,5,6].

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