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Récepteurs et voies d'entrée d'Echovirus 6 :
Rôle des quasi-espèces virales

Abstract : Two echovirus 6 (E6) strains were isolated from a clinical sample after successive sub-cultures in PLC and HeLa cells. The first strain retained its haemagglutinating capacity (HAE6) while the second became non-haemagglutinating (NHAE6). The lack of competition between the two viral strains during coinfections suggested that each strain used a different cell entry pathway. We provide evidence showing that HAE6 used preferentially the lipid raft-dependent caveolae pathway, whereas NHAE6 followed the clathrin-mediated pathway. Comparison of the sequences of HAE6 and NHAE6 revealed 4 amino acid changes in the VP1, VP2 and VP3 capsid proteins distributed in domains which are known to be highly immunogenic or suggested to be involved in receptor binding. Virus binding assay showed that HAE6 was capable of binding to DAF-expressing cells but not NHAE6 explaining the lipid raft-dependent pathway used by HAE6 as DAF is known to be localised in lipid raft domains. We then provide evidence that HAE6 and NHAE6 replication was unaffected by neuraminidase and phospholipase C treatments suggesting that sialic acid and glycosylphosphatidylinositol-anchored proteins were not essential for infection. Significant reduction of the viral load in the presence of heparin confirmed the role of heparan sulfates as an attachment molecule for echovirus 6. Single expression of CAR, DAF or VLA-2 could not mediate echovirus 6 infection whereas co-expression of DAF and CAR rendered CHO cells susceptible to infection showing evidence of the role of CAR as an echovirus receptor. Our results confirmed that a clinical isolate can be composed of a mixture of quasispecies capable of using different routes to achieve their entry into cells.
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https://tel.archives-ouvertes.fr/tel-00174060
Contributor : Nicolas Lévêque <>
Submitted on : Friday, September 21, 2007 - 2:12:56 PM
Last modification on : Friday, October 23, 2020 - 4:38:56 PM
Long-term archiving on: : Thursday, April 8, 2010 - 8:38:05 PM

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Nicolas Lévêque. Récepteurs et voies d'entrée d'Echovirus 6 :
Rôle des quasi-espèces virales. Autre [q-bio.OT]. Université Claude Bernard - Lyon I, 2007. Français. ⟨tel-00174060⟩

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