title: Encapsidation of host-derived factors correlates with enhanced infectivity of Sindbis virus.
abstract: The genus Alphavirus consists of a group of enveloped, single-stranded RNA viruses, many of which are transmitted by arthropods to a wide range of vertebrate host species. Here we report that Sindbis virus (SINV) produced from a representative mammalian cell line consists of at least two unique particle subpopulations, separable on the basis of virion density. In contrast, mosquito-derived SINV consists of a homogeneous population of particles. Our findings indicate that the denser particle subpopulation, SINV(Heavy), is more infectious on a per-particle basis than SINV(Light). SINV produced in mosquito cell lines (SINV(C6/36)) exhibited particle-to-PFU ratios similar to those observed for SINV(Heavy). In mammalian cells, viral RNA was synthesized and accumulated more rapidly following infection with SINV(Heavy) or SINV(C6/36) than following infection with SINV(Light), due partly to enhanced translation of viral genomic RNA early in infection. Analysis of the individual particle subpopulations indicated that SINV(Heavy) and SINV(C6/36) contain host-derived factors whose presence correlates with the enhanced translation, RNA synthesis, and infectivity observed for these particles.
authors.affiliation: Department of Biology, Indiana University, Bloomington, Indiana, USA.
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: Sokoloski
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Snyder
authors.forename: Natalia H
authors.initials: NH
authors.lastname: Liu
authors.forename: Chelsea A
authors.initials: CA
authors.lastname: Hayes
authors.forename: Suchetana
authors.initials: S
authors.lastname: Mukhopadhyay
authors.forename: Richard W
authors.initials: RW
authors.lastname: Hardy
mesh_terms: D018354:Alphavirus Infections / Q000635:transmission* / Q000821:virology; D000818:Animals; D002478:Cells, Cultured; D006224:Cricetinae; D003432:Cross-Linking Reagents; D009033:Culicidae / Q000821:virology*; D005347:Fibroblasts / Q000473:pathology / Q000821:virology*; D057809:HEK293 Cells; D054884:Host-Pathogen Interactions; D006801:Humans; D047468:Immunoprecipitation; D007668:Kidney / Q000473:pathology / Q000821:virology*; D051379:Mice; D016133:Polymerase Chain Reaction; D012367:RNA, Viral / Q000235:genetics; D012845:Sindbis Virus / Q000472:pathogenicity*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D053586:Virus Internalization; D014779:Virus Replication
chemical_list: D003432:Cross-Linking Reagents; D012367:RNA, Viral