title: Alterations of Nuclear Architecture and Epigenetic Signatures during African Swine Fever Virus Infection.
abstract: Viral interactions with host nucleus have been thoroughly studied, clarifying molecular mechanisms and providing new antiviral targets. Considering that African swine fever virus (ASFV) intranuclear phase of infection is poorly understood, viral interplay with subnuclear domains and chromatin architecture were addressed. Nuclear speckles, Cajal bodies, and promyelocytic leukaemia nuclear bodies (PML-NBs) were evaluated by immunofluorescence microscopy and Western blot. Further, efficient PML protein knockdown by shRNA lentiviral transduction was used to determine PML-NBs relevance during infection. Nuclear distribution of different histone H3 methylation marks at lysine's 9, 27 and 36, heterochromatin protein 1 isoforms (HP1α, HPβ and HPγ) and several histone deacetylases (HDACs) were also evaluated to assess chromatin status of the host. Our results reveal morphological disruption of all studied subnuclear domains and severe reduction of viral progeny in PML-knockdown cells. ASFV promotes H3K9me3 and HP1β foci formation from early infection, followed by HP1α and HDAC2 nuclear enrichment, suggesting heterochromatinization of host genome. Finally, closeness between DNA damage response factors, disrupted PML-NBs, and virus-induced heterochromatic regions were identified. In sum, our results demonstrate that ASFV orchestrates spatio-temporal nuclear rearrangements, changing subnuclear domains, relocating Ataxia Telangiectasia Mutated Rad-3 related (ATR)-related factors and promoting heterochromatinization, probably controlling transcription, repressing host gene expression, and favouring viral replication.
authors.affiliation: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida Universidade Técnica, 1300-477 Lisboa, Portugal. maggiesimo@gmail.com.
authors.forename: Margarida
authors.initials: M
authors.lastname: Simões
authors.affiliation: Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisboa, Portugal. joserino@medicina.ulisboa.pt.
authors.forename: José
authors.initials: J
authors.lastname: Rino
authors.affiliation: Department of Epigenetics, Max Planck Institute of Immunobiology and Epigenetics, 79108 Freiburg, Germany. inespirespinheiro@gmail.com.
authors.forename: Inês
authors.initials: I
authors.lastname: Pinheiro
authors.affiliation: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida Universidade Técnica, 1300-477 Lisboa, Portugal. cmartins@fmv.ulisboa.pt.
authors.forename: Carlos
authors.initials: C
authors.lastname: Martins
authors.affiliation: CIISA, Faculdade de Medicina Veterinária, Universidade de Lisboa, Avenida Universidade Técnica, 1300-477 Lisboa, Portugal. fernandof@fmv.ulisboa.pt.
authors.forename: Fernando
authors.initials: F
authors.lastname: Ferreira
mesh_terms: D000358:African Swine Fever Virus / Q000254:growth & development*; D000818:Animals; D002467:Cell Nucleus / Q000821:virology*; D002522:Chlorocebus aethiops; D002843:Chromatin / Q000737:chemistry* / Q000648:ultrastructure*; D044127:Epigenesis, Genetic; D054884:Host-Pathogen Interactions; D009687:Nuclear Proteins / Q000032:analysis; D014709:Vero Cells
chemical_list: D002843:Chromatin; D009687:Nuclear Proteins
keywords: African swine fever virus; Cajal bodies; heterochromatin protein 1; histone H3 methylation modifications; histone deacetylases; nuclear speckles; promyelocytic leukaemia nuclear bodies