rologie i - European Congress of Virology

5 th European Congress of VirologyWednesday 11 th September 2013,16h15 – 18h15WORKSHOP 27: “NEUROTROPIC VIRUSES”Chairpersons: Tomas BERGSTROM (Gothenburg, SWEDEN)& Monique LAFON (Paris, FRANCE)Room Tête d’OrKEYNOTE:Neurotropic VirusesJohn FAZAKERLEYThe Pirbright Institute, Surrey, UNITED KINGDOMMany viruses are capable of causing developmental CNS abnormalities,encephalitis, meningitis or neuritis in humans and other animals. Rubellainduced brain abnormalities; Herpes simplex virus temporal lobe encephalitis;shingles; progressive multifocal leukoencephalopathy; mumps andechovirus meningitis; Japanese, Venezuelan and West Nile encephalitides;rabies and canine distemper all provide prominent examples. Viruses havealso been suggested to be causative or contributing agents in multiple sclerosis,Parkinson’s disease, schizophrenia, motor neuron disease, dementiaand other neurological diseases. Viruses access the nervous system directlyfrom the blood or along nerves. In the absence of an ability to studydisease progress in the human CNS, understanding of the pathogenesis ofmany CNS virus diseases has been led by studies in experimental animalmodel systems. Importantly, the CNS has highly specialized long-livedcells and highly specialized immune responses. Many viruses replicatewell in immature neurons but some replicate less well, or unproductively,in mature neurons where, in the absence of the propensity of highlyspecialized CNS cells to undergo apoptosis, infection can become persistent.The resting CNS is an immunosuppressive environment but strongimmune responses can develop and there are well-documented examplesof the detailed mechanisms of both protective and destructive responses.This talk will provide an overview, illustrate key paradigms, present somerecent findings and outline outstanding questions.ORAL COMMUNICATIONSREF O19Viral DNA containing PML NBs (DCP NBs) are a hallmark of thenuclear associated antiviral response controlling the latency of a herpesvirusPatrick LOMONTE 1,2 , Catez FRÉDÉRIC 1 , Antoine ROUSSEAU 3 ,Nancy SAWTELL 4 , Marc LABETOULLE 31 Centre de Génétique et de Physiologie Moléculaire et CellulaireUMR5534 CNRS/UCBL1, Villeurbanne, France; 2 Laboratoired’excellence, LabEX DEVweCAN, Lyon, France; 3 Institut de VirologieMoléculaire et Structurale, CNRS UPR 3296, Gif sur Yvette, FRANCE;4 Division of Infectious Diseases, Cincinnati Children’s Hospital MedicalCenter, Cincinnati, USAHerpes simplex type 1 (HSV 1) is a neurotropic virus establishing latencyin trigeminal ganglia (TG) sensory neurons. During infection, the switchbetween the lytic cycle and latency is characterized by a change inviral gene transcription program. Nuclear architecture, including nucleardomains, is determinant for the control of gene expression and is likely toinfluence the fate of viral infection. We recently performed a fluorescentin situ hybridization (FISH) based study to analyse features of the HSV1 genome within TG neurons of latently infected mice. High resolutionimaging showed that viral genomes were present during latency withinnuclear domains containing the promyelocytic leukemia nuclear bodies(PML NBs or ND10) associated proteins, PML, Daxx, ATRX and SUMO2/3, that we named DNA containing PML NBs (DCP NBs). Infections ofPML KO mice demonstrated that PML protein was required for DCP NBsformation. We then analyzed the expression of a viral long non codingRNA, namely LAT, produced during latency, and showed that DCP NBsrestrict its expression, supporting the idea that DCP NBs are repressorsof viral transcription. Using the same approach, we investigated the DCPNBs formation at the initial stages of latency establishment, and confirmedthe affinity of PML NBs associated proteins towards viral genomes.In conclusion, our data support a role of DCP NBs in the physical andfunctional control of HSV 1 latency. This is the first study that describes atthe viral genome level, the role of PML NBs in the control of the biologyof a persistent virus.REF O20Molecular interactions of tick borne encephalitis virus with humanneural cellsDaniel RUZEK 1,2 , Martin PALUS 2,3 , Jana ELSTEROVA 2,3 , MarieVANCOVA 2,3 , Tomas BILY 21 Veterinary Research Institute, Brno, CZECH REPUBLIC; 2 Institute ofParasitology, Academy of Sciences of the Czech Republic, Ceske Budejovice,CZECH REPUBLIC; 3 Faculty of Science, University of SouthBohemia, Ceske Budejovice, CZECH REPUBLICTick borne encephalitis (TBE) virus causes severe encephalitis withserious sequelae in humans. However, the pathogenesis of TBE remainspoorly understood. TBE is a generalized infection. The virus invades thecentral nervous system after initial extraneuronal replication – virus replicationis first detected within draining lymph nodes, this is followed bydevelopment of viremia and during the viremic phase virus enter into thebrain. Our study was focused on the immunopathological features of thehost immune system during TBE, on the interaction of the virus with neuralcells, and on the role of the host blood brain barrier in the neuropathogenesisof TBE. We infected primary human neurons, astrocytes, perycites,and brain microvascular endothelial cells and examined their susceptibilityto the infection, changes in global gene expression and virus mediatedcytopathic effect including ultrastructural (3D cryoelecton microscopy)and apoptotic changes of the cells. We observed a number of ultrastructuralchanges in the infected cells that included e.g. enlargement of Golgiapparatus, presence of induced vesicles (smooth membrane structures)and convoluted membranes or disorganization of the rough endoplasmaticreticulum, as well as early features of apoptosis. Expression of keyinflammatory cytokines/chemokines was analyzed by real time RT PCRand ELISA. Moreover, changes in the expression of miRNA in infectedhuman neurons were investigated. Taken together, we contributed to thecharacterization of the complex molecular interactions of TBE virus withhuman neural cells.REF O21Understanding the role of NS1 protein in the neuropathogenicityof Japanese encephalitis virus (Flaviviridae)Melissanne DE WISPELAERE, Marie Pascale FRENKIEL, PhilippeDESPRESInstitut Pasteur, Paris, FRANCEJapanese Encephalitis Virus (JEV) is a member of the Flaviviridae familyand is transmitted by Culex species mosquitoes. This zoonotic arboviruscauses human encephalitis and remains an endemic disease in the AsiaPacific region. JEV has a positive sense RNA genome encoding threestructural proteins (C, prM, E), and seven non structural proteins (NS1,NS2A, NS2B, NS3, NS4A, NS4B, NS5). The Flavivirus NS1 is a multifunctionalglycosylated protein, that is secreted to the extracellular mediumVirologie, Vol 17, supplément 2, septembre 2013S45