rologie i - European Congress of Virology

5 th European Congress of VirologyREF 319Role of the Seg 10 and NS3 proteins in modulating Bluetongue virushosts interactionsNajate FTAICH 1 , Claire CIANCIA 1 , Gerald BARRY 2 ,EvaVERONESI 3 , Maxime RATINIER 2 , Marc BAILLY BECHET 4 , SimonCARPENTER 3 , Damien VITOUR 5 , Massimo PALMARINI 2 ,Christophe TERZIAN 1 , Frederick ARNAUD 11 UMR754, INRA, Université Claude Bernard, Ecole Pratique des HautesEtudes, Université de Lyon, SFR BioSciences Gerland Lyon Sud, Lyon,FRANCE; 2 MRC University of Glasgow Centre for Virus Research,Institute of Infection, Immunity and Inflammation, College of Medicaland V, Glasgow, UNITED KINGDOM; 3 Institute for Animal Health,Vector borne Viral Diseases Programme, Pirbright, Surrey, UNITEDKINGDOM; 4 Laboratoire de Biometrie et Biologie Evolutive, CentreNational de la Recherche Scientifique, UMR 5558, Université Lyon,Villeurbanne, FRANCE; 5 ANSES, Maisons Alfort Laboratory for AnimalHealth, ANSES, INRA, ENVA, UMR 1161 Virology, Maisons Alfort,FRANCEBluetongue virus (BTV) is an arbovirus (for arthropod borne virus) andthe etiological agent of bluetongue, a hemorrhagic disease of ruminantsthat can cause high levels of morbidity and mortality. BTV is transmittedbetween mammalian hosts by species of Culicoides biting midges. BTV isa complex non enveloped virus that belongs to the genus Orbivirus (Reoviridaefamily). It possesses a 10 segmented double stranded RNA (dsRNA)genome that encodes 7 structural proteins (VP1 7) and 5 non structuralproteins (NS1, NS2, NS3/NS3A and NS4). Several evidences indicatethat the NS3 proteins, encoded by the segment 10 (Seg 10), play a majorrole in BTV egress, suggesting that it may also influence viral replicationrate and therefore the pathogenicity in mammals and/or the vector competencein insects. To assess whether the Seg 10 nucleic acid sequencesand/or NS3 proteins of various BTV strains or serotypes affect BTV lifecycle, we generated reassortants viruses in a BTV 1 backbone with fivedifferent Seg 10 of various BTV strains or serotypes. Preliminary resultssuggest that indeed, depending on the Seg 10 considered, differences existin terms of viral replication rate and cytopathic effects in sheep choroidplexus cells. Further in vitro and in vivo experiments are ongoing to betterunderstand how different Seg 10/NS3 proteins can modulate BTV hostsinteractions.REF 320Evidence of vertical transmission of circovirus type 2 (PCV2) fromsows infected before or during gestationBéatrice GRASLAND, Roland CARIOLET, Lionel BIGAULT, CéciliaBERNARD, Anne Cécile HERNANDEZ NIGNOL, Lise GOURVES,André KÉRANFLEC’H, André JESTIN, Nicolas ROSEANSES Ploufragan/Plouzané, Ploufragan, FRANCEPorcine circovirus type 2 (PCV2) is associated with several diseases includingreproductive failure. Our aim was to determine if transplacentaltransmission of PCV2 followed by virus transmission to piglet depends onthe time of infection before or during the gestation. Four sows served asnegative controls. Ten sows, free of PCVs, were infected nasally at days65, 40, 35, 0, +35, +62 or +91 relating to the beginning of gestation. Thesows were killed few days before farrowing for hysterectomia. All fetuseswere identified and euthanized. Viral genomic loads in serum and organsand PCV2 specific antibodies levels were assessed. The trial was performedaccording EU regulations on animal experimentation. All infectedsows became viremic and seroconverted. All the piglets born to infectedsows were seronegative. All the piglets from the sows inoculated at +35days, before the time of foetus immuno competency, were negative for thepresence of PCV2. Few piglets from sows infected at days 65, 40, and +91had low genomic loads in organs. Moderate to high viral genomic loadswere detected in the organs of seronegative pigs from sows infected at days35, 0 and +62. In conclusion, placental transmission of the PCV2 from anon immune sow to fetuses occurs when the infection of the dam occursbefore gestation or after the time of the foetus immuno competency. Thelack of antibodies raised the question of the presence of immuno tolerantpersistently infected animals.Acknowledgements: this work was financially supported by an award ofBoerhinger Ingelheim animal health.REF 321Experimental infection of calves with porcine circovirus (PCV) type2Mohammad Yahya HALAMI, Hermann MÜLLER, Thomas W.VAHLENKAMPInstitute of Virology, Faculty of Veterinary Medicine, University of Leipzig,Leipzig, GERMANYCircoviruses are known to infect pigs and birds and cause a broad range ofsevere clinical symptoms. Recently circoviruses were identified in humanand chimpanzee faeces and new circovirus genomes were described fromchickens, goats, cows, and bats. Porcine circovirus type 2 (PCV 2), whichcauses PCV 2 associated disease (PCVAD) with severe economic losses,was detected in rodents, cattle, and calves affected with bovine neonatalpancytopenia (BNP). The aims of this study are to investigate the susceptibilityand immune response of calves to experimental PCV 2 inoculation.Animal groups were inoculated with (i) tissue culture grown PCV 2, (ii)bone marrow from calves with BNP, and (iii) immunized with a commercialinactivated PCV 2 vaccine. The results showed that the animalsinoculated with PCV 2 or with bone marrow from calves with BNP displayedswelling in lymph nodes, reddening of oral and ocular mucosa,abnormal behavior and diarrhoea (7 18 days p.i.). PCV 2 specific antibodieswere detected in the immunized and PCV 2 infected animals fromday 7 and 11 p.i. onwards, respectively, but not in the bone marrow inoculatedanimals. PCV 2 was detected by PCR only in the PCV 2 infectedanimals especially in the lymph tissues with high copy numbers betweendays 4 (5 log10 copies/g) and 46 (5.67 log10 copies/g) p.i. In conclusion,experimental PCV 2 inoculation of calves results in seroconversion andthe detection of PCV 2 in lymph tissues for an extended period of timewhich seems to indicate that host specificity of PCV 2 is not as restrictedas previously thought.REF 322Identification of single nucleotide polymorphisms on feline interferon gene and association with the outcome of feline coronavirus infectionLi En HSIEH, Ling Ling CHUEHGraduate Institute of Veterinary Medicine, School of Veterinary Medicine,National Taiwan University, Taipei, TAIWANFeline infectious peritonitis (FIP) is an immune mediated, highly lethaldisease caused by feline coronavirus (FCoV) infection. Currently no protectivevaccine and effective treatment for the disease is available. Cellularimmunity is thought to be important to against FCoV infection and preventthe occurrence of FIP. Diseased cats showed a significant decrease ofthe level of interferon . As single nucleotide polymorphisms (SNPs) ofhuman interferon gene (hIFNG) at the position +874 has been identifiedto be related with the outcomes of variable viral infection, e.g.Dengue virus and severe acute respiratory syndrome coronavirus. Thisstudy aim to identify hIFNG +874 homolog on the feline genome andinvestigate its association with the outcome of FCoV infection. Throughthe genetic analysis, hIFNG +874 homolog was mapped to the felineIFNG (fIFNG) on nucleotide 886 from the start codon. The region includingfIFNG +886 was amplified and sequenced from the blood samplesVirologie, Vol 17, supplément 2, septembre 2013S209