rologie i - European Congress of Virology

5 th European Congress of VirologyAlthough restricted to members of the Equidae, Equine Infectious AnemiaVirus (EIAV) has an almost worldwide distribution. EIAV belongs to theRetroviridae family, from the lentivirus genus related to HIV in humans;the induced EIA (Equine Infectious Anemia) is one of the eleven notifiableequine diseases listed by World Animal Health Organization (OIE).EIA is widely considered a blood borne disease primarily transmitted byhaematophagous insects or iatrogenically. Other routes of transmissionhave not been explored although there is evidence that EIA was spreadvia aerosolized particles during the 2006 EIAV outbreak in Ireland. Weexplored the potential of EIAV to induce pulmonary lesions in naturallyinfected equids. Lungs from 77 EIAV seropositive horses have been collectedin Romania in the context of the EIAV wide range National surveyamong farm horses. Three types of lesions have been scored on paraffinembedded lungs: lymphocyte infiltration, (peri)bronchiolar inflammation,and thickness of the alveolar septa. Expression of the p26 EIAV capsid(CA) protein has been evaluated by immunostaining. Compared toEIAV negative horses, 52% of the EIAV positive horses displayed a mildinflammation around the bronchi, 22% had a moderate inflammation withinflammatory cells inside the wall and epithelial bronchiolar hyperplasiaand 6.5% had a moderate to severe inflammation, with destruction of thebronchiolar epithelium and accumulation of smooth muscle cells withinthe pulmonary parenchyma. Changes in the thickness of the alveolar septawere also present. Interestingly, EIAV p26 was expressed in the cytoplasmof cells compatible by their morphology and localization with alveolar andbronchiolar epithelial cells. To summarize, we found lesions compatiblewith interstitial diffuse pneumonia similar to that observed during otherlentiviral infections such as FIV (Feline Immunodeficiency Virus) in cats,SRLV (Small Ruminant LentiVirus) in sheep and goat or HIV in youngchild. The presence of EIAV capsid in lung epithelial cells suggests thatEIAV might be responsible for the bronchointerstitial damages observed.Confirmation of this pulmonary route will have profound implications forunderstanding the epidemiology and pathogenesis of this disease, as EIAVis currently thought to be transmitted by blood and its tropism restrictedto cells of the monocyte/macrophage lineage.REF 066Synergistic Interactions Between the NS3hel and E Proteins Contributeto the Virulence of Dengue Virus Type 1Daisy STROTTMANN 1 , Luana DE BORBA 1 , Peter W. MASON 2 ,Claudia N. DUARTE DOS SANTOS 11 Instituto Carlos Chagas FIOCRUZ/PR, Curitiba, BRAZIL; 2 NovartisVaccines and Diagnostics, Cambridge, USADengue virus (DENV) constitutes a significant public health problem intropical regions of the world. Despite major advances in DENV biology,many aspects of dengue pathogenesis remain largely unknown. Some possibleviral genetic determinants of the intrinsic virulence of DENV inthe host have been identified; nevertheless, no conclusive evidence of acorrelation between viral genotype and virus transmissibility and pathogenicityhas been obtained. We use reverse genetics technology to engineerDENV 1 with subsets of mutations previous identified in highly neurovirulentstrains to provide insights into the molecular mechanisms underlyingdengue neuropathogenesis. We found that single mutations affecting theenvelope protein (E) and the helicase domain of the NS3 (NS3hel) protein,introduced in a different genetic context, had a synergistic effect increasingDENV replication capacity in human and mosquito derived cells. E mutationsalone generated no detectable virulence in the mouse model, however,the combination of these mutations with NS3hel mutations, which weremildly virulent on their own, resulted in a highly neurovirulent phenotype.We also demonstrated correlations between the presence of these mutationsand viral replication efficiency, viral loads, the induction of innateimmune response genes and pathogenesis in a mouse model. Given currentlimitations to our understanding of the molecular basis of dengue pathogenesis,these results could contribute to provide insights into virus/hostinteractions and new information about the mechanisms of basic denguebiology.REF 067Toll like receptor 2, 4 and 9 single nucleotide polymorphisms in cytomegalovirusinfectionMiroslawa STUDZINSKA 1 , Agnieszka JABLONSKA 1 , KatarzynaRUDNICKA 2 , Patrycja SUSKI 1 , Edyta PARADOWSKA 11 Laboratory of Molecular Virology and Biological Chemistry Instituteof Medical Biology, Polish Academy of Sciences, Lodz, Lodz, POLAND;2 Student of the University of Lodz, Faculty of Biology and EnvironmentalProtection, Division of Microbial Genetics, Lodz, POLANDToll like receptors (TLRs) play an important role in the subsequent initiationof innate and adaptive immune responses to microbial pathogens.Several single nucleotide polymorphisms (SNPs) within TLR genes seemto be associated with host pathogen defense mechanisms. Little is knownabout the role of TLR polymorphisms in the pathogenesis of human cytomegalovirus(HCMV) infection. In the present study, we investigated thepossible association between the polymorphisms of TLR2 (Arg677Trpand Arg753Gln), TLR4 (Asp299Gly) and TLR9 (T 1237C, T 1486C)with HCMV infection. Blood samples obtained from children and adultsdiagnosed with HCMV, and healthy control subjects were included in thisstudy. The SNPs were genotyping by PCR RFLP method. Digested PCRproducts were analysed by capillary electrophoresis.We did not observed differences in the frequencies of TLR2 (Arg753Gln),TLR4 and TLR9 genotypes among control and HCMV infected groups.Nonetheless, it is interesting that we found heterozygosity for the TLR2Arg677Trp SNP in 72% health adults. In contrast, none of the HCMVinfected patients and children showed a heterozygous TLR2 polymorphism.In conclusion, our study demonstrated that SNPs in the TLR2(Arg753Gln), TLR4 and TLR9 were not associated with HCMV infection.Acknowledgements: Project financed by the European Regional DevelopmentFound under the Operational Programme Innovative Economy,Grant No. POIG.01.01.02 10 107/09.REF 068Andes virus (ANDV) infection of an in vitro 3 dimensional organotypichuman lung modelKarin SUNDSTROM 1,2 , Anh Thu NGUYEN HOANG 3 , ShawonGUPTA 1,2 , Puran CHEN 3 , Clas AHLM 4 , Mattias SVENSSON 3 , JonasKLINGSTRÖM 1,2,31 Department of Microbiology, Tumor and Cell Biology/Karolinska Institute,Stockholm, SWEDEN; 2 Department of Preparedness/SwedishInstitute for Cummmunicable Disease Control, Solna, SWEDEN; 3 Centerfor Infectious Medicine/Karolinska Institute, Stockholm, SWEDEN;4 Department of Clinical Microbiology/Umeå University, Umeå, SWEDENAndes virus (ANDV) is a rodent borne hantavirus that causes hantaviruspulmonary syndrome (HPS) with a case fatality rate of 40%. Infectionsoccur via inhalation of virus contaminated excreta, and are followed byan approximately 18 days long incubation period. As of today, it is notwell known why hantaviruses cause disease in humans. In particular, verylittle is known regarding the effect hantaviruses may have at the initial siteof infection during the incubation period, and why infection change fromasymptomatic to a life threatening disease in humans. In this study weused a 3 dimensional organotypic model of human lung tissue to investigateearly and long term effects of ANDV infection. Increased progenyVirologie, Vol 17, supplément 2, septembre 2013S137