rologie i - European Congress of Virology

5 th European Congress of Virologyinfected in prebuberal period appeared to be infertile. Ascending infectionwas simulated in model IV and it was shown that HSV infectionresulted in leukocyte infiltration of interstitium and phagocytosis of malegametes. Conclusion: models obtained can be used to develop strategiesfor prophylaxis, diagnostics and treatment of HSV induced infertility.REF 086mTOR independent autophagy counteracts apoptosis in herpes simplexvirus type 1 infected U251 glioma cellsBiljana RISTIC 1 , Gordana TOVILOVIC 2 , Marina SILJIC 1 , ValentinaNIKOLIC 1 , Tamara KRAVIC STEVOVIC 3 , Marija DULOVIC 4 , MarinaMILENKOVIC 1 , Mihajlo BOSNJAK 3 , Vladimir BUMBASIREVIC 3 ,Maja STANOJEVIC 1 , Vladimir TRAJKOVIC 11 Institute of Microbiology and Immunology, School of Medicine, Universityof Belgrade, Belgrade, SERBIA; 2 Institute for Biological Research,University of Belgrade, Belgrade, SERBIA; 3 Institute of Histology andEmbriology, School of Medicine, University of Belgrade, Belgrade, SER-BIA; 4 Institute of Medical and Clinical Biochemistry, School of Medicine,University of Belgrade, Belgrade, SERBIAIn the present study, we investigated the role of autophagy, a process ofintracellular degradation of unnecessary or dysfunctional cellular components,in U251 human glioma cell death induced by herpes simplexvirus type 1 (HSV 1). HSV 1 induced apoptotic death in U251 cells, characterizedby phosphatidylserine externalization, caspase activation andDNA fragmentation. HSV 1 triggered autophagy was demonstrated bythe acridine orange staining of intracellular acidic vesicles, elcctron microscopyanalysis of autophagic vacuoles, and immunoblot assessment of theconversion of LC3 I to autophagosome associated LC3 II and degradationof the selective autophagic target p62. The phosphorylation of the majorautophagy repressor mTOR and its downstream target p70S6K was paradoxicallyincreased upon exposure to HSV 1, which was in agreementwith reduced phosphorylation of the mTOR negative regulator AMPKand augmented phosphorylation of mTOR activator Akt. HSV 1 triggeredapoptotic changes and cell death were accelerated in U251 cells treatedwith pharmacological autophagy inhibitors bafilomycin A1 or 3 methyladenine,as well as in cells in which the expression of autophagy essentialLC3 was downregulated by RNA interference. Taken together, these dataindicate that mTOR independent autophagy counteracts apoptotic deathof HSV 1 infected U251 glioma cells.REF 087p53 protein isoforms: key regulators in the front line of pathogeninfections? The example of influenza virusesOlivier TERRIER 1 , Jean Christophe BOURDON 2 , Bruno LINA 1 ,Manuel ROSA CALATRAVA 11 Laboratoire de Virologie et Pathologie Humaine VirPath, Equipe Vir-Cell, Université Claude Bernard Lyon 1, Université de Lyon, Lyon,France; 2 Division of Medical Sciences, Centre for Oncology and MolecularMedicine, University of Dundee, Ninewells Hospital, Dundee, UNITEDKINGDOMPrevious studies have described the role of p53 isoforms, including p53and 133p53a, in the modulation of activity of the full length p53,which regulates the cell fate outcome. Although several studies reporton the suppressive function of p53 isoforms and related deregulation oftheir expression in human cancers, investigations into the putative roleof p53 isoforms and their regulation in pathogen infections have onlyrecently begun. In the context of influenza infection, an interplay betweeninfluenza viruses and p53 has been previously described, p53 beinginvolved in the antiviral response. However, the role of physiological p53isoforms has never been explored in this context. We have demonstratedthat p53 isoforms play a role in influenza A virus infection, usingsilencing and transient expression strategies in human lung epithelialcells. In addition, with the help of a panel of different influenza virusesfrom different subtypes, we have also shown that the infection differentiallyregulates the expression of p53 and 133p53a. Altogether, ourresults highlight the role of p53 isoforms in the viral cycle of influenzaA viruses, acting as regulators of viral production in a p53 dependentmanner. Recent reports have recently highlighted the role of p53 isoformsin epithelial cells infected by other pathogens. Despite major differencesin term of models and experimental strategies, these studies share someinteresting preliminary conclusions regarding a new facet of p53 isoformbiology and will help to provide new insights into the roles of p53 inpathogenesis.REF 088Potential role of autophagy during Wolbachia antiviral interferenceagainst chikungunya virus in mosquito cellsVincent RAQUIN 1 *, Claire VALIENTE MORO 1 , ClaireBERNARDIN 2 , Florence TRAN 1 , Van TRAN VAN 1 , Patrick POTIER 1 ,Dimitri LAVILLETTE 1 , Patrick MAVINGUI 11 University of Lyon; Microbial Dynamics and Viral Transmission group,UMR 5557 Microbial Ecology, University Lyon 1, CNRS, Lyon, FRANCE;2 University of Lyon; Opportunistic Pathogenic Bacteria and Environmentgroup, UMR 5557 Microbial Ecology, University Lyon 1, CNRS, Lyon,FRANCEArthropod-borne virus (Arbovirus), such as dengue virus (DENV) andchikungunya virus (CHIKV), are major threats to public health. Eachyear, they are responsible for millions infections worldwide. Arbovirusare mainly transmitted by mosquitoes, whose vector competence relies onenvironmental, genetic and immune factors. Recently, it was demonstratedthat mosquito, like bacteria and fungi, could also modulate the vectorcompetence. For instance Wolbachia, an intracellular alphaproteobacterium,was shown to decrease the transmission rate of DENV, CHIKV,and Plasmodium, in some mosquito species. However, the cellular andmolecular mechanisms of this interference remain poorly understood.To improve our knowledge on the mechanisms involved, we used theC6/36 cell line derived from Aedes albopictus. We first established chroniccell infection with Wolbachia strain wAlbB, naturally infecting thismosquito species, and then performed viral infections. Results showedthat replication and infectiosity of CHIKV decrease in the presence ofWolbachia in comparison to aposymbiotic cells. In light of recent studiessuggesting the importance of autophagy during microbial infection,we further explored the contribution of such process in the modulationof co-infection Wolbachia-CHIKV in mosquito cells. The results willbe discussed in regard with the antiviral effect of Wolbachia againstCHIKV. We will speculate on the role autophagy may play in the bacterialinterference against mosquito-borne pathogens and, to a large extent, insymbiosis.Virologie, Vol 17, supplément 2, septembre 2013S143