rologie i - European Congress of Virology

5 th European Congress of Virologyflaviviruses targeting the glycoprotein part of the genome. In the presentstudy, our aim is to identify antigenic regions useful for assays to distinguishbetween vaccinations and natural infections. We synthesized TBEVgenome in 567 peptides onto amino PEG membrane. The membrane isprobed with sera of individuals with acute TBE patients, TBE vaccinationor old TBE immunity. Using the Pepspot assay, we have identifiednovel linear epitopes in the nonstructural region, particularly in NS2Band NS4B. These novel epitopes may further be developed to differentialdiagnostics.in a cohort of 12 years old girls screened for HPV memory B cells 1 6months after vaccination; 2) screen a cohort of Gardasil vaccinees thathave been vaccinated starting from year 2008 (12 years old girls versus25 45 years old women), to evaluate the long lasting response of memoryB cells 4 5 years after vaccination. In the cohort of Gardasil vaccinees weobserve a change in the number of specific memory B cells after 4 5 yearsfrom vaccination compared to the group tested 1 6 months after vaccination.Moreover preliminary data on the comparison between Cervarix andGardasil immunogenicity will be presented.REF 045Induction of cytolytic CD4+ T cell immune responses by ParvovirusB19 VP2 virus like particlesArun KUMAR 1 , Anu KANTELE 2,3 , Lea HEDMAN 1 , KlausHEDMAN 1,4 , Rauli FRANSSILA 11 Departments of Virology, Haartman Institute, University of Helsinki,Helsinki, FINLAND; 2 Department of Bacteriology and Immunology,Haartman Institute, University of Helsinki, Helsinki, FINLAND; 3 Divisionof Infectious Diseases, Helsinki University Central Hospital, Helsinki,FINLAND; 4 Helsinki University Central Hospital Laboratory Division,Helsinki, FINLANDBackground: A novel conception of CD4+ T cells with cytolytic potential(CD4+ CTL) is emerging. These cells appear to play a part in controllingmalignancies and chronic infections. Human parvovirus B19 can cause apersistent infection, yet no data have been reported that would show thepresence of B19 specific CD4+ CTLs. Such cells could have a role in thepathogenesis of autoimmune disorders and in some thyroid malignanciesassociated with B19.Methods: The cytolytic potential of human parvovirus B19 specific T cellswas explored by stimulating PBMC with recombinant B19 VP2 virus likeparticles. Cytolytic potentintial was evaluated by EIA based quantitationof Granzyme B (GrB) from tissue culture supernatants.Results: GrB responses with the B19 antigen were readily detectable inB19 seropositive individuals. The responses proved stronger than thosewith the HBoV control antigens. T cell depletion and HLA blocking experimentsshowed GrB to be secreted by CD4+ T cells. Interestingly, someB19 seronegative subjects also had GrB responses with B19 VLPs.Conclusions: A vigorous B19 specific GrB response was found in seropositiveindividuals which suggests a role for CD4+ CTL also in B19immunity. Such cells could function within, immune regulation and in thetriggering off autoimmune phenomena such as SLE or rheumatoid arthritis.REF 046Evaluation of B Cell immunity after HPV vaccinationBarbara MANTELLI 1 , Valentina TELATIN 1 , Laura SQUARZON 1 ,Tiziana LAZZAROTTO 2 , Liliana GABRIELLI 2 , LorenaGOTTARDELLO 3 , Ivana SIMONCELLO 3 , Luisa BARZON 1 , GiorgioPALÙ 1 , Antonella CAPUTO 11 Department of Molecular Medicine, University of Padua, Padua, ITALY;2 Policlinico S. Orsola Malpighi, Bologna, ITALY; 3 Department of PublicHealth, Azienda Ospedaliera di Padova, Padua, ITALYCervical cancer is one of the most common malignancies in womenworld wide and more than 95% of all cervical tumors are associated withhuman papillomavirus (HPV) infection. To date, two prophylactic vaccinesagainst HPV infections are available: a bivalent HPV16/18 L1 VLPvaccine (Cervarix) and a tetravalent HPV 6/11/16/18 L1 VLP vaccine(Gardasil). Both vaccines are safe, highly immunogenic and protective;nevertheless, several key issues are still open regarding the duration ofmemory B cell responses after HPV vaccination. We designed an independentstudy to 1) compare the immunogenicity of the two vaccinesREF 047A Novel Vaccine Strategy is Effective Against Congenital Cytomegalovirusin a Pre Clinical Animal ModelAlistair MCGREGOR 1 , Matthew ROOT 2 , Yeon CHOI 11 Texas A&M Health Science Center College of Medicine, College Station,USA; 2 University of Minnesota, Minneapolis, USACongenital CMV is a leading cause of mental retardation and deafness.The guinea pig is the only small animal model for congenital CMV. Weinvestigated a disabled infectious single cycle (DISC) vaccine strategy,where the virus lacks the ability to express an essential gene, except whengrown on a complementing cell line. The minor capsid gene (UL85) wasselected as it is essential for virus capsid assembly. A series of guinea pigCMV (GPCMV) BAC mutants were generated. In the DISC strain, theGP85 late promoter was removed and a tet off promoter and an upstreamSV40 polyA cassette were substituted to place GP85 expression understrict control of a tet off system. Transfection of mutant BACs onto tet offguinea pig fibroblast cells only resulted in virus from the mutant containingthe tet off promoter (vDISCGP85). The DISC vaccine immune responsewas investigated. Animals (n=6) induced an anti GPCMV antibody response(ELISA titer >1:1260) and a cell mediated response to the pp65 andIE1 homologs. In a congenital protection study, female guinea pigs (n=15)were vaccinated and mated. At late second trimester of pregnancy animalswere challenged (10 5 pfu wild type GPCMV). A control group, non vaccinatedpregnant animals (n=15) were similarly challenged. Animals wentto term and viral load in target organs of pups was analyzed. Based onlive pup numbers in the vaccinated and non vaccinated groups (94.4%vs 63.6%) the vaccine strategy was successful (P=0.002). Pups from thevaccinated group had zero or reduced viral load in target organs comparedto control pups. The vaccine failed to prevent brain infection in all pups(11% vs 50% in control). However, the outcome was statistically significant.The merits of modifying the vaccine to include neutralizing antibodytargets to a novel endocytic complex for virus infection of epi/endothelialcells will be discussed.REF 048Unusual features of vaccinia virus Extracellular Virion form (EV)neutralization resistance revealed in human antibody responses to thesmallpox vaccineMohammed RAFII EL IDRISSI BENHNIA 1 , Lilia KORIAZOVA 3 ,Shinichiro KATO 3 , Philip L. FELGNER 6 , Dirk ZAJONC 2 , Dennis R.BURTON 4 , Yan XIANG 6 , James E. CROWE JR 5 , Bjoern PETERS 1 ,Shane CROTTY 11 Division of Vaccine Discovery, La Jolla Institute for Allergy and Immunology(LIAI), LA JOLLA, USA; 2 Division of Cell Biology, LIAI, LA JOLLA,USA; 3 Kiowa Hakko Kirin California, LA JOLLA, USA; 4 Departmentof Immunology and Microbial Science and IAVI Neutralizing AntibodyCenter, LA JOLLA, USA; 5 Vanderbilt Vaccine Center, University MedicalCenter, Nashville, USA; 6 Division of Infectious Diseases, Department ofMedicine, University of California, Irvine, USA; 7 Department of Microbiologyand Immunology, University of Texas Health Science Center, SanAntonio, USAVirologie, Vol 17, supplément 2, septembre 2013S131