rologie i - European Congress of Virology

5 th European Congress of VirologyThe EV of vaccinia virus (VACV) is essential for viral pathogenesis andis difficult to neutralize with antibodies (Abs). We previously showed thathigh concentrations of anti B5 Abs are insufficient on their own to directlyneutralize VACV EV. This allowed for at least two possible interpretations:covering the virion surface is insufficient for neutralization, or there areinsufficient copies of B5 to allow anti B5 IgG to fully cover the surface ofthe virion and another viral receptor protein remains active. We endeavoredto test these possibilities, focusing on the Ab responses elicited immunizationagainst smallpox. We tested whether human monoclonal antibodies(MAbs) against the three major EV antigens, B5+A33+A56 could individuallyor together neutralize EV. While anti B5 or anti A33 (but notanti A56) MAbs of appropriate isotypes were capable of neutralizing EVin the presence of complement, a mixture of anti B5, anti A33, and antiA56 MAbs was incapable of directly neutralizing EV. This remained truewhen neutralizing the IHD J strain, which lacks a functional version ofthe fourth and final known EV surface protein, A34. These immunologicaldata are consistent with viral proteins not being the active component ofthe EV surface for target cell binding and infectivity. We conclude thatthe EV virion evades direct neutralization by human Ab responses to thesmallpox vaccine, and the protection afforded by the smallpox vaccineanti EV response is predominantly mediated not by direct neutralizationbut by isotype dependent effector functions.REF 049Kinetics of antibody response in heifers vaccinated with inactivatedgE negative BHV 1 marker vaccine by enzyme linked immunosorbentassayAtilla SIMSEK 2 , Orhan YAPICI 1 , Oguzhan AVCI 2 , Oya BULUT 2 ,Kamil ATLI 2 , Irmak DIK 2 , Sibel YAVRU 21 Kyrgzstan Turkey Manas University, School of Veterinary Science,Department of Virology, Bishkek, KYRGYZSTAN; 2 Selçuk University,School of Veterinary Science, Department of Virology, Konya, TURKEYIn countries with high prevalence of infection, the control of Bovine Herpesvirustype 1 (BHV 1) is associated with the vaccination of cattle withglycoprotein E (gE) negative marker vaccines. These marker vaccines,either inactivated or live attenuated, are deleted in the gene coding for thenon essential gE of BHV 1 in order to allow serological differentiation betweenvaccinated and infected cattle. The aim of the study was the assessmentof rise and persistence of antibodies to BHV 1 after two step vaccinationmarker inactivated vaccine with an interval of 21 days. Five heiferswere serologically surveyed regularly for one year period after vaccination.The kinetic of immunoglobulin in serum samples from heifers were monitoredby enzyme linked immunosorbent assay (ELISA). BHV 1 antibodiesin serum samples were first detected on average at day 8 after first vaccination.Maximum titres were obtained eight weeks after first vaccination.REF 050Monitoring HPV type specific neutralizing antibodies induced by aprophylactic quadrivalent human papillomavirus types 6/11/16/18 l1virus like particle vaccineLaura SQUARZON 1 , Monia PACENTI 2 , Serena MASIERO 1 , GiorgiaMARCATI 2 , Barbara MANTELLI 1 , Lorena GOTTARDELLO 3 ,Antonella CAPUTO 1,2 , Luisa BARZON 1,2 , Giorgio PALÙ 1,21 Department of Molecular Medicine, University of Padova, Padova,ITALY; 2 Clinical Microbiology and Virology, Padova University Hospital,Padova, ITALY; 3 Department of Hygiene and Public Health, ULSS16, Padova, ITALYVaccination programs with prophylactic human papillomavirus (HPV)vaccines are being widely implemented, targeting adolescent girls prior tosexual debut. Since the risk of HPV exposure persists throughout sexuallife, the duration of protection is critical to vaccine effectiveness. Aim ofthis independent study was to evaluate vaccine induced neutralizing antibodies(NAbs) in girls and young women vaccinated with the prophylacticquadrivalent HPV types 6/11/16/18 vaccine Gardasil ® (Merck) at differenttime points from the last vaccine dose. The study population included agroup of 200 females who attended vaccination centers of the Departmentof Public Health in Padova, Italy. NAbs specific for HPV16/18/6/11 weremeasured at 1 to 6 months, 2 years, 3 years and 4 years after completionof the third dose of vaccine by using pseudovirion based neutralizationassays (PBNAs). The presence of NAbs was defined by a titer of 1:40or higher, according to WHO guidelines. Seropositivity rates were 100%for HPV16 at all time points after vaccination, while 98.4% for HPV18at 1 6 months and 80% at 4 years after vaccination. Seropositivity rateswere lower (92%) for HPV6 and HPV11 at 1 6 months and declined withtime (80% and 60% at 4 years, respectively). Peak geometric mean titers(GMT) of HPV16 NAb was significantly higher than HPV18/6/11 NAbsand in adolescents than in young women. A significant decline of NAbtiters for all four HPV types was observed over time. Monitoring NAbsmight be useful to define the duration of protection and immunologicalcorrelates of protection.REF 051Equal protection against influenza viruses A/H5N1 and A/H1N1 inducedby flagellin delivering conserved consensus human and A/H5N1M2eLudmila STEPANOVA 1 , Anna KOVALEVA 1 , Marina POTAPCHUK 1 ,Alexander KOROTKOV 1 , Roman KOTLYAROV 2 , Nikolai RAVIN 2 ,Ludmila TSYBALOVA 1 , Oleg KISELEV 11 Research Institute of Influenza, St. Petersburg, RUSSIA; 2 Center ’Bioengineering’Russian Academy of Science, Moscow, RUSSIAWe developed a recombinant fusion protein (Flg 2M2eh2M2ek) containing2 consensus sequences of M2e human influenza A (M2eh) and 2copies of M2e/Chicken/Kurgan/5/05 NS R.G. 5:3 H5N1 (M2ek) linkedto the C terminal end of full length flagellin. Balb/c mice were immunizedintranasal 3 times at 2 weeks intervals with 7,5 g M2e. Antibodytiters (IgG, IgG1, IgG2a) in serum and sIgA, IgG in bronchoalveolarlavage (BAL) against synthetic M2e (M2eh, M2ek) were determined byELISA. Sera of immunized mice were tested for reactivity with MDCKcells infected by influenza A in MDCK whole cell ELISA assay. Weestimated the proliferative activity and intracellular cytokine staining inspleen lymphocytes of immunized mice after activation of M2ek. Immunizedmice were challenged with 5 LD50 adapted to mice A/PR/8/34(H1N1) and A/Chicken/Kurgan/5/05 NS R.G. 5:3 (H5N1). Immunizationwith Flg 2M2eh2M2ek induced high titers of IgG in serum and BAL,sIgA in BAL and titers against M2eh and M2ek were practically equal.Intranasal administration of Flg 2M2eh2M2ek lead to dominating IgG1response and formation of specific Tx2 memory cells producing IL 4.It was shown that sera of immunized mice bound specifically to PR8infected and A/Chicken/Kurgan infected MDCK cells, indicating that antiM2e antibodies recognize native M2e on the surface of influenza infectedcells. Mice were protected from lethal challenge of A/PR8/34 (70%survival) and Chicken/Kurgan/5/05 NS R.G. 5:3 (H5N1) (90% survival).Our results demonstrate the possibility of developing candidate influenzavaccine protecting as against human so avian influenza viruses.REF 052Improvement of Immunogenicity of Influenza Virus M2e ProteinLiudmila TSYBALOVA 1 , Liudmila STEPANOVA 1 , VictorKUPRIYANOV 2 , Marina POTAPCHUK 1 , Alexander KOROTKOV 1 ,Nikolay RAVIN 21 Research Institute of Influenza, Saint Petersburg, RUSSIA; 2 Centtre‘Bioengineering’ Russian Academy of Science, Moscow, RUSSIAS132 Virologie, Vol 17, supplément 2, septembre 2013