Day 1 :
Hokkaido University Research Center for Zoonosis Control, Japan
Time : 09:30-10:00
Hiroshi Kida, DVM, PhD, Member of the Japan Academy, is Professor Emeritus, Head of the Research Center for Zoonosis Control at Hokkaido University, Sapporo, Japan, Head of the OIE Reference Laboratory for Avian Influenza, and Head of the WHO Collaborating Centre for Zoonoses Control. He has experiences of the development of influenza and leptospirosis vaccines as Research Officer at Takeda Chemical Industries, Ltd (1969-1976). Since 1976, he has devoted himself to research and education at Hokkaido University and been the recipient of several awards and honors such as Japan Academy Prize for “Studies on Control of Influenza -Mechanism of Emergence of Pandemic Influenza Virus Strains in Poultry, Domestic Animals and Humans, and Molecular Basis of the Neutralization of Viral Infectivity with Antibodies”. He is the author of 304 original articles and 142 book chapters and reviews.
H5 highly pathogenic avian influenza viruses (HPAIVs) have spread around Eurasia and Africa. Unless these viruses are eradicated from poultry in Asia, those may perpetuate in the lakes where migratory water birds nest in summer in Siberia and outbreaks of HPAI must occur everywhere in Eurasia every year. We thus strongly propose to eradicate those HPAIVs from Asia by stamping-out without misuse of vaccine through international collaboration.\r\n Each of the past 4 pandemic influenza viruses is thought to be a reassortant generated in a pig between avian influenza virus and the preceding human strain. We have shown that pigs are susceptible to infection with both of avian and mammalian influenza viruses of different HA subtypes, generating reassortants with human receptor specificity. Since each of influenza A viruses of all known subtypes perpetuates among migratory ducks and their nesting lake water and avian viruses of any subtype can contribute genes in the generation of reassortants in pigs, none of viruses of the 16 HA and 9 NA subtypes can be ruled out as potential candidates for future pandemic strains. We have established a library of 2,000 low pathogenic avian influenza virus strains of 144 combinations of 16 HA and 9 NA subtypes for vaccine strain candidates and diagnostic use (http://virusdb.czc.hokudai.ac.Jp/vdbportal/view/index.jsp).\r\n In addition, it is strongly proposed that surveillance of swine influenza and drastic improvement of seasonal influenza vaccine are of crucial importance in order to assure the effective preparedness for pandemic influenza.\r\n
Chinese Academy of Sciences
Keynote: Both PB1 473V mutation in RNA polymerase activity and NP sumoylation play an important role in the pathogenesis of influenza virus infection
Time : 10:00-10:30
Bing Sun joined Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences, China and was a Chief of Lab of Molecular Immunology. He has been appointed as Co-Director and Head, Lab of Molecular Virology in Institute Pasteur of Shanghai, Chinese Academy of Sciences, China. He has been working on dendritic cell maturation and Th1/Th2 cell differentiation over twenty years. He has been working on viral ion channel protein; he has discovered 3a protein of SARS and P7 protein of HCV are an ion channel protein, which are important for viral life cycle and potential a drug target. He has been working on RNA polymerase in influenza A virus.
Inﬂuenza A virus is a substantial threat to human health. After 1997, the emergence of highly pathogenic H5N1 avian viruses in humans caused great concern about the possibility of a new pandemic. It is reported that PB2 627K plays an important role in the cross-species transmission of avian viruses. In the new emergence of H7N9 avian viruses, we found the PB2 E627K promoted the replication and pathogenicity in mice. However, some avian viruses carrying PB2 627E still can replicate well in mammalian cells and animals. That means there are some key points can compensate the loss function of PB2 627E. By the mini-replicon system, we identified that PB1 473V and 598P can compensate the polymerase activity of avian viruses carrying 627E in mammalian cells and can restore the pathogenicity of viruses in mice. During the life cycle, viruses take advantage of host post-translational modifications for their own benefit. It was recently reported that influenza A virus proteins interact extensively with the host sumoylation system. Thereby, several viral proteins, including NS1 we had reported, are sumoylated to facilitate viral replication. However, the sumoylation in other proteins of influenza A virus is not fully understood. In our study, we found that influenza A virus nucleoprotein (NP) is a target of sumoylation in both NP-transfected cells and virus-infected cells at the two most N-terminal residues, lysine 4 and lysine 7, and that the sumoylation at lysine 7 of NP is highly conserved across different influenza A subtypes and strains. The NP-sumoylation-defective virus, WSN-NPK4,7R virus, exhibited an early cytoplasmic localization of NP. The growth of the WSN-NPK4,7R virus was highly attenuated compared to that of WSN-WT virus. We evaluated whether members of the PIAS family, the best-characterized E3 ligases, could function as an E3 ligase for NP. Among all PIAS homologs, over-expression of PIASxa had the strongest effect on NP sumoylation, suggesting that PIASxa is the predominant E3 ligase for NP. Thus, sumoylation of influenza A virus NP is essential for intracellular trafficking of NP and for virus growth, illustrating sumoylation as a crucial strategy extensively exploited by influenza A virus for survival in the host.
Brunel University London
Time : 10:45-11:45
Dr Beatrice Nal graduated with a PhD in Immunology in 2002 (CIML, France). After a post-doc at Institut Pasteur in Paris she joined the Hong Kong University-Pasteur Research Centre and was appointed Research Assistant Professor and head of the Virus-Host Interactions group in 2006. She transfered her lab to Brunel University London in 2011. Her major research interest is the understanding of molecular determinants of viral pathogenesis. She has made new important discoveries on mechanisms of virus assembly and viral cellular interactomes for dengue virus, coronaviruses and influenza A virus.
Elucidation of networks of interactions between viruses and host cells will pave the way towards the understanding of molecular determinants of cytopathogenicity and ultimately the design of novel therapeutics. Our strategy is to identify human restricting and enhancing factors of viral infections. We focus on viral structural proteins, which not only play key roles at early and late stages of the replication cycle but also act as regulators of cellular processes through specific interactions with cellular pathways. We have conducted a series of yeast two-hybrid screens using the cytosolic domains of the structural proteins of human coronavirus and influenza A virus as baits. Our studies have revealed novel interactions that have opened new routes of investigation. We have identified a PDZ-binding motif in the C-terminal domain of the SARS-CoV small envelope protein, responsible for interaction and mislocation of the PDZ domain-containing tight junction protein PALS1, loss of epithelial cell polarity and potentially enhancement of viral dissemination. We found that the interaction between SARS-CoV Spike C-terminal tail and the cytoskeleton-binding protein ezrin is involved in restriction of viral entry and limits Spike-dependent fusion. We have identified that the C-terminal domain of influenza A virus M2 interacts with human annexin A6. We found that annexin A6 expression alters influenza A virus morphogenesis and restricts release of progeny virions.