Oral Presentation 9th Australasian Virology Society Meeting 2017

Binjari virus: a new insect-specific flavivirus provides a safe recombinant vehicle to develop diagnostic antigens for pathogenic flaviviruses (#40)

Jessica J Harrison 1 2 , Natalee D Newton 1 2 , Agathe MG Colmant 1 2 , David Warrilow 3 , Helle Bielefeldt-Ohmann 1 2 , Thisun BH Piyasena 1 2 , Weng K Chow 4 , Caitlin A O'Brien 1 2 , Laura J Vet 1 2 , Steven S Davis 5 , Peter Simmonds 6 , Cheryl A Johansen 7 8 , Daniel Watterson 1 2 , Nina Kurucz 9 , Jody Hobson-Peters 1 2 , Roy A Hall 1 2
  1. School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, Australia
  2. Australian Infectious Diseases Research Institute, Brisbane, Queensland, Australia
  3. Public Health Virology Laboratory, Department of Health, Queensland Government, Brisbane, Queensland, Australia
  4. Australian Army Malaria Institute, Gallipoli Barracks, Enoggera, Queensland, Australia
  5. Berrimah Veterinary Laboratory, Department of Primary Industries and Fisheries, Darwin, Northern Terrotory, Australia
  6. Nuffield Department of Medicine, University of Oxford, Oxford, England, United Kingdom
  7. School of Pathology and Laboratory Medicine, The University of Western Australia, Nedlands, Western Australia, Australia
  8. PathWest Laboratory Medicine, WA, Nedlands, Western Australia, Australia
  9. Centre for Disease Control, Health Protection Division, Northern Territory Department of Health, Darwin, Northern Territory, Australia

Mosquito-borne flaviviruses are responsible for significant diseases, such as dengue fever, Japanese encephalitis, West Nile fever, and Zika fever. However, a subgroup of flaviviruses known as insect-specific flavivirus (ISFs) are only found in mosquitoes and do not infect or replicate in vertebrates. ISFs are of particular interest due to their intriguing evolutionary origins and growing evidence that they can interfere with the transmission of some flavivirus pathogens. Moreover, they can provide the platform for the development of safe diagnostics and vaccines for flaviviral diseases. In this project, the biodiversity of ISFs in northern Australia was investigated using a novel broad-spectrum, sequence-independent virus screening system in addition to a pan-flavivirus RT-PCR. New flaviviruses were further characterised through deep sequencing, phylogenetic and antigenic analyses as well as infection studies in a range of vertebrate and mosquito cell lines. Two novel ISFs, tentatively named Binjari virus (BinJV) and Lily Creek virus (LiCV) were detected in and isolated from Aedes normanensis and Aedeomyia catasticta mosquitoes, respectively. Analysis of the full-length genome sequence of the new viruses revealed they were phylogenetically distinct from all other flaviviruses reported to date, but were most closely related to Lineage II ISFs. Monoclonal antibody binding profiles further revealed that BinJV and LiCV were antigenically distinct from other flaviviruses. Development of infectious DNAs of wild type and mutant BinJV as well as chimeric viruses formed between BinJV and West Nile, Zika or dengue virus provides a novel recombinant vehicle for efficient production of safe, next-generation flavivirus diagnostic antigens.