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Stuart Mather – 21 st October 2013. Journal Club. About the author – Ed Wright. BSc Virology (1999 – Edinburgh); PhD in Molecular Virology (2003 – Cambridge) MRC/UVRI Uganda Research Unit on AIDS (2004-2005) UCL – Postdoctoral Research Fellow in Robin Weiss lab – (2005-2011)
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Stuart Mather – 21st October 2013 Journal Club
About the author – Ed Wright • BSc Virology (1999 – Edinburgh); PhD in Molecular Virology (2003 – Cambridge) • MRC/UVRI Uganda Research Unit on AIDS (2004-2005) • UCL – Postdoctoral Research Fellow in Robin Weiss lab – (2005-2011) • University of Westminster – Senior Lecturer & Principal Investigator at VPU Fitzrovia labs – (2011-present)
Rabies • Viral infection of the brain and central nervous system – zoonotic (cross species; from animals to humans) • Transmitted in saliva – e.g. the bite of an infected dog http://asylumeclectica.com/asylum/malady/archives/rabies.htm http://dog-bitetreatment.com/category/rabies-in-dog-and-treatment • Symptoms – paraesthesia, malaise, fever, headache leading to acute pain, hyperactivity, excited/enraged behaviour, hydrophobia, paralysis and death • Symptomatic cases are nearly always fatal • Post-exposure prophylaxis (PEP) during virus incubation period can prevent illness – ≈15 million receive PEP annually
Global burden of rabies • ≈55,000 deaths per year – 95% in Africa and Asia • Over 3 billion people worldwide at a realistic risk of transmitting rabies
Rabies virus biology • Member of the Lyssavirusgenus and Rhabdoviridaefamily • Enveloped, bullet-shaped virus • ≈ 120nm long and 75nm wide • Negative sense, single-stranded, linear RNA genome of ≈11kb, encoding for 5 proteins • Glycoprotein (G) = responsible for virus binding to cellular receptors (e.g. nAChR– acetylcholine receptor) and membrane fusion • G is also the main virus antigen http://www.nhs.uk/Conditions/rabies/Pages/introduction.aspx http://viralzone.expasy.org/all_by_species/22.html
Lyssavirusgenus Banyard AC et al Adv Virus Res. 2011;79:239-89. doi: 10.1016/B978-0-12-387040-7.00012-3.
Traditional rabies serology • Fluorescent Antibody Virus Neutralisation (FAVN) Test • Rapid Fluorescent Focus Inhibition Test (RFFIT) • Enzyme Linked Immunosorbent Assay (ELISA) Infection http://www.vet.k-state.edu/depts/dmp/service/rabies/favn.htm Neutralisation http://www.cdc.gov/rabies/specific_groups/doctors/serology.html
Pseudotype viruses • ‘Chimeric’ viruses made up of a retroviral core (e.g. HIV), a heterologous envelope (e.g. rabies G) and encapsulating a quantifiable reporter gene (e.g. luciferase) • HIV - core • Rabies G – envelope • Luciferase – reporter • Non-infectious - Can be used instead of infectious virus in serological assays to determine neutralising antibody titres
Pseudotype virus production Mather et al (2013) Future Virology 8(8); 745-755
4 main aims of the study: • Comparative serology using RABV pseudotype neutralisation assay against FAVN in a vaccination trial • Production of Mokola (MOKV), Duvenhage (DUVV) and Lagos bat (LBV) pseudotype viruses • Incorporation of lacZas a pseudotype reporter gene • Stability of pseudotype viruses
Summary • Rabies pseudotype neutralisation assays perform as well as FAVN for vaccine evaluation • MOKV, LBV and DUVV lyssaviruspseudotypes have been successfully produced • lacZis a cheaper alternative to luciferase and GFP reporter genes • Rabies (CVS-11) pseudotypes are relatively stable after freeze-thawing and long term storage