Realising the potential of a genetically engineered and uniquely cross protective vaccine for Bluetongue disease

Lead Research Organisation: London School of Hygiene & Tropical Medicine
Department Name: Infectious and Tropical Diseases

Abstract

Bluetongue disease is a debilitating and, in severe cases, lethal, animal disease that is a major economic threat to livestock and agriculture. Current vaccines available for Bluetongue are not considered to be safe enough for widespread use. Our laboratory has developed a replication defective (DISC) virus that can be used safely as an alternative BTV vaccine with none of the existing issues. In order to commercialize this vaccine a number of optimizations are necessary. In particular, the stability of the specialized cells which support the growth of the vaccine virus will be optimized. Moreover, to ensure that the DISC virus does not change with time, we will monitor for potential changes in the growth of the virus, expression of virus proteins and genome. The optimal storage conditions for vaccine and number of dose required will be determined in sheep to ensure that protection afforded is maximized.
 
Description BTV DISC strains are a safe and effective vaccine against bluetongue disease with DIVA potential. The original DISC vaccine strains with GFP in S9 proved to be genetically stable, with alteration in dsRNA profile observed but no reversion to wild type. Therefore, a second generation DISC vaccine (DISC2) was developed and 7 vaccine strains (serotypes -1,-2,-4,-8,-9,-10 and -16) were generated. The DISC2 vaccine strains were genetically stable after continuous passage (up to 10 passages) with no recombination or reversion to wild type virus observed. The DISC2 viruses were highly stable and suitable for large scale production. The stable cell line BSR VP6, which is essential for DISC growth, had detectable VP6 expression and was able to successfully support high titre virus production after 10 or 15 passages in tissue culture. For the DISC vaccine to elicit protective immunity the infectivity of particles must be maintained, therefore optimal conditions for storage and transportation were investigated. We demonstrated that the DISC vaccine maintained infectivity when desiccated in the presence of trehalose. This condition removes the vaccine from cold-chain storage and transportation thus reducing costs of vaccine production. Furthermore, the effect of desiccation and trehalose did not affect the protective immune response of sheep upon vaccination.
Exploitation Route The findings from this follow-on grant can be applied directly to the commercialisation of a BTV or other related virus vaccine by any industrial partner. We are currently seeking an industrial partner to commercially produce these BTV vaccine strains.
Sectors Agriculture, Food and Drink

 
Description We have generated highly attenuated RG-based vaccines for BTV and currently trying to find interested industrial partner to test these vaccines in animals and to manufacture for marketing.
First Year Of Impact 2014
Sector Agriculture, Food and Drink
Impact Types Economic

 
Title AHSV1 and BTV1 VP2 tip-domain studies 
Description Set of constructs for E. Coli and Baculovirus expression of AHSV VP2 tip-domain: Bacterial expression constructs: pHis-GST-A1tip pHis-Sumo-A1tip pHis-Sumo-A1tip2 pET-TwinStrep-B1tip-Chis pET-A1tip-Strep pET-A1tip-FdSA Baculovirus expression constructs: pHT-HisTEV-A1VP2 pIP-A1tip-Strep pIP-A1tip-FdSA 
Type Of Material Model of mechanisms or symptoms - in vitro 
Provided To Others? No  
Impact The characterization of VP2 tip-domain is a powerful tool for virus - cellular receptor interaction studies. 
 
Title BSR-VP6 cell line stability 
Description Data on BSR-VP6 cell line stability; number of passages that the cell line can be continually passaged and VP6 is detectable by western immunoblot and can support DISC virus growth. 
Type Of Material Cell line 
Provided To Others? No  
Impact This test was conducted in order to study the genetic stability of the stable cell line expressing BTV VP6 that can be used for growing disabled viruses, potential vaccines. 
 
Title BTV DISC viruses 
Description BTV DISC viruses were able to grow in cells that provide the VP6 protein in trans (BSR-VP6 cell line) but were not able to go through a full replication cycle in normal cells. The restriction imposed by this replication deficiency suggests that these viruses will not represent a risk of wild type virus release. 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact These viruses has a potential for vaccine 
 
Title BTV replication defective virus 
Description BTV-1 with mutations in an essential gene which stops the virus from undergoing complete replication in normal wild type cells. Growth of the virus can only occur in cells that supply the complementary protein in trans. 
Type Of Material Model of mechanisms or symptoms - in vitro 
Provided To Others? No  
Impact Replication deficient viruses has a potential as vaccine candidates 
 
Title DISC 2 
Description A multiple mutated BTV segment S9 was designed in order to improve a new generation of vaccines. This new BTV-1 platform was name DISC 2. 
Type Of Material Model of mechanisms or symptoms - in vitro 
Provided To Others? No  
Impact This new research tool has improve the genetic stability of replication deficient BTV strains that can be tested as vaccine candidates 
 
Title DNA Plasmid 
Description Plasmid constructs (serotype specific exact copy and S9 deletion/mutations) 
Type Of Material Model of mechanisms or symptoms - in vitro 
Provided To Others? No  
Impact A range of mutation in BTV S9 (enconding VP6) were tested to generate cell lines and improve the reverse genetics system for BTV. 
 
Title Evaluation of vaccine efficacy 
Description Replication-deficient vaccine strains were tested in animals as monovalent or in multivalent combinations and the protection analysed by Elisa and serum neutralisation assays. 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact Testing these virus vaccine strains is essential to support them for commercial development 
 
Title RNA-RNA interaction and electrophoretic mobility shift assay (EMSA) 
Description For RNA-RNA interactions ssRNA segments, 150 ng linearized plasmid templates were transcribed either in pairs or combinations of multiple segments. RNA transcription was carried out in a buffer containing 40mM Tris, pH7.5; 10mM MgCl2; 20mM NaCl2, 3mM spermidine, 50mM DTT; 5mM each rNTPs; 10U RNase inhibitor and 40U of T7 RNA Polymerase (Thermo Scientific) for 3 h at 37°C followed by RNase free DNase 1 treatment. Immediately after DNase treatment, detection of RNA complexes was done by electrophoretic mobility shift assay (EMSA). Electrophoresis gel was run for 180 min at 150 V in TBM buffer (45mM Tris, pH8.3; 43mM boric acid; 0.1mM MgCl2) and stained with 0.01% (w/v) ethidium bromide. 
Type Of Material Technology assay or reagent 
Year Produced 2015 
Provided To Others? Yes  
Impact Understanding packaging signals is essential for development of antiviral reagents. 
URL https://www.ncbi.nlm.nih.gov/pubmed/27736800
 
Title Reassortant defective viruses 
Description All reassortant viruses were tested for their growth in complementary cells (BSR-VP6) and their inability to grow in normal cells (BSR) as a tested for vaccine candidate. 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact This tool was developed to test if BTV-1 can be used as a platform for a rapid generation of vaccines against different BTV serotypes. It was successful. 
 
Title Storing vaccine strains 
Description A range of reagents and conditions for storing vaccine strains was tested in order to optimise a formulation for the use of DISC viruses as vaccine 
Type Of Material Technology assay or reagent 
Provided To Others? No  
Impact Optimisation of transport and stability conditions for vaccine candidates is essential for a better cost-effective vaccine. 
 
Title Templates for T7 transcripts for different serotypes 
Description Vectors carrying exact copies of segments 2 (L2) and 5 (M5) from several serotypes were generated. pUCT7BTV-2L2, pUCT7BTV-2M5, pUCT7BTV-4L2, pUCT7BTV-4M5, pUCT7BTV-8L2, pUCT7BTV-8M5, pUCT7BTV-13L2, pUCT7BTV-13M5, pUCT7BTV-21L2, pUCT7BTV-21M5, pUCT7BTV-23L2, pUCT7BTV-23-M5, pUCT7BTV-24L2, pUCT7BTV-24M5. 
Type Of Material Model of mechanisms or symptoms - in vitro 
Provided To Others? No  
Impact This reagents were generated as a proof of concept to development of new set of vaccines against different BTV serotypes. 
 
Title Antibodies after vaccination 
Description Details of sheep antibodies post-vaccination 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
Impact Novel vaccine strains made by using reverse genetics have taught other orbivirus researchers how to develop safe vaccines. 
 
Description Assessment of DISC Vaccines 
Organisation French Agency for Food, Environmental and Occupational Health & Safety (ANSES)
Country France 
Sector Public 
PI Contribution Vaccination and challenge studies using DISC vaccines.
Start Year 2011
 
Description Natural host - BTV vaccine testing in animals - Germany 
Organisation Friedrich Loeffler Institute
Country Germany 
Sector Academic/University 
PI Contribution Development of BTV vaccine candidates.
Collaborator Contribution Testing of BTV vaccine candidates on animals.
Impact BTV vaccine candidates are safe, elicited immune responses and protected challenged animals.
Start Year 2012
 
Description Natural host - BTV vaccine testing in animals - Netherlands 
Organisation Central Veterinary Institute
Country Netherlands 
Sector Public 
PI Contribution Development of BTV vaccine candidates.
Collaborator Contribution Testing of BTV vaccine candidates on animals.
Impact BTV vaccine candidates are safe, elicited immune responses and protected challenged animals.
Start Year 2012
 
Title METHOD FOR PRODUCING VACCINAL VIRAL STRAIN OF A VIRUS OF THE REOVIRIDAE FAMILY 
Description The invention relates to a method for producing a modified viral strain of a virus which is a member of the Reoviridae family and, in particular, relates to vaccinal viral strains of the Orbivirus genus. 
IP Reference WO2009068870 
Protection Patent granted
Year Protection Granted 2009
Licensed No
Impact This will allow potentially for future BTV vaccine manufacturing and marketing. This discovery also lead to make similar vaccines for all strains of African Horse sickness virus, that are now currently ready for potential manufacturer . The technology has opened up understanding of virus life cycle and its impact on immune response and pathogenicity that are currently being studied by orbivirus virologists around the world.
 
Description 8th European Meeting on Viral Zoonoses 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact The 8th European Meeting on Viral Zoonoses was organised by the European Society for Virology. It brought together virologist from all over the world to discuss about ecology, epidemiology, evolution, virus-host interactions, prevention and control of current zoonotic viruses. The results concerning the protective efficacy of Bluetongue virus and African Horse Sickness virus replication-deficient vaccine strains were presented and discussed afterwards.
Year(s) Of Engagement Activity 2017
URL http://euroviralzoon.com/
 
Description PMB Seminar 2013 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Presentation of results for discussion with peer researchers
Year(s) Of Engagement Activity 2013
 
Description Scripps Research Institute 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Lecture given by Professor Roy Lecture topic: Phased replication by Bluetongue virus and its application to vaccine design A lecture and Powerpoint presentation.

no actual impacts realised to date
Year(s) Of Engagement Activity 2013
 
Description Vaccine Centre Seminar-2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Professional Practitioners
Results and Impact Present the results for the replication-deficient BTV strains in animal trials.
Year(s) Of Engagement Activity 2016
 
Description Vaccine Delivery Systems for the Future, Euroscicon 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Professor Roy was a keynote speaker at this conference Presentation: Non-Replicating Viral Vaccines and Novel Antigen Delivery System

no actual impacts realised to date
Year(s) Of Engagement Activity 2013