A sustained vaccine-vehicle for cattle pathogens

Lead Research Organisation: University of Edinburgh
Department Name: Sch of Biological Sciences

Abstract

Infectious diseases of cattle have an enormous financial and welfare impact world-wide. High incidence pathogens with importance either through cattle disease (with associated loss of productivity) or the potential for human zoonosis include salmonella, E.coli O157, tuberculosis and Campylobacter, to name but a few. With a world cattle population in excess of 1.3 billion, the potential market for bovine vaccine products is enormous (currently estimated at 1 billion US$). Most cattle harbour the non-pathogenic parasite Trypanosoma theileri. This protozoan is sustained at low-levels without affecting productivity in beef and dairy herds. By utilising the genetic tractability of trypanosomatid parasites, we have developed T. theileri as a potential delivery system for antigens in cattle. Importantly, the vehicle is expected to persist at a low-level in cattle for long periods enabling sustained antigen delivery. Our prior work has overcome the major hurdles to development of the vehicle: namely, long-term in vitro culture, production of the stably-engineered vehicle and the expression of heterologous proteins. By optimisation and validation of the delivery system, we now wish to widen the technology to a stage suitable for evaluation of its commerical viability. Significantly, the process and production costs of the proposed vaccine-vehicle are likely to be low in comparison to existing vaccine strategies. By providing prolonged release of recombinant protein, T. theileri has the potential to afford a novel and flexible expression vehicle for immunogens from cattle pathogens. Our aims in this development phase are to: -optimise expression of exogenous proteins by the engineered parasite; -develop and validate a biological containment strategy for the vaccine-vehicle, and -examine maintenance and protein expression of the vaccine-vehicle in cattle and to assay the resulting antigen-specific immune responses. This application represents a partnership between UK academics (based at the University of Edinburgh and Moredun Research Institute) and Industry (Intervet). This provides a unique skills base to maximise the potential for ultimate commericalisation. The Industrial Partner, Intervet, is among the three most prominent animal health companies in the world and the leading company for animal vaccines. As such, their involvement brings a strong focus to the industrial applications of the project providing expertise in vaccinology, disease knowledge, and reagents to prove practicality of the system. In addition to their direct financial commitment to the proposal, the Industrial Partner also will contribute to ongoing IP protection and extensive provision of specialist contained facilities for animal trials. Combined, this represents an 'in-kind' contribution in excess of £100,000, this equating to an approximately 20% financial contribution over-and above the 10% direct cash contribution required for an Industrial Partnership Application.

Technical Summary

We have developed a potential novel vehicle for vaccinating cattle. We aim to optimise the system to assess the efficacy of protein expression, persistence and antigen-presentation in vivo. This will provide proof-of-concept data essential for commercial development. The key objectives are: 1. Optimisation of protein expression. To maximise antigen production and presentation for sustained immune stimulation we will (i) optimise the gene expression control signals in already-proven expression constructs and (ii) exploit existing knowledge of protein trafficking in the vehicle to direct antigens to different sites (internal, surface, secreted) for presentation. 2. Containment of the vehicle. We will validate a biological containment strategy to prevent dissemination of the engineered vehicle. Transmission-disabled mutants will be assayed for their viability in culture. Non-viability of the genetically disabled vehicle in a suitable arthropod vector will also be confirmed. 3. Validation of the vehicle in cattle: The vehicle will be assayed for longevity and efficacy in cattle using dedicated facilities at Moredun Research Institute and the Industrial partner. Specifically, we will monitor: (i) The persistence of the vehicle alone, or in the context of a pre-existing population. (ii) The persistence of the vehicle in cattle when antigen is routed to different locations for expression. (iii) The sustained expression of the delivered protein after vaccination. (iv) The antibody responses generated to vaccine candidates in cattle. Our expertise in molecular cell biology (KRM), immunity to cattle parasites (JBM) and the expertise of the industrial partner in animal vaccine development will allow us to develop this novel vaccine delivery system for cattle.
 
Description We have developed a novel trypanosomatid based vaccine delivery system for the immunisation against cattle pathogens. We developed methods to grow, transfect and express heterologous proteins through the trypanosomatid vehicle. We then tested its immunogenicity in vivo in cattle and demonstrated effective immune responses were generated to the expressed antigen. In addition we completed the genome sequencing of the trypanosomatid that will be informative for those analysing the genome sequences of pathogenic trypanosomatids and this work was published :

An Alternative Strategy for Trypanosome Survival in the Mammalian Bloodstream Revealed through Genome and Transcriptome Analysis of the Ubiquitous Bovine Parasite Trypanosoma (Megatrypanum) theileri.
Kelly S, Ivens A, Mott GA, O'Neill E, Emms D, Macleod O, Voorheis P, Tyler K, Clark M, Matthews J, Matthews K, Carrington M.
Genome Biol Evol. 2017 Aug 1;9(8):2093-2109. doi: 10.1093/gbe/evx152.
Exploitation Route We have derived a cell line of Trypanosoma melophagium as a novel delivery platform for sheep vaccines. Methods of culture and transfection were generated. Also, the methods we have developed have been taken on by another group looking at immunmodulatory effects of pathogen molecules by their expression from Trypanosoma musculi, a mouse equivalent of the Trypanosoma theileri system we have developed:

Modulation of the Immune Response by Nematode Secreted Acetylcholinesterase Revealed by Heterologous Expression in Trypanosoma musculi.
Vaux R, Schnoeller C, Berkachy R, Roberts LB, Hagen J, Gounaris K, Selkirk ME.
PLoS Pathog. 2016 Nov 1;12(11):e1005998. doi: 10.1371/journal.ppat.1005998. PMID: 27802350

Further support for the work, and related experiments focused on a non pathogenic sheep trypanosomatid have secured funding support from the Supporting Evidence Based Interventions programme (funds from the Bill and Melinda Gates foundation) (for the cattle work) and form Roslin Technologies Ltd (for the sheep trypanosomatid work).
Sectors Agriculture, Food and Drink,Education

 
Description This project successfully developed a novel cattle vaccination approach based on a commensal protozoan antigen delivery vehicle. The technology, developed collaboratively with Intervet MSD has been patented, this being held by the Universty of Edinburgh. This research also made practical use of the extensive investment in the basic biology of trypanosomatid parasite. These are a model for ancient eukaryotic orgasisms and also important pathogens of the tropics. The methods developed in the project have secured further funding as BBSRC Super Follow on fund, and thereafter funding for a related project for sheep trypansomatids (supported by the Royal Society GCRF challenge scheme in 2016/2017 (Development of a non-pathogenic trypanosomatid of sheep as a sustained vaccine delivery vehicle for ovine infections in the developing world. Principal Applicant, Professor Keith R. Matthews. Royal Society GCRF Challenge grant. Royal Society, £117, 261) and for application to zoonotic infections (A novel livestock-vaccination platform to prevent zoonotic emerging infections. Principal applicant, Professor Keith R. Matthews. Innovate UK. £327,239.) Further development work has also been supported through a Bill and Melinda Gates Foundation award (Supporting Evidence based interventions) to explore the potential of the system for vaccination against pathogens of low and middle income countries, with a vaccine antigen from Theileria parasites being tested.
First Year Of Impact 2011
Sector Agriculture, Food and Drink,Education
Impact Types Economic

 
Description GCRF Challenge award
Amount £117,261 (GBP)
Funding ID CH160034 
Organisation The Royal Society 
Sector Charity/Non Profit
Country United Kingdom
Start 12/2016 
End 10/2018
 
Description SBRI Vaccines for Global Epidemics - Preclinical Stage 1
Amount £334,000 (GBP)
Funding ID 86235-544135 
Organisation Innovate UK 
Sector Public
Country United Kingdom
Start 04/2017 
End 04/2018
 
Description Collaboration with Moredun 
Organisation Moredun Research Institute
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Provision of transgenic T theileri for the infection of cattle in a contained facility to evaluate immune responses generated toe expressed antigens
Collaborator Contribution Provision of a contained cattle facility
Impact See publication linked to this output
Start Year 2009
 
Description Collaboration with researchers at Roslin Institute 
Organisation University of Edinburgh
Department The Roslin Institute
Country United Kingdom 
Sector Academic/University 
PI Contribution We expressed antigens of the cattle Parasite Trypanosoma congolense in Trypanosoma theileri and this was used as the basis of experiments to evaluate the ability of these T congolense antigens to generate immune responses in cattle.
Collaborator Contribution Antigen sequences were provided to generate the recombinant T. theileri cell lines and these are being evaluated by them for immunogenicity in cattle
Impact A funding application has been submitted to the Bill and Melinda Gates foundation to progress development of this vaccination approach
Start Year 2016
 
Description Intervet collaboration 
Organisation Intervet-Schering Plough
Country United States 
Sector Private 
PI Contribution We evaluated a novel vaccine vehicle for the delivery of antigens to cattle. We expressed an antigen provided by Intervet (after expression optimisation of the vaccine delivery vehicle) and tested its immunogenicity in cattle.
Collaborator Contribution Intervet provided technical guidance, reagents and IP protection support. They also provided a cash contribution to the award as required by the Industrial Partnership scheme.
Impact Publication Mott, G. A.; Wilson, R.; Fernando, A.; Robinson, A.; MacGregor, P.; Kennedy, D.; Schaap, D.; Matthews, J. B. and Matthews, K. R. (2011) Targetting cattle-borne zoonoses and cattle pathogens using a novel trypanosomatid-based delivery system. PLoS Pathogens, 7(10):e1002340. Outreach Wellcome Trust blog: http://blog.wellcome.ac.uk/2012/02/14/neglected-tropical-diseases-working-with-animals/ BBSRC news feature: http://www.bbsrc.ac.uk/news/food-security/2011/111028-pr-cattle-parasite-vaccine.aspx Veterinary record news report: http://veterinaryrecord.bmj.com/content/169/21/541.1.extract
Start Year 2009
 
Description collaboration with the 'Supporting Evidence based Interventions' programme at the University of Edinburgh 
Organisation University of Edinburgh
Country United Kingdom 
Sector Academic/University 
PI Contribution Our vaccine vehicle technology is being use din a collaboration with the Supporting Evidence Based interventions programme at the University of Edinburgh to investigate the potential of using the cattle vaccination approach to target thjileria parasites in Africa
Collaborator Contribution The SEBI programme seeks to develop novel technologies to address issues of livestock productivity in sub Saharan Africa. It is funded by the Bill and Melinda Gates foundation.
Impact The work is ongoing
Start Year 2018
 
Title 'Recombinant Trypanosoma theileri parasite' 
Description We developed Trypanosome theileri as a vaccine vehicle for the delivery of antigens and other therapeutics to cattle 
IP Reference WO2012013939 
Protection Patent application published
Year Protection Granted
Licensed No
Impact The patent application is under review in the US at present. Development work is being supported by a BBBSRC Super Follow on fund application
 
Title RECOMBINANT TRYPANOSOMA THEILERI PARASITE 
Description Patent for the production of recombinant Trypanosoma theileri for the purposes of vaccine delivery 
IP Reference EP2598163 
Protection Patent granted
Year Protection Granted 2017
Licensed No
Impact None
 
Title Recombinant Trypanosoma theileri as a vaccine vehicle 
Description We have developed Trypanosoma theileri as a vaccine delivery system. 
Type Of Technology New/Improved Technique/Technology 
Year Produced 2011 
Impact Patent submitted, as detailed under the Intellectual property section of the Portfolio