Production of genetically modified chickens resistant to important avian respiratory diseases.
Lead Research Organisation:
University of Cambridge
Department Name: Veterinary Medicine
Abstract
Our ultimate objective is to improve the resistance of livestock species to viral diseases. . This has important implications for animal health and welfare but avian species and pigs can also act as bridging hosts that enable novel strains of influenza virus to cause infection in humans. Currently we are focusing on chickens as a test-bed for identifying the most effective ways to achieve this objective. Producing AI resistant chickens would reduce the threat of a new pandemic influenza virus emerging in humans, contribute to global food security and decrease the economic consequences of controlling the infection in poultry. Our approach is to introduce novel genes into the chicken genome that become activated by influenza infection and produce molecules that specifically and potently suppress virus replication. These molecules are intrinsically harmless to the chicken, safe for consumption and in the absence of virus infection are produced at very low levels. Influenza virus infection results in the increased production of these inhibitory molecules which then either interfere directly with the virus replication machinery or trigger the production of normal cellular proteins with antiviral properties.
The project involves the construction and testing of a series of different inhibitory genes firstly in cell culture and then introducing the most effective ones into chickens using genetic modification techniques. These transgenic birds are then tested to determine whether they are resistant to AI infection. The project is described as a pipeline because the various inhibitory transgenes have reached different stages of development. Some have already been shown to be effective in GM chickens, some in cell culture and others are still at the conceptual phase. Most of the work is aimed at influenza virus. However, some preliminary work is proposed to determine whether similar approaches can be developed against other important avian virus infections.
The project involves the construction and testing of a series of different inhibitory genes firstly in cell culture and then introducing the most effective ones into chickens using genetic modification techniques. These transgenic birds are then tested to determine whether they are resistant to AI infection. The project is described as a pipeline because the various inhibitory transgenes have reached different stages of development. Some have already been shown to be effective in GM chickens, some in cell culture and others are still at the conceptual phase. Most of the work is aimed at influenza virus. However, some preliminary work is proposed to determine whether similar approaches can be developed against other important avian virus infections.
Technical Summary
Our objective is to use genetically modified chickens to improve our understanding of resistance to infection by avian influenza (AI) virus and other livestock viral diseases. We have previously generated transgenic chickens that express a small RNA decoy molecule (Decoy 5) that inhibited transmission of AIV from infected transgenic birds to other birds cohoused with them. We will extend this study by analysing the AIV shed by these birds to determine the basis of the block to transmission. We will generate homozygous Decoy 5 birds to test if a doubling of the transgene expression enhances protection. We have produced a new version of the decoy molecule that is more effective in in vitro assays. This will be used to generate transgenic chickens by lentivector injection into chick embryos that will be hatched and screened to identify germline transgenic birds. Transgenic offspring will be challenged with H5N1 virus to determine the effectiveness of the transgene in vivo.
Previous BBSRC funding enabled the development of an RNA replicon-based influenza-contingent gene expression system that can be used transgenically to produce inhibitory effector proteins in response to influenza virus infection. Flu-contingent expression of chicken tBID and interferon alpha caused potent inhibition of gene expression in cell culture. They await introduction into chickens and testing by in vivo challenge studies. We shall extend this strategy to induce expression of a strong CTL target protein from another avian virus routinely controlled by vaccination. Induction of this target protein by AI infection should result in cell lysis by CTLs generated by the normal vaccination schedule of chickens. We also intend to introduce a functional Mx gene under the control of the chMx promoter that might combine synergistically with the chIFN replicon described above.
We will also explore the potential of developing decoy and RNA replicon based strategies for Infectious bronchitis, Infectious bursal disease and Newcastle disease virus
Previous BBSRC funding enabled the development of an RNA replicon-based influenza-contingent gene expression system that can be used transgenically to produce inhibitory effector proteins in response to influenza virus infection. Flu-contingent expression of chicken tBID and interferon alpha caused potent inhibition of gene expression in cell culture. They await introduction into chickens and testing by in vivo challenge studies. We shall extend this strategy to induce expression of a strong CTL target protein from another avian virus routinely controlled by vaccination. Induction of this target protein by AI infection should result in cell lysis by CTLs generated by the normal vaccination schedule of chickens. We also intend to introduce a functional Mx gene under the control of the chMx promoter that might combine synergistically with the chIFN replicon described above.
We will also explore the potential of developing decoy and RNA replicon based strategies for Infectious bronchitis, Infectious bursal disease and Newcastle disease virus
Planned Impact
The work described in this programme has the potential to have a very wide impact. It may benefit the industrial partner directly but also the vaccine, poultry breeding and production industries. The prior research has already been noted by policy makers e.g. the applicants have been asked to POST notes by the Parliamentary office of science and technology, and this programme is likely to increase the interest of policy makers internationally. The wider public are interested in the programme and could be beneficiaries as consumers.
How will they benefit:
Industrial partner: the industrial partner will be in a position to evaluate the potential for improving disease resistance by alternative vaccination technologies, conventional genetic methods or GM technologies.
Producers: the elimination of avian influenza from the commercial poultry sector would have a major impact on the economic, food security, public health and animal welfare consequences of this disease. Currently in the UK AI is controlled by biosecurity measures. It is unlikely that this development would significantly reduce these costs because the measures are necessary to control other pathogens. However, stringent biosecurity measures are largely incompatible with free-range production, which is an expanding sector of the industry. Resistant chickens would reduce the vulnerability of this sector to production losses due to influenza infection.
In other parts of the world, vaccination is used as an adjunct or even as an alternative to biosecurity. This is also costly and unless rigorously maintained may become ineffective. The potential for production losses has been amply demonstrated by the consequences of the H5N1 epizootic in SE Asia and in parts of Africa. Influenza resistant chickens would eliminate the requirement for vaccination and the associated costs of updating vaccines against avian influenza virus.
Consumers: resistant chickens would reduce the threat of a severe epidemic causing shortages of this increasingly important source of the world's universally acceptable source of protein.
Scientists: The research will help evaluate alternative approaches to improving disease resistance of domestic livestock. The development of influenza virus resistant chickens would provide a highly persuasive example of the potential benefits of GM technologies for reducing the zoonotic threat posed by avian influenza virus and improving animal health, productivity and welfare. This could help to change public attitude to genetic modification to a more favourable view. Such a development would encourage other scientists in the UK and elsewhere to re-engage with GM research, particularly where it relates to zoonotic threats and food security.
The public at large: the public health threat of avian influenza is ever present and unlikely to be managed by vaccination against avian influenza.
How will they benefit:
Industrial partner: the industrial partner will be in a position to evaluate the potential for improving disease resistance by alternative vaccination technologies, conventional genetic methods or GM technologies.
Producers: the elimination of avian influenza from the commercial poultry sector would have a major impact on the economic, food security, public health and animal welfare consequences of this disease. Currently in the UK AI is controlled by biosecurity measures. It is unlikely that this development would significantly reduce these costs because the measures are necessary to control other pathogens. However, stringent biosecurity measures are largely incompatible with free-range production, which is an expanding sector of the industry. Resistant chickens would reduce the vulnerability of this sector to production losses due to influenza infection.
In other parts of the world, vaccination is used as an adjunct or even as an alternative to biosecurity. This is also costly and unless rigorously maintained may become ineffective. The potential for production losses has been amply demonstrated by the consequences of the H5N1 epizootic in SE Asia and in parts of Africa. Influenza resistant chickens would eliminate the requirement for vaccination and the associated costs of updating vaccines against avian influenza virus.
Consumers: resistant chickens would reduce the threat of a severe epidemic causing shortages of this increasingly important source of the world's universally acceptable source of protein.
Scientists: The research will help evaluate alternative approaches to improving disease resistance of domestic livestock. The development of influenza virus resistant chickens would provide a highly persuasive example of the potential benefits of GM technologies for reducing the zoonotic threat posed by avian influenza virus and improving animal health, productivity and welfare. This could help to change public attitude to genetic modification to a more favourable view. Such a development would encourage other scientists in the UK and elsewhere to re-engage with GM research, particularly where it relates to zoonotic threats and food security.
The public at large: the public health threat of avian influenza is ever present and unlikely to be managed by vaccination against avian influenza.
Publications
Bourret V
(2017)
Adaptation of avian influenza virus to a swine host
Bourret V
(2017)
Adaptation of avian influenza virus to a swine host.
in Virus evolution
McKinley T
(2020)
Efficient Bayesian Model Choice for Partially Observed Processes: With Application to an Experimental Transmission Study of an Infectious Disease
in Bayesian Analysis
Turrell L
(2013)
The role and assembly mechanism of nucleoprotein in influenza A virus ribonucleoprotein complexes.
in Nature communications
Tiley L
(2016)
Transgenic animals resistant to infectious diseases.
in Revue scientifique et technique (International Office of Epizootics)
Description | Our original "decoy" transgenic chickens showed a substantial reduction in transmission efficiency between ("donor") birds deliberately infected with highly pathogenic influenza virus H5N1 to birds placed in contact with them. However, where larger numbers of donor birds were used, transmission still occurred. We have developed two new lines of chickens. One uses enhanced decoys that have a stronger "transmission block" phenotype than the original decoy birds but are nevertheless still susceptible to direct infection. A second line that produces a virus inhibitory gene in response to virus infection has been shown to have reduced susceptibility to infection by highly pathogenic avian influenza virus. |
Exploitation Route | Genetic modification of commercial poultry and pig breeds to introduce influenza resistance. |
Sectors | Agriculture, Food and Drink |
Description | The findings have not yet been used commercially. The data have been disclosed to a poultry breeding company who are wiling to support the continued development a future grant application for further research in this area. |
First Year Of Impact | 2015 |
Sector | Agriculture, Food and Drink |
Description | Royal Society Contact Group on Gene Editing Technologies |
Geographic Reach | National |
Policy Influence Type | Participation in a guidance/advisory committee |
Description | Studentship funding |
Amount | £36,000 (GBP) |
Organisation | Genus plc |
Sector | Private |
Country | United Kingdom |
Start | 10/2014 |
End | 10/2016 |
Description | BW |
Organisation | University of Edinburgh |
Department | The Roslin Institute |
Country | United Kingdom |
Sector | Academic/University |
PI Contribution | Conception design and construction of transgenes intended to suppress influenza virus replication in pigs |
Collaborator Contribution | Gene editing and TALEN-based technology for introducing transgenes into swine germ line. |
Impact | Research funding from the TSB Catalyst scheme |
Start Year | 2013 |
Description | EW group |
Organisation | Aviagen Group |
Country | United States |
Sector | Private |
PI Contribution | Construction of GM chickens which display impaired transmission of avian influenza virus. |
Collaborator Contribution | Industrial partners in a BBSRC IPA BB/J017108/1 Provided chicken embryos for analysis of avian Mx antiviral activity. |
Impact | PMID: 20808435 PMID: 18508886 |
Start Year | 2008 |
Description | Genus |
Organisation | Genus plc |
Country | United Kingdom |
Sector | Private |
PI Contribution | Design of porcine ribozyme elements for processing short hairpin inhibitory RNA molecules. Provision of lentiviral vectors caring influenza virus inhibitory transgenes. Construction of shRNA expression system that does not stimulate RIG-I signalling pathway in porcine cells (ongoing project) |
Collaborator Contribution | 6 months financial support for postdoctoral researcher. University fees for a Ph.D student. |
Impact | None yet |
Start Year | 2011 |
Description | Cafe Scientifique, Brighton Science Festival |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | Talk in the Brighton Science Festival October 27 2018, "Genome editing in agriculture - a new apprpach or still GM?". Broad audience of engaged public including students from an access course, who engaged in long question/answer and discussion session after talk. |
Year(s) Of Engagement Activity | 2018 |
URL | http://www.brightonscience.com/events/genome-editing-in-agriculture/ |
Description | Come Dine With The Future |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Public/other audiences |
Results and Impact | What will we be eating in 50 years time? H Sang and 4 other presenters described what will be on their dinner menu, considering advances in technology and challenges of sustainability |
Year(s) Of Engagement Activity | 2016 |
URL | http://www.youtube.com/watch?v=Bkta-s7z9DY |
Description | Genome Editing and the Future of Farming |
Form Of Engagement Activity | Participation in an activity, workshop or similar |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Policymakers/politicians |
Results and Impact | On the 6th September The Roslin Institute opened its doors to an array of delegates from the worlds of research, industry and policy to discuss genome editing and its role in the future of farming, with many international colleagues including from USDA and OECD. The global challenge of food security is time critical as we will need to produce 70% more food by 2050 without destroying the environment. Innovations in food production techniques are urgently required. Editing the genomes of crops and livestock offers new possibilities to address this complex issue. The meeting discussed the status of the technologies in crops and farmed animals and the associated regualtory and societal challenges were debated, lead by presenters with a broad array of relevant expertise. My role was as chair of a session. |
Year(s) Of Engagement Activity | 2016 |
URL | http://www.nib.ac.uk/reporting-on-the-first-nib-specialist-meeting-genome-editing-and-the-future-of-... |
Description | Glasgow Skeptics: open meeting in Glasgow |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Local |
Primary Audience | Public/other audiences |
Results and Impact | "Would you eat a GM chicken?" A presentation about GM farm animals with a focus on flu resistance via GM, plenty of discussion after the talk. |
Year(s) Of Engagement Activity | 2014 |
Description | Interview by National Geographic journalist |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Telephone interview and subsequent written correspondence and provision of materials. Journalist writes for "The Plate" articles in National Geographic. Provided a balanced but generally pro-GM report on the potential of transgenic disease resistant animals. |
Year(s) Of Engagement Activity | 2015 |
URL | http://theplate.nationalgeographic.com/2015/08/05/want-a-bird-flu-free-world-consider-breeding-resis... |
Description | Interview for the magazine Science & Vie (Science & Life, the n°1 science magazine in France) |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Media (as a channel to the public) |
Results and Impact | Interview for an article on genetically modified farm animals resistant to infectious diseases. |
Year(s) Of Engagement Activity | 2017 |
Description | Interview on genetically modified animals for national magazine Science & Vie (Science & Life, the n°1 science magazine in France) |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | 30 minute interview with a journalist regarding the use of genetic modification to improve the health of livestock animals. This provided information that contributed to an article in Science & Vie, a high profile science magazine in France, a country with a notoriously strong mistrust of genetic modification. The article was reasonably balanced and fair. |
Year(s) Of Engagement Activity | 2017 |
URL | https://www.science-et-vie.com/corps-et-sante/animaux-genetiquement-modifies-bientot-dans-nos-assiet... |
Description | Interview with CBS News |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Telephone interview in response to outbreak of avian influenza in the USA. Positive reporting of GM options for disease control |
Year(s) Of Engagement Activity | 2015 |
URL | http://www.cbsnews.com/news/genetically-modified-glow-in-the-dark-chickens-could-beat-bird-flu/ |
Description | Interview with Reuters journalist |
Form Of Engagement Activity | A press release, press conference or response to a media enquiry/interview |
Part Of Official Scheme? | No |
Geographic Reach | International |
Primary Audience | Public/other audiences |
Results and Impact | Interview with Reuters journalist in response to avian influenza outbreak in USA. Generally pro-GM report on the potential of disease resistant GM animals. |
Year(s) Of Engagement Activity | 2015 |
URL | http://www.reuters.com/article/health-birdflu-gmo-idUSL1N11A22Z20150907#9clFB3AKTp8uO102.97 |
Description | Journalist interview for online "Genetic Literacy Project" |
Form Of Engagement Activity | A magazine, newsletter or online publication |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Public/other audiences |
Results and Impact | Interview in response to avian flu outbreak in USA. |
Year(s) Of Engagement Activity | 2015 |
URL | https://www.geneticliteracyproject.org/2015/08/06/gmo-chicken-could-solve-avian-flu-crisis-saving-mi... |
Description | NERC Public Engagement Strategy information event "Public engagement: discussing GM animals" |
Form Of Engagement Activity | A formal working group, expert panel or dialogue |
Part Of Official Scheme? | No |
Geographic Reach | National |
Primary Audience | Professional Practitioners |
Results and Impact | Presented on "Public engagement: discussing GM animals" to illustrate the benefits, interest and challenges of public engagement on a potentailly controversial topic |
Year(s) Of Engagement Activity | 2016 |
Description | TedX Glasgow "Why do we need GM chickens?" |
Form Of Engagement Activity | A talk or presentation |
Part Of Official Scheme? | No |
Geographic Reach | Regional |
Primary Audience | Other audiences |
Results and Impact | TedX Glasgow is a volunteer-run event attended by a an audience from school children to people supported by their employers to attend for personal development. The talks are very varied addressing a wide range of topics and so this was an opportunity to talk about GM technology in a Scottish context and in the context of sustainable agriculture. There was an oportunity at the end of the day to meet members of the audience freely and I had a lot of interesting discussions. The Youtube video has ~1390 views. https://www.youtube.com/watch?v=DUbqrh5otWs |
Year(s) Of Engagement Activity | 2017 |
URL | https://www.youtube.com/watch?v=DUbqrh5otWs |