The Pirbright Institute has generated the first pig antibodies against swine influenza (flu) that protect against infection and recognize the same parts of the flu virus as human antibodies. This indicates they could be used to develop and assess human antibody therapies and their delivery methods, a release from the group says. These antibodies also have the potential to improve how flu virus evolution is monitored and inform decisions about annual flu vaccine selection.
Antibodies are a part of the body’s immune system response and help fight off infection by latching on to important parts of foreign microorganisms to neutralize them. With flu viruses, antibodies target a protein on the surface of the virus called haemagglutinin, which prevents the virus from entering cells and replicating
Pirbright scientists worked in collaboration with the University of Oxford, The Francis Crick Institute and The Pirbright Livestock Antibody Hub to generate pig antibodies in the laboratory (known as monoclonal antibodies, or mAbs). These are the first pig mAbs to be generated which target the influenza virus, the release says.
These mAbs recognize the same two main sites of the flu virus haemagglutinin protein that are targeted by human antibodies and were found to be just as effective at neutralising the swine flu strain that caused the 2009 pandemic, it continues. The scientists then treated pigs with one of the mAbs prior to infection, and they were protected from severe disease. The flu virus was also eliminated from their lungs. This indicates that the mAbs have great therapeutic potential and could be used to evaluate mAb delivery methods.
The findings in the study, published in PLOS Pathogens, demonstrate that pig mAbs are more closely matched to human antibodies and could therefore improve the reliability of human vaccine selection, the release says. Right now, ferrets are commonly used as models to monitor flu virus evolution and to design or select vaccines that will provide the best protection against human seasonal flu strains. However, ferret antibodies only recognize one of the two main haemagglutinin sites that human antibodies target.
Dr. Elma Tchilian, Mucosal Immunology Group Leader at Pirbright, said in the release, “These data demonstrate that pigs and humans, which are both natural hosts for influenza viruses, generate very similar immune responses. This makes the pig an excellent translational model for testing novel vaccines and monoclonal antibody delivery methods.”
Professor John Hammond, leader of The Pirbright Livestock Antibody Hub, added: “These results are a fantastic demonstration of how The Pirbright Livestock Antibody Hub can promote the use of new tools and methods, providing the opportunity to examine detailed antibody responses to inform the next generation of vaccines and therapies. This work reinforces the use of pigs as powerful model to predict human responses in infection and vaccination.”
The full paper is available here.
This study was supported by the Bill & Melinda Gates Foundation and the Biotechnology and Biological Sciences Research Council (BBSRC), part of UK Research and Innovation (UKRI). Scientists from Oxford were also supported by the Chinese Academy of Medical Sciences (CAMS) Innovation Fund for Medical Sciences (CIFMS), China Grant, the Townsend-Jeantet Prize Charitable Trust and the Medical Research Council (MRC, UKRI). Scientists from The Francis Crick Institute were supported by Cancer Research UK, the Medical Research Council and the Wellcome Trust.
