Scientists produced pigs though gene editing that may be immune to swine infection that costs billions each year to the industry.
The research team has used advanced genetic editing techniques to produce pigs that are potentially resilient to Porcine Reproductive and Respiratory Syndrome (PRRS).
Early tests have revealed that cells from the pigs are completely resistant to infection with both major subtypes of the virus that causes the disease.
The pigs are otherwise healthy and the gene-editing technology should not affect their ability to fight off other major viral infections, the researchers say.
Porcine Reproductive and Respiratory Syndrome causes severe breathing problems in piglets and breeding failures in pregnant sows.
Studies revealed that PRRS virus attacks immune cells called macrophages. A molecule on the surface of these cells called CD163 plays a key role in enabling the PRRS virus to establish an infection.
The research team at the University of Edinburgh’s Roslin Institute, in collaboration with Genus, used a gene-editing tool called CRISPR/Cas9 to cut out a small section of the CD163 gene in the pigs’ DNA code.
Laboratory tests of cells from the pigs with the modified CD163 gene have confirmed that this change in the pig’s DNA blocks the virus from being able to cause infection.
The next stage in the study will be to test whether the pigs are resistant to infection when exposed to the virus.
Prior studies by another research team also produced pigs that are deficient of the entire CD163 molecule, and which don’t become ill when exposed to the said virus.
In recent studies, only the section of CD163 that interacts with Porcine Reproductive and Respiratory Syndrome Virus is removed and the molecule appears to retain its other functions.
PRRS Virus is endemic in most swine producing countries around the world. Most of the vaccines have failed to prevent the spreading of the disease, which continues to evolve quickly.
As a result, it is one of the utmost challenges facing pig producers of today. In Europe alone, the disease is estimated to cost the livestock industry more than €1.5 billion each year.
Head researcher Professor Alan Archibald said: “Genome-editing offers opportunities to boost food security by reducing waste and losses from infectious diseases, as well as improving animal welfare by reducing the burden of disease. Our results take us closer to realizing these benefits and specifically address the most important infectious disease problem for the pig industry worldwide.”