Porcine Reproductive and Respiratory Syndrome costs the swine industry billions each year. At the same time it makes meat more expensive as farms are constantly experiencing costs related to the disease. Now scientists used advanced genetic techniques to produce pigs that may be resilient to Porcine Reproductive and Respiratory Syndrome.
Initial tests are promising – there are two types of the disease and cells that scientists created are resilient to both. Furthermore, animals are healthy and their immune system is otherwise intact – they can still fight off other infections. Porcine Reproductive and Respiratory Syndrome causes breathing problems for young pigs and breeding problems. Virus establishes infection by attacking immune cells called macrophages. There is a molecule on the surface of these cells, called CD163, which helps the virus to attach to it. Scientists from University of Edinburgh used complex gene-editing techniques to cut CD163 gene out from the pigs’ DNA code.
Then some testing was done with cell samples and scientists could confirm that virus could not attach itself to modified cells. And now that the experiments with cell cultures are completed scientists will try it with animal models themselves. Interestingly, not the entire CD163 molecule is removed with this process – only the part that interests the virus. There have been studies that removed CD163 altogether, but it was found that it actually has other important functions and it would be better to retain it.
Porcine Reproductive and Respiratory Syndrome costs a lot of money for pig industry as well as consumers of pork. Jonathan Lightner, one of the researchers, said that this study “demonstrates that a targeted removal of the viral interacting domain can confer resistance while the reminder of the protein is present. This, and other gene edits, will be evaluated as Genus advances the development of gene editing to confer PRRSv resistance”.
Gene editing may actually solve problems of many viruses like this. Viruses have particular targets that they aim for when infecting the organism. Not all of these targets are crucial for the animal, so they could be removed of modified, making the entire population resistant to the virus without need for vaccines.