Researchers have been maximizing gene editing on chickens to pinpoint and alter parts of their DNA. These efforts may eventually hamper the spread of bird flu across the species.
Gene Editing on Chickens to Hamper Bird Flu Spread
According to a new study, researchers were able to restrict, but not totally block, bird flu from infecting chickens. They were able to do so by making adjustments on a small part of these birds' DNA. The chickens did not exhibit any signs that the DNA changes affected their well-being or health.
The scientists from the university of Edinburgh, the Imperial College London, and the Pirbright Institute bred the birds via gene editing to alter a DNA section that is responsible for the production of the ANP32A protein. In cases of infection, flu viruses attack this molecule for their further replication.
When the gene-edited birds were exposed to a normal H9B2-UDL strain dose of the bird flu, nine out of 10 of these chickens did not get infected. There was also no cross-chicken spread observed.
The gene-edited chickens were then exposed to an artificially high bird flu dose in order to examine their resilience further. When the chickens were exposed to this bigger dose, five out of ten ended up infected. Nevertheless, the gene edit still provided a certain degree of protection as the amount of virus infected was lower compared to those typically observed in chickens that are not gene-edited.
Aside from this, the gene editing in the chickens also hampered the further spread of the virus. In the experiment, only one of out four non-edited chickens got infected when they were kept inside one incubator. No transmission was observed among the chickens that were gene-edited.
The scientists also discovered that among the gene-edited chickens, the bird flu ended up adapting and getting the support of two proteins, namely ANP32B and ANP32E, for the virus to replicate. Further lab tests enabled the scientists to discover that some mutations allowed the virus to use the ANP32's human version. However, its replication stayed low in human airway cell cultures.
Gene Editing on More Proteins
While the gene editing exhibited some effects, the findings show that the single gene edit is not strong enough to be used in chicken production.
To stop escape viruses emergences, the team plans to target other DNA sections that take charge in the production of three proteins, namely, ANP32E, ANP32B, and ANP32A. In lab cell cultures, the virus' growth was blocked successfully in the cells where the three gene edits were done.
Moving forward, the scientist will try to breed chicken that has all three genes edited. At present, there are no such birds that have been produced.
The study stresses how important it is to conduct gene editing responsibly and to be alert of the risks that could unwarrantedly drive vial evolution if full resistance is not accomplished.
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