Porcine reproductive and respiratory syndrome (PRRS) gives pigs a fever and cough, but it costs American swine farmers over $600 million a year. Vaccines have been ineffective at fighting it, as has breeding pigs to be resistant. Last year, researchers in the Midwest used CRISPR-Cas9-based gene engineering to generate pigs that lack CD163, the protein that PRRS uses to infect its target cells in pigs. Now, the same team just demonstrated that the pigs lacking the receptor don’t get sick when exposed to PRRS.
While the science is pretty cool, in some ways I’m more interested to see how this type of manipulation is going to play out in terms of IP law. I presume it means that pig farmers will have to purchase a license and will be forbidden to breed the animals (or be fined for any hybrids found on their property), based on how it’s worked out in the corn industry.
I’m a bit skeptical of the statement that knocking out CD163 did not affect the pigs in any adverse way. In humans, the function of CD163 is:
as an acute phase-regulated receptor involved in the clearance and endocytosis of hemoglobin/haptoglobin complexes by macrophages, and may thereby protect tissues from free hemoglobin-mediated oxidative damage. This protein may also function as an innate immune sensor for bacteria and inducer of local inflammation.
I wonder if these knockout pigs might be more at risk for other diseases. The pigs were sacrificed at 1 month, so I doubt the researchers know yet.