In an effort to tackle the organ donor shortage, researchers in the United States have successfully created part-human, part-pig embryos and implanted them into a sow. Eventually, these animals could act as incubators for human organs, which concerns some ethicists.
To be clear: you can use your own cells in the pig chimera and get organs that are fully compatible with your own, genetically. While we hopefully figure out how to construct organs from scratch quickly and relatively cheaply, for the time being this is the best way to produce fully functional organs reliably.
Researchers from Temple University have used the CRISPR/Cas9 gene editing tool to clear out the entire HIV-1 genome from a patient’s infected immune cells. It’s a remarkable achievement that could have profound implications for the treatment of AIDS and other retroviruses.
It’s a little early to break out the champagne, but while medication for HIV has done wonders – HIV is notoriously good at hiding in the body. That’s where news like this brings hope that HIV positive people could one day be truly cured.
For the approximately 37 million people worldwide who are infected with HIV (human immunodeficiency virus), the newest cocktails of anti-retroviral drugs have come a long way in beating back the retrovirus and keeping an infection in check. Still, those drugs are no cure. While the treatments snarl the viral assembly line and thwart new infectious particles from invading the body’s cells, HIV itself is still there, hunkered in the DNA of a patient’s genome until there’s an opportunity for a comeback—say, when a patient goes off their medication.
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.
Editing the sequence of bases in a DNA molecule is pretty straightforward in a test tube. Until recently, editing the DNA of a living organism had been a very large challenge, one that was more often avoided than taken up. But a system bacteria use to defeat viruses has been repurposed to make a versatile DNA editing system.
Last week brought the horrifying news that the Ebola virus can live in the eyeballs of survivors, even after it’s been eliminated from the rest of the body. It shouldn’t have been a surprise, though. Viruses have always hidden in parts of our bodies you’d never expect. In fact, we’re all walking virus reservoirs.
CRISPR, a new genome editing tool, could transform the field of biology—and a recent study on genetically-engineered human embryos has converted this promise into media hype. But scientists have been tinkering with genomes for decades. Why is CRISPR suddenly such a big deal?