On February 19, Tim Abbott, a PhD candidate in Stanford's bioengineering department, examined the results of an experiment he was using as part of a team using the genetic manipulation Crispr technology Fight coronavirus. Abbott is working outside the laboratory of Stanley Qi, a pioneer in the development of Crispr, a tool that fights disease with debris such as cancer cells. Using a method called PAC-MAN [Prophylactic Antiviral Crispr in Human Cancer Cells], the idea is to attack the coronavirus by aiming Crispr torpedoes at it, attacking the genetic structure of the virus so that it can penetrate humans The cell then uses the cell's self-replicating machine.
In this particular experiment, he introduced the laboratory's Crispr-based system for discovering and destroying SARS-Cov 2 [scientists New coronavirus] Into a solution containing the inert synthetic fragment of the virus. Like All Crispr systemsThis part consists of two parts: an enzyme and a so-called "guide RNA". RNA directs this enzyme [Cas-13d in this case] to lock onto specific spots in the coronavirus genome and then makes a series of cuts. You can think of it as a pair of scissors that are programmed to scan recipes and shred only pages containing SARS-Cov-2 recipes.
After Abbott analyzed the data, he called Marie La Russa, the research scientist managing the project, to verify what he had seen. Crispr against coronavirus reduced the amount of virus in solution by 90%. They believe that if the kill rate is effectively transmitted, it may be enough to prevent humans from getting the disease.
The results and more a dissertation Posted last weekendPreprint Not yet peer-reviewed-suggesting we may be entering an era of developing new Crispr-based weapons to fight deadly viruses from flu to coronavirus. The author writes: "The PAC-MAN approach could be a rapidly implemented strategy for coronavirus response to emerging pandemic strains."
But before you get rid of the cheering in place, please "potentially" emphasize it. As the Stanford research team admits, their thesis is more of a blueprint or proof of concept than an actual medical treatment prepared for animal or human testing. The project has some serious X factors, including their inability to test PAC-MAN on actual coronaviruses. They have yet to develop a system to introduce it into human cells. And, as Fyodor Urnov, a professor at the University of California, Berkeley's Department of Molecular and Cell Biology, points out, even if it works, there is a long way to go between preprints and clinical tests. "Frankly, the likelihood that this method can be tested in humans in the next four to six months is zero," Urnov said. "And so on, if we try to go to the moon and return safely, this work shows that You can make rockets that can reach escape speed. "
No, this is not a quick solution, but shooting the moon is not a bad idea. "In human history, we should pursue every thoughtful thought that goes well beyond the tools we developed in the 13th century [isolation], 17th century [drugs], and 18th century [vaccinations / vaccinations]," said the University of Chicago. of Laurie Zoloth, senior adviser to the Dean's Social Ethics Program. "Crispr is a new thing that has not been proven in human disease, but logically it should work."
Crispr technology's gene-editing capabilities have been increasingly used to fight disease, initially for genetic diseases. But recently it has been exploited Fight against infectious diseases, Including now the new coronavirus. For example, multiple teams inside and outside academia are working on More effective testing with Crispr. A private company Mammoth Biosciences claims to have developed Covid-19 test Reduce results time from a few hours to less than 30 minutes. Sherlock Biosciences has produced a protocol that may enable some viable methods Like pregnancy testGive a positive signal on the test strip.
Among existing projects aimed at combating the flu and other infectious viruses, work to actually prevent or combat coronavirus using Crispr is also emerging. In 2018, Darpa started a four-year program called ready. According to its call for proposals, the idea was to use genetic methods to "generate new medical countermeasures for future use in humans." Qi's lab at Stanford University is one of several grantees. In April 2019, they began researching Crispr-based methods to fight the flu. Naturally, like coronavirus Spread this yearThe team noticed this and shifted focus in late January to viruses that have now changed our way of life.
Addressing this particular virus is a challenge. Qi said that the coronavirus has 30,000 nucleotides, while the guide RNA supported by Crispr can only target the 22 nucleotide region to be cut. For optimal attack location, a large amount of bioinformatics calculations and experiments are required.
Qi said that the attack itself was a two-tube genetic attack that affected the target. "One of the effects is to reduce the concentration of the viral genome in human cells," he said. "The second is to stop the production of viral proteins. Otherwise, it will be used to make copies of itself and suppress the body's defenses.
The nature of the attack inspired its arcade nickname. Qi said, "I like video games." "Pac-Man tried to eat cookies and was chased by a ghost. But when he came across a specific cookie called a power cookie [designed for Crispr Cas13 in our case] , It suddenly becomes very powerful. It can begin to devour ghosts and begin to clean up the entire battlefield. "