CRISPR halts coronavirus transmission in human cells

“Once the virus is recognized, the CRISPR enzyme is activated and chops up the virus.”

Using CRISPR, Australian researchers have prevented a coronavirus infection from spreading in human cells in the lab. They’re now looking for a way to develop the treatment into an oral drug that could halt coronavirus transmission in people — and potentially stop other viruses as well.

The challenge: While we do have effective COVID-19 vaccines, we’re still in need of better treatments. Right now, our best options are monoclonal antibodies, but those must be delivered intravenously, limiting their use to hospitals, and they are already becoming less effective against new variants.

This lack of treatments is a problem because, while restrictions have been eased or outright lifted in much of the United States, the pandemic is far from over — cases and deaths are on an upward trend in many parts of the nation.

The need: An oral medication that could be taken as soon as someone was diagnosed with COVID-19 could mark a turning point in the pandemic, and the Australian researchers think their CRISPR treatment could lead to the development of such a drug.

“This approach — test and treat — would only be feasible if we have a cheap, oral, and non-toxic antiviral,” lead author Sharon Lewin told Agence France-Presse (AFP).“That’s what we hope to achieve one day with this gene scissors approach.”

Blocking coronavirus transmission: CRISPR is a gene editing tool that originally evolved in bacteria as an antivirus system, for searching out viral genes and destroying them. 

In a newly published study, Australian scientists demonstrate how they programmed a CRISPR system to bind to and degrade specific parts of the coronavirus’ genome, blocking transmission between human cells.

“Once the virus is recognized, the CRISPR enzyme is activated and chops up the virus,” Lewin said. “We targeted several parts of the virus — parts that are very stable and don’t change and parts that are highly changeable — and all worked very well in chopping up the virus.”

“The power of this tool lies in its design-flexibility and adaptability.”

Mohamed Fareh

When they tested the system on infected human cells in the lab, it prevented coronavirus transmission between the cells, meaning the virus couldn’t spread from infected cells to non-infected cells.

The CRISPR treatment even worked on several troubling variants, including the one that emerged in the U.K., and could be easily tweaked to address the Delta variant or other strains, according to Lewin.

“The flexibility of CRISPR-Cas13 — which only needs the viral sequence — means we can look to rapidly design antivirals for COVID-19 and any new emerging viruses,” she said in a press release.

Looking ahead: Animal studies are next on the researchers’ agenda, and if those go well, clinical trials to see if the CRISPR treatment can prevent coronavirus transmission in humans could follow.

While Lewin said it’ll likely be “years, not months” before a medication is widely available, the coronavirus shows no signs of disappearing, so the treatment is still well worth pursuing — especially since it could potentially be adapted to treat diseases beyond COVID-19.

“Unlike conventional antiviral drugs, the power of this tool lies in its design-flexibility and adaptability, which make it a suitable drug against a multitude of pathogenic viruses, including influenza, Ebola, and possibly HIV,” co-author Mohamed Fareh told AFP.

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