Viruses come in many forms: DNA and RNA, double-stranded and single-stranded. Approximately two thirds of the viruses that infect humans are RNA viruses. Surprisingly, there are very few treatments available for RNA viruses. The RNA therapies that do exist typically use small molecules to interfere with viral replication. However, this approach does not work for newly emerging viruses, or ones that are evolving rapidly, like COVID-19.
Scientists have now found a way to fight RNA viruses within human cells, and unsurprisingly CRISPR may play a role. CRISPR is well-known as a Nobel-prize winning laboratory tool that can be used to edit DNA to fix genetic defects or to enhance certain traits. But lesser known is that it originally evolved as a defence mechanism used by bacteria to fend off viruses called bacteriophages. The opportunity for scientists is to harness this natural defence mechanism and to optimize it for human benefit.
Targeted COVID-19 detection using CRISPR technology
The most widely used COVID-19 tests use a method called ‘quantitative PCR’. Whilst this is recognised as the “gold standard” of testing, one of the issues with the PCR technique is that it requires DNA. Except COVID-19 is an RNA virus.
This means that the viral RNA must first be converted to DNA in order to undergo a PCR, by using specialized reagents. This severely limits the rollout of testing and causes delays in receiving results. It also contributes toward the incidence of false-positive results.
Now scientists from Sherlock Biosciences have developed a more accurate novel system by using CRISPR-Cas 13 technology to directly detect the presence of the viral genome without first requiring the conversion of viral RNA into DNA. The test produces a result in about one hour.
The technology has already received approval for emergency use by the FDA in the USA, though its use is still limited to labs. In an article by Nature, Chief Executive of Sherlock Biosciences said that the company is working toward developing single cartridges that can be used as a home test kit.
Targeted destruction of Covid 19 using CRISPR technology?
Scientists are now also working toward harnessing CRISPR’s natural viral-defense properties to develop a novel antiviral effective against COVID19. CRISPR-Cas13, which is a type of CRISPR system that targets RNA, rather than DNA, is being engineered to attack SARS-CoV-2 within patients.
Known today as the PAC-MAN (Prophylactic Anti-viral CRISPR in huMAN cells) technology, when tested under laboratory conditions on synthetic SARS-CoV-2 it decreased the count of the virus by 90%. Whilst it is still in the initial stages, scientists truly believe that the PAC-MAN technology could become a pan-coronavirus inhibition strategy, effective against all variants of coronavirus.
Of course, as of right now these novel innovations are mostly experimental. But they hint toward a world where scientists are better equipped to prevent and combat pandemics.
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Tej Kohli is a deep tech and real estate investor and is Chairman of Kohli Ventures. Tej Kohli is best known for his mission to end poverty-driven blindness at the not-for-profit Tej Kohli Foundation and the Tej Kohli Cornea Institute. In 2021 Tej Kohli launched the Tej Kohli & Ruit Foundation and began staging high-volume micro-surgical outreach camps to cure cataracts in poor and remote communities worldwide.
