Using CRISPR to combat COVID-19, a way to preserve humanity?
Despite being a potential gene-editing technology, one could have hardly anticipated that CRISPR would find its new testing grounds amidst the COVID-19 outbreak. With COVID-19 rapidly swathing across all countries, infecting millions with high mortality rates, preventing the spread and curing the affected population presents a real challenge. Without much success, worldwide, researchers have started scrambling through their research notes, published studies to devise a magic potion that could help save humanity. Could CRISPR be the ultimate tool in combating the deadly zoonotic micro-monster?
At this hour of COVID-19 pandemic, the tools needed to win the battle are straight-forward- rapid testing kits to detect affected people, medicine to cure the ill, and vaccine to help people develop active immunity.
The current method of detection of COVID-19 infection over-relies on real-time PCR. The technique which although is highly sensitive, needs access to instruments and reagents, the inadequacy of which slows down the testing rate, and thus albeit debatable reduces the actual detection. Researchers across leading institutions of Cambridge, USA have collaborated to find an alternative solution. They have described a protocol for COVID-19 detection that counts on CRISPR-based SHERLOCK (Specific High Sensitivity Enzymatic Reporter UnLOCKing) technique. CRISPR-based SHERLOCK technique uses purified RNA from the patient and synthetic COVID-19 RNA fragments, and researchers ‘have been able to consistently detect COVID-19 target sequences in a range between 20 and 200 aM (10-100 copies per microliter of input).’ (Zhang, Abudayyeh and Gootenberg, 2020) The method targets the S gene and Orf1ab gene of the COVID-19 genome which not only enhances the specificity of the detection assay but also reduces the possibility of off-targets resulting from other related human respiratory viral genomes.
Source: Zhang, Abudayyeh and Gootenberg (2020).
The entire detection procedure takes less than an hour, and with automation, these test kits promise to process a greater number of samples per day without the need for expensive and elaborate instrumentation set-up.
With pandemic COVID-19 driving the entire world into hysteria, researchers are fervently trying to explore therapies, some of which are already on clinical trial while others still at their infancy in various laboratories. Timothy Abbott and his team of researchers at the Standford University have come up with a novel ‘PAC-MAN’ approach (Prophylactic Antiviral CRISPR in huMAN cells) to kill COVID-19 and Influenza Virus A in infected human lung epithelial cells. The CRISPR approach uses guide RNA strand to direct the Cas-13 protease enzyme to hook onto specific sites of the COVID-19 genome and makes a continuous series of cuts in the viral genome. The method in solution is able to reduce 90% of the viral load and thus appears to have a potential prospect in COVID-19 therapeutics in humans.
Vaccination is the only way to stop the spread and eliminate a disease outbreak. Although a few COVID-19 vaccine candidates have stepped into their clinical trials, CRISPR technology is yet to make a breakthrough on that ground. However, previously documented research clearly shows that the CRISPR/Cas9 system has the potential for vaccine development against pathogens such as avian herpes virus, influenza, etc. Thus the possibility of developing vaccine candidates based on the CRISPR/Cas13 system remains widely speculated.
So whether CRISPR will be the panacea for COVID-19 is something we will have to wait for, but certainly, CRISPR technology has a lot to offer here.