How does CRISPR work?
In the late 1980s, Japanese molecular biologists discovered unusual repeating clusters in bacterial DNA. Over the years, other scientists confirmed these appearances and named them CRISPR. During the early 2000s, it was found that bacteria use CRISPR systems to protect themselves from constant virus attacks. After a viral attack, bacteria chop off parts of the virus’ genetic information and store it within its own DNA, in so-called CRISPR spaces. Using this information, bacteria are able to create a specialized attack enzyme – called Cas9 (standing for CRISPR associated protein 9) – that fights the virus by neutralizing its DNA with the same chopping technique. In 2012, it was shown that this technique from bacteria could be transferred to almost any living organism, including plants, animals, and humans. Scientists discovered that they could artificially feed the Cas9 enzyme not only with viral information but with almost any information they wanted. Shortly after receiving information, Cas9 starts searching and chopping the genome accordingly. The latest genome editing technique – the most precise genetic scissors imaginable – was born.Huge potential in fighting diseases
There is much excitement regarding CRISPR’s potential in the fight against diseases. The technique could allow scientists to detect disease-causing mutations in the genome, cut them out, and possibly replace them with more desirable information. It is especially convenient for many diseases that we know have genetic mutations, such as cancer. In 2020, CRISPR was used for the first time in mice to treat two of the deadliest cancer types among females (breast, ovary), increasing the survival rates by 80 and 30 percent, respectively. Furthermore, CRISPR could also help fight diseases indirectly. There are already experiments taking place to find out whether the method can reduce or eliminate mosquito-borne diseases. The genetic scissors are used to manipulate genes that are responsible for the insects’ fertility. The aim is to control the (in)fertility of a mosquito population and, as a result, put an end to diseases like malaria, which is still one of the most prevalent infectious diseases worldwide.Was CRISPR helpful in fighting COVID-19?
Despite the technique not being fully matured, CRISPR has already been used during the COVID-19 pandemic. Firstly, there were COVID-19 tests based on CRISPR technology that showed the potential to deliver a faster, more accurate diagnosis. With its nucleotide-targeting ability, CRISPR can detect the presence of viral RNA. Trials on test kits, which could be used at home assisted by a smartphone, showed extremely high accuracy rates. Secondly, with regard to potential COVID-19 vaccines and treatments, scientists working on CRISPR utilization in influenza viruses switched their focus to SARS-CoV-2. Trials were first conducted in human lung cells in solutions. The next step was testing treatments in an animal model against a live SARS-CoV-2 virus. It was shown that CRISPR-loaded nanoparticles can decrease the viral load and prevent lethal cases of COVID-19 infections. Therefore, while still in its infancy, CRISPR was already able to assist in the COVID-19 crisis, but it is widely regarded as a mighty tool in fighting future pandemics.Gene editing creates ethical debate
When it comes to discussions about CRISPR, one of the most extreme examples is its potential to manipulate unborn human lives. In 2018, there was an uproar within the scientific community when a Chinese doctor used CRISPR to ‘engineer’ babies born without receptors for the HI virus that causes AIDS. While many regard gene editing as revolutionary in treating and preventing diseases, there has been a widespread backlash against using the technique to ‘design’ babies. The predominant tone regarding the news from China in 2018 was that the act was disturbing and unethical. Many scientists state that it is still too early for trials in humans, while others call for clear restrictions on CRISPR research.Would you eat a ‘CRISPRed’ apple?
Human medicine is not the only area where this mighty technique shows new ways. In fact, scientists from the food industry first discovered the functioning and the purpose of CRISPR-systems in the mid-2000s. Fast-forward to now, the benefits of this gene-editing tool for the agriculture industry and the food industry are potentially huge. Everything now seems possible: rice with higher yields, wheat without gluten, coffee plants that grow decaffeinated beans, or cows without horns. Apples that have been modified to prevent turning brown are already available in some U.S. stores. It is estimated that CRISPRed food, on a larger scale, will appear in stores in about five to 10 years. Many scientists hope that attitudes towards CRISPRed products do not replicate public opinion about genetically modified food products. While luck played its part in classic genetic modification (scientists did not know the part of the genome in which the manipulation would take place), the latest genome editing technology is very precise and more accurate to control. However, there is – and always should be – room for caution and discussion.
