A Team of Stanford University is working on a pioneering method for the control of the Covid-19-disease.
Calculations according to the modified CRISPR can prevent 90 percent of all previously known Corona-viruses in the reproduction, is also the cause of the Covid-19-disease, the SARS-CoV-2. The theoretical foundations and the first laboratory studies published by the Team in may in the journal Cell. Now, the group has provided further evidence for the effectiveness.
The researchers, however, are not devoid of Humor; they, too, make a reference to Computer Games recognize: they call your method “Prophylactic Antiviral CRISPR in human cells” and shorten the name in a playful way to “PAC-MAN”. In fact, the Similarities to the eponymous computer game: as the on-screen male stud carves eating his way through a maze, so you must imagine the functioning of the modified CRISPR system: with a probe (guide, leader) – equipped Protein patrolled by the cell and zerschnippelt all to the probe matching against the pieces, so viral genome molecules.
In PAC-MAN, the researchers are combining molecular probes with the virus killer Protein Cas13d (cas Nuclease), which is used normally in the bacterium Ruminococcus flavefaciens virus protection. Such bacterial defense systems are running under the name of CRISPR/cas. General awareness is the System as a Gene-scissors CRISPR. It is used in the fight against Covid-19 so far, only to the diagnosis. What is new is that the Gene-scissors, as in bacteria should be brought against virus in position, however, in higher developed organisms, not only in humans but also in hosts, such as camels or bats.
The PAC-MAN-System of Stanford University can, in principle, against more than 90 percent of the previously known Corona-viruses use. The effectiveness of the method was in cell cultures to prove.
(Image: University Of Stanford)
Compass for Cutting
CRISPR/cas is in broad lines: The probes consist of short genome pieces, and the complementary (mirror image) to certain Parts of the enemy’s genetic material. Therefore, they adhere specifically to your counterparts. The use of bacteria to direct proteins from the class of Nucleases against genome intruders.
Because Nucleases to cut genomes efficiently, but in order to do that, you need to find your goals at all. To do this, cas need Nucleases fragments of the virus genome, which have deposited bacteria in your own genetic material for future use, If such custody is to be read, synthesized the bacterium both Nucleases as probes that match fragments of the virus genome. The defense system is complete and sharp, as soon as such a probe binds to the Nuclease. The Nuclease contains a matching fold; the process is in cells independently and immediately.
Then, such a Complex in the cell on Patrol. You will meet a counter-piece, by cutting the genome at this point. So it is hardly used as a template for further copies, or as a template for viral proteins, the infection will be banned. The fragments can then be used by non-specific Nucleases further digested.
Such a defense system in higher organisms is not known, but laboratories can synthesize such probes “with the left”, and also to Nucleases bind – missing just a suitable transport system, which brings the weapon into the body’s cells.
In principle, several are eligible. From the middle of March, when the Foundation work was already submitted to the magazine Cell, started making the Stanford Team in cooperation with the Berkeley Lab Molecular Foundry, the synthetic beads (Lipitoide), in order to bring the genetic material in cells. Now, the two groups report that Lipitoide, which are loaded with PAC-MAN, so with Cas13d in addition to the matching probe, the amount of SARS-CoV-2 virus in a cell can reduce crops by more than 90 percent. Next, animal experiments are planned, including with colleagues at the New York University and the Karolinska Institute in Sweden.
In principle, PAC can be used to YOU by means of specific probes against other virus up. The procedure should be proven in clinical Tests could make it to the quarantine, medication, and vaccinations, their inventions were already made centuries, a completely new approach to virus defense.
(dz)
This article is from c’t 14/2020.
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