Researchers at the University of Copenhagen, led by Spanish researcher Guillermo Montoya, have deciphered the keys to how bacteria defend themselves from external attackers such as viruses or other bacteria. They have also described how these CRISPR defenses can be activated at a precise moment. The finding could help design strategies to fight diseases in the future.
The team of molecular biologist Guillermo Montoya at the Novo Nordisk Foundation Center for Protein Research, at the University of Copenhagen, mapped for the first time the mechanisms used by bacterial cells to defend against attacks by viruses or other bacteria with CRISPR molecular scissors. To achieve this, they have used a state-of-the-art electronic cryomicroscope and synchrotron radiation sources. The results are published in the journal Nature Communications.
The work also describes the way in which these defenses can be activated at the right time. Specifically, researchers have shown how a bacterial cell attacked by a virus activates a molecule called COA (cyclic oligoadenylate), which, in turn, activates a complex of CRISPR Cas proteins, called CSX1, to eradicate the attacker.
Rafael Molina , the first signatory of the work says that in this study they have “been able to see the exact moment in which CSX1 begins to chop the invader with molecular scissors. In addition, we have been able to activate this biological process successfully,” highlights the Spanish researcher.
“To summarize, we have characterized the operation of the switch that turns on the bacterial cell defense system. Now, we know how to activate these defenses and thus prevent possible attacks,” Montoya says. This discovery, he adds, “can be of great importance in the fight against diseases in the future.”
A human-like immune system
It is the first time researchers have been able to map and activate a bacterial immune system. According to Montoya, “a few years ago, science didn’t even know that bacteria had some kind of immune defense system.” This was discovered by the Alicante microbiologist Francisco M. Mojica.
The new finding allows “further progress in the understanding of these mechanisms,” notes Montoya. In his opinion, the new discovery “is exciting because we have seen that the defense system in bacteria resembles, in many respects, the innate human immune system.”
Therefore, “it is a new step along the way to better understand our immune system. It could also help us design new strategies to fight against bacteria and viruses and even, in the long run, it could be useful to find ways to face multiple resistance,” the researcher points out.