A recent study from the University of Copenhagen could lead to improved treatments for infections, particularly in the fight against antibiotic resistance.
Bacteria, like a city under constant attack, have a defense system. For every bacterium, there are about ten viruses, known as bacteriophages, designed to invade bacteria, potentially harming beneficial bacteria and contributing to antibiotic resistance.
The study reveals that bacteria employ a defense mechanism called Zorya to protect against viral attacks. This system can capture viral assaults and destroy the virus’s DNA before it replicates.
“Many of the body’s defense mechanisms lead to cell death, as the cell sacrifices itself to prevent the spread of invading viruses. We were surprised to see that the Zorya system addresses the issue without harming the cell, which is a significant advantage,” explained Nicholas Taylor, a researcher at the Novo Nordisk Foundation Center for Protein Research and co-author of the study.
This research involved collaboration among scientists from Humboldt University in Germany, the University of Otago in New Zealand, ETH Zurich in Switzerland, and Oxford University in England.
The findings indicate that bacteria can adapt their molecular machinery to fend off viral infections, knowledge that could be applied in biotechnology and drug design.
“Our mapping of the Zorya system and its ability to intercept and combat bacteriophages in the early stages of infection represents groundbreaking new knowledge about this defense mechanism,” said Taylor.
He added that this insight not only enhances understanding of bacterial defenses but could also be crucial in developing new methods for treating antibiotic-resistant infections, artificial antiviral systems, and drugs that can block harmful bacteria's defense mechanisms, thus increasing the efficacy of clinical treatments.
“Moreover, our results may contribute to the development of antiviral defense mechanisms capable of intercepting viral infections,” stated Haidai Hu, the study’s lead author.
To understand how the Zorya system operates, researchers employed advanced techniques, including cryo-electron microscopy, which allows for the visualization of tiny structures, mutagenesis for gene alteration studies, and fluorescence microscopy to observe cells. Proteomics was also utilized.
“We isolated the Zorya system’s genes—ZorAB, ZorC, and ZorD—and transferred them to bacteria lacking this system. The modified bacteria proved particularly adept at defending against viral infections. In essence, the Zorya system can combat viruses without killing the cell,” Taylor noted.
“We used cryo-electron microscopy to examine ZorAB, described as a tiny motor powered by protons. This motor helps bacteria detect viral attacks and sends signals that activate other components of the Zorya system, which then destroys the virus’s DNA, preventing its spread.”
This study marks a significant advancement in understanding bacterial defense mechanisms. The next step involves further investigating the Zorya system to illuminate its biotechnological and medical potential.