New research finds that viruses may have 'eyes and ears' on us

The new research suggests that viruses are using information from their environment to "decide" when to sit inside their hosts and when to explode. There are implications for the work.

A virus's ability to sense its environment, including elements produced by its host, adds another layer of complexity to the viral-HOST interaction. Viruses are exploiting that ability right now. We could exploit it to their disadvantage in the future.

It's not a coincidence.

A new study focused on theviruses that cause the infections. Pili and flagella are the special appendages of the bacterium that allow it to move and mate with other organisms. The CtrA that is produced by thebacteria controls the appendages that are generated. The new paper shows that many appendage- dependent phages have binding sites in their genomes. It's unusual for a phage to have a binding site.

The paper's first author Elia Mascolo found that the binding sites were not unique to a single group of phages. CtrA binding sites were required by many different types of phages. They decided that it was a coincidence.

The ability to monitor CtrA levels has been invented many times. convergent evolution is a trait that distantly related species show.

It's all about timing.

The research team was able to identify CtrA binding sites in the first phage they encountered, but it was not the last one they would find. There are two types of cauliflowerbacterales, a "swarm" form that swims around freely, and a "stalked" form that sticks to a surface. The stalks don't have pili or flagella. CtrA regulates the cell cycle by determining if a cell will divide evenly into two more of the same cell type or if it will divide asymmetrically.

The best thing for the phages to do is to burst out of their host when there are lots of swarmer cells. The Caulobacterales are spread out in poor environments. When they find a good pocket of microhabitat, they become stalked cells and produce a lot of swarmer cells.

"We theorize that the phages are monitoring CtrA levels, which go up and down during the life cycle of the cells, to figure out when the swarmer cell is becoming a stalk cell and becoming a factory of swarmers," he said.

There is listening in.

Unfortunately, the method to prove this hypothesis is labor intensive and difficult, so that wasn't part of the paper. There is no other explanation for the proliferation of CtrA binding sites on so many different phages. The implications for viruses that affect other organisms are even more intriguing.

He says "everything that we know about phages, every single evolutionary strategy they have developed, has been shown to translate to viruses that cause diseases in plants and animals." It's pretty much a done deal. The viruses that affect humans are bound to be listening in as well.

There are a few other examples of phages monitoring their environment in interesting ways, but none of them include the same strategy against so manybacteria.

The first broad scope demonstration that phages are listening in on what's going on in the cell is what this research is about. There will be more examples on the way. He says that members of his lab have begun to look for other bacterial regulatory molecule in the phages.

There are new avenues for therapy.

If it's an evolutionary strategy that makes sense, evolution will discover that the virus is using cellular intel to make decisions.

To maximize its strategy for survival and replication, an animal virus might want to know how strong the host's immune response is. These discoveries open up avenues for new therapies, even though it might be unnerving to think about all the information viruses could gather.

If you know that the virus listens in on a particular signal, then you can fool it. It is several steps away. "We are just starting to realize how actively viruses have eyes on us and how they are monitoring what's going on around them and making decisions based on that." It's interesting.

More information: Elia Mascolo et al, The transcriptional regulator CtrA controls gene expression in Alphaproteobacteria phages: Evidence for a lytic deferment pathway, Frontiers in Microbiology (2022). DOI: 10.3389/fmicb.2022.918015 Journal information: Frontiers in Microbiology Citation: New research finds that viruses may have 'eyes and ears' on us (2022, September 23) retrieved 23 September 2022 from https://phys.org/news/2022-09-viruses-eyes-ears.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.