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Antibiotics weaken Flu defences in the lung by interfering with microbiota | Virus World | Scoop.it

From www.crick.ac.uk - July 9, 2019 5:38 PM

Antibiotics can leave the lung vulnerable to flu viruses, leading to significantly worse infections and symptoms, finds a new study in mice.

The research discovered that signals from gut bacteria help to maintain a first line of defence in the lining of the lung. When mice with healthy gut bacteria were infected with the flu, around 80% of them survived. However, only a third survived if they were given antibiotics before being infected.

"We found that antibiotics can wipe out early flu resistance, adding further evidence that they should not be taken or prescribed lightly," explains Dr Andreas Wack, who led the research at the Francis Crick Institute. "Inappropriate use not only promotes antibiotic resistance and kills helpful gut bacteria, but may also leave us more vulnerable to viruses. This could be relevant not only in humans but also livestock animals, as many farms around the world use antibiotics prophylactically. Further research in these environments is urgently needed to see whether this makes them more susceptible to viral infections."

To test whether the protective effect was related to gut bacteria rather than local processes in the lung, the researchers treated mice with antibiotics and then repopulated their gut bacteria through faecal transplant. This restored interferon signalling and associated flu resistance, suggesting that gut bacteria play a crucial role in maintaining defences.

These studies were published in Cell Reports:

https://doi.org/10.1016/j.celrep.2019.05.105

Novel directed evolution technique makes viruses create drug proteins in days | Virus World | Scoop.it

From newatlas.com - July 9, 2019 5:31 PM

By guiding evolution, scientists have managed to manipulate micro-organisms into producing useful new drugs and materials, but it’s a time-consuming process. Now, UNC researchers have developed a new tool that speeds up the process in mammalian cells, creating new therapeutics in a matter of days.

In nature, evolution begins as environmental factors place pressure on lifeforms. Over generations, random mutations in some individuals give them an edge, making them more likely to survive and reproduce. That in turn means those useful genes are passed down to their offspring, until that trait becomes standard in the species.

Directed evolution is essentially what happens when humans take the reins. By deliberately controlling the environmental pressures on microbes, scientists can guide them to evolve certain traits, then select the ones that do and repeat the process until they have the desired outcome. The groundbreaking technique earned its developers the2018 Nobel Prize in chemistry.

The new system has been dubbed VEGAS, which stands for Viral Evolution of Genetically Actuating Sequences. It's based around the Sindbis virus, because of its ability to quickly spread and mutate. The team introduce the virus into a culture dish of cells, and try to guide it to mutate so that it can perform a specific function in those mammalian cells – say, switch on certain genes or activate a protein. The scientists then tune the environment to conditions that allow only those desired mutant genes to thrive. In their experiments, the UNC researchers started by focusing on a protein called a tetracycline transactivator (tTA), a protein that activates genes and is a common subject in these kinds of tests. Certain antibiotics, such as doxycycline, usually prevent this protein from working, so the researchers tested the VEGAS system by trying to direct tTA to evolve a resistance to these antibiotics. And sure enough, the team managed to create a new version of tTA with 22 mutations that allowed it to keep working, even with high levels of doxycycline. Best of all, they managed to create this in just seven days.

These findings were published in Cell: https://doi.org/10.1016/j.cell.2019.05.051

Antibiotics weaken Flu defences in the lung by interfering with microbiota

Novel directed evolution technique makes viruses create drug proteins in days