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Scientists record a virus that “walks around” cells looking for a way to enter : ScienceAlert

Scientists record a virus that "walks around" cells looking for a way to enter : ScienceAlert
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For the first time, scientists have been able to make a real-time three-dimensional recording of the moment. virus hijacks a cell, giving us a deeper level of understanding of how infections take hold in the body.

The film of a microscopic nature lasts two and a half minutes and shows a genetically sterile virus thousands of times smaller than a grain of sand that travels along a wall of human intestinal cells in search of a point of entry.

understand how virus breaking into cells is crucial to finding better ways to defend against them, but tracking these particles is incredibly difficult, especially since they are so much smaller than the cells they navigate.

“It’s like you’re trying to take a photo of a person standing in front of a skyscraper.” says chemist Courtney Johnson, from Duke University in North Carolina. “You can’t get the whole skyscraper and see the details of the person in front of it with an image.”

Also, virus particles move much faster outside of the cell than they do inside it, making it even more challenging to create an imaging process that is fine-tuned to cope with these varying sizes and speeds.

The solution in this case is a system called 3D-TrIm, or 3D Tracking and Imaging Microscopy. It’s basically two microscopes in one: the first to ‘lock on’ to the fast-moving particle, and the second to capture 3D images of the surrounding cells. It’s a bit like a sat-nav app that tracks your car’s location amidst a wider landscape.

With the virus particle illuminated via a special fluorescent tag, its position can be traced 1,000 times per second, giving researchers a look at its movements throughout a key period in the infection process in unprecedented detail. .

In the following video from Duke University, the meandering path of the virus can be seen as a wavy purple line.

frameborder=”0″ allow=”accelerometer; auto-play; clipboard-write; encrypted media; gyroscope; picture-in-picture” allowfullscreen>

“Sometimes when I present this work, people ask, ‘Is this a video game or a simulation?'” johnson says. “No, this is something that came from a real microscope.”

We all breathe in millions of viruses every day, the vast majority of which do no harm, but scientists want to learn more about how certain viruses get through the protective layer of cells and mucus that lines the airways and intestines to establish an infection. .

This new 3D-Trim method should help, though it has its limitations: Virus particles must be labeled before imaging so they can be seen, and the fluorescent dye in them must be designed to last long enough to allow researchers to track the entire infection process.

Computer generated image of a yellow particle immersing itself in a cell membrane
The path (blue) of a virus as it moves along the surface of cells (purple) before attaching itself (yellow). (Johnson et al., Nature’s Methods2022)

However, the team behind 3D-Trim says there is potential for the system to quickly improve and adapt to other types of medical diagnostics, whether it’s monitoring viruses or monitoring drug delivery.

“More importantly, the application of this technique can be extended to any system where fast dynamics of nanoscale objects occurs at large volumetric scales, including the delivery of nanoscale drug candidates to the lungs and through the vasculature.” leaky tumor,” the researchers write in their published article.

The research has been published in Nature’s Methods.

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