For the first time, scientists have been able to create a three-dimensional, real-time recording of the moment a virus hijacks a cell, giving us a better understanding of how infections get trapped in the body.
The microscopic wildlife film lasts two and a half minutes and shows a genetically sterile virus many thousands of times smaller than a grain of sand traveling along a wall of human intestinal cells in search of an entrance.
Understanding how viruses enter cells is crucial to finding better ways to defend against them, but tracking these particles is incredibly difficult, not least because they are so much smaller than the cells they navigate.
“It’s like trying to take a picture of a person standing in front of a skyscraper,” says chemist Courtney Johnson of Duke University in North Carolina. “You can’t get the whole skyscraper and see the details of the person in front of it with one photo.”
In addition, virus particles move much faster outside the cell than inside, making it even more difficult to devise an imaging process that is tailored to these different sizes and speeds.
The solution in this case is a system called 3D-TrIm, or 3D Tracking and Imaging Microscopy. It’s actually two microscopes in one: the first to ‘lock’ the fast-moving particle and the second to capture 3D images of the surrounding cells. It’s a bit like a satellite navigation app that tracks your car’s location in the middle of a wider landscape.
With the virus particle illuminated via a special fluorescent label, its position can be plotted 1,000 times per second, allowing researchers to view its movements in a key period in the infection process in unprecedented detail.
In the Duke University video below, the virus’s meandering path can be seen as a squiggly purple line.frameborder=”0″ allow=”accelerometer; auto play; clipboard writing; encrypted media; gyroscope; picture-in-picture” allowfullscreen>
“When I present this work, people sometimes ask, ‘is this a video game or a simulation?'” says Johnson. “No, this is something that comes out of a real microscope.”
We all breathe in millions of viruses every day, the vast majority of which are harmless. infection.
This new 3D-Trim method should help, although it has its limitations: virus particles must be labeled prior to imaging so that they can be seen, and the fluorescent dye on them must be developed to last long enough for researchers to set the whole infection process.
However, the team behind 3D-Trim says the system has the potential to get better quickly and can be adapted to other forms of medical diagnostics, whether that be monitoring viruses or monitoring drug delivery.
“Importantly, the application of this technique can be extended to any system where rapid dynamics of nanoscale objects occur over large volumetric scales, including the delivery of nanoscale drug candidates to the lungs and through leaky tumor vasculature,” the researchers write. their published paper.
The research has been published in Nature Methods.