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Traffic jam observed in viruses!

Researchers have observed viruses passing through synthetic nanopores that mimic nuclear pores, the entry doors through which they infect cell nuclei. When the concentration is sufficient, plugs are formed and limit translocation, plugs whose characteristics provide information on the interactions between viruses and the surface of the nucleus.

Viruses have remarkable physical properties and complex interactions with their environment. We usually imagine the transport of these pathogens by the respiration infected people through droplets emitted upon exhalation, as popularized by numerous works during the emergence of Covid-19.

However, the movement of viruses towards the site of an infection is complex and very diverse. To enter the heart of cells and infect them, they must find their way in sometimes very confined environments. At the critical moment of penetrating the cell nucleus, some viruses must pass through the “gates” formed by the nuclear pores located on the surface of the nucleus, a phenomenon of capital importance for understanding viral infectivity.

It is this critical stage that teams of scientists from the Physics Laboratory (LPENSL, CNRS / ENS de ), theInstitut of Research in Infectiology from (IRIM, CNRS / Université of Montpellier), from the Institute of Molecular Chemistry (IPCM, CNRS / Sorbonne University), the International Center for Research in Infectiology (CIRI, CNRS / ENS de Lyon / INSERM / Université Claude Bernard), GULLIVER (CNRS / ESPCI Paris – PSL) and Interfaces, Treatments, Organisation et Dynamic of Systems (ITODYS, CNRS / Paris Cité University), using an approach in vitro which mimics the transport of viruses into the nucleus. To do this, they studied the passage of viruses through synthetic nanometric openings commonly called nanopores, by observing them using detection optical ultrasensible.

Surprisingly, the researchers discovered that viruses tend to interact with each other when forced into these pores and that they then easily form a traffic jam when the density is sufficient, mainly due to adhesion. viruses between them and on the surface of the pore. Using a physical model, scientists turn this state of affairs to their advantage by showing that we can use this plug phenomenon to quantify the interactions of viruses with each other and with the pore.


Virus bottling in a synthetic nanopore.
A) Artist’s impression of the formation of a virus plug at the entrance of the nanopore.
B) Measurement of the frequency of passage through a network of synthetic nanopores as a function of the pression applied to push viruses.
The significant reduction in passage frequency for an increase in virus concentration is the hallmark of the formation of a plug inside the pore. The points represent the experimental measurements and the solid lines represent the predictions of the physical model developed for this study.
© Vincent Demery, Fabien Montel & Leah Chazot-Franguiadakis.

This work therefore offers a new method for understanding and characterizing the interactions of viruses with their environment. For example, the influence of drugs on the transport of viruses into the nucleus can be tested by this type of experiment. We can also consider using this technique to control the aggregation of nanoparticles using a nanopore. These results are published in the journal Nature Communications.

References:
Soft jamming of viral particles in nanopores, Nature Communicationspublished on July 23, 2024.
Doi: 10.1038/s41467-024-50059-9 (open access)

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