The new SARS-CoV-2 coronavirus would primarily target the cells of the mucous membrane of the nose before invading the lungs.
- It is in the nasal mucosa that the molecule with which the coronavirus interacts to penetrate the cells is located
- This may explain the transmission of the virus by aerosol during sneezing
An international team of researchers has discovered that certain cells in the nose express in large quantities the molecule with which SARS-CoV-2 interacts before entering cells, in particular the lungs, and multiplying there. Conducted by researchers from British, French and Dutch institutions, the study was published in the journal NatureMedicine.
The virality of the virus explained
To make their discovery, the researchers relied on cellular data from the airways of healthy adult subjects collected by teams from the global Human Cell Atlas (HCA) consortium. “With the HCA project, we had a lot of data on airway cells (nose, trachea, bronchi)deciphers Doctor Pascal Barbry, who is part of the HCA, at World. The receptor and the cofactor of this new coronavirus having been identified, we were therefore able to quantify the level of expression of their RNAs in the respiratory tract. We have thus highlighted a higher level in the nasal cavity.”
In their study, the researchers looked at the ACE2 receptor, in the cells located on the surface of the respiratory tract, from the nose to the pulmonary alveoli, which the virus uses to infect cells. They found a stronger expression of this portal of entry of the virus into the nasal cavity. This probably explains why this virus is transmitted so easily through aerosols projected during sneezing or coughing, due to their location close to the orifice of the nostrils.
continue research
The ACE2 protein RNA is also present in the alveoli of the lungs, in type II cells, allowing the virus to lodge there. “There is a double effect during infection with SARS-CoV-2says Dr. Barbry. Its entry into the cells of the nose allows it to multiply and then to disseminate, and each inspiration leads it to the alveoli where it can attach to the same receptor present on type II alveolar cells and replicate again..”
This discovery gives hope for a treatment. Studies could thus target the ACE2 protein to control the entry of the virus into the cell. For these researchers, this publication is only the first and they intend to continue their research. “Access to more than a million cells analyzed by the HCA consortium will make it possible to determine the factors on which the expression of ACE2 may depend (age, sex, smoking status, etc.). This could help to understand why some people would be more susceptible than others to infection and/or transmission of the virus.concludes Dr. Barbry.
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