Nose cells offer points of attack for corona viruses
The exact transmission pathways of the novel coronavirus SARS-CoV-2 are still not fully understood. So far it was unclear what role the nose plays in the transmission. A Cambridge research team has now shown that certain cells in the nasal and intestinal mucosa have the necessary receptor proteins and enzymes for SARS-CoV-2 to penetrate.
Researchers at the Wellcome Sanger Institute in Cambridge, England, showed that cells in the nose and intestinal mucosa contain the receptor protein ACE2 and the enzyme TMPRSS2. Both are the basic prerequisites for the SARS-CoV-2 coronavirus to enter the cells. At first it was assumed that the virus mainly affects the epithelial cells of the respiratory tract. The findings were published in the two highly renowned specialist journals “Nature Medicine” and “Cell” presents.
Decoded new entry point for SARS-CoV-2
The origin and development (pathogenesis) of COVID-19 is still only known in the beginning. An English research team has now made a major contribution to understanding the new disease. The team identified two specific types of cells in the nose as probable points of infection for SARS-CoV-2. The researchers showed that calyx and ciliated cells in the nose have a high content of receptors that the virus uses to get into our cells.
COVID-19: The role of the nose was unclear
The new findings help explain the high transmission rate of COVID-19 and at the same time offer new approaches for treatments and strategies for containment. It is known that SARS-CoV-2 can spread via droplet infections and that the virus affects the throat and lungs. So far, what role the nose plays was unclear. The research team was now able to determine the exact cell types that are susceptible to SARS-CoV-2 in the nose.
20 different types of tissue were examined
Using the most modern methods, the researchers analyzed 20 different tissue types from non-infected people. These included, for example, cells from the lungs, nasal cavity, eye, intestine, heart, kidney and liver. The researchers looked for which cells express (express) the two most important entry proteins that SARS-CoV-2 needs to infect the cells.
The nose as the most likely first infection route
“We found that the receptor protein – ACE2 – and the TMPRSS2 protease, which can activate the entry of SARS-CoV-2, are expressed in cells of various organs, including the cells of the nasal cavity,” explains study author Dr. Waradon Sungnak. The investigations revealed that especially the mucus-producing goblet cells and cilia in the nose have a high concentration of the necessary entry proteins. “This makes these cells the most likely primary route of infection for the virus,” emphasizes Sungnak.
Viruses can quickly reach nasal cells
“This is the first time that these special cells in the nose have been associated with COVID-19,” adds Dr. Martijn Nawijn from the research team. The location of these cells on the surface of the inside of the nose makes them very accessible to the virus and could also promote transmission to other people. This is a possible explanation for the rapid spread.
Eye and intestinal cells also vulnerable
The two main entry proteins ACE2 and TMPRSS2 were also found in cells in the cornea of the eye and in the intestinal mucosa. This indicates another possible route of infection via the eye and tear ducts and also reveals the potential for a fecal or oral route of transmission.
The atlas of human cells
The investigations were carried out as part of the global “Human Cell Atlas Consortium”. In this ambitious project, all human cells are to be analyzed in order to better understand diseases and health-related processes. More than 1,600 people in 70 countries are involved in this project. The data should be available to researchers worldwide. The project has already provided important insights into COVID-19.
“While we are creating the atlas of human cells, it is already being used to understand COVID-19 and determine which cells are critical for initial infection and transmission,” emphasizes Dr. Sarah Teichmann, the co-chair of the project. According to Teichmann, the findings also provide a basis for developing potential treatments and strategies for containment.
The atlas offers new approaches
“By pinpointing the characteristics of each cell type, the Human Cell Atlas helps researchers diagnose, monitor and treat diseases including COVID-19 in a whole new way,” added Professor Sir Jeremy Farrar, director of the Wellcome Sanger Institute. Cross-border cooperation and the open exchange of research results are crucial for the rapid development of effective diagnostics and therapies to ensure that no country is left behind. (vb)
Graduate editor (FH) Volker Blasek
- Waradon Sungnak, Ni Huang, Christophe Bécavin, u.a .: SARS-CoV-2 entry factors are highly expressed in nasal epithelial cells together with innate immune genes; in: Nature Medicine, 2020, nature.com
- Carly G. K. Ziegler, Samuel J. Allon, Sarah K. Nyquist, et al .: SARS-CoV-2 receptor ACE2 is an interferon-stimulated gene in human airway epithelial cells and is detected in specific cell subsets across tissues; in: Cell 2020, cell.com
- Wellcome Sanger Institute: Key nose cells identified as likely COVID-19 entry points (published: April 23, 2020), sanger.ac.uk
This article contains general information only and should not be used for self-diagnosis or treatment. He can not substitute a visit at the doctor.