How is the new coronavirus found? The nose is a reservoir of viral infection for the new coronavirus
A team from the Wellcome Sanger Institute in the UK has published important findings in the prestigious journal Nature Medicine. The team believes that two types of cells in the nose are the initial sites of infection for the new coronavirus, and that these two types of cells are likely to be the reservoirs for efficient human-to-human transmission of the new coronavirus.
After analyzing single-cell RNA sequencing data from healthy human tissues in databases such as the Human Cell Atlas Consortium, the team found for the first time that ACE2, a receptor protein required for neocoronavirus entry into cells, and TMPRSS2, an essential protease, were both highly expressed in cupped cells (secretory cells) and ciliated cells of the nose. This suggests that these two types of cells in the nose may be the site of initial infection of the neo-coronavirus, and that these two types of cells are likely to be the reservoirs for efficient human-to-human transmission of the neo-coronavirus.
Recent clinical studies have also found that the viral load of nasal swabs is significantly higher than that of pharyngeal swabs in patients infected with neocoronavirus. This led Sungnak's team to suggest that nasal epithelial cells may be the gateway to initial infection and transmission of neocoronavirus. They found that gene expression levels associated with innate and antiviral immune function were elevated in cells with high levels of ACE2 expression. The researchers suggest that this may be because these cells are more susceptible to viral infection, so these cells also overexpress immune-related genes to reduce the risk of infection by the virus.
The team's data also showed that the ability of the virus to spread depends on the spatial distribution of relevant receptors and proteins in the respiratory tract. The nasal cuvettes are secretory cells, and it is possible that the new coronavirus could take advantage of the continuous secretory action of the cuvettes to initiate transmission before symptoms appear.
The nose is actually a mirror of the body's health. In case of serious illness, white blood cells secrete a green enzyme that causes the nose to appear yellow or green. The normal mucous membrane in the nose is pink. If the nasal mucosa appears blue, white or swollen, you may have allergic rhinitis or some kind of nasal allergy that causes inflammation, and the redness of the nasal cavity usually indicates the occurrence of infection.
Professor Zhong Nanshan, an academician of the Chinese Academy of Engineering, has pointed out that "the treatment of respiratory tract inflammation should be treated together with the nose and lungs, not the railroad police." The airway begins at the nose and ends at the lungs, including allergic rhinitis and asthma and other respiratory diseases, are not independent, but there are allergic problems from the nose to the lungs.
At the end of March this year, the team of Lu Lu and Jiang Shibo from the School of Basic Medicine of Fudan University and the Shanghai Public Health Clinical Center published an important research result in the prestigious journal Cell Research, suggesting that the lipopeptide drug they developed can effectively block the membrane fusion caused by the new coronavirus, and can be used to prevent viral infections by nasal administration. Until the drug is developed, it is very important to wear a mask and protect the nose and mouth.
