Infection of salivary glands and gum cells → Possibility of spreading to the lungs and digestive tract along with saliva
Researchers such as NIH in the United States have a paper in the journal’Nature Medicine’
[미국 NIDCR 블레이크 워너 박사 랩 Paola Perez 제공 / 재판매 및 DB 금지]
(Seoul = Yonhap News) Reporter Kicheon Han = The saliva of a patient with Corona 19 (new coronavirus infection) contains high levels of new corona particles.
Even if the saliva is tested for COVID-19 infection, research results show that the reliability of the test method will not be lower than the current test method, which collects a sample by putting a cotton swab deep in the nose.
What has not been clear so far is what part of the body has been transferred to the saliva.
For example, in COVID-19 patients with respiratory symptoms, the virus can spread to saliva through a runny nose or phlegm.
However, the new corona appears even in the saliva of a corona 19 patient who has few respiratory symptoms.
Finally, a study has emerged that can solve this question.
Researchers in the US have found that the novel corona directly infects cells in the mouth.
The research results, which were jointly conducted by scientists from the National Institutes of Health (NIH) and the North Carolina School of Dentistry, were published in the online edition of the journal Nature Medicine on the 25th (local time).
[미국 NIAID 제공 / 재판매 및 DB 금지]
The main targets of the novel coronavirus are the lungs and upper airways, but it can also infect the digestive system, blood vessels, and kidneys.
The results of this study show that the mouth plays a more important role than expected in the process of spreading the new corona into the body.
The novel corona may first infect oral cells and then mix with saliva and spread to the lungs and digestive tract.
The researchers examined the oral tissues of non-infected individuals and found RNAs involved in the production of ACE2 receptors and TMPRSS2 enzymes in some cells of the salivary glands and lining of the oral cavity, respectively.
Although few, in some salivary gland and gum cells, RNA containing information about the production of ACE2 and TMPRSS2 was simultaneously expressed.
These two proteins are a kind of’passage’ that is essential for cell infection of the novel corona.
Therefore, the high level of expression of these proteins in certain cells means that the risk of infection is high.
Dr. Blake Warner of NIH’s National Dental and Craniofacial Research Institute (NIDCR) who led the study said, “The level of expression in the mouth of these (cells) entry factors was similar to the area known to be well infected by the novel corona, such as the tissues of the nasal lining of the upper respiratory tract. “He said.
Image of spike protein with some bumps changed in the form of folded hairpins.
The spike protein was found to change shape after binding to the host cell’s ACE2 receptor.
[미 보스턴 아동병원 연구진 저널 ‘사이언스’ 논문 발췌 / 재판매 및 DB 금지]
The research team also tested samples of salivary gland tissue from corona19 deaths, confirming that more than half were infected with the novel corona.
In the salivary gland tissue of one deceased and one severely ill, a viral RNA sequence was also found showing that the novel corona particles were actively replicated within the infected cells.
It has also been confirmed that asymptomatic infected people can transmit the novel corona through saliva.
When the research team exposed the saliva of eight asymptomatically infected individuals to cultured normal cells, the saliva of two people caused corona infection.
By combining these results, the research team concluded that oral cell infection of the novel corona plays a large role in the spread of the body.
Swallowing infected saliva or inhaling fine droplets can spread to the throat, lungs, and intestines, scientists stressed.
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2021/03/26 17:18 sent