Science Read! How do neutral granulocytes enhance the body's susceptible to respiratory syncytial viruses?

October 21, 2020 // -- Having more bacteria-resistant immune cells in the nasal cavity and throat may help explain why some people are more likely to be infected with respiratory viruses in their skirts, a paper published in the international journal Science recently titled "Neutrophilic in the respiratory In a study by y mucosa predisposes to RSV infection, scientists from Institutions such as Imperial College found that RSV-infected volunteers had more white blood cells in the respiratory tract called neutral granulocytes before exposure to the virus than volunteers who were not infected with RSV, respiratory syncytial virus.
researchers say this type of neutral granulocyte-driven inflammation in the nasal cavity and throat, which is directly related to the body's fight against bacterial infections, may neutrally neutralate the body's ability to fight invasive viruses and make the body more susceptible to virus infections;
image source: CDC/Dr. Erskine Palmer/Public Domain researcher Ryan Thwaites says that if we think a group of 10 people were exposed to the same RSV strain under the same conditions, we suspect that about six people will be infected with the disease, but others will have symptoms of the disease. So far, we haven't been able to fully explain why this happens in the same situation, and some people may be more susceptible to respiratory viruses, and this study provides new clues and insights into how to improve the body's resistance to respiratory virus infections (even SARS-CoV-2).
RSV is a common respiratory virus that can cause common cold symptoms in healthy people, but for infants and the elderly, RSV can cause thousands of hospitalizations each year, and RSV infections can be even fatal for some patients.
Unlike other respiratory viruses such as influenza viruses or rhinoviruses, people may be infected with the same RSV at least once, and under the same conditions, people may not react the same when exposed to the virus, some people are less infectious, some may develop systemic symptoms, and some may not be infected at all.
study, researchers looked at the molecular mechanisms of RSV infection in populations and shed light on specific factors that alter the body's immune response in populations.
In this study, researchers recruited healthy adults and exposed them to RSV in a safe and controlled clinical environment, while the researchers closely monitored participants, and when they received nasal drops containing the virus, 57 percent of the volunteers were infected, and analysis of their blood samples suggested that the presence of protective antibodies and B and T cells might partially explain which individuals were infected with RSV.
However, when respiratory samples from participants exposed to the virus were collected and analyzed, the researchers found that neutral granulocytes in the nasal mucous membranes of infected participants were activated, and that these immune cells released special proteins to help create a threat-fighting antibacterial environment, but the researchers believe that this antimicrobial immune response may be costly and could make hosts more susceptible to the virus by effectively shutting down the early warning system.
researcher Peter Openshaw points out that the variable spread of respiratory viruses we observe depends in part on their dose and exposure time, but also on the immune defense mechanisms that the individual itself builds, which you might think is due to the presence of special protective antibodies, but despite years of great efforts by scientists, they don't really understand what makes some people more vulnerable to RSV infection, and some people are resistant to the virus.
's findings suggest that the state of the mucous membranes before the virus strikes may be the main determining factor, and that it is a major breakthrough in in-depth research, as if there were active neutral granulocytes in the inner walls of the respiratory tract, which would prevent the mucous membranes from responding to the virus or eliminating the infection in its infancy;
People with colds do not show evidence of early response, and those who are not infected react immediately before symptoms occur, and these findings are found only in experimental studies of volunteers, and researchers will never be able to find this result by waiting for a natural infection in the population."
In this paper, the study highlights the complexity of the body's immune system, which has different "arms" that provide different layers of protection for the body based on anatomical location (such as nasal cavity, lung or circulatory system, etc.) and timing.
The researchers then used animal models to detect the effects of the neutral granulocyte pathline on RSV infection, and in mice without neutral granulocyte inflammation, the body's immune system treated the virus as a threat and released immuno-mediators to clear the infection if the body did not show serious symptoms.
However, in mice with neutral granulocytes in the nasal mucous membrane, this early detection of the virus is weakened, and under these antibacterial conditions, the virus better invades the mucous membrane cells of the host body and causes infection, thus worsening symptoms and inducing the virus to fall off and spread the virus.
if the researchers can explain that the same mechanism does occur in the people most susceptible to RSV infection, it may help to effectively identify sub-groups of patients who are more susceptible to RSV infection.
researchers are now preparing to explore the mechanism in a larger patient population and investigate whether the same immune mechanism affects host infections of other respiratory viruses, from influenza viruses to coronavirus infections.
'Our preliminary results suggest that in healthy people, inflammation of neutral granulocytes in the trachea may be significantly associated with RSV infection, and if we can articulate that the same mechanism works in the most vulnerable populations, it may provide an opportunity to reduce infections from RSV and other respiratory viruses; Some, so in theory, pushing the immune response in the direction of fighting the virus during the seasonal peak winter season may be better for the health of the body, and perhaps researchers could delineate new treatments to temporarily suppress nexual granulocyte inflammation in certain areas, such as by using simple nasal sprays to enhance the body's protection against circulatory viruses, which may be possible in high-risk environments such as hospitals.
Final researcher Cecilia Johansson said understanding the body's susceptibility and protective mechanisms to respiratory viruses may hopefully help scientists develop new therapies, and now we're looking at RSV infection mechanisms in human volunteers and mice, or hopefully clarifying the delicate balance between the body's resistance to viral infections and lung diseases induced by these viruses.
() References: Maximillian S. Habibi, Ryan S. Thwaites, Meiping Chang, et al. Neutrophilics in the weathery mucosa predisposes to RSV. Science 09 Oct 2020: Vol. 370, Issue 6513, eaba9301 doi:10.1126/science.aba9301(2) Bacteria-fighting cells in the airways boosts from from virusesby Ryan O'Hare, Imperial College London<!--/ewebeditor:page->