What does survival for the fittest mean in a coronavirus pandemic? Look at the immune system

May 24, 2020 /PRNewswire
BIOON/--Darwin popularized the concept of survival for the fittest as a natural selection mechanism for the evolution of life: creatures with more environmentally appropriate genes are selected to survive and pass on to the next generationso that when a new infectious disease that has never been seen in the world comes out, the process of natural selection starts againwho is the "fittest" in the context of the coronavirus pandemic?this is a challenging issueBut, as researchers at the University of South Carolina'simmunologysay, one thing is clear: Without an effective treatment, the survival of coronavirus infection depends entirely on the patient's immune responseimagesource: https://cn.bing.com
researchers have been working on how the immune response can become a double-edged sword -- helping the host fight infection on the one hand and causing significant damage in the form ofautoimmunediseasetwo stages of the immune response
immune response is like a carIn order to reach your destination safely, you need a well-functioning accelerator (first stage) and a brake (phase 2)Failure on either side can have serious consequenceseffective immune response to the source of infection depends on the delicate balance between the two stagesWhen an infectious pathogen strikes, the body begins the first phase, which promotes inflammation -- a state in which multiple immune cells gather at the site of infection to destroy the pathogenfollowed by the second phase, in which immune cells called regulatory T cells suppress inflammation and allow infected tissue to fully healDefects in the first stage can cause the source of infection, such as a virus orbacteria, to grow uncontrolledDefects in the second stage can lead to large-scale inflammation, tissue damage and deathcoronavirus infects cells by attaching it to a receptor called angiotensin-converting enzyme 2 (ACE2), which is present in many tissues of the body, including the respiratory tract and cardiovascular systemThis infection triggers the first phase of the immune response, in which the B cells that produce antibodies produce neutralizing antibodies that bind to the virus and prevent the virus from binding to ACE2This inhibits the infection of more cellsin stage 1, immune cells also produce cytokines, a group of proteins that activate other immune cells and fight infectionAlso involved in the fight are killer T-cells, which destroy infected cells and prevent the virus from replicatingif the immune system is broken and works poorly in the first phase, the virus can replicate quicklyPeople with compromised immune systems include the elderly,organ transplantrecipients, patients with autoimmune diseases, cancer patients undergoing chemotherapy, and people with birth immunodeficiency Many of these people may not be able to produce enough antibodies or killer T-cells to fight the virus, causing the virus to multiply uninhibited and cause severe infection lung damage caused by inflammation
increased replication of SARS-CoV-2 can lead to complications in the lungs and other organs normal, the lungs have a variety of microorganisms, both harmful and harmless, they live harmoniously in the lungs However, as the coronavirus spreads, the resulting infections and inflammation are likely to disrupt this balance, allowing harmful bacteria in the lungs to dominate This leads to the development of pneumonia, the lung air bag, or alveoli, filled with fluid or pus, making it difficult to breathe this causes additional inflammation in the lungs, leading to acute respiratory distress syndrome (Acute Respiratory Distress Syndrome, ARDS), which occurs in one-third of COVID-19 patients The immune system can't control lung virus infections and other emerging pathogens, triggering a stronger inflammatory response by releasing more cytokines, a condition known as a cytokine storm at this stage, it may also be that the second stage of the immune response designed to suppress inflammation fails to control cytokine storms Such cytokine storms can trigger harmful, corrosive chemicals that destroy infected cells, which are released by the body's immune cells and can cause serious damage to the lungs and other organs in addition, since ACE2 is present throughout the body, the first stage of killer T cells can destroy multiple organs of virally infected cells, causing more extensive damage As a result, patients who produce too many cytokines and T cells may die not only from lung damage, but also from damage to other organs such as the heart and kidneys the balance function of the immune system
several questions about the prevention and treatment of COVID-19 are raised in the above case A vaccine that triggers neutralizing antibodies and T cells to prevent the virus from entering the cells and replicating is likely to be successful The key to an effective vaccine is that it does not cause excessive inflammation image source: https://cn.bing.com
In addition, new anti-inflammatory drugs are urgently needed in patients who are transitioning to more severe forms such as acute respiratory distress syndrome (ARDS) and cytokine storms (often fatal) These drugs can widely suppress cytokine storms without causing excessive immune resuppression, allowing patients to remove coronaviruses without damaging the lungs and other tissues these immunosuppressants may have only a small chance of being used effectively Such drugs should not be used in the early stages of infection, when the patient needs the immune system to fight the infection, but it should not be used long after THE ARDS has occurred, as a large amount of inflammation is out of control The window for this anti-inflammatory treatment can be determined by monitoring antibody and cytokine levels in the patient." therefore, for COVID-19, "survival of the fittest" refers to the normal phase 1 and 2 immune response of the individual This means that in the first stage there is a strong immune response to remove primary coronavirus infection and inhibit its spread in the lungs Then, the next step should be the best 2-stage reaction to prevent excessive inflammation in the form of a "cytokine storm" In order to be successful, vaccines and anti-inflammatory treatments need to be carefully balanced is infected with the coronavirus, it's hard to know who is the healthiest individual Not necessarily the youngest, strongest, or strongest people survive this coronavirus The fittest survive are those who have the "right" immune response, and they are able to quickly clear the infection without causing fatal excessive inflammation (Bio ValleyBioon.com) References: What dos 'survival of the fittest' mean in the coronavirus? Look to the immune system 2
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