Cells infected with the Covid-19 virus can “explode”, which contributes to the development of severe disease, researchers say.
Scientists from the United States and the United Kingdom examined blood samples from people infected with Covid and found that about 6% of monocytes – immune cells that patrol the body for foreign invaders – have undergone a type of cell death known as pyroptosis, which is associated with inflammation after infection with the virus.
A small proportion of macrophages – another type of immune cell that ingests and destroys foreign cell debris – also become inflamed after being infected with Sars-CoV-2.
In the case of both cell types, the virus is thought to activate what are known as inflamasomes: large molecules that trigger a cascade of inflammatory reactions that can culminate in cell death.
Studies have long shown that severe Covid disease is caused by inflammation that causes damage to the lungs and other organs.
Previous studies have shown that the immune system in people with Covid can effectively engage the body by releasing proteins that fight infections known as cytokines, which then attack healthy tissues. These “cytokine storms” are associated with serious illness.
A new study by researchers at the Royal Free Hospital in London on Boston Children’s Hospital now suggests that pyroptosis also plays a role in the disease’s escalation.
“Inflammation and cell death are important factors in severe Covid, and our study shows that pyroptosis is often the culprit,” Dr. Gautam Mehta, a consultant hepatologist at Royal Free Hospital, told The Mail On Sunday.
Dr. Mehta said the pyroptosis pathway acts as an “alarm system” for the body. “If it detects bacterial or viral particles in the cell, it causes the cell to ‘explode’ and release pro-inflammatory contents. This has the advantage of eliminating the infection, but can result in severe inflammation. Pyroptosis literally implies a “fiery” way of cell death. “
Infected immune cells could potentially offer a target for drug development, the researchers said, raising hopes that new treatments could be devised to prevent serious illness in a person infected with Covid.
“This is an important finding because our Covid treatments are currently targeting the virus itself,” said Dr. Mehta.
“If we can focus on the process that causes severe disease, we could develop an effective treatment that works even in patients for whom vaccines are not effective.”
A separate study, yet to be reviewed, showed how Sars-CoV-2 can enter immune cells – a previous point of bewilderment for scientists, given that these cells do not carry many of the ACE2 receptors the virus uses. to get an entry.
Researchers at Yale University School of Medicine have found that the virus is able to infiltrate human cells through another surface protein known as the Fcγ receptor, using antibodies.
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