Recently, it has been found that immune cells that directly eat the virus are rather infected with the Corona 19 virus, causing severe cases, and the fact that some of the antibodies attached to the virus actually help this infection. Courtesy of Getty Image Bank
American scientists have discovered a specific process that helps monocytes and macrophages, which are immune cells that directly fight the new coronavirus infection (COVID-19) virus, cause an excessive inflammatory response and help the virus to multiply when infected with the virus. Previously, these cells were cited as the cause of severe COVID-19, but this time, the specific pathway was revealed.
A joint research team from Harvard University Medical School, Massachusetts General Hospital Patient Treatment Research Center, and Cambridge University and University College London observed blood samples from severe COVID-19 patients and found that 6% of their monocytes were infected with COVID-19 and were apoptotic. found.
Monocytes move around in the blood and when they encounter pathogens such as viruses or bacteria, they surround themselves and absorb them. Pathogens eat up healthy cells before they infect them. Some of the monocytes enter the organ and become specially adapted to the tissue to become pathogen-eating macrophages. Pathogens eaten by monocytes or macrophages are decomposed while surrounded by intracellular substances like a bojagi (endosome).
The research team questioned the fact that cells in apoptosis are rapidly decomposed, but only 6% of them are found in the blood of severe COVID-19 patients. It was also questionable that the surface of monocytes or macrophages was infected with Corona 19 even though there were almost no receptors (ACE2) to which the Corona 19 virus can attach.
As a result of the study, it was found that the antibody that traps and destroys the virus rather helps monocytes and macrophages to become infected with the virus. They also found that patients with severe COVID-19 have more receptors (CD16) that bind to these antibodies on monocytes. This means that monocytes are more likely to be infected with the COVID-19 virus than other people and have a greater risk of aggravation.
The research team also found that the Corona 19 virus caught in the endosome can escape from the endosome and proliferate unlike other viruses. When the virus starts to multiply inside the infected cells, the immune system becomes inflamed, which notifies other immune cells as well. This is to increase immunity by causing other immune cells to flock to this area. However, if the cells infected with COVID-19 were monocytes or macrophages, this alarm system was excessively activated. This leads to an excessive inflammatory reaction, which increases the risk of becoming severe.
Judith Lieberman, a professor of pediatrics at Boston Children’s Hospital, said, “When the Corona 19 virus infects monocytes and starts to multiply within them, the inflammatory system is over-activated. “It’s hard to stop,” he explained.
The research team also compared blood samples from patients with severe COVID-19 with pneumonia from other causes and found that this phenomenon occurs more frequently in patients with COVID-19. Professor Lieberman said, “The blood of patients with severe COVID-19 showed more apoptotic monocytes and inflammation. explained that
The research team estimated that antibodies that help monocytes become infected with COVID-19 are not found in other types of coronavirus infection. It is analyzed that it was made in response to the COVID-19 infection. In addition, the experiment revealed that the antibody produced by the COVID-19 vaccine was not at all associated with monocyte infection or inflammatory response.
The research team expected that by making drugs that target these antibodies, it would be possible to prevent the spread of severe cases of COVID-19 infection. To this end, they plan to conduct further studies on what types of antibodies help monocytes infect the virus. The results of this study were published in the international scientific journal ‘Nature’ on the 6th.
On the 1st of this month, a research team at Yale University in the United States observed the lungs of mice infected with Corona 19, and as lung macrophages were infected with Corona 19, an excessive inflammatory reaction occurred. It was published in the ‘BioArchive’. Existing research results have even found that the cause of severe COVID-19 is an excessive inflammatory reaction caused by infection with monocytes and macrophages.