A recent study conducted at the Karolinska Institute in Sweden and published in the journal Immunity, discusses how macrophages, which are a type of immune cell, develop in the lungs and how some of them may be behind serious lung diseases. These immune cells are also known to contribute to the exacerbation of virus attack, but little research has been done on how human lungs develop.
Due to the structural nature of the lungs, they are exposed to bacteria and viruses from the blood as well as the air. Macrophages are intended to protect the lungs from these attacks, but have also been seen under the right conditions to contribute to severe lung disease, including chronic obstructive pulmonary disease (COPD). ) seen in patients with coronavirus 2019 (COVID-19).
Investigators were using a model that allowed them to study the development of these immune cells directly in living lungs. They also combined the model with a method called RNA sequencing that is used to study gene activity in individual cells.
The results showed how white blood cells grow into monocytes and then macrophages. There are 2 types of these monocytes, called classical and non-classical, and the researchers found that the non-classical monocytes that grow into macrophages do not migrate into the lung tissue. .
“Some macrophages in the lungs may be linked to a number of serious lung diseases. In respiratory diseases, for example, monocytes in the lungs grow into macrophages, which fight viruses and bacteria,” Elza Evren, the first author of the study, said: “But a particular type of macrophage may also contribute to severe inflammation and disease.”
The classic monocytes migrate into the tissue, and from there are converted to macrophages that protect the health and function of the lungs. The researchers believe that when someone is infected with COVID-19, the anti-inflammatory immune macrophages are substituted for those that are pro-inflammatory.
“These monocyte-derived blood macrophages have been shown in other studies to be linked to the severity of a person’s growth in COVID-19 and the extent of the damage to the lungs. Patients with COVID-19 also have HLA. DRhi monocytes in their blood, possibly because they move away from the blood into the lungs, “said Tim Willinger, director of the study. play an important role in rapid inflammatory responses, our results indicate that future treatments should focus on inflammatory macrophages and monocytes to reduce lung damage and mortality from COVID-19 mutation. “