New research may explain severe virus attacks

In some cases, immune cells in the lungs can contribute to exacerbation by virus attack.

In a new study, researchers at the Karolinska Institutet in Sweden describe how different types of immune cells, called macrophages, develop in the lungs and which of them may be behind severe lung diseases.

The study, published in Immunity, may contribute to future treatments for COVID-19, among other diseases.

The structure of the lungs is exposed to viruses and bacteria from both the air and the blood.

Macrophages are immune cells that, among other things, protect the lungs from such attacks.

But under certain conditions, lung macrophages can also contribute to severe lung diseases, such as chronic obstructive pulmonary disease (COPD) and COVID-19.

To date, research on the development of human lung macrophages has been limited.

Macrophages can have different origins and develop, among other things, from white blood cells, monocytes, which are divided into several major genetically determined strains.

In humans, two of these are “classical” CD14 + monocytes and “non-classical” CD16 + monocytes.

In a new study at Karolinska Institutet, researchers have used a model to study the development of lung macrophages directly in living lungs.

This was combined with a method to study gene activity in individual cells, RNA sequence, and thus found how blood monocytes become human lung macrophages.

The nonclassical monocytes, however, become macrophages in many blood vessels of the lungs and do not migrate into the lungs.