Lung Macrophages Found To Drive Allergic Inflammation
Key lung immune cells can switch from protectors to drivers of inflammation during asthma.
Researchers at the VIB-UGent Center for Inflammation Research have discovered that certain immune cells in the lungs play a dual role in allergic conditions like asthma. While these cells normally help keep the lungs healthy, they can actually contribute to additional inflammation during an allergic reaction.
These are alveolar macrophages, immune cells located in the lung alveoli. Under healthy conditions, they act as sentinels: they clear harmful particles and prevent the immune system from overreacting. However, the new research shows that these cells can change their function when exposed to allergens.
"Alveolar macrophages have long been considered peacemakers in the lungs," says Stijn Verwaerde (VIB-UGent), a physician, doctoral student, and first author of the study. "Our results show that during allergic reactions, they can actually do the opposite and fuel inflammation."
During an allergic reaction, macrophages switch to a pro-inflammatory state. They then send out signals that attract other immune cells, increasing inflammation in the lungs and potentially worsening symptoms such as shortness of breath and difficulty breathing. The researchers also observed that some macrophages merge into large cells that can alter the structure of lung tissue.
These findings challenge the classic view of alveolar macrophages as stable and unchanging cells. They appear remarkably adaptable and highly susceptible to environmental influences, sometimes with detrimental consequences for lung health.
The discovery offers new insights into how allergic lung diseases develop and worsen. By better understanding the role of these immune cells, researchers hope to develop future treatments that reduce inflammation without disrupting normal lung function.
Reference: Verwaerde S, Hastir JF, Schetters STT, et al. Innate type 2
lymphocytes trigger an inflammatory switch in alveolar macrophages. Immunity. doi: 10.1016/j.immuni.2025.11.015
This article has been republished from the following materials. Note: material may have been edited for length and content. For further information, please contact the cited source. Our press release publishing policy can be accessed here.
