Scientists discover macrophages that participate in alveolar regeneration

Researchers at the University of Liège in Belgium have identified a new population of macrophages that play a crucial role in the regeneration of alveoli in the lungs following injury from respiratory viruses. This discovery, published in the journal Science Immunology, enhances the understanding of the immune response after infections and could lead to innovative regenerative therapies. The study highlights that these atypical macrophages, which were previously overlooked due to their expression of a marker thought to be exclusive to neutrophils, are recruited during the early recovery phase and are essential for repairing lung tissue. The research team, led by Dr. Coraline Radermecker and Prof. Thomas Marichal, utilized advanced technologies such as flow cytometry and single-cell RNA sequencing to characterize these macrophages and their functions. The findings suggest that these macrophages assist in the regeneration of type 2 alveolar epithelial cells, which are vital for gas exchange in the lungs. The study counters the prevailing notion that macrophages are solely pathogenic after respiratory infections, proposing instead that they have a reparative role. By enhancing the function or proliferation of these macrophages, new therapeutic strategies could be developed to improve lung recovery and mitigate complications from severe respiratory infections and conditions like acute respiratory distress syndrome (ARDS). This research opens new avenues for treating respiratory diseases and improving patient outcomes following viral infections.