Smart-seq profiling of border-associated alveolar macrophages in fibrotic mouse lungs

Yet chronically injured tissues do not scar uniformly, indicating that local adaptive programs can buffer tissue stress and preserve structural integrity. Idiopathic pulmonary fibrosis (IPF) preferentially initiates within the subpleural region, but the cellular programs that bias subpleural remodeling toward fibrotic progression or preservation remain poorly understood.

In this study, we identified a spatially restricted population of enlarged, lipid-laden alveolar macrophages located at the subpleural border, which we termed border-associated alveolar macrophages (BAAMs). Smart-seq profiling of sorted alveolar macrophage (AM) populations from fibrotic lungs identified a discrete set of functional genes defined as the BAAM transcriptional signature.