Single-cell RNA sequencing of bronchoalveolar lavage cells from mouse

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). Single-cell transcriptomic profiling of BALF cells from fibrotic lungs provided insight into BAAMs as a transcriptionally distinct protective alveolar macrophage population.