Distinct developmental pathways from blood monocytes generate human lung macrophage diversity

RNA-sequencing data sets (1) Single-cell RNA-sequencing data of human lung myeloid cells from MISTRG mice on day 21 post-transplantation with human CD34⁺ cells (2) Single-cell RNA-sequencing data of human lung myeloid cells from MISTRG mice on day 36 post-transplantation with human CD34⁺ cells (3) Bulk RNA-sequencing data of human intravascular monocytes, intravascular macrophages, and extravascular macrophages from the lungs of MISTRG mice engrafted with human CD34⁺ cells Data collection methodsSee Resource DOI Publication abstractThe study of human macrophages and their ontogeny is an important unresolved issue. Here, we use a humanized mouse model expressing human cytokines to dissect the development of lung macrophages from human hematopoiesis in vivo. Human CD34+ hematopoietic stem and progenitor cells (HSPCs) generated three macrophage populations, occupying separate anatomical niches in the lung. Intravascular cell labeling, cell transplantation, and fate-mapping studies established that classical CD14+ blood monocytes derived from HSPCs migrated into lung tissue and gave rise to human interstitial and alveolar macrophages. In contrast, non-classical CD16+ blood monocytes preferentially generated macrophages resident in the lung vasculature (pulmonary intravascular macrophages). Finally, single-cell RNA-sequencing defined intermediate differentiation stages in human lung macrophage development from blood monocytes. This study identifies distinct developmental pathways from circulating monocytes to lung macrophages and reveals how cellular origin contributes to human macrophage identity, diversity, and localization in vivo.