Characterizing Macrophage Diversity in Metastasis-Bearing Lungs Reveals a Lipid-Associated Macrophage Subset

Single cell RNA sequencing was performed on CD45+Ly6G-CD64+MerTK+ macrophages isolated from the lungs of mice 5 weeks after transplantation of 4T1-Luc mammary gland tumors. The purpose of this study was to determine the unique macrophage subsets present in the lungs of mice bearing mammary tumor metastases. Overall design: Mice received injections of 10k 4T1-Luc cells into the #4 mammary gland. Tumors were allowed to progress for 5 weeks, at which point the lungs were harvested. The lungs were digested and macrophages were sorted by FACS, followed by single cell RNA sequencing.