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. 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.