Profiling immune cells in the mammary gland during pregnancy and lactation

The mammary gland undergoes profound structural and cellular changes during pregnancy and lactation, yet the changes in immunocyte populations are incompletely understood. We identified changes in all immunocyte populations including B cells, NK cells, myeloid cells, and T cells, specifically increases in CD4+ and CD8+ T effector cells in late pregnancy and lactation that are partly dependent on microbial signals. Overall design: Single-cell RNA seq of CD45+ immune cells from the mammary gland during different stages of pregnancy and lactation (nulliparous, gestation, lactation, involution, and regression). Includes Balb/c and germ-free mice to analyze changes in different backgrounds.