T cell dynamics in the mammary gland during lactogenesis

The mammary gland undergoes profound structural and cellular changes during pregnancy and lactation, yet the changes in immunocyte populations are incompletely understood. We identified increases in CD4+ and CD8+ T effector cells in late pregnancy and lactation that are partly dependent on microbial signals. Some of the mammary T effector cells share TCR clonotypes with intestinal T cells suggesting a possible route of migration. Overall design: RNA seq profiling of sorted immunocytes and epithelial cells from mammary glands of lactating and nulliparus germ free mice. Single cell RNA seq of mammary gland, small intestine, colon, thymus and spleen in lactating and virign mice.