Phagocytosis by fresh and cultured human decidual stromal cells: opposite effects of interleukin-1 alpha and progesterone.

Flow cytometry and transmission electron microscopy have been employed to show that a proportion of fresh and cultured human decidual stromal cells phagocytose latex particles. Phagocytosis of Escherichia coli by cultured decidual stromal cells was, however, very low. Stimulation of cultured decidual stromal cells with interleukin-1 alpha enhanced phagocytosis of both latex particles and E. coli. In contrast, when decidual stromal cells were cultured with progesterone under decidualizing conditions, phagocytic activity was reduced. These results suggest the existence of an immune-endocrine circuit involving decidual stromal cells.