Localization and production of human macrophage colony-stimulating factor (hM-CSF) in human placental and decidual tissues.

The localization of the human macrophage colony-stimulating factor (hM-CSF) in human trophoblast cells (syncytiotrophoblast and cytotrophoblast), decidual stromal cells, decidual lymphocytes, macrophages, and endometrial gland cells during the early stage of pregnancy was determined by the immunohistochemical examination and in situ hybridization. A large amount of hM-CSF was detected in the supernatant of the primary cultured cytotrophoblasts and decidual stromal cells. The decidual stromal cells secreted approximately 2 to 20 times as much hM-CSF as the trophoblast cells. Northern blot analysis showed that the placental and decidual tissues expressed the 4.0 kb hM-CSF-mRNA, however a larger amount of hM-CSF-related mRNA was found in the decidual than in the placental tissue. We also demonstrated the localization of hM-CSF mRNA expression in human decidual macrophages and CD16- CD56+ NK cells using the RT-PCR method. These findings indicate that hM-CSF is produced by decidual stromal cells, decidual macrophages, decidual CD16- CD56+ NK cells, and endometrial gland cells, as well as by trophoblasts. This increased production of hM-CSF may play a role in decidual function and placental function by the autocrine and paracrine system.