Production of granulocyte colony-stimulating factor at the materno-foetal interface in human pregnancy.

A bioassay specific for human granulocyte colony-stimulating factor (G-CSF) was developed and used to measure G-CSF production in human pregnancy tissues. G-CSF was secreted by both foetal chorionic villous and maternal decidual tissues taken in the first trimester and at term. The level of G-CSF production by placental tissue was 6750 (1250-10,000) units of bioactivity per g of tissue in 48 hr in the first trimester and 104 (83-190) U/g at term. Bioactive G-CSF was also secreted by decidual tissue, more in the first trimester than at term. ELISA immunoassays measured 75 (10-820) ng/g/48 hr of G-CSF antigen from first trimester placenta, 15 (10-50) ng/g from first trimester decidua and less than 2 ng/g from term placenta. RNA isolated from decidual and chorionic villous tissue or from cells purified by flow cytometry, contained G-CSF mRNA in both tissues. In decidua, mRNA for G-CSF was confined to the macrophages, and cytotrophoblast from term amniochorion contained no detectable G-CSF mRNA. No G-CSF, measured as bioactivity or as mRNA, was detectable in choriocarcinoma cell lines.