Problem: Type-I interferon (IFN) is the protein recognizing pregnancy in ruminants. Although IFN is secreted in early pregnancy, its role is not still clear in other species. Like other cytokines, IFN exerts its biological functions through specific membrane receptors. We have investigated the potential action of IFN in human pregnancy by studying the distribution of the receptors in the human placenta.
Method: Reactivity to monoclonal antibodies (mAbs) to the type-I IFN-receptor (R) was analyzed by immunohistochemistry in human placental tissues and in cytospins of first trimester trophoblast cells.
Results: Type-I IFN-R immunoreactivity was observed mostly in first trimester villous cytotrophoblasts and in the cytotrophoblast cell columns. Trophoblast in the decidua, the epithelium of the uterine glands, and most of the isolated trophoblast cells were also immunoreactive.
Conclusion: The expression of type-I IFN-R in the highly proliferating and migrating trophoblast suggests that this cytokine has a role in trophoblast growth and invasion.