Inverse regulation of the interferon-γ receptor and its signaling in human endometrial stromal cells during decidualization

Objective: To investigate whether human endometrial stromal cells (ESCs) express the interferon-gamma-receptor (IFN-gamma R) and whether the process of decidualization or human chorionic gonadotropin (hCG) regulate the IFN-gamma R and its signaling pathway. Design: In vitro experiment. Setting: Research laboratory at a medical university center. Patient(s): Premenopausal women undergoing hysterectomy for benign reasons. Intervention(s): Isolation and incubation of ESCs from hysterectomy specimens with 17 beta-estradiol, progesterone, recombinant hCG, and IFN-gamma as well as an IFN-gamma R-blocking antibody. Main Outcome Measure(s): We analyzed IFN-gamma R and the phosphorylation of signal transducer and activator of transcription 1 (STAT-1) by flow cytometry. We measured IFN-gamma R and interferon response factor 1 (IRF-1) mRNA using semiquantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR). Result(S): The IFN-gamma R is up-regulated in human ESCs during decidualization without affecting the phosphorylation of STAT-1. Stimulation of IRF-1 by IFN-gamma is reduced in decidualized ESCs. We found that hCG neither regulates the IFN-gamma R nor its signaling pathway. Conclusion(s): These results show an inverse regulation of the IFN-gamma R and its signaling response via STAT-1 and IRF-1 in human ESCs during decidualization. The early embryonic signal hCG has no effect on this process. This mechanism may finely modulate the reactivity of ESCs to IFN-gamma-mediated signals from immune cells at the implantation site. (Fertil Steril (R) 2009;91:2131-6. (C) 2009 by American Society for Reproductive Medicine.)