• Cytokines;
  • growth factor;
  • immunotolerance;
  • placenta;
  • pregnancy;
  • messenger ribonucleic acid

PROBLEM: Communication at the human maternal-fetal interface occurs by an intricate cytokine network. This study examines cytokine expression by normal first-trimester human chorionic villi.

METHOD OF STUDY: Tissues were obtained at elective pregnancy terminations (7–9 weeks). Total RNA was isolated from chorionic villi by guanidinium isothiocynate-acid phenol extraction. A reverse transcriptase-polymerase chain reaction technique was used to examine cytokine expression. β-Actin was used as the housekeeping gene, and mitogen-stimulated lymphocytes served as positive controls.

RESULTS: β-Actin was uniformly expressed by all chorionic villous samples. Interferon (IFN)-α and -β also were highly expressed. Moderate expression was noted for interleukin (IL)-10, IL-6, tumor necrosis factor (TNF)-α, and IL-1β. In contrast, transforming growth factor-β1, IFN-γ, IL-2, and IL-1α were either weakly expressed or absent in first-trimester villi. CONCLUSIONS: Cytokines may contribute to pregnancy immunotolerance (IFN-α, IFN-β, and IL-10), viral resistance (IFNs), hormone secretion (IL-1 and IL-6), and cellular remodeling (IFN-γ and TNF-α) within the chorionic villous.