Expression of the interferon-gamma receptor gene in mouse placentas is related to stage of gestation and is restricted to specific subpopulations of trophoblast cells.

In order to evaluate the potential of placental cells to bind the multifunctional cytokine, interferon-gamma (IFN-gamma), tissues collected from pregnant Swiss mice were analysed for IFN-gamma receptor (IFN-gamma R) mRNA and protein. Northern blot hybridization studies indicated that the relative abundance of IFN-gamma R mRNA increased as gestation progressed to term. Analysis by in situ hybridization revealed that trophoblast cells first contained high steady state levels of IFN-gamma R mRNA at g.d. 12. At g.d. 12 and 14, transcription was restricted to cells in the spongiotrophoblast region and nests of similar cells in the labyrinthine region. These cells also contained immunoreactive IFN-gamma R protein. By g.d. 18, IFN-gamma R mRNA was clearly detectable in large spongiotrophoblast cells and labyrinthine trophoblast. IFN-gamma R mRNA was low to absent in giant trophoblast cells at all stages of gestation. Specific mRNA was present in parietal and visceral yolk sac cells by g.d. 14. Thus, expression of the IFN-gamma R gene in mouse placental cells is influenced by stage of gestation, cell lineage and state of differentiation. Whether or not these cells respond vigorously to IFN-gamma with induction of antiviral proteins, increased MHC class I antigens and growth modulation may therefore be determined by their expression of specific receptors for this pluripotent cytokine.