LOCALIZATION OF 3 SUBTYPES OF FC-GAMMA-RECEPTORS IN HUMAN PLACENTA BY IMMUNOHISTOCHEMICAL ANALYSIS

We investigated the localization of the three subtypes of (FcγR) in the normal human placenta using immunohistochemical and immunocytochemical techniques with specific monoclonal antibodies. The analysis revealed that FcyRI was expressed on Hofbauer cells, that FcγRII was expressed on Hofbauer cells and endothelial cells of fetal vessels, while FcγRIII was expressed on trophoblasts, especially syncytiotrophoblasts. Moreover, we demonstrated that the expression of FcγRI and FcγRII on Hofbauer cells and endothelial cells of the fetal vessels in the 1st trimesterplacenta was different from that in the 3rd trimester placenta. These results, therefore, indicate that the three subtypes of FcγR in the human placenta may contribute to maintenance of placental functions, because each FcγR molecule displays unique biological functions similar to those on leukocytes. © 1991.