Cyclic variation in the expression of Fc gamma receptors in human endometrium

Cyclic variations of Fc gamma receptors (FcR) in human endometrium were studied in specimens from the fundal part, the lower part of the uterine cavity and from the endocervix obtained in the proliferative, ovulatory and early and late secretory phase. The three classes of FcR were studied using monoclonal antibodies (mAb) and indirect immunohistochemistry with avidin-biotin-peroxidase complexes. FcRI, FcRII and FcRIII were expressed on stomal cells throughout the cycle. In the late secretory phase some of the stromal cells had morphology comparable to predecidual cells. These cells express FcRIII only. FcRIII only were expressed on the glandular epithelium in all phases of the cycle. The endothelium was negative in the midcycle and positive early and late in the cycle for FcRI and FcRIII, although weak for FcRIII late in the cycle. FcRII was not expressed on the endothelium. Apparently the FcR activity in the endometrium does not vary during the menstrual cycle, except for small variation in the expression on the endothelium and the presence of FcRIII on positive predecidual cells. No differences in FcR expression were found in specimens taken from different parts of the uterine cavity.