Expression of intercellular adhesion molecules ICAM-1 and ICAM-2 in human endometrium: regulation by interferon-gamma

The purpose of this study was to localize intercellular adhesion molecule ( ICAM)-1 and ICAM-2 in human endometrium and myometrium throughout the menst rual cycle, and to determine whether the expression of these molecules is r egulated by interferon (IFN)-gamma. ICAM-1 and ICAM-2 distribution was exam ined in endometrial biopsies by immunocytochemistry, and Northern blotting was used to quantify ICAM-1 and ICAM-2 mRNA expression in isolated endometr ial glands. Stromal fibroblast cultures were exposed to IFN-gamma and the e ffect on expression of ICAM-1 and ICAM-2 was determined by immunocytochemis try and Northern blotting. ICAM-1 was localized in vivo to the apical surfa ce of the glandular epithelium, the vascular endothelium and endometrial st romal cells throughout the menstrual cycle. Stromal expression of ICAM-1 wa s up-regulated in menstrual specimens. Northern blotting confirmed the pres ence of ICAM-1 mRNA in isolated endometrial glands. The expression of ICAM- 1 antigen and message was increased in stromal cell culture after incubatio n with IFN-gamma in a time-dependent manner, suggesting that this cytokine stimulates the expression of ICAM-1 in the endometrial stroma. ICAM-2 antig en expression was restricted to the vascular endothelium. ICAM-2 mRNA was a bsent in endometrial glands. The widespread distribution of ICAM-1 in human endometrium suggests that this molecule is involved in the process of mens truation, the functioning of glands, blood vessels and stroma, and in regul ating leukocyte trafficking into the tissue. ICAM-2 is restricted to the va scular endothelium where it might modulate leukocyte invasion of the stroma and myometrial connective tissue.