EVIDENCE OF T-CELL ACTIVATION AND POTENTIAL CYTOKINE ACTION IN HUMAN ENDOMETRIUM

Antigenic epitopes have been described whose expression characterizes early or late stages of activation of Tcells. In this study the expression of early activation antigen, interleukin-2 receptor was compared with the expression of late activation antigens, HLA-DR, HLA-DP, and HLA-DQ molecules of the major histocompatibility complex II, and very late activation antigen, VLA-1 of the integrin superfamily of molecules in 43 human endometria. These molecules were localized by their reactivity with monoclonal antibodies in an avidinbiotin-complex procedure. Interleukin-2 receptor was not expressed in human endometria; however, endometrial T-cells within lymphoid aggregates, some scattered in endometrial stroma and a few within epithelium, expressed HLA-DR, HLADP, HLA-DQ, and VLA-1. In addition, expression of the receptor of interferon-ᵞ, a product of activated T-cells, was observed on endometrial epithelium. Evidence for activation of T-cells and expression of interferon-ᵞ receptor in human endometrial epithelium suggests that endometrium may be an active site for cytokine action. © 1990 by The Endocrine Society.