EXPRESSION OF CD69 ACTIVATION MARKER BY ENDOMETRIAL GRANULATED LYMPHOCYTES THROUGHOUT THE MENSTRUAL-CYCLE AND IN EARLY-PREGNANCY

Flow cytometry studies of first-trimester normal human decidua have pr oposed that a proportion of endometrial granulated lymphocytes (eGL), the predominant leucocyte population in early human pregnancy, co-expr ess CD69. The purpose of this study was to investigate CD69 expression by immunohistochemistry throughout the menstrual cycle and in first-t rimester human decidua and to determine whether CD69 expression by eGL is an in vivo characteristic or whether the antigen is acquired in vi tro after tissue disaggregation and cell purification. Single immunoen zymatic and double immunofluorescence labelling of tissue sections, su pplemented with double immunoenzymatic staining of purified eGL and fl ow cytometry, indicated that eGL do not co-express CD69 in situ but th at they acquire the molecule in vitro after cell purification and cult ure.