One of the long term objectives of this laboratory is to understand the role of uterine leukocytes in uterine maturation and embryo implantation. Changes in the uterine environment due to the introduction of pathogens, endometriosis, or autoimmunity can alter the recruitment and activation of the endometrial leukocytes. These changes can have severe consequences on the fertility of the affected woman. This proposal is designed to study the uterine changes that occur in a cohort of women with autoimmunity as a model of endometrial dysfunction. Leukocyte cells are recruited to the endometrium in a predictable fashion. Their numbers are low in the proliferative phase of the human menstrual cycle and increase at mid-secretory phase (the optimal time of implantation), concomitant with rising hormone levels. Factors that down- regulate the functions of the leukocyte cells are also in abundance in the mid-secretory phase of the menstrual cycle suggesting that they are also induced by the steroid hormones. Women with autoimmune thyroid disease (ATD) have been shown to have lower implantation rates and increases in very early pregnancy loss. Changes in both uterine T cell numbers and alterations in endometrial cytokine expression, consistent with leukocyte activation, suggest that these women can serve as a model for endometrial disregulation. Since most of the endometrial leukocyte cells do not express steroid hormone receptors it is the endometrial cytokine production, in response to the ovarian hormones, that is responsible for uterine leukocyte recruitment and activation state. This proposal will utilize an in vitro culture system of endometrial stroma and glandular epithelium to determine if the steroid responsiveness differs between women with ATD and controls. A semi-quantitative reverse transcription polymerase chain reaction will be performed to analyze the cytokine production in response to the steroid hormones from the endometrial tissues isolated from women with ATD and controls. Furthermore, differences in T cell cytotoxic activity will be determined using a redirected cytotoxic assay, while the uterine expression of co-stimulator ligands required for T cell activation will be determined by immunohistochemistry. By comparing hormone induced endometrial cytokine production and the activation state of the endometrial leukocytes in individuals with ATD to controls we hope to gain further insight into the role of leukocytes cells in implantation.