PROJECT SUMMARY Endometriosis, the presence of endometrial tissue at an extra-uterine site, is a common yet enigmatic gynecologic disease that dampens the quality of life for approximately 10-15% of reproductive-aged women. Although endometriosis is regarded as a benign condition, many women with this disease experience chronic episodes of debilitating pain, dyspareunia, dysmenorrhea, and/or infertility. Numerous theories have attempted to explain disease pathogenesis including retrograde menstruation, a genetic predisposition, and altered differentiation of non-uterine cells. Unfortunately, theories to date have failed to explain all incidences of disease occurrence. Thus, I am exploring the possibility that endometriosis is an adult-onset disease that emerges due to an early life disruption of endocrine-immune cross-communication. I hypothesize that an in utero toxicant exposure trains bone marrow-derived immune progenitor cells (BMDCs) and subsequently promotes the development of endometriosis in adulthood. Immune cell training refers to the development of memory of a previous infection, but it is unknown whether immune cells similarly “remember” a past toxicant exposure. Nevertheless, our laboratory has shown that in utero TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) exposure in mice results in a loss of uterine progesterone (P4) sensitivity and hyperinflammation as seen in women with endometriosis. Herein, I will utilize our established mouse model of toxicant exposure to determine if in utero TCDD exposure induces immune cell training prompting the development of the endometriosis-like uterine phenotype in adult mice. In Specific Aim 1, I will examine the relationship between toxicant-mediated peritoneal inflammation and reproductive dysfunction by characterizing the intraperitoneal immune phenotype and uterine phenotype of TCDD-exposed mice compared to wild-type C57/BL6 (WT) mice. Furthermore, I will determine if TCDD-mediated alterations of immune cells directly contribute to uterine dysfunction by adoptively transferring BMDCs from TCDD-exposed mice to control recipient mice. In Specific Aim 2, I will elucidate the molecular mechanisms underlying the TCDD-generated phenotype by examining the epigenetic, metabolic, and functional status of TCDD-exposed immune cells in comparison to unexposed immune cells. Overall, determining the specific contribution of immune cells to reduced P4 sensitivity within the uterus and identifying targetable pathways will determine the potential utility of immune cells as a diagnostic and/or therapeutic target. This proposal builds upon preliminary data that I have obtained and will provide me with the training I seek in reproductive toxicology, reproductive immunology, immunotoxicology, and immunometabolism. Aside from gaining this knowledge and technical skills, I will also gain necessary experience in data analysis, generation of manuscripts, communication of my results to scientific and lay audiences, and the formulation of testable hypotheses. At the conclusion of this fellowship, I will be well-positioned to undertake postdoctoral training in a leading laboratory and pursue my goal to be an independent investigator.

PROJECT NARRATIVE Endometriosis is a persistent and enigmatic gynecologic disease that affects approximately 10-15% of reproductive-aged women. The proposed research seeks to uncover mechanisms by which altered immune cell function potentially leads to uterine dysfunction and peritoneal inflammation as seen in women with endometriosis. We expect to identify an immunologic “footprint” of endometriosis which should foster the development of intervention and prevention strategies by using immune cells as diagnostic/ therapeutic tools.