Uterine Natural Killer Cells Modulate Endometrial Growth and Persistence in Endometriosis

Endometriosis is a chronic disease that affects 10% of reproductive-aged people with uteruses worldwide. It is characterized by growth of uterine endometrium in the peritoneum and marked by pelvic pain and infertility. There is currently no cure and treatments are limited in effectiveness. Recent work has revealed key changes in uterine NK Cells (uNK) in endometriosis as they dominate the uterine mucosa’s immune landscape and play a crucial role in endometrial homeostasis. However, much of this work decouples uNK phenotypes and activity from uNK spatial interactions with endometrial innate immune and stromal cells. We hypothesized that aberrant uNK patterns of maturity, cytotoxicity, and receptor profile, coupled with spatial information on uNK interactions and organization could identify key features that could classify endometriosis. Here we present the largest endometriosis single-cell spatial dataset employing Imaging Mass Cytometry (IMC) analysis of eutopic endometrial biopsies from over 80 patients with stage I/II, stage III/IV, or no endometriosis for identification of key functional and spatial features that contribute to endometriosis. With IMC data at 1um resolution, we segment and phenotype immune and stromal cells in the endometrium for downstream analysis. This method allows us to couple previous single-cell knowledge of uNK cells in endometriosis with in situ spatial information, including neighborhood analysis and differential activity of stratum functionalis uNK cells and stratum basalis uNK cells. This work will inform understanding of uNK modulation of the uterine endometrium and innate immune cells therein, and the aberrations in this modulation that lead to endometriosis.