AUTHOR=Patel Mickey V. , Hopkins Daniel C. , Barr Fiona D. , Wira Charles R. 

TITLE=Sex Hormones and Aging Modulate Interferon Lambda 1 Production and Signaling by Human Uterine Epithelial Cells and Fibroblasts

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.718380

DOI=10.3389/fimmu.2021.718380

ISSN=1664-3224

ABSTRACT=<p>Estradiol (E<sub>2</sub>) and progesterone (P) have potent effects on immune function in the human uterine endometrium which is essential for creating an environment conducive for successful reproduction. Type III/lambda (λ) interferons (IFN) are implicated in immune defense of the placenta against viral pathogens, which occurs against the backdrop of high E<sub>2</sub> and P levels. However, the effect of E<sub>2</sub> and P in modulating the expression and function of IFNλ1 in the non-pregnant human uterine endometrium is unknown. We generated purified <italic>in vitro</italic> cultures of human uterine epithelial cells and stromal fibroblast cells recovered from hysterectomy specimens. Poly (I:C), a viral dsRNA mimic, potently increased secretion of IFNλ1 by both epithelial cells and fibroblasts. The secretion of IFNλ1 by epithelial cells significantly increased with increasing age following poly (I:C) stimulation. Stimulation of either cell type with E<sub>2</sub> (5x10<sup>-8</sup>M) or P (1x10<sup>-7</sup>M) had no effect on expression or secretion of IFNλ1 either alone or in the presence of poly (I:C). E<sub>2</sub> suppressed the IFNλ1-induced upregulation of the antiviral IFN-stimulated genes (ISGs) MxA, OAS2 and ISG15 in epithelial cells, but not fibroblasts. Estrogen receptor alpha (ERα) blockade using Raloxifene indicated that E<sub>2</sub> mediated its inhibitory effects on ISG expression <italic>via</italic> ERα. In contrast to E<sub>2</sub>, P potentiated the upregulation of ISG15 in response to IFNλ1 but had no effect on MxA and OAS2 in epithelial cells. Our results demonstrate that the effects of E<sub>2</sub> and P on IFNλ1-induced ISGs are cell-type specific. E<sub>2</sub>-mediated suppression, and selective P-mediated stimulation, of IFNλ1-induced ISG expression in uterine epithelial cells suggest that the effects of IFNλ1 varies with menstrual cycle stage, pregnancy, and menopausal status. The suppressive effect of E<sub>2</sub> could be a potential mechanism by which ascending pathogens from the lower reproductive tract can infect the pregnant and non-pregnant endometrium.</p>