Related Experiment Video
Updated: Jul 7, 2026

Isolation of Primary Human Decidual Cells from the Fetal Membranes of Term Placentae
Published on: April 30, 2018
Cutting edge: progesterone regulates IFN-alpha production by plasmacytoid dendritic cells
Grant C Hughes1, Sunil Thomas, Chang Li
1Department of Medicine, Division of Rheumatology, National Regional Primate Research Center, University of Washington, Seattle, WA 98195, USA. hughesg@u.washington.edu
Abstract:
Use of the progesterone (Pg) birth control depot medroxyprogesterone acetate (DMPA) increases a woman's risk for sexually transmitted infection with HIV or HSV-2 via unknown mechanisms. Plasmacytoid dendritic cells (pDCs) are circulating and tissue-resident sentinels capable of making large quantities of IFN-alpha upon recognizing viruses through TLRs 7 and 9. In this study, we show that Pg inhibits TLR9-induced IFN-alpha production by human and mouse pDCs and that DMPA impairs TLR9- and virus-induced IFN-alpha production by pDCs in mice, providing a potential explanation for how DMPA impairs innate antiviral immunity in women. Pg failed to inhibit the Mda-5 pathway of IFN-alpha induction in dendritic cells, suggesting that Pg regulates select antiviral DC programs. This may occur through selective blockade of IFN regulatory factor-7 activation, a novel steroid action. Thus, through inhibition of TLR-mediated IFN-alpha production by pDCs, Pg may regulate antiviral immunity.
Related Concept Videos
TGF - β Signaling Pathway
Inflammatory Response
Inflammation can be triggered by various stimuli, such as impact, abrasion, chemical irritation, infections, and extreme hot or cold temperatures. These can damage cells and connective tissue fibers,...
Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
Gonadal and Placental Hormones
In males, testosterone is the primary gonadal androgen. It plays a central role in the maturation of male reproductive organs — the penis and testes. Additionally, testosterone is instrumental in the development of secondary sexual characteristics — a deep voice as well as facial and pubic hair growth — and...
Differentiation of Common Myeloid Progenitor Cells

