title: Estrogen protects against vaginal transmission of simian immunodeficiency virus.
abstract: Postmenopausal women and women who use injectable, progestin-based contraceptives are at increased risk of human immunodeficiency virus (HIV) infection, suggesting that progesterone and estrogen affect HIV-1 vaginal transmission. To evaluate the individual roles of these sex hormones in vaginal transmission, ovariectomized female macaques were treated with either progesterone or estrogen followed by intravaginal inoculation with SIVmac. All 6 untreated control macaques and 5 (83%) of 6 progesterone-treated animals became infected following intravaginal SIV inoculation. Conversely, none of 6 estrogen-treated macaques was infected. Vaginal subepithelial inoculation of estrogen-treated animals resulted in infection, which shows that the block occurred at the vaginal epithelium and/or lumen. These data suggest that estrogen-deficient women are at increased risk of HIV infection, because their vaginal microenvironments are rendered more susceptible. Moreover, topical vaginal estrogen therapy may be an effective means of reducing HIV vaginal transmission in these high-risk groups.
authors.affiliation: Infectious Diseases Section, Dept. of Internal Medicine, St. Michael's Medical Center, Newark, NJ 07102, USA. ssmith1824@aol.com
authors.forename: S M
authors.initials: SM
authors.lastname: Smith
authors.forename: G B
authors.initials: GB
authors.lastname: Baskin
authors.forename: P A
authors.initials: PA
authors.lastname: Marx
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D008253:Macaca mulatta; D009092:Mucous Membrane / Q000187:drug effects / Q000821:virology; D010052:Ovariectomy; D011374:Progesterone / Q000494:pharmacology; D016097:Simian Acquired Immunodeficiency Syndrome / Q000635:transmission*; D014621:Vagina / Q000187:drug effects / Q000821:virology
chemical_list: D004967:Estrogens; D011374:Progesterone