Vaginal progesterone, but not 17α-hydroxyprogesterone caproate, has antiinflammatory effects at the murine maternal-fetal interface.
OBJECTIVE
Progestogen (vaginal progesterone or 17-alpha-hydroxyprogesterone caproate [17OHP-C]) administration to patients at risk for preterm delivery is widely used for the prevention of preterm birth (PTB). The mechanisms by which these agents prevent PTB are poorly understood. Progestogens have immunomodulatory functions; therefore, we investigated the local effects of vaginal progesterone and 17OHP-C on adaptive and innate immune cells implicated in the process of parturition.


METHODS
Pregnant C57BL/6 mice received vaginal progesterone (1 mg per 200 μL, n = 10) or Replens (control, 200 μL, n = 10) from 13 to 17 days postcoitum (dpc) or were subcutaneously injected with 17OHP-C (2 mg per 100 μL, n = 10) or castor oil (control, 100 μL, n = 10) on 13, 15, and 17 dpc. Decidual and myometrial leukocytes were isolated prior to term delivery (18.5 dpc) for immunophenotyping by flow cytometry. Cervical tissue samples were collected to determine matrix metalloproteinase (MMP)-9 activity by in situ zymography and visualization of collagen content by Masson's trichrome staining. Plasma concentrations of progesterone, estradiol, and cytokines (interferon [IFN]γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12p70, keratinocyte-activated chemokine/growth-related oncogene, and tumor necrosis factor-α) were quantified by enzyme-linked immunosorbent assays. Pregnant mice pretreated with vaginal progesterone or Replens were injected with 10 μg of an endotoxin on 16.5 dpc (n = 10 each) and monitored via infrared camera until delivery to determine the effect of vaginal progesterone on the rate of PTB.


RESULTS
The following results were found: (1) vaginal progesterone, but not 17OHP-C, increased the proportion of decidual CD4+ regulatory T cells; (2) vaginal progesterone, but not 17OHP-C, decreased the proportion of decidual CD8+CD25+Foxp3+ T cells and macrophages; (3) vaginal progesterone did not result in M1→M2 macrophage polarization but reduced the proportion of myometrial IFNγ+ neutrophils and cervical active MMP-9-positive neutrophils and monocytes; (4) 17OHP-C did not reduce the proportion of myometrial IFNγ+ neutrophils; however, it increased the abundance of cervical active MMP-9-positive neutrophils and monocytes; (5) vaginal progesterone immune effects were associated with reduced systemic concentrations of IL-1β but not with alterations in progesterone or estradiol concentrations; and (6) vaginal progesterone pretreatment protected against endotoxin-induced PTB (effect size 50%, P = 0.011).


CONCLUSIONS
Vaginal progesterone, but not 17OHP-C, has local antiinflammatory effects at the maternal-fetal interface and the cervix and protects against endotoxin-induced PTB.
Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI.
Amy-Eunice
AE
Furcron
Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, University of Michigan Medical School, Ann Arbor, MI, Department of Epidemiology and Biostatistics, Michigan State University College of Human Medicine, East Lansing, MI, and Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI. Electronic address: romeror@mail.nih.gov.
Roberto
R
Romero
Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI.
Olesya
O
Plazyo
Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI.
Ronald
R
Unkel
Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI.
Yi
Y
Xu
Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI.
Sonia S
SS
Hassan
Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI.
Piya
P
Chaemsaithong
Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI.
Arushi
A
Mahajan
Perinatology Research Branch, Program for Perinatal Research and Obstetrics, Division of Intramural Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Department of Health and Human Services, Bethesda, MD, and Detroit, MI; Department of Obstetrics and Gynecology, Wayne State University School of Medicine, Detroit, MI; Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, MI. Electronic address: nardhy.gomez-lopez@wayne.edu.
Nardhy
N
Gomez-Lopez
D000077713:17 alpha-Hydroxyprogesterone Caproate; D000282:Administration, Intravaginal; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000378:metabolism; D002584:Cervix Uteri / Q000166:cytology; D003656:Decidua / Q000166:cytology; D004731:Endotoxins / Q000009:adverse effects; D004926:Escherichia coli; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006908:Hydroxyprogesterones / Q000008:administration & dosage; D007371:Interferon-gamma / Q000378:metabolism; D053583:Interleukin-1beta / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D008264:Macrophages / Q000378:metabolism; D020780:Matrix Metalloproteinase 9 / Q000378:metabolism; D008810:Mice, Inbred C57BL; D009000:Monocytes / Q000378:metabolism; D009215:Myometrium / Q000166:cytology; D009504:Neutrophils / Q000378:metabolism; D011247:Pregnancy; D047928:Premature Birth / Q000517:prevention & control*; D011374:Progesterone / Q000008:administration & dosage*; D045167:Progesterone Congeners / Q000008:administration & dosage
D000893:Anti-Inflammatory Agents; D004731:Endotoxins; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D006908:Hydroxyprogesterones; D053583:Interleukin-1beta; D053645:Interleukin-2 Receptor alpha Subunit; D045167:Progesterone Congeners; D000077713:17 alpha-Hydroxyprogesterone Caproate; D011374:Progesterone; D007371:Interferon-gamma; D020780:Matrix Metalloproteinase 9
decidua; endotoxin; interleukin-1β; macrophages; matrix metalloproteinase-9; myometrium; neutrophils; preterm birth; preterm labor; regulatory T cells