Maternal Monocytes Respond to Cell-Free Fetal DNA and Initiate Key Processes of Human Parturition.

Throughout gestation, the maternal immune system is tightly modulated to allow growth of a semiallogeneic fetus. During the third trimester, the maternal immune system shifts to a proinflammatory phenotype in preparation for labor. What induces this shift remains unclear. Cell-free fetal DNA (cffDNA) is shed by the placenta and enters maternal circulation throughout pregnancy. Levels of cffDNA are increased as gestation progresses and peak before labor, coinciding with a shift to proinflammatory maternal immunity. Furthermore, cffDNA is abnormally elevated in plasma from women with complications of pregnancy, including preterm labor. Given the changes in maternal immunity at the end of pregnancy and the role of sterile inflammation in the pathophysiology of spontaneous preterm birth, we hypothesized that cffDNA can act as a damage-associated molecular pattern inducing an inflammatory cytokine response that promotes hallmarks of parturition. To test this hypothesis, we stimulated human maternal leukocytes with cffDNA from primary term cytotrophoblasts or maternal plasma and observed significant IL-1ß and CXCL10 secretion, which coincides with phosphorylation of IFN regulatory factor 3 and caspase-1 cleavage. We then show that human maternal monocytes are crucial for the immune response to cffDNA and can activate bystander T cells to secrete proinflammatory IFN-γ and granzyme B. Lastly, we find that the monocyte response to cffDNA leads to vascular endothelium activation, induction of myometrial contractility, and PGE2 release in vitro. Our results suggest that the immune response to cffDNA can promote key features of the parturition cascade, which has physiologic consequences relevant to the timing of labor.

Frequency, timing and risk factors for primary maternal cytomegalovirus infection during pregnancy in Quebec.

INTRODUCTION: Maternal Cytomegalovirus (CMV) infection in the first trimester (T1) of pregnancy is a public health concern, as it increases the risk of severe neurodevelopmental outcomes associated with congenital infection compared to infections occurring later during pregnancy. OBJECTIVES: To determine CMV seroprevalence in T1 of pregnancy, its trend, risk factors and the incidence rate of primary infection during pregnancy. METHODS: Using the biobank of the prospective cohort "Grossesse en Santé de Québec" collected between April 2005 and March 2010 at the Québec-Laval Hospital, Québec, Canada, maternal CMV serology was determined using Abbott Architect Chemiluminescence microparticle immunoassays for immunoglobulin G(IgG), immunoglobulin M(IgM) titration and IgG avidity testing. Changepoint detection analysis was used to assess temporal trends. Risk factors associated with seropositivity were determined by multivariable logistic regression. RESULTS: CMV seroprevalence in T1 of pregnancy was 23.4% (965/4111, 95% CI, 22.1-24.7%). The incidence rate for CMV primary infection during pregnancy was 1.8 (95% CI, 1.2-2.6) per 100 person-years. No changepoint was identified in the maternal CMV-seroprevalence trend. Multivariable analyses showed that T1 maternal CMV seropositivity was associated with having one child OR 1.3 (95% CI, 1.10-1.73) or two or more children OR 1.5 (95%CI, 1.1-2.1), ethnicity other than Caucasian OR 2.1 (95% CI, 1.1-3.8) and country of birth other than Canada and the USA OR 2.8 (95% CI, 1.5-4.9). CONCLUSIONS: In this cohort, maternal seroprevalence in T1 of pregnancy and seroconversion rate were low. This information and identified risk factors could help guide the development and implementation of preventive actions and evidence-based health policies to prevent CMV infection during pregnancy.

Neutrophils in preterm birth: Friend or foe?

Preterm birth is a serious global health problem that affects 5-18% of pregnancies worldwide. In addition to being the major cause of neonatal mortality and morbidity, preterm birth is associated with short term and long term complications in the offspring. Despite this, the causes and pathogenesis of preterm birth remain unclear. Neutrophils are innate immune cells that infiltrate the maternal-fetal interface during normal parturition and their accumulation is dramatically increased during preterm birth, especially in the presence of an infection. Indeed, a defining feature of chorioamnionitis (inflammation of the chorioamnionic fetal membranes) that is associated with more than 40% of preterm births, is neutrophil accumulation. While these cells may play an important role during normal term parturition as well as preterm birth, their functions at the maternal-fetal interface are unclear. This review will provide a broad overview of the relevant studies to enable a better understanding of the roles of neutrophils during normal parturition and preterm birth.

Essential Role of Complement in Pregnancy: From Implantation to Parturition and Beyond.

The complement cascade was identified over 100 years ago, yet investigation of its role in pregnancy remains an area of intense research. Complement inhibitors at the maternal-fetal interface prevent inappropriate complement activation to protect the fetus. However, this versatile proteolytic cascade also favorably influences numerous stages of pregnancy, including implantation, fetal development, and labor. Inappropriate complement activation in pregnancy can have adverse lifelong sequelae for both mother and child. This review summarizes the current understanding of complement activation during all stages of pregnancy. In addition, consequences of complement dysregulation during adverse pregnancy outcomes from miscarriage, preeclampsia, and pre-term birth are examined. Finally, future research directions into complement activation during pregnancy are considered.

De novo Synthesis of SAA1 in the Placenta Participates in Parturition.

Serum amyloid A1 (SAA1) is an acute phase protein produced mainly by the liver to participate in immunomodulation in both sterile and non-sterile inflammation. However, non-hepatic tissues can also synthesize SAA1. It remains to be determined whether SAA1 synthesized locally in the placenta participates in parturition via eliciting inflammatory reactions. In this study, we investigated this issue by using human placenta and a mouse model. We found that SAA1 mRNA and protein were present in human placental villous trophoblasts, which was increased upon syncytialization as well as treatments with lipopolysaccharides (LPS), tumor necrosis factor-α (TNF-α), and cortisol. Moreover, significant increases in SAA1 abundance were observed in the placental tissue or in the maternal blood in spontaneous deliveries without infection at term and in preterm birth with histological chorioamnionitis. Serum amyloid A1 treatment significantly increased parturition-pertinent inflammatory gene expression including interleukin-1ß (IL-1ß), IL-8, TNF-α, and cyclooxygenase-2 (COX-2), along with increased PGF2α production in syncytiotrophoblasts. Mouse study showed that SAA1 was present in the placental junctional zone and yolk sac membrane, which was increased following intraperitoneal administration of LPS. Intraperitoneal injection of SAA1 not only induced preterm birth but also increased the abundance of IL-1ß, TNF-α, and COX-2 in the mouse placenta. Conclusively, SAA1 can be synthesized in the human placenta, which is increased upon trophoblast syncytialization. Parturition is accompanied with increased SAA1 abundance in the placenta. Serum amyloid A1 may participate in parturition in the presence and absence of infection by inducing the expression of inflammatory genes in the placenta.

CD8+ T Cell Functional Exhaustion Overrides Pregnancy-Induced Fetal Antigen Alloimmunization.

Pregnancy necessitates physiological exposure, and often re-exposure, to foreign fetal alloantigens. The consequences after pregnancy are highly varied, with evidence of both alloimmunization and expanded tolerance phenotypes. We show that pregnancy primes the accumulation of fetal-specific maternal CD8+ T cells and their persistence as an activated memory pool after parturition. Cytolysis and the potential for robust secondary expansion occurs with antigen re-encounter in non-reproductive contexts. Comparatively, CD8+ T cell functional exhaustion associated with increased PD-1 and LAG-3 expression occurs with fetal antigen re-stimulation during subsequent pregnancy. PD-L1/LAG-3 neutralization unleashes the activation of fetal-specific CD8+ T cells, causing fetal wastage selectively during secondary but not primary pregnancy. Thus, CD8+ T cells with fetal alloantigen specificity persist in mothers after pregnancy, and protection against fetal wastage in subsequent pregnancies is maintained by their unique susceptibility to functional exhaustion. Together, distinct mechanisms whereby fetal tolerance is maintained during primary compared with subsequent pregnancies are demonstrated.

[The immune microenvironment in maternal-fetal interface contributes to the parturition and preterm labor].

The maintenance of human pregnancy and the initiation of parturition are closely related with the dynamic balance of the maternal-fetal immune microenvironment. Implantation of the blastocyst into the maternal decidua is the first step in pregnancy establishment, which is favored by the abundant blood flow and the immunotolerant microenvironment maintained by the balance of immune cells. The parturition resembles an inflammatory response that includes secretion of cytokines by resident and infiltrating immune cells into reproductive tissues and the maternal-fetal interface, which promotes the delivery of fetus from maternal organism. Therefore, the immune microenvironment in maternal-fetal interface regulates the critical steps of pregnancy and parturition. When the maternal-fetal immune microenvironment is imbalanced or impaired, miscarriage or preterm labor would happen. This article reviews the roles and mechanisms of several important immune cells in the maternal-fetal interface during the parturition and preterm labor.

Activation of the Complement System in the Lower Genital Tract During Pregnancy and Delivery.

Background: Human pregnancy alters profoundly the immune system. The local involvement and mechanisms of activation of the complement system in the cervicovaginal milieu during pregnancy and delivery remain unexplored. Objectives: To determine whether normal pregnancy and delivery are associated with local activation of complement or changes in the immunoglobulin profile in the cervix. Study Design: This study was designed to assess IgA, IgG, and complement activation in the cervicovaginal area in three groups of patients: i) 49 pregnant women (week 41+3-42+0) not in active labor, ii) 24 women in active labor (38+4-42+2), and iii) a control group of nonpregnant women (n=23) at child-bearing age. We collected mucosal samples from the lateral fornix of the vagina and external cervix during routine visits and delivery. The Western blot technique was used to detect complement C3 and its activation products. For semiquantitative analysis, the bands of the electrophoresed proteins in gels were digitized on a flatbed photo scanner and analyzed. IgA and IgG were analyzed by Western blotting and quantified by ELISA. One-way ANOVA and Tukey's Multiple Comparison tests were used for statistical comparisons. Results: A higher abundance but lower activation level of C3 in both the external cervix (P<0.001) and lateral fornix of the vagina (P<0.001) was observed during delivery (58 ± 22, n= 24) in comparison to the groups of nonpregnant (72 ± 13%; mean ± SD, n=23) and pregnant women (78 ± 22%, n=49). Complement activating IgG was detected in higher abundance than IgA in the cervicovaginal secretions of pregnant women. In a small proportion samples also C3-IgG complexes were detected. Conclusions: Our results reveal an unexpectedly strong activation of the complement system and the presence IgG immunoglobulins in the cervicovaginal area during pregnancy, active labor, and among nonpregnant women. In contrast to the higher amounts of C3 in the cervicovaginal secretions during labor, its activation level was lower. Complement activating IgG was detected in higher concentrations than IgA in the mucosal secretions during pregnancy and labor. Taken together our results imply the presence a locally operating humoral immune system in the cervicovaginal mucosa.

Toll-like receptor 4 contributes to uterine activation by upregulating pro-inflammatory cytokine and CAP expression via the NF-κB/P38MAPK signaling pathway during pregnancy.

Evidence indicates that inflammatory response is significant during the physiological process of human parturition; however, the specific signaling pathway that triggers inflammation is undefined. Toll-like receptors (TLRs) are key upstream gatekeepers that control inflammatory activation before preterm delivery. Our previous study showed that TLR4 expression was significantly increased in human pregnancy tissue during preterm and term labor. Therefore, we explore whether TLR4 plays a role in term labor by initiating inflammatory responses, therefore promoting uterine activation. The results showed that expression of TLR4, interleukin-1ß (IL-1ß), IL-6, tumor necrosis factor-α (TNF-α), CC chemokine ligand 2 (CCL-2), and uterine contraction-associated proteins (CAPs) was upregulated in the human and mice term labor (TL) group compared with the not-in-labor (TNL) group, and the TLR4 level positively correlated with CAP expression. In pregnant TLR4-knockout (TLR4-/- ) mice, gestation length was extended by 8 hr compared with the wild-type group, and the expression of IL-1ß, IL-6, TNF-α, CCL-2, and CAPs was decreased in TLR4-/- mice. Furthermore, nuclear factor-κB (NF-κB) and P38MAPK activation is involved in the initiation of labor but was inhibited in TLR4-/- mice. In uterine smooth muscle cells, the expression of inflammatory cytokines and CAPs decreased when the NF-κB and P38MAPK pathway was inhibited. Our data suggest that TLR4 is a key factor in regulating the inflammatory response that drives uterine activation and delivery initiation via activating the NF-κB/P38MAPK pathway.

Incidence of maternal peripartum infection: A systematic review and meta-analysis.

BACKGROUND: Infection is an important, preventable cause of maternal morbidity, and pregnancy-related sepsis accounts for 11% of maternal deaths. However, frequency of maternal infection is poorly described, and, to our knowledge, it remains the one major cause of maternal mortality without a systematic review of incidence. Our objective was to estimate the average global incidence of maternal peripartum infection. METHODS AND FINDINGS: We searched Medline, EMBASE, Global Health, and five other databases from January 2005 to June 2016 (PROSPERO: CRD42017074591). Specific outcomes comprised chorioamnionitis in labour, puerperal endometritis, wound infection following cesarean section or perineal trauma, and sepsis occurring from onset of labour until 42 days postpartum. We assessed studies irrespective of language or study design. We excluded conference abstracts, studies of high-risk women, and data collected before 1990. Three reviewers independently selected studies, extracted data, and appraised quality. Quality criteria for incidence/prevalence studies were adapted from the Joanna Briggs Institute. We used random-effects models to obtain weighted pooled estimates of incidence risk for each outcome and metaregression to identify study-level characteristics affecting incidence. From 31,528 potentially relevant articles, we included 111 studies of infection in women in labour or postpartum from 46 countries. Four studies were randomised controlled trials, two were before-after intervention studies, and the remainder were observational cohort or cross-sectional studies. The pooled incidence in high-quality studies was 3.9% (95% Confidence Interval [CI] 1.8%-6.8%) for chorioamnionitis, 1.6% (95% CI 0.9%-2.5%) for endometritis, 1.2% (95% CI 1.0%-1.5%) for wound infection, 0.05% (95% CI 0.03%-0.07%) for sepsis, and 1.1% (95% CI 0.3%-2.4%) for maternal peripartum infection. 19% of studies met all quality criteria. There were few data from developing countries and marked heterogeneity in study designs and infection definitions, limiting the interpretation of these estimates as measures of global infection incidence. A limitation of this review is the inclusion of studies that were facility-based or restricted to low-risk groups of women. CONCLUSIONS: In this study, we observed pooled infection estimates of almost 4% in labour and between 1%-2% of each infection outcome postpartum. This indicates maternal peripartum infection is an important complication of childbirth and that preventive efforts should be increased in light of antimicrobial resistance. Incidence risk appears lower than modelled global estimates, although differences in definitions limit comparability. Better-quality research, using standard definitions, is required to improve comparability between study settings and to demonstrate the influence of risk factors and protective interventions.

[The relationship between inflammatory and immunological processes during pregnancy. Practical aspects]. / A gyulladásos és immunológiai folyamatok kapcsolata a várandósság alatt. Gyakorlati vonatkozások.

The aim of this review is to explore, in addition to revealing the biological background, new conceptual and therapeutic approaches for reproductive clinicians to provide better and more effective care for sterile and infertile couples. In humans, 75% of unsuccessful pregnancies are the result of failures of implantation, and implantation failure is the limiting factor for in vitro fertilization treatment. A modified "good" inflammation is necessary for implantation and parturition, but for most of pregnancy, inflammation threatens the continuation of pregnancy. During this period, maintaining the non-inflammatory condition is extremely important, enabling the maternal epigenetic effects to occur in the fetus, making it possible for the offspring to adapt as much as possible to the extrauterine life. In the maintenance of the non-inflammatory condition of pregnancy, a large amount of progesterone hormone produced by the placenta (after the luteo-placental shift) plays a crucial role. It has been reported that the role of inflammation during implantation is an ancestral response to the embryo as a foreign body. During normal pregnancy, this inflammation is initiated by the trophoblast and involves the suppression of neutrophil infiltration, the recruitment of natural killer cells to the site of implantation as well as the production of a range of proinflammatory cytokines. During the "implantation window", the uterus is primed to produce several inflammatory signals such as prostaglandin E2 and a range of proinflammatory cytokines, including TNF, IL6 and IFNγ. The feto-placental unit is a semi-foreign graft called a "semi allograft", and the recognition of pregnancy by the mother (host) and the resulting maternal immune tolerance is an essential part of successful pregnancy and the birth of a healthy fetus. Because of the functional or absolute reduction of circulating progesterone (due to the decreasing hormone production of the physiologically "aging" placenta after around the 36th week of pregnancy) progesterone effects become insufficient. Therefore it is unable to suppress the production of IL8 and other inflammatory cytokines and the term inflammation, leading to cervical ripening, uterus contractions and parturition ("good" inflammation). Orv Hetil. 2019; 160(32): 1247-1259.

Hepatitis B Birth Dose Vaccination among Vietnamese Children: Implications for the Expanded Program on Immunization.

BACKGROUND: This study assesses the prevalence of Vietnamese children receiving the hepatitis B (HepB) vaccine birth dose and explores its associated socioeconomic factors. METHODS: We used the data of the Multiple Indicator Cluster Survey, 2014. We estimated the overall percentage of HepB birth dose vaccination among 0-23-month-old children and its percentages according to selected characteristics. Multiple logistic regression was applied. RESULTS: 62.8% of children received the HepB vaccine birth dose. The prevalence rates by selected factors ranged from 35.3% to 76.7%. The categories with the lowest prevalence rates were children who had low birth weight (41.6%), had a mother aged less than 20 years (35.3%), had a mother with primary or less education (42.7%), belonged to ethnic minorities (30.3%), resided in rural areas (59.9%), and were in the 1st quintile of mother's socioeconomic status (38.6%). Receiving HepB vaccine birth dose was associated with child's birth weight, mother's age, mother's education, socioeconomic status, and ethnicity. CONCLUSIONS: This study identified vulnerable groups, upon which policy-makers should focus their efforts to equitably and sustainably tackle birth dose HepB vaccine coverage as well as the full vaccination coverage, thereby promoting long-lasting herd immunity in this country.

Sheep and goats raised in mixed flocks have diverse immune status around parturition.

Several physiological and metabolic changes take place in dairy ruminants around parturition (late pregnancy, parturition, and early lactation). Dairy species are genetically selected for their higher milk production compared with non-dairy species. This fact causes a constant stress that impairs the immune status of the animal, with consequences for its welfare and performance. In the present study, we assessed the immune status of high-yield dairy sheep and goats by quantifying IgG and IgM concentrations, as well as chitotriosidase (ChT) and complement system [total complement system (TC) and alternative complement pathway (AC)] activity in blood plasma around parturition. We also measured IgG and IgM concentrations and ChT activity in colostrum and milk during the first 40 d postpartum. The lowest blood IgG concentration was at parturition in both species. We detected no differences in blood IgG concentrations between species. Blood IgM concentrations were constant in both species throughout the study period. However, blood IgM concentrations were greater in sheep than in goats. Blood ChT activity was greater in goats than in sheep, and both species showed constant activity of this enzyme throughout the study period. We observed no differences in complement system (TC and AC) activity between sheep and goats. In addition, both TC and AC activity were constant in both species throughout the experiment. In general, IgG and IgM concentrations were greater in sheep colostrum than in goat colostrum, but these differences disappeared after d 4 (IgG) and d 3 (IgM) postpartum. In both species, the highest IgG and IgM concentrations were measured in colostrum, gradually decreasing during the first days postpartum. Chitotriosidase activity decreased in both species from colostrum to milk, although goats always showed greater ChT activity than sheep. Both sheep and goats seemed to be more susceptible to infectious diseases around parturition. As well, goats showed greater ChT activity in blood, colostrum, and milk than sheep. This fact may give these animals additional protection against parasite and fungal infections.

High-mobility group box 1 at the time of parturition in women with gestational diabetes mellitus.

PROBLEM: High-mobility group box 1 (HMGB1), a danger-associated molecular pattern marker, may indicate sterile inflammation through innate immune pathways. HMGB1 is implicated in hyperglycemia and excess glucose in trophoblast. Metabolic dysfunction and dyslipidemia are associated with gestational diabetes mellitus (GDM), but few studies examined associations between HMGB1 and GDM. We determined HMGB1 levels, and the ratio of HMGB1 to innate immune markers, in women with GDM at parturition. METHOD OF STUDY: This case-control study of 50 GDM pregnancies and 100 healthy controls utilized data and plasma samples from PeriBank. HMGB1, pentraxin-3, and interleukin (IL)-6 were measured by ELISA. Logistic regression calculated odds ratios (OR) and 95% confidence intervals (CI) adjusting for age, pre-pregnancy body mass index, and type of labor. RESULTS: There were no significant associations between HMGB1 and GDM. The ratio of HMGB1 to pentraxin-3 and IL-6 did not alter the odds of GDM. There was a significant statistical interaction between HMGB1 and maternal age (P = .02). When associations were examined by age groups, HMGB1 was associated with reduced odds of HMGB1 among women ≤25 (AOR = 0.007 CI 95% <0.001-0.3). Odds ratios increased as age increased (AOR range 1.2-3.8) but results were not statistically significant. CONCLUSION: High-mobility group box 1 was not associated with GDM. However, we found evidence that maternal age was a potential effect modifier of the relationship between HMGB1 and GDM. As there is growing evidence that HMGB1 may play important roles in reproduction, future studies should explore maternal factors that may alter HMGB1 levels.

Evaluation of the immune status of peripheral blood monocytes from dairy cows during the periparturition period.

Calving is a critical but stressful event required for milk production in dairy cows. In the present study, we investigated the immune status of peripheral blood mononuclear cells (PBMCs) isolated from periparturient cows to better understand and, thus, possibly prevent stress during the periparturient period. To evaluate the immune response of PBMCs, we assessed their proliferation with or without a mitogen (concanavalin A, ConA). Blood samples were collected 24 h before and after calving and 1 week after calving. The proliferation of non-treated cells remained unchanged throughout the examination period. The immune response of PBMCs isolated from the cows before calving was relatively low, even after ConA stimulation; however, the immune response of PBMCs collected at both time points after calving was significantly higher than those of non-stimulated controls. Next, we examined the expression patterns of T cell related and inflammatory cytokine genes in PBMCs. We found that the mRNA expression levels of both CD4 and CD8 showed decreasing trends after calving. The expression of the Th1 cell marker gene IFNG also decreased after calving. The mRNA expression level of the inflammatory cytokine gene TNFA increased after parturition. Overall, our results suggest that the PBMC immune response was weakened in cows before delivery and part of the expression of the immune cell-related genes in these cells is altered 24 h before and after calving.

Expression and function of macrophage-inducible C-type lectin (Mincle) in inflammation driven parturition in fetal membranes and myometrium.

The pivotal role of inflammatory processes in human parturition is well known, but not completely understood. We have performed a study to examine the role of macrophage-inducible C-type lectin (Mincle) in inflammation-associated parturition. Using human samples, we show that spontaneous labour is associated with up-regulated Mincle expression in the myometrium and fetal membranes. Mincle expression was also increased in fetal membranes and myometrium in the presence of pro-labour mediators, the proinflammatory cytokines interleukin (IL)-1B and tumour necrosis factor (TNF), and Toll-like receptor (TLR) ligands fsl-1, poly(I:C), lipopolysaccharide (LPS) and flagellin. These clinical studies are supported by mouse studies, where an inflammatory challenge in a mouse model of preterm birth increased Mincle expression in the uterus. Importantly, elimination of Mincle decreased the effectiveness of proinflammatory cytokines and TLR ligands to induce the expression of pro-labour mediators; namely, proinflammatory cytokines and chemokines, contraction-associated proteins and prostaglandins, and extracellular matrix remodelling enzymes, matrix metalloproteinases. The data presented in this study suggest that Mincle is required when inflammatory activation precipitates parturition.

Toll-like receptor 9, maternal cell-free DNA and myometrial cell response to CpG oligodeoxynucleotide stimulation.

PROBLEM: Among mechanisms triggering onset of parturition, it has been recently postulated that Toll-Like Receptor (TLR)9 engagement by cell-free DNA (cfDNA) triggers inflammation, myometrial contractions, and labor in absence of infection. The current study evaluated whether direct (myometrial) or indirect (decidual) TLR9 engagement enhances human myometrial contractility. METHOD OF STUDY: Toll-like receptor 9 expression and cellular localization were surveyed by immunohistochemistry of placenta, fetal membranes, and myometrium in term (gestational age [GA]: >37 weeks) labor (TL, n = 7) or term non-labor (TNL, n = 7) tissues. Non-pregnant myometrium (n = 4) served as reference. TLR9 mRNA expression relative to other TLRs was evaluated through the mining of an RNA-seq dataset and confirmed by RT-PCR. Immortalized human myometrial cells (hTERT-HM) were treated with incremental concentrations of TLR9 agonist ODN2395, TNF-α, or LPS. Secreted cytokines were quantified by multiplex immunoassay, and contractility was assessed by an in-gel cell contraction assay (n = 9). Induction of hTERT-HM contractility was also evaluated indirectly following exposure to conditioned media from primary term decidual cells (n = 4) previously stimulated with ODN2395. RESULTS: Toll-like receptor 9 immunostaining in placenta and amniochorion was strongest in decidual cells, but unrelated to labor. TLR9 staining intensity was significantly decreased in TL compared with TNL myometrium (P = 0.002). Although total cfDNA in maternal circulation increased in TL (P = 0.025 vs TNL), difference in cffDNA was non-significant. Myometrial TLR9 mRNA levels were unaffected by contractile status and far less abundant than other pro-inflammatory TLRs. hTERT-HM contractility was enhanced by LPS (P = 0.002) and TNF-α (P = 0.003), but not by ODN2395 (P = 0.345) or supernatant of TLR9-stimulated decidual cells. CONCLUSION: Myometrial and decidual TLR9 are unlikely to directly regulate human parturition.

Neuroautonomic activity evidences parturition as a complex and integrated neuro-immune-endocrine process.

Parturition in mammals demands a precise coordination of several neuro-immune-endocrine interactions including: a sterile inflammatory response that involves secretion of inflammation mediators like cytokines/chemokines; changes in the secretion of hormones such as progestogen, estrogens, cortisol, and oxytocin; as well as adjustments of the neuroautonomic function. Specifically, the so-called cholinergic anti-inflammatory pathway seems to play a key role in the homeostasis of the neuro-immune-endocrine axis by adjusting the vagus nerve activity during parturition. Here, we provide insights into the importance of the vagus during parturition from an autonomic, endocrine, and immune interplay perspective, and describe the potential role of heart rate variability analysis to explore these interactions noninvasively, economically, and accessibly.

Cervical hyaluronan biology in pregnancy, parturition and preterm birth.

Cervical hyaluronan (HA) synthesis is robustly induced in late pregnancy in numerous species including women and mice. Recent evidence highlights the diverse and dynamic functions of HA in cervical biology that stem from its expression in the cervical stroma, epithelia and immune cells, changes in HA molecular weight and cell specific expression of HA binding partners. Mice deficient in HA in the lower reproductive tract confirm a structural role of HA to increase spacing and disorganization of fibrillar collagen, though this function is not critical for pregnancy and parturition. In addition, cervical HA depletion via targeted deletion of HA synthase genes, disrupts cell signaling required for the differentiation of epithelia and their mucosal and junctional barrier, resulting in increased susceptibility to ascending infection-mediated preterm birth. Finally the generation of HA disaccharides by bacterial hyaluronidases as made by Group B streptococcus can ligate toll like receptors TLR2/4 thus preventing appropriate inflammatory responses as needed to fight ascending infection and preterm birth. This review summarizes our current understanding of HA's novel and unique roles in cervical remodeling in the process of birth.