Gestational age-dependent expression of IL-10 and its receptor in human placental tissues and isolated cytotrophoblasts

Novel Interleukin-10 Gene Polymorphism Is Linked to Gestational Diabetes in Taiwanese Population

Objective: The association of interleukin-10 (IL-10) polymorphism with diabetes and its complication was recently established, while there were few researches considering the potential role of IL-10 in gestational diabetes (GDM). This study aimed to investigate the association between IL-10 gene rs1800896 (−1082 A/G), rs1800871 (−819 T/C), rs1800872 (−592 A/C), and rs3021094 (3388 A/C) single nucleotide polymorphisms (SNPs) and GDM susceptibility.

Methods: This study included 72 GDM patients and 100 healthy pregnant women. Direct sequencing of the products from polymerase chain reactions of the extracted genomic DNA from study subjects were conducted for analyzing IL-10 gene polymorphism and further genotype frequencies were compared. Plasma IL-10 concentration was measured by ELISA method.

Results: The results revealed no significant difference in −592 A/C, −819 T/C, and −1082 A/G genotypes. Significantly increased prevalence of A allele (P = 0.028, OR = 1.69, 95% CI = 1.081–2.64) and A/A genotype (P = 0.031, OR = 2.881, 95% CI = 1.145–7.250) at a previously un-characterized rs3021094 SNP were discovered in the GDM group. Increased IL-10 levels and insulin resistance were also related to the genotype of rs3021094. The risk of GDM was increased when IL-10 level was over 6.5 pg/ml.

Conclusion: Our study demonstrated that A allele and A/A genotype of rs3021094 SNP in IL-10 gene were linked to increased risk for GDM, IL-10 plasma level and insulin resistance, which could be potential targets for early screening and detection of GDM.

IL-1β, IL-2 and IL-4 concentration during porcine gestation

In pigs, given the type of epitheliochorial and non-invasive placenta, the trophoblast is in intimate contact with maternal tissues. The dialogue established between the conceptus and the endometrium involves, among others, the immune system, which minimizes the chances of rejection of the embryo and promotes the establishment of pregnancy. The aim of this work was to determine the concentration of IL-1β, IL-2 and IL-4 in sera and in extracts of maternal and fetal placenta from sows of different gestational periods. Reproductive tracts from 23 crossbreed sows, between 30 and 114 days of gestation (dg), and from 8 non-pregnant sows were used. The concentration of the cytokines was determined by ELISA. IL-1β, IL-2 and IL-4 demonstrated a similar pattern of concentration at the placental interface and serum; they were found elevated in tissues at 30 and 60-70 dg, and significantly decreased at term, period in which the cytokines were significantly increased in serum. These results show that IL-1β, IL-2, and IL-4 are differentially modulated during pregnancy and at term, and suggest an important role of these cytokines in defining the proinflammatory stage of these periods.

Association of pro- and anti-inflammatory cytokines in preeclampsia

Introduction

The pro‐ and anti‐inflammatory cytokines play crucial role in the development and functions of placenta. Any changes in these cytokines may be associated with many pregnancy‐related disorders like preeclampsia. Therefore, the present study is aimed to study the expression of pro‐inflammatory (TNF‐α, IL‐6) and anti‐inflammatory (IL‐4, IL‐10) cytokines in placenta and serum of preeclamptic pregnant women.

Material and Methods

For this study, a total of 194 cases of preeclamptic and control cases were enrolled in two Groups as per the gestational age that is, Group I (28‐36 weeks) and II (37 weeks onwards). The number of samples was 55 in Group I and 139 in Group II. The immunohistochemistry (IHC) and enzyme‐linked immunosorbent assay (ELISA) were conducted on placenta and serum of both preeclamptic and normal samples, respectively. IHC results were revalidated by reverse transcriptase PCR (RT‐PCR).

Results

Both Groups (I, II) of preeclampsia showed amended levels of pro‐ and anti‐inflammatory cytokines in placental tissues and serum samples. The levels of TNF‐α and IL‐6 were significantly increased in preeclamptic cases (P = 0.0001, P = 0.0001) while the IL‐4 and IL‐10 were downregulated (P = 0.0001, P = 0.0001) in comparison to control. In addition, a negative correlation was also observed between the two in preeclampsia (P = 0.0001).

Conclusion

The balanced ratio of pro‐ and anti‐inflammatory cytokines is essential to regulate the maternal inflammation system throughout pregnancy. Therefore, the gradual cytokine profiling of the pregnant women may be useful for the management of preeclampsia.

Repeated lipopolysaccharide exposure leads to placental endotoxin tolerance

PROBLEM

Placental infection induces increased levels of pro-inflammatory cytokines, which have been implicated in the pathogenesis of pre-term labor. Endotoxin tolerance is a phenomenon in which exposure to a dose of endotoxin makes tissue less responsive to subsequent exposures. The objective of our study was to determine whether repeated exposure to endotoxin will induce a tolerant phenotype in normal human second-trimester placental tissue.

METHODS OF STUDY

Human second-trimester placental explants from elective termination of pregnancy were cultured and exposed to endotoxin (LPS). After 24 hours, the media was collected for analysis, and the explants were re-exposed to LPS after adding fresh media for another 24 hours. This process was repeated for a total of 4 LPS doses. The media was collected from each day and analyzed for cytokine levels.

RESULTS

The first LPS treatment stimulated the secretion of the pro-inflammatory cytokines IL-1β and TNF-α. However, their production was significantly diminished with repeated LPS doses. Production of the anti-inflammatory cytokines, IL-1ra and IL-10, was also stimulated by the first LPS treatment, but secretion was more gradually and moderately decreased with repeated LPS doses compared to the pro-inflammatory cytokines. The ratios of the anti-inflammatory/pro-inflammatory mediators (IL-1ra/IL-1β and IL-10/TNF-α) indicate a progressively more anti-inflammatory milieu with repeated LPS doses.

CONCLUSION

Repeated LPS exposure of human second-trimester placental tissues induced endotoxin tolerance. We speculate that endotoxin tolerance at the maternal-fetal interface will protect the fetus from exaggerated inflammatory responses after repeated infectious exposure.

Cell-Free DNA Release by Mouse Fetal Membranes

INTRODUCTION

Cell-free "fetal" DNA is released from the placenta. Because the fetal membranes also arise from the trophectoderm layer of the blastocyst, these studies sought to test the hypothesis that the membranes also release cell-free DNA (cfDNA).

METHODS

Fetal membranes were harvested from pregnant CD-1 mice and cultured in 12-well plates containing media alone or with staurosporine and thapsigargin (apoptosis stimulators), Q-VD-OPh (caspase inhibitor), Trolox (vitamin E analog), and lipopolysaccharide and tumor necrosis factor α (TNFα; inflammatory mediators). The cfDNA in the media was extracted, quantified, and normalized for tissue weight. Media was used for a lactate dehydrogenase (LDH) assay. Membrane homogenates were used to assess activated caspase levels and the expression of DNA fragmentation factor B (DFFB) and BAX proteins. 5-Methylcytosine was assessed using a 5-mC DNA enzyme-linked immunosorbent assay. The cfDNA was used to stimulate interleukin 6 (IL6) release by J774A.1 mouse macrophage cells.

RESULTS

Increased cfDNA release at 6 and 21 hours occurred in parallel with increasing LDH levels. The cfDNA concentrations were significantly suppressed by Q-VD-OPh and Trolox and increased by thapsigargin and TNFα. Increased caspase activity was suppressed by Q-VD-OPh and increased by TNFα, thapsigargin, and staurosporine. The expression of BAX and DFFB proteins significantly increased by 21 hours. 5-Methylcytosine levels were significantly lower in fetal membranes and placentas and below detectable in the cfDNA released by the explants. The cfDNA-stimulated IL6 release by macrophage cells was suppressed by chloroquine, a Toll-like receptor 9 (TLR9) inhibitor.

CONCLUSIONS

These studies have confirmed cfDNA release by the mouse fetal membranes; cfDNA was markedly hypomethylated and a robust stimulator of TLR9.

The role of interleukins in preeclampsia: A comprehensive review

Preeclampsia is a multi-system hypertensive disorder of pregnancy, with significant rates of maternal and neonatal morbidity. It represents a major cause of preterm birth, as definitive treatment demands fetal delivery. Although its pathophysiology is complicated, placental hypoxia and endothelial dysfunction constitute established pathogenetic steps of the disease. Inflammation is considered to be a crucial mediator of preeclampsia process, as an imbalance between T_H 1, T_H 2, and T_H 17 immune responses is observed. The present review accumulates current knowledge about the contribution of interleukins in preeclampsia, summarizing the pathways through which each interleukin exerts its function in the disease. Also, the role of genetic polymorphisms is explored and the predictive efficacy of maternal serum interleukin levels is evaluated. Finally, recommendations about the safe interpretation of the outcomes, as well as guidance for future research, are provided.

Fetal-placental crosstalk occurs through fetal cytokine synthesis and placental clearance

BACKGROUND

Cytokines modulate fetal well-being and contribute to parturition. Their origin in fetal blood, whether maternal, placental or fetal, at the time of parturition remains unclear.

OBJECTIVE

To determine fetal and placental contributions to circulating fetal cytokines by measuring umbilical arterial (UmA) and venous (UmV) concentration differences in uncomplicated term pregnancies in the absence and presence of labor.

METHODS

Term uncomplicated pregnancies were assessed: Group 1 were not in labor and delivered by elective cesarean section (n = 20); Group 2 delivered vaginally following uncomplicated pregnancy and labor (n = 30). UmA and UmV blood was collected before delivery of the placenta to measure circulating cytokines. Placental tissue was collected for histology and to determine cytokine contents and localization.

RESULTS

Group 1 UmA and UmV IL-10 concentrations were similar (504 ± 15 and 468 ± 16 pg/ml, respectively; P ≥ 0.1); other cytokines were below level of detection. During labor, IL-10 concentrations increased 15-34%, but placental contents decreased. Group 2 UmA IL-6 and IL-8 concentrations increased (P < 0.001) to 16.7 ± 1.6 and 18.4 ± 4.3 pg/ml, respectively, but were less (P < 0.001) in UmV, 0.29 ± 0.2 and 0.74 ± 0.3 pg/ml, respectively, demonstrating placental clearances ≥97%. This was associated with >6-fold increases in placental IL-6/IL-8 contents (P < 0.001) and chorioamniotic infiltration of activated maternal neutrophils. IL-6 and IL-10 were localized to villous syncytiotrophoblasts.

CONCLUSIONS

In uncomplicated term pregnancies fetal circulating IL-10 is likely of placental origin, whereas IL-6/IL-8 are derived from the fetus, increase during parturition, and circulating levels are modulated by non-saturable placental clearance, revealing a novel pathway for fetal-placental crosstalk and signaling.

Hypoxia regulates placental angiogenesis via alternatively activated macrophages

PROBLEM

Uterine and placental macrophages play critical roles in maintaining a normal pregnancy. The majority of these macrophages are believed to be alternatively activated macrophages (M2).

METHOD OF STUDY

Mouse bone marrow cells were differentiated into macrophages and polarized to M2 in vitro by treatment with IL-4 [M2a] or IL-10 [M2c] and M1 with LPS/IFN-γ as controls. Macrophage subtypes were confirmed by surface markers and characterized by gene expression profiles.

RESULTS

Compared to M1, M2 showed strong pro-angiogenic activity by expressing higher mRNA for angiogenic-associated factors (Cxcl12, Vegfa, PlGF, Mmp2). M2c produced the highest levels of PlGF, Mmp2, and Cxcr4. To mimic the normal placental microenvironment, M2 were exposed to hypoxia and sex hormones (progesterone, estrogen). In both M2c and M2a, severe hypoxic (1%-3% O₂ ) exposure significantly suppressed PlGF, Cxcl12, and Mmp2 mRNA, but not Vegfa, compared to normoxia (21% O₂ ) or physiological hypoxia (5% O₂ ). mRNA expression returned to normal when hypoxic cells were returned to normoxia. Hypoxia (1%) reduced antioxidant levels in M2 and re-exposure to normoxia significantly increased superoxide dismutase (Sod1, Sod2) and heme oxygenase-1 (HO-1) levels in M2a, and only glutathione peroxidase (Gpx1, Gpx3, Gpx4) in M2c. However, progesterone and estrogen treatment had minimal effects on angiogenic factor expression in M2.

CONCLUSION

M2, particularly M2c, displayed strong pro-angiogenic potential, which decreased under severe hypoxia such as in early pregnancy. Thus, conditions that alter the placental oxygen microenvironment or macrophage response in early pregnancy might cause aberrant angiogenesis and vascular remodeling, and lead to abnormal placental vascular development.

Anti-Cytokine Therapy to Attenuate Ischemic-Reperfusion Associated Brain Injury in the Perinatal Period

Perinatal brain injury is a major cause of morbidity and long-standing disability in newborns. Hypothermia is the only therapy approved to attenuate brain injury in the newborn. However, this treatment is unfortunately only partially neuroprotective and can only be used to treat hypoxic-ischemic encephalopathy in full term infants. Therefore, there is an urgent need for adjunctive therapeutic strategies. Post-ischemic neuro-inflammation is a crucial contributor to the evolution of brain injury in neonates and constitutes a promising therapeutic target. Recently, we demonstrated encouraging neuroprotective capacities of anti-cytokine monoclonal antibodies (mAbs) in an ischemic-reperfusion (I/R) model of brain injury in the ovine fetus. The purpose of this review is to summarize the current knowledge regarding the inflammatory response in the perinatal sheep brain after I/R injury and to review our recent findings regarding the beneficial effects of treatment with anti-cytokine mAbs.

A pronounced uterine pro-inflammatory response at parturition is an ancient feature in mammals

Regulating maternal immunity is necessary for successful human pregnancy. Whether this is needed in mammals with less invasive placentation is subject to debate. Indeed, the short gestation times in marsupials have been hypothesized to be due to a lack of immune regulation during pregnancy. Alternatively, the maternal marsupial immune system may be unstimulated in the absence of a highly invasive placenta. Transcripts encoding pro-inflammatory cytokines were found to be overrepresented in the whole uterine transcriptome at terminal pregnancy in the opossum, Monodelphis domestica To investigate this further, immune gene transcripts were quantified throughout opossum gestation. Transcripts encoding pro-inflammatory cytokines remained relatively low during pre- and peri-attachment pregnancy stages. Levels dramatically increased late in gestation, peaking within 12 h prior to parturition. These results mirror the spike of inflammation seen at eutherian parturition but not at attachment or implantation. Our results are consistent with the role of pro-inflammatory cytokines at parturition being an ancient and conserved birth mechanism in therian mammals.

The Role of Interleukin-10 in the Pathophysiology of Preeclampsia

PURPOSE OF REVIEW

The pathophysiology of preeclampsia is complex and not entirely understood. A key feature in preeclampsia development is an immunological imbalance that shifts the maternal immune response from one of tolerance towards one promoting chronic inflammation and endothelial dysfunction. As a key regulator of immunity, IL-10 not only has immunomodulatory activity, but also directly benefits vasculature and promotes successful cellular interactions at the maternal-fetal interface. Here we focus on the mechanisms by which the dysregulation of IL-10 may contribute to the pathophysiology of preeclampsia.

RECENT FINDINGS

Dysregulation of IL-10 has been demonstrated in various animal models of preeclampsia. Decreased IL-10 production in both placenta and peripheral blood mononuclear cells has been reported in human studies, but with inconsistent results. The significance of IL-10 in preeclampsia has shifted from a key biomarker to one with therapeutic potential. As such, a better understanding of the role of this cytokine in the pathophysiology of preeclampsia is of paramount importance.

Social conditions and immune response in human immunodeficiency virus-seropositive pregnant women: a cross-sectional study in Brazil

INTRODUCTION

The functioning of the immune system during pregnancy is altered in both human immunodeficiency virus (HIV)-infected and uninfected women. Unfavorable socioeconomic conditions have been indicative of higher morbidity and mortality and worsening of the immune system. The aim of this study was to correlate social status with levels of interleukin (IL)-10 (non-inflammatory) and interferon-gamma (IFN-γ; inflammatory) cytokines.

METHODS

A cross-sectional study was conducted with three groups of women: 33 pregnant HIV-infected (G1); 40 non-pregnant, HIV-infected (G2); and 35 pregnant, HIV-uninfected. To measure the social status, a compound indicator called the social status index (SSI), was established using sociodemographic variables (i.e., education level, housing conditions, per capita income, and habitation and sanitary conditions).

RESULTS

The HIV-infected women had a higher proportion of unfavorable SSI (73% and 75% of G1 and G2, respectively). There were significantly lower IL-10 levels in the G1 group with both unfavorable and favorable SSI than in the other groups. No significant difference in IFN-γ levels was observed among groups. However, the G1 group had higher IFN-γ values among both favorable and unfavorable SSI groups.

CONCLUSIONS

Higher rates of unfavorable conditions, including lower education levels, IL-10 levels, and a trend for higher IFN-γ levels, were identified among HIV-infected women, pregnant and non-pregnant. These factors may interfere in health care and lead to poor outcomes during pregnancy. Therefore, we suggest that health policies could be created to specifically address these factors in this population.

Preeclampsia: From Inflammation to Immunoregulation

Preeclampsia (PE) affects 5% to 7% of pregnant women each year worldwide, accounts for up to 18% of maternal deaths in the United States each year, and is the number 1 cause of premature births. Preeclampsia is associated with hypertension after the 20th week of gestation with or without proteinuria, in conjunction with fetal growth restriction, maternal endothelial dysfunction, and chronic immune activation. The mechanisms leading to the development of PE are unclear. However, it is thought that shallow trophoblast invasion and insufficient remodeling of uterine spiral arteries result in placental ischemia. Consequently, an immune imbalance characterized by increases in proinflammatory CD4⁺ T cells and cytokines along with decreases in regulatory T cells and anti-inflammatory cytokines occurs. This imbalance leads to chronic inflammation and ensuing oxidative stress, proinflammatory cytokines, and autoantibodies. Studies performed in our laboratories, using the Reduced Uterine Perfusion Pressure (RUPP) rat model of placental ischemia, have demonstrated a role for this immune imbalance to mediate PE pathophysiology and identified potential mechanisms of immunoregulation that may be of benefit in the treatment of PE. Therefore, the purpose of this commentary is to review studies demonstrating the positive effects of immunoregulatory factors in the RUPP rat model of PE. Restoration of the immune balance in PE may be a potential strategy for the development of therapeutic interventions that could improve maternal and fetal outcomes associated with this maternal syndrome.

Regulatory Cytokine Expression and Preterm Birth: Case-Control Study Nested in a Cohort

Background

Currently known risk factors explain only a small fraction of preterm birth (PTB). Previous PTB is one of the most important predictors. However, this information is not available in primiparous women. Few studies have looked at associations between regulatory cytokine expression (RCE) and PTB and the results are conflicting.

Objective

To investigate the association of RCE–Interleukin 10 (IL-10) and Transforming Growth Factor β (TGF-β)–with PTB, and to assess whether bacterial vaginosis (BV) is involved in this relationship.

Methods

This was a case-control study nested in a prospective cohort–called BRISA. Women with singleton pregnancies were interviewed from 22 to 25 weeks of gestational age (GA). Women were recruited from health services in São Luís, Brazil. A blood sample was collected and gynecological examination was performed. Serum IL-10 and TGF-β were determined using cytometric bead array. Nugent score >7 and/or the presence of clue cells were used for BV diagnosis. All PTB estimated by ultrasound dating performed before 20 weeks of gestational age were considered cases. Controls were selected by simple random sampling from the rest of the cohort, at a 2:1 ratio. Different models were tested, according to the main independent variable. Odds ratios (OR) and 95% confidence intervals (95%CI) were estimated by regression analyses.

Results

The study included 327 pregnant women, 109 cases and 218 controls. No associations were found between BV and PTB (P = 1.44; 95%CI: 0.51–3.77). Low levels of IL-10 (OR = 2.92 95%CI: 1.38–6.16) or TGF-β (OR = 16.90 95%CI: 6.42–44.51) or both simultaneously (OR = 77.16 95%CI: 7.99–744.88) were associated with increasing odds of PTB, even after adjustment for confounding.

Conclusion

Decreased RCE is a risk factor for PTB. This relationship, however, is not triggered by the presence of BV. Low IL-10/TGF-β levels from 22 to 25 weeks of GA could be used as early predictors of PTB. We suggest monitoring of these RCE, especially among primiparous women, for whom history of previous PTB is not available.

Mitogen-Activated Protein Kinases Are Activated in Placental Injury in Rat Model of Acute Pancreatitis in Pregnancy

OBJECTIVES

To establish a rat model of acute pancreatitis in pregnancy (APIP) and evaluate its general presentations, assess placental injury, and discuss possible mechanisms.

METHODS

The APIP rat model was induced by sodium taurocholate in Sprague-Dawley rats of later gestation. Normal and sham-operated (SO) rats in later gestation were set as controls, 3 time points were set in SO and APIP groups to determine optimal modeling time. Histological changes of pancreas and placenta were assessed. Placental injury was determined by immunohistochemistry stain of caspase-3. Serum levels of amylase, lipase, and Ca; proinflammatory cytokines as tumor necrosis factor-α, interleukin-1β (IL-1β), IL-6, and anti-inflammatory cytokine IL-10 by enzyme-linked immunosorbent assay; mitogen-activated protein kinases and their phosphorylated forms by Western blotting.

RESULTS

Pancreatic necrotizing and placental injury occurred in time-dependent patterns. Serum levels of amylase and lipase significantly increased but Ca decreased; tumor necrosis factor-α, IL-1β, IL-6, and IL-10 were all increased in the APIP group; c-Jun N-terminal kinase, p38, and ERK1/2 were activated but with different distributing patterns in the placenta.

CONCLUSIONS

Placental injury is involved in the rat model of APIP, and a modeling time of 6 hours is optimal and conducive to further studies; c-Jun N-terminal kinase and p38 may play important roles in placental injury during APIP.

The bacterial etiology of preterm birth

Preterm birth is the leading cause of infant morbidity and mortality. Very preterm births, those occurring before 32 completed weeks of gestation, are associated with the greatest risks. The leading cause of very preterm birth is intrauterine infection, which can lead to an inflammatory response that triggers labor or preterm premature rupture of membranes. How bacteria invade the uterine cavity, which is normally a sterile environment, and the reasons why different species vary in their capacity to induce inflammation and preterm birth are still incompletely understood. However, advanced techniques that circumvent the need for cultivating bacteria, deep sequence analysis that allows for the comprehensive characterization of the microbiome of a given body site and detection of low-prevalence species, and transcriptomics and metabolomics approaches that shed light on the host response to bacterial invasion are all providing a more complete picture of the progression from vaginal colonization to uterine invasion to preterm labor and preterm birth.

Identifying immune mechanisms mediating the hypertension during preeclampsia

Preeclampsia (PE) is a pregnancy-associated disorder that affects 5-8% of pregnancies and is a major cause of maternal, fetal, and neonatal morbidity and mortality. Hallmark characteristics of PE are new onset hypertension after 20 wk gestation with or without proteinuria, chronic immune activation, fetal growth restriction, and maternal endothelial dysfunction. However, the pathophysiological mechanisms that lead to the development of PE are poorly understood. Recent data from studies of both clinical and animal models demonstrate an imbalance in the subpopulations of CD4+ T cells and a role for these cells as mediators of inflammation and hypertension during pregnancy. Specifically, it has been proposed that the imbalance between two CD4+ T cell subtypes, regulatory T cells (Tregs) and T-helper 17 cells (Th17s), is involved in the pathophysiology of PE. Studies from our laboratory highlighting how this imbalance contributes to vasoactive factors, endothelial dysfunction, and hypertension during pregnancy will be discussed in this review. Therefore, the purpose of this review is to highlight hypertensive mechanisms stimulated by inflammatory factors in response to placental ischemia, thereby elucidating a role.

TNF-α alters the inflammatory secretion profile of human first trimester placenta

Implantation and subsequent placental development depend on a well-orchestrated interaction between fetal and maternal tissues, involving a fine balanced synergistic cross-talk of inflammatory and immune-modulating factors. Tumor necrosis factor (TNF)-α has been increasingly recognized as pivotal factor for successful pregnancy, although high maternal TNF-α levels are associated with a number of adverse pregnancy conditions including gestational hypertension and gestational diabetes mellitus. This study describes effects of exogenously applied TNF-α, mimicking increased maternal TNF-α levels, on the secretion profile of inflammation associated factors in human first trimester villous placenta. Conditioned culture media from first trimester villous placental explants were analyzed by inflammation antibody arrays and ELISA after 48 h culture in the presence or absence of TNF-α. Inflammation antibody arrays identified interleukin (IL)-6, IL-8, chemokine (C-C motif) ligand 2 (CCL2), CCL4, and granulocyte-macrophage colony-stimulating factor (GM-CSF) as the most abundantly secreted inflammation-associated factors under basal culture conditions. In the presence of TNF-α, secretion of GM-CSF, CCL5, and IL-10 increased, whereas IL-4 and macrophage CSF levels decreased compared with controls. ELISA analysis verified antibody arrays by showing significantly increased synthesis and release of GM-CSF and CCL5 by placental explants in response to TNF-α. Immunohistochemistry localized GM-CSF in the villous trophoblast compartment, whereas CCL5 was detected in maternal platelets adhering to perivillous fibrin deposits on the villous surface. mRNA-based in situ padlock probe approach localized GM-CSF and CCL5 transcripts in the villous trophoblast layer and the villous stroma. Results from this study suggest that the inflammatory secretion profile of human first trimester placenta shifts towards increased levels of GM-CSF, CCL5, and IL10 in response to elevated maternal TNF-α levels, whereas IL-6 and IL-8 remain unaffected. This shift may represent a protective mechanism by human first trimester villous placenta to sustain trophoblast function and dampen inflammatory processes in the intervillous space.

High levels of circulating extracellular vesicles with altered expression and function during pregnancy

Extracellular vesicles (EVs) are widely considered important modulators of cell-cell communication and may interact with target cells locally and on a systemic level. Several studies had shown that circulating EVs' levels are increased during pregnancy. However, EVs characteristics, composition and biological functions in pregnancy still need to be clarified. This study aims to determine if circulating EVs during pregnancy are modified regarding levels, markers and cytokine profile as well as their reactivity towards peripheral blood cells. 26 pregnant women (PW) being in the second gestational trimester and 59 non-pregnant women (NPW) were investigated. EVs enrichment was performed by ExoQuick™ or ultracentrifugation; nanoparticle tracking analysis, SDS-PAGE followed by Western Blotting and densitometry, and IFN-γ, IL-10 and TGF-β1 ELISA for EVs characterization; imaging flow cytometry to analyze EVs' uptake by peripheral blood cells and flow cytometry were performed to analyze EVs function regarding induction of caspase-3 activity. Circulating EVs' levels were increased during pregnancy [26.9×10(6)EVs/ml (range: 6.4-46.3); p=0.003] vs NPW [18.9×10(6)EVs/ml (range: 2.5-61.3)]. Importantly, the immunosuppressive TGF-β1 and IL-10 cytokine cargo were increased in EVs of PW even after normalization to 1 million EVs [TGF-β1: 0.25pg/10(6)EVs (range: 0.0-2.0); p<0.0001] and [IL-10: 0.21pg/10(6)EVs (range: 0.0-16.8); p=0.006] vs NPW. Although EVs derived from non-pregnant and pregnant women were taken up by NK cells, the latter exclusively enhanced the caspase-3 activity in CD56(dim) NK cells (8.2±0.9; p=0.02). The qualitative and quantitative pregnancy-related alterations of circulating EVs provide first hints for an immune modulating role of circulating EVs during pregnancy.

The role of inflammation in the pathology of preeclampsia

Preeclampsia (PE) affects 5-7% of all pregnancies in the United States and is the leading cause of maternal and prenatal morbidity. PE is associated with hypertension after week 20 of gestation, decreased renal function and small-for-gestational-age babies. Women with PE exhibit chronic inflammation and production of autoantibodies. It is hypothesized that during PE, placental ischaemia occurs as a result of shallow trophoblast invasion which is associated with an immune imbalance where pro-inflammatory CD4(+) T-cells are increased and T regulatory cells (Tregs) are decreased. This imbalance leads to chronic inflammation characterized by oxidative stress, pro-inflammatory cytokines and autoantibodies. Studies conducted in our laboratory have demonstrated the importance of this immune imbalance in causing hypertension in response to placental ischaemia in pregnant rats. These studies confirm that increased CD4(+) T-cells and decreased Tregs during pregnancy leads to elevated inflammatory cytokines, endothelin (ET-1), reactive oxygen species (ROS) and agonistic autoantibodies to the angiotensin II (Ang II), type 1 receptor (AT1-AA). All of these factors taken together play an important role in increasing the blood pressure during pregnancy. Specifically, this review focuses on the decrease in Tregs, and their associated regulatory cytokine interleukin (IL)-10, which is seen in response to placental ischaemia during pregnancy. This study will also examine the effect of regulatory immune cell repopulation on the pathophysiology of PE. These studies show that restoring the balance of the immune system through increasing Tregs, either by adoptive transfer or by infusing IL-10, reduces the blood pressure and pathophysiology associated with placental ischaemia in pregnant rats.

Inflammation and preterm birth

Preterm birth is the leading cause of neonatal morbidity and mortality. Although the underlying causes of pregnancy-associated complication are numerous, it is well established that infection and inflammation represent a highly significant risk factor in preterm birth. However, despite the clinical and public health significance, infectious agents, molecular trigger(s), and immune pathways underlying the pathogenesis of preterm birth remain underdefined and represent a major gap in knowledge. Here, we provide an overview of recent clinical and animal model data focused on the interplay between infection-driven inflammation and induction of preterm birth. Furthermore, here, we highlight the critical gaps in knowledge that warrant future investigations into the interplay between immune responses and induction of preterm birth.

In vitro morphology, viability and cytokine secretion of uterine telocyte-activated mouse peritoneal macrophages

Telocytes (TCs), a distinct interstitial cell population, have been identified in the uterus, oviduct and placenta, with multiple proposed potential biological functions. Their unique structure allows them to form intercellular junctions with various immunocytes, both in normal and diseased tissues, suggesting a potential functional relationship with the local immune response. It has been hypothesized that through direct heterocellular junctions or indirect paracrine effects, TCs influence the activity of local immunocytes that are involved in the inflammatory process and in immune-mediated reproductive abnormalities. However, no reliable cytological evidence for this hypothesis is currently available. In this study, we cultured primary murine uterine TCs and collected TC conditioned media (TCM). Mouse peritoneal macrophages (pMACs) were co-cultured for 48 hrs with TCM or with DMEM/F12 or lipopolysaccharide (LPS) as negative and positive controls, respectively. Normal uterine TCs with a typical structure and a CD-34-positive/vimentin-positive/c-kit-negative immunophenotype were observed during culture. Morphologically, TCM-treated pMACs displayed an obvious activation/immunoresponse, in contrast to over-stimulation and cell death after LPS treatment and no sign of activation in the presence of DMEM/F12. Accordingly, a cell counting kit 8 (CCK-8) assay indicated significant activation of pMACs by TCM and LPS compared to DMEM/F12, thus supporting the marked morphological differences among these groups of cells. Furthermore, within a panel of macrophage-derived cytokines/enzymes, interleukin-6 (IL-6) and inducible nitric oxide synthase were significantly elevated in TCM-treated pMACs; tumour necrosis factor α, IL1-R1, and IL-10 were slightly, but significantly, up-regulated; and no changes were observed for transforming growth factor-β1, IL-1β, IL-23α and IL-18. Our results indicate that TCs are not simply innocent bystanders but are rather functional players in the activation of pMACs; they trigger and maintain the immune response, likely through indirect paracrine effects. Thus, we provide preliminary in vitro evidence of immunoregulatory and immunosurveillance roles for TCs.

Effects of adrenomedullin on the expression of inflammatory cytokines and chemokines in oviducts from women with tubal ectopic pregnancy: an in-vitro experimental study

BACKGROUND

The occurrence of tubal ectopic pregnancy (tEP) is related to the inflammation of the oviduct. Recently, Adrenomedullin (ADM) was found highly expression in human oviduct. The current study is to investigate whether ADM have a modulatory action on inflammatory cytokines and chemokines in oviductal tissue from women with tubal ectopic pregnancy (tEP).

METHODS

Oviductal isthmus samples were collected from women with tEP undergoing salpingectomy, and women undergoing hysterectomy for benign gynaecological conditions. The mRNA and protein levels of inflammatory cytokines/chemokines were assayed by PCR (n = 6 for tEP, n = 5 for controls) and protein microarray methods (n = 5 for both tEP and controls) respectively.

RESULTS

Some of the inflammatory cytokines/chemokines were upregulated by ADM in oviducts from tEP patients at both mRNA and protein levels. Incubation of oviduct from tEP patients with ADM for 24 h down-regulated some of these cytokines/chemokines.

CONCLUSION

Our results suggest an additional mechanism whereby ADM insufficiency may increase the susceptibility to tEP through diminished anti-inflammatory activity. The actual impact of the relationship between ADM and inflammatory process on tubal implantation needs further exploration.

Cell-Free Fetal DNA, Telomeres, and the Spontaneous Onset of Parturition

Multiple previous reports have provided compelling support for the premise that spontaneous parturition is mediated by activation of inflammation-related signaling pathways leading to increased secretion of cytokines and chemokines, the influx of neutrophils and macrophages into the pregnant uterus, increased production of uterine activation proteins (eg, connexin-43, cyclo-oxygenase-2, oxytocin receptors, etc), activation of matrix metalloproteinases, and the release of uterotonins leading to cervical ripening, membrane rupture, and myometrial contractions. The missing link has been the fetal/placental signal that triggers these proinflammatory events in the absence of microbial invasion and intrauterine infection. This article reviews the biomedical literature regarding the increase in cell-free fetal DNA (cffDNA), which is released during apoptosis in the placenta and fetal membranes at term, the ability of apoptosis modified vertebrate DNA to stimulate toll-like receptor-9 (TLR9) leading to increased release of cytokines and chemokines, and the potential "fail-safe" role for the anti-inflammatory cytokine IL-10. This article also reviews the literature supporting the key role that telomere loss plays in regard to increasing the ability of vertebrate (including placental) DNA to stimulate TLR9, and in regard to signaling the onset of apoptosis in the placenta and fetal membranes, thereby providing a biologic clock that determines the length of gestation and the timing for the onset of parturition. In summary, this literature review provides a strong rationale for future research to test the hypothesis that telomere loss and increased cffDNA levels trigger the proinflammatory events leading to the spontaneous onset of parturition in mammals: the "cffDNA/telomere hypothesis."

IL10, TGF beta1, and IFN gamma modulate intracellular signaling pathways and cytokine production to control Toxoplasma gondii infection in BeWo trophoblast cells

Considering that interleukin 10 (IL10), transforming growth factor beta1 (TGFB1), and interferon gamma (IFNG) are involved in the susceptibility of BeWo trophoblast cells to Toxoplasma gondii infection, the aim of the present study was to investigate the effector mechanisms triggered by these cytokines in the control of T. gondii in BeWo cells. For this purpose, infected/uninfected BeWo cells were treated with IL10, TGFB1 (50 ng/ml), and IFNG (20 or 100 ng/ml) in order to verify the phosphorylation of signal transducers and activators of transcription 1 (STAT1), STAT3, and Smad2, parasite intracellular proliferation, as well as the Th1/Th2/IL17A cytokine production. The treatment of BeWo cells with IL10 and TGFB1 favored T. gondii proliferation, and these findings were associated with STAT3 and Smad2 phosphorylation, respectively (P < 0.05). Also, these cytokine treatments were able to down-modulate TNF alpha (TNFA) and IL6 production (P < 0.05). Low concentration of IFNG was unable to control T. gondii infection but was able to trigger STAT1 phosphorylation and up-regulate IL6 and IL17A production; whereas a high concentration of IFNG was unable to activate STAT1 but down-modulated IL6 and TNFA and increased T. gondii proliferation (P < 0.05). IL10, TGFB1, and IFNG regulate a differential T. gondii proliferation in BeWo cells because they distinctly trigger intracellular signaling pathways and cytokine production, especially IL6 and TNFA. Our data open new windows to understand the mechanisms triggered by IL10, TGFB1, and IFNG at the maternal-fetal interface in the presence of T. gondii, contributing to recognizing the importance of these effector mechanisms involved in the vertical transmission of this parasite.

Cotreatment with interleukin 4 and interleukin 10 modulates immune cells and prevents hypertension in pregnant mice

BACKGROUND

Excessive maternal immune system activation plays a central role in the development of the hypertensive disorder of pregnancy preeclampsia (PE). The immunomodulatory cytokines interleukin 4 (IL-4) and interleukin 10 (IL-10) are dysregulated during PE; therefore we hypothesized that treatment with both recombinant IL-4 and IL-10 during pregnancy could prevent the development of PE in mice.

METHODS

Using our mouse model of PE in which immune system activation is induced by the double-stranded RNA receptor agonist poly I:C, we gave daily injections of IL-4, IL-10, or both on days 13-17 of pregnancy. Mice were then killed on day 18.

RESULTS

Poly I:C caused a significant increase in systolic blood pressure in pregnant (P-PIC) mice compared with vehicle-treated pregnant (P) mice. All 3 treatments significantly decreased blood pressure in P-PIC mice to P levels, ameliorated the endothelial dysfunction, and decreased placental TLR3 levels in P-PIC mice. However, only IL-4/IL-10 cotreatment prevented the proteinuria and increased incidence of fetal demise in P-PIC mice; IL-4 or IL-10 alone had no effect. Additionally, only IL-4/IL-10 cotreatment prevented the significant increase in CD3(+)/γδ(+) T cells and CD11c(+) dendritic cells and significant decrease in CD11b(+)/CD14(-) suppressor monocytes, as well as completely prevented placental necrosis, in P-PIC mice. Importantly, IL-4/IL-10 cotreatment in P mice had no detrimental effects.

CONCLUSIONS

Taken together, these data demonstrate that exogenous IL-4 and IL-10 administration concurrently during pregnancy can normalize immune cell subsets and prevent PE induced by maternal immune system activation.

Interleukin-10: a pleiotropic regulator in pregnancy

Pregnancy is a unique and well-choreographed physiological process that involves intricate interplay of inflammatory and anti-inflammatory milieu, hormonal changes, and cellular and molecular events at the maternal-fetal interface. IL-10 is a pregnancy compatible cytokine that plays a vital role in maintaining immune tolerance. A wide array of cell types including both immune and non-immune cells secret IL-10 in an autocrine and paracrine manner. IL-10 binds to a specific receptor complex and activates JAK-STAT and PI3K-Akt signaling pathways while inhibiting NF-κB signaling pathway. IL-10 exerts its anti-inflammatory effects mainly by decreasing pro-inflammatory cytokines such as IL-1, IL-6, IL-12, and TNF-α, by inducing heme oxygenase-1, and by inhibiting antigen presentation via blocking major histocompatibility complex (MHC) class II expression. Prior studies from our group and others have shown that IL-10 also functions as a potent protector against vascular dysfunction, and enhancement of IL-10 may serve as an immunotherapeutic intervention to treat adverse pregnancy outcomes. This review seeks to critically evaluate the archetypal functions of IL-10 as an immune suppressive factor as well as its novel functions as a vascular protector and modulator of endoplasmic reticulum (ER) stress and autophagy in the context of normal and adverse pregnancy outcomes.

Leukocyte population dynamics and detection of IL-9 as a major cytokine at the mouse fetal-maternal interface

Despite much interest in the mechanisms regulating fetal-maternal interactions, information on leukocyte populations and major cytokines present in uterus and placenta remains fragmentary. This report presents a detailed and quantitative study of leukocyte populations at the mouse fetal-maternal interface, including a comparison between pregnancies from syngeneic and allogeneic crosses. Our results provide evidence for drastic differences not only in the composition of leukocyte populations in the uterus during pregnancy, but also between uterine and placental tissues. Interestingly, we have observed a significant decrease in the number of myeloid Gr1+ cells including monocytes, and myeloid CD11c+ cells including DCs in placenta from an allogeneic pregnancy. In addition, we have compared the expression levels of a panel of cytokines in non-pregnant (NP) or pregnant mouse uterus, in placenta, or in their isolated resident leukocytes. Qualitative and quantitative differences have emerged between NP, pregnant uterus and placenta. Unexpectedly, IL-9 was the major cytokine in NP uterus, and was maintained at high levels during pregnancy both in uterus and placenta. Moreover, we have found that pregnancy is associated with an increase in uterine IL-1a and a significant decrease in uterine G-CSF and GM-CSF. Comparing allogeneic versus syngeneic pregnancy, less allogeneic placental pro-inflammatory cytokines CCL2 (MCP-1), CXCL10 (IP-10) and more IL1-α in whole uterus was reproducibly observed. To our knowledge, this is the first report showing a detailed overview of the leukocyte and cytokine repertoire in the uterus of virgin females and at the fetal-maternal interface, including a comparison between syngeneic and allogeneic pregnancy. This is also the first evidence for the presence of IL-9 in NP uterus and at the maternal-fetal interface, suggesting a major role in the regulation of local inflammatory or immune responses potentially detrimental to the conceptus.

Unexplained infertility patients have increased serum IL-2, IL-4, IL-6, IL-8, IL-21, TNFα, IFNγ and increased Tfh/CD4 T cell ratio: increased Tfh and IL-21 strongly correlate with presence of autoantibodies

Infertility is a disease of the reproductive system that affects millions of people globally. Reproductive failure is a major medical issue adversely affecting human health in the 21st century. Many factors contribute to infertility, including immune conditions which may lead to immune infertility (immunologic infertility). It is known that specific T helper cells (Th) and their cytokines are involved in the stages of infertility. The aim of this study is to provide a new diagnostic approach to immunologic infertility by investigating the correlation of follicular helper T cells (Tfh) and their secreted cytokines with the autoantibodies in peripheral blood samples from immunologically infertile patients. Thirty (30) patients suffering from immune infertility and 20 control subjects were selected as the sample base for this study. The levels of Tfh, 20 cytokines and 4 antibodies were evaluated for this investigation and evaluated using flow cytometry, antibody chip and ELISA technologies. It was found that, in immunologically infertile patients, Tfh cell numbers were significantly higher than those in the control group. Likewise, seven (7) serum cytokines were expressed to a greater degree in infertile patients compared to the control group. Finally, four (4) antibodies were found to be higher in immunologically infertile patients. The results show that, among patients with immunologic infertility, the levels of Tfh cells and IL-21 were increased significantly in peripheral blood samples and correlate positively with the autoantibodies. IL-12 was positively correlated with the two antibodies, while TNFα was negatively correlated with two additional antibodies. The detection and quantification of Tfh cells, IL-21, IL-12 and TNFα may provide new diagnostic indicators to screen for immunologic infertility.

Regulation of the Anti-Inflammatory Cytokines Interleukin-4 and Interleukin-10 during Pregnancy

Inflammation mediated by both innate and adaptive immune cells is necessary for several important processes during pregnancy. Pro-inflammatory immune cell activation plays a critical role in embryo implantation, placentation, and parturition; however dysregulation of these cells can lead to detrimental pregnancy outcomes including spontaneous abortion, fetal growth restriction, maternal pathology including hypertensive disorders, or fetal and maternal death. The resolution of inflammation plays an important role throughout pregnancy and is largely mediated by immune cells that produce interleukin (IL)-4 and IL-10. The temporal and spatial aspects of reducing inflammation during pregnancy represent a complex process that if not functioning optimally can lead to persistent inflammation and pregnancy complications. In this review, we examine how immune cells that produce IL-4 and IL-10 are regulated throughout pregnancy as well as the effects that reduced IL-4 and IL-10 signaling has on fetal and maternal physiology.

Longitudinal profiling of inflammatory cytokines and C-reactive protein during uncomplicated and preterm pregnancy

PROBLEM

Previous studies have investigated the utility of inflammation markers as predictors of preterm birth, but none have compared trends in levels between uncomplicated and preterm pregnancy.

METHOD OF STUDY

We explored longitudinal changes in plasma cytokines, including IL-1β, IL-6, IL-10, and TNF-α, as well as C-reactive protein in pregnant women from a nested case-control study.

RESULTS

IL-6 was associated with increased odds of spontaneous preterm birth, defined by presentation of spontaneous preterm labor and/or preterm premature rupture of the membranes. Associations were strongest later in pregnancy. IL-10 was associated with increased odds of placentally mediated preterm birth, defined by presentation with preeclampsia or intrauterine growth restriction, and odds ratios were also highest near the end of pregnancy.

CONCLUSION

Maternal inflammation markers were associated with increased risk of preterm birth, and relationships differed by etiology of preterm delivery and gestational age at sample collection.

IL-10 gene promoter and intron polymorphisms and changes in IL-10 secretion in women with idiopathic recurrent miscarriage

STUDY QUESTION

Is recurrent pregnancy loss (RPL) associated with polymorphisms in the promoter and intron regions of the interleukin-10 (IL-10) gene?

SUMMARY ANSWER

IL-10 rs1518111 was found to be associated with RPL but the commonly studied promoter variants rs1800872, rs1800871 and 1800896 were not.

WHAT IS KNOWN ALREADY

Reduced expression of IL-10 is implicated in RPL, due to defective maternal immune tolerance (causing early miscarriages) or placental vascular insufficiency (causing late losses). IL-10 production is in part inherited, and IL-10 gene variants associated with reduced IL-10 expression have been analyzed for their association with RPL, often with inconclusive results.

STUDY DESIGN, SIZE, DURATION

A retrospective case-control study was performed between January 2011 and April 2012. The subjects comprised 296 RPL cases and 305 control women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Genotyping of the IL-10 intron (rs1878672, rs3024492, rs1554286, rs1518111, rs3024491, rs3024490) and promoter (rs1800872, rs1800871, rs1800896) variants was done by real-time PCR, with defined clusters.

MAIN RESULTS AND THE ROLE OF CHANCE

A higher minor allele frequency (MAF) of rs1518111 (P = 0.03) was in seen RPL cases; but the MAFs of the remaining SNPs were comparable between cases and controls. Setting the homozygous major allele genotype (1/1) as the reference, significantly higher frequencies of heterozygous rs1554286 and rs1800872, and homozygous rs1800896 genotype carriers, and a reduced frequency of homozygous rs1518111 genotype carriers, were seen in RPL cases, while the distribution of the remaining genotypes were comparable between cases and controls. Serum IL-10 levels were significantly reduced in RPL cases compared with control women (P = 0.002), and this correlated with rs1518111 and rs1800871 genotypes in both groups, and with the rs1800872 genotype among control women. A nine-locus (rs1878672, rs3024492, rs1554286, rs1518111, rs3024491, rs3024490, rs1800872, rs1800871 and rs1800896) haploview analysis demonstrated an increased frequency of haplotype 112112121 in RPL cases, thus conferring a disease susceptibility nature to this haplotype.

LIMITATIONS, REASONS FOR CAUTION

The main limitation of this study was that it was limited to Bahraini Arabs, thereby necessitating parallel studies of other ethnic groups. Another limitation is the study design, which prompts speculation on whether it is a cause-effect relationship.

WIDER IMPLICATIONS OF THE FINDINGS

While the lack of association of the various IL-10 promoter variants with RPL was in agreement with reports from varied ethnic groups, this is the first study to confirm the association between IL-10 rs151811 intronic variant and RPL.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by grants from the Arabian Gulf University Research Fund. None of the authors report any competing interests.

Serum level of IL-10 is increased in patients with endometriosis, and IL-10 promotes the growth of lesions in a murine model

Immune dysregulation may be involved in the development of endometriosis. The anti-inflammatory cytokine IL-10 plays an important role in eliminating unwanted cells and cellular debris in a silent way. We investigated the modulatory role of IL-10 in the development of endometriosis. We observed that the serum level of IL-10 in patients with endometriosis was significantly higher than that in healthy subjects or in control subjects with other gynecological disease. Monocyte-derived dendritic cells acquired from male donors and subsequently conditioned with serum from women with endometriosis exhibited a tolerogenic phenotype, including increased IL-10 production, lower IL-12 secretion, and down-regulation of CD86 and HLA-DR molecules. Depletion of IL-10 activity in a C57BL/6 mouse model of surgically induced endometriosis significantly decreased the size of endometrial lesions. In contrast, IL-10 administration promoted the growth of endometrial lesions in this model. In addition, infiltrated plasmacytoid dendritic cells were the primary IL-10-secreting immune cells in endometrial lesions. Our findings suggest that IL-10 may suppress immunity against endometrial implants, contributing to development of endometriosis.

Tissue-specific IL-10 secretion profile from term human fetal membranes stimulated with pathogenic microorganisms associated with preterm labor in a two-compartment tissue culture system

OBJECTIVE

Interleukin (IL)-10 is a cytokine with anti-inflammatory properties that plays pivotal roles in immune recognition and maintenance of pregnancy, limiting the harmful effects of pro-inflammatory modulators. The aim of this work was to characterize the contribution of amnion and choriodecidua regions of the human fetal membranes in the production of IL-10 after selective stimulation with Candida albicans, Gardnerella vaginalis and Streptococcus agalactiae.

METHODS

Pre-labor human fetal membranes were cultured in a two-compartment tissue culture system and stimulated with 1 × 10(6) CFU/ml of each pathogen added to either the amniotic or choriodecidual region or both.

RESULTS

Candida albicans and G. vaginalis were the pathogens most effective in inducing IL-10 secretion, increasing 20 and 10 times, respectively, the levels of this cytokine in the choriodecidual compartment. Stimulation with S. agalactiae was effective only in the choriodecidual region, increasing two times IL-10 concentration.

CONCLUSIONS

Synthesis and secretion of IL-10 in response to three different pathogens associated with intrauterine infection and preterm birth are differential and depend on the nature of the microorganism and initial contact region.