Circulating Immune Cells from Early- and Late-onset Pre-eclampsia Displays Distinct Profiles with Differential Impact on Endothelial Activation

Pre-eclampsia (PE) affects 5-8% of pregnancies and has detrimental effects on maternal-fetal health. PE is characterized by de novo hypertension after 20 wk of gestation and end-organ damage. Systemic inflammatory imbalance has been associated with PE, but its contribution to the pathology is poorly understood. Our objective was to investigate maternal systemic immune changes in early-onset PE (EOPE) and late-onset PE (LOPE) versus uncomplicated pregnancies (control [CTRL]), and their contribution to endothelial activation, hallmark of hypertension. Blood samples were analyzed by flow cytometry, multiplex assay, intracellular cytokine staining, and single-cell RNA sequencing. We performed cocultures between circulating immune cells and HUVECs to assess endothelial activation. We found that EOPE had decreased regulatory T cells (4.64±0.33, p < 0.05) and monocytes (33.92±3.08, p < 0.01), whereas LOPE had decreased regulatory T cells (4.60±0.30, p < 0.05) and Th2 cells (7.50±0.62, p < 0.01) versus CTRL. Compared to CTRL, elevated cytokines/chemokines, and growth factors were observed in LOPE, whereas EOPE primarily showed decreased levels. Using intracellular cytokine staining, we observed more monocytes producing IL-12, TNF-α, and IL-1β (all p < 0.05) in LOPE versus CTRL. At the transcriptomic level, we found differentially expressed genes between EOPE and CTRL, predominantly related to upregulation of immune activation pathways. Lastly, EOPE PBMCs induced heightened endothelial activation in vitro observed by increased ICAM-1 and ET-1 (p < 0.05), whereas LOPE PBMCs required LPS stimulation. Although significant proteomic changes are observed in the LOPE group, the EOPE displayed changes mostly at the transcriptomic levels and could induce endothelial activation in vitro.

The rebalancing of the immune system at the maternal-fetal interface ameliorates autism-like behavior in adult offspring

Maternal immune activation (MIA) is critical for imparting neuropathology and altered behaviors in offspring; however, maternal-fetal immune cell populations have not been thoroughly investigated in MIA-induced autism spectrum disorders (ASDs). Here, we report the single-cell transcriptional landscape of placental cells in both PBS- and poly(I:C)-induced MIA dams. We observed a decrease in regulatory T (Treg) cells but an increase in the M1 macrophage population at the maternal-fetal interface in MIA dams. Based on the Treg-targeting approach, we investigate an immunoregulatory protein, the helminth-derived heat shock protein 90α (Sjp90α), that induces maternal Treg cells and subsequently rescues the autism-like behaviors in adult offspring. Furthermore, in vivo depletion of maternal macrophages attenuates placental inflammatory reaction and reverses behavioral abnormalities in adult offspring. Notably, Sjp90α induces CD4+ T cell differentiation via scavenger receptor A (SR-A) on the macrophage in vitro. Our findings suggest a maternal Treg-targeted approach to alleviate MIA-induced autism-like behavior in adult offspring.

Progression of HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis after Pregnancy: A Case Series and Review of the Literature

HTLV-1-associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP) is a progressive non-remitting and incapacitating disease more frequently seen in women and with a patchy worldwide distribution. HAM/TSP develops in a small percentage of HTLV-1-infected individuals during their lifetime and etiologic factors for disease progression are still unclear. This study aims to describe the first case series of the progression of HAM/TSP in relation to pregnancy. Between January and March of 2012, we reviewed medical charts of women with HAM/TSP currently enrolled in the HTLV-1 cohort at the institute of tropical medicine of Cayetano Heredia University. Inclusion criteria included having a diagnosis of HAM/TSP according to the WHO guidelines and self-reported initial symptoms of HAM/TSP during pregnancy or within six months of delivery. Fifteen women reported having had symptoms compatible with HAM/TSP within four months of delivery. Among them, ten women had no symptoms before pregnancy and reported gait impairment after delivery. Five women with mild gait impairment before pregnancy noticed a worsening of their symptoms after delivery. Symptoms worsened after successive pregnancies. Recent studies have shown that HTLV-1 infection induces a strong T cell-mediated response and that the quality of this response plays a role in HAM/TSP pathogenesis. The relative immunosuppression during pregnancy, including blunting of the T-cell response, might allowed in certain women enhanced replication of HTLV-1 and disease progression in the postpartum. This is the first study looking specifically at HAM/TSP and pregnancy and the number of cases is remarkable. Further prospective studies of HTLV-1-infected women assessing immune markers during pregnancy are warranted. Breastfeeding was the main route of transmission. Strategies to prevent vertical transmission need to be evaluated in HTLV-1 endemic countries of Latin America.

Mesenchymal stem cell-derived exosomes in preeclampsia: A next-generation therapeutic tool

Preeclampsia (PE) is a major gestational disorder that causes both long- and short-term damage to both the mother and the fetus. Endometrium decidualization and the formation of the placenta are orchestrated by mesenchymal stem cells (MSCs). MSCs obtained from patients with PE exhibit an elevated rate of aging and apoptosis, which impairs the interplay between MSCs and endothelium, trophoblast, and immune cells in the placenta, accelerating the onset of PE. Preclinical and clinical evidence imply that the MSC-based therapy approach for PE is prospective. Importantly, as a novel cell-free approach, MSC-derived exosomes can improve symptoms and maternal-fetal survival in PE models by raising cell metabolism, encouraging angiogenesis balance, and regulating immune responses. Even following allogeneic administration, the likelihood of immune rejection is very limited as a result of the small quantity of exosome membrane-bound proteins. Furthermore, because exosomes do not expand, developing tumors is not probable. As a result, MSC-derived exosomes show superiority over MSCs in terms of safety. For the first time, we outline the properties of MSC-exosomes and highlight their functions and potential as a new paradigm for PE therapy in this review.

The Distribution of Foxp3 and CD68 in Preeclamptic and Healthy Placentas: A Histomorphological Evaluation

Preeclampsia is a complication of pregnancy that affects 3-5% of pregnancies and is one of the major causes of maternal/neonatal mortality and morbidities worldwide. We aimed to investigate the distribution of Foxp3+ regulatory T-cells and CD68+ Hofbauer cells in the placenta of preeclamptic and healthy pregnant women with a special focus on correlating these findings with placental histology. Decidua and chorionic villi of the placenta obtained from healthy and preeclamptic pregnancies were evaluated in full-thickness sections. Sections were stained with hematoxylin and eosin and Masson's trichrome and immunostained for Foxp3 and CD68 for histological analyses. The total histomorphological score for placentas was found to be higher in preeclamptic placentas than that in the controls. The CD68 immunoreactivity was higher in the chorionic villi of preeclamptic placentas than that in the controls. The immunoreactivity of Foxp3 was found widely distributed within the decidua in both the groups and did not differ significantly. Interestingly, Foxp3 immunoreactivity in the chorionic villi was found mainly in the villous core and, to a lesser extent, in the syncytiotrophoblasts. We found no significant relation between Foxp3 expressions and morphological changes observed in preeclamptic placentas. Although extensive research is being carried out regarding the pathophysiology of preeclampsia, the findings are still controversial.

Preeclampsia-Derived Exosomes Imbalance the Activity of Th17 and Treg in PBMCs from Healthy Pregnant Women

The disturbance of maternofetal immune tolerance is identified as one of the important issues in the pathology of preeclampsia (PE). PE exosomes are believed to possess significant roles in immune abnormalities. In this study, to assess the possible effects of PE exosomes in the pathophysiology of preeclampsia patients, exosomes were isolated from the serum of PE patients and incubated with peripheral blood mononuclear cells (PBMCs) of healthy pregnant women. Also, exosomes from healthy pregnant women were utilized as the control. Th17/Treg ratio in PE and healthy pregnant women and the effects of PE exosomes on expression level of Th17 and Treg transcription factors, as well as their related cytokines in PBMCs of healthy pregnant women, were evaluated. A significant decrease in Treg cell number and increase in Th17 cells and Th17/Treg ratio were observed in PE patients. Following PE-exosome intervention, a significant increase in mRNA expression level of RORγt, IL-17, IL-23, IL-1β, and IL-6, and significant decrease in IL-10 and TGFβ were evident. On the other hand, no significant difference in FoxP3 level was detected. Additionally, increased IL-6, IL-17, IL-23, and IL-1β levels and decreased IL-10 level in the supernatant of cultured PBMCs from healthy pregnant women following PE-exosome intervention were exhibited. However, TGF-β level did not change significantly. Based on our findings, PE exosomes are able to alter the activity of Th17 and Treg cells as well as their related gene expression and cytokine profiles. These findings support the probable role of PE exosomes in PE pathogenesis.

Histone methyltransferase Nsd2 ensures maternal-fetal immune tolerance by promoting regulatory T-cell recruitment

Regulatory T cells (Tregs) are fundamentally important for maintaining systemic immune homeostasis and are also required for immune tolerance at the maternal-fetal interface during pregnancy. Recent studies have suggested that epigenetic regulation is critically involved in Treg development and function. However, the role of H3K36me has not yet been investigated. Here, we found that the H3K36me2 methyltransferase Nsd2 was highly expressed in Tregs. Although loss of Nsd2 did not impair systemic Treg development or function, the level of Tregs at the maternal-fetal interface was significantly decreased in pregnant Nsd2 conditional knockout mice. Consequently, maternal-fetal immune tolerance was disrupted in the absence of Nsd2 in Tregs, and the pregnant mice showed severe fetal loss. Mechanistically, Nsd2 was found to upregulate CXCR4 expression via H3K36me2 modification to promote Treg cell recruitment into the decidua and suppress the anti-fetal immune response. Overall, our data identified Nsd2 as a critical epigenetic regulator of Treg recruitment for maternal-fetal tolerance.

Cellular immune responses in the pathophysiology of preeclampsia

Preeclampsia, defined as new-onset hypertension accompanied by proteinuria occurring at 20 weeks of gestation or later, is a leading cause of perinatal morbidity and mortality worldwide. The pathophysiology of this major multi-systemic syndrome includes defective deep placentation, oxidative stress, endothelial dysfunction, the presence of an anti-angiogenic state, and intravascular inflammation, among others. In this review, we provide a comprehensive overview of the cellular immune responses involved in the pathogenesis of preeclampsia. Specifically, we summarize the role of innate and adaptive immune cells in the maternal circulation, reproductive tissues, and at the maternal-fetal interface of women affected by this pregnancy complication. The major cellular subsets involved in the pathogenesis of preeclampsia are regulatory T cells, effector T cells, NK cells, monocytes, macrophages, and neutrophils. We also summarize the literature on those immune cells that have been less characterized in this clinical condition, such as γδ T cells, invariant natural killer T cells, dendritic cells, mast cells, and B cells. Moreover, we discuss in vivo studies utilizing a variety of animal models of preeclampsia to further support the role of immune cells in this disease. Finally, we highlight the existing gaps in knowledge of the immunobiology of preeclampsia that require further investigation. The goal of this review is to promote translational research leading to clinically relevant strategies that can improve adverse perinatal outcomes resulting from the obstetrical syndrome of preeclampsia.

Characteristics of preeclampsia in donor cell gestations

Pregnancies conceived through donor oocytes or sperm show increased risk for preeclampsia. We studied this issue in a preeclampsia case-control cohort (n = 2778), and found overrepresentation of donor cell gestations among women with preeclampsia (14/1627, 0.86%; OR 1.81; 95% CI: 1.07-3.08; P = 0.025) compared to the population data. Moreover, we observed excess of male births from donor cell pregnancies (male-to-female ratio 2.5 vs. 0.97; OR 2.57; 95% CI 1.02-6.36; P = 0.043). Maternal age (36.7 vs. 30.2; P < 0.0001) and preterm deliveries (64% vs. 38%; P = 0.046) distinguished donor cell gestations from other pregnancies with preeclampsia. These results support foreign fetal antigens as modulators of preeclampsia.

Regulatory T Cells in Pregnancy Adverse Outcomes: A Systematic Review and Meta-Analysis

Background

Several studies report the role of Regulatory T-cells (Tregs) in the pathophysiology of pregnancy adverse outcomes.

Objective

The aim of this systematic review and meta-analysis was to determine whether there is an association between regulatory T cell levels and pregnancy adverse outcomes (PAOs), including pre-eclampsia and preterm birth (PTB).

Method

Literature searches were conducted in PubMed/MEDLINE, Embase, and Cochrane CENTRAL databases. Inclusion criteria were original articles (clinical trials, case-control studies and cohort studies) comparing Tregs, sampled from the decidua or maternal blood, in healthy pregnant women versus women with pre-eclampsia or PTB. The outcome was standardised mean difference (SMD) in Treg numbers. The tau-squared (Tau²), inconsistency index (I²), and chi-squared (χ²) test quantified heterogeneity among different studies. Analyses were performed in RevMan software V.5.4.0 for Mac using a random-effects model with outcome data reported with 95% confidence intervals (CI). This study was prospectively registered with PROSPERO (CRD42020205469). PRISMA guidelines were followed.

Results

From 4,085 unique studies identified, 36 were included in qualitative synthesis, and 34 were included in quantitative synthesis (meta-analysis). In total, there were 1,783 participants in these studies: healthy controls=964, pre-eclampsia=759, PTB=60. Thirty-two studies compared Tregs in healthy pregnant women and women with pre-eclampsia, and 30 of these sampled Tregs from peripheral blood showing significantly higher Treg numbers in healthy pregnancies (SMD; 1.46; 95% CI, 1.03-1.88; I²=92%). Four studies sampled Tregs from the maternal decidua showing higher Tregs in healthy pregnancies (SMD, 0.76; 95% CI, -0.13-1.65; I²=84%). No difference was found in the number of Tregs between early versus late pre-eclampsia (SMD,-1.17; 95% CI, -2.79-0.44; I²=94%). For PTB, two studies compared Tregs sampled from the peripheral blood with a tendency for higher Tregs in healthy pregnancies but this did not reach significance (SMD, 2.18; 95% CI, -1.34-5.70; I²=96%). Subcohort analysis using Treg analysis (flow cytometry vs. qPCR vs. immunofluorescence tissue staining) showed similar associations.

Conclusion

Lower Tregs in pregnancy, sampled from the maternal peripheral blood, are associated with pre-eclampsia. There is a need for further studies to confirm a relationship between low Tregs and PTB. As the precise mechanisms by which Tregs may mediate pre-eclampsia and PTB remain unclear, further fundamental research is necessary to elucidate the underlying processes and highlight the causative link.

Systematic Review Registration

PROSPERO, identifier CRD42020205469.

Maternal one carbon metabolism and interleukin-10 &-17 synergistically influence the mode of delivery in women with Early Onset Pre-Eclampsia

OBJECTIVE

Studies on One Carbon Metabolism (OCM), Interleukins-10 &-17 (IL-10/-17) & βhCG in pre-eclampsia and its delivery outcome (preterm birth) reveal contradictory results, attributed to clinical heterogeneity (early/late onset pre-eclampsia) or preterm/term birth. Disturbed OCM also influences IL-10 &-17 during pregnancy. We sought to investigate the synergism between OCM and IL-10/-17 mediated immune-regulation through βhCG in Early onset pre-eclampsia (EO-PE) patients, delivering preterm, among North Indian women.

STUDY DESIGN

Case-control study with a total of 399 pregnant women (EO-PE delivering preterm = 199; Normotensives delivering at term = 200). Maternal genotypes & biochemical estimations along with fetal genotypes on subset (n = 72) pertaining to OCM and IL-10/-17 regulation were assessed.

MAIN OUTCOME MEASURES

Association of 1) maternal plasma levels with EO-PE 2) maternal and fetal genotypes with EO-PE. 3) Effect of Hyper-homocysteinemia (surrogate of disturbed OCM) on differential immune regulation (IL10,-17, βhCG) in EO-PE and mode of delivery.

RESULTS

Hyper-homocysteinemia posed an increased risk of three folds for EO-PE. Both, folate and B12 deficiencies were associated with elevated homocysteine in EO-PE. Further, MTHFR 677TT homozygotes was present only in EO-PE indicating its detrimental role. However, maternal IL17-197AA genotype showed decreased risk for EO-PE. Furthermore, elevated maternal plasma IL-17 along with elevated IL-10 & βhCG were observed in EO-PE. Taken together, altered homocysteine metabolism was associated with high IL10 in EO-PE; and was more pronounced in spontaneous vaginal deliveries as compared to induced/caesarean section deliveries.

CONCLUSIONS

We report homocysteine mediated IL-10 &17 dysregulation and its influence on mode of delivery in EO-PE, possibly through initiation of cervical ripening. Further, these could serve potential biomarkers of EO-PE & its delivery outcome among vulnerable populations with similar nutritional & genetic predispositions.

Decreased Frequency of CD8+HLA-G+ T Cell in the Peripheral Blood of Primary Unexplained Infertile Females

Most of the findings have focused on the importance of CD4⁺HLA-G⁺ and CD8⁺HLA-G⁺ regulatory T cells (Treg) during pregnancy. It has been demonstrated that these HLA-G⁺ T cell subsets could induce maternal immune tolerance against semi-allogenic conceptus during pregnancy. There are only a few experiments regarding the Treg cells in the context of unexplained infertility (UI). Thirty-five participants including 18 primary unexplained infertile and 17 fertile females were enrolled in this study. A total of 3-5 ml blood samples were taken, and peripheral blood mononuclear cells (PBMCs) were separated by using Ficoll. Using a flow cytometer, the frequency of CD4⁺HLA-G⁺ and CD8⁺ HLA-G⁺ T cells was assessed in the peripheral blood samples of primary unexplained infertile and fertile females. Our results showed that the frequency of CD8⁺HLA-G⁺ Treg cells was significantly lower in primary unexplained infertile females than fertile females (P = 0.048). Although the frequency of CD4⁺HLA-G⁺ Treg cells in the primary unexplained infertile females was lower than fertile females, the difference was not statistically significant (P = 0.25). Regarding the important role of CD8⁺HLA-G⁺ Treg cells during pregnancy and its decrease in females with primary UI, it seems that reduced CD8⁺ HLA-G⁺ Treg cells could be a leading immunological factor in the context of infertility. Nevertheless, more researches are needed in this field.

17-Hydroxyprogesterone caproate improves hypertension and renal endothelin-1 in response to sFlt-1 induced hypertension in pregnant rats

Preeclampsia (PE) is characterized by new onset hypertension in association with elevated soluble fms-like tyrosine kinase-1 (sFlt-1) and preproendothelin-1 (PPET-1) levels. Currently there is no effective treatment for PE except for early delivery of the fetal placental unit, making PE a leading cause for premature births worldwide. Administration of 17-hydroxyprogesterone caproate (17-OHPC) is used for prevention of recurrent preterm birth. This study was designed to test the hypothesis that 17-OHPC improves hypertension and ET-1 in response to elevated sFlt-1 in pregnant rats. sFlt-1 was infused into normal pregnant (NP) Sprague-Dawley rats (3.7 μg·kg^-1·day^-1 for 6 days, gestation days 13-19) in the presence or absence of 17-OHPC (3.32 mg/kg) administered via intraperitoneal injection on gestational days 15 and 18. Mean arterial blood pressure (MAP), pup and placenta weights, renal cortex PPET-1 mRNA levels and nitrate-nitrite levels were measured on GD 19. Infusion of sFlt-1 into NP rats elevated mean arterial pressure (MAP) compared with control NP rats: 115 ± 1 (n = 13) vs. 99 ± 2 mmHg (n = 12, p < 0.05). 17-OHPC attenuated this hypertension reducing MAP to 102 ± 3 mmHg in sFlt-1 treated pregnant rats (n = 8). Neither pup nor placental weight was affected by sFlt-1 or 17-OHPC. Importantly, renal cortex PPET-1 mRNA levels were elevated 3 fold in NP + sFlt-1 rats compare to NP rats, which decreased with 17-OHPC administration. Plasma nitrate-nitrite levels were 44 ± 9 µM in NP rats (n = 9), 20 ± 3 µM in NP + sFlt-1 (n = 7), which increased to 42 ± 11 µM NP + sFlt-1 + 17OHPC (n = 6). Administration of 17-OHPC improves clinical characteristics of preeclampsia in response to elevated sFlt-1 during pregnancy.

Analysis of regulatory T cells and CTLA-4 expression in pregnant women according to seropositivity to Toxoplasma gondii

Pregnancy is considered a period in which immunomodulation occurs, although it is important for the maintenance of the foetus, could contribute to infections as Toxoplasma gondii. Immune response cells such as regulatory T cells participate in this immunomodulation, and surface molecules such as CTLA-4 develop an immunosuppressive role, could contribute to the establishment of the parasite. This study aimed to evaluate the presence of regulatory T cells and the expression of CTLA-4 in parturient and non-pregnant seropositive and seronegative for anti-T. gondii antibodies. Sixty-two participants were evaluated, 14 parturient with negative serology, 23 parturient with positive serology, 16 non-pregnant women seronegative and 9 non-pregnant women seropositive. Immunophenotyping was performed for characterize TCD4+Foxp3+ cells, T CD4+CD25-Foxp3+, TCD4+CD25highFoxp3+, TCD4+CTLA-4+, TCD4+CD25-CTLA-4+ and TCD4+CD25highCTLA-4+. We observed a lower level of CD4+CD25highFoxp3+ cells from seropositive parturient compared with seropositive non-pregnant cells. Significative levels of CD4+CD25-Foxp3+ cells from seronegative pregnant were observed compared with seropositive pregnant cells. Furthermore, the higher level of CD4+CD25-CTLA-4+ cells populations was detected in seropositive pregnant cells compared with seropositive non-pregnant. Although a significant increase in CTLA-4 cells was observed in pregnant women positive for anti-T. gondii antibodies, this increase did not cause a risk of reactivation of the infection.

Dysfunction of Tregs contributes to FGR pathogenesis via regulating Smads signalling pathway

Fetal growth restriction (FGR) is ranked number two of most common complication of abnormal pregnancy worldwide. The pathogenesis of FGR is complicated due to multiple aetiologies and the exact mechanism for FGR development is currently unknown. T regulatory cells (Tregs) are proven to play central roles in the maintenance of normal pregnancy. Peripheral blood samples of 102 pregnant human were collected analysed using flow cytometry to identify Tregs. We found that reduced Tregs and down-regulation of Foxp3 were observed in peripheral blood of FGR patients. In FGR mouse model, we have found that Tregs were not only reduced in spleen but also in placenta. In vitro, Foxp3 and its transcription regulatory signalling molecules, including P-Smad2, P-Smad3 and Smad4, were diminished as well. Inhibition on Foxp3 expression was partially reversed by overexpression of Smad2 and Smad4. In FGR patients, Western blot results revealed that Foxp3, P-Smad2, P-Smad3 and Smad4 expression was inhibited in placenta. Our preliminary result suggests that maternal-foetal immune tolerance mediated by Tregs plays an essential role in the development of FGR. The inhibited expression of Foxp3 and down-regulated Smad2/Smad3/Smad4 signalling pathway were involved in the FGR pathogenesis. Targeting maternal-foetal immune tolerance through Tregs might represent a novel therapeutic option for FGR.

Immunological adaptations in pregnancy that modulate rheumatoid arthritis disease activity

During pregnancy, the fetus that grows within the maternal uterus is not rejected by the maternal immune system. To enable both tolerance towards the fetus and defence against pathogens, modifications of the maternal immune system occur during gestation. These modifications are able to bring about a natural improvement in disease activity of some autoimmune diseases, such as rheumatoid arthritis (RA). Various mechanisms of the immune system contribute to the phenomenon of pregnancy-related improvement of RA, and the cessation of these immunomodulatory mechanisms after delivery correlates with postpartum disease flare. HLA disparity between mother and fetus, glycosylation of IgG, immunoregulatory pathways, and alterations in innate and adaptive immune cells and their cytokines have important roles in pregnancy and in pregnancy-related amelioration of RA.

17-Hydroxyprogesterone caproate improves T cells and NK cells in response to placental ischemia; new mechanisms of action for an old drug

Preeclampsia (PE) is new onset hypertension during pregnancy associated with increased uterine artery resistance (UARI) and an imbalance among CD4 + T lymphocytes and natural killer (NK) cells. We have shown an important role for 17-hydroxyprogesterone caproate (17-OHPC) to improve hypertension and fetal demise in the RUPP rat model of PE. However we have not examined a role for 17-OHPC to improve NK cells and CD4⁺TH2 cells as possible mechanisms for improved fetal weight and hypertension. Therefore, we hypothesized that 17-OHPC lowers NK cells while improving the T cell ratio in the RUPP rat. RUPP was surgically induced on gestational day 14 in pregnant rats. 17-OHPC (3.32 mg/kg) was administered intraperitoneal on day 15, UARI was measured on day 18. Blood pressure (MAP), blood and tissues were collected on GD 19. MAP in NP rats (n = 9) was 100 ± 2, 104 ± 6 in Sham rats (n = 8), 128 ± 2 in RUPP (n = 11) and 115 ± 3 mmHg in RUPP + 17-OHPC (n = 10), p < 0.05. Pup weight and UARI were improved after 17-OHPC. Total and cytolytic placental NK cells were 38 ± 5, and 12 ± 2% gate in RUPP rats which decreased to 1.6 ± 0.5 and 0.4 ± 0.2% gate in RUPP + 17OHPC rats. CD4⁺ T cells were 40 ± 3 in RUPP rats, which significantly decreased to 7 ± 1 RUPP + 17-OHPC rats. Circulating and placental TH2 cells were 6.0 ± 1, 0.3 ± 0.1% gate in RUPP rats and 12 ± 1%, 2 ± 0.5% gate in RUPP + 17-OHPC rats, p < 0.05 This study identifies new mechanisms whereby 17-OHPC improves outcomes in response to placental ischemia.

Inflammatory mediators: a causal link to hypertension during preeclampsia

Preeclampsia (PE) is a hypertensive disorder that occurs after 20 weeks of gestation, implicating the placenta as a key offender. PE is associated with an imbalance among B lymphocytes, CD4+ T lymphocytes, NK cells and increased inflammatory cytokines. During early onset PE, trophoblast invasion and placentation are impaired, leading to reduced blood flow to the fetus. In all spectrums of this disorder, a shift towards a pro-inflammatory state where regulatory cells and cytokines are decreased occurs. Specifically, inflammatory CD4+ T-cells and inflammatory cytokines are increased while CD4+ T regulatory cells (Tregs) and immunosuppressive cytokines such as IL-4 and IL-10 are decreased resulting in B cell activation, production of autoantibodies, endothelial dysfunction and hypertension associated with PE. However, the stimulus for these imbalances is unknown and need to be fully understood so that effective treatments that target the pathogenesis of the disease can be designed. Therefore, this review will focus on the pathways involving CD4+ , TH1, TH2, Tregs, TH17s, B cells, and NK cells in the pathophysiology of PE. LINKED ARTICLES: This article is part of a themed section on Immune Targets in Hypertension. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.12/issuetoc.

Interleukin-4 supplementation improves the pathophysiology of hypertension in response to placental ischemia in RUPP rats

Preeclampsia (PE) is characterized by chronic inflammation and elevated agonistic autoantibodies to the angiotensin type 1 receptor (AT₁-AA), endothelin-1, and uterine artery resistance index (UARI) during pregnancy. Previous studies report an imbalance among immune cells, with T-helper type 2 (Th2) cells being decreased during PE. We hypothesized that interleukin-4 (IL-4) would increase Th2 cells and improve the pathophysiology in response to placental ischemia during pregnancy. IL-4 (600 ng/day) was administered via osmotic minipump on gestational day 14 to normal pregnant (NP) and reduced uterine perfusion pressure (RUPP) rats. Carotid catheters were inserted, and Doppler ultrasound was performed on gestational day 18. Blood pressure (mean arterial pressure), TNF-α, IL-6, AT₁-AA, natural killer cells, Th2 cells, and B cells were measured on gestational day 19. Mean arterial pressure was 97 ± 2 mmHg in NP ( n = 9), 101 ± 3 mmHg in IL-4-treated NP ( n = 14), and 137 ± 4 mmHg in RUPP ( n = 8) rats and improved to 108 ± 3 mmHg in IL-4-treated RUPP rats ( n = 17) ( P < 0.05). UARI was 0.5 ± 0.03 in NP and 0.8 in RUPP rats and normalized to 0.5 in IL-4-treated RUPP rats ( P < 0.05). Plasma nitrate-nitrite levels increased in IL-4-treated RUPP rats, while placental preproendothelin-1 expression, plasma TNF-α and IL-6, and AT₁-AA decreased in IL-4-treated RUPP rats compared with untreated RUPP rats ( P < 0.05). Circulating B cells and placental cytolytic natural killer cells decreased after IL-4 administration, while Th2 cells increased in IL-4-treated RUPP compared with untreated RUPP rats. This study illustrates that IL-4 decreased inflammation and improved Th2 numbers in RUPP rats and, ultimately, improved hypertension in response to placental ischemia during pregnancy.

TGFb1 suppresses the activation of distinct dNK subpopulations in preeclampsia

BACKGROUND

Decidual natural killer (dNK) cells are the predominant lymphocytes accumulated at the maternal-fetal interface. Regulatory mechanism of dNK cells in preeclampsia, a gestational complication characterized by high blood pressure and increased proteinuria occurring after 20 weeks pregnancy, is not completely understood.

METHODS

Multi-parameter flow cytometry is applied to investigate the phenotype and function of dNK cells freshly isolated from decidual samples or conditionally cultured by TGFb stimulation.

FINDINGS

In preeclampsia, we documented elevated numbers of CD56⁺ CD3^- dNK cells in close proximity to Foxp3⁺ regulatory T (Treg) cells within the decidua. In vitro experiments using dNK cells from early gestation showed that dNK activation (IFNG, IL-8 and CD107a) can be downregulated by Treg cells. The expression of these markers by dNK cells was significantly lower in preeclampsia. We also observed a positive correlation between the expression of dNK activation receptors (NKp30 and NKG2D) and the expression of IFNG in specific dNK subsets. TGFb levels are increased in the decidua of preeclamptic pregnancies. We analyzed co-expression of activation (IFNG/IL-8/CD107a) and angiogenic (VEGF) markers in dNK cells. TGFb treatment reduced while blockade of TGFb increased co-expression of these markers.

INTERPRETATION

Our findings suggest that elevated decidual TGFb1 supresses the activation of specific subsets of dNK which in turn contributes to the uteroplacental pathology associated with the onset of preeclampsia.

The imbalance of Th17/Treg axis involved in the pathogenesis of preeclampsia

PROBLEM

Inappropriate activation of the immune system, particularly the imbalance of T-helper type 17 (Th17)/regulatory T (Treg) cells is thought to play considerable roles in preeclampsia (PE). To investigate the probable effects of the adaptive immune system in the pathophysiology of PE, we analyzed the dynamic changes of Th17/Treg cells, cytokines profile, and transcription pattern of Th17/Treg-related genes and microRNAs (miRNAs) in 50 women suffering from PE in comparison with 50 healthy pregnant women.

METHODS

Expressions of cytokines, specific transcription factors, and related miRNAs were measured by real-time polymerase chain reaction (PCR). Enzyme-linked immunosorbent assay (ELISA) was used to test the interleukin (IL)-17, IL-23, IL-6, and IL-10 and transforming growth factor β in serum and supernatant of peripheral blood mononuclear cells (PBMCs). The frequency of Th17 and Treg cells were determined by flow cytometry.

RESULTS

PE patients exhibited a decreased number of Treg cells (p = 0.006), while Th17 cells were increased ( p = 0.004). Forkhead box P3 and IL-10 mRNA expressions were reduced ( p = 0.0001 and 0.0028, respectively), while expressions of retinoic acid receptor-related orphan nuclear receptor γt, IL-17, IL-23, and IL-6 were enhanced ( p < 0.0001, 0.0018, 0.0014, and 0.027, respectively). ELISA results also showed increased levels of IL-6, IL-17, and IL-23 ( p = 0.022, 0.0005, 0.0081, respectively), and decreased levels of IL-10 in the supernatant of PBMCs of PE patients compared with control group ( p = 0.0011). There was significant upregulation of miR-106b and miR-326 ( p = 0.0048 and 0.028, respectively) in PE patients in comparison with the control group.

CONCLUSIONS

These findings suggest that imbalance of Th17/Treg cells, regulated possibly via microRNAs, may be involved in the pathogenesis of PE, emphasizing on the importance of these cells in feto-maternal immune cross-talk.

Immunological Basis for Recurrent Fetal Loss and Pregnancy Complications

Pregnancy stimulates an elaborate assortment of dynamic changes, allowing intimate approximation of genetically discordant maternal and fetal tissues. Although the cellular and molecular details about how this works remain largely undefined, important clues arise from evaluating how a prior pregnancy influences the outcome of a future pregnancy. The risk of complications is consistently increased when complications occurred in a prior pregnancy. Reciprocally, a prior successful pregnancy protects against complications in a future pregnancy. Here, we summarize immunological perturbations associated with fetal loss, with particular focus on how both harmful and protective adaptations may persist in mothers. Immunological aberrancy as a root cause of pregnancy complications is also considered, given their shared overlapping risk factors and the sustained requirement for averting maternal-fetal conflict throughout pregnancy. Understanding pregnancy-induced immunological changes may expose not only new therapeutic strategies for improving pregnancy outcomes but also new facets of how immune tolerance works that may be applicable to other physiological and pathological contexts.

Abnormal lymphatic vessel development is associated with decreased decidual regulatory T cells in severe preeclampsia

PROBLEM

The lymphatic vasculature controls leukocytes trafficking and limits the adaptive immune response. In previous models of preeclampsia (PE), defective immune function caused by disruption of lymphangiogenesis was shown to be involved in the disease pathophysiology. Especially, the dysfunction of regulatory T cells (Treg) at the maternal-fetal interface may be one of the causes of severe PE. In particular, activation of Tregs to obtain immune tolerance requires adequate antigen presentation through the lymphatic system. We hypothesized that impaired lymphangiogenesis and imbalanced Tregs at the maternal-fetal interface are associated with the pathophysiology of severe PE. However, the current research addressing this hypothesis is limited. Therefore, to compare differences in lymphangiogenesis in severe PE and normal conditions, we aimed to examine the location of lymphatics at the maternal-fetal interface and to investigate the association between lymphangiogenesis and Tregs in severe PE.

METHOD OF STUDY

We obtained entire uterus from normal pregnant mice. Placental and fetal membranes, including decidua, were obtained from 10 pregnant women with severe PE and 10 gestational age-matched controls. Immunohistochemistry for LYVE1 was used to localize the distribution of lymphatic vessels and CD4, CD25, and FOXP3 for Treg.

RESULTS

LYVE1-positive vessels were present in the uterine wall of mice. LYVE1-positive lymphatic vessels were localized on the human decidua. Tubular lymphatics were abundant in the control decidua, but significantly reduced in severe PE. Furthermore, lymphatic vessel density correlated with the number of decidual Tregs.

CONCLUSION

Abnormal decidual lymphangiogenesis is associated with reduced numbers of decidual Tregs in severe PE.

Inhibition of pregnancy-associated granulocytic myeloid-derived suppressor cell expansion and arginase-1 production in preeclampsia

Myeloid-derived suppressor cells (MDSCs) expand in maternal peripheral blood and cord blood during normal pregnancy to maintain maternal-fetal tolerance. Here we investigated the expansion and function of MDSCs in preeclampsia (PE) patients. Maternal peripheral blood mononuclear cells (PBMCs) and cord blood mononuclear cells (CBMCs) were sampled from healthy pregnant women and PE patients, and analyzed for the frequencies and phenotypes of MDSCs and T cells. Serum levels of key human MDSC effector enzymes were measured using appropriate detection kits. Peripheral blood samples of healthy non-pregnant women were used as controls. We found that normal pregnancy is associated with a significant increase of immunosuppressive MDSCs and regulatory T (Treg) cells. There was no significant difference in the frequency of Treg cells between normal pregnancies and PE patients, but the pregnancy-associated increase of granulocytic MDSCs (G-MDSCs), but not monocytic MDSCs (M-MDSCs), in both PBMCs and CBMCs was markedly inhibited in PE patients. Furthermore, serum levels of Arg-1, an important effector molecule for G-MDSC were significantly reduced in PE patients compared to healthy pregnant women. In conclusion, the lack of G-MDSC expansion is a most notable feature of PE-associated immune-cell alterations, suggesting that restoring G-MDSCs may have the potential to treat PE.

Early pregnancy immune biomarkers in peripheral blood may predict preeclampsia

We performed a prospective cohort study in 197 pregnant women. Peripheral blood was collected between 5 and 16 weeks of gestation. Intracellular cytokine analysis and immunophenotype were performed by flow-cytometry. Serum levels of cytokines and chemokines were analyzed by multiplex assay. 86 patients were eligible for the analysis and 10.5% (n=9) developed preeclampsia. Patients with preeclampsia had significantly higher percentage of CD3⁺CD4⁺TNFα⁺ T helper (Th) 1 cells (45.4±10.3 vs 37.1±8.5, P=0.032) and CD3⁺CD4⁺IL17⁺ Th 17 cells (2.4±1.3 vs 1.6±1.1, P=0.029) when compared to those of patients without preeclampsia. CD3⁺CD4⁺CD25⁺CD127^dim/- T regulatory cells (Treg) cells (5.7±1.2% vs 7.0±1.6%, P=0.015) were significantly lower in patients with preeclampsia when compared to those without preeclampsia. Patients with preeclampsia had significantly higher TNFα/IL-10 cell ratio (43.8±10.3 vs 34.3±7.9, P=0.005) and Th17/Treg cell ratio (0.5±0.3 vs 0.2±0.2, P=0.011) when compared to those of patients without preeclampsia. IL-8 and Macrophage inflammatory protein (MIP)-1α serum levels were significantly higher in patients with preeclampsia when compared with patients without preeclampsia (Median=341.0 vs 87.6, U=152, P=0.020 and Median=35.7 vs 17.7, U=120, P=0.029 respectively). Serum MCP-1 levels were significantly lower in patients with preeclampsia when compared with patients without preeclampsia (Median=233.8 vs 390.9, U=183, P=0.021). The logistic regression predictive model combining TNFα/IL-10 ratios, IL-8 and MCP-1 serum levels had the best performance (AUC=0.886, 95%CI 0.8-0.9). We concluded that elevated Th1 and Th17 cell percentages, elevated TNFα/IL-10 and Th17/Treg cell ratios and decreased Treg cell percentages in early pregnancy are associated with preeclampsia.

Changes in T Cell and Dendritic Cell Phenotype from Mid to Late Pregnancy Are Indicative of a Shift from Immune Tolerance to Immune Activation

During pregnancy, the mother allows the immunologically distinct fetoplacental unit to develop and grow. Opinions are divided as to whether this represents a state of fetal-specific tolerance or of a generalized suppression of the maternal immune system. We hypothesized that antigen-specific T cell responses are modulated by an inhibitory T cell phenotype and modified dendritic cell (DC) phenotype in a gestation-dependent manner. We analyzed changes in surface markers of peripheral blood T cells, ex vivo antigen-specific T cell responses, indoleamine 2,3-dioxygenase (IDO) activity (kynurenine/tryptophan ratio, KTR), plasma neopterin concentration, and the in vitro expression of progesterone-induced blocking factor (PIBF) in response to peripheral blood mononuclear cell culture with progesterone. We found that mid gestation is characterized by reduced antigen-specific T cell responses associated with (1) predominance of effector memory over other T cell subsets; (2) upregulation of inhibitory markers (programmed death ligand 1); (3) heightened response to progesterone (PIBF); and (4) reduced proportions of myeloid DC and concurrent IDO activity (KTR). Conversely, antigen-specific T cell responses normalized in late pregnancy and were associated with increased markers of T cell activation (CD38, neopterin). However, these changes occur with a simultaneous upregulation of immune suppressive mechanisms including apoptosis (CD95), coinhibition (TIM-3), and immune regulation (IL-10) through the course of pregnancy. Together, our data suggest that immune tolerance dominates in the second trimester and that it is gradually reversed in the third trimester in association with immune activation as the end of pregnancy approaches.

Association between cytokine profile and transcription factors produced by T-cell subsets in early- and late-onset pre-eclampsia

Pre-eclampsia (PE) is an obstetric pathology characterized by abnormal activation of the innate and adaptive immune systems dependent on the imbalance of T helper subsets. The present study aimed to evaluate the gene and protein expression of T helper type 1 (Th1)/Th2/Th17/regulatory T (Treg) cell transcription factors in peripheral blood lymphocytes from pregnant women with PE employing quantitative RT-PCR and flow cytometry techniques, as well as the cytokine profile produced by these CD4+ T-cell subsets in the plasma of pregnant women with PE, classified as early-onset PE (n = 20), late-onset PE (n = 20) and normotensive pregnant women (n = 20). Results showed a higher percentage of CD4+ T cells expressing the RORc transcription factor (Th17) and a lower percentage of cells expressing FoxP3 (Treg) in women with early-onset PE compared with late-onset PE and normotensive groups. A lower gene expression of GATA-3 transcription factor was detected in cells of women with early-onset PE compared with the late-onset PE group. Endogenous plasma levels of interleukin-6 (IL-6), IL-17 and tumour necrosis factor-α were significantly higher in the early-onset PE group than in the late-onset PE and normotensive groups, whereas IL-4 (Th2 profile) and IL-22 (Th17 profile), were not significantly different between the studied groups. The endogenous levels of transforming growth factor-β and IL-10 were significantly lower in the pre-eclamptic than in the normotensive groups of the same gestational age, with a significant difference between early- and late-onset PE. The results show that in women with PE there is an imbalance between inflammatory and anti-inflammatory profiles in CD4+ T-cell subsets, with polarization to Th17 profiles in the early-onset PE, considered as the severe form of PE.

Neutrophils induce proangiogenic T cells with a regulatory phenotype in pregnancy

Although neutrophils are known to be fundamental in controlling innate immune responses, their role in regulating adaptive immunity is just starting to be appreciated. We report that human neutrophils exposed to pregnancy hormones progesterone and estriol promote the establishment of maternal tolerance through the induction of a population of CD4⁺ T cells displaying a GARP⁺CD127^loFOXP3⁺ phenotype following antigen activation. Neutrophil-induced T (niT) cells produce IL-10, IL-17, and VEGF and promote vessel growth in vitro. Neutrophil depletion during murine pregnancy leads to abnormal development of the fetal-maternal unit and reduced empbryo development, with placental architecture displaying poor trophoblast invasion and spiral artery development in the maternal decidua, accompanied by significantly attenuated niT cell numbers in draining lymph nodes. Using CD45 congenic cells, we show that induction of niT cells and their regulatory function occurs via transfer of apoptotic neutrophil-derived proteins, including forkhead box protein 1 (FOXO1), to T cells. Unlike in women with healthy pregnancies, neutrophils from blood and placental samples of preeclamptic women fail to induce niT cells as a direct consequence of their inability to transfer FOXO1 to T cells. Finally, neutrophil-selective FOXO1 knockdown leads to defective placentation and compromised embryo development, similar to that resulting from neutrophil depletion. These data define a nonredundant function of neutrophil-T cell interactions in the regulation of vascularization at the maternal-fetal interface.

Preeclampsia and health risks later in life: an immunological link

Pregnancy represents a period of physiological stress, and although this stress is experienced for a very modest portion of life, it is now recognized as a window to women's future health, often by unmasking predispositions to conditions that only become symptomatic later in life. In normal pregnancy, the mother experiences mild metabolic syndrome-like condition through week 20 of gestation. A pronounced phenotype of metabolic syndrome may program pregnancy complications such as preeclampsia. Preeclampsia is a serious complication with a myriad of manifestations for mother and offspring. This pregnancy syndrome is a polygenic disease and has been now linked to higher incidence of cardiovascular disease, diabetes, and several other disorders associated with vulnerable organs. Furthermore, the offspring born to preeclamptic mothers also exhibit an elevated risk of cardiovascular disease, stroke, and mental disorders during adulthood. This suggests that preeclampsia not only exposes the mother and the fetus to complications during pregnancy but also programs chronic diseases in later life. The etiology of preeclampsia is thought to be primarily associated with poor placentation and entails excessive maternal inflammation and endothelial dysfunction. It is well established now that the maternal immune system and the placenta are involved in a highly choreographed cross-talk that underlies adequate spiral artery remodeling required for uteroplacental perfusion and free flow of nutrients to the fetus. Since normal pregnancy is associated with a sequence of events represented by temporal events of inflammation (implantation), anti-inflammation (gestation), and inflammation (parturition), it is quite possible that unscheduled alterations in these regulatory responses may lead to pathologic consequences. Although it is not clear whether immunological alterations occur early in pregnancy, it is proposed that dysregulated systemic and placental immunity contribute to impaired angiogenesis and the onset of preeclampsia. This review will focus on important aspects of the immune system that coordinate with placental dysfunction to program preeclampsia and influence health in later life.

The PD-1/PD-L1 inhibitory pathway is altered in pre-eclampsia and regulates T cell responses in pre-eclamptic rats

The programmed cell death-1(PD-1)/PD-ligand 1 (PD-L1) pathway is critical to immune homeostasis by promoting regulatory T (Treg) development and inhibiting effector T (such as Th17) cell responses. However, the association between the PD-1/PD-L1 pathway and the Treg/Th17 imbalance has not been fully investigated in pre-eclampsia (PE). In this study, we observed an inverse correlation between the percentages of Treg and Th17 cells, and the expression of PD-1 and PD-L1 on the two subsets also changed in PE compared with normal pregnancy. We further explored their relationship in vivo using the L-NG-Nitroarginine Methyl Ester (L-NAME) induced PE-like rat models, also characterized by Treg/Th17 imbalance. Administration of PD-L1-Fc protein provides a protective effects on the pre-eclamptic models, both to the mother and the fetuses, by reversing Treg/Th17 imbalance through inhibiting PI3K/AKT/m-TOR signaling and enhancing PTEN expression. In addition, we also observed a protective effect of PD-L1-Fc on the placenta by reversing placental damages. These results suggested that altered PD-1/PD-L1 pathway contributed to Treg/Th17 imbalance in PE. Treatment with PD-L1-Fc posed protective effects on pre-eclamptic models, indicating that the use of PD-L1-Fc might be a potential therapeutic target in PE treatment.

Modulation of an aqueous extract of Chinese medicine prescription Anzi Heji () on ratio of CD4+CD25+FOXP3+ regulatory T cells in anticardiolipin antibody-positive patients with threatened abortion

OBJECTIVE

To evaluate Chinese medicine prescription, Anzi Heji (, AZHJ), on immune regulation of CD4+CD25+FOXP3+ regulatory T cells (Tregs) in anticardiolipin antibody (ACA)-positive patients with threatened abortion.

METHODS

Twenty-seven ACA-positive female patients with threatened abortion in the study group were treated with an aqueous extract of AZHJ 125 mL, twice daily for 4 consecutive weeks. The results were compared with control group composed by 15 healthy pregnant women. The ratio of CD4+CD25+FOXP3+ Treg in peripheral blood was identified by flow cytometry. The indicators of ACA were detected by enzyme-linked immunosorbent assay, and embryo development was checked by B-ultrasound.

RESULTS

Compared with the control group, the ratio of CD4+CD25+FOXP3+ Treg cells in the study group was significantly lower before AZHJ treatment (P<0.01) and significantly increased after AZHJ treatment (P<0.01). After treatment, 20 of 27 patients (85%) showed that ACA indicators turned into negative, and 7 cases of quantitative indicators of ACA titers were significantly decreased (P<0.01). Total efficiency of treating miscarriage by AZHJ was 92.59%.

CONCLUSION

AZHJ can regulate the immune function of pregnant women by increasing number of CD4+CD25+FOXP3+ Tregs.

Regulatory T-cells and preeclampsia: an overview of literature

Regulatory T-cells (Tregs) are key players in successful pregnancy and their deficiencies are implicated in pregnancy complications such as preeclampsia (PE), but the results are inconsistent among studies. This study aims to compile an overview of the studies about the associations of Tregs and PE risk and to provide recommendations for future research. A sensitive search of three databases including PubMed, Scopus and Google scholar (from 1995 to January 9, 2015) identified 636 unique titles. An accurate process of study selection, data extraction and method qualification were independently conducted by authors on retrieved papers. Seventeen papers met the inclusion criteria and were included in quality assessment. Regarding the source of Tregs, 14 studies assessed Tregs in peripheral blood, 2 studies in peripheral blood and decidua and one study in peripheral blood and umbilical cord blood. Despite variation in the combinations of markers and other aspects of the studies designs, remarkable constancy in the results of studies that measured Tregs as CD4+FoxP3+ or CD4+CD25+FoxP3+ cells (but not CD4+CD25(high/low)FoxP3+ markers) was found, which in broad terms showed a shift towards fewer Treg cells in PE. This review revealed an association between lower percentage of circulating CD4+FoxP3+ or CD4+CD25+FoxP3+ Tregs and the risk of PE. Given the above issue and regarding the high consistency of studies on reduction of suppressive activity of Tregs in PE, we have proposed a model in which the Tregs deficiency is a reflection of immune endocrine imbalance, which reverses maternal tolerance and results in development of preeclampsia.

The Frequency of Peripheral Blood CD4+FoxP3+ Regulatory T Cells in Women With Pre-eclampsia and Those With High-risk Factors for Pre-eclampsia

OBJECTIVE

We compared the frequency of peripheral blood Treg cells in women with pre-eclampsia (PE) and in those without, and investigated whether the frequency of Treg cells in women with high-risk factor for PE changed during pregnancy.

METHODS

We examined the frequency of CD4⁺FoxP3⁺ Treg cells in the peripheral blood using flow cytometry. Eleven women with PE and 10 women without PE (controls) were included. Every control had any risk factors for PE, such as high blood pressure, bilateral notching or a past history of PE or gestational hypertension. Blood sampling was conducted 1-3 times in the controls.

RESULTS

No significant differences were observed in the frequency of Treg cells between women with PE and the controls [mean ± SE (%): 5.74 ± 0.91 versus 5.48 ± 0.94, p = 0.843]. In five controls with serial sampling, the frequency of Treg cells significantly decreased from 5.83 ± 1.20 to 2.99 ± 0.54 (p = 0.046) (week of the first sampling to that of the last sampling [mean ± SD]: 21.5 ± 1.6 weeks to 31.2 ± 2.5 weeks).

CONCLUSION

The frequency of Treg cells in women with PE was almost identical to that in the controls. The frequency of Treg cells in the controls was reduced by half from the second trimester to the third trimester. These results suggested that the levels of Treg cells in a high-risk pregnant cohort were decreased to those in women with PE in the third trimester irrespective of the occurrence of PE.

Maternal pre-eclampsia as a risk factor for necrotizing enterocolitis

OBJECTIVE

Similar pro-inflammatory responses are present in pre-eclampsia (PE) and necrotizing enterocolitis (NEC). We hypothesized that maternal PE is an independent risk factor for the development of NEC.

METHODS

A retrospective database of all live births (2008-2011) at a tertiary center was constructed. Infant and maternal characteristics were gathered. Babies born to mothers with or without PE were compared. Data were analyzed using Mann-Whitney U, Pearson's χ(2), binary logistic regression and relative risks.

RESULTS

Incidence of NEC was 1.5% in non-PE and 4.6% in the PE group (p < 0.001), but once controlled for gestational age and birth weight, the difference lost statistical significance. PE babies were more frequently preterm (41.4% versus 14.5%, p < 0.001) and had intrauterine growth restriction (IUGR) (10.2% versus 6.3%, p < 0.001). Within preterm babies, 9.0% of non-PE and 10.8% of PE babies developed NEC (p = 0.25). Effect of PE was significant in sub-group of IUGR babies, with NEC in 1.5% of non-PE and 13.6% in PE babies (p < 0.001).

CONCLUSIONS

Maternal PE is an independent risk factor for the development of NEC in some sub-groups of babies, most notably with IUGR. Fetal hypoxia caused by abnormal placentation in PE leads to restricted growth, and may be the underlying mechanism that predisposes the newborn to NEC.

An increased population of regulatory T cells improves the pathophysiology of placental ischemia in a rat model of preeclampsia

The reduced uterine perfusion pressure (RUPP) rat model of preeclampsia exhibits much of the pathology characterizing this disease, such as hypertension, inflammation, suppressed regulatory T cells (TRegs), reactive oxygen species (ROS), and autoantibodies to the ANG II type I receptor (AT1-AA) during pregnancy. The objective of this study was to determine whether supplementation of normal pregnant (NP) TRegs into RUPP rats would attenuate the pathophysiology associated with preeclampsia during pregnancy. CD4(+)/CD25(+) T cells were isolated from spleens of NP and RUPP rats, cultured, and injected into gestation day (GD) 12 normal pregnant rats that underwent the RUPP procedure on GD 14. On GD 1, mean arterial pressure (MAP) was recorded, and blood and tissues were collected for analysis. One-way ANOVA was used for statistical analysis. MAP increased from 99 ± 2 mmHg in NP (n = 12) to 127 ± 2 mmHg in RUPP (n = 21) but decreased to 118 ± 2 mmHg in RUPP+NP TRegs (n = 17). Circulating IL-6 and IL-10 were not significantly changed, while circulating TNF-α and IL-17 were significantly decreased after supplementation of TRegs. Placental and renal ROS were 339 ± 58.7 and 603 ± 88.1 RLU·min(-1)·mg(-1) in RUPP and significantly decreased to 178 ± 27.8 and 171 ± 55.6 RLU·min(-1)·mg(-1), respectively, in RUPP+NP TRegs; AT1-AA was 17.81 ± 1.1 beats per minute (bpm) in RUPP but was attenuated to 0.50 ± 0.3 bpm with NP TRegs. This study demonstrates that NP TRegs can significantly improve inflammatory mediators, such as IL-17, TNF-α, and AT1-AA, which have been shown to increase blood pressure during pregnancy.

Preeclampsia: long-term consequences for vascular health

Preeclampsia (PE) is a pregnancy-specific syndrome and one of the leading causes of preterm birth, neonatal and maternal morbidity and mortality. This disease is characterized by new onset hypertension usually in the third trimester of pregnancy and is sometimes associated with proteinuria, although proteinuria is not a requirement for the diagnosis of PE. In developing countries, women have a higher risk of death due to PE than more affluent countries and one of the most frequent causes of death is high blood pressure and stroke. Although PE only affects approximately 2%-8% of pregnancies worldwide it is associated with severe complications such as eclampsia, hemorrhagic stroke, hemolysis, elevated liver enzymes and low platelets (HELLP syndrome), renal failure and pulmonary edema. Importantly, there is no "cure" for the disease except for early delivery of the baby and placenta, leaving PE a health care risk for babies born from PE moms. In addition, PE is linked to the development of cardiovascular disease and stroke in women after reproductive age, leaving PE a risk factor for long-term health in women. This review will highlight factors implicated in the pathophysiology of PE that may contribute to long-term effects in women with preeclamptic pregnancies.