Inflammation and pregnancy: the role of the immune system at the implantation site

Altered Preconception Fatty Acid Intake Is Associated with Improved Pregnancy Rates in Overweight and Obese Women Undertaking in Vitro Fertilisation

Maternal preconception diet is proposed to affect fertility. Prior research assessing the effect of altering the fatty acid profile on female fertility is conflicting. The aim of this study was to assess the effect of preconception maternal diet, specifically fatty acid profile, on pregnancies and live births following in vitro fertilisation (IVF). Forty-six overweight and obese women undergoing IVF were randomised to a diet and physical activity intervention (intervention) or standard care (control). Outcome measures included pregnancy, live birth and pre-study dietary intake from food frequency questionnaire. Twenty pregnancies (n = 12/18 vs. n = 8/20, p = 0.12) and 12 live births (n = 7/18 vs. n = 5/20, p = 0.48) occurred following the intervention with no differences between the treatment groups. On analysis adjusted for BMI and smoking status, women who became pregnant had higher levels of polyunsaturated fatty acid (PUFA) intake (p = 0.03), specifically omega-6 PUFA and linoleic acid (LA) (p = 0.045) with a trend for an elevated intake of omega-3 PUFA (p = 0.06). There were no dietary differences for women who did or did not have a live birth. Maternal preconception PUFA, and specifically omega-6 and LA intake, are associated with improved pregnancy rates in overweight and obese women undergoing IVF. This has implications for optimising fertility through preconception nutrition.

Induction of Asherman's Syndrome in Rabbit

BACKGROUND

Uterine synechiae or Asherman's syndrome is a condition that can cause infertility. The present experimental study was designed to establish the rabbit as an animal model for human Asherman's syndrome using the endometrial curettage.

METHODS

In an experimental study, female adult rabbits (n=18) were randomly divided into intact and ovariectomized groups. One third of caudal part of both uteri was submitted to traumatic endometrial curettage. One group was simultaneously ovariectomized. The intact rabbits were artificially induced ovulation during 10 days after surgery. One third of cranial part of both uteri was selected as the control. Synechiae occurring, luminal area/total area (LA/TA), endometrial area/total area (EA/TA), myometrial and perimetrial area/total area (MPA/TA), endometrial area/uterine wall area (EA/UWA), and myometrial and perimetrial area/uterine wall area (MPA/UWA) ratios of both uteri in six subdivided groups (n=6) were analysed in curetted and intact control parts. On days 15, 30 and 45 following surgery by two-way ANOVA and LSD test (p<0.05).

RESULTS

Histopathologic findings showed significant epithelial damage together with significant inflammatory reaction in the intact curettage group. The LA/TA ratios of the intact curettage group on days 15 and 45 were more than the intact control group on day 15. The EA/TA ratio of the intact curettage group on day 30 was less than the intact control group on day 30.

CONCLUSION

Uterine fibrosis was observed in intact curettage group, and this modified animal model showed a pathogenesis condition similar to intrauterine adhesions observed in human.

Decidual vascular endothelial cells promote maternal-fetal immune tolerance by inducing regulatory T cells through canonical Notch1 signaling

Adaptation of the maternal immune response to accommodate the semiallogeneic fetus is necessary for pregnancy success. However, the mechanisms by which the fetus avoids rejection despite expression of paternal alloantigens remain incompletely understood. Regulatory T cells (Treg cells) are pivotal for maintaining immune homeostasis, preventing autoimmune disease and fetus rejection. In this study, we found that maternal decidual vascular endothelial cells (DVECs) sustained Foxp3 expression in resting Treg cells in vitro. Moreover, under in vitro Treg cell induction condition with agonistic antibodies and transforming growth factor (TGF)-β, DVECs promoted Treg cell differentiation from non-Treg conventional T cells. Consistent with the promotion of Treg cell maintenance and differentiation, Treg cell-associated gene expression such as TGF-β, Epstein-Barr-induced gene-3, CD39 and glucocorticoid-induced tumor necrosis factor receptor was also increased in the presence of DVECs. Further study revealed that DVECs expressed Notch ligands such as Jagged-1, Delta-like protein 1 (DLL-1) and DLL-4, while Treg cells expressed Notch1 on their surface. The effects of DVECs on Treg cells was inhibited by siRNA-induced knockdown of expression of Jagged-1 and DLL-1 in DVECs. Downregulation of Notch1 in Treg cells using lentiviral shRNA transduction decreased Foxp3 expression in Treg cells. Adoptive transfer of Notch1-deficient Treg cells increased abortion rate in a murine semiallogeneic pregnancy model. Taken together, our study suggests that maternal DVECs are able to maintain decidual Treg cell identity and promote Treg cell differentiation through activation of Notch1 signal pathway in Treg cells and subsequently inhibit the immune response against semiallogeneic fetuses and preventing spontaneous abortion.

Pregnancy-Induced Changes in Systemic Gene Expression among Healthy Women and Women with Rheumatoid Arthritis

Background

Pregnancy induces drastic biological changes systemically, and has a beneficial effect on some autoimmune conditions such as rheumatoid arthritis (RA). However, specific systemic changes that occur as a result of pregnancy have not been thoroughly examined in healthy women or women with RA. The goal of this study was to identify genes with expression patterns associated with pregnancy, compared to pre-pregnancy as baseline and determine whether those associations are modified by presence of RA.

Results

In our RNA sequencing (RNA-seq) dataset from 5 healthy women and 20 women with RA, normalized expression levels of 4,710 genes were significantly associated with pregnancy status (pre-pregnancy, first, second and third trimesters) over time, irrespective of presence of RA (False Discovery Rate (FDR)-adjusted p value<0.05). These genes were enriched in pathways spanning multiple systems, as would be expected during pregnancy. A subset of these genes (n = 256) showed greater than two-fold change in expression during pregnancy compared to baseline levels, with distinct temporal trends through pregnancy. Another 98 genes involved in various biological processes including immune regulation exhibited expression patterns that were differentially associated with pregnancy in the presence or absence of RA.

Conclusions

Our findings support the hypothesis that the maternal immune system plays an active role during pregnancy, and also provide insight into other systemic changes that occur in the maternal transcriptome during pregnancy compared to the pre-pregnancy state. Only a small proportion of genes modulated by pregnancy were influenced by presence of RA in our data.

Inflammatory and Epigenetic Pathways for Perinatal Depression

Depression during the perinatal period is common and can have adverse consequences for women and their children. Yet, the biobehavioral mechanisms underlying perinatal depression are not known. Adverse early life experiences increase the risk for adult depression. One potential mechanism by which this increased risk occurs is epigenetic embedding of inflammatory pathways. The purpose of this article is to propose a conceptual model that explicates the linkage between early life adversity and the risk for maternal depression. The model posits that early life adversity embeds a proinflammatory epigenetic signature (altered DNA methylation) that predisposes vulnerable women to depression during pregnancy and the postpartum period. As proposed, women with a history of early life adversity are more likely to exhibit higher levels of proinflammatory cytokines and lower levels of oxytocin in response to the demands of pregnancy and new motherhood, both of which are associated with the risk for perinatal depression. The model is designed to guide investigations into the biobehavioral basis for perinatal depression, with emphasis upon the impact of early life adversity. Testing this model will provide a better understanding of maternal depressive risk and improve identification of vulnerable women who would benefit from targeted interventions that can reduce the impact of perinatal depression on maternal–infant health.

Uterine blood flow indices, antinuclear autoantibodies and unexplained recurrent miscarriage

OBJECTIVE

To study the correlation between 2D and 3D uterine flow indexes and the presence or the absence of antinuclear antibodies (ANA) in women with unexplained recurrent miscarriage (uRM).

METHODS

Fifty-two subjects (26 uRM and 26 control women) underwent 2D Doppler measurement of pulsatility index and resistance index of the uterine arteries in both the follicular and midluteal phase of the cycle. Additionally, 3D ultrasonography determination of vascularisation index, flow index, and vascularisation flow index was carried out with the aid of the VOCAL technique. Serum assay for the presence of ANA was performed in all women.

RESULTS

Pulsatility index of ANA+ uRM women was higher than that of ANA- uRM women and control ANA+ and ANAwomen, both in the follicular and in the midluteal phase of the cycle. Vascularisation index in ANA- uRM women was significantly higher than that in ANA+ control women. Flow index in uRM ANA+ women was significantly lower than that of each of the other groups.

CONCLUSION

ANA might be involved in uRM by determining an impairment in uterine blood flow hemodynamic, particularly in uterine blood flow intensity and uterine artery impedance.

To serve and to protect: the role of decidual innate immune cells on human pregnancy

The maternal-fetal interface undergoes dynamic changes that promote successful development of the embryo/fetal allograft during pregnancy. This immune privilege of the conceptus is mediated through local and systemic cellular responses. In species in which endometrial decidualization accompanies pregnancy, unique immune cell niches are found. Many studies have addressed the enigmatic roles of uterine (u)NK cells as killers and helpers because they are frequently found in the uterine lining and decidua of normal and pathological pregnancies. Accumulating evidence indicates that uNK cells are induced and transformed by sensing signals within their microenvironment to both protect the mother from the fetal allograft and support the fetus during its development. Here, we review the mechanisms that modulate these functions of uNK cells during pregnancy. We suggest that uNK cells must be tightly regulated in order to serve these two roles and support a healthy pregnancy.

NLRP3 Deficiency Improves Angiotensin II-Induced Hypertension But Not Fetal Growth Restriction During Pregnancy

Preeclampsia is a pregnancy-specific syndrome characterized by elevated blood pressure, proteinuria, and intrauterine growth restriction (IUGR). Although sterile inflammation appears to be involved, its pathogenesis remains unclear. Recent evidence indicates that sterile inflammation is mediated through the nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3) inflammasomes, composed of NLRP3, apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC), and caspase-1. Here we investigated the role of the NLRP3 inflammasomes in the pathogenesis of preeclampsia using Nlrp3(-/-) and Asc(-/-) (Nlrp3 and Asc deficient) pregnant mice. During pregnancy in mice, continuous infusion of high-dose angiotensin II (AngII) induced hypertension, proteinuria, and IUGR, whereas infusion of low-dose AngII caused hypertension alone. AngII-induced hypertension was prevented in Nlrp3(-/-) mice but not in Asc(-/-), indicating that NLRP3 contributes to gestational hypertension independently of ASC-mediated inflammasomes. Although NLRP3 deficiency had no effect on IUGR, it restored the IL-6 up-regulation in the placenta and kidney of AngII-infused mice. Furthermore, treatment with hydralazine prevented the development of gestational hypertension but not IUGR or IL-6 expression in the placenta and kidney. These findings demonstrate that NLRP3 contributes to the development of gestational hypertension independently of the inflammasomes and that IUGR and kidney injury can occur independent of blood pressure elevation during pregnancy.

The value of eutherian-marsupial comparisons for understanding the function of glucocorticoids in female mammal reproduction

This article is part of a Special Issue "SBN 2014". Chronic stress is known to inhibit female reproductive function. Consequently, it is often assumed that glucocorticoid (GC) concentrations should be negatively correlated with reproductive success because of the role they play in stress physiology. In contrast, a growing body of evidence indicates that GCs play an active role in promoting reproductive function. It is precisely because GCs are so integral to the entire process that disruptions to adrenal activity have negative consequences for reproduction. The goal of this paper is to draw attention to the increasing evidence showing that increases in adrenal activity are important for healthy female reproduction. Furthermore, we outline several hypotheses about the functional role(s) that GCs may play in mediating reproduction and argue that comparative studies between eutherian and marsupial mammals, which exhibit some pronounced differences in reproductive physiology, may be particularly useful for testing different hypotheses about the functional role of GCs in reproduction. Much of our current thinking about GCs and reproduction comes from research involving stress-induced levels of GCs and has led to broad assumptions about the effects of GCs on reproduction. Unfortunately, this has left a gaping hole in our knowledge about basal GC levels and how they may influence reproductive function, thereby preventing a broader understanding of adrenal physiology and obscuring potential solutions for reproductive dysfunction.

The Relationship of Longitudinal Levels of Complement Bb During Pregnancy with Preeclampsia

PROBLEM

To determine the understudied relationship between complement Bb during pregnancy in subjects with preeclampsia compared with normotensive controls.

METHOD OF STUDY

Nested case-control study.

RESULTS

Average Bb levels significantly decreased over time in pregnancy [weekly slope (S.E.): -0.0094 (0.0005), P < 0.01]. Cross-sectionally, at less than 10 weeks, Bb levels decreased with increasing gestational age in women who remained normotensive [weekly slope (S.E.): -0.007 (0.02) and for women who developed preeclampsia (weekly slope (S.E.): -0.059 (0.03) P = 0.12]. Among women who developed preeclampsia, Bb levels were greatest when samples were drawn in the gestational window of 15-20 weeks [(weekly slope (S.E.): 0.06 (0.02)], while levels among normotensive women were inversely related with gestational age [weekly slope (S.E.): -0.02 (0.01)]. The differences in slopes between cases and controls between 10 and 21 weeks' gestation were statistically significant (P = 0.003).

CONCLUSIONS

We suggest dysregulation of Bb activation between 10 and 20 weeks' gestation in women who develop preeclampsia.

Vitamin D and Inflammatory Cytokines in Healthy and Preeclamptic Pregnancies

Preeclampsia is a pregnancy disease characterized by hypertension and proteinuria. Among several disorders, the imbalance of inflammatory cytokines and the alteration of vitamin D metabolism have been reported in preeclampsia. The effects of calcitriol upon inflammatory cytokines has been demonstrated. In healthy pregnant women there is a shift toward a Th2 cytokine profile, which is necessary for an adequate pregnancy outcome. As compared with normal pregnancy, high pro-inflammatory and low anti-inflammatory cytokine levels have been observed in preeclamptic women. Preeclampsia has been associated with low calcitriol levels and vitamin D deficiency is correlated with a higher risk of the development of this disease. It has been demonstrated that placenta is a source as well as the target of calcitriol and cytokines and placental dysfunction has been associated with preeclampsia. Therefore, the present manuscript includes a review about serum calcitriol levels in non-pregnant, pregnant, and preeclamptic women as well as a review on the fetoplacental vitamin D metabolism in healthy and preeclamptic pregnancies. In addition, circulating and fetoplacental inflammatory cytokines in healthy and preeclamptic pregnancies are reviewed. Finally, the effects of calcitriol upon placental pro-inflammatory cytokines are also explored. In conclusion, maternal and placental calcitriol levels are low in preeclampsia which may explain, at least in part, high pro-inflammatory cytokine levels in this disease.

Decreased mean platelet volume is associated with the developing stage of fetoplacental unit in spontaneous abortion

AIM

The aim was to evaluate the place of mean platelet volume (MPV) in predicting spontaneous miscarriage and to identify any differences in its values following miscarriage after biochemical and clinical pregnancy.

MATERIAL AND METHOD

We retrospectively evaluated the data of 305 spontaneous miscarriages and 168 control subjects. The miscarriage subjects were evaluated in two groups: miscarriage after biochemical pregnancy (n=79) (BA group) and miscarriage after clinical pregnancy (n=226) (CA group). Demographic and laboratory data of all subjects were statistically compared.

RESULTS

No statistically significant difference was found between the miscarriage and control subjects in terms of demographic data and Hb, Htc, WBC, and Plt values. The mean platelet volume (MPV) value in the miscarriage group (8.99±1.47 fl) was statistically significantly lower than in the control group (9.66±1.64 fl) (P<0.001). A statistically significant difference was present between the BA, CA and control group, with the lowest MPV value in the BA group (8.64±1.34 fl, 9.11±1.49 fl, and 9.66±1.64 fl, respectively) (P<0.001).

DISCUSSION

MPV was significantly lower in patients with miscarriage than the control group, and this was correlated with the gestational stage when the miscarriage occurred.

Probiotics in obstetrics and gynaecology

Despite the great advances in modern medicine, our understanding of the most basic function of our complete genetic makeup is extremely poor. Our complete genetic make up is complemented by 100 trillion cells living within or on our body and is called the microbiome. Manipulation of the microbiome is in the embryological stages of investigation but promises great hope in targeting both pregnancy specific and general medical / gynaecological conditions. This review presents an undertanding of the microbiome manipulation with probiotics in women's health in 2015.

Itaconic Acid: The Surprising Role of an Industrial Compound as a Mammalian Antimicrobial Metabolite

Itaconic acid is well known as a precursor for polymer synthesis and has been involved in industrial processes for decades. In a recent surprising discovery, itaconic acid was found to play a role as an immune-supportive metabolite in mammalian immune cells, where it is synthesized as an antimicrobial compound from the citric acid cycle intermediate cis-aconitic acid. Although the immune-responsive gene 1 protein (IRG1) has been associated to immune response without a mechanistic function, the critical link to itaconic acid production through an enzymatic function of this protein was only recently revealed. In this review, we highlight the history of itaconic acid as an industrial and antimicrobial compound, starting with its biotechnological synthesis and ending with its antimicrobial function in mammalian immune cells.

Inflammation in maternal obesity and gestational diabetes mellitus

BACKGROUND

The prevalence of maternal obesity is rising rapidly worldwide and constitutes a major obstetric problem, increasing mortality and morbidity in both mother and offspring. Obese women are predisposed to pregnancy complications such as gestational diabetes mellitus (GDM), and children of obese mothers are more likely to develop cardiovascular and metabolic disease in later life. Maternal obesity and GDM may be associated with a state of chronic, low-grade inflammation termed "metainflammation", as opposed to an acute inflammatory response. This inflammatory environment may be one mechanism by which offspring of obese women are programmed to develop adult disorders.

METHODS

Herein we review the evidence that maternal obesity and GDM are associated with changes in the maternal, fetal and placental inflammatory profile.

RESULTS

Maternal inflammation in obesity and GDM may not always be associated with fetal inflammation.

CONCLUSION

We propose that the placenta 'senses' and adapts to the maternal inflammatory environment, and plays a central role as both a target and producer of inflammatory mediators. In this manner, maternal obesity and GDM may indirectly program the fetus for later disease by influencing placental function.

Alkaline phosphatase protects lipopolysaccharide-induced early pregnancy defects in mice

Excessive cytokine inflammatory response due to chronic or superphysiological level of microbial infection during pregnancy leads to pregnancy complications such as early pregnancy defects/loss and preterm birth. Bacterial toxin lipopolysaccharide (LPS), long recognized as a potent proinflammatory mediator, has been identified as a risk factor for pregnancy complications. Alkaline phosphatase (AP) isozymes have been shown to detoxify LPS by dephosphorylation. In this study, we examined the role of alkaline phosphatase (AP) in mitigating LPS-induced early pregnancy complications in mice. We found that 1) the uterus prior to implantation and implantation sites following embryo implantation produce LPS recognition and dephosphorylation molecules TLR4 and tissue non-specific AP (TNAP) isozyme, respectively; 2) uterine TNAP isozyme dephosphorylates LPS at its sites of production; 3) while LPS administration following embryo implantation elicits proinflammatory cytokine mRNA levels at the embryo implantation sites (EISs) and causes early pregnancy loss, dephosphorylated LPS neither triggers proinflammatory cytokine mRNA levels at the EISs nor induces pregnancy complications; 4) AP isozyme supplementation to accelerate LPS detoxification attenuates LPS-induced pregnancy complications following embryo implantation. These findings suggest that a LPS dephosphorylation strategy using AP isozyme may have a unique therapeutic potential to mitigate LPS- or Gram-negative bacteria-induced pregnancy complications in at-risk women.

Morphological Changes and Expression of Cytokine After Local Endometrial Injury in a Mouse Model

OBJECTIVE

To establish a mouse model for endometrial injury and determine the underlying mechanism regarding its favorable effect on embryo implantation.

STUDY DESIGN

Female Kunming mice were randomly allocated into 4 groups: group I, normal control; group II, injury procedure control; and group III and group IV, the mice being scratched with a blunt syringe on the right uterine horn or both, respectively. All the mice were mated with the males during the next estrus phase. The number of implanted embryos on each side of uterus was calculated on day 8 of pregnancy. The endometrial samples were taken on day 4 of pregnancy, and the local morphological changes and cytokine expressions were examined.

RESULTS

Compared to group II, our results showed that in group IV (1) there were significantly higher numbers of implanted embryos, (2) the endometrial glands and vasculatures in stroma were obviously increased and the pinopodes were abundant and well developed, and (3) the local levels of cytokines leukemia inhibitory factor (LIF) and oncostatin M (OSM) messenger RNA and protein expression were significantly increased.

CONCLUSIONS

Local mechanical injury on mouse uteri enhanced endometrial receptivity and improved embryo implantation, which were correlated with the characteristic changes in endometrial morphology and the upregulation of LIF and OSM gene and protein expression.

Repeated implantation failure: a new potential treatment option

BACKGROUND

Previous studies have shown that the intrauterine administration of peripheral blood mononuclear cells (PBMC) may improve pregnancy outcome of women with repeated implantation failure (RIF). We have demonstrated that, during implantation, corticotropin-releasing hormone (CRH) plays a key role in facilitating endometrial decidualization and maternal-foetal immunotolerance. In the present preliminary study, we investigated whether the intrauterine administration of autologous CRH-treated PBMC can improve clinical pregnancy rates of women with RIF.

METHODS

Forty-five (n = 45) women with at least three failed in vitro fertilization (IVF) attempts and no previously reported clinical pregnancy were included in this crossover study. All women underwent controlled ovarian stimulation using the long GnRH agonist protocol. PBMC were isolated at day of oocyte retrieval, treated with CRH and administered in the uterine cavity at day 2, following oocyte retrieval. Blastocyst transfer was performed on day 5.

RESULTS

Following the CRH-PBMC intrauterine administration, a significant increase was observed in the clinical pregnancy rate of this cohort of women with RIF (20/45 women had a clinical pregnancy; 44.44%, P < 10(-3)) compared to the previous null clinical pregnancy rate prior to the intervention.

CONCLUSION

The current findings support a possible role for the intrauterine administration of autologous CRH-treated PBMC in treating women with RIF. Further randomized controlled trials are needed to investigate the efficacy of this intervention.

Activation of the transcription factor nuclear factor-kappa B in uterine luminal epithelial cells by interleukin 1 Beta 2: a novel interleukin 1 expressed by the elongating pig conceptus

Conceptus mortality is greatest in mammals during the peri-implantation period, a time when conceptuses appose and attach to the uterine surface epithelium while releasing proinflammatory molecules. Interleukin 1 beta (IL1B), a master proinflammatory cytokine, is released by the primate, rodent, and pig blastocyst during the peri-implantation period and is believed to be essential for establishment of pregnancy. The gene encoding IL1B has duplicated in the pig, resulting in a novel gene. Preliminary observations indicate that the novel IL1B is specifically expressed by pig conceptuses during the peri-implantation period. To verify this, IL1B was cloned from mRNA isolated from Day 12 pig conceptuses and compared with IL1B cloned from mRNA isolated from pig peripheral blood leukocytes (PBLs). The pig conceptuses, but not the PBLs, expressed a novel IL1B, referred to here as interleukin 1 beta 2 (IL1B2). Porcine endometrium was treated with recombinant porcine interleukin 1 beta 1 (IL1B1), the prototypical cytokine, and IL1B2 proteins. Immunohistochemistry and real-time RT-PCR were used to measure activation of nuclear factor-kappa B (NFKB) and NFKB-regulated transcripts, respectively, within the endometrium. Both IL1B1 and IL1B2 activated NFKB in the uterine luminal epithelium within 4 h. The NFKB activation and related gene expression, however, were lower in endometrium treated with IL1B2, suggesting that the conceptus-derived cytokine may have reduced activity within the uterus. In conclusion, the peri-implantation pig conceptus expresses a novel IL1B that can activate NFKB within the uterine surface epithelium, likely creating a proinflammatory microenvironment during establishment of pregnancy in the pig.

Do all roads lead to Rome? The role of neuro-immune interactions before birth in the programming of offspring obesity

The functions of the nervous system can be powerfully modulated by the immune system. Although traditionally considered to be quite separate, neuro-immune interactions are increasingly recognized as critical for both normal and pathological nervous system function in the adult. However, a growing body of information supports a critical role for neuro-immune interactions before birth, particularly in the prenatal programming of later-life neurobehavioral disease risk. This review will focus on maternal obesity, as it represents an environment of pathological immune system function during pregnancy that elevates offspring neurobehavioral disease risk. We will first delineate the normal role of the immune system during pregnancy, including the role of the placenta as both a barrier and relayer of inflammatory information between the maternal and fetal environments. This will be followed by the current exciting findings of how immuno-modulatory molecules may elevate offspring risk of neurobehavioral disease by altering brain development and, consequently, later life function. Finally, by drawing parallels with pregnancy complications other than obesity, we will suggest that aberrant immune activation, irrespective of its origin, may lead to neuro-immune interactions that otherwise would not exist in the developing brain. These interactions could conceivably derail normal brain development and/or later life function, and thereby elevate risk for obesity and other neurobehavioral disorders later in the offspring's life.

Stress and Immune Function during Pregnancy: An Emerging Focus in Mind-Body Medicine

Maternal psychosocial stress during pregnancy is associated with risks to maternal health, birth outcomes, as well as adverse health and behavioral outcomes in offspring. Maternal immune dysregulation, particularly disruption of inflammatory processes, is also implicated in adverse perinatal health outcomes, with the greatest evidence in relation to preterm birth. Increasingly, the extent to which psychosocial stress induces dysregulation of inflammatory processes during pregnancy is being considered. In this article, I describe studies linking stress to immune function during pregnancy, with an emphasis on studies from our group on inflammation. As will be reviewed, research utilizing psychoneuroimmunology models in pregnancy is a rapidly developing area with abundant opportunities to address questions of clinical relevance for both maternal and child health.

IRG1 induced by heme oxygenase-1/carbon monoxide inhibits LPS-mediated sepsis and pro-inflammatory cytokine production

The immunoresponsive gene 1 (IRG1) protein has crucial functions in embryonic implantation and neurodegeneration. IRG1 promotes endotoxin tolerance by increasing A20 expression in macrophages through reactive oxygen species (ROS). The cytoprotective protein heme oxygenase-1 (HO-1), which generates endogenous carbon monoxide (CO), is expressed in the lung during Lipopolysaccharide (LPS) tolerance and cross tolerance. However, the detailed molecular mechanisms and functional links between IRG1 and HO-1 in the innate immune system remain unknown. In the present study, we found that the CO releasing molecule-2 (CORM-2) and chemical inducers of HO-1 increased IRG1 expression in a time- and dose-dependent fashion in RAW264.7 cells. Furthermore, inhibition of HO-1 activity by zinc protoporphyrin IX (ZnPP) and HO-1 siRNA significantly reduced expression of IRG1 under these conditions. In addition, treatment with CO and HO-1 induction significantly increased A20 expression, which was reversed by ZnPP and HO-1 siRNA. LPS-stimulated TNF-α was significantly decreased, whereas IRG1 and A20 were increased by CORM-2 application and HO-1 induction, which in turn were abrogated by ZnPP. Interestingly, siRNA against IRG1 and A20 reversed the effects of CO and HO-1 on LPS-stimulated TNF-α production. Additionally, CO and HO-1 inducers significantly increased IRG1 and A20 expression and downregulated TNF-α production in a LPS-stimulated sepsis mice model. Furthermore, the effects of CO and HO-1 on TNF-α production were significantly reversed when ZnPP was administered. In conclusion, CO and HO-1 induction regulates IRG1 and A20 expression, leading to inhibition of inflammation in vitro and in an in vivo mice model.

Progestin-Containing Contraceptives Alter Expression of Host Defense-Related Genes of the Endometrium and Cervix

Epidemiological studies indicate that progestin-containing contraceptives increase susceptibility to HIV, although the underlying mechanisms involving the upper female reproductive tract are undefined. To determine the effects of depot medroxyprogesterone acetate (DMPA) and the levonorgestrel intrauterine system (LNG-IUS) on gene expression and physiology of human endometrial and cervical transformation zone (TZ), microarray analyses were performed on whole tissue biopsies. In endometrium, activated pathways included leukocyte chemotaxis, attachment, and inflammation in DMPA and LNG-IUS users, and individual genes included pattern recognition receptors, complement components, and other immune mediators. In cervical TZ, progestin treatment altered expression of tissue remodeling and viability but not immune function genes. Together, these results indicate that progestins influence expression of immune-related genes in endometrium relevant to local recruitment of HIV target cells with potential to increase susceptibility and underscore the importance of the upper reproductive tract when assessing the safety of contraceptive products.

The contribution of the maternal immune system to the establishment of pregnancy in cattle

Immune cells play an integral role in affecting successful reproductive function. Indeed, disturbed or aberrant immune function has been identified as primary mechanisms behind infertility. In contrast to the extensive body of literature that exists for human and mouse, studies detailing the immunological interaction between the embryo and the maternal endometrium are quite few in cattle. Nevertheless, by reviewing the existing studies and extrapolating from sheep, pig, mouse, and human data, we can draw a reasonably comprehensive picture. Key contributions of immune cell populations include granulocyte involvement in follicle differentiation and gamete transfer, monocyte invasion of the peri-ovulatory follicle and their subsequent role in corpus luteum formation and the pivotal roles of maternal macrophage and dendritic cells in key steps of the establishment of pregnancy, particularly, the maternal immune response to the embryo. These contributions are reviewed in detail below and key findings are discussed.

Intrauterine insemination of cultured peripheral blood mononuclear cells prior to embryo transfer improves clinical outcome for patients with repeated implantation failures

Implantation failure is a major limiting factor in assisted reproduction improvement. Dysfunction of embryo–maternal immuno-tolerance pathways may be responsible for repeated implantation failures. This fact is supported by immunotropic theory stipulating that maternal immune cells, essentially uterine CD56+ natural killer cells, are determinants of implantation success. In order to test this hypothesis, we applied endometrium immuno-modulation prior to fresh embryo transfer for patients with repeated implantation failures. Peripheral blood mononuclear cells were isolated from repeated implantation failure patients undergoing assisted reproductive technology cycles. On the day of ovulation induction, cells were isolated and then cultured for 3 days and transferred into the endometrium cavity prior to fresh embryo transfer. This immunotherapy was performed on 27 patients with repeated implantation failures and compared with another 27 patients who served as controls. Implantation and clinical pregnancy were increased significantly in the peripheral blood mononuclear cell test versus control (21.54, 44.44 vs. 8.62, 14.81%). This finding suggests a clear role for endometrium immuno-modulation and the inflammation process in implantation success. Our study showed the feasibility of intrauterine administration of autologous peripheral blood mononuclear cells as an effective therapy to improve clinical outcomes for patients with repeated implantation failures and who are undergoing in vitro fertilization cycles.

The balancing act - PPAR-γ's roles at the maternal-fetal interface

Peroxisome proliferator-activated receptor-gamma (PPAR-γ) belongs to the nuclear hormone receptor superfamily. Apart from being involved in lipid metabolism, like its other subtypes PPAR α and β, it is implicated to be crucial for successful placentation. While its role in extravillous trophoblast (EVT) differentiation has been studied, the involvement in villous trophoblast (VT) differentiation, fatty-acid metabolism, inflammatory responses, and oxidative pathways during pregnancy deserves more attention. PPAR-γ's potential role in balancing structural development and functional responsibilities at the maternal-fetal interface suggest a more central role for the receptor. The central role of PPAR-γ in pathways related to placental pathologies suggests a potential role of PPAR-γ in placental function. The molecular regulation of PPAR-γ in this context has been widely disregarded. In this review, we discuss the less explored functions of PPAR-γ in the areas of immunological responses and management of oxidative stress in the placenta. We also shed light on the involvement of PPAR-γ in pathologic pregnancies and briefly discuss the current models in the field. The ability to modulate PPAR-γ's activity using already available drugs makes it a tempting therapeutic target. Elucidation of the molecular pathways and specific targets regulated by PPAR-γ will provide more information on the role of PPAR-γ in placentation and related disorders in pregnancy. Furthermore it will close the critical gap in our knowledge about the differential regulation of PPAR-γ in the two trophoblast lineages. This will help to evaluate the usefulness and timing of PPAR-γ modulation in at risk pregnancies to improve placental and endothelial function.

Longitudinal changes in serum proinflammatory markers across pregnancy and postpartum: effects of maternal body mass index

BACKGROUND

The maternal immune system undergoes substantial changes to support healthy pregnancy. Although obesity is a primary driver of inflammation and predictive of perinatal complications, additive effects of pregnancy and obesity on changes in inflammatory processes are not well delineated.

METHODS

This study examined serum proinflammatory markers interleukin(IL)-6, IL-8, tumor necrosis factor (TNF)-α, IL-1β, and C-reactive protein (CRP) during each trimester of pregnancy and 4-6 weeks postpartum among 57 women.

RESULTS

Overall, IL-6 showed an increasing trend across pregnancy and significant increase at postpartum. Similarly, TNF-α increased significantly across gestation, with a further increase at postpartum. Both IL-8 and IL-1β showed a U-shaped curve, decreasing from early to later pregnancy, and increasing at postpartum. Finally, serum CRP decreased significantly across pregnancy, with further decreases at postpartum. Maternal obesity predicted higher IL-6 at each study visit. Obese women showed a trend toward elevated serum CRP during pregnancy, and significantly higher levels at postpartum.

DISCUSSION

The course of pregnancy and postpartum is characterized by significant changes in serum proinflammatory mediators. Obese women show elevations in serum proinflammatory markers relative to normal weight women during pregnancy and postpartum. Further research is needed to determine the extent to which obesity-induced inflammation affects maternal and fetal health.

M1/M2 macrophage polarity in normal and complicated pregnancy

Tissue macrophages play an important role in all stages of pregnancy, including uterine stromal remodeling (decidualization) before embryo implantation, parturition, and post-partum uterine involution. The activation state and function of utero-placental macrophages are largely dependent on the local tissue microenvironment. Thus, macrophages are involved in a variety of activities such as regulation of immune cell activities, placental cell invasion, angiogenesis, and tissue remodeling. Disruption of the uterine microenvironment, particularly during the early stages of pregnancy (decidualization, implantation, and placentation) can have profound effects on macrophage activity and subsequently impact pregnancy outcome. In this review, we will provide an overview of the temporal and spatial regulation of utero-placental macrophage activation during normal pregnancy in human beings and rodents with a focus on more recent findings. We will also discuss the role of M1/M2 dysregulation within the intrauterine environment during adverse pregnancy outcomes.

A clear and present danger: inflammasomes DAMPing down disorders of pregnancy

BACKGROUND

When the normal progression of pregnancy is threatened, inflammatory processes are often amplified in order to minimize detrimental effects and eliminate noxious agents. Inflammasomes are unique, intracellular, multiprotein assemblies that enable caspase-1 mediated proteolytic processing of the proinflammatory cytokine interleukin-1β, levels of which are elevated in some forms of preterm birth and maternal metabolic disorders.

METHODS

A comprehensive review based on a search of PubMed and Medline for terms and combinations of terms incorporating 'inflammation', 'inflammasome', 'pregnancy', 'preterm birth', 'pre-eclampsia', 'interleukin-1', 'caspase-1' and others selected to capture key articles.

RESULTS

In the decade since the discovery of the inflammasome, between January 2002 and June 2014 over 2200 articles have been published. Articles in the reproductive field are scarce but there is clear evidence for a role of the inflammasome axis in pregnancy, preterm birth and the maternal metabolic syndrome.

CONCLUSION

Further investigations on the inflammasome in pregnancy are needed in order to elucidate the biology of this unique structure in reproduction. Coordination of maternal, fetal and placental aspects of inflammasome function will potentially yield new information on the detection and transduction of host and non-host signals in the inflammatory response.

In vivo experiments reveal the good, the bad and the ugly faces of sFlt-1 in pregnancy

Objective

Soluble fms-like tyrosine kinase (sFlt)-1-e15a, a primate-specific sFlt-1-isoform most abundant in the human placenta in preeclampsia, can induce preeclampsia in mice. This study compared the effects of full-length human (h)sFlt-1-e15a with those of truncated mouse (m)sFlt-1(1-3) used in previous preeclampsia studies on pregnancy outcome and clinical symptoms in preeclampsia.

Methods

Mice were injected with adenoviruses or fiber-mutant adenoviruses overexpressing hsFlt-1-e15a, msFlt-1(1-3) or control GFP under the CMV or CYP19A1 promoters on gestational day 8 (GD8) and GD11. Placentas and pups were delivered by cesarean section, and dams were monitored postpartum. Blood pressure was telemetrically recorded. Urine samples were collected with cystocentesis and examined for albumin/creatinine ratios. Tissue specimens were evaluated for transgene as well as endogenous mFlt-1 and msFlt-1-i13 expression. H&E-, Jones- and PAS-stained kidney sections were histopathologically examined. Placental GFP expression and aortic ring assays were investigated with confocal microscopy.

Results

Mean arterial blood pressure (MAP) was elevated before delivery in hsFlt-1-e15a-treated mice compared to controls (GD18: ΔMAP = 7.8 mmHg, p = 0.009), while ΔMAP was 12.8 mmHg (GD18, p = 0.005) in msFlt-1(1-3)-treated mice. Urine albumin/creatinine ratio was higher in hsFlt-1-e15a-treated mice than in controls (GD18, p = 0.04; PPD8, p = 0.03), and msFlt-1(1-3)-treated mice had marked proteinuria postpartum (PPD8, p = 4×10⁻⁵). Focal glomerular changes were detected in hsFlt-1-e15a and msFlt-1(1-3)-treated mice. Aortic ring microvessel outgrowth was decreased in hsFlt-1-e15a (p = 0.007) and msFlt-1(1-3)-treated (p = 0.02) mice. Full-length msFlt-1-i13 expression was unique for the placenta. In hsFlt-1-e15a-treated mice, the number of pups (p = 0.046), total weight of living pups (p = 0.04) and maternal weights (p = 0.04) were higher than in controls. These differences were not observed in truncated msFlt-1(1-3)-treated mice.

Conclusions

Truncated msFlt-1(1-3) simulated the preeclampsia-promoting effects of full-length hsFlt-1. MsFlt-1(1-3) had strong effect on maternal endothelium but not on placentas and embryos. In contrast, hsFlt-1-e15a induced preeclampsia-like symptoms; however, it also increased litter size. In accord with the predominant placental expression of hsFlt-1-e15a and msFlt-1-i13, full-length sFlt-1 may have a role in the regulation of embryonic development. These observations point to the difference in the biological effects of full-length and truncated sFlt-1 and the changes in the effect of full-length sFlt-1 during pregnancy, and may have important implications in the management of preeclampsia.

Undernutrition, the acute phase response to infection, and its effects on micronutrient status indicators

Infection and undernutrition are prevalent in developing countries and demonstrate a synergistic relation. Undernutrition increases infection-related morbidity and mortality. The acute phase response (APR) is an innate, systemic inflammatory reaction to a wide array of disruptions in a host's homeostasis, including infection. Released from immune cells in response to deleterious stimuli, proinflammatory cytokines act on distant tissues to induce behavioral (e.g., anorexia, weakness, and fatigue) and systemic effects of the APR. Cytokines act to increase energy and protein requirements to manifest fever and support hepatic acute phase protein (APP) production. Blood concentrations of glucose and lipid are augmented to provide energy to immune cells in response to cytokines. Additionally, infection decreases intestinal absorption of nutrients and can cause direct loss of micronutrients. Traditional indicators of iron, zinc, and vitamin A status are altered during the APR, leading to inaccurate estimations of deficiency in populations with a high or unknown prevalence of infection. Blood concentrations of APPs can be measured in nutrition interventions to assess the time stage and severity of infection and correct for the APR; however, standardized cutoffs for nutrition applications are needed. Protein-energy malnutrition leads to increased gut permeability to pathogens, abnormal immune cell populations, and impaired APP response. Micronutrient deficiencies cause specific immune impairments that affect both innate and adaptive responses. This review describes the antagonistic interaction between the APR and nutritional status and emphasizes the need for integrated interventions to address undernutrition and to reduce disease burden in developing countries.

Ultrastructure alteration of decidual natural killer cells in women with unexplained recurrent miscarriage: a possible association with impaired decidual vascular remodelling

This study aimed to evaluate the extent of remodelling of intra-decidual segments of the spiral arteries in human deciduas between the 6th and 10th gestational weeks in women with unexplained recurrent miscarriages (RM) in comparison to gestational-matched controls. A possible association with the number, immunoexpressive behaviour and ultrastructural changes of decidual natural killer cells (dNKCs) was investigated. Decidual biopsies were obtained from RM cases (n = 40) and women with no history of spontaneous miscarriage and at least one live birth at term (n = 30). Staining was performed using PAS, anti-CD34 and anti-CD56 antibodies, using an avidin-biotin-peroxides technique. Analysis by means of light and transmission electron microscopy was employed. To determine the extent of remodelling of decidual vessels, a quantitative score was analysed using histological criteria of vascular transformation and then related to the number of CD56(+) dNKCs. In RM, dNKCs were distributed among decidual cells and around the vessels. They possessed numerous polyploidic protrusions on cell membranes crossing from one cell to another. The cells became more irregular and exhibited heterogeneous electron-dense granules in their cytoplasm compared to controls. The non-remodelling score and number of dNKCs were significantly increased in RM group (p < 0.001). The number of dNKCs was significantly correlated with the scores in both control (r = 0.491; p = 0.006) and RM (r = 0.852; p < 0.001) groups. It appears that dNKCs play a key role in impaired decidual artery remodelling that may be involved with early RM. This may be due to increased numbers of cells or impaired cellular interactions resulting from alterations to the ultrastructure.

Maternal inflammation at delivery affects assessment of maternal iron status

Pregnant adolescents (aged ≤ 18 y, n = 253) were followed from ≥ 12 wk of gestation to delivery to assess longitudinal changes in anemia and iron status and to explore associations between iron status indicators, hepcidin, and inflammatory markers. Hemoglobin, soluble transferrin receptor (sTfR), ferritin, serum iron, erythropoietin (EPO), hepcidin, C-reactive protein, interleukin-6 (IL-6), folate, and vitamin B-12 were measured, and total body iron (TBI) (milligrams per kilogram) was calculated using sTfR and ferritin values. Anemia prevalence increased from trimesters 1 and 2 (3-5%, <28 wk) to trimester 3 (25%, 33.2 ± 3.7 wk, P < 0.0001). The prevalence of iron deficiency (sTfR > 8.5 mg/L) doubled from pregnancy to delivery (7% to 14%, P = 0.04). Ferritin and hepcidin concentrations at delivery may have been elevated as a consequence of inflammation because IL-6 concentrations at delivery were 1.6-fold higher than those obtained at 26.1 ± 3.3 wk of gestation (P < 0.0001), and a positive association was found between IL-6 and both hepcidin and ferritin at delivery (P < 0.01). EPO was consistently correlated with hemoglobin (r = -0.36 and -0.43, P < 0.001), ferritin (r = -0.37 and -0.32, P < 0.0001), sTfR (r = 0.35 and 0.25, P < 0.001), TBI (r = -0.44 and -0.37, P < 0.0001), and serum iron (r = -0.22 and -0.16, P < 0.05) at mid-gestation and at delivery, respectively. EPO alone explained the largest proportion of variance in hemoglobin at 26.0 ± 3.3 wk of gestation (R(2) = 0.13, P = 0.0001, n = 113) and at delivery (R(2) = 0.19, P < 0.0001, n = 192). Pregnant adolescents are at high risk of anemia. EPO is a sensitive indicator of iron status across gestation, is not affected by systemic inflammation, and may better predict risk of anemia at term. The trial was registered at clinicaltrials.gov as NCT01019902.

Rapamycin and everolimus facilitate hepatitis E virus replication: revealing a basal defense mechanism of PI3K-PKB-mTOR pathway

BACKGROUND & AIMS

Humans are frequently exposed to hepatitis E virus (HEV). Nevertheless, the disease mainly affects pregnant women and immunocompromised individuals. Organ recipients receiving immunosuppressants, such as rapalogs, to prevent rejection have a high risk for developing chronic hepatitis following HEV infection. Rapalogs constitute potent inhibitors of mTOR including rapamycin and everolimus. As a master kinase, the mechanism-of-action of mTOR is not only associated with the immunosuppressive capacity of rapalogs but is also tightly regulated during pregnancy because of increased nutritional demands.

METHODS

We thus investigated the role of mTOR in HEV infection by using two state-of-the-art cell culture models: a subgenomic HEV containing luciferase reporter and a full-length HEV infectious cell culture system.

RESULTS

In both subgenomic and full-length HEV models, HEV infection was aggressively escalated by treatment of rapamycin or everolimus. Inhibition of mTOR was confirmed by Western blot showing the inhibition of its downstream target, S6 phosphorylation. Consistently, stable silencing of mTOR by lentiviral RNAi resulted in a significant increase in intracellular HEV RNA, suggesting an antiviral function of mTOR in HEV infection. By targeting a series of other up- and downstream elements of mTOR signaling, we further revealed an effective basal defense mechanism of the PI3K-PKB-mTOR pathway against HEV, which is through the phosphorylated eIF4E-binding protein 1 (4E-BP1), however independent of autophagy formation.

CONCLUSIONS

The discovery that PI3K-PKB-mTOR pathway limits HEV infection through 4E-BP1 and acts as a gate-keeper in human HEV target cells bears significant implications in managing immunosuppression in HEV-infected organ transplantation recipients.

Global ablation of the mouse Rab11a gene impairs early embryogenesis and matrix metalloproteinase secretion

Rab11a has been conceived as a prominent regulatory component of the recycling endosome, which acts as a nexus in the endo- and exocytotic networks. The precise in vivo role of Rab11a in mouse embryonic development is unknown. We globally ablated Rab11a and examined the phenotypic and molecular outcomes in Rab11a(null) blastocysts and mouse embryonic fibroblasts. Using multiple trafficking assays and complementation analyses, we determined, among multiple important membrane-associated and soluble cargos, the critical contribution of Rab11a vesicular traffic to the secretion of multiple soluble MMPs. Rab11a(null) embryos were able to properly form normal blastocysts but died at peri-implantation stages. Our data suggest that Rab11a critically controls mouse blastocyst development and soluble matrix metalloproteinase secretion.

Cross-species transcriptomic approach reveals genes in hamster implantation sites

The mouse model has greatly contributed to understanding molecular mechanisms involved in the regulation of progesterone (P4) plus estrogen (E)-dependent blastocyst implantation process. However, little is known about contributory molecular mechanisms of the P4-only-dependent blastocyst implantation process that occurs in species such as hamsters, guineapigs, rabbits, pigs, rhesus monkeys, and perhaps humans. We used the hamster as a model of P4-only-dependent blastocyst implantation and carried out cross-species microarray (CSM) analyses to reveal differentially expressed genes at the blastocyst implantation site (BIS), in order to advance the understanding of molecular mechanisms of implantation. Upregulation of 112 genes and downregulation of 77 genes at the BIS were identified using a mouse microarray platform, while use of the human microarray revealed 62 up- and 38 down-regulated genes at the BIS. Excitingly, a sizable number of genes (30 up- and 11 down-regulated genes) were identified as a shared pool by both CSMs. Real-time RT-PCR and in situ hybridization validated the expression patterns of several up- and down-regulated genes identified by both CSMs at the hamster and mouse BIS to demonstrate the merit of CSM findings across species, in addition to revealing genes specific to hamsters. Functional annotation analysis found that genes involved in the spliceosome, proteasome, and ubiquination pathways are enriched at the hamster BIS, while genes associated with tight junction, SAPK/JNK signaling, and PPARα/RXRα signalings are repressed at the BIS. Overall, this study provides a pool of genes and evidence of their participation in up- and down-regulated cellular functions/pathways at the hamster BIS.

Relationships among prenatal depression, plasma cortisol, and inflammatory cytokines

A secondary pilot study was carried out as part of a larger parent study of thyroid function in pregnancy and postpartum. All women in the parent study (N = 631) had blood samples, demographic data, and measures of perceived stress and dysphoric moods collected between 16 and 26 weeks' gestation. The current study was completed with a subset of 105 pregnant women to examine the relationships among perceived stress, depression, plasma cortisol, and cytokines during the second trimester of pregnancy. Stress was measured using Cohen's Perceived Stress Scale and dysphoric moods using the Profile of Mood States Depression/Dejection Scale. Cytokines were measured by a 12-plex analysis on a Luminex-200, and cortisol was measured by enzyme-linked immunosorbent assay on stored plasma samples. Stress and depression scores were highly correlated, and depressive symptoms were inversely correlated with 3 of the 12 cytokines: interleukin (IL)-1β, tumor necrosis factor (TNF)-α, and IL-7. Cortisol was inversely correlated with proinflammatory cytokines (IL-1β and TNF-α) and anti-inflammatory cytokines (IL-4, IL-5, IL-10, and IL-13). These data support the new conceptualizations of normal pregnancy as an inflammatory state that is carefully regulated, as both excessive and inadequate inflammation are potentially hazardous to the health of the pregnancy and fetus.

B cell development undergoes profound modifications and adaptations during pregnancy in mice

Pregnancy hides an immunological riddle combining two antagonistic characteristics of immunology: the existence of a tolerance that allows the gestation of a semiallogeneic fetus and proper protection against pathogens threatening the health of the immunocompromised mother. Despite the fundamental role that B cells play in orchestrating an immune response, their behavior in the context of pregnancy has been barely investigated. Here we demonstrate that numbers of pre/pro and immature B cells were progressively diminished in the bone marrow (BM) of pregnant mice, leading to a reduced influx of B cells in blood and spleen. Correspondingly, lower levels of B cell-activating factor of the TNF family were observed in serum of pregnant mice. In contrast to immature B cells, mature B cells were accumulated in the BM during pregnancy. Accordingly, higher numbers of mature B cells were observed in the lymph nodes draining the uterus as well as in the peritoneal cavity of pregnant mice, both tissues in close contact with the fetuses. Despite an increase in spleen size, pregnant mice showed lower numbers of splenic B cells, which was mirrored by lower numbers of immature and FO B cells. However, marginal zone B cells in the spleen increased during pregnancy. Additionally, serum IgM, IgA, and IgG3 titers were elevated in pregnant mice. Collectively, our data show how the B cell compartment adapts to the presence of the semiallogeneic fetus during gravidity.

Trophoblast induces monocyte differentiation into CD14+/CD16+ macrophages

PROBLEM

During early pregnancy, macrophages and trophoblast come into close contact during placenta development, and regulated cross talk between these cellular compartments is crucial for maintaining a healthy pregnancy. As trophoblast cells constitutively secrete many chemokines and cytokines, we hypothesize that trophoblast-secreted factors can differentiate monocytes into a decidual phenotype. In this study, we describe a unique macrophage phenotype, following monocytes' exposure to trophoblast-soluble factors.

METHOD OF STUDY

Peripheral blood monocytes were treated with or without conditioned media (CM) from first trimester trophoblast cells. Phenotypic changes and phagocytic capacity were determined by flow cytometry. Cytokine and chemokine production was determined by multiplex analysis.

RESULTS

Monocytes exposed to trophoblast factors undergo morphologic changes characterized by a gain in size and complexity and acquire a unique phenotype characterized by gain of CD14 surface expression as well as CD16. The presence of CD14+/CD16+ macrophages was confirmed in normal decidua. These cells secrete higher levels of IL-1b, IL-10, and IP-10 and have increased capacity for phagocytosis.

CONCLUSION

We demonstrate that trophoblast-secreted factors can induce monocyte differentiation into a unique macrophage phenotype. These findings suggest that the microenvironment of the placenta can modulate the phenotype of macrophages present at the decidua.

Regulatory T-cells in pregnancy: historical perspective, state of the art, and burning questions

In this review, we first revisit the original concept of "suppressor T-cells" in pregnancy, put it in a historical perspective, and then highlight the main data that licensed its resurrection and revision into the concept of "regulatory T-cells" (Tregs) in pregnancy. We review the evidence for a major role of Tregs in murine and human pregnancy and discuss Treg interactions with dendritic and uterine natural killer cells, other players of maternal-fetal tolerance. Finally, we highlight what we consider as the most important questions in the field.

Preterm birth and its long-term effects: methylation to mechanisms

The epigenetic patterns established during development may influence gene expression over a lifetime and increase susceptibility to chronic disease. Being born preterm (<37 weeks of gestation) is associated with increased risk mortality and morbidity from birth until adulthood. This brief review explores the potential role of DNA methylation in preterm birth (PTB) and its possible long-term consequences and provides an overview of the physiological processes central to PTB and recent DNA methylation studies of PTB.

Placental Protein 13 (PP13) - A Placental Immunoregulatory Galectin Protecting Pregnancy

Galectins are glycan-binding proteins that regulate innate and adaptive immune responses, and some confer maternal-fetal immune tolerance in eutherian mammals. A chromosome 19 cluster of galectins has emerged in anthropoid primates, species with deep placentation and long gestation. Three of the five human cluster galectins are solely expressed in the placenta, where they may confer additional immunoregulatory functions to enable deep placentation. One of these is galectin-13, also known as Placental Protein 13 (PP13). It has a "jelly-roll" fold, carbohydrate-recognition domain and sugar-binding preference resembling other mammalian galectins. PP13 is predominantly expressed by the syncytiotrophoblast and released from the placenta into the maternal circulation. Its ability to induce apoptosis of activated T cells in vitro, and to divert and kill T cells as well as macrophages in the maternal decidua in situ, suggests important immune functions. Indeed, mutations in the promoter and an exon of LGALS13 presumably leading to altered or non-functional protein expression are associated with a higher frequency of preeclampsia and other obstetrical syndromes, which involve immune dysregulation. Moreover, decreased placental expression of PP13 and its low concentrations in first trimester maternal sera are associated with elevated risk of preeclampsia. Indeed, PP13 turned to be a good early biomarker to assess maternal risk for the subsequent development of pregnancy complications caused by impaired placentation. Due to the ischemic placental stress in preterm preeclampsia, there is increased trophoblastic shedding of PP13 immunopositive microvesicles starting in the second trimester, which leads to high maternal blood PP13 concentrations. Our meta-analysis suggests that this phenomenon may enable the potential use of PP13 in directing patient management near to or at the time of delivery. Recent findings on the beneficial effects of PP13 on decreasing blood pressure due to vasodilatation in pregnant animals suggest its therapeutic potential in preeclampsia.

Profile of IL-2, IL-4, IL-10, IFN- ? , TNF- ? and KC-like cytokines in pregnant bitches

The aim of this study was to determine the profile of IL-2, IL-4, IL-10, IFN-γ, and TNF-α cytokines and KC-like cells (natural killer) in pregnant bitches, unpublished values for the species. A total of 27 females of the Shi Tzu, Pug, English Bulldog and French breeds, weighing 4-20kg and aged 4-6 years were used. Blood samples were collected from bitches during the anestrous and on the 2nd, 5th, 6th, 7th and 8th week of pregnancy. Serum levels of cytokines were measured by panel MILLIPLEX MAP (CCYTO-90K, MILLIPORE, Billerica, Massachusetts, USA) validated for dogs. Twenty four females showed physiological pregnancy and three bitches showed pathological pregnancy. There was no difference between cytokine values during anestrous and gestational weeks of bitches (P>0.05). However, it was possible to verify the physiological behavior of serum levels during modulation of immune response in the gestational process of animals. In animals with gestational disorders, abnormal values for IL-2, IL-4 and INF-y were noted. It was concluded that serum levels of cytokines evaluated in pregnant bitches can help the better understanding of physiological and pathological gestational processes and correlated immunology in this species.