Th1/Th2/Th17 and regulatory T-cell paradigm in pregnancy

Differences in human birth weight and corollary attributes as a result of temperature regime

BACKGROUND

Birth weight (BW) is an important attribute of human populations affecting post-natal mortality and later life morbidity, such as diabetes and reduced cognitive skills. BW is influenced by many factors, whereof temperature regime represents an important factor.

METHODS

By applying a generalized linear model, the impact of temperatures, altitude, nutrition, age at motherhood and other potential causes for BW variation were evaluated in more than 60 countries worldwide. National IQ scores were analysed in the same model.

RESULTS

This study identified a model explaining 2/3 of the global variation in BW. This model suggests that BW will decrease by 0.44-1.05% per °C increase in temperature under projected climate change. National IQ scores revealed a close relationship between IQ and BW. However, the model of IQ variation did not appear robust when challenged with variables not correlated with BW.

CONCLUSION

Climate change will affect BW, but it cannot be assumed that other human attributes such as IQ will change because (i) BW, in mainly being sensitive to intra-uterine conditions in the last quarter of pregnancy, is a poor predictor of intra-uterine conditions as such and (ii) developmental plasticity may require post-natal stimuli to unfold.

Aberrant Pregnancy Adaptations in the Peripheral Immune Response in Type 1 Diabetes: A Rat Model

Introduction

Despite tight glycemic control, pregnancy complication rate in type 1 diabetes patients is higher than in normal pregnancy. Other etiological factors may be responsible for the development of adverse pregnancy outcome. Acceptance of the semi-allogeneic fetus is accompanied by adaptations in the maternal immune-response. Maladaptations of the immune-response has been shown to contribute to pregnancy complications. We hypothesized that type 1 diabetes, as an autoimmune disease, may be associated with maladaptations of the immune-response to pregnancy, possibly resulting in pregnancy complications.

Methods

We studied pregnancy outcome and pregnancy-induced immunological adaptations in a normoglycemic rat-model of type 1 diabetes, i.e. biobreeding diabetes-prone rats (BBDP; 5 non-pregnant rats, 7 pregnant day 10 rats and 6 pregnant day 18 rats) , versus non-diabetic control rats (i.e. congenic non-diabetic biobreeding diabetes-resistant (BBDR; 6 non-pregnant rats, 6 pregnant day 10 rats and 6 pregnant day 18 rats) and Wistar-rats (6 non-pregnant, 6 pregnant day 10 rats and 5 pregnant day 18 rats)).

Results

We observed reduced litter size, lower fetal weight of viable fetuses and increased numbers of resorptions versus control rats. These complications are accompanied by various differences in the immune-response between BBDP and control rats in both pregnant and non-pregnant animals. The immune-response in non-pregnant BBDP-rats was characterized by decreased percentages of lymphocytes, increased percentages of effector T-cells, regulatory T-cells and natural killer cells, an increased Th1/Th2-ratio and activated monocytes versus Wistar and BBDR-rats. Furthermore, pregnancy-induced adaptations in BBDP-rats coincided with an increased Th1/Th2-ratio, a decreased mean fluorescence intensity CD161a/NKR-P1b ratio and no further activation of monocytes versus non-diabetic control rats.

Conclusion

This study suggests that even in the face of strict normoglycemia, pregnancy complications still occur in type 1 diabetic pregnancies. This adverse pregnancy outcome may be related to the aberrant immunological adaptations to pregnancy in diabetic rats.

Indoleamine 2,3-dioxygenase 1 (ido1) is involved in the control of mouse caput epididymis immune environment

The epididymis maintains a state of immune tolerance towards spermatozoa while also protecting them and itself against infection and acute inflammation. The immunosuppressive enzyme indoleamine 2,3-dioxygenase 1 (Ido1) participates in this delicate local equilibrium. Using the mouse Ido1(-/-) model, we show here that the absence of IDO1 expression leads in the epididymis but not in serum to (1) an increase in the inflammatory state as evidenced by changes in the content of cytokines and chemokines, (2) the engagement of a Th1-driven inflammatory response as evidenced by changes in the Th17/Treg as well as Th1/Th2 equilibria, as well as (3) differences in the content of lipid intermediates classically involved in inflammation. Despite this more pronounced inflammatory state, Ido1(-/-) animals succeed in preserving the local epididymal immune situation due to the activation of compensatory mechanisms that are discussed.

Cytokine Gene Expression in CD4 Positive Cells of the Japanese Pufferfish, Takifugu rubripes

CD4⁺ T (Th) cells are a central component of the adaptive immune response and are divided into distinct sets based on their specific cytokine production pattern. Several reports have suggested that fish possess Th subset activity similar to that of mammals. The aim of the present study was to isolate CD4⁺ T cells from the blood of Japanese pufferfish, Fugu rubripes, and to characterize their cytokine expression profile. We produced a specific antibody against Fugu CD4 and performed cell sorting with the magnetic activated cell sorting system. Sorted Fugu CD4⁺ cells were characterized by morphology and expression analysis of cell marker genes. Fugu CD4⁺ cells expressed T-cell marker genes but not macrophage or B-cell marker genes. In addition, peripheral blood lymphocytes were stimulated with lipopolysaccharide (LPS), polycytidylic acid (polyI:C), concanavalin A (ConA) prior to sorting, and then Multiplex RT-PCR was used to examine the expression of Th cytokines by the stimulated Fugu CD4⁺ cells. LPS and polyI:C stimulation upregulated the expression of Th1, Th17 and Treg cytokines and downregulated the expression of Th2 cytokines. ConA stimulation upregulated the expression of all Th cytokines. These results suggest that fish exhibit the same upregulation of Th-specific cytokine expression as in mammals.

Regulation of the expression of Th17 cells and regulatory T cells by IL-27 in patients with unexplained early recurrent miscarriage

In normal pregnancy, tolerance of the maternal immune system with regard to the genetically incompatible fetus depends on the interactions of an array of cytokines secreted by maternal and fetal cells at the site of implantation. Earlier research indicating that altered immunity exists in unexplained recurrent miscarriage (RM) has been dominated by the Th1/Th2 hypothesis. Recently, the Th1/Th2 paradigm has been expanded into the Th1/Th2/Th17 and regulatory T cells paradigm. We recently demonstrated a prevalence of Th17 cells, an inverse relationship between Th17 cells and regulatory T cells and deregulation of Th17 cells by regulatory T cells in early pregnancy in unexplained RM patients. In this study, we investigated the expression of IL-27 and the role of the cytokine IL-27 in the regulation of Th17/Treg expression. Quantitative real-time RT-PCR and Western blot analyses were performed to evaluate IL-27 expression in deciduas from unexplained RM patients, spontaneous miscarriage (SM) patients and healthy women following elective abortion in the early stages of normal pregnancy (control). Regulation of IL-17, TGF-β and IL-10 expression in CD4(+) T cells in unexplained RM patients by IL-27 was assessed using enzyme-linked immunosorbent assay (ELISA). Expression of IL-27 was lower in deciduas of patients with unexplained RM compared with SM and control subjects. IL-27 inhibited IL-17 expression and enhanced IL-10 expression in a dose-dependent manner. IL-27 had no effect on TGF-β expression. IL-27 regulates the expression of IL-17 and IL-10, which are predominantly secreted by Th17 cells and regulatory T cells in unexplained RM patients.

B7h (ICOS-L) maintains tolerance at the fetomaternal interface

In a successful pregnancy, the semiallogeneic fetus is not rejected by the maternal immune system, which implies tolerance mechanisms protecting fetal tissues from maternal immune attack. Here we report that the ICOS-B7h costimulatory pathway plays a critical role in maintaining the equilibrium at the fetomaternal interface. Blockade of this pathway increased fetal resorption and decreased fetal survival in an allogeneic pregnancy model (CBA female × B6 male). Locally in the placenta, levels of regulatory markers such as IDO and TGF-β1 were reduced after anti-B7h monoclonal antibody treatment, whereas levels of effector cytokines (eg, IFN-γ) were significantly increased. In secondary lymphoid organs, enhanced IFN-γ and granzyme B production (predominantly by CD8(+) T cells) was observed in the anti-B7h-treated group. The deleterious effect of B7h blockade in pregnancy was maintained only in CD4 knockout mice, not in CD8 knockout mice, which suggests a role for CD8(+) T cells in immune regulation by the ICOS-B7h pathway. In accord, regulatory CD8(+) T cells (in particular, CD8(+)CD103(+) cells) were significantly decreased after anti-B7h monoclonal antibody treatment, and adoptive transfer of this subset abrogated the deleterious effect of B7h blockade in fetomaternal tolerance. Taken together, these data support the hypothesis that B7h blockade abrogates tolerance at the fetomaternal interface by enhancing CD8(+) effector response and reducing local immunomodulation mediated by CD8(+) regulatory T cells.

The Placenta in Toxicology. Part II

During pregnancy, the maternal immune system is challenged by the semiallogeneic fetus, which must be tolerated without compromising fetal or maternal health. This review updates the systemic and local immune changes taking place during human pregnancy, including some examples in rodents. Systemic changes are induced by contact of maternal blood with placental factors and include enhanced innate immunity with increased activation of granulocytes and nonclassical monocytes. Although a bias toward T helper (Th2) and regulatory T cell (Treg) immunity has been associated with healthy pregnancy, the relationship between different circulating Th cell subsets is not straightforward. Instead, these adaptations appear most evidently at the fetal–maternal interface, where for instance Tregs are enriched and promote fetal tolerance. Also innate immune cells, that is, natural killer cells and macrophages, are enriched, constituting the majority of decidual leukocytes. These cells not only contribute to immune regulation but also aid in establishing the placenta by promoting trophoblast recruitment and angiogenesis. Thus, proper interaction between leukocytes and placental trophoblasts is necessary for normal placentation and immune adaptation. Consequently, spontaneous maladaptation or interference of the immune system with toxic substances may be important contributing factors for the development of pregnancy complications such as preeclampsia, preterm labor, and recurrent miscarriages.

Cytokine levels in gestational diabetes mellitus: a systematic review of the literature

PROBLEM

Gestational diabetes mellitus (GDM) is an inflammatory condition that involves unbalanced cytokine production. We carried out a systematic review on the relationship between GDM and maternal circulating levels of cytokines in the 2nd/3rd trimesters.

METHOD OF STUDY

Three electronic databases (MEDLINE, EMBASE and LILACS), were searched. Duplicate study selection, extraction and quality assessment was performed.

RESULTS

Twenty-two studies with 1982 participants reporting levels of 9 cytokines (IL-1B, IL-2, IL-6, IL-10, IL-13, IL-18, IFN-G, TGF-B and TNF-A) were included. Most studies differed considerably in selection criteria, sampling and assay methods and in reporting their results. Consequently, only two studies could be pooled: TNF-A concentration was slightly higher in GDM than in control patients, although not significant (WMD=0.45, 95% CI -0.34-1.23).

CONCLUSIONS

New studies with well-defined, more homogeneous methodological parameters are needed to detect whether there are significant differences in circulating levels of cytokines in patients with GDM.

Tolerance induction at the early maternal-placental interface through selective cell recruitment and targeting by immune polypeptides

Pregnancy challenges immune cells and immunomodulatory circuits of the mother and the developing fetus to dynamically adapt to each other in an homeostatic and tolerant environment for fetal growth. This entails the coordination of multiple cellular processes all devoted to accommodate and nourish the fetus while protecting the mother from endogenous and exogenous threatens. From the earliest stages of pregnancy, several strategies to efficiently communicate immune and trophoblast cells within the interface or at a distance were identified and chemokines might act at on different targets through direct or indirect mechanisms. Here, we briefly review some mechanisms of T regulatory cell recruitment to the early maternal-placental interfaces to accomplish immunotolerance and homeostatic control and we discuss evidence on two locally released polypeptides, RANTES (regulated on activation, normal, T-cell expressed, and secreted) and vasoactive intestinal peptide (VIP), as novel contributors to the multiplicity of immune tolerant responses and uterine quiescence requirements.

Decidual regulatory T cells in placental pathology and pregnancy complications

Regulatory T cells (Tregs) have been identified as immunomodulatory cells, which induce tolerance. Evidence from numerous recent studies implicates these cells as critical for maternal tolerance to the fetal-derived placenta, proper functioning of which is required for normal gestation and growth and development of the fetus in utero. This review focuses on the recent studies of Tregs at the maternal-fetal interface in pregnancy complications, as well as their identification in specific inflammatory lesions in the placenta.

To B or not to B cells-mediate a healthy start to life

Maternal immune responses during pregnancy are critical in programming the future health of a newborn. The maternal immune system is required to accommodate fetal immune tolerance as well as to provide a protective defence against infections for the immunocompromised mother and her baby during gestation and lactation. Natural immunity and antibody production by maternal B cells play a significant role in providing such immunoprotection. However, aberrations in the B cell compartment as a consequence of maternal autoimmunity can pose serious risks to both the mother and her baby. Despite their potential implication in shaping pregnancy outcomes, the role of B cells in human pregnancy has been poorly studied. This review focuses on the role of B cells and the implications of B cell depletion therapy in pregnancy. It highlights the evidence of an association between aberrant B cell compartment and obstetric conditions. It also alludes to the potential mechanisms that amplify these B cell aberrances and thereby contribute to exacerbation of some maternal autoimmune conditions and poor neonatal outcomes. Clinical and experimental evidence suggests strongly that maternal autoantibodies contribute directly to the pathologies of obstetric and neonatal conditions that have significant implications for the lifelong health of a newborn. The evidence for clinical benefit and safety of B cell depletion therapies in pregnancy is reviewed, and an argument is mounted for further clinical evaluation of B cell-targeted therapies in high-risk pregnancy, with an emphasis on improving neonatal outcomes and prevention of neonatal conditions such as congenital heart block and fetal/neonatal alloimmune thrombocytopenia.

Immunology of the maternal-fetal interface

The immune cells that reside at the interface between the placenta and uterus are thought to play many important roles in pregnancy. Recent work has revealed that the composition and function of these cells are locally controlled by the specialized uterine stroma (the decidua) that surrounds the implanted conceptus. Here, I discuss how key immune cell types (natural killer cells, macrophages, dendritic cells, and T cells) are either enriched or excluded from the decidua, how their function is regulated within the decidua, and how they variously contribute to pregnancy success or failure. The discussion emphasizes the relationship between human and mouse studies. Deeper understanding of the immunology of the maternal-fetal interface promises to yield significant insight into the pathogenesis of many human pregnancy complications, including preeclampsia, intrauterine growth restriction, spontaneous abortion, preterm birth, and congenital infection.

Physiological and molecular determinants of embryo implantation

Embryo implantation involves the intimate interaction between an implantation-competent blastocyst and a receptive uterus, which occurs in a limited time period known as the window of implantation. Emerging evidence shows that defects originating during embryo implantation induce ripple effects with adverse consequences on later gestation events, highlighting the significance of this event for pregnancy success. Although a multitude of cellular events and molecular pathways involved in embryo-uterine crosstalk during implantation have been identified through gene expression studies and genetically engineered mouse models, a comprehensive understanding of the nature of embryo implantation is still missing. This review focuses on recent progress with particular attention to physiological and molecular determinants of blastocyst activation, uterine receptivity, blastocyst attachment and uterine decidualization. A better understanding of underlying mechanisms governing embryo implantation should generate new strategies to rectify implantation failure and improve pregnancy rates in women.

Mechanisms in endocrinology. Role of emotional stress in the pathophysiology of Graves' disease

The role of stress in the pathophysiology of Graves' disease is suggested by several clinical observations, by recent advances in immunology and by better understanding of autoimmune diseases which provides new insights into potential effects of stress hormones on T helper cell imbalance involved in the pathogenesis of autoimmune diseases. Stress management should therefore be an important part of the treatment of Graves' disease, as stress reduction may improve the effect of therapy. However, this field still requires interventional data to support stress management in the treatment of Graves' disease.

Natural killer cells promote immune tolerance by regulating inflammatory TH17 cells at the human maternal-fetal interface

Natural killer (NK) cells accumulate at the maternal-fetal interface in large numbers, but their exact roles in successful pregnancy remain poorly defined. Here, we provide evidence that T(H)17 cells and local inflammation can occur at the maternal-fetal interface during natural allogenic pregnancies. We found that decidual NK cells promote immune tolerance and successful pregnancy by dampening inflammatory T(H)17 cells via IFN-γ secreted by the CD56(bright)CD27(+) NK subset. This NK-cell-mediated regulatory response is lost in patients who experience recurrent spontaneous abortions, which results in a prominent T(H)17 response and extensive local inflammation. This local inflammatory response further affects the regulatory function of NK cells, leading to the eventual loss of maternal-fetal tolerance. Thus, our data identify NK cells as key regulatory cells at the maternal-fetal interface by suppressing T(H)17-mediated local inflammation.

Specific infiltration pattern of FOXP3+ regulatory T cells in chronic histiocytic intervillositis of unknown etiology

INTRODUCTION

Chronic histiocytic intervillositis of unknown etiology (CIUE) is a rare placental lesion characterized by an intervillous mononuclear inflammatory infiltrate of maternal origin. Although the mechanism and origin of these lesions are currently not understood, they appear to be related to an immune conflict between mother and fetus cells.

AIM

To clarify the inflammatory cell profile and evaluate the T regulatory lymphocyte (Treg) status in CIUE.

MATERIALS AND METHODS

All cases of CIUE that occurred over an 8-year period were analyzed using immunohistochemistry.

RESULTS

The inflammatory profile of CIUE was characterized by a clearly predominant component of histiocytic cells (80% ± 6.9) associated with some T cells (24% ± 5.7). The ratio of CD4+ versus CD8+ T cells was close to 1. This profile differs from infectious disease and chronic histiocytic villitis, the main differential diagnoses of CIUE. As for normal pregnancies most regulatory T cells were localized in the decidua basalis. Nevertheless, their appearance was also noted in the intervillous space. In both the intervillous space and the deciduas the number of Tregs gradually increased from grade 1 to 3.

CONCLUSION

We found that CIUE is associated with an increase in Treg lymphocytes in the decidua basalis and the intervillous space. Contrary to previously published data on human miscarriage, this result appears to be specific to CIUE and would support the hypothesis of an immunopathological disorder for CIUE.

Mechanisms of T cell tolerance towards the allogeneic fetus

Work on the mechanisms of fetomaternal tolerance has undergone a renaissance in recent years, and the general outlines of a solution to this long-standing paradox of 'transplantation' immunology have come into view. Here, we discuss several mechanisms, recently described in mice, that either minimize the activation of maternal T cells with fetal or placental specificity, or minimize the possibility that such T cells, if activated, are able to harm the fetus. The T cell response to antigens expressed by the conceptus serves as a paradigm for the study of tissue-specific immune tolerance and is relevant to the pathogenesis of immune-mediated pregnancy complications.

Defects in the vasoactive intestinal peptide (VIP)/VPAC system during early stages of the placental-maternal leucocyte interaction impair the maternal tolerogenic response

Successful embryo implantation occurs followed by a local inflammatory/T helper type 1 (Th1) response, subsequently redirected towards a tolerogenic predominant profile. The lack of control of this initial local inflammatory response may be an underlying cause of early pregnancy complications as recurrent spontaneous abortions (RSA). Considering that vasoactive intestinal peptide (VIP) mediates anti-inflammatory and tolerogenic effects in several conditions we hypothesized that VIP might contribute to tolerance towards trophoblast antigens during the early interaction of maternal leucocytes and trophoblast cells. In this study we investigated VIP/VPAC system activity and expression on maternal peripheral blood mononuclear cells (PBMCs) after interaction with immortalized trophoblast cells (Swan-71 cell line) as an in-vitro model of feto-maternal interaction, and we analysed whether it modulates maternal regulatory T cell (T(reg))/Th1 responses. We also investigated the contribution of the endogenous VIP/VPAC system to RSA pathogenesis. VIP decreased T-bet expression significantly, reduced monocyte chemotactic protein-1 (MCP-1) and nitrite production in co-cultures of PBMCs from fertile women with trophoblast cells; while it increased the frequency of CD4(+) CD25(+) forkhead box protein 3 (Foxp3)(+) cells, transforming growth factor (TGF)-β expression and interleukin (IL)-10 secretion. These effects were prevented by VIP-specific antagonist. Interestingly, PBMCs from RSA patients displayed significantly higher T-bet expression, lower T(reg) frequency and lower frequency of VIP-producer CD4 lymphocytes after the interaction with trophoblast cells. Moreover, the patients displayed a significantly lower frequency of endometrial CD4(+) VIP(+) cells in comparison with fertile women. VIP showed a Th1-limiting and T(reg) -promoting response in vitro that would favour early pregnancy outcome. Because RSA patients displayed defects in the VIP/VPAC system, this neuropeptide could be a promising candidate for diagnostic biomarker or surrogate biomarker for recurrent spontaneous abortions.

Contribution of JAK2 and STAT3 variants to the genetic susceptibility of recurrent spontaneous miscarriage in a Tunisian population

AIMS

Th1 and Th2 balance is crucial for maintenance of pregnancy, and intracellular JAK and STAT proteins significantly contribute to it. In view of evidence linking JAK2 and STAT3 variants with recurrent spontaneous miscarriage (RSM), here we investigated the association of JAK2 (rs2230724) and STAT3 (rs1053023 and rs1053004) to RSM susceptibility in Tunisians.

SUBJECTS AND METHODS

A retrospective case-control study. Subjects comprised 235 RSM cases and 235 control subjects. JAK2 and STAT3 were genotyped by the allelic discrimination method.

RESULTS

STAT3 rs1053023 and, to a lower extent, rs1053004 were significantly associated with RSM under the additive and dominant, but not recessive models. This remained significant after adjustment for the covariates age, smoking, and gravida. In contrast to STAT3 variants, JAK2 rs2230724 was not associated with RSM under any of the genetic models tested. Two-locus STAT3 (rs1053023/rs1053004) haplotype analysis revealed increased frequency of the C/G haplotype in patients with RSM. Multivariate regression analysis confirmed the association of C/G haplotype with RSM (p=0.001; odds ratio=2.01; 95% confidence interval=1.32-3.07), thus conferring RSM susceptibility nature. These differences remained significant after applying the Bonferroni correction for multiple testing (Pc=0.004).

CONCLUSIONS

STAT3 rs1053023, more so than the STAT3 rs1053004 or JAK2 rs2230724 polymorphisms, is associated with RSM risk.

Effect of progesterone on Th1/Th2/Th17 and regulatory T cell-related genes in peripheral blood mononuclear cells during pregnancy in cows

T helper (Th) cells play a central role in immune responses and new Th1/Th2/Th17 and regulatory T (Treg)-cell paradigm in pregnancy has developed. Progesterone (P(4)) is essential for the maintenance of pregnancy; however the effect of P(4) on Th1/Th2/Th17 and Treg paradigm is unclear in cows. We evaluated the effect of P(4) on the expression of Th1/Th2/Th17 and Treg-related cytokines, transcription factors, and P(4) receptors in the peripheral blood mononuclear cells (PBMCs) from 8 pregnant (163.1 ± 16.9 days of gestation) and 8 non-pregnant luteal phase cows. PBMCs were stimulated with P(4) at 0, 0.1, 1 or 10 μg/ml, and the mRNA expression of Th1, Th2, Th17 and Treg-related cytokines (IFN-γ, IL-4, IL-17 and TGF-β), transcription factors (T-bet, GATA-3, RORC and Foxp3) and P(4) receptors (PGR, PGRMC1 and PGRMC2) were analyzed by real time RT-PCR. In both pregnant and non-pregnant cows, P(4) significantly inhibited the expression of IFN-γ and IL-17 dose-dependently, whereas P(4) did not affect the expression of TGF-β and Foxp3. In addition, P(4) significantly decreased the expression of T-bet and RORC, and enhanced the expression of IL-4 in the pregnant cows, but this reaction was not found in the non-pregnant cows. P(4) tended to increase PGRMC1 in the pregnant cows but not in the non-pregnant cows, indicating that PGRMC1 may be involved in the regulation of the effect of P(4) during bovine pregnancy. These results indicate that P(4) is an important regulator of Th1/Th2/Th17 and Treg immunity, and higher Th2 immunity is characteristic in the pregnant cows.

Effect of 1,25(OH)2 vitamin D3 on cytokine production by endometrial cells of women with repeated implantation failure

Repeated implantation failure (RIF) is a worldwide health problem that imposes a great deal of cost on patients and health care system. Vitamin D(3) has been proposed to have positive impact on the process of implantation. The present study was performed to compare the effect of 1,25-dihydroxy vitamin D(3) (1,25(OH)(2)D(3)) on cytokine production by endometrial cells of women with RIF and healthy fertile controls. Whole endometrial cells (WECs) and endometrial stromal cells (ESCs) from RIF and normal fertile women were treated with 1,25(OH)(2)D(3). The levels of IL-10, TGF-β, IFNγ, Il-6, IL-8 and IL-17 in culture supernatants were assayed by ELISA. Also, ability of the cells from both groups to produce 1,25(OH)(2)D(3) was evaluated and compared. 1,25(OH)(2)D(3) down-regulated cytokine production in WECs from both groups except for IL-8 which was upraised. Similar trends were also observed in ESCs except up-regulation of TGF-β in RIF group. Endometrial cells of both groups had comparable capacity to produce 1,25(OH)(2)D(3). Based on the minimal differential immunoregulatory effect of vitamin D(3) on endometrial cells from RIF and control women, it may be suggested that circulating levels of maternal vitamin D(3) be the subject of further investigation.

Exposure of rats to extremely low-frequency electromagnetic fields (ELF-EMF) alters cytokines production

Investigations indicate a potential link between exposure to extremely low-frequency electromagnetic field (ELF-EMF) and some cancers. Carcinogenesis of ELF-EMF may be mediated by effect on the immune system. During an immune response, naïve T cells differentiate to effector type 1 helper T cells (T(H)1), T(H)2, or T(H)17 subsets according to existence of different cytokines and T(H)1 is important in defense against tumors. Therefore, it will be reasonable to test whether ELF-EMF can change cytokines like interferon gamma (IFN-γ), interleukin-4 (IL-4), IL-6, and IL-12 that regulate T(H)1/T(H)2/T(H)17 balance. Forty adult male rats were randomly separated into ELF-EMF-exposed and sham-exposed control groups. The ELF-EMF group was exposed to a flux density of 100 μT, frequency 50 Hz, 2 h/day for 3 months. The controls were placed in identical chamber without ELF-EMF. The results showed there were no significant differences between the mean mass of rats, thymuses, and spleens in ELF-EMF exposed group compared with controls. Serum IL-12 level was decreased from 418 ± 47 pg/ml in controls to 300 ± 23 pg/ml (p < 0.05) in ELF-EMF-exposed group. Phytohemagglutinin activated of in vitro production of IL-6 by the whole spleen culture (1356 ± 92 pg/ml) and total blood culture (418 ± 40 pg/ml) of ELF-EMF-exposed rats were higher (p < 0.001) comparing with controls (905 ± 74 pg/ml), (182 ± 26 pg/ml), respectively. However, the levels of IFN-γ, IL-4, and IL-6 of serum and IFN-γ, IL-4, and IL-12 in spleen culture and total blood culture of two groups were not significantly different. It seems that ELF-EMF may change T(H)1/T(H)2/T(H)17 balance toward down regulation of T(H)1 and upregulation T(H)17 type responses.

A novel role of IGFBP7 in mouse uterus: regulating uterine receptivity through Th1/Th2 lymphocyte balance and decidualization

Previously we have screened out Insulin-like Growth Factor Binding Protein 7 (IGFBP7) as a differentially expressed gene in post-implantation uterus versus pre-implantation uterus by suppressive subtractive hybridation. However its function in uterus was not clearly identified. In this research, the expression and function of IGFBP7 during post-implantation were studied. We found that IGFBP7 was mainly located in the glandular epithelium and the stroma, and was upregulated after embryo implantation. The vector pCR3.1-IGFBP7-t expressing partial IGFBP7 was constructed. Inhibition of IGFBP7 by specific DNA immunization induced significant reduction of implanted embryos and pregnancy rate. The number of implanted embryos (5.68±0.46) was significantly reduced after immunization with pCR3.1-IGFBP7-t, as compared with that of the mice immunized with the control vector (12.29±0.36) or saline (14.58±0.40) (p<0.01). After specific inhibition of IGFBP7, the T helper type 1 (Th1) cytokine IFNγ, was significantly elevated (p<0.05) and the Th2 cytokines IL-4 and IL-10, were reduced in uteri (p<0.05). The increase of Tbet and the decrease of Gata3 were found in mice peripheral lymphocytes by flow cytometry. The expression of decidualization marker IGFBP1 and angiogenesis regulator VEGF were declined in uteri (p<0.05). The expression of apoptosis-associated proteins, caspase3 and Bcl-2, were also declined (p<0.05). These results showed that inhibition of IGFBP7 induced pregnancy failure by shifting uterine cytokines to Th1 type dominance and repressing uterine decidualization.

Glycodelin-A stimulates interleukin-6 secretion by human monocytes and macrophages through L-selectin and the extracellular signal-regulated kinase pathway

Macrophages represent the second major type of decidual leukocytes at the fetomaternal interface. Changes in macrophage number and activity are associated with fetal loss and pregnancy complications. Glycodelin-A (GdA) is an abundant glycoprotein in the first-trimester decidua. It is involved in fetomaternal defense and early placental development through its regulatory activities in various immune cells. The N-glycosylation of GdA mediates the binding and therefore the activities of the molecule. In this study, we studied the biological activities of GdA in the functions of human monocytes/macrophages. GdA was purified from amniotic fluid by affinity chromatography. GdA treatment did not affect the viability, cell death, or phagocytic activity of the monocytes/macrophages. GdA, but not recombinant glycodelin without glycosylation, induced IL-6 production as demonstrated by cytokine array, intracellular staining, and ELISA. GdA also induced phosphorylation of ERK in monocytes/macrophages. The involvement of ERKs in IL-6 induction was confirmed using pharmacological inhibitors. Co-immunoprecipitation showed that L-selectin on the monocytes/macrophages was the binding protein of GdA. Treatment with anti-L-selectin antibody reduced GdA binding and GdA-induced IL-6 production. GdA-treated macrophages suppressed IFN-γ expression by co-cultured T-helper cells in an IL-6-dependent manner. These results show that GdA interacts with L-selectin to induce IL-6 production in monocytes/macrophages by activating the ERK signaling pathway. In turn, the increased IL-6 production suppresses IFN-γ expression in T-helper cells, which may play an important role in inducing a Th-2-polarized cytokine environment that flavors the immunotolerance of the fetoplacental unit.

[Immunological aspect of pregnancy]

Pregnancy is a temporary semi-allograft that survives for nine months. The importance of this event for the survival of the species justifies several tolerance mechanisms that are put into place at the beginning of pregnancy, some of which occur even at the time of implantation. The presence of multiple tolerance mechanisms and the richness of the means employed underline the central importance of the trophoblast. Understanding these mechanisms, and in particular, their integration into an overall scheme, enables the anomalies encountered in certain pathologies of pregnancy to be placed into context. Understanding these mechanisms and their interruption at the end of pregnancy should improve our understanding of disappointing results from current immunological treatments facilitate the implementation of new prophylactic and therapeutic strategies.

Decidual macrophages are significantly increased in spontaneous miscarriages and over-express FasL: a potential role for macrophages in trophoblast apoptosis

Decidual macrophages (DM) are the second most abundant population in the fetal-maternal interface. Their role has been so far identified as being local immuno-modulators favoring the maternal tolerance to the fetus. Herein we investigated tissue samples from 11 cases of spontaneous miscarriages and from 9 cases of elective terminations of pregnancy. Using immunohistochemistry and dual immunofluorescence we have demonstrated that in spontaneous miscarriages the DM are significantly increased. Additionally, we noted a significant up-regulation of macrophage FasL expression. Our results further support a dual role for DM during pregnancy and miscarriages. We hypothesize that the baseline DM population in normal pregnancy is in line with an M2 phenotype supporting the ongoing gestation. In contrast, during spontaneous miscarriages, the increased FasL-expressing population could be a part of an M1 phenotype participating in Fas/FasL-related apoptosis. Our results highlight a new aspect of macrophage biology in pregnancy physiology and pathophysiology. Further studies with larger samples are needed to verify the current results and evaluate their clinical impact.

Toll-like receptor (TLR) 2 and TLR4 differentially regulate doxorubicin induced cardiomyopathy in mice

Recent evidence indicates that toll-like receptor (TLR) 2 and 4 are involved in the pathogenesis of dilated cardiomyopathy (DCM), but the exact mechanisms of their actions have not been elucidated. We explored the therapeutic potential of blocking TLRs in mice with established cardiomyopathy. Cardiomyopathy was generated by a single intraperitoneal injection of doxorubicin (10 mg/kg). Two weeks later, the mice were treated with TLR2 or TLR4 neutralizing antibody. Blocking TLR2, but not TLR4, activity not only reduced mortality, but also attenuated doxorubicin-induced cardiac dysfunction by 20% and inhibited myocardial fibrosis. To determine the differential effects of blocking TLR2 and TLR4 in chronic cardiomyopathy, mice were injected with doxorubicin (3.5 mg/kg) once a week for 8 weeks, followed by treatment with TLR2 or TLR4 neutralizing antibody for 40 days. Blocking TLR2 activity blunted cardiac dysfunction by 13% and inhibited cardiac fibrosis, which was associated with a significant suppression of myocardial inflammation. The underlying mechanism involved interrupting the interaction of TLR2 with its endogenous ligands, resulting in attenuation of inflammation and fibrosis. In contrast, blocking TLR4 exacerbated cardiac dysfunction and fibrosis by amplifying inflammation and suppressing autophagy. Our studies demonstrate that TLR2 and TLR4 play distinct roles in the progression of doxorubicin-induced DCM. TLR4 activity is crucial for the resolution of inflammation and cardiac fibrosis, while blocking TLR2 activity has therapeutic potential for the treatment of DCM.

Smoking during pregnancy influences the maternal immune response in mice and humans

OBJECTIVE

During pregnancy the maternal immune system has to adapt its response to accommodate the fetus. The objective of this study was to analyze the effects of smoking on the maternal immune system.

STUDY DESIGN

First-trimester decidual tissue and peripheral blood of smoking and nonsmoking women were analyzed by real time reverse transcription-polymerase chain reaction (RT-PCR) and flow cytometry. A mouse model was used to further analyze the effects of smoking. Murine tissue was analyzed by flow cytometry, real-time RT-PCR, and immunohistochemistry.

RESULTS

Smoking caused lower percentages of viable pups in mice and lower birthweights in humans. Smoking mothers, both mice and human, had more natural killer cells and inflammatory macrophages locally, whereas systemically they had lower percentages of regulatory T cells than nonsmoking controls.

CONCLUSION

Maternal smoke exposure during pregnancy influences local and systemic immune responses in both women and mice. Such changes may be involved in adverse pregnancy outcomes in smoking individuals.

Galectin-1 confers immune privilege to human trophoblast: implications in recurrent fetal loss

Mechanisms accounting for the protection of the fetal semi-allograft from maternal immune cells remain incompletely understood. In previous studies, we showed that galectin-1 (Gal1), an immunoregulatory glycan-binding protein, hierarchically triggers a cascade of tolerogenic events at the mouse fetomaternal interface. Here, we show that Gal1 confers immune privilege to human trophoblast cells through the modulation of a number of regulatory mechanisms. Gal1 was mainly expressed in invasive extravillous trophoblast cells of human first trimester and term placenta in direct contact with maternal tissue. Expression of Gal1 by the human trophoblast cell line JEG-3 was primarily controlled by progesterone and pro-inflammatory cytokines and impaired T-cell responses by limiting T cell viability, suppressing the secretion of Th1-type cytokines and favoring the expansion of CD4(+)CD25(+)FoxP3(+) regulatory T (T(reg)) cells. Targeted inhibition of Gal1 expression through antibody (Ab)-mediated blockade, addition of the specific disaccharide lactose or retroviral-mediated siRNA strategies prevented these immunoregulatory effects. Consistent with a homeostatic role of endogenous Gal1, patients with recurrent pregnancy loss showed considerably lower levels of circulating Gal1 and had higher frequency of anti-Gal1 auto-Abs in their sera compared with fertile women. Thus, endogenous Gal1 confers immune privilege to human trophoblast cells by triggering a broad tolerogenic program with potential implications in threatened pregnancies.

Female reproductive issues in multiple sclerosis

Multiple sclerosis (MS) is more common in females than males and frequently affects women during their reproductive years. Thus, issues surrounding pregnancy and reproduction are of concern to women with MS. This review documents studies that shed light on reproductive issues in women with MS. The available literature was searched for papers relating to pregnancy and MS. Pregnancy is protective in MS in the short term, perhaps due to modulation of the immune system in pregnancy. It also possible that changes in the brain in pregnancy could protect against the effects of inflammation. The long-term effects of pregnancy also seem to be beneficial to MS, perhaps due to long-term epigenetic changes or possibly due to the effects of fetal microchimerism. Obstetric outcomes in women with MS are similar to those in the general population. In addition, there have been no reports of severe fetal abnormalities in babies exposed to first-line MS therapies. There is no good evidence that breast-feeding is protective in MS. There is no evidence that oral contraceptive pill use predisposes to MS, nor influences the clinical course of MS. After menopause, there is possible deterioration of MS, but it’s difficult to disentangle this from the effects of aging and the natural progressive history of MS. The strong biological effect of pregnancy on MS deserves further study, so that these mechanisms can possibly be replicated as therapies for MS.

Human decidual stromal cells secrete C-X-C motif chemokine 13, express B cell-activating factor and rescue B lymphocytes from apoptosis: distinctive characteristics of follicular dendritic cells

BACKGROUND

Decidual stromal cells (DSCs) have classically been considered fibroblastic cells, although their function, cell lineage and origin are not fully understood. We previously demonstrated that human DSCs showed similarities with follicular dendritic cells (FDCs): DSCs expressed FDC-associated antigens, both types of cells are contractile and both are related to mesenchymal stem cells (MSCs). To further characterize DSCs, we investigated whether DSCs and FDCs share any distinctive phenotypical and functional characteristics.

METHODS

Human FDC lines were obtained from tonsillectomy samples, human DSC lines from elective termination of pregnancy samples and human MSC lines from bone marrow aspirates. We isolated DSC, FDC and MSC lines and compared their characteristics with flow cytometry and enzyme-linked immunosorbent assay. Cell lines were cultured with tumour necrosis factor (TNF) and lymphotoxin (LT)α(1)β(2), cytokines involved in FDC differentiation. Cell lines were also differentiated in culture after exposure to progesterone and cAMP, factors involved in the differentiation (decidualization) of DSC.

RESULTS

Like MSCs, DSCs and FDCs expressed MSC-associated antigens (CD10, CD29, CD54, CD73, CD106, α-smooth muscle actin and STRO-1) and lacked CD45 expression, and all three types of cell line showed increased expression of CD54 (ICAM-1) and CD106 (VCAM-1) when cultured TNF and LTα(1)β(2). DSCs and FDCs, however, exhibited characteristics not observed in MSCs: DSCs expressed FDC-associated antigens CD14, CD21 and CD23, B cell-activating factor and secreted C-X-C motif chemokine 13. Moreover, DSC lines but not MSC lines inhibited the spontaneous apoptosis of B lymphocytes, a typical functional attribute of FDC. During culture with progesterone and cAMP, FDCs, like DSCs but in contrast to MSCs, changed their morphology from a fibroblastic to a rounder shape, and cells secreted prolactin.

CONCLUSIONS

Our results suggest that DSCs and FDCs share a common precursor in MSCs but this precursor acquires new capacities when it homes to peripheral tissues. We discuss these shared properties in the context of immune-endocrine regulation during pregnancy.

The role of interleukin-1β in human trophoblast motility

The pleiotropic cytokine interleukin-1β (IL-1β) can promote physiological cell migration, as well as cancer cell invasion and metastasis. Its role in human trophoblast invasion, however, has not been satisfactorily answered since direct, indirect as well as no effects on trophoblast motility have been published. Therefore, the role of IL-1β has been re-evaluated by exclusively using human primary trophoblast model systems. Immunofluorescence of first trimester placentae indicated IL-1 receptor 1 (IL-1R1) protein expression in first trimester villous cytotrophoblasts (vCTB) and extravillous trophoblasts (EVT). The latter expressed higher mRNA levels of the receptor as shown by comparative gene chip data of vCTB and EVT. Similarly, Western blot analyses and immunofluorescence revealed a time- and differentiation-dependent increase of IL-1R1 in primary EVT seeded on fibronectin. IL-1β dose-dependently elevated migration of isolated first trimester EVT through fibronectin-coated transwells, which was inhibited in the presence of IL-1R antagonist (IL-1Ra), whereas proliferation of these cells was not affected. Similarly, the interleukin did not alter proliferation of vCTB and cell column trophoblasts in floating villi of early pregnancy, but promoted migration in villous explant cultures seeded on collagen I. Western blot analyses of supernatants of primary EVT and first trimester villous explant cultures revealed IL-1β induced secretion of urokinase plasminogen activator (uPA), plasminogen activator inhibitor (PAI)-1 and PAI-2, which was diminished upon combined IL-1β/IL-1Ra treatment. In conclusion, these data suggest that IL-1β directly promotes trophoblast motility of first trimester EVT involving the uPA/PAI system.

AMPK activation reduces vascular permeability and airway inflammation by regulating HIF/VEGFA pathway in a murine model of toluene diisocyanate-induced asthma

BACKGROUND

Occupational asthma is characterized by airway inflammation and hyperresponsiveness associated with increased vascular permeability. AMP-activated protein kinase (AMPK) has been suggested to be a novel signaling molecule modulating inflammatory responses.

OBJECTIVE

We sought to evaluate the involvement of AMPK in pathogenesis of occupational asthma and more specifically investigate the effect and molecular mechanisms of AMPK activation in regulating vascular permeability.

METHODS

The mechanisms of action and therapeutic potential of an AMPK activator, 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) were tested in a murine model of toluene diisocyanate (TDI)-induced asthma.

RESULTS

AICAR attenuated airway inflammation and hyperresponsiveness increased by TDI inhalation. Moreover, TDI-induced increases in levels of hypoxia-inducible factor (HIF)-1α, HIF-2α, vascular endothelial growth factor A (VEGFA), and plasma exudation were substantially decreased by treatment with AICAR. Our results also showed that VEGFA expression was remarkably reduced by inhibition of HIF-1α and HIF-2α with 2-methoxyestradiol (2ME2) and that an inhibitor of VEGFA activity, CBO-P11 as well as 2ME2 significantly suppressed vascular permeability, airway infiltration of inflammatory cells, and airway hyperresponsiveness induced by TDI. In addition, AICAR reduced reactive oxygen species (ROS) generation and levels of malondialdehyde and T-helper type 2 cytokines (IL-4, IL-5, and IL-13), while this agent enhanced expression of an anti-inflammatory cytokine, IL-10.

CONCLUSIONS

These results suggest that AMPK activation ameliorates airway inflammatory responses by reducing vascular permeability via HIF/VEGFA pathway as well as by inhibiting ROS production and thus may be a possible therapeutic strategy for TDI-induced asthma and other airway inflammatory diseases.

The Th1:th2 dichotomy of pregnancy and preterm labour

Pregnancy is a unique immunological state in which a balance of immune tolerance and suppression is needed to protect the fetus without compromising the mother. It has long been established that a bias from the T helper 1 cytokine profile towards the T helper 2 profile contributes towards successful pregnancy maintenance. The majority of publications that report on aberrant Th1:Th2 balance focus on early pregnancy loss and preeclampsia. Over the last few decades, there has been an increased awareness of the role of infection and inflammation in preterm labour, and the search for new biomarkers to predict preterm labour continues. In this paper, we explore the evidence for an aberrant Th1:Th2 profile associated with preterm labour. We also consider the potential for its use in screening women at high risk of preterm labour and for prophylactic therapeutic measures for the prevention of preterm labour and associated neonatal adverse outcomes.

Pregnancy-associated inflammatory markers are elevated in pregnant women with systemic lupus erythematosus

During normal pregnancy a dampening in T cell-mediated immunity is compensated by an increased pro-inflammatory activity. Likewise, the autoimmune disease systemic lupus erythematosus (SLE) is associated with inflammatory activity and pregnancy complications occur frequently in women with SLE. The aim of this study was to elucidate how SLE influences the chemokine and cytokine balance during and after pregnancy. Blood samples were taken from pregnant women with or without SLE at second and third trimester and 8-12 weeks after pregnancy. Cytokines (interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-10, IL-12p70, IL-17A, TNF, IFN-γ and IFN-α), chemokines (CXCL8/IL-8, CXCL9/MIG, CXCL10/IP-10, CCL2/MCP-1, CCL5/RANTES and CCL17/TARC), soluble IL-6 receptor (sIL-6R) and soluble glycoprotein 130 (gp130) were measured in serum using cytometric bead array (CBA) or enzyme-linked immunosorbent assay (ELISA). Women with SLE had increased serum concentrations of CXCL8/IL-8, CXCL9/MIG, CXCL10/IP-10 and IL-10 compared to controls both during and after pregnancy. Further, when dividing the patients based on disease activity, the women with active disease had the highest levels. Importantly, women with SLE seemed to respond to pregnancy in a similar way as controls, since the changes of cytokines and chemokines over the course of pregnancy were similar but with overall higher levels in the patient group. In conclusion, changes in pro- and anti-inflammatory serum components during pregnancy in women with SLE, occurring on top of already more pro-inflammatory levels, might increase their risk for pregnancy complications and flares. How their children are affected by this heightened inflammatory milieu during pregnancy needs further investigation.

Imbalance of placental regulatory T cell and Th17 cell population dynamics in the FIV-infected pregnant cat

BACKGROUND

An appropriate balance in placental regulatory T cells (Tregs), an immunosuppressive cell population, and Th17 cells, a pro-inflammatory cell population, is essential in allowing tolerance of the semi-allogeneic fetus. TGF-β and IL-6 are cytokines that promote differentiation of Tregs and Th17 cells from a common progenitor; aberrant expression of the cytokines may perturb the balance in the two cell populations. We previously reported a pro-inflammatory placental environment with decreased levels of FoxP3, a Treg marker, and increased levels of IL-6 in the placentas of FIV-infected cats at early pregnancy. Thus, we hypothesized that FIV infection in the pregnant cat causes altered placental Treg and Th17 cell populations, possibly resulting in placental inflammation.

METHODS

We examined the effect of FIV infection on Treg and Th17 populations in placentas at early pregnancy using quantitative confocal microscopy to measure FoxP3 or RORγ, a Th17 marker, and qPCR to quantify expression of the key cytokines TGF-β and IL-6.

RESULTS

FoxP3 and RORγ were positively correlated in FIV-infected placentas at early pregnancy, but not placentas from normal cats, indicating virus-induced alteration in the balance of these cell populations. In control cats the expression of IL-6 and RORγ was positively correlated as predicted, but this relationship was disrupted in infected animals. TGF-β was reduced in infected queens, an occurrence that could dysregulate both Treg and Th17 cell populations. Co-expression analyses revealed a highly significant positive correlation between IL-6 and TGF-β expression in control animals that did not occur in infected animals.

CONCLUSION

Collectively, these data point toward potential disruption in the balance of Treg and Th17 cell populations that may contribute to FIV-induced inflammation in the feline placenta.

Promoter region polymorphisms in the transforming growth factor beta-1 (TGFβ1) gene and serum TGFβ1 concentration in preeclamptic and control Iranian women

Preeclampsia (PE) is a pregnancy associated disorder characterized by hypertension and proteinuria, which causes neonatal and maternal morbidity and mortality. The Th1/Th2 cytokine paradigm of the immune adaptation in pregnancy is now expanded to include Th1/Th2/Th17 and regulatory T (Treg) cells. Among cytokines, TGFβ1 has properties that justify evaluation of its role in PE etiopathology. In this investigation the polymorphisms of the TGFβ1 gene at promoter region, positions -800G→A and -509C→T, were studied in 142 PE and 140 normal pregnant female subjects using PCR-RFLP. Additionally, serum TGFβ1 was determined by ELISA. At position -800G→A genotypes and allele frequencies showed no significant differences between PE patients (GG 73.9%; GA 21.1%; AA 4.93%) and normal control (GG 70%; GA 28.6%; AA 1.4%) women. However the AA genotype at this position was more frequent in PE patients than in the control group. At -509C→T position, genotypes and allele frequencies showed no significant differences between PE patients and control individuals. The CC genotype at -509C→T position was more prevalent in PE patients than in the control group. The mean serum TGFβ1 level was significantly higher (62.14 ng/ml) in PE patients compared with pregnant and non-pregnant control groups (and 47.01 and 40.68 ng/ml, respectively). In conclusion, the promoter region polymorphisms of TGFβ1 may not be associated with PE, but serum levels of this cytokine may contribute to the etiopathology of PE.

The expressions of CD200 and CD200R molecules on myeloid and lymphoid dendritic cells in pre-eclampsia and normal pregnancy

PROBLEM

The purpose of our study was to test the hypothesis that the expressions of CD200 and CD200R tolerance molecules are increased on peripheral blood dendritic cells (DCs) in normal pregnancy and decreased on peripheral blood DCs in pre-eclampsia.

METHOD OF STUDY

Thirty-three patients with pre-eclampsia, 38 normal pregnant women, and 10 healthy non-pregnant women were included in the study. Dendritic cells were isolated from peripheral blood, stained with monoclonal antibodies against blood dendritic cell antigens as well as CD200 and CD200R antigens, and estimated using flow cytometry.

RESULTS

The expressions of CD200 and CD200R molecules on CD1c(+) myeloid and BDCA-2(+) lymphoid DCs in the first trimester of normal pregnancy were significantly higher when compared to the luteal phase of the ovarian cycle. The expressions of CD200 molecule on CD1c(+) myeloid DCs were significantly lower in the third trimester of normal pregnancy when compared to the second trimester. The expressions of CD200R molecule on CD1c(+) myeloid DCs and BDCA-2(+) lymphoid DCs did not differ in pre-eclampsia and healthy third trimester pregnant women. However, the expressions of CD200 molecule on CD1c(+) myeloid and BDCA-2(+) lymphoid DCs were significantly higher in pre-eclampsia when compared to the healthy third trimester pregnant women.

CONCLUSION

The results suggest increased tolerogenic properties of myeloid and lymphoid DCs in normal human pregnancy. Moreover, they suggest a decrease in tolerogenic properties of DCs before delivery. It seems possible that higher expressions of CD200 molecule on CD1c(+) myeloid and BDCA-2(+) lymphoid DCs in pre-eclampsia may constitute the tolerogenic mechanism secondary to the pro-inflammatory response that is observed in this syndrome.

Sex-related factors in multiple sclerosis susceptibility and progression

The pathogenesis of multiple sclerosis (MS) involves complex interactions between genetic susceptibility and environmental triggers. Clinical observations suggest that the study of sex differences might provide important insight into mechanisms of pathogenesis and progression of the disease in patients. MS occurs more frequently in women than in men, indicating that sex-related factors have an effect on an individual's susceptibility to developing the condition. These factors include hormonal, genetic and environmental influences, as well as gene-environment interactions and epigenetic mechanisms. Interestingly, women do not have a poorer prognosis than men with MS despite a higher incidence of the disease and more-robust immune responses, which suggests a mechanism of resilience. Furthermore, the state of pregnancy has a substantial effect on disease activity, characterized by a reduction in relapse rates during the third trimester but an increased relapse rate in the postpartum period. However, pregnancy has little effect on long-term disability in women with MS. The unravelling of the mechanisms underlying these clinical observations in the laboratory and application of the results to the clinical setting is a unique and potentially fruitful strategy to develop novel therapeutic approaches for MS.

LIF and sIL-2R plasma concentrations in IVF patients on the day of embryo transfer: predictive markers of IVF outcome

Successful implantation is still the limiting step in IVF. We hypothesized that maternal plasma concentrations of certain cytokines at the time of embryo transfer could predict the likelihood of successful implantation and pregnancy. sIL-2R, IL-6, LIF, and MMP2 concentrations were measured in plasma from 160 IVF patients (natural and stimulated IVF cycles) on the morning of the embryo transfer (ET0) and 14 days later (ET+14). Patients were ultimately subdivided into four groups depending on the IVF treatment outcome (pregnancy failure, biochemical pregnancy, first-trimester miscarriage and normal term delivery). In natural and stimulated IVF cycles at ET0, sIL-2R concentrations were threefold higher in biochemical pregnancies than in pregnancy failures (P=0.020), and in natural cycles only, 2.5-fold higher in normal term deliveries than in pregnancy failures (P=0.023). Conversely, in natural and stimulated IVF cycles at ET0, LIF concentrations were one third lower in biochemical pregnancies/first-trimester miscarriages compared with pregnancy failures (P=0.042). We suggest that high sIL-2R and low LIF concentrations in maternal plasma on the morning of the embryo transfer might be associated with increased risks of early pregnancy loss, while a basal level of sIL-2R is necessary for normal term delivery outcome. Both cytokine measurements might therefore be useful in the management of IVF patients, and modulation of their concentrations could be investigated as a therapeutic alternative for women with abnormal concentrations at the time of embryo transfer.

Effect of pregnancy on serum cytokines in SLE patients

Introduction

The aim of this study was to evaluate an extensive panel of cytokines involved in immune regulation during pregnancy in patients with systemic lupus erythematosus (SLE) and in healthy women.

Methods

A total of 47 consecutive successful pregnancies in 46 SLE patients and 56 pregnancies in 56 matched healthy subjects, as controls, were prospectively studied. Serum interleukin (IL)-1-α, IL-1-β, IL-2, IL-6, IL-8, IL-10, IL-12p70, interferon (INF)-γ and tumor necrosis factor (TNF)-α were detected in sera obtained at the first and third trimester of pregnancy by a highly sensitive, multiplexed sandwich ELISA.

Results

Medians (pg/ml) of serum levels of most helper T (Th)1-type cytokines were significantly lower in the third trimester compared with those observed in the first trimester of pregnancy in healthy women: INF-γ 2.0 vs 3.4, TNF-α 10.2 vs 11.5, IL-1-α 0.9 vs 1.1, IL-1-β 0.6 vs 1.0, IL-2 3.0 vs 3.5, and IL-12p70 4.9 vs 5.6 (P-values < 0.02 for all). By contrast, only the IL-1-α serum levels were lower in the third trimester compared with the first trimester in SLE patients (P = 0.006). IFN-γ/IL-6 and IFN-γ/IL-10 ratios were higher in controls than in SLE (P = 0.002, and P = 0.001, respectively); moreover, they were significantly reduced in the third compared to the first trimester of pregnancy in healthy women, but not in SLE.

Conclusions

In SLE patients, Th1/Th2 cytokine serum level ratio does not decrease during pregnancy progression as much as in healthy pregnant women. This could account for the observation of a low frequency of disease flares in the third trimester of gestation.

Methylome of fetal and maternal monocytes and macrophages at the feto-maternal interface

PROBLEM

Decidual macrophages (dMφ) of the mother and placental macrophages (Hofbauer cells, HC) of the fetus are deployed at a critical location: the feto-maternal interface. This study was conducted to compare the DNA methylome of maternal and fetal monocytes, dMφ, and HC and thereby to determine the immunobiological importance of DNA methylation in pregnancy.

METHOD OF STUDY

Paired samples were obtained from normal pregnant women at term not in labor and their neonates. Maternal monocytes (MMo) and fetal monocytes (FMo) were isolated from the peripheral blood of mothers and fetal cord blood, respectively. dMφ and HC were obtained from the decidua of fetal membranes and placentas, respectively. DNA methylation profiling was performed using the Illumina Infinium Human Methylation27 BeadChip. Quantitative real-time PCR and Western Blot were performed for validation experiments.

RESULTS

(i) Significant differences in DNA methylation were found in each comparison (MMo versus FMo, 65 loci; dMφ versus HC, 266 loci; MMo versus dMφ, 199 loci; FMo versus HC, 1030 loci). (ii) Many of the immune response-related genes were hypermethylated in fetal cells (FMo and HC) compared to maternal cells (MMo and dMφ). (iii) Genes encoding markers of classical macrophage activation were hypermethylated, and genes encoding alternative macrophage activation were hypomethylated in dMφ and HC compared to MMo and FMo, respectively. (iv) mRNA expressions of DNMT1, DNMT3A, and DNMT3B were significantly lower in dMφ than in HC. (v) 5-azacytidine treatment increased expression of INCA1 in dMφ.

CONCLUSIONS

The findings herein indicate that DNA methylation patterns change during monocyte-macrophage differentiation at the feto-maternal interface. It is also suggested that DNA methylation is an important component of the biological machinery conferring an anti-inflammatory phenotype to macrophages at the feto-maternal interface.