Expression and localization of the Th2-type cytokine interleukin-13 and its receptor in the placenta during human pregnancy

Different Lengths of Gestational Exposure to Secondhand Smoke or e-Cigarette Vapor Induce the Development of Placental Disease Symptoms

Exposure to cigarette smoke is known to induce disease during pregnancy. Recent evidence showed that exposure to secondhand smoke (SHS) negatively impacts fetal and placental weights, leading to the development of intrauterine growth restriction (IUGR). Electronic cigarettes (eCigs) represent a phenomenon that has recently emerged, and their use is also steadily rising. Even so, the effects of SHS or eCigs during gestation remain limited. In the present study, we wanted to characterize the effects of SHS or eCig exposure at two different important gestational points during mouse pregnancy. C57/Bl6 mice were exposed to SHS or eCigs via a nose-only delivery system for 4 days (from 14.5 to 17.5 gestational days (dGA) or for 6 days (from 12.5 dGA to 17.5 dGA)). At the time of necropsy (18.5 dGA), placental and fetal weights were recorded, maternal blood pressure was determined, and a dipstick test to measure proteinuria was performed. Placental tissues were collected, and inflammatory molecules in the placenta were identified. Treatment with SHS showed the following: (1) a significant decrease in placental and fetal weights following four days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. Treatment with eCigs showed the following: (1) a significant decrease in placental weight and fetal weight following four or six days of exposure, (2) higher systolic and diastolic blood pressure following six days of exposure, and (3) increased proteinuria after six days of exposure. We also observed different inflammatory markers associated with the development of IUGR or PE. We conclude that the detrimental effects of SHS or eCig treatment coincide with the length of maternal exposure. These results could be beneficial in understanding the long-term effects of SHS or eCig exposure in the development of placental diseases.

Recurrent implantation failure and inflammatory markers in serum and follicle fluid of women undergoing assisted reproduction

It has been shown previously that the immune system plays a role in implantation and embryo development. The objective was therefore to evaluate cytokine levels and Th1/Th2 ratio in women with recurrent implantation failure in this nested case-control study. Women with no implantation after ≥ 3 embryo transfers were included in the recurrent implantation failure group (n = 29) and were compared with women with successful pregnancy after the first embryo transfer, with an indication of male factor (n = 26). Cytokines analyzed with the Meso scale discovery (MSD) technology Proinflammatory Human Kit 1 and calculated Th1/Th2 ratios were the main outcome measures. In serum there was a difference between the recurrent implantation failure group and the control group in ratios for IFN-γ/IL-10 (p = 0.01), IL-1β/IL-10 (p = 0.04), IL-2/IL-10 (p = 0.00), TNF-α/IL-10 (p = 0.02), IFN-γ/IL-13 (p = 0.01), IL-12/IL-13 (p = 0.02), IL-2/IL-13 (p = 0.00), and TNF-α/IL-13 (p = 0.00), where the control group had higher ratios, i.e. a shift towards a Th1 pro-inflammatory profile before treatment start. In follicular fluid there were differences in ratios between IL-2/IL-10 (p = 0.02), IL-8/IL-10 (p = 0.02), TNF-α/IL-10 (p = 0.02), IFN-γ/IL-13 (p = 0.01), and TNF-α/IL-13 (p = 0.03). The recurrent implantation failure group had higher ratios except for IFN-γ/IL-13, indicating a shift towards a Th1 pro-inflammatory profile in their follicular fluid. Pro-inflammatory activity in both serum and follicle fluid differs in recurrent implantation failure patients and patients with successful assisted reproduction treatment. Women at risk of immune-related recurrent implantation failure could be identified proactively. Because it is taken at a timepoint closer to implantation, ratios in follicular fluid are specifically interesting as risk markers.

Cytokine imbalance at materno-embryonic interface as a potential immune mechanism for recurrent pregnancy loss

Recurrent pregnancy loss (RPL) is a prominent reproductive disease that distresses about 2%-5% of couples. RPL is the loss of two or more successive spontaneous pregnancies prior to the 20th week of embryo development. The commencement of pregnancy necessitates implantation of the embryo into responsive maternal decidua synchronized with the process of placentation, decidual and myometrial trophoblast incursion as well as refashioning of spiral blood arteries of uterus. The collapse of any of the processes fundamental for pregnancy success may result into an array of pregnancy problems including spontaneous pregnancy loss. Endometrium of human female manufactures an extensive range of cytokines during the proliferative and secretory stage of the menstrual cycle. These endometrial cytokines are thought as major players for making the uterus ready for embryo implantation and placental development during pregnancy. Decidual cytokines regulate the invasion of trophoblast and remodeling of spiral arteries as well as take part in immune suppression to accomplish the pregnancy. Deterrence of maternal rejection of embryo needs a regulated milieu, which takes place essentially at the embryo-maternal interface and the tissues of the uterus. The reasons of RPL remain anonymous in a large number of cases that lead to difficulties in management and severe trauma in couples. Cytokine modulatory therapies have been shown promising for preventing RPL. Further study of novel factors is wanted to establish more effective RPL treatment protocols. The present study aims to review the outcome of cytokine breach at materno-embryonic interface and the efficacy of cytokine modulatory therapies in RPL.

Fetal growth restriction is a host specific response to infection with an impaired spiral artery remodeling-inducing strain of Porphyromonas gingivalis

Porphyromonas gingivalis is a periodontal pathogen implicated in a range of pregnancy disorders that involve impaired spiral artery remodeling (ISAR) with or without fetal growth restriction (FGR). Using a rodent periodontitis model, we assessed the ability of P. gingivalis to produce ISAR and FGR in Sprague Dawley (SD) and Wistar (WIS) rats. Both infected SD and WIS rats developed ISAR, but only WIS rats developed FGR despite both rat strains having equivalent microbial loads within the placenta. Neither maternal systemic inflammation nor placental (fetal) inflammation was a feature of FGR in WIS rats. Unique to infected WIS rats, was loss of trophoblast cell density within the junctional zone of the placenta that was not present in SD tissues. In addition, infected WIS rats had a higher proportion of junctional zone trophoblast cells positive for cytoplasmic high temperature requirement A1 (Htra1), a marker of cellular oxidative stress. Our results show a novel phenomenon present in P. gingivalis-induced FGR, with relevance to human disease since dysregulation of placental Htra1 and placental oxidative stress are features of preeclamptic placentas and preeclampsia with FGR.

Innate lymphoid cells at the human maternal-fetal interface in spontaneous preterm labor

PROBLEM

Pathological inflammation is causally linked to preterm labor and birth, the leading cause of neonatal morbidity and mortality worldwide. Our aims were to investigate whether (i) the newly described family of innate lymphoid cells (ILCs) was present at the human maternal-fetal interface and (ii) ILC inflammatory subsets were associated with the pathological process of preterm labor.

METHODS OF STUDY

Decidual leukocytes were isolated from women with preterm or term labor as well as from gestational age-matched non-labor controls. ILCs (CD15- CD14- CD3- CD19- CD56- CD11b- CD127+ cells) and their subsets (ILC1, T-bet+ ILCs; ILC2, GATA3+ ILCs; and ILC3, RORγt+ ILCs) and cytokine expression were identified in the decidual tissues using immunophenotyping.

RESULTS

(i) The proportion of total ILCs was increased in the decidua parietalis of women with preterm labor; (ii) ILC1s were a minor subset of decidual ILCs during preterm and term gestations; (iii) ILC2s were the most abundant ILC subset in the decidua during preterm and term gestations; (iv) the proportion of ILC2s was increased in the decidua basalis of women with preterm labor; (v) the proportion of ILC3s was increased in the decidua parietalis of women with preterm labor; and (vi) during preterm labor, ILC3s had higher expression of IL-22, IL-17A, IL-13, and IFN-γ compared to ILC2s in the decidua.

CONCLUSION

ILC2s were the most abundant ILC subset at the human maternal-fetal interface during preterm and term gestations. Yet, during preterm labor, an increase in ILC2s and ILC3s was observed in the decidua basalis and decidua parietalis, respectively. These findings provide evidence demonstrating a role for ILCs at the maternal-fetal interface during the pathological process of preterm labor.

Medroxyprogesterone acetate drives M2 macrophage differentiation toward a phenotype of decidual macrophage

M1 macrophage differentiation plays a crucial role in enhanced inflammation during pregnancy, which may lead to pregnancy complications. Therefore, modulation of macrophage differentiation toward the M2 phenotype is desirable to ensure a successful pregnancy. Medroxyprogesterone acetate (MPA) is a potent progestin with an anti-inflammatory property, but its effect on macrophage differentiation is unknown. This study aimed to examine whether MPA can induce an M2 macrophage differentiation by using the human monocytes cell line THP-1 or primary monocytes. THP-1 cells were primed with phorbol-12-myristate-13 acetate (PMA) to initiate macrophage differentiation. By incubating with MPA, the cells (denoted as MPA-pTHP-1) underwent M2 macrophage differentiation with downregulations of CD11c, IL-1β and TNF-α, and upregulations of CD163 and IL-10; while cells incubated with progesterone (P4) did not show the M2 phenotype. Primary monocytes treated with MPA also had the same M2 phenotype. Moreover, M1 macrophages derived from IFN-γ/LPS-treated THP-1 cells, which had high levels of IL-1b and iNOS, and low levels of IL-10 and IDO, were reversed to the M2 phenotype by the MPA treatment. We also found that the MPA-pTHP-1 promoted the decidualization of endometrial stromal cells and the invasion of trophoblast cells. To mimic conditions of exposure to various pathogens, MPA-pTHP-1 cells were stimulated by different types of TLR ligands. We found they produced lower levels of IL-1β and TNF-α, as well as a higher level of IL-10, compared to untreated cells. Finally, we found the level of phosphorylated ERK in the MPA-pTHP-1 cells was increased, but its IL-10 production was suppressed by either the progesterone/glucocorticoid antagonist (Mifepristone) or MEK inhibitor (U0126). Taken together, MPA could drive monocyte differentiation toward an M2 phenotype that mimics decidual macrophages. This finding holds great potential to combat chronic endometrial inflammation.

The Immune System and the Role of Inflammation in Perinatal Depression

Major depression during pregnancy is a common psychiatric disorder that arises from a complex and multifactorial etiology. Psychosocial stress, sex, hormones, and genetic vulnerability increase the risk for triggering mood disorders. Microglia and toll-like receptor 4 play a crucial role in triggering wide and varied stress-induced responses mediated through activation of the inflammasome; this leads to the secretion of inflammatory cytokines, increased serotonin metabolism, and reduction of neurotransmitter availability along with hypothalamic-pituitary-adrenal axis hyperactivity. Dysregulation of this intricate neuroimmune communication network during pregnancy modifies the maternal milieu, enhancing the emergence of depressive symptoms and negative obstetric and neuropsychiatric outcomes. Although several studies have clearly demonstrated the role of the innate immune system in major depression, it is still unclear how the placenta, the brain, and the monoaminergic and neuroendocrine systems interact during perinatal depression. Thus, in the present review we describe the cellular and molecular interactions between these systems in major depression during pregnancy, proposing that the same stress-related mechanisms involved in the activation of the NLRP3 inflammasome in microglia and peripheral myeloid cells in depressed patients operate in a similar fashion in the neuroimmune placenta during perinatal depression. Thus, activation of Toll-like receptor 2 and 4 signaling and the NLRP3 inflammasome in placental immune cells may promote a shift of the Th1/Th2 bias towards a predominant Th1/Th17 inflammatory response, associated with increased secretion of pro-inflammatory cytokines, among other secreted autocrine and paracrine mediators, which play a crucial role in triggering and/or exacerbating depressive symptoms during pregnancy.

An M1-like Macrophage Polarization in Decidual Tissue during Spontaneous Preterm Labor That Is Attenuated by Rosiglitazone Treatment

Decidual macrophages are implicated in the local inflammatory response that accompanies spontaneous preterm labor/birth; however, their role is poorly understood. We hypothesized that decidual macrophages undergo a proinflammatory (M1) polarization during spontaneous preterm labor and that PPARγ activation via rosiglitazone (RSG) would attenuate the macrophage-mediated inflammatory response, preventing preterm birth. In this study, we show that: 1) decidual macrophages undergo an M1-like polarization during spontaneous term and preterm labor; 2) anti-inflammatory (M2)-like macrophages are more abundant than M1-like macrophages in decidual tissue; 3) decidual M2-like macrophages are reduced in preterm pregnancies compared with term pregnancies, regardless of the presence of labor; 4) decidual macrophages express high levels of TNF and IL-12 but low levels of peroxisome proliferator-activated receptor γ (PPARγ) during spontaneous preterm labor; 5) decidual macrophages from women who underwent spontaneous preterm labor display plasticity by M1↔M2 polarization in vitro; 6) incubation with RSG reduces the expression of TNF and IL-12 in decidual macrophages from women who underwent spontaneous preterm labor; and 7) treatment with RSG reduces the rate of LPS-induced preterm birth and improves neonatal outcomes by reducing the systemic proinflammatory response and downregulating mRNA and protein expression of NF-κB, TNF, and IL-10 in decidual and myometrial macrophages in C57BL/6J mice. In summary, we demonstrated that decidual M1-like macrophages are associated with spontaneous preterm labor and that PPARγ activation via RSG can attenuate the macrophage-mediated proinflammatory response, preventing preterm birth and improving neonatal outcomes. These findings suggest that the PPARγ pathway is a new molecular target for future preventative strategies for spontaneous preterm labor/birth.

Neonatal Basophils Stifle the Function of Early-Life Dendritic Cells To Curtail Th1 Immunity in Newborn Mice

Neonatal immunity exhibits weak Th1 but excessive Th2 responses, and the underlying mechanisms remain elusive. In this article, we show that neonatal basophils readily produce IL-4, a cytokine that proved to be pivotal in shaping the programs of both lymphocyte subsets. Besides promoting Th2 programs, IL-4 is captured by the IL-4 heteroreceptor (IL-4Rα/IL-13Rα1) expressed on dendritic cells and instigates IL-12 downregulation. Under these circumstances, differentiating Th1 cells upregulate IL-13Rα1, leading to an unusual expression of the heteroreceptor, which will serve as a death marker for these Th1 cells during rechallenge with Ag. The resulting Th1/Th2 imbalance impacts childhood immunity culminating in sensitivity to allergic reactions, susceptibility to microbial infection and perhaps poor efficacy of pediatric vaccines.

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.

Macrophages at the fetal-maternal interface express markers of alternative activation and are induced by M-CSF and IL-10

During pregnancy, the maternal immune system is challenged by the presence of the fetus, which must be tolerated despite being semiallogeneic. Uterine mucosal (or decidual) macrophages (M), one of the major leukocyte populations at the fetal-maternal interface, have been implicated in fetal tolerance, but information regarding their regulation is scarce. In this study, we investigated the role of several factors potentially involved in the differentiation and polarization of decidual M with an in vitro M differentiation model. By using flow cytometry, we showed that M-CSF and IL-10 were potent inducers of M2 (immunoregulatory) M markers expressed on human decidual M (CD14, CD163, CD206, CD209). In contrast, proinflammatory stimuli, and unexpectedly also the Th2-associated IL-4 and IL-13, induced different patterns of expression, indicating that a Th2-dominated environment is not required for decidual M polarization. M-CSF/IL-10-stimulated and decidual M also showed similar cytokine secretion patterns, with production of IL-10 as well as IL-6, TNF, and CCL4. Conversely, the proinflammatory, LPS/IFN-γ-stimulated M produced significantly higher levels of TNF and no IL-10. We also used a gene array with 420 M-related genes, of which 100 were previously reported to be regulated in a global gene expression profiling of decidual M, confirming that M-CSF/IL-10-induced M are closely related to decidual M. Taken together, our results consistently point to a central role for M-CSF and in particular IL-10 in the shaping of decidual M with regulatory properties. These cytokines may therefore play an important role in supporting the homeostatic and tolerant immune milieu required for a successful pregnancy.

High viral load and deregulation of the progesterone receptor signaling pathway: association with hepatitis E-related poor pregnancy outcome

BACKGROUND & AIMS

Hepatitis E virus (HEV) infection is associated with high maternal and fetal mortalities. A prospective study was undertaken to evaluate the role of viral and host factors in HEV related pregnancy outcomes.

METHODS

The study included HEV infected pregnancy cases; acute viral hepatitis (AVH), n=100 and fulminant hepatic failure (FHF), n=43, and healthy pregnancy cases, n=50. HEV genotypes and viremia were studied by nucleotide sequencing and real time PCR, respectively. Progesterone receptor (PR) gene mutations (PROGINS) were studied by PCR, PR expression at the mRNA and protein levels in the placenta were studied by semi-quantitative RT-PCR and immunohistochemistry, respectively. Progesterone induced blocking factor (PIBF) expression was studied by RT-PCR in blood. Serum interleukin-10 (IL-10) and interleukin-12 (IL-12) levels were assayed by ELISA.

RESULTS

HEV viral load was significantly higher in FHF than AVH (p<0.001) and in cases with fetal mortality in AVH (p=0.001) and FHF (p=0.018). PROGINS were predominant in FHF compared to AVH (p=0.26) and showed reduced mRNA and protein expression. The risk of fetal mortality in AVH was two times higher (OR, 2.190; CI, 0.303-15.85) and maternal and fetal mortalities in FHF were 4-fold (OR, 4.0; CI, 0.363-44.113) increased in PROGINS carriers. PR and PIBF expression was lower in AVH and even lower in FHF compared to healthy controls. The higher IL-12/IL-10 ratio observed in FHF compared to other groups correlated with fetal mortality in AVH and FHF (p<0.001).

CONCLUSIONS

In conclusion, reduced expression of PR and PIBF, a higher IL-12/IL-10 ratio, and a high viral load results in poor pregnancy outcome in Hepatitis E.

Induction of a disintegrin and metalloprotease 33 during embryonic lung development and the influence of IL-13 or maternal allergy

BACKGROUND

Asthma pathogenesis involves gene and environmental interactions. A disintegrin and metalloprotease 33 (ADAM33)/Adam33 is a susceptibility gene for asthma and bronchial hyperresponsiveness in human beings and mice. ADAM33 is almost exclusively expressed in mesenchymal cells, including mesenchymal progenitors in developing lungs.

OBJECTIVE

Because maternal allergy is a risk factor for asthma, we hypothesized that an allergic environment affects ADAM33/Adam33 expression during human and mouse lung development.

METHODS

Human embryonic/fetal lung (HEL) tissues were collected from first-trimester terminations of pregnancy. These were processed immediately or used for explant culture +/- IL-13. MF1 mice or ovalbumin-sensitized A/J mice (Bronchial hyperresponsivness (Bhr)1/Adam33 locus-positive) were time-mated and challenged with ovalbumin (A/J mice only) during pregnancy. Lungs were harvested at different times during gestation and post partum. ADAM33/Adam33 expression was analyzed by using reverse transcriptase quantitative polymerase chain reaction and Western blotting.

RESULTS

ADAM33 mRNA was detectable in HELs in the pseudoglandular stage of development and showed a significant increase from 7 to 9 weeks postconception. IL-13 significantly suppressed ADAM33 mRNA in HEL explants. In developing murine lungs, Adam33 mRNA and protein expression increased significantly in the early pseudoglandular stage and showed another large increase post partum. In A/J mice, maternal allergy significantly suppressed Adam33 mRNA in lungs of newborn pups, whereas processed Adam33 protein increased and several smaller isoforms were detected.

CONCLUSION

Adam33/Adam33 shows 2 significant increments in expression during lung morphogenesis, suggesting important developmental regulation. The ability of maternal allergy or exogenous IL-13 to suppress Adam33/ADAM33 mRNA but enhance Adam33 processing suggests a gene-environment interaction that may be relevant for asthma pathogenesis.

Gene expression profiling of human decidual macrophages: evidence for immunosuppressive phenotype

Background

Although uterine macrophages are thought to play an important regulatory role at the maternal-fetal interface, their global gene expression profile is not known.

Methodology/Principal Findings

Using micro-array comprising approximately 14,000 genes, the gene expression pattern of human first trimester decidual CD14+ monocytes/macrophages was characterized and compared with the expression profile of the corresponding cells in blood. Some of the key findings were confirmed by real time PCR or by secreted protein. A unique gene expression pattern intrinsic of first trimester decidual CD14+ cells was demonstrated. A large number of regulated genes were functionally related to immunomodulation and tissue remodelling, corroborating polarization patterns of differentiated macrophages mainly of the alternatively activated M2 phenotype. These include known M2 markers such as CCL-18, CD209, insulin-like growth factor (IGF)-1, mannose receptor c type (MRC)-1 and fibronectin-1. Further, the selective up-regulation of triggering receptor expressed on myeloid cells (TREM)-2, alpha-2-macroglobulin (A2M) and prostaglandin D2 synthase (PGDS) provides new insights into the regulatory function of decidual macrophages in pregnancy that may have implications in pregnancy complications.

Conclusions/Significance

The molecular characterization of decidual macrophages presents a unique transcriptional profile replete with important components for fetal immunoprotection and provides several clues for further studies of these cells.

Discovering susceptibility genes for asthma and allergy

Asthma and asthma-related traits are complex diseases with strong genetic and environmental components. Rapid progress in asthma genetics has led to the identification of several candidate genes that are associated with asthma-related traits. Typically the phenotypic impact of each of these genes, including the ones most often replicated in association studies, is mild, but larger effects may occur when multiple variants synergize within a permissive environmental context. Despite the achievements made in asthma genetics formidable challenges remain. The development of novel, powerful tools for gene discovery, and a closer integration of genetics and biology, should help to overcome these challenges.

Comparison of macrophage phenotype between decidua basalis and decidua parietalis by flow cytometry

The two regions of the maternal decidua, decidua basalis and decidua parietalis, differ in the extent of trophoblast invasion and consequently in cytokines and other biological mediators, extracellular matrix and cellular components. Our aim was to compare the phenotypic features of macrophages from the two decidual regions across a broad gestational age range. We isolated macrophages by enzymatic digestion from healthy decidua samples obtained after elective abortions, at 9-18-week and at 19-23-weeks, or after term deliveries (caesarean sections at term and spontaneous term vaginal deliveries). Macrophages were analysed by flow cytometry applying the same instrument settings to all the samples to allow semi-quantitative comparison of the expression of a particular marker between different samples. We found higher expressions of CD80, CD86 and HLA-DR, suggestive of a more activated phenotype of decidual macrophages, at early/mid pregnancy than at term. Marginal differences were found between term decidual macrophages obtained after spontaneous vaginal deliveries or caesarean sections which imply that the parturient process is not associated with decidual macrophage activation. The expressions of CD105, DC-SIGN and MMR were the strongest in decidua basalis of mid pregnancy and indicate the importance of decidual macrophages in tissue homeostasis at the uteroplacental interface.

IL-35 is a novel cytokine with therapeutic effects against collagen-induced arthritis through the expansion of regulatory T cells and suppression of Th17 cells

Epstein-Barr virus-induced gene 3 (EBI3) and the p35 subunit of IL-12 have been reported to form a heterodimeric hematopoietin in human and mouse. We have constructed a heterodimeric protein covalently linking EBI3 and p35, to form a novel cytokine which we now call IL-35. The Fc fusion protein of IL-35 induced proliferation of murine CD4(+)CD25(+) and CD4(+)CD25(-) T cells when stimulated with immobilized anti-CD3 and anti-CD28 antibodies in vitro. The IL-35-expanded CD4(+)CD25(+) T cell population expressed Foxp3 and produced elevated levels of IL-10, whereas the IL-35-induced CD4(+)CD25(-) T cells produced IFN-gamma but not IL-4. The in vitro expanded CD4(+)CD25(+) T cells retained their suppressive functions against CD4(+)CD25(-) effector cells. Furthermore, when cultured with soluble anti-CD3 antibody and antigen-presenting cells, IL-35 suppressed the proliferation of CD4(+)CD25(-) effector cells. Moreover, IL-35 inhibited the differentiation of Th17 cells in vitro. In vivo, IL-35 effectively attenuated established collagen-induced arthritis in mice, with concomitant suppression of IL-17 production but enhanced IFN-gamma synthesis. Thus, IL-35 is a novel anti-inflammatory cytokine suppressing the immune response through the expansion of regulatory T cells and suppression of Th17 cell development.

Interleukin-13 stimulates the secretion of vascular endothelial growth factor and soluble fms-like tyrosine kinase-1 by human oviductal epithelial cells

OBJECTIVE

The aim of this study is to evaluate the effects of interleukin (IL)-13, a Th2 cytokine, on the production of vascular endothelial growth factor (VEGF) and soluble fms-like tyrosine kinase-1 (sFlt-1) in human oviductal cells in vitro.

STUDY DESIGN

Human oviductal epithelial cells (OECs) were isolated from five premenopausal patients. The secretion of VEGF(165) and sFlt-1 by cultured OECs in response to IL-13 was measured using an enzyme-linked immunosorbent assay.

RESULTS

The secretion of VEGF(165) and sFlt-1 was detected in cultured OECs under untreated conditions. IL-13 enhanced the secretion of VEGF(165) and sFlt-1 by OECs in a dose-dependent manner.

CONCLUSION

The present findings suggest that IL-13 is a regulatory factor of VEGF and sFlt-1 production in the human fallopian tubes. IL-13 in the local environment may stimulate oviductal vascular permeability by inducing the production of VEGF by oviductal cells. The modulation of VEGF secretion by IL-13 secreted by the peri-implantation embryo may contribute to the normal and pathological processes of human reproduction during the peri-implantation period.

Maternal influence in the transmission of asthma susceptibility

Asthma is one of the most common chronic diseases in children, with increasing morbidity and mortality. A genetic predisposition and exposure to allergens have been implicated as major risk factors for the development of asthma. However, increasing evidence indicates that the mother plays a crucial role in mediating the development of fetal-infant immune responses to inhaled allergens. The exact nature and mechanism of this maternal influence and how it might be associated with the development of allergic sensitization and asthma are not clear. Under normal conditions, the maternal environment during pregnancy promotes an initial Th2 skewed immune response in the offspring which transitions to a nonallergic Th1 type response after birth. However, the allergic mother's influence may delay the normal transition to a nonallergic immune response to inhaled allergens in her children, thus increasing the risk for the development of allergic sensitization and/or asthma. Understanding the underlying mechanisms by which the maternal immune environment can influence the development of the fetal-infant immune response to inhaled allergens may lead to identifying new targets for the prevention of allergic sensitization and asthma.

Th2 cell-selective enhancement of human IL13 transcription by IL13-1112C>T, a polymorphism associated with allergic inflammation

IL-13 is a central mediator of allergic inflammation. The single nucleotide polymorphism IL13-1112C>T (rs1800925) is associated with allergic phenotypes in ethnically distinct populations, but the underlying mechanism(s) remain unknown. Using in vivo, in vitro, and in silico analysis, we show that the IL13-1112T allele enhanced IL13 promoter activity in primary human and murine CD4(+) Th2 lymphocytes. Increased expression of IL13-1112T in Th2 cells was associated with the creation of a Yin-Yang 1 binding site that overlapped a STAT motif involved in negative regulation of IL13 expression and attenuated STAT6-mediated transcriptional repression. Because IL-13 secretion was increased in IL13-1112TT homozygotes, we propose that increased expression of IL13-1112T in vivo may underlie its association with susceptibility to allergic inflammation. Interestingly, IL13-1112T had opposite transcriptional effects in nonpolarized CD4(+) T cells, paralleled by distinct patterns of DNA-protein interactions at the IL13 promoter. Our findings suggest the nuclear milieu dictates the functional outcome of genetic variation.

Tumour necrosis factor-alpha impairs chorionic gonadotrophin beta-subunit expression and cell fusion of human villous cytotrophoblast

Growth factors expressed at the fetal-maternal interface modulate hormone expression of placental trophoblasts. The aim of this study was to investigate the effects of different cytokines on hCG subunit mRNA expression in differentiating villous cytotrophoblasts. Quantitative real-time PCR revealed a 1.8- and 6.9-fold increase of hCG-alpha and hCG-beta mRNA levels, respectively, between 36 and 60 h of term trophoblast syncytialization. Compared with controls, neither interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-10, IL-13 and IL-15 nor tumour necrosis factor (TNF)-alpha significantly altered hCG-alpha mRNA expression. Similarly, the ILs did not affect hCG-beta transcript levels. In contrast, TNF-alpha suppressed hCG-beta mRNA 3.8- and 1.8-fold at 36 and 60 h of term trophoblast differentiation. Accordingly, hCG secretion was impaired by TNF-alpha but not by the different ILs. Moreover, TNF-alpha reduced luciferase expression of reporter plasmids harbouring the proximal hCG-beta5 promoter to 35 and 77%, respectively, in primary term trophoblasts and trophoblastic SHGPL-5 cells. In addition, counting of nuclei in syncytialized, desmoplakin-negative areas revealed a 1.9-fold reduction of term trophoblast fusion in the presence of TNF-alpha. Similarly, floating explant cultures prepared from first trimester-denuded villi recovered the syncytium 2.8-fold less efficiently during 72 h of cytokine treatment. Concomitantly, TNF-alpha impaired induction of endogenous and secreted hCG-beta protein levels in these cultures. The data suggest that TNF-alpha decreases hCG-beta mRNA and protein expression by reducing gene transcription and trophoblast cell fusion. Suppression of these processes by TNF-alpha could partly explain the adverse effects of the cytokine on placental function and pregnancy outcome.

Tibolone and metabolites induce prolactin production in human endometrial stromal cells in vitro: evidence for cell-specific metabolism

In this study, we assessed the effects of tibolone and its metabolites on the production of a progesterone sensitive parameter, prolactin, in human endometrium stroma cells in vitro. In addition, the metabolism of the compounds by isolated stromal and epithelial cells was evaluated. The reference compounds, progesterone, Org 2058, and DHT all induced prolactin production. Oestradiol also slightly induced prolactin production and enhanced the response to Org 2058. Tibolone and Delta4-tibolone were similar with regard to potency to induce prolactin levels in the culture supernatant. Their potency was lower than that of Org 2058, similar to that of progesterone and higher than that of DHT. The efficacies of tibolone, Delta4-tibolone and Org 2058 were similar (approximately 200-fold induction). The estrogenic tibolone metabolites 3alpha- and 3beta-OH tibolone also significantly stimulated prolactin production. Their potency, however, was low since significance was reached only at the highest concentrations tested. The PR antagonist Org 31710 inhibited both tibolone- and Delta4-tibolone-induced prolactin production. The responses of tibolone and Delta4-tibolone were not affected by co-incubation with the androgen receptor antagonist OH-flutamide. The effect of tibolone, but not Delta4-tibolone, was antagonized approximately 50% in combination with the highest dose (1 microM) estrogen receptor antagonist, ICI 164384. The induction of prolactin by 3alpha- and 3beta-OH tibolone was antagonized most potently by Org 31710, but also by ICI 164384 and OH-flutamide. Tibolone is metabolized differently in epithelial and stromal cells of the human endometrium. The epithelial cells mostly produce the progestagenic/androgenic Delta4-tibolone. The stromal cells produce predominantly the 3beta-OH tibolone, and some Delta4-tibolone, but the net effect observed with regard to prolactin production is progestagenic. When the metabolites 3alpha-OH, 3beta-OH, and Delta4-tibolone were added to the cultures no conversions were observed. The HPLC analyses showed no evidence for the production of sulfated metabolites. In conclusion, the net effects on endometrial stromal cells are predominantly progestagenic. Tibolone is converted by epithelial cells into Delta4-tibolone which displays progestagenic and androgenic activities, whereas in stromal cells also the estrogenic metabolites 3alpha- and 3beta-OH tibolone are formed.

Th1/Th2 cytokines balance--yin and yang of reproductive immunology

For years conception of Th2 overbalance during pregnancy has been a paradigm for immunology of reproduction, while Th1 activity has been presented as unwanted component. Studies concerning Th1/Th2 balance in physiological and complicated pregnancy have been reviewed. Th1 activity during early peri-implantation period, premature and term labour not only accompanies but even predominates over Th2 activity. Th1 activity plays important role in promotion of Th2 response, regulation of placentation process, defense against infections and initiation of delivery. Together with Th2 activity it is necessary component of immunological reactions during pregnancy, both activities being inseparable like yin and yang. So paradigm of "Th1-Th2 cooperation" is much closer to reality than "Th2 phenomenon".

Progesterone and the immunology of pregnancy

The foetal-placental unit is a semi-allograft and the immunological recognition of pregnancy, together with the subsequent response of the maternal immune system, is necessary for a successful pregnancy. This recognition of pregnancy results in an upregulation of progesterone receptors on activated lymphocytes amongst placental cells and decidual CD56+ cells. In the presence of sufficient progesterone, these cells synthesise progesterone induced blocking factor (PIBF), a mediator that exerts substantial anti-abortive activities. PIBF affects B cells and induces an increased production of asymmetric, non-cytotoxic antibodies. It also alters the profile of cytokine secretion by activated lymphocytes resulting in an increase in the production of non-inflammatory, non-cytotoxic interleukins (IL) (e.g. IL-3, IL-4 and IL-10) and a reduction in the production of inflammatory, cytotoxic cytokines (e.g. interferon (IFN)-delta, tumour necrosis factor (TNF)-alpha and IL-2). PIBF also inhibits the cytotoxicity of natural killer (NK) cells by blocking their degranulation and perforin release, as well as inhibiting IFN-delta, TNF-alpha and IL-2-mediated transformation of NK cells into detrimental lymphokine activated killer (LAK) cells.

Correlation of human decidual and cord blood mononuclear cell cytokine production

Human decidua has been shown to produce a number of cytokines. We hypothesized that decidual cytokine production influences cord blood mononuclear cell (CBMC) cytokine production and that cytokine profiles of decidua from allergic women differ from those of decidua from nonallergic women. Using enzyme-linked immunosorbent assay, we measured unstimulated and concanavalin A/phorbol myristate acetate-stimulated production of interleukin-4 (IL-4), IL-5, IL-10, IL-13 and interferon- gamma (IFN-gamma) by decidual explants from 59 healthy women delivered by unlabored cesarean section and from corresponding CBMCs in 39 of the 59. Except for IL-10, there was little or no unstimulated cytokine production. There was a strong correlation between stimulated decidual and stimulated CBMC IFN-gamma production (p = 0.01). In allergic women the ratio of IL-13 to IL-4 production was increased in stimulated explants (p = 0.03). Stimulated CBMCs from infants of allergic mothers were more likely to produce detectable levels of IL-5 than those from infants of nonallergic mothers (p = 0.04) and had a tendency toward higher IL-13 levels as well (p = 0.07). These results suggest that maternal and fetal IFN-gamma production is closely linked and that maternal allergy appears to influence cytokine production in the neonate for IL-5 and possibly IL-13.

Cultured human endometrial epithelial cells produce thymus and activation-regulated chemokine with stimulation of interleukin-4 and interleukin-13

OBJECTIVE

To evaluate the effects of T-helper (Th)1 and Th2 cytokines on the production of thymus and activation-regulated chemokine (TARC) and macrophage-derived chemokine (MDC) by cultured endometrial epithelial cells (EEC) and endometrial stromal cells (ESC).

DESIGN

The effects of interleukin (IL)-2, IL-4, IL-5, IL-10, IL-12, IL-13, interferon-gamma (IFN-gamma), and tumor necrosis factor-beta (TNF-beta) on the production of TARC and MDC were investigated.

SETTING

Research laboratory at a medical school.

PATIENT(S)

Fifteen endometrial specimens in the mid-late secretory phase were used.

INTERVENTION(S)

The EEC and ESC were incubated for 24 hours with recombinant human IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, IFN-gamma, and TNF-beta.

MAIN OUTCOME MEASURE(S)

The concentrations of TARC and MDC in the culture media were measured using ELISA.

RESULT(S)

Small amounts of TARC were detected in the culture medium of nonstimulated EEC. The increase in levels of TARC in the culture media of EEC paralleled the addition of increasing amounts of IL-4 and IL-13. Other cytokines, however, did not affect the production of TARC by EEC. Production of TARC by ESC was not detected under either nonstimulated or cytokine-stimulated conditions. Production of MDC was not detected in the culture media of EEC and ESC.

CONCLUSION(S)

These results suggest that IL-4 and IL-13 secreted from the embryo during the implantation period may selectively up-regulate the production of TARC by EEC. The controlled production of TARC in the endometrium may contribute to the modulation of the immune reaction by the regulation of Th2 lymphocyte trafficking and functions.

Localization and variation of TRAIL and its receptors in human placenta during gestation

The localization of TRAIL and its receptors in human placenta was studied under light microscopy using immunohistochemistry method. The variation of TRAIL and its receptors with development was also detected by in situ semi-quantification. The syncytiotrophoblast, cytotrophoblast, stromal cells and the capillary endothelium cells in human placenta all appeared to be TRAIL immunoreactive and the immunoreactive material was distributed on membrane and in cytoplasm with negative nuclei. During whole gestation there was no obvious variation of the staining of TRAIL. Although DR4, DR5, DcR1 and DcR2 can also be detected in the placenta throughout pregnancy, DR4 and DR5 staining increased with development whereas DcR1 and DcR2 staining decreased. Interestingly, at the beginning of the gestation DR4 and DR5 staining distributed on the cytotrophoblast mainly, whereas DcR1 and DcR2 mainly located in the syncytiotrophoblast cells. Collectively, these results suggest that human placenta may not only produce TRAIL but also be a TRAIL target organ, and that TRAIL/TRAILR system could take part in the self-homeostasis of placenta during whole gestation.

Maternal fish oil supplementation in pregnancy reduces interleukin-13 levels in cord blood of infants at high risk of atopy

BACKGROUND AND OBJECTIVES

The epidemiological association between higher dietary n-3 polyunsaturated fatty acids (PUFA) and lower prevalence of asthma, has led to interest in the role of early dietary modification in allergic disease prevention. In this study we examined the effects of maternal n-3 (PUFA)-rich fish oil supplementation on cord blood (CB) IgE and cytokine levels in neonates at risk of developing allergic disease.

METHODS

In a randomized double-blind, placebo-controlled trial, 83 atopic pregnant women received either fish oil capsules (n = 40) containing 3.7 g n-3 PUFA/day or placebo capsules (n = 43) from 20 weeks gestation until delivery. CB cytokine levels (IL-4, IL-5, IL-6, IL-10, IL-12, IL-13, TNF-alpha and IFN-gamma) and total IgE levels were measured and compared between the two groups. Fatty acid composition of red cell membranes was analysed by gas chromatography and the relationships among PUFA, cytokine and IgE levels were examined.

RESULTS

Maternal fish oil supplementation resulted in a significant increase in n-3 PUFA levels (P < 0.001) in neonatal erythrocyte membranes. Neonates whose mothers had fish oil supplementation had significantly lower plasma IL-13 (P < 0.05) compared to the control group. There was also a significant inverse relationship between levels of n-3 PUFA in neonatal cell membranes and plasma IL-13. There was no difference in levels of IgE and the other cytokines measured.

CONCLUSIONS

This study provides preliminary evidence that increasing neonatal n-3 PUFA levels with maternal dietary supplementation can achieve subtle modification of neonatal cytokine levels. Further assessment of immune function and clinical follow-up of these infants will help determine if there are any significant effects on postnatal immune development and expression of allergic disease.

Unique appearance of proliferating antigen-presenting cells expressing DC-SIGN (CD209) in the decidua of early human pregnancy

Intact human pregnancy can be regarded as an immunological paradox in that the maternal immune system accepts the allogeneic embryo without general immunosuppression. Because dendritic cell (DC) subsets could be involved in peripheral tolerance, the uterine mucosa (decidua) was investigated for DC populations. Here we describe the detailed immunohistochemical and functional characterization of HLA-DR-positive antigen-presenting cells (APCs) in early pregnancy decidua. In contrast to classical macrophages and CD83(+) DCs, which were found in comparable numbers in decidua and nonpregnant endometrium, only decidua harbored a significant population of HLA-DR(+)/DC-SIGN(+) APCs further phenotyped as CD14(+)/CD4(+)/CD68(+/-)/CD83(-)/CD25(-). These cells exhibited a remarkable proliferation rate (9.2 to 9.8% of all CD209(+) cells) by double staining with Ki67 and proliferating cell nuclear antigen. Unique within the DC-family, the majority of DC-SIGN(+) decidual APCs were observed in situ to have intimate contact with CD56(+)/CD16(-)/ICAM-3(+) decidual natural killer cells, another pregnancy-restricted cell population. In vitro, freshly isolated CD14(+)/DC-SIGN(+) decidual cells efficiently took up antigen, but could not stimulate naive allogeneic T cells at all. Treatment with an inflammatory cytokine cocktail resulted in down-regulation of antigen uptake capacity and evolving capacity to effectively stimulate resting T cells. Fluorescence-activated cell sorting analysis confirmed the maturation of CD14(+)/DC-SIGN(+) decidual cells into CD25(+)/CD83(+) mature DCs. In summary, this is the first identification of a uterine immature DC population expressing DC-SIGN, that appears only in pregnancy-associated tissue, has a high proliferation rate, and a conspicuous association with a natural killer subset.

Interleukin-13 and tumor necrosis factor-beta differentially regulate the production of cytokines by cultured human endometrial stromal cells

OBJECTIVE

To evaluate the effects of interleukin (IL)-13, a T-helper (Th)2 cytokine, and tumor necrosis factor (TNF)-beta, a Th1 cytokine, on the production of IL-6 family cytokines and chemokines by endometrial stromal cells (ESC).

DESIGN

The effects of IL-13 and TNF-beta, on the production of IL-6, IL-11, leukemia inhibitory factor (LIF), IL-8, growth-regulated oncogene alpha (GROalpha), monocyte chemoattractant protein-1 (MCP-1), regulated on activation, T-cell expressed and secreted (RANTES), and eotaxin were investigated.

SETTING

Research laboratory at a medical university.

PATIENT(S)

Thirteen endometrial specimens in the late proliferative phase were used.

INTERVENTION(S)

The ESC were incubated for 24 hours with recombinant human IL-13 and recombinant human TNF-beta.

MAIN OUTCOME MEASURE(S)

The concentration of IL-6, IL-11, LIF, IL-8, GROalpha, MCP-1, RANTES, and eotaxin in the culture media was measured using ELISA.

RESULT(S)

The increase in levels of IL-6, IL-8, MCP-1, and eotaxin in the culture media of ESC paralleled the addition of increasing amounts of IL-13 and TNF-beta, whereas the levels of IL-11 and LIF were decreased with increasing amounts of IL-13, but were increased with increasing amounts of TNF-beta. Tumor necrosis factor-beta enhanced the production of GROalpha and RANTES in dose-dependent manner; however, IL-13 did not affect the expression of GROalpha or RANTES.

CONCLUSION(S)

These results suggest that IL-13 and TNF-beta secreted in the cyclic endometrial tissue and in the decidua may differentially regulate the production of IL-6 family cytokines and chemokines by ESC. The controlled expression of these cytokines in the endometrium may contribute to the modulation of the immune reaction during the menstrual cycle and in early pregnancy by the regulation of leukocyte trafficking and functions.

Cytokines of the placenta and extra-placental membranes: biosynthesis, secretion and roles in establishment of pregnancy in women

Virtually all known cytokines have been demonstrated to be expressed in the placenta and associated fetal and maternal membranes during normal gestation. In addition to playing their traditional roles as modulators of immunological function, cytokines derived from the placenta and extraplacental membranes, together with other locally-derived growth factors, appear to be implicated in various aspects of implantation and placental development. Imbalances in the intrauterine cytokine milieu around the time of implantation and invasion may play a causative role in disorders associated with early pregnancy failure, and are also associated with the abnormal trophoblast development seen in gestational trophoblastic disease. Cytokines thus appear to be an important component of a paracrine/autocrine communication network operating within the feto-maternal interface to ensure the successful establishment of pregnancy.

Localization of pro-inflammatory (IL-12, IL-15) and anti-inflammatory (IL-11, IL-13) cytokines at the foetomaternal interface during murine pregnancy

The involvement of some interleukins (ILs) in early and established pregnancy has been convincingly demonstrated, but little is known about the potential role of the more recently discovered ones. However, since many of these have positive or negative regulatory effects on both NK and T cells, it is highly probable that they also have regulatory functions in both implantation and placental development. Therefore, as a first step in tackling this problem, we have investigated whether several recently described pro- (IL-12, IL-15) and anti-inflammatory (IL-11, IL-13) cytokines were expressed at the uteroplacental interface by use of immunohistochemistry at different stages of gestation in mice. Each of these molecules was found at the foetomaternal interface, with specific distributions and patterns of expression depending on both the cytokine itself and the stage of pregnancy. The significance of these data is discussed.

Expression of Epstein-Barr virus-induced gene 3, an interleukin-12 p40-related molecule, throughout human pregnancy: involvement of syncytiotrophoblasts and extravillous trophoblasts

In human pregnancy, trophoblasts are the only cells of fetal origin in direct contact with the maternal immune system: syncytiotrophoblasts are in contact with maternal blood, whereas extravillous trophoblasts are in contact with numerous maternal uterine natural killer (NK) cells. Therefore, trophoblasts are thought to play a key role in maternal tolerance to the semiallogeneic fetus, in part through cytokine production and NK cell interaction. Epstein-Barr virus-induced gene 3 (EBI3) encodes a soluble hematopoietin receptor related to the p40 subunit of interleukin-12. Previous studies indicated that EBI3 is expressed in the spleen and tonsils, and at high levels in full-term placenta. To investigate further EBI3 expression throughout human pregnancy, we generated monoclonal antibodies specific for EBI3 and developed an EBI3 enzyme-linked immunosorbent assay. Immunohistochemical experiments with EBI3 monoclonal antibody on first-, second-, and third-trimester placental tissues demonstrated that EBI3 was expressed throughout pregnancy by syncytiotrophoblasts and extravillous trophoblasts (cytotrophoblast cell columns, interstitial trophoblasts, multinucleated giant cells, and trophoblasts of the chorion laeve). EBI3 expression was also induced during in vitro differentiation of trophoblast cell lines. In addition, large amounts of secreted EBI3 were detected in explant cultures from first-trimester and term placentae. Consistent with these data, EBI3 levels were strongly up-regulated in sera from pregnant women and gradually increased with gestational age. These data, together with the finding that EBI3 peptide is presented by HLA-G, suggest that EBI3 is an important immunomodulator in the fetal-maternal relationship, possibly involved in NK cell regulation.

Pregnancy: success and failure within the Th1/Th2/Th3 paradigm

Evidence from studies on murine and human pregnancy points to a strong association between maternal Th2-type immunity and successful pregnancy on the one hand and between Th1-type immune reactivity and pregnancy loss on the other. While there is a paucity of data from human pregnancy indicating that Th1-type immune effectors actually lead to pregnancy, it is difficult to ignore the compelling evidence linking inappropriate Th1-type immunity to pregnancy loss. Th2-type immunity and TGF beta secreted by Th3 cells may play protective roles during pregnancy, hence the nexus between a Th2/Th3 shift and successful pregnancy. This paper examines these associations and discusses possible mechanisms underlying immunologically mediated pregnancy failure.

Crucial role of cytokines in sex steroid formation in normal and tumoral tissues

There is evidence suggesting that local intracrine formation of sex steroids from inactive precursors, dehydroepiandrosterone (DHEA), its sulfate (DHEA-S) and 4-androstenedione (4-DIONE) plays an important role in the regulation of growth and function of peripheral target tissues. Moreover, human solid tumors are often infiltrated by stromal/immune cells secreting a wide spectra of cytokines. These cytokines might in turn regulate the activity of both immune and neoplastic cells. Our data demonstrate that the potent regulatory effects of interleukin-4 (IL-4) and IL-6 on both estrogenic and androgenic 17beta-HSD/KSR activities in breast cancer cells depend on the cell-specific gene expression of various types of 17beta-HSD/KSR enzymes. However, in both estrogen-receptor (ER)-positive (ZR-75-1, T-47D) and ER-negative (MDA-MB-231, BT-20) human breast cancer cells, exposure to IL-4 and IL-13 caused a rapid and potent induction of 3beta-HSD type 1 gene expression. Such an induction was also observed in normal human mammary and prostate epithelial cells in primary culture as well as in human HaCaT immortalized keratinocytes, ME-180 cervix cancer cells, and HT-29 colon cancer cells. The DNA-binding activity of Stat6, a member of the Signal Transducers and Activators of Transcription gene family, was activated after a 30 min exposure to IL-4 in all the cell types where IL-4 induced 3beta-HSD expression, but not in those that failed to respond to IL-4. Our data therefore suggest that IL-4 and IL-13 may play a role in the biosynthesis of active sex steroids from the inactive adrenal steroid DHEA, not only in breast cells but also in various cell types derived from peripheral target tissues.

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

Control of antifetal immune responses is thought to be regulated locally by the placenta. Because the physiologic programming of the placenta across gestation is likely to influence the local immunity, we hypothesize that a potent anti-inflammatory cytokine such as IL-10 may be produced in a gestational age-dependent manner. In the present study, we examined the expression of IL-10 and its receptor in placental explants or freshly isolated cytotrophoblasts from different gestational ages and compared it with the expression profiles of other cytokines. First and second trimester placental tissues from normal pregnancies predominantly expressed IL-10, whereas the levels of IL-2, IL-4, and IFN-gamma were mostly below detection throughout pregnancy. The expression of IL-10, but not its receptor, diminished significantly in term placental tissues collected "before" the onset of labor and did not change appreciably "after" labor. On the other hand, TNF-alpha and IL-1beta were significantly up-regulated in response to labor-associated conditions. IL-10 expression was transcriptionally attenuated at term as observed in cytotrophoblasts. In contrast to the placental cytokine milieu, autologous PBMCs, when activated with PHA, secreted significant amounts of IL-2, IL-4, IL-10, and IFN-gamma, albeit with a statistically significantly enhanced IL-10 production in first trimester compared with age-matched nonpregnant women. These data suggest that IL-10 is expressed in the placenta in a gestational age-dependent manner and that its down-regulation at term may be an important mechanism underlying the subtle changes associated with parturition.

Fetal and neonatal IL-13 production during pregnancy and at birth and subsequent development of atopic symptoms

BACKGROUND

Cytokine production at the materno-fetal interface may influence the development of atopy-predisposing immune responses. Because IL-13 possesses IL-4-like activity and may regulate the immune responses observed in atopy, it may contribute to the expression of the atopic phenotype initiated during intrauterine life.

OBJECTIVE

We sought to examine IL-13 expression by fetal and neonatal cells and the placenta.

METHODS

The production of IL-13 by neonatal and fetal T cells was examined by culturing the cells in the presence or absence of PHA. Production of IL-13 at term was considered in the context of the later development of atopic disease in the child. IL-13 expression in the placenta was assessed by using immunohistochemistry.

RESULTS

IL-13 immunoreactivity within the placenta was restricted to 16 to 27 weeks' gestation (6/6 positive vs 0/10 at >27 weeks' gestation). In contrast, spontaneous release of IL-13 by fetal mononuclear cells was first observed from 27 weeks' gestation but was undetectable after 37 weeks' gestation. PHA-stimulated mononuclear cells showed increased IL-13 levels in 80% of samples. Term babies (>37 weeks' gestation) with a parental history of atopy with atopic symptoms by 3 years of age produced significantly lower concentrations of PHA-induced IL-13 when compared with babies with no parental history of atopy (P =.034).

CONCLUSION

Thus babies at risk of atopic disease in infancy display defective IL-13 production at birth. This may represent an inherent immaturity in the development of T cell-cytokine responses in babies at genetic risk for atopy or could be a consequence of downregulation of responses by other factors. Normal pregnancy, irrespective of atopic status, is associated with the production of appreciable quantities of IL-13 initially by the placenta and subsequently by the fetus. The regulation of this production and its consequences for the mother and fetus remains to be elaborated.

Induction of 3beta-hydroxysteroid dehydrogenase/isomerase type 1 expression by interleukin-4 in human normal prostate epithelial cells, immortalized keratinocytes, colon, and cervix cancer cell lines

The 3beta-hydroxysteroid dehydrogenase/isomerase (3beta-HSD) isoenzymes catalyze an essential step in the formation of all classes of active steroid hormones. In humans there are two 3beta-HSD isoenzymes, the type 1 gene being predominantly expressed in the placenta and peripheral tissues, whereas the type 2 gene is the predominant 3beta-HSD expressed in the adrenal glands and gonads. We have recently showed that interleukin (IL)-4 and IL-13 induce 3beta-HSD type 1 gene expression in human breast cancer cell lines as well as in normal human mammary epithelial cells. The present study was designed to investigate whether such a cytokine-induced 3beta-HSD type 1 expression would also be observed in cell types derived from other peripheral sex steroid target tissues. To gain further knowledge about the molecular mechanism of IL-4 action, we have studied whether the induction of 3beta-HSD type 1 expression in IL-4-responsive cell types would always be associated with the activation of Stat6, a member of the Signal Transducers and Activators of Transcription (STAT) gene family. Stat6 is recognized as the principal transcription factor mediating the effects of IL-4. In normal human prostate epithelial cells (PrEC), no 3beta-HSD activity was detectable under basal culture conditions, while exposure to IL-4 or IL-13 caused a potent induction of this activity. This effect results from a rapid induction of 3beta-HSD type 1 messenger RNA levels as determined by Northern blot and RT-PCR analyses. Furthermore, IL-4 and IL-13 also increased 3beta-HSD type 1 gene expression in human HaCaT immortalized keratinocytes, ME-180 cervix cancer cells, HT-29 colon cancer cells as well as in BT-20 and ZR-75-1 breast cancer cells. However, IL-4 and IL-13 failed to modulate the 3beta-HSD type 1 expression in human LnCAP and PC-3 prostate cancer cells, Caco-2 colon cancer cells as well as in JAR and JEG-3 choriocarcinoma cell lines. The DNA-binding activity of Stat6 was activated after a 30-min exposure to IL-4 in PrEC and in all the cell types where IL-4 induced 3beta-HSD expression, but not in those that failed to respond to IL-4. Our data therefore suggest that IL-4 and IL-13 may play a role in the biosynthesis of active sex steroids from the inactive adrenal steroid dehydroepiandrosterone, not only in breast cells but also in various cell types derived from peripheral target tissues, such as normal human prostate epithelial cells, immortalized keratinocytes, as well as colon and cervix cancer cell lines. Our data also demonstrates that the stimulatory effect of IL-4 was always associated with the activation of Stat6, thus supporting the essential role of Stat6 in this induction of 3beta-HSD type 1 gene expression.

Maternal Th1- and Th2-type reactivity to placental antigens in normal human pregnancy and unexplained recurrent spontaneous abortions

Spontaneous abortion is the most common complication of pregnancy, but the etiology of a significant proportion of abortions is still unknown. We have examined the production of Th1- and Th2-type cytokines by women with unexplained recurrent spontaneous abortion (RSA) since it appears that successful murine pregnancy occurs in a Th2-dominant situation and that Th1-type immunity is associated with pregnancy failure. We have compared maternal reactivity toward placental antigens in women with a history of successful pregnancy with that in women with a history of RSA. This was done by coculturing maternal peripheral blood mononuclear cells (PBMC) with autologous placental cells and also by stimulating maternal PBMC with antigens from a choriocarcinoma cell line of trophoblastic origin. We detected significantly greater levels of the Th2 cytokines IL-6 and IL-10 in normal pregnancy compared to unexplained RSA and significantly higher levels of the Th1 cytokine IFN-gamma in RSA compared to normal pregnancy. These results suggest that women with normal pregnancy have a higher Th2 bias, while women with a history of RSA evince a bias toward Th1-type reactivity.