CD83 monocyte-derived dendritic cells are present in human decidua and progesterone induces their differentiation in vitro

Dendritic Cells and the Establishment of Fetomaternal Tolerance for Successful Human Pregnancy

Pregnancy is a remarkable event where the semi-allogeneic fetus develops in the mother's uterus, despite genetic and immunological differences. The antigen handling and processing at the maternal-fetal interface during pregnancy appear to be crucial for the adaptation of the maternal immune system and for tolerance to the developing fetus and placenta. Maternal antigen-presenting cells (APCs), such as macrophages (Mφs) and dendritic cells (DCs), are present at the maternal-fetal interface throughout pregnancy and are believed to play a crucial role in this process. Despite numerous studies focusing on the significance of Mφs, there is limited knowledge regarding the contribution of DCs in fetomaternal tolerance during pregnancy, making it a relatively new and growing field of research. This review focuses on how the behavior of DCs at the maternal-fetal interface adapts to pregnancy's unique demands. Moreover, it discusses how DCs interact with other cells in the decidual leukocyte network to regulate uterine and placental homeostasis and the local maternal immune responses to the fetus. The review particularly examines the different cell lineages of DCs with specific surface markers, which have not been critically reviewed in previous publications. Additionally, it emphasizes the impact that even minor disruptions in DC functions can have on pregnancy-related complications and proposes further research into the potential therapeutic benefits of targeting DCs to manage these complications.

The effects of progesterone on immune cellular function at the maternal-fetal interface and in maternal circulation

Progesterone is a sex steroid hormone that plays a critical role in the establishment and maintenance of pregnancy. This hormone drives numerous maternal physiological adaptations to ensure the continuation of pregnancy and to facilitate fetal growth, including broad and potent modulation of the maternal immune system to promote maternal-fetal tolerance. In this brief review, we provide an overview of the immunomodulatory functions of progesterone in the decidua, placenta, myometrium, and maternal circulation during pregnancy. Specifically, we summarize current evidence of the regulated functions of innate and adaptive immune cells induced by progesterone and its downstream effector molecules in these compartments, including observations in human pregnancy and in animal models. Our review highlights the gaps in knowledge of interactions between progesterone and maternal cellular immunity that may direct future research.

Hormone-Related Cancer and Autoimmune Diseases: A Complex Interplay to be Discovered

Neoplasic transformation is a continuous process that occurs in the body. Even before clinical signs, the immune system is capable of recognizing these aberrant cells and reacting to suppress them. However, transformed cells acquire the ability to evade innate and adaptive immune defenses through the secretion of molecules that inhibit immune effector functions, resulting in tumor progression. Hormones have the ability to modulate the immune system and are involved in the pathogenesis of autoimmune diseases, and cancer. Hormones can control both the innate and adaptive immune systems in men and women. For example androgens reduce immunity through modulating the production of pro-inflammatory and anti-inflammatory mediators. Women are more prone than men to suffer from autoimmune diseases such as systemic lupus erythematosus, psoriasis and others. This is linked to female hormones modulating the immune system. Patients with autoimmune diseases consistently have an increased risk of cancer, either as a result of underlying immune system dysregulation or as a side effect of pharmaceutical treatments. Epidemiological data on cancer incidence emphasize the link between the immune system and cancer. We outline and illustrate the occurrence of hormone-related cancer and its relationship to the immune system or autoimmune diseases in this review. It is obvious that some observations are contentious and require explanation of molecular mechanisms and validation. As a result, future research should clarify the molecular pathways involved, including any causal relationships, in order to eventually allocate information that will aid in the treatment of hormone-sensitive cancer and autoimmune illness.

Dendritic Cells and Antiphospholipid Syndrome: An Updated Systematic Review

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by autoreactive B and T cells against β2-glycoprotein I (B2GPI), with vascular thrombosis or obstetrical complications. Dendritic cells (DCs) are crucial in the generation of autoimmunity. Here, we conducted a comprehensive systematic review on the relationship between DC and APS. We performed a literature search of PubMed as of 26 March 2021. A total of 33 articles were extracted. DCs are pivotal in inducing inflammatory responses and orchestrating adaptive immunity. DCs contribute to the local inflammation regarding vascular thrombosis or obstetrical complications. Both B2GPI and antiphospholipid antibodies (aPL) can promote antigen presentation by DCs and the generation or maintenance of autoimmunity. In addition, plasmacytoid DC activation is enhanced by aPL, thereby augmenting the inflammatory response. In line with these findings, DC modulation appears promising as a future treatment for APS. In conclusion, our review indicated the crucial role of DCs in the pathogenesis of APS. Deeper understanding of the complex relationship would help in developing new treatment strategies.

COVID-19 and Progesterone: Part 1.SARS-CoV-2, Progesterone and its potential clinical use

SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) infection is a global medical challenge. Experience based medicines and therapies are being attempted and vaccines are being developed. SARS-CoV-2 exhibits varied patterns of infection and clinical presentations with varied disease outcomes. These attributes are strongly suggestive of some variables that differ among individuals and that affect the course of SARS-CoV-2 infection and symptoms of COVID-19 (Corona Virus Disease of 2019). Sex hormones vary with ageing, between the sexes, among individuals and populations. Sex hormones are known to play a role in immunity and infections. Progesterone is a critical host factor to promote faster recovery following Influenza A virus infection. Anti-inflammatory effects of progesterone are noted. In part 1 of the current study the regulatory role of progesterone for SARS-CoV-2 infection and COVID-19 is analyzed. The role of progesterone at different stages of the SARS CoV-2 infection is investigated with respect to two types of immunity status: immune regulation and immune dysregulation. Progesterone could have various alleviating impacts from SARS-CoV-2 entry till recovery: reversing of hypoxia, stabilizing of blood pressure, controlling thrombosis, balancing electrolytes, reducing the viral load, regulation of immune responses, damage repair, and clearance of debris among others. The present research adds to the available evidence by providing a comprehensive and thorough evaluation of the regulatory role of progesterone in SARS COV-2 infection, COVID-19 pathogenesis, and immune dysregulation. The available evidence has implications for upcoming studies about pathophysiology of COVID-19, as well as the roles of progesterone and other hormones in other infectious diseases.

Dendritic cells in pregnancy and pregnancy-associated diseases

Dendritic cells (DCs) play a critical immuno-modulating role in pregnancy, which requires the maternal immune system to tolerate semiallogeneic fetus and at the same time to maintain adequate defense against pathogens. DCs interact closely with other immune components such as T cells, natural killer cells and macrophages, as well as the endocrine system to keep a pregnancy-friendly environment. Aberrant DC activities have been related to various pregnancy-associated diseases such as recurrent spontaneous abortion, preterm birth, pre-eclampsia, peripartum cardiomyopathy and infectious pregnancy complications. These findings make DCs an attractive candidate for prevention or therapy on the pregnancy-associated diseases. Here, we review recent findings that provide new insights into the roles of DCs in pregnancy and the related diseases. We also discuss the medical potentials to manipulate DCs in clinics. Whereas this is an emerging area with much work remaining, we anticipate that a better understanding of the role of DCs in maternal-fetal immunotolerance and a therapeutic manipulation of DCs will help women suffering from the pregnancy-associated diseases.

Immunological Processes Driving IgE Sensitisation and Disease Development in Males and Females

IgE sensitisation has increased significantly over the last decades and is a crucial factor in the development of allergic diseases. IgE antibodies are produced by B cells through the process of antigen presentation by dendritic cells, subsequent differentiation of CD4⁺ Th2 cells, and class switching in B cells. However, many of the factors regulating these processes remain unclear. These processes affect males and females differently, resulting in a significantly higher prevalence of IgE sensitisation in males compared to females from an early age. Before the onset of puberty, this increased prevalence of IgE sensitisation is also associated with a higher prevalence of clinical symptoms in males; however, after puberty, females experience a surge in the incidence of allergic symptoms. This is particularly apparent in allergic asthma, but also in other allergic diseases such as food and contact allergies. This has been partly attributed to the pro- versus anti-allergic effects of female versus male sex hormones; however, it remains unclear how the expression of sex hormones translates IgE sensitisation into clinical symptoms. In this review, we describe the recent epidemiological findings on IgE sensitisation in male and females and discuss recent mechanistic studies casting further light on how the expression of sex hormones may influence the innate and adaptive immune system at mucosal surfaces and how sex hormones may be involved in translating IgE sensitisation into clinical manifestations.

Role of chemerin/CMKLR1 in the maintenance of early pregnancy

Chemerin is a cytokine that attracts much attention in the reproductive process. This study aimed to explore the effects of chemerin and its receptor chemokine-like receptor 1 (CMKLR1) on the maintenance of early pregnancy. The expression levels of chemerin and CMKLR1 in the decidua tissues of 20 early normal pregnant women and 20 early spontaneous abortion women were examined by Western blot and real-time polymerase chain reaction analyses. CMKLR1 receptor antagonist (α-NETA) was then intrauterinely injected into normal pregnant mice model to assess its effect on the outcome of pregnancy and the phosphorylation rate of ERK1/2 in decidua tissues.We found that the expression level of chemerin in women who had experienced early spontaneous abortion was lower than in those who had experienced normal early pregnancy (P < 0.01); conversely, CMKLR1 expression was higher in the former than in the latter (P < 0.01). In a pregnant-mouse model, the embryo resorption rate of α-NETA group was higher than that in the negative control group (61.5% vs. 10.8%) (P < 0.001). Compared with the control group, ERK1/2 phosphorylation in decidua tissues decreased in the α-NETA-treated group (P < 0.01). These results suggested that the inhibition of the chemerin/CMKLR1 signaling pathway can lead to the abortion of mouse embryos, and that chemerin/CMKLR1 may play an important role in the maintenance of early pregnancy possibly by regulating ERK1/2 phosphorylation.

Single-cell transcriptomics of the human placenta: inferring the cell communication network of the maternal-fetal interface

Organismal function is, to a great extent, determined by interactions among their fundamental building blocks, the cells. In this work, we studied the cell-cell interactome of fetal placental trophoblast cells and maternal endometrial stromal cells, using single-cell transcriptomics. The placental interface mediates the interaction between two semiallogenic individuals, the mother and the fetus, and is thus the epitome of cell interactions. To study these, we inferred the cell-cell interactome by assessing the gene expression of receptor-ligand pairs across cell types. We find a highly cell-type-specific expression of G-protein-coupled receptors, implying that ligand-receptor profiles could be a reliable tool for cell type identification. Furthermore, we find that uterine decidual cells represent a cell-cell interaction hub with a large number of potential incoming and outgoing signals. Decidual cells differentiate from their precursors, the endometrial stromal fibroblasts, during uterine preparation for pregnancy. We show that decidualization (even in vitro) enhances the ability to communicate with the fetus, as most of the receptors and ligands up-regulated during decidualization have their counterpart expressed in trophoblast cells. Among the signals transmitted, growth factors and immune signals dominate, and suggest a delicate balance of enhancing and suppressive signals. Finally, this study provides a rich resource of gene expression profiles of term intravillous and extravillous trophoblasts, including the transcriptome of the multinucleated syncytiotrophoblast.

Interleukin 23 regulates the functions of human decidual immune cells during early pregnancy

BACKGROUND

This study investigated the effects of interleukin 23 (IL-23) on the production of cytokines (IL-1, IL-4, IL-10, and IL-17), the differentiation of Treg/Th17 and STAT3 (i.e., signal transducer and activator of transcription 3) in human decidual immune cells (DICs) during early pregnancy.

METHODS

DICs were treated with recombinant human IL-23 and an antibody against IL-23 subunit p19. The differentiation of Treg and Th17 cells was detected by flow cytometry. Levels of IL-23 receptor (IL-23R), STAT3, and phosphorylated STAT3 (pSTAT3) was examined by Western blot. The production of IL1, IL4, IL10, and IL-17 in DICs was measured by ELISA.

RESULTS

Exogenous recombinant human IL-23 significantly promoted the differentiation of Th17 cells from DICs, while anti-IL-23 antibody significantly promoted the differentiation of Treg cells from DICs. Consistent with the differentiation of Th17 and Tregs cells, levels of IL-1β and IL-17 correlated positively with IL-23 treatment, and anti-IL-23 antibody increased the secretion of IL-4 and IL-10 from DICs. Levels of pSTAT3, but not STAT3 or IL-23R, were significantly elevated by recombinant IL-23 treatment; anti-IL-23 antibody significantly decreased the levels of pSTAT3 and IL-23R in DICs.

CONCLUSIONS

IL-23 mediates the differentiation of Th17 and Treg cells and the production of associated cytokines in DICs. The potential mechanism likely involves the STAT3 pathway.

Gender differences in autoimmune disease

Autoimmune diseases are a range of diseases in which the immune response to self-antigens results in damage or dysfunction of tissues. Autoimmune diseases can be systemic or can affect specific organs or body systems. For most autoimmune diseases there is a clear sex difference in prevalence, whereby females are generally more frequently affected than males. In this review, we consider gender differences in systemic and organ-specific autoimmune diseases, and we summarize human data that outlines the prevalence of common autoimmune diseases specific to adult males and females in countries commonly surveyed. We discuss possible mechanisms for sex specific differences including gender differences in immune response and organ vulnerability, reproductive capacity including pregnancy, sex hormones, genetic predisposition, parental inheritance, and epigenetics. Evidence demonstrates that gender has a significant influence on the development of autoimmune disease. Thus, considerations of gender should be at the forefront of all studies that attempt to define mechanisms that underpin autoimmune disease.

Progesterone induces mucosal immunity in a rodent model of human taeniosis by Taenia solium

More than one quarter of human world's population is exposed to intestinal helminth parasites. The Taenia solium tapeworm carrier is the main risk factor in the transmission of both human neurocysticercosis and porcine cysticercosis. Sex steroids play an important role during T. solium infection, particularly progesterone has been proposed as a key immunomodulatory hormone involved in susceptibility to human taeniosis in woman and cysticercosis in pregnant pigs. Thus, we evaluated the effect of progesterone administration upon the experimental taeniosis in golden hamsters (Mesocricetus auratus). Intact female adult hamsters were randomly divided into 3 groups: progesterone-subcutaneously treated; olive oil-treated as the vehicle group; and untreated controls. Animals were treated every other day during 4 weeks. After 2 weeks of treatment, all hamsters were orally infected with 4 viable T. solium cysticerci. After 2 weeks post infection, progesterone-treated hamsters showed reduction in adult worm recovery by 80%, compared to both vehicle-treated and non-manipulated infected animals. In contrast to control and vehicle groups, progesterone treatment diminished tapeworm length by 75% and increased proliferation rate of leukocytes from spleen and mesenteric lymph nodes of infected hamsters by 5-fold. The latter exhibited high expression levels of IL-4, IL-6 and TNF-α at the duodenal mucosa, accompanied with polymorphonuclear leukocytes infiltration. These results support that progesterone protects hamsters from the T. solium adult tapeworm establishment by improving the intestinal mucosal immunity, suggesting a potential use of analogues of this hormone as novel inductors of the gut immune response against intestinal helminth infections and probably other bowel-related disorders.

Role of gender in multiple sclerosis: clinical effects and potential molecular mechanisms

Multiple sclerosis (MS) is more prevalent in females than males, and this female predominance is increasing as time goes by. Additionally, gender appears to play critical roles in development, progression and treatment of MS, and is therefore an aspect that should always be considered in the design and interpretation of research and clinical trials for MS. In this review, factors that could potentially explain the gender-biased observations in MS are discussed. These include sex-specific differences between the male and female immune systems and nervous systems, genetic and epigenetic or environmental-related effects, the effects of gonadal hormones, and materno-fetal interactions.

Progesterone regulation of uterine dendritic cell function in rodents is dependent on the stage of estrous cycle

Steroid hormones, such as progesterone, are able to modify immunity and influence disease outcome. Dendritic cells (DCs) drive potent immune responses, express receptors for steroid hormones, and may be a primary target of steroid hormone actions during infection of the genital tract, including uterine tissue. Here, we report that progesterone limited DC-associated activation marker expression and inhibited cytokine secretion by uterine DCs, which was associated with changes in signal transducer and activator of transcription 1 (STAT1) activity. We also found that DCs from mice at stages with higher progesterone concentrations (diestrus, metaestrus) were more sensitive to progesterone than those in stages with lower progesterone concentrations (proestrus, estrus), both in vitro and in vivo. This difference correlated with the levels of progesterone receptor expressed by DCs. These data suggest that progesterone regulates DC function and could contribute to the susceptibility of females to uterine and other genital tract infections at selected time periods throughout the life cycle.

The effect of human placenta cytotrophoblast cells on the maturation and T cell stimulating ability of dendritic cells in vitro

The success of pregnancy depends upon regulatory mechanisms that allow the fetus to survive and develop to term in the uterus, despite maternal immune cells' awareness of paternal alloantigens. At least some of these specific mechanisms are mediated by the effect of fetal trophoblast cells. In the present study we examine the effect of human placental cytotrophoblast cells (CTCs) on the maturation of dendritic cells (DCs) in vitro. For that purpose, CTCs were isolated from samples of placentae at 5-11 weeks of gestation and co-cultured with peripheral blood monocytes under conditions inducing DC maturation. CTC were shown to alter the morphology, phenotype and functional properties of DCs. As a result, a significant portion of cells acquire fibroblast-like morphology and some of the cells retain the expression of CD14. DCs matured in the presence of CTCs do not differ from usual DCs in terms of CD80, CD83 and CD86 expression, as well as the ability to induce allogenic lymphocytes proliferation. However, CTCs reduce significantly the ability of DCs to stimulate interferon-γ production and the loss of CD62L by T cells. The results obtained indicate that DCs may be involved in pregnancy-associated changes of cytokine production and T cell migration.

Expression and role of interleukin-23 in human endometrium throughout the menstrual cycle and early pregnancy

Interleukin-23 (IL-23) is a novel cytokine involved in the regulation of organ-specific immune responses. We hypothesized that expression of IL-23 in the human endometrium is menstrual cycle and pregnancy dependent, and is involved in endometrial immune regulation. IL-23 expression and regulation was investigated in the human endometrium and placenta in vivo using immunohistochemistry and in vitro using Western blot and cell viability analyses. IL-23 immunoreactivity in endometrial glandular cells was highest in the late proliferative and early secretory phases, as compared to other cycle phases and first trimester tissues. Endometrial stromal cells (ESC) showed weak IL-23 immunoreactivity without significant changes in intensity and distribution throughout the menstrual cycle. First trimester decidual cells revealed significantly stronger IL-23 staining compared to ESC from non-pregnant endometrium. Both villous cytotrophoblasts and syncytiotrophoblasts also showed positive IL-23 immunoreactivity, with a higher staining in syncytiotrophoblasts. In the trophoblastic cell line HRT8, IL-23 expression increased in a time-dependent manner, but was undetectable in stromal cells under all treatment conditions. ESC treated with recombinant IL-23 showed significantly decreased IL-8 secretion and cell viability. These results suggest a possible regulatory role for IL-23 in the menstrual cycle and in early pregnancy, although the extent and function of this role are yet to be determined.

New target cells of the immunomodulatory effects of progesterone

It is well known that the reproductive steroid hormones, particularly progesterone, in addition to its widely recognized effects on endometrial epithelial and stromal cells and spiral arteries, affect the activities of T cells and natural killer cells in the deciduas, thus inducing active immune tolerance against the fetal antigens. The immunomodulatory effects of progesterone on T cells, B cells and natural killer cells have been discussed extensively in the literature. The aim of the present review is to sum up and discuss the results from this and other laboratories of investigations on the effects of progesterone on dendritic cells and adult stem cells, which are some of the other cell populations present at the fetal-maternal interface and possibly are related to the immunoregulation during pregnancy. These cells have been shown to have a number of specific functions but their involvement in the entire process of regulation of the immune response in pregnancy is still under discussion. The present review focuses on facts showing that the progesterone is a kind of 'regulator of regulators' in the decidua, thus creating the most favourable conditions for the development of the semi-allogeneic fetus in successful pregnancy.

Human uterine epithelial cell secretions regulate dendritic cell differentiation and responses to TLR ligands

The balance between immunity and tolerance in the endometrium is governed by dynamic interactions of UEC and immune cells including DC. In this study, we tested the hypothesis that soluble immune mediators secreted by UEC modulate the differentiation and functions of human DC. We found that DC differentiated with CM from polarized UEC (i.e., CM-DC) expressed significantly lower surface CD86. Upon activation with LPS or PIC, the expression of CD80, CD86, and CD83 was decreased significantly on CM-DC relative to Con-DC. Further, mRNA for TLR3, TLR4, and TLR5 was decreased significantly in CM-DC relative to Con-DC. As a functional read-out of the effect of CM on DC, we determined the following parameters: First, analysis of cytokine production showed that when compared with Con-DC, CM-DC responded to LPS or PIC stimulation with enhanced IL-10 production but undetectable IL-12p70 secretion. Second, RT-PCR analysis showed that CM-DC significantly expressed higher mRNA for IDO, an immune tolerance-promoting enzyme. Lastly, in a MLR assay, CM-DC induced significantly lower allogeneic proliferative responses compared with Con-DC. These findings indicate collectively that epithelial cells confer a tolerogenic phenotype to DC in the endometrium. Our results suggest novel cellular and molecular mechanisms for the regulation of adaptive immunity within the FRT.

Impact of female sex hormones on the maturation and function of human dendritic cells

PROBLEM

During pregnancy, the immune and the endocrine system cooperate to ensure that the fetal allograft develops without eliciting a maternal immune response. This is presumably in part achieved by dendritic cells (DCs) that play a dominant role in maintaining peripheral tolerance. In this study, we investigated whether female sex hormones, such as human chorionic gonadotropin (hCG), progesterone (Prog), and estradiol (E2), which are highly elevated during pregnancy, induce the differentiation of DCs into a tolerance-inducing phenotype.

METHODS/RESULTS

Immature DCs were generated from blood-derived monocytes and differentiated in the presence of hCG, Prog, E2, or Dexamethasone (Dex) as a control. Unlike Dex, female sex hormones did not prevent the upregulation of surface markers characteristic for mature DCs, such as CD40, CD83, and CD86, except for hCG, which inhibited HLA-DR expression. Similarly, hCG, Prog, and E2 had any impact on neither the rearrangement of the F-actin cytoskeleton nor the enhanced chemokine secretion following DC maturation, both of which were strongly altered by Dex. Nevertheless, the T-cell stimulatory capacity of DCs was significantly reduced after hCG and E2 exposure.

CONCLUSION

Our findings suggest that the female sex hormones hCG and E2 inhibit the T-cell stimulatory capacity of DCs, which may help in preventing an allogenic T-cell response against the embryo.

Regulation of dendritic cells by female sex steroids: Relevance to immunity and autoimmunity

Dendritic cells (DCs) are critical mediators of adaptive immunity, tolerance and autoimmunity. The human immune system exhibits sexual dimorphism, which is most evident in the female predominance of autoimmune diseases such as systemic lupus erythematosus (SLE). Female sex steroids are strongly implicated in mediating immune sexual dimorphism, in part because estrogen accentuates disease in several models of lupus autoimmunity. In contrast, progesterone may prevent disease development. While much investigation has focused on the effects of estrogen and progesterone on lymphocyte functions, far less attention has been paid to the effects of these hormones on DCs. Current evidence now indicates estrogen can activate DCs, while in contrast, progesterone inhibits DC functions. Thus, we hypothesize that the opposite effects these two hormones have on lupus autoimmunity reflect opposing effects on DC functions. Thus, through direct actions on DCs, female sex steroids may influence autoimmunity, immunity and tolerance.

Identification and hormonal regulation of a novel form of NKp30 in human endometrial epithelium

This study reports the discovery and steroid hormonal regulation of a novel glycosylated form of NKp30 in human endometrial epithelium. NKp30 is a member of the immunoglobulin superfamily and one of three existing natural cytotoxicity-triggering receptors. NKp30 is a glycosylated protein and is thought to be selectively expressed in resting and activated natural killer cells. The aims of the present study were to fully characterize NKp30 mRNA and protein in human endometrium during the menstrual cycle, and to investigate the hormonal regulation of NKp30. NKp30 mRNA was significantly up-regulated in fresh tissues during late secretory phase of the menstrual cycle. Interestingly, NKp30 mRNA was also present in clonally derived endometrial epithelial cells (CEE) in comparable amounts to fresh tissue. NKp30 protein was predominantly found in the endometrial glands and luminal epithelia of the secretory phase endometrium. Western blotting and de-glycosylation studies show that a novel glycosylated form of NKp30 is present in endometrial epithelium and that it can dimerize. Further phenotyping of CEE by flow cytometry revealed that they are CK8(+)CD49f(+)NKp30(+)CD45(-)CD56(-). The data also show that transcription and translation of the novel form of NKp30 can be induced by progesterone treatment after 48 h in endometrial explants in vitro. This is the first report to show the presence of both NKp30 mRNA and a novel glycosylated form of NKp30 protein in endometrial epithelial cells.

Exodus-1 (CCL20): evidence for the participation of this chemokine in spontaneous labor at term, preterm labor, and intrauterine infection

AIM

CCL20, also known as MIP-3 alpha, is a chemokine that participates in chemotaxis of immature dendritic cells, effector/memory T-cells, and B-lymphocytes. The objectives of this study were to determine whether CCL20 can be detected in amniotic fluid (AF) and if AF concentration of this chemokine changes with advancing gestational age, parturition (term and preterm), and intra-amniotic infection/inflammation (IAI).

METHODS

A cross-sectional study was conducted including the following groups: (1) mid-trimester of pregnancy (n=65); (2) term not in labor (TNL; n=22); (3) term in labor (TIL; n=47); (4) spontaneous preterm labor (PTL) who delivered at term (n=57); (5) spontaneous PTL without IAI who delivered preterm (n=71); and (6) spontaneous PTL with IAI (n=38). AF CCL20 concentrations were determined using ELISA.

RESULTS

(1) The median AF CCL20 concentration in TNL was higher than that of mid-trimester patients; (2) Women in spontaneous labor at term had a higher median AF concentration of CCL20 than patients at term not in labor; (3) Patients with spontaneous PTL and IAI had a significantly higher median AF concentration of CCL20 than those without IAI who delivered preterm and those who delivered at term. Moreover, women with spontaneous PTL without IAI who delivered preterm had a significantly higher median AF concentration than those with PTL who subsequently delivered at term.

CONCLUSIONS

(1) CCL20 is a physiologic constituent of AF and its concentration increases as term approaches; (2) spontaneous labor (term and preterm) in the absence of IAI is associated with increased bioavailability of AF CCL20 suggesting that an increase in CCL20 is part of the common pathway of human parturition; (3) patients with IAI had dramatic elevations in the AF CCL20 concentrations suggesting that this chemokine participates in the host response to infection or other stimuli associated with intra-amniotic infection.

Antigen-presenting cells and materno-fetal tolerance: an emerging role for dendritic cells

During pregnancy, a delicate balance of innate and adaptive immune responses at the maternal-fetal interface promotes survival of the semi-allogeneic embryo and, at the same time, allows effective immunity to protect the mother from environmental pathogens. As in other tissues, antigen handling and processing in the decidualized endometrium constitutes a primary event in the onset of immune responses and is therefore likely to determine their stimulatory or tolerogenic nature. Maternal antigen-presenting cells [macrophages and dendritic cells (DCs)] are scattered throughout the decidualized endometrium during all stages of pregnancy and appear to be important players in this feto-maternal immune adjustment. This review focuses on the characterization of decidual macrophages and DCs, as well as their involvement in cell-cell interactions within the decidual leukocyte network, which are likely to influence uterine and placental homeostasis as well as the local maternal immune responses to the fetus during pregnancy.

Pulmonary exposure to particles during pregnancy causes increased neonatal asthma susceptibility

Maternal immune responses can promote allergy development in offspring, as shown in a model of increased susceptibility to asthma in babies of ovalbumin (OVA)-sensitized and -challenged mother mice. We investigated whether inflammatory responses to air pollution particles (diesel exhaust particles, DEP) or control "inert" titanium dioxide (TiO(2)) particles are enhanced during pregnancy and whether exposure to particles can cause increased neonatal susceptibility to asthma. Pregnant BALB/c mice (or nonpregnant controls) received particle suspensions intranasally at Day 14 of pregnancy. Lung inflammatory responses were evaluated 48 hours after exposure. Offspring of particle- or buffer-treated mothers were sensitized and aerosolized with OVA, followed by assays of airway hyperresponsiveness (AHR) and allergic inflammation (AI). Nonpregnant females had the expected minimal response to "inert" TiO(2). In contrast, pregnant mice showed robust and persistent acute inflammation after both TiO(2) and DEP. Genomic profiling identified genes differentially expressed in pregnant lungs exposed to TiO(2). Neonates of mothers exposed to TiO(2) (and DEP, but not PBS) developed AHR and AI, indicating that pregnancy exposure to both "inert" TiO(2) and DEP caused increased asthma susceptibility in offspring. We conclude that (1) pregnancy enhances lung inflammatory responses to otherwise relatively innocuous inert particles; and (2) exposures of nonallergic pregnant females to inert or toxic environmental air particles can cause increased allergic susceptibility in offspring.

Progesterone-Modulated Phosphatidylserine Externalization in Apoptosis and Activation of Jurkat Cells

PROBLEM

During pregnancy the elevated levels of progesterone (Pg) have immunomodulating effects. It is important to follow-up Pg effects on basic biological processes at cell level as apoptosis and activation which was the aim of this study.

METHODS OF STUDY

Jurkat cells cultured in the presence or absence of Pg were used as a model system. Apoptosis was induced by H(2)O(2) and activation by phorbol myriastate acetate. The induced changes in the phosphatidylserine (PS) externalization and cell surface CD69 expression were followed by fluorescence-activated cell sorter and immunofluorescence.

RESULTS

After the induction of apoptosis PS externalizes in 52.3% of Jurkat cells. Cells cultured with Pg show tendency to a decrease of PS positive cells (42%). The opposite effect is observed in activated cells--PS externalization increase from 33.8% of control cells to 40.1% of Pg-treated cells.

CONCLUSIONS

These findings would suggest that by increasing activation and decreasing apoptosis Pg could regulate local immune system during pregnancy.

Progesterone is involved in the maturation of murine spleen CD11c-positive dendritic cells

Progesterone (Prog), a female sex steroid hormone, not only plays an important role in the female mammary pregnancy but also influences the immune response. In the present study, murine spleen CD11c-positive dendritic cells (SDCs) were treated with various concentrations of Prog for 24 h, and their viability, phenotype, nuclear factor kappa B P65 (NF-kappaB P65), endocytosis, stimulatory capacity, and cytokine expression were analyzed. The results showed that Prog increased the expressions of MHC-II and CD40, stimulatory capacity and intracellular levels of IL-6 and IL-10, while decreased the expressions of CD54 and IL-12, endocytosis and nuclear level of NF-kappaB P65 of SDCs. These data suggested that Prog may promote the maturation of SDCs and enhance their ability to interact with T cells so as to change the course of autoimmune diseases.