Human Early Pregnancy Decidua Research Articles

Profiling the expression and function of oestrogen receptor isoform ER46 in human endometrial tissues and uterine natural killer cells.

STUDY QUESTIONDoes the oestrogen receptor isoform, ER46, contribute to regulation of endometrial function?SUMMARY ANSWERER46 is expressed in endometrial tissues, is the predominant ER isoform in first trimester decidua and is localised to the cell membrane of uterine natural killer (uNK) cells where activation of ER46 increases cell motility.WHAT IS KNOWN ALREADYOestrogens acting via their cognate receptors are essential regulators of endometrial function and play key roles in establishment of pregnancy. ER46 is a 46-kDa truncated isoform of full length ERα (ER66, encoded by ESR1) that contains both ligand- and DNA-binding domains. Expression of ER46 in the human endometrium has not been investigated previously. ER46 is located at the cell membrane of peripheral blood leukocytes and mediates rapid responses to oestrogens. uNK cells are a phenotypically distinct (CD56brightCD16−) population of tissue-resident immune cells that regulate vascular remodelling within the endometrium and decidua. We have shown that oestrogens stimulate rapid increases in uNK cell motility. Previous characterisation of uNK cells suggests they are ER66-negative, but expression of ER46 has not been characterised. We hypothesise that uNK cells express ER46 and that rapid responses to oestrogens are mediated via this receptor.STUDY DESIGN, SIZE, DURATIONThis laboratory-based study used primary human endometrial (n = 24) and decidual tissue biopsies (n = 30) as well as uNK cells which were freshly isolated from first trimester human decidua (n = 18).PARTICIPANTS/MATERIALS, SETTING, METHODSPrimary human endometrial and first trimester decidual tissue biopsies were collected using methods approved by the local institutional ethics committee (LREC/05/51104/12 and LREC/10/51402/59). The expression of ERs (ER66, ER46 and ERβ) was assessed by quantitative PCR, western blot and immunohistochemistry. uNK cells were isolated from first-trimester human decidua by magnetic bead sorting. Cell motility of uNK cells was measured by live cell imaging: cells were treated with 17β-oestradiol conjugated to bovine serum albumin (E2-BSA, 10 nM equivalent), the ERβ-selective agonist 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN; 10 nM) or dimethylsulphoxide vehicle control.MAIN RESULTS AND THE ROLE OF CHANCEER46 was detected in proliferative and secretory phase tissues by western blot and was the predominant ER isoform in first-trimester decidua samples. Immunohistochemistry revealed that ER46 was co-localised with ER66 in cell nuclei during the proliferative phase but detected in both the cytoplasm and cell membrane of stromal cells in the secretory phase and in decidua. Triple immunofluorescence staining of decidua tissues identified expression of ER46 in the cell membrane of CD56-positive uNK cells which were otherwise ER66-negative. Profiling of isolated uNK cells confirmed expression of ER46 by quantitative PCR and western blot and localised ER46 protein to the cell membrane by immunocytochemistry. Functional analysis of isolated uNK cells using live cell imaging demonstrated that activation of ER46 with E2-BSA significantly increased uNK cell motility.LARGE SCALE DATAN/A.LIMITATIONS, REASONS FOR CAUTIONExpression pattern in endometrial tissue was only determined using samples from proliferative and secretory phases. Assessment of first trimester decidua samples was from a range of gestational ages, which may have precluded insights into gestation-specific changes in these tissues. Our results are based on in vitro responses of primary human cells and we cannot be certain that similar mechanisms occur in situ.WIDER IMPLICATIONS OF THE FINDINGSE2 is an essential regulator of reproductive competence. This study provides the first evidence for expression of ER46 in the human endometrium and decidua of early pregnancy. We describe a mechanism for regulating the function of human uNK cells via expression of ER46 and demonstrate that selective targeting with E2-BSA regulates uNK cell motility. These novel findings identify a role for ER46 in the human endometrium and provide unique insight into the importance of membrane-initiated signalling in modulating the impact of E2 on uNK cell function in women. Given the importance of uNK cells to regulating vascular remodelling in early pregnancy and the potential for selective targeting of ER46, this may be an attractive future therapeutic target in the treatment of reproductive disorders.STUDY FUNDING/COMPETING INTEREST(S)These studies were supported by Medical Research Council (MRC) Programme Grants G1100356/1 and MR/N024524/1 to PTKS. H.O.D.C. was supported by MRC grant G1002033. The authors declare no competing interests related to the published work.

Elevated expression of EP4 in human decidua is associated with delayed embryo expulsion during medical abortion by promoting decidual cell proliferation

Purpose: Mifepristone in conjunction with misoprostol, is widely used in China as an effective medical abortifacient. However, a small proportion of women experience the unpleasant side effects of prolonged vaginal bleeding caused by delayed embryo expulsion. The aims of this study were to determine whether the expression levels of prostanoid receptors in human decidua are associated with delayed embryo expulsion in mifepristone-misoprostol induced an early medical abortion.Methods: Discharged decidua tissues were collected from females undergoing an artificial abortion (AA) (n = 28), females with early embryo expulsion during a medical abortion (EEMA) (n = 20) and delayed embryo expulsion in medical abortion (DEMA) (n = 30). The expression levels of prostanoid receptors in human decidua were assessed with immunohistochemistry and real-time PCR methods. Further, the RNAi method was used to silence prostanoid receptors 4 (EP4) in the primary decidual cells and human endometrial adenocarcinoma cell line Ishikawa cells in vitro and cell cycle analysis of these cells was performed.Results: All five prostanoid receptors (EP1-4, FP) were observed in human early pregnancy decidua. The protein and mRNA expression level of EP4 in the DEMA group were all significantly higher than that in the EEMA group. EP4 silence induced G1/S arrest of primary decidual cells and Ishikawa cells in vitro.Conclusions: Elevated expression level of EP4 in human decidua was significantly associated with delayed embryo expulsion in early medical abortion by promoting decidual cell proliferation. Detailed studies on the nature of roles EP4 plays in human decidua will help us to develop more effective prevention and noninvasive intervention approaches for delayed embryo expulsion during a medical abortion.

CD33(+) /HLA-DR(neg) and CD33(+) /HLA-DR(+/-) Cells: Rare Populations in the Human Decidua with Characteristics of MDSC.

Human pregnancy needs a remarkable local immune tolerance toward the conceptus. Myeloid-derived suppressor cells (MDSC) are important players promoting cancer initiation and progression by suppressing T-cell functions and thus inducing immune tolerance. Therefore, MDSC were expected within decidua. Subpopulations of CD33(+) immune cells were isolated from human early pregnancy decidua and characterized phenotypically and functionally by microscopy, FACS analysis, RT-PCR, Western blotting and in the coculture with T cells. Decidua harbors CD33(+) /HLA-DR(neg) and CD33(+) /HLA-DR(+/-) cells which both express arginase, iNOS and IDO and a typical cytokine profile. Both subtypes potently suppress T-cell proliferation and therefore fulfill the criteria of MDSC. We characterized a new population of CD33(+) /HLA-DR(neg) and CD33(+) /HLA-DR(+/-) cells in human early pregnancy decidua with properties of classical MDSC and thus potentially being an important player in immune tolerance in pregnancy.

Comparative efficacy of Albendazole, Fenbendazole and Levamisole against gastrointestinal nematodiasis in cattle of Bangladesh

Prolactin (PRL), a peptide hormone of the anterior pituitary, greatly increases in both plasma and amniotic fluid during pregnancy. The pattern of measurable PRL differs according to gestational stage and between plasma and amniotic fluid levels. This variation has led to several opinions regarding the production site of PRL during pregnancy. In this paper, the authors describe the production and localization of PRL-materializing tissues of human placenta and decidua both in early pregnancy and at term. Immunohistologic investigations with highly purified antiserum obtained by immunization of albino rabbits and reacted with human PRL alone revealed that syncytial trophoblast was a site of PRL production. PRL was also detected in decidual tissue, but the latter did not show a pattern of production. By a method of double staining, the production and localization of either anti-beta-subunit of human chorionic gonadotropin (hCG-beta) or human placental lactogen (hPL) were manifestly differentiated from those of PRL in syncytial trophoblast.

Quantification of the Predominant Immune Cell Populations in Decidua Throughout Human Pregnancy

To date, a multiplicity of factors contributing to the establishment and progression of a successful pregnancy have been postulated. There is emerging evidence that decidual leukocytes could be decisive factors during pregnancy. Despite numerous investigations on immune cells in human early pregnancy decidua, little is known about the physiological composition and proportion of the various immune cell populations during the different phases of pregnancy. In this study, we therefore analyzed the proportion of the dominant decidual leukocytes in human tissue samples derived from all phases of pregnancy. Single cell suspensions were prepared from decidual samples from 205 patients at 6-40 weeks of gestation. Cell populations were analyzed by flow cytometry, and immune cell populations were quantified as percentage of decidual CD45(+) cells. There was generally no difference in immune cell counts comparing decidua of healthy gestations and those with systemic inflammation. Overall, the proportion of uNK cells continuously decreased, while the amount of monocytes, immature dendritic cells, and T cells increased until term. Striking modifications in cell counts were seen during the 7th week compared with the 6th and later weeks of gestation. Studying the proportion of decidual immune cells during pregnancy, we detected a unique pattern which could be useful to design novel therapies for pathological conditions during pregnancy.

Th2 biased immune response at the human early pregnancy decidua

Th2 biased immune response at the human early pregnancy decidua

A role for lipoxin A4 as an anti-inflammatory mediator in the human endometrium

Lipoxin A4 is a lipid mediator that elicits anti-inflammatory and pro-resolution actions via its receptor, formyl peptide receptor 2 (FPR2/ALX). In this study, we aimed to investigate the expression and potential role of lipoxin A4 and FPR2/ALX in the regulation of inflammation associated with cyclical remodeling of the human endometrium across the menstrual cycle and during early pregnancy. Using quantitative RT-PCR analysis, we found that FPR2/ALX expression is upregulated during the menstrual phase of the cycle and in decidua tissue from the first trimester of pregnancy. We localized the site of expression of FPR2/ALX in menstrual phase endometrium and first-trimester decidua tissue to glandular epithelial cells and cells within the stromal compartment, including cells lining the blood vessels and immune cells. Measurement of serum lipoxin A4 by ELISA revealed no difference in its levels across the menstrual cycle but an elevation in early pregnancy (P<0.001). We found that lipoxin A4 was regulated by human chorionic gonadotrophin (hCG) during early pregnancy, because treatment of human decidua tissue with hCG increased lipoxin A4 release (P<0.01). Finally, we have shown that lipoxin A4 can suppress phorbol myristate acetate-induced expression of the inflammatory cytokines interleukin 6 and 8 in human endometrium and decidua tissue. These results demonstrate for the first time that lipoxin A4 and its receptor FPR2/ALX can regulate inflammatory events in the human endometrium and decidua of early pregnancy.

Maternal Foxp3 Expressing CD4+ CD25+ and CD4+ CD25− Regulatory T‐Cell Populations are Enriched in Human Early Normal Pregnancy Decidua: A Phenotypic Study of Paired Decidual and Peripheral Blood Samples

Citation Dimova T, Nagaeva O, Stenqvist A‐Christin, Hedlund M, Kjellberg L, Strand M, Dehlin E, Mincheva‐Nilsson L. Maternal Foxp3 Expressing CD4+ CD25+ and CD4+ CD25− Regulatory T‐Cell Populations are Enriched in Human Early Normal Pregnancy Decidua: A Phenotypic Study of Paired Decidual and Peripheral Blood Samples. Am J Reprod Immunol 2011; 66 (Suppl. 1): 44–56Problem Regulatory T cells (Treg cells), a small subset of CD4+ T cells maintaining tolerance by immunosuppression, are proposed contributors to the survival of the fetal semiallograft. We investigated Treg cells in paired decidual and peripheral blood (PB) samples from healthy women in early pregnancy and PB samples from non‐pregnant women.Method of study Distribution, location, cytokine mRNA, and phenotype were assessed in CD4+ CD25+ Treg cells from paired samples using immunohistochemistry, immunofluorescence, flow cytometry, and real‐time quantitative RT‐PCR.Results The presence and in situ distribution of CD4+ Foxp3+ Treg cells in decidua are hereby demonstrated for the first time. Three Foxp3+ cell populations, CD4+ CD25++ Foxp3+, CD4+ CD25+ Foxp3+, and CD4+ CD25− Foxp3+, were enriched locally in decidua. In contrast, no statistically significant difference in numbers of circulating Treg cells between pregnant and non‐pregnant women was found. The Foxp3+ cells expressed the surface molecules CD45RO, CTLA‐4, CD103, Neuropilin‐1, LAG‐3, CD62L, and TGFβ1 mRNA consistent with Treg phenotype. The population of CD4+ CD25− Foxp3+ cells, not described in human decidua before, was enriched 10‐fold compared with PB in paired samples. Their cytokine expression was often similar to Th3 profile, and the Foxp3 mRNA expression level in CD4+ CD25− cells was stable and comparable to that of CD4+ CD25+ Treg cells implying that the majority of CD4+ CD25− Foxp3+ cells might be naïve Treg cells.Conclusion (i) There is a local enrichment of Treg cells in decidua (ii) The exclusive accumulation of decidual CD4+ CD25− Foxp3+ cells suggests an additional reservoir of Foxp3+ naïve Treg cells that can be converted to ‘classical’ Treg cells in uterus.

Side population cells in the human decidua of early pregnancy exhibit stem/progenitor cell-like characteristics

It is proposed that human decidua contains a population of stem cells that are responsible for the proliferation ability during the process of embryo implantation and placenta formation and that factors in the crosstalk between the decidua and chorion may mediate decidual stem cell differentiation. This study analysed the phenotype of side population (SP) cells and investigated the clonogenicity and differentiation ability of SP cells in human decidua of early pregnancy. Serum-free culture-conditioned media of human decidua and chorion were obtained from decidua and chorion explant culture. Decidual SP cells were isolated by fluorescence-activated cell sorting. Different inducing media were added and the functional differentiation of decidual SP cells was examined. Decidual SP cells were negative for the mature decidual cell marker CD13 and prolactin and negative for CD34 and CD45 expression. Decidual SP cells formed clones after culture in colony-forming medium and they could form clones again. Differentiated cells expressing CD13 and prolactin were observed and stroma-like structures expressing CD13 were obtained. These results indicate that decidual SP cells are enriched for stem cell activity. Oestradiol, progesterone and factors in culture-conditioned media of human decidua and chorion induced their proliferation and differentiation.

G protein-coupled estrogen receptor 1 (GPER, GPR 30) in normal human endometrium and early pregnancy decidua

The recently identified trans-membrane G protein-coupled estrogen receptor 1 (GPER, GPR30) has been implicated in rapid non-genomic effects of estrogens. This focuses on expression and localization of GPER mRNA and protein in normal cyclic endometrium and early pregnancy decidua. Real-time PCR, western blotting, in situ hybridization and immuno-histochemistry were used. Endometrial expression of GPER mRNA was lower in the secretory phase than in the proliferative phase, and even lower in the decidua. The expression pattern was similar to that of ERα mRNA, but different from that of ERβ mRNA. Western blot detected GPER protein as a 54 kDa band in all endometrial and decidual samples. In contrast to the mRNA, GPER protein did not show cyclic variations. Apparently, a lower amount of mRNA is sufficient to maintain protein levels in the secretory phase. GPER mRNA was predominantly localized in the epithelium of mid- and late-proliferative phase endometrium, whereas expression in early proliferative and secretory glands could not be distinguished from the diffuse stromal signal, which was present throughout the cycle. Immuno-staining for GPER was stronger in glandular and luminal epithelium than in the stroma throughout the cycle. The cyclic variations of GPER mRNA obviously relate to strong epithelial expression in the proliferative phase, and the expression pattern suggests regulation by ovarian steroids. GPER protein is present in endometrial tissue throughout the cycle, and the epithelial localization suggests potential functions during sperm migration at mid-cycle, as well as decidualization and blastocyst implantation in the mid-secretory phase.

Review: Functional role of uterine natural killer (uNK) cells in human early pregnancy decidua

Leukocytes comprise approximately 30–40% of decidual stromal cells in early human pregnancy. The major leukocyte component is the uterine natural killer (uNK) cells. Despite over 20 years of research the functional role of these cells in situ remains unknown although they have been proposed to play roles in immunotolerance, regulation of trophoblast invasion and remodeling of the spiral arteries. Herein we review the functional roles of this important decidual cell type.

Enrichment of Foxp3 + T regs and reduction of T H17 cells in human early pregnancy decidua indicate immunosuppressive T cell dominance

Enrichment of Foxp3 + T regs and reduction of T H17 cells in human early pregnancy decidua indicate immunosuppressive T cell dominance

Profiling Chemokines, Cytokines and Growth Factors in Human Early Pregnancy Decidua By Protein Array

In human decidua, a significant increase of leukocytes including CD56(++)CD16(-) uterine natural killer (uNK) cells and CD14(+) monocytes has been observed with the onset of pregnancy. The mechanisms required for the recruitment of those cells to the uterus are still under debate. Cytokines and chemokines have been suggested as key factors for the regulation of these complex cellular migration and interaction processes. Investigation of the expression patterns of cytokines, chemokines and growth factors in human decidual tissue (7-8 weeks of gestation) was performed by protein array analysis. Isolated decidual leukocytes, i.e. CD56(++)CD16(-) uNK, CD14(+) monocytes as well as cytotrophoblast (CTB) and stromal cells were tested separately. This analysis revealed the production of monocyte attracting chemokines (GRO, MCP-1), angiogenetic substances (EGF, VEGF, Angiogenin) as well as granulocyte activating peptides (ENA-78, IL-1beta, RANTES, IL-8) by decidual tissue and its cell subsets. The observed pattern supports the role of decidua as a tissue which promotes angiogenesis, attracts monocytes and modulates the function of the latter.

The organic cation transporters (OCT1, OCT2, EMT) and the plasma membrane monoamine transporter (PMAT) show differential distribution and cyclic expression pattern in human endometrium and early pregnancy decidua

The non-neuronal monoamine transporters (OCT1, OCT2, EMT, and PMAT) play a key role in the clearance of monoamines from extracellular compartments. In a previous report we described endometrial distribution and cyclic variation of the vesicular monoamine transporter (VMAT2) mRNA and the neuronal norepinephrine transporter (NET) mRNA. In the present study we used in situ hybridization, real-time PCR and immunohistochemistry to reveal tissue distribution and cyclic variation of mRNA for the non-neuronal monoamine transporters in the human endometrium and early pregnancy decidua. We found that non-neuronal monoamine transporters are predominantly expressed in the stroma. The plasma membrane monoamine transporter (PMAT) mRNA expression peaked in the proliferative phase, whereas the extra-neuronal monoamine transporter (EMT) mRNA expression peaked in the secretory phase. The organic cation transporter 2 (OCT2) mRNA expression was exclusively detected in few scattered stromal cells and OCT1 mRNA was not detected at all. Our present results demonstrate that PMAT, EMT, and OCT2 transporters are expressed in the endometrial stroma and can potentially regulate reuptake of monoamines in general and histamine in particular. Taken together with our previous finding of VMAT2 mRNA in epithelial cells, we suggest a paracrine interaction between stromal and epithelial cells, which may modulate certain steps of the reproductive process.

Galectin-9: A New Endometrial Epithelial Marker for the Mid- and Late-Secretory and Decidual Phases in Humans

The galectin family has been reported to play a role in the regulation of cell growth, cell adhesion, apoptosis, inflammation, and immunomodulation, all of which are important for endometrial function, as well as implantation. The objective of the study was to investigate the expression and regulation of galectin-9, a beta-galactoside-binding lectin in the human endometrium. Galectin-9 mRNA and protein were analyzed in dated endometrial biopsies throughout the menstrual cycle and in human early-pregnancy decidua, as well as in the different endometrial cell compartments. Regulation of galectin-9 by estradiol, progesterone, epidermal growth factor, and interferon-gamma in endometrial epithelial cells in vitro was studied. Galectin-9 mRNA analyzed by RNase protection assay is expressed in the human endometrium, specifically in the human endometrial epithelial cells but not in stromal or immune cells. It is expressed at very low concentrations during the proliferative phase and the early-secretory phase and shows a sharp and significant increase in the mid- and late-secretory phases, the window of implantation, as well as in the decidua. Accordingly, galectin-9 protein is also exclusively increased in human endometrial epithelial cells during the mid- and late-secretory phases and in the decidua, however, not in endometrial stromal cells or decidualized cells in vivo or in vitro. A regulation in vitro by estradiol, progesterone, epidermal growth factor, and interferon-gamma could not be detected. Based on these findings and on the functional studies of other galectins, we suggest galectin-9 as a novel endometrial marker for the mid- and late-secretory and decidual phases.

Human Decidual Natural Killer Cells Are a Unique NK Cell Subset with Immunomodulatory Potential

Natural killer cells constitute 50–90% of lymphocytes in human uterine decidua in early pregnancy. Here, CD56bright uterine decidual NK (dNK) cells were compared with the CD56bright and CD56dim peripheral NK cell subsets by microarray analysis, with verification of results by flow cytometry and RT-PCR. Among the ∼10,000 genes studied, 278 genes showed at least a threefold change with P ≤ 0.001 when comparing the dNK and peripheral NK cell subsets, most displaying increased expression in dNK cells. The largest number of these encoded surface proteins, including the unusual lectinlike receptors NKG2E and Ly-49L, several killer cell Ig-like receptors, the integrin subunits αD, αX, β1, and β5, and multiple tetraspanins (CD9, CD151, CD53, CD63, and TSPAN-5). Additionally, two secreted proteins, galectin-1 and progestagen-associated protein 14, known to have immunomodulatory functions, were selectively expressed in dNK cells.

Dominant IL‐10 and TGF‐β mRNA Expression in γδT Cells of Human Early Pregnancy Decidua Suggests Immunoregulatory Potential

To examine the cytokine gene expression in gammadeltaT-cells from human early pregnancy decidua. The cytokine messenger RNA (mRNA) expression in isolated decidual T-cell receptor (TCR)gammadelta+/CD56+ and TCRgammadelta single positive cells was investigated with a panel of cytokine primers and probes selected to distinguish between T helper (Th)1, Th2, Th3 and regulatory T-cells (Tr1) type of immune response using real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). TCRgammadelta+/CD56+ cells express almost exclusively the immunosuppressive cytokines interleukin-10 (IL-10) and transforming growth factor (TGF)-beta. The TCRgammadelta single positive cells enhance their transcription of IL-10 and TGF-beta, compared with the TCRgammadelta+ CD56+ cells and additionally express mRNA for IL-1beta and IL-6. The present findings suggest that gammadeltaT cells in normal pregnancy create a cytokine milieu promoting immunotolerance to the fetus. We hypothesize that through the production of the immunosuppressive cytokines IL-10 and/or TGF-beta the gammadeltaT cells could function directly as regulatory T cells or induce the differentiation of Th0 TCRalphabeta+ cells into regulatory/suppresser cells.

A Th2 chemokine, TARC, produced by trophoblasts and endometrial gland cells, regulates the infiltration of CCR4+ T lymphocytes into human decidua at early pregnancy.

A chemokine receptor, CCR4 preferentially expressed on type 2 helper T (Th2-type) cells, and its ligand, thymus and activation regulated chemokine--(TARC/CCL)--play important roles in the recruitment of Th2-type cells. We examined the distribution of CCR4 expressing CD4+ and CD8+-T cells in human decidua at early pregnancy, and localized TARC in the decidual tissue and chorionic tissue. Decidual tissue was obtained by legal abortion. The percentages of CCR4 expressing CD4+ and CD8+-T cells were analyzed by flow cytometry. Localization of TARC protein was evaluated by immunofluorescence staining. The expression of TARC mRNA in the choriocarcinoma cell line and endometrial cell line was analyzed by reverse transcriptase polymerase chain reaction (RT-PCR). The percentages of CCR4+ cells in CD4+-T cells and CD8+-T cells were significantly increased in human early pregnancy decidua compared with those in peripheral blood. An another marker of human Th2 and Tc2 cells, CRTH2 molecules was also expressed on CCR4+ CD4+-T cells and CCR4+ CD8+-T cells. In addition, we found that trophoblasts, uterine epithelial cells and endometrial gland cells produce TARC by immunohistochemical staining and the RT-PCR method. Our findings imply that TARC secreted in decidua mediates the infiltration of CCR4+ T-cell migration into the fetomaternal interface, decidua, resulting in the maintenance of pregnancy.

Human Decidua Contains Potent Immunostimulatory CD83 + Dendritic Cells

Dendritic cells (DCs) are sentinel cells of the immune system important in initiating antigen-specific T-cell responses to microbial and transplantation antigens. DCs are particularly found in surface tissues such as skin and mucosa, where the organism is threatened by infectious agents. The human decidua, despite its proposed immunosuppressive function, hosts a variety of immunocompetent CD45 cells such as natural killer cells, macrophages, and T cells. Here we describe the detection, isolation, and characterization of CD45(+), CD40(+), HLA-DR(++), and CD83(+) cells from human early pregnancy decidua with typical DC morphology. CD83(+) as well as CD1a(+) cells were found in close vicinity to endometrial glands, with preference to the basal layer of the decidua. In vitro, decidual CD83(+) cells could be enriched to approximately 30%, with the remainder of cells encompassing DC-bound CD3(+) T cells. Stimulation of allogeneic T cells in a mixed leukocyte reaction by the decidual cell fraction enriched for CD83(+) cells, was similar to that obtained with blood monocyte-derived DCs, demonstrating the potent immunostimulatory capacity of these cells. Decidual DCs with morphological, phenotypic, and functional characteristics of immunostimulatory DCs might be important mediators in the regulation of immunological balance between maternal and fetal tissue, leading to successful pregnancy.

Gammadelta T cells of human early pregnancy decidua: evidence for cytotoxic potency.

The immune compromise in decidua allows a semiallogeneic fetus to survive without impairing the ability of the maternal immune system to fight infections. Cytotoxic mechanisms are likely to be important in this compromise. Using RT-PCR, immunoflow cytometry and immunoelectron microscopy, the cytotoxic potential of isolated human decidual gammadelta T cells was studied. mRNA for perforin (Pf), granzymes A and B, granulysin and Fas ligand (FasL) was simultaneously expressed in decidual gammadelta T cells. Pf and FasL were not expressed on the cell surface. However, the cells constitutively synthesized Pf and stored it in cytolytic granules. Within the granules Pf mainly resided in the granule core formed by Pf-containing microvesicles. Ultrastructurally, three groups of Pf-containing granules were distinguished. They probably represent different stages of granule maturation in a process where Pf-containing microvesicles first attach to the core cortex and then are translocated across the cortex into the core. Presynthesized FasL was also stored in the core and microvesicles of the cytolytic granules. Upon degranulation by ionomycin/Ca(2+) treatment, FasL was rapidly translocated to the cell surface, demonstrating that its surface expression was not controlled by de novo biosynthesis. Thus decidual gammadelta T cells appear to perform Pf- and FasL-mediated cytotoxicity utilizing a common secretory mechanism based on cytolytic granule exocytosis. The first cytochemical visualization of lipids in the cytolytic granules is provided. These intragranular lipids probably wrap up the core and participate in packaging of the cytotoxic proteins as well as in the killing process. An ultrastructural model of a cytolytic granule is presented.