miR-132-3p Modulates DUSP9-Dependent p38/JNK Signaling Pathways to Enhance Inflammation in the Amnion Leading to Labor

Labor is a process of inflammation and hormonal changes involving both fetal and maternal compartments. MicroRNA-132-3p (miR-132-3p) has been reported to be involved in the development of inflammation-related diseases. However, little is known about its potential role in labor onset. This study aimed to explore the mechanism of miR-132-3p in amnion for labor initiation. In the mouse amnion membranes, the expression of miR-132-3p was found to increase gradually during late gestation. In human amniotic epithelial cell line (WISH), upregulation of miR-132-3p was found to increase proinflammatory cytokines and cyclooxygenase 2 (COX2) as well as prostaglandin E2 (PGE2), which was suppressed by miR-132-3p inhibitor. Dual-specificity phosphatase 9 (DUSP9) was identified as a novel target gene of miR-132-3p, which could be negatively regulated by miR-132-3p. DUSP9 was present in the mouse amnion epithelial cells, with a decrease in its abundance at 18.5 days post coitum (dpc) relative to 15.5 dpc. Silencing DUSP9 was found to facilitate the expression of proinflammatory cytokines and COX2 as well as PGE2 secretion in WISH cells, which could be attenuated by p38 inhibitor SB203580 or JNK inhibitor SP600125. Additionally, intraperitoneal injection of pregnant mice with miR-132-3p agomir not only caused preterm birth, but also promoted the abundance of COX2 as well as phosphorylated JNK and p38 levels, and decreased DUSP9 level in mouse amnion membranes. Collectively, miR-132-3p might participate in inflammation and PGE2 release via targeting DUSP9-dependent p38 and JNK signaling pathways to cause preterm birth.

The effect of human amnion epithelial cells on lung development and inflammation in preterm lambs exposed to antenatal inflammation

Background

Lung inflammation and impaired alveolarization are hallmarks of bronchopulmonary dysplasia (BPD). We hypothesize that human amnion epithelial cells (hAECs) are anti-inflammatory and reduce lung injury in preterm lambs born after antenatal exposure to inflammation.

Methods

Pregnant ewes received either intra-amniotic lipopolysaccharide (LPS, from E.coli 055:B5; 4mg) or saline (Sal) on day 126 of gestation. Lambs were delivered by cesarean section at 128 d gestation (term ~150 d). Lambs received intravenous hAECs (LPS/hAECs: n = 7; 30x10⁶ cells) or equivalent volumes of saline (LPS/Sal, n = 10; or Sal/Sal, n = 9) immediately after birth. Respiratory support was gradually de-escalated, aimed at early weaning from mechanical ventilation towards unassisted respiration. Lung tissue was collected 1 week after birth. Lung morphology was assessed and mRNA levels for inflammatory mediators were measured.

Results

Respiratory support required by LPS/hAEC lambs was not different to Sal/Sal or LPS/Sal lambs. Lung tissue:airspace ratio was lower in the LPS/Sal compared to Sal/Sal lambs (P<0.05), but not LPS/hAEC lambs. LPS/hAEC lambs tended to have increased septation in their lungs versus LPS/Sal (P = 0.08). Expression of inflammatory cytokines was highest in LPS/hAECs lambs.

Conclusions

Postnatal administration of a single dose of hAECs stimulates a pulmonary immune response without changing ventilator requirements in preterm lambs born after intrauterine inflammation.

Human Amnion Epithelial Cells Impair T Cell Proliferation: The Role of HLA-G and HLA-E Molecules

The immunoprivilege status characteristic of human amnion epithelial cells (hAECs) has been recently highlighted in the context of xenogenic transplantation. However, the mechanism(s) involved in such regulatory functions have been so far only partially been clarified. Here, we have analyzed the expression of HLA-Ib molecules in isolated hAEC obtained from full term placentae. Moreover, we asked whether these molecules are involved in the immunoregulatory functions of hAEC. Human amnion-derived cells expressed surface HLA-G and HLA-F at high levels, whereas the commonly expressed HLA-E molecule has been measured at a very low level or null on freshly isolated cells. HLA-Ib molecules can be expressed as membrane-bound and soluble forms, and in all hAEC batches analyzed we measured high levels of sHLA-G and sHLA-E when hAEC were maintained in culture, and such a release was time-dependent. Moreover, HLA-G was present in extracellular vesicles (EVs) released by hAEC. hAEC suppressed T cell proliferation in vitro at different hAEC:T cell ratios, as previously reported. Moreover, inhibition of T cell proliferation was partially reverted by pretreating hAEC with anti-HLA-G, anti-HLA-E and anti-β2 microglobulin, thus suggesting that HLA-G and -E molecules are involved in hAEC-mediated suppression of T cell proliferation. Finally, either large-size EV (lsEV) or small-size EV (ssEV) derived from hAEC significantly modulated T-cell proliferation. In conclusion, we have here characterized one of the mechanism(s) underlying immunomodulatory functions of hAEC, related to the expression and release of HLA-Ib molecules.

The Immunomodulatory Properties of the Human Amnion-Derived Mesenchymal Stromal/Stem Cells Are Induced by INF-γ Produced by Activated Lymphomonocytes and Are Mediated by Cell-To-Cell Contact and Soluble Factors

Human mesenchymal stromal/stem cells (MSCs), being immunoprivileged and having immunomodulatory ability, represent a promising tool to be applied in the field of regenerative medicine. Based on numerous in vitro evidences, the immunological effects of MSCs on immune cells could depend on different mechanisms as cell-to-cell contact and paracrine signals. Furthermore, recent studies have shown that the immunomodulatory activity of MSCs is initiated by activated immune cells; thus, their interaction represents a potential homeostatic mechanism by which MSCs regulate the immune response. MSCs also release exosomes able to give different effects, in a paracrine manner, by influencing inflammatory processes. In this study, we aimed to establish the potential role of human amnion-derived MSCs (hAMSCs), in immunomodulation. We found that the immunosuppressive properties of hAMSCs are not constitutive, but require "supportive signals" capable of promoting these properties. Indeed, we observed that hAMSCs alone are not able to produce an adequate amount of soluble immunomodulatory factors. Here, we studied, in depth, the strong immunomodulatory licensing signal deriving from the direct interaction between hAMSCs and stimulated peripheral blood mononuclear cells. We found that the immunomodulatory effect of hAMSCs also depends on cell-to-cell contact through the contribution of the PDL-1/PD-1 axis. We then investigated the IFN-γ priming of hAMSCs (γ-hAMSCs), which induce the increase of PDL-1 expression, high production of IDO, and upregulation of different immunomodulatory exosome-derived miRNAs. Our miRNA-target network analysis revealed that nine of the deregulated miRNAs are involved in the regulation of key proteins that control both T cell activation/anergy and monocyte differentiation pathways. Finally, we observed that γ-hAMSCs induce in monocytes both M2-like phenotype and the increase of IL-10 production. The extensive implications of MSCs in modulating different aspects of the immune system make these cells attractive candidates to be employed in therapeutic application in immune-based diseases. For these reasons, we aimed, with this study, to shed light on the potential of hAMSCs, and how they could become a useful tool for treating different inflammatory diseases, including end-stage pathologies or adverse effects in transplanted patients.

Fetal T Cell Activation in the Amniotic Cavity during Preterm Labor: A Potential Mechanism for a Subset of Idiopathic Preterm Birth

Prematurity is the leading cause of perinatal morbidity and mortality worldwide. In most cases, preterm birth is preceded by spontaneous preterm labor, a syndrome that is associated with intra-amniotic inflammation, the most studied etiology. However, the remaining etiologies of preterm labor are poorly understood; therefore, most preterm births are categorized as idiopathic. In this study, we provide evidence showing that the fetal immune system undergoes premature activation in women with preterm labor without intra-amniotic inflammation, providing a potential new mechanism of disease for some cases of idiopathic preterm birth. First, we showed that fetal T cells are a predominant leukocyte population in amniotic fluid during preterm gestations. Interestingly, only fetal CD4+ T cells were increased in amniotic fluid of women who underwent idiopathic preterm labor and birth. This increase in fetal CD4+ T cells was accompanied by elevated amniotic fluid concentrations of T cell cytokines such as IL-2, IL-4, and IL-13, which are produced by these cells upon in vitro stimulation, but was not associated with the prototypical cytokine profile observed in women with intra-amniotic inflammation. Also, we found that cord blood T cells, mainly CD4+ T cells, obtained from women with idiopathic preterm labor and birth displayed enhanced ex vivo activation, which is similar to that observed in women with intra-amniotic inflammation. Finally, we showed that the intra-amniotic administration of activated neonatal CD4+ T cells induces preterm birth in mice. Collectively, these findings provide evidence suggesting that fetal T cell activation is implicated in the pathogenesis of idiopathic preterm labor and birth.

MicroRNAs of Equine Amniotic Mesenchymal Cell-derived Microvesicles and Their Involvement in Anti-inflammatory Processes

Cell-derived microvesicles (MVs) are a recently discovered mechanism of cell-to-cell communication. Our previous data show that MVs secreted by equine amniotic mesenchymal-derived cells (AMCs) are involved in downregulation of proinflammatory genes in lipopolysaccharide-stressed equine tendon and endometrial cells. The aim of the present study was to evaluate whether AMC-MVs contain selected microRNAs (miRNAs) involved in inflammation. Two pools of cells, derived from 3 amniotic membranes each, and their respective MVs were collected. Small RNAs were extracted and deep sequenced, followed by miRNA in silico detection. The analysis identified 1,285 miRNAs, which were quantified both in AMCs and MVs. Among these miRNAs, 401 were classified as Equus caballus miRNAs, 257 were predicted by homology with other species (cow, sheep, and goat), and 627 were novel candidate miRNAs. Moreover, 146 miRNAs differentially expressed (DE) in AMCs and MVs were identified, 36 of which were known and the remaining were novel. Among the known DE miRNAs, 17 showed higher expression in MVs. Three of these were validated by real time polymerase chain reaction: eca-miR-26, eca-miR-146a, and eca-miR-223. Gene ontology analysis of validated targets showed that the DE miRNAs in cells and MVs could be involved both in immune system regulation by modulating interleukin signaling and in the inflammatory process. In conclusion, this study suggests a significant role of AMCs in modulating immune response through cell–cell communication via MV-shuttling miRNAs.

Neutrophil Extracellular Traps in the Amniotic Cavity of Women with Intra-Amniotic Infection: A New Mechanism of Host Defense

OBJECTIVE

Neutrophil extracellular traps (NETs) control microbial infections through their antimicrobial activities attributed to DNA, histones, granules, and cytoplasmic proteins (eg, elastase). Intra-amniotic infection is characterized by the influx of neutrophils into the amniotic cavity; therefore, the aim of this study was to determine whether amniotic fluid neutrophils form NETs in this inflammatory process.

METHODS

Amniotic fluid samples from women with intra-amniotic infection (n = 15) were stained for bacteria detection using fluorescent dyes. Amniotic fluid neutrophils were purified by filtration. As controls, neutrophils from maternal blood samples (n = 3) were isolated by density gradients. Isolated neutrophils were plated onto glass cover slips for culture with and without 100 nM of phorbol-12-myristate-13-acetate (PMA). NET formation was assessed by 4',6-diamidino-2-phenylindole (DAPI) staining and scanning electron microscopy. Different stages of NET formation were visualized using antibodies against elastase and histone H3, in combination with DAPI staining, by confocal microscopy. Finally, maternal or neonatal neutrophils were added to amniotic fluid samples from women without intra-amniotic infection (n = 4), and NET formation was evaluated by DAPI staining.

RESULTS

(1) NETs were present in the amniotic fluid of women with intra-amniotic infection; (2) all of the amniotic fluid samples had detectable live and dead bacteria associated with the presence of NETs; (3) in contrast to neutrophils from the maternal circulation, amniotic fluid neutrophils did not require PMA stimulation to form NETs; (4) different stages of NET formation were observed by co-localizing elastase, histone H3, and DNA in amniotic fluid neutrophils; and (5) neither maternal nor neonatal neutrophils form NETs in the amniotic fluid of women without intra-amniotic infection.

CONCLUSION

NETs are detectable in the amniotic fluid of women with intra-amniotic infection.

Progesterone prevents epithelial-mesenchymal transition of ovine amniotic epithelial cells and enhances their immunomodulatory properties

The in vitro expansion is detrimental to therapeutic applications of amniotic epithelial cells (AEC), an emerging source of fetal stem cells. This study provides molecular evidences of progesterone (P4) role in preventing epithelial-mesenchymal transition (EMT) in ovine AEC (oAEC). oAEC amplified under standard conditions spontaneously acquired mesenchymal properties through the up-regulation of EMT-transcription factors. P4 supplementation prevented phenotype shift by inhibiting the EMT-inducing mechanism such as the autocrine production of TGF-β and the activation of intracellular-related signaling. The effect of P4 still persisted for one passage after steroid removal from culture as well as steroid supplementation promptly reversed mesenchymal phenotype in oAEC which have experienced EMT during amplification. Furthermore, P4 promoted an acute up-regulation of pluripotent genes whereas enhanced basal and LPS-induced oAEC anti-inflammatory response with an increase in anti-inflammatory and a decrease in pro-inflammatory cytokines expression. Altogether, these results indicate that P4 supplementation is crucial to preserve epithelial phenotype and to enhance biological properties in expanded oAEC. Therefore, an innovative cultural approach is proposed in order to improve therapeutic potential of this promising source of epithelial stem cells.

Human amnion epithelial cells modulate the inflammatory response to ventilation in preterm lambs

Ventilation of preterm neonates causes pulmonary inflammation that can contribute to lung injury, propagate systemically and result in long-term disease. Modulation of this initial response may reduce lung injury and its sequelae. We aimed to determine the effect of human amnion epithelial cells (hAECs) on immune activation and lung injury in preterm neonatal lambs. Preterm lambs received intratracheal hAECs (90x106) or vehicle, prior to 2 h of mechanical ventilation. Within 5 min of ventilation onset, lambs also received intravenous hAECs (90x106) or vehicle. Lung histology, bronchoalveolar lavage (BAL) cell phenotypes, and cytokine profiles were examined after 2 h of ventilation, and in unventilated controls. Histological indices of lung injury were higher than control, in vehicle-treated ventilated lambs but not in hAEC-treated ventilated lambs. Ventilation-induced pulmonary leukocyte recruitment was greater in hAEC-treated lambs than in vehicle-treated lambs. Lung IL-1β and IL-6 mRNA expression was higher in vehicle- and hAEC-treated ventilated lambs than in controls but IL-8 mRNA levels were greater than control only in vehicle-treated ventilated lambs. Numbers of CD44+ and CD21+ lymphocytes and macrophages from the lungs were altered in vehicle- and hAEC-treated ventilated lambs. Numbers of CD8+ macrophages were lower in hAEC-treated ventilated lambs than in vehicle-treated ventilated lambs. Indices of systemic inflammation were not different between vehicle- and hAEC-treated lambs. Human amnion epithelial cells modulate the pulmonary inflammatory response to ventilation in preterm lambs, and reduce acute lung injury. Immunomodulatory effects of hAECs reduce lung injury in preterm neonates and may protect against longer-term respiratory disease.

Human amnion epithelial cells rescue cell death via immunomodulation of microglia in a mouse model of perinatal brain injury

BACKGROUND

Human amnion epithelial cells (hAECs) are clonogenic and have been proposed to reduce inflammatory-induced tissue injury. Perturbation of the immune response is implicated in the pathogenesis of perinatal brain injury; modulating this response could thus be a novel therapy for treating or preventing such injury. The immunomodulatory properties of hAECs have been shown in other animal models, but a detailed investigation of the effects on brain immune cells following injury has not been undertaken. Here, we investigate the effects of hAECs on microglia, the first immune responders to injury within the brain.

METHODS

We generated a mouse model combining neonatal inflammation and perinatal hyperoxia, both of which are risk factors associated with perinatal brain injury. On embryonic day 16 we administered lipopolysaccharide (LPS), or saline (control), intra-amniotically to C57Bl/6 J mouse pups. On postnatal day (P)0, LPS pups were placed in hyperoxia (65% oxygen) and control pups in normoxia for 14 days. Pups were given either hAECs or saline intravenously on P4.

RESULTS

At P14, relative to controls, LPS and hyperoxia pups had reduced body weight, increased density of apoptotic cells (TUNEL) in the cortex, striatum and white matter, astrocytes (GFAP) in the white matter and activated microglia (CD68) in the cortex and striatum, but no change in total microglia density (Iba1). hAEC administration rescued the decreased body weight and reduced apoptosis and astrocyte areal coverage in the white matter, but increased the density of total and activated microglia. We then stimulated primary microglia (CD45lowCD11b+) with LPS for 24 h, followed by co-culture with hAEC conditioned medium for 48 h. hAEC conditioned medium increased microglial phagocytic activity, decreased microglia apoptosis and decreased M1 activation markers (CD86). Stimulating hAECs for 24 h with LPS did not alter release of cytokines known to modulate microglia activity.

CONCLUSIONS

These data demonstrate that hAECs can directly immunomodulate brain microglia, probably via release of trophic factors. This observation offers promise that hAECs may afford therapeutic utility in the management of perinatal brain injury.

Escherichia coli-induced temporal and differential secretion of heat-shock protein 70 and interleukin-1β by human fetal membranes in a two-compartment culture system

INTRODUCTION

Escherichia coli is recognized as an etiological bacteria associated with chorioamnionitis and the preterm premature rupture of fetal membranes. This pathological condition induces pro-inflammatory cytokines and degradative metalloproteinases, which are considered biological markers secreted in an acute stage of infection. Heat-shock proteins (HSPs) are an important component of the innate immunity response and are found in different pathological conditions. They have not been previously measured in human fetal membranes in response to infectious conditions. We hypothesized that the choriodecidual tissue and amniotic epithelium secreted temporal and differential Hsp-60, Hsp-70, and interleukin (IL)-1β mediated by E. coli infection.

METHODS

Fetal membranes were mounted in a two-compartment culture system and infected with two passes of live E. coli at different doses (10², 10⁴, 10⁵, and 10⁶ colony-forming units (CFU)/mL) and intervals of incubation (3, 6, and 24 h). The culture medium was collected, and Hsp-60, Hsp-70, and IL-1β were assessed using the enzyme-linked immunosorbent assay (ELISA) method.

RESULTS

After 3 and 6 h of infection, E. coli induced an increase in Hsp-70 secretion in the choriodecidual tissue. However, after 24 h of incubation, Hsp-70 was downregulated and we observed an increase in IL-1β secretion. By contrast, E. coli induced a lower Hsp-60 secretion in the amnion compared to Hsp-70.

DISCUSSION

Human fetal membranes responded actively to E. coli infection, with an increase in Hsp-70 during the first hours of infection. After 24 h, there was an increase in the liberation of IL-1β.

Effects of human amniotic mesenchymal stromal cells on rabbit T-cell responses in a xenolymphocyte reaction assay

OBJECTIVES

To evaluate the immunomodulatory properties of human amniotic mesenchymal stromal cells.

MATERIALS AND METHODS

Human amniotic mesenchymal stromal cells were isolated, characterized by flow cytometry, cultured in vitro, and evaluated in allogeneic and xenogeneic mixed lymphocyte reactions. The proliferation of T cells and the expression of interleukin 2 and interferon gamma by T cells were evaluated in the presence of human amniotic mesenchymal stromal cells.

RESULTS

Human amniotic mesenchymal stromal cells were successfully isolated from human amniotic membranes and had well-defined human mesenchymal stem cell markers (CD90, CD73, CD105, and CD166). The human amniotic mesenchymal stromal cells inhibited the proliferation of human and rabbit T cells and the secretion of interleukin-2 and interferon gamma by human T cells.

CONCLUSIONS

Human amniotic mesenchymal stromal cells may be useful for cell therapy and tissue engineering because of availability, phenotypic plasticity, and immunomodulatory properties.

The diagnostic performance of the Mass Restricted (MR) score in the identification of microbial invasion of the amniotic cavity or intra-amniotic inflammation is not superior to amniotic fluid interleukin-6

OBJECTIVE

Intra-amniotic infection/inflammation are major causes of spontaneous preterm labor and delivery. However, diagnosis of intra-amniotic infection is challenging because most are subclinical and amniotic fluid (AF) cultures take several days before results are available. Several tests have been proposed for the rapid diagnosis of microbial invasion of the amniotic cavity (MIAC) or intra-amniotic inflammation. The aim of this study was to examine the diagnostic performance of the AF Mass Restricted (MR) score in comparison with interleukin-6 (IL-6) and matrix metalloproteinase-8 (MMP-8) for the identification of MIAC or inflammation.

METHODS

AF samples were collected from patients with singleton gestations and symptoms of preterm labor (n = 100). Intra-amniotic inflammation was defined as >100 white blood cells/mm(3) (WBCs) in AF; MIAC was defined as a positive AF culture. AF IL-6 and MMP-8 were determined using ELISA. The MR score was obtained using the Surface-Enhanced Laser Desorption Ionization Time of Flight (SELDI-TOF) mass spectrometry. Sensitivity and specificity were calculated and logistic regression models were fit to construct receiver-operating characteristic (ROC) curves for the identification of each outcome. The McNemar's test and paired sample non-parametric statistical techniques were used to test for differences in diagnostic performance metrics.

RESULTS

(1) The prevalence of MIAC and intra-amniotic inflammation was 34% (34/100) and 40% (40/100), respectively; (2) there were no significant differences in sensitivity of the three tests under study (MR score, IL-6 or MMP-8) in the identification of either MIAC or intra-amniotic inflammation (using the following cutoffs: MR score >2, IL-6 >11.4 ng/mL, and MMP-8 >23 ng/mL); (3) there was no significant difference in the sensitivity among the three tests for the same outcomes when the false positive rate was fixed at 15%; (4) the specificity for IL-6 was not significantly different from that of the MR score in identifying either MIAC or intra-amniotic inflammation when using previously reported thresholds; and (5) there were no significant differences in the area under the ROC curve when comparing the MR score, IL-6 or MMP-8 in the identification of these outcomes.

CONCLUSIONS

IL-6 and the MR score have equivalent diagnostic performance in the identification of MIAC or intra-amniotic inflammation. Selection from among these three tests (MR score, IL-6 and MMP-8) for diagnostic purposes should be based on factors such as availability, reproducibility, and cost. The MR score requires a protein chip and a SELDI-TOF instrument which are not widely available or considered "state of the art". In contrast, immunoassays for IL-6 can be performed in the majority of clinical laboratories.

Human amnion membrane as a substrate for the detection of autoantibodies in pemphigus vulgaris and bullous pemphigoid

BACKGROUND

Human amnion membrane (HAM) was suggested to be a superior antigenic substrate for immunoblotting in detecting autoantibodies of autoimmune bullous skin diseases.

OBJECTIVES

To determine the properties of HAM as an antigenic substrate for the detection of autoantibodies in pemphigus vulgaris and bullous pemphigoid.

METHODS

Immunomapping and tandem liquid chromatography mass spectrometry were used to delineate the antigenic structure of HAM. Immunoblotting and indirect immunofluorescence were used to study the diagnostic utility of HAM in 25 pemphigus patients, 41 pemphigoid patients, and 36 controls, and the results were compared to those of indirect immunofluorescence on monkey esophagus, immunoblotting using normal human skin, and enzyme-linked immunosorbent assay.

RESULTS

Immunomapping demonstrated the presence of all the antigens known to be targeted in autoimmune bullous skin diseases, in both normal human skin and HAM, except for the absence of BP230, and low threshold levels of Dsg1, Dsg3 and Dsc3 in HAM. HAM indirect immunofluorescence demonstrated anti-basement membrane zone antibodies in 48.7% of the pemphigoid patients, and anti-intercellular space antibodies in 72.0% of the pemphigus patients. HAM immunoblotting did not demonstrate anti-BP230 antibodies, but detected anti-BP180 antibodies in 53.7% of the pemphigoid patients. It did not demonstrate anti-Dsg1 and/ or anti-Dsg3 antibodies in any of the pemphigus patients. These results were inferior to those of ELISA and monkey esophagus indirect immunofluorescence.

CONCLUSIONS

Compared to other studied methods, HAM does not offer advantages in detecting autoantibodies in bullous pemphigoid and pemphigus vulgaris.

In utero repair of myelomeningocele with autologous amniotic membrane in the fetal lamb model

BACKGROUND

Despite advances in prenatal repair, myelomeningocele (MMC) still produces devastating neurologic deficits. The amniotic membranes (AM) are a biologically active tissue that has been used anecdotally for human fetal MMC repair. This study evaluated the use of autologous AM compared to skin closure in an established fetal MMC model.

METHODS

Seven fetal lambs underwent surgical creation of MMC at gestational age of 75days followed by in utero repair at gestational age of 100days. Lambs were repaired with an autologous AM patch followed by skin closure (n=4) or skin closure alone (n=3). Gross necropsy and histopathology of the spinal cords were performed at term to assess neuronal preservation at the lesion.

RESULTS

An increase in preserved motor neurons and a larger area of spinal cord tissue were seen in AM-repaired lambs, as was decreased wound healing of the overlying skin. Loss of nearly all spinal cord tissue with limited motor neuron preservation was seen in skin only-repaired lambs.

CONCLUSIONS

AM-repaired lambs showed increased protection of spinal cord tissue compared to skin only-repaired lambs, but the overlying skin failed to close in AM-repaired lambs. These results suggest a potential role for AM in fetal MMC repair that warrants further study.

The effect of omega-3 polyunsaturated fatty acids on the inflammatory response of the amnion

OBJECTIVE

To investigate the effect of omega-3 PUFAs, eicosapentanoic acid (EPA) and docosohexanoic acid (DHA) on inflammatory cytokine production in the amnion.

STUDY DESIGN

Amnion explants were obtained at elective caesarean sections and cultured in vitro with EPA and DHA. IL-8 and IL-6 secretion was determined by ELISA, the role of PPARγ was investigated using specific agonists and antagonists and activity of MMP assessed by gelatin zymography.

RESULTS

A combination of EPA and DHA significantly reduced the concentration of IL-8 and IL-6 released into the supernatant compared to untreated controls (p<0.001). Stimulation of PPARγ with troglitazone reduced IL-8 production, and the PPARγ antagonist GW9662 partially reversed this effect. The activity of MMP-9 was also significantly reduced by treatment with EPA and DHA in combination compared to untreated control (p<0.05).

CONCLUSION

The omega-3 PUFAs EPA and DHA decrease the inflammatory response of the amnion, and this may be partially mediated through PPARγ.

Antimicrobial peptide response to group B Streptococcus in human extraplacental membranes in culture

OBJECTIVE

Streptococcus agalactiae (GBS) is an important cause of chorioamnionitis. This study characterizes GBS colonization and stimulation of antimicrobial responses in human extraplacental membranes using an ex vivo transwell two-compartment system of full-thickness membranes and live GBS.

STUDY DESIGN

Human extraplacental membranes were affixed to transwell frames (without synthetic membranes). Live GBS was added to the decidual side of membranes in transwell cultures, and cocultures were incubated for 4, 8 and 24 h. GBS recovery from homogenized membranes and culture medium was determined by enumerating colony forming units (CFU) on blood agar. Antimicrobial peptide expression was identified using immunohistochemistry and ELISA. GBS killing by HBDs was assessed in vitro by incubating GBS with different human beta defensins (HBDs) for 3 h, then enumerating CFU.

RESULTS

GBS recovery from membranes markedly decreased over time (P < 0.05). The antimicrobial peptides HBD-1, HBD-2, HBD-3, and lactoferrin were expressed in both GBS-exposed and non-exposed tissues. Notably, a pattern of localized increased HBD-2 in the amnion of GBS-infected tissue was observed. Moreover, GBS-treated membranes released increased amounts of HBD-2 into the amniotic and decidual compartments of the transwell cultures after 24 h (P < 0.05). In bacterial cultures, HBD-2 decreased GBS viability in a concentration-dependent manner (P < 0.05).

CONCLUSION

Innate immune responses in ex vivo human extraplacental membranes suppress GBS growth. HBD-2 was implicated in this GBS suppression with evidence of signal transduction across the tissue. Antimicrobial peptides may be important for innate immune defense against intrauterine GBS infections during pregnancy.

Amniotic fluid protein profiles of intraamniotic inflammatory response to Ureaplasma spp. and other bacteria

OBJECTIVE

This study aimed to evaluate the amniotic fluid protein profiles and the intensity of intraamniotic inflammatory response to Ureaplasma spp. and other bacteria, using the multiplex xMAP technology.

METHODS

A retrospective cohort study was undertaken in the Department of Obstetrics and Gynecology, University Hospital Hradec Kralove, Czech Republic. A total of 145 pregnant women with preterm prelabor rupture of membranes between gestational age 24+0 and 36+6 weeks were included in the study. Amniocenteses were performed. The presence of Ureaplasma spp. and other bacteria was evaluated using 16S rRNA gene sequencing. The levels of specific proteins were determined using multiplex xMAP technology.

RESULTS

The presence of Ureaplasma spp. and other bacteria in the amniotic fluid was associated with increased levels of interleukin (IL)-6, IL-8, IL-10, brain-derived neurotropic factor, granulocyte macrophage colony stimulating factor, monocyte chemotactic protein-1, macrophage inflammatory protein-1, and matrix metalloproteinasis-9. Ureaplasma spp. were also associated with increased levels of neurotropin-3 and triggering receptor expressed on myeloid cells-1.

CONCLUSIONS

The presence of Ureaplasma spp. in the amniotic fluid is associated with a slightly different protein profile of inflammatory response, but the intensity of inflammatory response to Ureaplasma spp. is comparable with the inflammatory response to other bacteria.

Tissue-specific human beta-defensins (HBD)-1, HBD-2 and HBD-3 secretion profile from human amniochorionic membranes stimulated with Candida albicans in a two-compartment tissue culture system

BACKGROUND

During intrauterine infection, amniochorionic membranes represent a mechanical and immunological barrier against dissemination of infection. Human beta defensins (HBD)-1, HBD-2, and HBD-3 are key elements of innate immunity that represent the first line of defense against different pathogen microorganisms associated with preterm labor. The aim of this work was to characterize the individual contribution of the amnion (AMN) and choriodecidua (CHD) regions to the secretion of HBD-1, HBD-2 and HBD-3, after stimulation with Candida albicans.

METHODS

Full-thickness human amniochorionic membranes were obtained after delivery by elective cesarean section from women at 37-40 wk of gestation with no evidence of active labor. The membranes were cultured in a two-compartment experimental model in which the upper compartment is delimited by the amnion and the lower chamber by the choriodecidual membrane. One million of Candida albicans were added to either the AMN or the CHD face or to both and compartmentalized secretion profiles of HBD-1, HBD-2, and HBD-3 were quantified by ELISA. Tissue immunolocalization was performed to detect the presence of HBD-1, -2, -3 in tissue sections stimulated with Candida albicans.

RESULTS

HBD-1 secretion level by the CHD compartment increased 2.6 times (27.30 [20.9-38.25] pg/micrograms protein) when the stimulus with Candida albicans was applied only on this side of the membrane and 2.4 times (26.55 [19.4-42.5] pg/micrograms protein) when applied to both compartments simultaneously. HBD-1 in the amniotic compartment remained without significant changes. HBD-2 secretion level increased significantly in the CHD when the stimulus was applied only to this region (2.49 [1.49-2.95] pg/micrograms protein) and simultaneously to both compartments (2.14 [1.67- 2.91] pg/micrograms protein). When the stimulus was done in the amniotic compartment HBD-2 remained without significant changes in both compartments. HBD-3 remained without significant changes in both compartments regardless of the stimulation modality. Localization of immune-reactive forms of HBD-1, HBD-2, and HBD-3 was carried out by immunohistochemistry confirming the cellular origin of these peptides.

CONCLUSION

Selective stimulation of amniochorionic membranes with Candida albicans resulted in tissue-specific secretion of HBD-1 and HBD-2, mainly in the CHD, which is the first region to become infected during an ascending infection.

The role of the multiple banded antigen of Ureaplasma parvum in intra-amniotic infection: major virulence factor or decoy?

The multiple banded antigen (MBA) is a predicted virulence factor of Ureaplasma species. Antigenic variation of the MBA is a potential mechanism by which ureaplasmas avoid immune recognition and cause chronic infections of the upper genital tract of pregnant women. We tested whether the MBA is involved in the pathogenesis of intra-amniotic infection and chorioamnionitis by injecting virulent or avirulent-derived ureaplasma clones (expressing single MBA variants) into the amniotic fluid of pregnant sheep. At 55 days of gestation pregnant ewes (n = 20) received intra-amniotic injections of virulent-derived or avirulent-derived U. parvum serovar 6 strains (2×10⁴ CFU), or 10B medium (n = 5). Amniotic fluid was collected every two weeks post-infection and fetal tissues were collected at the time of surgical delivery of the fetus (140 days of gestation). Whilst chronic colonisation was established in the amniotic fluid of animals infected with avirulent-derived and virulent-derived ureaplasmas, the severity of chorioamnionitis and fetal inflammation was not different between these groups (p>0.05). MBA size variants (32–170 kDa) were generated in vivo in amniotic fluid samples from both the avirulent and virulent groups, whereas in vitro antibody selection experiments led to the emergence of MBA-negative escape variants in both strains. Anti-ureaplasma IgG antibodies were detected in the maternal serum of animals from the avirulent (40%) and virulent (55%) groups, and these antibodies correlated with increased IL-1β, IL-6 and IL-8 expression in chorioamnion tissue (p<0.05). We demonstrate that ureaplasmas are capable of MBA phase variation in vitro; however, ureaplasmas undergo MBA size variation in vivo, to potentially prevent eradication by the immune response. Size variation of the MBA did not correlate with the severity of chorioamnionitis. Nonetheless, the correlation between a maternal humoral response and the expression of chorioamnion cytokines is a novel finding. This host response may be important in the pathogenesis of inflammation-mediated adverse pregnancy outcomes.

Evidence for extended age dependent maternal immunity in infected children: mother to child transmission of HIV infection and potential interventions including sulfatides of the human fetal adnexa and complementary or alternative medicines

The two neighboring southwestern states of India, Karnataka and Maharashtra, have high incidence of HIV/AIDS and are among the six most high prevalence HIV infected states. In Karnataka state, the northern districts of Bagalkot, Belgaum and Bijapur (the three Bs) and in Maharashtra state, the southern districts of Sangli, Satara, and Solapur (the three Ss) are the areas with the highest incidence of HIV/AIDS. We have evaluated the incidence of maternal to child transmission (MTCT) of HIV-1 infection in Belgaum District which is more than 500 kilometers distance by road from the campus in greater Bangalore (Karnataka State). We have obtained the prenatal CD4 counts of HIV infected pregnant mothers. We have also screened the HIV infected children in two orphanages (rehabilitation centres for HIV infected children) in Belgaum District. The clinical conditions of these infected children were assessed for their CD4 counts, anti-retroviral therapy (ART) intake status, outpatient illnesses and body composition. We have observed that there is an influence of the age factor on the CD4 counts of the HIV infected children. Further, in view of the role of our recently found involvement of sulfatide, 3-O- galactosylceramide, in inhibition of HIV-1 replication and enhancement of hematopoiesis which is otherwise inhibited due to such infection, we have discussed the possible role of sulfatides that biologically occur in the fetal adnexa (placentatrophoblasts /amnion/chorion-umbilical cord), in containing HIV infection as a potential safer alternative to the ART regimens currently approved to be clinically practiced. Lastly, we have discussed the complementary and alternative medicine (CAM) therapies such as evidence based yoga and ayurveda as add-on to ART in potential elimination of MTCT of HIV infection. Out of a total of 150 children delivered by HIV infected mothers, 13 children were found to be positive as determined by the dried blood smear (DBS) for virological testing, giving an incidence of about 8.66% in the Belgaum district during the last two years, in spite of the prescription of currently available ART regimens. All the 13 HIV-transmitting mothers had normal vaginal deliveries. Though 12% of the total 150 deliveries required lower segment caesarean section (LSCS), none among them resulted in MTCT of HIV. Comparison of the prenatal CD4 counts between transmitting and non-transmitting mothers did not show significant differences (p=0.25) thus suggesting indirectly that HIV-1 proviral loads (undetermined / unavailable) need not necessarily determine the fate of incidence of vertical transmission. The mean age of 44 HIV infected children (14 females, 30 males) that were screened in two orphanages was 10.8±3.1 years. Out of these 44 children, 27 were taking ART (61.36%) with mean duration of consumption being 2.8±2.28 years. Fifty percent (n=22) of the children were suffering from at least one outpatient illness, out of which 13 were taking ART. Their mean basal metabolic rate (BMR), body mass index (BMI), muscle mass, fat mass and fat % were 795.45±106.9, 14.55±1.9 kg/m(2), 9.54±3.4 kg, 3.69±2.24 kg and 15.04±7.8% respectively. Comparison between the children taking ART (on-ART, n=27) and those not taking ART (non-ART, n= 17) showed that though there was no significant difference in the average age of the two groups, on-ART children had significantly higher BMR (p=0.05), and muscle mass (p=0.004), than non-ART. The CD4 counts, BMI, fat mass and fat percentage did not show significant statistical differences between the two groups. The CD4 counts of the children (both on-ART and non-ART) of age 8 years and below (n=12) were found to be significantly higher (p=0.04) than those of age 14 and above (n=10). All the children in age group of 14 years and above (n=10) except one child were on ART, whereas 7 out of 12 children in age group of 8 years and below were on-ART. In one of the rehabilitation centers called Aadhar, among non-ART children, a significant correlation was observed between the age of the child and CD4 counts (measured separately in the months of June 2011 and December 2011). Both the CD4 counts measured in June 2011 (n=6; r=-0.82, p= 0.04) as well as in December 2011 (n=6; r=-0.97, p=0.001) showed a significant decline as the age progressed. Also, at the same center, among on-ART children, the CD4 counts in June 2011 (n=7) and December 2011 (n=8) were significantly different between the children in the age group of 8 below years, and those in the age group of 14 years and above (p= 0.005). As HIV infected children grow in age, they may lose maternal derived immunity as shown by the decrease in CD4 counts, irrespective of their ART status. It is to be expected from these results that the conferred maternal immunity (possibly primarily humoral and secondarily cytotoxic immune responses) to the virus acquired at child birth taper off and eventually overcome by the generation of mutant HIV strains in the children, as the life spans of the infected children progress. We have discussed safer therapeutic interventions whose efficacy on HIV/AIDS may be synergistic to or even substitute the existing treatment strategies. Some of such interventions may even be customized to help eliminate MTCT. Further, these virus infected pregnant mother patient blood / serum samples could prove useful in the vaccine development against HIV infection.

[Comparison of immunologic regulatory characteristics of mesenchymal stem cells derived from human umbilical cord amnion and adult bone marrow]

This study was aimed to compare the immunoregulatory effects of mesenchymal stem cells derived from human umbilical cord amnion (AMSC) and adult bone marrow (BMMSC) in vitro, so as to provide the experimental basis for allogeneic hematopoietic stem cell transplantation in clinic. The AMSC were isolated from human umbilical cord amnion by using digestion with collagenase. They were identified by morphology, growth characteristics, immunophenotyping and differentiation ability. Furthermore, the immunoregulatory effects of AMSC and BMMSC were tested by lymphocyte transformation and mixed lymphocyte reaction. The results showed that AMSC and BMMSC possessed similar biological characteristics such as exhibition of fibroblastic morphology and strong proliferation ability in vitro. Flow cytometric analysis revealed that the AMSC highly expressed CD73, CD90, CD105, but negative for CD34, CD45, HLA-DR, and CD86 of BMMSC. Functionally, they all could differentiate into adipocyte, osteocytes and chondrocytes. Moreover, AMSC could inhibit cellular or nonspecific mitogenic stimuli-induced T cell proliferation with a dose-dependent manner. Reverse transcriptional-polymerase chain reaction also demonstrated expression of the similar immune cytokines in AMSC and BMNSC. It is concluded that the MSC derived from human umbilical cord amnion may be an excellent alternative source for experimental and clinical application.

The expression of interleukin-1 alpha, TNF and VEGF in corneal cells of patients with bullous keratopathy

Bullous keratopathy (BK) is a chronic corneal edema with or without subepithelial bullae as a result of a loss of the endothelial cells. 15 patients with BK after cataract surgery with intraocular lens implantation, due to Fuchs dystrophy (n = 3) or corneal endothelial trauma (n = 12) were included in the study. All patients were treated by amniotic membrane transplantation (AMT). Corneal epithelial cells in patients suffering from BK secreted 3.91 +/- 3.09 pg/mL of IL-1 alpha, 4446 +/- 16.8 pg/mL of TNF and 81.43 +/- 37.81 pg/mL of VEGF-I. Levels of all 3 investigated cytokines were significantly higher as compared to controls (p < 0.005). Amniotic membranes that were used to treat investigated patients contained 638.98 +/- 613.98 pg/mL of IL-1ra, 0.026 +/- 0.009 pg/mL of sTNF and 81.39 +/- 21.01 pg/mL of VEGF-R. Beneficial clinical effect of the AMT in treating BK could be explained by its natural production of pro-inflammatory cytokine antagonists such as IL-ra, sTNF antagonist and VEGF-R.

Transplantation of amniotic membrane in corneal ulcers and persistant epithelial defects

Amniotic membrane transplantation (AMT) leads to reduction of inflammatory symptoms and causes faster epithelisation in corneal ulcers and persistant epithelial defect. 21 patients with corneal ulcer (n = 18) or non-healing epithelial defect (n = 3) unresponsive to conventional treatment were included in the study. All patients were treated by AMT. Corneal epithelial cells in patients suffering from corneal ulcer secreted 3.51 +/- 1.79 of IL-1alpha, 64.27 +/- 31.53 pg/mL of TNFalpha and 209.07 +/- 201.82 pg/mL of VEGF. Levels of all 3 investigated cytokines were significantly higher as compared to controls (p < 0.005). Amniotic membranes that were used contained 775.69 +/- 613.98 pg/mL of IL-1alpha, 0.036 +/- 0.033 pg/mL of sTNF and 175.01 +/- 166.63 pg/mL of VEGF-R. Supporting effect of the AMT could be explained by the fact that AM secretes its natural antinflammatory antagonists IL-1ra, sTNF and VEGF-R.

Basement membrane zone and dermal extracellular matrix of the vulva, vagina and amnion: An immunohistochemical study with comparison with non-reproductive epithelium

BACKGROUND/OBJECTIVES

The basement membrane zone (BMZ) is an anatomically defined region present in all types of skin and mucosa, linking the epithelium to the mesenchyme with a complex structure to provide adhesion. Altered antigenic expression of the BMZ is implicated in interface dermatoses, and the BMZ is targeted by autoantibodies in subepidermal immunobullous dermatoses. This study aims to compare the antigenic expression of the BMZ and the dermal extracellular matrix in female genital skin and mucosa and amnion, with non-reproductive skin and mucosa.

METHODS

An indirect immunofluorescence technique was used to compare the antigenic expression of hemidesmosome, lamina lucida, anchoring filaments, lamina densa, anchoring fibrils and extracellular matrix in samples of non-reproductive skin (three), oral mucosa (three), vulval skin (two), vagina (three) and amnion (four).

RESULTS

Antigenic expression was similar in the stratified epithelium of reproductive and non-reproductive skin and mucosa, but differed in the simple cuboidal epithelium of amnion, which had reduced expression of dermal-associated antigens.

CONCLUSIONS

The BMZ and dermal extracellular matrix of vagina and vulva are very similar to those of non-reproductive skin and mucosa despite their various functions, but differs from amnion. Their antigenic expression does not fully account for the anatomical distribution of immunobullous and interface dermatoses.

Therapeutic effect of amniotic membrane in persistent epithelial defects and corneal ulcers in herpetic keratitis

Amniotic membrane transplantation (AMT) promotes rapid epithelialization and reduces stromal inflammation and ulceration in HSV-1 keratitis. 18 patients with non-healing epithelial defect or corneal ulcer caused by herpetic keratitis were included in the study. All patients were treated by AMT. Corneal epithelial cells in patients suffering from herpetic keratitis secreted 5+/-4.8 pg/ml of IL-1alpha and 0.16+/-0.47 pg/ml of IL-1beta (mean+/-SD). IL-1alpha level was significantly higher as compared to controls (p<0.005). Amniotic membranes that were used to treat investigated patients contained 339.87+/-105 pg/ml of IL-1ra. In herpetic keratitis pro-inflammatory cytokine IL-1alpha is secreted from corneal epithelial cells in significantly higher level then in controls. Beneficial effect of the AMT in such patients could be explained by the fact that AM secretes its natural antagonist IL-1ra.

[A comparative study on immunocompatibility and histological turnover after fresh or preserved human amniotic membrane xenotransplantation]

OBJECTIVE

To investigate the immunoreaction, histological reaction and turnover by comparing the xenotransplantation of fresh human amniotic membrane (HAM) with that of preserved HAM, and to analyze the clinical application value of different kinds of HAM preparations.

METHODS

Subcutaneous implant models were established in 150 BALB/C mice, which were randomized into 5 groups of 30 mice each, based on different implants: fresh amniotic membrane (FAM), double fresh amniotic membrane (DFAM), glycerin preserved amniotic membrane (GPAM), chorion (positive control) or merely operation (negative control). The tissue samples from grafted area were observed with SABC and HE staining, and the inflammatory cells were calculated with light microscopy. 1, 2, 4, 8 and 12 weeks after surgery.

RESULTS

The mice in all of groups were normal in eating and moving, and the wound surface healed well. In all of AM groups, the expression of MHC II and the calculation of inflammatory cells were much less than those in chorion groups, showing significant differences (P < 0.01). At 1, 8 and 12 weeks after surgery, there were no significant differences in the expression of MHC II and the calculation of inflammatory cells in all of AM groups, compared with other groups (P > 0.05). From 2 weeks to 4 weeks after surgery, there were no significant differences in the expression of MHC II and the calculation of inflammatory cells between FAM and DFAM groups (P > 0.05), but they were both more than those in GPAM groups, showing significant differences (P < 0.05). At the 4th week after surgery, in all of AM groups, the expression of MHC II and the calculation of inflammatory cells were less than those at the 2nd week, showing significant difference (P < 0.01). The amniotic epithelium was still alive in fresh AM groups until 4 weeks after transplantation. Early after surgery, fibroblasts infiltrated AM from the substantia basilaris layer while made fibrous capsule around the epithelium. After 12 weeks, the amnion absorbed.

CONCLUSION

As a kind of heterologous biomaterial, whether fresh or preserved, HAM can be seemed of ideal immunocompatibility and histocompatibility. Fresh HAM with alive epithelium may be more successful in area of repair and reconstruction.

Concise review: isolation and characterization of cells from human term placenta: outcome of the first international Workshop on Placenta Derived Stem Cells

Placental tissue draws great interest as a source of cells for regenerative medicine because of the phenotypic plasticity of many of the cell types isolated from this tissue. Furthermore, placenta, which is involved in maintaining fetal tolerance, contains cells that display immunomodulatory properties. These two features could prove useful for future cell therapy-based clinical applications. Placental tissue is readily available and easily procured without invasive procedures, and its use does not elicit ethical debate. Numerous reports describing stem cells from different parts of the placenta, using nearly as numerous isolation and characterization procedures, have been published. Considering the complexity of the placenta, an urgent need exists to define, as clearly as possible, the region of origin and methods of isolation of cells derived from this tissue. On March 23-24, 2007, the first international Workshop on Placenta Derived Stem Cells was held in Brescia, Italy. Most of the research published in this area focuses on mesenchymal stromal cells isolated from various parts of the placenta or epithelial cells isolated from amniotic membrane. The aim of this review is to summarize and provide the state of the art of research in this field, addressing aspects such as cell isolation protocols and characteristics of these cells, as well as providing preliminary indications of the possibilities for use of these cells in future clinical applications.

Human amnion mesenchyme harbors cells with allogeneic T-cell suppression and stimulation capabilities

Cells derived from the amniotic membrane of human placenta have been receiving particular attention because of their stem cell potentiality and immunomodulatory properties, which make them an attractive candidate source for cell therapy approaches. In this study, we isolated cells from the mesenchymal region of amnion and identified two subpopulations discordant for expression of the HLA-DR, CD45, CD14, and CD86 cellular markers. We therefore refer to the unfractionated cell population derived from this region as amniotic mesenchymal tissue cells (AMTC). We studied the suppressive and stimulatory characteristics of the unfractionated, HLA-DR-positive, and HLA-DR-negative AMTC populations and demonstrated that all three fail to induce an allogeneic T-cell response. However, unfractionated AMTC, which could inhibit T-cell allogeneic proliferation responses, induced proliferation of T cells stimulated via the T-cell receptor (TcR), in a cell-cell contact setting. We have shown that this stimulatory capacity can be attributed to the HLA-DR-positive AMTC subpopulation. Indeed, even though the HLA-DR-positive AMTC fraction surprisingly failed to induce proliferation of resting allogeneic T cells, they could cause strong proliferation of anti-CD3-primed allogeneic T cells. This stimulatory effect was not observed using the HLA-DR-negative AMTC fraction. The revelation that human amniotic mesenchyme possesses cell populations with both suppressive and stimulatory properties sheds additional light on the immunomodulatory functions of this tissue and may contribute to the clarification of some ongoing controversies associated with mesenchymal stromal cells of other sources, such as the presence of HLA-DR-positive cells and the suppressive versus stimulatory properties of these cells.

Dose-dependent immunomodulatory effect of human stem cells from amniotic membrane: a comparison with human mesenchymal stem cells from adipose tissue

Bone marrow-derived mesenchymal stem cells (BMSCs) have been used for allogeneic application in tissue engineering but have certain drawbacks. Therefore, stem cells (SC)s derived from other adult tissue sources have been considered as an alternative. However, there is only limited knowledge on their immunomodulatory properties. The aim of our study was to compare the immunomodulatory potential of human amniotic mesenchymal and human amniotic epithelial cells with that of human adipose-derived SCs under identical experimental conditions. We have demonstrated a dose-dependent inhibition of peripheral blood mononuclear cell (PBMC) immune responses in mixed lymphocyte reactions (up to 66-93% inhibition) and phytohemagglutinin activation assays (up to 67-96% inhibition). The lowest SC-to-PBMC ratio able to inhibit PBMC proliferation significantly was 1:8. Subcultivation (passage 2-6) did not alter immunoinhibitory properties, whereas cryopreservation significantly reduced the immunomodulatory potential. Using transwell systems, we have demonstrated an inhibition mechanism that is dependent on cell contact. Additionally, in coculture with allogeneic PBMCs, SCs were well tolerated and at most provoked mild alloreactions in singular cases. This study demonstrates, for the first time, contact- and dose-dependent immunosuppression of mesenchymal and epithelial amniotic SC populations, as well as of adipose tissue-derived SCs. All three cell types may be considered as possible alternatives to BMSCs for allogeneic application in tissue engineering.

Expanded Adipose-Derived Stem Cells Suppress Mixed Lymphocyte Reaction by Secretion of Prostaglandin E2

Multipotent mesenchymal stem cells (MSCs) in adult tissue are known to be less immunogenic and immunosuppressive. Previous study showed that primary cultures of human adipose-derived stem cells (ADSCs) shared their immunomodulatory properties with other MSCs. However, whether passaged human ADSCs can retain their immunomodulatory effect after in vitro expansion remains unknown. In addition, the mechanism of ADSC-mediated immunomodulatory effect remains to be elucidated. This study aimed to investigate these issues by using passaged human ADSCs as an in vitro study model. Flow cytometry showed that passaged ADSCs expressed human leukocyte antigen (HLA) class I but not class II molecules, which could be induced to express to a high level with interferon-gamma (IFN-gamma) treatment. The study found that passaged ADSCs could not elicit lymphocyte proliferation after co-culturing with them, even after IFN-gamma treatment. In addition, either IFN-gamma-treated or non-treated ADSCs could inhibit phytohemagglutinin (PHA)-stimulated lymphocyte proliferation. Moreover, passaged ADSCs could serve as the third-party cells to inhibited two-way mixed lymphocyte reaction (MLR). Further study using a transwell system also showed that this type of immunosuppressive effect was not cell-cell contact dependent. In defining possible soluble factors, we found that passaged ADSCs significantly increased their secretion of prostaglandin E2 (PGE2), but not transforming growth factor-beta (TGF-beta) and hepatocyte growth factor (HGF), when they were co-cultured with MLR. Furthermore, the result demonstrated that only PGE2 production inhibitor indomethacine, but not TGF-beta- and HGF-neutralizing antibodies, could significantly counteract ADSC-mediated suppression on allogeneic lymphocyte proliferation. These results indicated that in vitro expanded ADSCs retain low immunogenicity and immunosuppressive effect, and PGE2 might be the major soluble factor involved in the in vitro inhibition of allogeneic lymphocyte reaction.

Tubal abortions but not viable tubal pregnancies are characterized by an increased number of CD8 + T cells

OBJECTIVE

To examine immune cell phenotypes in viable tubal pregnancies (VTP) and in tubal abortions (TA).

METHODS

Paraffin-embedded specimens of VTP (n=7) and ongoing TA (n=6) were double-stained for cytokeratin for trophoblast as well as for CD45, CD3, CD8, CD68 and CD20 for immune cell phenotypes. In all cases, the amniotic sac was detected by ultrasound. Histological examination showed no evidence of necrosis within the tissues included in this study. Quantification of the subpopulations was performed in each slide by two independent examiners in five areas (0.085 mm2 each) of the invasion zone as marked by cytokeratin-positive stromal extravillous trophoblast (EVT) cells. For statistical analysis, the non-parametric two-tailed t-test was used (p<0.05).

RESULTS

The differences in the number of CD45(+), CD68(+) and CD20(+) cells was significant (p=0.0423, p=0.0469 and p=0.0494, respectively); however, the number of CD3(+), and among those the number of CD8(+) cells, was approximately eight-fold higher in TA than in VTP (p<0.0001 and p=0.0012, respectively).

CONCLUSION

The unequal distribution of CD8(+) cells in VTP and TA suggests a significant role of this immune cell phenotype in the further outcome of a tubal pregnancy either to an abortive or a viable, potentially life-threatening, entity.

[Study on allergenicity of fresh HAM for type I hypersensitivity]

To investigate whether human amniotic membrane (HAM) preparations have the possibility to type I hypersensitivity and its allergenicity. In systemic active allergic test model, 30 guinea pigs were equally divided into three groups. Each 10 guinea pigs were immunized with fresh HAM homogenate, albumen solution (positive control) and PBS (negative control). After the animals were stimulated with corresponding allergen, observe their reaction till dying or 3 h, then obtain blood samples, to determine blood histamine concentrations using chemical fluorometry and four hemorheologic markers by hemorheology analysis system. The guinea pigs responded to fresh HAM homogenate in almost the same manner as to PBS, and no obvious allergic reaction was observed in the animals except those in positive control group. The blood histamine concentration and four hemorheologic markers showed no significant differences between HAM and PBS (P > 0.05), both were much lower than positive control group (P < 0.01). Fresh HAM won't lead to type I hypersensitivity for lack of allergen performance.

Immunological Characteristics of Amniotic Epithelium

We review recent experimental evidence of the immunosuppressive and immunogenic potential of amniotic epithelial cells. Since cryopreserved amniotic membrane (AM) has been used in clinical applications, much research has focused on the beneficial effects of amniotic stromal matrix rather than on the function of viable amniotic cells. However, viable human amniotic epithelial cells (HAECs) have been shown to elicit beneficial effects on secretion of anti-inflammatory factors. Topical application of culture supernatant from HAECs leads to profound suppression of suture-induced neovascularization in cornea and fewer major histocompatibility complex (MHC) class II antigen-presenting cells (APCs) in inflamed cornea after thermal cautery. Furthermore, expression of interleukin (IL)-1beta mRNA was suppressed in cauterized cornea. These results suggest that HAECs are a source of soluble anti-inflammatory factors that suppress corneal inflammation. However, viable amniotic epithelial cells display antigenicity and immunogenicity as allografts. Fresh allogeneic amniotic epithelium (AE) expresses MHC class I antigens and sensitizes recipients when placed in the eye, although long-term memory of allo-specific delayed hypersensitivity (DH) was not acquired. Allogeneic AE was clearly vulnerable to acute immune rejection in specifically sensitized recipients and recipients of repeated AE transplantation. We therefore suggest that immunogenicity of AE should not be ignored, and use of AM from different donor placentas should be emphasized when repeated AM transplantation is required in patients clinically.

Differences in the placental membrane cytokine response: a possible explanation for the racial disparity in preterm birth

PROBLEM

The prematurity rate is higher in African-Americans (AA) compared with Caucasians (C). As spontaneous preterm labor has been hypothesized to be a host inflammatory response disease racial differences in human placental membrane inflammatory cytokine and prostaglandin pathway gene expression patterns between AA and C were examined in this report.

METHOD OF STUDY

Placental membranes (amniochorion) collected from AA and C women from cesareans at term were maintained in an organ explant system and stimulated with endotoxin (lipopolysaccharide, LPS). Microarray analysis and enzyme-linked immunosorbent assay was performed on mRNAs and culture media from AA- and C-derived membranes to document any differences in mRNA expression and protein production of IL-1, IL-6, IL-8, IL-10 and expression of cyclooxygenase 1 (COX-1), COX-2 and 15-hydroxyprostaglandin dehydrogenase (PGDH).

RESULTS

Increased mRNA expression of IL-1, IL-8 and COX-2 in AA and IL-6, IL-10, COX-1 and PGDH in C were documented after LPS stimulation. Concentration of IL-1 was significantly higher in media derived from AA whereas IL-6 and IL-10 concentrations were higher in C with no differences observed in IL-8 after LPS stimulation compared with respective unstimulated controls.

CONCLUSION

These data document ethnic diversity in placental membrane immune response.

Immunogenicity and antigenicity of allogeneic amniotic epithelial transplants grafted to the cornea, conjunctiva, and anterior chamber

PURPOSE

To determine the immunogenic characterization of amniotic epithelium (AE), by examining the fate of allogeneic AE grafts heterotopically transplanted in the eye.

METHODS

Intact AE from enhanced green fluorescence protein (EGFP) transgenic mice (C57BL/6 background) and wild-type C57BL/6 mice were transplanted onto cornea or conjunctiva, or inserted into the anterior chamber (AC) of normal BALB/c mice, C57BL/6 mice, or BALB/c mice presensitized to donor antigens. For repeated AE transplantation experiments, AE was grafted in the other eye 7 days after the first grafting. Graft fate was assessed clinically and histologically at selected intervals after grafting. Infiltrating inflammatory cells were examined immunohistochemically. Sensitization to alloantigens by AE was assessed by the delayed hypersensitivity (DH) response.

RESULTS

In normal recipients, GFP+ cells were absent in EGFP donor-derived AE grafts by day 21 on cornea and by day 7 on conjunctiva. AE grafts implanted in the AC survived for >8 weeks. In presensitized recipients and recipients that underwent repeated AE implantation, graft survival was markedly shorter than in normal recipients. DH was induced at 2 weeks, but failed to be induced at 4 weeks after grafting on cornea or at 8 weeks after grafting on conjunctiva and in the AC of normal recipients.

CONCLUSIONS

Fresh allogeneic AE expressed immunogenicity when placed on the ocular surface, although no memory of allospecific DH was acquired. Allogeneic AE is clearly vulnerable to immune rejection in specifically sensitized recipients.

[The application and biological improvement of amniotic membrane]

The special structure and biological viability of amniotic membrane (AM) allow it to be an ideal biological material. Biological improvement of the AM opens a new research field and allows it to be used broadly in clinical practice. The histological structure, physiological property, immunological behavior, the history and current status of the application of AM, the mechanism and the classification of various ophthalmic applications of AM and the mechanism of AM transplantation, as well as the biological improvement of AM were summarized and discussed.

Incubation of human chorioamniotic membranes with Candida albicans induces differential synthesis and secretion of interleukin-1beta, interleukin-6, prostaglandin E, and 92 kDa type IV collagenase

Ascendant colonization of pathogenic microorganisms from the vagina to the uterus is strongly associated to preterm labour and premature rupture of membranes. This study evaluated the secretion of interleukin (IL)-1beta, tumour necrosis factor (TNF)alpha, IL-6, prostaglandin E(2) (PGE(2)), and metalloproteinases 9 and 2 by the human chorioamnion stimulated with Candida albicans. Chorioamniotic membranes were obtained after delivery by elective Cesarean section from women at 37-40 weeks of gestation without evidence of active labour. The membranes were mounted in Transwell devices that form two independent compartments, which allow testing the individual responses and contributions of the amnion and choriodecidua. One million CFU ml(-1) of C. albicans was added to either the amniotic or choriodecidual surface and secretions of the markers were measured in both compartments using specific enzyme-linked immunosorbent assay and zymography. Fetal membranes followed different secretion patterns of proinflammatory cytokines depending on the side to which the stimulus was applied. IL-1beta was produced in higher amounts in the presence of C. albicans when applied to the choriodecidual side; TNFalpha and IL-6 secretion did not change in either the amnion or choriodecidual region. PGE(2) synthesis depicted a different pattern, the amniotic tissue was more responsive than the choriodecidual tissue, and this response tended to be higher even when only the amniotic side was stimulated. Matrix metalloproteinases (MMP)-9 increased after stimulation, being the choriodecidua its main source. Selective stimulation with C. albicans induced a differential secretion of IL-1beta, PGE(2), and MMP-9, resulting from a cooperative and bidirectional communication between the amnion and the choriodecidua.

Effect of tocolytics on interleukin-8 production by human amniotic and decidual cells

Preterm labor is associated with the release of various cytokines that play an important role in its pathophysiology. In preterm labor, tocolytics are used to inhibit uterine contractions and prolong gestation. We tested the hypothesis that tocolytics alter endotoxin-induced interleukin (IL-8) production from amniotic and decidual cells in vitro. Amniotic and decidual cells were isolated from patients undergoing elective repeat cesarean section at term. Cells were grown in tissue culture flasks. Cells were subsequently incubated with 100 ng/ml of endotoxin in 24 well plates in the presence of increasing concentrations of magnesium sulfate, nifedipine and terbutaline. After 24 h, IL-8 levels in each well were measured by ELISA. Endotoxin caused a significant elevation in IL-8 production in both amniotic and decidual cells. Magnesium sulfate dose dependently inhibited the endotoxin-stimulated IL-8 production in both decidual and amniotic cells. However, nifedipine and terbutaline did not significantly affect IL-8 production in either cell type. In conclusion, magnesium sulfate differentially suppresses endotoxin-stimulated IL-8 production in amniotic and decidual cells in vitro. The cellular mechanisms of this suppression and its clinical relevance in the setting of preterm labor merit further investigation.

Suppression of inflammatory and fibrotic responses in allergic inflammation by the amniotic membrane stromal matrix

BACKGROUND

The amniotic membrane (AM), which is the innermost layer of the placenta, was shown to possess anti-inflammatory and anti-fibrotic properties in various in vitro and clinical studies.

PURPOSE

To evaluate the anti-fibrotic and anti-inflammatory effects of the AM matrix (AMM) on human conjunctival and lung fibroblasts in an in vitro system that tests fibrotic and inflammatory responses at the effector stages of allergic inflammation.

METHODS

Human conjunctival or lung fibroblasts were seeded on plastic or on the stromal aspect of the AM, which was mounted on plastic inserts. Sonicates of human peripheral blood eosinophils activated with lipopolysaccharide (LPS), or human mast cell (HMC-1) leukaemia cell sonicates, were added to sub-confluent fibroblast monolayers. Proliferation of the sub-confluent fibroblasts was assessed using the [3H]-thymidine incorporation assay. The production of transforming growth factor (TGF)-beta1, granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-8 in conjunctival or lung fibroblasts was measured in conditioned media from these cultures by ELISA.

RESULTS

After 4 days in culture, the [3H]-thymidine incorporation assay indicated a reduced proliferation of activated conjunctival and lung fibroblasts when cultured directly on the AMM. The production of both TGF-beta1 and IL-8 was significantly suppressed in activated conjunctival fibroblasts cultured on the AMM compared with those cultured on plastic, while the production of both TGF-beta1 and GM-CSF was decreased in human lung fibroblast cultured on the AMM.

CONCLUSIONS

The AMM is capable of suppressing fibrotic responses in an in vitro system of effector stages of ocular allergic inflammation. These data may provide a basis for exploring matrix components in the AM for the treatment of allergic eye disease.

Evidence for a role of phosphodiesterase 4 in lipopolysaccharide-stimulated prostaglandin E2 production and matrix metalloproteinase-9 activity in human amniochorionic membranes

Chorioamniotic infection is a leading cause of preterm premature rupture of fetal membranes (amnion and chorion). Bacterial infection induces an inflammatory response characterized by elevated production of proinflammatory cytokines; the latter activate the production of both PGs that stimulate uterine contractions, and matrix metalloproteinases (MMPs) that degrade the extracellular matrix of the chorioamniotic membranes. The inflammatory response is under the control of cAMP content, which is partly regulated by phosphodiesterases (PDE). In this study, we investigated the role of the PDE4 family in the inflammatory process triggered by LPS in a model of amniochorionic explants. We found that PDE4 family is the major cAMP-PDE expressed in human fetal membranes and that PDE4 activity is increased by LPS treatment. Selective inhibition of PDE4 activity affected LPS signaling, because PDE4 inhibitors (rolipram and/or cilomilast) reduced the release of the proinflammatory cytokine TNF-alpha and increased the release of the anti-inflammatory cytokine IL-10. PDE4 inhibition reduced cyclooxygenase-2 protein expression and PGE(2) production and also modulated MMP-9, a key mediator of the membrane rupture process, by inhibiting pro-MMP-9 mRNA expression and pro-MMP-9 activity. These results demonstrate that the PDE4 family participates in the regulation of the inflammatory response associated with fetal membrane rupture during infection. The PDE4 family may be an appropriate pharmacological target for the management of infection-induced preterm delivery.

Expression of inflammatory markers in pig amnion after intraamniotic infection with nonpathogenic or enteropathogenic Escherichia coli

The pig amnion was in vivo intraamniotically infected with E. coli for 10 h at 80-85 d of gestation either with the nonpathogenic O86 strain or enteropathogenic O55 strain. TNF-alpha, IL-10, IL-1beta and IFN-gamma were determined in amniotic fluids by ELISA, the expression of cytokines and some other inflammatory markers was determined by immunohistochemistry. Intraamniotic infection induced high levels of TNF-alpha in amniotic fluids which correlated with bacterial virulence whereas IL-10 was induced only by O86. The IL-1beta level did not increase significantly and was expressed in all infected membranes. IFN-gamma was negligible or absent. TNF-alpha, IL-12p40, calprotectin, HSP65 and gp91phox were found by immunohistochemistry only in amnion membranes infected with the enteropathogenic strain 055.

Neovascularization of the amniotic membrane as a biological immune barrier

The clinical application of islet transplantation is limited due to the limited source and the morbidity of systemic immunosuppression to prevent rejection. The two problems can be solved by using encapsulated islets. We have used amniotic membranes as biocompatible natural immune barriers. The objective of this study was to assess the revascularization of the membrane, which is necessary to ensure islet viability when the membrane is used for islet encapsulation. The amniotic membranes, obtained from full-term pregnant female dogs, were molded to form macrocapsules, which were implanted in the peritoneal cavity. The capsules were removed after 3, 10, 15, and 30 days and examined histopathologically using hematoxylin and eosin and by immunohistochemistry for neovascularization using factor VIII to detect angiogenesis. Upon histopathological examination, all specimens showed localized, moderate inflammation and congested blood vessels with no thrombosis or rejection. There was a mild degree of fibroblast proliferation starting from day 10 to day 30. Immunohistochemical staining revealed that the number of blood vessels was 7, 11, 13, 10 per high-power microscopic field on days 3, 10, 15, and 30, respectively. We concluded from this study that implanted amniotic sac capsules were vascularized within the omental tissue from day 10 on with significant blood vessel formation starting on day 3 by immunohistochemical study.

Topical application of culture supernatant from human amniotic epithelial cells suppresses inflammatory reactions in cornea

Human amniotic epithelial cells (HAEC) may be a source of soluble anti-inflammatory factors. The purpose of this study is to determine the effect of topically applied HAEC culture supernatant on corneal inflammatory reactions. HAEC were obtained from a placenta and cultured for 48 hr, and the supernatant was collected. The conditioned medium from HAEC contained small amounts of human interleukin-1 receptor antagonist (IL-1ra). Intrastromal sutures were placed in the cornea of BALB/c mice to induce corneal neovascularisation. Superficial cauterisation was applied to induce recruitment or activation of antigen presenting cells (APCs) in the cornea without neovascularisation. HAEC conditioned medium, placebo, or recombinant human IL-1ra was topically applied three times daily for 2 weeks. Suture-induced corneal neovascularisation was evaluated microscopically for 8 weeks. The cauterised corneas were harvested at 2 weeks, and the MHC class II(+) APCs were quantified by immunofluorescent staining and confocal microscopy. Inflammatory cytokine gene expression in the cauterised corneas was analyzed by a multiprobe ribonuclease protection assay. Conditioned medium from HAEC led to a profound suppression of corneal neovascularisation and fewer MHC class II(+) APCs in the epithelium. In contrast, human IL-1ra was only slightly effective in suppressing corneal inflammatory reactions. mRNA expression of murine IL-1ra and IL-1beta in the cauterised corneas was markedly suppressed after application of the conditioned medium. These results suggest that HAEC are a source of soluble anti-inflammatory factors and that conditioned medium from HAEC contains factors other than IL-1ra that suppress corneal inflammation.

Induction of pro-inflammatory cytokine gene expression and apoptosis in human chorion cells of fetal membranes by influenza virus infection: possible implications for maintenance and interruption of pregnancy during infection

Human fetal membranes are composed of amnion, chorion and decidua tissues, which play a critical role in defense barriers as well as maintenance of pregnancy and parturition. Pro-inflammatory cytokines, such as interleukin (IL)-1beta, IL-6 and tumor necrosis factor (TNF)-alpha, produced by the tissues are postulated to facilitate parturition. Influenza virus infection is one of causes of pregnancy-associated complications, such as premature delivery, abortion and stillbirth. Recent studies have demonstrated that influenza virus infection induced the gene expression of a set of pro-inflammatory cytokines, such as IL-1beta, IL-6, TNF-alpha, interferon (IFN)-beta, IFN-gamma and granulocyte macrophage colony-stimulating factor (GM-CSF), and the secretion of unidentified monocyte differentiation-inducing factor(s) from primary cultured chorion cells undergoing apoptosis. These phenomena were not observed in primary cultured amnion cells infected with the virus. This article reviews, (1) the production of cytokines in fetal membrane tissues and their functions; (2) the differential induction of pro-inflammatory cytokine gene expression and apoptosis in fetal membrane chorion and amnion cells by influenza virus infection. An accumulating number of evidence suggests that interactive reactions between fetal membrane chorion cells and maternal monocytes/macrophages may play a critical role in defense barriers against the virus infection. Understanding the interactions would make important contributions to the elucidation of the pathogenesis of influenza virus infection during pregnancy.

The novel antimicrobial peptide beta3-defensin is produced by the amnion: a possible role of the fetal membranes in innate immunity of the amniotic cavity

BACKGROUND

Innate immunity evolved to eliminate microorganisms before, or after their entry into the tissues, but before enough antigen is available to activate an adaptive, immune response. Innate immunity is so successful that the majority of encountered microbes are neutralized. The beta-defensins are antimicrobial peptides produced by skin and mucosal surfaces and are an integral part of the innate immune system. The ability of the amnion cells, which are epithelial derivatives, to produce antimicrobial beta-defensins has not been explored.

OBJECTIVE

This study was undertaken to test the hypothesis that amnion cells synthesize beta-defensins under either basal or stimulated conditions.

METHODS

Amnion epithelial FL cells (ATCC CCL 62) were cultured in Ham's F12 and Dulbecco's modified Eagle medium plus 10% fetal calf serum until confluence, then replated into 24-well plates at 1.5 million cells per well. Cells from triplicate wells were harvested after 1, 3, 6, and 24 hours of exposure to microbial wall components (lipopolysaccharide [LPS]: 1 microg/mL or peptidoglycan [PG]: 10 microg/mL). Reverse transcription real-time polymerase chain reaction was performed with the use of human-specific primers for beta1, beta2, beta3, and beta4 defensins to compare basal messenger RNA (mRNA) levels of defensins and in response to treatment. beta-actin was used for standardization. Protein expression was investigated by immunofluorescence of the cells in culture, and by immunohistochemistry in paraffin sections of human fetal membranes from pregnancies with or without histologic chorioamnionitis.

RESULTS

Amnion FL cells expressed mRNA for all known beta-defensins with beta3-defensin mRNA levels significantly higher compared with others ( P < .001, 1-way analysis of variance [ANOVA]). beta3 was the only beta-defensin whose mRNA was upregulated in response to the microbial mimics LPS (1-way ANOVA, P = .019) and PG (1-way ANOVA, P = .011). Immunofluorescence confirmed that beta3-defensin protein was present in cultured amnion cells, and upregulated in response to PG and LPS in distinct cells. Similarly, in tissue sections of human fetal membranes amnion epithelium was intensely positive for beta3-defensin protein by immunohistochemistry. Conspicuous beta3-defensin staining was also detected in the chorio-decidua.

CONCLUSION

Amnion cells have the ability to produce beta-defensins. The beta3-defensin appears to be the predominant epithelial defensin expressed. Its induction by microbial mimics suggests that the amniotic epithelium may play a role in the innate immunity of the amniotic cavity.

Secretions of interleukin-1beta and tumor necrosis factor alpha by whole fetal membranes depend on initial interactions of amnion or choriodecidua with lipopolysaccharides or group B streptococci

The present study evaluated the secretions of interleukin (IL)-1beta and tumor necrosis factor (TNF) alpha by fetal membranes stimulated with group B streptococci (GBS) and lipopolysaccharide (LPS). The aim was to evaluate the initial response of full-thickness membranes to the microbial insult using an in vitro experimental model that allowed testing of the individual contributions of amnion and choriodecidua to stimulation. Full-thickness membranes were obtained after delivery by elective cesarean section from women at 37-40 wk of gestation without evidence of active labor. The membranes were mounted in Transwell devices, physically separating the upper and lower chambers. The LPS (500 ng/ml) or GBS (1 x 10(6) colony-forming units/ml) was added to either the amniotic or choriodecidual surface, and accumulation of IL-1beta and TNFalpha were measured in both compartments using a specific ELISA. Fetal membranes followed different patterns of secretion of proinflammatory cytokines that depended on the side to which the stimulus was added or the nature of the stimulus itself. The TNFalpha was secreted by amnion and choriodecidua in the presence of LPS or GBS, and stimulation with GBS induced a greater synthesis of IL-1beta than did stimulation with LPS. Choriodecidual tissue was more responsive than amniotic tissue, and this response tended to be higher even when the stimulation was only on the amniotic side. However, the amnion plays an active role in recognizing LPS or GBS, contributing a significant amount of TNFalpha. Thus, cooperative and bidirectional communications occur between amnion and choriodecidua in response to bacterial products, which include intermembranous cytokine traffic and signaling between tissues.

Racial disparity in membrane response to infectious stimuli: a possible explanation for observed differences in the incidence of prematurity. Community Award Paper

OBJECTIVE

This study compares the immune responsiveness of amniochorionic membranes (AC) derived from African American (AA) and white (C) women to an infectious stimulus ex vivo.

STUDY DESIGN

AC derived from AA and C women were placed in an organ explant culture for 48 hours and then stimulated with endotoxin. Enzyme-linked immunosorbent assay measured the concentration of matrix metalloproteinase 9 (MMP9), tumor necrosis factor-alpha (TNF-alpha), and soluble TNF receptors (sTNFR1 and sTNFR2) in culture media from stimulated and unstimulated AC.

RESULTS

The C group produced 8-fold more TNF-alpha after stimulation than did the AA group. Both soluble receptor (R1 and R2) production increased in the C group and decreased in the AA group after stimulation. Although the C group-derived membranes produced more MMP9 at rest, a 6-fold increase in MMP9 concentration was seen in the AA group-derived membranes after stimulation. No change in MMP9 concentration was seen after stimulation of the C group-derived membranes.

CONCLUSION

Although the C group produced more TNF, they also produce higher sTNFRs, which may serve a protective role. The increased MMP9 release by the AA group may be suggestive of the greater risk of premature rupture of membranes in the AA group.

[Factors and conditions affecting the process of infecting the fetus during different pregnancy stages]

Etiology, pathogenesis of intrauterine infection of the fetus, factors promoting such infection and the status of the local immune system are elucidated in the paper. A changed reactivity of the immune homeostasis of a pregnant woman with a chronic infection was shown to be potentially an important factor of pathogenesis of defects in her baby. The local immunity factors of the reproductive tract, i.e. the vagina and neck of uterus, are in the forefront of anti-infectious protection, which signal an alert or limit the microorganisms' reproduction; besides, they prevent the microorganisms from penetrating into the upper genitals. The therapeutic-and-preventive schemes applicable to infected women must comprise measures targeted at eliminating an infectious agent and at normalizing the pathological changes in the performance of the immune system activity.

Enhancement of glucocorticoid-induced 11beta-hydroxysteroid dehydrogenase type 1 expression by proinflammatory cytokines in cultured human amnion fibroblasts

Glucocorticoids and proinflammatory cytokines may be involved in parturition by stimulation of prostaglandin production in the fetal membranes. The actions of glucocorticoids on the fetal membranes are amplified by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), which converts biologically inactive cortisone into active cortisol. Whether glucocorticoids and proinflammatory cytokines regulate the expression of 11beta-HSD1 in the major prostaglandin-producing tissue, amnion, thus further increasing prostaglandin production, is not known. In this study, we found that term amnion fibroblasts had higher 11beta-HSD1 mRNA and activity per cell than amnion epithelial cells. Both isoforms of glucocorticoid receptor (alpha and beta) were expressed in amnion fibroblasts and epithelial cells. Quantitative real-time PCR showed that dexamethasone (0.01-1 microm) dose-dependently induced 11beta-HSD1 mRNA expression only in amnion fibroblasts but not in amnion epithelial cells. The induction of 11beta-HSD1 mRNA expression by dexamethasone was blocked by glucocorticoid receptor antagonist RU486. Although only a modest increase or no change in 11beta-HSD1 mRNA expression and activity was observed with IL-1beta (10 ng/ml) or TNFalpha (10 ng/ml) treatment, respectively, in amnion fibroblasts, combination of dexamethasone with either IL-1beta or TNFalpha significantly enhanced the induction of 11beta-HSD1 mRNA expression and activity, as compared with dexamethasone treatment alone. With prior induction of 11beta-HSD1 expression by dexamethasone, cortisone caused more prostaglandin E2 production in the amnion fibroblast. This study suggests that glucocorticoids can positively induce 11beta-HSD1 expression in amnion fibroblasts, an effect further strengthened by proinflammatory cytokines.