Immune profiling of BALB/C and C57BL/6 mice reveals a correlation between Ureaplasma parvum-Induced fetal inflammatory response syndrome-like pathology and increased placental expression of TLR2 and CD14

Modeling an ascending infection by Ureaplasma parvum and its cell signaling and inflammatory response at the feto-maternal interface

PROBLEM

Ascending bacterial infection is associated with ∼ 40% of spontaneous preterm birth (PTB), and Ureaplasma spp. is one of the most common bacteria isolated from the amniotic fluid. Developing novel in vitro models that mimic in vivo uterine physiology is essential to study microbial pathogenesis. We utilized the feto-maternal interface organ-on-chip (FMi-OOC) device and determined the propagation of Ureaplasma parvum, and its impact on cell signaling and inflammation.

METHOD OF STUDY

FMi-OOC is a microphysiologic device mimicking fetal membrane/decidua interconnected through microchannels. The impact of resident decidual CD45+ leukocytes was also determined by incorporating them into the decidual chamber in different combinations with U. parvum. We tested the propagation of live U. parvum from the decidual to the amniochorion membranes (immunocytochemistry and quantitative PCR), determined its impact on cytotoxicity (LDH assay), cell signaling (JESSTM Western Blot), cellular transition (immunostaining for vimentin and cytokeratin), and inflammation (cytokine bead array).

RESULTS

U. parvum transversed the chorion and reached the amnion epithelium after 72 hours but did not induce cell signaling kinases (p38MAPK and JNK) activation, or cellular transition (epithelial-mesenchymal), regardless of the presence of immune cells. The inflammatory response was limited to the choriodecidual interface and did not promote inflammation in the amnion layer.

CONCLUSIONS

Our data suggest that U. parvum is poorly immunogenic and does not produce massive inflammatory changes at the feto-maternal interface. We speculate that the presence of U. parvum may still compromise the feto-maternal interface making it susceptible to other pathogenic infection.

Ureaplasma diversum clearance in lung mice infection is mediated by neutrophils

Pneumonia in cattle is one of the causes of morbidity rates and economic loss. The host response to lung infections caused by Ureaplasma diversum in bovines is virtually unknown. Here in the immune response was evaluated in a murine model for an experimental pulmonary infection by U. diversum. Therefore, AJ, BALB/C and C57BL/6 mice received intratracheal inoculation of U. diversum and were evaluated after 1, 2, 3, 7 and 14 days and the clinical specimens were collected. In bronchoalveolar lavages (BAL) an increase of inflammatory cells was observed. Neutrophils were the main cells recruited to the site of infection and the infiltration was coincided with the production of pro-inflammatory cytokines. We found a large amount of neutrophil in this initial period, followed by a decrease 7 and 14 days post infection, accompanied by bacterial clearance. Our results evidenced the presence of U. diversum within the neutrophil that suggests a phagocytic role of this cell in the elimination of the infection. The immune response features reported here are the initial evidence that healthy immune systems may control these microorganisms. This may be the first step to design new strategies immune based to control the infections in naturally infected hosts.

Proteomic Study of Fetal Membrane: Inflammation-Triggered Proteolysis of Extracellular Matrix May Present a Pathogenic Pathway for Spontaneous Preterm Birth

INTRODUCTION

Spontaneous preterm birth (sPTB), which predominantly presents as spontaneous preterm labor (sPTL) or prelabor premature rupture of membranes (PPROM), is a syndrome that accounts for 5-10% of live births annually. The long-term morbidity in surviving preterm infants is significantly higher than that in full-term neonates. The causes of sPTB are complex and not fully understood. Human placenta, the maternal and fetal interface, is an environmental core of fetal intrauterine life, mediates fetal oxygen exchange, nutrient uptake, and waste elimination and functions as an immune-defense organ. In this study, the molecular signature of preterm birth placenta was assessed and compared to full-term placenta by proteomic profiling.

MATERIALS AND METHODS

Four groups of fetal membranes (the amniochorionic membranes), with five cases in each group in the discovery study and 30 cases in each group for validation, were included: groups A: sPTL; B: PPROM; C: full-term birth (FTB); and D: full-term premature rupture of membrane (PROM). Fetal membranes were dissected and used for proteome quantification study. Maxquant and Perseus were used for protein quantitation and statistical analysis. Both fetal membranes and placental villi samples were used to validate proteomic discovery.

RESULTS

Proteomics analysis of fetal membranes identified 2,800 proteins across four groups. Sixty-two proteins show statistical differences between the preterm and full-term groups. Among these differentially expressed proteins are (1) proteins involved in inflammation (HPGD), T cell activation (PTPRC), macrophage activation (CAPG, CD14, and CD163), (2) cell adhesion (ICAM and ITGAM), (3) proteolysis (CTSG, ELANE, and MMP9), (4) antioxidant (MPO), (5) extracellular matrix (ECM) proteins (APMAP, COL4A1, LAMA2, LMNB1, LMNB2, FBLN2, and CSRP1) and (6) metabolism of glycolysis (PKM and ADPGK), fatty acid synthesis (ACOX1 and ACSL3), and energy biosynthesis (ATP6AP1 and CYBB).

CONCLUSION

Our molecular signature study of preterm fetal membranes revealed inflammation as a major event, which is inconsistent with previous findings. Proteolysis may play an important role in fetal membrane rupture. Extracellular matrix s have been altered in preterm fetal membranes due to proteolysis. Metabolism was also altered in preterm fetal membranes. The molecular changes in the fetal membranes provided a significant molecular signature for PPROM in preterm syndrome.

Cervical epithelial damage promotes Ureaplasma parvum ascending infection, intrauterine inflammation and preterm birth induction in mice

Around 40% of preterm births are attributed to ascending intrauterine infection, and Ureaplasma parvum (UP) is commonly isolated in these cases. Here we present a mouse model of ascending UP infection that resembles human disease, using vaginal inoculation combined with mild cervical injury induced by a common spermicide (Nonoxynol-9, as a surrogate for any mechanism of cervical epithelial damage). We measure bacterial load in a non-invasive manner using a luciferase-expressing UP strain, and post-mortem by qPCR and bacterial titration. Cervical exposure to Nonoxynol-9, 24 h pre-inoculation, facilitates intrauterine UP infection, upregulates pro-inflammatory cytokines, and increases preterm birth rates from 13 to 28%. Our results highlight the crucial role of the cervical epithelium as a barrier against ascending infection. In addition, we expect the mouse model will facilitate further research on the potential links between UP infection and preterm birth.

The relationship between histologic chorioamnionitis and decidual macrophage polarization and their influence on outcomes of neonates born before the 32nd gestational week

PURPOSE

To explore the relationship between histologic chorioamnionitis (HCA) and decidual macrophage (DM) polarization and their influence on outcomes of neonates born before the 32nd gestational week.

MATERIALS AND METHODS

Eighty-four neonates and their placentas were included in this retrospective case-control study and divided into two groups: with and without HCA present (HCA + and HCA-). Neonatal, maternal, and placental risk factors were explored and their influence on neonatal outcomes was examined. We used CD68 and iNOS as markers for polarized DMs type 1 (M1) and CD163, CD206 and arginase (Arg-1) for polarized DMs type 2 (M2).

RESULTS

HCA was present in 47 (56%) cases, and 37 (44%) cases were without the present HCA. There was no statistically significant difference in neonatal risk factors between the two groups (HCA + and HCA-). Higher rates of HCA (p = .042) were observed in mothers who received antepartum corticosteroid therapy. The frequency of vaginal deliveries in HCA + pregnancies was significantly higher than in HCA- pregnancies where deliveries by cesarean section were more frequently observed (p < .001). M2 DM were more abundant in the HCA + group (p = .035). Multiple regression model assessed the association between the presence of HCA, M1, and M2 DM with ROP stages. It has been observed that HCA is a risk factor for ROP stages (β coefficient = 0.34, r_partial = 0.246, p = .024). With the logistic regression model, the association between the presence of HCA, M1, and M2 DM with neonatal nCPAP respiratory support and necrotizing enterocolitis (NEC) was assessed. The presence of M2 macrophages in decidua is an independent risk factor for neonatal nCPAP respiratory support (coefficient -0.07, OR = 0.928, 95% CI 0.87-0.99, p = .024) and the presence of M1 macrophages in decidua increases the risk for NEC (coefficient 0.010, OR = 1.0108, 95% CI 1.00-1.02, p = .032).

CONCLUSIONS

The significantly more abundant presence of M2 DM was detected in HCA + placentas and their association with the increased risk for neonatal nCPAP respiratory support was observed. On the contrary, the presence of M1 DM increases the risk for NEC. The presence of HCA is a risk factor for ROP stages.

Porphyromonas gingivalis strain-dependent inhibition of uterine spiral artery remodeling in the pregnant rat

Porphyromonas gingivalis (Pg) is an important periodontal pathogen that is also implicated in pregnancy complications involving defective deep placentation (DDP). We hypothesized that Pg invasion of the placental bed promotes DDP. Pregnant rats were intravenously inoculated with sterile vehicle, Pg strain W83, or A7436 at gestation day (GD) 14 (acute cohort). Nonpregnant rats received repeated oral inoculations for 3 months before breeding (chronic cohort). Tissues and/or sera were collected at GD18 for analysis. Pg infection status was determined by seroconversion (chronic cohort) and by presence of Pg antigen in utero-placental tissues processed for histology and morphometric assessment of spiral artery remodeling. Mesometrial tissues from seropositive dams were analyzed for expression of interleukin 1β, 6, and 10, TNF, TGF-β, follistatin-related protein 3, and inhibin beta A chain since these genes regulate extravillous trophoblast invasion. The in situ distribution of W83 and A7436 antigen in utero-placental tissues was similar in both cohorts. In the acute cohort, mesometrial stromal necrosis was more common with W83, but arteritis was more common with A7436 infection (P < 0.05). Increased vascular necrosis was seen in mesometrium of chronically infected groups (P < 0.05). Only A7436-infected animals had increased fetal deaths, reduced spiral artery remodeling, reduced inhibin beta A expression, and an increased proportion of FSLT3 positive extravillous trophoblasts within spiral arteries. While infection with both Pg strains produced varying pathology of the deep placental bed, only infection with strain A7436 resulted in impaired spiral artery remodeling.

Ureaplasma Species Differentially Modulate Pro- and Anti-Inflammatory Cytokine Responses in Newborn and Adult Human Monocytes Pushing the State Toward Pro-Inflammation

Background:Ureaplasma species have been associated with chorioamnionitis and preterm birth and have been implicated in the pathogenesis of neonatal short and long-term morbidity. However, being mostly commensal bacteria, controversy remains on the pro-inflammatory capacity of Ureaplasma. Discussions are ongoing on the incidence and impact of prenatal, perinatal, and postnatal infection. The present study addressed the impact of Ureaplasma isolates on monocyte-driven inflammation. Methods: Cord blood monocytes of term neonates and adult monocytes, either native or LPS-primed, were cultured with Ureaplasma urealyticum (U. urealyticum) serovar 8 (Uu8) and Ureaplasma parvum serovar 3 (Up3). Using qRT-PCR, cytokine flow cytometry, and multi-analyte immunoassay, we assessed mRNA and protein expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-8, IL-12p40, IL-10, and IL-1 receptor antagonist (IL-1ra) as well as Toll-like receptor (TLR) 2 and TLR4. Results: Uu8 and Up3 induced mRNA expression and protein release of TNF-α, IL-1β and IL-8 in term neonatal and adult monocytes (p < 0.01 and p < 0.05). Intracellular protein expression of TNF-α, IL-1β and IL-8 in Ureaplasma-stimulated cells paralleled those results. Ureaplasma-induced cytokine levels did not significantly differ from LPS-mediated levels except for lower intracellular IL-1β in adult monocytes (Uu8: p < 0.05). Remarkably, ureaplasmas did not induce IL-12p40 response and promoted lower amounts of anti-inflammatory IL-10 and IL-1ra than LPS, provoking a cytokine imbalance more in favor of pro-inflammation (IL-1β/IL-10, IL-8/IL-10 and IL-8/IL-1ra: p < 0.01, vs. LPS). In contrast to LPS, both isolates induced TLR2 mRNA in neonatal and adult cells (p < 0.001 and p < 0.05) and suppressed TLR4 mRNA in adult monocytes (p < 0.05). Upon co-stimulation, Uu8 and Up3 inhibited LPS-induced intracellular IL-1β (p < 0.001 and p < 0.05) and IL-8 in adult monocytes (p < 0.01), while LPS-induced neonatal cytokines were maintained or aggravated (p < 0.05). Conclusion: Our data demonstrate a considerable pro-inflammatory capacity of Ureaplasma isolates in human monocytes. Stimulating pro-inflammatory cytokine responses while hardly inducing immunomodulatory and anti-inflammatory cytokines, ureaplasmas might push monocyte immune responses toward pro-inflammation. Inhibition of LPS-induced cytokines in adult monocytes in contrast to sustained inflammation in term neonatal monocytes indicates a differential modulation of host immune responses to a second stimulus. Modification of TLR2 and TLR4 expression may shape host susceptibility to inflammation.

STAT3-blocked whole-cell hepatoma vaccine induces cellular and humoral immune response against HCC

Background

Whole-cell tumor vaccines have shown much promise; however, only limited success has been achieved for the goal of eliciting robust tumor-specific T-cell responses.

Methods

Hepatocellular carcinoma (HCC) cells, H22 and Hepa1–6, were modified by blocking the STAT3 signaling pathway with a STAT3 decoy oligodeoxynucleotide, and the immunogenicity and possibility of using these cell lysates as a vaccine were evaluated.

Results

STAT3-blocked whole HCC cell lysates inhibited tumor growth and tumorigenesis, and prolonged the survival of tumor-bearing mice. In addition, STAT3-blocked whole HCC cell lysates stimulated the activation of T cells and natural killer (NK) cells, and enhanced the infiltration of cytotoxic CD8⁺ T cells in the tumor tissues. In addition, the maturation of dendritic cells (DCs) was enhanced, which promoted the generation of immunological memory against HCC. Furthermore, secondary immune responses could be primed as soon as these immunized mice were challenged with HCC cells, accompanied by T cell and NK cell activation and infiltration. Additionally, immunization with this vaccine decreased the generation of Tregs and the production of TGF-β and IL-10. Importantly, STAT3-blocked whole HCC cell lysates prevented HCC-mediated exhaustion of T cells and NK cells, showing low expression of checkpoint molecules such as PD-1 and TIGIT on T cells and NK cells in the immunized mice.

Conclusions

The newly generated STAT3-blocked whole-cell HCC vaccine has potential for cancer cell vaccination.

Electronic supplementary material

The online version of this article (10.1186/s13046-017-0623-0) contains supplementary material, which is available to authorized users.

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.

The Human Ureaplasma Species as Causative Agents of Chorioamnionitis

The human Ureaplasma species are the most frequently isolated microorganisms from the amniotic fluid and placentae of women who deliver preterm and are also associated with spontaneous abortions or miscarriages, neonatal respiratory diseases, and chorioamnionitis. Despite the fact that these microorganisms have been habitually found within placentae of pregnancies with chorioamnionitis, the role of Ureaplasma species as a causative agent has not been satisfactorily explained. There is also controversy surrounding their role in disease, particularly as not all women infected with Ureaplasma spp. develop chorioamnionitis. In this review, we provide evidence that Ureaplasma spp. are associated with diseases of pregnancy and discuss recent findings which demonstrate that Ureaplasma spp. are associated with chorioamnionitis, regardless of gestational age at the time of delivery. Here, we also discuss the proposed major virulence factors of Ureaplasma spp., with a focus on the multiple-banded antigen (MBA), which may facilitate modulation/alteration of the host immune response and potentially explain why only subpopulations of infected women experience adverse pregnancy outcomes. The information presented within this review confirms that Ureaplasma spp. are not simply "innocent bystanders" in disease and highlights that these microorganisms are an often underestimated pathogen of pregnancy.

Neonatal CNS infection and inflammation caused by Ureaplasma species: rare or relevant?

Colonization with Ureaplasma species has been associated with adverse pregnancy outcome, and perinatal transmission has been implicated in the development of bronchopulmonary dysplasia in preterm neonates. Little is known about Ureaplasma-mediated infection and inflammation of the CNS in neonates. Controversy remains concerning its incidence and implication in the pathogenesis of neonatal brain injury. In vivo and in vitro data are limited. Despite improving care options for extremely immature preterm infants, relevant complications remain. Systematic knowledge of ureaplasmal infection may be of great benefit. This review aims to summarize pathogenic mechanisms, clinical data and diagnostic pitfalls. Studies in preterm and term neonates are critically discussed with regard to their limitations. Clinical questions concerning therapy or prophylaxis are posed. We conclude that ureaplasmas may be true pathogens, especially in preterm neonates, and may cause CNS inflammation in a complex interplay of host susceptibility, serovar pathogenicity and gestational age-dependent CNS vulnerability.

M1/M2 macrophage polarity in normal and complicated pregnancy

Tissue macrophages play an important role in all stages of pregnancy, including uterine stromal remodeling (decidualization) before embryo implantation, parturition, and post-partum uterine involution. The activation state and function of utero-placental macrophages are largely dependent on the local tissue microenvironment. Thus, macrophages are involved in a variety of activities such as regulation of immune cell activities, placental cell invasion, angiogenesis, and tissue remodeling. Disruption of the uterine microenvironment, particularly during the early stages of pregnancy (decidualization, implantation, and placentation) can have profound effects on macrophage activity and subsequently impact pregnancy outcome. In this review, we will provide an overview of the temporal and spatial regulation of utero-placental macrophage activation during normal pregnancy in human beings and rodents with a focus on more recent findings. We will also discuss the role of M1/M2 dysregulation within the intrauterine environment during adverse pregnancy outcomes.