Bacterial protein domains with a novel Ig-like fold target human CEACAM receptors.

Streptococcus agalactiae, also known as group B Streptococcus (GBS), is the major cause of neonatal sepsis in humans. A critical step to infection is adhesion of bacteria to epithelial surfaces. GBS adhesins have been identified to bind extracellular matrix components and cellular receptors. However, several putative adhesins have no host binding partner characterised. We report here that surface-expressed ß protein of GBS binds to human CEACAM1 and CEACAM5 receptors. A crystal structure of the complex showed that an IgSF domain in ß represents a novel Ig-fold subtype called IgI3, in which unique features allow binding to CEACAM1. Bioinformatic assessment revealed that this newly identified IgI3 fold is not exclusively present in GBS but is predicted to be present in adhesins from other clinically important human pathogens. In agreement with this prediction, we found that CEACAM1 binds to an IgI3 domain found in an adhesin from a different streptococcal species. Overall, our results indicate that the IgI3 fold could provide a broadly applied mechanism for bacteria to target CEACAMs.

Proof of Principle of Combining Fluorescence-Guided Surgery with Photoimmunotherapy to Improve the Outcome of Pancreatic Cancer Therapy in an Orthotopic Mouse Model.

BACKGROUND: Pancreatic cancer is a recalcitrant disease in which R0 resection is often not achieved owing to difficulty in visualization of the tumor margins and proximity of adjacent vessels. To improve outcomes, we have developed fluorescence-guided surgery (FGS) and photoimmunotherapy (PIT) using a fluorescent tumor-specific antibody. METHODS: Nude mice received surgical orthotopic implantation (SOI) of the human pancreatic cancer cell line BxPC-3 expressing green fluorescent protein. An anti-carcinoembryonic antigen-related cell adhesion molecule (CEACAM) monoclonal antibody (6G5j) was conjugated to the 700-nm fluorescent dye IR700DyeDX (6G5j-IR700DX). Three weeks after SOI, 16 mice received 50 µg 6G5j-IR700DX via the tail vein 24 h before surgery and were randomized to two groups: FGS-only (n = 8) and FGS + PIT (n = 8). All tumors were imaged with the Pearl Trilogy imaging system and resected under the guidance of the FLARE imaging system. The FGS + PIT group received PIT of the post-surgical bed at an intensity of 150 mW/cm2 for 30 min. Mice were sacrificed 4 weeks after initial surgery, and tumors were imaged with a Dino-Lite digital microscope, excised, and weighed. RESULTS: The 6G5j-IR700DX dye illuminated the orthotopic pancreatic tumors for FGS and PIT. The metastatic recurrence rate was 100.0% for FGS-only and 25.0% for FGS + PIT (p = 0.007). The average total recurrent tumor weight was 2370.3 ± 1907.8 mg for FGS-only and 705.5 ± 1200.0 mg for FGS + PIT (p = 0.039). CONCLUSIONS: FGS and adjuvant PIT can be combined by using a single antibody-fluorophore conjugate to significantly reduce the frequency of pancreatic cancer recurrence.

CEACAMs serve as toxin-stimulated receptors for enterotoxigenic Escherichia coli.

The enterotoxigenic Escherichia coli (ETEC) are among the most common causes of diarrheal illness and death due to diarrhea among young children in low-/middle-income countries (LMICs). ETEC have also been associated with important sequelae including malnutrition and stunting, placing children at further risk of death from diarrhea and other infections. Our understanding of the molecular pathogenesis of acute diarrheal disease as well as the sequelae linked to ETEC are still evolving. It has long been known that ETEC heat-labile toxin (LT) activates production of cAMP in the cell, signaling the modulation of cellular ion channels that results in a net efflux of salt and water into the intestinal lumen, culminating in watery diarrhea. However, as LT also promotes ETEC adhesion to intestinal epithelial cells, we postulated that increases in cAMP, a critical cellular "second messenger," may be linked to changes in cellular architecture that favor pathogen-host interactions. Indeed, here we show that ETEC use LT to up-regulate carcinoembryonic antigenrelated cell adhesion molecules (CEACAMs) on the surface of small intestinal epithelia, where they serve as critical bacterial receptors. Moreover, we show that bacteria are specifically recruited to areas of CEACAM expression, in particular CEACAM6, and that deletion of this CEACAM abrogates both bacterial adhesion and toxin delivery. Collectively, these results provide a paradigm for the molecular pathogenesis of ETEC in which the bacteria use toxin to drive up-regulation of cellular targets that enhances subsequent pathogen-host interactions.

Helicobacter pylori adhesin HopQ disrupts trans dimerization in human CEACAMs.

The human gastric pathogen Helicobacter pylori is a major causative agent of gastritis, peptic ulcer disease, and gastric cancer. As part of its adhesive lifestyle, the bacterium targets members of the carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family by the conserved outer membrane adhesin HopQ. The HopQ-CEACAM1 interaction is associated with inflammatory responses and enables the intracellular delivery and phosphorylation of the CagA oncoprotein via a yet unknown mechanism. Here, we generated crystal structures of HopQ isotypes I and II bound to the N-terminal domain of human CEACAM1 (C1ND) and elucidated the structural basis of H. pylori specificity toward human CEACAM receptors. Both HopQ alleles target the ß-strands G, F, and C of C1ND, which form the trans dimerization interface in homo- and heterophilic CEACAM interactions. Using SAXS, we show that the HopQ ectodomain is sufficient to induce C1ND monomerization and thus providing H. pylori a route to influence CEACAM-mediated cell adherence and signaling events.

Antibody ligation of CEACAM1, CEACAM3, and CEACAM6, differentially enhance the cytokine release of human neutrophils in responses to Candida albicans.

Invasive candidiasis is a healthcare-associated fungal infection with a high mortality rate. Neutrophils, the first line of defense during fungal infections, express the immunoregulatory Candida albicans receptors CEACAM1, CEACAM3, and CEACAM6. We analyzed the effects of specific antibodies on C. albicans-induced neutrophil responses. CEACAM6 ligation by 1H7-4B and to some extent CEACAM1 ligation by B3-17, but not CEACAM3 ligation by 308/3-3, resulted in the immediate release of stored CXCL8 and altered transcriptional responses of the C. albicans-stimulated neutrophils. Integrated network analyses and dynamic simulations of signaling cascades predicted alterations in apoptosis and cytokine secretion. We verified that CEACAM6 ligation enhanced Candida-induced neutrophil apoptosis and increased long-term IL-1ß/IL-6 release in responses to C. albicans. CEACAM3 ligation, but not CEACAM1 ligation, increased the long-term release of pro-inflammatory IL-1ß/IL-6. Taken together, we demonstrated for the first time that ligation of CEACAM receptors differentially affects the regulation of C. albicans-induced immune functions in human neutrophils.

A Novel Color-Coded Liver Metastasis Mouse Model to Distinguish Tumor and Adjacent Liver Segment.

BACKGROUND: It is difficult to distinguish between a tumor and its liver segment with traditional use of indocyanine green (ICG) alone. In the present study, a method was used to limit ICG to the liver segment adjacent to a tumor. A spectrally-distinct fluorescently-labeled tumor-specific antibody against human carcinoembryonic antigen-related cell-adhesion molecules was used to label the metastatic tumor in a patient-derived orthotopic xenograft mouse model to enable color-coded visualization and distinction of a colon-cancer liver metastases and its adjacent liver segment. MATERIALS AND METHODS: Nude mice received surgical orthotopic implantation in the liver of colon-cancer liver metastases derived from two patients. An anti- carcinoembryonic antigen-related cell-adhesion molecules monoclonal antibody (mAb 6G5j) was conjugated to a near-infrared dye IR700DX (6G5j-IR700DX). After three weeks, mice received 6G5j-IR700DX via tail-vein injection 48 hours before surgery. ICG was intravenously injected after ligation of the left or left lateral Glissonean pedicle resulting in labeling of the segment with preserved blood-flow in the liver. Imaging was performed with the Pearl Trilogy and FLARE Imaging Systems. RESULTS: The metastatic liver tumor had a clear fluorescence signal due to selective tumor targeting by 6G5j-IR700DX, which was imaged on the 700 nm channel. The adjacent liver segment, with preserved blood-flow in the liver, had a clear fluorescence ICG 800 nm signal, while the left or left lateral segment had no fluorescence signal. Overlay of the images showed clear color-coded differentiation between the tumor fluorescing at 700 nm and the adjacent liver segment fluorescing at 800 nm. CONCLUSIONS: Color-coding of a liver tumor and uninvolved liver segment has the potential for improved liver resection.

CEACAM1 inhibits Toll-like receptor 2-triggered antibacterial responses of human pulmonary epithelial cells.

Although Moraxella catarrhalis and Neisseria meningitidis are important human pathogens, they often colonize the human respiratory tract without causing overt clinical symptoms. Both pathogens express structurally unrelated proteins that share the ability to stimulate the adhesion molecule CEACAM1 expressed on human cells. Here we demonstrate that the interaction of CEACAM1 with ubiquitous surface protein A1 expressed on M. catarrhalis or with opacity-associated proteins on N. meningitidis resulted in reduced Toll-like receptor 2-initiated transcription factor NF-kappaB-dependent inflammatory responses of primary pulmonary epithelial cells. These inhibitory effects were mediated by tyrosine phosphorylation of the immunoreceptor tyrosine-based inhibitory motif of CEACAM1 and by recruitment of the phosphatase SHP-1, which negatively regulated Toll-like receptor 2-dependent activation of the phosphatidylinositol 3-OH kinase-Akt kinase pathway. Our results identify a CEACAM1-dependent immune-evasion strategy.

Expression of CEACAM1 or CEACAM5 in AZ-521 cells restores the type IV secretion deficiency for translocation of CagA by Helicobacter pylori.

Helicobacter pylori represents an important pathogen involved in diseases ranging from gastritis, peptic ulceration, to gastric malignancies. Prominent virulence factors comprise the vacuolating cytotoxin VacA and the cytotoxin-associated genes pathogenicity island (cagPAI)-encoded type IV secretion system (T4SS). The T4SS effector protein CagA can be translocated into AGS and other gastric epithelial cells followed by phosphorylation through c-Src and c-Abl tyrosin kinases to hijack signalling networks. The duodenal cell line AZ-521 has been recently introduced as novel model system to investigate CagA delivery and phosphorylation in a VacA-dependent fashion. In contrast, we discovered that AZ-521 cells display a T4SS incompetence phenotype for CagA injection, which represents the first reported gastrointestinal cell line with a remarkable T4SS defect. We proposed that this deficiency may be due to an imbalanced coexpression of T4SS receptor integrin-ß1 or carcinoembryonic antigen-related cell adhesion molecules (CEACAMs), which were described recently as novel H. pylori receptors. We demonstrate that AZ-521 cells readily express integrin-ß1 , but overexpression of integrin-ß1 constructs did not restore the T4SS defect. We further show that AZ-521 cells lack the expression of CEACAMs. We demonstrate that genetic introduction of either CEACAM1 or CEACAM5, but not CEACAM6, in AZ-521 cells is sufficient to permit injection and phosphorylation of CagA by H. pylori to degrees observed in the AGS cell model. Expression of CEACAM1 or CEACAM5 in infected AZ-521 cells was also accompanied by tyrosine dephosphorylation of the cytoskeletal proteins vinculin and cortactin, a hallmark of H. pylori-infected AGS cells. Our results suggest the existence of an integrin-ß1 - and CEACAM1- or CEACAM5-dependent T4SS delivery pathway for CagA, which is clearly independent of VacA. The presence of two essential host protein receptors during infection with H. pylori represents a unique feature in the bacterial T4SS world. Further detailed investigation of these T4SS functions will help to better understand infection strategies by bacterial pathogens.

Carcinoembryonic antigen-related cell adhesion molecule 1 controls IL-2-dependent regulatory T-cell induction in immune-mediated hepatitis in mice.

A dysbalance between effector T cells (Tconv) and regulatory T cells (Tregs) and impaired Treg function can cause autoimmune liver disease. Therefore, it is important to identify molecular mechanisms that control Treg homeostasis. Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1; CD66a) is an immune coreceptor with dichotomous roles in T-cell regulation: its short isoform (CEACAM1S) can activate T cells and induce Tregs, whereas its long isoform (CEACAM1L), containing two intracellular immune receptor tyrosine-based inhibitory motifs, can inhibit activated T-cell function. In the liver, CEACAM1 has antifibrotic effects in models of nonalcoholic steatohepatitis. However, its role in immune-mediated hepatitis is unknown. In the mouse model of concanavalin A-induced CD4+ T-cell-dependent liver injury, liver damage was aggravated and persisted in Ceacam1-/- mice. Concomitantly, we observed hyperexpansion of Tconv, but reduction of interleukin (IL)-2 production and hepatic forkhead box protein P3+ (Foxp3+ )CD4+ Treg numbers. CEACAM1-/- CD4+ T cells showed impaired IL-2-mediated signal transducer and activator of transcription 5 (STAT5) phosphorylation, which correlated with a failure of naïve CEACAM1-/- CD4+ T cells to convert into Tregs in vitro. Furthermore, CEACAM1-/- Tregs expressed reduced levels of Foxp3, CD25, and B-cell lymphoma 2. Adoptive transfer experiments demonstrated that hepatic Treg expansion and suppressive activity required CEACAM1 expression on both CD4+ T cells and Tregs. We identified predominant CEACAM1S expression on hepatic CD4+ T cells and Tregs from mice with acute liver injury and expression of both isoforms in liver-derived CD4+ T-cell clones from patients with liver injury. CONCLUSION: Our data suggest that CEACAM1S expression in CD4+ T cells augments IL-2 production and STAT5 phosphorylation leading to enhanced Treg induction and stability, which, ultimately, confers protection from T-cell-mediated liver injury. (Hepatology 2018;68:200-214).

Functional capacities of human IgM memory B cells in early inflammatory responses and secondary germinal center reactions.

The generation and functions of human peripheral blood (PB) IgM(+)IgD(+)CD27(+) B lymphocytes with somatically mutated IgV genes are controversially discussed. We determined their differential gene expression to naive B cells and to IgM-only and IgG(+) memory B cells. This analysis revealed a high similarity of IgM(+)(IgD(+))CD27(+) and IgG(+) memory B cells but also pointed at distinct functional capacities of both subsets. In vitro analyses revealed a tendency of activated IgM(+)IgD(+)CD27(+) B cells to migrate to B-cell follicles and undergo germinal center (GC) B-cell differentiation, whereas activated IgG(+) memory B cells preferentially showed a plasma cell (PC) fate. This observation was supported by reverse regulation of B-cell lymphoma 6 and PR domain containing 1 and differential BTB and CNC homology 1, basic leucine zipper transcription factor 2 expression. Moreover, IgM(+)IgD(+)CD27(+) B lymphocytes preferentially responded to neutrophil-derived cytokines. Costimulation with catecholamines, carcinoembryonic antigen cell adhesion molecule 8 (CEACAM8), and IFN-γ caused differentiation of IgM(+)IgD(+)CD27(+) B cells into PCs, induced class switching to IgG2, and was reproducible in cocultures with neutrophils. In conclusion, this study substantiates memory B-cell characteristics of human IgM(+)IgD(+)CD27(+) B cells in that they share typical memory B-cell transcription patterns with IgG(+) post-GC B cells and show a faster and more vigorous restimulation potential, a hallmark of immune memory. Moreover, this work reveals a functional plasticity of human IgM memory B cells by showing their propensity to undergo secondary GC reactions upon reactivation, but also by their special role in early inflammation via interaction with immunomodulatory neutrophils.

Björn J. Öbrink (1943-2015).

Family members, friends and colleagues of Prof. Dr. Dr. h.c. Björn Öbrink were deeply saddened to learn of his sudden death on August 21, 2015. Björn was one of the pioneers in cell adhesion research. Reading an article written by Björn, one quickly recognizes his outstanding qualities as a scientist: knowledgeable, innovative, precise and detailed in order to enable reproduction of his reported results. When meeting Björn, you were captured by his personality: warm-hearted, modest, and, above all, devoted to truth.

Moraxella catarrhalis induces an immune response in the murine lung that is independent of human CEACAM5 expression and long-term smoke exposure.

In patients with chronic obstructive pulmonary disease (COPD), Moraxella catarrhalis infection of the lower airways is associated with chronic colonization and inflammation during stable disease and acute exacerbations. Chronic smoke exposure induces chronic inflammation and impairs mucociliary clearance, thus contributing to bacterial colonization of the lower airways in COPD patients. The human-specific carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 5, expressed in human airways, has been shown to contribute to epithelial colonization of CEACAM-binding pathogens. To investigate the impact of CEACAM5 expression on pulmonary M. catarrhalis colonization, we infected mice transgenic for human CEACAM5 (hCEACAM5) and wild type mice intratracheally with M. catarrhalis with or without preceding smoke exposure and analyzed bacterial colonization and local and systemic inflammation. Our results show that airway infection with M. catarrhalis accelerated acute local but not systemic inflammation, albeit independent of hCEACAM5 expression. Long-term smoke exposure alone or prior to M. catarrhalis infection did not contribute to increased local or systemic inflammation. No difference was found in pulmonary clearance of M. catarrhalis in hCEACAM5-transgenic mice compared with wild-type mice. Smoke exposure neither altered time nor extent of persistence of M. catarrhalis in the lungs of both genotypes. In conclusion, M. catarrhalis induced a local acute immune response in murine airways. Neither hCEACAM5 expression nor chronic smoke exposure nor a combination of both was sufficient as prerequisites for the establishment of chronic M. catarrhalis colonization. Our results demonstrate the difficulties in mirroring conditions of chronic airways colonization of M. catarrhalis in a murine model.

Single nucleotide polymorphisms of the EpCAM-coding gene TACSTD1 in patients with ovarian cancer and their potential translational aspects.

PURPOSE: EpCAM is overexpressed in many neoplasms including ovarian cancer. We screened the EpCAM-coding gene TACSTD1 for single nucleotide polymorphisms (SNPs), which could alter ovarian cancer risk, impact upon disease progression, or alter binding of the therapeutic EpCAM-binding antibody, catumaxomab. METHODS: DNA fragments of 10 healthy volunteers were analyzed to identify SNPs. Subsequently, DNA of ovarian cancer patients (n = 117) and age-matched healthy controls (n = 115) was genotyped by restriction fragment length polymorphism and pyrosequencing. TACSTD1 genotypes 4461T>C were cloned into a gene expression vector; Hek293 cells were subsequently used for stable transfection. FACS analysis of the transfected Hek293 cells was conducted with HO-3-the EpCAM binding site of catumaxomab-to determine antibody binding. RESULTS: One SNP was detected in exon 3 (4461T>C; rs1126497), resulting in an amino acid exchange at position 115 (Met115Thr). Another polymorphism was found in the 3'UTR (17225A>G; rs1421). Genotyping of patients and controls for these SNPs did not reveal significant differences in genotype distribution. Regarding 17225A>G, the homozygous AA-genotype was associated with diminished progression-free survival (PFS; p = 0.032). Overall survival, FIGO-stage, grading, and age did not differ significantly between genotypes. FACS analysis of transfected Hek293 cells overexpressing EpCAM 115Met/Thr showed binding of HO-3 to both proteins. CONCLUSIONS: The AA-genotype of 17225A>G seems to be associated with diminished PFS in ovarian cancer patients. The amino acid exchange resulting from 4461T>C does not appear to alter binding of HO-3, suggesting that treatment with catumaxomab can be offered to patients regardless of their TACSTD1-genotype.

CEACAM1 expression in oligodendrocytes of the developing rat brain shows a spatiotemporal relation to myelination and is altered in a model of encephalopathy of prematurity.

CEACAM1 is the founder molecule of the family of 'carcinoembryonic antigen-related cell adhesion molecules' and part of the immunoglobulin superfamily. Due to its role as a coreceptor to many other receptors (e.g. Toll-like receptor 2, Toll-like receptor 4, T-cell receptor, B-cell receptor, epidermal growth factor receptor and vascular endothelial growth factor receptor) and its different isoforms, CEACAM1 is a multifunctional protein with an impact on proliferation and differentiation of multiple cell types. Although different modes of action in other tissues are described, the role of CEACAM1 in the developing brain remains elusive. Here we report for the first time that CEACAM1 is expressed ontogenetically in oligodendrocytes of the developing rat brain, and that CEACAM1 expression has a spatiotemporal relation to myelination. In addition, CEACAM1 expression is altered in a model of hyperoxia- and inflammation-induced encephalopathy of prematurity, a myelination disorder of children born preterm. Furthermore, primary oligodendrocytes stimulated with CEACAM1 show increased myelination. Therefore, we postulate that CEACAM1 is, at least in part, involved in hyperoxia- and inflammation-induced disruption of myelination, but may also play a role in intact myelination as it is ontogenetically expressed in myelinating oligodendrocytes.

Carcinoembryonic antigen (CEA)-related cell adhesion molecules are co-expressed in the human lung and their expression can be modulated in bronchial epithelial cells by non-typable Haemophilus influenzae, Moraxella catarrhalis, TLR3, and type I and II interferons.

BACKGROUND: The carcinoembryonic antigen (CEA)-related cell adhesion molecules CEACAM1 (BGP, CD66a), CEACAM5 (CEA, CD66e) and CEACAM6 (NCA, CD66c) are expressed in human lung. They play a role in innate and adaptive immunity and are targets for various bacterial and viral adhesins. Two pathogens that colonize the normally sterile lower respiratory tract in patients with chronic obstructive pulmonary disease (COPD) are non-typable Haemophilus influenzae (NTHI) and Moraxella catarrhalis. Both pathogens bind to CEACAMs and elicit a variety of cellular reactions, including bacterial internalization, cell adhesion and apoptosis. METHODS: To analyze the (co-) expression of CEACAM1, CEACAM5 and CEACAM6 in different lung tissues with respect to COPD, smoking status and granulocyte infiltration, immunohistochemically stained paraffin sections of 19 donors were studied. To address short-term effects of cigarette smoke and acute inflammation, transcriptional regulation of CEACAM5, CEACAM6 and different CEACAM1 isoforms by cigarette smoke extract, interferons, Toll-like receptor agonists, and bacteria was tested in normal human bronchial epithelial (NHBE) cells by quantitative PCR. Corresponding CEACAM protein levels were determined by flow cytometry. RESULTS: Immunohistochemical analysis of lung sections showed the most frequent and intense staining for CEACAM1, CEACAM5 and CEACAM6 in bronchial and alveolar epithelium, but revealed no significant differences in connection with COPD, smoking status and granulocyte infiltration. In NHBE cells, mRNA expression of CEACAM1 isoforms CEACAM1-4L, CEACAM1-4S, CEACAM1-3L and CEACAM1-3S were up-regulated by interferons alpha, beta and gamma, as well as the TLR3 agonist polyinosinic:polycytidylic acid (poly I:C). Interferon-gamma also increased CEACAM5 expression. These results were confirmed on protein level by FACS analysis. Importantly, also NTHI and M. catarrhalis increased CEACAM1 mRNA levels. This effect was independent of the ability to bind to CEACAM1. The expression of CEACAM6 was not affected by any treatment or bacterial infection. CONCLUSIONS: While we did not find a direct correlation between CEACAM1 expression and COPD, the COPD-associated bacteria NTHi and M. catarrhalis were able to increase the expression of their own receptor on host cells. Further, the data suggest a role for CEACAM1 and CEACAM5 in the phenomenon of increased host susceptibility to bacterial infection upon viral challenge in the human respiratory tract.

Forskolin versus cAMP-Induced Decidualization and Survival of Endometrial Stromal Cells of Endometriosis Patients.

Impairment of decidualization of eutopic human endometrial stromal cells (hESCs) may cause an increase in cell survival of endometrial tissue in the peritoneal cavity constituting a precondition for endometriosis development. Decidualization is a physiological process involving progesterone action and cAMP signaling. We here evaluated the effect of 8-Br-cAMP, the adenylate cyclase activator forskolin and of the progestin progesterone and medroxyprogesterone acetate (MPA) alone and in combination on decidualization induction using prolactin ELISA, and on cell size, cell granularity, and cell survival via flow cytometry in hESCs of patients with and without endometriosis. While progestins alone did not induce functional decidualization in hESCs, 8-Br-cAMP and forskolin induced decidualization in hESCs from both cohorts, whereas the induction of FOXO1 transcription and prolactin secretion by forskolin was significantly lower than by 8-Br-cAMP. 8-Br-cAMP- and forskolin-induced prolactin secretion was significantly enhanced by MPA, but not by progesterone. Decidualization entailed a decrease in cell size and in cell granularity. In general, hESCs from women with mild (ASRM I/II) as well as severe (ASRM III/IV) endometriosis in trend displayed a higher granularity, whereas mainly hESCs from severe endometriosis showed a stronger resistance to the induction of cell death after decidualization induction. In both cohorts, the amount of the decidual marker protein prolactin rather exhibited an anti-proportional correlation to cell death induction during six day treatment. This study contributes to widen our understanding of the connection of decidualization and cell death in endometriosis.

Human CEACAM1 is targeted by a Streptococcus pyogenes adhesin implicated in puerperal sepsis pathogenesis.

Life-threatening bacterial infections in women after childbirth, known as puerperal sepsis, resulted in classical epidemics and remain a global health problem. While outbreaks of puerperal sepsis have been ascribed to Streptococcus pyogenes, little is known about disease mechanisms. Here, we show that the bacterial R28 protein, which is epidemiologically associated with outbreaks of puerperal sepsis, specifically targets the human receptor CEACAM1. This interaction triggers events that would favor the development of puerperal sepsis, including adhesion to cervical cells, suppression of epithelial wound repair and subversion of innate immune responses. High-resolution structural analysis showed that an R28 domain with IgI3-like fold binds to the N-terminal domain of CEACAM1. Together, these findings demonstrate that a single adhesin-receptor interaction can drive the pathogenesis of bacterial sepsis and provide molecular insights into the pathogenesis of one of the most important infectious diseases in medical history.

Loss of CEACAM1 in endothelial cells causes hepatic fibrosis.

OBJECTIVES: Hepatocytic CEACAM1 plays a critical role in NASH pathogenesis, as bolstered by the development of insulin resistance, visceral obesity, steatohepatitis and fibrosis in mice with global Ceacam1 (Cc1) deletion. In contrast, VECadCre+Cc1fl/fl mice with endothelial loss of Cc1 manifested insulin sensitivity with no visceral obesity despite elevated NF-κB signaling and increased systemic inflammation. We herein investigated whether VECadCre+Cc1fl/fl male mice develop hepatic fibrosis and whether this is mediated by increased production of endothelin1 (ET1), a transcriptional NF-κB target. METHODS: VECadCre+Et1.Cc1fl/fl mice with combined endothelial loss of Cc1/Et1 genes were generated. Histological and immunohistochemical analyses were conducted on their livers and on liver tissue biopsies from adult patients undergoing bariatric surgery or from patients with NASH diagnosis receiving liver transplant. RESULTS: Hepatic fibrosis and inflammatory infiltration developed in VECadCre+Cc1fl/fl liver parenchyma. This was preceded by increased ET1 production and reversed with combined endothelial loss of Et1. Conditioned media from VECadCre+Cc1fl/fl, but not VECadCre+Et1.Cc1fl/fl primary liver endothelial cells activated wild-type hepatic stellate cells; a process inhibited by bosentan, an ETAR/ETBR dual antagonist. Consistently, immunohistochemical analysis of liver biopsies from patients with NASH showed a decline in endothelial CEACAM1 in parallel with increased plasma endothelin1 levels and progression of hepatic fibrosis stage. CONCLUSIONS: The data demonstrated that endothelial CEACAM1 plays a key role in preventing hepatic fibrogenesis by reducing autocrine endothelin1 production.

High insulin-like growth factor mRNA-binding protein 3 (IMP3) protein expression is associated with poor survival in muscle-invasive bladder cancer.

UNLABELLED: What's known on the subject? and What does the study add? Insulin-like growth factor mRNA-binding protein 3 (IMP3) is an oncofetal protein found to be re-expressed in a series of human cancers including bladder cancer. In vitro analyses showed an invasion and proliferation promoting effect for IMP3. Further in vitro studies suggested that IMP3 is able to bind to the mRNAs of CD44 and insulin-like growth factor 2 (IGF2), enhancing their stability and expression. However, this molecular interaction has not yet been analysed in tumour samples. In the present study, we identified for the first time high IMP3 tissue protein expression as an independent predictor of poor patients' survival in muscle-invasive bladder cancer. Furthermore, there was no correlation between IMP3 and its molecular targets in bladder carcinoma specimens and concluded that the tumour-promoting effect of IMP3 is not related to its regulatory action on IGF2 and CD44. OBJECTIVE: To assess the prognostic value and molecular actions of the oncofetal protein insulin-like growth factor mRNA-binding protein 3 (IMP3) in muscle-invasive bladder cancer (BC). PATIENTS AND METHODS: IMP3 expression was analysed by immunohistochemistry, real-time polymerase chain reaction and Western blot analysis in 224 patients with BC. The molecular targets of IMP3; CD44, insulin-like growth factor 2 (IGF2) and its receptor the IGF1 receptor (IGF1-R) were also investigated. Expression levels were correlated with clinical follow-up data by using both univariate and multivariate Cox regression analyses. RESULTS: IMP3 mRNA and protein levels were significantly elevated in high-stage and high-grade muscle-invasive BC. In muscle-invasive BC IMP3 protein but not gene expression proved to be an independent predictor of disease-specific (hazard ratio [HR] 2.58, 95% confidence interval [CI] 1.28-4.56, P = 0.004) and overall survival (HR 2.07, 95% CI 1.12-3.82, P = 0.020). The expression levels of IGF2 and CD44 showed no correlation with that of IMP3. CONCLUSIONS: High IMP3 protein levels may identify patients with BC at high risk of disease progression and may therefore select patients for a more intensive therapy or for a strict follow-up. Its high expression in high-grade bladder carcinoma cells makes IMP3 for an attractive target for therapy. The tumour promoting effect of IMP3 is independent from its regulatory action on IGF2 and CD44 expression.