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Scott D Grayowen - One of the best experts on this subject based on the ideXlab platform.

  • characterization of CEACAM1 and lipid raft nanoclustering association and structure by dstorm and homo fret imaging
    Biophysical Journal, 2016
    Co-Authors: Amine Driouchi, Maximilano Giuliani, Scott D Grayowen
    Abstract:

    The advent of super-resolution microscopy has revealed that most membrane proteins cluster at nanoscale lengths. Clustering and compartmentalization of membrane proteins is partially caused by lipid rafts that exist at small spatial (10-100 nm) and temporal scales, that are not perceptible using classic fluorescence microscopy (1,2). Carcinoembryonic antigen-related cellular adhesion molecules (CEACAMs) are cell surface glycoproteins involved in homo- and hetero-philic intercellular interactions that control cellular growth, differentiation, tumourigenesis, inflammation and infection. Here, we investigate the association of lipid rafts with CEACAMs using direct stochastic optical reconstruction microscopy (dSTORM). We have previously demonstrated using live cell TIRF-homoFRET-dSTORM that CEACAM1 can exist as monomers and oligomers at the cell membrane, with the monomers being predominantly organized in clustered regions and the dimers in more diffuse regions. We super-resolved CEACAM1 and lipid rafts using an anti-GFP labeled nanobody and a labeled Cholera Toxin subunit B, respectively. This approach allows us to obtain super-resolved images from which coordinates with a localization precision of 20 nm can be derived. Subsequent clustering analyses allowed us to quantify the degree of association between lipid rafts and CEACAM1. Moreover, correlating homo-FRET CEACAM data with these super-resolved maps allowed us to elucidate CEACAM monomer/oligomer distribution and association with lipid rafts. Our results show that both CEACAM1 and lipid rafts exhibit nano and micro-sized clusters of various shapes and partial spatial colocalization. This reinforces the body of work suggesting that lipid rafts are necessary to support cell adhesion, pathogen binding and intercellular signalling.

  • inside out signaling promotes dynamic changes in the carcinoembryonic antigen related cellular adhesion molecule 1 CEACAM1 oligomeric state to control its cell adhesion properties
    Journal of Biological Chemistry, 2013
    Co-Authors: Prerna C Patel, Aaron Y K Ming, Arianna Rath, Charles M Deber, Jonathan V Rocheleau, Scott D Grayowen
    Abstract:

    Cell-cell contacts are fundamental to multicellular organisms and are subject to exquisite levels of control. The carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) can engage in both cis-homophilic (parallel) oligomerization and trans-homophilic (anti-parallel) binding. In this study, we establish that the CEACAM1 transmembrane domain has a propensity to form cis-dimers via the transmembrane-embedded 432GXXXG436 motif and that this basal state is overcome when activated calmodulin binds to the CEACAM1 cytoplasmic domain. Although mutation of the 432GXXXG436 motif reduced CEACAM1 oligomerization, it did not affect surface localization of the receptor or influence CEACAM1-dependent cellular invasion by the pathogenic Neisseria. The mutation did, however, have a striking effect on CEACAM1-dependent cellular aggregation, increasing both the kinetics of cell-cell association and the size of cellular aggregates formed. CEACAM1 association with tyrosine kinase c-Src and tyrosine phosphatases SHP-1 and SHP-2 was not affected by the 432GXXXG436 mutation, consistent with their association with the monomeric form of wild type CEACAM1. Collectively, our results establish that a dynamic oligomer-to-monomer shift in surface-expressed CEACAM1 facilitates trans-homophilic binding and downstream effector signaling.

  • CEACAM1 dynamics during neisseria gonorrhoeae suppression of cd4 t lymphocyte activation
    Journal of Immunology, 2008
    Co-Authors: Mario A Ostrowski, Scott D Grayowen
    Abstract:

    Neisseria gonorrhoeae colony opacity-associated (Opa) proteins bind to human carcinoembryonic antigen cellular adhesion molecules (CEACAM) found on host cells including T lymphocytes. Opa binding to CEACAM1 suppresses the activation of CD4+ T cells in response to a variety of stimuli. In this study, we use primary human CD4+ T cells isolated from peripheral blood to define the molecular events occurring subsequent to Opa-CEACAM1 binding. We establish that, in contrast to other cell types, T cells do not engulf N. gonorrhoeae upon CEACAM1 binding. Instead, the bacteria recruit CEACAM1 from intracellular stores and maintain it on the T cell surface. Upon TCR ligation, the co-engaged CEACAM1 becomes phosphorylated on tyrosine residues within the ITIMs apparent in the cytoplasmic domain. This allows the recruitment and subsequent activation of the src homology domain 2-containing tyrosine phosphatases SHP-1 and SHP-2 at the site of bacterial attachment, which prevents the normal tyrosine phosphorylation of the CD3ζ-chain and ZAP-70 kinase in response to TCR engagement. Combined, this dynamic response allows the bacteria to effectively harness the coinhibitory function of CEACAM1 to suppress the adaptive immune response at its earliest step.

  • CEACAM1 cd66a promotes human monocyte survival via a phosphatidylinositol 3 kinase and akt dependent pathway
    Journal of Biological Chemistry, 2006
    Co-Authors: Qigui Yu, Scott D Grayowen, Edith M C Chow, Henry K Wong, Jenny X Gu, Ofer Mandelboim, Mario A Ostrowski
    Abstract:

    Abstract CEACAM1 (also known as CD66a) is a transmembrane glycoprotein that mediates homophilic intercellular interactions that influence cellular growth, immune cell activation, and tissue morphogenesis. Various studies have suggested a link between CEACAM1 and cellular apoptosis, including a recent demonstration that ERK1/2 signaling is triggered downstream of CEACAM1. In this study, we reveal that CEACAM1-long binding confers survival signals to human peripheral blood mononuclear cells. CEACAM-specific antibodies effectively protected peripheral blood mononuclear cells from apoptosis, with this effect being particularly dramatic for primary monocytes that undergo spontaneous apoptosis during in vitro culture. This protective effect was reiterated when using soluble CEACAM1, which binds to cell-surface CEACAM1 via homophilic interactions. Monocyte survival correlated with a CEACAM1-dependent up-regulation of the cellular inhibitor of apoptosis Bcl-2 and the abrogation of caspase-3 activation. CEACAM1 binding triggered a phosphatidylinositol 3-kinase-dependent activation of the protein kinase Akt without influencing the activity of extracellular signal-related kinase ERK, whereas the phosphatidylinositol 3-kinase-specific inhibitor LY294002 effectively blocked the protective effect of CEACAM1. Together, this work indicates that CEACAM1 confers a phosphatidylinositol 3-kinase- and Akt-dependent survival signal that inhibits mitochondrion-dependent apoptosis of monocytes. By controlling both ERK/MEK and PI3K/Akt pathways, CEACAM1 functions as a key regulator of contact-dependent control of cell survival, differentiation, and growth.

  • CEACAM1 contact dependent control of immunity
    Nature Reviews Immunology, 2006
    Co-Authors: Scott D Grayowen, Richard S Blumberg
    Abstract:

    The carcinoembryonic-antigen-related cell-adhesion molecule (CEACAM) family of proteins has been implicated in various intercellular-adhesion and intracellular-signalling-mediated effects that govern the growth and differentiation of normal and cancerous cells. Recent studies show that there is an important role for members of the CEACAM family in modulating the immune responses associated with infection, inflammation and cancer. In this Review, we consider the evidence for CEACAM involvement in immunity, with a particular emphasis on CEACAM1, which functions as a regulatory co-receptor for both lymphoid and myeloid cell types.

Christoph Wagener - One of the best experts on this subject based on the ideXlab platform.

  • CEACAM1 in Liver Injury, Metabolic and Immune Regulation
    International Journal of Molecular Sciences, 2018
    Co-Authors: Andrea Kristina Horst, Sonia M. Najjar, Christoph Wagener, Gisa Tiegs
    Abstract:

    Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is a transmembrane glycoprotein that is expressed on epithelial, endothelial and immune cells. CEACAM1 is a differentiation antigen involved in the maintenance of epithelial polarity that is induced during hepatocyte differentiation and liver regeneration. CEACAM1 regulates insulin sensitivity by promoting hepatic insulin clearance, and controls liver tolerance and mucosal immunity. Obese insulin-resistant humans with non-alcoholic fatty liver disease manifest loss of hepatic CEACAM1. In mice, deletion or functional inactivation of CEACAM1 impairs insulin clearance and compromises metabolic homeostasis which initiates the development of obesity and hepatic steatosis and fibrosis with other features of non-alcoholic steatohepatitis, and adipogenesis in white adipose depot. This is followed by inflammation and endothelial and cardiovascular dysfunctions. In obstructive and inflammatory liver diseases, soluble CEACAM1 is shed into human bile where it can serve as an indicator of liver disease. On immune cells, CEACAM1 acts as an immune checkpoint regulator, and deletion of CEACAM1 gene in mice causes exacerbation of inflammation and hyperactivation of myeloid cells and lymphocytes. Hence, hepatic CEACAM1 resides at the central hub of immune and metabolic homeostasis in both humans and mice. This review focuses on the regulatory role of CEACAM1 in liver and biliary tract architecture in health and disease, and on its metabolic role and function as an immune checkpoint regulator of hepatic inflammation.

  • CEACAM1 inhibits mmp 9 mediated blood brain barrier breakdown in a mouse model for ischemic stroke
    Circulation Research, 2013
    Co-Authors: Peter Ludewig, Christoph Wagener, Jan Sedlacik, Mathias Gelderblom, Christian Bernreuther, Yucel Korkusuz, Christian Gerloff, Jens Fiehler, Tim Magnus, Andrea Kristina Horst
    Abstract:

    Rationale: Blood-brain-barrier (BBB) breakdown and cerebral edema result from postischemic inflammation and contribute to mortality and morbidity after ischemic stroke. A functional role for the carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in the regulation of reperfusion injury has not yet been demonstrated. Objective: We sought to identify and characterize the relevance of CEACAM1- expressing inflammatory cells in BBB breakdown and outcome after ischemic stroke in CEACAM1-/- and wild type (WT) mice. Methods and Results: Focal ischemia was induced by temporary occlusion of the middle cerebral artery (tMCAO) with a microfilament. Using magnetic resonance imaging (MRI) and Evans blue permeability assays, we observed increased stroke volumes, BBB breakdown and edema formation, reduction of cerebral perfusion and brain atrophy in CEACAM1-/- mice.This translated into poor performance in neurological scoring and high post stroke-associated mortality. Elevated neutrophil influx, hyperproduction and release of neutrophil-related matrix metalloproteinase (MMP)-9 in CEACAM1-/- mice were confirmed by immune fluorescence, flow cytometry, zymography and stimulation of neutrophils. Importantly, neutralization of MMP-9 activity in CEACAM1-/- mice was sufficient to alleviate stroke sizes and improve survival to the level of CEACAM1-competent animals. Immune histochemistry of murine and human post-stroke autoptic brains congruently identified abundance of CEACAM1+MMP9+ neutrophils in the ischemic hemispheres. Conclusions: CEACAM1 controls MMP-9 secretion by neutrophils in postischemic inflammation at the BBB after stroke. We propose CEACAM1 as an important inhibitory regulator of neutrophil-mediated tissue damage and BBB breakdown in focal cerebral ischemia.

  • CEACAM1 Expression in Pancreatic Endocrine Tumors
    Applied Immunohistochemistry & Molecular Morphology, 2009
    Co-Authors: Stefano Serra, Christoph Wagener, Ana-maria Bamberger, Runjan Chetty
    Abstract:

    The aim of this study was to examine the expression of carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) in pancreatic endocrine tumors (PETs) and to correlate it with clinicopathologic parameters. Sixty-nine PETs were examined for tumor size, necrosis, local peripancreatic invasion and lymphovascular invasion, lymph node, and liver metastasis. The mitotic count, expressed per 10 high-power fields (HPF) and MIB1 index were assessed and tumors were classified according to the World Health Organization classification. A tissue microarray was constructed and stained with an extensive panel of endocrine markers and CEACAM1. Twenty-nine tumors were from males and 40 from females, age range: 23 to 80 years (mean 52.4 y), tumor size ranged from 0.8 to 11 cm (mean 3.5 cm), 8 patients had multiple endocrine neoplasia 1 syndrome, and 1 had von Hippel-Lindau disease. Twenty tumors demonstrated local invasion, 32 had lymphovascular invasion, 16 had lymph node metastasis, and 10 had liver metastasis. CEACAM1 was positive in 47 cases and negative in 22 cases (31.9%). Ninety percent of the CEACAM1-negative cases had a MIB1 index ≤2%, whereas 88.9% of CEACAM1-positive cases had a MIB1 index >2% (P=0.02). 86.4% of the CEACAM1-negative PETs had a mitotic count ≤2/10 HPF, whereas 75% of the CEACAM-positive PETs had a mitotic count >2/10 HPF. In addition, 80% of tumors ≥2 cm in diameter were CEACAM positive (P

  • CEACAM1 myeloid cells control angiogenesis in inflammation
    Blood, 2009
    Co-Authors: Andrea Kristina Horst, Nicole Beauchemin, Thomas Bickert, Nancy Brewig, Peter Ludewig, Nico Van Rooijen, Udo Schumacher, Bernhard Fleischer, Christoph Wagener
    Abstract:

    Local inflammation during cutaneous leishmaniasis is accompanied by accumulation of CD11b+ cells at the site of the infection. A functional role for these monocytic cells in local angiogenesis in leishmaniasis has not been described so far. Here, we show that CD11b+ cells express high levels of the myeloid differentiation antigen carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1). In experimental cutaneous leishmaniasis in C57BL/6 wild-type (B6.WT) and B6. CEACAM1 −/− mice, we found that only B6. CEACAM1 −/− mice develop edemas and exhibit impairment of both hemangiogenesis and lymphangiogenesis. Because CEACAM1 expression correlates with functional angiogenesis, we further analyzed the role of the CD11b+ population. In B6. CEACAM1 −/− mice, we found systemic reduction of Ly-6Chigh/CD11bhigh monocyte precursors. To investigate whether CEACAM1+ myeloid cells are causally related to efficient angiogenesis, we used reverse bone marrow transplants (BMTs) to restore CEACAM1+ or CEACAM1− bone marrow in B6. CEACAM1 −/− or B6.WT recipients, respectively. We found that angiogenesis was restored by CEACAM1+ BMT only. In addition, we observed reduced morphogenic potential of inflammatory cells in Matrigel implants in CEACAM1− backgrounds or after systemic depletion of CD11bhigh macrophages. Taken together, we show for the first time that CEACAM1+ myeloid cells are crucial for angiogenesis in inflammation.

  • CEACAM1 an adhesion molecule of human granulocytes is fucosylated by fucosyltransferase ix and interacts with dc sign of dendritic cells via lewis x residues
    Glycobiology, 2006
    Co-Authors: Valentina Bogoevska, Christoph Wagener, Andrea Kristina Horst, Lothar Lucka, Birgit Klampe, Peter Nollau
    Abstract:

    The CEA-related cell adhesion molecule 1, CEACAM1, is a glycoprotein expressed on the surface of human granulocytes and lymphocytes, endothelia, and many epithelia. CEACAM1 is involved in the regulation of important biological processes, such as tumor growth, angiogenesis, and modulation of the immune response. CEACAM1, a member of the immunoglobulin superfamily carries several Lewis x (Lex) structures as we recently demonstrated by mass spectrometry of native CEACAM1 from human granulocytes. Since Lex residues of pathogens bind to the C-type lectin dendritic cell-specific ICAM-3 grabbing nonintegrin (DC-SIGN) expressed on human DCs, we hypothesized that Lex glycans of CEACAM1 are recognized by DC-SIGN. Here, we demonstrate that CEACAM1, the major carrier of Lex residues in human granulocytes, is specifically recognized by DC-SIGN via Lex residues mediating the internalization of CEACAM1 into immature DCs. Expression studies with CEACAM1 in combination with different fucosyltransferases (FUTs) revealed that FUTIX plays a key role in the synthesis of Lex groups of CEACAM1. As Lex groups on CEACAM1 are selectively attached and specifically interact with DC-SIGN, our findings suggest that CEACAM1 participates in immune regulation in physiological conditions and in pathological conditions, such as inflammation, autoimmune disease, and cancer.

John E. Shively - One of the best experts on this subject based on the ideXlab platform.

  • Loss of CEACAM1 is associated with poor prognosis and peritoneal dissemination of patients with gastric cancer.
    Scientific Reports, 2019
    Co-Authors: Akihiro Takeuchi, Shunsuke Yamaguchi, Shozo Yokoyama, Yasuyuki Mitani, John E. Shively, Mikihito Nakamori, Masaki Nakamura, Toshiyasu Ojima, Hiroki Yamaue
    Abstract:

    CEACAM1 is associated with malignant potential of various cancers. The current study aims to clarify the association between carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) expression and malignant potential of gastric cancer and to address whether CEACAM1 cytoplasmic domain isoform balance modulates the properties of gastric cancer cells. Immunohistochemical analyses for CEACAM1 were performed in 235 patients with gastric cancer who underwent surgery. Risk factors for overall survival and peritoneal metastasis were calculated based on CEACAM1 expression in the gastric cancer tissue. Patients with CEACAM1 long (CEACAM1-L) or short (CEACAM1-S) cytoplasmic isoform dominance were compared with patients with null CEACAM1 expression in terms of overall survival. CEACAM1 transfected or knockdown gastric cancer cell line, NUGC3 and MKN7 cells, were examined by invasion assay and three dimensional (3D) culture, in order to clarify whether CEACAM1 modulate invasion, lumen formation and tumor growth of gastric cancer cells. Multivariate analysis demonstrated that gastric cancer without CEACAM1 is an independent prognostic factor and a risk factor for peritoneal dissemination. Patients with CEACAM1-S dominance had better prognosis than those with CEACAM1-L. CEACAM1-4L overexpression induced less invasion, more lumen formation, and less tumor growth of NUGC3 cells. CEACAM1-4S overexpression had less invasion and more lumen formations, but not less tumor growth. Knockdown of CEACAM1 expression had less invasion, but not less lumen formations of MKN7 cells. Loss of CEACAM1 is associated with poor prognosis and peritoneal dissemination of patients with gastric cancer. Expression of CEACAM1 in gastric cancer cells modulates invasiveness, lumen formation, and tumor growth.

  • interferon regulatory factor 1 and a variant of heterogeneous nuclear ribonucleoprotein l coordinately silence the gene for adhesion protein CEACAM1
    Journal of Biological Chemistry, 2018
    Co-Authors: Kenneth J Dery, Craig Silver, Lu Yang, John E. Shively
    Abstract:

    The adhesion protein carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is widely expressed in epithelial cells as a short cytoplasmic isoform (S-iso) and in leukocytes as a long cytoplasmic isoform (L-iso) and is frequently silenced in cancer by unknown mechanisms. Previously, we reported that interferon response factor 1 (IRF1) biases alternative splicing (AS) to include the variable exon 7 (E7) in CEACAM1, generating long cytoplasmic isoforms. We now show that IRF1 and a variant of heterogeneous nuclear ribonucleoprotein L (Lv1) coordinately silence the CEACAM1 gene. RNAi-mediated Lv1 depletion in IRF1-treated HeLa and melanoma cells induced significant CEACAM1 protein expression, reversed by ectopic Lv1 expression. The Lv1-mediated CEACAM1 repression resided in residues Gly71-Gly89 and Ala38-Gly89 in Lv1's N-terminal extension. ChIP analysis of IRF1- and FLAG-tagged Lv1-treated HeLa cells and global treatment with the global epigenetic modifiers 5-aza-2'-deoxycytidine and trichostatin A indicated that IRF1 and Lv1 together induce chromatin remodeling, restricting IRF1 access to the CEACAM1 promoter. In interferon γ-treated HeLa cells, the transcription factor SP1 did not associate with the CEACAM1 promoter, but binding by upstream transcription factor 1 (USF1), a known CEACAM1 regulator, was greatly enhanced. ChIP-sequencing revealed that Lv1 overexpression in IRF1-treated cells induces transcriptional silencing across many genes, including DCC (deleted in colorectal carcinoma), associated with CEACAM5 in colon cancer. Notably, IRF1, but not IRF3 and IRF7, affected CEACAM1 expression via translational repression. We conclude that IRF1 and Lv1 coordinately regulate CEACAM1 transcription, alternative splicing, and translation and may significantly contribute to CEACAM1 silencing in cancer.

  • CEACAM1 is associated with recurrence after hepatectomy for colorectal liver metastasis
    Journal of Surgical Research, 2017
    Co-Authors: Shunsuke Yamaguchi, Shozo Yokoyama, Masaki Ueno, Shinya Hayami, Yasuyuki Mitani, Akihiro Takeuchi, John E. Shively, Hiroki Yamaue
    Abstract:

    Abstract Background Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is re-expressed at the invasion front of colorectal cancer. CEACAM1 expression at metastatic sites remains to be investigated. The current study aims to clarify the association between CEACAM1 expression and recurrence after hepatectomy of colorectal liver metastasis and to address whether CEACAM1 induces tumor-initiating properties needed for growth at metastatic sites. Methods Immunohistochemical analyses for CEACAM1 were performed in 67 patients with liver metastasis of colorectal cancer who had undergone curative hepatectomy. The risk factors for postoperative recurrence were calculated based on a CEACAM1 cytoplasmic domain isoform at the primary tumor invasion front. To investigate the effects of CEACAM1 cytoplasmic isoforms on HT29 and HCT116 colorectal cancer cells, Western blotting for CD44 and CD133, flow cytometry for ALDH1 activity, and soft-agar colony formation assay were performed. Results CEACAM1 long (CEACAM1-L) and short (CEACAM1-S) cytoplasmic domain isoforms are strongly expressed on cancer cells in the liver metastases. Enhanced CEACAM1-S expression in the state of CEACAM1-L dominance at the primary tumor invasion front was an independent factor for colorectal cancer recurrence after curative hepatectomy. CEACAM1-4S-transfected HT29 and HCT116 cells had significantly higher CD44 expression and ALDH1 activity and increased the growth in anchorage-independent condition. Conclusions High expression of CEACAM1-S at the primary lesion invasion front is associated with recurrence and prognosis of patients with colorectal liver metastasis after curative hepatectomy. The expression of CEACAM1-4S enhances the tumor-initiating property of colorectal cancer cells.

  • role of CEACAM1 and ceacam20 in an in vitro model of prostate morphogenesis
    PLOS ONE, 2013
    Co-Authors: Hui Zhang, Wolfgang Zimmermann, Andreas Eisenried, John E. Shively
    Abstract:

    CEACAM20, a novel member of the CEACAM1 gene family with expression limited to the lumen of small intestine, testes, and prostate, is co-expressed with CEACAM1 in adult prostate tissue and down-regulated to the same extent as CEACAM1 in prostate cancer. Since prostate cancer often involves loss of epithelial lumen formation, we hypothesized that CEACAM20 and CEACAM1 play important roles in lumen formation of normal prostate epithelium. When prostate cells were grown on Matrigel as a source of extracellular matrix (ECM), they differentiated into acinar structures with single tubules and well-defined lumina closely resembling embryonic prostate organoids. Confocal microscopic analysis revealed restriction of CEACAM20 to acini and CEACAM1 to tubule structures, respectively. Inhibition of CEACAM1 with antibodies or soluble CEACAM1 or antisense oligonucleotides inhibited tubule formation by over 50% while the remaining tubules were stunted. Inhibition of CEACAM20 with antisense oligonucleotides completely inhibited tubule formation and stunted the growth of acini. We conclude that CEACAM20 and CEACAM1 not only mark the lumina of adult prostate tissue but also play a critical role in the vitro generation of prostate organoids.

  • CEACAM1 negatively regulates il 1β production in lps activated neutrophils by recruiting shp 1 to a syk tlr4 CEACAM1 complex
    PLOS Pathogens, 2012
    Co-Authors: Rongze Lu, John E. Shively
    Abstract:

    LPS-activated neutrophils secrete IL-1β by activation of TLR-4. Based on studies in macrophages, it is likely that ROS and lysosomal destabilization regulated by Syk activation may also be involved. Since neutrophils have abundant expression of the ITIM-containing co-receptor CEACAM1 and Gram-negative bacteria such as Neisseria utilize CEACAM1 as a receptor that inhibits inflammation, we hypothesized that the overall production of IL-1β in LPS treated neutrophils may be negatively regulated by CEACAM1. We found that LPS treated neutrophils induced phosphorylation of Syk resulting in the formation of a complex including TLR4, p-Syk, and p-CEACAM1, which in turn, recruited the inhibitory phosphatase SHP-1. LPS treatment leads to ROS production, lysosomal damage, caspase-1 activation and IL-1β secretion in neutrophils. The absence of this regulation in CEACAM1−/− neutrophils led to hyper production of IL-1β in response to LPS. The hyper production of IL-1β was abrogated by in vivo reconstitution of wild type but not ITIM-mutated CEACAM1 bone marrow stem cells. Blocking Syk activation by kinase inhibitors or RNAi reduced Syk phosphorylation, lysosomal destabilization, ROS production, and caspase-1 activation in CEACAM1−/− neutrophils. We conclude that LPS treatment of neutrophils triggers formation of a complex of TLR4 with pSyk and pCEACAM1, which upon recruitment of SHP-1 to the ITIMs of pCEACAM1, inhibits IL-1β production by the inflammasome. Thus, CEACAM1 fine-tunes IL-1β production in LPS treated neutrophils, explaining why the additional utilization of CEACAM1 as a pathogen receptor would further inhibit inflammation.

Bernhard B Singer - One of the best experts on this subject based on the ideXlab platform.

  • mitf is a critical regulator of the carcinoembryonic antigen related cell adhesion molecule 1 CEACAM1 in malignant melanoma
    Pigment Cell & Melanoma Research, 2015
    Co-Authors: Nico Ullrich, Bernhard B Singer, Stefanie Loffek, Susanne Horn, Marie Ennen, Luis Sanchezdelcampo, Fang Zhao, Frank Breitenbuecher, Irwin Davidson, Dirk Schadendorf
    Abstract:

    Summary The multifunctional Ig-like carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is neo-expressed in the majority of malignant melanoma lesions. CEACAM1 acts as a driver of tumor cell invasion, and its expression correlates with poor patient prognosis. Despite its importance in melanoma progression, how CEACAM1 expression is regulated is largely unknown. Here, we show that CEACAM1 expression in melanoma cell lines and melanoma tissue strongly correlates with that of the microphthalmia-associated transcription factor (MITF), a key regulator of melanoma proliferation and invasiveness. MITF is revealed as a direct and positive regulator for CEACAM1 expression via binding to an M-box motif located in the CEACAM1 promoter. Taken together, our study provides novel insights into the regulation of CEACAM1 expression and suggests an MITF-CEACAM1 axis as a potential determinant of melanoma progression.

  • CEACAM1 3s drives melanoma cells into nk cell mediated cytolysis and enhances patient survival
    Cancer Research, 2015
    Co-Authors: Nico Ullrich, Bernhard B Singer, Inka Scheffrahn, Anja Heinemann, Elena Nilewski, Joachim Klode, Andre Scherag, Dirk Schadendorf, Iris Helfrich
    Abstract:

    CEACAM1 is a widely expressed multifunctional cell–cell adhesion protein reported to serve as a poor prognosis marker in melanoma patients. In this study, we examine the functional and clinical contributions of the four splice isoforms of CEACAM1. Specifically, we present in vitro and in vivo evidence that they affect melanoma progression and immune surveillance in a negative or positive manner that is isoform specific in action. In contrast with isoforms CEACAM1-4S and CEACAM1-4L, expression of isoforms CEACAM1-3S and CEACAM1-3L is induced during disease progression shown to correlate with clinical stage. Unexpectedly, overall survival was prolonged in patients with advanced melanomas expressing CEACAM1-3S. The favorable effects of CEACAM1-3S related to enhanced immunogenicity, which was mediated by cell surface upregulation of NKG2D receptor ligands, thereby sensitizing melanoma cells to lysis by natural killer cells. Conversely, CEACAM1-4L downregulated cell surface levels of the NKG2D ligands MICA and ULBP2 by enhanced shedding, thereby promoting malignant character. Overall, our results define the splice isoform-specific immunomodulatory and cell biologic functions of CEACAM1 in melanoma pathogenesis. Cancer Res; 75(9); 1897–907. ©2015 AACR .

  • soluble ceacam8 interacts with CEACAM1 inhibiting tlr2 triggered immune responses
    PLOS ONE, 2014
    Co-Authors: Bernhard B Singer, Annina Heinrich, Frauke Schreiber, Ramona Bindingliermann, Luis Carlos Berrocalalmanza, Kerstin A Heyl, Mario M Muller, Andreas Weimann, Janine Zweigner, Hortense Slevogt
    Abstract:

    Lower respiratory tract bacterial infections are characterized by neutrophilic inflammation in the airways. The carcinoembryonic antigen-related cell adhesion molecule (CEACAM) 8 is expressed in and released by human granulocytes. Our study demonstrates that human granulocytes release CEACAM8 in response to bacterial DNA in a TLR9-dependent manner. Individuals with a high percentage of bronchial lavage fluid (BALF) granulocytes were more likely to have detectable levels of released CEACAM8 in the BALF than those with a normal granulocyte count. Soluble, recombinant CEACAM8-Fc binds to CEACAM1 expressed on human airway epithelium. Application of CEACAM8-Fc to CEACAM1-positive human pulmonary epithelial cells resulted in reduced TLR2-dependent inflammatory responses. These inhibitory effects were accompanied by tyrosine phosphorylation of the immunoreceptor tyrosine-based inhibitory motif (ITIM) of CEACAM1 and by recruitment of the phosphatase SHP-1, which could negatively regulate Toll-like receptor 2-dependent activation of the phosphatidylinositol 3-OH kinase-Akt kinase pathway. Our results suggest a new mechanism by which granulocytes reduce pro-inflammatory immune responses in human airways via secretion of CEACAM8 in neutrophil-driven bacterial infections.

  • 54 CEACAM1 in Brain Development and Preterm Brain Injury
    Archives of Disease in Childhood, 2012
    Co-Authors: S Prager, Bernhard B Singer, M Keller, I Bendix, G Schlager, Ralf Herrmann, Süleyman Ergün, Ursula Felderhoff-müser
    Abstract:

    Background and aims About 10% of all neonates are born preterm before 37 weeks of gestation. These babies are at high risk to develop morbidities such as neurocognitive disorders (encephalopathy of prematurity) which are a huge burden on the children and their families. Multiple factors are causal, e.g. hyperoxia and maternal/neonatal inflammation. We demonstrated that CEACAM1, a member of the carcinoembryonic antigen-related cell adhesion molecule (CEACAM) family, is expressed ontogenetically in oligodendrocytes of the developing brain. Since CEACAM1 is involved in inflammation-associated signaling we hypothesize that CEACAM1 might contribute to inflammation-induced preterm brain injury. Material and Methods In a rat model of inflammation-induced encephalopathy of prematurity (LPS at p3), changes in CEACAM1 expression were quantified on RNA level at p6 and p11. Animals were anesthetized, transcardially perfused, and forebrains were immediately removed and snap-frozen. RNA from forebrains was isolated according to standard protocols. CEACAM1 isoform expression was quantified by qRT-PCR. Results LPS exposure at p3 induces significant changes in CEACAM1 expression in the developing brain. We report a significant increase of the soluble isoform CEACAM1–4C2 at p6, and a subsequent increase of the CEACAM1–4L isoform and an isoform shift from CEACAM1–4S towards CEACAM1–4L at p11. Conclusions Although underlying mechanisms are still elusive we demonstrate that CEACAM1 expression in oligodendrocytes is significantly altered in a model of inflammation-induced encephalopathy of prematurity. This finding emphasizes our hypothesis that CEACAM1 is involved in detrimental processes in the immature brain.

  • homophilic adhesion and CEACAM1 s regulate dimerization of CEACAM1 l and recruitment of shp 2 and c src
    Journal of Cell Biology, 2009
    Co-Authors: Mario M Muller, Bernhard B Singer, Esther Klaile, Olga Vorontsova, Björn Öbrink
    Abstract:

    Carcinoembryonic antigen (CEA)–related cell adhesion molecule 1 (CAM1 [CEACAM1]) mediates homophilic cell adhesion and regulates signaling. Although there is evidence that CEACAM1 binds and activates SHP-1, SHP-2, and c-Src, knowledge about the mechanism of transmembrane signaling is lacking. To analyze the regulation of SHP-1/SHP-2/c-Src binding, we expressed various CFP/YFP-tagged CEACAM1 isoforms in epithelial cells. The supramolecular organization of CEACAM1 was examined by cross-linking, coclustering, coimmunoprecipitation, and fluorescence resonance energy transfer. SHP-1/SHP-2/c-Src binding was monitored by coimmunoprecipitation and phosphotyrosine-induced recruitment to CEACAM1-L in cellular monolayers. We find that trans-homophilic CEACAM1 binding induces cis-dimerization by an allosteric mechanism transmitted by the N-terminal immunoglobulin-like domain. The balance of SHP-2 and c-Src binding is dependent on the monomer/dimer equilibrium of CEACAM1-L and is regulated by trans-binding, whereas SHP-1 does not bind under physiological conditions. CEACAM1-L homodimer formation is reduced by coexpression of CEACAM1-S and modulated by antibody ligation. These data suggest that transmembrane signaling by CEACAM1 operates by alteration of the monomer/dimer equilibrium, which leads to changes in the SHP-2/c-Src–binding ratio.

Nicole Beauchemin - One of the best experts on this subject based on the ideXlab platform.

  • (In Press) CEACAM1 regulates integrin αIIbβ3-mediated functions in platelets
    Platelets, 2020
    Co-Authors: Musaed M. Alshahrani, Nicole Beauchemin, Denise E. Jackson
    Abstract:

    Previous studies have implicated that the Ig-ITIM superfamily member, CEACAM1 may regulate integrin function. While CEACAM1 has been demonstrated to play a role as an inhibitory co-receptor of ITAM-associated GPVI/FcR γ-chain signaling pathways in platelets, its physiologic role in integrin αIIbβ3-mediated platelet function is unclear. In this study, we investigate the functional importance of CEACAM1 in murine platelets. We show that CEACAM1 is constitutively associated with integrin αIIbβ3 in resting human and mouse platelets as demonstrated by co-immunoprecipitation studies. Using CEACAM1-deficient mice, we show that they have prolonged tail bleeding times and volume of blood lost that is corrected by reconstitution with platelet CEACAM1. CEACAM1 - / - platelets have moderate integrin αIIbβ3 mediated functional defects with impaired kinetics of platelet spreading on fibrinogen and failure to retract fibrin clots in vitro. This functional integrin αIIbβ3 defect could not be attributed to altered integrin αIIbβ3 expression. CEACAM1 -/- platelets displayed normal "inside-out" signaling properties as demonstrated by normal agonist-induced binding of soluble (fluorescein isothiocyanate) FITC-fibrinogen, JON/A antibody binding, and increases in cytosolic free calcium levels. This study provides direct evidence that CEACAM1 is essential for normal integrin αIIbβ3-mediated platelet function and that disruption of mouse CEACAM1 induced moderate integrin αIIbβ3-mediated functional defects.

  • CEACAM1 deficiency delays important wound healing processes.
    Wound Repair and Regeneration, 2020
    Co-Authors: Sarah Leblanc, Claire Turbide, Nicole Beauchemin, Azadeh Arabzadeh, Valerie Breton, Samantha Benlolo, Annelaure Nouvion
    Abstract:

    Cutaneous wound healing is a complex process that requires the coordination of many cell types to achieve proper tissue repair. Four major overlapping processes have been identified in wound healing: hemostasis, inflammation, reepithelialization and granulation tissue formation, and tissue remodeling. Carcinoembryonic antigen- related cell adhesion molecule 1 (CEACAM1) is a glycoprotein expressed in epithe- lial, endothelial, lymphoid, and myeloid cells. Given its known roles in angiogenesis, cell migration, and immune functions, we hypothesized that CEACAM1 might also be involved in cutaneous wound healing and that a number of relevant CEACAM1- positive cell types might contribute to wound healing. To evaluate the role of CEACAM1 in these processes, 6-mm-diameter skin wounds were inflicted on CEACAM1 -/- and wild-type mice. Herein, we demonstrate that CEACAM1 deletion indeed affects wound healing in three key ways. Infiltration of F4/80 + macrophages was decreased in CEACAM1 -/- wounds, altering inflammatory processes. Reepithelial- ization in CEACAM1 -/- wounds was delayed. Furthermore, the vascular density of the granulation tissue in CEACAM1 -/- wounds was significantly diminished. These results confirm CEACAM1's role as an important regulator of key processes in cutaneous wound healing, although whether this works via a specific cell type or alterations in the functioning of multiple processes remains to be determined.

  • CEACAM1 regulates integrin αIIbβ3-mediated functions in platelets
    Platelets, 2015
    Co-Authors: Musaed M. Alshahrani, Nicole Beauchemin, Denise E. Jackson
    Abstract:

    AbstractPrevious studies have implicated that the Ig-ITIM superfamily member, CEACAM1 may regulate integrin function. While CEACAM1 has been demonstrated to play a role as an inhibitory co-receptor of ITAM-associated GPVI/FcR γ-chain signaling pathways in platelets, its physiologic role in integrin αIIbβ3-mediated platelet function is unclear. In this study, we investigate the functional importance of CEACAM1 in murine platelets. We show that CEACAM1 is constitutively associated with integrin αIIbβ3 in resting human and mouse platelets as demonstrated by co-immunoprecipitation studies. Using CEACAM1-deficient mice, we show that they have prolonged tail bleeding times and volume of blood lost that is corrected by reconstitution with platelet CEACAM1. CEACAM1−/− platelets have moderate integrin αIIbβ3 mediated functional defects with impaired kinetics of platelet spreading on fibrinogen and failure to retract fibrin clots in vitro. This functional integrin αIIbβ3 defect could not be attributed to altered in...

  • CEACAM1 dampens antitumor immunity by down regulating nkg2d ligand expression on tumor cells
    Journal of Experimental Medicine, 2011
    Co-Authors: Zhangguo Chen, Nicole Beauchemin, Yuhwa Huang, Ofer Mandelboim, Kristi Baker, Lanfen Chen, Torsten Olszak, Sebastian Zeissig, Lewis L Lanier, Richard S Blumberg
    Abstract:

    Although carcinoembryonic antigen (CEA)–related cell adhesion molecule 1 (CEACAM1) has been viewed as a tumor suppressor, increasing clinical evidence shows that high levels of CEACAM1 expression on tumors correlates with poor prognosis and high risk of metastasis. Here, we examined the consequences of CEACAM1 expression on tumor cells. We show that tumor cell–associated CEACAM1 causes intracellular retention of various NKG2D ligands in mouse and human tumor cells. CEACAM1-silenced tumor cells expressed more cell surface NKG2D ligands and exhibited greater sensitivity to natural killer cell–mediated cytolysis in vitro and rejection in vivo. Our studies reveal a novel mechanism through which CEACAM1-bearing tumor cells may escape immune-surveillance.

  • Abstract 5172: Role of CEACAM1 on cancer cell endothelial adhesion and liver metastasis in vivo
    Cancer Research, 2010
    Co-Authors: Carlos H.f. Chan, Claire Turbide, Nicole Beauchemin, Azadeh Arabzadeh, Luisa Demarte, Jonathan Spicer, Pnina Brodt, Lorenzo E. Ferri
    Abstract:

    Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Background: There are emerging data to suggest that tumor over-expression of the carcinoembryonic antigen-related cell adhesion molecules (CEACAM1, 5 and 6) may influence cancer metastasis; however, the mechanisms for this are unclear. CEACAM1 was shown to bind homotypically to itself and heterotypically to CEACAM5 and CEACAM6. Since CEACAM1 is the only known CEACAM family member expressed on the hepatic endothelium, we hypothesized that CEACAM1 promotes cancer metastasis by directly mediating binding between circulating tumor cells and the sinusoidal endothelium. Methods: Using intra-vital microscopy (IVM), a physiologically relevant model system to assess the early stages of liver metastasis in vivo, we have compared the hepatic endothelial adhesion of intra-splenically injected MC38 cells (mouse colon cancer cell line with minimal CEACAM1 expression) between CEACAM1+/+ and CEACAM1−/− mice. A CEACAM1-negative population of MC38 cells (MC38-null) was sorted out by FACS using specific anti-CEACAM1 antibodies. MC38-null cells were then infected with retroviruses produced from ψ2 packaging cells carrying pLXSN-CEACAM1 expression construct and infected cells were selected using neomycin-containing media. A CEACAM1-positive population of MC38 cells (MC38-CC1) was sorted out by FACS using specific anti-CEACAM1 antibodies. The migratory ability of MC38-null and MC38-CC1 cells were compared by IVM in CEACAM1+/+ mice as mentioned above. Liver metastasis assays were performed by means of intra-splenic injection of MC38 cells into the CEACAM1+/+ and CEACAM1−/− mice. Data expressed as mean ± SEM, student t-test determined significance (*p