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Sample records for adapter molecule myd88

  1. Molecular cloning and expression studies of the adapter molecule myeloid differentiation factor 88 (MyD88) in turbot (Scophthalmus maximus).

    PubMed

    Lin, Jing-Yun; Hu, Guo-Bin; Yu, Chang-Hong; Li, Song; Liu, Qiu-Ming; Zhang, Shi-Cui

    2015-10-01

    Myeloid differentiation factor 88 (MyD88) is an adapter protein involved in the interleukin-1 receptor (IL-1R) and Toll-like receptor (TLR)-mediated activation of nuclear factor-kappaB (NF-κB). In this study, a full length cDNA of MyD88 was cloned from turbot, Scophthalmus maximus. It is 1619 bp in length and contains an 858-bp open reading frame that encodes a peptide of 285 amino acid residues. The putative turbot (Sm)MyD88 protein possesses a N-terminal death domain and a C-terminal Toll/IL-1 receptor (TIR) domain known to be important for the functions of MyD88 in mammals. Phylogenetic analysis grouped SmMyD88 with other fish MyD88s. SmMyD88 mRNA was ubiquitously expressed in all examined tissues of healthy turbots, with higher levels observed in immune-relevant organs. To explore the role of SmMyD88, its gene expression profile in response to stimulation of lipopolysaccharide (LPS), CpG oligodeoxynucleotide (CpG-ODN) or turbot reddish body iridovirus (TRBIV) was studied in the head kidney, spleen, gills and muscle over a 7-day time course. The results showed an up-regulation of SmMyD88 transcript levels by the three immunostimulants in all four examined tissues, with the induction by CpG-ODN strongest and initiated earliest and inducibility in the muscle very weak. Additionally, TRBIV challenge resulted in a quite high level of SmMyD88 expression in the spleen, whereas the two synthetic immunostimulants induced the higher levels in the head kidney. These data provide insights into the roles of SmMyD88 in the TLR/IL-1R signaling pathway of the innate immune system in turbot. PMID:26025195

  2. TLR adaptor MyD88 is essential for pathogen control during oral toxoplasma gondii infection but not adaptive immunity induced by a vaccine strain of the parasite.

    PubMed

    Sukhumavasi, Woraporn; Egan, Charlotte E; Warren, Amy L; Taylor, Gregory A; Fox, Barbara A; Bzik, David J; Denkers, Eric Y

    2008-09-01

    TLR adaptor MyD88 activation is important in host resistance to Toxoplasma gondii during i.p. infection, but the function of this signaling pathway during oral infection, in which mucosal immunity assumes a predominant role, has not been examined. In this study, we show that MyD88(-/-) mice fail to control the parasite and succumb within 2 wk of oral infection. Early during infection, T cell IFN-gamma production, recruitment of neutrophils and induction of p47 GTPase IGTP (Irgm3) in the intestinal mucosa were dependent upon functional MyD88. Unexpectedly, these responses were MyD88-independent later during acute infection. In particular, CD4(+) T cell IFN-gamma reached normal levels independently of MyD88, despite continued absence of IL-12 in these animals. The i.p. vaccination of MyD88(-/-) mice with an avirulent T. gondii uracil auxotroph elicited robust IFN-gamma responses and protective immunity to challenge with a high virulence T. gondii strain. Our results demonstrate that MyD88 is required to control Toxoplasma infection, but that the parasite can trigger adaptive immunity without the need for this TLR adaptor molecule. PMID:18714019

  3. The Adaptor Protein Myd88 Is a Key Signaling Molecule in the Pathogenesis of Irinotecan-Induced Intestinal Mucositis

    PubMed Central

    Wong, Deysi V. T.; Lima-Júnior, Roberto C. P.; Carvalho, Cibele B. M.; Borges, Vanessa F.; Wanderley, Carlos W. S.; Bem, Amanda X. C.; Leite, Caio A. V. G.; Teixeira, Maraiza A.; Batista, Gabriela L. P.; Silva, Rangel L.; Cunha, Thiago M.; Brito, Gerly A. C.; Almeida, Paulo R. C.; Cunha, Fernando Q.; Ribeiro, Ronaldo A.

    2015-01-01

    Intestinal mucositis is a common side effect of irinotecan-based anticancer regimens. Mucositis causes cell damage, bacterial/endotoxin translocation and production of cytokines including IL–1 and IL–18. These molecules and toll-like receptors (TLRs) activate a common signaling pathway that involves the Myeloid Differentiation adaptor protein, MyD88, whose role in intestinal mucositis is unknown. Then, we evaluated the involvement of TLRs and MyD88 in the pathogenesis of irinotecan-induced intestinal mucositis. MyD88-, TLR2- or TLR9-knockout mice and C57BL/6 (WT) mice were given either saline or irinotecan (75 mg/kg, i.p. for 4 days). On day 7, animal survival, diarrhea and bacteremia were assessed, and following euthanasia, samples of the ileum were obtained for morphometric analysis, myeloperoxidase (MPO) assay and measurement of pro-inflammatory markers. Irinotecan reduced the animal survival (50%) and induced a pronounced diarrhea, increased bacteremia, neutrophil accumulation in the intestinal tissue, intestinal damage and more than twofold increased expression of MyD88 (200%), TLR9 (400%), TRAF6 (236%), IL–1β (405%), IL–18 (365%), COX–2 (2,777%) and NF-κB (245%) in the WT animals when compared with saline-injected group (P<0.05). Genetic deletion of MyD88, TLR2 or TLR9 effectively controlled the signs of intestinal injury when compared with irinotecan-administered WT controls (P<0.05). In contrast to the MyD88-/- and TLR2-/- mice, the irinotecan-injected TLR9-/- mice showed a reduced survival, a marked diarrhea and an enhanced expression of IL–18 versus irinotecan-injected WT controls. Additionally, the expression of MyD88 was reduced in the TLR2-/- or TLR9-/- mice. This study shows a critical role of the MyD88-mediated TLR2 and TLR9 signaling in the pathogenesis of irinotecan-induced intestinal mucositis. PMID:26440613

  4. Toll-Like Receptor Adaptor MyD88 is Essential for Pathogen Control During Oral Toxoplasma gondii Infection but not Adaptive Immunity Induced by a Vaccine Strain of the Parasite1

    PubMed Central

    Sukhumavasi, Woraporn; Egan, Charlotte E.; Warren, Amy L.; Taylor, Gregory A.; Fox, Barbara A.; Bzik, David J.; Denkers, Eric Y.

    2008-01-01

    Toll-like receptor (TLR)/MyD88 activation is important in host resistance to Toxoplasma gondii during i. p. infection, but the function of this signaling pathway during oral infection, in which mucosal immunity assumes a predominant role, has not been examined. Here, we show that MyD88−/− mice fail to control the parasite and succumb within two weeks of oral infection. Early during infection, T cell IFN-γ production, recruitment of neutrophils and induction of p47 GTPase Irgm3/IGTP in the intestinal mucosa were dependent upon functional MyD88. Unexpectedly, these responses were MyD88-independent later during acute infection. In particular, CD4+ T cell IFN-γ reached normal levels independently of MyD88, despite continued absence of IL-12 in these animals. Intraperitoneal vaccination of MyD88−/− mice with an avirulent T. gondii uracil axotroph elicited robust IFN-γ responses and protective immunity to challenge with a high virulence T. gondii strain. Our results demonstrate that MyD88 is required to control Toxoplasma infection, but that the parasite can trigger adaptive immunity without the need for this TLR adaptor molecule. PMID:18714019

  5. MyD88 Is Required for Protection from Lethal Infection with a Mouse-Adapted SARS-CoV

    PubMed Central

    Funkhouser, William; Uematsu, Satoshi; Akira, Shizou; Baric, Ralph S.; Heise, Mark T.

    2008-01-01

    A novel human coronavirus, SARS-CoV, emerged suddenly in 2003, causing approximately 8000 human cases and more than 700 deaths worldwide. Since most animal models fail to faithfully recapitulate the clinical course of SARS-CoV in humans, the virus and host factors that mediate disease pathogenesis remain unclear. Recently, our laboratory and others developed a recombinant mouse-adapted SARS-CoV (rMA15) that was lethal in BALB/c mice. In contrast, intranasal infection of young 10-week-old C57BL/6 mice with rMA15 results in a nonlethal infection characterized by high titer replication within the lungs, lung inflammation, destruction of lung tissue, and loss of body weight, thus providing a useful model to identify host mediators of protection. Here, we report that mice deficient in MyD88 (MyD88−/−), an adapter protein that mediates Toll-like receptor (TLR), IL-1R, and IL-18R signaling, are far more susceptible to rMA15 infection. The genetic absence of MyD88 resulted in enhanced pulmonary pathology and greater than 90% mortality by day 6 post-infection. MyD88−/− mice had significantly higher viral loads in lung tissue throughout the course of infection. Despite increased viral loads, the expression of multiple proinflammatory cytokines and chemokines within lung tissue and recruitment of inflammatory monocytes/macrophages to the lung was severely impaired in MyD88−/− mice compared to wild-type mice. Furthermore, mice deficient in chemokine receptors that contribute to monocyte recruitment to the lung were more susceptible to rMA15-induced disease and exhibited severe lung pathology similar to that seen in MyD88−/−mice. These data suggest that MyD88-mediated innate immune signaling and inflammatory cell recruitment to the lung are required for protection from lethal rMA15 infection. PMID:19079579

  6. Discovery of small molecule inhibitors of MyD88-dependent signaling pathways using a computational screen

    PubMed Central

    Olson, Mark A.; Lee, Michael S.; Kissner, Teri L.; Alam, Shahabuddin; Waugh, David S.; Saikh, Kamal U.

    2015-01-01

    In this study, we used high-throughput computational screening to discover drug-like inhibitors of the host MyD88 protein-protein signaling interaction implicated in the potentially lethal immune response associated with Staphylococcal enterotoxins. We built a protein-protein dimeric docking model of the Toll-interleukin receptor (TIR)-domain of MyD88 and identified a binding site for docking small molecules. Computational screening of 5 million drug-like compounds led to testing of 30 small molecules; one of these molecules inhibits the TIR-TIR domain interaction and attenuates pro-inflammatory cytokine production in human primary cell cultures. Compounds chemically similar to this hit from the PubChem database were observed to be more potent with improved drug-like properties. Most of these 2nd generation compounds inhibit Staphylococcal enterotoxin B (SEB)-induced TNF-α, IFN-γ, IL-6, and IL-1β production at 2–10 μM in human primary cells. Biochemical analysis and a cell-based reporter assay revealed that the most promising compound, T6167923, disrupts MyD88 homodimeric formation, which is critical for its signaling function. Furthermore, we observed that administration of a single dose of T6167923 completely protects mice from lethal SEB-induced toxic shock. In summary, our in silico approach has identified anti-inflammatory inhibitors against in vitro and in vivo toxin exposure with promise to treat other MyD88-related pro-inflammatory diseases. PMID:26381092

  7. MyD88-Dependent Silencing of Transgene Expression During the Innate and Adaptive Immune Response to Helper-Dependent Adenovirus

    PubMed Central

    Suzuki, Masataka; Cerullo, Vincenzo; Bertin, Terry K.; Cela, Racel; Clarke, Christian; Guenther, Margaretha; Brunetti-Pierri, Nicola

    2010-01-01

    Abstract Activation of the host innate immune response after systemic administration of adenoviral vectors constitutes a principal impediment to successful clinical gene replacement therapies. Although helper-dependent adenoviruses (HDAds) lack all viral functional genes, systemic administration of a high dose of HDAd still elicits a potent innate immune response in host animals. Toll-like receptors (TLRs) are innate receptors that sense microbial products and trigger the maturation of antigen-presenting cells and cytokine production via MyD88-dependent signaling (except TLR3). Here we show that mice lacking MyD88 exhibit a dramatic reduction in proinflammatory cytokines after intravenous injection of a high dose of HDAd, and show significantly reduced induction of the adaptive immune response when compared with wild-type and TLR2-deficient mice. Importantly, MyD88–/– mice also show significantly higher and longer sustained transgene expression than do wild-type mice. Chromatin immunoprecipitation studies using wild-type and MyD88-deficient primary mouse embryonic fibroblasts showed significant MyD88-dependent transcriptional silencing of the HDAd-encoded transgenes. Our results demonstrate that MyD88 signaling, activated by systemic delivery of HDAd, initiates an innate immune response that suppresses transgene expression at the transcriptional level before initiation of the adaptive immune response. PMID:19824822

  8. Pivotal Role of Toll-Like Receptors 2 and 4, Its Adaptor Molecule MyD88, and Inflammasome Complex in Experimental Tubule-Interstitial Nephritis

    PubMed Central

    Correa-Costa, Matheus; Braga, Tarcio Teodoro; Semedo, Patricia; Hayashida, Caroline Yuri; Bechara, Luiz Roberto Grassmann; Elias, Rosa Maria; Barreto, Claudiene Rodrigues; Silva-Cunha, Claudia; Hyane, Meire Ioshie; Gonçalves, Giselle Martins; Brum, Patricia Chakur; Fujihara, Clarice; Zatz, Roberto; Pacheco-Silva, Alvaro; Zamboni, Dario S.; Camara, Niels Olsen Saraiva

    2011-01-01

    Tubule-interstitial nephritis (TIN) results in decreased renal function and interstitial inflammation, which ultimately leads to fibrosis. Excessive adenine intake can cause TIN because xanthine dehydrogenase (XDH) can convert this purine into an insoluble compound, which precipitates in the tubuli. Innate immune sensors, such as Toll-like receptors (TLR) and inflammasome complex, play a crucial role in the initiation of inflammation. The aim of this study was to evaluate the roles of TLR-2 and -4, Myd88 and inflammasome complex in an experimental model of TIN. Here, we show that wild-type (WT) mice fed adenine-enriched food exhibited significant renal dysfunction and enhanced cellular infiltration accompanied by collagen deposition. They also presented higher gene and protein expression of pro-inflammatory cytokines. In contrast, TLR-2, -4, MyD88, ASC and Caspase-1 KO mice showed renoprotection associated with expression of inflammatory molecules at levels comparable to controls. Furthermore, treatment of WT animals with allopurinol, an XDH inhibitor, led to reduced levels of uric acid, oxidative stress, collagen deposition and a downregulation of the NF-kB signaling pathway. We concluded that MyD88 signaling and inflammasome participate in the development of TIN. Furthermore, inhibition of XDH seems to be a promising way to therapeutically target the developing inflammatory process. PMID:22194975

  9. Two adaptor molecules of MyD88 and TRAF6 in Apostichopus japonicus Toll signaling cascade: molecular cloning and expression analysis.

    PubMed

    Lu, Yali; Li, Chenghua; Zhang, Peng; Shao, Yina; Su, Xiurong; Li, Ye; Li, Taiwu

    2013-12-01

    Myeloid differentiation factor 88 (MyD88) and tumor necrosis factor receptor-associated factor 6 (TRAF6) are two key adaptor molecules in Toll-like receptor signal transduction that triggers downstream cascades involved in innate immunity. Here we reported the isolation and characterization the full-length cDNAs of MyD88 and TRAF6 from sea cucumber Apostichopus japonicus (denoted as AjMyD88 and AjTRAF6, respectively). Both of two factors shared a remarkable high degree of structural conservation with their mammalian and Drosophila orthologs, such as a typical death domain (DD) and a conservative Toll/IL-1R (TIR) domain for the deduced amino acid of AjMyD88, a zinc finger of RING-type, two zinc fingers of TRAF-type, a coiled-coil region, and a MATH domain for that of AjTRAF6. Constitutive expression patterns were also observed in the two genes with different expression levels. AjMyD88 mRNA transcripts were higher expressed in intestine and respiratory trees, and AjTRAF6 were abundant in coelomocytes and tentacle. During Vibrio splendidus challenge experiment, the expression levels of two genes were increased significantly with larger amplitude and longer duration in AjTRAF6. The peak expression levels were detected at 6 h for AjMyD88 with 1.80-fold increase, and at 24 h for AjTRAF6 with 2.73-fold increase compared with that in the control group. All these results suggested that AjMyD88 and AjTRAF6 might be involved into immune response toward V. splendidus challenge. PMID:23886491

  10. MyD88 Shapes Vaccine Immunity by Extrinsically Regulating Survival of CD4+ T Cells during the Contraction Phase

    PubMed Central

    Wang, Huafeng; Hung, Chiung Yu; Sinha, Meenal; Lee, Linda M.; Wiesner, Darin L.; LeBert, Vanessa; Lerksuthirat, Tassanee; Suresh, Marulasiddappa; DeFranco, Anthony L.; Lowell, Clifford A.; Klein, Bruce S.; Wüthrich, Marcel

    2016-01-01

    Soaring rates of systemic fungal infections worldwide underscore the need for vaccine prevention. An understanding of the elements that promote vaccine immunity is essential. We previously reported that Th17 cells are required for vaccine immunity to the systemic dimorphic fungi of North America, and that Card9 and MyD88 signaling are required for the development of protective Th17 cells. Herein, we investigated where, when and how MyD88 regulates T cell development. We uncovered a novel mechanism in which MyD88 extrinsically regulates the survival of activated T cells during the contraction phase and in the absence of inflammation, but is dispensable for the expansion and differentiation of the cells. The poor survival of activated T cells in Myd88-/- mice is linked to increased caspase3-mediated apoptosis, but not to Fas- or Bim-dependent apoptotic pathways, nor to reduced expression of the anti-apoptotic molecules Bcl-2 or Bcl-xL. Moreover, TLR3, 7, and/or 9, but not TLR2 or 4, also were required extrinsically for MyD88-dependent Th17 cell responses and vaccine immunity. Similar MyD88 requirements governed the survival of virus primed T cells. Our data identify unappreciated new requirements for eliciting adaptive immunity and have implications for designing vaccines. PMID:27542117

  11. Characterization, genomic organization, and expression profiles of MyD88, a key adaptor molecule in the TLR signaling pathways in miiuy croaker (Miichthys miiuy).

    PubMed

    Tang, Da; Gao, Yunhang; Wang, Rixin; Sun, Yuena; Xu, Tianjun

    2012-12-01

    Myeloid differentiation factor 88 (MyD88) is an important adaptor protein in the TLR signaling pathways. In the present study, we firstly cloned and characterized Miichthys miiuy MyD88 (Mimi-MyD88) cDNA and gene. The Mimi-MyD88 gene was 3,470 bp consisting of five exons and four introns. The cDNA was composed of 1,627 bp with an 867-bp open reading frame encoding a polypeptide of 288 amino acid residues. The theoretical molecular mass and isoelectric point of this polypeptide were 33.25 and 4.96 kDa. Comparison of the deduced amino acid sequence showed that the conserved death domain and the typical Toll/IL-1 receptor domain are very similar to those presented in other mammals, amphibians, and fishes. To identify potential role of MyD88 in fish innate immunological surveillance, the constitutive Mimi-MyD88 mRNA is detected by real-time quantitative polymerase chain reaction. Results demonstrated that Mimi-MyD88 is broadly expressed in ten normal tissues, with the lowest expression was observed in kidney and the highest was in liver. The transcriptional expression also revealed that Mimi-MyD88 was significantly up-regulated in liver, kidney, and spleen after challenge by Gram-negative bacteria, Vibrio anguillarum. Via contrasted the expression of MyD88 and TLR2 in kidney, we evaluated TLR2 plays an indispensable role in MyD88 transcription, but not absolutely dominant. The combined expression still indicated that MyD88 plays a universal role in keeping immune surveillance for pathogens. Phylogenetic analysis suggested that Mimi-MyD88 gene is classified into the piscine cluster and most closely related to large yellow croaker Larimichthys crocea. PMID:23053604

  12. Regulatory T cell expressed MyD88 is critical for prolongation of allograft survival.

    PubMed

    Borges, Christopher M; Reichenbach, Dawn K; Kim, Beom Seok; Misra, Aditya; Blazar, Bruce R; Turka, Laurence A

    2016-08-01

    MyD88 signaling directly promotes T-cell survival and is required for optimal T-cell responses to pathogens. To examine the role of T-cell-intrinsic MyD88 signals in transplantation, we studied mice with targeted T-cell-specific MyD88 deletion. Contrary to expectations, we found that these mice were relatively resistant to prolongation of graft survival with anti-CD154 plus rapamycin in a class II-mismatched system. To specifically examine the role of MyD88 in Tregs, we created a Treg-specific MyD88-deficient mouse. Transplant studies in these animals replicated the findings observed with a global T-cell MyD88 knockout. Surprisingly, given the role of MyD88 in conventional T-cell survival, we found no defect in the survival of MyD88-deficient Tregs in vitro or in the transplant recipients and also observed intact cell homing and expression of Treg effector molecules. MyD88-deficient Tregs also fail to protect allogeneic bone marrow transplant recipients from chronic graft-versus-host disease, confirming the observations of defective regulation seen in a solid organ transplant system. Together, our data define MyD88 as having a divergent requirement for cell survival in non-Tregs and Tregs, and a yet-to-be defined survival-independent requirement for Treg function during the response to alloantigen. PMID:27112509

  13. Fas (CD95) Induces Macrophage Pro-Inflammatory Chemokine Production via a MyD88-dependent, Caspase-independent Pathway

    PubMed Central

    Altemeier, William A.; Zhu, Xiaodong; Berrington, William R.; Harlan, John M.; Liles, W. Conrad

    2015-01-01

    Activation of the prototypical death receptor, Fas (CD95), can induce both caspase-dependent cell death and production of pro-inflammatory chemokines, leading to neutrophil recruitment and end-organ injury. The precise mechanism(s), by which Fas upregulates chemokine production and release, is currently unclear. We hypothesized that Fas-induced chemokine release by macrophages is dependent on the MyD88 adapter molecule and independent of caspase activity. To test this hypothesis, we measured chemokine response to Fas activation both in RAW 264.7 cells with RNAi-attenuated MyD88 expression and in MyD88-deficient primary macrophages. We found that Fas-induced chemokine release was abrogated in the absence of MyD88. In vivo, MyD88−/− mice had impaired CXCL1/KC release and polymorphonuclear cell recruitment in response to intratracheal treatment with the Fas-activating monoclonal antibody, Jo-2. Furthermore, Fas-induced chemokine release was not dependent on either IL-1 receptor signaling or on caspase activity. We conclude that MyD88 plays an integral role in Fas-induced macrophage-mediated inflammation. PMID:17576821

  14. Mycobacterial Phosphatidylinositol Mannosides Negatively Regulate Host Toll-like Receptor 4, MyD88-dependent Proinflammatory Cytokines, and TRIF-dependent Co-stimulatory Molecule Expression*

    PubMed Central

    Doz, Emilie; Rose, Stéphanie; Court, Nathalie; Front, Sophie; Vasseur, Virginie; Charron, Sabine; Gilleron, Martine; Puzo, Germain; Fremaux, Isabelle; Delneste, Yves; Erard, François; Ryffel, Bernhard; Martin, Olivier R.; Quesniaux, Valerie F. J.

    2009-01-01

    Mycobacterium tuberculosis modulates host immune responses through proteins and complex glycolipids. Here, we report that the glycosylphosphatidylinositol anchor phosphatidyl-myo-inositol hexamannosides PIM6 or PIM2 exert potent anti-inflammatory activities. PIM strongly inhibited the Toll-like receptor (TLR4) and myeloid differentiation protein 88 (MyD88)-mediated release of NO, cytokines, and chemokines, including tumor necrosis factor (TNF), interleukin 12 (IL-12) p40, IL-6, keratinocyte-derived chemokine, and also IL-10 by lipopolysaccharide (LPS)-activated macrophages. This effect was independent of the presence of TLR2. PIM also reduced the LPS-induced MyD88-independent, TIR domain-containing adaptor protein inducing interferon β (TRIF)-mediated expression of co-stimulatory receptors. PIM inhibited LPS/TLR4-induced NFκB translocation. Synthetic PIM1 and a PIM2 mimetic recapitulated these in vitro activities and inhibited endotoxin-induced airway inflammation, TNF and keratinocyte-derived chemokine secretion, and neutrophil recruitment in vivo. Mannosyl, two acyl chains, and phosphatidyl residues are essential for PIM anti-inflammatory activity, whereas the inosityl moiety is dispensable. Therefore, PIM exert potent antiinflammatory effects both in vitro and in vivo that may contribute to the strategy developed by mycobacteria for repressing the host innate immunity, and synthetic PIM analogs represent powerful anti-inflammatory leads. PMID:19561082

  15. Pyogenic Bacterial Infections in Humans with MyD88 Deficiency

    PubMed Central

    von Bernuth, Horst; Picard, Capucine; Jin, Zhongbo; Pankla, Rungnapa; Xiao, Hui; Ku, Cheng-Lung; Chrabieh, Maya; Mustapha, Imen Ben; Ghandil, Pegah; Camcioglu, Yildiz; Vasconcelos, Júlia; Sirvent, Nicolas; Guedes, Margarida; Vitor, Artur Bonito; Herrero-Mata, María José; Aróstegui, Juan Ignacio; Rodrigo, Carlos; Alsina, Laia; Ruiz-Ortiz, Estibaliz; Juan, Manel; Fortuny, Claudia; Yagüe, Jordi; Antón, Jordi; Pascal, Mariona; Chang, Huey-Hsuan; Janniere, Lucile; Rose, Yoann; Garty, Ben-Zion; Chapel, Helen; Issekutz, Andrew; Maródi, László; Rodriguez-Gallego, Carlos; Banchereau, Jacques; Abel, Laurent; Li, Xiaoxia; Chaussabel, Damien; Puel, Anne; Casanova1, Jean-Laurent

    2009-01-01

    MyD88 is a key downstream adapter for most Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs). MyD88 deficiency in mice leads to susceptibility to a broad range of pathogens in experimental settings of infection. We describe a distinct situation in a natural setting of human infection. Nine children with autosomal recessive MyD88 deficiency suffered from life-threatening, often recurrent pyogenic bacterial infections, including invasive pneumococcal disease. However, these patients were otherwise healthy, with normal resistance to other microbes. Their clinical status improved with age, but not due to any cellular leakiness in MyD88 deficiency. The MyD88-dependent TLRs and IL-1Rs are therefore essential for protective immunity to a small number of pyogenic bacteria, but redundant for host defense to most natural infections. PMID:18669862

  16. MyD88 expression in the rat dental follicle: Implications for osteoclastogenesis and tooth eruption

    PubMed Central

    Liu, Dawen; Yao, Shaomian; Wise, Gary E.

    2010-01-01

    Myeloid differentiation factor 88 (MyD88) is a key adaptor molecule in the interleukin-1 (IL-1) and IL-18 Toll-like receptor signaling pathway. Because it is present in dental follicle (DF) cells in vitro, the purpose of this study was to determine its chronological expression in vivo, as well as its possible role in osteoclastogenesis and tooth eruption. An oligo DNA microarray was used to determine gene expression of MyD88 in vivo in the DFs from the first mandibular molars of postnatal rats from days 1–11. The results showed that MyD88 was expressed maximally at day 3. Using siRNA to knock down MyD88 expression in the DF cells also reduced the gene expression of nuclear factor-kappa B-1 (NFKB1) and monocyte chemoattractant protein 1 (MCP-1). IL-1α up-regulated the expression of NFKB1, MCP-1 and receptor activator of nuclear factor kappa B ligand (RANKL), but knockdown of MyD88 nullified this IL-1α effect. Conditioned medium from DF cells with MyD88 knocked down reduced chemotactic activity for mononuclear cells and reduced osteoclastogenesis as opposed to controls. In conclusion, the maximal expression of MyD88 at day 3 in the DF may contribute to the major burst of osteoclastogenesis needed for eruption by up-regulating MCP-1 and RANKL expression. PMID:20662905

  17. Opposing roles of RAGE and Myd88 signaling in extensive liver resection

    PubMed Central

    Zeng, Shan; Zhang, Qing Yin; Huang, Jianzhong; Vedantham, Srinivasan; Rosario, Rosa; Ananthakrishnan, Radha; Yan, Shi Fang; Ramasamy, Ravichandran; DeMatteo, Ronald P.; Emond, Jean C.; Friedman, Richard A.; Schmidt, Ann Marie

    2012-01-01

    In extensive liver resection secondary to primary or metastatic liver tumors, or in living donor liver transplantation, strategies to quell deleterious inflammatory responses and facilitate regeneration are essential. The receptor for advanced glycation endproducts (RAGE) and myeloid differentiating factor 88 (Myd88) are implicated in the inflammatory response. To establish the contributions of RAGE vs. Myd88 signaling in extensive liver resection, we probed the effect of RAGE and/or Myd88, the latter primarily a key transducer of major toll-like receptors and also implicated in interleukin-1 (Il1) signaling, in a murine model of extensive (85%) hepatectomy. We report that, although Myd88 is thoroughly essential for survival via regulation of NF-κB and TNF-α, deletion of RAGE significantly improved survival compared to wild-type, Myd88-null, or RAGE-null/Myd88-null mice. RAGE opposes Myd88 signaling at multiple levels: by suppression of p65 levels, thereby reducing activation of NF-κB and consequent production of cyclin D1, and by suppression of Il6-mediated phosphorylation of Stat3, thereby down-regulating Pim1 and suppressing the hyperplastic response. Further, RAGE-dependent suppression of glyoxalase1, a detoxification pathway for pre-AGEs, enhances AGE levels and suppresses Il6 action. We conclude that blockade of RAGE may rescue liver remnants from the multiple signals that preclude adaptive proliferation triggered primarily by Myd88 signaling pathways.—Zeng, S., Zhang, Q. Y., Huang, J., Vedantham, S., Rosario, R., Ananthakrishnan, R., Yan, S. F., Ramasamy, R., DeMatteo, R. P., Emond, J. C., Friedman, R. A., Schmidt, A. M. Opposing roles of RAGE and Myd88 signaling in extensive liver resection. PMID:22075646

  18. MyD88 Deficiency Ameliorates β-Amyloidosis in an Animal Model of Alzheimer's Disease

    PubMed Central

    Lim, Jeong-Eun; Kou, Jinghong; Song, Min; Pattanayak, Abhinandan; Jin, Jingji; Lalonde, Robert; Fukuchi, Ken-ichiro

    2011-01-01

    The accumulation of β-amyloid protein (Aβ) in the brain is thought to be a primary etiologic event in Alzheimer's disease (AD). Fibrillar Aβ plaques, a hallmark of AD abnormality, are closely associated with activated microglia. Activated microglia have contradictory roles in the pathogenesis of AD, being either neuroprotective (by clearing harmful Aβ and repairing damaged tissues) or neurotoxic (by producing proinflammatory cytokines and reactive oxygen species). Aβ aggregates can activate microglia by interacting with multiple toll-like receptors (TLRs), the pattern-recognition receptors of the innate immune system. Because the adapter protein MyD88 is essential for the downstream signaling of all TLRs, except TLR3, we investigated the effects of MyD88 deficiency (MyD88−/−) on Aβ accumulation and microglial activation in an AD mouse model. MyD88 deficiency decreased Aβ load and microglial activation in the brain. The decrease in Aβ load in an MyD88−/− AD mouse model was associated with increased and decreased protein expression of apolipoprotein E (apoE) and CX3CR1, respectively, compared with that in an MyD88 wild-type AD mouse model. These results suggest that MyD88 deficiency may reduce Aβ load by enhancing the phagocytic capability of microglia through fractalkine (the ligand of CX3CR1) signaling and by promoting apoE-mediated clearance of Aβ from the brain. These findings also suggest that chronic inflammatory responses induced by Aβ accumulation via the MyD88–dependent signaling pathway exacerbate β-amyloidosis in AD. PMID:21763676

  19. Intrinsic MyD88-Akt1-mTOR Signaling Coordinates Disparate Tc17 and Tc1 Responses during Vaccine Immunity against Fungal Pneumonia

    PubMed Central

    Nanjappa, Som Gowda; Hernández-Santos, Nydiaris; Galles, Kevin; Wüthrich, Marcel; Suresh, M.; Klein, Bruce S.

    2015-01-01

    Fungal infections have skyrocketed in immune-compromised patients lacking CD4+ T cells, underscoring the need for vaccine prevention. An understanding of the elements that promote vaccine immunity in this setting is essential. We previously demonstrated that vaccine-induced IL-17A+ CD8+ T cells (Tc17) are required for resistance against lethal fungal pneumonia in CD4+ T cell-deficient hosts, whereas the individual type I cytokines IFN-γ, TNF-α and GM-CSF, are dispensable. Here, we report that T cell-intrinsic MyD88 signals are crucial for these Tc17 cell responses and vaccine immunity against lethal fungal pneumonia in mice. In contrast, IFN-γ+ CD8+ cell (Tc1) responses are largely normal in the absence of intrinsic MyD88 signaling in CD8+ T cells. The poor accumulation of MyD88-deficient Tc17 cells was not linked to an early onset of contraction, nor to accelerated cell death or diminished expression of anti-apoptotic molecules Bcl-2 or Bcl-xL. Instead, intrinsic MyD88 was required to sustain the proliferation of Tc17 cells through the activation of mTOR via Akt1. Moreover, intrinsic IL-1R and TLR2, but not IL-18R, were required for MyD88 dependent Tc17 responses. Our data identify unappreciated targets for augmenting adaptive immunity against fungi. Our findings have implications for designing fungal vaccines and immune-based therapies in immune-compromised patients. PMID:26367276

  20. Intrinsic MyD88-Akt1-mTOR Signaling Coordinates Disparate Tc17 and Tc1 Responses during Vaccine Immunity against Fungal Pneumonia.

    PubMed

    Nanjappa, Som Gowda; Hernández-Santos, Nydiaris; Galles, Kevin; Wüthrich, Marcel; Suresh, M; Klein, Bruce S

    2015-09-01

    Fungal infections have skyrocketed in immune-compromised patients lacking CD4+ T cells, underscoring the need for vaccine prevention. An understanding of the elements that promote vaccine immunity in this setting is essential. We previously demonstrated that vaccine-induced IL-17A+ CD8+ T cells (Tc17) are required for resistance against lethal fungal pneumonia in CD4+ T cell-deficient hosts, whereas the individual type I cytokines IFN-γ, TNF-α and GM-CSF, are dispensable. Here, we report that T cell-intrinsic MyD88 signals are crucial for these Tc17 cell responses and vaccine immunity against lethal fungal pneumonia in mice. In contrast, IFN-γ+ CD8+ cell (Tc1) responses are largely normal in the absence of intrinsic MyD88 signaling in CD8+ T cells. The poor accumulation of MyD88-deficient Tc17 cells was not linked to an early onset of contraction, nor to accelerated cell death or diminished expression of anti-apoptotic molecules Bcl-2 or Bcl-xL. Instead, intrinsic MyD88 was required to sustain the proliferation of Tc17 cells through the activation of mTOR via Akt1. Moreover, intrinsic IL-1R and TLR2, but not IL-18R, were required for MyD88 dependent Tc17 responses. Our data identify unappreciated targets for augmenting adaptive immunity against fungi. Our findings have implications for designing fungal vaccines and immune-based therapies in immune-compromised patients. PMID:26367276

  1. Immunogenicity and efficacy of a plasmid DNA rabies vaccine incorporating Myd88 as a genetic adjuvant

    PubMed Central

    Ullas, Padinjaremattathil Thankappan; Desai, Anita

    2014-01-01

    Purpose Myeloid differentiation factor 88 (Myd88), a ubiquitous Toll-like receptor adaptor molecule, has been reported to play important roles in B cell responses to infections and vaccination. The present study evaluated the effects of genetic adjuvanting with Myd88 on the immune responses to a plasmid DNA rabies vaccine. Materials and Methods Plasmids encoding rabies glycoprotein alone (pIRES-Rgp) or a fragment of Myd88 gene in addition (pIRES-Rgp-Myd) were constructed and administered intramuscularly or intrademally in Swiss albino mice (on days 0, 7, and 21). Rabies virus neutralizing antibody (RVNA) titres were estimated in the mice sera on days 14 and 28 by rapid fluorescent focus inhibition test. The protective efficacy of the constructs was evaluated by an intracerebral challenge with challenge virus standard virus on day 35. Results Co-expression of Myd88 increased RVNA responses to pIRES-Rgp by 3- and 2-folds, following intramuscular and intradermal immunization, respectively. pIRES-Rgp protected 80% of the mice following intramuscular and intradermal immunizations, while pIRES-Rgp-Myd afforded 100% protection following similar administrations. Conclusion Genetic adjuvanting with Myd88 enhanced the RVNA responses and protective efficacy of a plasmid DNA rabies vaccine. This strategy might be useful for rabies vaccination of canines in the field, and needs further evaluation. PMID:25003094

  2. Ultraviolet radiation signaling through TLR4/MyD88 constrains DNA repair and plays a role in cutaneous immunosuppression.

    PubMed

    Harberts, Erin; Zhou, Hua; Fishelevich, Rita; Liu, Juan; Gaspari, Anthony A

    2015-04-01

    UV radiation (UVR) induces DNA damage, leading to the accumulation of mutations in epidermal keratinocytes and immunosuppression, which contribute to the development of nonmelanoma skin cancer. We reported previously that the TLR4-MyD88 signaling axis is necessary for UV-induced apoptosis. In the dinitrofluorobenzene contact hypersensitivity model, UV-irradiated MyD88-deficient (MyD88(-/-)) C57BL/6 mice had intact ear swelling, exaggerated inflammation, and higher levels of dinitrofluorobenzene-specific IgG2a compared with wild-type (WT) mice. Even with normal UV-induced, dendritic cell migration, DNA damage in the local lymph nodes was less pronounced in MyD88(-/-) mice compared with WT mice. Cultured, UV-irradiated WT APCs showed cleavage (inactivation) of the DNA damage-recognition molecule PARP, whereas PARP persisted in MyD88(-/-) and TLR4(-/-) APCs. Epidermal DNA from in vivo UV-irradiated MyD88(-/-) mice had an increased resolution rate of cyclobutane pyrimidine dimers. Both in vitro treatment of MyD88(-/-) APCs with and intradermal in vivo injections of PARP inhibitor, PJ-34, caused WT-level cyclobutane pyrimidine dimer repair. Lymphoblasts deficient in DNA repair (derived from a xeroderma pigmentosum group A patient) failed to augment DNA repair after MyD88 knockdown after UVR, in contrast to lymphoblasts from a healthy control. These data suggest that interference with the TLR4/MyD88 pathway may be a useful tool in promoting DNA repair and maintaining immune responses following UVR-induced damage. PMID:25716994

  3. Deubiquitinase CYLD acts as a negative regulator for bacterium NTHi-induced inflammation by suppressing K63-linked ubiquitination of MyD88

    PubMed Central

    Lee, Byung-Cheol; Miyata, Masanori; Lim, Jae Hyang; Li, Jian-Dong

    2016-01-01

    Myeloid differentiation factor 88 (MyD88) acts as a crucial adaptor molecule for Toll-like receptors (TLRs) and interleukin (IL)-1 receptor signaling. In contrast to the well-studied positive regulation of MyD88 signaling, how MyD88 signaling is negatively regulated still remains largely unknown. Here, we demonstrate for the first time to our knowledge that MyD88 protein undergoes lysine 63 (K63)-linked polyubiquitination, which is functionally critical for mediating TLR–MyD88-dependent signaling. Deubiquitinase CYLD negatively regulates MyD88-mediated signaling by directly interacting with MyD88 and deubiquitinating nontypeable Haemophilus influenzae (NTHi)-induced K63-linked polyubiquitination of MyD88 at lysine 231. Importantly, we further confirmed this finding in the lungs of mice in vivo by using MyD88−/−CYLD−/− mice. Understanding how CYLD deubiquitinates K63-linked polyubiquitination of MyD88 may not only bring insights into the negative regulation of TLR–MyD88-dependent signaling, but may also lead to the development of a previously unidentified therapeutic strategy for uncontrolled inflammation. PMID:26719415

  4. Functional analysis of a zebrafish myd88 mutant identifies key transcriptional components of the innate immune system.

    PubMed

    van der Vaart, Michiel; van Soest, Joost J; Spaink, Herman P; Meijer, Annemarie H

    2013-05-01

    Toll-like receptors (TLRs) are an important class of pattern recognition receptors (PRRs) that recognize microbial and danger signals. Their downstream signaling upon ligand binding is vital for initiation of the innate immune response. In human and mammalian models, myeloid differentiation factor 88 (MYD88) is known for its central role as an adaptor molecule in interleukin 1 receptor (IL-1R) and TLR signaling. The zebrafish is increasingly used as a complementary model system for disease research and drug screening. Here, we describe a zebrafish line with a truncated version of MyD88 as the first zebrafish mutant for a TLR signaling component. We show that this immune-compromised mutant has a lower survival rate under standard rearing conditions and is more susceptible to challenge with the acute bacterial pathogens Edwardsiella tarda and Salmonella typhimurium. Microarray and quantitative PCR analysis revealed that expression of genes for transcription factors central to innate immunity (including NF-ĸB and AP-1) and the pro-inflammatory cytokine Il1b, is dependent on MyD88 signaling during these bacterial infections. Nevertheless, expression of immune genes independent of MyD88 in the myd88 mutant line was sufficient to limit growth of an attenuated S. typhimurium strain. In the case of infection with the chronic bacterial pathogen Mycobacterium marinum, we show that MyD88 signaling has an important protective role during early pathogenesis. During mycobacterial infection, the myd88 mutant shows accelerated formation of granuloma-like aggregates and increased bacterial burden, with associated lower induction of genes central to innate immunity. This zebrafish myd88 mutant will be a valuable tool for further study of the role of IL1R and TLR signaling in the innate immunity processes underlying infectious diseases, inflammatory disorders and cancer. PMID:23471913

  5. MyD88 Polymorphisms and Association with Susceptibility to Salmonella Pullorum

    PubMed Central

    Liu, Xian-Qing; Wang, Fei; Jin, Jie; Zhou, Yu-Guang; Ran, Jin-Shan; Feng, Ze-Qing; Wang, Yan; Liu, Yi-Ping

    2015-01-01

    Myeloid differentiation primary response gene 88 (MYD88), a universal adapter protein, plays an important role in activating the nuclear factor-κB (NF-κB) and regulating the expression of proinflammatory genes like tumor necrosis factor (TNF) and interleukin-1 (IL-1), which were highly involved in Salmonella Pullorum infection. To detect the relationship between polymorphisms of the MyD88 gene and Salmonella Pullorum disease, we screened the coding region (CDS) of the MYD88 gene by DNA pool construction and sequencing based on case-control study. Eight single nucleotide polymorphisms (SNPs) in the sequenced fragment (5 exons), 7 known loci and one novel mutation named G4810372T (SNP8), were found in the fifth exon. In addition, we found 7 nonsynonymous substitutions. The allele frequency of only one SNP, g.4810191C > T (SNP1), was significantly different (P < 0.05) between case and control groups. The genotype frequencies of SNP1 (g.4810191C > T) and SNP3 (g.4810257G > T) were of significant difference between the case and the control groups (P < 0.05). Collectively, SNPs of the MyD88 gene were significantly associated with susceptibility to Salmonella Pullorum infection, which can be used as a disease-resistant marker in chicken. These results provided a theoretical basis for future research on chicken breeding by marker-assisted selection. PMID:26881204

  6. Sepsis Induces Hematopoietic Stem Cell Exhaustion and Myelosuppression through Distinct Contributions of TRIF and MYD88.

    PubMed

    Zhang, Huajia; Rodriguez, Sonia; Wang, Lin; Wang, Soujuan; Serezani, Henrique; Kapur, Reuben; Cardoso, Angelo A; Carlesso, Nadia

    2016-06-14

    Toll-like receptor 4 (TLR4) plays a central role in host responses to bacterial infection, but the precise mechanism(s) by which its downstream signaling components coordinate the bone marrow response to sepsis is poorly understood. Using mice deficient in TLR4 downstream adapters MYD88 or TRIF, we demonstrate that both cell-autonomous and non-cell-autonomous MYD88 activation are major causes of myelosuppression during sepsis, while having a modest impact on hematopoietic stem cell (HSC) functions. In contrast, cell-intrinsic TRIF activation severely compromises HSC self-renewal without directly affecting myeloid cells. Lipopolysaccharide-induced activation of MYD88 or TRIF contributes to cell-cycle activation of HSC and induces rapid and permanent changes in transcriptional programs, as indicated by persistent downregulation of Spi1 and CebpA expression after transplantation. Thus, distinct mechanisms downstream of TLR4 signaling mediate myelosuppression and HSC exhaustion during sepsis through unique effects of MyD88 and TRIF. PMID:27264973

  7. Genetics Home Reference: MyD88 deficiency

    MedlinePlus

    ... and pus production (abscesses) on internal organs. In addition, affected individuals can have localized infections of the ears, nose, or throat. Although fever is a common reaction to bacterial infections, many people with MyD88 deficiency ...

  8. Reduced photoreceptor death and improved retinal function during retinal degeneration in mice lacking innate immunity adaptor protein MyD88

    PubMed Central

    Syeda, Sarah; Patel, Amit K.; Lee, Tinthu; Hackam, Abigail S.

    2015-01-01

    The injury inflammatory response mediated by the innate immune system is an important contributor to neurodegeneration in the central nervous system (CNS) and retina. A major branch of the innate immune system is regulated by the Toll-like receptors (TLRs), which are receptors for endogenous damage associated molecules released from injured cells as well as pathogen-derived molecules, and interleukin-1 receptors (IL-1R), which are activated by IL-1α, IL-1β and IL-18 cytokines. TLRs and IL-1R are expressed on immune and non-immune cell types and act as first responders to cell damage, which results in tissue repair, or inflammation and apoptosis. Both TLR and IL-1R require the adaptor protein myeloid differentiation primary response gene 88 (MyD88) for signaling. Although inflammation is implicated in neuronal death in the retina, the role of MyD88-dependent TLR and IL-1R signaling in retinal degeneration is unknown. Therefore, the purpose of this study was to investigate the role of MyD88-mediated signaling in neuronal degeneration in the retinal degeneration 1 (rd1) mouse model, which exhibits a phenotype of rapid photoreceptor death and inflammation. To generate rd1 mice lacking the MyD88 gene, rd1 were bred with MyD88 knockout mice (MyD88-/-) for several generations to produce rd1/MyD88+/+ and rd1/MyD88-/- genotypes. Chemokine mRNA expression levels were analyzed by qRT-PCR, and recruitment of activated microglia was quantified by immunodetection of the IBA-1 protein. Retinal outer nuclear layer cell counts were performed to quantify photoreceptor degeneration, and retinal function was assessed using electroretinograms (ERG). Our results revealed that retinal expression of Ccl2, Ccl4, Ccl7 and Cxcl10 was reduced by 2 to 8-fold in rd1/MyD88-/- mice compared with rd1/MyD88+/+ mice (p<0.05), which coincided with attenuated microglial activation, higher numbers of photoreceptors and higher retina responses to photopic and scotopic stimuli. At later ages, rd1/MyD88

  9. Early MyD88-dependent induction of interleukin-17A expression during Salmonella colitis.

    PubMed

    Keestra, A Marijke; Godinez, Ivan; Xavier, Mariana N; Winter, Maria G; Winter, Sebastian E; Tsolis, Renée M; Bäumler, Andreas J

    2011-08-01

    The development of T helper 17 (T(H)17) cells is a well-established adaptive mechanism for the production of interleukin-17A (IL-17A), a cytokine involved in neutrophil recruitment. However, pathways contributing to mucosal expression of IL-17A during the initial phase of a bacterial infection have received less attention. Here we used the mouse colitis model of Salmonella enterica serotype Typhimurium infection to investigate the contribution of myeloid differentiation primary response protein 88 (MyD88) to inflammation and mucosal IL-17A expression. Expression of IL-23 in the cecal mucosa during S. Typhimurium colitis was dependent on the presence of MyD88. Furthermore, initial expression of IL-17A at 24 h after S. Typhimurium infection was dependent on MyD88 and the receptor for IL-1β. IL-23 and IL-1β synergized in inducing expression of IL-17A in splenic T cells in vitro. In the intestinal mucosa, IL-17A was produced by three distinct T cell populations, including δγ T cells, T(H)17 cells, and CD4(-)CD8(-) T cells. The absence of IL-1β signaling or IL-17 signaling reduced CXC chemokine expression but did not alter the overall severity of pathological lesions in the cecal mucosa. In contrast, cecal pathology and neutrophil recruitment were markedly reduced in Myd88-deficient mice during the initial phases of S. Typhimurium infection. Collectively, these data demonstrate that MyD88-dependent mechanisms, including an initial expression of IL-17A, are important for orchestrating early inflammatory responses during S. Typhimurium colitis. PMID:21576324

  10. Mucus clearance, MyD88-dependent and MyD88-independent immunity modulate lung susceptibility to spontaneous bacterial infection and inflammation

    PubMed Central

    Livraghi-Butrico, Alessandra; Kelly, E. Jane; Klem, Erich R.; Dang, Hong; Wolfgang, Matthew C.; Boucher, Richard C.; Randell, Scott H.; O’Neal, Wanda K.

    2012-01-01

    It has been postulated that mucus stasis is central to the pathogenesis of obstructive lung diseases. In Scnn1b-transgenic (Scnn1b-Tg+) mice, airway-targeted overexpression of the epithelial Na+ channel β subunit causes airway surface dehydration, which results in mucus stasis and inflammation. Bronchoalveolar lavage from neonatal Scnn1b-Tg+ mice, but not wild-type littermates, contained increased mucus, bacteria, and neutrophils, which declined with age. Scnn1b-Tg+ mice lung bacterial flora included environmental and oropharyngeal species, suggesting inhalation and/or aspiration as routes of entry. Genetic deletion of the Toll/Interleukin-1 receptor adapter molecule MyD88 in Scnn1b-Tg+ mice did not modify airway mucus obstruction, but caused defective neutrophil recruitment and increased bacterial infection, which persisted into adulthood. Scnn1b-Tg+ mice derived into germ-free conditions exhibited mucus obstruction similar to conventional Scnn1b-Tg+ mice and sterile inflammation. Collectively, these data suggest that dehydration-induced mucus stasis promotes infection, compounds defects in other immune mechanisms, and alone is sufficient to trigger airway inflammation. PMID:22419116

  11. MyD88 Mediates Instructive Signaling in Dendritic Cells and Protective Inflammatory Response during Rickettsial Infection.

    PubMed

    Bechelli, Jeremy; Smalley, Claire; Zhao, Xuemei; Judy, Barbara; Valdes, Patricia; Walker, David H; Fang, Rong

    2016-04-01

    Spotted fever group rickettsiae cause potentially life-threatening infections throughout the world. Several members of the Toll-like receptor (TLR) family are involved in host response to rickettsiae, and yet the mechanisms by which these TLRs mediate host immunity remain incompletely understood. In the present study, we found that host susceptibility of MyD88(-/-)mice to infection with Rickettsia conorii or Rickettsia australis was significantly greater than in wild-type (WT) mice, in association with severely impaired bacterial clearance in vivo R. australis-infected MyD88(-/-)mice showed significantly lower expression levels of gamma interferon (IFN-γ), interleukin-6 (IL-6), and IL-1β, accompanied by significantly fewer inflammatory infiltrates of macrophages and neutrophils in infected tissues, than WT mice. The serum levels of IFN-γ, IL-12, IL-6, and granulocyte colony-stimulating factor were significantly reduced, while monocyte chemoattractant protein 1, macrophage inflammatory protein 1α, and RANTES were significantly increased in infected MyD88(-/-)mice compared to WT mice. Strikingly, R. australis infection was incapable of promoting increased expression of MHC-II(high)and production of IL-12p40 in MyD88(-/-)bone marrow-derived dendritic cells (BMDCs) compared to WT BMDCs, although costimulatory molecules were upregulated in both types of BMDCs. Furthermore, the secretion levels of IL-1β by Rickettsia-infected BMDCs and in the sera of infected mice were significantly reduced in MyD88(-/-)mice compared to WT controls, suggesting that in vitro and in vivo production of IL-1β is MyD88 dependent. Taken together, our results suggest that MyD88 signaling mediates instructive signals in DCs and secretion of IL-1β and type 1 immune cytokines, which may account for the protective inflammatory response during rickettsial infection. PMID:26755162

  12. Oncogenically active MYD88 mutations in human lymphoma

    PubMed Central

    Ngo, Vu N.; Young, Ryan M.; Schmitz, Roland; Jhavar, Sameer; Xiao, Wenming; Lim, Kian-Huat; Kohlhammer, Holger; Xu, Weihong; Yang, Yandan; Zhao, Hong; Shaffer, Arthur L.; Romesser, Paul; Wright, George; Powell, John; Rosenwald, Andreas; Muller-Hermelink, Hans Konrad; Ott, German; Gascoyne, Randy D.; Connors, Joseph M.; Rimsza, Lisa M.; Campo, Elias; Jaffe, Elaine S.; Delabie, Jan; Smeland, Erlend B.; Fisher, Richard I.; Braziel, Rita M.; Tubbs, Raymond R.; Cook, J. R.; Weisenburger, Denny D.; Chan, Wing C.; Staudt, Louis M.

    2016-01-01

    The activated B-cell-like (ABC) subtype of diffuse large B-cell lymphoma (DLBCL) remains the least curable form of this malignancy despite recent advances in therapy1. Constitutive nuclear factor (NF)-κB and JAK kinase signalling promotes malignant cell survival in these lymphomas, but the genetic basis for this signalling is incompletely understood. Here we describe the dependence of ABC DLBCLs on MYD88, an adaptor protein that mediates toll and interleukin (IL)-1 receptor signalling2,3, and the discovery of highly recurrent oncogenic mutations affecting MYD88 in ABC DLBCL tumours. RNA interference screening revealed that MYD88 and the associated kinases IRAK1 and IRAK4 are essential for ABC DLBCL survival. High-throughput RNA resequencing uncovered MYD88 mutations in ABC DLBCL lines. Notably, 29% of ABC DLBCL tumours harboured the same amino acid substitution, L265P, in the MYD88 Toll/IL-1 receptor (TIR) domain at an evolutionarily invariant residue in its hydrophobic core. This mutation was rare or absent in other DLBCL subtypes and Burkitt’s lymphoma, but was observed in 9% of mucosa-associated lymphoid tissue lymphomas. At a lower frequency, additional mutations were observed in the MYD88 TIR domain, occurring in both the ABC and germinal centre B-cell-like (GCB) DLBCL subtypes. Survival of ABC DLBCL cells bearing the L265P mutation was sustained by the mutant but not the wild-type MYD88 isoform, demonstrating that L265P is a gain-of-function driver mutation. The L265P mutant promoted cell survival by spontaneously assembling a protein complex containing IRAK1 and IRAK4, leading to IRAK4 kinase activity, IRAK1 phosphorylation, NF-κB signalling, JAK kinase activation of STAT3, and secretion of IL-6, IL-10 and interferon-β. Hence, theMYD88 signalling pathway is integral to the pathogenesis of ABC DLBCL, supporting the development of inhibitors of IRAK4 kinase and other components of this pathway for the treatment of tumours bearing oncogenic MYD88 mutations

  13. Compartment-specific and sequential role of MyD88 and CARD9 in chemokine induction and innate defense during respiratory fungal infection.

    PubMed

    Jhingran, Anupam; Kasahara, Shinji; Shepardson, Kelly M; Junecko, Beth A Fallert; Heung, Lena J; Kumasaka, Debra K; Knoblaugh, Sue E; Lin, Xin; Kazmierczak, Barbara I; Reinhart, Todd A; Cramer, Robert A; Hohl, Tobias M

    2015-01-01

    Aspergillus fumigatus forms ubiquitous airborne conidia that humans inhale on a daily basis. Although respiratory fungal infection activates the adaptor proteins CARD9 and MyD88 via C-type lectin, Toll-like, and interleukin-1 family receptor signals, defining the temporal and spatial pattern of MyD88- and CARD9-coupled signals in immune activation and fungal clearance has been difficult to achieve. Herein, we demonstrate that MyD88 and CARD9 act in two discrete phases and in two cellular compartments to direct chemokine- and neutrophil-dependent host defense. The first phase depends on MyD88 signaling because genetic deletion of MyD88 leads to delayed induction of the neutrophil chemokines CXCL1 and CXCL5, delayed neutrophil lung trafficking, and fatal pulmonary damage at the onset of respiratory fungal infection. MyD88 expression in lung epithelial cells restores rapid chemokine induction and neutrophil recruitment via interleukin-1 receptor signaling. Exogenous CXCL1 administration reverses murine mortality in MyD88-deficient mice. The second phase depends predominately on CARD9 signaling because genetic deletion of CARD9 in radiosensitive hematopoietic cells interrupts CXCL1 and CXCL2 production and lung neutrophil recruitment beyond the initial MyD88-dependent phase. Using a CXCL2 reporter mouse, we show that lung-infiltrating neutrophils represent the major cellular source of CXCL2 during CARD9-dependent recruitment. Although neutrophil-intrinsic MyD88 and CARD9 function are dispensable for neutrophil conidial uptake and killing in the lung, global deletion of both adaptor proteins triggers rapidly progressive invasive disease when mice are challenged with an inoculum that is sub-lethal for single adapter protein knockout mice. Our findings demonstrate that distinct signal transduction pathways in the respiratory epithelium and hematopoietic compartment partially overlap to ensure optimal chemokine induction, neutrophil recruitment, and fungal clearance within

  14. Compartment-Specific and Sequential Role of MyD88 and CARD9 in Chemokine Induction and Innate Defense during Respiratory Fungal Infection

    PubMed Central

    Jhingran, Anupam; Kasahara, Shinji; Shepardson, Kelly M.; Junecko, Beth A. Fallert; Heung, Lena J.; Kumasaka, Debra K.; Knoblaugh, Sue E.; Lin, Xin; Kazmierczak, Barbara I.; Reinhart, Todd A.; Cramer, Robert A.; Hohl, Tobias M.

    2015-01-01

    Aspergillus fumigatus forms ubiquitous airborne conidia that humans inhale on a daily basis. Although respiratory fungal infection activates the adaptor proteins CARD9 and MyD88 via C-type lectin, Toll-like, and interleukin-1 family receptor signals, defining the temporal and spatial pattern of MyD88- and CARD9-coupled signals in immune activation and fungal clearance has been difficult to achieve. Herein, we demonstrate that MyD88 and CARD9 act in two discrete phases and in two cellular compartments to direct chemokine- and neutrophil-dependent host defense. The first phase depends on MyD88 signaling because genetic deletion of MyD88 leads to delayed induction of the neutrophil chemokines CXCL1 and CXCL5, delayed neutrophil lung trafficking, and fatal pulmonary damage at the onset of respiratory fungal infection. MyD88 expression in lung epithelial cells restores rapid chemokine induction and neutrophil recruitment via interleukin-1 receptor signaling. Exogenous CXCL1 administration reverses murine mortality in MyD88-deficient mice. The second phase depends predominately on CARD9 signaling because genetic deletion of CARD9 in radiosensitive hematopoietic cells interrupts CXCL1 and CXCL2 production and lung neutrophil recruitment beyond the initial MyD88-dependent phase. Using a CXCL2 reporter mouse, we show that lung-infiltrating neutrophils represent the major cellular source of CXCL2 during CARD9-dependent recruitment. Although neutrophil-intrinsic MyD88 and CARD9 function are dispensable for neutrophil conidial uptake and killing in the lung, global deletion of both adaptor proteins triggers rapidly progressive invasive disease when mice are challenged with an inoculum that is sub-lethal for single adapter protein knockout mice. Our findings demonstrate that distinct signal transduction pathways in the respiratory epithelium and hematopoietic compartment partially overlap to ensure optimal chemokine induction, neutrophil recruitment, and fungal clearance within

  15. Dendritic cell specific targeting of MyD88 signalling pathways in vivo.

    PubMed

    Arnold-Schrauf, Catharina; Berod, Luciana; Sparwasser, Tim

    2015-01-01

    Dendritic cells (DCs) are key regulators of both innate and adaptive immunity. During infection, DCs recognise pathogen-associated molecular patterns (PAMPs) via pattern recognition receptors (PRRs) including the Toll-like receptor (TLR) family. TLRs mainly signal via the adaptor protein MyD88. This signalling pathway is required for immune protection during many infections, which are lethal in the absence of MyD88. However, the cell type specific importance of this pathway during both innate and adaptive immune responses against pathogens in vivo remains ill-defined. We discuss recent findings from conditional KO or gain-of-function mouse models targeting TLR/MyD88 signalling pathways in DCs and other myeloid cells during infection. While the general assumption that MyD88-dependent recognition by DCs is essential for inducing protective immunity holds true in some instances, the results surprisingly indicate a much more complex context-dependent requirement for this pathway in DCs and other myeloid or lymphoid cell-types in vivo. Furthermore, we highlight the advantages of Cre-mediated DC targeting approaches and their possible limitations. We also present future perspectives on the development of new genetic mouse models to target distinct DC subsets in vivo. Such models will serve to understand the functional heterogeneity of DCs in vivo. PMID:25403892

  16. Differential induction of the toll-like receptor 4-MyD88-dependent and -independent signaling pathways by endotoxins.

    PubMed

    Zughaier, Susu M; Zimmer, Shanta M; Datta, Anup; Carlson, Russell W; Stephens, David S

    2005-05-01

    The biological response to endotoxin mediated through the Toll-like receptor 4 (TLR4)-MD-2 receptor complex is directly related to lipid A structure or configuration. Endotoxin structure may also influence activation of the MyD88-dependent and -independent signaling pathways of TLR4. To address this possibility, human macrophage-like cell lines (THP-1, U937, and MM6) or murine macrophage RAW 264.7 cells were stimulated with picomolar concentrations of highly purified endotoxins. Harvested supernatants from previously stimulated cells were also used to stimulate RAW 264.7 or 23ScCr (TLR4-deficient) macrophages (i.e., indirect induction). Neisseria meningitidis lipooligosaccharide (LOS) was a potent direct inducer of the MyD88-dependent pathway molecules tumor necrosis factor alpha (TNF-alpha), interleukin-1beta (IL-1beta), monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein 3alpha (MIP-3alpha), and the MyD88-independent molecules beta interferon (IFN-beta), nitric oxide, and IFN-gamma-inducible protein 10 (IP-10). Escherichia coli 55:B5 and Vibrio cholerae lipopolysaccharides (LPSs) at the same pmole/ml lipid A concentrations induced comparable levels of TNF-alpha, IL-1beta, and MIP-3alpha, but significantly less IFN-beta, nitric oxide, and IP-10. In contrast, LPS from Salmonella enterica serovars Minnesota and Typhimurium induced amounts of IFN-beta, nitric oxide, and IP-10 similar to meningococcal LOS but much less TNF-alpha and MIP-3alpha in time course and dose-response experiments. No MyD88-dependent or -independent response to endotoxin was seen in TLR4-deficient cell lines (C3H/HeJ and 23ScCr) and response was restored in TLR4-MD-2-transfected human embryonic kidney 293 cells. Blocking the MyD88-dependent pathway by DNMyD88 resulted in significant reduction of TNF-alpha release but did not influence nitric oxide release. IFN-beta polyclonal antibody and IFN-alpha/beta receptor 1 antibody significantly reduced nitric oxide release. N

  17. Gliadin stimulation of murine macrophage inflammatory gene expression and intestinal permeability are MyD88-dependent: role of the innate immune response in Celiac disease.

    PubMed

    Thomas, Karen E; Sapone, Anna; Fasano, Alessio; Vogel, Stefanie N

    2006-02-15

    Recent studies have demonstrated the importance of TLR signaling in intestinal homeostasis. Celiac disease (CD) is an autoimmune enteropathy triggered in susceptible individuals by the ingestion of gliadin-containing grains. In this study, we sought to test the hypothesis that gliadin initiates this response by stimulating the innate immune response to increase intestinal permeability and by up-regulating macrophage proinflammatory gene expression and cytokine production. To this end, intestinal permeability and the release of zonulin (an endogenous mediator of gut permeability) in vitro, as well as proinflammatory gene expression and cytokine release by primary murine macrophage cultures, were measured. Gliadin and its peptide derivatives, 33-mer and p31-43, were found to be potent inducers of both a zonulin-dependent increase in intestinal permeability and macrophage proinflammatory gene expression and cytokine secretion. Gliadin-induced zonulin release, increased intestinal permeability, and cytokine production were dependent on myeloid differentiation factor 88 (MyD88), a key adapter molecule in the TLR/IL-1R signaling pathways, but were neither TLR2- nor TLR4-dependent. Our data support the following model for the innate immune response to gliadin in the initiation of CD. Gliadin interaction with the intestinal epithelium increases intestinal permeability through the MyD88-dependent release of zonulin that, in turn, enables paracellular translocation of gliadin and its subsequent interaction with macrophages within the intestinal submucosa. There, the interaction of gliadin with macrophages elicits a MyD88-dependent proinflammatory cytokine milieu that facilitates the interaction of T cells with APCs, leading ultimately to the Ag-specific adaptive immune response seen in patients with CD. PMID:16456012

  18. Therapeutic Inhibition of Pro-Inflammatory Signaling and Toxicity to Staphylococcal Enterotoxin B by a Synthetic Dimeric BB-Loop Mimetic of MyD88

    PubMed Central

    Kissner, Teri L.; Ruthel, Gordon; Alam, Shahabuddin; Mann, Enrique; Ajami, Dariush; Rebek, Mitra; Larkin, Eileen; Fernandez, Stefan; Ulrich, Robert G.; Ping, Sun; Waugh, David S.; Rebek, Julius; Saikh, Kamal U.

    2012-01-01

    Staphylococcal enterotoxin B (SEB) exposure triggers an exaggerated pro-inflammatory cytokine response that often leads to toxic shock syndrome (TSS) associated with organ failure and death. MyD88 mediates pro-inflammatory cytokine signaling induced by SEB exposure and MyD88−/− mice are resistant to SEB intoxication, suggesting that MyD88 may be a potential target for therapeutic intervention. We targeted the BB loop region of the Toll/IL-1 receptor (TIR) domain of MyD88 to develop small-molecule therapeutics. Here, we report that a synthetic compound (EM-163), mimic to dimeric form of BB-loop of MyD88 attenuated tumor necrosis factor (TNF)- α, interferon (IFN)-γ, interleukin (IL)-1β, IL-2 and IL-6 production in human primary cells, whether administered pre- or post-SEB exposure. Results from a direct binding assay, and from MyD88 co-transfection/co-immunoprecipitation experiments, suggest that EM-163 inhibits TIR-TIR domain interaction. Additional results indicate that EM-163 prevents MyD88 from mediating downstream signaling. In an NF-kB-driven reporter assay of lipopolysaccharide-stimulated MyD88 signaling, EM-163 demonstrated a dose-dependent inhibition of reporter activity as well as TNF-α and IL-1β production. Importantly, administration of EM-163 pre- or post exposure to a lethal dose of SEB abrogated pro-inflammatory cytokine responses and protected mice from toxic shock-induced death. Taken together, our results suggest that EM-163 exhibits a potential for therapeutic use against SEB intoxication. PMID:22848400

  19. Poly(I:C) Induces Antiviral Immune Responses in Japanese Flounder (Paralichthys olivaceus) That Require TLR3 and MDA5 and Is Negatively Regulated by Myd88

    PubMed Central

    Zhou, Zhi-xia; Zhang, Bao-cun; Sun, Li

    2014-01-01

    Polyinosinic:polycytidylic acid (poly(I:C)) is a ligand of toll-like receptor (TLR) 3 that has been used as an immunostimulant in humans and mice against viral diseases based on its ability to enhance innate and adapt immunity. Antiviral effect of poly(I:C) has also been observed in teleost, however, the underling mechanism is not clear. In this study, we investigated the potential and signaling mechanism of poly(I:C) as an antiviral agent in a model of Japanese flounder (Paralichthys olivaceus) infected with megalocytivirus. We found that poly(I:C) exhibited strong antiviral activity and enhanced activation of head kidney macrophages and peripheral blood leukocytes. In vivo studies showed that (i) TLR3 as well as MDA5 knockdown reduced poly(I:C)-mediated immune response and antiviral activity to significant extents; (ii) when Myd88 was overexpressed in flounder, poly(I:C)-mediated antiviral activity was significantly decreased; (iii) when Myd88 was inactivated, the antiviral effect of poly(I:C) was significantly increased. Cellular study showed that (i) the NF-κB activity induced by poly(I:C) was upregulated in Myd88-overexpressing cells and unaffected in Myd88-inactivated cells; (ii) Myd88 overexpression inhibited and upregulated the expression of poly(I:C)-induced antiviral genes and inflammatory genes respectively; (iii) Myd88 inactivation enhanced the expression of the antiviral genes induced by poly(I:C). Taken together, these results indicate that poly(I:C) is an immunostimulant with antiviral potential, and that the immune response of poly(I:C) requires TLR3 and MDA5 and is negatively regulated by Myd88 in a manner not involving NK-κB. These results provide insights to the working mechanism of poly(I:C), TLR3, and Myd88 in fish. PMID:25393122

  20. MyD88 Deficiency Markedly Worsens Tissue Inflammation and Bacterial Clearance in Mice Infected with Treponema pallidum, the Agent of Syphilis

    PubMed Central

    Silver, Adam C.; Dunne, Dana W.; Zeiss, Caroline J.; Bockenstedt, Linda K.; Radolf, Justin D.; Salazar, Juan C.; Fikrig, Erol

    2013-01-01

    Research on syphilis, a sexually transmitted infection caused by the non-cultivatable spirochete Treponema pallidum, has been hampered by the lack of an inbred animal model. We hypothesized that Toll-like receptor (TLR)-dependent responses are essential for clearance of T. pallidum and, consequently, compared infection in wild-type (WT) mice and animals lacking MyD88, the adaptor molecule required for signaling by most TLRs. MyD88-deficient mice had significantly higher pathogen burdens and more extensive inflammation than control animals. Whereas tissue infiltrates in WT mice consisted of mixed mononuclear and plasma cells, infiltrates in MyD88-deficient animals were predominantly neutrophilic. Although both WT and MyD88-deficient mice produced antibodies that promoted uptake of treponemes by WT macrophages, MyD88-deficient macrophages were deficient in opsonophagocytosis of treponemes. Our results demonstrate that TLR-mediated responses are major contributors to the resistance of mice to syphilitic disease and that MyD88 signaling and FcR-mediated opsonophagocytosis are linked to the macrophage-mediated clearance of treponemes. PMID:23940747

  1. MyD88-dependent IL-1 receptor signaling is essential for gouty inflammation stimulated by monosodium urate crystals

    PubMed Central

    Chen, Chun-Jen; Shi, Yan; Hearn, Arron; Fitzgerald, Kate; Golenbock, Douglas; Reed, George; Akira, Shizuo; Rock, Kenneth L.

    2006-01-01

    While it is known that monosodium urate (MSU) crystals cause the disease gout, the mechanism by which these crystals stimulate this inflammatory condition has not been clear. Here we find that the Toll/IL-1R (TIR) signal transduction adaptor myeloid differentiation primary response protein 88 (MyD88) is required for acute gouty inflammation. In contrast, other TIR adaptor molecules, TIRAP/Mal, TRIF, and TRAM, are not required for this process. The MyD88-dependent TLR1, -2, -4, -6, -7, -9, and -11 and IL-18 receptor (IL-18R) are not essential for MSU-induced inflammation. Moreover, MSU does not stimulate HEK cells expressing TLR1–11 to activate NF-κB. In contrast, mice deficient in the MyD88-dependent IL-1R showed reduced inflammatory responses, similar to those observed in MyD88-deficient mice. Similarly, mice treated with IL-1 neutralizing antibodies also showed reduced MSU-induced inflammation, demonstrating that IL-1 production and IL-1R activation play essential roles in MSU-triggered inflammation. IL-1R deficiency in bone marrow–derived cells did not affect the inflammatory response; however, it was required in non–bone marrow–derived cells. These results indicate that IL-1 is essential for the MSU-induced inflammatory response and that the requirement of MyD88 in this process is primarily through its function as an adaptor molecule in the IL-1R signaling pathway. PMID:16886064

  2. Andrographolide alleviates imiquimod-induced psoriasis in mice via inducing autophagic proteolysis of MyD88.

    PubMed

    Shao, Fenli; Tan, Tao; Tan, Yang; Sun, Yang; Wu, Xingxin; Xu, Qiang

    2016-09-01

    Psoriasis is a chronic inflammatory skin disease with excessive activation of toll-like receptors (TLRs), which play important roles in developing psoriasis. Targeting TLR signaling remains a challenge for treating psoriasis. Here, we found that andrographolide (Andro), a small-molecule natural product, alleviated imiquimod- but not interleukin 23 (IL-23)-induced psoriasis in mice with reducing expressions of IL-23 and IL-1β in the skin. The improvement in imiquimod-induced psoriasis by Andro was not observed in microtubule-associated protein 1 light chain 3 beta (MAP1LC3B) knockout mice. Furthermore, Andro inhibited mRNA expressions of IL-23, IL-6 and IL-1β but not CD80 and CD86 in bone-marrow derived dendritic cells (BMDCs) treated with lipopolysaccharide (LPS) in a MAP1LC3B-dependent manner. In addition, Andro inhibited imiquimod-induced mRNA expressions of IL-23, IL-6, IL-1β, CD80 and CD86 in BMDCs from mice. Interestingly, Andro induced a degradation of myeloid differentiation factor 88 (MyD88) and blocked the recruitment of TNF receptor-associated factor 6 (TRAF6) to MyD88 upon LPS stimulation in BMDCs from mice. Blockade of autophagic proteolysis using NH4Cl or MAP1LC3B(-/-) BMDCs abolished the Andro-induced MyD88 degradation. In conclusion, Andro controls activation of MyD88-dependent cytokines and alleviates psoriasis in mice via inducing autophagic proteolysis of MyD88, which could be a novel strategy to treat psoriasis. PMID:27265145

  3. Early MyD88-Dependent Induction of Interleukin-17A Expression during Salmonella Colitis ▿ †

    PubMed Central

    Keestra, A. Marijke; Godinez, Ivan; Xavier, Mariana N.; Winter, Maria G.; Winter, Sebastian E.; Tsolis, Renée M.; Bäumler, Andreas J.

    2011-01-01

    The development of T helper 17 (TH17) cells is a well-established adaptive mechanism for the production of interleukin-17A (IL-17A), a cytokine involved in neutrophil recruitment. However, pathways contributing to mucosal expression of IL-17A during the initial phase of a bacterial infection have received less attention. Here we used the mouse colitis model of Salmonella enterica serotype Typhimurium infection to investigate the contribution of myeloid differentiation primary response protein 88 (MyD88) to inflammation and mucosal IL-17A expression. Expression of IL-23 in the cecal mucosa during S. Typhimurium colitis was dependent on the presence of MyD88. Furthermore, initial expression of IL-17A at 24 h after S. Typhimurium infection was dependent on MyD88 and the receptor for IL-1β. IL-23 and IL-1β synergized in inducing expression of IL-17A in splenic T cells in vitro. In the intestinal mucosa, IL-17A was produced by three distinct T cell populations, including δγ T cells, TH17 cells, and CD4−CD8− T cells. The absence of IL-1β signaling or IL-17 signaling reduced CXC chemokine expression but did not alter the overall severity of pathological lesions in the cecal mucosa. In contrast, cecal pathology and neutrophil recruitment were markedly reduced in Myd88-deficient mice during the initial phases of S. Typhimurium infection. Collectively, these data demonstrate that MyD88-dependent mechanisms, including an initial expression of IL-17A, are important for orchestrating early inflammatory responses during S. Typhimurium colitis. PMID:21576324

  4. HCK is a survival determinant transactivated by mutated MYD88, and a direct target of ibrutinib.

    PubMed

    Yang, Guang; Buhrlage, Sara J; Tan, Li; Liu, Xia; Chen, Jie; Xu, Lian; Tsakmaklis, Nicholas; Chen, Jiaji G; Patterson, Christopher J; Brown, Jennifer R; Castillo, Jorge J; Zhang, Wei; Zhang, Xiaofeng; Liu, Shuai; Cohen, Philip; Hunter, Zachary R; Gray, Nathanael; Treon, Steven P

    2016-06-23

    Activating mutations in MYD88 are present in ∼95% of patients with Waldenström macroglobulinemia (WM), as well as other B-cell malignancies including activated B-cell (ABC) diffuse large B-cell lymphoma (DLBCL). In WM, mutated MYD88 triggers activation of Bruton tyrosine kinase (BTK). Ibrutinib, a pleiotropic kinase inhibitor that targets BTK, is highly active in patients with mutated MYD88. We observed that mutated MYD88 WM and ABC DLBCL cell lines, as well as primary WM cells show enhanced hematopoietic cell kinase (HCK) transcription and activation, and that HCK is activated by interleukin 6 (IL-6). Over-expression of mutated MYD88 triggers HCK and IL-6 transcription, whereas knockdown of HCK reduced survival and attenuated BTK, phosphoinositide 3-kinase/AKT, and mitogen-activated protein kinase/extracellular signal-regulated kinase signaling in mutated MYD88 WM and/or ABC DLBCL cells. Ibrutinib and the more potent HCK inhibitor A419259, blocked HCK activation and induced apoptosis in mutated MYD88 WM and ABC DLBCL cells. Docking and pull-down studies confirmed that HCK was a target of ibrutinib. Ibrutinib and A419259 also blocked adenosine triphosphate binding to HCK, whereas transduction of mutated MYD88 expressing WM cells with a mutated HCK gatekeeper greatly increased the half maximal effective concentration for ibrutinib and A419259. The findings support that HCK expression and activation is triggered by mutated MYD88, supports the growth and survival of mutated MYD88 WM and ABC DLBCL cells, and is a direct target of ibrutinib. HCK represents a novel target for therapeutic development in MYD88-mutated WM and ABC DLBCL, and possibly other diseases driven by mutated MYD88. PMID:27143257

  5. Identification of MyD88 as a novel target of miR-155, involved in negative regulation of Helicobacter pylori-induced inflammation.

    PubMed

    Tang, Bin; Xiao, Bin; Liu, Zhen; Li, Na; Zhu, En-Dong; Li, Bo-Sheng; Xie, Qing-Hua; Zhuang, Yuan; Zou, Quan-Ming; Mao, Xu-Hu

    2010-04-16

    MicroRNA-155 (miR-155) has been implicated as a central regulator of the immune system. We have previously reported that miR-155 negatively regulates Helicobacter pylori (H. pylori)-induced inflammation, but the molecular mechanism of miR-155 regulating the inflammation is not fully clear. Here, we identified myeloid differentiation protein 88 (MyD88) as a target gene of miR-155, and found that miR-155 decreased MyD88 expression at the protein but not the mRNA message level, suggesting that the miR-155-mediated inhibition is a post-transcriptional event. Furthermore, the overexpression of miR-155 led to significantly reduced IL-8 production induced by H. pylori infection. Thus, we have demonstrated that miR-155 can negatively regulate inflammation by targeting a key adaptor molecule MyD88 in inflammatory pathways. PMID:20219467

  6. Selective utilization of Toll-like receptor and MyD88 signaling in B cells for enhancement of the anti-viral germinal center response

    PubMed Central

    Hou, Baidong; Saudan, Philippe; Ott, Gary; Wheeler, Matthew L.; Ji, Ming; Kuzmich, Lili; Lee, Linda M.; Coffman, Robert L.; Bachmann, Martin F.; DeFranco, Anthony L.

    2011-01-01

    Summary The contribution of Toll-like receptor (TLR) signaling to T cell-dependent (TD) antibody responses was assessed by using mice lacking the TLR signaling adaptor MyD88 in individual cell types. When a soluble TLR9 ligand was used as adjuvant for a protein antigen, MyD88 was required in dendritic cells but not in B cells to enhance the TD antibody response, regardless of the inherent immunogenicity of the antigen. In contrast, a TLR9 ligand contained within a virus-like particle substantially augmented the TD germinal center IgG antibody response, and this augmentation required B cell MyD88. The ability of B cells to discriminate between antigens based the physical form of a TLR ligand likely reflects an adaptation to facilitate strong anti-viral antibody responses. PMID:21353603

  7. LFP-20, a porcine lactoferrin peptide, ameliorates LPS-induced inflammation via the MyD88/NF-κB and MyD88/MAPK signaling pathways.

    PubMed

    Zong, Xin; Song, Deguang; Wang, Tenghao; Xia, Xi; Hu, Wangyang; Han, Feifei; Wang, Yizhen

    2015-10-01

    LFP-20 is one of the 20 amino acid anti-microbial peptides identified in the N terminus of porcine lactoferrin. Apart from its extensively studied direct anti-bacterial activity, its potential as an activator of immune-related cellular functions is unknown. Therefore, this study investigated its anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated pig alveolar macrophages in vitro and systemic inflammation in an in vivo mouse model. We found that the inhibitory effects of LFP-20 on production of pro-inflammatory cytokines were independent of its LPS-binding activity. However, they were associated with NF-κB and MAPK-dependent signaling. Furthermore, LFP-20 might directly influence MyD88 levels to block its interaction with NF-κB and MAPK-dependent signaling molecules that might alter LPS-mediated inflammatory responses in activated macrophages. Taken together, our data indicated that LFP-20 prevents the LPS-induced inflammatory response by inhibiting MyD88/NF-κB and MyD88/MAPK signaling pathways, and sheds light on the potential use of LFP-20 in the therapy of LPS-mediated sepsis. PMID:26003437

  8. Grouper (Epinephelus coioides) MyD88 and Tollip: intracellular localization and signal transduction function.

    PubMed

    Li, Yan-Wei; Wang, Zheng; Mo, Ze-Quan; Li, Xia; Luo, Xiao-Chun; Dan, Xue-Ming; Li, An-Xing

    2015-01-01

    Myeloid differentiation factor 88 (MyD88) and Toll-interacting protein (Tollip) are two important regulatory proteins of the Toll-like receptor (TLR) signaling pathways. In this paper, a Tollip sequence of grouper (Epinephelus coioides) was identified and the signal transduction functions of Tollip and MyD88 were studied. The full length of E. coioides Tollip (EcTollip) cDNA with an open reading frame (ORF) of 1734 nucleotides encoded a putative protein of 274 amino acid residues. The EcTollip protein had conservative domains with mammalian homologous proteins, and high identity (78%-95%) with other vertebrates. MyD88 and Tollip were distributed in the HeLa cytoplasm in a highly condensed form. Over-expression of MyD88 could activate nuclear factor-κB (NF-κB) and its function was dependent on the death domain and ID domain on the N-terminal. Some important functional sites of mammalian MyD88 also affected fish MyD88 signal transduction. Tollip impaired NF-κB signals activated by MyD88, and its activity was dependent on the coupling of ubiquitin to the endoplasmic reticulum degradation (CUE) domain on the C-terminal. These results suggest that MyD88 and Tollip of fish and mammals are conservative on function during evolution. PMID:25449381

  9. Vaccine-Induced Antibody Isotypes Are Skewed by Impaired CD4 T Cell and Invariant NKT Cell Effector Responses in MyD88-Deficient Mice1

    PubMed Central

    Iweala, Onyinye I.; Smith, Donald W.; Matharu, Kabir S.; Sada-Ovalle, Isabel; Nguyen, Deanna D.; DeKruyff, Rosemarie H.; Umetsu, Dale T.; Behar, Samuel M.; Nagler, Cathryn R.

    2015-01-01

    The requirement for TLR signaling in the initiation of an Ag-specific Ab response is controversial. In this report we show that a novel OVA-expressing recombinant Salmonella vaccine (Salmonella-OVA) elicits a Th1-biased cell-mediated and serum Ab response upon oral or i.p. immunization of C57BL/6 mice. In MyD88−/−mice, Th1-dependent Ab responses are greatly reduced while Th2-dependent Ab isotypes are elevated in response to oral and i.p., but not s.c. footpad, immunization. When the T effector response to oral vaccination is examined we find that activated, adoptively transferred Ag-specific CD4+ T cells accumulate in the draining lymph nodes, but fail to produce IFN-γ, in MyD88−/− mice. Moreover, CD1d tetramer staining shows that invariant NKT cells are activated in response to oral Salmonella-OVA vaccination in wild-type, but not MyD88−/−, mice. Treatment with neutralizing Ab to CD1d reduces the OVA-specific Ab response only in MyD88-sufficient wild-type mice, suggesting that both Ag-specific CD4 T cell and invariant NKT cell effector responses to Salmonella-OVA vaccination are MyD88 dependent. Taken together, our data indicate that the type of adaptive immune response generated to this live attenuated vaccine is regulated by both the presence of MyD88-mediated signals and vaccination route, which may have important implications for future vaccine design. PMID:19620295

  10. MyD88 Signaling Contributes to Early Pulmonary Responses to Aspergillus fumigatus▿

    PubMed Central

    Bretz, Camille; Gersuk, Geoff; Knoblaugh, Sue; Chaudhary, Neelkamal; Randolph-Habecker, Julie; Hackman, Robert C.; Staab, Janet; Marr, Kieren A.

    2008-01-01

    Toll-like receptors and the β-glucan receptor, dectin-1, mediate macrophage inflammatory responses to Aspergillus fumigatus through MyD88-dependent and -independent signaling mechanisms; however, pulmonary inflammatory responses in MyD88-deficient mice challenged with A. fumigatus are poorly defined. The role of MyD88 signaling in early pulmonary inflammation and fungal clearance was evaluated in C57BL/6J wild-type (WT) and MyD88-deficient (MyD88−/−) mice. Early (<48 h) after infection, MyD88−/− mice had higher fungal burdens than those of WT mice, although fungal burdens rapidly declined (>72 h) in both. MyD88−/− mice had less consolidated inflammation, with fewer NK cells, in lung tissue early (24 h) after infection than did WT mice. At the latter time point, MyD88−/− mouse lungs were characterized by a large amount of necrotic cellular debris and fibrin, while WT lungs had organized inflammation. Although there were equivalent numbers of macrophages in WT and MyD88−/− mouse lung tissues, MyD88−/− cells demonstrated delayed uptake of green fluorescent protein-expressing A. fumigatus (GFP-Af293); histologically, MyD88−/− mouse lungs had more hyphal invasion of terminal airways and vessels, the appearance of bronchiolar epithelial cell necrosis, and necrotizing vasculitis. MyD88−/− lung homogenates contained comparatively decreased amounts of interleukin-1β (IL-1β), IL-6, KC, and gamma interferon and paradoxically increased amounts of tumor necrosis factor alpha and macrophage inflammatory protein 1α. These data indicate that the MyD88-dependent pathway mediates acute pulmonary fungal clearance, inflammation, and tissue injury very early after infection. Resolution of abnormalities within a 3-day window demonstrates the importance of redundant signaling pathways in mediating pulmonary inflammatory responses to fungi. PMID:18039832

  11. Myd88 deficiency influences murine tracheal epithelial metaplasia and submucosal gland abundance.

    PubMed

    Giangreco, Adam; Lu, Liwen; Mazzatti, Dawn J; Spencer-Dene, Bradley; Nye, Emma; Teixeira, Vitor Hugo; Janes, Sam M

    2011-06-01

    Tracheal epithelial remodelling, excess mucus production, and submucosal gland hyperplasia are features of numerous lung diseases, yet their origins remain poorly understood. Previous studies have suggested that NF-κB signalling may regulate airway epithelial homeostasis. The purpose of this study was to determine whether deletion of the NF-κB signalling pathway protein myeloid differentiation factor 88 (Myd88) influenced tracheal epithelial cell phenotype. We compared wild-type and Myd88-deficient or pharmacologically inhibited adult mouse tracheas and determined that in vivo Myd88 deletion resulted in increased submucosal gland number, secretory cell metaplasia, and excess mucus cell abundance. We also found that Myd88 was required for normal resolution after acute tracheal epithelial injury. Microarray analysis revealed that uninjured Myd88-deficient tracheas contained 103 transcripts that were differentially expressed relative to wild-type and all injured whole tracheal samples. These clustered into several ontologies and networks that are known to functionally influence epithelial cell phenotype. Comparing these transcripts to those expressed in airway progenitor cells revealed only five common genes, suggesting that Myd88 influences tracheal epithelial homeostasis through an extrinsic mechanism. Overall, this study represents the first identification of Myd88 as a regulator of adult tracheal epithelial cell phenotype. PMID:21557220

  12. Neohesperidin dihydrochalcone down-regulates MyD88-dependent and -independent signaling by inhibiting endotoxin-induced trafficking of TLR4 to lipid rafts.

    PubMed

    Xia, Xiaomin; Fu, Juanli; Song, Xiufang; Shi, Qiong; Su, Chuanyang; Song, Erqun; Song, Yang

    2015-12-01

    Fulminant hepatic failure (FHF) is a lethal clinical syndrome characterized by the activation of macrophages and the increased production of inflammatory mediators. The purpose of this study was to investigate the effects of neohesperidin dihydrochalcone (NHDC), a widely-used low caloric artificial sweetener against FHF. An FHF experimental model was established in mice by intraperitoneal injection of D-galactosamine (d-GalN) (400mg/kg)/lipopolysaccharides (LPS) (10 μg/kg). Mice were orally administered NHDC for 6 continuous days and at 1h before d-GalN/LPS administration. RAW264.7 macrophages were used as an in vitro model. Cells were pre-treated with NHDC for 1h before stimulation with LPS (10 μg/ml) for 6h. d-GalN/LPS markedly increased the serum transaminase activities and levels of oxidative and inflammatory markers, which were significantly attenuated by NHDC. Mechanistic analysis indicated that NHDC inhibited LPS-induced myeloid differentiation factor 88 (MyD88) and TIR-containing adapter molecule (TRIF)-dependent signaling. Transient transfection of TLR4 or MyD88 siRNA inhibited the downstream inflammatory signaling. This effect could also be achieved by the pretreatment with NHDC. The fluorescence microscopy and flow cytometry results suggested that NHDC potently inhibited the binding of LPS to TLR4 in RAW264.7 macrophages. In addition, the inhibitory effect of NHDC on LPS-induced translocation of TLR4 into lipid raft domains played an important role in the amelioration of production of downstream pro-inflammatory molecules. Furthermore, the activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) by NHDC inhibited TLR4 signaling. In conclusion, our results suggest that NHDC attenuates d-GalN/LPS-induced FHF by inhibiting the TLR4-mediated inflammatory pathway, demonstrating a new application of NHDC as a hepatoprotective agent. PMID:26453923

  13. MyD88 and TRIF mediate divergent inflammatory and regenerative responses to skeletal muscle ischemia

    PubMed Central

    Sachdev, Ulka; Cui, Xiangdong; Xu, Jia; Xu, Jun; Tzeng, Edith

    2014-01-01

    Abstract We have previously shown that MyD88 KO mice appear protected from ischemic muscle injury while TRIF KO mice exhibit sustained necrosis after femoral artery ligation (FAL). However, our previous data did not differentiate whether the protective effect of absent MyD88 signaling was secondary to attenuated injury after FAL or quicker recovery from the insult. The purpose of this study was to delineate these different possibilities. On the basis of previous findings, we hypothesized that MyD88 signaling promotes enhanced inflammation while TRIF mediates regeneration after skeletal muscle ischemia. Our results show that after FAL, both MyD88 KO mice and TRIF KO mice have evidence of ischemia, as do their control counterparts. However, MyD88 KO mice had lower levels of serum IL‐6 24 h after FAL, while TRIF KO mice demonstrated sustained serum IL‐6 up to 1 week after injury. Additionally, MyD88 KO mice had higher nuclear content and larger myofibers than control animals 1 week after injury. IL‐6 is known to have differential effects in myoblast function, and can inhibit proliferation and differentiation. In tibialis anterior muscle harvested from injured animals, IL‐6 levels were higher and the proliferative marker MyoD was lower in TRIF KO mice by PCR. Furthermore, expression of MyD88 appeared to be higher in skeletal muscle of TRIF KO mice. In vitro, we showed that myoblast differentiation and proliferation were attenuated in response to IL‐6 treatment giving credence to the finding that low IL‐6 in MyD88 KO mice may be responsible for larger myocyte sizes 1 week after FAL. We conclude that MyD88 and TRIF work in concert to mediate a balanced response to ischemic injury. PMID:24844636

  14. MyD88 Deficiency Alters Expression of Antimicrobial Factors in Mouse Salivary Glands

    PubMed Central

    Into, Takeshi; Takigawa, Toshiya; Niida, Shumpei; Shibata, Ken-ichiro

    2014-01-01

    The surfaces of oral mucosa are protected from infections by antimicrobial proteins and natural immunoglobulins that are constantly secreted in saliva, serving as principal innate immune defense in the oral cavity. MyD88 is an important adaptor protein for signal transduction downstream of Toll-like receptors and TACI, receptors for regulation of innate immunity and B cell responses, respectively. Although MyD88-mediated signaling has a regulatory role in the intestinal mucosal immunity, its specific role in the oral cavity has remained elusive. In the present study, we assessed the influence of MyD88 deficiency on the oral innate defense, particularly the expression of antimicrobial proteins in salivary glands and production of salivary basal immunoglobulins, in mice. Microarray analysis of the whole tissues of submandibular glands revealed that the expression of several genes encoding salivary antimicrobial proteins, such as secretory leukocyte peptidase inhibitor (SLPI), S100A8, and lactotransferrin, was reduced due to MyD88 deficiency. Histologically, SLPI-expressing acinar cells were evidently decreased in the glands from MyD88 deficient mice compared to wild-type mice. Flow cytometric analysis revealed that B cell populations, including B-1 cells and IgA+ plasma cells, residing in submandibular glands were increased by MyD88 deficiency. The level of salivary anti-phosphorylcholine IgA was elevated in MyD88 deficient mice compared to wild-type mice. Thus, this study provides a detailed description of the effect of MyD88 deficiency on expression of several salivary antimicrobial factors in mice, illustrating the role for MyD88-mediated signaling in the innate immune defense in the oral cavity. PMID:25415419

  15. Immobilization stress-induced anorexia is mediated independent of MyD88.

    PubMed

    Hosoi, Toru; Yamawaki, Yosuke; Kimura, Hitomi; Ozawa, Koichiro

    2016-09-01

    MyD88 is an adaptor protein for the toll-like receptor, which is involved in regulating innate immune function. Lipopolysaccharide-induced activation of toll-like receptor 4 signaling induces hypothalamic signal transducer and activator of transcription 3 (STAT3) phosphorylation and anorexia through MyD88. In the present study, we investigated the possible role of MyD88 in psychological stress-induced anorexia. We found that immobilization stress inhibited food intake in both wild-type mice and MyD88-deficient mice. Immobilization stress slightly increased STAT3 phosphorylation in the hypothalamus, but it was weaker than the lipopolysaccharide-induced increase in STAT3 phosphorylation. These observations suggest that the mechanisms involved in psychological stress-induced anorexia may be regulated differently from those involved in anorexia that is induced by infection. PMID:27391428

  16. Lactobacillus rhamnosus GR-1 Limits Escherichia coli-Induced Inflammatory Responses via Attenuating MyD88-Dependent and MyD88-Independent Pathway Activation in Bovine Endometrial Epithelial Cells.

    PubMed

    Liu, Mingchao; Wu, Qiong; Wang, Mengling; Fu, Yunhe; Wang, Jiufeng

    2016-08-01

    Intrauterine Escherichia coli infection after calving reduces fertility and causes major economic losses in the dairy industry. We investigated the protective effect of the probiotic Lactobacillus rhamnosus GR-1 on E. coli-induced cell damage and inflammation in primary bovine endometrial epithelial cells (BEECs). L. rhamnosus GR-1 reduced ultrastructure alterations and the percentage of BEECs apoptosis after E. coli challenge. Increased messenger RNA (mRNA) expression of immune response indicators, including pattern recognition receptors (toll-like receptor [TLR]2, TLR4, nucleotide-binding oligomerization domain [NOD]1, and NOD2), inflammasome proteins (NOD-like receptor family member pyrin domain-containing protein 3, apoptosis-associated speck-like protein, and caspase-1), TLR4 downstream adaptor molecules (myeloid differentiation antigen 88 [MyD88], toll-like receptor adaptor molecule 2 [TICAM2]), nuclear transcription factor kB (NF-kB), and the inflammatory cytokines tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-18, and interferon (IFN)-β, was observed following E. coli challenge. However, these increases were attenuated by L. rhamnosus GR-1 pretreatment. Our data indicate that L. rhamnosus GR-1 ameliorates the E. coli-induced disruption of cellular ultrastructure, subsequently reducing the percentage of BEECs apoptosis and limiting inflammatory responses, partly via attenuation of MyD88-dependent and MyD88-independent pathway activation. Certain probiotics could potentially prevent postpartum uterine diseases in dairy cows, ultimately reducing the use of antibiotics. PMID:27236308

  17. In Vitro Reconstitution of the Toll/Interleukin-1 Receptor (TIR) Domain Complex Between TLR5/6 and Myd88.

    PubMed

    Jang, Tae-Ho; Narayanan, Kannan Badri; Park, Hyun Ho

    2016-01-01

    Toll-like receptors (TLRs) are evolutionarily conserved receptors with trimodular structure to respond to endogenous ligands and exogenous ligands from microbial pathogens. The highly conserved cytoplasmic C-terminal Toll/interleukin-1 receptor (TIR) domain of TLRs plays a crucial role in inflammatory reactions. In myeloid differentiation primary-response protein 88 (MyD88)- dependent signaling pathway, the interaction of TLRsTIR with cytosolic adaptor protein, MyD88TIR recruits IL-1R-associated kinases (IRAK) for subsequent activation of transcription factors nuclear factor kB (NF-kB) and activation protein 1 (AP-1) and other effector molecules. In the present investigation, TLR5TIR, TLR6TIR and MyD88TIR genes were subcloned and overexpressed in bacterium Escherichia coli strain BL- 21 (DE3). The purification and biochemical characterization of TLR5TIR and TLR6TIR&, and MyD88TIR proteins were also performed. The protein-protein interactions between TIR domains of TLR5 and TLR6 with MyD88, respectively, were evaluated in vitro at physiological pH and salt concentration. The in vitro reconstitution results showed that under physiological pH and salt concentration, MyD88TIR interacted with TLR5TIR, and did not interact with TLR6TIR protein. Both TIR domain-containing TLR5 and TLR6 proteins were prone to aggregation in a temperature-dependent manner at room temperature. At normal physiological pH and salt concentration, with the addition of binding partner MyD88TIR to TLR5/6TIR, time-dependent aggregation was not observed in both TLRsTIR at both room temperature and 4 ºC for 2 d, influencing the solubility of TLR5/6TIR. Moreover, TLR5TIR alone exhibited increase in solubility of the protein with increase in the salt concentration of the buffered solution from 0.025 M to 1.25 M at room temperature. PMID:26548862

  18. Deficiency in MyD88 Signaling Results in Decreased Antibody Responses to an Adeno-Associated Virus Vector in Murine Pompe Disease

    PubMed Central

    Zhang, Ping; Luo, Xiaoyan; Bird, Andrew; Li, Songtao

    2012-01-01

    Abstract We have previously shown that antibody and T cell responses limit the efficacy of an adeno-associated virus (AAV) pseudotype 8 (2/8) vector containing the universally active cytomegalovirus enhancer/chicken β-actin regulatory cassette (AAV2/8-CBhGAA) in treating murine Pompe disease. However, the innate immune responses to AAV2/8-CBhGAA are largely unknown. In this study, we investigated acute immune responses to AAV2/8-CBhGAA and the role of MyD88/TRIF signaling pathway in shaping adaptive immune responses to this vector. We showed here that a small and transient increase in CXCL-1 and IL-1β expression in livers of acid-α-glucosidase knockout (GAAKO) mice 6 h following injection with AAV2/8-CBhGAA. There was a robust antibody response to GAA in wild-type mice injected with this vector. In contrast, the anti-GAA IgG1 response was diminished in MyD88KO mice, and showed a trend toward a decrease in TRIFKO mice. In addition, the vector genome and GAA activity were significantly higher in MyD88KO livers compared with wild-type livers, suggesting reduced cytotoxic T cell responses. Importantly, elevated CD4+ T cells were detected by immunohistochemistry in MyD88KO livers. When adoptively transferred to wild-type mice, these CD4+ T cells have an ability to suppress antibody responses against AAV2/8-CBhGAA and to prevent further immunization against rhGAA. Our study suggests that the MyD88 deficiency leads to the suppression of deleterious immune responses to AAV2/8-CBhGAA, which has implications for gene therapy in Pompe disease. PMID:23514839

  19. Deficiency in MyD88 Signaling Results in Decreased Antibody Responses to an Adeno-Associated Virus Vector in Murine Pompe Disease.

    PubMed

    Zhang, Ping; Luo, Xiaoyan; Bird, Andrew; Li, Songtao; Koeberl, Dwight D

    2012-06-01

    We have previously shown that antibody and T cell responses limit the efficacy of an adeno-associated virus (AAV) pseudotype 8 (2/8) vector containing the universally active cytomegalovirus enhancer/chicken β-actin regulatory cassette (AAV2/8-CBhGAA) in treating murine Pompe disease. However, the innate immune responses to AAV2/8-CBhGAA are largely unknown. In this study, we investigated acute immune responses to AAV2/8-CBhGAA and the role of MyD88/TRIF signaling pathway in shaping adaptive immune responses to this vector. We showed here that a small and transient increase in CXCL-1 and IL-1β expression in livers of acid-α-glucosidase knockout (GAAKO) mice 6 h following injection with AAV2/8-CBhGAA. There was a robust antibody response to GAA in wild-type mice injected with this vector. In contrast, the anti-GAA IgG1 response was diminished in MyD88KO mice, and showed a trend toward a decrease in TRIFKO mice. In addition, the vector genome and GAA activity were significantly higher in MyD88KO livers compared with wild-type livers, suggesting reduced cytotoxic T cell responses. Importantly, elevated CD4(+) T cells were detected by immunohistochemistry in MyD88KO livers. When adoptively transferred to wild-type mice, these CD4(+) T cells have an ability to suppress antibody responses against AAV2/8-CBhGAA and to prevent further immunization against rhGAA. Our study suggests that the MyD88 deficiency leads to the suppression of deleterious immune responses to AAV2/8-CBhGAA, which has implications for gene therapy in Pompe disease. PMID:23514839

  20. Mutations in TLR/MYD88 pathway identify a subset of young chronic lymphocytic leukemia patients with favorable outcome.

    PubMed

    Martínez-Trillos, Alejandra; Pinyol, Magda; Navarro, Alba; Aymerich, Marta; Jares, Pedro; Juan, Manel; Rozman, María; Colomer, Dolors; Delgado, Julio; Giné, Eva; González-Díaz, Marcos; Hernández-Rivas, Jesús M; Colado, Enrique; Rayón, Consolación; Payer, Angel R; Terol, Maria José; Navarro, Blanca; Quesada, Victor; Puente, Xosé S; Rozman, Ciril; López-Otín, Carlos; Campo, Elías; López-Guillermo, Armando; Villamor, Neus

    2014-06-12

    Mutations in Toll-like receptor (TLR) and myeloid differentiation primary response 88 (MYD88) genes have been found in chronic lymphocytic leukemia (CLL) at low frequency. We analyzed the incidence, clinicobiological characteristics, and outcome of patients with TLR/MYD88 mutations in 587 CLL patients. Twenty-three patients (3.9%) had mutations, 19 in MYD88 (one with concurrent IRAK1 mutation), 2 TLR2 (one with concomitant TLR6 mutation), 1 IRAK1, and 1 TLR5. No mutations were found in IRAK2 and IRAK4. TLR/MYD88-mutated CLL overexpressed genes of the nuclear factor κB pathway. Patients with TLR/MYD88 mutations were significantly younger (83% age ≤50 years) than those with no mutations. TLR/MYD88 mutations were the most frequent in young patients. Patients with mutated TLR/MYD88 CLL had a higher frequency of mutated IGHV and low expression of CD38 and ZAP-70. Overall survival (OS) was better in TLR/MYD88-mutated than unmutated patients in the whole series (10-year OS, 100% vs 62%; P = .002), and in the subset of patients age ≤50 years (100% vs 70%; P = .02). In addition, relative OS of TLR/MYD88-mutated patients was similar to that in the age- and gender-matched population. In summary, TLR/MYD88 mutations identify a population of young CLL patients with favorable outcome. PMID:24782504

  1. Cloning, Characterization, and Expression Analysis of MyD88 in Rana dybowskii.

    PubMed

    Niu, Shudong; Shi, Xuecan; Zhang, Jingyu; Chai, Longhui; Xiao, Xianghong

    2016-05-01

    immunity in R. dybowskii. This report firstly characterized one adaptor molecule of the TLR signaling pathways in R. dybowskii, thereby providing reference for further researches on the amphibian innate immune system. PMID:26811029

  2. Consequences of the recurrent MYD88(L265P) somatic mutation for B cell tolerance.

    PubMed

    Wang, James Q; Jeelall, Yogesh S; Beutler, Bruce; Horikawa, Keisuke; Goodnow, Christopher C

    2014-03-10

    MYD88(L265P) has recently been discovered as an extraordinarily frequent somatic mutation in benign monoclonal IgM gammopathy, Waldenström's macroglobulinemia, and diffuse large B cell lymphoma. In this study, we analyze the consequences for antigen-activated primary B cells of acquiring MYD88(L265P). The mutation induced rapid B cell division in the absence of exogenous TLR ligands and was inhibited by Unc93b1(3d) mutation and chloroquine or TLR9 deficiency, indicating continued dependence on upstream TLR9 activation. Proliferation and NF-κB activation induced by MYD88(L265P) were nevertheless rapidly countered by the induction of TNFAIP3, an NF-κB inhibitor frequently inactivated in MYD88(L265P)-bearing lymphomas, and extinguished by Bim-dependent apoptosis. MYD88(L265P) caused self-reactive B cells to accumulate in vivo only when apoptosis was opposed by Bcl2 overexpression. These results reveal checkpoints that fortify TLR responses against aberrant B cell proliferation in response to ubiquitous TLR and BCR self-ligands and suggest that tolerance failure requires the accumulation of multiple somatic mutations. PMID:24534189

  3. SARM1, Not MyD88, Mediates TLR7/TLR9-Induced Apoptosis in Neurons.

    PubMed

    Mukherjee, Piyali; Winkler, Clayton W; Taylor, Katherine G; Woods, Tyson A; Nair, Vinod; Khan, Burhan A; Peterson, Karin E

    2015-11-15

    Neuronal apoptosis is a key aspect of many different neurologic diseases, but the mechanisms remain unresolved. Recent studies have suggested a mechanism of innate immune-induced neuronal apoptosis through the stimulation of endosomal TLRs in neurons. TLRs are stimulated both by pathogen-associated molecular patterns as well as by damage-associated molecular patterns, including microRNAs released by damaged neurons. In the present study, we identified the mechanism responsible for TLR7/TLR9-mediated neuronal apoptosis. TLR-induced apoptosis required endosomal localization of TLRs but was independent of MyD88 signaling. Instead, apoptosis required the TLR adaptor molecule SARM1, which localized to the mitochondria following TLR activation and was associated with mitochondrial accumulation in neurites. Deficiency in SARM1 inhibited both mitochondrial accumulation in neurites and TLR-induced apoptosis. These studies identify a non-MyD88 pathway of TLR7/ TLR9 signaling in neurons and provide a mechanism for how innate immune responses in the CNS directly induce neuronal damage. PMID:26423149

  4. MyD88 in lung resident cells governs airway inflammatory and pulmonary function responses to organic dust treatment.

    PubMed

    Poole, Jill A; Wyatt, Todd A; Romberger, Debra J; Staab, Elizabeth; Simet, Samantha; Reynolds, Stephen J; Sisson, Joseph H; Kielian, Tammy

    2015-01-01

    Inhalation of organic dusts within agriculture environments contributes to the development and/or severity of airway diseases, including asthma and chronic bronchitis. MyD88 KO (knockout) mice are nearly completely protected against the inflammatory and bronchoconstriction effects induced by acute organic dust extract (ODE) treatments. However, the contribution of MyD88 in lung epithelial cell responses remains unclear. In the present study, we first addressed whether ODE-induced changes in epithelial cell responses were MyD88-dependent by quantitating ciliary beat frequency and cell migration following wounding by electric cell-substrate impedance sensing. We demonstrate that the normative ciliary beat slowing response to ODE is delayed in MyD88 KO tracheal epithelial cells as compared to wild type (WT) control. Similarly, the normative ODE-induced slowing of cell migration in response to wound repair was aberrant in MyD88 KO cells. Next, we created MyD88 bone marrow chimera mice to investigate the relative contribution of MyD88-dependent signaling in lung resident (predominately epithelial cells) versus hematopoietic cells. Importantly, we demonstrate that ODE-induced airway hyperresponsiveness is MyD88-dependent in lung resident cells, whereas MyD88 action in hematopoietic cells is mainly responsible for ODE-induced TNF-α release. MyD88 signaling in lung resident and hematopoietic cells are necessary for ODE-induced IL-6 and neutrophil chemoattractant (CXCL1 and CXCL2) release and neutrophil influx. Collectively, these findings underscore an important role for MyD88 in lung resident cells for regulating ciliary motility, wound repair and inflammatory responses to ODE, and moreover, show that airway hyperresponsiveness appears uncoupled from airway inflammatory consequences to organic dust challenge in terms of MyD88 involvement. PMID:26376975

  5. MyD88-deficient Hydra reveal an ancient function of TLR signaling in sensing bacterial colonizers

    PubMed Central

    Franzenburg, Sören; Fraune, Sebastian; Künzel, Sven; Baines, John F.; Domazet-Lošo, Tomislav; Bosch, Thomas C. G.

    2012-01-01

    Toll-like receptor (TLR) signaling is one of the most important signaling cascades of the innate immune system of vertebrates. Studies in invertebrates have focused on the fruit fly Drosophila melanogaster and the nematode Caenorhabditis elegans, and there is little information regarding the evolutionary origin and ancestral function of TLR signaling. In Drosophila, members of the Toll-like receptor family are involved in both embryonic development and innate immunity. In C. elegans, a clear immune function of the TLR homolog TOL-1 is controversial and central components of vertebrate TLR signaling including the key adapter protein myeloid differentiation primary response gene 88 (MyD88) and the transcription factor NF-κB are not present. In basal metazoans such as the cnidarians Hydra magnipapillata and Nematostella vectensis, all components of the vertebrate TLR signaling cascade are present, but their role in immunity is unknown. Here, we use a MyD88 loss-of-function approach in Hydra to demonstrate that recognition of bacteria is an ancestral function of TLR signaling and that this process contributes to both host-mediated recolonization by commensal bacteria as well as to defense against bacterial pathogens. PMID:23112184

  6. Uncoupling between Inflammatory and Fibrotic Responses to Silica: Evidence from MyD88 Knockout Mice

    PubMed Central

    Lo Re, Sandra; Yakoub, Yousof; Devosse, Raynal; Uwambayinema, Francine; Couillin, Isabelle; Ryffel, Bernard; Marbaix, Etienne; Lison, Dominique; Huaux, François

    2014-01-01

    The exact implication of innate immunity in granuloma formation and irreversible lung fibrosis remains to be determined. In this study, we examined the lung inflammatory and fibrotic responses to silica in MyD88-knockout (KO) mice. In comparison to wild-type (WT) mice, we found that MyD88-KO animals developed attenuated lung inflammation, neutrophil accumulation and IL-1β release in response to silica. Granuloma formation was also less pronounced in MyD88-KO mice after silica. This limited inflammatory response was not accompanied by a concomitant attenuation of lung collagen accumulation after silica. Histological analyses revealed that while pulmonary fibrosis was localized in granulomas in WT animals, it was diffusely distributed throughout the parenchyma in MyD88-KO mice. Robust collagen accumulation was also observed in mice KO for several other components of innate immunity (IL-1R, IL-1, ASC, NALP3, IL-18R, IL-33R, TRIF, and TLR2-3-4,). We additionally show that pulmonary fibrosis in MyD88-KO mice was associated with the accumulation of pro-fibrotic regulatory T lymphocytes (T regs) and pro-fibrotic cytokine expression (TGF-β, IL-10 and PDGF-B), not with T helper (Th) 17 cell influx. Our findings indicate that the activation of MyD88-related innate immunity is central in the establishment of particle-induced lung inflammatory and granuloma responses. The development of lung fibrosis appears uncoupled from inflammation and may be orchestrated by a T reg-associated pathway. PMID:25050810

  7. The role of the MYD88-dependent pathway in MPTP-induced brain dopaminergic degeneration

    PubMed Central

    2011-01-01

    Background Mounting evidence supports a significant role of inflammation in Parkinson's disease (PD) pathophysiology, with several inflammatory pathways being suggested as playing a role in the dopaminergic degeneration seen in humans and animal models of the disease. These include tumor necrosis factor, prostaglandins and oxidative-related stress components. However, the role of innate immunity has not been established in PD. Methods Based on the fact that the myeloid differentiation primary response gene (88) (MyD88) is the most common adaptor protein implicated in toll-like receptor (TLR) signaling, critical in the innate immune response, we undertook a study to investigate the potential contribution of this specific pathway to MPTP-induced brain dopaminergic degeneration using MyD88 knock out mice (MyD88-/-), following our observations that the MyD88-dependent pathway was critical for MPTP dopaminergic toxicity in the enteric nervous system. Post-mortem analyses assessing nigrostriatal dopaminergic degeneration and inflammation were performed using HPLC, western blots, autoradiography and immunofluorescence. Results Our results demonstrate that MyD88-/- mice are as vulnerable to MPTP-induced dopamine and DOPAC striatal depletion as wild type mice. Furthermore, MyD88-/- mice show similar striatal dopamine transporter and tyrosine hydroxylase loss, as well as dopaminergic cell loss in the substantia nigra pars compacta in response to MPTP. To evaluate the extent of the inflammatory response created by the MPTP regimen utilized, we further performed bioluminescence imaging using TLR2-luc/gfp transgenic mice and microglial density analysis, which revealed a modest brain microglial response following MPTP. This was accompanied by a significant astrocytic reaction in the striatum, which was of similar magnitude both in wild type and MyD88-/- mice. Conclusions Our results suggest that subacute MPTP-induced dopaminergic degeneration observed in the central nervous system is MyD88-independent, in contrast to our recent observations that this pathway, in the same cohort of animals, is critical in the loss of dopaminergic neurons in the enteric nervous system. PMID:21989292

  8. Characterization of bbtTICAM from amphioxus suggests the emergence of a MyD88-independent pathway in basal chordates

    PubMed Central

    Yang, Manyi; Yuan, Shaochun; Huang, Shengfeng; Li, Jun; Xu, Liqun; Huang, Huiqing; Tao, Xin; Peng, Jian; Xu, Anlong

    2011-01-01

    The MyD88-independent pathway, one of the two crucial TLR signaling routes, is thought to be a vertebrate innovation. However, a novel Toll/interleukin-1 receptor (TIR) adaptor, designated bbtTICAM, which was identified in the basal chordate amphioxus, links this pathway to invertebrates. The protein architecture of bbtTICAM is similar to that of vertebrate TICAM1 (TIR-containing adaptor molecule-1, also known as TRIF), while phylogenetic analysis based on the TIR domain indicated that bbtTICAM is the oldest ortholog of vertebrate TICAM1 and TICAM2 (TIR-containing adaptor molecule-2, also known as TRAM). Similar to human TICAM1, bbtTICAM activates NF-κB in a MyD88-independent manner by interacting with receptor interacting protein (RIP) via its RHIM motif. Such activation requires bbtTICAM to form homodimers in endosomes, and it may be negatively regulated by amphioxus SARM (sterile α and armadillo motif-containing protein) and TRAF2. However, bbtTICAM did not induce the production of type I interferon. Thus, our study not only presents the ancestral features of vertebrate TICAM1 and TICAM2, but also reveals the evolutionary origin of the MyD88-independent pathway from basal chordates, which will aid in understanding the development of the vertebrate TLR network. PMID:21931360

  9. Requirement for MyD88 signaling in B cells and dendritic cells for germinal center anti-nuclear antibody production in Lyn-deficient mice1

    PubMed Central

    Hua, Zhaolin; Gross, Andrew J.; Lamagna, Chrystelle; Ramos-Hernández, Natalia M.; Scapini, Patrizia; Ji, Ming; Shao, Haitao; Lowell, Clifford A.; Hou, Baidong; DeFranco, Anthony L.

    2014-01-01

    The intracellular tyrosine kinase Lyn mediates inhibitory receptor function in B cells and myeloid cells, and Lyn−/− mice spontaneously develop an autoimmune and inflammatory disease that closely resembles human systemic lupus erythematosus. TLR signaling pathways have been implicated in the production of anti-nuclear antibodies in SLE and mouse models of it. We used a conditional allele of Myd88 to determine whether the autoimmunity of Lyn−/− mice is dependent on TLR/MyD88 signaling in B cells and/or in dendritic cells (DCs). The production of IgG anti-nuclear antibodies, as well as the deposition of these antibodies in the glomeruli of the kidneys, leading to glomerulonephritis in Lyn−/− mice were completely abolished by selective deletion of Myd88 in B cells and the autoantibody production and glomerulonepritis were delayed or decreased by deletion of Myd88 in DCs. The reduced autoantibody production in mice lacking MyD88 in B cells or DCs was accompanied by a dramatic decrease of the spontaneous germinal center (GC) response, suggesting that autoantibodies in Lyn−/− mice may depend on GC responses. Consistent with this view, IgG anti-nuclear antibodies were absent if T cells were deleted (TCRβ−/− TCRδ−/− mice) or if T cells were unable to contribute to GC responses due to mutation of the adaptor molecule SAP. Thus, the autoimmunity of Lyn−/− mice was dependent on T cells and on TLR/MyD88 signaling in B cells and in DCs, supporting a model whereby DC hyperactivity combines with defects in tolerance in B cells to lead to a T cell-dependent systemic autoimmunity in Lyn−/− mice. PMID:24379120

  10. MyD88-dependent Toll-like receptor 4 signal pathway in intervertebral disc degeneration

    PubMed Central

    Qin, Chuqiang; Zhang, Bo; Zhang, Liang; Zhang, Zhi; Wang, Le; Tang, Long; Li, Shuangqing; Yang, Yixi; Yang, Fuguo; Zhang, Ping; Yang, Bo

    2016-01-01

    Lower back pain (LBP) is a common and remitting problem. One of the primary causes of LBP is thought to be degeneration of the intervertebral disc (IVD). The aim of the present study was to investigate the role of the myeloid differentiation primary-response protein 88 (MyD88)-dependent Toll-like receptor 4 (TLR4) signal pathway in the mechanism of IVD degeneration. IVD nucleus pulposus cells isolated and cultured from the lumbar vertebrae of Wistar rats were stimulated by various doses of lipopolysaccharide (LPS; 0.1, 1, 10 and 100 µg/ml) to simulate IVD degeneration. Cells were rinsed and cultured in serum-free Dulbecco's modified Eagle's medium/F12. Reverse transcription-quantitative polymerase chain reaction was used to determine the levels of TLR4, MyD88, tumor necrosis factor α (TNFα), and interleukin-1β (IL-1β) mRNA expression after 1, 3, 6, 9 and 12 h of incubation. Additionally, western blot and enzyme-linked immunosorbent assay analyses were used to determine the levels of TLR4, MyD88, TNFα, and IL-1β protein expression after 24, 48 and 72 h of incubation. The levels of TLR4, MyD88, TNFα and IL-1β mRNA all increased in the cells stimulated by 10 µg/ml LPS at 3, 6 and 9 h (all P<0.001). Furthermore, the levels of TLR4, MyD88, TNFα and IL-1β protein all increased at 24, 48 and 72 h (all P<0.001). Additionally, the mRNA and protein levels of TLR4, MyD88, TNFα and IL-1β increased significantly in the cells stimulated by 1, 10 and 100 µg/ml LPS compared with the control group, and reached a peak in the 10 µg/ml LPS group (all P<0.001). These results suggest that the MyD88-dependent TLR4 signal pathway is a target pathway in IVD degeneration. This pathway is time phase- and dose-dependent, and when activated can lead to the release of inflammatory factors that participate in IVD degeneration. PMID:27446251

  11. Expression of TLR4-MyD88 and NF-κB in the Iris during Endotoxin-Induced Uveitis

    PubMed Central

    Li, Shang; Lu, Hong; Hu, Xiaofeng; Chen, Wei; Xu, Yingzhi; Wang, Jing

    2010-01-01

    Purpose. To observe the expression of Toll-like receptor-4 (TLR4), myeloid differentiation factor 88 (MyD88), and nuclear factor kappa B p65 (NF-κB p65) in iris tissue during endotoxin-induced uveitis (EIU) and evaluate the significance of these factors in uveitis. Methods. Wistar rats were randomly divided into 5 groups (0 h, 12 h, 24 h, 48 h, and 72 h, n = 10/group). Animal model of acute anterior uveitis was established by a hind footpad injection of 200 μg Cholera vibrio LPS. Expression of TLR4, MyD88, and NF-κB p65 in iris ciliary body tissue was detected through immunohistochemical staining. Results. Expression of TLR4 was not detected in normal iris-ciliary body complex, TLR4 positive cells with round morphology appeared in the iris stroma 12 hours after injection, significantly increased (P < .001) 48 hours after injection, and decreased gradually 72 hours after injection. Expression of MyD88 and NF-κB p65 is consistent with the change of the TLR4. Conclusions. The increased expression of TLR4 and its downstream signal transduction moleculesMyD88, NF-κB p65 indicate the potential role of pathway in the pathogenesis of acute anterior uveitis (AAU). PMID:20847811

  12. Methicillin-Resistant Staphylococcus Aureus infection exacerbates NSCLC cell metastasis by up-regulating TLR4/MyD88 pathway.

    PubMed

    An, J; Li, Z; Dong, Y; Ren, J; Guo, K

    2016-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) infection is a major public health problem worldwide, which brings to a more great threat for cancer patients. It's necessary to give attentions to lung cancer combined with MRSA. This study mainly focuses on the influences of MRSA on lung cancer cells (A549). We first found that MRSA infection can enhance metastasis ability of A549 cell and increase matrix metalloproteinase (MMP2 and MMP9) expressions in MRSA-infected A549 cell. Toll-like receptors (TLRs) have been reported to play an important role in tumor cell initiation and migration, and regulate the expression of MMPs in tumors. Our further research indicates that Toll-like receptor 4 (TLR4)/molecules myeloid differentiation factor 88 (MyD88) signaling was up-regulated in MRSA-infected A549 cell. After silencing TLR4 or MyD88 gene, the enhanced metastasis ability of A549 cell by MRSA was decreased significantly; Also, MMP2 and MMP9 expression increase was reversed. In conclusion, MRSA infection can enhance NSCLC cell metastasis by up-regulating TLR4/MyD88 signaling. PMID:27545207

  13. LPS INHIBITION OF GLUCOSE PRODUCTION THROUGH THE TLR4, MYD88, NFκB PATHWAY

    PubMed Central

    Raetzsch, Carl F.; Brooks, Natasha L.; Alderman, J. McKee; Moore, Kelli S.; Hosick, Peter A.; Klebanov, Simon; Akira, Shizuo; Bear, James E.; Baldwin, Albert S.; Mackman, Nigel; Combs, Terry P.

    2010-01-01

    Acute exposure to lipopolysaccharide (LPS) can cause hypoglycemia and insulin resistance; the underlying mechanisms however, are unclear. We set out to determine whether insulin resistance is linked to hypoglycemia through TLR4, MyD88 and NFκB, a cell signaling pathway that mediates LPS induction of the proinflammatory cytokine TNFα. LPS induction of hypoglycemia was blocked in TLR4−/− and MyD88−/− mice but not in TNFα−/− mice. Both glucose production and glucose utilization were decreased during hypoglycemia. Hypoglycemia was associated with the activation of NFκB in the liver. LPS inhibition of glucose production was blocked in hepatocytes isolated from TLR4−/− and MyD88−/− mice and hepatoma cells expressing an IκB mutant that interferes with NFκB activation. Thus, LPS-induced hypoglycemia was mediated by the inhibition of glucose production from the liver through the TLR4, MyD88, NFκB pathway, independent of LPS induced TNFα. LPS inhibition of glucose production was not blocked by pharmacologic inhibition of the insulin signaling intermediate PI3K in hepatoma cells. Insulin injection caused a similar reduction of circulating glucose in TLR4−/− and TLR4+/+ mice. These two results suggest that LPS and insulin inhibit glucose production by separate pathways. Recovery from LPS induced hypoglycemia was linked to glucose intolerance and hyperinsulinemia in TLR4+/+ mice, but not in TLR4−/− mice. Conclusion Insulin resistance is linked to the inhibition of glucose production by the TLR4, MyD88 and NFκB pathway. PMID:19492426

  14. Two myeloid differentiation factor 88 (MyD88) isoforms identified in ducks.

    PubMed

    Cheng, Yuqiang; Wang, Hengan; Yan, Yaxian; Ding, Chan; Sun, Jianhe

    2015-10-01

    MyD88 is an adaptor protein involved in the interleukin-1 receptor-induced and Toll-like receptor (TLR)-induced activation of nuclear factor-κB (NF-κB). In this study, we identified two isoforms of MyD88 gene, designated DuMyD88-X1 and DuMyD88-X2, from duck cells. Both variants were determined to have a death domain at the N-terminal and a Toll/IL-1R (TIR) domain at the C-terminal; however, the TIR domain of DuMyD88-X2 was incomplete and was 81 amino acids shorter than DuMyD88-X1. Quantitative real-time reverse transcription PCR revealed broad expression of both MyD88s. During Newcastle disease virus (NDV) challenge experiments, expression of the two genes increased significantly, with DuMyD88-X1 having a larger amplitude and longer duration. Overexpression of DuMyD88-X1 and DuMyD88-X2 induced the activation of NF-κB and IL-6 in vitro, suggesting that DuMyD88-X1 and DuMyD88-X2 may be important in the innate immune response. The results verify the existence of a MyD88-dependent signaling pathway in ducks and contribute to understanding the potential role of MyD88s in the innate immune response. PMID:26004012

  15. Innate immune adaptor MyD88 mediates neutrophil recruitment and myocardial injury after ischemia-reperfusion in mice.

    PubMed

    Feng, Yan; Zhao, Huailong; Xu, Xinhua; Buys, Emmanuel S; Raher, Michael J; Bopassa, Jean C; Thibault, Helene; Scherrer-Crosbie, Marielle; Schmidt, Ulrich; Chao, Wei

    2008-09-01

    MyD88 is an adaptor protein critical for innate immune response against microbial infection and in certain noninfectious tissue injury. The present study examined the role of MyD88 in myocardial inflammation and injury after ischemia-reperfusion (I/R). I/R was produced by coronary artery ligation for 30 min followed by reperfusion. The ratios of area at risk to left ventricle (LV) were similar between wild-type (WT) and MyD88-deficient (MyD88-/-) mice. However, 24 h after I/R, the ratios of myocardial infarction to area at risk were 58% less in MyD88(-/-) than in WT mice (14 +/- 2% vs. 33 +/- 6%, P = 0.01). Serial echocardiographic studies demonstrated that there was no difference in baseline LV contractile function between the two groups. Twenty-four hours after I/R, LV ejection fraction (EF) and fractional shortening (FS) in WT mice were reduced by 44% and 62% (EF, 51 +/- 2%, and FS, 22 +/- 1%, P < 0.001), respectively, and remained depressed on the seventh day after I/R. In comparison, EF and FS in MyD88(-/-) mice were 67 +/- 3% and 33 +/- 2%, respectively, after I/R (P < 0.001 vs. WT). Similarly, LV function, as demonstrated by invasive hemodynamic measurements, was better preserved in MyD88(-/-) compared with WT mice after I/R. Furthermore, when compared with WT mice, MyD88(-/-) mice subjected to I/R had a marked decrease in myocardial inflammation as demonstrated by attenuated neutrophil recruitment and decreased expression of the proinflammatory mediators keratinocyte chemoattractant, monocyte chemoattractant protein-1, and ICAM-1. Taken together, these data suggest that MyD88 modulates myocardial inflammatory injury and contributes to myocardial infarction and LV dysfunction during I/R. PMID:18660455

  16. MyD88 in macrophages is critical for abscess resolution in staphylococcal skin infection.

    PubMed

    Feuerstein, Reinhild; Seidl, Maximilian; Prinz, Marco; Henneke, Philipp

    2015-03-15

    When Staphylococcus aureus penetrates the epidermis and reaches the dermis, polymorphonuclear leukocytes (PMLs) accumulate and an abscess is formed. However, the molecular mechanisms that orchestrate initiation and termination of inflammation in skin infection are incompletely understood. In human myeloid differentiation primary response gene 88 (MyD88) deficiency, staphylococcal skin and soft tissue infections are a leading and potentially life-threatening problem. In this study, we found that MyD88-dependent sensing of S. aureus by dermal macrophages (Mϕ) contributes to both timely escalation and termination of PML-mediated inflammation in a mouse model of staphylococcal skin infection. Mϕs were key to recruit PML within hours in response to staphylococci, irrespective of bacterial viability. In contrast with bone marrow-derived Mϕs, dermal Mϕs did not require UNC-93B or TLR2 for activation. Moreover, PMLs, once recruited, were highly activated in an MyD88-independent fashion, yet failed to clear the infection if Mϕs were missing or functionally impaired. In normal mice, clearance of the infection and contraction of the PML infiltrate were accompanied by expansion of resident Mϕs in a CCR2-dependent fashion. Thus, whereas monocytes were dispensable for the early immune response to staphylococci, they contributed to Mϕ renewal after the infection was overcome. Taken together, MyD88-dependent sensing of staphylococci by resident dermal Mϕs is key for a rapid and balanced immune response, and PMLs are dependent on intact Mϕ for full function. Renewal of resident Mϕs requires both local control of bacteria and inflammatory monocytes entering the skin. PMID:25681348

  17. Clinical Features and Outcome of Patients With IRAK-4 and MyD88 Deficiency

    PubMed Central

    Picard, Capucine; von Bernuth, Horst; Ghandil, Pegah; Chrabieh, Maya; Levy, Ofer; Arkwright, Peter D.; McDonald, Douglas; Geha, Raif S.; Takada, Hidetoshi; Krause, Jens C.; Creech, C. Buddy; Ku, Cheng-Lung; Ehl, Stephan; Maŕodi, Ĺaszĺo; Al-Muhsen, Saleh; Al-Hajjar, Sami; Al-Ghonaium, Abdulaziz; Day-Good, Noorbibi K.; Holland, Steven M.; Gallin, John; Chapel, Helen; Speert, David P.; Rodriguez-Gallego, Carlos; Colino, Elena; Garty, Ben-Zion; Roifman, Chaim; Hara, Toshiro; Yoshikawa, Hideto; Nonoyama, Shigeaki; Domachowske, Joseph; Issekutz, Andrew C.; Tang, Mimi; Smart, Joanne; Zitnik, Simona Eva; Hoarau, Cyrille; Kumararatne, Dinakantha; Thrasher, Adrian; Davies, E. Graham; Bethune, Claire; Sirvent, Nicolas; de Ricaud, Dominique; Camcioglu, Yildiz; Vasconcelos, J́ulia; Guedes, Margarida; Vitor, Artur Bonito; Rodrigo, Carlos; AlmaŸan, Francisco; Ḿendez, Maria; Aŕostegui, Juan Ignacio; Alsina, Laia; Fortuny, Claudia; Reichenbach, Janine; Verbsky, James W; Bossuyt, Xavier; Doffinger, Rainer; Abel, Laurent; Puel, Anne; Casanova, Jean-Laurent

    2011-01-01

    Autosomal recessive interleukin-1 receptor-associated kinase (IRAK)-4 and myeloid differentiation factor (MyD)88 deficiencies impair Toll-like receptor (TLR)- and interleukin-1 receptor-mediated immunity. We documented the clinical features and outcome of 48 patients with IRAK-4 deficiency and 12 patients with MyD88 deficiency, from 37 kindreds in 15 countries. The clinical features of IRAK-4 and MyD88 deficiency were indistinguishable. There were no severe viral, parasitic, and fungal diseases, and the range of bacterial infections was narrow. Noninvasive bacterial infections occurred in 52 patients, with a high incidence of infections of the upper respiratory tract and the skin, mostly caused by Pseudomonas aeruginosa and Staphylococcus aureus, respectively. The leading threat was invasive pneumococcal disease, documented in 41 patients (68%) and causing 72 documented invasive infections (52.2%). P. aeruginosa and Staph. aureus documented invasive infections also occurred (16.7% and 16%, respectively, in 25% and 25% of patients). Systemic signs of inflammation were usually weak or delayed. The first invasive infection occurred before the age of 2 years in 53 (88.3%) and in the neonatal period in 19 (32.7%) patients. Multiple or recurrent invasive infections were observed in most survivors (n = 36/50, 72%). PMID:21057262

  18. Microbiota signalling through MyD88 is necessary for a systemic neutrophilic inflammatory response

    PubMed Central

    Karmarkar, Dipti; Rock, Kenneth L

    2013-01-01

    In the present study, we have found that intestinal flora strongly influence peritoneal neutrophilic inflammatory responses to diverse stimuli, including pathogen-derived particles like zymosan and sterile irritant particles like crystals. When germ-free and flora-deficient (antibiotic-treated) mice are challenged with zymosan intraperitoneally, neutrophils are markedly impaired in their ability to extravasate from blood into the peritoneum. In contrast, in these animals, neutrophils can extravasate in response to an intraperitoneal injection of the chemokine, macrophage inflammatory protein 2. Neutrophil recruitment upon inflammatory challenge requires stimulation by microbiota through a myeloid differentiation primary response gene (88) (MyD88) -dependent pathway. MyD88 signalling is crucial during the development of the immune system but depending upon the ligand it may be dispensable at the time of the actual inflammatory challenge. Furthermore, pre-treatment of flora-deficient mice with a purified MyD88-pathway agonist is sufficient to restore neutrophil migration. In summary, this study provides insight into the role of gut microbiota in influencing acute inflammation at sites outside the gastrointestinal tract. PMID:23909393

  19. Epithelial-specific blockade of MyD88-dependent pathway causes spontaneous small intestinal inflammation.

    PubMed

    Gong, Jianfeng; Xu, Jingyue; Zhu, Weiming; Gao, Xiang; Li, Ning; Li, Jieshou

    2010-08-01

    Accumulating evidence suggests a role for Toll-like receptor (TLR) signaling at the intestinal epithelial cells (IECs) level for intestinal protection against exogenous injury or pathogenic infection. We hypothesized that MyD88 dependent TLR signaling at intestinal epithelium is critical for mucosal immune homeostasis. In the current study, a transgenic mouse model was generated in which a dominant-negative mutant of MyD88 (dnMyD88) was driven by an intestinal epithelial-specific murine villin promoter. Aged transgenic mice spontaneously developed chronic small intestinal inflammation, as revealed by increased CD4+ and CD8+ lymphocytes, neutrophil and macrophage infiltration, increased production of cytokines as TNF-alpha, IFN-gamma, IL-1beta, and IL-17, crypt abscesses, lymphedema, and Goblet cell depletion. The chronic inflammation was not due to increased epithelial apoptosis or permeability, but to a decreased Paneth cell-derived alpha-defensins (cryptdins) and RegIII-gamma and increased commensal bacteria translocation. Thus, epithelial MyD88-dependent pathway plays an essential role in limiting mucosal microflora penetration and preventing mucosal immunoregulation disturbance in vivo. PMID:20452828

  20. Penta-O-galloyl-β-D-glucose ameliorates inflammation by inhibiting MyD88/NF-κB and MyD88/MAPK signalling pathways

    PubMed Central

    Jang, Se-Eun; Hyam, Supriya R; Jeong, Jin-Ju; Han, Myung Joo; Kim, Dong-Hyun

    2013-01-01

    Background and Purpose The gallnut of Rhus chinensis MILL and its main constituent penta-O-galloyl-β-D-glucose (PGG) inhibited NF-κB activation in LPS-stimulated peritoneal and colonic macrophages. Here we have investigated PGG mechanisms underlying anti-inflammatory effects of PGG in vitro and in vivo. Experimental Approach Male C57BL/6 mice (18–22 g, 6 weeks old) were used to prepare peritoneal and colonic macrophages and for the induction of colitis by intrarectal administration of 2,3,4-trinitrobenzene sulphonic acid (TNBS). A range of inflammatory markers and transcription factors were evaluated by elisa, immunoblotting, flow cytometry and confocal microscopy. Key Results Expression of Toll-like receptor (TLR)-4 or Lipopolysaccharide (LPS) binding to TLR-4 in LPS-stimulated peritoneal macrophages was not affected by PGG. However PGG inhibited binding of an anti-MyD88 antibody to peritoneal macrophages, but did not reduce binding of anti–IL-1 receptor-associated kinase (IRAK1) and IRAK4 antibodies to the macrophages with or without transfection with MyD88 siRNA. PGG potently reduced the activation of IRAK1, NF-κB, and MAPKs in LPS- or pepetidoglycan-stimulated peritoneal and colonic macrophages. PGG suppressed IL-1β, TNF-α and IL-6 in LPS-stimulated peritoneal macrophages, while increasing expression of the anti-inflammatorycytokine IL-10. Oral administration of PGG inhibited colon shortening and myeloperoxidase activity in mice with TNBS-induced colitis, along with reducing NF-κB activation and IL-1β, TNF-α, and IL-6 levels, whereas it increased IL-10. Conclusions and Implications PGG reduced activation of NF-κB and MAPK signalling pathways by directly interacting with the MyD88 adaptor protein. PGG may ameliorate inflammatory diseases such as colitis. PMID:23941302

  1. Differential requirements of MyD88 and TRIF pathways in TLR4-mediated immune responses in murine B cells.

    PubMed

    Yanagibashi, Tsutomu; Nagai, Yoshinori; Watanabe, Yasuharu; Ikutani, Masashi; Hirai, Yoshikatsu; Takatsu, Kiyoshi

    2015-01-01

    LPS stimulates the TLR4/Myeloid differentiation protein-2 (MD-2) complex and promotes a variety of immune responses in B cells. TLR4 has two main signaling pathways, MyD88 and Toll/IL-1R (TIR)-domain-containing adaptor-inducing interferon-β (TRIF) pathways, but relatively few studies have examined these pathways in B cells. In this study, we investigated MyD88- or TRIF-dependent LPS responses in B cells by utilizing their knockout mice. Compared with wild-type (WT) B cells, MyD88(-/-) B cells were markedly impaired in up-regulation of CD86 and proliferation induced by lipid A moiety of LPS. TRIF(-/-) B cells were also impaired in these responses compared with WT B cells, but showed better responses than MyD88(-/-) B cells. Regarding class switch recombination (CSR) elicited by lipid A plus IL-4, MyD88(-/-) B cells showed similar patterns of CSR to WT B cells. However, TRIF(-/-) B cells showed the impaired in the CSR. Compared with WT and MyD88(-/-) B cells, TRIF(-/-) B cells exhibited reduced cell division, fewer IgG1(+) cells per division, and decreased activation-induced cytidine deaminase (Aicda) mRNA expression in response to lipid A plus IL-4. Finally, IgG1 production to trinitrophenyl (TNP)-LPS immunization was impaired in TRIF(-/-) mice, while MyD88(-/-) mice exhibited increased IgG1 production. Thus, MyD88 and TRIF pathways differently regulate TLR4-induced immune responses in B cells. PMID:25448706

  2. MyD88 expression by CNS-resident cells is pivotal for eliciting protective immunity in brain abscesses

    PubMed Central

    Garg, Sarita; Nichols, Jessica R; Esen, Nilufer; Liu, Shuliang; Phulwani, Nirmal K; Syed, Mohsin Md.; Wood, William H; Zhang, Yongqing; Becker, Kevin G; Aldrich, Amy; Kielian, Tammy

    2009-01-01

    MyD88 KO (knockout) mice are exquisitely sensitive to CNS (central nervous system) infection with Staphylococcus aureus, a common aetiological agent of brain abscess, exhibiting global defects in innate immunity and exacerbated tissue damage. However, since brain abscesses are typified by the involvement of both activated CNS-resident and infiltrating immune cells, in our previous studies it has been impossible to determine the relative contribution of MyD88-dependent signalling in the CNS compared with the peripheral immune cell compartments. In the present study we addressed this by examining the course of S. aureus infection in MyD88 bone marrow chimaera mice. Interestingly, chimaeras where MyD88 was present in the CNS, but not bone marrow-derived cells, mounted pro-inflammatory mediator expression profiles and neutrophil recruitment equivalent to or exceeding that detected in WT (wild-type) mice. These results implicate CNS MyD88 as essential in eliciting the initial wave of inflammation during the acute response to parenchymal infection. Microarray analysis of infected MyD88 KO compared with WT mice revealed a preponderance of differentially regulated genes involved in apoptotic pathways, suggesting that the extensive tissue damage characteristic of brain abscesses from MyD88 KO mice could result from dysregulated apoptosis. Collectively, the findings of the present study highlight a novel mechanism for CNS-resident cells in initiating a protective innate immune response in the infected brain and, in the absence of MyD88 in this compartment, immunity is compromised. PMID:19570030

  3. Helical assembly in the MyD88-IRAK4-IRAK2 complex in TLR/IL-1R signalling

    SciTech Connect

    Lin, Su-Chang; Lo, Yu-Chih; Wu, Hao

    2010-08-23

    MyD88, IRAK4 and IRAK2 are critical signalling mediators of the TLR/IL1-R superfamily. Here we report the crystal structure of the MyD88-IRAK4-IRAK2 death domain (DD) complex, which surprisingly reveals a left-handed helical oligomer that consists of 6 MyD88, 4 IRAK4 and 4 IRAK2 DDs. Assembly of this helical signalling tower is hierarchical, in which MyD88 recruits IRAK4 and the MyD88-IRAK4 complex recruits the IRAK4 substrates IRAK2 or the related IRAK1. Formation of these Myddosome complexes brings the kinase domains of IRAKs into proximity for phosphorylation and activation. Composite binding sites are required for recruitment of the individual DDs in the complex, which are confirmed by mutagenesis and previously identified signalling mutations. Specificities in Myddosome formation are dictated by both molecular complementarity and correspondence of surface electrostatics. The MyD88-IRAK4-IRAK2 complex provides a template for Toll signalling in Drosophila and an elegant mechanism for versatile assembly and regulation of DD complexes in signal transduction.

  4. Unique properties of the chicken TLR4/MD-2 complex: selective lipopolysaccharide activation of the MyD88-dependent pathway.

    PubMed

    Keestra, A Marijke; van Putten, Jos P M

    2008-09-15

    During evolution, mammals have evolved a powerful innate immune response to LPS. Chickens are much more resistant to LPS-induced septic shock. Herein we report that chickens sense LPS via orthologs of mammalian TLR4 and myeloid differentiation protein-2 (MD-2) rather than the previously implicated chicken TLR2 isoform type 2 (chTLR2t2) receptor. Cloning and expression of recombinant chTLR4 and chMD-2 in HeLa 57A cells activated NF-kappaB at concentrations of LPS as low as 100 pg/ml. Differential pairing of chicken and mammalian TLR4 and MD-2 indicated that the protein interaction was species-specific in contrast to the formation of functional human and murine chimeric complexes. The chicken LPS receptor responded to a wide variety of LPS derivatives and to the synthetic lipid A compounds 406 and 506. The LPS specificity resembled the functionality of the murine rather than the human TLR4/MD-2 complex. Polymorphism in chTLR4 (Tyr(383)His and Gln(611)Arg) did not influence the LPS response. Interestingly, LPS consistently failed to activate the MyD88-independent induction of IFN-beta in chicken cells, in contrast to the TLR3 agonist poly(I:C) that yielded a potent IFN-beta response. These results suggest that chicken lack a functional LPS-specific TRAM-TRIF (TRIF-related adapter molecule/TIR-domain-containing adapter-inducing IFN-beta) signaling pathway, which may explain their aberrant response to LPS compared with the mammalian species. PMID:18768894

  5. Reduced MyD88 dependency of ISCOMATRIX™ adjuvant in a DNA prime-protein boost HIV vaccine

    PubMed Central

    Buglione-Corbett, Rachel; Pouliot, Kimberly; Marty-Roix, Robyn; Li, Wei; West, Kim; Wang, Shixia; Morelli, Adriana Baz; Lien, Egil; Lu, Shan

    2014-01-01

    ISCOMATRIX™ adjuvant is an integrated adjuvant system due to its ability to both facilitate antigen delivery and immunomodulate the innate and adaptive immune responses to vaccination. ISCOMATRIX™ adjuvant strongly induces both humoral and cell-mediated immunity in formulation with a range of antigens in pre-clinical and clinical evaluations. In this study, we describe the adaptive and innate immune responses associated with ISCOMATRIX™ adjuvant in the context of a previously described HIV-1 vaccine, DP6-001. The DP6-001 vaccine consists of a unique pentavalent HIV-1 Env DNA prime-protein boost regimen. This study demonstrates the potent induction of vaccine-specific antibodies in a mouse model, as well as broadly neutralizing antibodies in immunized rabbits. In addition, we identify a potentially critical role for DNA priming in the induction of the vaccine-specific immune response as well as the serum cytokine profiles associated with ISCOMATRIX™ adjuvant. Most interestingly, DNA prime immunizations made ISCOMATRIX™ adjuvant less dependent on the central innate immune adaptor MyD88, revealing a previously unknown mechanism that may expand our knowledge on the use of adjuvants. PMID:24513632

  6. Role of interleukin-1 receptor 1/MyD88 signalling in the development and progression of pulmonary hypertension.

    PubMed

    Parpaleix, Aurélien; Amsellem, Valérie; Houssaini, Amal; Abid, Shariq; Breau, Marielle; Marcos, Elisabeth; Sawaki, Daigo; Delcroix, Marion; Quarck, Rozenn; Maillard, Aurélie; Couillin, Isabelle; Ryffel, Bernhard; Adnot, Serge

    2016-08-01

    Pulmonary artery smooth muscle cell (PA-SMC) proliferation and inflammation are key components of pulmonary arterial hypertension (PAH). Interleukin (IL)-1β binds to IL-1 receptor (R)1, thereby recruiting the molecular adaptor myeloid differentiation primary response protein 88 (MyD88) (involved in IL-1R1 and Toll-like receptor signal transduction) and inducing IL-1, IL-6 and tumour necrosis factor-α synthesis through nuclear factor-κB activation.We investigated the IL-1R1/MyD88 pathway in the pathogenesis of pulmonary hypertension.Marked IL-1R1 and MyD88 expression with predominant PA-SMC immunostaining was found in lungs from patients with idiopathic PAH, mice with hypoxia-induced pulmonary hypertension and SM22-5-HTT(+) mice. Elevations in lung IL-1β, IL-1R1, MyD88 and IL-6 preceded pulmonary hypertension in hypoxic mice. IL-1R1(-/-), MyD88(-/-) and control mice given the IL-1R1 antagonist anakinra were protected similarly against hypoxic pulmonary hypertension and perivascular macrophage recruitment. Anakinra reversed pulmonary hypertension partially in SM22-5-HTT(+) mice and markedly in monocrotaline-treated rats. IL-1β-mediated stimulation of mouse PA-SMC growth was abolished by anakinra and absent in IL-1R1(-/-) and MyD88(-/-) mice. Gene deletion confined to the myeloid lineage (M.lys-Cre MyD88(fl/fl) mice) decreased pulmonary hypertension severity versus controls, suggesting IL-1β-mediated effects on PA-SMCs and macrophages. The growth-promoting effect of media conditioned by M1 or M2 macrophages from M.lys-Cre MyD88(fl/fl) mice was attenuated.Pulmonary vessel remodelling and inflammation during pulmonary hypertension require IL-1R1/MyD88 signalling. Targeting the IL-1β/IL-1R1 pathway may hold promise for treating human PAH. PMID:27418552

  7. Innate immune adaptor MyD88 mediates neutrophil recruitment and myocardial injury after ischemia-reperfusion in mice

    PubMed Central

    Feng , Yan; Zhao, Huailong; Xu, Xinhua; Buys, Emmanuel S.; Raher, Michael J.; Bopassa, Jean C.; Thibault, Helene; Scherrer-Crosbie, Marielle; Schmidt, Ulrich; Chao, Wei

    2008-01-01

    MyD88 is an adaptor protein critical for innate immune response against microbial infection and in certain noninfectious tissue injury. The present study examined the role of MyD88 in myocardial inflammation and injury after ischemia-reperfusion (I/R). I/R was produced by coronary artery ligation for 30 min followed by reperfusion. The ratios of area at risk to left ventricle (LV) were similar between wild-type (WT) and MyD88-deficient (MyD88−/−) mice. However, 24 h after I/R, the ratios of myocardial infarction to area at risk were 58% less in MyD88−/− than in WT mice (14 ± 2% vs. 33 ± 6%, P = 0.01). Serial echocardiographic studies demonstrated that there was no difference in baseline LV contractile function between the two groups. Twenty-four hours after I/R, LV ejection fraction (EF) and fractional shortening (FS) in WT mice were reduced by 44% and 62% (EF, 51 ± 2%, and FS, 22 ± 1%, P < 0.001), respectively, and remained depressed on the seventh day after I/R. In comparison, EF and FS in MyD88−/− mice were 67 ± 3% and 33 ± 2%, respectively, after I/R (P < 0.001 vs. WT). Similarly, LV function, as demonstrated by invasive hemodynamic measurements, was better preserved in MyD88−/− compared with WT mice after I/R. Furthermore, when compared with WT mice, MyD88−/− mice subjected to I/R had a marked decrease in myocardial inflammation as demonstrated by attenuated neutrophil recruitment and decreased expression of the proinflammatory mediators keratinocyte chemoattractant, monocyte chemoattractant protein-1, and ICAM-1. Taken together, these data suggest that MyD88 modulates myocardial inflammatory injury and contributes to myocardial infarction and LV dysfunction during I/R. PMID:18660455

  8. MYD88 L265P and CXCR4 mutations in lymphoplasmacytic lymphoma identify cases with high disease activity.

    PubMed

    Schmidt, Janine; Federmann, Birgit; Schindler, Natalie; Steinhilber, Julia; Bonzheim, Irina; Fend, Falko; Quintanilla-Martinez, Leticia

    2015-06-01

    Recurrent mutations in MYD88 have been identified in >90% of lymphoplasmacytic lymphoma (LPL). Recently, WHIM (warts, hypogammaglobulinaemia, infections, myelokathexis) syndrome-like mutations in CXCR4 have been described in 28% of LPL cases, and seem to impact clinical presentation and response to therapy. We investigated the presence of the MYD88 L265P mutation in 90 decalcified, formalin-fixed, paraffin-embedded (FFPE) bone marrow (BM) biopsies, including 51 cases of LPL, 14 cases of B-cell chronic lymphocytic leukaemia (CLL), 13 cases of marginal zone lymphoma (MZL) and 12 normal controls. In addition, the C-terminal domain of CXCR4 was sequenced in LPL cases. MYD88 L265P was found in 49/51 (96%) LPL cases and in 1/13 (7·6%) MZL (splenic type), whereas all CLL samples remained negative. The two MYD88 wild type LPL cases were associated with cold agglutinin disease. Mutations in CXCR4 were detected in 17/47 (36·2%) LPL cases, which showed a higher extent of BM infiltration and lower leucocyte counts (P = 0·02), haemoglobin (P = 0·05) and platelet counts (P = 0·01). In conclusion the detection of MYD88 L265P mutation in FFPE samples is reliable and useful for subtyping small B-cell lymphomas in BM biopsies. In addition, the presence of CXCR4 mutations identifies a subgroup of LPL patients with higher disease activity. PMID:25819228

  9. Intestinal epithelial MyD88 is a sensor switching host metabolism towards obesity according to nutritional status

    PubMed Central

    Everard, Amandine; Geurts, Lucie; Caesar, Robert; Van Hul, Matthias; Matamoros, Sébastien; Duparc, Thibaut; Denis, Raphael G. P.; Cochez, Perrine; Pierard, Florian; Castel, Julien; Bindels, Laure B.; Plovier, Hubert; Robine, Sylvie; Muccioli, Giulio G.; Renauld, Jean-Christophe; Dumoutier, Laure; Delzenne, Nathalie M.; Luquet, Serge; Bäckhed, Fredrik; Cani, Patrice D.

    2014-01-01

    Obesity is associated with a cluster of metabolic disorders, low-grade inflammation and altered gut microbiota. Whether host metabolism is controlled by intestinal innate immune system and the gut microbiota is unknown. Here we report that inducible intestinal epithelial cell-specific deletion of MyD88 partially protects against diet-induced obesity, diabetes and inflammation. This is associated with increased energy expenditure, an improved glucose homeostasis, reduced hepatic steatosis, fat mass and inflammation. Protection is transferred following gut microbiota transplantation to germ-free recipients. We also demonstrate that intestinal epithelial MyD88 deletion increases anti-inflammatory endocannabinoids, restores antimicrobial peptides production and increases intestinal regulatory T cells during diet-induced obesity. Targeting MyD88 after the onset of obesity reduces fat mass and inflammation. Our work thus identifies intestinal epithelial MyD88 as a sensor changing host metabolism according to the nutritional status and we show that targeting intestinal epithelial MyD88 constitutes a putative therapeutic target for obesity and related disorders. PMID:25476696

  10. Simultaneous targeting of MyD88 and Nur77 as an effective approach for the treatment of inflammatory diseases

    PubMed Central

    Uzma, Saqib; Baig, Mirza S

    2016-01-01

    Myeloid differentiation primary response protein 88 (MyD88) has long been considered a central player in the inflammatory pathway. Recent studies clearly suggest that it is an important therapeutic target in inflammation. On the other hand, a recent study on the interaction between the orphan nuclear receptor (Nur77) and p38α, leading to increased lipopolysaccharide-induced hyperinflammatory response, suggests this binary complex as a therapeutic target. In this study, we have designed inhibitors that can inhibit both MyD88 and Nur77 at the same time. Since both MyD88 and Nur77 are an integral part of the pathways involving lipopolysaccharide-induced activation of NF-κB-mediated inflammation, we tried to target both proteins with the same library in order to retrieve compounds having dual inhibitory properties. To perform this, we developed a homodimeric model of MyD88 and, along with the crystal structure of Nur77, screened a virtual library of compounds from the traditional Chinese medicine database containing ~61,000 compounds. We analyzed the resulting hits for their efficacy for dual binding and probed them for developing a common pharmacophore model that could be used as a prototype to screen compound libraries as well as to guide combinatorial library design to search for ideal dual-target inhibitors. Thus, our study explores the identification of novel leads having dual inhibiting effects due to binding to both MyD88 and Nur77 targets. PMID:27217723

  11. Early activation of MyD88-mediated autophagy sustains HSV-1 replication in human monocytic THP-1 cells.

    PubMed

    Siracusano, Gabriel; Venuti, Assunta; Lombardo, Daniele; Mastino, Antonio; Esclatine, Audrey; Sciortino, Maria Teresa

    2016-01-01

    Autophagy is a cellular degradation pathway that exerts numerous functions in vital biological processes. Among these, it contributes to both innate and adaptive immunity. On the other hand, pathogens have evolved strategies to manipulate autophagy for their own advantage. By monitoring autophagic markers, we showed that HSV-1 transiently induced autophagosome formation during early times of the infection of monocytic THP-1 cells and human monocytes. Autophagy is induced in THP-1 cells by a mechanism independent of viral gene expression or viral DNA accumulation. We found that the MyD88 signaling pathway is required for HSV-1-mediated autophagy, and it is linked to the toll-like receptor 2 (TLR2). Interestingly, autophagy inhibition by pharmacological modulators or siRNA knockdown impaired viral replication in both THP-1 cells and human monocytes, suggest that the virus exploits the autophagic machinery to its own benefit in these cells. Taken together, these findings indicate that the early autophagic response induced by HSV-1 exerts a proviral role, improving viral production in a semi-permissive model such as THP-1 cells and human monocytes. PMID:27509841

  12. Early activation of MyD88-mediated autophagy sustains HSV-1 replication in human monocytic THP-1 cells

    PubMed Central

    Siracusano, Gabriel; Venuti, Assunta; Lombardo, Daniele; Mastino, Antonio; Esclatine, Audrey; Sciortino, Maria Teresa

    2016-01-01

    Autophagy is a cellular degradation pathway that exerts numerous functions in vital biological processes. Among these, it contributes to both innate and adaptive immunity. On the other hand, pathogens have evolved strategies to manipulate autophagy for their own advantage. By monitoring autophagic markers, we showed that HSV-1 transiently induced autophagosome formation during early times of the infection of monocytic THP-1 cells and human monocytes. Autophagy is induced in THP-1 cells by a mechanism independent of viral gene expression or viral DNA accumulation. We found that the MyD88 signaling pathway is required for HSV-1-mediated autophagy, and it is linked to the toll-like receptor 2 (TLR2). Interestingly, autophagy inhibition by pharmacological modulators or siRNA knockdown impaired viral replication in both THP-1 cells and human monocytes, suggest that the virus exploits the autophagic machinery to its own benefit in these cells. Taken together, these findings indicate that the early autophagic response induced by HSV-1 exerts a proviral role, improving viral production in a semi-permissive model such as THP-1 cells and human monocytes. PMID:27509841

  13. The categorization and mutual modulation of expanded MyD88s in Crassostrea gigas.

    PubMed

    Xin, Lusheng; Wang, Mengqiang; Zhang, Huan; Li, Meijia; Wang, Hao; Wang, Lingling; Song, Linsheng

    2016-07-01

    MyD88 serves as a critical cytosolic adaptor mediating activation of NF-κB in innate immunity. It has been found that there is a considerable expansion of MyD88 in Crassostrea gigas. In the present study, four typical MyD88 genes in Crassostrea gigas (CgMyD88-A to CgMyD88-D) were successfully cloned and their potential functions were investigated together with another two known ones (CgMyD88-T1 and CgMyD88-T2). Multiple alignments revealed that CgMyD88-B and CgMyD88-C remained the conserved DD and TIR domains, while there was a significant variation of E51Q in the DD of CgMyD88-A, and some variations in both DD and TIR domains of CgMyD88-D, respectively. Both truncated CgMyD88-T1 and CgMyD88-T2 lacked Box II in their only TIR domains. Expression pattern analysis showed that CgMyD88-B and CgMyD88-C genes possessed higher expression in normal tissues, compared with the other four. When oysters were under bacteria challenge, CgMyD88-B, CgMyD88-C, CgMyD88-T1 and CgMyD88-T2 were firstly induced, while CgMyD88-A and CgMyD88-D were suppressed. Dual luciferase reporter assays showed that CgMyD88-B and CgMyD88-C could promote the activation of NF-κB signaling pathway, while the other four CgMyD88 genes failed or even suppressed the activities of CgMyD88-B and CgMyD88-C on the activation of NF-κB signaling. It was deduced that after oysters were challenged by bacteria, CgMyD88-B and CgMyD88-C could rapidly and efficiently activate NF-κB signaling pathway to elicit anti-pathogen responses before suppressor CgMyD88 genes (CgMyD88-T1 and CgMyD88-T2) exceeding their expression level. These results suggested that there was mutual modulation of expanded CgMyD88 genes on activating NF-κB signaling pathway in oyster C. gigas. PMID:27074442

  14. Recurrent candidiasis and early-onset gastric cancer in a patient with a genetically defined partial MYD88 defect.

    PubMed

    Vogelaar, Ingrid P; Ligtenberg, Marjolijn J L; van der Post, Rachel S; de Voer, Richarda M; Kets, C Marleen; Jansen, Trees J G; Jacobs, Liesbeth; Schreibelt, Gerty; de Vries, I Jolanda M; Netea, Mihai G; Hoogerbrugge, Nicoline

    2016-04-01

    Gastric cancer is caused by both genetic and environmental factors. A woman who suffered from recurrent candidiasis throughout her life developed diffuse-type gastric cancer at the age of 23 years. Using whole-exome sequencing we identified a germline homozygous missense variant in MYD88. Immunological assays on peripheral blood mononuclear cells revealed an impaired immune response upon stimulation with Candida albicans, characterized by a defective production of the cytokine interleukin-17. Our data suggest that a genetic defect in MYD88 results in an impaired immune response and may increase gastric cancer risk. PMID:26700889

  15. Lung epithelial MyD88 drives early pulmonary clearance of Pseudomonas aeruginosa by a flagellin dependent mechanism.

    PubMed

    Anas, Adam A; van Lieshout, Miriam H P; Claushuis, Theodora A M; de Vos, Alex F; Florquin, Sandrine; de Boer, Onno J; Hou, Baidong; Van't Veer, Cornelis; van der Poll, Tom

    2016-08-01

    Pseudomonas aeruginosa is a flagellated pathogen frequently causing pneumonia in hospitalized patients and sufferers of chronic lung disease. Here we investigated the role of the common Toll-like receptor (TLR) adaptor myeloid differentiation factor (MyD)88 in myeloid vs. lung epithelial cells in clearance of P. aeruginosa from the airways. Mice deficient for MyD88 in lung epithelial cells (Sftpccre-MyD88-lox mice) or myeloid cells (LysMcre-MyD88-lox mice) and bone marrow chimeric mice deficient for TLR5 (the receptor recognizing Pseudomonas flagellin) in either parenchymal or hematopoietic cells were infected with P. aeruginosa via the airways. Sftpccre-MyD88-lox mice demonstrated a reduced influx of neutrophils into the bronchoalveolar space and an impaired early antibacterial defense after infection with P. aeruginosa, whereas the response of LysMcre-MyD88-lox mice did not differ from control mice. The immune-enhancing role of epithelial MyD88 was dependent on recognition of pathogen-derived flagellin by epithelial TLR5, as demonstrated by an unaltered clearance of mutant P. aeruginosa lacking flagellin from the lungs of Sftpccre-MyD88-lox mice and an impaired bacterial clearance in bone marrow chimeric mice lacking TLR5 in parenchymal cells. These data indicate that early clearance of P. aeruginosa from the airways is dependent on flagellin-TLR5-MyD88-dependent signaling in respiratory epithelial cells. PMID:27288486

  16. SARM modulates MyD88-mediated TLR activation through BB-loop dependent TIR-TIR interactions.

    PubMed

    Carlsson, Emil; Ding, Jeak Ling; Byrne, Bernadette

    2016-02-01

    Toll-like receptors (TLRs) recognise invading pathogens and initiate an innate immune response by recruiting intracellular adaptor proteins via heterotypic Toll/interleukin-1 receptor (TIR) domain interactions. Of the five TIR domain-containing adaptor proteins identified, Sterile α- and armadillo-motif-containing protein (SARM) is functionally unique; suppressing immune signalling instead of promoting it. Here we demonstrate that the recombinantly expressed and purified SARM TIR domain interacts with both the major human TLR adaptors, MyD88 and TRIF. A single glycine residue located in the BB-loop of the SARM TIR domain, G601, was identified as essential for interaction. A short peptide derived from this motif was also found to interact with MyD88 in vitro. SARM expression in HEK293 cells was found to significantly suppress lipopolysaccharide (LPS)-mediated upregulation of inflammatory cytokines, IL-8 and TNF-α, an effect lost in the G601A mutant. The same result was observed with cytokine activation initiated by MyD88 expression and stimulation of TLR2 with lipoteichoic acid (LTA), suggesting that SARM is capable of suppressing both TRIF- and MyD88- dependent TLR signalling. Our findings indicate that SARM acts on a broader set of target proteins than previously thought, and that the BB-loop motif is functionally important, giving further insight into the endogenous mechanisms used to suppress inflammation in immune cells. PMID:26592460

  17. Liver Fibrosis Occurs Through Dysregulation of MyD88-dependent Innate B cell Activity

    PubMed Central

    Thapa, Manoj; Chinnadurai, Raghavan; Velazquez, Victoria M.; Tedesco, Dana; Elrod, Elizabeth; Han, Jin-Hwan; Sharma, Prachi; Ibegbu, Chris; Gewirtz, Andrew; Anania, Frank; Pulendran, Bali; Suthar, Mehul S.; Grakoui, Arash

    2015-01-01

    Chronic liver disease mediated by activation of hepatic stellate cells (HSCs) leads to liver fibrosis. Here, we postulated that the immune regulatory properties of HSCs might promote the profibrogenic activity of B cells. Fibrosis is completely attenuated in carbon tetrachloride (CCl4)-treated B cell deficient μMT mice showing that B cells are required. The retinoic acid produced by HSCs augmented B cell survival, plasma cell marker CD138 expression, and IgG production. These activities were reversed following the addition of the retinoic acid inhibitor, LE540. Transcriptional profiling of fibrotic liver B cells revealed an increased expression of genes related to NF-κB activation, proinflammatory cytokine production and CD40 signaling suggesting that these B cells are activated and may be acting as inflammatory cells. Biological validation experiments also revealed increased activation (CD44 and CD86 expressions), constitutive IgG production and secretion of the proinflammatory cytokines TNF-α, MCP-1 and MIP1-α. Likewise targeted deletion of B-cell-intrinsic MyD88 signaling, an innate adaptor with involvement in RA signaling, resulted in reduced infiltration of migratory CD11c+ dendritic cells and Ly6C++ monocytes, and hence reduced liver pathology. Conclusion Our findings demonstrate that liver fibrosis occurs through a mechanism of HSC-mediated augmentation of innate B cell activity and highlight B cells as an important ‘first responders’ of the intrahepatic immune environment. PMID:25711908

  18. Impaired Innate Immunity in Tlr4−/− Mice but Preserved CD8+ T Cell Responses against Trypanosoma cruzi in Tlr4-, Tlr2-, Tlr9- or Myd88-Deficient Mice

    PubMed Central

    Tzelepis, Fanny; Klezewsky, Weberton; da Silva, Raquel N.; Neves, Fabieni S.; Cavalcanti, Gisele S.; Boscardin, Silvia; Nunes, Marise P.; Santiago, Marcelo F.; Nóbrega, Alberto; Rodrigues, Maurício M.; Bellio, Maria

    2010-01-01

    The murine model of T. cruzi infection has provided compelling evidence that development of host resistance against intracellular protozoans critically depends on the activation of members of the Toll-like receptor (TLR) family via the MyD88 adaptor molecule. However, the possibility that TLR/MyD88 signaling pathways also control the induction of immunoprotective CD8+ T cell-mediated effector functions has not been investigated to date. We addressed this question by measuring the frequencies of IFN-γ secreting CD8+ T cells specific for H-2Kb-restricted immunodominant peptides as well as the in vivo Ag-specific cytotoxic response in infected animals that are deficient either in TLR2, TLR4, TLR9 or MyD88 signaling pathways. Strikingly, we found that T. cruzi-infected Tlr2−/−, Tlr4−/−, Tlr9−/− or Myd88−/− mice generated both specific cytotoxic responses and IFN-γ secreting CD8+ T cells at levels comparable to WT mice, although the frequency of IFN-γ+CD4+ cells was diminished in infected Myd88−/− mice. We also analyzed the efficiency of TLR4-driven immune responses against T. cruzi using TLR4-deficient mice on the C57BL genetic background (B6 and B10). Our studies demonstrated that TLR4 signaling is required for optimal production of IFN-γ, TNF-α and nitric oxide (NO) in the spleen of infected animals and, as a consequence, Tlr4−/− mice display higher parasitemia levels. Collectively, our results indicate that TLR4, as well as previously shown for TLR2, TLR9 and MyD88, contributes to the innate immune response and, consequently, resistance in the acute phase of infection, although each of these pathways is not individually essential for the generation of class I-restricted responses against T. cruzi. PMID:20442858

  19. Measurement of TLR-Induced Macrophage Spreading by Automated Image Analysis: Differential Role of Myd88 and MAPK in Early and Late Responses

    PubMed Central

    Wenzel, Jens; Held, Christian; Palmisano, Ralf; Teufel, Stefan; David, Jean-Pierre; Wittenberg, Thomas; Lang, Roland

    2011-01-01

    Sensing of infectious danger by toll-like receptors (TLRs) on macrophages causes not only a reprogramming of the transcriptome but also changes in the cytoskeleton important for cell spreading and motility. Since manual determination of cell contact areas from fluorescence micrographs is very time-consuming and prone to bias, we have developed and tested algorithms for automated measurement of macrophage spreading. The two-step method combines identification of cells by nuclear staining with DAPI and cell surface staining of the integrin CD11b. Automated image analysis correlated very well with manual annotation in resting macrophages and early after stimulation, whereas at later time points the automated cell segmentation algorithm and manual annotation showed slightly larger variation. The method was applied to investigate the impact of genetic or pharmacological inhibition of known TLR signaling components. Deficiency in the adapter protein Myd88 strongly reduced spreading activity at the late time points, but had no impact early after LPS-stimulation. A similar effect was observed upon pharmacological inhibition of MEK1, the kinase activating the mitogen-activated protein kinases (MAPK) ERK1/2, indicating that ERK1/2 mediates Myd88-dependent macrophages spreading. In contrast, macrophages lacking the MAPK p38 were impaired in the initial spreading response but responded normally 8–24 h after stimulation. The dichotomy of p38 and ERK1/2 MAPK effects on early and late macrophage spreading raises the question which of the respective substrate proteins mediate(s) cytoskeletal remodeling and spreading. The automated measurement of cell spreading described here increases the objectivity and greatly reduces the time required for such investigations and is therefore expected to facilitate larger throughput analysis of macrophage spreading, e.g., in siRNA knockdown screens. PMID:22028692

  20. Ligand-independent TLR signals generated by ectopic overexpression of MyD88 generate local and systemic anti-tumor immunity

    PubMed Central

    Hartman, Zachary C.; Osada, Takuya; Glass, Oliver; Yang, Xiao Y.; Lei, Gang-jun; Lyerly, H. Kim; Clay, Timothy M.

    2010-01-01

    Although critical for initiating and regulating immune responses, the therapeutic use of individual cytokines as anti-cancer immunotherapeutic agents has achieved only modest clinical success. Consequently, many current strategies have focused on the use of specific immunotherapeutic agonists that engage individual receptors of innate immune networks, such as the Toll Like-Receptor (TLR) system, each resulting in specific patterns of gene expression, cytokine production and inflammatory outcome. However, these immunotherapeutics are constrained by variable cellular TLR expression and responsiveness to particular TLR agonists, as well as the specific cellular context of different tumors. We hypothesized that overexpression of MyD88, a pivotal regulator of multiple TLR signaling pathways, could circumvent these constraints and mimic coordinated TLR signaling across all cell types in a ligand independent fashion. To explore this hypothesis, we generated an adenoviral vector expressing MyD88 and demonstrate that Ad-MyD88 infection elicits extensive Th1-specific transcriptional and secreted cytokine signatures in all murine and human cell types tested in vitro and in vivo. Importantly, in vivo intratumoral injection of Ad-MyD88 into established tumor masses enhanced adaptive immune responses and inhibited local tumor immunosuppression, resulting in significantly inhibited local and systemic growth of multiple tumor types. Finally, Ad-MyD88 infection of primary human dendritic cells, tumor associated fibroblasts, and colorectal carcinoma cells elicited significant Th1-type cytokine responses, resulting in enhanced tumor cell lysis and expansion of human tumor antigen-specific T-cells. Thus, Ad-MyD88 initiated robust anti-tumor activity in established murine tumor microenvironments and in human contexts, suggesting its potential effectiveness as a clinical immunotherapeutic strategy. PMID:20823152

  1. IRAK-4 and MyD88 deficiencies impair IgM responses against T-independent bacterial antigens.

    PubMed

    Maglione, Paul J; Simchoni, Noa; Black, Samuel; Radigan, Lin; Overbey, Jessica R; Bagiella, Emilia; Bussel, James B; Bossuyt, Xavier; Casanova, Jean-Laurent; Meyts, Isabelle; Cerutti, Andrea; Picard, Capucine; Cunningham-Rundles, Charlotte

    2014-12-01

    IRAK-4 and MyD88 deficiencies impair interleukin 1 receptor and Toll-like receptor (TLR) signaling and lead to heightened susceptibility to invasive bacterial infections. Individuals with these primary immunodeficiencies have fewer immunoglobulin M (IgM)(+)IgD(+)CD27(+) B cells, a population that resembles murine splenic marginal zone B cells that mount T-independent antibody responses against bacterial antigens. However, the significance of this B-cell subset in humans is poorly understood. Using both a 610 carbohydrate array and enzyme-linked immunosorbent assay, we found that patients with IRAK-4 and MyD88 deficiencies have reduced serum IgM, but not IgG antibody, recognizing T-independent bacterial antigens. Moreover, the quantity of specific IgM correlated with IgM(+)IgD(+)CD27(+) B-cell frequencies. As with mouse marginal zone B cells, human IgM(+)CD27(+) B cells activated by TLR7 or TLR9 agonists produced phosphorylcholine-specific IgM. Further linking splenic IgM(+)IgD(+)CD27(+) B cells with production of T-independent IgM, serum from splenectomized subjects, who also have few IgM(+)IgD(+)CD27(+) B cells, had reduced antibacterial IgM. IRAK-4 and MyD88 deficiencies impaired TLR-induced proliferation of this B-cell subset, suggesting a means by which loss of this activation pathway leads to reduced cell numbers. Thus, by bolstering the IgM(+)IgD(+)CD27(+) B-cell subset, IRAK-4 and MyD88 promote optimal T-independent IgM antibody responses against bacteria in humans. PMID:25320238

  2. Pneumoviruses infect eosinophils and elicit MyD88-dependent release of chemoattractant cytokines and interleukin-6

    PubMed Central

    Percopo, Caroline M.; Fischer, Elizabeth R.; Gabryszewski, Stanislaw J.; Rosenberg, Helene F.

    2009-01-01

    Eosinophils are recruited to the lung in response to infection with pneumovirus pathogens and have been associated with both the pathophysiologic sequelae of infection and, more recently, with accelerated virus clearance. Here, we demonstrate that the pneumovirus pathogens, respiratory syncytial virus (RSV) and pneumonia virus of mice (PVM), can infect human and mouse eosinophils, respectively, and that virus infection of eosinophils elicits the release of disease-related proinflammatory mediators from eosinophils. RSV replication in human eosinophils results in the release of infectious virions and in the release of the proinflammatory mediator, interleukin-6 (IL-6). PVM replication in cultured bone marrow eosinophils (bmEos) likewise results in release of infectious virions and the proinflammatory mediators IL-6, IP-10, CCL2, and CCL3. In contrast to the findings reported in lung tissue of RSV-challenged mice, PVM replication is accelerated in MyD88 gene-deleted bmEos, whereas release of cytokines is diminished. Interestingly, exogenous IL-6 suppresses virus replication in MyD88 gene-deleted bmEos, suggesting a role for a MyD88-dependent cytokine-mediated feedback circuit in modulating this response. Taken together, our findings suggest that eosinophils are targets of virus infection and may have varied and complex contributions to the pathogenesis and resolution of pneumovirus disease. PMID:19652202

  3. Inhibition of IL-1R1/MyD88 signalling promotes mesenchymal stem cell-driven tissue regeneration

    PubMed Central

    Martino, Mikaël M.; Maruyama, Kenta; Kuhn, Gisela A.; Satoh, Takashi; Takeuchi, Osamu; Müller, Ralph; Akira, Shizuo

    2016-01-01

    Tissue injury and the healing response lead to the release of endogenous danger signals including Toll-like receptor (TLR) and interleukin-1 receptor, type 1 (IL-1R1) ligands, which modulate the immune microenvironment. Because TLRs and IL-1R1 have been shown to influence the repair process of various tissues, we explored their role during bone regeneration, seeking to design regenerative strategies integrating a control of their signalling. Here we show that IL-1R1/MyD88 signalling negatively regulates bone regeneration, in the mouse. Furthermore, IL-1β which is released at the bone injury site, inhibits the regenerative capacities of mesenchymal stem cells (MSCs). Mechanistically, IL-1R1/MyD88 signalling impairs MSC proliferation, migration and differentiation by inhibiting the Akt/GSK-3β/β-catenin pathway. Lastly, as a proof of concept, we engineer a MSC delivery system integrating inhibitors of IL-1R1/MyD88 signalling. Using this strategy, we considerably improve MSC-based bone regeneration in the mouse, demonstrating that this approach may be useful in regenerative medicine applications. PMID:27001940

  4. Inhibition of IL-1R1/MyD88 signalling promotes mesenchymal stem cell-driven tissue regeneration.

    PubMed

    Martino, Mikaël M; Maruyama, Kenta; Kuhn, Gisela A; Satoh, Takashi; Takeuchi, Osamu; Müller, Ralph; Akira, Shizuo

    2016-01-01

    Tissue injury and the healing response lead to the release of endogenous danger signals including Toll-like receptor (TLR) and interleukin-1 receptor, type 1 (IL-1R1) ligands, which modulate the immune microenvironment. Because TLRs and IL-1R1 have been shown to influence the repair process of various tissues, we explored their role during bone regeneration, seeking to design regenerative strategies integrating a control of their signalling. Here we show that IL-1R1/MyD88 signalling negatively regulates bone regeneration, in the mouse. Furthermore, IL-1β which is released at the bone injury site, inhibits the regenerative capacities of mesenchymal stem cells (MSCs). Mechanistically, IL-1R1/MyD88 signalling impairs MSC proliferation, migration and differentiation by inhibiting the Akt/GSK-3β/β-catenin pathway. Lastly, as a proof of concept, we engineer a MSC delivery system integrating inhibitors of IL-1R1/MyD88 signalling. Using this strategy, we considerably improve MSC-based bone regeneration in the mouse, demonstrating that this approach may be useful in regenerative medicine applications. PMID:27001940

  5. A potential link between TSLP/TSLPR/STAT5 and TLR2/MyD88/NFκB-p65 in human corneal epithelial cells for Aspergillus fumigatus tolerance.

    PubMed

    Ren, Xiaoxiao; Wang, Leyi; Wu, Xinyi

    2016-03-01

    Our previous studies reported that pattern recognition receptors (PRRs), including the cell surface Toll-like receptors (TLRs) and cytoplasmic NOD-like receptors (NLRs), recognize pathogen-associated molecular patterns (PAMPS) to initiate downstream signal cascades to active immunity responses. Thymic stromal lymphopoietin (TSLP) has recently emerged as a key cytokine in the development of type 2 adaptive immune responses. However, the crosstalk between PRRs and TSLP has not been well elucidated in Aspergillus fumigates keratitis. Our studies demonstrated that HCECs not only respond to TSLP, but also initiate immunological regulation through TSLP/TSLPR/STAT5 signaling pathway. In addition, we revealed that zymosan TLR2 agonist enhanced the expression of TSLP and TSLPR and phosphorylation of STAT5. Furthermore, neutralization of TLR2 with monoclonal Ab prevented the production of TSLP and TSLPR and phosphorylation of STAT5 from increasing which induced by A. fumigatus hyphae. Interestingly, we also found that human recombinant TSLP induced the increase of TLR2 downstream signal molecules, and TSLP knockdown could reduce the increase of TLR2 downstream signaling molecules(MyD88 and NF-κB-p65) induced by A. fumigatus hyphae. These studies indicated that HCECs represent a novel target of TSLP, TSLP/TSLPR/STAT5 signaling plays an important role in response to A. fumigatus infection in HCECs, and TLR2 downstream signaling molecules up regulate TSLP/TSLPR/STAT5 signaling as well as TSLP downstream signaling molecules up regulate TLR2/MyD88/NFκB-p65 signaling in this phenomenon. PMID:26874828

  6. Natural Killer Cell Sensing of Infected Cells Compensates for MyD88 Deficiency but Not IFN-I Activity in Resistance to Mouse Cytomegalovirus.

    PubMed

    Cocita, Clément; Guiton, Rachel; Bessou, Gilles; Chasson, Lionel; Boyron, Marilyn; Crozat, Karine; Dalod, Marc

    2015-05-01

    In mice, plasmacytoid dendritic cells (pDC) and natural killer (NK) cells both contribute to resistance to systemic infections with herpes viruses including mouse Cytomegalovirus (MCMV). pDCs are the major source of type I IFN (IFN-I) during MCMV infection. This response requires pDC-intrinsic MyD88-dependent signaling by Toll-Like Receptors 7 and 9. Provided that they express appropriate recognition receptors such as Ly49H, NK cells can directly sense and kill MCMV-infected cells. The loss of any one of these responses increases susceptibility to infection. However, the relative importance of these antiviral immune responses and how they are related remain unclear. In humans, while IFN-I responses are essential, MyD88 is dispensable for antiviral immunity. Hence, a higher redundancy has been proposed in the mechanisms promoting protective immune responses against systemic infections by herpes viruses during natural infections in humans. It has been assumed, but not proven, that mice fail to mount protective MyD88-independent IFN-I responses. In humans, the mechanism that compensates MyD88 deficiency has not been elucidated. To address these issues, we compared resistance to MCMV infection and immune responses between mouse strains deficient for MyD88, the IFN-I receptor and/or Ly49H. We show that selective depletion of pDC or genetic deficiencies for MyD88 or TLR9 drastically decreased production of IFN-I, but not the protective antiviral responses. Moreover, MyD88, but not IFN-I receptor, deficiency could largely be compensated by Ly49H-mediated antiviral NK cell responses. Thus, contrary to the current dogma but consistent with the situation in humans, we conclude that, in mice, in our experimental settings, MyD88 is redundant for IFN-I responses and overall defense against a systemic herpes virus infection. Moreover, we identified direct NK cell sensing of infected cells as one mechanism able to compensate for MyD88 deficiency in mice. Similar mechanisms likely contribute to protect MyD88- or IRAK4-deficient patients from viral infections. PMID:25954804

  7. Induction of diabetes in the RIP-B7.1 mouse model is critically dependent on TLR3 and MyD88 pathways and is associated with alterations in the intestinal microbiome.

    PubMed

    Alkanani, Aimon K; Hara, Naoko; Lien, Egil; Ir, Diana; Kotter, Cassandra V; Robertson, Charles E; Wagner, Brandie D; Frank, Daniel N; Zipris, Danny

    2014-02-01

    RIP-B7.1 transgenic mice express B7.1 costimulatory molecules in pancreatic islets and develop diabetes after treatment with polyinosinic:polycytidylic acid (poly I:C), a synthetic double-stranded RNA and agonist of Toll-like receptor (TLR) 3 and retinoic acid-inducible protein I. We used this model to investigate the role of TLR pathways and intestinal microbiota in disease progression. RIP-B7.1 mice homozygous for targeted disruption of TLR9, TLR3, and myeloid differentiation factor-88 (MyD88), and most of the wild-type RIP-B7.1 mice housed under normal conditions remained diabetes-free after poly I:C administration. However, the majority of TLR9-deficient mice and wild-type animals treated with poly I:C and an antibiotic developed disease. In sharp contrast, TLR3- and MyD88-deficient mice were protected from diabetes following the same treatment regimen. High-throughput DNA sequencing demonstrated that TLR9-deficient mice treated with antibiotics plus poly I:C had higher bacterial diversity compared with disease-resistant mice. Furthermore, principal component analysis suggested that TLR9-deficient mice had distinct gut microbiome compared with the diabetes-resistant mice. Finally, the administration of sulfatrim plus poly I:C to TLR9-deficient mice resulted in alterations in the abundance of gut bacterial communities at the phylum and genus levels. These data imply that the induction of diabetes in the RIP-B7.1 model is critically dependent on TLR3 and MyD88 pathways, and involves modulation of the intestinal microbiota. PMID:24353176

  8. Fas activation in alveolar epithelial cells induces KC (CXCL1) release by a MyD88-dependent mechanism.

    PubMed

    Farnand, Alex W; Eastman, Alison J; Herrero, Raquel; Hanson, Josiah F; Mongovin, Steve; Altemeier, William A; Matute-Bello, Gustavo

    2011-09-01

    Activation of the Fas/Fas ligand (FasL) system is associated with activation of apoptotic and proinflammatory pathways that lead to the development of acute lung injury. Previous studies in chimeric mice and macrophage-depleted mice suggested that the main effector cell in Fas-mediated lung injury is not a myeloid cell, but likely an epithelial cell. The goal of this study was to determine whether epithelial cells release proinflammatory cytokines after Fas activation, and to identify the relevant pathways. Incubation of the murine alveolar epithelial cell line, MLE-12, with the Fas-activating monoclonal antibody, Jo2, resulted in release of the CXC chemokine, KC, in a dose-dependent manner. KC release was not prevented by the pan-caspase inhibitor, zVAD.fmk. Silencing of the adaptor protein, MyD88, with small interfering (si)RNA resulted in attenuation of KC release in response to Jo2. Fas activation resulted in phosphorylation of the mitogen-activated kinases extracellular signal-regulated kinase (ERK) and c-Jun-N-terminal kinase (JNK), and pharmacologic inhibition of ERK and JNK attenuated KC release in a dose-response manner. Similarly, primary human small airways epithelial cells released IL-8 in response to soluble FasL, and this was abrogated by inhibition of JNK and ERK. In vivo confirmatory studies showed that MyD88-null mice are protected from Fas-induced acute lung injury. In summary, we conclude that Fas induces KC release in MLE-12 cells by a mechanism requiring MyD88, mitogen-activated protein kinases, and likely activator protein-1. PMID:21257927

  9. Retinol-Binding Protein 4 Induces Cardiomyocyte Hypertrophy by Activating TLR4/MyD88 Pathway.

    PubMed

    Gao, Wei; Wang, Hao; Zhang, Lin; Cao, Yang; Bao, Ji-Zhang; Liu, Zheng-Xia; Wang, Lian-Sheng; Yang, Qin; Lu, Xiang

    2016-06-01

    Insulin resistance plays a major role in the development and progression of cardiac hypertrophy and heart failure. Heart failure in turn promotes insulin resistance and increases the risk for diabetes. The vicious cycle determines significant mortality in patients with heart failure and diabetes. However, the underlying mechanisms for the vicious cycle are not fully elucidated. Here we show that circulating levels and adipose expression of retinol-binding protein 4 (RBP4), an adipokine that contributes to systemic insulin resistance, were elevated in cardiac hypertrophy induced by transverse aortic constriction and angiotensin-II (Ang-II) infusion. Ang-II increased RBP4 expression in adipocytes, which was abolished by losartan, an Ang-II receptor blocker. The elevated RBP4 in cardiac hypertrophy may have pathophysiological consequences because RBP4 increased cell size, enhanced protein synthesis, and elevated the expression of hypertrophic markers including Anp, Bnp, and Myh7 in primary cardiomyocytes. Mechanistically, RBP4 induced the expression and activity of toll-like receptor 4 (TLR4) and myeloid differentiation primary response gene 88 (MyD88) in cardiomyocytes, resulting in enhanced inflammation and reactive oxygen species production. Inhibition or knockdown of the TLR4/MyD88 pathway attenuated inflammatory and hypertrophic responses to RBP4 stimulation. Importantly, RBP4 also reduced the expression of glucose transporter-4 and impaired insulin-stimulated glucose uptake in cardiomyocytes. This impairment was ameliorated in cardiomyocytes from TLR4 knockout mice. Therefore, RBP4 may be a critical modulator promoting the vicious cycle of insulin resistance and heart failure by activating TLR4/MyD88-mediated inflammatory pathways. Potentially, lowering RBP4 might break the vicious cycle and improve both insulin resistance and cardiac hypertrophy. PMID:27100622

  10. Dioscin reduces lipopolysaccharide-induced inflammatory liver injury via regulating TLR4/MyD88 signal pathway.

    PubMed

    Yao, Hong; Hu, Changsheng; Yin, Lianhong; Tao, Xufeng; Xu, Lina; Qi, Yan; Han, Xu; Xu, Youwei; Zhao, Yanyan; Wang, Changyuan; Peng, Jinyong

    2016-07-01

    We previously reported the effects of dioscin against carbon tetrachloride-, acetaminophen- and alcohol-induced acute liver damage. However, its effect on lipopolysaccharide (LPS)-induced inflammatory liver injury remains unknown. In the present work, liver injury in mice and rats was induced by LPS, and dioscin was intragastrically administered for 7days. In vitro, the AML-12 cells and HepG-2 cells were treated with LPS after dioscin treatment. The results showed that dioscin not only markedly reduced serum ALT, AST levels and relative liver weights, but also restored cell injury caused by LPS. In mechanism study, dioscin significantly attenuated inflammation through down-regulating the levels of toll-like receptor (TLR) 4, myeloid differentiation factor 88 (MyD88), interleukin-1 receptor-associated kinase 1 (IRAK1), tumor necrosis factor receptor-associated factor 6 (TRAF6), phosphorylated inhibitor of nuclear factor κB kinase (p-IKK), phosphorylated inhibitor of nuclear factor κB alpha (p-IκBα), phosphorylated nuclear factor κB p65 (p-NF-κB p65), high-mobility group protein 1 (HMGB-1), interleukin (IL)-1, IL-6 and tumor necrosis factor-α (TNF-α). TLR4 overexpression was also decreased by dioscin, leading to the markedly decreased levels of MyD88, IRAK1, TRAF6, p-IKK, p-IκBα, p-NF-κB p65 and HMGB-1. Suppression of MyD88 by ST2825 eliminated the inhibitory effects of dioscin on the levels of IRAK1, TRAF6, p-IKK, p-IκBα, p-NF-κB p65, HMGB-1, IL-1β, IL-6 and TNF-α. Our results suggested that dioscin exhibited protective effect against LPS-induced liver injury via altering TLR4/MyD88 pathway, which should be developed as one potent candidate for the treatment of acute inflammatory liver injury in the future. PMID:27135544

  11. Conformational dynamics of cancer-associated MyD88-TIR domain mutant L252P (L265P) allosterically tilts the landscape toward homo-dimerization.

    PubMed

    Zhan, Chendi; Qi, Ruxi; Wei, Guanghong; Guven-Maiorov, Emine; Nussinov, Ruth; Ma, Buyong

    2016-09-01

    MyD88 is an essential adaptor protein, which mediates the signaling of the toll-like and interleukin-1 receptors' superfamily. The MyD88 L252P (L265P) mutation has been identified in diffuse large B-cell lymphoma. The identification of this mutation has been a major advance in the diagnosis of patients with aldenstrom macroglobulinemia and related lymphoid neoplasms. Here we used computational methods to characterize the conformational effects of the mutation. Our molecular dynamics simulations revealed that the mutation allosterically quenched the global conformational dynamics of the toll/IL-1R (TIR) domain, and readjusted its salt bridges and dynamic community network. Specifically, the mutation changed the orientation and reduced the fluctuation of α-helix 3, possibly through eliminating/weakening ~8 salt bridges and enhancing the salt bridge D225-K258. Using the energy landscape of the TIR domains of MyD88, we identified two dynamic conformational basins, which correspond to the binding sites used in homo- and hetero-oligomerization, respectively. Our results indicate that the mutation stabilizes the core of the homo-dimer interface of the MyD88-TIR domain, and increases the population of homo-dimer-compatible conformational states in MyD88 family proteins. However, the dampened motion restricts its ability to heterodimerize with other TIR domains, thereby curtailing physiological signaling. In conclusion, the L252P both shifts the landscape toward homo-dimerization and restrains the dynamics of the MyD88-TIR domain, which disfavors its hetero-dimerization with other TIR domains. We further put these observations within the framework of MyD88-mediated cell signaling. PMID:27503954

  12. Desert dust induces TLR signaling to trigger Th2-dominant lung allergic inflammation via a MyD88-dependent signaling pathway.

    PubMed

    He, Miao; Ichinose, Takamichi; Song, Yuan; Yoshida, Yasuhiro; Bekki, Kanae; Arashidani, Keiichi; Yoshida, Seiichi; Nishikawa, Masataka; Takano, Hirohisa; Shibamoto, Takayuki; Sun, Guifan

    2016-04-01

    Asian sand dust (ASD) is known to exacerbate asthma, although its mechanism is not yet well understood. In this study, when the effects on inflammatory response by LPS present in ASD was investigated by measuring the gene expression of cytokines and chemokines in RAW264.7 cells treated with ASD and/or polymyxin B (PMB), the ASD effects were attenuated by PMB, but not completely. When an in vitro study was performed using bone marrow-derived macrophages (BMDMs) from WT, TLR2(-/-), TLR4(-/-), and MyD88(-/-) BALB/c mice and BMDMs from WT, TLR2(-/-), TLR4(-/-), TLR2/4(-/-), TLR7/9(-/-), and MyD88(-/-) C57BL/6J mice, cytokine (IL-6, IL-12) production in BMDMs was higher in ASD-stimulated TLR2(-/-) cells than in TLR4(-/-) cells, whereas it was lower or undetectable in TLR2/4(-/-) and MyD88(-/-) cells. These results suggest that ASD causes cytokine production predominantly in a TLR4/MyD88-dependent pathway. When WT and TLRs 2(-/-), 4(-/-), and MyD88(-/-) BALB/c mice were intratracheally challenged with OVA and/or ASD, ASD caused exacerbation of lung eosinophilia along with Th2 cytokine and eosinophil-relevant chemokine production. Serum OVA-specific IgE and IgG1 similar to WT was observed in TLRs 2(-/-), 4(-/-) mice, but not in MyD88(-/-) mice. The Th2 responses in TLR2(-/-) mice were attenuated remarkably by PMB. These results indicate that ASD exacerbates lung eosinophilia in a MyD88-dependent pathway. TLRs 2 and 4 signaling may be important in the increase in lung eosinophilia. Also, the TLR4 ligand LPS and TLR2 ligand like β-glucan may be strong candidates for exacerbation of lung eosinophilia. PMID:26882889

  13. B-cell-specific conditional expression of Myd88p.L252P leads to the development of diffuse large B-cell lymphoma in mice.

    PubMed

    Knittel, Gero; Liedgens, Paul; Korovkina, Darya; Seeger, Jens M; Al-Baldawi, Yussor; Al-Maarri, Mona; Fritz, Christian; Vlantis, Katerina; Bezhanova, Svetlana; Scheel, Andreas H; Wolz, Olaf-Oliver; Reimann, Maurice; Möller, Peter; López, Cristina; Schlesner, Matthias; Lohneis, Philipp; Weber, Alexander N R; Trümper, Lorenz; Staudt, Louis M; Ortmann, Monika; Pasparakis, Manolis; Siebert, Reiner; Schmitt, Clemens A; Klatt, Andreas R; Wunderlich, F Thomas; Schäfer, Stephan C; Persigehl, Thorsten; Montesinos-Rongen, Manuel; Odenthal, Margarete; Büttner, Reinhard; Frenzel, Lukas P; Kashkar, Hamid; Reinhardt, H Christian

    2016-06-01

    The adaptor protein MYD88 is critical for relaying activation of Toll-like receptor signaling to NF-κB activation. MYD88 mutations, particularly the p.L265P mutation, have been described in numerous distinct B-cell malignancies, including diffuse large B-cell lymphoma (DLBCL). Twenty-nine percent of activated B-cell-type DLBCL (ABC-DLBCL), which is characterized by constitutive activation of the NF-κB pathway, carry the p.L265P mutation. In addition, ABC-DLBCL frequently displays focal copy number gains affecting BCL2 Here, we generated a novel mouse model in which Cre-mediated recombination, specifically in B cells, leads to the conditional expression of Myd88(p.L252P) (the orthologous position of the human MYD88(p.L265P) mutation) from the endogenous locus. These mice develop a lymphoproliferative disease and occasional transformation into clonal lymphomas. The clonal disease displays the morphologic and immunophenotypical characteristics of ABC-DLBCL. Lymphomagenesis can be accelerated by crossing in a further novel allele, which mediates conditional overexpression of BCL2 Cross-validation experiments in human DLBCL samples revealed that both MYD88 and CD79B mutations are substantially enriched in ABC-DLBCL compared with germinal center B-cell DLBCL. Furthermore, analyses of human DLBCL genome sequencing data confirmed that BCL2 amplifications frequently co-occurred with MYD88 mutations, further validating our approach. Finally, in silico experiments revealed that MYD88-mutant ABC-DLBCL cells in particular display an actionable addiction to BCL2. Altogether, we generated a novel autochthonous mouse model of ABC-DLBCL that could be used as a preclinical platform for the development and validation of novel therapeutic approaches for the treatment of ABC-DLBCL. PMID:27048211

  14. SNP-SNP Interaction between TLR4 and MyD88 in Susceptibility to Coronary Artery Disease in the Chinese Han Population

    PubMed Central

    Sun, Dandan; Sun, Liping; Xu, Qian; Gong, Yuehua; Wang, Honghu; Yang, Jun; Yuan, Yuan

    2016-01-01

    The toll-like receptor 4 (TLR4)-myeloid differentiation factor 88 (MyD88)-dependent signaling pathway plays a role in the initiation and progression of coronary artery disease (CAD). We investigated SNP–SNP interactions between the TLR4 and MyD88 genes in CAD susceptibility and assessed whether the effects of such interactions were modified by confounding risk factors (hyperglycemia, hyperlipidemia and Helicobacter pylori (H. pylori) infection). Participants with CAD (n = 424) and controls (n = 424) without CAD were enrolled. Polymerase chain restriction-restriction fragment length polymorphism was performed on genomic DNA to detect polymorphisms in TLR4 (rs10116253, rs10983755, and rs11536889) and MyD88 (rs7744). H. pylori infections were evaluated by enzyme-linked immunosorbent assays, and the cardiovascular risk factors for each subject were evaluated clinically. The significant interaction between TLR4 rs11536889 and MyD88 rs7744 was associated with an increased CAD risk (p value for interaction = 0.024). In conditions of hyperglycemia, the interaction effect was strengthened between TLR4 rs11536889 and MyD88 rs7744 (p value for interaction = 0.004). In hyperlipidemic participants, the interaction strength was also enhanced for TLR4 rs11536889 and MyD88 rs7744 (p value for interaction = 0.006). Thus, the novel interaction between TLR4 rs11536889 and MyD88 rs7744 was related with an increased risk of CAD, that could be strengthened by the presence of hyperglycemia or hyperlipidemia. PMID:26959040

  15. The Double-Stranded RNA Bluetongue Virus Induces Type I Interferon in Plasmacytoid Dendritic Cells via a MYD88-Dependent TLR7/8-Independent Signaling Pathway

    PubMed Central

    Ruscanu, Suzana; Pascale, Florentina; Bourge, Mickael; Hemati, Behzad; Elhmouzi-Younes, Jamila; Urien, Céline; Bonneau, Michel; Takamatsu, Haru; Hope, Jayne; Mertens, Peter; Meyer, Gilles; Stewart, Meredith; Roy, Polly; Meurs, Eliane F.; Dabo, Stéphanie; Zientara, Stéphan; Breard, Emmanuel; Sailleau, Corinne; Chauveau, Emilie; Vitour, Damien; Charley, Bernard

    2012-01-01

    Dendritic cells (DCs), especially plasmacytoid DCs (pDCs), produce large amounts of alpha/beta interferon (IFN-α/β) upon infection with DNA or RNA viruses, which has impacts on the physiopathology of the viral infections and on the quality of the adaptive immunity. However, little is known about the IFN-α/β production by DCs during infections by double-stranded RNA (dsRNA) viruses. We present here novel information about the production of IFN-α/β induced by bluetongue virus (BTV), a vector-borne dsRNA Orbivirus of ruminants, in sheep primary DCs. We found that BTV induced IFN-α/β in skin lymph and in blood in vivo. Although BTV replicated in a substantial fraction of the conventional DCs (cDCs) and pDCs in vitro, only pDCs responded to BTV by producing a significant amount of IFN-α/β. BTV replication in pDCs was not mandatory for IFN-α/β production since it was still induced by UV-inactivated BTV (UV-BTV). Other inflammatory cytokines, including tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and IL-12p40, were also induced by UV-BTV in primary pDCs. The induction of IFN-α/β required endo-/lysosomal acidification and maturation. However, despite being an RNA virus, UV-BTV did not signal through Toll-like receptor 7 (TLR7) for IFN-α/β induction. In contrast, pathways involving the MyD88 adaptor and kinases dsRNA-activated protein kinase (PKR) and stress-activated protein kinase (SAPK)/Jun N-terminal protein kinase (JNK) were implicated. This work highlights the importance of pDCs for the production of innate immunity cytokines induced by a dsRNA virus, and it shows that a dsRNA virus can induce IFN-α/β in pDCs via a novel TLR-independent and Myd88-dependent pathway. These findings have implications for the design of efficient vaccines against dsRNA viruses. PMID:22438548

  16. Trichinella spiralis Excretory-Secretory Products Protect against Polymicrobial Sepsis by Suppressing MyD88 via Mannose Receptor

    PubMed Central

    Du, Linlin; Liu, Lihua; Yu, Yang; Shan, Hui; Li, Leiqing

    2014-01-01

    Trichinella spiralis (T. spiralis) or its excretory-secretory products (TsES) protect hosts from autoimmune diseases, which depend on inducing host T helper (Th) 2 immune response and inhibiting inflammatory factors. Sepsis is a systemic inflammatory response syndrome (SIRS) evoked by infection. Little is known about the effects of helminths or their excretory-secretory products on sepsis. Here, we investigated the effects of TsES in a mice model of polymicrobial sepsis. TsES improved survival, reduced organ injury, and enhanced bacterial clearance in septic mice. To investigate the molecular mechanism, macrophages from septic patients or the control group were incubated with TsES. TsES reduced sepsis-inducing inflammatory cytokines mediated by Toll-like receptors (TLR) in vitro by suppressing TLR adaptor-transducer myeloid differentiation factor 88 (MyD88) and nuclear factor- (NF-)-κB. Furthermore, TsES upregulated mannose receptor (MR) expression during sepsis. MR blocking attenuated the effects of TsES on MyD88 and NF-κB expression. In vivo, MR RNAi reduced the survival rate of septic mice treated with TsES, suggesting that TsES-mediated protection against polymicrobial sepsis is dependent on MR. Thus, TsES administration might be a potential therapeutic strategy for treating sepsis. PMID:25054155

  17. MyD88 Dependence of Beryllium-Induced Dendritic Cell Trafficking and CD4+ T Cell Priming

    PubMed Central

    McKee, Amy S.; Mack, Douglas G.; Crawford, Frances; Fontenot, Andrew P.

    2015-01-01

    Beryllium exposure results in beryllium hypersensitivity in a subset of exposed individuals, leading to granulomatous inflammation and fibrosis in the lung. In addition to its antigenic properties, beryllium has potent adjuvant activity that contributes to sensitization via unknown pathways. Here, we show that beryllium induces cellular death and release of IL-1α and DNA into the lung. Release of IL-1α was inflammasome-independent and required for beryllium-induced neutrophil recruitment into the lung. Beryllium enhanced classical dendritic cell (cDC) migration from the lung to draining LNs in an IL-1R-independent manner, and the accumulation of activated cDCs in the LN was associated with increased priming of CD4+ T cells. DC migration was reduced in TLR9KO mice; however, cDCs in the LNs of TLR9-deficient mice were highly activated, suggesting a role for more than one innate receptor in the effects on DCs. The adjuvant effects of beryllium on CD4+ T cell priming were similar in WT, IL-1R, caspase-1, TLR2, TLR4, TLR7, and TLR9 deficient mice. In contrast, DC migration, activation and the adjuvant effects of beryllium were significantly reduced in MyD88KO mice. Collectively, these data suggest that beryllium exposure results in the release of DAMPs that engage MyD88-dependent receptors to enhance pulmonary DC function. PMID:25760420

  18. Deletion of FADD in Macrophages and Granulocytes Results in RIP3- and MyD88-Dependent Systemic Inflammation

    PubMed Central

    He, Tina H.; Sun, Yuefang; Winoto, Astar

    2015-01-01

    Myeloid cells, which include monocytes, macrophages, and granulocytes, are important innate immune cells, but the mechanism and downstream effect of their cell death on the immune system is not completely clear. Necroptosis is an alternate form of cell death that can be triggered when death receptor-mediated apoptosis is blocked, for example, in stimulated Fas-associated Death Domain (FADD) deficient cells. We report here that mice deficient for FADD in myeloid cells (mFADD-/-) exhibit systemic inflammation with elevated inflammatory cytokines and increased levels of myeloid and B cell populations while their dendritic and T cell numbers are normal. These phenotypes were abolished when RIP3 deficiency was introduced, suggesting that systemic inflammation is caused by RIP3-dependent necroptotic and/or inflammatory activity. We further found that loss of MyD88 can rescue the systemic inflammation observed in these mice. These phenotypes are surprisingly similar to that of dendritic cell (DC)-specific FADD deficient mice with the exception that DC numbers are normal in mFADD-/- mice. Together these data support the notion that innate immune cells are constantly being stimulated through the MyD88-dependent pathway and aberrations in their cell death machinery can result in systemic effects on the immune system. PMID:25874713

  19. Rare Circulating Cells in Familial Waldenström Macroglobulinemia Displaying the MYD88 L265P Mutation Are Enriched by Epstein-Barr Virus Immortalization

    PubMed Central

    Pertesi, Maroulio; Galia, Perrine; Nazaret, Nicolas; Vallée, Maxime; Garderet, Laurent; Leleu, Xavier; Avet-Loiseau, Hervé; Foll, Matthieu; Byrnes, Graham; Lachuer, Joel; McKay, James D.; Dumontet, Charles

    2015-01-01

    The MYD88 L265P is a recurrent somatic mutation in neoplastic cells from patients with Waldenström Macroglobulinemia (WM). We identified the MYD88 L265P mutation in three individuals from unrelated families, but its presence did not explain the disease segregation within these WM pedigrees. We observed the mutation in these three individuals at high allele fractions in DNA extracted from EBV-immortalized Lymphoblastoid cell lines established from peripheral blood (LCL), but at much lower allele fractions in DNA extracted directly from peripheral blood, suggesting that this mutation is present in a clonal cell subpopulation rather than of germ-line origin. Furthermore, we observed that the MYD88 L265P mutation is enriched in WM families, detected in 40.5% of patients with familial WM or MGUS (10/22 WM, 5/15 MGUS), compared to 3.5% of patients with familial MM or MGUS (0/72 MM, 4/41 MGUS) (p = 10−7). The mutant allele frequency increased with passages in vitro after immortalization with Epstein-Barr virus (EBV) consistent with the MYD88 L265P described gain-of-function proposed for this mutation. The MYD88 L265P mutation appears to be frequently present in circulating cells in patients with WM, and MGUS, and these cells are amenable to immortalization by EBV. PMID:26352266

  20. TLR signaling adaptor protein MyD88 in primary sensory neurons contributes to persistent inflammatory and neuropathic pain and neuroinflammation.

    PubMed

    Liu, Xing-Jun; Liu, Tong; Chen, Gang; Wang, Bing; Yu, Xiao-Lu; Yin, Cui; Ji, Ru-Rong

    2016-01-01

    Increasing evidence suggests that neuro-immune and neuro-glial interactions are critically involved in chronic pain sensitization. It is well studied how immune/glial mediators sensitize pain, but how sensory neurons control neuroinflammation remains unclear. We employed Myd88 conditional knockout (CKO) mice, in which Myd88 was deleted in sodium channel subunit Nav1.8-expressing primary sensory neurons, to examine the unique role of neuronal MyD88 in regulating acute and chronic pain, and possible underlying mechanisms. We found that baseline pain and the formalin induced acute inflammatory pain were intact in CKO mice. However, the late phase inflammatory pain following complete Freund's adjuvant injection and the late phase neuropathic pain following chronic constriction injury (CCI), were reduced in CKO mice. CCI induced up-regulation of MyD88 and chemokine C-C motif ligand 2 expression in DRG neurons and macrophage infiltration into DRGs, and microglia activation in spinal dorsal horns in wild-type mice, but all these changes were compromised in CKO mice. Finally, the pain hypersensitivity induced by intraplantar IL-1β was reduced in CKO mice. Our findings suggest that MyD88 in primary sensory neurons plays an active role in regulating IL-1β signaling and neuroinflammation in the peripheral and the central nervous systems, and contributes to the maintenance of persistent pain. PMID:27312666

  1. Inhibition of myeloid differentiation factor 88(MyD88) by ST2825 provides neuroprotection after experimental traumatic brain injury in mice.

    PubMed

    Zhang, Hua-Sheng; Li, Hua; Zhang, Ding-Ding; Yan, Hui-Ying; Zhang, Zi-Huan; Zhou, Chen-Hui; Ye, Zhen-Nan; Chen, Qiang; Jiang, Tian-Wei; Liu, Jing-Peng; Hang, Chun-Hua

    2016-07-15

    Myeloid differentiation factor 88(MyD88) is an endogenous adaptor protein that plays an important role in coordinating intracellular inflammatory responses induced by agonists of the Toll-like receptor and interleukin-1 receptor families. MyD88 has been reported to be essential for neuronal death in animal models and may represent a therapeutic target for pharmacologic inhibition following traumatic brain injury (TBI). The purpose of the current study was to investigate the neuroprotective effect of MyD88 specific inhibitor ST2825 in an experimental mouse model of TBI. Intracerebroventricular (ICV) injection of high concentration (20μg/μL) ST2825 (15min post TBI) attenuated the development of TBI in mice, markedly improved neurological function and reduced brain edema. Decreased neural apoptosis and increased neuronal survival were also observed. Biochemically, the high concentration of ST2825 significantly reduced the levels of MyD88, further decreased TAK1, p-TAK1, nuclear p65 and increased IκB-α. Additionally, ST2825 significantly reduced the levels of Iba-1 and inflammatory factors TNF-α and IL-1β. These data provide an experimental rationale for evaluation of MyD88 as a drug target and highlight the potential therapeutic implications of ST2825 in TBI. PMID:27155455

  2. NOD2 Signaling Contributes to the Innate Immune Response Against Helper-Dependent Adenovirus Vectors Independently of MyD88 In Vivo

    PubMed Central

    Suzuki, Masataka; Cela, Racel; Bertin, Terry K.; Sule, Gautam; Cerullo, Vincenzo; Rodgers, John R.

    2011-01-01

    Abstract We previously demonstrated that Toll-like receptor/myeloid differentiation primary response gene 88 (MyD88) signaling is required for maximal innate and acquired [T helper cell type 1 (Th1)] immune responses following systemic administration of helper-dependent adenoviral vectors (HDAds). However, MyD88-deficient mice injected with HDAdLacZ exhibited only partial reduction of innate immune cytokine expression compared with wild-type mice, suggesting MyD88-independent pathways also respond to HDAds. We now show that NOD2, a nucleotide-binding and oligomerization domain (NOD)–like receptor known to detect muramyl dipeptides in bacterial peptidoglycans, also contributes to innate responses to HDAds, but not to humoral or Th1 immune responses. We established NOD2/MyD88 double-deficient mice that, when challenged with HDAds, showed a significant reduction of the innate response compared with mice deficient for either gene singly, suggesting that NOD2 signaling contributes to the innate response independently of MyD88 signaling following systemic administration of HDAds. In addition, NOD2-deficient mice exhibited significantly higher transgene expression than did wild-type mice at an early time point (before development of an acquired response), but not at a later time point (after development of an acquired response). These results indicate that the intracellular sensor NOD2 is required for innate responses to HDAds and can limit transgene expression during early phases of infection. PMID:21561248

  3. TLR signaling adaptor protein MyD88 in primary sensory neurons contributes to persistent inflammatory and neuropathic pain and neuroinflammation

    PubMed Central

    Liu, Xing-Jun; Liu, Tong; Chen, Gang; Wang, Bing; Yu, Xiao-Lu; Yin, Cui; Ji, Ru-Rong

    2016-01-01

    Increasing evidence suggests that neuro-immune and neuro-glial interactions are critically involved in chronic pain sensitization. It is well studied how immune/glial mediators sensitize pain, but how sensory neurons control neuroinflammation remains unclear. We employed Myd88 conditional knockout (CKO) mice, in which Myd88 was deleted in sodium channel subunit Nav1.8-expressing primary sensory neurons, to examine the unique role of neuronal MyD88 in regulating acute and chronic pain, and possible underlying mechanisms. We found that baseline pain and the formalin induced acute inflammatory pain were intact in CKO mice. However, the late phase inflammatory pain following complete Freund’s adjuvant injection and the late phase neuropathic pain following chronic constriction injury (CCI), were reduced in CKO mice. CCI induced up-regulation of MyD88 and chemokine C-C motif ligand 2 expression in DRG neurons and macrophage infiltration into DRGs, and microglia activation in spinal dorsal horns in wild-type mice, but all these changes were compromised in CKO mice. Finally, the pain hypersensitivity induced by intraplantar IL-1β was reduced in CKO mice. Our findings suggest that MyD88 in primary sensory neurons plays an active role in regulating IL-1β signaling and neuroinflammation in the peripheral and the central nervous systems, and contributes to the maintenance of persistent pain. PMID:27312666

  4. Carnosic acid inhibits TLR4-MyD88 signaling pathway in LPS-stimulated 3T3-L1 adipocytes

    PubMed Central

    Park, Mi-Young

    2014-01-01

    BACKGROUND/OBJECTIVES Carnosic acid (CA), found in rosemary (Rosemarinus officinalis) leaves, is known to exhibit anti-obesity and anti-inflammatory activities. However, whether its anti-inflammatory potency can contribute to the amelioration of obesity has not been elucidated. The aim of the current study was to investigate the effect of CA on Toll-like receptor 4 (TLR4) pathways in the presence of lipopolysaccharide (LPS) in 3T3-L1 adipocytes. MATERIALS/METHODS 3T3-L1 adipocytes were treated with CA (0-20 µM) for 1 h, followed by treatment with LPS for 30 min; mRNA expression of adipokines and protein expression of TLR4-related molecules were then measured. RESULTS LPS-stimulated 3T3-L1 adipocytes showed elevated mRNA expression of tumor necrosis factor (TNF)-α, interleukin-6, and monocyte chemoattractant protein-1, and CA significantly inhibited the expression of these adipokine genes. LPS-induced up regulation of TLR4, myeloid differentiation factor 88, TNF receptor-associated factor 6, and nuclear factor-κB, as well as phosphorylated extracellular receptor-activated kinase were also suppressed by pre-treatment of 3T3-L1 adipocytes with CA. CONCLUSIONS Results of this study suggest that CA directly inhibits TLR4-MyD88-dependent signaling pathways and decreases the inflammatory response in adipocytes. PMID:25324930

  5. Activation of MyD88-dependent TLR1/2 signaling by misfolded α-synuclein, a protein linked to neurodegenerative disorders

    PubMed Central

    Daniele, Stefano G.; Béraud, Dawn; Davenport, Connor; Cheng, Kui; Yin, Hang; Maguire-Zeiss, Kathleen A.

    2015-01-01

    Synucleinopathies, such as Parkinson’s disease and diffuse Lewy body disease, are progressive neurodegenerative disorders characterized by selective neuronal death, abnormal accumulation of misfolded α-synuclein, and sustained microglial activation. In addition to inducing neuronal toxicity, higher-ordered oligomeric α-synuclein causes proinflammatory responses in the brain parenchyma by triggering microglial activation, which may exacerbate pathogenic processes by establishing a chronic neuroinflammatory milieu. Here, we found that higher-ordered oligomeric α-synuclein induced a proinflammatory microglial phenotype by directly engaging the heterodimer TLR1/2 (Toll-like receptor 1 and 2) at the cell membrane, leading to the nuclear translocation of NF-κB (nuclear factor κB) and the increased production of the proinflammatory cytokines TNF-α and IL-1β in a MyD88-dependent manner. Blocking signaling by the TLR1/2 heterodimer with the small molecule inhibitor, CU-CPT22, reduced the expression and secretion of these inflammatory cytokines from cultured primary mouse microglia. Candesartan cilexetil, a drug approved for treating hypertension and that inhibits the expression of TLR2, reversed the activated proinflammatory phenotype of primary microglia exposed to oligomeric α-synuclein, supporting the possibility of repurposing this drug for synucleinopathies. PMID:25969543

  6. MyD88 adaptor-like (Mal) functions in the epithelial barrier and contributes to intestinal integrity via protein kinase C.

    PubMed

    Corr, S C; Palsson-McDermott, E M; Grishina, I; Barry, S P; Aviello, G; Bernard, N J; Casey, P G; Ward, J B J; Keely, S J; Dandekar, S; Fallon, P G; O'Neill, L A J

    2014-01-01

    MyD88 adapter-like (Mal)-deficient mice displayed increased susceptibility to oral but not intraperitoneal infection with Salmonella Typhimurium. Bone marrow chimeras demonstrated that mice with Mal-deficient non-hematopoietic cells were more susceptible to infection, indicating a role for Mal in non-myeloid cells. We observed perturbed barrier function in Mal(-/-) mice, as indicated by reduced electrical resistance and increased mucosa blood permeability following infection. Altered expression of occludin, Zonula occludens-1, and claudin-3 in intestinal epithelia from Mal(-/-) mice suggest that Mal regulates tight junction formation, which may in part contribute to intestinal integrity. Mal interacted with several protein kinase C (PKC) isoforms in a Caco-2 model of intestinal epithelia and inhibition of Mal or PKC increased permeability and bacterial invasion via a paracellular route, while a pan-PKC inhibitor increased susceptibility to oral infection in mice. Mal signaling is therefore beneficial to the integrity of the intestinal barrier during infection. PMID:23612054

  7. MyD88-dependent expansion of an immature GR-1+CD11b+ population induces T cell suppression and Th2 polarization in sepsis

    PubMed Central

    Delano, Matthew J.; Scumpia, Philip O.; Weinstein, Jason S.; Coco, Dominique; Nagaraj, Srinivas; Kelly-Scumpia, Kindra M.; O'Malley, Kerri A.; Wynn, James L.; Antonenko, Svetlana; Al-Quran, Samer Z.; Swan, Ryan; Chung, Chun-Shiang; Atkinson, Mark A.; Ramphal, Reuben; Gabrilovich, Dmitry I.; Reeves, Wesley H.; Ayala, Alfred; Phillips, Joseph; LaFace, Drake; Heyworth, Paul G.; Clare-Salzler, Michael; Moldawer, Lyle L.

    2007-01-01

    Polymicrobial sepsis alters the adaptive immune response and induces T cell suppression and Th2 immune polarization. We identify a GR-1+CD11b+ population whose numbers dramatically increase and remain elevated in the spleen, lymph nodes, and bone marrow during polymicrobial sepsis. Phenotypically, these cells are heterogeneous, immature, predominantly myeloid progenitors that express interleukin 10 and several other cytokines and chemokines. Splenic GR-1+ cells effectively suppress antigen-specific CD8+ T cell interferon (IFN) γ production but only modestly suppress antigen-specific and nonspecific CD4+ T cell proliferation. GR-1+ cell depletion in vivo prevents both the sepsis-induced augmentation of Th2 cell–dependent and depression of Th1 cell–dependent antibody production. Signaling through MyD88, but not Toll-like receptor 4, TIR domain–containing adaptor-inducing IFN-β, or the IFN-α/β receptor, is required for complete GR-1+CD11b+ expansion. GR-1+CD11b+ cells contribute to sepsis-induced T cell suppression and preferential Th2 polarization. PMID:17548519

  8. Interleukin-1 receptor but not Toll-like receptor 2 is essential for MyD88-dependent Th17 immunity to Coccidioides infection.

    PubMed

    Hung, Chiung-Yu; Jiménez-Alzate, María del Pilar; Gonzalez, Angel; Wüthrich, Marcel; Klein, Bruce S; Cole, Garry T

    2014-05-01

    Interleukin-17A (IL-17A)-producing CD4(+) T helper (Th17) cells have been shown to be essential for defense against pulmonary infection with Coccidioides species. However, we have just begun to identify the required pattern recognition receptors and understand the signal pathways that lead to Th17 cell activation after fungal infection. We previously reported that Card9(-/-) mice vaccinated with formalin-killed spherules failed to acquire resistance to Coccidioides infection. Here, we report that both MyD88(-/-) and Card9(-/-) mice immunized with a live, attenuated vaccine also fail to acquire protective immunity to this respiratory disease. Like Card9(-/-) mice, vaccinated MyD88(-/-) mice revealed a significant reduction in numbers of both Th17 and Th1 cells in their lungs after Coccidioides infection. Both Toll-like receptor 2 (TLR2) and IL-1 receptor type 1 (IL-1r1) upstream of MyD88 have been implicated in Th17 cell differentiation. Surprisingly, vaccinated TLR2(-/-) and wild-type (WT) mice showed similar outcomes after pulmonary infection with Coccidioides, while vaccinated IL-1r1(-/-) mice revealed a significant reduction in the number of Th17 cells in their infected lungs compared to WT mice. Thus, activation of both IL-1r1/MyD88- and Card9-mediated Th17 immunity is essential for protection against Coccidioides infection. Our data also reveal that the numbers of Th17 cells were reduced in IL-1r1(-/-) mice to a lesser extent than in MyD88(-/-) mice, raising the possibility that other TLRs are involved in MyD88-dependent Th17 immunity to coccidioidomycosis. An antimicrobial action of Th17 cells is to promote early recruitment of neutrophils to infection sites. Our data revealed that neutrophils are required for vaccine immunity to this respiratory disease. PMID:24614655

  9. Inhibitory effect of miR-125b on hepatitis C virus core protein-induced TLR2/MyD88 signaling in THP-1 cells

    PubMed Central

    Peng, Cheng; Wang, Hua; Zhang, Wen-Jing; Jie, Sheng-Hua; Tong, Qiao-Xia; Lu, Meng-Ji; Yang, Dong-Liang

    2016-01-01

    AIM: To investigate the role of miR-125b in regulating monocyte immune responses induced by hepatitis C virus (HCV) core protein. METHODS: Monocytic THP-1 cells were treated with various concentrations of recombinant HCV core protein, and cytokines and miR-125b expression in these cells were analyzed. The requirement of Toll-like receptor 2 (TLR2) or MyD88 gene for HCV core protein-induced immune responses was determined by the transfection of THP-1 cells with gene knockdown vectors expressing either TLR2 siRNA or MyD88 siRNA. The effect of miR-125b overexpression on TLR2/MyD88 signaling was examined by transfecting THP-1 cells with miR-125b mimic RNA oligos. RESULTS: In response to HCV core protein stimulation, cytokine production was up-regulated and miR-125b expression was down-regulated in THP-1 cells. The modulatory effect of HCV core protein on cellular events was dose-dependent and required functional TLR2 or MyD88 gene. Forced miR-125b expression abolished the HCV core protein-induced enhancement of tumor necrosis factor-α, interleukin (IL)-6, and IL-10 expression by 66%, 54%, and 66%, respectively (P < 0.001), by inhibiting MyD88-mediated signaling, including phosphorylation of NF-κBp65, ERK, and P38. CONCLUSION: The inverse correlation between miR-125b and cytokine expression after HCV core challenge suggests that miR-125b may negatively regulate HCV-induced immune responses by targeting TLR2/MyD88 signaling in monocytes. PMID:27158204

  10. Blunt Snout Bream (Megalobrama amblycephala) MyD88 and TRAF6: Characterisation, Comparative Homology Modelling and Expression

    PubMed Central

    Tran, Ngoc Tuan; Liu, Han; Jakovlić, Ivan; Wang, Wei-Min

    2015-01-01

    MyD88 and TRAF6 play an essential role in the innate immune response in most animals. This study reports the full-length MaMyD88 and MaTRAF6 genes identified from the blunt snout bream (Megalobrama amblycephala) transcriptome profile. MaMyD88 is 2501 base pairs (bp) long, encoding a putative protein of 284 amino acids (aa), including the N-terminal DEATH domain of 78 aa and the C-terminal TIR domain of 138 aa. MaTRAF6 is 2252 bp long, encoding a putative protein of 542 aa, including the N-terminal low-complexity region, RING domain (40 aa), a coiled-coil region (64 aa) and C-terminal MATH domain (147 aa). Coding regions of MaMyD88 and MaTRAF6 genomic sequences consisted of five and six exons, respectively. Physicochemical and functional characteristics of the proteins were analysed. Alpha helices were dominant in the secondary structure of the proteins. Homology models of the MaMyD88 and MaTRAF6 domains were constructed applying the comparative modelling method. RT-qPCR was used to analyse the expression of MaMyD88 and MaTRAF6 mRNA transcripts in response to Aeromonas hydrophila challenge. Both genes were highly upregulated in the liver, spleen and kidney during the first 24 h after the challenge. While MyD88 and TRAF6 have been reported in various aquatic species, this is the first report and characterisation of these genes in blunt snout bream. This research also provides evidence of the important roles of these two genes in the blunt snout bream innate immune system. PMID:25830478

  11. Blunt Snout Bream (Megalobrama amblycephala) MyD88 and TRAF6: characterisation, comparative homology modelling and expression.

    PubMed

    Tran, Ngoc Tuan; Liu, Han; Jakovlić, Ivan; Wang, Wei-Min

    2015-01-01

    MyD88 and TRAF6 play an essential role in the innate immune response in most animals. This study reports the full-length MaMyD88 and MaTRAF6 genes identified from the blunt snout bream (Megalobrama amblycephala) transcriptome profile. MaMyD88 is 2501 base pairs (bp) long, encoding a putative protein of 284 amino acids (aa), including the N-terminal DEATH domain of 78 aa and the C-terminal TIR domain of 138 aa. MaTRAF6 is 5474 bp long, encoding a putative protein of 542 aa, including the N-terminal low-complexity region, RING domain (40 aa), a coiled-coil region (64 aa) and C-terminal MATH domain (147 aa). Coding regions of MaMyD88 and MaTRAF6 genomic sequences consisted of five and six exons, respectively. Physicochemical and functional characteristics of the proteins were analysed. Alpha helices were dominant in the secondary structure of the proteins. Homology models of the MaMyD88 and MaTRAF6 domains were constructed applying the comparative modelling method. RT-qPCR was used to analyse the expression of MaMyD88 and MaTRAF6 mRNA transcripts in response to Aeromonas hydrophila challenge. Both genes were highly upregulated in the liver, spleen and kidney during the first 24 h after the challenge. While MyD88 and TRAF6 have been reported in various aquatic species, this is the first report and characterisation of these genes in blunt snout bream. This research also provides evidence of the important roles of these two genes in the blunt snout bream innate immune system. PMID:25830478

  12. The many faces of small B cell lymphomas with plasmacytic differentiation and the contribution of MYD88 testing.

    PubMed

    Swerdlow, Steven H; Kuzu, Isinsu; Dogan, Ahmet; Dirnhofer, Stephan; Chan, John K C; Sander, Birgitta; Ott, German; Xerri, Luc; Quintanilla-Martinez, Leticia; Campo, Elias

    2016-03-01

    Plasmacytic differentiation may occur in almost all small B cell lymphomas (SBLs), although it varies from being uniformly present (as in lymphoplasmacytic lymphoma (LPL)) to very uncommon (as in mantle cell lymphomas (MCLs)). The discovery of MYD88 L265P mutations in the vast majority of LPLs has had a major impact on the study of these lymphomas. Review of the cases contributed to the 2014 European Association for Haematopathology/Society for Hematopathology slide workshop illustrated how mutational testing has helped refine the diagnostic criteria for LPL, emphasizing the importance of identifying a clonal monotonous lymphoplasmacytic population and highlighting how LPL can still be diagnosed with extensive nodal architectural effacement, very subtle plasmacytic differentiation, follicular colonization, or uncommon phenotypes such as CD5 or CD10 expression. MYD88 L265P mutations were found in 11/11 LPL cases versus only 2 of 28 other SBLs included in its differential diagnosis. Mutational testing also helped to exclude other cases that would have been considered LPL in the past. The workshop also highlighted how plasmacytic differentiation can occur in chronic lymphocytic leukemia/small lymphocytic lymphoma, follicular lymphoma, SOX11 negative MCL, and particularly in marginal zone lymphomas, all of which can cause diagnostic confusion with LPL. The cases also highlighted the difficulty in distinguishing lymphomas with marked plasmacytic differentiation from plasma cell neoplasms. Some SBLs with plasmacytic differentiation can be associated with amyloid, other immunoglobulin deposition, or crystal-storing histiocytosis, which may obscure the underlying neoplasm. Finally, although generally indolent, LPL may transform, with the workshop cases suggesting a role for TP53 abnormalities. PMID:26454445

  13. The many faces of small B cell lymphomas with plasmacytic differentiation and the contribution of MYD88 testing

    PubMed Central

    Kuzu, Isinsu; Dogan, Ahmet; Dirnhofer, Stephan; Chan, John K. C.; Sander, Birgitta; Ott, German; Xerri, Luc; Quintanilla-Martinez, Leticia; Campo, Elias

    2016-01-01

    Plasmacytic differentiation may occur in almost all small B cell lymphomas (SBLs), although it varies from being uniformly present (as in lymphoplasmacytic lymphoma (LPL)) to very uncommon (as in mantle cell lymphomas (MCLs)). The discovery of MYD88 L265P mutations in the vast majority of LPLs has had a major impact on the study of these lymphomas. Review of the cases contributed to the 2014 European Association for Haematopathology/Society for Hematopathology slide workshop illustrated how mutational testing has helped refine the diagnostic criteria for LPL, emphasizing the importance of identifying a clonal monotonous lymphoplasmacytic population and highlighting how LPL can still be diagnosed with extensive nodal architectural effacement, very subtle plasmacytic differentiation, follicular colonization, or uncommon phenotypes such as CD5 or CD10 expression. MYD88 L265P mutations were found in 11/11 LPL cases versus only 2 of 28 other SBLs included in its differential diagnosis. Mutational testing also helped to exclude other cases that would have been considered LPL in the past. The workshop also highlighted how plasmacytic differentiation can occur in chronic lymphocytic leukemia/small lymphocytic lymphoma, follicular lymphoma, SOX11 negative MCL, and particularly in marginal zone lymphomas, all of which can cause diagnostic confusion with LPL. The cases also highlighted the difficulty in distinguishing lymphomas with marked plasmacytic differentiation from plasma cell neoplasms. Some SBLs with plasmacytic differentiation can be associated with amyloid, other immunoglobulin deposition, or crystal-storing histiocytosis, which may obscure the underlying neoplasm. Finally, although generally indolent, LPL may transform, with the workshop cases suggesting a role for TP53 abnormalities. PMID:26454445

  14. Rare Variants in MYD88, IRAK4 and IKBKG and Susceptibility to Invasive Pneumococcal Disease: A Population-Based Case-Control Study

    PubMed Central

    Ellis, Magda K.; Elliott, Katherine S.; Rautanen, Anna; Crook, Derrick W.; Hill, Adrian V. S.; Chapman, Stephen J.

    2015-01-01

    Although rare variants within the Toll-like receptor signalling pathway genes have been found to underlie human primary immunodeficiencies associated with selective predisposition to invasive pneumococcal disease (IPD), the contribution of variants in these genes to IPD susceptibility at the population level remains unknown. Complete re-sequencing of IRAK4, MYD88 and IKBKG genes was undertaken in 164 IPD cases from the UK and 164 geographically-matched population-based controls. 233 single-nucleotide variants (SNVs) were identified, of which ten were in coding regions. Four rare coding variants were predicted to be deleterious, two variants in MYD88 and two in IRAK4. The predicted deleterious variants in MYD88 were observed as two heterozygote cases but not seen in controls. Frequencies of predicted deleterious IRAK4 SNVs were the same in cases and controls. Our findings suggest that rare, functional variants in MYD88, IRAK4 or IKBKG do not significantly contribute to IPD susceptibility in adults at the population level. PMID:25886387

  15. Clinicopathological features of 49 primary gastrointestinal diffuse large B-cell lymphoma cases; comparison with location, cell-of-origin, and frequency of MYD88 L265P.

    PubMed

    Nagakita, Keina; Takata, Katsuyoshi; Taniguchi, Kohei; Miyata-Takata, Tomoko; Sato, Yasuharu; Tari, Akira; Ohnishi, Nobuhiko; Noujima-Harada, Mai; Omote, Shizuma; Nakamura, Naoya; Iwamuro, Masaya; Maeda, Yoshinobu; Okada, Hiroyuki; Tanimoto, Mitsune; Yoshino, Tadashi

    2016-08-01

    The gastrointestinal (GI) tract is the most common primary site of extranodal diffuse large B-cell lymphoma (DLBCL), with approximately one-third of extranodal DLBCL occurring in the GI tract. We investigated the clinicopathological features and immunohistochemically-assessed cell-of-origin of 49 GI DLBCL cases (stomach, 24; small intestine, 10; colon, 15) and also examined the presence of MYD88 L265P as recently this mutation has been frequently identified in ABC-like DLBCL, particularly in extranodal sites. Small intestinal DLBCL was characterized by the preponderance of women (P = 0.041) and elevated LDH (P = 0.002) and soluble interleukin-2 receptor (P = 0.033). Small intestinal DLBCL more frequently showed anemia (P = 0.031) and elevated CRP (P = 0.029) than gastric DLBCL. ABC-like phenotype was seen in 71.4 % cases (stomach, 79 %; small intestine, 70 %; colon, 60 %). MYD88 L265P was detected in 6.1 % cases; all were primary gastric DLBCL with ABC-like phenotype but had no distinct clinicopathological features. In conclusion, GI DLBCL had different clinicopathological features according to the primary site especially in the small intestine. Also, MYD88 L265P had little involvement in GI DLBCL compared with other extranodal DLBCLs, suggesting that its pathogenesis might be different from that of organs with a high frequency of MYD88 L265P. PMID:27439595

  16. Adjuvanticity of the oil-in-water emulsion MF59 is independent of Nlrp3 inflammasome but requires the adaptor protein MyD88

    PubMed Central

    Seubert, Anja; Calabro, Samuele; Santini, Laura; Galli, Barbara; Genovese, Alessia; Valentini, Sara; Aprea, Susanna; Colaprico, Annalisa; D'Oro, Ugo; Giuliani, Marzia M.; Pallaoro, Michele; Pizza, Mariagrazia; O'Hagan, Derek T.; Wack, Andreas; Rappuoli, Rino; De Gregorio, Ennio

    2011-01-01

    Oil-in-water emulsions have been successfully used to increase the efficacy, immunogenicity, and cross-protection of human vaccines; however, their mechanism of action is still largely unknown. Nlrp3 inflammasome has been previously associated to the activity of alum, another adjuvant broadly used in human vaccines, and MyD88 adaptor protein is required for the adjuvanticity of most Toll-like receptor agonists. We compared the contribution of Nlrp3 and MyD88 to the adjuvanticity of alum, the oil-in-water emulsion MF59, and complete Freund's adjuvant in mice using a three-component vaccine against serogroup B Neisseria meningitidis (rMenB). Although the basal antibody responses to the nonadjuvanted rMenB vaccine were largely dependent on Nlrp3, the high-level antibody responses induced by alum, MF59, or complete Freund's adjuvant did not require Nlrp3. Surprisingly, we found that MF59 requires MyD88 to enhance bactericidal antibody responses to the rMenB vaccine. Because MF59 did not activate any of the Toll-like receptors in vitro, we propose that MF59 requires MyD88 for a Toll-like receptor-independent signaling pathway. PMID:21690334

  17. Critical Role of TLR2 and MyD88 for Functional Response of Macrophages to a Group IIA-Secreted Phospholipase A2 from Snake Venom

    PubMed Central

    Leiguez, Elbio; Giannotti, Karina Cristina; Moreira, Vanessa; Matsubara, Márcio Hideki; Gutiérrez, José María; Lomonte, Bruno; Rodríguez, Juan Pablo; Balsinde, Jesús; Teixeira, Catarina

    2014-01-01

    The snake venom MT-III is a group IIA secreted phospholipase A2 (sPLA2) enzyme with functional and structural similarities with mammalian pro-inflammatory sPLA2s of the same group. Previously, we demonstrated that MT-III directly activates the innate inflammatory response of macrophages, including release of inflammatory mediators and formation of lipid droplets (LDs). However, the mechanisms coordinating these processes remain unclear. In the present study, by using TLR2−/− or MyD88−/− or C57BL/6 (WT) male mice, we report that TLR2 and MyD88 signaling have a critical role in MT-III-induced inflammatory response in macrophages. MT-III caused a marked release of PGE2, PGD2, PGJ2, IL-1β and IL-10 and increased the number of LDs in WT macrophages. In MT-III-stimulated TLR2−/− macrophages, formation of LDs and release of eicosanoids and cytokines were abrogated. In MyD88−/− macrophages, MT-III-induced release of PGE2, IL-1β and IL-10 was abrogated, but release of PGD2 and PGJ2 was maintained. In addition, COX-2 protein expression seen in MT-III-stimulated WT macrophages was abolished in both TLR2−/− and MyD88−/− cells, while perilipin 2 expression was abolished only in MyD88−/− cells. We further demonstrated a reduction of saturated, monounsaturated and polyunsaturated fatty acids and a release of the TLR2 agonists palmitic and oleic acid from MT-III-stimulated WT macrophages compared with WT control cells, thus suggesting these fatty acids as major messengers for MT-III-induced engagement of TLR2/MyD88 signaling. Collectively, our findings identify for the first time a TLR2 and MyD88-dependent mechanism that underlies group IIA sPLA2-induced inflammatory response in macrophages. PMID:24718259

  18. TLR2, TLR4 AND MyD88 Mediate Allergic Airway Disease (AAD) and Streptococcus pneumoniae-Induced Suppression of AAD

    PubMed Central

    Thorburn, Alison N.; Tseng, Hsin-Yi; Donovan, Chantal; Hansbro, Nicole G.; Jarnicki, Andrew G.; Foster, Paul S.; Gibson, Peter G.; Hansbro, Philip M.

    2016-01-01

    Background Exposure to non-pathogenic Streptococcus pneumoniae and vaccination are inversely associated with asthma. Studies in animal models demonstrate that airway administration of S. pneumoniae (live or killed), or its vaccines or components, suppresses the characteristic features of asthma in mouse models of allergic airway disease (AAD). These components could be developed into immunoregulatory therapies. S. pneumoniae components are recognized by Toll-like receptors (TLR) 2 and TLR4, and both induce inflammatory cell responses through the adaptor protein myeloid differentiation primary response gene 88 (MyD88). The involvement of TLR2, TLR4 and MyD88 in the pathogenesis of AAD and asthma is incompletely understood, and has not been studied in S. pneumoniae-mediated suppression of AAD. We investigated the role of TLR2, TLR4 and MyD88 in the development of AAD and S. pneumoniae-mediated suppression of AAD. Methods and Findings OVA-induced AAD and killed S. pneumoniae-mediated suppression of AAD were assessed in wild-type, TLR2-/-, TLR4-/-, TLR2/4-/- and MyD88-/- BALB/c mice. During OVA-induced AAD, TLR2, TLR4 and MyD88 were variously involved in promoting eosinophil accumulation in bronchoalveolar lavage fluid and blood, and T-helper type (Th)2 cytokine release from mediastinal lymph node T cells and splenocytes. However, all were required for the induction of airways hyperresponsiveness (AHR). In S. pneumoniae-mediated suppression of AAD, TLR2, TLR4 and MyD88 were variously involved in the suppression of eosinophilic and splenocyte Th2 responses but all were required for the reduction in AHR. Conclusions These results highlight important but complex roles for TLR2, TLR4 and MyD88 in promoting the development of OVA-induced AAD, but conversely in the S. pneumoniae-mediated suppression of AAD, with consistent and major contributions in both the induction and suppression of AHR. Thus, TLR signaling is likely required for both the development of asthma and the suppression of asthma by S. pneumoniae, and potentially other immunoregulatory therapies. PMID:27309732

  19. Pharmacological inhibition of MyD88 homodimerization counteracts renal ischemia reperfusion-induced progressive renal injury in vivo and in vitro

    PubMed Central

    Zhang, Li-Min; Liu, Jian-Hua; Xue, Cheng-Biao; Li, Ming-Qiang; Xing, Shuai; Zhang, Xue; He, Wen-Tao; Jiang, Feng-Chao; Lu, Xia; Zhou, Ping

    2016-01-01

    The activation of innate immunity via myeloid differentiation factor 88 (MyD88) contributes to ischemia reperfusion (I/R) induced acute kidney injury (AKI) and chronic kidney injury. However, since there have not yet been any effective therapy, the exact pharmacological role of MyD88 in the prevention and treatment of renal ischemia reperfusion injury (IRI) is not known. We designed a small molecular compound, TJ-M2010-2, which inhibited MyD88 homodimerization. We used an established unilateral I/R mouse model. All mice undergoing 80 min ischemia through uninephrectomy died within five days without intervention. However, treatment with TJ-M2010-2 alone significantly improved the survival rate to 58.3%. Co-treatment of TJ-M2010-2 with the CD154 antagonist increased survival rates up to 100%. Twenty-eight days post-I/R of 60 min ischemia without nephrectomy, TJ-M2010-2 markedly attenuated renal interstitial and inhibited TGF-β1-induced epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells. Furthermore, TJ-M2010-2 remarkably inhibited TLR/MyD88 signaling in vivo and in vitro. In conclusion, our findings highlight the promising clinical potential of MyD88 inhibitor in preventing and treating acute or chronic renal I/R injuries, and the therapeutic functionality of dual-system inhibition strategy in IRI-induced AKI. Moreover, MyD88 inhibition ameliorates renal I/R injury-induced tubular interstitial fibrosis by suppressing EMT. PMID:27246399

  20. Dioscin attenuates renal ischemia/reperfusion injury by inhibiting the TLR4/MyD88 signaling pathway via up-regulation of HSP70.

    PubMed

    Qi, Meng; Zheng, Lingli; Qi, Yan; Han, Xu; Xu, Youwei; Xu, Lina; Yin, Lianhong; Wang, Changyuan; Zhao, Yanyan; Sun, Huijun; Liu, Kexin; Peng, Jinyong

    2015-10-01

    We previously reported the effect of dioscin against hepatic ischemia/reperfusion injury (IRI) in rats. However, little is known concerning the role of dioscin in renal IRI. In the present study, rats were subjected to IRI and dioscin was intragastrically administered for seven consecutive days before surgery. In vitro models of hypoxia/reoxygenation were developed in NRK-52E and HK-2 cells, which were prophylactically treated with or without dioscin. The results showed that dioscin significantly decreased serum BUN and Cr levels, and markedly attenuated cell injury. Mechanistic studies showed that dioscin significantly increased HSP70 levels, decreased the levels of TLR4, MyD88, TRAF6, COX-2, JNK, ERK and p38 MAPK phosphorylation, suppressed the nuclear translocation of NF-κB and HMGB1, and subsequently decreased the mRNA levels of IL-1β, IL-6, TNF-α, ICAM-1 and IFN-γ. Moreover, HSP70 siRNA or TLR4 DNA reversed the nephroprotective effects of dioscin, while dioscin still significantly down-regulated the TLR4 signaling pathway. Furthermore, by inhibiting MyD88 with ST2825 (a MyD88 inhibitor), renal IRI was significantly attenuated, suggesting that the effect of dioscin against renal IRI depended on MyD88. Our results suggested that dioscin had a potent effect against renal IRI through suppressing the TLR4/MyD88 signaling pathway by up-regulating HSP70. These data provide new insights for investigating the natural product with the nephroprotective effect against IRI, which should be developed as a new therapeutic agent for the treatment of acute kidney injury in the future. PMID:26348276

  1. Pharmacological inhibition of MyD88 homodimerization counteracts renal ischemia reperfusion-induced progressive renal injury in vivo and in vitro.

    PubMed

    Zhang, Li-Min; Liu, Jian-Hua; Xue, Cheng-Biao; Li, Ming-Qiang; Xing, Shuai; Zhang, Xue; He, Wen-Tao; Jiang, Feng-Chao; Lu, Xia; Zhou, Ping

    2016-01-01

    The activation of innate immunity via myeloid differentiation factor 88 (MyD88) contributes to ischemia reperfusion (I/R) induced acute kidney injury (AKI) and chronic kidney injury. However, since there have not yet been any effective therapy, the exact pharmacological role of MyD88 in the prevention and treatment of renal ischemia reperfusion injury (IRI) is not known. We designed a small molecular compound, TJ-M2010-2, which inhibited MyD88 homodimerization. We used an established unilateral I/R mouse model. All mice undergoing 80 min ischemia through uninephrectomy died within five days without intervention. However, treatment with TJ-M2010-2 alone significantly improved the survival rate to 58.3%. Co-treatment of TJ-M2010-2 with the CD154 antagonist increased survival rates up to 100%. Twenty-eight days post-I/R of 60 min ischemia without nephrectomy, TJ-M2010-2 markedly attenuated renal interstitial and inhibited TGF-β1-induced epithelial-mesenchymal transition (EMT) of renal tubular epithelial cells. Furthermore, TJ-M2010-2 remarkably inhibited TLR/MyD88 signaling in vivo and in vitro. In conclusion, our findings highlight the promising clinical potential of MyD88 inhibitor in preventing and treating acute or chronic renal I/R injuries, and the therapeutic functionality of dual-system inhibition strategy in IRI-induced AKI. Moreover, MyD88 inhibition ameliorates renal I/R injury-induced tubular interstitial fibrosis by suppressing EMT. PMID:27246399

  2. Differential adapter recruitment by TLR2 co-receptors.

    PubMed

    Piao, Wenji; Ru, Lisa W; Toshchakov, Vladimir Y

    2016-07-01

    TLR2 heterodimers with TLR1 or TLR6 recognize distinct pathogen-associated molecules such as tri- and di-acylated lipopeptides. The activated TLR2 heterodimers recruit Toll-IL-1R domain- (TIR-) containing adapter proteins, TIRAP and MyD88, through the receptor TIR domains. Molecular recognition mechanisms responsible for agonist-driven, TIR domain-mediated receptor-adapter interactions as well as the structure of resultant signaling complexes remain unknown. We previously reported that the cell-permeable peptide derived from helix D of TLR2 TIR (2R9) specifically binds TIRAP in vitro and in cells and thereby inhibits TIRAP-dependent TLR signaling. This study demonstrates that cell-permeable peptides from D helix of TLR1 or TLR6, peptides 1R9 and 6R9 respectively, inhibit signaling mediated by cognate TLR2 co-receptors. Interestingly, 1R9 and 6R9 bind different TLR2 adapters, as they selectively bind MyD88 and TIRAP TIR, respectively. Both peptides block the agonist-induced co-immunoprecipitation (co-IP) of TLR2 with TIRAP or MyD88, but not TLR2 co-IP with co-receptors. Our data suggest that D helices of TLR1 and TLR6 TIR domains are adapter recruitment sites in both co-receptors; yet the sites recruit different adapters. The D helix in TLR1 is the MyD88 docking site, whereas in TLR6 this site recruits TIRAP. PMID:27150837

  3. Heart-resident CCR2+ macrophages promote neutrophil extravasation through TLR9/MyD88/CXCL5 signaling

    PubMed Central

    Li, Wenjun; Hsiao, Hsi-Min; Higashikubo, Ryuji; Saunders, Brian T.; Bharat, Ankit; Goldstein, Daniel R.; Krupnick, Alexander S.; Gelman, Andrew E.; Lavine, Kory J.; Kreisel, Daniel

    2016-01-01

    It is well established that maladaptive innate immune responses to sterile tissue injury represent a fundamental mechanism of disease pathogenesis. In the context of cardiac ischemia reperfusion injury, neutrophils enter inflamed heart tissue, where they play an important role in potentiating tissue damage and contributing to contractile dysfunction. The precise mechanisms that govern how neutrophils are recruited to and enter the injured heart are incompletely understood. Using a model of cardiac transplant–mediated ischemia reperfusion injury and intravital 2-photon imaging of beating mouse hearts, we determined that tissue-resident CCR2+ monocyte–derived macrophages are essential mediators of neutrophil recruitment into ischemic myocardial tissue. Our studies revealed that neutrophil extravasation is mediated by a TLR9/MyD88/CXCL5 pathway. Intravital 2-photon imaging demonstrated that CXCL2 and CXCL5 play critical and nonredundant roles in guiding neutrophil adhesion and crawling, respectively. Together, these findings uncover a specific role for a tissue-resident monocyte-derived macrophage subset in sterile tissue inflammation and support the evolving concept that macrophage ontogeny is an important determinant of function. Furthermore, our results provide the framework for targeting of cell-specific signaling pathways in myocardial ischemia reperfusion injury. PMID:27536731

  4. Salvianolic Acid B Ameliorates Cerebral Ischemia/Reperfusion Injury Through Inhibiting TLR4/MyD88 Signaling Pathway.

    PubMed

    Wang, Yujue; Chen, Guang; Yu, Xiangdong; Li, Yunchao; Zhang, Li; He, Zongze; Zhang, Nannan; Yang, Xiuping; Zhao, Yansheng; Li, Na; Qiu, Hong

    2016-08-01

    Ischemic stroke can activate multiple transcription factors and cause inflammatory reactions, which involve pattern recognition receptors with immunostimulatory effects. Toll-like receptor 4 (TLR4) is one of the receptors related to innate immunity and several inflammatory reactions. The promising anti- inflammatory activity of salvianolic acid B (SAB) had been previously reported, but its effect on ischemic stroke remains unknown. An oxygen-glucose deprivation and reoxygenation (OGD/R) model in vitro and a middle cerebral artery occlusion (MCAO) model in vivo were used in this paper, and the results showned that SAB remarkably increased the viabilities of PC12 cells and primary cortical neurons after OGD/R injury and notably prevented cerebral ischemia/reperfusion (I/R) injury. SAB also significantly ameliorated NeuN release from primary cortical neurons. Further research indicated that the neuroprotection of SAB was completed through inhibiting the TLR4/MyD88/TRAF6 signaling pathway. The blocking of TLR4 by SAB also restrained NF-kB transcriptional activity and pro-inflammatory cytokine responses (IL-1β, IL-6, and TNF-α). These findings supply a new insight that will aid in clarifying the effect of SAB against cerebral I/R injury and provide the development of SAB as a potential candidate for treating ischemic stroke. PMID:27255374

  5. Toll-like Receptor 4 and MyD88 Dependent Signaling Mechanisms of the Innate Immune System are Essential for the Response to Lipopolysaccharide by Epithelial and Stromal Cells of the Bovine Endometrium

    PubMed Central

    Cronin, James G; Turner, Matthew L; Goetze, Leopold; Bryant, Clare E; Sheldon, I Martin

    2015-01-01

    Infection of the bovine endometrium with Gram-negative bacteria commonly causes uterine disease. Toll-like receptor 4 (TLR4) on cells of the immune system bind Gram-negative bacterial lipopolysaccharide (LPS), stimulating the secretion of the pro-inflammatory cytokines interleukin (IL)-1β and IL-6, and the chemokine IL-8. As the endometrium is the first barrier to infection of the uterus, the signaling cascade triggered by LPS and the subsequent expression of inflammatory mediators was investigated in endometrial epithelial and stromal cells, and the key pathways identified using short interfering RNA (siRNA) and biochemical inhibitors. Treatment of endometrial cells with ultrapure LPS stimulated an inflammatory response characterized by increased IL1B, IL6 and IL8 mRNA expression, and IL-6 protein accumulation in epithelial cells; and increased IL1B and IL8 mRNA expression, and IL-6 and IL-8 protein accumulation in stromal cells. Treatment of endometrial cells with LPS also induced the degradation of IκB and the nuclear translocation of NF-κB, as well as rapid phosphorylation of MAPK3/1 and MAPK14. Knockdown of TLR4 or its signaling adaptor molecule, MYD88, using siRNA reduced the inflammatory response to LPS in epithelial and stromal cells. Biochemical inhibition of MAPK3/1, but not JNK, or MAPK14, reduced LPS-induced IL1B, IL6 and IL8 expression in endometrial cells. In conclusion, epithelial and stromal cells have an intrinsic role in innate immune surveillance in the endometrium, and in the case of LPS this recognition occurs via TLR4 and MyD88 dependent cell signaling pathways. PMID:22053092

  6. MyD88-dependent pro-inflammatory activity in Vi polysaccharide vaccine against typhoid promotes Ab switching to IgG.

    PubMed

    Garg, Rohini; Akhade, Ajay Suresh; Yadav, Jitender; Qadri, Ayub

    2015-10-01

    Vi capsular polysaccharide is currently in use as a vaccine against human typhoid caused by Salmonella Typhi. The vaccine efficacy correlates with IgG anti-Vi Abs. We have recently reported that Vi can generate inflammatory responses through activation of the TLR2/TLR1 complex. In the present study, we show that immunization with Vi produces IgM as well as IgG Abs in wild type mice. This ability is not compromised in mice deficient in T cells. However, immunization of mice lacking the TLR adaptor protein, MyD88, with Vi elicits only IgM Abs. These results suggest that MyD88-dependent pro-inflammatory ability of the Vi vaccine might be vital in generating IgG Abs with this T-independent Ag. PMID:26303218

  7. SF3B1 mutations correlated to cytogenetics and mutations in NOTCH1, FBXW7, MYD88, XPO1 and TP53 in 1160 untreated CLL patients.

    PubMed

    Jeromin, S; Weissmann, S; Haferlach, C; Dicker, F; Bayer, K; Grossmann, V; Alpermann, T; Roller, A; Kohlmann, A; Haferlach, T; Kern, W; Schnittger, S

    2014-01-01

    We analyzed a large cohort of 1160 untreated CLL patients for novel genetic markers (SF3B1, NOTCH1, FBXW7, MYD88, XPO1) in the context of molecular, immunophenotypic and cytogenetic data. NOTCH1 mutations (mut) (12.3%), SF3B1mut (9.0%) and TP53mut (7.1%) were more frequent than XPO1mut (3.4%), FBXW7mut (2.5%) and MYD88mut (1.5%). SF3B1mut, NOTCH1mut, TP53mut and XPO1mut were highly correlated to unmutated, whereas MYD88mut were associated with mutated IGHV status. Associations of diverse cytogenetic aberrations and mutations emerged: (1) SF3B1mut with del(11q), (2) NOTCH1mut and FBXW7mut with trisomy 12 and nearly exclusiveness of SF3B1mut, (3) MYD88mut with del(13q) sole and low frequencies of SF3B1mut, NOTCH1mut and FBXW7mut. In patients with normal karyotype only SF3B1mut were frequent, whereas NOTCH1mut rarely occurred. An adverse prognostic impact on time to treatment (TTT) and overall survival (OS) was observed for SF3B1mut, NOTCH1mut and TP53 disruption. In multivariate analyses SF3B1mut, IGHV mutational status and del(11q) were the only independent genetic markers for TTT, whereas for OS SF3B1mut, IGHV mutational status and TP53 disruption presented with significant impact. Finally, our data suggest that analysis of gene mutations refines the risk stratification of cytogenetic prognostic subgroups and confirms data of a recently proposed model integrating molecular and cytogenetic data. PMID:24113472

  8. Lipopolysaccharide- and Lipoteichoic Acid-mediated Pro-inflammatory Cytokine Production and Modulation of TLR2, TLR4 and MyD88 Expression in Human Endometrial Cells

    PubMed Central

    Rashidi, Nesa; Mirahmadian, Mahroo; Jeddi-Tehrani, Mahmood; Rezania, Simin; Ghasemi, Jamileh; Kazemnejad, Somaieh; Mirzadegan, Ebrahim; Vafaei, Sedigheh; Kashanian, Maryam; Rasoulzadeh, Zahra; Zarnani, Amir-Hassan

    2015-01-01

    Background Toll-like receptor (TLR)-mediated inflammatory processes are supposed to be involved in pathophysiology of spontaneous abortion and preterm labor. Here, we investigated functional responses of human endometrial stromal cells (ESCs) and whole endometrial cells (WECs) to lipopolysaccharide (LPS) and lipoteichoic acid (LTA). Methods Endometrial tissues were obtained from 15 cycling women who underwent laparoscopic tubal ligation. Modulation of TLR2, TLR4 and MyD88 expression and production of pro-inflammatory cytokines by WECs and ESCs in response to LPS and LTA were assessed. Results WECs and ESCs expressed significant levels of TLR4 and MyD88 transcripts but, unlike WECs, ESCs failed to express TLR2 gene. Regardless of positive results of Western blotting, ESCs did not express TLR4 at their surface as judged by flow cytometry. Immunofluorescent staining revealed intracellular localization of TLR4 with predominant perinuclear pattern. LPS stimulation marginally increased TLR4 gene expression in both cell types, whereas such treatment significantly upregulated MyD88 gene expression after 8 hr (p < 0.05). At the protein level, however, LPS activation significantly increased TLR4 expression by ESCs (p < 0.05). LTA stimulation of WECs was accompanied with non-significant increase of TLR2 and MyD88 transcripts. LPS and LTA stimulation of WECs caused significant production of IL-6 and IL-8 in a dose-dependent manner (p < 0.05). Similarly, ESCs produced significant amounts of IL-6, IL-8 and also TNF-α in response to LPS activation (p < 0.05). Conclusion Our results provided further evidence of initiation of inflammatory processes following endometrial TLR activation by bacterial components which could potentially be harmful to developing fetus. PMID:25927023

  9. Dioscin alleviates alcoholic liver fibrosis by attenuating hepatic stellate cell activation via the TLR4/MyD88/NF-κB signaling pathway

    PubMed Central

    Liu, Min; Xu, Youwei; Han, Xu; Yin, Lianhong; Xu, Lina; Qi, Yan; Zhao, Yanyan; Liu, Kexin; Peng, Jinyong

    2015-01-01

    The present work aimed to investigate the activities and underlying mechanisms of dioscin against alcoholic liver fibrosis (ALF). In vivo liver fibrosis in mice was induced by an alcoholic liquid diet, and in vitro studies were performed on activated HSC-T6 and LX2 cells treated with lipopolysaccharide. Our results showed that dioscin significantly attenuated hepatic stellate cells (HSCs) activation, improved collagen accumulation, and attenuated inflammation through down-regulating the levels of myeloid differentiation factor 88 (MyD88), nuclear factor κB (NF-κB), interleukin (IL)-1, IL-6 and tumour necrosis factor-α by decreasing Toll-like receptor (TLR)4 expression both in vivo and in vitro. TLR4 overexpression was also decreased by dioscin, leading to the markedly down-regulated levels of MyD88, NF-κB, transforming growth factor-β1 (TGF-β1), α-smooth muscle actin (α-SMA) and type I collagen (COL1A1) in cultured HSCs. Suppression of cellular MyD88 by ST2825 or abrogation of NF-κB by pyrrolidine dithiocarbamate eliminated the inhibitory effects of dioscin on the levels of TGF-β1, α-SMA and COL1A1. In a word, dioscin exhibited potent effects against ALF via altering TLR4/MyD88/NF-κB signaling pathway, which provided novel insights into the mechanisms of this compound as an antifibrogenic candidate for the treatment of ALF in the future. PMID:26655640

  10. Blood-Brain Barrier Deterioration and Hippocampal Gene Expression in Polymicrobial Sepsis: An Evaluation of Endothelial MyD88 and the Vagus Nerve.

    PubMed

    Honig, Gerard; Mader, Simone; Chen, Huiyi; Porat, Amit; Ochani, Mahendar; Wang, Ping; Volpe, Bruce T; Diamond, Betty

    2016-01-01

    Systemic infection can initiate or exacerbate central nervous system (CNS) pathology, even in the absence of overt invasion of bacteria into the CNS. Recent epidemiological studies have demonstrated that human survivors of sepsis have an increased risk of long-term neurocognitive decline. There is thus a need for improved understanding of the physiological mechanisms whereby acute sepsis affects the CNS. In particular, MyD88-dependent activation of brain microvascular endothelial cells and a resulting loss of blood-brain barrier integrity have been proposed to play an important role in the effects of systemic inflammation on the CNS. Signaling through the vagus nerve has also been considered to be an important component of CNS responses to systemic infection. Here, we demonstrate that blood-brain barrier permeabilization and hippocampal transcriptional responses during polymicrobial sepsis occur even in the absence of MyD88-dependent signaling in cerebrovascular endothelial cells. We further demonstrate that these transcriptional responses can occur without vagus nerve input. These results suggest that redundant signals mediate CNS responses in sepsis. Either endothelial or vagus nerve activation may be individually sufficient to transmit systemic inflammation to the central nervous system. Transcriptional activation in the forebrain in sepsis may be mediated by MyD88-independent endothelial mechanisms or by non-vagal neuronal pathways. PMID:26790027

  11. Blood-Brain Barrier Deterioration and Hippocampal Gene Expression in Polymicrobial Sepsis: An Evaluation of Endothelial MyD88 and the Vagus Nerve

    PubMed Central

    Honig, Gerard; Mader, Simone; Chen, Huiyi; Porat, Amit; Ochani, Mahendar; Wang, Ping; Volpe, Bruce T.; Diamond, Betty

    2016-01-01

    Systemic infection can initiate or exacerbate central nervous system (CNS) pathology, even in the absence of overt invasion of bacteria into the CNS. Recent epidemiological studies have demonstrated that human survivors of sepsis have an increased risk of long-term neurocognitive decline. There is thus a need for improved understanding of the physiological mechanisms whereby acute sepsis affects the CNS. In particular, MyD88-dependent activation of brain microvascular endothelial cells and a resulting loss of blood-brain barrier integrity have been proposed to play an important role in the effects of systemic inflammation on the CNS. Signaling through the vagus nerve has also been considered to be an important component of CNS responses to systemic infection. Here, we demonstrate that blood-brain barrier permeabilization and hippocampal transcriptional responses during polymicrobial sepsis occur even in the absence of MyD88-dependent signaling in cerebrovascular endothelial cells. We further demonstrate that these transcriptional responses can occur without vagus nerve input. These results suggest that redundant signals mediate CNS responses in sepsis. Either endothelial or vagus nerve activation may be individually sufficient to transmit systemic inflammation to the central nervous system. Transcriptional activation in the forebrain in sepsis may be mediated by MyD88-independent endothelial mechanisms or by non-vagal neuronal pathways. PMID:26790027

  12. miR-489 inhibits silica-induced pulmonary fibrosis by targeting MyD88 and Smad3 and is negatively regulated by lncRNA CHRF.

    PubMed

    Wu, Qiuyun; Han, Lei; Yan, Weiwen; Ji, Xiaoming; Han, Ruhui; Yang, Jingjin; Yuan, Jiali; Ni, Chunhui

    2016-01-01

    Silicosis is an incurable occupational disease associated with inflammation, fibroblast proliferation and the accumulation of extracellular matrix in lung tissues. The dysregulation of lncRNAs and miRNAs has been implicated in many complex diseases; however, the current understanding of their roles in fibrotic lung diseases, especially silicosis, remains limited. Our previous microRNA (miRNA, miR) microarray data have indicated decreased expression levels of miR-489 in lung tissues of silica-induced pulmonary fibrosis. Here, we further explored the role of miR-489 in a mouse model of silicosis. Interestingly, miR-489 levels were reduced in both macrophages that were exposed to silica and fibroblasts that were exposed to TGF-β1. Additionally, the overexpressed miR-489 carried out its anti-fibrotic role by attenuating inflammation and fibrotic progression in vivo. Our molecular study further demonstrated that miR-489 inhibited silica-induced pulmonary fibrosis primarily by repressing its target genes MyD88 and Smad3. Moreover, the up-regulated lncRNA cardiac hypertrophy-related factor (CHRF) reversed the inhibitory effect of miR-489 on MyD88 and Smad3 and then triggered the inflammation and fibrotic signaling pathways. Overall, our data indicate that the CHRF-miR-489-MyD88 Smad3 signaling axis exerts key functions in silica-induced pulmonary fibrosis and may represent a therapeutic target for silicosis. PMID:27506999

  13. miR-489 inhibits silica-induced pulmonary fibrosis by targeting MyD88 and Smad3 and is negatively regulated by lncRNA CHRF

    PubMed Central

    Wu, Qiuyun; Han, Lei; Yan, Weiwen; Ji, Xiaoming; Han, Ruhui; Yang, Jingjin; Yuan, Jiali; Ni, Chunhui

    2016-01-01

    Silicosis is an incurable occupational disease associated with inflammation, fibroblast proliferation and the accumulation of extracellular matrix in lung tissues. The dysregulation of lncRNAs and miRNAs has been implicated in many complex diseases; however, the current understanding of their roles in fibrotic lung diseases, especially silicosis, remains limited. Our previous microRNA (miRNA, miR) microarray data have indicated decreased expression levels of miR-489 in lung tissues of silica-induced pulmonary fibrosis. Here, we further explored the role of miR-489 in a mouse model of silicosis. Interestingly, miR-489 levels were reduced in both macrophages that were exposed to silica and fibroblasts that were exposed to TGF-β1. Additionally, the overexpressed miR-489 carried out its anti-fibrotic role by attenuating inflammation and fibrotic progression in vivo. Our molecular study further demonstrated that miR-489 inhibited silica-induced pulmonary fibrosis primarily by repressing its target genes MyD88 and Smad3. Moreover, the up-regulated lncRNA cardiac hypertrophy-related factor (CHRF) reversed the inhibitory effect of miR-489 on MyD88 and Smad3 and then triggered the inflammation and fibrotic signaling pathways. Overall, our data indicate that the CHRF-miR-489-MyD88 Smad3 signaling axis exerts key functions in silica-induced pulmonary fibrosis and may represent a therapeutic target for silicosis. PMID:27506999

  14. TLR4-HMGB1-, MyD88- and TRIF-dependent signaling in mouse intestinal ischemia/reperfusion injury

    PubMed Central

    Wang, Jie; He, Gui-Zhen; Wang, Yu-Kang; Zhu, Qian-Kun; Chen, Wei; Guo, Tai

    2015-01-01

    AIM: To characterize high-mobility group protein 1-toll-like receptor 4 (HMGB1-TLR4) and downstream signaling pathways in intestinal ischemia/reperfusion (I/R) injury. METHODS: Forty specific-pathogen-free male C57BL/6 mice were randomly divided into five groups (n = 8 per group): sham, control, anti-HMGB1, anti-myeloid differentiation gene 88 (MyD88), and anti-translocating-chain-associating membrane protein (TRIF) antibody groups. Vehicle with the control IgG antibody, anti-HMGB1, anti-MyD88, or anti-TRIF antibodies (all 1 mg/kg, 0.025%) were injected via the caudal vein 30 min prior to ischemia. After anesthetization, the abdominal wall was opened and the superior mesenteric artery was exposed, followed by 60 min mesenteric ischemia and then 60 min reperfusion. For the sham group, the abdominal wall was opened for 120 min without I/R. Levels of serum nuclear factor (NF)-κB p65, interleukin (IL)-6, and tumor necrosis factor (TNF)-α were measured, along with myeloperoxidase activity in the lung and liver. In addition,morphologic changes that occurred in the lung and intestinal tissues were evaluated. Levels of mRNA transcripts encoding HMGB1 and NF-κB were measured by real-time quantitative PCR, and levels of HMGB1 and NF-κB protein were measured by Western blot. Results were analyzed using one-way analysis of variance. RESULTS: Blocking HMGB1, MyD88, and TRIF expression by injecting anti-HMGB1, anti-MyD88, or anti-TRIF antibodies prior to ischemia reduced the levels of inflammatory cytokines in serum; NF-κB p65: 104.64 ± 11.89, 228.53 ± 24.85, 145.00 ± 33.63, 191.12 ± 13.22, and 183.73 ± 10.81 (P < 0.05); IL-6: 50.02 ± 6.33, 104.91 ± 31.18, 62.28 ± 6.73, 85.90 ± 17.37, and 78.14 ± 7.38 (P < 0.05); TNF-α, 43.79 ± 4.18, 70.81 ± 6.97, 52.76 ± 5.71, 63.19 ± 5.47, and 59.70 ± 4.63 (P < 0.05) for the sham, control, anti-HMGB1, anti-MyD88, and anti-TRIF groups, respectively (all in pg/mL).Antibodies also alleviated tissue injury in the lung and small intestine compared with the control group in the mouse intestinal I/R model. The administration of anti-HMGB1, anti-MyD88, and anti-TRIF antibodies markedly reduced damage caused by I/R, for which anti-HMGB1 antibody had the most obvious effect. CONCLUSION: HMGB1 and its downstream signaling pathway play important roles in the mouse intestinal I/R injury, and the effect of the TRIF-dependent pathway is slightly greater. PMID:26217083

  15. A TIR Domain Protein from E. faecalis Attenuates MyD88-Mediated Signaling and NF-κB Activation

    PubMed Central

    Zou, Jun; Baghdayan, Arto S.; Payne, Sarah J.; Shankar, Nathan

    2014-01-01

    Toll-like receptor signaling, mediated by functional Toll/interleukin-1 receptor (TIR) domains, plays a critical role in activating the innate immune response responsible for controlling and clearing infection. Bacterial protein mimics of components of this signaling pathway have been identified and function through inhibition of interactions between Toll-like receptors (TLRs) and their adaptor proteins, mediated by TIR domains. A previously uncharacterized gene, which we have named tcpF (for TIR domain-containing protein in E. faecalis) was identified in the genome of Enterococcus faecalis V583, and predicted to encode a protein resembling mammalian and bacterial TIR proteins. We overexpressed and purified TcpF from E. coli and found that the recombinant protein could bind to phosphatidylinositol phosphates in vitro, suggesting a mechanism by which TcpF may be anchored to the plasma membrane in close proximity to TIR domains of TLRs and adaptor proteins. Purified TcpF was also found to interact specifically with the TIR adaptor protein MyD88, and this interaction was dependent on the BB loop domain in the Box 2 region of TcpF. Despite no evidence of TcpF being a secreted protein, recombinant TcpF was effectively able to enter RAW264.7 cells in vitro although the mechanism by which this occurs remains to be determined. Overexpression of TcpF in mammalian cells suppressed the NF-κB activation induced by bacterial lipoteichoic acid. A mutant lacking the tcpF gene was attenuated for survival in macrophages, with increased ability to activate NF-κB compared to the wild type strain. Complementation in trans restored growth, and inhibition of NF-κB, to that of wild type levels. No appreciable difference in bacterial persistence, dissemination or pathogenesis was observed between the wild type and mutant in a mouse peritonitis model however, which suggested either a subtle role for TcpF or functional overlap with other redundant factor(s) in this virulence model. PMID:25369374

  16. MyD88 mediates in vivo effector functions of alveolar macrophages in acute lung inflammatory responses to carbon nanotube exposure.

    PubMed

    Frank, Evan A; Birch, M Eileen; Yadav, Jagjit S

    2015-11-01

    Carbon nanotubes (CNTs) are rapidly emerging as high-priority occupational toxicants. CNT powders contain fibrous particles that aerosolize readily in places of manufacture and handling, posing an inhalation risk for workers. Studies using animal models indicate that lung exposure to CNTs causes prolonged inflammatory responses and diffuse alveolar injury. The mechanisms governing CNT-induced lung inflammation are not fully understood but have been suggested to involve alveolar macrophages (AMs). In the current study, we sought to systematically assess the effector role of AMs in vivo in the induction of lung inflammatory responses to CNT exposures and investigate their cell type-specific mechanisms. Multi-wall CNTs characterized for various physicochemical attributes were used as the CNT type. Using an AM-specific depletion and repopulation approach in a mouse model, we unambiguously demonstrated that AMs are major effector cells necessary for the in vivo elaboration of CNT-induced lung inflammation. We further investigated in vitro AM responses and identified molecular targets which proved critical to pro-inflammatory responses in this model, namely MyD88 as well as MAPKs and Ca(2+)/CamKII. We further demonstrated that MyD88 inhibition in donor AMs abrogated their capacity to reconstitute CNT-induced inflammation when adoptively transferred into AM-depleted mice. Taken together, this is the first in vivo demonstration that AMs act as critical effector cell types in CNT-induced lung inflammation and that MyD88 is required for this in vivo effector function. AMs and their cell type-specific mechanisms may therefore represent potential targets for future therapeutic intervention of CNT-related lung injury. PMID:26272622

  17. Card9- and MyD88-Mediated Gamma Interferon and Nitric Oxide Production Is Essential for Resistance to Subcutaneous Coccidioides posadasii Infection.

    PubMed

    Hung, Chiung-Yu; Castro-Lopez, Natalia; Cole, Garry T

    2016-04-01

    Coccidioidomycosis is a potentially life-threatening respiratory disease which is endemic to the southwestern United States and arid regions of Central and South America. It is responsible for approximately 150,000 infections annually in the United States alone. Almost every human organ has been reported to harbor parasitic cells of Coccidioides spp. in collective cases of the disseminated form of this mycosis. Current understanding of the mechanisms of protective immunity against lung infection has been largely derived from murine models of pulmonary coccidioidomycosis. However, little is known about the nature of the host response to Coccidioides in extrapulmonary tissue. Primary subcutaneous coccidioidal infection is rare but has been reported to result in disseminated disease. Here, we show that activation of MyD88 and Card9 signal pathways are required for resistance to Coccidioides infection following subcutaneous challenge of C57BL/6 mice, which correlates with earlier findings of the protective response to pulmonary infection. MyD88(-/-) andCard9(-/-) mice recruited reduced numbers of T cells, B cells, and neutrophils to the Coccidioides-infected hypodermis com pared to wild-type mice; however, neutrophils were dispensable for resistance to skin infection. Further studies have shown that gamma interferon (IFN-γ) production and activation of Th1 cells characterize resistance to subcutaneous infection. Furthermore, activation of a phagosomal enzyme, inducible nitric oxide synthase, which is necessary for NO production, is a requisite for fungal clearance in the hypodermis. Collectively, our data demonstrate that MyD88- and Card9-mediated IFN-γ and nitric oxide production is essential for protection against subcutaneous Coccidioides infection. PMID:26857574

  18. TLR2/MyD88/NF-κB Pathway, Reactive Oxygen Species, Potassium Efflux Activates NLRP3/ASC Inflammasome during Respiratory Syncytial Virus Infection

    PubMed Central

    Mgbemena, Victoria; Tsai, Su-Yu; Chang, Te-Hung; Berton, Michael T.; Morris, Ian R.; Allen, Irving C.; Ting, Jenny P.-Y.; Bose, Santanu

    2012-01-01

    Human respiratory syncytial virus (RSV) constitute highly pathogenic virus that cause severe respiratory diseases in newborn, children, elderly and immuno-compromised individuals. Airway inflammation is a critical regulator of disease outcome in RSV infected hosts. Although “controlled” inflammation is required for virus clearance, aberrant and exaggerated inflammation during RSV infection results in development of inflammatory diseases like pneumonia and bronchiolitis. Interleukin-1β (IL-1β) plays an important role in inflammation by orchestrating the pro-inflammatory response. IL-1β is synthesized as an immature pro-IL-1β form. It is cleaved by activated caspase-1 to yield mature IL-1β that is secreted extracellularly. Activation of caspase-1 is mediated by a multi-protein complex known as the inflammasome. Although RSV infection results in IL-1β release, the mechanism is unknown. Here in, we have characterized the mechanism of IL-1β secretion following RSV infection. Our study revealed that NLRP3/ASC inflammasome activation is crucial for IL-1β production during RSV infection. Further studies illustrated that prior to inflammasome formation; the “first signal” constitutes activation of toll-like receptor-2 (TLR2)/MyD88/NF-κB pathway. TLR2/MyD88/NF-κB signaling is required for pro-IL-1β and NLRP3 gene expression during RSV infection. Following expression of these genes, two “second signals” are essential for triggering inflammasome activation. Intracellular reactive oxygen species (ROS) and potassium (K+) efflux due to stimulation of ATP-sensitive ion channel promote inflammasome activation following RSV infection. Thus, our studies have underscored the requirement of TLR2/MyD88/NF-κB pathway (first signal) and ROS/potassium efflux (second signal) for NLRP3/ASC inflammasome formation, leading to caspase-1 activation and subsequent IL-1β release during RSV infection. PMID:22295065

  19. The effects of MyD88 deficiency on disease phenotype in dysferlin-deficient A/J mice: role of endogenous TLR ligands

    PubMed Central

    Uaesoontrachoon, Kitipong; Cha, Hee-Jae; Ampong, Beryl; Sali, Arpana; Vandermeulen, Jack; Wei, Benjamin; Creeden, Brittany; Huynh, Tony; Quinn, James; Tatem, Kathleen; Rayavarapu, Sree; Hoffman, Eric P; Nagaraju, Kanneboyina

    2014-01-01

    An absence of dysferlin leads to activation of innate immune receptors such as Toll-like receptors (TLRs) and skeletal muscle inflammation. Myeloid differentiation primary response gene 88 (MyD88) is a key mediator of TLR-dependent innate immune signalling. We hypothesized that endogenous TLR ligands released from the leaking dysferlin-deficient muscle fibres engage TLRs on muscle and immune cells and contribute to disease progression. To test this hypothesis, we generated and characterized dysferlin and MyD88 double-deficient mice. Double-deficient mice exhibited improved body weight, grip strength, and maximum muscle contractile force at 6–8 months of age when compared to MyD88-sufficient, dysferlin-deficient A/J mice. Double-deficient mice also showed a decrease in total fibre number, which contributed to the observed increase in the number of central nuclei/fibres. These results indicate that there was less regeneration in the double-deficient mice. We next tested the hypothesis that endogenous ligands, such as single-stranded ribonucleic acids (ssRNAs), released from damaged muscle cells bind to TLR-7/8 and perpetuate the disease progression. We found that injection of ssRNA into the skeletal muscle of pre-symptomatic mice (2 months old) resulted in a significant increase in degenerative fibres, inflammation, and regenerating fibres in A/J mice. In contrast, characteristic histological features were significantly decreased in double-deficient mice. These data point to a clear role for the TLR pathway in the pathogenesis of dysferlin deficiency and suggest that TLR-7/8 antagonists may have therapeutic value in this disease. PMID:23857504

  20. The effects of MyD88 deficiency on disease phenotype in dysferlin-deficient A/J mice: role of endogenous TLR ligands.

    PubMed

    Uaesoontrachoon, Kitipong; Cha, Hee-Jae; Ampong, Beryl; Sali, Arpana; Vandermeulen, Jack; Wei, Benjamin; Creeden, Brittany; Huynh, Tony; Quinn, James; Tatem, Kathleen; Rayavarapu, Sree; Hoffman, Eric P; Nagaraju, Kanneboyina

    2013-10-01

    An absence of dysferlin leads to activation of innate immune receptors such as Toll-like receptors (TLRs) and skeletal muscle inflammation. Myeloid differentiation primary response gene 88 (MyD88) is a key mediator of TLR-dependent innate immune signalling. We hypothesized that endogenous TLR ligands released from the leaking dysferlin-deficient muscle fibres engage TLRs on muscle and immune cells and contribute to disease progression. To test this hypothesis, we generated and characterized dysferlin and MyD88 double-deficient mice. Double-deficient mice exhibited improved body weight, grip strength, and maximum muscle contractile force at 6-8 months of age when compared to MyD88-sufficient, dysferlin-deficient A/J mice. Double-deficient mice also showed a decrease in total fibre number, which contributed to the observed increase in the number of central nuclei/fibres. These results indicate that there was less regeneration in the double-deficient mice. We next tested the hypothesis that endogenous ligands, such as single-stranded ribonucleic acids (ssRNAs), released from damaged muscle cells bind to TLR-7/8 and perpetuate the disease progression. We found that injection of ssRNA into the skeletal muscle of pre-symptomatic mice (2 months old) resulted in a significant increase in degenerative fibres, inflammation, and regenerating fibres in A/J mice. In contrast, characteristic histological features were significantly decreased in double-deficient mice. These data point to a clear role for the TLR pathway in the pathogenesis of dysferlin deficiency and suggest that TLR-7/8 antagonists may have therapeutic value in this disease. PMID:23857504

  1. Salmonid Tollip and MyD88 factors can functionally replace their mammalian orthologues in TLR-mediated trout SAA promoter activation.

    PubMed

    Rebl, Alexander; Rebl, Henrike; Liu, Shuzhen; Goldammer, Tom; Seyfert, Hans-Martin

    2011-01-01

    Many functional details of the piscine Toll-like receptor (TLR) signal-mediated activation of immune defense are still elusive. We used an established reconstitution system of mammalian TLR signaling to examine if this system would allow for pathogen-dependent promoter activation of the serum amyloid A (SAA)-encoding gene from rainbow trout (Oncorhynchus mykiss) and if the key mediators MyD88 and Tollip from trout can functionally substitute for their mammalian orthologues. Cells of the established human embryonic kidney line HEK-293 were transiently co-transfected with vectors expressing bovine TLR2 or TLR4 factors and a reporter gene driven by the promoter of the trout SAA gene. Escherichia coli stimulation increased reporter gene expression more than 3-fold. Deletion series and point mutations identified in the proximal SAA promoter a composite overlapping binding site for NF-κB and CEBP factors as crucial for promoter activation. Overexpression of NF-κB p65, but not of p50 or different members of the CEBP factor family proved this factor as an essential driver for SAA expression. Overexpression of a transdominant-negative mutant of the trout MyD88 factor reduced TLR-mediated SAA promoter activation confirming functional conservation of its TIR domain. Overexpression of the Tollip factor from trout also quenched TLR-mediated NF-κB and TLR4-mediated SAA promoter activation. The MyD88 mutant and Tollip expression studies confirm the functional homology of both piscine factors and their mammalian counterparts. We provide for the first time evidence that also the Tollip-mediated negative loop of TLR signaling may be conserved in non-mammalian organisms. PMID:20813127

  2. Lipopolysaccharide induced LOX-1 expression via TLR4/MyD88/ROS activated p38MAPK-NF-κB pathway.

    PubMed

    Zhao, Wenwen; Ma, Guixin; Chen, Xiuping

    2014-12-01

    Lectin-like receptor for oxidized low density lipoprotein (LOX-1) plays a key role in endothelial ox-LDL endocytosis, endothelial dysfunction and atherogenesis. In the present study, the effect of lipopolysaccharide (LPS) on LOX-1 expression and the underlying molecular pathways were investigated. Human umbilical vein endothelial cells (HUVECs) were treated with LPS and the protein expressions of LOX-1, TLR4, TLR2, MyD88, Nox4, Nox2, PI3K, p38MAPK, JNK, ERK, Nrf1, Nrf2 and p65 were examined by Western blotting. The intracellular reactive oxygen species (ROS) production was examined by flow cytometry with fluorescence probe DCFH2-DA. The role of TLR4, MyD88 and Nox4 were determined with specific siRNA. The endothelial ox-LDL uptake and the endothelial-monocyte adhesion were evaluated with DiI-ox-LDL and Hoechst 33342 respectively. The effect of LPS on LOX-1 expression in aorta tissue was also studied with male C57/BL6 mice by intraperitoneal injection of LPS. The results showed that LPS induced LOX-1 protein expression in a time- and concentration-dependent manner. The mRNA expression of LOX-1 was also upregulated. The protein expression of LOX-1 and phosphorylated p38MAPK, p65 was significantly enhanced by LPS both in vitro and in vivo. LPS induced LOX-1 expression was blocked by siRNA for TLR4, MyD88, and Nox4 and inhibitors for p38MAPK, NF-κB, cyclooxygenase-2, and NADPH oxidase. Both LPS induced ox-LDL uptake and endothelial-monocyte adhesion were significantly inhibited by anti-LOX-1 antibody. LPS dramatically induced LOX-1 protein expression in aorta tissues. In conclusion, our data suggested that LPS induces LOX-1 expression via TLR4/MyD88/ROS activated p38MAPK/NF-κB pathway in endothelial cells, which provides new regulatory mechanisms for LOX-1 expression. PMID:25135647

  3. The Co-Stimulatory Effects of MyD88-Dependent Toll-Like Receptor Signaling on Activation of Murine γδ T Cells

    PubMed Central

    Xie, Guorui; Welte, Thomas; Saxena, Vandana; Wicker, Jason; Mann, Brian; Soong, Lynn; Barrett, Alan; Born, Willi; O'Brien, Rebecca; Wang, Tian

    2014-01-01

    γδ T cells express several different toll-like receptor (TLR)s. The role of MyD88- dependent TLR signaling in TCR activation of murine γδ T cells is incompletely defined. Here, we report that Pam3CSK4 (PAM, TLR2 agonist) and CL097 (TLR7 agonist), but not lipopolysaccharide (TLR4 agonist), increased CD69 expression and Th1-type cytokine production upon anti-CD3 stimulation of γδ T cells from young adult mice (6-to 10-week-old). However, these agonists alone did not induce γδ T cell activation. Additionally, we noted that neither PAM nor CL097 synergized with anti-CD3 in inducing CD69 expression on γδ T cells of aged mice (21-to 22-month-old). Compared to young γδ T cells, PAM and CL097 increased Th-1 type cytokine production with a lower magnitude from anti-CD3- stimulated, aged γδ T cells. Vγ1+ and Vγ4+ cells are two subpopulations of splenic γδ T cells. PAM had similar effects in anti-CD3-activated control and Vγ4+ subset- depleted γδ T cells; whereas CL097 induced more IFN-γ production from Vγ4+ subset-depleted γδ T cells than from the control group. Finally, we studied the role of MyD88-dependent TLRs in γδ T cell activation during West Nile virus (WNV) infection. γδ T cell, in particular, Vγ1+ subset expansion was significantly reduced in both MyD88- and TLR7- deficient mice. Treatment with TLR7 agonist induced more Vγ1+ cell expansion in wild-type mice during WNV infection. In summary, these results suggest that MyD88-dependent TLRs provide co-stimulatory signals during TCR activation of γδ T cells and these have differential effects on distinct subsets. PMID:25232836

  4. TLR4/MyD88/NF-κB signaling and PPAR-γ within the paraventricular nucleus are involved in the effects of telmisartan in hypertension.

    PubMed

    Li, Hong-Bao; Li, Xiang; Huo, Chan-Juan; Su, Qing; Guo, Jing; Yuan, Zu-Yi; Zhu, Guo-Qing; Shi, Xiao-Lian; Liu, Jin-Jun; Kang, Yu-Ming

    2016-08-15

    Previous findings from our laboratory and others indicate that the main therapeutic effect of angiotensin II type 1 receptor (AT1-R) antagonists is to decrease blood pressure and exert anti-inflammatory effects in the cardiovascular system. In this study, we determined whether AT1-R antagonist telmisartan within the hypothalamic paraventricular nucleus (PVN) attenuates hypertension and hypothalamic inflammation via both the TLR4/MyD88/NF-κB signaling pathway and peroxisome proliferator-activated receptor-γ (PPAR-γ) in the PVN in hypertensive rats. Spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) rats were treated for 4weeks through bilateral PVN infusion with the AT1-R antagonist telmisartan (TEL, 10μg/h), or losartan (LOS, 20μg/h), or the PPAR-γ antagonist GW9662 (GW, 100μg/h), or vehicle via osmotic minipump. Mean arterial pressure (MAP) was recorded by a tail-cuff occlusion method. PVN tissue and blood were collected for the measurement of AT1-R, PPAR-γ, pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6), inducible nitric oxide synthase (iNOS), TLR4, MyD88, nuclear factor-kappa B (NF-κB) activity and plasma norepinephrine (NE), respectively. Hypertensive rats exhibited significantly higher level of AT1-R and lower level of PPAR-γ in the PVN. PVN treatment with TEL attenuated MAP, improved cardiac hypertrophy, reduced TNF-α, IL-1β, IL-6, iNOS levels, and plasma NE in SHR but not in WKY rats. These results were associated with reduced TLR4, MyD88 and NF-κB levels and increased PPAR-γ level in the PVN of hypertensive rats. Our findings suggest that TLR4/MyD88/NF-κB signaling and PPAR-γ within the PVN are involved in the beneficial effects of telmisartan in hypertension. PMID:27292124

  5. Positive Correlation between Enhanced Expression of TLR4/MyD88/NF-κB with Insulin Resistance in Placentae of Gestational Diabetes Mellitus

    PubMed Central

    Feng, Hui; Wang, Chen; Lin, Li; Ma, Jingmei; Yang, Huixia

    2016-01-01

    Insulin resistance (IR) is a critical factor of the pathophysiology of Gestational diabetes mellitus (GDM). Studies on key organs involved in IR, such as livers and adipose tissues, showed that Toll-like receptor 4 (TLR4) can regulate insulin sensitivity. As a maternal-fetal interface with multi-functions, placentae could contribute to the development of IR for GDM. Thus, we investigated the expressions of TLR4/Myeloid Differentiation factor 88 (MyD88)/Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-kB) in term placentae from 33 GDM women and 36 healthy pregnant women with normal glucose tolerance, evaluated local and systemic IR and furthermore identified the association between placental TLR4 and IR. TLR4 protein was expressed in various cells of term placenta, particularly in syncytiotrophoblast of villi. Compared with normal pregnancy, the expression of TLR4/MyD88/NF-kB pathway increased in the placenta of GDM (p<0.05), and these differences were more pronounced in the maternal section of the placenta and the syncytiotrophoblast of villi. In addition, more severe IR was observed in the placenta of GDM patients than the control group, evidenced with higher pIRS-1(ser312) (p<0.001) and lower IRS-1 (p<0.05) as well as pAkt proteins (p<0.01). The expression of TLR4 in placentae is positively correlated with local IR (pIRS-1: r = 0.76, p <0.001 and pAkt: r = -0.47, p <0.001) and maternal fasting (r = 0.42, p <0.01), one-hour (r = 0.52, p <0.01) and two-hour glucose (r = 0.54, p <0.01) at OGTT. We found an that enhanced expression of the TLR4-MyD88-NF-kB pathway occurs in GDM placentae, which positively correlates with heightened local IR in placentae and higher maternal hyperglycemia. The TLR4/MyD88/NF-kB pathway may play a potential role in the development of IR in placentae of GDM. PMID:27340831

  6. MYD88 L265P in Waldenström macroglobulinemia, immunoglobulin M monoclonal gammopathy, and other B-cell lymphoproliferative disorders using conventional and quantitative allele-specific polymerase chain reaction

    PubMed Central

    Xu, Lian; Hunter, Zachary R.; Yang, Guang; Zhou, Yangsheng; Cao, Yang; Liu, Xia; Morra, Enrica; Trojani, Alessandra; Greco, Antonino; Arcaini, Luca; Varettoni, Maria; Brown, Jennifer R.; Tai, Yu-Tzu; Anderson, Kenneth C.; Munshi, Nikhil C.; Patterson, Christopher J.; Manning, Robert J.; Tripsas, Christina K.; Lindeman, Neal I.

    2013-01-01

    By whole-genome and/or Sanger sequencing, we recently identified a somatic mutation (MYD88 L265P) that stimulates nuclear factor κB activity and is present in >90% of Waldenström macroglobulinemia (WM) patients. MYD88 L265P was absent in 90% of immunoglobulin M (IgM) monoclonal gammopathy of undetermined significance (MGUS) patients. We therefore developed conventional and real-time allele-specific polymerase chain reaction (AS-PCR) assays for more sensitive detection and quantification of MYD88 L265P. Using either assay, MYD88 L265P was detected in 97 of 104 (93%) WM and 13 of 24 (54%) IgM MGUS patients and was either absent or rarely expressed in samples from splenic marginal zone lymphoma (2/20; 10%), CLL (1/26; 4%), multiple myeloma (including IgM cases, 0/14), and immunoglobulin G MGUS (0/9) patients as well as healthy donors (0/40; P < 1.5 × 10−5 for WM vs other cohorts). Real-time AS-PCR identified IgM MGUS patients progressing to WM and showed a high rate of concordance between MYD88 L265P ΔCT and BM disease involvement (r = 0.89, P = .008) in WM patients undergoing treatment. These studies identify MYD88 L265P as a widely present mutation in WM and IgM MGUS patients using highly sensitive and specific AS-PCR assays with potential use in diagnostic discrimination and/or response assessment. The finding of this mutation in many IgM MGUS patients suggests that MYD88 L265P may be an early oncogenic event in WM pathogenesis. PMID:23321251

  7. Toll-pathway in tiger shrimp (Penaeus monodon) responds to white spot syndrome virus infection: evidence through molecular characterisation and expression profiles of MyD88, TRAF6 and TLR genes.

    PubMed

    Deepika, A; Sreedharan, K; Paria, Anutosh; Makesh, M; Rajendran, K V

    2014-12-01

    The Toll-pathway plays key roles in regulating the innate immune response in invertebrates. Myeloid differentiation factor 88 (MyD88) and Tumour necrosis factor receptor (TNFR)-associated factor 6 (TRAF6) are key molecules in this signalling pathway. To investigate the role of Toll-pathway in innate immune response of shrimp, Penaeus monodon, MyD88 (PmMyD88) and TRAF6 (PmTRAF6) were identified and characterised. PmMyD88 cDNA is 1716 bp long with an open reading frame (ORF) of 1449 bp encoding a putative protein of 482 amino acids, with a death domain, a TIR domain and C-terminal extension domain. PmTRAF6 cDNA is 2563 bp long with an ORF of 1785 bp (594 amino acids) with an N-terminal RING-type zinc finger domain, two TRAF-type zinc finger domains, a coiled region and a MATH domain. In healthy shrimp, PmMyD88, PmTRAF6 and PmToll were detected in 15 tissues with the highest expression in midgut, eyestalk and lymphoid organ, respectively. Responses of these genes to WSSV in experimentally-infected P. monodon as well as in cultured haemocytes and also effect of poly I:C on the gene expression in vitro was investigated at six time-points in seven tissues. PmToll showed significant up-regulation at all time-points of infection in six tissues and until 24 h post-infection in vitro. However, poly I:C-induced haemocytes showed up-regulation of the gene until 48 h post-exposure. WSSV caused significant up-regulation of PmMyD88 in most of the tissues tested. The virus challenge as well as poly I:C induction in vitro also resulted in significant up-regulation of the gene. Up-regulated expression of PmTRAF6 was detected in haemocytes and lymphoid organ at late stage of infection. In vitro virus challenge showed significant up-regulation of PmTRAF6 at almost all time-points whereas no significant change in the expression was observed on poly I:C induction. The responses of these key genes, observed in the present study, suggest that Toll-pathway as a whole may play a crucial

  8. Protective Effects of Celastrol on Diabetic Liver Injury via TLR4/MyD88/NF-κB Signaling Pathway in Type 2 Diabetic Rats

    PubMed Central

    Han, Li-ping; Li, Chun-jun; Sun, Bei; Xie, Yun; Guan, Yue; Ma, Ze-jun; Chen, Li-ming

    2016-01-01

    Immune and inflammatory pathways play a central role in the pathogenesis of diabetic liver injury. Celastrol is a potent immunosuppressive and anti-inflammatory agent. So far, there is no evidence regarding the mechanism of innate immune alterations of celastrol on diabetic liver injury in type 2 diabetic animal models. The present study was aimed at investigating protective effects of celastrol on the liver injury in diabetic rats and at elucidating the possible involved mechanisms. We analyzed the liver histopathological and biochemical changes and the expressions of TLR4 mediated signaling pathway. Compared to the normal control group, diabetic rats were found to have obvious steatohepatitis and proinflammatory cytokine activities were significantly upregulated. Celastrol-treated diabetic rats show reduced hepatic inflammation and macrophages infiltration. The expressions of TLR4, MyD88, NF-κB, and downstream inflammatory factors IL-1β and TNFα in the hepatic tissue of treated rats were downregulated in a dose-dependent manner. We firstly found that celastrol treatment could delay the progression of diabetic liver disease in type 2 diabetic rats via inhibition of TLR4/MyD88/NF-κB signaling cascade pathways and its downstream inflammatory effectors. PMID:27057550

  9. Bovine viral diarrhea virus type 2 in vivo infection modulates TLR4 responsiveness in differentiated myeloid cells which is associated with decreased MyD88 expression.

    PubMed

    Schaut, Robert G; McGill, Jodi L; Neill, John D; Ridpath, Julia F; Sacco, Randy E

    2015-10-01

    Symptoms of bovine viral diarrhea virus (BVDV) infection range from subclinical to severe, depending on strain virulence. Several in vitro studies showed BVDV infection impaired leukocyte function. Fewer studies have examined the effects of in vivo BVDV infection on monocyte/macrophage function, especially with strains of differing virulence. We characterized cytokine production by bovine myeloid cells isolated early or late in high (HV) or low virulence (LV) BVDV2 infection. Given BVDV infection may enhance susceptibility to secondary bacterial infection, LPS responses were examined as well. Monocytes from HV and LV infected calves produced higher levels of cytokines compared to cells from controls. In contrast, monocyte-derived macrophage cytokine levels were generally reduced. Modulated cytokine expression in HV BVDV2 macrophages was associated with decreased MyD88 expression, likely due to its interaction with viral NS5A. These data and those of others, suggest that certain Flaviviridae may have evolved strategies for subverting receptor signaling pathways involving MyD88. PMID:26043978

  10. Comparative genomic evidence for duplication of TLR1 subfamily and miiuy croaker TLR1 perceives LPS stimulation via MyD88 and TIRAP.

    PubMed

    Xu, Tianjun; Wang, Yanjin; Li, Jinrui; Shu, Chang; Han, Jingjing; Chu, Qing

    2016-09-01

    Being indispensable pattern recognition receptors in innate immune responses in host protection, Toll-like receptors (TLRs) play an important role in pathogen recognition. Fish TLRs exhibit high variety and distinct features, although little is known about their function on ligand recognition and signaling pathway in fish. This paper reports the evolutionary spectrum of the TLR1 subfamily (referred to as TLR1, TLR6, and TLR10) as determined using the comparative genomic approach. We hypothesized that the TLR1 subfamily underwent two rounds of gene duplication events; the first duplication occurred prior to the divergence of amphibians, and the second one occurred prior to the divergence of eutherians. To further study the function of fish TLR1, we identified miiuy croaker (Miichthys miiuy) TLR1 (mmiTLR1) and determined its potential ability to perceive Vibrio anguillarum and lipopolysaccharide stimulation. Data further suggested that mmiTLR1 is dependent on TIRAP and MyD88 for signal transmission. In addition, immunocytochemistry showed the speculative interaction between MyD88 and mmiTLR1 TIR domain. Overall, we systematically and comprehensively analyzed evolution of TLR1 subfamily and the function of mmiTLR1, which will provide the basis for future scientific research on fish TLRs. PMID:27431585

  11. MyD88 mediates the protective effects of probiotics against the arteriolar thrombosis and leukocyte recruitment associated with experimental colitis

    PubMed Central

    Souza, Daniele G.; Senchenkova, Elena Y.; Russell, Janice; Granger, D. Neil

    2014-01-01

    Several studies in IBD patients and in animal models of IBD have revealed a protective effect of probiotics in reducing clinical symptoms of disease and in blunting the gut inflammation that accompanies this condition. However, the mechanism underlying the therapeutic effect of probiotics is currently unknown. Furthermore, the ability of probiotics to influence the enhanced thrombus development that accompanies IBD has not been studied. This study addresses whether the enhanced extra-intestinal thrombosis (induced by light/dye injury) associated with experimental colitis is altered by oral treatment with the probiotic preparation VSL#3 or by the absence of microbiota. Colitis was induced by DSS 3% in Swiss Webster mice, germ free mice, C57BL/6 WT or Myd88−/− mice. In some experiments, mice received VSL#3 for 8 days before and during DSS feeding. Swiss Webster mice were also subjected to a chronic model of DSS colitis and the effect of VSL#3 was evaluated. VSL#3 treatment significantly attenuated the accelerated thrombus formation observed in both acute and chronic models of colitis. VSL#3-treated mice also exhibited attenuated inflammatory response and injury in the colon. The protective effects of VSL#3 on colitis-associated thrombogenesis and inflammation were not evident in MyD88-deficient mice. Our results suggest that improved control of the enteric microflora in IBD may afford protection against the hypercoagulable, prothrombotic state that follows this condition. PMID:25738377

  12. MYD88-DEPENDENT PROTECTIVE IMMUNITY ELICITED BY ADENOVIRUS 5 EXPRESSING THE SURFACE ANTIGEN 1 FROM TOXOPLASMA GONDII IS MEDIATED BY CD8+ T LYMPHOCYTES

    PubMed Central

    Mendes, Érica A.; Caetano, Bráulia C.; Penido, Marcus L. O.; Bruna-Romero, Oscar; Gazzinelli, Ricardo T.

    2011-01-01

    Toxoplasma gondii is an intracellular parasite widely spread around the world. The Surface Antigens (SAG) 1, 2 and 3 are the main proteins expressed on the surface of T. gondii tachyzoites. Replication-defective adenovirus serotype 5 (rAd5) is one of the most potent recombinant viral vectors for eliciting T cell-mediated immunity in mice and humans. Here we show that vaccination with rAd5 expressing SAG1 (AdSAG1), but neither SAG2 nor SAG3, induces protective immunity in the highly susceptible C57BL/6 mice challenged with T. gondii. Furthermore, we evaluated different immunological components involved on viral induced protective immunity. We observed that host protection elicited by AdSAG1 is highly dependent on IL-12, IFN-γ and CD8+ T lymphocytes. Importantly, the induction of protective immunity (T cell-derived IFN-γ) was also dependent on Myeloid Differentiation Factor 88 (MyD88), and thus, likely to involve Toll-Like receptors. We conclude that protective parasite specific-CD8+ T cells are elicited by a mechanism that involves MyD88-dependent induction of IL-12. PMID:21549794

  13. Frequencies of SF3B1, NOTCH1, MYD88, BIRC3 and IGHV mutations and TP53 disruptions in Chinese with chronic lymphocytic leukemia: disparities with Europeans.

    PubMed

    Xia, Yi; Fan, Lei; Wang, Li; Gale, Robert Peter; Wang, Man; Tian, Tian; Wu, Wei; Yu, Liang; Chen, Yao-Yu; Xu, Wei; Li, Jian-Yong

    2015-03-10

    We studied 307 consecutive Chinese with chronic lymphocytic leukemia (CLL) in diverse disease-stages before and after diverse therapies for mutations in several CLL-related genes. Mutation frequencies were SF3B1, 5%, NOTCH1, 8%, MYD88, 8%, BIRC3, 2%, TP53, 15% and IGHV, 60%. Several of these frequencies differ from those reported in persons of predominately European descent with CLL. Biological and clinical associations were detected including SF3B1 and NOTCH1 mutations with un-mutated IGHV, MYD88 mutations with mutated IGHV, SF3B1 mutations with fludarabine-resistant CLL and NOTCH1 mutation with advanced Binet disease stage and with +12. The NOTCH1 correlation with briefer survival was confirmed in multivariate analyses but the SF3B1 correlation was confounded by concurrent mutations in TP53 and germline IGHV. We show differences in incidence and prognostic impact of mutations in Chinese and CLL compared with persons of predominately European descent with CLL. These data may give insights into the etiology and biology of CLL and suggests different risk stratification models may be needed for different CLL populations. PMID:25605254

  14. Differential Effect of MyD88 Signal in Donor T Cells on Graft-versus-Leukemia Effect and Graft-versus-Host Disease after Experimental Allogeneic Stem Cell Transplantation

    PubMed Central

    Lim, Ji-Young; Ryu, Da-Bin; Lee, Sung-Eun; Park, Gyeongsin; Choi, Eun Young; Min, Chang-Ki

    2015-01-01

    Despite the presence of toll like receptor (TLR) expression in conventional TCRαβ T cells, the direct role of TLR signaling via myeloid differentiation factor 88 (MyD88) within T lymphocytes on graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation (allo-SCT) remains unknown. In the allo-SCT model of C57BL/6 (H-2b) → B6D2F1 (H-2b/d), recipients received transplants of wild type (WT) T-cell-depleted (TCD) bone marrow (BM) and splenic T cells from either WT or MyD88 deficient (MyD88KO) donors. Host-type (H-2d) P815 mastocytoma or L1210 leukemia cells were injected either subcutaneously or intravenously to generate a GVHD/GVL model. Allogeneic recipients of MyD88KO T cells demonstrated a greater tumor growth without attenuation of GVHD severity. Moreover, GVHD-induced GVL effect, caused by increasing the conditioning intensity was also not observed in the recipients of MyD88KO T cells. In vitro, the absence of MyD88 in T cells resulted in defective cytolytic activity to tumor targets with reduced ability to produce IFN-γ or granzyme B, which are known to critical for the GVL effect. However, donor T cell expansion with effector and memory T-cell differentiation were more enhanced in GVHD hosts of MyD88KO T cells. Recipients of MyD88KO T cells experienced greater expansion of Foxp3- and IL4-expressing T cells with reduced INF-γ producing T cells in the spleen and tumor-draining lymph nodes early after transplantation. Taken together, these results highlight a differential role for MyD88 deficiency on donor T-cells, with decreased GVL effect without attenuation of the GVHD severity after experimental allo-SCT. PMID:26552489

  15. Differential Effect of MyD88 Signal in Donor T Cells on Graft-versus-Leukemia Effect and Graft-versus-Host Disease after Experimental Allogeneic Stem Cell Transplantation.

    PubMed

    Lim, Ji-Young; Ryu, Da-Bin; Lee, Sung-Eun; Park, Gyeongsin; Choi, Eun Young; Min, Chang-Ki

    2015-11-01

    Despite the presence of toll like receptor (TLR) expression in conventional TCRαβ T cells, the direct role of TLR signaling via myeloid differentiation factor 88 (MyD88) within T lymphocytes on graft-versus-host disease (GVHD) and graft-versus-leukemia (GVL) effect after allogeneic stem cell transplantation (allo-SCT) remains unknown. In the allo-SCT model of C57BL/6 (H-2(b)) → B6D2F1 (H-2(b/d)), recipients received transplants of wild type (WT) T-cell-depleted (TCD) bone marrow (BM) and splenic T cells from either WT or MyD88 deficient (MyD88KO) donors. Host-type (H-2(d)) P815 mastocytoma or L1210 leukemia cells were injected either subcutaneously or intravenously to generate a GVHD/GVL model. Allogeneic recipients of MyD88KO T cells demonstrated a greater tumor growth without attenuation of GVHD severity. Moreover, GVHD-induced GVL effect, caused by increasing the conditioning intensity was also not observed in the recipients of MyD88KO T cells. In vitro, the absence of MyD88 in T cells resulted in defective cytolytic activity to tumor targets with reduced ability to produce IFN-γ or granzyme B, which are known to critical for the GVL effect. However, donor T cell expansion with effector and memory T-cell differentiation were more enhanced in GVHD hosts of MyD88KO T cells. Recipients of MyD88KO T cells experienced greater expansion of Foxp3- and IL4-expressing T cells with reduced INF-γ producing T cells in the spleen and tumor-draining lymph nodes early after transplantation. Taken together, these results highlight a differential role for MyD88 deficiency on donor T-cells, with decreased GVL effect without attenuation of the GVHD severity after experimental allo-SCT. PMID:26552489

  16. Clonotypic Analysis of Immunoglobulin Heavy Chain Sequences in Patients with Waldenström's Macroglobulinemia: Correlation with MYD88 L265P Somatic Mutation Status, Clinical Features, and Outcome

    PubMed Central

    Roumelioti, Maria; Georgiou, George; Tzenou, Tatiana; Panayiotidis, Panayiotis

    2014-01-01

    We performed IGH clonotypic sequence analysis in WM in order to determine whether a preferential IGH gene rearrangement was observed and to assess IGHV mutational status in blood and/or bone marrow samples from 36 WM patients. In addition we investigated the presence of MYD88 L265P somatic mutation. After IGH VDJ locus amplification, monoclonal VDJ rearranged fragments were sequenced and analyzed. MYD88 L265P mutation was detected by AS-PCR. The most frequent family usage was IGHV3 (74%); IGHV3-23 and IGHV3-74 segments were used in 26% and 17%, respectively. Somatic hypermutation was seen in 91% of cases. MYD88 L265P mutation was found in 65,5% of patients and absent in the 3 unmutated. These findings did not correlate with clinical findings and outcome. Conclusion. IGH genes' repertoire differed in WM from those observed in other B-cell disorders with a recurrent IGHV3-23 and IGHV3-74 usage; monoclonal IGHV was mutated in most cases, and a high but not omnipresent prevalence of MYD88 L265P mutation was observed. In addition, the identification of 3 patients with unmutated IGHV gene segments, negative for the MYD88 L265P mutation, could support the hypothesis that an extra-germinal B-cell may represent the originating malignant cell in this minority of WM patients. PMID:25197661

  17. Tumor-released autophagosomes induce IL-10-producing B cells with suppressive activity on T lymphocytes via TLR2-MyD88-NF-κB signal pathway.

    PubMed

    Zhou, Meng; Wen, Zhifa; Cheng, Feng; Ma, Jie; Li, Weixia; Ren, Hongyan; Sheng, Yemeng; Dong, Huixia; Lu, Liwei; Hu, Hong-Ming; Wang, Li-Xin

    2016-07-01

    Recent studies have shown that tumor cells can release autophagosomes, which transport a broad array of biologically active molecules with potential modulatory effects on immune cell functions. In this study, we aimed to investigate the role of tumor cells-released autophagosomes (i.e. TRAP) in regulating B cell differentiation and function. TRAPs from murine tumor cell lines were found to induce splenic B cells to differentiate into IL-10-producing regulatory B cells (Bregs) with a distinct phenotype of CD1d(+) CD5(+), which could potently inhibit CD8(+) and CD4(+) T cell responses in IL-10-depedent manner both in vitro and in vivo. Notably, adoptive transfer of TRAP-induced Bregs abrogated the immune response and antitumor effect induced by OVA-loaded DC vaccinations in E.G7-OVA-bearing mouse model. Mechanistic studies revealed that membrane-bound high-mobility group B1 (HMGB1) on the intact TRAPs was crucial for inducing Breg differentiation via the activation of TLR2-MyD88-NF-κB signal pathway in B cells. Moreover, TRAPs enriched from malignant effusions of cancer patients could induce human B cells to differentiate into IL-10-producing B cells with immunoregulatory functions, the frequency of which were positively correlated with the HMGB1 levels on TRAPs. Together, our findings have demonstrated that TRAPs promote the generation of IL-10(+) Bregs, which may contribute to the suppression of antitumor immunity. PMID:27622036

  18. Telmisartan mediates anti-inflammatory and not cognitive function through PPAR-γ agonism via SARM and MyD88 signaling.

    PubMed

    Prathab Balaji, S; Vijay Chand, C; Justin, A; Ramanathan, M

    2015-10-01

    Telmisartan (TM), an angiotensin II receptor I (AT1) blocker, has been reported to have agonist property with respect to PPAR-γ. Activation of PPAR-γ receptor by TM attenuated the lipopolysaccharide (LPS) mediated TLR4 central downstream inflammatory responses. However, the missing link between PPAR-γ and TLR4 signaling with TM stimulation has not been clarified. Hence, the present study has been designed to evaluate the molecular mechanism involving PPARγ-TLR4 signaling with TM stimulation in LPS induced inflammatory model. LPS was administered in rats through ICV and the rats were treated with either PPAR-γ antagonist GW9662 (GW) or TM or both. After 14days of LPS administration, the rats were subjected to behavioral tests and their brains were isolated for blotting techniques. The protein study includes NF-κB, PPAR-γ receptors, and their downstream proteins (MyD88 & SARM). The pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) levels were measured by ELISA and cresyl violet staining in the hippocampus region to measure the neuroprotective activity. Results have shown that TM significantly increased the motor co-ordination, cognitive functions, and activated SARM and PPAR-γ protein levels. Also, TM treatment decreased the NF-κB, MyD88 activation, and cytokines release in LPS rats. The co-administration of GW attenuated the TM responses in the parameters studied except cognitive functions. TM (10mg/kg) has significantly reduced the LPS mediated inflammatory responses. This resulted in effective regeneration of hippocampal neurons as observed by cresyl violet staining. It can be concluded that the activation of PPAR-γ receptors may increase the SARM and decrease the MyD88 and NF-κB expression. This negative regulation of SARM dependent inflammation control could be a possible mechanism for TM anti-neuroinflammatory activity. This study of TM in neuro-inflammatory model may further confirm the dual activities of TM that controls hypertension and cognition through AT1 blockade and also attenuates neuro-inflammation via PPAR-γ agonistic property. PMID:26264163

  19. Antimony-Resistant Leishmania donovani Exploits miR-466i To Deactivate Host MyD88 for Regulating IL-10/IL-12 Levels during Early Hours of Infection.

    PubMed

    Mukherjee, Budhaditya; Paul, Joydeep; Mukherjee, Sandip; Mukhopadhyay, Rupkatha; Das, Shantanabha; Naskar, Kshudiram; Sundar, Shyam; Dujardin, Jean-Claude; Saha, Bhaskar; Roy, Syamal

    2015-09-15

    Infection with antimony-resistant Leishmania donovani (Sb(R)LD) induces aggressive pathology in the mammalian hosts as compared with ones with antimony-sensitive L. donovani (Sb(S)LD) infection. Sb(R)LD, but not Sb(S)LD, interacts with TLR2/TLR6 to induce IL-10 by exploiting p50/c-Rel subunits of NF-κB in infected macrophages (Mϕs). Most of the TLRs exploit the universal adaptor protein MyD88 to activate NF-κB. We now show that infection of Mϕs from MyD88(-/-) mice with Sb(R)LD gave rise to significantly higher intracellular parasite number coupled with elevated IL-10/IL-12 ratio in the culture supernatant as compared with infection in wild type (WT) Mϕs. Τhese attributes were not seen with Sb(S)LD in similar experiments. Further, Sb(R)LD infection upregulated miR-466i, which binds with 3'-untranslated region, leading to the downregulation of MyD88. Infection of MyD88(-/-) Mϕ or IL-12(-/-) Mϕ with Sb(R)LD induced IL-10 surge at 4 h, whereas the same in WT Mϕ started from 12 h. Thus, absence of IL-12 in MyD88(-/-) mice favored early binding of NF-κB subunits to the IL-10 promoter, resulting in IL-10 surge. Infection of MyD88(-/-) mice with Sb(R)LD showed significantly higher organ parasites coupled with ill-defined and immature hepatic granulomas, whereas in WT mice there were less organ parasites and the granulomas were well defined. From the survival kinetics it was observed that Sb(R)LD-infected MyD88(-/-) mice died by 60 d postinfection, whereas the WT mice continued to survive. Our results demonstrate that Sb(R)LD has evolved a unique strategy to evade host antileishmanial immune repertoire by manipulating host MyD88 to its advantage. PMID:26283478

  20. Caspase-8 Acts as a Molecular Rheostat to Limit RIPK1- and MyD88-Mediated Dendritic Cell Activation1

    PubMed Central

    Cuda, Carla M.; Misharin, Alexander V.; Gierut, Angelica K.; Saber, Rana; Haines, G. Kenneth; Hutcheson, Jack; Hedrick, Stephen M.; Mohan, Chandra; Budinger, G. Scott; Stehlik, Christian; Perlman, Harris

    2014-01-01

    Caspase-8, an executioner enzyme in the death receptor pathway, has previously been shown to initiate apoptosis and suppress necroptosis. Here, we identify a novel, cell death-independent role for caspase-8 in dendritic cells (DCs); namely, DC-specific expression of caspase-8 prevents the onset of systemic autoimmunity. Failure to express caspase-8 has no effect on the life-span of DCs but instead leads to an enhanced intrinsic activation and subsequently more mature and autoreactive lymphocytes. Uncontrolled toll-like receptor activation in a RIPK1-dependent manner is responsible for the enhanced functionality of caspase-8-deficient DCs, as deletion of TLR signaling mediator, MyD88, ameliorates systemic autoimmunity induced by caspase-8 deficiency. Taken together, these data demonstrate that caspase-8 functions in a cell-type-specific manner and acts uniquely in DCs to maintain tolerance. PMID:24808358

  1. Signalling through MyD88 drives surface expression of the mycobacterial receptors MCL (Clecsf8, Clec4d) and Mincle (Clec4e) following microbial stimulation.

    PubMed

    Kerscher, Bernhard; Dambuza, Ivy M; Christofi, Maria; Reid, Delyth M; Yamasaki, Sho; Willment, Janet A; Brown, Gordon D

    2016-01-01

    The heterodimeric mycobacterial receptors, macrophage C-type lectin (MCL) and macrophage inducible C-type lectin (Mincle), are upregulated at the cell surface following microbial challenge, but the mechanisms underlying this response are unclear. Here we report that microbial stimulation triggers Mincle expression through the myeloid differentiation primary response gene 88 (MyD88) pathway; a process that does not require MCL. Conversely, we show that MCL is constitutively expressed but retained intracellularly until Mincle is induced, whereupon the receptors form heterodimers which are translocated to the cell surface. Thus this "two-step" model for induction of these key receptors provides new insights into the underlying mechanisms of anti-mycobacterial immunity. PMID:27005451

  2. TLR4, TLR7/8 agonist-induced miR-146a promotes macrophage tolerance to MyD88-dependent TLR agonists.

    PubMed

    Nahid, M Abu; Benso, Lia M; Shin, John D; Mehmet, Huseyin; Hicks, Alexandra; Ramadas, Ravisankar A

    2016-08-01

    TLRs facilitate the recognition of pathogens by immune cells and the initiation of the immune response, leading to the production of proinflammatory cytokines and chemokines. Production of proinflammatory mediators by innate immune cells, such as macrophages, is tightly regulated to facilitate pathogen clearance while limiting an adverse impact on host tissue. Exposure of innate immune cells to TLR ligands induces a state of temporary refractoriness to a subsequent exposure of a TLR ligand, a phenomenon referred to as "tolerance." This study sought to evaluate the mechanistic regulation of TLR4 and TLR7/8 ligand-induced tolerance to other TLRs by microRNA-146a. With the use of THP-1 macrophages, as well as human classic and alternative macrophages, we demonstrate that priming with a TLR4 agonist (LPS) or a TLR7/8 agonist (R848) induces homologous and heterologous tolerance to various TLR ligands in macrophages, leading to the impaired production of cytokines and chemokines. We also demonstrate that overexpression of microRNA-146a is sufficient to mimic LPS or R848-induced hyporesponsiveness. Conversely, inhibition of microRNA-146a activity leads to LPS- or R848-induced TLR hyper-responsiveness in TLR signaling tolerance. Furthermore, we demonstrate that microRNA-146a dampens cytokine production following a primary stimulus with MyD88-dependent but not MyD88-independent TLR pathways. Collectively, these data provide comprehensive evidence of the central role of microRNA-146a in TLR signaling tolerance to plasma membrane, as well as endosomal TLR ligands in human macrophages. PMID:26908827

  3. MyD88 dependence of beryllium-induced dendritic cell trafficking and CD4⁺ T-cell priming.

    PubMed

    McKee, A S; Mack, D G; Crawford, F; Fontenot, A P

    2015-11-01

    Beryllium exposure results in beryllium hypersensitivity in a subset of exposed individuals, leading to granulomatous inflammation and fibrosis in the lung. In addition to its antigenic properties, beryllium has potent adjuvant activity that contributes to sensitization via unknown pathways. Here we show that beryllium induces cellular death and release of interleukin (IL)-1α and DNA into the lung. Release of IL-1α was inflammasome independent and required for beryllium-induced neutrophil recruitment into the lung. Beryllium enhanced classical dendritic cell (cDC) migration from the lung to draining lymph nodes (LNs) in an IL-1R-independent manner, and the accumulation of activated cDCs in the LN was associated with increased priming of CD4(+) T cells. DC migration was reduced in Toll-like receptor 9 knockout (TLR9KO) mice; however, cDCs in the LNs of TLR9-deficient mice were highly activated, suggesting a role for more than one innate receptor in the effects on DCs. The adjuvant effects of beryllium on CD4(+) T-cell priming were similar in wild-type, IL-1R-, caspase-1-, TLR2-, TLR4-, TLR7-, and TLR9-deficient mice. In contrast, DC migration, activation, and the adjuvant effects of beryllium were significantly reduced in myeloid differentiation primary response gene 88 knockout (MyD88KO) mice. Collectively, these data suggest that beryllium exposure results in the release of damage-associated molecular patterns that engage MyD88-dependent receptors to enhance pulmonary DC function. PMID:25760420

  4. Myxoma virus induces type I interferon production in murine plasmacytoid dendritic cells via a TLR9/MyD88-, IRF5/IRF7-, and IFNAR-dependent pathway.

    PubMed

    Dai, Peihong; Cao, Hua; Merghoub, Taha; Avogadri, Francesca; Wang, Weiyi; Parikh, Tanvi; Fang, Chee-Mun; Pitha, Paula M; Fitzgerald, Katherine A; Rahman, Masmudur M; McFadden, Grant; Hu, Xiaoyu; Houghton, Alan N; Shuman, Stewart; Deng, Liang

    2011-10-01

    Poxviruses are large DNA viruses that replicate in the cytoplasm of infected cells. Myxoma virus is a rabbit poxvirus that belongs to the Leporipoxvirus genus. It causes a lethal disease called myxomatosis in European rabbits but cannot sustain any detectable infection in nonlagomorphs. Vaccinia virus is a prototypal orthopoxvirus that was used as a vaccine to eradicate smallpox. Myxoma virus is nonpathogenic in mice, whereas systemic infection with vaccinia virus can be lethal even in immunocompetent mice. Plasmacytoid dendritic cells (pDCs) are potent type I interferon (IFN)-producing cells that play important roles in antiviral innate immunity. How poxviruses are sensed by pDCs to induce type I IFN production is not well understood. Here we report that infection of primary murine pDCs with myxoma virus, but not with vaccinia virus, induces IFN-α, IFN-β, tumor necrosis factor (TNF), and interleukin-12p70 (IL-12p70) production. Using pDCs derived from genetic knockout mice, we show that the myxoma virus-induced innate immune response requires the endosomal DNA sensor TLR9 and its adaptor MyD88, transcription factors IRF5 and IRF7, and the type I IFN positive-feedback loop mediated by IFNAR1. It is independent of the cytoplasmic RNA sensing pathway mediated by the mitochondrial adaptor molecule MAVS, the TLR3 adaptor TRIF, or the transcription factor IRF3. Using pharmacological inhibitors, we demonstrate that myxoma virus-induced type I IFN and IL-12p70 production in murine pDCs is also dependent on phosphatidylinositol 3-kinase (PI3K) and Akt. Furthermore, our results reveal that the N-terminal Z-DNA/RNA binding domain of vaccinia virulence factor E3, which is missing in the orthologous M029 protein expressed by myxoma virus, plays an inhibitory role in poxvirus sensing and innate cytokine production by murine pDCs. PMID:21835795

  5. IL-1R/TLR2 through MyD88 Divergently Modulates Osteoclastogenesis through Regulation of Nuclear Factor of Activated T Cells c1 (NFATc1) and B Lymphocyte-induced Maturation Protein-1 (Blimp1).

    PubMed

    Chen, Zhihong; Su, Lingkai; Xu, Qingan; Katz, Jenny; Michalek, Suzanne M; Fan, Mingwen; Feng, Xu; Zhang, Ping

    2015-12-11

    Toll-like receptors (TLR) and the receptor for interleukin-1 (IL-1R) signaling play an important role in bacteria-mediated bone loss diseases including periodontitis, rheumatoid arthritis, and osteomyelitis. Recent studies have shown that TLR ligands inhibit the receptor activator of NF-κB ligand (RANKL)-induced osteoclast differentiation from un-committed osteoclast precursors, whereas IL-1 potentiates RANKL-induced osteoclast formation. However, IL-1R and TLR belong to the same IL-1R/TLR superfamily, and activate similar intracellular signaling pathways. Here, we investigate the molecular mechanisms underlying the distinct effects of IL-1 and Porphyromonas gingivalis lipopolysaccharide (LPS-PG) on RANKL-induced osteoclast formation. Our results show that LPS-PG and IL-1 differentially regulate RANKL-induced activation of osteoclast genes encoding Car2, Ctsk, MMP9, and TRAP, as well as expression of NFATc1, a master transcription factor of osteoclastogenesis. Regulation of osteoclast genes and NFATc1 by LPS-PG and IL-1 is dependent on MyD88, an important signaling adaptor for both TLR and IL-1R family members. Furthermore, LPS-PG and IL-1 differentially regulate RANKL-costimulatory receptor OSCAR (osteoclast-associated receptor) expression and Ca(2+) oscillations induced by RANKL. Moreover, LPS-PG completely abrogates RANKL-induced gene expression of B lymphocyte-induced maturation protein-1 (Blimp1), a global transcriptional repressor of anti-osteoclastogenic genes encoding Bcl6, IRF8, and MafB. However, IL-1 enhances RANKL-induced blimp1 gene expression but suppresses the gene expression of bcl6, irf8, and mafb. Our study reveals the involvement of multiple signaling molecules in the differential regulation of RANKL-induced osteoclastogenesis by TLR2 and IL-1 signaling. Understanding the signaling cross-talk among TLR, IL-1R, and RANK is critical for identifying therapeutic strategies to control bacteria-mediated bone loss. PMID:26483549

  6. IL-1beta induces a MyD88-dependent and ceramide-mediated activation of Src in anterior hypothalamic neurons.

    PubMed

    Davis, Christopher N; Tabarean, Iustin; Gaidarova, Svetlana; Behrens, M Margarita; Bartfai, Tamas

    2006-09-01

    The proinflammatory cytokine interleukin 1beta (IL-1beta), acting at IL-1R1 receptors, affects neuronal signaling under both physiological and pathophysiological conditions. The molecular mechanism of the rapid synaptic actions of IL-1beta in neurons is not known. We show here that within minutes of IL-1beta exposure, the firing rate of anterior hypothalamic (AH) neurons in culture was inhibited. This effect was prevented by pre-exposure of the cells to the Src family inhibitor, PP2, suggesting the involvement of Src in the hyperpolarizing effects of IL-1beta. The IL-1beta stimulation of neurons induced a rapid increase in the phosphorylation of the tyrosine kinase Src and kinase suppressor of Ras (ceramide activated protein kinase (CAPK)/KSR) in neurons grown on glia from IL-1RI(-/-) mice. These effects of IL-1beta were dependent on the association of the cytosolic adaptor protein, MyD88, to the IL-1 receptor, and on the activation of the neutral sphingomyelinase, leading to production of ceramide. A cell-permeable analog of ceramide mimicked the effects of IL-1beta on the cultured AH neurons. These results suggest that ceramide may be the second messenger of the fast IL-1beta actions in AH neurons, and that this IL-1beta/ceramide pathway may underlie the fast non-transcription-dependent, electrophysiological effects of IL-1beta observed in AH neurons in vivo. PMID:16771830

  7. Enhanced TLR-MYD88 Signaling Stimulates Autoinflammation in SH3BP2 Cherubism Mice and Defines the Etiology of Cherubism

    PubMed Central

    Yoshitaka, Teruhito; Mukai, Tomoyuki; Kittaka, Mizuho; Alford, Lisa M.; Masrani, Salome; Ishida, Shu; Yamaguchi, Ken; Yamada, Motohiko; Mizuno, Noriyoshi; Olsen, Bjorn R.; Reichenberger, Ernst J.; Ueki, Yasuyoshi

    2014-01-01

    Summary Cherubism is caused by mutations in SH3BP2. Studies of cherubism mice showed that TNF-α-dependent autoinflammation is a major cause for the disorder, but failed to explain why human cherubism lesions are restricted to jaws and regress after puberty. We demonstrate that the inflammation in cherubism mice is MYD88-dependent and is rescued in the absence of TLR2 and TLR4. However, germ-free cherubism mice also develop inflammation. Mutant macrophages are hyper-responsive to PAMPs (pathogen-associated molecular patterns) and DAMPs (damage-associated molecular patterns) that activate TLRs, resulting in TNF-α overproduction. Phosphorylation of SH3BP2 at Y183 is critical for the TNF-α production. Finally, SYK depletion in macrophages prevents the inflammation. These data suggest that the presence of a large amount of TLR ligands, presumably oral bacteria and DAMPs during jawbone remodeling, may cause the jaw-specific development of human cherubism lesions. Reduced levels of DAMPs after stabilization of jaw remodeling may contribute to the age-dependent regression. PMID:25220465

  8. Gamma-Irradiated Influenza Virus Uniquely Induces IFN-I Mediated Lymphocyte Activation Independent of the TLR7/MyD88 Pathway

    PubMed Central

    Furuya, Yoichi; Chan, Jennifer; Wan, En-Chi; Koskinen, Aulikki; Diener, Kerrilyn R.; Hayball, John D.; Regner, Matthias; Müllbacher, Arno; Alsharifi, Mohammed

    2011-01-01

    Background We have shown previously in mice, that infection with live viruses, including influenza/A and Semliki Forest virus (SFV), induces systemic partial activation of lymphocytes, characterized by cell surface expression of CD69 and CD86, but not CD25. This partial lymphocytes activation is mediated by type-I interferons (IFN-I). Importantly, we have shown that γ-irradiated SFV does not induce IFN-I and the associated lymphocyte activation. Principal Findings Here we report that, in contrast to SFV, γ-irradiated influenza A virus elicits partial lymphocyte activation in vivo. Furthermore, we show that when using influenza viruses inactivated by a variety of methods (UV, ionising radiation and formalin treatment), as well as commercially available influenza vaccines, only γ-irradiated influenza virus is able to trigger IFN-I-dependent partial lymphocyte activation in the absence of the TLR7/MyD88 signalling pathways. Conclusions Our data suggest an important mechanism for the recognition of γ-irradiated influenza vaccine by cytosolic receptors, which correspond with the ability of γ-irradiated influenza virus to induce cross-reactive and cross-protective cytotoxic T cell responses. PMID:21998693

  9. Porcine circovirus type 2 induces type I interferon production via MyD88-IKKα-IRFs signaling rather than NF-κB in porcine alveolar macrophages in vitro.

    PubMed

    Chen, Mengmeng; Han, Junyuan; Zhang, Yaqun; Duan, Dianning; Zhang, Shuxia

    2016-02-01

    Type I interferon (IFN-I) plays important roles in host antiviral responses. The interferon regulatory factor (IRF) and NF-κB transcription factors are thought to be important in the processes of viral secretion and triggering of interferon production. Recently, studies have shown that porcine circovirus type 2 (PCV2) can induce IFN-I production in vivo and in vitro, but the mechanisms underlying the production of PAMs infected with PCV2 remains unknown. Treatment of these cells with BAY11-7082, an inhibitor of NF-κB activation, allowed us to study the secretion of IFN-α and IFN-β in PAMs infected with PCV2. We found that IFN-α expression was induced following virus infection of PAMs. Notably, even after inhibitor treatment of PAMs infected with PCV2, secretion of IFN-α was significantly higher (P<0.05) compared with the PCV2 infection alone group. Our findings suggest that NF-κB plays a minor role in PCV2-induced type I interferon responses. To further characterize the signaling pathway that drives IFN-I expression in PAMs in response to PCV2, we used siRNA to silence the expression of Myeloid differentiation factor 88 (MyD88) and study the role of MyD88-IKKα-IRF signaling in IFN-I production in PAMs induced by PCV2. Our findings show that PCV2 induced IFN-α mRNA transcription, which is associated with the activities of MyD88, IRF7, and IRF3. Thus, PCV2 can induce IFN-I transcription via the MyD88-IKKα-IRF signaling axis. PMID:26850559

  10. Mycoplasma bovis-derived lipid-associated membrane proteins activate IL-1β production through the NF-κB pathway via toll-like receptor 2 and MyD88.

    PubMed

    Wang, Yang; Liu, Suli; Li, Yuan; Wang, Qi; Shao, Jiari; Chen, Ying; Xin, Jiuqing

    2016-02-01

    Mycoplasma bovis causes pneumonia, otitis media, and arthritis in young calves, resulting in economic losses to the cattle industry worldwide. M. bovis pathogenesis results in part from excessive immune responses. Lipid-associated membrane proteins (LAMPs) can potently induce host innate immunity. However, interactions between M. bovis-derived LAMPs and Toll-like receptors (TLRs), or signaling pathways eliciting active inflammation and NF-κB activation, are incompletely understood. Here, we found that IL-1β expression was induced in embryonic bovine lung (EBL) cells stimulated with M. bovis-derived LAMPs. Subcellular-localization analysis revealed nuclear p65 translocation following EBL cell stimulation with M. bovis-derived LAMPs. An NF-κB inhibitor reversed M. bovis-derived LAMP-induced IL-1β expression. TLR2 and myeloid differentiation primary response gene 88 (MyD88) overexpression increased LAMP-dependent IL-1β induction. TLR2-neutralizing antibodies reduced IL-1β expression during LAMP stimulation. LAMPs also inhibited IL-1β expression following overexpression of a dominant-negative MyD88 protein. These results suggested that M. bovis-derived LAMPs activate IL-1β production through the NF-κB pathway via TLR2 and MyD88. PMID:26499291

  11. Immune effects of R848: evidences that suggest an essential role of TLR7/8-induced, Myd88- and NF-κB-dependent signaling in the antiviral immunity of Japanese flounder (Paralichthys olivaceus).

    PubMed

    Zhou, Zhi-Xia; Sun, Li

    2015-03-01

    The imidazoquinoline compound R848 is a specific agonist of toll-like receptor (TLR) 7/TLR8 that has been used as an immunostimulant in humans against viral diseases. Although R848-induced immune response has been reported in teleost fish, the relevant mechanism is not clear. In this study, we investigated the antiviral potential and the signaling pathway of R848 in a model of Japanese flounder (Paralichthys olivaceus). We found that R848 was able to inhibit the replication of megalocytivirus, stimulated the proliferation of peripheral blood leukocytes (PBL), enhanced the expression of immune genes, and reduced apoptosis of PBL. When endosomal acidification was blocked by chloroquine (CQ), R848-mediated antiviral activity and immune response were significantly reduced. Likewise, inhibition of Myd88 activation markedly impaired the pro-proliferation and anti-apoptosis effect of R848. Cellular study showed that cultured founder cells treated with R848 exhibited augmented NF-κB activity, which, however, was dramatically reduced in the presence of CQ and Myd88 inhibitor. Furthermore, when NF-κB was inactivated, the effect of R848 on cell proliferation and apoptosis was significantly decreased. Taken together, these results indicate that R848 is an immunostimulant with antiviral property in a teleost species, and that the immune response of R848 is mediated by, most likely, TLR7/TLR8 signaling pathway, in which Myd88 and NK-κB play an essential role. PMID:25475963

  12. Association of polymorphisms in the MyD88, IRAK4 and TRAF6 genes and susceptibility to type 2 diabetes mellitus and diabetic nephropathy in a southern Han Chinese population.

    PubMed

    Guo, Congcong; Zhang, Liju; Nie, Lihong; Zhang, Na; Xiao, Di; Ye, Xingguang; Ou, Meiling; Liu, Yang; Zhang, Baohuan; Wang, Man; Lin, Hansheng; Yang, Guang; Jing, Chunxia

    2016-07-01

    Type 2 diabetes mellitus (T2DM) has been linked to a state of low-grade inflammation resulting from abnormalities in the innate immune pathway. MyD88 is an essential adaptor protein for TLR signaling, which is involved in activating NF-κB through IRAK4 and TRAF6. To investigate the effects of the MyD88, IRAK4 and TRAF6 polymorphisms in the susceptibility of T2DM and diabetic vascular complications, eight SNPs were analyzed in 553 T2DM patients and 553 matched healthy controls. Gene-gene interactions and haplotype associations were also evaluated. We found a significant increased risk of T2DM for the AG genotype of rs6853 in MyD88 gene and the CT genotype of rs4251532 in IRAK4 gene. Significant association was also found between rs16928973 in TRAF6 gene and diabetic nephropathy (DN) under the allelic model. Moreover, the TA haplotype in TRAF6 was negatively associated with DN. No significant gene-gene interactions were found. In conclusion, our results indicate that the polymorphisms in TLR-MyD88-NF-κB signaling pathway confer genetic susceptibility to T2DM and DN. PMID:27062898

  13. Anti-Inflammatory Activity of Bee Venom in BV2 Microglial Cells: Mediation of MyD88-Dependent NF-κB Signaling Pathway

    PubMed Central

    Kim, Su Jung; Hong, Seung Bok; Park, Jin-Kyu

    2016-01-01

    Bee venom has long been used as a traditional folk medicine in Korea. It has been reportedly used for the treatment of arthritis, cancer, and inflammation. Although its anti-inflammatory activity in lipopolysaccharide- (LPS-) stimulated inflammatory cells has been reported, the exact mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, the aim of this study was to investigate the anti-inflammatory mechanism of bee venom in BV2 microglial cells. We first investigated whether NO production in LPS-activated BV2 cells was inhibited by bee venom, and further iNOS mRNA and protein expressions were determined. The mRNA and protein levels of proinflammatory cytokines were examined using semiquantitative RT-PCR and immunoblotting, respectively. Moreover, modulation of the transcription factor NF-κB by bee venom was also investigated using a luciferase assay. LPS-induced NO production in BV2 microglial cells was significantly inhibited in a concentration-dependent manner upon pretreatment with bee venom. Bee venom markedly reduced the mRNA expression of COX-2, TNF-α, IL-1β, and IL-6 and suppressed LPS-induced activation of MyD88 and IRAK1 and phosphorylation of TAK1. Moreover, NF-κB translocation by IKKα/β phosphorylation and subsequent IκB-α degradation were also attenuated. Thus, collectively, these results indicate that bee venom exerts its anti-inflammatory activity via the IRAK1/TAK1/NF-κB signaling pathway. PMID:27563334

  14. Anti-Inflammatory Activity of Bee Venom in BV2 Microglial Cells: Mediation of MyD88-Dependent NF-κB Signaling Pathway.

    PubMed

    Im, Eun Ju; Kim, Su Jung; Hong, Seung Bok; Park, Jin-Kyu; Rhee, Man Hee

    2016-01-01

    Bee venom has long been used as a traditional folk medicine in Korea. It has been reportedly used for the treatment of arthritis, cancer, and inflammation. Although its anti-inflammatory activity in lipopolysaccharide- (LPS-) stimulated inflammatory cells has been reported, the exact mechanism of its anti-inflammatory action has not been fully elucidated. Therefore, the aim of this study was to investigate the anti-inflammatory mechanism of bee venom in BV2 microglial cells. We first investigated whether NO production in LPS-activated BV2 cells was inhibited by bee venom, and further iNOS mRNA and protein expressions were determined. The mRNA and protein levels of proinflammatory cytokines were examined using semiquantitative RT-PCR and immunoblotting, respectively. Moreover, modulation of the transcription factor NF-κB by bee venom was also investigated using a luciferase assay. LPS-induced NO production in BV2 microglial cells was significantly inhibited in a concentration-dependent manner upon pretreatment with bee venom. Bee venom markedly reduced the mRNA expression of COX-2, TNF-α, IL-1β, and IL-6 and suppressed LPS-induced activation of MyD88 and IRAK1 and phosphorylation of TAK1. Moreover, NF-κB translocation by IKKα/β phosphorylation and subsequent IκB-α degradation were also attenuated. Thus, collectively, these results indicate that bee venom exerts its anti-inflammatory activity via the IRAK1/TAK1/NF-κB signaling pathway. PMID:27563334

  15. Loss of MyD88 alters neuroinflammatory response and attenuates early Purkinje cell loss in a spinocerebellar ataxia type 6 mouse model

    PubMed Central

    Aikawa, Tomonori; Mogushi, Kaoru; Iijima-Tsutsui, Kumiko; Ishikawa, Kinya; Sakurai, Miyano; Tanaka, Hiroshi; Mizusawa, Hidehiro; Watase, Kei

    2015-01-01

    Spinocerebellar ataxia type 6 (SCA6) is dominantly inherited neurodegenerative disease, caused by an expansion of CAG repeat encoding a polyglutamine (PolyQ) tract in the Cav2.1 voltage-gated calcium channel. Its key pathological features include selective degeneration of the cerebellar Purkinje cells (PCs), a common target for PolyQ-induced toxicity in various SCAs. Mutant Cav2.1 confers toxicity primarily through a toxic gain-of-function mechanism; however, its molecular basis remains elusive. Here, we studied the cerebellar gene expression patterns of young Sca6-MPI118Q/118Q knockin (KI) mice, which expressed mutant Cav2.1 from an endogenous locus and recapitulated many phenotypic features of human SCA6. Transcriptional signatures in the MPI118Q/118Q mice were distinct from those in the Sca1154Q/2Q mice, a faithful SCA1 KI mouse model. Temporal expression profiles of the candidate genes revealed that the up-regulation of genes associated with microglial activation was initiated before PC degeneration and was augmented as the disease progressed. Histological analysis of the MPI118Q/118Q cerebellum showed the predominance of M1-like pro-inflammatory microglia and it was concomitant with elevated expression levels of tumor necrosis factor, interleukin-6, Toll-like receptor (TLR) 2 and 7. Genetic ablation of MyD88, a major adaptor protein conveying TLR signaling, altered expression patterns of M1/M2 microglial phenotypic markers in the MPI118Q/118Q cerebellum. More importantly, it ameliorated PC loss and partially rescued motor impairments in the early disease phase. These results suggest that early neuroinflammatory response may play an important role in the pathogenesis of SCA6 and its modulation could pave the way for slowing the disease progression during the early stage of the disease. PMID:26034136

  16. CARMA1- and MyD88-dependent activation of Jun/ATF-type AP-1 complexes is a hallmark of ABC diffuse large B-cell lymphomas

    PubMed Central

    Juilland, Mélanie; Gonzalez, Montserrat; Erdmann, Tabea; Banz, Yara; Jevnikar, Zala; Hailfinger, Stephan; Tzankov, Alexandar; Grau, Michael; Lenz, Georg; Novak, Urban

    2016-01-01

    A hallmark of the diffuse large B-cell lymphoma (DLBCL) of the activated B-cell (ABC) type, a molecular subtype characterized by adverse outcome, is constitutive activation of the transcription factor nuclear factor–κB (NF-κB), which controls expression of genes promoting cellular survival and proliferation. Much less, however, is known about the role of the transcription factor activator protein-1 (AP-1) in ABC DLBCL. Here, we show that AP-1, like NF-κB, was controlled by constitutive activation of the B-cell receptor signaling component caspase recruitment domain-containing membrane-associated guanylate kinase 1 (CARMA1) and/or the Toll-like receptor signaling component myeloid differentiation primary response gene 88 (MyD88) in ABC DLBCL cell lines. In contrast to germinal center (GC) B-cell (GCB) DLBCL, ABC DLBCL cell lines expressed high levels of the AP-1 family members c-Jun, JunB, and JunD, which formed heterodimeric complexes with the AP-1 family members activating transcription factor (ATF) 2, ATF3, and ATF7. Inhibition of these complexes by a dominant-negative approach led to impaired growth of a majority of ABC DLBCL cell lines. Individual silencing of c-Jun, ATF2, or ATF3 decreased cellular survival and revealed c-Jun/ATF2-dependent control of ATF3 expression. As a consequence, ATF3 expression was much higher in ABC vs GCB DLBCL cell lines. Samples derived from DLBCL patients showed a clear trend toward high and nuclear ATF3 expression in nodal DLBCL of the non-GC or ABC subtype. These findings identify the activation of AP-1 complexes of the Jun/ATF-type as an important element controlling the growth of ABC DLBCL. PMID:26747248

  17. Comprehensive genomic profiling of orbital and ocular adnexal lymphomas identifies frequent alterations in MYD88 and chromatin modifiers: new routes to targeted therapies.

    PubMed

    Cani, Andi K; Soliman, Moaaz; Hovelson, Daniel H; Liu, Chia-Jen; McDaniel, Andrew S; Haller, Michaela J; Bratley, Jarred V; Rahrig, Samantha E; Li, Qiang; Briceño, César A; Tomlins, Scott A; Rao, Rajesh C

    2016-07-01

    Non-Hodgkin lymphoma of the orbit and ocular adnexa is the most common primary orbital malignancy. Treatments for low- (extra-nodal marginal zone and follicular lymphomas) and high-grade (diffuse large B-cell lymphoma) are associated with local and vision-threatening toxicities. High-grade lymphomas relapse frequently and exhibit poor survival rates. Despite advances in genomic profiling and precision medicine, orbital and ocular adnexal lymphomas remain poorly characterized molecularly. We performed targeted next-generation sequencing (NGS) profiling of 38 formalin-fixed, paraffin-embedded orbital and ocular adnexal lymphomas obtained from a single-center using a panel targeting near-term, clinically relevant genes. Potentially actionable mutations and copy number alterations were prioritized based on gain- and loss-of-function analyses, and catalogued, approved, and investigational therapies. Of 36 informative samples, including marginal zone lymphomas (n=20), follicular lymphomas (n=9), and diffuse large B-cell lymphomas (n=7), 53% harbored a prioritized alteration (median=1, range 0-5/sample). MYD88 was the most frequently altered gene in our cohort, with potentially clinically relevant hotspot gain-of-function mutations identified in 71% of diffuse large B-cell lymphomas and 25% of marginal zone lymphomas. Prioritized alterations in epigenetic modulators were common and included gain-of-function EZH2 and loss-of-function ARID1A mutations (14% of diffuse large B-cell lymphomas and 22% of follicular lymphomas contained alterations in each of these two genes). Single prioritized alterations were also identified in the histone methyltransferases KMT2B (follicular lymphoma) and KMT3B (diffuse large B-cell lymphoma). Loss-of-function mutations and copy number alterations in the tumor suppressors TP53 (diffuse large B-cell and follicular lymphoma), CDKN2A (diffuse large B-cell and marginal zone lymphoma), PTEN (diffuse large B-cell lymphoma), ATM (diffuse large B

  18. The HIV Protease Inhibitor Saquinavir Inhibits HMGB1-Driven Inflammation by Targeting the Interaction of Cathepsin V with TLR4/MyD88

    PubMed Central

    Pribis, John P; Al-Abed, Yousef; Yang, Huan; Gero, Domokos; Xu, Hongbo; Montenegro, Marcelo F; Bauer, Eileen M; Kim, Sodam; Chavan, Sangeeta S; Cai, Changchun; Li, Tunliang; Szoleczky, Petra; Szabo, Csaba; Tracey, Kevin J; Billiar, Timothy R

    2015-01-01

    Extracellular high-mobility group box 1 (HMGB1) (disulfide form), via activation of toll-like receptor 4 (TLR4)-dependent signaling, is a strong driver of pathologic inflammation in both acute and chronic conditions. Identification of selective inhibitors of HMGB1-TLR4 signaling could offer novel therapies that selectively target proximal endogenous activators of inflammation. A cell-based screening strategy led us to identify first generation HIV-protease inhibitors (PI) as potential inhibitors of HMGB1-TLR4 driven cytokine production. Here we report that the first-generation HIV-PI saquinavir (SQV), as well as a newly identified mammalian protease inhibitor STO33438 (334), potently block disulfide HMGB1-induced TLR4 activation, as assayed by the production of TNF-α by human monocyte-derived macrophages (THP-1). We further report on the identification of mammalian cathepsin V, a protease, as a novel target of these inhibitors. Cellular as well as recombinant protein studies show that the mechanism of action involves a direct interaction between cathepsin V with TLR4 and its adaptor protein MyD88. Treatment with SQV, 334 or the known cathepsin inhibitor SID26681509 (SID) significantly improved survival in murine models of sepsis and reduced liver damage following warm liver ischemia/reperfusion (I/R) models, both characterized by strong HMGB1-TLR4 driven pathology. The current study demonstrates a novel role for cathepsin V in TLR4 signaling and implicates cathepsin V as a novel target for first-generation HIV-PI compounds. The identification of cathepsin V as a target to block HMGB1-TLR4-driven inflammation could allow for a rapid transition of the discovery from the bench to the bedside. Disulfide HMGB1 drives pathologic inflammation in many models by activating signaling through TLR4. Cell-based screening identified the mammalian protease cathepsin V as a novel therapeutic target to inhibit TLR4-mediated inflammation induced by extracellular HMGB1 (disulfide form). We identified two protease inhibitors (PIs) that block cathepsin V and thereby inhibit disulfide HMGB1-induced TLR4 activation: saquinavir (SQV), a first-generation PI targeting viral HIV protease and STO33438 (334), targeting mammalian proteases. We discovered that cathepsin V binds TLR4 under basal and HMGB1-stimulated conditions, but dissociates in the presence of SQV over time. Thus cathepsin V is a novel target for first-generation HIV PIs and represents a potential therapeutic target of pathologic inflammation. PMID:26349060

  19. Suppression of Adaptive Immune Cell Activation Does Not Alter Innate Immune Adipose Inflammation or Insulin Resistance in Obesity

    PubMed Central

    Subramanian, Manikandan; Ozcan, Lale; Ghorpade, Devram Sampat; Ferrante, Anthony W.; Tabas, Ira

    2015-01-01

    Obesity-induced inflammation in visceral adipose tissue (VAT) is a major contributor to insulin resistance and type 2 diabetes. Whereas innate immune cells, notably macrophages, contribute to visceral adipose tissue (VAT) inflammation and insulin resistance, the role of adaptive immunity is less well defined. To address this critical gap, we used a model in which endogenous activation of T cells was suppressed in obese mice by blocking MyD88-mediated maturation of CD11c+ antigen-presenting cells. VAT CD11c+ cells from Cd11cCre+Myd88fl/fl vs. control Myd88fl/fl mice were defective in activating T cells in vitro, and VAT T and B cell activation was markedly reduced in Cd11cCre+Myd88fl/fl obese mice. However, neither macrophage-mediated VAT inflammation nor systemic inflammation were altered in Cd11cCre+Myd88fl/fl mice, thereby enabling a focused analysis on adaptive immunity. Unexpectedly, fasting blood glucose, plasma insulin, and the glucose response to glucose and insulin were completely unaltered in Cd11cCre+Myd88fl/fl vs. control obese mice. Thus, CD11c+ cells activate VAT T and B cells in obese mice, but suppression of this process does not have a discernible effect on macrophage-mediated VAT inflammation or systemic glucose homeostasis. PMID:26317499

  20. The TIR-domain-containing adapter inducing interferon-β-dependent signaling cascade plays a crucial role in ischemia–reperfusion-induced retinal injury, whereas the contribution of the myeloid differentiation primary response 88-dependent signaling cascade is not as pivotal

    PubMed Central

    Dvoriantchikova, Galina; Santos, Andrea Rachelle C; Danek, Dagmara; Dvoriantchikova, Xenia; Ivanov, Dmitry

    2014-01-01

    Toll-like receptor 4 (Tlr4) plays an important role in ischemia–reperfusion (IR)-induced retinal inflammation and damage. However, the role of two Tlr4-dependent signaling cascades, myeloid differentiation primary response 88 (Myd88) and TIR-domain-containing adapter inducing interferon-β (Trif), in retinal IR injury is poorly understood. In this study, we investigated the contribution of the Myd88-dependent and Trif-dependent signaling cascades in retinal damage and inflammation triggered by IR, by using Myd88 knockout (Myd88KO) and Trif knockout (TrifKO) mice. Retinal IR injury was induced by unilateral elevation of intraocular pressure for 45 min by direct corneal cannulation. To study IR-induced retinal ganglion cell (RGC) death in vitro, we used an oxygen and glucose deprivation (OGD) model. Our data suggested that Myd88 was present in many retinal layers of sham-operated and ischemic mice, whereas Trif was mainly present in the ganglion cell layer (GCL). The level of Myd88 was increased in the retina after IR. We found that retinas of TrifKO mice had a significantly reduced neurotoxic pro-inflammatory response and significantly increased survival of the GCL neurons after IR. Although Myd88KO mice had relatively low levels of inflammation in ischemic retinas, their levels of IR-induced retinal damage were notably higher than those of TrifKO mice. We also found that Trif-deficient RGCs were more resistant to death induced by OGD than were RGCs isolated from Myd88KO mice. These data suggested that, as compared with the Myd88-dependent signaling cascade, Trif signaling contributes significantly to retinal damage after IR. PMID:24754835

  1. Rifaximin Improves Clostridium difficile Toxin A-Induced Toxicity in Caco-2 Cells by the PXR-Dependent TLR4/MyD88/NF-κB Pathway

    PubMed Central

    Esposito, Giuseppe; Nobile, Nicola; Gigli, Stefano; Seguella, Luisa; Pesce, Marcella; d’Alessandro, Alessandra; Bruzzese, Eugenia; Capoccia, Elena; Steardo, Luca; Cuomo, Rosario; Sarnelli, Giovanni

    2016-01-01

    Background: Clostridium difficile infections (CDIs) caused by Clostridium difficile toxin A (TcdA) lead to severe ulceration, inflammation and bleeding of the colon, and are difficult to treat. Aim: The study aimed to evaluate the effect of rifaximin on TcdA-induced apoptosis in intestinal epithelial cells and investigate the role of PXR in its mechanism of action. Methods: Caco-2 cells were incubated with TcdA and treated with rifaximin (0.1-10 μM) with or without ketoconazole (10 μM). The transepithelial electrical resistance (TEER) and viability of the treated cells was determined. Also, the expression of zona occludens-1 (ZO-1), toll-like receptor 4 (TLR4), Bcl-2-associated X protein (Bax), transforming growth factor-β-activated kinase-1 (TAK1), myeloid differentiation factor 88 (MyD88), and nuclear factor-kappaB (NF-κB) was determined. Results: Rifaximin treatment (0.1, 1.0, and 10 μM) caused a significant and concentration-dependent increase in the TEER of Caco-2 cells (360, 480, and 680% vs. TcdA treatment) 24 h after the treatment and improved their viability (61, 79, and 105%). Treatment also concentration-dependently decreased the expression of Bax protein (-29, -65, and -77%) and increased the expression of ZO-1 (25, 54, and 87%) and occludin (71, 114, and 262%) versus TcdA treatment. The expression of TLR4 (-33, -50, and -75%), MyD88 (-29, -60, and -81%) and TAK1 (-37, -63, and -79%) were also reduced with rifaximin versus TcdA treatment. Ketoconazole treatment inhibited these effects. Conclusion: Rifaximin improved TcdA-induced toxicity in Caco-2 cells by the PXR-dependent TLR4/MyD88/NF-κB pathway mechanism, and may be useful in the treatment of CDIs. PMID:27242527

  2. Tongue sole (Cynoglossus semilaevis) prothymosin alpha: Cytokine-like activities associated with the intact protein and the C-terminal region that lead to antiviral immunity via Myd88-dependent and -independent pathways respectively.

    PubMed

    Zhang, Bao-cun; Sun, Li

    2015-11-01

    Prothymosin alpha (ProTα) is a small protein that in mammals is known to participate in diverse biological processes including immunomodulation. In teleost, the immunological function of ProTα is unknown. In the current study, we investigated the expression and function of the ProTα (named CsProTα) from the teleost fish tongue sole (Cynoglossus semilaevis). We found that CsProTα expression was abundant in immune relevant tissues and upregulated by megalocytivirus infection. Immunoblot detected secretion of CsProTα by peripheral blood leukocytes. Recombinant CsProTα (rCsProTα) as well as the C-terminal 11-residue (Ct11) were able to bind head kidney monocytes (HKM) and induce immune gene expression; however, the induction patterns caused by rCsProTα and Ct11 differed considerably. When introduced in vivo, rCsProTα and Ct11 significantly reduced megalocytivirus infection in fish tissues, whereas rCsProTα antibody significantly promoted viral replication. Blocking of Myd88 activity abolished the virus-inhibitory effect of rCsProTα but not Ct11. Taken together, these results demonstrate for the first time that both the intact protein and the C-terminal segment of a teleost ProTα can act like cytokines and induce antiviral immunity via, however, distinct signaling pathways that differ in the requirement of Myd88. PMID:26162512

  3. Rosmarinic Acid Methyl Ester Inhibits LPS-Induced NO Production via Suppression of MyD88- Dependent and -Independent Pathways and Induction of HO-1 in RAW 264.7 Cells.

    PubMed

    So, Yangkang; Lee, Seung Young; Han, Ah-Reum; Kim, Jin-Baek; Jeong, Hye Gwang; Jin, Chang Hyun

    2016-01-01

    In this study, we investigated the anti-inflammatory effect of rosmarinic acid methyl ester (RAME) isolated from a mutant cultivar of Perilla frutescens (L.) Britton. We found that RAME inhibits lipopolysaccharide (LPS)-induced nitric oxide (NO) production, with an IC50 of 14.25 µM, in RAW 264.7 cells. RAME inhibited the LPS-induced expression of pro-inflammatory cytokines including interleukin (IL)-1β, IL-6, IL-10, monocyte chemoattractant protein-1, interferon-β, and inducible nitric oxide synthase (iNOS). Moreover, RAME suppressed the activation of nuclear factor kappa B. These results suggest that the downregulation of iNOS expression by RAME was due to myeloid differentiation primary response gene 88 (MyD88)-dependent and -independent pathways. Furthermore, RAME induced the expression of heme oxygenase-1 (HO-1) through activation of nuclear factor-erythroid 2-related factor 2. Treatment with tin protoporphyrin, an inhibitor of HO-1, reversed the RAME-induced suppression of NO production. Taken together, RAME isolated from P. frutescens inhibited NO production in LPS-treated RAW 264.7 cells through simultaneous induction of HO-1 and inhibition of MyD88-dependent and -independent pathways. PMID:27548124

  4. Suppression of OVA-alum induced allergy by Heligmosomoides polygyrus products is MyD88-, TRIF-, regulatory T- and B cell-independent, but is associated with reduced innate lymphoid cell activation.

    PubMed

    McSorley, Henry J; Blair, Natalie F; Robertson, Elaine; Maizels, Rick M

    2015-11-01

    The murine intestinal nematode Heligmosomoides polygyrus exerts multiple immunomodulatory effects in the host, including the suppression of allergic inflammation in mice sensitized to allergen presented with alum adjuvant. Similar suppression is attained by co-administration of H. polygyrus excretory/secretory products (HES) with the sensitizing dose of ovalbumin (OVA) in alum. We investigated the mechanism of suppression by HES in this model, and found it was maintained in MyD88xTRIF-deficient mice, implying no role for helminth- or host-derived TLR ligands, or IL-1 family cytokines that signal in a MyD88- or TRIF-dependent manner. We also found suppression was unchanged in µMT mice, which lack B2 B cells, and that suppression was not abrogated when regulatory T cells were depleted in Foxp3.LuciDTR-4 mice. However, reduced IL-5 production was seen in the first 12 h after injection of OVA-alum when HES was co-administered, associated with reduced activation of IL-5(+) and IL-13(+) group 2 innate lymphoid cells. Thus, the suppressive effects of HES on alum-mediated OVA sensitization are reflected in the very earliest innate response to allergen exposure in vivo. PMID:25728231

  5. Intramammary infusion of Panax ginseng extract in bovine mammary gland at cessation of milking induces changes in the expression of toll-like receptors, MyD88 and NF-kB during early involution.

    PubMed

    Baravalle, Celina; Silvestrini, Paula; Cadoche, Mónica C; Beccaria, Camila; Andreotti, Carolina S; Renna, María S; Pereyra, Elizabeth A L; Ortega, Hugo H; Calvinho, Luis F; Dallard, Bibiana E

    2015-06-01

    The purposes of this study were to explore TLR2 and TLR4 participation and MyD88 and NF-κB activation in bovine mammary glands (BMG) treated with Panax ginseng (PG) at involution and verify the effect of PG in the cytokine expression. Quarters were infused at the end of lactation with PG solution (3 mg/ml), placebo or kept as uninoculated controls. Cows were slaughtered at 7 d after cessation of milking and mammary tissue samples were taken. A significant increase of TLR2, TLR4, MyD88, NF-κB, IL-1β, IL-6 and TGF-β1 mRNA expression was observed in PG-treated quarters. Immunostaining of TLR2 and TLR4 was significantly higher in PG mammary tissues. The percentages of immunopositive cells for NF-κB-p65 were significantly higher in PG-treated quarters. The BMG responded to PG extract components possibly by TLR2 and TLR4 signaling pathway. These results provide an insight into potential mechanisms by which PG stimulates innate immunity during BMG involution. PMID:25866011

  6. CXC195 suppresses proliferation and inflammatory response in LPS-induced human hepatocellular carcinoma cells via regulating TLR4-MyD88-TAK1-mediated NF-κB and MAPK pathway

    SciTech Connect

    Wang, Yiting; Tu, Qunfei; Yan, Wei; Xiao, Dan; Zeng, Zhimin; Ouyang, Yuming; Huang, Long; Cai, Jing; Zeng, Xiaoli; Chen, Ya-Jie; Liu, Anwen

    2015-01-02

    Highlights: • CXC195 exhibited significant anti-proliferative effect and induced cell cycle arrest in LPS-induced HepG2 cells. • CXC195 suppressed the release of pro-inflammatory mediators in LPS-induced HepG2 cells. • CXC195 regulated TLR4-MyD88-TAK1-mediated NF-κB and MAPK pathway in LPS-induced HepG2 cells. - Abstract: CXC195 showed strong protective effects in neuronal apoptosis by exerting its antioxidant activity. However, the anti-cancer effects of CXC195 is still with limited acquaintance. Here, we investigated the role of CXC195 in lipopolysaccharide (LPS)-induced human hepatocellular carcinoma (HCC) cells lines (HepG2) and the possible signaling pathways. CXC195 exhibited significant anti-proliferative effect and induced cell cycle arrest in LPS-induced HepG2 cells. In addition, CXC195 suppressed the release of pro-inflammatory mediators in LPS-induced HepG2 cells, including TNF-α, iNOS, IL-1β, IL-6, CC chemokine ligand (CCL)-2, CCL-22 and epidermal growth factor receptor (EGFR). Moreover, CXC195 inhibited the expressions and interactions of TLR4, MyD88 and TAK1, NF-κB translocation to nucleus and its DNA binding activity, phosphorylation of ERK1/2, p38 and JNK. Our results suggested that treatment with CXC195 could attenuate the TLR4-mediated proliferation and inflammatory response in LPS-induced HepG2 cells, thus might be beneficial for the treatment of HCC.

  7. A liquid crystal of ascorbyl palmitate, used as vaccine platform, provides sustained release of antigen and has intrinsic pro-inflammatory and adjuvant activities which are dependent on MyD88 adaptor protein.

    PubMed

    Sánchez Vallecillo, María F; Minguito de la Escalera, María M; Aguirre, María V; Ullio Gamboa, Gabriela V; Palma, Santiago D; González-Cintado, Leticia; Chiodetti, Ana L; Soldano, Germán; Morón, Gabriel; Allemandi, Daniel A; Ardavín, Carlos; Pistoresi-Palencia, María C; Maletto, Belkys A

    2015-09-28

    Modern subunit vaccines require the development of new adjuvant strategies. Recently, we showed that CpG-ODN formulated with a liquid crystal nanostructure formed by self-assembly of 6-O-ascorbyl palmitate (Coa-ASC16) is an attractive system for promoting an antigen-specific immune response to weak antigens. Here, we showed that after subcutaneous injection of mice with near-infrared fluorescent dye-labeled OVA antigen formulated with Coa-ASC16, the dye-OVA was retained at the injection site for a longer period than when soluble dye-OVA was administered. Coa-ASC16 alone elicited a local inflammation, but how this material triggers this response has not been described yet. Although it is known that some materials used as a platform are not immunologically inert, very few studies have directly focused on this topic. In this study, we explored the underlying mechanisms concerning the interaction between Coa-ASC16 and the immune system and we found that the whole inflammatory response elicited by Coa-ASC16 (leukocyte recruitment and IL-1β, IL-6 and IL-12 production) was dependent on the MyD88 protein. TLR2, TLR4, TLR7 and NLRP3-inflammasome signaling were not required for induction of this inflammatory response. Coa-ASC16 induced local release of self-DNA, and in TLR9-deficient mice IL-6 production was absent. In addition, Coa-ASC16 revealed an intrinsic adjuvant activity which was affected by MyD88 and IL-6 absence. Taken together these results indicate that Coa-ASC16 used as a vaccine platform is effective due to the combination of the controlled release of antigen and its intrinsic pro-inflammatory activity. Understanding how Coa-ASC16 works might have significant implications for rational vaccine design. PMID:26188153

  8. Molecular cloning, characterization and expression analysis of TLR9, MyD88 and TRAF6 genes in common carp (Cyprinus carpio)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Induction of innate immune pathways is critical for early host defense but there is limited understanding of how teleost fish recognize pathogen molecules and activate these pathways. In mammals, cells of the innate immune system detect pathogenic molecular structures using pattern recognition rece...

  9. Anti-neuroinflammatory effects of citreohybridonol involving TLR4-MyD88-mediated inhibition of NF-кB and MAPK signaling pathways in lipopolysaccharide-stimulated BV2 cells.

    PubMed

    Cho, Kwang-Ho; Kim, Dong-Cheol; Yoon, Chi-Su; Ko, Won Min; Lee, Seung Jun; Sohn, Jae Hak; Jang, Jae-Hyuk; Ahn, Jong Seog; Kim, Youn-Chul; Oh, Hyuncheol

    2016-05-01

    In the course of searching for anti-neuroinflammatory metabolites from marine fungi, citreohybridonol was isolated from marine-derived fungal strain Toxicocladosporium sp. SF-5699. Citreohybridonol inhibited production of nitric oxide (NO) and prostaglandin E2 (PGE2) in BV2 cells stimulated by lipopolysaccharide (LPS). Citreohybridonol also suppressed the expression of inducible NO synthase (iNOS), cyclooxygenase-2 (COX-2), and other pro-inflammatory cytokines including interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the LPS-stimulated cells. In the further study, citreohybridonol disturbed nuclear translocation of nuclear factor-kappa B (NF-κB) in LPS-stimulated BV2 cells by inhibiting the phosphorylation of the inhibitor kappa B-α (IκB-α). Citreohybridonol also had inhibitory effect on the LPS-stimulated phosphorylation of p38 mitogen-activated protein kinase (MAPK). Finally, citreohybridonol suppressed the protein expression of Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 (MyD88) in LPS-induced BV2 cells. These results suggest that citreohybridonol has anti-neuroinflammatory effect in LPS-stimulated BV2 cells by modulating TLR4-mediated several inflammatory pathways such as NF-κB and p38 MAPK pathways. PMID:26724567

  10. Inhibitory effects of alternaramide on inflammatory mediator expression through TLR4-MyD88-mediated inhibition of NF-кB and MAPK pathway signaling in lipopolysaccharide-stimulated RAW264.7 and BV2 cells.

    PubMed

    Ko, Wonmin; Sohn, Jae Hak; Jang, Jae-Hyuk; Ahn, Jong Seog; Kang, Dae Gill; Lee, Ho Sub; Kim, Jong-Su; Kim, Youn-Chul; Oh, Hyuncheol

    2016-01-25

    Alternaramide (1), a novel lipophilic depsipeptide, has been isolated from the extract of the marine-derived fungus Alternaria sp. SF-5016. In the course of extensive biological evaluation of 1, its anti-inflammatory effects in lipopolysaccharide (LPS)-stimulated RAW264.7 and BV2 cells were observed. In our initial study of the anti-inflammatory effects of 1, the compound suppressed production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS-stimulated RAW264.7 and BV2 cells. Suppression of NO and PGE2 production was correlated with the inhibitory effect of 1 on expression of LPS-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) at the protein level in RAW264.7 and BV2 cells. In addition, 1 reduced production of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-12 in LPS-stimulated RAW264.7 and BV2 cells. In the evaluation of the molecular mechanisms underlying the anti-inflammatory effects of 1, the compound was found to suppress the nuclear factor-kappa B (NF-κB) signaling pathway in RAW264.7 and BV2 cells stimulated with LPS. This suppression was mediated by disruption of phosphorylation and degradation of IκBα, an inhibitor of NF-κB, in the cytoplasm, and blocking of nuclear translocation of the NF-κB p50-p65 heterodimer. Furthermore, 1 inhibited phosphorylation of c-Jun N-terminal kinases (JNKs) and p38 mitogen-activated protein kinase (MAPK), demonstrating its capacity to inhibit MAPK signaling. Finally, 1 markedly reduced expression of Toll-like receptor 4 (TLR4) and myeloid differentiation primary response gene 88 (MyD88) at the mRNA and protein levels in LPS-stimulated RAW264.7 and BV2 cells. Taken together, the results of the present study suggest that 1 modulates several TLR4-mediated inflammatory pathways, demonstrating its potential in the treatment of inflammatory and neuroinflammatory conditions. PMID:26620692

  11. Species adaptation in a protein molecule.

    PubMed

    Perutz, M F

    1983-12-01

    The allosteric properties of hemoglobins, especially their responses to ligands other than oxygen, vary widely in different classes of vertebrates. Knowing the stereochemistry of the cooperative effects in human hemoglobin, one can infer the stereochemical basis of these variations from the changes in amino acid sequence. The results indicate that the tertiary and quaternary structures of deoxy- and oxyhemoglobin have remained almost invariant during vertebrate evolution and that most of the amino acid replacements between species are functionally neutral. Adaptations leading to responses to new chemical stimuli have evolved by only a few (one to five) amino acid substitutions in key positions. Once such a response has become superfluous, it may be inactivated, not necessarily by a reversal of one of the original substitutions but by any other that happens to inhibit it. PMID:6400645

  12. Analyte sensing mediated by adapter/carrier molecules

    DOEpatents

    Bayley, Hagan; Braha, Orit; Gu, LiQun

    2002-07-30

    This invention relates to an improved method and system for sensing of one or more analytes. A host molecule, which serves as an adapter/carrier, is used to facilitate interaction between the analyte and the sensor element. A detectable signal is produced reflecting the identity and concentration of analyte present.

  13. Interleukin-33 and Mast Cells Bridge Innate and Adaptive Immunity: From the Allergologist’s Perspective

    PubMed Central

    Jang, Tae Young; Kim, Young Hyo

    2015-01-01

    Interleukin (IL) 33, a member of the IL-1 superfamily, is an “alarmin” protein and is secreted in its active form from damaged cells undergoing necrotic cell death. Mast cells are one of the main effector cell types in allergic disorders. They secrete a variety of mediators, including T helper 2 cytokines. As mast cells have high-affinity IgE receptors (FcεRI) on their surface, they can capture circulating IgE. IgE-bound mast cells degranulate large amounts of histamine, heparin, and proteases when they encounter antigens. As IL-33 is an important mediator of innate immunity and mast cells play an important role in adaptive immune responses, interactions between the two could link innate and adaptive immunity. IL-33 promotes the adhesion of mast cells to laminin, fibronectin, and vitronectin. IL-33 increases the expression of adhesion molecules, such as intracellular adhesion molecule-1 and vascular cell adhesion molecule-1, in endothelial cells, thus enhancing mast cell adhesion to blood vessel walls. IL-33 stimulates mast cell proliferation by activating the ST2/Myd88 pathway; increases mast cell survival by the activation of survival proteins such as Bcl-XL; and promotes the growth, development, and maturation of mast cell progenitors. IL-33 is also involved in the activation of mature mast cells and production of different proinflammatory cytokines. The interaction of IL-33 and mast cells could have important clinical implications in the field of clinical urology. Epithelial dysfunction and mast cells could play an important role in the pathogenesis of interstitial cystitis. Urinary levels of IL-33 significantly increase in patients with interstitial cystitis. In addition, the number of mast cells significantly increase in the urinary bladders of patients with interstitial cystitis. Therefore, inhibition of mast cell activation and degranulation in response to increase in IL-33 is a potential therapeutic target in the treatment of interstitial cystitis

  14. Inhibition of TLR2 signaling by small molecule inhibitors targeting a pocket within the TLR2 TIR domain.

    PubMed

    Mistry, Pragnesh; Laird, Michelle H W; Schwarz, Ryan S; Greene, Shannon; Dyson, Tristan; Snyder, Greg A; Xiao, Tsan Sam; Chauhan, Jay; Fletcher, Steven; Toshchakov, Vladimir Y; MacKerell, Alexander D; Vogel, Stefanie N

    2015-04-28

    Toll-like receptor (TLR) signaling is initiated by dimerization of intracellular Toll/IL-1 receptor resistance (TIR) domains. For all TLRs except TLR3, recruitment of the adapter, myeloid differentiation primary response gene 88 (MyD88), to TLR TIR domains results in downstream signaling culminating in proinflammatory cytokine production. Therefore, blocking TLR TIR dimerization may ameliorate TLR2-mediated hyperinflammatory states. The BB loop within the TLR TIR domain is critical for mediating certain protein-protein interactions. Examination of the human TLR2 TIR domain crystal structure revealed a pocket adjacent to the highly conserved P681 and G682 BB loop residues. Using computer-aided drug design (CADD), we sought to identify a small molecule inhibitor(s) that would fit within this pocket and potentially disrupt TLR2 signaling. In silico screening identified 149 compounds and 20 US Food and Drug Administration-approved drugs based on their predicted ability to bind in the BB loop pocket. These compounds were screened in HEK293T-TLR2 transfectants for the ability to inhibit TLR2-mediated IL-8 mRNA. C16H15NO4 (C29) was identified as a potential TLR2 inhibitor. C29, and its derivative, ortho-vanillin (o-vanillin), inhibited TLR2/1 and TLR2/6 signaling induced by synthetic and bacterial TLR2 agonists in human HEK-TLR2 and THP-1 cells, but only TLR2/1 signaling in murine macrophages. C29 failed to inhibit signaling induced by other TLR agonists and TNF-α. Mutagenesis of BB loop pocket residues revealed an indispensable role for TLR2/1, but not TLR2/6, signaling, suggesting divergent roles. Mice treated with o-vanillin exhibited reduced TLR2-induced inflammation. Our data provide proof of principle that targeting the BB loop pocket is an effective approach for identification of TLR2 signaling inhibitors. PMID:25870276

  15. What the Myddosome structure tells us about the initiation of innate immunity.

    PubMed

    Gay, Nicholas J; Gangloff, Monique; O'Neill, Luke A J

    2011-03-01

    Signaling by the toll-like receptor (TLR) and interleukin-1 receptor superfamily requires the adapter protein myeloid differentiation primary response protein 88 (MyD88). The recent determination of the structure of the so-called Myddosome provides us with new insights into the structural basis for innate immune signaling. Other information on the biochemistry and genetics of MyD88 and other adapters, such as MyDD adapter-like and TRIF-related adapter molecule, allows us to describe in some detail the signaling process activated by TLRs and provides new insights into the role these important proteins play in innate immunity. PMID:21269878

  16. Adaptive resolution simulation of an atomistic DNA molecule in MARTINI salt solution

    NASA Astrophysics Data System (ADS)

    Zavadlav, J.; Podgornik, R.; Melo, M. N.; Marrink, S. J.; Praprotnik, M.

    2016-07-01

    We present a dual-resolution model of a deoxyribonucleic acid (DNA) molecule in a bathing solution, where we concurrently couple atomistic bundled water and ions with the coarse-grained MARTINI model of the solvent. We use our fine-grained salt solution model as a solvent in the inner shell surrounding the DNA molecule, whereas the solvent in the outer shell is modeled by the coarse-grained model. The solvent entities can exchange between the two domains and adapt their resolution accordingly. We critically asses the performance of our multiscale model in adaptive resolution simulations of an infinitely long DNA molecule, focusing on the structural characteristics of the solvent around DNA. Our analysis shows that the adaptive resolution scheme does not produce any noticeable artifacts in comparison to a reference system simulated in full detail. The effect of using a bundled-SPC model, required for multiscaling, compared to the standard free SPC model is also evaluated. Our multiscale approach opens the way for large scale applications of DNA and other biomolecules which require a large solvent reservoir to avoid boundary effects.

  17. Photoelectron spectra of some important biological molecules: symmetry-adapted-cluster configuration interaction study.

    PubMed

    Farrokhpour, Hossein; Ghandehari, Maryam

    2013-05-23

    In this work, the valence vertical ionization energies (up to 5) of some important biologically active molecules including 2,4-dinitrophenol, 2,4-dinitroanisole, nicotinic acid, nicotinic acid methyl ester, nicotinamide, N,N-diethylnicotinamide, barbituric acid, uric acid, cytosine, β-carotene, and menadione were calculated in the gas phase and compared with the experimental data reported in the literature. The symmetry-adapted-cluster configuration interaction (SAC-CI) general-R method was used to calculate the ionization energies. The intensity of each ionization band was evaluated using the monopole approximation. Comparison of the calculated photoelectron spectrum of each molecule with its corresponding experimental spectra allowed for assigning the photoelectron bands by natural bonding orbital (NBO) calculations even though some of the associated bands were significantly overlapped for some molecules. Among the considered molecules, there was no agreement between the experimental and calculated photoelectron spectrum of β-carotene. The reason for this disagreement was theoretically investigated and attributed to the degradation and decomposition of β-carotene. The calculated first ionization energies of the considered molecules were correlated with their Hückel k-index to obtain Coulomb (α) and resonance (β) integrals of the Hückel molecular orbital theory for the biomolecules considered in this study. A linear correlation was found between the first ionization energy and the Hückel k-index. PMID:23659524

  18. Adaptive Control Model Reveals Systematic Feedback and Key Molecules in Metabolic Pathway Regulation

    PubMed Central

    Moffitt, Richard A.; Merrill, Alfred H.; Wang, May D.

    2011-01-01

    Abstract Robust behavior in metabolic pathways resembles stabilized performance in systems under autonomous control. This suggests we can apply control theory to study existing regulation in these cellular networks. Here, we use model-reference adaptive control (MRAC) to investigate the dynamics of de novo sphingolipid synthesis regulation in a combined theoretical and experimental case study. The effects of serine palmitoyltransferase over-expression on this pathway are studied in vitro using human embryonic kidney cells. We report two key results from comparing numerical simulations with observed data. First, MRAC simulations of pathway dynamics are comparable to simulations from a standard model using mass action kinetics. The root-sum-square (RSS) between data and simulations in both cases differ by less than 5%. Second, MRAC simulations suggest systematic pathway regulation in terms of adaptive feedback from individual molecules. In response to increased metabolite levels available for de novo sphingolipid synthesis, feedback from molecules along the main artery of the pathway is regulated more frequently and with greater amplitude than from other molecules along the branches. These biological insights are consistent with current knowledge while being new that they may guide future research in sphingolipid biology. In summary, we report a novel approach to study regulation in cellular networks by applying control theory in the context of robust metabolic pathways. We do this to uncover potential insight into the dynamics of regulation and the reverse engineering of cellular networks for systems biology. This new modeling approach and the implementation routines designed for this case study may be extended to other systems. Supplementary Material is available at www.liebertonline.com/cmb. PMID:21314456

  19. Madm (Mlf1 adapter molecule) cooperates with Bunched A to promote growth in Drosophila

    PubMed Central

    2010-01-01

    Background The TSC-22 domain family (TSC22DF) consists of putative transcription factors harboring a DNA-binding TSC-box and an adjacent leucine zipper at their carboxyl termini. Both short and long TSC22DF isoforms are conserved from flies to humans. Whereas the short isoforms include the tumor suppressor TSC-22 (Transforming growth factor-β1 stimulated clone-22), the long isoforms are largely uncharacterized. In Drosophila, the long isoform Bunched A (BunA) acts as a growth promoter, but how BunA controls growth has remained obscure. Results In order to test for functional conservation among TSC22DF members, we expressed the human TSC22DF proteins in the fly and found that all long isoforms can replace BunA function. Furthermore, we combined a proteomics-based approach with a genetic screen to identify proteins that interact with BunA. Madm (Mlf1 adapter molecule) physically associates with BunA via a conserved motif that is only contained in long TSC22DF proteins. Moreover, Drosophila Madm acts as a growth-promoting gene that displays growth phenotypes strikingly similar to bunA phenotypes. When overexpressed, Madm and BunA synergize to increase organ growth. Conclusions The growth-promoting potential of long TSC22DF proteins is evolutionarily conserved. Furthermore, we provide biochemical and genetic evidence for a growth-regulating complex involving the long TSC22DF protein BunA and the adapter molecule Madm. See minireview at http://jbiol.com/content/9/1/8. PMID:20149264

  20. Adapting phase-switch Monte Carlo method for flexible organic molecules

    NASA Astrophysics Data System (ADS)

    Bridgwater, Sally; Quigley, David

    2014-03-01

    The role of cholesterol in lipid bilayers has been widely studied via molecular simulation, however, there has been relatively little work on crystalline cholesterol in biological environments. Recent work has linked the crystallisation of cholesterol in the body with heart attacks and strokes. Any attempt to model this process will require new models and advanced sampling methods to capture and quantify the subtle polymorphism of solid cholesterol, in which two crystalline phases are separated by a phase transition close to body temperature. To this end, we have adapted phase-switch Monte Carlo for use with flexible molecules, to calculate the free energy between crystal polymorphs to a high degree of accuracy. The method samples an order parameter , which divides a displacement space for the N molecules, into regions energetically favourable for each polymorph; which is traversed using biased Monte Carlo. Results for a simple model of butane will be presented, demonstrating that conformational flexibility can be correctly incorporated within a phase-switching scheme. Extension to a coarse grained model of cholesterol and the resulting free energies will be discussed.

  1. In Silico Approach to Inhibition of Signaling Pathways of Toll-Like Receptors 2 and 4 by ST2L

    PubMed Central

    Basith, Shaherin; Manavalan, Balachandran; Govindaraj, Rajiv Gandhi; Choi, Sangdun

    2011-01-01

    Toll-like receptors (TLRs) activate a potent immunostimulatory response. There is clear evidence that overactivation of TLRs leads to infectious and inflammatory diseases. Recent biochemical studies have shown that the membrane-bound form of ST2 (ST2L), a member of the Toll-like/IL-1 receptor superfamily, negatively regulates MyD88-dependent TLR signaling pathways by sequestrating the adapters MyD88 and Mal (TIRAP). Specifically, ST2L attenuates the recruitment of Mal and MyD88 adapters to their receptors through its intracellular TIR domain. Thus, ST2L is a potent molecule that acts as a key regulator of endotoxin tolerance and modulates innate immunity. So far, the inhibitory mechanism of ST2L at the molecular level remains elusive. To develop a working hypothesis for the interactions between ST2L, TLRs (TLR1, 2, 4, and 6), and adapter molecules (MyD88 and Mal), we constructed three-dimensional models of the TIR domains of TLR4, 6, Mal, and ST2L based on homology modeling. Since the crystal structures of the TIR domains of TLR1, 2 as well as the NMR solution structure of MyD88 are known, we utilized these structures in our analysis. The TIR domains of TLR1, 2, 4, 6, MyD88, Mal and ST2L were subjected to molecular dynamics (MD) simulations in an explicit solvent environment. The refined structures obtained from the MD simulations were subsequently used in molecular docking studies to probe for potential sites of interactions. Through protein-protein docking analysis, models of the essential complexes involved in TLR2 and 4 signaling and ST2L inhibiting processes were developed. Our results suggest that ST2L may exert its inhibitory effect by blocking the molecular interface of Mal and MyD88 adapters mainly through its BB-loop region. Our predicted oligomeric signaling models may provide a basis for the understanding of the assembly process of TIR domain interactions, which has thus far proven to be difficult via in vivo studies. PMID:21897866

  2. High Mobility Group Box Protein 1 (HMGB1)-Partner Molecule Complexes Enhance Cytokine Production by Signaling Through the Partner Molecule Receptor

    PubMed Central

    Hreggvidsdóttir, Hulda Sigridur; Lundberg, Anna M; Aveberger, Ann-Charlotte; Klevenvall, Lena; Andersson, Ulf; Harris, Helena Erlandsson

    2012-01-01

    The nuclear protein high mobility group box protein 1 (HMGB1) promotes inflammation upon extracellular release. HMGB1 induces proinflammatory cytokine production in macrophages via Toll-like receptor (TLR)-4 signaling in a redox-dependent fashion. Independent of its redox state and endogenous cytokine-inducing ability, HMGB1 can form highly immunostimulatory complexes by interaction with certain proinflammatory mediators. Such complexes have the ability to enhance the induced immune response up to 100-fold, compared with induction by the ligand alone. To clarify the mechanisms for these strong synergistic effects, we studied receptor requirements. Interleukin (IL)-6 production was assessed in supernatants from cultured peritoneal macrophages from mice each deficient in one of the HMGB1 receptors (receptor for advanced glycation end products [RAGE], TLR2 or TLR4) or from wild-type controls. The cultures were stimulated with the TLR4 ligand lipopolysaccaride (LPS), the TLR2 ligand Pam3CysSerLys4 (Pam3CSK4), noninflammatory HMGB1 or each TLR ligand in complex with noninflammatory HMGB1. The activity of the HMGB1-TLR ligand complexes relied on engagement of the same receptor as for the noncomplexed TLR ligand, since HMGB1-LPS complexes used TLR4 and HMGB1-Pam3CSK4 complexes used TLR2. Deletion of any of the intracellular adaptor molecules used by TLR2 (myeloid differentiation factor-88 [MyD88], TIR domain–containing adaptor protein [TIRAP]) or TLR4 (MyD88, TIRAP, TIR domain–containing adaptor-inducing interferon-β [TRIF], TRIF-related adaptor molecule [TRAM]) had similar effects on HMGB1 complex activation compared with noncomplexed LPS or Pam3CSK4. This result implies that the enhancing effects of HMGB1-partner molecule complexes are not regulated by the induction of additional signaling cascades. Elucidating HMGB1 receptor usage in processes where HMGB1 acts alone or in complex with other molecules is essential for the understanding of basic HMGB1 biology and

  3. Adaptive-Partitioning QM/MM Dynamics Simulations: 3. Solvent Molecules Entering and Leaving Protein Binding Sites.

    PubMed

    Pezeshki, Soroosh; Davis, Christal; Heyden, Andreas; Lin, Hai

    2014-11-11

    The adaptive-partitioning (AP) schemes for combined quantum-mechanical/molecular-mechanical (QM/MM) calculations allow on-the-fly reclassifications of atoms and molecules as QM or MM in dynamics simulations. The permuted-AP (PAP) scheme (J. Phys. Chem. B 2007, 111, 2231) introduces a thin layer of buffer zone between the QM subsystem (also called active zone) and the MM subsystem (also known as the environmental zone) to provide a continuous and smooth transition and expresses the potential energy in a many-body expansion manner. The PAP scheme has been successfully applied to study small molecules solvated in bulk solvent. Here, we propose two modifications to the original PAP scheme to treat solvent molecules entering and leaving protein binding sites. First, the center of the active zone is placed at a pseudoatom in the binding site, whose position is not affected by the movements of ligand or residues in the binding site. Second, the extra forces due to the smoothing functions are deleted. The modified PAP scheme no longer describes a Hamiltonian system, but it satisfies the conservation of momentum. As a proof-of-concept experiment, the modified PAP scheme is applied to the simulations under the canonical ensemble for two binding sites of the Escherichia coli CLC chloride ion transport protein, in particular, the intracellular binding site Sint discovered by crystallography and one putative additional binding site Sadd suggested by molecular modeling. The exchange of water molecules between the binding sites and bulk solvent is monitored. For comparison, simulations are also carried out using the same model system and setup with only one exception: the extra forces due to the smoothing functions are retained. The simulations are benchmarked against conventional QM/MM simulations with large QM subsystems. The results demonstrate that the active zone centered at the pseudo atom is a reasonable and convenient representation of the binding site. Moreover, the

  4. The adaptor molecule Trif contributes to murine host defense during Leptospiral infection.

    PubMed

    Jayaraman, Priya A; Devlin, Amy A; Miller, Jennifer C; Scholle, Frank

    2016-09-01

    Leptospirosis is a zoonotic disease and is caused by pathogenic species of the Leptospira genus, including Leptospira interrogans (L. interrogans). Humans, domestic and wild animals are susceptible to acute or chronic infection. The innate immune response is a critical defense mechanism against Leptospira interrogans, and has been investigated in mouse models. Murine Toll-like receptors (TLRs) have been shown to be key factors in sensing and responding to L. interrogans infection. Specifically, TLR2, TLR4 and the TLR adaptor molecule MyD88 are essential for host defense against L. interrogans; however, the role of the TLR adaptor molecule TIR-domain-containing adaptor-inducing interferon β (TRIF) in the response to L. interrogans has not been previously determined. In the present study, TRIF was found to play an important role during leptospiral infection. Following challenge with L. interrogans, Trif(-/-) mice exhibited delayed weight gain compared to wild-type mice. Moreover, Trif(-/-) mice exhibited an increase in L. interrogans burden in the kidneys, lungs, and blood at early time points (less than 7days post infection). Multiple components of the innate immune responses were dampened in response to leptospiral infection including transcription and production of cytokines, and the humoral response, which suggested that TRIF contributes to expression and production of cytokines important for the host defense against L. interrogans. PMID:27259371

  5. Adaptive Particle Swarm Optimizer with Varying Acceleration Coefficients for Finding the Most Stable Conformer of Small Molecules.

    PubMed

    Agrawal, Shikha; Silakari, Sanjay; Agrawal, Jitendra

    2015-11-01

    A novel parameter automation strategy for Particle Swarm Optimization called APSO (Adaptive PSO) is proposed. The algorithm is designed to efficiently control the local search and convergence to the global optimum solution. Parameters c1 controls the impact of the cognitive component on the particle trajectory and c2 controls the impact of the social component. Instead of fixing the value of c1 and c2 , this paper updates the value of these acceleration coefficients by considering time variation of evaluation function along with varying inertia weight factor in PSO. Here the maximum and minimum value of evaluation function is use to gradually decrease and increase the value of c1 and c2 respectively. Molecular energy minimization is one of the most challenging unsolved problems and it can be formulated as a global optimization problem. The aim of the present paper is to investigate the effect of newly developed APSO on the highly complex molecular potential energy function and to check the efficiency of the proposed algorithm to find the global minimum of the function under consideration. The proposed algorithm APSO is therefore applied in two cases: Firstly, for the minimization of a potential energy of small molecules with up to 100 degrees of freedom and finally for finding the global minimum energy conformation of 1,2,3-trichloro-1-flouro-propane molecule based on a realistic potential energy function. The computational results of all the cases show that the proposed method performs significantly better than the other algorithms. PMID:27491033

  6. Loss of cell adhesion molecule CHL1 improves homeostatic adaptation and survival in hypoxic stress.

    PubMed

    Huang, X; Sun, J; Rong, W; Zhao, T; Li, D H; Ding, X; Wu, L Y; Wu, K; Schachner, M; Xiao, Z C; Zhu, L L; Fan, M

    2013-01-01

    Close homologue of L1 (CHL1) is a transmembrane cell adhesion molecule that is critical for brain development and for the maintenance of neural circuits in adults. Recent studies revealed that CHL1 has diverse roles and is involved in the regulation of recovery after spinal cord injury. CHL1 expression was downregulated in the cerebral cortex, hypothalamus, and brain stem after the induction of acute hypoxia (AH). In the current study, we sought to address the role of CHL1 in regulating homeostasis responses to hypoxia using CHL1-knockout (CHL1(-/-)) mice. We found that, compared with wild-type littermates, CHL1(-/-) mice showed a dramatically lower mortality rate and an augmented ventilatory response after they were subjected to AH. Immunofluorescence staining revealed that CHL1 was expressed in the carotid body (CB), the key oxygen sensor in rodents, and CHL1 expression level in the CB as assayed by western blot was decreased after hypoxic exposure. The number of glomus cells and the expression of tyrosine hydroxylase (a marker for glomus cells) in the CB of CHL1(-/-) mice appeared to be increased compared with CHL1(+/+) mice. In addition, in the ex vivo CB preparation, hypoxia induced a significantly greater afferent nerve discharge in CHL1(-/-) mice compared with CHL1(+/+) mice. Furthermore, the arterial blood pressure and plasma catecholamine levels of CHL1(-/-) mice were also significantly higher than those of CHL1(+/+) mice. Our findings first demonstrate that CHL1 is a novel intrinsic factor that is involved in CB function and in the ventilatory response to AH. PMID:23949217

  7. Differential expression of Toll-like receptor (TLR) and B cell receptor (BCR) signaling molecules in primary diffuse large B-cell lymphoma of the central nervous system.

    PubMed

    Akhter, Ariz; Masir, Noraidah; Elyamany, Ghaleb; Phang, Kean-Chang; Mahe, Etienne; Al-Zahrani, Ali Matar; Shabani-Rad, Meer-Taher; Stewart, Douglas Allan; Mansoor, Adnan

    2015-01-01

    Primary diffuse large B-cell lymphoma of the central nervous system (CNS DLBCL) is a distinct and aggressive lymphoma that is confined to CNS. Since, central nervous system is barrier-protected and immunologically silent; role of TLR/BCR signaling in pathogenesis and biology of CNS DLBCL is intriguing. Genomic mutations in key regulators of TLR/BCR signaling pathway (MYD88/CD79B/CARD11) have recently been reported in this disease. These observations raised possible implications in novel targeted therapies; however, expression pattern of molecules related to TLR/BCR pathways in this lymphoma remains unknown. We have analyzed the expression of 19 genes encoding TLR/BCR pathways and targets in CNS DLBCLs (n = 20) by Nanostring nCounter™ analysis and compared it with expression patterns in purified reactive B-lymphocytes and systemic diffuse large B cell lymphoma (DLBCL) (n = 20). Relative expression of TLR4, TLR5, TLR9, CD79B and BLNK was higher in CNS DLBCLs than in control B-lymphocytes; where as TLR7, MALT1, BCL10, CD79A and LYN was lower in CNS DLBCLs (P < 0.0001). When compared with systemic DLBCL samples, higher expression of TLR9, CD79B, CARD11, LYN and BLNK was noted in CNS DLBCL (>1.5 fold change; P < 0.01). The B cell receptor molecules like BLNK and CD79B were also associated with higher expression of MYD88 dependent TLRs (TLR4/5/9). In conclusion, we have shown over expression of TLR/BCR related genes or their targets, where genomic mutations have commonly been identified in CNS DLBCL. We have also demonstrated that TLR over expression closely relate with up regulation of genes associated with BCR pathway like CD79B/BLNK and CARD11, which play an important role in NF-kB pathway activation. Our results provide an important insight into the possibility of TLR and/or B-cell receptor signaling molecules as possible therapeutic targets in CNS DLBCL. PMID:25391967

  8. Gain-of-Function Mutations in the Toll-Like Receptor Pathway: TPL2-Mediated ERK1/ERK2 MAPK Activation, a Path to Tumorigenesis in Lymphoid Neoplasms?

    PubMed Central

    Rousseau, Simon; Martel, Guy

    2016-01-01

    Lymphoid neoplasms form a family of cancers affecting B-cells, T-cells, and NK cells. The Toll-Like Receptor (TLR) signaling adapter molecule MYD88 is the most frequently mutated gene in these neoplasms. This signaling adaptor relays signals from TLRs to downstream effector pathways such as the Nuclear Factor kappa B (NFκB) and Mitogen Activated Protein Kinase (MAPK) pathways to regulate innate immune responses. Gain-of-function mutations such as MYD88[L265P] activate downstream signaling pathways in absence of cognate ligands for TLRs, resulting in increased cellular proliferation and survival. This article reports an analysis of non-synonymous somatic mutations found in the TLR signaling network in lymphoid neoplasms. In accordance with previous reports, mutations map to MYD88 pro-inflammatory signaling and not TRIF-mediated Type I IFN production. Interestingly, the analysis of somatic mutations found downstream of the core TLR-signaling network uncovered a strong association with the ERK1/2 MAPK cascade. In support of this analysis, heterologous expression of MYD88[L265P] in HEK293 cells led to ERK1/2 MAPK phosphorylation in addition to NFκB activation. Moreover, this activation is dependent on the protein kinase Tumor Promoting Locus 2 (TPL2), activated downstream of the IKK complex. Activation of ERK1/2 would then lead to activation, amongst others, of MYC and hnRNPA1, two proteins previously shown to contribute to tumor formation in lymphoid neoplasms. Taken together, this analysis suggests that TLR-mediated ERK1/2 activation via TPL2 may be a novel path to tumorigenesis. Therefore, the hypothesis proposed is that inhibition of ERK1/2 MAPK activation would prevent tumor growth downstream of MYD88[L265]. It will be interesting to test whether pharmacological inhibitors of this pathway show efficacy in primary tumor cells derived from hematologic malignancies such as Waldenstrom's Macroglobulinemia, where the majority of the cells carry the MYD88[L265P

  9. Adaptation.

    PubMed

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  10. Dendritic Cell Expression of the Signaling Molecule TRAF6 is Critical for Gut Microbiota-Dependent Immune Tolerance

    PubMed Central

    Han, Daehee; Walsh, Matthew C.; Cejas, Pedro J.; Dang, Nicholas N.; Kim, Youngmi F.; Kim, Jihyun; Charrier-Hisamuddin, Laetitia; Chau, Lillian; Zhang, Qin; Bittinger, Kyle; Bushman, Frederic D.; Turka, Laurence A.; Shen, Hao; Reizis, Boris; DeFranco, Anthony L.; Wu, Gary D.; Choi, Yongwon

    2013-01-01

    SUMMARY The intracellular signaling molecule TRAF6 is critical for Toll-like receptor (TLR)-mediated activation of dendritic cells (DCs). We now report that DC-specific deletion of TRAF6 (TRAF6ΔDC) resulted, unexpectedly, in loss of mucosal tolerance, characterized by spontaneous development of T helper 2 (Th2) cells in the lamina propria, and eosinophilic enteritis and fibrosis in the small intestine. Loss of tolerance required the presence of gut commensal microbiota, but was independent of DC-expressed MyD88. Further, TRAF6ΔDC mice exhibited decreased regulatory T (Treg) cell numbers in the small intestine, and diminished induction of iTreg cells in response to model antigen. Evidence suggested this defect was associated with diminished DC expression of interleukin-2 (IL-2). Finally, we demonstrate that aberrant Th2 cell-associated responses in TRAF6ΔDC mice could be mitigated via restoration of Treg cell activity. Collectively, our findings reveal a role for TRAF6 in directing DC maintenance of intestinal immune tolerance through balanced induction of Treg versus Th2 cell immunity. PMID:23791643

  11. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  12. Designing Anti-inflammatory Drugs from Parasitic Worms: A Synthetic Small Molecule Analogue of the Acanthocheilonema viteae Product ES-62 Prevents Development of Collagen-Induced Arthritis

    PubMed Central

    2013-01-01

    In spite of increasing evidence that parasitic worms may protect humans from developing allergic and autoimmune diseases and the continuing identification of defined helminth-derived immunomodulatory molecules, to date no new anti-inflammatory drugs have been developed from these organisms. We have approached this matter in a novel manner by synthesizing a library of drug-like small molecules based upon phosphorylcholine, the active moiety of the anti-inflammatory Acanthocheilonema viteae product, ES-62, which as an immunogenic protein is unsuitable for use as a drug. Following preliminary in vitro screening for inhibitory effects on relevant macrophage cytokine responses, a sulfone-containing phosphorylcholine analogue (11a) was selected for testing in an in vivo model of inflammation, collagen-induced arthritis (CIA). Testing revealed that 11a was as effective as ES-62 in protecting DBA/1 mice from developing CIA and mirrored its mechanism of action in downregulating the TLR/IL-1R transducer, MyD88. 11a is thus a novel prototype for anti-inflammatory drug development. PMID:24228757

  13. TLR4-mediated activation of dendritic cells by the heat shock protein DnaK from Francisella tularensis

    PubMed Central

    Ashtekar, Amit R.; Zhang, Ping; Katz, Jannet; Deivanayagam, Champion C. S.; Rallabhandi, Prasad; Vogel, Stefanie N.; Michalek, Suzanne M.

    2008-01-01

    Francisella tularensis is the causative agent of tularemia, a severe, debilitating disease of humans and other mammals. As this microorganism is also classified as a “category-A pathogen” and a potential biowarfare agent, there is a need for an effective vaccine. Several antigens of F. tularensis, including the heat shock protein DnaK, have been proposed for use in a potential subunit vaccine. In this study, we characterized the innate immune response of murine bone marrow-derived dendritic cells (DC) to F. tularensis DnaK. Recombinant DnaK was produced using a bacterial expression system and purified using affinity, ion-exchange, and size-exclusion chromatography. DnaK induced the activation of MAPKs and NF-κB in DC and the production of the proinflammatory cytokines IL-6, TNF-α, and IL-12 p40, as well as low levels of IL-10. DnaK induced phenotypic maturation of DC, as demonstrated by an up-regulation of costimulatory molecules CD40, CD80, and CD86. DnaK stimulated DC through TLR4 and the adapters MyD88 and Toll/IL-1R domain-containing adaptor-inducing IFN-β (TRIF) that mediated differential responses. DnaK induced activation of MAPKs and NF-κB in a MyD88- or TRIF-dependent manner. However, the presence of MyD88- and TRIF-dependent signaling pathways was essential for an optimal, DnaK-induced cytokine response in DC. In contrast, DnaK induced DC maturation in a TRIF-dependent, MyD88-independent manner. These results provide insight about the molecular interactions between an immunodominant antigen of F. tularensis and host immune cells, which is crucial for the rational design and development of a safe and efficacious vaccine against tularemia. PMID:18708593

  14. TLR signaling controls lethal encephalitis in WNV-infected brain.

    PubMed

    Sabouri, Amir H; Marcondes, Maria Cecilia Garibaldi; Flynn, Claudia; Berger, Michael; Xiao, Nengming; Fox, Howard S; Sarvetnick, Nora E

    2014-07-29

    Toll-like receptors (TLRs) are known to be activated in Central Nervous System (CNS) viral infections and are recognized to be a critical component in innate immunity. Several reports state a role for particular TLRs in various CNS viral infections. However, excessive TLR activation was previously reported by us in correlation with a pathogenic, rather than a protective, outcome, in a model of SIV encephalitis. Here we aimed at understanding the impact of TLR-mediated pathways by evaluating the early course of pathogenesis in the total absence of TLR signaling during CNS viral infections. We utilized a mouse model of sublethal West Nile virus (WNV) infection. WNV is an emerging neurotropic flavivirus, and a significant global cause of viral encephalitis. The virus was peripherally injected into animals that simultaneously lacked two key adapter molecules of TLR signaling, MyD88 and TRIF. On day 2 pi (post infection), MyD88/Trif-/- mice showed an increased susceptibility to WNV infection, and revealed an impairment in innate immune cytokines, when compared to wild type mice (WT). By day 6 pi, there was an increase in viral burden and robust expression of inflammatory cytokines as well as higher cell infiltration into the CNS in MyD88/Trif-/-, when compared to infected WT. A drastic increase in microglia activation, astrogliosis, and inflammatory trafficking were also observed on day 6 pi in MyD88/Trif-/-. Our observations show a protective role for TLR signaling pathways in preventing lethal encephalitis at early stages of WNV infection. PMID:24928618

  15. Lymphocyte-derived ACh regulates local innate but not adaptive immunity

    PubMed Central

    Reardon, Colin; Duncan, Gordon S.; Brüstle, Anne; Brenner, Dirk; Tusche, Michael W.; Olofsson, Peder S.; Rosas-Ballina, Mauricio; Tracey, Kevin J.; Mak, Tak W.

    2013-01-01

    Appropriate control of immune responses is a critical determinant of health. Here, we show that choline acetyltransferase (ChAT) is expressed and ACh is produced by B cells and other immune cells that have an impact on innate immunity. ChAT expression occurs in mucosal-associated lymph tissue, subsequent to microbial colonization, and is reduced by antibiotic treatment. MyD88-dependent Toll-like receptor up-regulates ChAT in a transient manner. Unlike the previously described CD4+ T-cell population that is stimulated by norepinephrine to release ACh, ChAT+ B cells release ACh after stimulation with sulfated cholecystokinin but not norepinephrine. ACh-producing B-cells reduce peritoneal neutrophil recruitment during sterile endotoxemia independent of the vagus nerve, without affecting innate immune cell activation. Endothelial cells treated with ACh in vitro reduced endothelial cell adhesion molecule expression in a muscarinic receptor-dependent manner. Despite this ability, ChAT+ B cells were unable to suppress effector T-cell function in vivo. Therefore, ACh produced by lymphocytes has specific functions, with ChAT+ B cells controlling the local recruitment of neutrophils. PMID:23297238

  16. Lung epithelium and myeloid cells cooperate to clear acute pneumococcal infection.

    PubMed

    Dudek, M; Puttur, F; Arnold-Schrauf, C; Kühl, A A; Holzmann, B; Henriques-Normark, B; Berod, L; Sparwasser, T

    2016-09-01

    The Gram-positive bacterium Streptococcus pneumoniae causes life-threatening infections, especially among immunocompromised patients. The host's immune system senses S. pneumoniae via different families of pattern recognition receptors, in particular the Toll-like receptor (TLR) family that promotes immune cell activation. Yet, while single TLRs are dispensable for initiating inflammatory responses against S. pneumoniae, the central TLR adapter protein myeloid differentiation factor 88 (MyD88) is of vital importance, as MyD88-deficient mice succumb rapidly to infection. Since MyD88 is ubiquitously expressed in hematopoietic and non-hematopoietic cells, the extent to which MyD88 signaling is required in different cell types to control S. pneumoniae is unknown. Therefore, we used novel conditional knockin mice to investigate the necessity of MyD88 signaling in distinct lung-resident myeloid and epithelial cells for the initiation of a protective immune response against S. pneumoniae. Here, we show that MyD88 signaling in lysozyme M (LysM)- and CD11c-expressing myeloid cells, as well as in pulmonary epithelial cells, is critical to restore inflammatory cytokine and antimicrobial peptide production, leading to efficient neutrophil recruitment and enhanced bacterial clearance. Overall, we show a novel synergistic requirement of compartment-specific MyD88 signaling in S. pneumoniae immunity. PMID:26627460

  17. Lung epithelium and myeloid cells cooperate to clear acute pneumococcal infection

    PubMed Central

    Dudek, M; Puttur, F; Arnold-Schrauf, C; Kühl, A A; Holzmann, B; Henriques-Normark, B; Berod, L; Sparwasser, T

    2016-01-01

    The Gram-positive bacterium Streptococcus pneumoniae causes life-threatening infections, especially among immunocompromised patients. The host's immune system senses S. pneumoniae via different families of pattern recognition receptors, in particular the Toll-like receptor (TLR) family that promotes immune cell activation. Yet, while single TLRs are dispensable for initiating inflammatory responses against S. pneumoniae, the central TLR adapter protein myeloid differentiation factor 88 (MyD88) is of vital importance, as MyD88-deficient mice succumb rapidly to infection. Since MyD88 is ubiquitously expressed in hematopoietic and non-hematopoietic cells, the extent to which MyD88 signaling is required in different cell types to control S. pneumoniae is unknown. Therefore, we used novel conditional knockin mice to investigate the necessity of MyD88 signaling in distinct lung-resident myeloid and epithelial cells for the initiation of a protective immune response against S. pneumoniae. Here, we show that MyD88 signaling in lysozyme M (LysM)– and CD11c-expressing myeloid cells, as well as in pulmonary epithelial cells, is critical to restore inflammatory cytokine and antimicrobial peptide production, leading to efficient neutrophil recruitment and enhanced bacterial clearance. Overall, we show a novel synergistic requirement of compartment-specific MyD88 signaling in S. pneumoniae immunity. PMID:26627460

  18. Electronic excitation of molecules in solution calculated using the symmetry-adapted cluster–configuration interaction method in the polarizable continuum model

    SciTech Connect

    Fukuda, Ryoichi Ehara, Masahiro

    2015-12-31

    The effects from solvent environment are specific to the electronic states; therefore, a computational scheme for solvent effects consistent with the electronic states is necessary to discuss electronic excitation of molecules in solution. The PCM (polarizable continuum model) SAC (symmetry-adapted cluster) and SAC-CI (configuration interaction) methods are developed for such purposes. The PCM SAC-CI adopts the state-specific (SS) solvation scheme where solvent effects are self-consistently considered for every ground and excited states. For efficient computations of many excited states, we develop a perturbative approximation for the PCM SAC-CI method, which is called corrected linear response (cLR) scheme. Our test calculations show that the cLR PCM SAC-CI is a very good approximation of the SS PCM SAC-CI method for polar and nonpolar solvents.

  19. Electronic excitation spectra of molecules in solution calculated using the symmetry-adapted cluster-configuration interaction method in the polarizable continuum model with perturbative approach

    SciTech Connect

    Fukuda, Ryoichi Ehara, Masahiro; Cammi, Roberto

    2014-02-14

    A perturbative approximation of the state specific polarizable continuum model (PCM) symmetry-adapted cluster-configuration interaction (SAC-CI) method is proposed for efficient calculations of the electronic excitations and absorption spectra of molecules in solutions. This first-order PCM SAC-CI method considers the solvent effects on the energies of excited states up to the first-order with using the zeroth-order wavefunctions. This method can avoid the costly iterative procedure of the self-consistent reaction field calculations. The first-order PCM SAC-CI calculations well reproduce the results obtained by the iterative method for various types of excitations of molecules in polar and nonpolar solvents. The first-order contribution is significant for the excitation energies. The results obtained by the zeroth-order PCM SAC-CI, which considers the fixed ground-state reaction field for the excited-state calculations, are deviated from the results by the iterative method about 0.1 eV, and the zeroth-order PCM SAC-CI cannot predict even the direction of solvent shifts in n-hexane for many cases. The first-order PCM SAC-CI is applied to studying the solvatochromisms of (2,2{sup ′}-bipyridine)tetracarbonyltungsten [W(CO){sub 4}(bpy), bpy = 2,2{sup ′}-bipyridine] and bis(pentacarbonyltungsten)pyrazine [(OC){sub 5}W(pyz)W(CO){sub 5}, pyz = pyrazine]. The SAC-CI calculations reveal the detailed character of the excited states and the mechanisms of solvent shifts. The energies of metal to ligand charge transfer states are significantly sensitive to solvents. The first-order PCM SAC-CI well reproduces the observed absorption spectra of the tungsten carbonyl complexes in several solvents.

  20. Adapting SAFT-γ perturbation theory to site-based molecular dynamics simulation. III. Molecules with partial charges at bulk phases, confined geometries and interfaces

    SciTech Connect

    Ghobadi, Ahmadreza F.; Elliott, J. Richard

    2014-09-07

    In Paper I [A. F. Ghobadi and J. R. Elliott, J. Chem. Phys. 139(23), 234104 (2013)], we showed that how a third-order Weeks–Chandler–Anderson (WCA) Thermodynamic Perturbation Theory and molecular simulation can be integrated to characterize the repulsive and dispersive contributions to the Helmholtz free energy for realistic molecular conformations. To this end, we focused on n-alkanes to develop a theory for fused and soft chains. In Paper II [A. F. Ghobadi and J. R. Elliott, J. Chem. Phys. 141(2), 024708 (2014)], we adapted the classical Density Functional Theory and studied the microstructure of the realistic molecular fluids in confined geometries and vapor-liquid interfaces. We demonstrated that a detailed consistency between molecular simulation and theory can be achieved for both bulk and inhomogeneous phases. In this paper, we extend the methodology to molecules with partial charges such as carbon dioxide, water, 1-alkanols, nitriles, and ethers. We show that the electrostatic interactions can be captured via an effective association potential in the framework of Statistical Associating Fluid Theory (SAFT). Implementation of the resulting association contribution in assessing the properties of these molecules at confined geometries and interfaces presents satisfactory agreement with molecular simulation and experimental data. For example, the predicted surface tension deviates less than 4% comparing to full potential simulations. Also, the theory, referred to as SAFT-γ WCA, is able to reproduce the specific orientation of hydrophilic head and hydrophobic tail of 1-alkanols at the vapor-liquid interface of water.

  1. Adapting SAFT-γ perturbation theory to site-based molecular dynamics simulation. III. Molecules with partial charges at bulk phases, confined geometries and interfaces

    NASA Astrophysics Data System (ADS)

    Ghobadi, Ahmadreza F.; Elliott, J. Richard

    2014-09-01

    In Paper I [A. F. Ghobadi and J. R. Elliott, J. Chem. Phys. 139(23), 234104 (2013)], we showed that how a third-order Weeks-Chandler-Anderson (WCA) Thermodynamic Perturbation Theory and molecular simulation can be integrated to characterize the repulsive and dispersive contributions to the Helmholtz free energy for realistic molecular conformations. To this end, we focused on n-alkanes to develop a theory for fused and soft chains. In Paper II [A. F. Ghobadi and J. R. Elliott, J. Chem. Phys. 141(2), 024708 (2014)], we adapted the classical Density Functional Theory and studied the microstructure of the realistic molecular fluids in confined geometries and vapor-liquid interfaces. We demonstrated that a detailed consistency between molecular simulation and theory can be achieved for both bulk and inhomogeneous phases. In this paper, we extend the methodology to molecules with partial charges such as carbon dioxide, water, 1-alkanols, nitriles, and ethers. We show that the electrostatic interactions can be captured via an effective association potential in the framework of Statistical Associating Fluid Theory (SAFT). Implementation of the resulting association contribution in assessing the properties of these molecules at confined geometries and interfaces presents satisfactory agreement with molecular simulation and experimental data. For example, the predicted surface tension deviates less than 4% comparing to full potential simulations. Also, the theory, referred to as SAFT-γ WCA, is able to reproduce the specific orientation of hydrophilic head and hydrophobic tail of 1-alkanols at the vapor-liquid interface of water.

  2. Backbone 1H, 13C, and 15N assignments for the tandem ubiquitin binding domains of signal transducing adapter molecule 1.

    PubMed

    Lim, Jongsoo; Hong, Yoon-Hun; Lee, Bong-Jin; Ahn, Hee-Chul

    2011-04-01

    Signal transducing adapter molecule (STAM) forms the endosomal sorting complex required for transport-0 (ESCRT-0) complex with hepatocyte growth factor-regulated substrate (Hrs) to sort the ubiquitinated cargo proteins from the early endosomes to the ESCRT-1 complex. ESCRT-0 complex, STAM and Hrs, contains multiple ubiquitin binding domains, in which STAM has two ubiquitin binding domains, Vps27/Hrs/Stam (VHS) and ubiquitin interacting motif (UIM) at its N-terminus. By the cooperation of the multiple ubiquitin binding domains, the ESCRT-0 complex recognizes poly-ubiquitin, especially Lys63-linked ubiquitin. Here, we report the backbone resonance assignments and the secondary structure of the N-terminal 191 amino acids of the human STAM1 which includes the VHS domain and UIM. The {(1)H}-(15)N heteronuclear NOE experiments revealed that an unstructured and flexible loop region connects the VHS domain and UIM. Our work provides the basic information for the further NMR investigation of the interaction between STAM1 and poly-ubiquitin. PMID:20927613

  3. The CO donor CORM-2 inhibits LPS-induced vascular cell adhesion molecule-1 expression and leukocyte adhesion in human rheumatoid synovial fibroblasts

    PubMed Central

    Chi, Pei-Ling; Chuang, Yu-Chen; Chen, Yu-Wen; Lin, Chih-Chung; Hsiao, Li-Der; Yang, Chuen-Mao

    2014-01-01

    BACKGROUND AND PURPOSE Infection with Gram-negative bacteria has been recognized as an initiator of rheumatoid arthritis, which is characterized by chronic inflammation and infiltration of immune cells. Carbon monoxide (CO) exhibits anti-inflammatory properties. Here we have investigated the detailed mechanisms of vascular cell adhesion molecule-1 (VCAM-1) expression induced by LPS and if CO inhibited LPS-induced leukocyte adhesion to synovial fibroblasts by suppressing VCAM-1 expression. EXPERIMENTAL APPROACH Human rheumatoid arthritis synovial fibroblasts (RASFs) were incubated with LPS and/or the CO-releasing compound CORM-2. Effects of LPS on VCAM-1 levels were determined by analysing mRNA expression, promoter activity, protein expression, and immunohistochemical staining. The molecular mechanisms were investigated by determining the expression, activation, and binding activity of transcriptional factors using target signal antagonists. KEY RESULTS CORM-2 significantly inhibited inflammatory responses in LPS-treated RASFs by down-regulating the expression of adhesion molecule VCAM-1 and leukocyte infiltration. The down-regulation of LPS-induced VCAM-1 expression involved inhibition of the expression of phosphorylated-NF-κB p65 and AP-1 (p-c-Jun, c-Jun and c-Fos mRNA levels). These results were confirmed by chromatin immunoprecipitation assay to detect NF-κB and AP-1 DNA binding activity. CONCLUSIONS AND IMPLICATIONS LPS-mediated formation of the TLR4/MyD88/TRAF6/c-Src complex regulated NF-κB and MAPKs/AP-1 activation leading to VCAM-1 expression and leukocyte adhesion. CORM-2, which liberates CO to elicit direct biological activities, attenuated LPS-induced VCAM-1 expression by interfering with NF-κB and AP-1 activation, and significantly reduced LPS-induced immune cell infiltration of the synovium. PMID:24628691

  4. Selective interleukin-1 receptor–associated kinase 4 inhibitors for the treatment of autoimmune disorders and lymphoid malignancy

    PubMed Central

    Kelly, Priscilla N.; Romero, Donna L.; Yang, Yibin; Shaffer, Arthur L.; Chaudhary, Divya; Robinson, Shaughnessy; Miao, Wenyan; Rui, Lixin; Westlin, William F.; Kapeller, Rosana

    2015-01-01

    Pathological activation of the Toll-like receptor signaling adaptor protein MYD88 underlies many autoimmune and inflammatory disease states. In the activated B cell–like (ABC) subtype of diffuse large B cell lymphoma (DLBCL), the oncogenic MYD88 L265P mutation occurs in 29% of cases, making it the most prevalent activating mutation in this malignancy. IRAK4 kinase accounts for almost all of the biological functions of MYD88, highlighting IRAK4 as a therapeutic target for diseases driven by aberrant MYD88 signaling. Using innovative structure-based drug design methodologies, we report the development of highly selective and bioavailable small molecule IRAK4 inhibitors, ND-2158 and ND-2110. These small molecules suppressed LPS-induced TNF production, alleviated collagen-induced arthritis, and blocked gout formation in mouse models. IRAK4 inhibition promoted killing of ABC DLBCL lines harboring MYD88 L265P, by down-modulating survival signals, including NF-κB and autocrine IL-6/IL-10 engagement of the JAK–STAT3 pathway. In ABC DLBCL xenograft models, IRAK4 inhibition suppressed tumor growth as a single agent, and in combination with the Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib or the Bcl-2 inhibitor ABT-199. Our findings support pharmacological inhibition of IRAK4 as a therapeutic strategy in autoimmune disorders, in a genetically defined population of ABC DLBCL, and possibly other malignancies dependent on aberrant MYD88 signaling. PMID:26621451

  5. Selective interleukin-1 receptor-associated kinase 4 inhibitors for the treatment of autoimmune disorders and lymphoid malignancy.

    PubMed

    Kelly, Priscilla N; Romero, Donna L; Yang, Yibin; Shaffer, Arthur L; Chaudhary, Divya; Robinson, Shaughnessy; Miao, Wenyan; Rui, Lixin; Westlin, William F; Kapeller, Rosana; Staudt, Louis M

    2015-12-14

    Pathological activation of the Toll-like receptor signaling adaptor protein MYD88 underlies many autoimmune and inflammatory disease states. In the activated B cell-like (ABC) subtype of diffuse large B cell lymphoma (DLBCL), the oncogenic MYD88 L265P mutation occurs in 29% of cases, making it the most prevalent activating mutation in this malignancy. IRAK4 kinase accounts for almost all of the biological functions of MYD88, highlighting IRAK4 as a therapeutic target for diseases driven by aberrant MYD88 signaling. Using innovative structure-based drug design methodologies, we report the development of highly selective and bioavailable small molecule IRAK4 inhibitors, ND-2158 and ND-2110. These small molecules suppressed LPS-induced TNF production, alleviated collagen-induced arthritis, and blocked gout formation in mouse models. IRAK4 inhibition promoted killing of ABC DLBCL lines harboring MYD88 L265P, by down-modulating survival signals, including NF-κB and autocrine IL-6/IL-10 engagement of the JAK-STAT3 pathway. In ABC DLBCL xenograft models, IRAK4 inhibition suppressed tumor growth as a single agent, and in combination with the Bruton's tyrosine kinase (BTK) inhibitor ibrutinib or the Bcl-2 inhibitor ABT-199. Our findings support pharmacological inhibition of IRAK4 as a therapeutic strategy in autoimmune disorders, in a genetically defined population of ABC DLBCL, and possibly other malignancies dependent on aberrant MYD88 signaling. PMID:26621451

  6. CSTMP Exerts Anti-Inflammatory Effects on LPS-Induced Human Renal Proximal Tubular Epithelial Cells by Inhibiting TLR4-Mediated NF-κB Pathways.

    PubMed

    Ding, Yan; Liao, Wang; He, Xiaojie; Xiang, Wei; Lu, Qianjin

    2016-04-01

    (E)-2-(2-chlorostyryl)-3,5,6-trimethylpyrazine (CSTMP), a novel stilbene derivative, have been shown to have cytoprotective effects against H2O2-induced oxidative stress in human endothelial cells. However, little is known about its anti-inflammatory effects in lupus nephritis (LN). In the present study, we investigated the anti-inflammatory effects of CSTMP on lipopolysaccharide (LPS)-induced human renal proximal tubular epithelial cells (hRPTECs) and elucidated its molecular mechanisms. CSTMP significantly attenuated the cytotoxicity and suppressed the release of proinflammatory mediators, including iNOS, COX-2, TNF-α, IL-6, IL-8, CCL-2, ICAM-1, IL-1β, and MCP-1 in LPS-induced hRPTECs. In addition, CSTMP decreased the expression of TLR4 and its adapter molecules (MyD88, phosphorylation of TAK1, TRAF6, and IRAK1) and abolished its interactions with these adapter molecules in LPS-induced hRPTECs, resulting in an inhibition of the TLR4/MyD88/TAK1/ TRAF6/IRAK1 complex. Moreover, CSTMP also attenuated phosphorylation of IκB and IKK-α/β, and P50-NF-κB and P65-NF-κB translocation to nucleus in LPS-induced hRPTECs. These findings provided new insights to understand the mode of action of CSTMP in treatment of inflammatory diseases, such as LN. PMID:26956469

  7. Integrin CD11b positively regulates TLR4-induced signalling pathways in dendritic cells but not in macrophages

    NASA Astrophysics Data System (ADS)

    Ling, Guang Sheng; Bennett, Jason; Woollard, Kevin J.; Szajna, Marta; Fossati-Jimack, Liliane; Taylor, Philip R.; Scott, Diane; Franzoso, Guido; Cook, H. Terence; Botto, Marina

    2014-01-01

    Tuned and distinct responses of macrophages and dendritic cells to Toll-like receptor 4 (TLR4) activation induced by lipopolysaccharide (LPS) underpin the balance between innate and adaptive immunity. However, the molecule(s) that confer these cell-type-specific LPS-induced effects remain poorly understood. Here we report that the integrin αM (CD11b) positively regulates LPS-induced signalling pathways selectively in myeloid dendritic cells but not in macrophages. In dendritic cells, which express lower levels of CD14 and TLR4 than macrophages, CD11b promotes MyD88-dependent and MyD88-independent signalling pathways. In particular, in dendritic cells CD11b facilitates LPS-induced TLR4 endocytosis and is required for the subsequent signalling in the endosomes. Consistent with this, CD11b deficiency dampens dendritic cell-mediated TLR4-triggered responses in vivo leading to impaired T-cell activation. Thus, by modulating the trafficking and signalling functions of TLR4 in a cell-type-specific manner CD11b fine tunes the balance between adaptive and innate immune responses initiated by LPS.

  8. Integrin CD11b positively regulates TLR4-induced signalling pathways in dendritic cells but not in macrophages.

    PubMed

    Ling, Guang Sheng; Bennett, Jason; Woollard, Kevin J; Szajna, Marta; Fossati-Jimack, Liliane; Taylor, Philip R; Scott, Diane; Franzoso, Guido; Cook, H Terence; Botto, Marina

    2014-01-01

    Tuned and distinct responses of macrophages and dendritic cells to Toll-like receptor 4 (TLR4) activation induced by lipopolysaccharide (LPS) underpin the balance between innate and adaptive immunity. However, the molecule(s) that confer these cell-type-specific LPS-induced effects remain poorly understood. Here we report that the integrin α(M) (CD11b) positively regulates LPS-induced signalling pathways selectively in myeloid dendritic cells but not in macrophages. In dendritic cells, which express lower levels of CD14 and TLR4 than macrophages, CD11b promotes MyD88-dependent and MyD88-independent signalling pathways. In particular, in dendritic cells CD11b facilitates LPS-induced TLR4 endocytosis and is required for the subsequent signalling in the endosomes. Consistent with this, CD11b deficiency dampens dendritic cell-mediated TLR4-triggered responses in vivo leading to impaired T-cell activation. Thus, by modulating the trafficking and signalling functions of TLR4 in a cell-type-specific manner CD11b fine tunes the balance between adaptive and innate immune responses initiated by LPS. PMID:24423728

  9. CD14 dependence of TLR4 endocytosis and TRIF signaling displays ligand specificity and is dissociable in endotoxin tolerance

    PubMed Central

    Rajaiah, Rajesh; Perkins, Darren J.; Ireland, Derek D. C.; Vogel, Stefanie N.

    2015-01-01

    Dimerization of Toll-like receptor 4 (TLR4)/myeloid differentiation factor 2 (MD2) heterodimers is critical for both MyD88- and TIR-domain–containing adapter-inducing IFN-β (TRIF)-mediated signaling pathways. Recently, Zanoni et al. [(2011) Cell 147(4):868–880] reported that cluster of differentiation 14 (CD14) is required for LPS-/Escherichia coli- induced TLR4 internalization into endosomes and activation of TRIF-mediated signaling in macrophages. We confirmed their findings with LPS but report here that CD14 is not required for receptor endocytosis and downstream signaling mediated by TLR4/MD2 agonistic antibody (UT12) and synthetic small-molecule TLR4 ligands (1Z105) in murine macrophages. CD14 deficiency completely ablated the LPS-induced TBK1/IRF3 signaling axis that mediates production of IFN-β in murine macrophages without affecting MyD88-mediated signaling, including NF-κB, MAPK activation, and TNF-α and IL-6 production. However, neither the MyD88- nor TRIF-signaling pathways and their associated cytokine profiles were altered in the absence of CD14 in UT12- or 1Z105-treated murine macrophages. Eritoran (E5564), a lipid A antagonist that binds the MD2 “pocket,” completely blocked LPS- and 1Z105-driven, but not UT12-induced, TLR4 dimerization and endocytosis. Furthermore, TLR4 endocytosis is induced in macrophages tolerized by exposure to either LPS or UT12 and is independent of CD14. These data indicate that TLR4 receptor endocytosis and the TRIF-signaling pathway are dissociable and that TLR4 internalization in macrophages can be induced by UT12, 1Z105, and during endotoxin tolerance in the absence of CD14. PMID:26106158

  10. The anti-inflammatory drug BAY 11-7082 suppresses the MyD88-dependent signalling network by targeting the ubiquitin system

    PubMed Central

    Strickson, Sam; Campbell, David G.; Emmerich, Christoph H.; Knebel, Axel; Plater, Lorna; Ritorto, Maria Stella; Shpiro, Natalia; Cohen, Philip

    2013-01-01

    The compound BAY 11-7082 inhibits IκBα [inhibitor of NF-κB (nuclear factor κB)α] phosphorylation in cells and has been used to implicate the canonical IKKs (IκB kinases) and NF-κB in >350 publications. In the present study we report that BAY 11-7082 does not inhibit the IKKs, but suppresses their activation in LPS (lipopolysaccharide)-stimulated RAW macrophages and IL (interleukin)-1-stimulated IL-1R (IL-1 receptor) HEK (human embryonic kidney)-293 cells. BAY 11-7082 exerts these effects by inactivating the E2-conjugating enzymes Ubc (ubiquitin conjugating) 13 and UbcH7 and the E3 ligase LUBAC (linear ubiquitin assembly complex), thereby preventing the formation of Lys63-linked and linear polyubiquitin chains. BAY 11-7082 prevents ubiquitin conjugation to Ubc13 and UbcH7 by forming a covalent adduct with their reactive cysteine residues via Michael addition at the C3 atom of BAY 11-7082, followed by the release of 4-methylbenzene-sulfinic acid. BAY 11-7082 stimulated Lys48-linked polyubiquitin chain formation in cells and protected HIF1α (hypoxia-inducible factor 1α) from proteasomal degradation, suggesting that it inhibits the proteasome. The results of the present study indicate that the anti-inflammatory effects of BAY 11-7082, its ability to induce B-cell lymphoma and leukaemic T-cell death and to prevent the recruitment of proteins to sites of DNA damage are exerted via inhibition of components of the ubiquitin system and not by inhibiting NF-κB. PMID:23441730

  11. The anti-inflammatory drug BAY 11-7082 suppresses the MyD88-dependent signalling network by targeting the ubiquitin system.

    PubMed

    Strickson, Sam; Campbell, David G; Emmerich, Christoph H; Knebel, Axel; Plater, Lorna; Ritorto, Maria Stella; Shpiro, Natalia; Cohen, Philip

    2013-05-01

    The compound BAY 11-7082 inhibits IκBα [inhibitor of NF-κB (nuclear factor κB)α] phosphorylation in cells and has been used to implicate the canonical IKKs (IκB kinases) and NF-κB in >350 publications. In the present study we report that BAY 11-7082 does not inhibit the IKKs, but suppresses their activation in LPS (lipopolysaccharide)-stimulated RAW macrophages and IL (interleukin)-1-stimulated IL-1R (IL-1 receptor) HEK (human embryonic kidney)-293 cells. BAY 11-7082 exerts these effects by inactivating the E2-conjugating enzymes Ubc (ubiquitin conjugating) 13 and UbcH7 and the E3 ligase LUBAC (linear ubiquitin assembly complex), thereby preventing the formation of Lys63-linked and linear polyubiquitin chains. BAY 11-7082 prevents ubiquitin conjugation to Ubc13 and UbcH7 by forming a covalent adduct with their reactive cysteine residues via Michael addition at the C3 atom of BAY 11-7082, followed by the release of 4-methylbenzene-sulfinic acid. BAY 11-7082 stimulated Lys48-linked polyubiquitin chain formation in cells and protected HIF1α (hypoxia-inducible factor 1α) from proteasomal degradation, suggesting that it inhibits the proteasome. The results of the present study indicate that the anti-inflammatory effects of BAY 11-7082, its ability to induce B-cell lymphoma and leukaemic T-cell death and to prevent the recruitment of proteins to sites of DNA damage are exerted via inhibition of components of the ubiquitin system and not by inhibiting NF-κB. PMID:23441730

  12. IL-33-induced alterations in murine intestinal function and cytokine responses are MyD88, STAT6, and IL-13-dependent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    IL-33 is a recently identified cytokine member of the IL-1 family. The biological activities of IL-33 are associated with promotion of Th2 and inhibition of Th1/Th17 immune responses. Exogenous IL-33 induces a typical “type 2” immune response in the gastrointestinal tract, yet the underlying mechani...

  13. Bovine viral diarrhea virus type 2 in vivo infection modulates TLR4 responsiveness in differentiated Myeloid cells which is associated with decreased MyD88 expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bovine viral diarrhea virus (BVDV) causes clinical signs in cattle ranging from mild to severe acute infection which can lead to increased susceptibility to secondary bacteria. In this study we examined the effects of BVDV genotype 2 (BVDV2) infection on the ability of myeloid lineage cells derived...

  14. Characterization and Structure of the Vaccinia Virus NF-κB Antagonist A46 *

    PubMed Central

    Fedosyuk, Sofiya; Grishkovskaya, Irina; de Almeida Ribeiro, Euripedes; Skern, Tim

    2014-01-01

    Successful vaccinia virus (VACV) replication in the host requires expression of viral proteins that interfere with host immunity, such as antagonists of the activation of the proinflammatory transcription factor NF-κB. Two such VACV proteins are A46 and A52. A46 interacts with the Toll-like receptor/interleukin-1R (TIR) domain of Toll-like receptors and intracellular adaptors such as MAL (MyD88 adapter-like), TRAM (TIR domain-containing adapter-inducing interferon-β (TRIF)-related adaptor molecule), TRIF, and MyD88, whereas A52 binds to the downstream signaling components TRAF6 and IRAK2. Here, we characterize A46 biochemically, determine by microscale thermophoresis binding constants for the interaction of A46 with the TIR domains of MyD88 and MAL, and present the 2.0 Å resolution crystal structure of A46 residues 87–229. Full-length A46 behaves as a tetramer; variants lacking the N-terminal 80 residues are dimeric. Nevertheless, both bind to the Toll-like receptor domains of MAL and MyD88 with KD values in the low μm range. Like A52, A46 also shows a Bcl-2-like fold but with biologically relevant differences from that of A52. Thus, A46 uses helices α4 and α6 to dimerize, compared with the α1-α6 face used by A52 and other Bcl-2 like VACV proteins. Furthermore, the loop between A46 helices α4-α5 is flexible and shorter than in A52; there is also evidence for an intramolecular disulfide bridge between consecutive cysteine residues. We used molecular docking to propose how A46 interacts with the BB loop of the TRAM TIR domain. Comparisons of A46 and A52 exemplify how subtle changes in viral proteins with the same fold lead to crucial differences in biological activity. PMID:24356965

  15. Apple polysaccharide reduces NF-Kb mediated colitis-associated colon carcinogenesis.

    PubMed

    Zhang, Dian; Mi, Man; Jiang, Fengliang; Sun, Yang; Li, Yuhua; Yang, Libin; Fan, Lei; Li, Qian; Meng, Jin; Yue, Zhenggang; Liu, Li; Mei, Qibing

    2015-01-01

    Nuclear factor-kappa B (NF-κB) is an important molecule in mediating inflammatory colitis, which can lead to colorectal cancer (CRC). The aim of this study was to evaluate the chemopreventive efficacy of apple polysaccharide extract (AP) in inhibiting NF-κB-mediated inflammation pathways in CRC. We evaluated AP in vitro in HT-29 and SW620 human CRC cells. We also used the azoxymethane and dextran sodium sulphate (AOM/DSS) model to induce colon carcinogenesis in vivo. The chemoprotective effects of AP were assessed using Western blot, immunofluorescence assay, real-time PCR, electrophoretic mobility shift assay, and flow cytometry. AP reduced AOM/DSS-associated toxicities, prevented carcinogenesis, and decreased the expression of TLR4, MD2, MyD88, TRAM, TRIF-related adapter molecule, interferon-β, tumor necrosis factor-α, and interleukin-6. The protective effects of AP may be related to the inhibition of TLR4/MD2-mediated signaling, including MyD88 and TRIF, as well as the inhibition of NF-κB-mediated inflammatory signaling pathways. Therefore, AP could be used in combination therapy for the prevention of colitis-associated colon cancer. PMID:25412264

  16. Toll-like receptor signaling adapter proteins govern spread of neuropathic pain and recovery following nerve injury in male mice

    PubMed Central

    2013-01-01

    Background Spinal Toll-like receptors (TLRs) and signaling intermediaries have been implicated in persistent pain states. We examined the roles of two major TLR signaling pathways and selected TLRs in a mononeuropathic allodynia. Methods L5 spinal nerve ligation (SNL) was performed in wild type (WT, C57BL/6) male and female mice and in male Tlr2 -/- Tlr3 -/- , Tlr4 -/- , Tlr5 -/- , Myd88 -/- , Trif lps2 , Myd88/Trif lps2 , Tnf -/- , and Ifnar1 -/- mice. We also examined L5 ligation in Tlr4 -/- female mice. We examined tactile allodynia using von Frey hairs. Iba-1 (microglia) and GFAP (astrocytes) were assessed in spinal cords by immunostaining. Tactile thresholds were analyzed by 1- and 2-way ANOVA and the Bonferroni post hoc test was used. Results In WT male and female mice, SNL lesions resulted in a persistent and robust ipsilateral, tactile allodynia. In males with TLR2, 3, 4, or 5 deficiencies, tactile allodynia was significantly, but incompletely, reversed (approximately 50%) as compared to WT. This effect was not seen in female Tlr4 -/- mice. Increases in ipsilateral lumbar Iba-1 and GFAP were seen in mutant and WT mice. Mice deficient in MyD88, or MyD88 and TRIF, showed an approximately 50% reduction in withdrawal thresholds and reduced ipsilateral Iba-1. In contrast, TRIF and interferon receptor null mice developed a profound ipsilateral and contralateral tactile allodynia. In lumbar sections of the spinal cords, we observed a greater increase in Iba-1 immunoreactivity in the TRIF-signaling deficient mice as compared to WT, but no significant increase in GFAP. Removing MyD88 abrogated the contralateral allodynia in the TRIF signaling-deficient mice. Conversely, IFNβ, released downstream to TRIF signaling, administered intrathecally, temporarily reversed the tactile allodynia. Conclusions These observations suggest a critical role for the MyD88 pathway in initiating neuropathic pain, but a distinct role for the TRIF pathway and interferon in regulating

  17. The immunobiology of Campylobacter jejuni: Innate immunity and autoimmune diseases.

    PubMed

    Phongsisay, Vongsavanh

    2016-04-01

    The Gram-negative bacterium Campylobacter jejuni causes gastroenteritis and Guillain-Barré syndrome in humans. Recent advances in the immunobiology of C. jejuni have been made. This review summarizes C. jejuni-binding innate receptors and highlights the role of innate immunity in autoimmune diseases. This human pathogen produces a variety of glycoconjugates, including human ganglioside-like determinants and multiple activators of Toll-like receptors (TLRs). Furthermore, C. jejuni targets MyD88, NLRP3 inflammasome, TIR-domain-containing adapter-inducing interferon-β (TRIF), sialic acid-binding immunoglobulin-like lectins (Siglecs), macrophage galactose-type lectin (MGL), and immunoglobulin-like receptors (TREM2, LMIR5/CD300b). The roles of these innate receptors and signaling molecules have been extensively studied. MyD88-mediated TLR activation or inflammasome-dependent IL-1β secretion is essential for autoimmune induction. TRIF mediates the production of type I interferons that promote humoral immune responses and immunoglobulin class-switching. Siglec-1 and Siglec-7 interact directly with gangliosides. Siglec-1 activation enhances phagocytosis and inflammatory responses. MGL internalizes GalNAc-containing glycoconjugates. TREM2 is well-known for its role in phagocytosis. LMIR5 recognizes C. jejuni components and endogenous sulfoglycolipids. Several lines of evidence from animal models of autoimmune diseases suggest that simultaneous activation of innate immunity in the presence of autoreactive lymphocytes or antigen mimicry may link C. jejuni to immunopathology. PMID:26709064

  18. SAMe Prevents the Up Regulation of Toll-Like Receptor Signaling in Mallory-Denk Body Forming Hepatocytes

    PubMed Central

    Bardag-Gorce, Fawzia; Oliva, Joan; Lin, Andrew; Li, Jun; French, Barbara A.; French, Samuel W.

    2010-01-01

    Mallory-Denk body (MDB) formation is a component of alcoholic and non alcoholic hepatitis. In the present study, the role of the toll-like receptor (TLR) signaling pathway was investigated in the mechanism of MDB formation in the DDC-fed mouse model. Microarray analysis data mining, performed on the livers of drug primed mice refed DDC, showed that TLR2/4 gene expression was significantly up regulated by DDC refeeding. SAMe supplementation prevented this up regulation and prevented the formation of MDBs. qRT-PCR analysis confirmed these results. TLR2/4 activates the adapter protein MyD88. The levels of MyD88 were increased by DDC refeeding. The increase of MyD88 was also prevented by SAMe supplementation. Results showed that MyD88-independent TLR3/4-TRIF-IRF3 pathway was not up regulated in the liver of DDC refed mice. Tumor necrosis factor receptor-associated factor 6 (TRAF6) is the down stream protein recruited by the MyD88/IRAK protein complex, and is involved in the regulation of innate immune responses. Results showed a significant increase in the levels of TRAF-6. TRAF-6 activation leads to activation of NFkB and the mitogen-activated protein kinase (MAPK) cascade. The TRAF-6 increase was ameliorated by SAMe supplementation. These results suggest that DDC induces MDB formation through the TLR2/4 and MyD88-dependent signaling pathway. In conclusion, SAMe blocked the over-expression of TLR2/4, and their downstream signaling components MyD88 and TRAF-6. SAMe prevented the DDC-induced up regulation of the TLR signaling pathways, probably by preventing the up regulation of INF-γ receptors by DDC feeding. INFγ stimulates the up regulation of TLR2. The ability of SAMe feeding to prevent TLR signaling up regulation has not been previously described. PMID:20206621

  19. Optimizing electrostatic field calculations with the Adaptive Poisson-Boltzmann Solver to predict electric fields at protein-protein interfaces II: explicit near-probe and hydrogen-bonding water molecules.

    PubMed

    Ritchie, Andrew W; Webb, Lauren J

    2014-07-17

    We have examined the effects of including explicit, near-probe solvent molecules in a continuum electrostatics strategy using the linear Poisson-Boltzmann equation with the Adaptive Poisson-Boltzmann Solver (APBS) to calculate electric fields at the midpoint of a nitrile bond both at the surface of a monomeric protein and when docked at a protein-protein interface. Results were compared to experimental vibrational absorption energy measurements of the nitrile oscillator. We examined three methods for selecting explicit water molecules: (1) all water molecules within 5 Å of the nitrile nitrogen; (2) the water molecule closest to the nitrile nitrogen; and (3) any single water molecule hydrogen-bonding to the nitrile. The correlation between absolute field strengths with experimental absorption energies were calculated and it was observed that method 1 was only an improvement for the monomer calculations, while methods 2 and 3 were not significantly different from the purely implicit solvent calculations for all protein systems examined. Upon taking the difference in calculated electrostatic fields and comparing to the difference in absorption frequencies, we typically observed an increase in experimental correlation for all methods, with method 1 showing the largest gain, likely due to the improved absolute monomer correlations using that method. These results suggest that, unlike with quantum mechanical methods, when calculating absolute fields using entirely classical models, implicit solvent is typically sufficient and additional work to identify hydrogen-bonding or nearest waters does not significantly impact the results. Although we observed that a sphere of solvent near the field of interest improved results for relative field calculations, it should not be consider a panacea for all situations. PMID:24446740

  20. Adaptation of a Small-Molecule Hydrogen-Bond Donor Catalyst to an Enantioselective Hetero-Diels–Alder Reaction Hypothesized for Brevianamide Biosynthesis

    PubMed Central

    2015-01-01

    Chiral diamine-derived hydrogen-bond donors were evaluated for their ability to effect stereocontrol in an intramolecular hetero-Diels–Alder (HDA) reaction hypothesized in the biosynthesis of brevianamides A and B. Collectively, these results provide proof of principle that small-molecule hydrogen-bond catalysis, if even based on a hypothetical biosynthesis construct, holds significant potential within enantioselective natural product synthesis. PMID:25697748

  1. An efficient computational scheme for electronic excitation spectra of molecules in solution using the symmetry-adapted cluster-configuration interaction method: The accuracy of excitation energies and intuitive charge-transfer indices

    NASA Astrophysics Data System (ADS)

    Fukuda, Ryoichi; Ehara, Masahiro

    2014-10-01

    Solvent effects on electronic excitation spectra are considerable in many situations; therefore, we propose an efficient and reliable computational scheme that is based on the symmetry-adapted cluster-configuration interaction (SAC-CI) method and the polarizable continuum model (PCM) for describing electronic excitations in solution. The new scheme combines the recently proposed first-order PCM SAC-CI method with the PTE (perturbation theory at the energy level) PCM SAC scheme. This is essentially equivalent to the usual SAC and SAC-CI computations with using the PCM Hartree-Fock orbital and integrals, except for the additional correction terms that represent solute-solvent interactions. The test calculations demonstrate that the present method is a very good approximation of the more costly iterative PCM SAC-CI method for excitation energies of closed-shell molecules in their equilibrium geometry. This method provides very accurate values of electric dipole moments but is insufficient for describing the charge-transfer (CT) indices in polar solvent. The present method accurately reproduces the absorption spectra and their solvatochromism of push-pull type 2,2'-bithiophene molecules. Significant solvent and substituent effects on these molecules are intuitively visualized using the CT indices. The present method is the simplest and theoretically consistent extension of SAC-CI method for including PCM environment, and therefore, it is useful for theoretical and computational spectroscopy.

  2. An efficient computational scheme for electronic excitation spectra of molecules in solution using the symmetry-adapted cluster–configuration interaction method: The accuracy of excitation energies and intuitive charge-transfer indices

    SciTech Connect

    Fukuda, Ryoichi Ehara, Masahiro

    2014-10-21

    Solvent effects on electronic excitation spectra are considerable in many situations; therefore, we propose an efficient and reliable computational scheme that is based on the symmetry-adapted cluster-configuration interaction (SAC-CI) method and the polarizable continuum model (PCM) for describing electronic excitations in solution. The new scheme combines the recently proposed first-order PCM SAC-CI method with the PTE (perturbation theory at the energy level) PCM SAC scheme. This is essentially equivalent to the usual SAC and SAC-CI computations with using the PCM Hartree-Fock orbital and integrals, except for the additional correction terms that represent solute-solvent interactions. The test calculations demonstrate that the present method is a very good approximation of the more costly iterative PCM SAC-CI method for excitation energies of closed-shell molecules in their equilibrium geometry. This method provides very accurate values of electric dipole moments but is insufficient for describing the charge-transfer (CT) indices in polar solvent. The present method accurately reproduces the absorption spectra and their solvatochromism of push-pull type 2,2{sup ′}-bithiophene molecules. Significant solvent and substituent effects on these molecules are intuitively visualized using the CT indices. The present method is the simplest and theoretically consistent extension of SAC-CI method for including PCM environment, and therefore, it is useful for theoretical and computational spectroscopy.

  3. Molecule nanoweaver

    DOEpatents

    Gerald, II; Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2009-03-10

    A method, apparatus, and system for constructing uniform macroscopic films with tailored geometric assemblies of molecules on the nanometer scale. The method, apparatus, and system include providing starting molecules of selected character, applying one or more force fields to the molecules to cause them to order and condense with NMR spectra and images being used to monitor progress in creating the desired geometrical assembly and functionality of molecules that comprise the films.

  4. Small Molecule Inhibition of miR-544 Biogenesis Disrupts Adaptive Responses to Hypoxia by Modulating ATM-mTOR Signaling.

    PubMed

    Haga, Christopher L; Velagapudi, Sai Pradeep; Strivelli, Jacqueline R; Yang, Wang-Yong; Disney, Matthew D; Phinney, Donald G

    2015-10-16

    Hypoxia induces a complex circuit of gene expression that drives tumor progression and increases drug resistance. Defining these changes allows for an understanding of how hypoxia alters tumor biology and informs design of lead therapeutics. We probed the role of microRNA-544 (miR-544), which silences mammalian target of rapamycin (mTOR), in a hypoxic breast cancer model by using a small molecule (1) that selectively impedes the microRNA's biogenesis. Application of 1 to hypoxic tumor cells selectively inhibited production of the mature microRNA, sensitized cells to 5-fluorouracil, and derepressed mRNAs affected by miR-544 in cellulo and in vivo, including boosting mTOR expression. Thus, small molecule inhibition of miR-544 reverses a tumor cell's physiological response to hypoxia. Importantly, 1 sensitized tumor cells to hypoxia-associated apoptosis at a 25-fold lower concentration than a 2'-O-methyl RNA antagomir and was as selective. Further, the apoptotic effect of 1 was suppressed by treatment of cell with rapamycin, a well-known inhibitor of the mTOR signaling pathway, illustrating the selectivity of the compound. Thus, RNA-directed chemical probes, which could also serve as lead therapeutics, enable interrogation of complex cellular networks in cells and animals. PMID:26181590

  5. TLR-2/TLR-4 TREM-1 Signaling Pathway Is Dispensable in Inflammatory Myeloid Cells during Sterile Kidney Injury

    PubMed Central

    Campanholle, Gabriela; Mittelsteadt, Kristen; Nakagawa, Shunsaku; Kobayashi, Akio; Lin, Shuei-Liong; Gharib, Sina A.; Heinecke, Jay W.; Hamerman, Jessica A.; Altemeier, William A.; Duffield, Jeremy S.

    2013-01-01

    Inflammatory macrophages are abundant in kidney disease, stimulating repair, or driving chronic inflammation and fibrosis. Damage associated molecules (DAMPs), released from injured cells engage pattern recognition receptors (PRRs) on macrophages, contributing to activation. Understanding mechanisms of macrophage activation during kidney injury may lead to strategies to alleviate chronic disease. We identified Triggering-Receptor-in-Myeloid-cells (TREM)-1, a regulator of TLR signaling, as highly upregulated in kidney inflammatory macrophages and tested the roles of these receptors in macrophage activation and kidney disease. Kidney DAMPs activated macrophages in vitro, independently of TREM-1, but partially dependent on TLR-2/−4, MyD88. In two models of progressive interstitial kidney disease, TREM-1 blockade had no impact on disease or macrophage activation in vivo, but TLR-2/−4, or MyD88 deficiency was anti-inflammatory and anti-fibrotic. When MyD88 was mutated only in the myeloid lineage, however, there was no bearing on macrophage activation or disease progression. Instead, TLR-2/−4 or MyD88 deficiency reduced activation of mesenchyme lineage cells resulting in reduced inflammation and fibrosis, indicating that these pathways play dominant roles in activation of myofibroblasts but not macrophages. To conclude, TREM-1, TLR2/4 and MyD88 signaling pathways are redundant in myeloid cell activation in kidney injury, but the latter appear to regulate activation of mesenchymal cells. PMID:23844229

  6. Haptoglobin activates innate immunity to enhance acute transplant rejection in mice

    PubMed Central

    Shen, Hua; Song, Yang; Colangelo, Christopher M.; Wu, Terence; Bruce, Can; Scabia, Gaia; Galan, Anjela; Maffei, Margherita; Goldstein, Daniel R.

    2011-01-01

    Immune tolerance to transplanted organs is impaired when the innate immune system is activated in response to the tissue necrosis that occurs during harvesting and implantation procedures. A key molecule in this immune pathway is the intracellular TLR signal adaptor known as myeloid differentiation primary response gene 88 (MyD88). After transplantation, MyD88 induces DC maturation as well as the production of inflammatory mediators, such as IL-6 and TNF-α. However, upstream activators of MyD88 function in response to transplantation have not been identified. Here, we show that haptoglobin, an acute phase protein, is an initiator of this MyD88-dependent inflammatory process in a mouse model of skin transplantation. Necrotic lysates from transplanted skin elicited higher inflammatory responses in DCs than did nontransplanted lysates, suggesting DC-mediated responses are triggered by factors released during transplantation. Analysis of transplanted lysates identified haptoglobin as one of the proteins upregulated during transplantation. Expression of donor haptoglobin enhanced the onset of acute skin transplant rejection, whereas haptoglobin-deficient skin grafts showed delayed acute rejection and antidonor T cell priming in a MyD88-dependent graft rejection model. Thus, our results show that haptoglobin release following skin necrosis contributes to accelerated transplant rejection, with potential implications for the development of localized immunosuppressive therapies. PMID:22156194

  7. Adaptive homeostasis.

    PubMed

    Davies, Kelvin J A

    2016-06-01

    Homeostasis is a central pillar of modern Physiology. The term homeostasis was invented by Walter Bradford Cannon in an attempt to extend and codify the principle of 'milieu intérieur,' or a constant interior bodily environment, that had previously been postulated by Claude Bernard. Clearly, 'milieu intérieur' and homeostasis have served us well for over a century. Nevertheless, research on signal transduction systems that regulate gene expression, or that cause biochemical alterations to existing enzymes, in response to external and internal stimuli, makes it clear that biological systems are continuously making short-term adaptations both to set-points, and to the range of 'normal' capacity. These transient adaptations typically occur in response to relatively mild changes in conditions, to programs of exercise training, or to sub-toxic, non-damaging levels of chemical agents; thus, the terms hormesis, heterostasis, and allostasis are not accurate descriptors. Therefore, an operational adjustment to our understanding of homeostasis suggests that the modified term, Adaptive Homeostasis, may be useful especially in studies of stress, toxicology, disease, and aging. Adaptive Homeostasis may be defined as follows: 'The transient expansion or contraction of the homeostatic range in response to exposure to sub-toxic, non-damaging, signaling molecules or events, or the removal or cessation of such molecules or events.' PMID:27112802

  8. Excited-state geometries and vibrational frequencies studied using the analytical energy gradients of the direct symmetry-adapted cluster-configuration interaction method. I. HAX-type molecules

    NASA Astrophysics Data System (ADS)

    Ehara, Masahiro; Oyagi, Fumito; Abe, Yoko; Fukuda, Ryoichi; Nakatsuji, Hiroshi

    2011-07-01

    In this series of studies, we systematically apply the analytical energy gradients of the direct symmetry-adapted cluster-configuration interaction singles and doubles nonvariational method to calculate the equilibrium geometries and vibrational frequencies of excited and ionized states of molecules. The harmonic vibrational frequencies were calculated using the second derivatives numerically computed from the analytical first derivatives and the anharmonicity was evaluated from the three-dimensional potential energy surfaces around the local minima. In this paper, the method is applied to the low-lying valence singlet and triplet excited states of HAX-type molecules, HCF, HCCl, HSiF, HSiCl, HNO, HPO, and their deuterium isotopomers. The vibrational level emission spectra of HSiF and DSiF and absorption spectra of HSiCl and DSiCl were also simulated within the Franck-Condon approximation and agree well with the experimental spectra. The results show that the present method is useful and reliable for calculating these quantities and spectra. The change in geometry in the excited states was qualitatively interpreted in the light of the electrostatic force theory. The effect of perturbation selection with the localized molecular orbitals on the geometrical parameters and harmonic vibrational frequencies is also discussed.

  9. Interstellar molecules

    NASA Astrophysics Data System (ADS)

    Smith, D.

    1987-09-01

    Some 70 different molecular species have so far been detected variously in diffuse interstellar clouds, dense interstellar clouds, and circumstellar shells. Only simple (diatomic and triatomic) species exist in diffuse clouds because of the penetration of destructive UV radiations, whereas more complex (polyatomic) molecules survive in dense clouds as a result of the shielding against this UV radiation provided by dust grains. A current list of interstellar molecules is given together with a few other molecular species that have so far been detected only in circumstellar shells. Also listed are those interstellar species that contain rare isotopes of several elements. The gas phase ion chemistry is outlined via which the observed molecules are synthesized, and the process by which enrichment of the rare isotopes occurs in some interstellar molecules is described.

  10. Interstellar Molecules

    ERIC Educational Resources Information Center

    Solomon, Philip M.

    1973-01-01

    Radioastronomy reveals that clouds between the stars, once believed to consist of simple atoms, contain molecules as complex as seven atoms and may be the most massive objects in our Galaxy. (Author/DF)

  11. Modeling Molecules

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The molecule modeling method known as Multibody Order (N) Dynamics, or MBO(N)D, was developed by Moldyn, Inc. at Goddard Space Flight Center through funding provided by the SBIR program. The software can model the dynamics of molecules through technology which stimulates low-frequency molecular motions and properties, such as movements among a molecule's constituent parts. With MBO(N)D, a molecule is substructured into a set of interconnected rigid and flexible bodies. These bodies replace the computation burden of mapping individual atoms. Moldyn's technology cuts computation time while increasing accuracy. The MBO(N)D technology is available as Insight II 97.0 from Molecular Simulations, Inc. Currently the technology is used to account for forces on spacecraft parts and to perform molecular analyses for pharmaceutical purposes. It permits the solution of molecular dynamics problems on a moderate workstation, as opposed to on a supercomputer.

  12. Enumerating molecules.

    SciTech Connect

    Visco, Donald Patrick, Jr.; Faulon, Jean-Loup Michel; Roe, Diana C.

    2004-04-01

    This report is a comprehensive review of the field of molecular enumeration from early isomer counting theories to evolutionary algorithms that design molecules in silico. The core of the review is a detail account on how molecules are counted, enumerated, and sampled. The practical applications of molecular enumeration are also reviewed for chemical information, structure elucidation, molecular design, and combinatorial library design purposes. This review is to appear as a chapter in Reviews in Computational Chemistry volume 21 edited by Kenny B. Lipkowitz.

  13. Origins of adaptive immunity.

    PubMed

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity. PMID:21395512

  14. Activation of toll-like receptor signaling pathways leading to nitric oxide-mediated antiviral responses.

    PubMed

    Abdul-Cader, Mohamed Sarjoon; Amarasinghe, Aruna; Abdul-Careem, Mohamed Faizal

    2016-08-01

    Toll-like receptors (TLRs), well-characterized pattern-recognizing receptors of the innate arm of the immune system, are vital in detecting pathogen-associated molecular patterns (PAMPs). The TLR-PAMP interaction initiates an intracellular signaling cascade, predominantly culminating in upregulation of antiviral components, including inducible nitric oxide synthase (iNOS). After activation, various TLR pathways can promote iNOS production via the myeloid differentiation primary response-88 (MyD-88) adapter protein. Subsequently, iNOS facilitates production of nitric oxide (NO), a highly reactive and potent antiviral molecule that can inhibit replication of RNA and DNA viruses. Furthermore, NO can diffuse freely across cell membranes and elicit antiviral mechanisms in various ways, including direct and indirect damage to viral genomes. This review emphasizes current knowledge of NO-mediated antiviral responses elicited after activation of TLR signaling pathways. PMID:27233799

  15. Intrinsic and Extrinsic Regulation of Innate Immune Receptors

    PubMed Central

    Jeong, Eunshil

    2011-01-01

    Pattern recognition receptors (PRRs) in innate immune cells play a pivotal role in the first line of host defense system. PRRs recognize pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs) to initiate and regulate innate and adaptive immune responses. PRRs include Toll-like receptors (TLRs), RIG-I-like receptors (RLRs) and NOD-like receptors (NLRs), which have their own features in ligand recognition and cellular location. Activated PRRs deliver signals to adaptor molecules (MyD88, TRIF, MAL/TIRAP, TRAM, IPS-1) which act as important messengers to activate downstream kinases (IKK complex, MAPKs, TBK1, RIP-1) and transcription factors (NF-κB, AP-1, IRF3), which produce effecter molecules including cytokines, chemokines, inflammatory enzymes, and type I interferones. Since excessive PRR activation is closely linked to the development of chronic inflammatory diseases, the role of intrinsic and extrinsic regulators in the prevention of over- or unnecessary activation of PRRs has been widely studied. Intracellular regulators include MyD88s, SOCS1, TOLLIP, A20, and CYLD. Extrinsic regulators have also been identified with their molecular targets in PRR signaling pathways. TLR dimerization has been suggested as an inhibitory target for small molecules such as curcumin, cinnamaldehyde, and sulforaphane. TBK1 kinase can be a target for certain flavonoids such as EGCG, luteolin, quercetin, chrysin, and eriodictyol to regulate TRIF-dependent TLR pathways. This review focuses on the features of PRR signaling pathways and the therapeutic targets of intrinsic and extrinsic regulators in order to provide beneficial strategies for controlling the activity of PRRs and the related inflammatory diseases and immune disorders. PMID:21488180

  16. Suppression of the TRIF-dependent signaling pathway of Toll-like receptors by luteolin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Toll-like receptors (TLRs) play an important role in induction of immune and inflammatory responses by recognizing invading pathogens. TLRs have two major downstream signaling pathways activated through the interaction with adaptor molecules, MyD88 and TRIF, leading to the expression of proinflammat...

  17. Toll-Like Receptor-4 Signaling in Mantle Cell Lymphoma: Effects on Tumor Growth and Immune Evasion

    PubMed Central

    Wang, Lijuan; Zhao, Yi; Qian, Jianfei; Sun, Luhong; Lu, Yong; Li, Haiyan; Li, Yi; Yang, Jing; Cai, Zhen; Yi, Qing

    2012-01-01

    BACKGROUND Mantle cell lymphoma (MCL) is an incurable B-cell malignancy with the poorest prognosis among B-cell lymphoma patients. The signal pathways that trigger MCL escape from immune surveillance are unclear. As Toll-like receptors (TLRs) initiate innate and adaptive immune responses against invading pathogens, we investigated the impact of TLR signaling in MCL cells. METHODS We examined TLR expression on MCL cell lines and primary tumor cells from patients. We focused on TLR4 and its ligand lipopolysacharide (LPS) on MCL cells and their function on MCL proliferation and immune evasion. RESULTS MCL cells expressed multiple TLRs and TLR4 was among the highest-expressed molecules. Activation of TLR4 signaling in MCL cells by LPS induced MCL proliferation, and upregulated the secretion of cytokines such as interleukin (IL)-6 and IL-10, and vascular endothelial growth factor (VEGF). LPS-pretreated MCL cells inhibited the proliferation and cytolytic activity of T cells by secreted IL-10 and VEGF, and neutralizing antibodies against these cytokines restored their functions. Similar results were also observed in TLR4+MyD88+ but not in TLR4+MyD88− primary lymphoma cells from MCL patients. Knockdown of TLR4 on MCL cells abrogated the effect of LPS on MCLs in term of cell growth or secretion of the cytokines, and evasion of the immune system. CONCLUSION Our study indicates that TLR4 signaling triggers a cascade leading to MCL growth and evasion from the immune surveillance. Thus, TLR4 signaling molecules could be novel therapeutic targets for cancer therapy in MCL. PMID:22915070

  18. Mind Molecules

    PubMed Central

    Snyder, Solomon H.

    2011-01-01

    Scientific styles vary tremendously. For me, research is largely about the unfettered pursuit of novel ideas and experiments that can test multiple ideas in a day, not a year, an approach that I learned from my mentor Julius “Julie” Axelrod. This focus on creative conceptualizations has been my métier since working in the summers during medical school at the National Institutes of Health, during my two years in the Axelrod laboratory, and throughout my forty-five years at Johns Hopkins University School of Medicine. Equally important has been the “high” that emerges from brainstorming with my students. Nothing can compare with the eureka moments when, together, we sense new insights and, better yet, when high-risk, high-payoff experiments succeed. Although I have studied many different questions over the years, a common theme emerges: simple biochemical approaches to understanding molecular messengers, usually small molecules. Equally important has been identifying, purifying, and cloning the messengers' relevant biosynthetic, degradative, or target proteins, at all times seeking potential therapeutic relevance in the form of drugs. In the interests of brevity, this Reflections article is highly selective, and, with a few exceptions, literature citations are only of findings of our laboratory that illustrate notable themes. PMID:21543333

  19. TLR2, TLR4 and CD14 Recognize Venom-Associated Molecular Patterns from Tityus serrulatus to Induce Macrophage-Derived Inflammatory Mediators

    PubMed Central

    Zoccal, Karina Furlani; Bitencourt, Claudia da Silva; Paula-Silva, Francisco Wanderley Garcia; Sorgi, Carlos Artério; de Castro Figueiredo Bordon, Karla; Arantes, Eliane Candiani; Faccioli, Lúcia Helena

    2014-01-01

    Scorpion sting-induced human envenomation provokes an intense inflammatory reaction. However, the mechanisms behind the recognition of scorpion venom and the induction of mediator release in mammalian cells are unknown. We demonstrated that TLR2, TLR4 and CD14 receptors sense Tityus serrulatus venom (TsV) and its major component, toxin 1 (Ts1), to mediate cytokine and lipid mediator production. Additionally, we demonstrated that TsV induces TLR2- and TLR4/MyD88-dependent NF-κB activation and TLR4-dependent and TLR2/MyD88-independent c-Jun activation. Similar to TsV, Ts1 induces MyD88-dependent NF-κB phosphorylation via TLR2 and TLR4 receptors, while c-Jun activation is dependent on neither TLR2 nor TLR4/MyD88. Therefore, we propose the term venom-associated molecular pattern (VAMP) to refer to molecules that are introduced into the host by stings and are recognized by PRRs, resulting in inflammation. PMID:24516606

  20. The Architecture of the TIR Domain Signalosome in the Toll-like Receptor-4 Signaling Pathway

    PubMed Central

    Guven-Maiorov, Emine; Keskin, Ozlem; Gursoy, Attila; VanWaes, Carter; Chen, Zhong; Tsai, Chung-Jung; Nussinov, Ruth

    2015-01-01

    Activated Toll-like receptors (TLRs) cluster in lipid rafts and induce pro- and anti-tumor responses. The organization of the assembly is critical to the understanding of how these key receptors control major signaling pathways in the cell. Although several models for individual interactions were proposed, the entire TIR-domain signalosome architecture has not been worked out, possibly due to its complexity. We employ a powerful algorithm, crystal structures and experimental data to model the TLR4 and its cluster. The architecture that we obtain with 8 MyD88 molecules provides the structural basis for the MyD88-templated myddosome helical assembly and receptor clustering; it also provides clues to pro- and anti-inflammatory signaling pathways branching at the signalosome level to Mal/MyD88 and TRAM/TRIF pro- and anti-inflammatory pathways. The assembly of MyD88 death domain (DD) with TRAF3 (anti-viral/anti-inflammatory) and TRAF6 (pro-inflammatory) suggest that TRAF3/TRAF6 binding sites on MyD88 DD partially overlap, as do IRAK4 and FADD. Significantly, the organization illuminates mechanisms of oncogenic mutations, demonstrates that almost all TLR4 parallel pathways are competitive and clarifies decisions at pathway branching points. The architectures are compatible with the currently-available experimental data and provide compelling insights into signaling in cancer and inflammation pathways. PMID:26293885

  1. The Architecture of the TIR Domain Signalosome in the Toll-like Receptor-4 Signaling Pathway.

    PubMed

    Guven-Maiorov, Emine; Keskin, Ozlem; Gursoy, Attila; VanWaes, Carter; Chen, Zhong; Tsai, Chung-Jung; Nussinov, Ruth

    2015-01-01

    Activated Toll-like receptors (TLRs) cluster in lipid rafts and induce pro- and anti-tumor responses. The organization of the assembly is critical to the understanding of how these key receptors control major signaling pathways in the cell. Although several models for individual interactions were proposed, the entire TIR-domain signalosome architecture has not been worked out, possibly due to its complexity. We employ a powerful algorithm, crystal structures and experimental data to model the TLR4 and its cluster. The architecture that we obtain with 8 MyD88 molecules provides the structural basis for the MyD88-templated myddosome helical assembly and receptor clustering; it also provides clues to pro- and anti-inflammatory signaling pathways branching at the signalosome level to Mal/MyD88 and TRAM/TRIF pro- and anti-inflammatory pathways. The assembly of MyD88 death domain (DD) with TRAF3 (anti-viral/anti-inflammatory) and TRAF6 (pro-inflammatory) suggest that TRAF3/TRAF6 binding sites on MyD88 DD partially overlap, as do IRAK4 and FADD. Significantly, the organization illuminates mechanisms of oncogenic mutations, demonstrates that almost all TLR4 parallel pathways are competitive and clarifies decisions at pathway branching points. The architectures are compatible with the currently-available experimental data and provide compelling insights into signaling in cancer and inflammation pathways. PMID:26293885

  2. Inhibition of myeloid differentiation factor 88 signaling mediated by histidine-grafted poly(β-amino ester) ester nanovector induces donor-specific liver allograft tolerance.

    PubMed

    Hu, Fanguo; Wang, Hanjie; Zhang, Shuangnan; Peng, Yao; Su, Lin; Chang, Jin; Liu, Gang

    2015-01-01

    Toll-like receptors (TLRs) activate biochemical pathways that evoke activation of innate immunity, which leads to dendritic cell maturation and initiation of adaptive immune responses that provoke allograft rejection. We aimed to prolong allograft survival by selectively inhibiting expression of myeloid differentiation factor 88 (MyD88), which is an essential adaptor in TLR signaling. We designed and synthesized a novel histidine-grafted poly(β-amino ester) (HGPAE) nanovector, which was shown to be safe and efficient both in vitro and in vivo for the delivery of a plasmid containing shRNA targeting MyD88 (pMyD88). We also demonstrated that the pMyD88/HGPAE complex mediated remarkable inhibition of MyD88 expression in rat liver in vivo. We transplanted Dark Agouti rat livers lacking MyD88 as result of transfection with the pMyD88/HGPAE complex into Lewis rats. The recipients survived longer and graft rejection of the donor liver as well as serum levels of IL-2 and IFN-γ in the recipient were significantly reduced. PMID:26185440

  3. Unexpected Roles for Toll-Like Receptor 4 and TRIF in Intraocular Infection with Gram-Positive Bacteria

    PubMed Central

    Parkunan, Salai Madhumathi; Randall, C. Blake; Coburn, Phillip S.; Astley, Roger A.; Staats, Rachel L.

    2015-01-01

    Inflammation caused by infection with Gram-positive bacteria is typically initiated by interactions with Toll-like receptor 2 (TLR2). Endophthalmitis, an infection and inflammation of the posterior segment of the eye, can lead to vision loss when initiated by a virulent microbial pathogen. Endophthalmitis caused by Bacillus cereus develops as acute inflammation with infiltrating neutrophils, and vision loss is potentially catastrophic. Residual inflammation observed during B. cereus endophthalmitis in TLR2−/− mice led us to investigate additional innate pathways that may trigger intraocular inflammation. We first hypothesized that intraocular inflammation during B. cereus endophthalmitis would be controlled by MyD88- and TRIF-mediated signaling, since MyD88 and TRIF are the major adaptor molecules for all bacterial TLRs. In MyD88−/− and TRIF−/− mice, we observed significantly less intraocular inflammation than in eyes from infected C57BL/6J mice, suggesting an important role for these TLR adaptors in B. cereus endophthalmitis. These results led to a second hypothesis, that TLR4, the only TLR that signals through both MyD88 and TRIF signaling pathways, contributed to inflammation during B. cereus endophthalmitis. Surprisingly, B. cereus-infected TLR4−/− eyes also had significantly less intraocular inflammation than infected C57BL/6J eyes, indicating an important role for TLR4 in B. cereus endophthalmitis. Taken together, our results suggest that TLR4, TRIF, and MyD88 are important components of the intraocular inflammatory response observed in experimental B. cereus endophthalmitis, identifying a novel innate immune interaction for B. cereus and for this disease. PMID:26195555

  4. Toll-Like Receptor 9 Is Required for Full Host Resistance to Mycobacterium avium Infection but Plays No Role in Induction of Th1 Responses▿

    PubMed Central

    Carvalho, Natália B.; Oliveira, Fernanda S.; Durães, Fernanda V.; de Almeida, Leonardo A.; Flórido, Manuela; Prata, Luana O.; Caliari, Marcelo V.; Appelberg, Rui; Oliveira, Sérgio C.

    2011-01-01

    To investigate the role of Toll-like receptor 9 (TLR9) in innate immunity to Mycobacterium avium, TLR9, TLR2, and MyD88 knockout (KO) mice were infected with this bacterium. Bacterial burdens were higher in the spleens, livers, and lungs of infected TLR9 KO mice than in those of C57BL/6 mice, indicating that TLR9 is required for efficient control of M. avium infection. However, TLR9 KO or TLR2 KO spleen cells displayed normal M. avium-induced tumor necrosis factor alpha (TNF-α) and gamma interferon (IFN-γ) responses. This finding was confirmed by determining the number of splenic CD4+ T cells producing IFN-γ by flow cytometry. Furthermore, TLR2 and MyD88, but not TLR9, played a major role in interleukin-12 and TNF-α production by M. avium-infected macrophages and dendritic cells (DCs). We also found that major histocompatibility complex class II molecule expression on DCs is regulated by TLR2 and MyD88 signaling but not by TLR9. Finally, lack of TLR9, TLR2, or MyD88 reduced the numbers of macrophages, epithelioid cells, and lymphocytes in M. avium-induced granulomas but only MyD88 deficiency affected the number of liver granulomas. In summary, our data demonstrated that the involvement of TLR9 in the control of M. avium infection is not related to the induction of Th1 responses. PMID:21300776

  5. Electron Collisions with Large Molecules

    NASA Astrophysics Data System (ADS)

    McKoy, Vincent

    2006-10-01

    In recent years, interest in electron-molecule collisions has increasingly shifted to large molecules. Applications within the semiconductor industry, for example, require electron collision data for molecules such as perfluorocyclobutane, while almost all biological applications involve macromolecules such as DNA. A significant development in recent years has been the realization that slow electrons can directly damage DNA. This discovery has spurred studies of low-energy collisions with the constituents of DNA, including the bases, deoxyribose, the phosphate, and larger moieties assembled from them. In semiconductor applications, a key goal is development of electron cross section sets for plasma chemistry modeling, while biological studies are largely focused on understanding the role of localized resonances in inducing DNA strand breaks. Accurate calculations of low-energy electron collisions with polyatomic molecules are computationally demanding because of the low symmetry and inherent many-electron nature of the problem; moreover, the computational requirements scale rapidly with the size of the molecule. To pursue such studies, we have adapted our computational procedure, known as the Schwinger multichannel method, to run efficiently on highly parallel computers. In this talk, we will present some of our recent results for fluorocarbon etchants used in the semiconductor industry and for constituents of DNA and RNA. In collaboration with Carl Winstead, California Institute of Technology.

  6. Anesthetic agent propofol inhibits myeloid differentiation factor 88-dependent and independent signaling and mitigates lipopolysaccharide-mediated reactive oxygen species production in human neutrophils in vitro.

    PubMed

    Ren, Xuli; Lv, Fei; Fang, Bo; Liu, Song; Lv, Huangwei; He, Guannan; Ma, Hong; Cao, Yaming; Wang, Yue

    2014-12-01

    Engagement of toll-like receptor 4 (TLR4) can activate the myeloid differentiation factor 88 (MyD88)/toll-interleukin-1-resistance domain-containing adapter-inducing interferon-β (TRIF) dependent pathways, inducing production of reactive oxygen species (ROS) in neutrophils. Propofol (PPF) has both anti-oxidant and anti-inflammatory properties. However, the molecular mechanism by which PPF influences human neutrophil function is yet to be elucidated. This study aimed to investigate the influence of PPF on lipopolysaccharide (LPS)-induced reactive oxygen species production in human neutrophils. We isolated neutrophils from the peripheral blood of 10 healthy male donors. Neither 1 µg/ml LPS nor 10-150 μmol/L PPF influenced the rate of neutrophil apoptosis, but PPF significantly inhibited LPS-mediated reactive oxygen species production in a dose-dependent manner. PPF inhibited LPS-induced expression of MyD88, tumor necrosis factor receptor-associated factor 6, and TRIF, but not the expression of interferon regulatory factor 3 or phosphorylation of p47(phox), p38-mitogen-activated protein kinase, and nuclear factor (NF)-κB, particularly in the neutrophils in which MyD88 or TRIF had been silenced by siRNA. The inhibitory effect of PPF on LPS-induced activation of p47(phox), p38-mitogen-activated protein kinase, and NF-κB was partially antagonized by over-expression of MyD88 or TRIF in neutrophils. These observations provide insights into the mechanisms responsible for the anti-inflammatory properties of PPF. PPF reduces LPS-induced production of reactive oxygen species in neutrophils via inhibiting expression of MyD88 and TRIF signaling. PMID:25446563

  7. Microbiota regulates type 1 diabetes through Toll-like receptors

    PubMed Central

    Burrows, Michael P.; Volchkov, Pavel; Kobayashi, Koichi S.; Chervonsky, Alexander V.

    2015-01-01

    Deletion of the innate immune adaptor myeloid differentiation primary response gene 88 (MyD88) in the nonobese diabetic (NOD) mouse model of type 1 diabetes (T1D) results in microbiota-dependent protection from the disease: MyD88-negative mice in germ-free (GF), but not in specific pathogen-free conditions develop the disease. These results could be explained by expansion of particular protective bacteria (“specific lineage hypothesis”) or by dominance of negative (tolerizing) signaling over proinflammatory signaling (“balanced signal hypothesis”) in mutant mice. Here we found that colonization of GF mice with a variety of intestinal bacteria was capable of reducing T1D in MyD88-negative (but not wild-type NOD mice), favoring the balanced signal hypothesis. However, the receptors and signaling pathways involved in prevention or facilitation of the disease remained unknown. The protective signals triggered by the microbiota were revealed by testing NOD mice lacking MyD88 in combination with knockouts of several critical components of innate immune sensing for development of T1D. Only MyD88- and TIR-domain containing adapter inducing IFN β (TRIF) double deficient NOD mice developed the disease. Thus, TRIF signaling (likely downstream of Toll-like receptor 4, TLR4) serves as one of the microbiota-induced tolerizing pathways. At the same time another TLR (TLR2) provided prodiabetic signaling by controlling the microbiota, as reduction in T1D incidence caused by TLR2 deletion was reversed in GF TLR2-negative mice. Our results support the balanced signal hypothesis, in which microbes provide signals that both promote and inhibit autoimmunity by signaling through different receptors, including receptors of the TLR family. PMID:26216961

  8. Physics of Molecules

    NASA Astrophysics Data System (ADS)

    Williams, D.; Murdin, P.

    2000-11-01

    Many varieties of molecule have been detected in the Milky Way and in other galaxies. The processes by which these molecules are formed and destroyed are now broadly understood (see INTERSTELLAR CHEMISTRY). These molecules are important components of galaxies in two ways. Firstly, radiation emitted by molecules enables us to trace the presence of diffuse gas, to infer its physical properties and ...

  9. Adaptive Management

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive managem...

  10. Adaptive SPECT

    PubMed Central

    Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

    2008-01-01

    Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

  11. Rapid CD4+ T-cell responses to bacterial flagellin require dendritic cell expression of Syk and CARD9.

    PubMed

    Atif, Shaikh M; Lee, Seung-Joo; Li, Lin-Xi; Uematsu, Satoshi; Akira, Shizuo; Gorjestani, Sara; Lin, Xin; Schweighoffer, Edina; Tybulewicz, Victor L J; McSorley, Stephen J

    2015-02-01

    Toll-like receptors (TLRs) can recognize microbial patterns and utilize adaptor molecules, such as-MyD88 or (TRIF TIR-domain-containing adapter-inducing interferon-β), to initiate downstream signaling that ultimately affects the initiation of adaptive immunity. In addition to this inflammatory role, TLR5 expression on dendritic cells can favor antigen presentation of flagellin peptides and thus increase the sensitivity of flagellin-specific T-cell responses in vitro and in vivo. Here, we examined the role of alternative signaling pathways that might regulate flagellin antigen presentation in addition to MyD88. These studies suggest a requirement for spleen tyrosine kinase, a noncanonical TLR-signaling adaptor molecule, and its downstream molecule CARD9 in regulating the sensitivity of flagellin-specific CD4(+) T-cell responses in vitro and in vivo. Thus, a previously unappreciated signaling pathway plays an important role in regulating the dominance of flagellin-specific T-cell responses. PMID:25430631

  12. Rapid CD4+ T-cell responses to bacterial flagellin require dendritic cell expression of Syk and CARD9

    PubMed Central

    Atif, Shaikh M; Lee, Seung-Joo; Li, Lin-Xi; Uematsu, Satoshi; Akira, Shizuo; Gorjestani, Sara; Lin, Xin; Schweighoffer, Edina; Tybulewicz, Victor L J; McSorley, Stephen J

    2015-01-01

    Toll-like receptors (TLRs) can recognize microbial patterns and utilize adaptor molecules, such as-MyD88 or (TRIF TIR-domain-containing adapter-inducing interferon-β), to initiate downstream signaling that ultimately affects the initiation of adaptive immunity. In addition to this inflammatory role, TLR5 expression on dendritic cells can favor antigen presentation of flagellin peptides and thus increase the sensitivity of flagellin-specific T-cell responses in vitro and in vivo. Here, we examined the role of alternative signaling pathways that might regulate flagellin antigen presentation in addition to MyD88. These studies suggest a requirement for spleen tyrosine kinase, a noncanonical TLR-signaling adaptor molecule, and its downstream molecule CARD9 in regulating the sensitivity of flagellin-specific CD4+ T-cell responses in vitro and in vivo. Thus, a previously unappreciated signaling pathway plays an important role in regulating the dominance of flagellin-specific T-cell responses. PMID:25430631

  13. Reversible Aptamer-Au Plasmon Rulers for Secreted Single Molecules

    SciTech Connect

    Lee, Somin Eunice; Chen, Qian; Bhat, Ramray; Petkiewicz, Shayne; Smith, Jessica M.; Ferry, Vivian E.; Correia, Ana Luisa; Alivisatos, A. Paul; Bissell, Mina J.

    2015-06-03

    Plasmon rulers, consisting of pairs of gold nanoparticles, allow single-molecule analysis without photobleaching or blinking; however, current plasmon rulers are irreversible, restricting detection to only single events. Here, we present a reversible plasmon ruler, comprised of coupled gold nanoparticles linked by a single aptamer, capable of binding individual secreted molecules with high specificity. We show that the binding of target secreted molecules to the reversible plasmon ruler is characterized by single-molecule sensitivity, high specificity, and reversibility. Lastly, such reversible plasmon rulers should enable dynamic and adaptive live-cell measurement of secreted single molecules in their local microenvironment.

  14. Invariant chain is a new chaperone for TLR7 in B cells.

    PubMed

    Tohmé, Mira; Manoury, Bénédicte

    2015-12-01

    The innate immune system provides the first barrier against pathogens. Intracellular Toll-like receptors (TLR3, 7 and 9) localise in endosomes and sense nucleotides from viruses and bacteria. This recognition induces their conformational changes resulting in the production of proinflammatory cytokines and MHC class II (MHCII) antigenic presentation. In the absence of stimulation, TLRs are retained in the endoplasmic reticulum. Upon stimulation, they relocate to the endo-lysosomal compartment, allowing the recruitment of the adaptor molecules, MyD88 or TRIF. Increasing evidences describe a cross talk between proteins that regulate both innate and adaptive immune responses. For example, proteolytic enzymes which are required for breaking down exogenous antigen to generate suitable peptides for MHCII molecules are also essential to activate endosomal TLRs and MHCII molecules were recently described to regulate TLR signalling. But other proteins are possibly involved and regulated differentially between cell types. We have observed that intracellular TLR trafficking and signalling in B cells are different from dendritic cells and macrophages and involved the MHCII chaperone molecule, the invariant chain (Ii). PMID:26198699

  15. Morphine compromises bronchial epithelial TLR2/IL17R signaling crosstalk, necessary for lung IL17 homeostasis

    PubMed Central

    Banerjee, Santanu; Ninkovic, Jana; Meng, Jingjing; Sharma, Umakant; Ma, Jing; Charboneau, Richard; Roy, Sabita

    2015-01-01

    Opportunistic lung infection and inflammation is a hallmark of chronic recreational/clinical use of morphine. We show that early induction of IL17 from the bronchial epithelium, following pathogenic encounter is a protective response, which contributes to pathogenic clearance and currently attributed to TLR2 activation in immune cells. Concurrent activation of TLR2 and IL17R in bronchial epithelium results in the sequestration of MyD88 (TLR2 adapter) by Act1/CIKS (IL17R adapter), thereby turning off TLR2 signaling to restore homeostasis. Morphine inhibits the early IL17 release and interaction between Act1 and MyD88, leading to decreased pathogenic clearance and sustained inflammation. Hence, we propose that therapeutically targeting either TLR2 or IL17 in bronchial epithelia, in the context of morphine, can restore inflammatory homeostasis. PMID:26072707

  16. CD1d, a Sentinel Molecule Bridging Innate and Adaptive Immunity, Is Downregulated by the Human Papillomavirus (HPV) E5 Protein: a Possible Mechanism for Immune Evasion by HPV▿

    PubMed Central

    Miura, Shiho; Kawana, Kei; Schust, Danny J.; Fujii, Tomoyuki; Yokoyama, Terufumi; Iwasawa, Yuki; Nagamatsu, Takeshi; Adachi, Katsuyuki; Tomio, Ayako; Tomio, Kensuke; Kojima, Satoko; Yasugi, Toshiharu; Kozuma, Shiro; Taketani, Yuji

    2010-01-01

    CD1d and CD1d-restricted natural killer T (NKT) cells serve as a natural bridge between innate and adaptive immune responses to microbes. CD1d downregulation is utilized by a variety of microbes to evade immune detection. We demonstrate here that CD1d is downregulated in human papillomavirus (HPV)-positive cells in vivo and in vitro. CD1d immunoreactivity was strong in HPV-negative normal cervical epithelium but absent in HPV16-positive CIN1 and HPV6-positive condyloma lesions. We used two cell lines for in vitro assay; one was stably CD1d-transfected cells established from an HPV-negative cervical cancer cell line, C33A (C33A/CD1d), and the other was normal human vaginal keratinocyte bearing endogenous CD1d (Vag). Flow cytometry revealed that cell surface CD1d was downregulated in both C33A/CD1d and Vag cells stably transfected with HPV6 E5 and HPV16 E5. Although the steady-state levels of CD1d protein decreased in both E5-expressing cell lines compared to empty retrovirus-infected cells, CD1d mRNA levels were not affected. Confocal microscopy demonstrated that residual CD1d was not trafficked to the E5-expressing cell surface but colocalized with E5 near the endoplasmic reticulum (ER). In the ER, E5 interacted with calnexin, an ER chaperone known to mediate folding of CD1d. CD1d protein levels were rescued by the proteasome inhibitor, MG132, indicating a role for proteasome-mediated degradation in HPV-associated CD1d downregulation. Taken together, our data suggest that E5 targets CD1d to the cytosolic proteolytic pathway by inhibiting calnexin-related CD1d trafficking. Finally, CD1d-mediated production of interleukin-12 from the C33A/CD1d cells was abrogated in both E5-expressing cell lines. Decreased CD1d expression in the presence of HPV E5 may help HPV-infected cells evade protective immunological surveillance. PMID:20810727

  17. Gedunin Binds to Myeloid Differentiation Protein 2 and Impairs Lipopolysaccharide-Induced Toll-Like Receptor 4 Signaling in Macrophages.

    PubMed

    Borges, Perla Villani; Moret, Katelim Hottz; Maya-Monteiro, Clarissa Menezes; Souza-Silva, Franklin; Alves, Carlos Roberto; Batista, Paulo Ricardo; Caffarena, Ernesto Raúl; Pacheco, Patrícia; Henriques, Maria das Graças; Penido, Carmen

    2015-11-01

    Recognition of bacterial lipopolysaccharide (LPS) by innate immune system is mediated by the cluster of differentiation 14/Toll-like receptor 4/myeloid differentiation protein 2 (MD-2) complex. In this study, we investigated the modulatory effect of gedunin, a limonoid from species of the Meliaceae family described as a heat shock protein Hsp90 inhibitor, on LPS-induced response in immortalized murine macrophages. The pretreatment of wild-type (WT) macrophages with gedunin (0.01-100 µM, noncytotoxic concentrations) inhibited LPS (50 ng/ml)-induced calcium influx, tumor necrosis factor-α, and nitric oxide production in a concentration-dependent manner. The selective effect of gedunin on MyD88-adapter-like/myeloid differentiation primary response 88- and TRIF-related adaptor molecule/TIR domain-containing adapter-inducing interferon-β-dependent signaling pathways was further investigated. The pretreatment of WT, TIR domain-containing adapter-inducing interferon-β knockout, and MyD88 adapter-like knockout macrophages with gedunin (10 µM) significantly inhibited LPS (50 ng/ml)-induced tumor necrosis factor-α and interleukin-6 production, at 6 hours and 24 hours, suggesting that gedunin modulates a common event between both signaling pathways. Furthermore, gedunin (10 µM) inhibited LPS-induced prostaglandin E2 production, cyclooxygenase-2 expression, and nuclear factor κB translocation into the nucleus of WT macrophages, demonstrating a wide-range effect of this chemical compound. In addition to the ability to inhibit LPS-induced proinflammatory mediators, gedunin also triggered anti-inflammatory factors interleukin-10, heme oxygenase-1, and Hsp70 in macrophages stimulated or not with LPS. In silico modeling studies revealed that gedunin efficiently docked into the MD-2 LPS binding site, a phenomenon further confirmed by surface plasmon resonance. Our results reveal that, in addition to Hsp90 modulation, gedunin acts as a competitive inhibitor of LPS, blocking

  18. Oncogenic protein interfaces: small molecules, big challenges.

    PubMed

    Nero, Tracy L; Morton, Craig J; Holien, Jessica K; Wielens, Jerome; Parker, Michael W

    2014-04-01

    Historically, targeting protein-protein interactions with small molecules was not thought possible because the corresponding interfaces were considered mostly flat and featureless and therefore 'undruggable'. Instead, such interactions were targeted with larger molecules, such as peptides and antibodies. However, the past decade has seen encouraging breakthroughs through the refinement of existing techniques and the development of new ones, together with the identification and exploitation of unexpected aspects of protein-protein interaction surfaces. In this Review, we describe some of the latest techniques to discover modulators of protein-protein interactions and how current drug discovery approaches have been adapted to successfully target these interfaces. PMID:24622521

  19. Enzymatic DNA molecules

    NASA Technical Reports Server (NTRS)

    Joyce, Gerald F. (Inventor); Breaker, Ronald R. (Inventor)

    1998-01-01

    The present invention discloses deoxyribonucleic acid enzymes--catalytic or enzymatic DNA molecules--capable of cleaving nucleic acid sequences or molecules, particularly RNA, in a site-specific manner, as well as compositions including same. Methods of making and using the disclosed enzymes and compositions are also disclosed.

  20. Adhesion molecules and receptors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adhesion molecules are necessary for leukocyte trafficking and differentiation. They serve to initiate cell-cell interactions under conditions of shear, and they sustain the cell-cell and cell-matrix interactions needed for cellular locomotion. They also can serve directly as signaling molecules act...

  1. Molecules between the Stars.

    ERIC Educational Resources Information Center

    Verschuur, Gerrit L.

    1987-01-01

    Provides a listing of molecules discovered to date in the vast interstellar clouds of dust and gas. Emphasizes the recent discoveries of organic molecules. Discusses molecular spectral lines, MASERs (microwave amplification by stimulated emission of radiation), molecular clouds, and star birth. (TW)

  2. Stimulation of Toll-Like Receptors profoundly influences the titer of polyreactive antibodies in the circulation.

    PubMed

    Gunti, Sreenivasulu; Messer, Ronald J; Xu, Chengfu; Yan, Ming; Coleman, William G; Peterson, Karin E; Hasenkrug, Kim J; Notkins, Abner L

    2015-01-01

    Polyreactive antibodies are a major component of the natural antibody repertoire and bind to a variety of structurally unrelated molecules. These antibodies are thought to provide a first line of defense against bacterial infections and play a major role in the clearance of apoptotic cells. What triggers the secretion of these antibodies has remained an enigma. Using a surrogate assay for measuring polyreactive antibodies, we found that about 50% of serum IgM is polyreactive and that stimulation of TLR4(+/+), but not TLR4(-/-), mice resulted in a 40 fold increase in polyreactive antibodies. Stimulation of TLRs 3, 7, 9 also increased the secretion of polyreactive antibodies. Infection with a virus or tissue damage induced by a toxin similarly led to an increase in polyreactive antibodies in MyD88(+/+), but not MyD88(-/-) mice. We conclude that stimulation of TLRs is a key link in the mechanism of polyreactive antibody secretion into the circulation. PMID:26463758

  3. Different dimerisation mode for TLR4 upon endosomal acidification?

    PubMed Central

    Gangloff, Monique

    2012-01-01

    TLR4 is unique among pathogen-recognition receptors in that it initiates different pathways in different cellular locations. Binding of a bridging factor, Mal, allows recruitment of an adapter protein, MyD88, at the plasma membrane, which leads to the production of proinflammatory cytokines. Upon internalization, TLR4 uses a different bridging factor, TRAM, to activate a MyD88-independent pathway that results in type I interferon expression. Interestingly, both Mal and TRAM are localised initially at the plasma membrane. In this Opinion, I suggest a possible mechanism by which endosomal acidification triggers the differential adaptor usage of TLR4. I discuss the evidence of the pH sensitivity of TLR4 and propose a new dimerisation mode for TLR4 based on the crystal structure of the related receptor TLR3 bound to its ligand, double-stranded RNA. PMID:22196451

  4. Different dimerisation mode for TLR4 upon endosomal acidification?

    PubMed

    Gangloff, Monique

    2012-03-01

    TLR4 is unique among pathogen-recognition receptors in that it initiates different pathways in different cellular locations. Binding of a bridging factor, Mal, allows recruitment of an adapter protein, MyD88, at the plasma membrane, which leads to the production of proinflammatory cytokines. Upon internalization, TLR4 uses a different bridging factor, TRAM, to activate a MyD88-independent pathway that results in type I interferon expression. Interestingly, both Mal and TRAM are localised initially at the plasma membrane. In this Opinion, I suggest a possible mechanism by which endosomal acidification triggers the differential adaptor usage of TLR4. I discuss the evidence of the pH sensitivity of TLR4 and propose a new dimerisation mode for TLR4 based on the crystal structure of the related receptor TLR3 bound to its ligand, double-stranded RNA. PMID:22196451

  5. Adaptive Development

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

  6. Ultracold polar KRb molecules

    NASA Astrophysics Data System (ADS)

    Neyenhuis, Brian; Chotia, Amodsen; Moses, Steven; Ye, Jun; Jin, Deborah

    2011-05-01

    Ultracold polar molecules in the quantum degenerate regime open the possibility of realizing quantum gases with long-range, and spatially anisotropic, interparticle interactions. Currently, we can create a gas of ultracold fermionic ground-state KRb molecules in with a peak density of 1012 cm-3 and a temperature just 1.4 times the Fermi temperature. We will report on efforts to further cool this gas of molecules. One possibility is to evaporatively cool a spin-polarized molecular Fermi gas confined in quasi-2D, where we would rely on dipole-dipole interactions for rethermalization. We acknowledge funding from NIST, NSF, and AFOSR-MURI.

  7. Poisson's spot with molecules

    SciTech Connect

    Reisinger, Thomas; Holst, Bodil; Patel, Amil A.; Smith, Henry I.; Reingruber, Herbert; Fladischer, Katrin; Ernst, Wolfgang E.; Bracco, Gianangelo

    2009-05-15

    In the Poisson-spot experiment, waves emanating from a source are blocked by a circular obstacle. Due to their positive on-axis interference an image of the source (the Poisson spot) is observed within the geometrical shadow of the obstacle. In this paper we report the observation of Poisson's spot using a beam of neutral deuterium molecules. The wavelength independence and the weak constraints on angular alignment and position of the circular obstacle make Poisson's spot a promising candidate for applications ranging from the study of large molecule diffraction to patterning with molecules.

  8. Poisson's spot with molecules

    NASA Astrophysics Data System (ADS)

    Reisinger, Thomas; Patel, Amil A.; Reingruber, Herbert; Fladischer, Katrin; Ernst, Wolfgang E.; Bracco, Gianangelo; Smith, Henry I.; Holst, Bodil

    2009-05-01

    In the Poisson-spot experiment, waves emanating from a source are blocked by a circular obstacle. Due to their positive on-axis interference an image of the source (the Poisson spot) is observed within the geometrical shadow of the obstacle. In this paper we report the observation of Poisson’s spot using a beam of neutral deuterium molecules. The wavelength independence and the weak constraints on angular alignment and position of the circular obstacle make Poisson’s spot a promising candidate for applications ranging from the study of large molecule diffraction to patterning with molecules.

  9. Single-Molecule Enzymology

    SciTech Connect

    Xie, Xiaoliang; Lu, H PETER.

    1999-06-04

    Viewing a movie of an enzyme molecule made from molecular dynamics (MD) simulation, we see incredible details of molecular motions, be it a change of the conformation or the action of a chemical reaction.

  10. Of Molecules and Models.

    ERIC Educational Resources Information Center

    Brinner, Bonnie

    1992-01-01

    Presents an activity in which models help students visualize both the DNA process and transcription. After constructing DNA, RNA messenger, and RNA transfer molecules; students model cells, protein synthesis, codons, and RNA movement. (MDH)

  11. Delineating the Requirement for the Borrelia burgdorferi Virulence Factor OspC in the Mammalian Host

    PubMed Central

    Stewart, Philip E.; Wang, Xiaohui; Bueschel, Dawn M.; Clifton, Dawn R.; Grimm, Dorothee; Tilly, Kit; Carroll, James A.; Weis, Janis J.; Rosa, Patricia A.

    2006-01-01

    We previously demonstrated that outer surface protein C (OspC) of Borrelia burgdorferi is essential for establishing mammalian infection. However, the role of OspC in mammalian infection is unknown. Here, we report experiments designed to distinguish between two models of OspC function in the mammalian host: (i) OspC fulfills an essential physiological role for growth and host adaptation or (ii) OspC provides a protective role for evasion of components of the innate immune response. We found that a B. burgdorferi ospC mutant, previously demonstrated to be noninfectious in both immunocompetent and SCID mice, could survive in the relatively immune-privileged environment of dialysis membrane chambers implanted within the peritoneum of a rat. The ospC mutant also adapts to the mammalian environment, as determined by the protein profiles of the chamber-cultivated spirochetes. Therefore, OspC does not appear to provide a physiological function for the survival of B. burgdorferi within the mammalian host. The second model, evasion of the innate immune system, was tested by assessing the infectivity of the ospC mutant in mice deficient for myeloid differentiation protein 88 (MyD88). Recent studies have shown that B. burgdorferi is prevented from reaching high cell numbers in the mammalian host by MyD88-dependent signaling pathways. The ospC mutant was incapable of infecting MyD88-deficient mice, suggesting that the role of OspC cannot be related solely to evasion of MyD88-mediated innate immunity. These results reiterate the importance of OspC in mammalian infection and eliminate simple models of function for this enigmatic protein. PMID:16714587

  12. Adapting Animals.

    ERIC Educational Resources Information Center

    Wedman, John; Wedman, Judy

    1985-01-01

    The "Animals" program found on the Apple II and IIe system master disk can be adapted for use in the mathematics classroom. Instructions for making the necessary changes and suggestions for using it in lessons related to geometric shapes are provided. (JN)

  13. Adaptive Thresholds

    SciTech Connect

    Bremer, P. -T.

    2014-08-26

    ADAPT is a topological analysis code that allow to compute local threshold, in particular relevance based thresholds for features defined in scalar fields. The initial target application is vortex detection but the software is more generally applicable to all threshold based feature definitions.

  14. Polyatomic molecule vibrations

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Polyatomic molecule vibrations are analyzed as harmonic vibrations along normal coordinates. The energy eigenvalues are found for linear and nonlinear symmetric triatomic molecules for valence bond models of the potential function with arbitrary coupling coefficients; such models can usually be fitted to observed energy levels with reasonably good accuracy. Approximate normal coordinates for the H2O molecule are discussed. Degenerate vibrational modes such as occur in CO2 are analyzed and expressions for Fermi resonance between close-lying states of the same symmetry are developed. The bending modes of linear triatomic molecules are expressed in terms of Laguerre polynomials in cylindrical coordinates as well as in terms of Hermite polynomials in Cartesian coordinates. The effects of large-amplitude bending such as occur in the C3 molecule are analyzed, along with anharmonic effects, which split the usually degenerate bending mode energy levels. Finally, the vibrational frequencies, degeneracies, and symmetry properties of XY3, X2Y2, and XY4 type molecules are discussed.

  15. Toward a 2-D magneto-optical trap for polar molecules

    NASA Astrophysics Data System (ADS)

    Hummon, Matthew; Stuhl, Benjamin; Yeo, Mark; Collopy, Alejandra; Ye, Jun

    2012-06-01

    The additional structure that arises from the rotational degree of freedom in diatomic molecules makes difficult the adaptation of a traditional atomic magneto-optical trap (MOT) for use with molecules. We describe progress toward development of a 2-D MOT for laser cooled yttrium monoxide molecules based on a resonant LC baseball coil geometry.

  16. Positron binding to molecules

    NASA Astrophysics Data System (ADS)

    Danielson, J. R.

    2011-05-01

    While there is theoretical evidence that positrons can bind to atoms, calculations for molecules are much less precise. Unfortunately, there have been no measurements of positron-atom binding, due primarily to the difficulty in forming positron-atom bound states in two-body collisions. In contrast, positrons attach to molecules via Feshbach resonances (VFR) in which a vibrational mode absorbs the excess energy. Using a high-resolution positron beam, this VFR process has been studied to measure binding energies for more than 40 molecules. New measurements will be described in two areas: positron binding to relatively simple molecules, for which theoretical calculations appear to be possible; and positron binding to molecules with large permanent dipole moments, which can be compared to analogous, weakly bound electron-molecule (negative-ion) states. Binding energies range from 75 meV for CS2 (no dipole moment) to 180 meV for acetonitrile (CH3CN). Other species studied include aldehydes and ketones, which have permanent dipole moments in the range 2.5 - 3.0 debye. The measured binding energies are surprisingly large (by a factor of 10 to 100) compared to those for the analogous negative ions, and these differences will be discussed. New theoretical calculations for positron-molecule binding are in progress, and a recent result for acetonitrile will be discussed. This ability to compare theory and experiment represents a significant step in attempts to understand positron binding to matter. In collaboration with A. C. L. Jones, J. J. Gosselin, and C. M. Surko, and supported by NSF grant PHY 07-55809.

  17. Connector adapter

    NASA Technical Reports Server (NTRS)

    Hacker, Scott C. (Inventor); Dean, Richard J. (Inventor); Burge, Scott W. (Inventor); Dartez, Toby W. (Inventor)

    2007-01-01

    An adapter for installing a connector to a terminal post, wherein the connector is attached to a cable, is presented. In an embodiment, the adapter is comprised of an elongated collet member having a longitudinal axis comprised of a first collet member end, a second collet member end, an outer collet member surface, and an inner collet member surface. The inner collet member surface at the first collet member end is used to engage the connector. The outer collet member surface at the first collet member end is tapered for a predetermined first length at a predetermined taper angle. The collet includes a longitudinal slot that extends along the longitudinal axis initiating at the first collet member end for a predetermined second length. The first collet member end is formed of a predetermined number of sections segregated by a predetermined number of channels and the longitudinal slot.

  18. Adaptive sampler

    DOEpatents

    Watson, Bobby L.; Aeby, Ian

    1982-01-01

    An adaptive data compression device for compressing data having variable frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  19. Adaptive sampler

    DOEpatents

    Watson, B.L.; Aeby, I.

    1980-08-26

    An adaptive data compression device for compressing data is described. The device has a frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  20. Understanding ultracold polar molecules

    NASA Astrophysics Data System (ADS)

    Julienne, Paul

    2009-05-01

    The successful production of a dense sample of ultracold ground state KRb polar molecules [1] opens the door to a new era of research with dipolar gases and lattices of such species. This feat was achieved by first associating a K and a Rb atom to make a weakly bound Feshbach molecule and then coherently transferring the population to the ground vibrational level of the molecule. This talk focuses on theoretical issues associated with making and using ultracold polar molecules, using KRb as an example [2]. Full understanding of this species and the processes by which it is made requires taking advantage of accurate molecular potentials [3], ab initio calculations [4], and the properties of the long-range potential. A highly accurate model is available for KRb for all bound states below the ground state separated atom limit and could be constructed for other species. The next step is to develop an understanding of the interactions between polar molecules, and their control in the ultracold domain. Understanding long-range interactions and threshold resonances will be crucial for future work. [1] K.-K. Ni, et al, Science 322, 231(2008). [2] P. S. Julienne, arXiv:0812:1233. [3] Pashov et al., Phys. Rev. A76, 022511 (2007). [4] S. Kotochigova, et al., arXiv:0901.1486.

  1. Figuration and detection of single molecules

    NASA Astrophysics Data System (ADS)

    Nevels, R.; Welch, G. R.; Cremer, P. S.; Hemmer, P.; Phillips, T.; Scully, S.; Sokolov, A. V.; Svidzinsky, A. A.; Xia, H.; Zheltikov, A.; Scully, M. O.

    2012-08-01

    Recent advances in the description of atoms and molecules based on Dimensional scaling analysis, developed by Dudley Herschbach and co-workers, provided new insights into visualization of molecular structure and chemical bonding. Prof. Herschbach is also a giant in the field of single molecule scattering. We here report on the engineering of molecular detectors. Such systems have a wide range of application from medical diagnostics to the monitoring of chemical, biological and environmental hazards. We discuss ways to identify preselected molecules, in particular, mycotoxin contaminants using coherent laser spectroscopy. Mycotoxin contaminants, e.g. aflatoxin B1 which is present in corn and peanuts, are usually analysed by time-consuming microscopic, chemical and biological assays. We present a new approach that derives from recent experiments in which molecules are prepared by one (or more) femtosecond laser(s) and probed by another set. We call this technique FAST CARS (femto second adaptive spectroscopic technique for coherent anti-Stokes Raman spectroscopy). We propose and analyse ways in which FAST CARS can be used to identify preselected molecules, e.g. aflatoxin, rapidly and economically.

  2. Adaptive antennas

    NASA Astrophysics Data System (ADS)

    Barton, P.

    1987-04-01

    The basic principles of adaptive antennas are outlined in terms of the Wiener-Hopf expression for maximizing signal to noise ratio in an arbitrary noise environment; the analogy with generalized matched filter theory provides a useful aid to understanding. For many applications, there is insufficient information to achieve the above solution and thus non-optimum constrained null steering algorithms are also described, together with a summary of methods for preventing wanted signals being nulled by the adaptive system. The three generic approaches to adaptive weight control are discussed; correlation steepest descent, weight perturbation and direct solutions based on sample matrix conversion. The tradeoffs between hardware complexity and performance in terms of null depth and convergence rate are outlined. The sidelobe cancellor technique is described. Performance variation with jammer power and angular distribution is summarized and the key performance limitations identified. The configuration and performance characteristics of both multiple beam and phase scan array antennas are covered, with a brief discussion of performance factors.

  3. Molecules on ice

    SciTech Connect

    Clary, D.C.

    1996-03-15

    The ozone hole that forms in the spring months over the Antarctic is thought to be produced through a network of chemical reactions catalyzed by the surfaces of ice crystals in polar stratospheric clouds (PSCs). A reaction between chlorine reservoir molecules, such as HCl + ClONO{sub 2} > HNO{sub 3} + Cl{sub 2}, is kinetically forbidden in the gas phase but proceeds quickly on the surface of ice and produces Cl{sub 2} molecules that are photodissociated by sunlight to yield the Cl atoms that destroy ozone. This destructive chain of events begins when HCl molecules stick to the ice crystals, and the mechanism for this crucial sticking process has been the subject of much debate. Recent work describes a mechanism that explains how HCl sticks to ice. This article goes on to detail research focusing surface reactions in stratospheric chemistry. 9 refs., 1 fig.

  4. Positronium ions and molecules

    NASA Technical Reports Server (NTRS)

    Ho, Y. K.

    1990-01-01

    Recent theoretical studies on positronium ions and molecules are discussed. A positronium ion is a three particle system consisting of two electrons in singlet spin state, and a positron. Recent studies include calculations of its binding energy, positron annihilation rate, and investigations of its doubly excited resonant states. A positronium molecule is a four body system consisting of two positrons and two electrons in an overall singlet spin state. The recent calculations of its binding energy against the dissociation into two positronium atoms, and studies of auto-detaching states in positronium molecules are discussed. These auto-dissociating states, which are believed to be part of the Rydberg series as a result of a positron attaching to a negatively charged positronium ion, Ps-, would appear as resonances in Ps-Ps scattering.

  5. Atomic branching in molecules

    NASA Astrophysics Data System (ADS)

    Estrada, Ernesto; Rodríguez-Velázquez, Juan A.; Randić, Milan

    A graph theoretic measure of extended atomic branching is defined that accounts for the effects of all atoms in the molecule, giving higher weight to the nearest neighbors. It is based on the counting of all substructures in which an atom takes part in a molecule. We prove a theorem that permits the exact calculation of this measure based on the eigenvalues and eigenvectors of the adjacency matrix of the graph representing a molecule. The definition of this measure within the context of the Hückel molecular orbital (HMO) and its calculation for benzenoid hydrocarbons are also studied. We show that the extended atomic branching can be defined using any real symmetric matrix, as well as any Hermitian (self-adjoint) matrix, which permits its calculation in topological, geometrical, and quantum chemical contexts.

  6. Single-Molecule Bioelectronics

    PubMed Central

    Rosenstein, Jacob K.; Lemay, Serge G.; Shepard, Kenneth L.

    2014-01-01

    Experimental techniques which interface single biomolecules directly with microelectronic systems are increasingly being used in a wide range of powerful applications, from fundamental studies of biomolecules to ultra-sensitive assays. Here we review several technologies which can perform electronic measurements of single molecules in solution: ion channels, nanopore sensors, carbon nanotube field-effect transistors, electron tunneling gaps, and redox cycling. We discuss the shared features among these techniques that enable them to resolve individual molecules, and discuss their limitations. Recordings from each of these methods all rely on similar electronic instrumentation, and we discuss the relevant circuit implementations and potential for scaling these single-molecule bioelectronic interfaces to high-throughput arrayed sensing platforms. PMID:25529538

  7. Single-molecule bioelectronics.

    PubMed

    Rosenstein, Jacob K; Lemay, Serge G; Shepard, Kenneth L

    2015-01-01

    Experimental techniques that interface single biomolecules directly with microelectronic systems are increasingly being used in a wide range of powerful applications, from fundamental studies of biomolecules to ultra-sensitive assays. In this study, we review several technologies that can perform electronic measurements of single molecules in solution: ion channels, nanopore sensors, carbon nanotube field-effect transistors, electron tunneling gaps, and redox cycling. We discuss the shared features among these techniques that enable them to resolve individual molecules, and discuss their limitations. Recordings from each of these methods all rely on similar electronic instrumentation, and we discuss the relevant circuit implementations and potential for scaling these single-molecule bioelectronic interfaces to high-throughput arrayed sensing platforms. PMID:25529538

  8. Photochemistry of interstellar molecules

    NASA Technical Reports Server (NTRS)

    Stief, L. J.

    1971-01-01

    The photochemistry of two diatomic and eight polyatomic molecules is discussed quantitatively. For an interstellar molecule, the lifetime against photodecomposition depends upon the absorption cross section, the quantum yield or probability of dissociation following photon absorption, and the interstellar radiation field. The constant energy density of Habing is used for the unobserved regions of interstellar radiation field, and the field in obscuring clouds is estimated by combining the constant flux with the observed interstellar extinction curve covering the visible and ultraviolet regions. Lifetimes against photodecomposition in the unobscured regions and as a function of increasing optical thickness in obscuring clouds are calculated for the ten species. The results show that, except for CO, all the molecules have comparable lifetimes of less than one hundred years. Thus they can exist only in dense clouds and can never have been exposed to the unobscured radiation. The calculations further show that the lifetimes in clouds of moderate opacity are of the order of one million years.

  9. Molecules in η Carinae

    NASA Astrophysics Data System (ADS)

    Loinard, Laurent; Menten, Karl M.; Güsten, Rolf; Zapata, Luis A.; Rodríguez, Luis F.

    2012-04-01

    We report the detection toward η Carinae of six new molecules, CO, CN, HCO+, HCN, HNC, and N2H+, and of two of their less abundant isotopic counterparts, 13CO and H13CN. The line profiles are moderately broad (~100 km s-1), indicating that the emission originates in the dense, possibly clumpy, central arcsecond of the Homunculus Nebula. Contrary to previous claims, CO and HCO+ do not appear to be underabundant in η Carinae. On the other hand, molecules containing nitrogen or the 13C isotope of carbon are overabundant by about one order of magnitude. This demonstrates that, together with the dust responsible for the dimming of η Carinae following the Great Eruption, the molecules detected here must have formed in situ out of CNO-processed stellar material.

  10. Poisson's Spot with Molecules

    NASA Astrophysics Data System (ADS)

    Reisinger, Thomas; Patel, Amil; Reingruber, Herbert; Fladischer, Katrin; Ernst, Wolfgang E.; Bracco, Gianangelo; Smith, Henry I.; Holst, Bodil

    2009-03-01

    In the Poisson-Spot experiment, waves emanating from a source are blocked by a circular obstacle. Due to their positive on-axis interference an image of the source (the Poisson spot) is observed within the geometrical shadow of the obstacle. The Poisson spot is the last of the classical optics experiments to be realized with neutral matter waves. In this paper we report the observation of Poisson's Spot using a beam of neutral deuterium molecules. The wavelength-independence and the weak constraints on angular alignment and position of the circular obstacle make Poisson's spot a promising candidate for applications ranging from the study of large-molecule diffraction and coherence in atom-lasers to patterning with large molecules.

  11. MOLECULES IN {eta} CARINAE

    SciTech Connect

    Loinard, Laurent; Menten, Karl M.; Guesten, Rolf; Zapata, Luis A.; Rodriguez, Luis F.

    2012-04-10

    We report the detection toward {eta} Carinae of six new molecules, CO, CN, HCO{sup +}, HCN, HNC, and N{sub 2}H{sup +}, and of two of their less abundant isotopic counterparts, {sup 13}CO and H{sup 13}CN. The line profiles are moderately broad ({approx}100 km s{sup -1}), indicating that the emission originates in the dense, possibly clumpy, central arcsecond of the Homunculus Nebula. Contrary to previous claims, CO and HCO{sup +} do not appear to be underabundant in {eta} Carinae. On the other hand, molecules containing nitrogen or the {sup 13}C isotope of carbon are overabundant by about one order of magnitude. This demonstrates that, together with the dust responsible for the dimming of {eta} Carinae following the Great Eruption, the molecules detected here must have formed in situ out of CNO-processed stellar material.

  12. Towards single molecule switches.

    PubMed

    Zhang, Jia Lin; Zhong, Jian Qiang; Lin, Jia Dan; Hu, Wen Ping; Wu, Kai; Xu, Guo Qin; Wee, Andrew T S; Chen, Wei

    2015-05-21

    The concept of using single molecules as key building blocks for logic gates, diodes and transistors to perform basic functions of digital electronic devices at the molecular scale has been explored over the past decades. However, in addition to mimicking the basic functions of current silicon devices, molecules often possess unique properties that have no parallel in conventional materials and promise new hybrid devices with novel functions that cannot be achieved with equivalent solid-state devices. The most appealing example is the molecular switch. Over the past decade, molecular switches on surfaces have been intensely investigated. A variety of external stimuli such as light, electric field, temperature, tunneling electrons and even chemical stimulus have been used to activate these molecular switches between bistable or even multiple states by manipulating molecular conformations, dipole orientations, spin states, charge states and even chemical bond formation. The switching event can occur either on surfaces or in break junctions. The aim of this review is to highlight recent advances in molecular switches triggered by various external stimuli, as investigated by low-temperature scanning tunneling microscopy (LT-STM) and the break junction technique. We begin by presenting the molecular switches triggered by various external stimuli that do not provide single molecule selectivity, referred to as non-selective switching. Special focus is then given to selective single molecule switching realized using the LT-STM tip on surfaces. Single molecule switches operated by different mechanisms are reviewed and discussed. Finally, molecular switches embedded in self-assembled monolayers (SAMs) and single molecule junctions are addressed. PMID:25757483

  13. Toll-like receptor 2 (TLR2) mediates intracellular signalling in human keratinocytes in response to Malassezia furfur.

    PubMed

    Baroni, Adone; Orlando, Manuela; Donnarumma, Giovanna; Farro, Pietro; Iovene, Maria Rosaria; Tufano, Maria Antonietta; Buommino, Elisabetta

    2006-01-01

    Toll-like receptors (TLRs) are crucial players in the innate immune response to microbial invaders. The lipophilic yeast Malassezia furfur has been implicated in the triggering of scalp lesions in psoriasis. The aim of the present study was to assess the role of TLRs in the defence against M. furfur infection. The expression of the myeloid differentiation factor 88 (MyD88) gene, which is involved in the signalling pathway of many TLRs, was also analysed. In addition, a possible correlation of antimicrobial peptides of the beta-defensin family to TLRs was tested. Human keratinocytes infected with M. furfur and a variety of M. furfur-positive psoriatic skin biopsies were analysed by RT-PCR, for TLRs, MyD88, human beta-defensin 2 (HBD-2), HBD-3 and interleukin-8 (IL-8) mRNA expression. When keratinocytes were infected with M. furfur, an up-regulation for TLR2, MyD88, HBD-2, HBD-3 and IL-8 mRNA was demonstrated, compared to the untreated cells. The same results were obtained when psoriatic skin biopsies were analysed. The M. furfur-induced increase in HBD-2 and IL-8 gene expression is inhibited by anti-TLR2 neutralising antibodies, suggesting that TLR2 is involved in the M. furfur-induced expression of these molecules. These findings suggest the importance of TLRs in skin protection against fungi and the importance of keratinocytes as a component of innate immunity. PMID:16283346

  14. Plasmonic nanostructures: artificial molecules.

    PubMed

    Wang, Hui; Brandl, Daniel W; Nordlander, Peter; Halas, Naomi J

    2007-01-01

    This Account describes a new paradigm for the relationship between the geometry of metallic nanostructures and their optical properties. While the interaction of light with metallic nanoparticles is determined by their collective electronic or plasmon response, a compelling analogy exists between plasmon resonances of metallic nanoparticles and wave functions of simple atoms and molecules. Based on this insight, an entire family of plasmonic nanostructures, artificial molecules, has been developed whose optical properties can be understood within this picture: nanoparticles (nanoshells, nanoeggs, nanomatryushkas, nanorice), multi-nanoparticle assemblies (dimers, trimers, quadrumers), and a nanoparticle-over-metallic film, an electromagnetic analog of the spinless Anderson model. PMID:17226945

  15. Genomic characterization of primary central nervous system lymphoma.

    PubMed

    Fukumura, Kazutaka; Kawazu, Masahito; Kojima, Shinya; Ueno, Toshihide; Sai, Eirin; Soda, Manabu; Ueda, Hiroki; Yasuda, Takahiko; Yamaguchi, Hiroyuki; Lee, Jeunghun; Shishido-Hara, Yukiko; Sasaki, Atsushi; Shirahata, Mitsuaki; Mishima, Kazuhiko; Ichimura, Koichi; Mukasa, Akitake; Narita, Yoshitaka; Saito, Nobuhito; Aburatani, Hiroyuki; Nishikawa, Ryo; Nagane, Motoo; Mano, Hiroyuki

    2016-06-01

    Primary central nervous system lymphoma (PCNSL) is a rare malignancy confined to the central nervous system (CNS), and majority of PCNSL is pathologically classified as diffuse large B-cell lymphoma (DLBCL). We have now performed whole-exome sequencing for 41 tumor tissues of DLBCL-type PCNSL and paired normal specimens and also RNA-sequencing for 30 tumors, revealing a very high frequency of nonsynonymous somatic mutations in PIM1 (100 %), BTG2 (92.7 %), and MYD88 (85.4 %). Many genes in the NF-κB pathway are concurrently mutated within the same tumors. Further, focal deletion or somatic mutations in the HLA genes are associated with poor prognosis. Copy number amplification and overexpression of genes at chromosome 7q35 were both found to predict short progression-free survival as well. Oncogenic mutations in GRB2 were also detected, the effects of which in cultured cells were attenuated by inhibitors of the downstream kinases MAP2K1 and MAP2K2. Individuals with tumors positive for MYD88 mutations also harbored the same mutations at a low frequency in peripheral blood mononuclear cells, suggesting that MYD88 mutation-positive precancerous cells originate outside of the CNS and develop into lymphoma after additional genetic hits that confer adaptation to the CNS environment. PMID:26757737

  16. Suppression of TLRs signaling pathways by 1-[5-methoxy-2-(2-nitrovinyl)phenyl]pyrrolidine.

    PubMed

    Ahn, Sang-Il; Kim, Ji-Soo; Shin, Hyeon-Myeong; Kim, Ah-Yeon; Gu, Gyo-Jeong; Shim, Hyun-Jin; Kim, Yeon Joo; Koh, Kwang Oh; Mang, Joo Yang; Kim, Dae Young; Youn, Hyung-Sun

    2016-06-01

    Toll-like receptors (TLRs) play significant roles in recognizing the pathogen-associated molecular patterns that induce innate immunity, and subsequently, acquired immunity. In general, TLRs have two downstream signaling pathways, the myeloid differential factor 88 (MyD88)-dependent and toll-interleukin-1 receptor domain-containing adapter-inducing interferon-β (TRIF)-dependent pathways, which lead to the activation of nuclear factor-kappa B (NF-κB) and interferon regulatory factor 3 (IRF3). 1-[5-methoxy-2-(2-nitrovinyl)phenyl]pyrrolidine (MNP) has been previously synthesized in our laboratory. To evaluate the therapeutic potential of MNP, its effect on signal transduction via the TLR signaling pathways was examined. MNP was shown to inhibit the activation of NF-κB and IRF3 induced by TLR agonists, as well as to inhibit the expression of cyclooxygenase-2, inducible nitric oxide synthase, and interferon inducible protein-10. MNP also inhibited the activation of NF-κB and IRF3 induced by the overexpression of downstream signaling components of the MyD88- or TRIF-dependent signaling pathways. These results suggest that MNP can modulate MyD88- and TRIF-dependent signaling pathways of TLRs, leading to decreased inflammatory gene expression. PMID:27064546

  17. T cell responses are elicited against Respiratory Syncytial Virus in the absence of signalling through TLRs, RLRs and IL-1R/IL-18R

    PubMed Central

    Goritzka, Michelle; Pereira, Catherine; Makris, Spyridon; Durant, Lydia R.; Johansson, Cecilia

    2015-01-01

    Pattern recognition receptors (PRRs) and cytokine receptors are key players in the initiation of immune responses to infection. PRRs detecting viral RNA, such as toll like receptor (TLR)-3, -7/8, and RIG-I like receptors (RLRs; RIG-I and MDA-5), as well as cytokine receptors such as interleukin 1 receptor (IL-1R), have been implicated in responses to RNA viruses that infect the airways. The latter includes respiratory syncytial virus (RSV), a human pathogen that can cause severe lower respiratory tract infections, especially in infants. To evaluate the collective contribution of PRRs and IL-1R signalling to RSV immunity, we generated Myd88/Trif/Mavs−/− mice that are deficient in signalling by all TLRs, RLRs and IL-1R, as well as other cytokine receptors such as IL-18 receptor. Early production of pro-inflammatory mediators and lung infiltration by immune cells were completely abrogated in infected Myd88/Trif/Mavs−/− mice. However, RSV-specific CD8+ T cells were elicited and recruited into the lungs and airways. Consistent with these findings, Myd88/Trif/Mavs−/− mice survived RSV infection but displayed higher viral load and weight loss. These data highlight an unappreciated level of redundancy in pathways that couple innate virus sensing to adaptive immunity, providing the host with remarkable resilience to infection. PMID:26688048

  18. [Cell-free DNA fragments increase transcription in human mesenchymal stem cells, activate TLR-dependent signal pathway and supress apoptosis].

    PubMed

    Kostiuk, S V; Malinovskaia, E M; Ermakov, A V; Smirnova, T D; Kameneva, L V; Chvartatskaia, O V; Loseva, P A; Ershova, E S; Liubchenko, L N; Veĭko, N N

    2012-01-01

    Human mesenchymal stem cells (MSCs) are now widely adopted in regenerative medicine. However, many questions on the role of different signaling pathways in the regulation of stem cell (SC) functional activity within the organism remain unaswered. In damaged regions the level of cell death increases and DNA fragments from dead cells (cell-free DNA, cfDNA) are accumulated in blood. We showed that in adipose-derived MSCs exposed in vitro to cfDNA fragments the transcription level increased (the total amount of cellular RNA and the rRNA amount rose). GC-rich CfDNA fragments (GC-DNA) activated the TLR9-dependent signal pathway: the expression of TLR9 and of TLR9-signaling pathway adapter--MyD88--was up-regulated. AT-rich DNA fragments did not increase the TLR9 expression, though, the MyD88 expression level rose. So we suggest that AT-DNA acts via some other receptors that nevertheless activate MyD88-dependent signalling in MSCs. We also showed that cfDNA fragments decreased the activity of caspase, an apoptotic enzyme. So, ctDNA can significantly influence the functional activity ofMSC by activating TLR9- and MyD88-dependent signal pathways and lowering the apoptosis level. PMID:23350199

  19. Prebiologically Important Interstellar Molecules

    NASA Astrophysics Data System (ADS)

    Kuan, Y.-J.; Huang, H.-C.; Charnley, S. B.; Tseng, W.-L.; Snyder, L. E.; Ehrenfreund, P.; Kisiel, Z.; Thorwirth, S.; Bohn, R. K.; Wilson, T. L.

    2004-06-01

    Understanding the organic chemistry of molecular clouds, particularly the formation of biologically important molecules, is fundamental to the study of the processes which lead to the origin, evolution and distribution of life in the Galaxy. Determining the level of molecular complexity attainable in the clouds, and the nature of the complex organic material available to protostellar disks and the planetary systems that form from them, requires an understanding of the possible chemical pathways and is therefore a central question in astrochemistry. We have thus searched for prebiologically important molecules in the hot molecular cloud cores: Sgr B2(N-LMH), W51 e1/e2 and Orion-KL. Among the molecules searched: Pyrimidine is the unsubstituted ring analogue for three of the DNA and RNA bases. 2H-Azirine and Aziridine are azaheterocyclic compounds. And Glycine is the simplest amino acid. Detections of these interstellar organic molecular species will thus have important implications for Astrobiology. Our preliminary results indicate a tentative detection of interstellar glycine. If confirmed, this will be the first detection of an amino acid in interstellar space and will greatly strengthen the thesis that interstellar organic molecules could have played a pivotal role in the prebiotic chemistry of the early Earth.

  20. Algebraic theory of molecules

    NASA Technical Reports Server (NTRS)

    Iachello, Franco

    1995-01-01

    An algebraic formulation of quantum mechanics is presented. In this formulation, operators of interest are expanded onto elements of an algebra, G. For bound state problems in nu dimensions the algebra G is taken to be U(nu + 1). Applications to the structure of molecules are presented.

  1. Mighty Molecule Models

    ERIC Educational Resources Information Center

    Brown, Tom; Rushton, Greg; Bencomo, Marie

    2008-01-01

    As part of the SMATHematics Project: The Wonder of Science, The Power of Mathematics--a collaborative partnership between Kennesaw State University and two local school districts, fifth graders had the opportunity to puzzle out chemical formulas of propane, methanol, and other important molecules. In addition, they explored properties that…

  2. Diversity in Biological Molecules

    ERIC Educational Resources Information Center

    Newbury, H. John

    2010-01-01

    One of the striking characteristics of fundamental biological processes, such as genetic inheritance, development and primary metabolism, is the limited amount of variation in the molecules involved. Natural selective pressures act strongly on these core processes and individuals carrying mutations and producing slightly sub-optimal versions of…

  3. The Science of Molecules

    ERIC Educational Resources Information Center

    Flory, Paul J.

    1974-01-01

    The author maintains that chemistry has a key role as the science of molecules and rejects the concept of chemistry as a branch of physics. The scope of chemistry, the philosophies underlying its practice, and the teaching of the subject also are discussed. (DT)

  4. OMG: Open Molecule Generator

    PubMed Central

    2012-01-01

    Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG), which for a given elemental composition produces all non-isomorphic chemical structures that match that elemental composition. Furthermore, this structure generator can accept as additional input one or multiple non-overlapping prescribed substructures to drastically reduce the number of possible chemical structures. Being open source allows for customization and future extension of its functionality. OMG relies on a modified version of the Canonical Augmentation Path, which grows intermediate chemical structures by adding bonds and checks that at each step only unique molecules are produced. In order to benchmark the tool, we generated chemical structures for the elemental formulas and substructures of different metabolites and compared the results with a commercially available structure generator. The results obtained, i.e. the number of molecules generated, were identical for elemental compositions having only C, O and H. For elemental compositions containing C, O, H, N, P and S, OMG produces all the chemically valid molecules while the other generator produces more, yet chemically impossible, molecules. The chemical completeness of the OMG results comes at the expense of being slower than the commercial generator. In addition to being open source, OMG clearly showed the added value of constraining the solution space by using multiple prescribed substructures as input. We expect this structure generator to be useful in many fields, but to be especially of great importance for metabolomics, where identifying unknown metabolites is still a major bottleneck. PMID:22985496

  5. OMG: Open Molecule Generator.

    PubMed

    Peironcely, Julio E; Rojas-Chertó, Miguel; Fichera, Davide; Reijmers, Theo; Coulier, Leon; Faulon, Jean-Loup; Hankemeier, Thomas

    2012-01-01

    Computer Assisted Structure Elucidation has been used for decades to discover the chemical structure of unknown compounds. In this work we introduce the first open source structure generator, Open Molecule Generator (OMG), which for a given elemental composition produces all non-isomorphic chemical structures that match that elemental composition. Furthermore, this structure generator can accept as additional input one or multiple non-overlapping prescribed substructures to drastically reduce the number of possible chemical structures. Being open source allows for customization and future extension of its functionality. OMG relies on a modified version of the Canonical Augmentation Path, which grows intermediate chemical structures by adding bonds and checks that at each step only unique molecules are produced. In order to benchmark the tool, we generated chemical structures for the elemental formulas and substructures of different metabolites and compared the results with a commercially available structure generator. The results obtained, i.e. the number of molecules generated, were identical for elemental compositions having only C, O and H. For elemental compositions containing C, O, H, N, P and S, OMG produces all the chemically valid molecules while the other generator produces more, yet chemically impossible, molecules. The chemical completeness of the OMG results comes at the expense of being slower than the commercial generator. In addition to being open source, OMG clearly showed the added value of constraining the solution space by using multiple prescribed substructures as input. We expect this structure generator to be useful in many fields, but to be especially of great importance for metabolomics, where identifying unknown metabolites is still a major bottleneck. PMID:22985496

  6. Bacterial invasion reconstructed molecule by molecule

    SciTech Connect

    Werner, James H

    2009-01-01

    We propose to visualize the initial stages of bacterial infection of a human host cell with unmatched spatial and temporal resolution. This work will develop a new capability for the laboratory (super-resolution optical imaging), will test unresolved scientific hypotheses regarding host-pathogen interaction dynamics, and leverages state of the art 3D molecular tracking instrumentation developed recently by our group. There is much to be gained by applying new single molecule tools to the important and familiar problem of pathogen entry into a host cell. For example, conventional fluorescence microscopy has identified key host receptors, such as CD44 and {alpha}5{beta}1 integrin, that aggregate near the site of Salmonella typhimurium infection of human cells. However, due to the small size of the bacteria ({approx} 2 {micro}m) and the diffraction of the emitted light, one just sees a fluorescent 'blob' of host receptors that aggregate at the site of attachment, making it difficult to determine the exact number of receptors present or whether there is any particular spatial arrangement of the receptors that facilitates bacterial adhesion/entry. Using newly developed single molecule based super-resolution imaging methods, we will visualize how host receptors are directed to the site of pathogen adhesion and whether host receptors adopt a specific spatial arrangement for successful infection. Furthermore, we will employ our 3D molecular tracking methods to follow the injection of virulence proteins, or effectors, into the host cell by the pathogen Type III secretion system (TTSS). We expect these studies to provide mechanistic insights into the early events of pathogen infection that have here-to-fore been technically beyond our reach. Our Research Goals are: Goal 1--Construct a super-resolution fluorescence microscope and use this new capability to image the spatial distribution of different host receptors (e.g. CD44, as {alpha}5{beta}1 integrin) at the point of

  7. Single-molecule electrophoresis

    SciTech Connect

    Castro, A.; Shera, E.B.

    1995-09-15

    A novel method for the detection and identification of single molecules in solution has been devised, computer simulated, and experimentally achieved. The technique involves the determination of electrophoretic velocities by measuring the time required for individual molecules to travel a fixed distance between two laser beams. Computer simulations of the process were performed before-hand in order to estimate the experimental feasibility of the method and to determine the optimum values for the various experimental parameters. Examples of the use of the technique for the ultrasensitive detection and identification of rhodamine-6G, a mixture of DNA restriction fragments, and a mixture of proteins in aqueous solution are presented. 20 refs., 8 figs.

  8. Strange skyrmion molecules

    NASA Astrophysics Data System (ADS)

    Kopeliovich, Vladimir B.; Stern, Boris E.

    1997-05-01

    Composed skyrmions with B=2, strangeness content close to 0.5 and the binding energy of several tens of Mev are described. These skyrmions are obtained starting from the system of two B=1 hedgehogs located in different SU(2) subgroups of SU(3) and have the mass and baryon number distribution of molecular (dipole) type. The quantization of zero modes of skyrmion molecules and physics consequences of their existence are discussed.

  9. Strange skyrmion molecules

    SciTech Connect

    Kopeliovich, Vladimir B.; Stern, Boris E.

    1997-05-20

    Composed skyrmions with B=2, strangeness content close to 0.5 and the binding energy of several tens of Mev are described. These skyrmions are obtained starting from the system of two B=1 hedgehogs located in different SU(2) subgroups of SU(3) and have the mass and baryon number distribution of molecular (dipole) type. The quantization of zero modes of skyrmion molecules and physics consequences of their existence are discussed.

  10. Adaptive DNA Computing Algorithm by Using PCR and Restriction Enzyme

    NASA Astrophysics Data System (ADS)

    Kon, Yuji; Yabe, Kaoru; Rajaee, Nordiana; Ono, Osamu

    In this paper, we introduce an adaptive DNA computing algorithm by using polymerase chain reaction (PCR) and restriction enzyme. The adaptive algorithm is designed based on Adleman-Lipton paradigm[3] of DNA computing. In this work, however, unlike the Adleman- Lipton architecture a cutting operation has been introduced to the algorithm and the mechanism in which the molecules used by computation were feedback to the next cycle devised. Moreover, the amplification by PCR is performed in the molecule used by feedback and the difference concentration arisen in the base sequence can be used again. By this operation the molecules which serve as a solution candidate can be reduced down and the optimal solution is carried out in the shortest path problem. The validity of the proposed adaptive algorithm is considered with the logical simulation and finally we go on to propose applying adaptive algorithm to the chemical experiment which used the actual DNA molecules for solving an optimal network problem.

  11. Single Molecule Mechanochemistry

    NASA Astrophysics Data System (ADS)

    Li, Shaowei; Zhang, Yanxing; Ho, Wilson; Wu, Ruqian; Ruqian Wu, Yanxing Zhang Team; Wilson Ho, Shaowei Li Team

    Mechanical forces can be used to trigger chemical reactions through bending and stretching of chemical bonds. Using the reciprocating movement of the tip of a scanning tunneling microscope (STM), mechanical energy can be provided to a single molecule sandwiched between the tip and substrate. When the mechanical pulse center was moved to the outer ring feature of a CO molecule, the reaction rate was significantly increased compared with bare Cu surface and over Au atoms. First, DFT calculations show that the presence of CO makes the Cu cavity more attractive toward H2 Second, H2 prefers the horizontal adsorption geometry in the Cu-Cu and Au-Cu cavities and no hybridization occurs between the antibonding states of H2 and states of Cu atoms. While H2 loses electrons from its bonding state in all three cavities, the filling of its anti-bonding state only occurs in the CO-Cu cavity. Both make the CO-Cu cavity much more effectively to chop the H2 molecule. Work was supported by the National Science Foundation Center for Chemical Innovation on Chemistry at the Space-Time Limit (CaSTL) under Grant No. CHE-1414466.

  12. Model molecules mimicking asphaltenes.

    PubMed

    Sjöblom, Johan; Simon, Sébastien; Xu, Zhenghe

    2015-04-01

    Asphalthenes are typically defined as the fraction of petroleum insoluble in n-alkanes (typically heptane, but also hexane or pentane) but soluble in toluene. This fraction causes problems of emulsion formation and deposition/precipitation during crude oil production, processing and transport. From the definition it follows that asphaltenes are not a homogeneous fraction but is composed of molecules polydisperse in molecular weight, structure and functionalities. Their complexity makes the understanding of their properties difficult. Proper model molecules with well-defined structures which can resemble the properties of real asphaltenes can help to improve this understanding. Over the last ten years different research groups have proposed different asphaltene model molecules and studied them to determine how well they can mimic the properties of asphaltenes and determine the mechanisms behind the properties of asphaltenes. This article reviews the properties of the different classes of model compounds proposed and present their properties by comparison with fractionated asphaltenes. After presenting the interest of developing model asphaltenes, the composition and properties of asphaltenes are presented, followed by the presentation of approaches and accomplishments of different schools working on asphaltene model compounds. The presentation of bulk and interfacial properties of perylene-based model asphaltene compounds developed by Sjöblom et al. is the subject of the next part. Finally the emulsion-stabilization properties of fractionated asphaltenes and model asphaltene compounds is presented and discussed. PMID:25638443

  13. Photonic Molecule Lasers Revisited

    NASA Astrophysics Data System (ADS)

    Gagnon, Denis; Dumont, Joey; Déziel, Jean-Luc; Dubé, Louis J.

    2014-05-01

    Photonic molecules (PMs) formed by coupling two or more optical resonators are ideal candidates for the fabrication of integrated microlasers, photonic molecule lasers. Whereas most calculations on PM lasers have been based on cold-cavity (passive) modes, i.e. quasi-bound states, a recently formulated steady-state ab initio laser theory (SALT) offers the possibility to take into account the spectral properties of the underlying gain transition, its position and linewidth, as well as incorporating an arbitrary pump profile. We will combine two theoretical approaches to characterize the lasing properties of PM lasers: for two-dimensional systems, the generalized Lorenz-Mie theory will obtain the resonant modes of the coupled molecules in an active medium described by SALT. Not only is then the theoretical description more complete, the use of an active medium provides additional parameters to control, engineer and harness the lasing properties of PM lasers for ultra-low threshold and directional single-mode emission. We will extend our recent study and present new results for a number of promising geometries. The authors acknowledge financial support from NSERC (Canada) and the CERC in Photonic Innovations of Y. Messaddeq.

  14. Molecules in interstellar clouds

    NASA Astrophysics Data System (ADS)

    Irvine, W. M.; Hjalmarson, A.; Rydbeck, O. E. H.

    The physical conditions and chemical compositions of the gas in interstellar clouds are reviewed in light of the importance of interstellar clouds for star formation and the origin of life. The Orion A region is discussed as an example of a giant molecular cloud where massive stars are being formed, and it is pointed out that conditions in the core of the cloud, with a kinetic temperature of about 75 K and a density of 100,000-1,000,000 molecules/cu cm, may support gas phase ion-molecule chemistry. The Taurus Molecular Clouds are then considered as examples of cold, dark, relatively dense interstellar clouds which may be the birthplaces of solar-type stars and which have been found to contain the heaviest interstellar molecules yet discovered. The molecular species identified in each of these regions are tabulated, including such building blocks of biological monomers as H2O, NH3, H2CO, CO, H2S, CH3CN and H2, and more complex species such as HCOOCH3 and CH3CH2CN.

  15. Epithelial Cell Adhesion Molecule

    PubMed Central

    Trzpis, Monika; McLaughlin, Pamela M.J.; de Leij, Lou M.F.H.; Harmsen, Martin C.

    2007-01-01

    The epithelial cell adhesion molecule (EpCAM, CD326) is a glycoprotein of ∼40 kd that was originally identified as a marker for carcinoma, attributable to its high expression on rapidly proliferating tumors of epithelial origin. Normal epithelia express EpCAM at a variable but generally lower level than carcinoma cells. In early studies, EpCAM was proposed to be a cell-cell adhesion molecule. However, recent insights revealed a more versatile role for EpCAM that is not limited only to cell adhesion but includes diverse processes such as signaling, cell migration, proliferation, and differentiation. Cell surface expression of EpCAM may actually prevent cell-cell adhesion. Here, we provide a comprehensive review of the current knowledge on EpCAM biology in relation to other cell adhesion molecules. We discuss the implications of the newly identified functions of EpCAM in view of its prognostic relevance in carcinoma, inflammatory pathophysiology, and tissue development and regeneration as well as its role in normal epithelial homeostasis. PMID:17600130

  16. Finding small molecules for the 'next Ebola'.

    PubMed

    Ekins, Sean; Southan, Christopher; Coffee, Megan

    2015-01-01

    The current Ebola virus epidemic may provide some suggestions of how we can better prepare for the next pathogen outbreak. We propose several cost effective steps that could be taken that would impact the discovery and use of small molecule therapeutics including: 1. text mine the literature, 2. patent assignees and/or inventors should openly declare their relevant filings, 3. reagents and assays could be commoditized, 4. using manual curation to enhance database links, 5. engage database and curation teams, 6. consider open science approaches, 7. adapt the "box" model for shareable reference compounds, and 8. involve the physician's perspective. PMID:25949804

  17. Toll-Like Receptor 9 Signaling in Dendritic Cells Regulates Neutrophil Recruitment to Inflammatory Foci following Leishmania infantum Infection

    PubMed Central

    Sacramento, Laís; Trevelin, Silvia C.; Nascimento, Manuela S.; Lima-Jùnior, Djalma S.; Costa, Diego L.; Almeida, Roque P.; Cunha, Fernando Q.

    2015-01-01

    Leishmania infantum is a protozoan parasite that causes visceral leishmaniasis (VL). This infection triggers dendritic cell (DC) activation through the recognition of microbial products by Toll-like receptors (TLRs). Among the TLRs, TLR9 is required for DC activation by different Leishmania species. We demonstrated that TLR9 is upregulated in vitro and in vivo during infection. We show that C57BL/6 mice deficient in TLR9 expression (TLR9−/− mice) are more susceptible to infection and display higher parasite numbers in the spleen and liver. The increased susceptibility of TLR9−/− mice was due to the impaired recruitment of neutrophils to the infection foci associated with reduced levels of neutrophil chemoattractants released by DCs in the target organs. Moreover, both Th1 and Th17 cells were also committed in TLR9−/− mice. TLR9-dependent neutrophil recruitment is mediated via the MyD88 signaling pathway but is TIR domain-containing adapter-inducing interferon beta (TRIF) independent. Furthermore, L. infantum failed to activate both plasmacytoid and myeloid DCs from TLR9−/− mice, which presented reduced surface costimulatory molecule expression and chemokine release. Interestingly, neutrophil chemotaxis was affected both in vitro and in vivo when DCs were derived from TLR9−/− mice. Our results suggest that TLR9 plays a critical role in neutrophil recruitment during the protective response against L. infantum infection that could be associated with DC activation. PMID:26371124

  18. TLR-signaling Networks

    PubMed Central

    Brown, J.; Wang, H.; Hajishengallis, G.N.; Martin, M.

    2011-01-01

    Toll-like receptors play a critical role in innate immunity by detecting invading pathogens. The ability of TLRs to engage different intracellular signaling molecules and cross-talk with other regulatory pathways is an important factor in shaping the type, magnitude, and duration of the inflammatory response. The present review will cover the fundamental signaling pathways utilized by TLRs and how these pathways regulate the innate immune response to pathogens. Abbreviations: TLR, Toll-like receptor; PRR, pattern recognition receptor; PAMP, pathogen-associated molecular pattern; LPS, lipopolysaccharide; APC, antigen-presenting cell; IL, interleukin; TIR, Toll/IL-1R homology; MyD88, myeloid differentiation factor 88; IFN, interferon; TRIF, TIR-domain-containing adapter-inducing interferon-β; IRAK, IL-1R-associated kinase; TAK1, TGF-β-activated kinase; TAB1, TAK1-binding protein; NF-κB, nuclear factor kappa-light-chain-enhancer of activated B-cells; MAPK, mitogen-activated protein kinase; NLR, NOD-like receptors; LRR, leucine-rich repeats; DC, dendritic cell; PI3K, phosphoinositide 3-kinases; GSK3, glycogen synthase kinase-3; mTOR, mammalian target of rapamycin; DAF, decay-accelerating factor; IKK, IκB kinase; IRF, interferon regulatory factors; TBK1, TANK-binding kinase 1; CARD, caspase activation and recruitment domain; PYD, pyrin N-terminal homology domain; ATF, activating transcription factor; and PTEN, phosphatase and tensin homolog. PMID:20940366

  19. Negative ions of polyatomic molecules.

    PubMed Central

    Christophorou, L G

    1980-01-01

    In this paper general concepts relating to, and recent advances in, the study of negative ions of polyatomic molecules area discussed with emphasis on halocarbons. The topics dealt with in the paper are as follows: basic electron attachment processes, modes of electron capture by molecules, short-lived transient negative ions, dissociative electron attachment to ground-state molecules and to "hot" molecules (effects of temperature on electron attachment), parent negative ions, effect of density, nature, and state of the medium on electron attachment, electron attachment to electronically excited molecules, the binding of attached electrons to molecules ("electron affinity"), and the basic and the applied significance of negative-ion studies. PMID:7428744

  20. Watching single molecules dance

    NASA Astrophysics Data System (ADS)

    Mehta, Amit Dinesh

    Molecular motors convert chemical energy, from ATP hydrolysis or ion flow, into mechanical motion. A variety of increasingly precise mechanical probes have been developed to monitor and perturb these motors at the single molecule level. Several outstanding questions can be best approached at the single molecule level. These include: how far does a motor progress per energy quanta consumed? how does its reaction cycle respond to load? how many productive catalytic cycles can it undergo per diffusional encounter with its track? and what is the mechanical stiffness of a single molecule connection? A dual beam optical trap, in conjunction with in vitro ensemble motility assays, has been used to characterize two members of the myosin superfamily: muscle myosin II and chick brain myosin V. Both move the helical polymer actin, but myosin II acts in large ensembles to drive muscle contraction or cytokinesis, while myosin V acts in small numbers to transport vesicles. An optical trapping apparatus was rendered sufficiently precise to identify a myosin working stroke with 1nm or so, barring systematic errors such as those perhaps due to random protein orientations. This and other light microscopic motility assays were used to characterize myosin V: unlike myosin II this vesicle transport protein moves through many increments of travel while remaining strongly bound to a single actin filament. The step size, stall force, and travel distance of myosin V reveal a remarkably efficient motor capable of moving along a helical track for over a micrometer without significantly spiraling around it. Such properties are fully consistent with the putative role of an organelle transport motor, present in small numbers to maintain movement over long ranges relative to cellular size scales. The contrast between myosin II and myosin V resembles that between a human running on the moon and one walking on earth, where the former allows for faster motion when in larger ensembles but for less

  1. Leucocyte cellular adhesion molecules.

    PubMed

    Yong, K; Khwaja, A

    1990-12-01

    Leucocytes express adhesion promoting receptors which mediate cell-cell and cell-matrix interactions. These adhesive interactions are crucial to the regulation of haemopoiesis and thymocyte maturation, the direction and control of leucocyte traffic and migration through tissues, and in the development of immune and non-immune inflammatory responses. Several families of adhesion receptors have been identified (Table). The leucocyte integrin family comprises 3 alpha beta heterodimeric membrane glycoproteins which share a common beta subunit, designated CD18. The alpha subunits of each of the 3 members, lymphocyte function associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1) and p150,95 are designated CD11a, b and c respectively. These adhesion molecules play a critical part in the immune and inflammatory responses of leucocytes. The leucocyte integrin family is, in turn, part of the integrin superfamily, members of which are evolutionally, structurally and functionally related. Another Integrin subfamily found on leucocytes is the VLA group, so-called because the 'very late activation antigens' VLA-1 and VLA-2 were originally found to appear late in T-cell activation. Members of this family function mainly as extracellular matrix adhesion receptors and are found both on haemopoietic and non-haemopoietic cells. They play a part in diverse cellular functions including tissue organisation, lymphocyte recirculation and T-cell immune responses. A third integrin subfamily, the cytoadhesins, are receptors on platelets and endothelial cells which bind extracellular matrix proteins. A second family of adhesion receptors is the immunoglobulin superfamily, members of which include CD2, LFA-3 and ICAM-1, which participate in T-cell adhesive interactions, and the antigen-specific receptors of T and B cells, CD4, CD8 and the MHC Class I and II molecules. A recently recognised family of adhesion receptors is the selectins, characterised by a common lectin domain. Leucocyte

  2. Single Molecule Transcription Elongation

    PubMed Central

    Galburt, Eric A.; Grill, Stephan W.; Bustamante, Carlos

    2009-01-01

    Single molecule optical trapping assays have now been applied to a great number of macromolecular systems including DNA, RNA, cargo motors, restriction enzymes, DNA helicases, chromosome remodelers, DNA polymerases and both viral and bacterial RNA polymerases. The advantages of the technique are the ability to observe dynamic, unsynchronized molecular processes, to determine the distributions of experimental quantities and to apply force to the system while monitoring the response over time. Here, we describe the application of these powerful techniques to study the dynamics of transcription elongation by RNA polymerase II from Saccharomyces cerevisiae. PMID:19426807

  3. Ultra-cold molecule production.

    SciTech Connect

    Ramirez-Serrano, Jamie; Chandler, David W.; Strecker, Kevin; Rahn, Larry A.

    2005-12-01

    The production of Ultra-cold molecules is a goal of many laboratories through out the world. Here we are pursuing a unique technique that utilizes the kinematics of atomic and molecular collisions to achieve the goal of producing substantial numbers of sub Kelvin molecules confined in a trap. Here a trap is defined as an apparatus that spatially localizes, in a known location in the laboratory, a sample of molecules whose temperature is below one degree absolute Kelvin. Further, the storage time for the molecules must be sufficient to measure and possibly further cool the molecules. We utilize a technique unique to Sandia to form cold molecules from near mass degenerate collisions between atoms and molecules. This report describes the progress we have made using this novel technique and the further progress towards trapping molecules we have cooled.

  4. Covalent Chemistry beyond Molecules.

    PubMed

    Jiang, Juncong; Zhao, Yingbo; Yaghi, Omar M

    2016-03-16

    Linking molecular building units by covalent bonds to make crystalline extended structures has given rise to metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), thus bringing the precision and versatility of covalent chemistry beyond discrete molecules to extended structures. The key advance in this regard has been the development of strategies to overcome the "crystallization problem", which is usually encountered when attempting to link molecular building units into covalent solids. Currently, numerous MOFs and COFs are made as crystalline materials in which the large size of the constituent units provides for open frameworks. The molecular units thus reticulated become part of a new environment where they have (a) lower degrees of freedom because they are fixed into position within the framework; (b) well-defined spatial arrangements where their properties are influenced by the intricacies of the pores; and (c) ordered patterns onto which functional groups can be covalently attached to produce chemical complexity. The notion of covalent chemistry beyond molecules is further strengthened by the fact that covalent reactions can be carried out on such frameworks, with full retention of their crystallinity and porosity. MOFs are exemplars of how this chemistry has led to porosity with designed metrics and functionality, chemically-rich sequences of information within their frameworks, and well-defined mesoscopic constructs in which nanoMOFs enclose inorganic nanocrystals and give them new levels of spatial definition, stability, and functionality. PMID:26863450

  5. A systemic defect in Toll-like receptor 4 signaling increases lipopolysaccharide-induced suppression of IL-2-dependent T-cell proliferation in COPD.

    PubMed

    Knobloch, Jürgen; Chikosi, Sarah-Jane; Yanik, Sarah; Rupp, Jan; Jungck, David; Koch, Andrea

    2016-01-01

    The susceptibility to bacterial infections is increased in chronic obstructive pulmonary disease (COPD). This promotes exacerbations. IL-2 triggers CD4(+)/Th1-cell proliferation, which is important for infection defense. Bacterial endotoxin (LPS) activates MyD88/IRAK and TRIF/IKKε/TBK1 pathways via Toll-like receptor-4 (TLR4) in Th1 cells. Systemic defects in TLR pathways in CD4(+)/Th1 cells cause an impairment of IL-2-dependent immune responses to bacterial infections in COPD. Peripheral blood CD4(+) T cells of never smokers, smokers without COPD, and smokers with COPD (each n = 10) were ex vivo activated towards Th1 and stimulated with LPS. IL-2, MyD88, and TRIF expression, and cell proliferation was analyzed by ELISA, quantitative RT-PCR, and bromodeoxyuridine (BrdU) and trypan blue staining comparative among the cohorts. IL-2 release from activated T cells was increased in COPD vs. smokers and never smokers. LPS reduced IL-2 expression and T-cell proliferation. These effects were increased in COPD vs. never smokers and inversely correlated with FEV1 (%predicted). The MyD88/TRIF ratio was decreased in Th1 cells of COPD. The suppression of IL-2 by LPS was abolished by MyD88/IRAK blockade in never smokers but by TRIF/IKKε/TBK1 blockade in COPD. Moxifloxacin restored IL-2 expression and T-cell proliferation in the presence of LPS by blocking p38 MAPK. The increased IL-2 release from Th1 cells in COPD might contribute to airway inflammation in disease exacerbations. A switch from MyD88/IRAK to TRIF/IKKε/TBK1 signaling amplifies the suppression of IL-2-dependent proliferation of CD4(+) T cells by LPS in COPD. This molecular pathology is of systemic origin, might impair adaptive immune responses, and could explain the increased susceptibility to bacterial infections in COPD. Targeting TLR4-downstream signaling, for example, with moxifloxacin, might reduce exacerbation rates. PMID:26498252

  6. Adaptive Femtosecond Quantum Control

    NASA Astrophysics Data System (ADS)

    Gerber, Gustav

    2003-03-01

    Obtaining active control over the dynamics of quantum-mechanical systems is a fascinating perspective in modern physics. A promising tool for this purpose is available with femtosecond laser technologies. The intrinsically broad spectral distribution and the phase function of femtosecond laser pulses can be specifically manipulated by pulse shapers to drive molecular systems coherently into the desired reaction pathways [1]. The approach of adaptive femtosecond quantum control follows the suggestion of Judson and Rabitz [2], in which a computer-controlled pulse shaper is used in combination with a learning algorithm [3] and direct feedback from the experiment to achieve coherent control over quantum-mechanical processes in an automated fashion, without requiring any model for the system's response. This technique can be applied to the control of gas-phase photodissociation processes [4]. Different bond-cleaving reactions can be preferentially selected, resulting in chemically different products. Prior knowledge about molecular Hamiltonians or reaction mechanisms is not required in this automated control loop, and this scheme works for complex systems. Adaptive pulse-shaping techniques can be transferred to the control of photoprocesses in the liquid phase as well, motivated by the wish to achieve control at particle densities high enough for (bimolecular) synthetic-chemical applications. Chemically selective molecular excitation is achieved by many-parameter adaptive quantum control [5], despite the failure of typical single-parameter approaches (such as wavelength control, intensity control, or linear chirp control). This experiment demonstrates that photoprocesses in two different molecular species can be controlled simultaneously. Applications are envisioned in bimolecular reaction control where specific educt molecules could selectively be "activated" for purposes of chemical synthesis. A new technological development further increases the possibilities and

  7. ADAPTATION AND ADAPTABILITY, THE BELLEFAIRE FOLLOWUP STUDY.

    ERIC Educational Resources Information Center

    ALLERHAND, MELVIN E.; AND OTHERS

    A RESEARCH TEAM STUDIED INFLUENCES, ADAPTATION, AND ADAPTABILITY IN 50 POORLY ADAPTING BOYS AT BELLEFAIRE, A REGIONAL CHILD CARE CENTER FOR EMOTIONALLY DISTURBED CHILDREN. THE TEAM ATTEMPTED TO GAUGE THE SUCCESS OF THE RESIDENTIAL TREATMENT CENTER IN TERMS OF THE PSYCHOLOGICAL PATTERNS AND ROLE PERFORMANCES OF THE BOYS DURING INDIVIDUAL CASEWORK…

  8. Molecules in the Spotlight

    SciTech Connect

    Cryan, James

    2010-01-26

    SLAC has just unveiled the world's first X-ray laser, the LCLS. This machine produces pulses of X-rays that are ten billion times brighter than those from conventional sources. One of the goals of this machine is to make movies of chemical reactions, including reactions necessary for life and reactions that might power new energy technologies. This public lecture will show the first results from the LCLS. As a first target, we have chosen nitrogen gas, the main component of the air we breathe. Using the unprecedented power of the LCLS X-rays as a blasting torch, we have created new forms of this molecule and with unique electronic arrangements. Please share with us the first insights from this new technology.

  9. Emerging small molecule drugs.

    PubMed

    Colin, Sophie; Chinetti-Gbaguidi, Giulia; Kuivenhoven, Jan A; Staels, Bart

    2015-01-01

    Dyslipidaemia is a major risk factor for cardiovascular diseases. Pharmacological lowering of LDL-C levels using statins reduces cardiovascular risk. However, a substantial residual risk persists especially in patients with type 2 diabetes mellitus. Because of the inverse association observed in epidemiological studies of HDL-C with the risk for cardiovascular diseases, novel therapeutic strategies to raise HDL-C levels or improve HDL functionality are developed as complementary therapy for cardiovascular diseases. However, until now most therapies targeting HDL-C levels failed in clinical trials because of side effects or absence of clinical benefits. This chapter will highlight the emerging small molecules currently developed and tested in clinical trials to pharmacologically modulate HDL-C and functionality including new CETP inhibitors (anacetrapib, evacetrapib), novel PPAR agonists (K-877, CER-002, DSP-8658, INT131 and GFT505), LXR agonists (ATI-111, LXR-623, XL-652) and RVX-208. PMID:25523004

  10. Biochips - Can molecules compute?

    NASA Astrophysics Data System (ADS)

    Tucker, J. B.

    1984-02-01

    In recent years the possibility has been considered to build 'biochip' computers, in which the silicon transistors of present machines would be replaced by large organic molecules or genetically engineered proteins. Two major advantages of such biochips over current devices would be related to vastly increased densities of computing elements, and entirely new styles of data processing, suited to such high-level tasks as pattern recognition and context-dependent analysis. The limitations of the semiconductor chip with respect to the density of elementary units due to size considerations and heat development could be overcome by making use of molecular switches. Attention is given to soliton switching, soliton logic, bulk molecular devices, analog biochips, 'intelligent' switches based on the employment of enzymes, robot vision, questions of biochip fabrication, protein engineering, and a strategy for the development of biochips.

  11. Forces in molecules.

    PubMed

    Hernández-Trujillo, Jesús; Cortés-Guzmán, Fernando; Fang, De-Chai; Bader, Richard F W

    2007-01-01

    Chemistry is determined by the electrostatic forces acting within a collection of nuclei and electrons. The attraction of the nuclei for the electrons is the only attractive force in a molecule and is the force responsible for the bonding between atoms. This is the attractive force acting on the electrons in the Ehrenfest force and on the nuclei in the Feynman force, one that is countered by the repulsion between the electrons in the former and by the repulsion between the nuclei in the latter. The virial theorem relates these forces to the energy changes resulting from interactions between atoms. All bonding, as signified by the presence of a bond path, has a common origin in terms of the mechanics determined by the Ehrenfest, Feynman and virial theorems. This paper is concerned in particular with the mechanics of interaction encountered in what are classically described as 'nonbonded interactions'--are atoms that 'touch' bonded or repelling one another? PMID:17328425

  12. Adaptive Image Denoising by Mixture Adaptation.

    PubMed

    Luo, Enming; Chan, Stanley H; Nguyen, Truong Q

    2016-10-01

    We propose an adaptive learning procedure to learn patch-based image priors for image denoising. The new algorithm, called the expectation-maximization (EM) adaptation, takes a generic prior learned from a generic external database and adapts it to the noisy image to generate a specific prior. Different from existing methods that combine internal and external statistics in ad hoc ways, the proposed algorithm is rigorously derived from a Bayesian hyper-prior perspective. There are two contributions of this paper. First, we provide full derivation of the EM adaptation algorithm and demonstrate methods to improve the computational complexity. Second, in the absence of the latent clean image, we show how EM adaptation can be modified based on pre-filtering. The experimental results show that the proposed adaptation algorithm yields consistently better denoising results than the one without adaptation and is superior to several state-of-the-art algorithms. PMID:27416593

  13. Geranyl diphosphate synthase molecules, and nucleic acid molecules encoding same

    SciTech Connect

    Croteau, Rodney Bruce; Burke, Charles Cullen

    2008-06-24

    In one aspect, the present invention provides isolated nucleic acid molecules that each encode a geranyl diphosphate synthase protein, wherein each isolated nucleic acid molecule hybridizes to a nucleic acid molecule consisting of the sequence set forth in SEQ ID NO:1 under conditions of 5.times.SSC at 45.degree. C. for one hour. The present invention also provides isolated geranyl diphosphate synthase proteins, and methods for altering the level of expression of geranyl diphosphate synthase protein in a host cell.

  14. Organic Molecules in Meteorites

    NASA Astrophysics Data System (ADS)

    Martins, Zita

    2015-08-01

    Carbonaceous meteorites are primitive samples from the asteroid belt, containing 3-5wt% organic carbon. The exogenous delivery of organic matter by carbonaceous meteorites may have contributed to the organic inventory of the early Earth. The majority (>70%) of the meteoritic organic material consist of insoluble organic matter (IOM) [1]. The remaining meteoritic organic material (<30%) consists of a rich organic inventory of soluble organic compounds, including key compounds important in terrestrial biochemistry [2-4]. Different carbonaceous meteorites contain soluble organic molecules with different abundances and distributions, which may reflect the extension of aqueous alteration or thermal metamorphism on the meteorite parent bodies. Extensive aqueous alteration on the meteorite parent body may result on 1) the decomposition of α-amino acids [5, 6]; 2) synthesis of β- and γ-amino acids [2, 6-9]; 3) higher relative abundances of alkylated polycyclic aromatic hydrocarbons (PAHs) [6, 10]; and 4) higher L-enantiomer excess (Lee) value of isovaline [6, 11, 12].The soluble organic content of carbonaceous meteorites may also have a contribution from Fischer-Tropsch/Haber-Bosch type gas-grain reactions after the meteorite parent body cooled to lower temperatures [13, 14].The analysis of the abundances and distribution of the organic molecules present in meteorites helps to determine the physical and chemical conditions of the early solar system, and the prebiotic organic compounds available on the early Earth.[1] Cody and Alexander (2005) GCA 69, 1085. [2] Cronin and Chang (1993) in: The Chemistry of Life’s Origin. pp. 209-258. [3] Martins and Sephton (2009) in: Amino acids, peptides and proteins in organic chemistry. pp. 1-42. [4] Martins (2011) Elements 7, 35. [5] Botta et al. (2007) MAPS 42, 81. [6] Martins et al. (2015) MAPS, in press. [7] Cooper and Cronin (1995) GCA 59, 1003. [8] Glavin et al. (2006) MAPS. 41, 889. [9] Glavin et al. (2011) MAPS 45, 1948. [10

  15. Electrochromic graphene molecules.

    PubMed

    Ji, Zhiqiang; Doorn, Stephen K; Sykora, Milan

    2015-04-28

    Polyclic aromatic hydrocarbons also called Graphene Molecules (GMs), with chemical composition C132H36(COOH)2 were synthesized in situ on the surface of transparent nanocrystalline indium tin oxide (nc-ITO) electrodes and their electronic structure was studied electrochemically and spectro-electrochemically. Variations in the potential applied onto the nc-ITO/GM electrodes induce only small changes in the observed current, but they produce dramatic changes in the absorption of the GMs, which are associated with their oxidation and reduction. Analysis of the absorption changes using a modified Nernst equation is used to determine standard potentials associated with the individual charge transfer processes. For the GMs prepared here, these were found to be E1,ox(0) = 0.77 ± 0.01 V and E2,ox(0) = 1.24 ± 0.02 V vs NHE for the first and second oxidation and E1,red(0) = -1.50 ± 0.04 V for the first reduction. The charge transfer processes are found to be nonideal. The nonideality factors associated with the oxidation and reduction processes are attributed to strong interactions between the GM redox centers. Under the conditions of potential cycling, GMs show rapid (seconds) color change with high contrast and stability. An electrochromic application is demonstrated wherein the GMs are used as the optically active component. PMID:25768313

  16. Electrochromic Graphene Molecules

    DOE PAGESBeta

    Ji, Zhiqiang; Doorn, Stephen K.; Sykora, Milan

    2015-03-13

    Polyclic aromatic hydrocarbons, also called Graphene Molecules (GMs), with chemical composition C132H36(COOH)2 were synthesized in-situ on the surface of transparent nanocrystaline indium tin oxide (nc-ITO) electrodes. Their electronic structure was studied electrochemically and spectro-electrochemically. Variations in the potential applied onto the nc-ITO/GM electrodes induce only small changes in the observed current but they produce dramatic changes in the absorption of the GMs, which are associated with their oxidation and reduction. Analysis of the absorption changes using modified Nernst equation is used to determine standard potentials associated with the individual charge transfer processes. For the GMs prepared here these were foundmore » to be E1,ox 0 = 0.77± 0.01 V and E2,ox 0 = 1.24 ± 0.02 V vs. NHE for the first and second oxidation and E1,red 0 = -1.50 ± 0.04 V for the first reduction. The charge transfer processes are found to be non-ideal. The non-ideality factors associated with the oxidation and reduction processes suggest presence of strong interactions between the GM redox centers. Under the conditions of potential cycling GMs show rapid (seconds) color change with high contrast and stability. An electrochromic application is demonstrated wherein the GMs are used as the optically active component.« less

  17. Reactions of oriented molecules.

    PubMed

    Brooks, P R

    1976-07-01

    Beams of oriented molecules have been used to directly study geometrical requirements in chemical reactions. These studies have shown that reactivity is much greater in some orientations than others and demonstrated the existence of steric effects. For some reactions portions of the orientation results are in good accord with traditional views of steric hindrance, but for others it is clear that our chemical intuition needs recalibrating. Indeed, the information gained from simultaneously orienting the reactants and observing the scattering angle of the products may lead to new insights about the detailed mechanism of certain reactions. Further work must be done to extend the scope and detail of the studies described here. More detailed information is needed on the CH(3)I reaction and the CF(3)I reaction. The effects of alkyl groups of various sizes and alkali metals of various sizes are of interest. In addition, reactions where a long-lived complex is formed should be studied to see if orientation is important. Finally, it would be of interest to apply the technique to the sort of reactions that led to our interest in the first place: the S(N)2 displacements in alkyl halides where the fascinating Walden inversion occurs. PMID:17793988

  18. Single molecule tracking

    DOEpatents

    Shera, E. Brooks

    1988-01-01

    A detection system is provided for identifying individual particles or molecules having characteristic emission in a flow train of the particles in a flow cell. A position sensitive sensor is located adjacent the flow cell in a position effective to detect the emissions from the particles within the flow cell and to assign spatial and temporal coordinates for the detected emissions. A computer is then enabled to predict spatial and temporal coordinates for the particle in the flow train as a function of a first detected emission. Comparison hardware or software then compares subsequent detected spatial and temporal coordinates with the predicted spatial and temporal coordinates to determine whether subsequently detected emissions originate from a particle in the train of particles. In one embodiment, the particles include fluorescent dyes which are excited to fluoresce a spectrum characteristic of the particular particle. Photones are emitted adjacent at least one microchannel plate sensor to enable spatial and temporal coordinates to be assigned. The effect of comparing detected coordinates with predicted coordinates is to define a moving sample volume which effectively precludes the effects of background emissions.

  19. Single molecule tracking

    DOEpatents

    Shera, E.B.

    1987-10-07

    A detection system is provided for identifying individual particles or molecules having characteristic emission in a flow train of the particles in a flow cell. A position sensitive sensor is located adjacent the flow cell in a position effective to detect the emissions from the particles within the flow cell and to assign spatial and temporal coordinates for the detected emissions. A computer is then enabled to predict spatial and temporal coordinates for the particle in the flow train as a function of a first detected emission. Comparison hardware or software then compares subsequent detected spatial and temporal coordinates with the predicted spatial and temporal coordinates to determine whether subsequently detected emissions originate from a particle in the train of particles. In one embodiment, the particles include fluorescent dyes which are excited to fluoresce a spectrum characteristic of the particular particle. Photons are emitted adjacent at least one microchannel plate sensor to enable spatial and temporal coordinates to be assigned. The effect of comparing detected coordinates with predicted coordinates is to define a moving sample volume which effectively precludes the effects of background emissions. 3 figs.

  20. Strongly interacting ultracold polar molecules

    NASA Astrophysics Data System (ADS)

    Gadway, Bryce; Yan, Bo

    2016-08-01

    This paper reviews recent advances in the study of strongly interacting systems of dipolar molecules. Heteronuclear molecules feature large and tunable electric dipole moments, which give rise to long-range and anisotropic dipole–dipole interactions. Ultracold samples of dipolar molecules with long-range interactions offer a unique platform for quantum simulations and the study of correlated many-body physics. We provide an introduction to the physics of dipolar quantum gases, both electric and magnetic, and summarize the multipronged efforts to bring dipolar molecules into the quantum regime. We discuss in detail the recent experimental progress in realizing and studying strongly interacting systems of polar molecules trapped in optical lattices, with particular emphasis on the study of interacting spin systems and non-equilibrium quantum magnetism. Finally, we conclude with a brief discussion of the future prospects for studies of strongly interacting dipolar molecules.

  1. Adsorption kinetics of diatomic molecules.

    PubMed

    Burde, Jared T; Calbi, M Mercedes

    2014-05-01

    The adsorption dynamics of diatomic molecules on solid surfaces is examined by using a Kinetic Monte Carlo algorithm. Equilibration times at increasing loadings are obtained, and explained based on the elementary processes that lead to the formation of the adsorbed film. The ability of the molecules to change their orientation accelerates the overall uptake and leads to competitive kinetic behaviour between the different orientations. The dependence of the equilibration time on coverage follows the same decreasing trend obtained experimentally for ethane adsorption on closed-end carbon nanotube bundles. The exploration of molecule-molecule interaction effects on this trend provides relevant insights to understand the kinetic behaviour of other species, from simpler molecules to larger polyatomic molecules, adsorbing on surfaces with different binding strength. PMID:24654004

  2. Trapping Single Molecules by Dielectrophoresis

    NASA Astrophysics Data System (ADS)

    Hölzel, Ralph; Calander, Nils; Chiragwandi, Zackary; Willander, Magnus; Bier, Frank F.

    2005-09-01

    We have trapped single protein molecules of R-phycoerythrin in an aqueous solution by an alternating electric field. A radio frequency voltage is applied to sharp nanoelectrodes and hence produces a strong electric field gradient. The resulting dielectrophoretic forces attract freely diffusing protein molecules. Trapping takes place at the electrode tips. Switching off the field immediately releases the molecules. The electric field distribution is computed, and from this the dielectrophoretic response of the molecules is calculated using a standard polarization model. The resulting forces are compared to the impact of Brownian motion. Finally, we discuss the experimental observations on the basis of the model calculations.

  3. Aromatic molecules as spintronic devices

    SciTech Connect

    Ojeda, J. H.; Orellana, P. A.; Laroze, D.

    2014-03-14

    In this paper, we study the spin-dependent electron transport through aromatic molecular chains attached to two semi-infinite leads. We model this system taking into account different geometrical configurations which are all characterized by a tight binding Hamiltonian. Based on the Green's function approach with a Landauer formalism, we find spin-dependent transport in short aromatic molecules by applying external magnetic fields. Additionally, we find that the magnetoresistance of aromatic molecules can reach different values, which are dependent on the variations in the applied magnetic field, length of the molecules, and the interactions between the contacts and the aromatic molecule.

  4. Electrical Transport through Organic Molecules

    NASA Astrophysics Data System (ADS)

    Lau, C. N.; Chang, Shun-Chi; Williams, Stan

    2003-03-01

    We investigate electrical transport properties of single organic molecules using electromigration break junctions[1]. A self-assembled monolayer of various organic molecules such as 1,4-di(phenylethynyl-4'-methanethiol)benzene was grown on narrow metal wires, and single or a few molecules were incorporated into the junctions which were created by applying a large voltage and breaking the wires. The transport properties of these molecules were then measured at low temperatures. Latest experimental results will be discussed. [1] Park, J. et al, Nature, 417, 722 (2002); Liang W. et al, Nature, 417, 725 (2002).

  5. Electrochromic Graphene Molecules

    SciTech Connect

    Ji, Zhiqiang; Doorn, Stephen K.; Sykora, Milan

    2015-03-13

    Polyclic aromatic hydrocarbons, also called Graphene Molecules (GMs), with chemical composition C132H36(COOH)2 were synthesized in-situ on the surface of transparent nanocrystaline indium tin oxide (nc-ITO) electrodes. Their electronic structure was studied electrochemically and spectro-electrochemically. Variations in the potential applied onto the nc-ITO/GM electrodes induce only small changes in the observed current but they produce dramatic changes in the absorption of the GMs, which are associated with their oxidation and reduction. Analysis of the absorption changes using modified Nernst equation is used to determine standard potentials associated with the individual charge transfer processes. For the GMs prepared here these were found to be E1,ox 0 = 0.77± 0.01 V and E2,ox 0 = 1.24 ± 0.02 V vs. NHE for the first and second oxidation and E1,red 0 = -1.50 ± 0.04 V for the first reduction. The charge transfer processes are found to be non-ideal. The non-ideality factors associated with the oxidation and reduction processes suggest presence of strong interactions between the GM redox centers. Under the conditions of potential cycling GMs show rapid (seconds) color change with high contrast and stability. An electrochromic application is demonstrated wherein the GMs are used as the optically active component.

  6. A simple model for electronic properties of surface adsorbed molecules

    NASA Astrophysics Data System (ADS)

    Dhakal, Rajesh; Schwalm, William

    We adapt a minimal approximation to one electron quantum theory of molecules referred as Fast Accurate Kinetic Energy method. This in principle handles large complex molecular structures with less computational effort to compute electronic properties of adsorbed molecules. Kinetic energy integrals are calculated accurately but multi-electron potential energy integrals are approximated. The neighboring atom interactions are included also. For layers of isopthalic acids formed on pyrolytic graphite the configuration changes as a function of length of hydrocarbon tails. We study properties of this system as a function of tail length.

  7. Detection of pathogenic DNA at the single-molecule level

    NASA Astrophysics Data System (ADS)

    Yahiatène, Idir; Klamp, Tobias; Schüttpelz, Mark; Sauer, Markus

    2011-03-01

    We demonstrate ultrasensitive detection of pathogenic DNA in a homogeneous assay at the single-molecule level applying two-color coincidence analysis. The target molecule we quantify is a 100 nucleotide long synthetic single-stranded oligonucleotide adapted from Streptococcus pneumoniae, a bacterium causing lower respiratory tract infections. Using spontaneous hybridization of two differently fluorescing Molecular Beacons we demonstrate a detection sensitivity of 100 fM (10-13M) in 30 seconds applying a simple microfluidic device with a 100 μm channel and confocal two-color fluorescence microscopy.

  8. Adhesion molecules in cutaneous inflammation.

    PubMed

    Barker, J N

    1995-01-01

    As in other organs, leukocyte adhesion molecules and their ligands play a major role in cutaneous inflammatory events both by directing leukocyte trafficking and by their effects on antigen presentation. Skin biopsies of inflamed skin from patients with diseases such as as psoriasis or atopic dermatitis reveal up-regulation of endothelial cell expression of P- and E-selectin, vascular cell adhesion molecule 1 and intercellular adhesion molecule 1. Studies of evolving lesions following UVB irradiation, Mantoux reaction or application of contact allergen, demonstrate that expression of these adhesion molecules parallels leukocyte infiltration into skin. When cutaneous inflammation is widespread (e.g. in erythroderma), soluble forms of these molecules are detectable in serum. In vitro studies predict that peptide mediators are important regulatory factors for endothelial adhesion molecules. Intradermal injection of the cytokines interleukin 1, tumour necrosis factor alpha and interferon gamma into normal human skin leads to induction of endothelial adhesion molecules with concomitant infiltration of leukocytes. In addition, neuropeptides rapidly induce P-selectin translocation to the cell membrane and expression of E-selectin. Adhesion molecules also play a crucial role as accessory molecules in the presentation of antigen to T lymphocytes by Langerhans' cells. Expression of selectin ligands by Langerhans' cells is up-regulated by various inflammatory stimuli, suggesting that adhesion molecules may be important in Langerhans' cell migration. The skin, because of its accessibility, is an ideal organ in which to study expression of adhesion molecules and their relationship to inflammatory events. Inflammatory skin diseases are common and inhibition of lymphocyte accumulation in skin is likely to prove of great therapeutic benefit. PMID:7587640

  9. Habituation of visual adaptation

    PubMed Central

    Dong, Xue; Gao, Yi; Lv, Lili; Bao, Min

    2016-01-01

    Our sensory system adjusts its function driven by both shorter-term (e.g. adaptation) and longer-term (e.g. learning) experiences. Most past adaptation literature focuses on short-term adaptation. Only recently researchers have begun to investigate how adaptation changes over a span of days. This question is important, since in real life many environmental changes stretch over multiple days or longer. However, the answer to the question remains largely unclear. Here we addressed this issue by tracking perceptual bias (also known as aftereffect) induced by motion or contrast adaptation across multiple daily adaptation sessions. Aftereffects were measured every day after adaptation, which corresponded to the degree of adaptation on each day. For passively viewed adapters, repeated adaptation attenuated aftereffects. Once adapters were presented with an attentional task, aftereffects could either reduce for easy tasks, or initially show an increase followed by a later decrease for demanding tasks. Quantitative analysis of the decay rates in contrast adaptation showed that repeated exposure of the adapter appeared to be equivalent to adaptation to a weaker stimulus. These results suggest that both attention and a non-attentional habituation-like mechanism jointly determine how adaptation develops across multiple daily sessions. PMID:26739917

  10. Habituation of visual adaptation.

    PubMed

    Dong, Xue; Gao, Yi; Lv, Lili; Bao, Min

    2016-01-01

    Our sensory system adjusts its function driven by both shorter-term (e.g. adaptation) and longer-term (e.g. learning) experiences. Most past adaptation literature focuses on short-term adaptation. Only recently researchers have begun to investigate how adaptation changes over a span of days. This question is important, since in real life many environmental changes stretch over multiple days or longer. However, the answer to the question remains largely unclear. Here we addressed this issue by tracking perceptual bias (also known as aftereffect) induced by motion or contrast adaptation across multiple daily adaptation sessions. Aftereffects were measured every day after adaptation, which corresponded to the degree of adaptation on each day. For passively viewed adapters, repeated adaptation attenuated aftereffects. Once adapters were presented with an attentional task, aftereffects could either reduce for easy tasks, or initially show an increase followed by a later decrease for demanding tasks. Quantitative analysis of the decay rates in contrast adaptation showed that repeated exposure of the adapter appeared to be equivalent to adaptation to a weaker stimulus. These results suggest that both attention and a non-attentional habituation-like mechanism jointly determine how adaptation develops across multiple daily sessions. PMID:26739917

  11. Micro-Kelvin cold molecules.

    SciTech Connect

    Strecker, Kevin E.; Chandler, David W.

    2009-10-01

    We have developed a novel experimental technique for direct production of cold molecules using a combination of techniques from atomic optical and molecular physics and physical chemistry. The ability to produce samples of cold molecules has application in a broad spectrum of technical fields high-resolution spectroscopy, remote sensing, quantum computing, materials simulation, and understanding fundamental chemical dynamics. Researchers around the world are currently exploring many techniques for producing samples of cold molecules, but to-date these attempts have offered only limited success achieving milli-Kelvin temperatures with low densities. This Laboratory Directed Research and Development project is to develops a new experimental technique for producing micro-Kelvin temperature molecules via collisions with laser cooled samples of trapped atoms. The technique relies on near mass degenerate collisions between the molecule of interest and a laser cooled (micro-Kelvin) atom. A subset of collisions will transfer all (nearly all) of the kinetic energy from the 'hot' molecule, cooling the molecule at the expense of heating the atom. Further collisions with the remaining laser cooled atoms will thermally equilibrate the molecules to the micro-Kelvin temperature of the laser-cooled atoms.

  12. Featured Molecules: Sucrose and Vanillin

    NASA Astrophysics Data System (ADS)

    Coleman, William F.; Wildman, Randall J.

    2003-04-01

    The WebWare molecules of the month for April relate to the sense of taste. Apple Fool, the JCE Classroom Activity, mentions sucrose and vanillin and their use as flavorings. Fully manipulable (Chime) versions of these and other molecules are available at Only@JCE Online.

  13. Proregenerative Properties of ECM Molecules

    PubMed Central

    Plantman, Stefan

    2013-01-01

    After traumatic injuries to the nervous system, regrowing axons encounter a complex microenvironment where mechanisms that promote regeneration compete with inhibitory processes. Sprouting and axonal regrowth are key components of functional recovery but are often counteracted by inhibitory molecules. This review covers extracellular matrix molecules that support neuron axonal outgrowth. PMID:24195084

  14. Loosely-Bound Diatomic Molecules.

    ERIC Educational Resources Information Center

    Balfour, W. J.

    1979-01-01

    Discusses concept of covalent bonding as related to homonuclear diatomic molecules. Article draws attention to the existence of bound rare gas and alkaline earth diatomic molecules. Summarizes their molecular parameters and offers spectroscopic data. Strength and variation with distance of interatomic attractive forces is given. (Author/SA)

  15. Single-molecule spectroscopy using microfluidic platforms.

    PubMed

    Kim, Samuel; Zare, Richard N

    2010-01-01

    Microfluidics serves as a convenient platform for single-molecule experiments by providing manipulation of small amounts of liquids and micron-sized particles. An adapted version of capillary electrophoresis (CE) on a microchip can be utilized to separate chemical species with high resolution based on their ionic mobilities (i.e., charges and sizes), but identification of separated species is not trivial, especially for complex mixtures of sticky biomolecules. We describe here how to use a surfactant mixture system for CE on a poly(dimethylsiloxane) (PDMS) microchip, capture separated peaks within a 50-pl chamber using microvalves, analyze the fluorescence signals with correlation spectroscopy to extract molecular diffusion characteristics, and to identify the biomolecular clusters in a model immunocomplex system. PMID:20580962

  16. Enzyme molecules in solitary confinement.

    PubMed

    Liebherr, Raphaela B; Gorris, Hans H

    2014-01-01

    Large arrays of homogeneous microwells each defining a femtoliter volume are a versatile platform for monitoring the substrate turnover of many individual enzyme molecules in parallel. The high degree of parallelization enables the analysis of a statistically representative enzyme population. Enclosing individual enzyme molecules in microwells does not require any surface immobilization step and enables the kinetic investigation of enzymes free in solution. This review describes various microwell array formats and explores their applications for the detection and investigation of single enzyme molecules. The development of new fabrication techniques and sensitive detection methods drives the field of single molecule enzymology. Here, we introduce recent progress in single enzyme molecule analysis in microwell arrays and discuss the challenges and opportunities. PMID:25221867

  17. Magnetoassociation of KRb Feshbach molecules

    NASA Astrophysics Data System (ADS)

    Cumby, Tyler; Perreault, John; Shewmon, Ruth; Jin, Deborah

    2010-03-01

    I will discuss experiments in which we study the creation of ^40K^87Rb Feshbach molecules via magnetoassociation. We measure the molecule number as a function of the magnetic-field sweep rate through the interspecies Feshbach resonance and explore the dependence of association on the initial atom gas conditions. This study of the Feshbach molecule creation process may be relevant to the production of ultracold polar molecules, where magnetoassociated Feshbach molecules can be a crucial first step [1].[4pt] [1] K.-K. Ni, S. Ospelkaus, M. H. G. de Miranda, A. Peer, B. Neyenhuis, J. J. Zirbel, S. Kotochigova, P. S. Julienne, D. S. Jin, and J. Ye, Science, 2008, 322, 231- 235.

  18. Magnetoassociation of KRb Feshbach molecules

    NASA Astrophysics Data System (ADS)

    Cumby, Tyler; Perreault, John; Shewmon, Ruth; Jin, Deborah

    2010-03-01

    I will discuss experiments in which we study the creation of ^40K^87Rb Feshbach molecules via magnetoassociation. We measure the molecule number as a function of the magnetic-field sweep rate through the interspecies Feshbach resonance and explore the dependence of association on the initial atom gas conditions. This study of the Feshbach molecule creation process may be relevant to the production of ultracold polar molecules, where magnetoassociated Feshbach molecules can be a crucial first step [1].[4pt] [1] K.-K. Ni, S. Ospelkaus, M. H. G. de Miranda, A. Peer, B. Neyenhuis, J. J. Zirbel, S. Kotochigova, P. S. Julienne, D. S. Jin, and J. Ye, Science, 2008, 322, 231-235.

  19. Molecule-hugging graphene nanopores.

    PubMed

    Garaj, Slaven; Liu, Song; Golovchenko, Jene A; Branton, Daniel

    2013-07-23

    It has recently been recognized that solid-state nanopores in single-atomic-layer graphene membranes can be used to electronically detect and characterize single long charged polymer molecules. We have now fabricated nanopores in single-layer graphene that are closely matched to the diameter of a double-stranded DNA molecule. Ionic current signals during electrophoretically driven translocation of DNA through these nanopores were experimentally explored and theoretically modeled. Our experiments show that these nanopores have unusually high sensitivity (0.65 nA/Å) to extremely small changes in the translocating molecule's outer diameter. Such atomically short graphene nanopores can also resolve nanoscale-spaced molecular structures along the length of a polymer, but do so with greatest sensitivity only when the pore and molecule diameters are closely matched. Modeling confirms that our most closely matched pores have an inherent resolution of ≤ 0.6 nm along the length of the molecule. PMID:23836648

  20. Cold molecules, collisions and reactions

    NASA Astrophysics Data System (ADS)

    Hecker Denschlag, Johannes

    2016-05-01

    I will report on recent experiments of my group where we have been studying the formation of ultracold diatomic molecules and their subsequent inelastic/reactive collisions. For example, in one of these experiments we investigate collisions of triplet Rb2 molecules in the rovibrational ground state. We observe fast molecular loss and compare the measured loss rates to predictions based on universality. In another set of experiments we investigate the formation of (BaRb)+ molecules after three-body recombination of a single Ba+ ion with two Rb atoms in an ultracold gas of Rb atoms. Our investigations indicate that the formed (BaRb)+ molecules are weakly bound and that several secondary processes take place ranging from photodissociation of the (BaRb)+ molecule to reactive collisions with Rb atoms. I will explain how we can experimentally distinguish these processes and what the typical reaction rates are. Support from the German Research foundation DFG and the European Community is acknowledged.

  1. Exposure to stressful environments - Strategy of adaptive responses

    NASA Technical Reports Server (NTRS)

    Farhi, Leon E.

    1991-01-01

    Stresses such as hypoxia, water lack, and heat exposure can produce strains in more than a single organ system, in turn stimulating the body to adapt in multiple ways. Nevertheless, a general strategy of the various adaptive responses emerges when the challenges are divided into three groups: (1) conditions that affect the supply of essential molecules, (2) stresses that prevent the body from regulating properly the output of waste products such as CO2 and heat, and (3) environments that disrupt body transport systems. Problems may arise when there is a conflict between two stresses requiring conflicting adaptive changes. An alternative to adaptation, creation of microenvironment, is often favored by the animal.

  2. Expressing Adaptation Strategies Using Adaptation Patterns

    ERIC Educational Resources Information Center

    Zemirline, N.; Bourda, Y.; Reynaud, C.

    2012-01-01

    Today, there is a real challenge to enable personalized access to information. Several systems have been proposed to address this challenge including Adaptive Hypermedia Systems (AHSs). However, the specification of adaptation strategies remains a difficult task for creators of such systems. In this paper, we consider the problem of the definition…

  3. Role of Toll-like receptors in diabetic renal lesions in a miniature pig model.

    PubMed

    Feng, Yuanyuan; Yang, Shulin; Ma, Yuxiang; Bai, Xue-Yuan; Chen, Xiangmei

    2015-06-01

    The mechanisms of diabetic renal injury remain unclear. Recent studies have shown that immunological and inflammatory elements play important roles in the initiation and development of diabetic nephropathy (DN). Toll-like receptors (TLRs) comprise a superfamily of innate immune system receptors. The roles and mechanisms of TLRs in the pathogenesis of diabetic renal lesions are mostly unknown. Compared with rodents, miniature pigs are more similar to humans with respect to metabolism, kidney structure, and immune system, and therefore represent an ideal large-animal model for DN mechanistic studies. A diabetes model was established by feeding miniature pigs with high-sugar and high-fat diets. Functional and pathological markers, expression and activation of endogenous TLR ligands [HSP70 (heat shock protein 70) and HMGB1], TLR1 to TLR11 and their downstream signaling pathway molecules (MyD88, IRAK-1, and IRF-3), nuclear factor κB (NF-κB) signaling pathway molecules (IKKβ, IκBα, and NF-κBp65), inflammatory cytokines [IL-6 (interleukin-6), MIP-2, MCP-1, CCL5, and VCAM-1 (vascular cell adhesion molecule-1)], and infiltration of inflammatory cells were systematically evaluated. The expression of HSP70 was significantly increased in diabetic pig kidneys. The expression of MyD88-dependent TLR2, TLR4, TLR5, TLR7, TLR8, and TLR11 and their downstream signaling molecules MyD88 and phospho-IRAK-1 (activated IRAK-1), as well as that of MyD88-independent TLR3 and TLR4 and their downstream signaling molecule phospho-IRF-3 (activated IRF-3), was significantly up-regulated. The expression and activation of NF-κB pathway molecules phospho-IKKβ, phospho-IκBα, NF-κBp65, and phospho-NF-κBp65 were significantly increased. Levels of IL-6, MIP-2, MCP-1, CCL5, VCAM-1, and macrophage marker CD68 were significantly increased in diabetic pig kidneys. These results suggested that the metabolic inflammation activated by TLRs might play an important role in diabetic renal injuries

  4. Antibody Fc: Linking Adaptive and Innate Immunity

    PubMed Central

    Reichert, Janice M.

    2014-01-01

    Antibody Fc: Linking Adaptive and Innate Immunity, edited by Margaret E. Ackerman and Falk Nimmerjahn and published by Academic Press, provides a highly detailed examination of the involvement of the antibody Fc in mechanisms critical to both innate and adaptive immune responses. Despite a recent increase in format diversity, most marketed antibodies are full-length IgG molecules and the majority of the commercial clinical pipeline of antibody therapeutics is composed of Fc-containing IgG molecules, which underscores the importance of understanding how the Fc domain affects biological responses. The book is divided into six sections that include a total of 20 chapters. In order of their appearance, the sections provide extensive coverage of effector mechanisms, effector cells, Fc receptors, variability of the Fc domain, genetic associations, and evolving areas.

  5. Single Molecule Electronics and Devices

    PubMed Central

    Tsutsui, Makusu; Taniguchi, Masateru

    2012-01-01

    The manufacture of integrated circuits with single-molecule building blocks is a goal of molecular electronics. While research in the past has been limited to bulk experiments on self-assembled monolayers, advances in technology have now enabled us to fabricate single-molecule junctions. This has led to significant progress in understanding electron transport in molecular systems at the single-molecule level and the concomitant emergence of new device concepts. Here, we review recent developments in this field. We summarize the methods currently used to form metal-molecule-metal structures and some single-molecule techniques essential for characterizing molecular junctions such as inelastic electron tunnelling spectroscopy. We then highlight several important achievements, including demonstration of single-molecule diodes, transistors, and switches that make use of electrical, photo, and mechanical stimulation to control the electron transport. We also discuss intriguing issues to be addressed further in the future such as heat and thermoelectric transport in an individual molecule. PMID:22969345

  6. Indexing molecules with chemical graph identifiers.

    PubMed

    Gregori-Puigjané, Elisabet; Garriga-Sust, Rut; Mestres, Jordi

    2011-09-01

    Fast and robust algorithms for indexing molecules have been historically considered strategic tools for the management and storage of large chemical libraries. This work introduces a modified and further extended version of the molecular equivalence number naming adaptation of the Morgan algorithm (J Chem Inf Comput Sci 2001, 41, 181-185) for the generation of a chemical graph identifier (CGI). This new version corrects for the collisions recognized in the original adaptation and includes the ability to deal with graph canonicalization, ensembles (salts), and isomerism (tautomerism, regioisomerism, optical isomerism, and geometrical isomerism) in a flexible manner. Validation of the current CGI implementation was performed on the open NCI database and the drug-like subset of the ZINC database containing 260,071 and 5,348,089 structures, respectively. The results were compared with those obtained with some of the most widely used indexing codes, such as the CACTVS hash code and the new InChIKey. The analyses emphasize the fact that compound management activities, like duplicate analysis of chemical libraries, are sensitive to the exact definition of compound uniqueness and thus still depend, to a minor extent, on the type and flexibility of the molecular index being used. PMID:21647928

  7. Relative Sizes of Organic Molecules

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This computer graphic depicts the relative complexity of crystallizing large proteins in order to study their structures through x-ray crystallography. Insulin is a vital protein whose structure has several subtle points that scientists are still trying to determine. Large molecules such as insuline are complex with structures that are comparatively difficult to understand. For comparison, a sugar molecule (which many people have grown as hard crystals in science glass) and a water molecule are shown. These images were produced with the Macmolecule program. Photo credit: NASA/Marshall Space Flight Center (MSFC)

  8. Quantum transport through aromatic molecules

    SciTech Connect

    Ojeda, J. H.; Rey-González, R. R.; Laroze, D.

    2013-12-07

    In this paper, we study the electronic transport properties through aromatic molecules connected to two semi-infinite leads. The molecules are in different geometrical configurations including arrays. Using a nearest neighbor tight-binding approach, the transport properties are analyzed into a Green's function technique within a real-space renormalization scheme. We calculate the transmission probability and the Current-Voltage characteristics as a function of a molecule-leads coupling parameter. Our results show different transport regimes for these systems, exhibiting metal-semiconductor-insulator transitions and the possibility to employ them in molecular devices.

  9. Organic heterocyclic molecules become superalkalis.

    PubMed

    Reddy, G Naaresh; Giri, Santanab

    2016-09-21

    An organic molecule which behaves like a superalkali has been designed from an aromatic heterocyclic molecule, pyrrole. Using first-principles calculation and a systematic two-step approach, we can have superalkali molecules with a low ionization energy, even lower than that of Cs. Couple cluster (CCSD) calculation reveals that a new heterocycle, C3N2(CH3)5 derived from a well-known aromatic heterocycle, pyrrole (C4H5N) has an ionization energy close to 3.0 eV. A molecular dynamics calculation on C3N2(CH3)5 reveals that the structure is dynamically stable. PMID:27530344

  10. Nonsequential double ionization of molecules

    SciTech Connect

    Prauzner-Bechcicki, Jakub S.; Sacha, Krzysztof; Zakrzewski, Jakub; Eckhardt, Bruno

    2005-03-01

    Double ionization of diatomic molecules by short linearly polarized laser pulses is analyzed. We consider the final stage of the ionization process, that is the decay of a highly excited two electron molecule, which is formed after rescattering. The saddles of the effective adiabatic potential energy close to which simultaneous escape of electrons takes place are identified. Numerical simulations of the ionization of molecules show that the process can be dominated by either sequential or nonsequential events. In order to increase the ratio of nonsequential to sequential ionizations very short laser pulses should be applied.

  11. Resolving metal-molecule interfaces at single-molecule junctions

    PubMed Central

    Komoto, Yuki; Fujii, Shintaro; Nakamura, Hisao; Tada, Tomofumi; Nishino, Tomoaki; Kiguchi, Manabu

    2016-01-01

    Electronic and structural detail at the electrode-molecule interface have a significant influence on charge transport across molecular junctions. Despite the decisive role of the metal-molecule interface, a complete electronic and structural characterization of the interface remains a challenge. This is in no small part due to current experimental limitations. Here, we present a comprehensive approach to obtain a detailed description of the metal-molecule interface in single-molecule junctions, based on current-voltage (I-V) measurements. Contrary to conventional conductance studies, this I-V approach provides a correlated statistical description of both, the degree of electronic coupling across the metal-molecule interface, and the energy alignment between the conduction orbital and the Fermi level of the electrode. This exhaustive statistical approach was employed to study single-molecule junctions of 1,4-benzenediamine (BDA), 1,4-butanediamine (C4DA), and 1,4-benzenedithiol (BDT). A single interfacial configuration was observed for both BDA and C4DA junctions, while three different interfacial arrangements were resolved for BDT. This multiplicity is due to different molecular adsorption sites on the Au surface namely on-top, hollow, and bridge. Furthermore, C4DA junctions present a fluctuating I-V curve arising from the greater conformational freedom of the saturated alkyl chain, in sharp contrast with the rigid aromatic backbone of both BDA and BDT. PMID:27221947

  12. Resolving metal-molecule interfaces at single-molecule junctions

    NASA Astrophysics Data System (ADS)

    Komoto, Yuki; Fujii, Shintaro; Nakamura, Hisao; Tada, Tomofumi; Nishino, Tomoaki; Kiguchi, Manabu

    2016-05-01

    Electronic and structural detail at the electrode-molecule interface have a significant influence on charge transport across molecular junctions. Despite the decisive role of the metal-molecule interface, a complete electronic and structural characterization of the interface remains a challenge. This is in no small part due to current experimental limitations. Here, we present a comprehensive approach to obtain a detailed description of the metal-molecule interface in single-molecule junctions, based on current-voltage (I-V) measurements. Contrary to conventional conductance studies, this I-V approach provides a correlated statistical description of both, the degree of electronic coupling across the metal-molecule interface, and the energy alignment between the conduction orbital and the Fermi level of the electrode. This exhaustive statistical approach was employed to study single-molecule junctions of 1,4-benzenediamine (BDA), 1,4-butanediamine (C4DA), and 1,4-benzenedithiol (BDT). A single interfacial configuration was observed for both BDA and C4DA junctions, while three different interfacial arrangements were resolved for BDT. This multiplicity is due to different molecular adsorption sites on the Au surface namely on-top, hollow, and bridge. Furthermore, C4DA junctions present a fluctuating I-V curve arising from the greater conformational freedom of the saturated alkyl chain, in sharp contrast with the rigid aromatic backbone of both BDA and BDT.

  13. Glutathione as a signaling molecule: another challenge to pathogens.

    PubMed

    Ghanta, Srijani; Chattopadhyay, Sharmila

    2011-06-01

    Plants harbor a variety of signaling molecules which are members of a vast array of signaling networks in maintaining their physiological balance. The well known members up till now are salicylic acid (SA), jasmonic acid (JA), ethylene (ET), abscissic acid (ABA) and reactive oxygen species (ROS) which are employed by plants for their adaptation to various environmental stresses in order to survive. GSH is gradually gaining importance and becoming a molecule of interest to a number of researchers especially in relation to plant defense to pathogens. Although the role of GSH in plant defense has long been known, a dearth of information still exists regarding the mechanism underlying this defense response. This review highlights on the progress made in the cross-communication of GSH with other established signaling molecules through which GSH acts in abating biotic stress PMID:21969955

  14. Kohn-Sham potentials for fullerenes and spherical molecules

    SciTech Connect

    Pavlyukh, Y.; Berakdar, J.

    2010-04-15

    We present a procedure for the construction of accurate Kohn-Sham potentials of quasispherical molecules starting from the first-principles valence densities. The method is demonstrated for the case of icosahedral C{sub 20}{sup 2+} and C{sub 60} molecules. Provided the density is N representable the Hohenberg-Kohn theorem guarantees the uniqueness of the obtained potentials. The potential is iteratively built following the suggestion of R. van Leeuwen and E. J. Baerends [Phys. Rev. A 49, 2421 (1994)]. The high symmetry of the molecules allows a parametrization of the angular dependence of the densities and the potentials using a small number of symmetry-adapted spherical harmonics. The radial behavior of these quantities is represented on a grid and the density is reconstructed from the approximate potential by numerically solving the coupled-channel Kohn-Sham equations. Subsequently, the potential is updated and the procedure is continued until convergence is achieved.

  15. Fructose-1,6-bisphosphate suppresses lipopolysaccharide-induced expression of ICAM-1 through modulation of toll-like receptor-4 signaling in brain endothelial cells.

    PubMed

    Seok, Sun Mi; Park, Tae Yeop; Park, Hye-Si; Baik, Eun Joo; Lee, Soo Hwan

    2015-05-01

    Fructose-1,6-bisphosphate (FBP) is a glycolytic intermediate with salutary effects in various brain injury models, but its neuroprotective mechanism is incompletely understood. In this study, we examined the effects of FBP on the expression of adhesion molecules in cerebrovascular endothelial cells and explored the possible mechanisms therein involved. FBP significantly down-regulated lipopolysaccharide (LPS)-induced expression of adhesion molecules and leukocyte adhesion to brain endothelial cells and inhibited NF-κB activity, which is implicated in the expression of adhesion molecules. FBP abrogated ICAM-1 expression and NF-κB activation induced by macrophage-activating lipopeptide 2-kDa (MALP-2) or overexpression of MyD88 or TRAF6. FBP suppressed TRAF6-induced phosphorylation of TAK1, IKKβ and IκBα, but fail to affect NF-κB activity induced by ectopic expression of IKKβ. In addition, LPS-induced IRAK-1 phosphorylation was inhibited by FBP, suggesting the presence of multiple molecular targets of FBP in MyD88-dependent signaling pathway. FBP significantly attenuated ICAM-1 expression and NF-κB activity induced by poly[I:C] or overexpression of TRIF or TBK1. FBP significantly repressed the expression of interferon-β (IFN-β) and the activation of IFN regulatory factor 3 (IRF3) induced by LPS, poly[I:C] or overexpression of TRIF or TBK1, but fail to affect IRF3 activity induced by ectopic expression of constitutively active IRF3. Overall, our results demonstrate that FBP modulates both MyD88- and TRIF-dependent signaling pathways of TLR4 and subsequent inflammatory responses in brain endothelial cells, providing insight into its neuroprotective mechanism in brain injury associated with inflammation. PMID:25843256

  16. Moving Molecules and Mothball Madness.

    ERIC Educational Resources Information Center

    Strain, John

    1993-01-01

    Describes concrete demonstrations on the states of matter. In the first demonstration, students represent molecules; and, in the second demonstration, moth balls are heated to produce a change of state. (PR)

  17. Surface chemistry of deuterated molecules

    NASA Astrophysics Data System (ADS)

    Tielens, A. G. G. M.

    1983-03-01

    The chemical composition of grain mantles is calculated in order to determine the concentration of deuterated molecules relative to their hydrogenated counterparts in grain mantles. The computation takes into account reactions involving deuterium in the gas phase and on grain surfaces. The results show that the abundance of deuterium molecules in grain mantles is much higher than expected on the basis of the cosmic abundance ratio of D to H. HDCO has a relatively high abundance in grain mantles as compared to other deuterated molecules, due to the fact that H abstraction from HDCO has a lower activation barrier than D abstraction. The infrared characteristics of the calculated grain mantles are discussed and observational tests of the model calcultions are suggested. The contribution of grain surface chemistry to the concentration of molecules in the gas phase is briefly considered.

  18. Cobalt single-molecule magnet

    NASA Astrophysics Data System (ADS)

    Yang, En-Che; Hendrickson, David N.; Wernsdorfer, Wolfgang; Nakano, Motohiro; Zakharov, Lev N.; Sommer, Roger D.; Rheingold, Arnold L.; Ledezma-Gairaud, Marisol; Christou, George

    2002-05-01

    A cobalt molecule that functions as a single-molecule magnet, [Co4(hmp)4(MeOH)4Cl4], where hmp- is the anion of hydroxymethylpyridine, is reported. The core of the molecule consists of four Co(II) cations and four hmp- oxygen atom ions at the corners of a cube. Variable-field and variable-temperature magnetization data have been analyzed to establish that the molecule has a S=6 ground state with considerable negative magnetoanisotropy. Single-ion zero-field interactions (DSz2) at each cobalt ion are the origin of the negative magnetoanisotropy. A single crystal of the compound was studied by means of a micro-superconducting quantum interference device magnetometer in the range of 0.040-1.0 K. Hysteresis was found in the magnetization versus magnetic field response of this single crystal.

  19. Spin tunneling in magnetic molecules

    NASA Astrophysics Data System (ADS)

    Kececioglu, Ersin

    In this thesis, we will focus on spin tunneling in a family of systems called magnetic molecules such as Fe8 and Mn12. This is comparatively new, in relation to other tunneling problems. Many issues are not completely solved and/or understood yet. The magnetic molecule Fe 8 has been observed to have a rich pattern of degeneracies in its magnetic spectrum. We focus on these degeneracies from several points of view. We start with the simplest anisotropy Hamiltonian to describe the Fe 8 molecule and extend our discussion to include higher order anisotropy terms. We give analytical expressions as much as we can, for the degeneracies in the semi-classical limit in both cases. We reintroduce jump instantons to the instanton formalism. Finally, we discuss the effect of the environment on the molecule. Our results, for all different models and techniques, agree well with both experimental and numerical results.

  20. Molecule-hugging graphene nanopores

    PubMed Central

    Garaj, Slaven; Liu, Song; Golovchenko, Jene A.; Branton, Daniel

    2013-01-01

    It has recently been recognized that solid-state nanopores in single-atomic-layer graphene membranes can be used to electronically detect and characterize single long charged polymer molecules. We have now fabricated nanopores in single-layer graphene that are closely matched to the diameter of a double-stranded DNA molecule. Ionic current signals during electrophoretically driven translocation of DNA through these nanopores were experimentally explored and theoretically modeled. Our experiments show that these nanopores have unusually high sensitivity (0.65 nA/Å) to extremely small changes in the translocating molecule’s outer diameter. Such atomically short graphene nanopores can also resolve nanoscale-spaced molecular structures along the length of a polymer, but do so with greatest sensitivity only when the pore and molecule diameters are closely matched. Modeling confirms that our most closely matched pores have an inherent resolution of ≤0.6 nm along the length of the molecule. PMID:23836648

  1. Single-Molecule DNA Analysis

    NASA Astrophysics Data System (ADS)

    Efcavitch, J. William; Thompson, John F.

    2010-07-01

    The ability to detect single molecules of DNA or RNA has led to an extremely rich area of exploration of the single most important biomolecule in nature. In cases in which the nucleic acid molecules are tethered to a solid support, confined to a channel, or simply allowed to diffuse into a detection volume, novel techniques have been developed to manipulate the DNA and to examine properties such as structural dynamics and protein-DNA interactions. Beyond the analysis of the properties of nucleic acids themselves, single-molecule detection has enabled dramatic improvements in the throughput of DNA sequencing and holds promise for continuing progress. Both optical and nonoptical detection methods that use surfaces, nanopores, and zero-mode waveguides have been attempted, and one optically based instrument is already commercially available. The breadth of literature related to single-molecule DNA analysis is vast; this review focuses on a survey of efforts in molecular dynamics and nucleic acid sequencing.

  2. Fluorescence Microscopy of Single Molecules

    ERIC Educational Resources Information Center

    Zimmermann, Jan; van Dorp, Arthur; Renn, Alois

    2004-01-01

    The investigation of photochemistry and photophysics of individual quantum systems is described with the help of a wide-field fluorescence microscopy approach. The fluorescence single molecules are observed in real time.

  3. Collisional decoherence of polar molecules

    NASA Astrophysics Data System (ADS)

    Walter, Kai; Stickler, Benjamin A.; Hornberger, Klaus

    2016-06-01

    The quantum state of motion of a large and rotating polar molecule can lose coherence through the collisions with gas atoms. We show how the associated quantum master equation for the center of mass can be expressed in terms of the orientationally averaged differential and total scattering cross sections, for which we provide approximate analytic expressions. The master equation is then utilized to quantify collisional decoherence in a interference experiment with polar molecules.

  4. Nanochannel Based Single Molecule Recycling

    PubMed Central

    Lesoine, John F.; Venkataraman, Prahnesh A.; Maloney, Peter C.; Dumont, Mark

    2012-01-01

    We present a method for measuring the fluorescence from a single molecule hundreds of times without surface immobilization. The approach is based on the use of electroosmosis to repeatedly drive a single target molecule in a fused silica nanochannel through a stationary laser focus. Single molecule fluorescence detected during the transit time through the laser focus is used to repeatedly reverse the electrical potential controlling the flow direction. Our method does not rely on continuous observation and therefore is less susceptible to fluorescence blinking than existing fluorescence-based trapping schemes. The variation in the turnaround times can be used to measure the diffusion coefficient on a single molecule level. We demonstrate the ability to recycle both proteins and DNA in nanochannels and show that the procedure can be combined with single-pair Förster energy transfer. Nanochannel-based single molecule recycling holds promise for studying conformational dynamics on the same single molecule in solution and without surface tethering. PMID:22662745

  5. Combining single-molecule manipulation and single-molecule detection.

    PubMed

    Cordova, Juan Carlos; Das, Dibyendu Kumar; Manning, Harris W; Lang, Matthew J

    2014-10-01

    Single molecule force manipulation combined with fluorescence techniques offers much promise in revealing mechanistic details of biomolecular machinery. Here, we review force-fluorescence microscopy, which combines the best features of manipulation and detection techniques. Three of the mainstay manipulation methods (optical traps, magnetic traps and atomic force microscopy) are discussed with respect to milestones in combination developments, in addition to highlight recent contributions to the field. An overview of additional strategies is discussed, including fluorescence based force sensors for force measurement in vivo. Armed with recent exciting demonstrations of this technology, the field of combined single-molecule manipulation and single-molecule detection is poised to provide unprecedented views of molecular machinery. PMID:25255052

  6. Raman Optical Activity Spectra for Large Molecules through Molecules-in-Molecules Fragment-Based Approach.

    PubMed

    Jovan Jose, K V; Raghavachari, Krishnan

    2016-02-01

    We present an efficient method for the calculation of the Raman optical activity (ROA) spectra for large molecules through the molecules-in-molecules (MIM) fragment-based method. The relevant higher energy derivatives from smaller fragments are used to build the property tensors of the parent molecule to enable the extension of the MIM method for evaluating ROA spectra (MIM-ROA). Two factors were found to be particularly important in yielding accurate results. First, the link-atom tensor components are projected back onto the corresponding host and supporting atoms through the Jacobian projection method, yielding a mathematically rigorous method. Second, the long-range interactions between fragments are taken into account by using a less computationally expensive lower level of theory. The performance of the MIM-ROA model is calibrated on the enantiomeric pairs of 10 carbohydrate benchmark molecules, with strong intramolecular interactions. The vibrational frequencies and ROA intensities are accurately reproduced relative to the full, unfragmented, results for these systems. In addition, the MIM-ROA method is employed to predict the ROA spectra of d-maltose, α-D-cyclodextrin, and cryptophane-A, yielding spectra in excellent agreement with experiment. The accuracy and performance of the benchmark systems validate the MIM-ROA model for exploring ROA spectra of large molecules. PMID:26760444

  7. Measuring an antibody affinity distribution molecule by molecule

    SciTech Connect

    Bradbury, Andrew M; Werner, James H; Temirov, Jamshid

    2008-01-01

    Single molecule fluorescence mIcroscopy was used to observe the binding and unbinding of hapten decorated quantum dots with individual surface immobilized antibodies. The fluorescence time history from an individual antibody site can be used to calculate its binding affinity. While quantum dot blinking occurs during these measurements, we describe a simple empirical method to correct the apparent/observed affinity to account for the blinking contribution. The combination of many single molecule affinity measurements from different antibodies yields not only the average affinity, it directly measures the full shape and character of the surface affinity distribution function.

  8. Organizational Adaptation and Higher Education.

    ERIC Educational Resources Information Center

    Cameron, Kim S.

    1984-01-01

    Organizational adaptation and types of adaptation needed in academe in the future are reviewed and major conceptual approaches to organizational adaptation are presented. The probable environment that institutions will face in the future that will require adaptation is discussed. (MLW)

  9. Spectroscopic modeling of water molecule

    NASA Astrophysics Data System (ADS)

    Danylo, R. I.; Okhrimenko, B. A.

    2013-12-01

    This research is devoted to the vibrational spectroscopy inverse problem solution that gives a possibility to design a molecule and make conclusions about its geometry. The valence angle finding based on the usage of inverse spectral vibrational spectroscopy problem is a well-known task. 3N-matrix method was chosen to solve the proposed task. The usage of this method permits to make no assumptions about the molecule force field, besides it can be applied to molecules of matter in liquid state. Anharmonicity constants assessment is an important part of the valence angle finding. The reduction to zero vibrations is necessary because used matrix analytical expression were found in the harmonic approach. In order to find the single-valued inverse spectral problem of vibrational spectroscopy solution a shape parameter characterizing "mixing" of ω1 and ω2 vibrations forms must be found. The minimum of such a function Υ called a divergence parameter was found. This function characterizes method's accuracy. The valence angle assessment was reduced to the divergence parameter minimization. The β value concerning divergence parameter minimum was interpreted as the desired valence angle. The proposed method was applied for water molecule in liquid state: β = (88,8 ±1,7)° . The found angle fits the water molecule nearest surrounding tetrahedral model including hydrogen bond curvature in the first approximation.

  10. Parasite molecules and host responses in cystic echinococcosis.

    PubMed

    Díaz, A; Casaravilla, C; Barrios, A A; Ferreira, A M

    2016-03-01

    Cystic echinococcosis is the infection by the larvae of cestode parasites belonging to the Echinococcus granulosus sensu lato species complex. Local host responses are strikingly subdued in relation to the size and persistence of these larvae, which develop within mammalian organs as 'hydatid cysts' measuring up to tens of cm in diameter. In a context in which helminth-derived immune-suppressive, as well as Th2-inducing, molecules garner much interest, knowledge on the interactions between E. granulosus molecules and the immune system lags behind. Here, we discuss what is known and what are the open questions on E. granulosus molecules and structures interacting with the innate and adaptive immune systems, potentially or in demonstrated form. We attempt a global biological approach on molecules that have been given consideration primarily as protective (Eg95) or diagnostic antigens (antigen B, antigen 5). We integrate glycobiological information, which traverses the discussions on antigen 5, the mucin-based protective laminated layer and immunologically active preparations from protoscoleces. We also highlight some less well-known molecules that appear as promising candidates to possess immune-regulatory activities. Finally, we point out gaps in the molecular-level knowledge of this infectious agent that hinder our understanding of its immunology. PMID:26425838

  11. Room temperature single molecule microscopes

    SciTech Connect

    Ambrose, W.P.; Goodwin, P.M.; Enderlein, G.; Semin, D.J.; Keller, R.A.

    1997-12-31

    We have developed three capabilities to image the locations of and interrogate immobilized single fluorescent molecules: near-field scanning optical, confocal scanning optical, and wide-field epi-fluorescence microscopy. Each microscopy has its own advantages. Near-field illumination can beat the diffraction limit. Confocal microscopy has high brightness and temporal resolution. Wide-field has the quickest (parallel) imaging capability. With confocal microscopy, we have verified that single fluorescent spots in our images are due to single molecules by observing photon antibunching. Using all three microscopies, we have observed that xanthene molecules dispersed on dry silica curiously exhibit intensity fluctuations on millisecond to minute time scales. We are exploring the connection between the intensity fluctuations and fluctuations in individual photophysical parameters. The fluorescence lifetimes of Rhodamine 6G on silica fluctuate. The complex nature of the intensity and lifetime fluctuations is consistent with a mechanism that perturbs more than one photophysical parameter.

  12. Guidance molecules in lung cancer

    PubMed Central

    Nasarre, Patrick; Potiron, Vincent; Drabkin, Harry

    2010-01-01

    Guidance molecules were first described in the nervous system to control axon outgrowth direction. They are also widely expressed outside the nervous system where they control cell migration, tissue development and establishment of the vascular network. In addition, they are involved in cancer development, tumor angiogenesis and metastasis. This review is primarily focused on their functions in lung cancer and their involvement in lung development is also presented. Five guidance molecule families and their corresponding receptors are described, including the semaphorins/neuropilins/plexins, ephrins and Eph receptors, netrin/DCC/UNC5, Slit/Robo and Notch/Delta. In addition, the possibility to target these molecules as a therapeutic approach in cancer is discussed. PMID:20139699

  13. Phase structure of soliton molecules

    SciTech Connect

    Hause, A.; Hartwig, H.; Seifert, B.; Stolz, H.; Boehm, M.; Mitschke, F.

    2007-06-15

    Temporal optical soliton molecules were recently demonstrated; they potentially allow further increase of data rates in optical telecommunication. Their binding mechanism relies on the internal phases, but these have not been experimentally accessible so far. Conventional frequency-resolved optical gating techniques are not suited for measurement of their phase profile: Their algorithms fail to converge due to zeros both in their temporal and their spectral profile. We show that the VAMPIRE (very advanced method of phase and intensity retrieval of E-fields) method performs reliably. With VAMPIRE the phase profile of soliton molecules has been measured, and further insight into the mechanism is obtained.

  14. Phase structure of soliton molecules

    NASA Astrophysics Data System (ADS)

    Hause, A.; Hartwig, H.; Seifert, B.; Stolz, H.; Böhm, M.; Mitschke, F.

    2007-06-01

    Temporal optical soliton molecules were recently demonstrated; they potentially allow further increase of data rates in optical telecommunication. Their binding mechanism relies on the internal phases, but these have not been experimentally accessible so far. Conventional frequency-resolved optical gating techniques are not suited for measurement of their phase profile: Their algorithms fail to converge due to zeros both in their temporal and their spectral profile. We show that the VAMPIRE (very advanced method of phase and intensity retrieval of E -fields) method performs reliably. With VAMPIRE the phase profile of soliton molecules has been measured, and further insight into the mechanism is obtained.

  15. Orbital molecules in electronic materials

    SciTech Connect

    Attfield, J. Paul

    2015-04-01

    Orbital molecules are made up of coupled orbital states on several metal ions within an orbitally ordered (and sometimes also charge-ordered) solid such as a transition metal oxide. Spin-singlet dimers are known in many materials, but recent discoveries of more exotic species such as 18-electron heptamers in AlV{sub 2}O{sub 4} and magnetic 3-atom trimerons in magnetite (Fe{sub 3}O{sub 4}) have shown that orbital molecules constitute a general new class of quantum electronic states in solids.

  16. Dipolar molecules in optical lattices.

    PubMed

    Sowiński, Tomasz; Dutta, Omjyoti; Hauke, Philipp; Tagliacozzo, Luca; Lewenstein, Maciej

    2012-03-16

    We study the extended Bose-Hubbard model describing an ultracold gas of dipolar molecules in an optical lattice, taking into account all on-site and nearest-neighbor interactions, including occupation-dependent tunneling and pair tunneling terms. Using exact diagonalization and the multiscale entanglement renormalization ansatz, we show that these terms can destroy insulating phases and lead to novel quantum phases. These considerable changes of the phase diagram have to be taken into account in upcoming experiments with dipolar molecules. PMID:22540482

  17. Nonadiabatic reaction of energetic molecules.

    PubMed

    Bhattacharya, Atanu; Guo, Yuanqing; Bernstein, Elliot R

    2010-12-21

    Energetic materials store a large amount of chemical energy that can be readily converted into mechanical energy via decomposition. A number of different ignition processes such as sparks, shocks, heat, or arcs can initiate the excited electronic state decomposition of energetic materials. Experiments have demonstrated the essential role of excited electronic state decomposition in the energy conversion process. A full understanding of the mechanisms for the decomposition of energetic materials from excited electronic states will require the investigation and analysis of the specific topography of the excited electronic potential energy surfaces (PESs) of these molecules. The crossing of multidimensional electronic PESs creates a funnel-like topography, known as conical intersections (CIs). CIs are well established as a controlling factor in the excited electronic state decomposition of polyatomic molecules. This Account summarizes our current understanding of the nonadiabatic unimolecular chemistry of energetic materials through CIs and presents the essential role of CIs in the determination of decomposition pathways of these energetic systems. Because of the involvement of more than one PES, a decomposition process involving CIs is an electronically nonadiabatic mechanism. Based on our experimental observations and theoretical calculations, we find that a nonadiabatic reaction through CIs dominates the initial decomposition process of energetic materials from excited electronic states. Although the nonadiabatic behavior of some polyatomic molecules has been well studied, the role of nonadiabatic reactions in the excited electronic state decomposition of energetic molecules has not been well investigated. We use both nanosecond energy-resolved and femtosecond time-resolved spectroscopic techniques to determine the decomposition mechanism and dynamics of energetic species experimentally. Subsequently, we employ multiconfigurational methodologies (such as, CASSCF

  18. Piezoresistivity in single DNA molecules

    PubMed Central

    Bruot, Christopher; Palma, Julio L.; Xiang, Limin; Mujica, Vladimiro; Ratner, Mark A.; Tao, Nongjian

    2015-01-01

    Piezoresistivity is a fundamental property of materials that has found many device applications. Here we report piezoresistivity in double helical DNA molecules. By studying the dependence of molecular conductance and piezoresistivity of single DNA molecules with different sequences and lengths, and performing molecular orbital calculations, we show that the piezoresistivity of DNA is caused by force-induced changes in the π–π electronic coupling between neighbouring bases, and in the activation energy of hole hopping. We describe the results in terms of thermal activated hopping model together with the ladder-based mechanical model for DNA proposed by de Gennes. PMID:26337293

  19. Piezoresistivity in single DNA molecules

    NASA Astrophysics Data System (ADS)

    Bruot, Christopher; Palma, Julio L.; Xiang, Limin; Mujica, Vladimiro; Ratner, Mark A.; Tao, Nongjian

    2015-09-01

    Piezoresistivity is a fundamental property of materials that has found many device applications. Here we report piezoresistivity in double helical DNA molecules. By studying the dependence of molecular conductance and piezoresistivity of single DNA molecules with different sequences and lengths, and performing molecular orbital calculations, we show that the piezoresistivity of DNA is caused by force-induced changes in the π-π electronic coupling between neighbouring bases, and in the activation energy of hole hopping. We describe the results in terms of thermal activated hopping model together with the ladder-based mechanical model for DNA proposed by de Gennes.

  20. Piezoresistivity in single DNA molecules.

    PubMed

    Bruot, Christopher; Palma, Julio L; Xiang, Limin; Mujica, Vladimiro; Ratner, Mark A; Tao, Nongjian

    2015-01-01

    Piezoresistivity is a fundamental property of materials that has found many device applications. Here we report piezoresistivity in double helical DNA molecules. By studying the dependence of molecular conductance and piezoresistivity of single DNA molecules with different sequences and lengths, and performing molecular orbital calculations, we show that the piezoresistivity of DNA is caused by force-induced changes in the π-π electronic coupling between neighbouring bases, and in the activation energy of hole hopping. We describe the results in terms of thermal activated hopping model together with the ladder-based mechanical model for DNA proposed by de Gennes. PMID:26337293

  1. Parallel Anisotropic Tetrahedral Adaptation

    NASA Technical Reports Server (NTRS)

    Park, Michael A.; Darmofal, David L.

    2008-01-01

    An adaptive method that robustly produces high aspect ratio tetrahedra to a general 3D metric specification without introducing hybrid semi-structured regions is presented. The elemental operators and higher-level logic is described with their respective domain-decomposed parallelizations. An anisotropic tetrahedral grid adaptation scheme is demonstrated for 1000-1 stretching for a simple cube geometry. This form of adaptation is applicable to more complex domain boundaries via a cut-cell approach as demonstrated by a parallel 3D supersonic simulation of a complex fighter aircraft. To avoid the assumptions and approximations required to form a metric to specify adaptation, an approach is introduced that directly evaluates interpolation error. The grid is adapted to reduce and equidistribute this interpolation error calculation without the use of an intervening anisotropic metric. Direct interpolation error adaptation is illustrated for 1D and 3D domains.

  2. Gravitational adaptation of animals

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Burton, R. R.

    1982-01-01

    The effect of gravitational adaptation is studied in a group of five Leghorn cocks which had become physiologically adapted to 2 G after 162 days of centrifugation. After this period of adaptation, they are periodically exposed to a 2 G field, accompanied by five previously unexposed hatch-mates, and the degree of retained acceleration adaptation is estimated from the decrease in lymphocyte frequency after 24 hr at 2 G. Results show that the previously adapted birds exhibit an 84% greater lymphopenia than the unexposed birds, and that the lymphocyte frequency does not decrease to a level below that found at the end of 162 days at 2 G. In addition, the capacity for adaptation to chronic acceleration is found to be highly heritable. An acceleration tolerant strain of birds shows lesser mortality during chronic acceleration, particularly in intermediate fields, although the result of acceleration selection is largely quantitative (a greater number of survivors) rather than qualitative (behavioral or physiological changes).

  3. Technology transfer for adaptation

    NASA Astrophysics Data System (ADS)

    Biagini, Bonizella; Kuhl, Laura; Gallagher, Kelly Sims; Ortiz, Claudia

    2014-09-01

    Technology alone will not be able to solve adaptation challenges, but it is likely to play an important role. As a result of the role of technology in adaptation and the importance of international collaboration for climate change, technology transfer for adaptation is a critical but understudied issue. Through an analysis of Global Environment Facility-managed adaptation projects, we find there is significantly more technology transfer occurring in adaptation projects than might be expected given the pessimistic rhetoric surrounding technology transfer for adaptation. Most projects focused on demonstration and early deployment/niche formation for existing technologies rather than earlier stages of innovation, which is understandable considering the pilot nature of the projects. Key challenges for the transfer process, including technology selection and appropriateness under climate change, markets and access to technology, and diffusion strategies are discussed in more detail.

  4. Adaptation as organism design

    PubMed Central

    Gardner, Andy

    2009-01-01

    The problem of adaptation is to explain the apparent design of organisms. Darwin solved this problem with the theory of natural selection. However, population geneticists, whose responsibility it is to formalize evolutionary theory, have long neglected the link between natural selection and organismal design. Here, I review the major historical developments in theory of organismal adaptation, clarifying what adaptation is and what it is not, and I point out future avenues for research. PMID:19793739

  5. The contribution of transcriptomic and proteomic analysis in elucidating stress adaptation responses of Listeria monocytogenes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The foodborne transmission of Listeria monocytogenes requires physiological adaptation to various conditions, including the cold, osmotic, heat, acid, alkaline, and oxidative stresses, associated with food hygiene, processing, and preservation measures. We review the current knowledge on the molecul...

  6. Phase Adaptation and Correction by Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Tiziani, Hans J.

    2010-04-01

    Adaptive optical elements and systems for imaging or laser beam propagation are used for some time in particular in astronomy, where the image quality is degraded by atmospheric turbulence. In astronomical telescopes a deformable mirror is frequently used to compensate wavefront-errors due to deformations of the large mirror, vibrations as well as turbulence and hence to increase the image quality. In the last few years interesting elements like Spatial Light Modulators, SLM's, such as photorefractive crystals, liquid crystals and micro mirrors and membrane mirrors were introduced. The development of liquid crystals and micro mirrors was driven by data projectors as consumer products. They contain typically a matrix of individually addressable pixels of liquid crystals and flip mirrors respectively or more recently piston mirrors for special applications. Pixel sizes are in the order of a few microns and therefore also appropriate as active diffractive elements in digital holography or miniature masks. Although liquid crystals are mainly optimized for intensity modulation; they can be used for phase modulation. Adaptive optics is a technology for beam shaping and wavefront adaptation. The application of spatial light modulators for wavefront adaptation and correction and defect analysis as well as sensing will be discussed. Dynamic digital holograms are generated with liquid crystal devices (LCD) and used for wavefront correction as well as for beam shaping and phase manipulation, for instance. Furthermore, adaptive optics is very useful to extend the measuring range of wavefront sensors and for the wavefront adaptation in order to measure and compare the shape of high precision aspherical surfaces.

  7. The non-equilibrium and energetic cost of sensory adaptation

    SciTech Connect

    Lan, G.; Sartori, Pablo; Tu, Y.

    2011-03-24

    Biological sensory systems respond to external signals in short time and adapt to permanent environmental changes over a longer timescale to maintain high sensitivity in widely varying environments. In this work we have shown how all adaptation dynamics are intrinsically non-equilibrium and free energy is dissipated. We show that the dissipated energy is utilized to maintain adaptation accuracy. A universal relation between the energy dissipation and the optimum adaptation accuracy is established by both a general continuum model and a discrete model i n the specific case of the well-known E. coli chemo-sensory adaptation. Our study suggests that cellular level adaptations are fueled by hydrolysis of high energy biomolecules, such as ATP. The relevance of this work lies on linking the functionality of a biological system (sensory adaptation) with a concept rooted in statistical physics (energy dissipation), by a mathematical law. This has been made possible by identifying a general sensory system with a non-equilibrium steady state (a stationary state in which the probability current is not zero, but its divergence is, see figure), and then numerically and analytically solving the Fokker-Planck and Master Equations which describe the sensory adaptive system. The application of our general results to the case of E. Coli has shed light on why this system uses the high energy SAM molecule to perform adaptation, since using the more common ATP would not suffice to obtain the required adaptation accuracy.

  8. Human adaptation to smog

    SciTech Connect

    Evans, G.W. Jacobs, S.V.; Frager, N.B.

    1982-10-01

    This study examined the health effects of human adaptation to photochemical smog. A group of recent arrivals to the Los Angeles air basin were compared to long-term residents of the basin. Evidence for adaptation included greater irritation and respiratory problems among the recent arrivals and desensitization among the long-term residents in their judgments of the severity of the smog problem to their health. There was no evidence for biochemical adaptation as measured by hemoglobin response to oxidant challenge. The results were discussed in terms of psychological adaption to chronic environmental stressors.

  9. Adaptive parallel logic networks

    NASA Technical Reports Server (NTRS)

    Martinez, Tony R.; Vidal, Jacques J.

    1988-01-01

    Adaptive, self-organizing concurrent systems (ASOCS) that combine self-organization with massive parallelism for such applications as adaptive logic devices, robotics, process control, and system malfunction management, are presently discussed. In ASOCS, an adaptive network composed of many simple computing elements operating in combinational and asynchronous fashion is used and problems are specified by presenting if-then rules to the system in the form of Boolean conjunctions. During data processing, which is a different operational phase from adaptation, the network acts as a parallel hardware circuit.

  10. Quantifying the Adaptive Cycle

    PubMed Central

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems. PMID:26716453

  11. Decentralized adaptive control

    NASA Technical Reports Server (NTRS)

    Oh, B. J.; Jamshidi, M.; Seraji, H.

    1988-01-01

    A decentralized adaptive control is proposed to stabilize and track the nonlinear, interconnected subsystems with unknown parameters. The adaptation of the controller gain is derived by using model reference adaptive control theory based on Lyapunov's direct method. The adaptive gains consist of sigma, proportional, and integral combination of the measured and reference values of the corresponding subsystem. The proposed control is applied to the joint control of a two-link robot manipulator, and the performance in computer simulation corresponds with what is expected in theoretical development.

  12. Single-Molecule Trapping Dynamics of Sugar-Uptake Channels in Marine Bacteria

    NASA Astrophysics Data System (ADS)

    Suginta, Wipa; Smith, M. F.

    2013-06-01

    Stochastic fluctuations of ion current through one chitoporin (ChiP) channel within a bilayer lipid membrane in sugar solution are analyzed. These reflect single-molecule dynamics, which indicate that ChiP has multiple binding sites for sugar and exploits interactions between bound molecules to direct sugar passage. Since ChiP is used by marine bacteria, this is likely an adaptive strategy to enhance sugar translocation from rough water.

  13. QPSO-Based Adaptive DNA Computing Algorithm

    PubMed Central

    Karakose, Mehmet; Cigdem, Ugur

    2013-01-01

    DNA (deoxyribonucleic acid) computing that is a new computation model based on DNA molecules for information storage has been increasingly used for optimization and data analysis in recent years. However, DNA computing algorithm has some limitations in terms of convergence speed, adaptability, and effectiveness. In this paper, a new approach for improvement of DNA computing is proposed. This new approach aims to perform DNA computing algorithm with adaptive parameters towards the desired goal using quantum-behaved particle swarm optimization (QPSO). Some contributions provided by the proposed QPSO based on adaptive DNA computing algorithm are as follows: (1) parameters of population size, crossover rate, maximum number of operations, enzyme and virus mutation rate, and fitness function of DNA computing algorithm are simultaneously tuned for adaptive process, (2) adaptive algorithm is performed using QPSO algorithm for goal-driven progress, faster operation, and flexibility in data, and (3) numerical realization of DNA computing algorithm with proposed approach is implemented in system identification. Two experiments with different systems were carried out to evaluate the performance of the proposed approach with comparative results. Experimental results obtained with Matlab and FPGA demonstrate ability to provide effective optimization, considerable convergence speed, and high accuracy according to DNA computing algorithm. PMID:23935409

  14. Monitoring Molecules: Insights and Progress

    PubMed Central

    2015-01-01

    In August, 2014, neuroscientists and physical scientists gathered together on the campus of the University of California, Los Angeles to discuss how to monitor molecules in neuroscience. This field has seen significant growth since its inception in the 1970s. Here, the advances in this field are documented, including its advance into understanding the actions that specific neurotransmitters mediate during behavior. PMID:25514501

  15. Nucleic Acids as Information Molecules.

    ERIC Educational Resources Information Center

    McInerney, Joseph D.

    1996-01-01

    Presents an activity that aims at enabling students to recognize that DNA and RNA are information molecules whose function is to store, copy, and make available the information in biological systems, without feeling overwhelmed by the specialized vocabulary and the minutia of the central dogma. (JRH)

  16. Nanodevices for Single Molecule Studies

    NASA Astrophysics Data System (ADS)

    Craighead, H. G.; Stavis, S. M.; Samiee, K. T.

    During the last two decades, biotechnology research has resulted in progress in fields as diverse as the life sciences, agriculture and healthcare. While existing technology enables the analysis of a variety of biological systems, new tools are needed for increasing the efficiency of current methods, and for developing new ones altogether. Interest has grown in single molecule analysis for these reasons.

  17. Dialkylresorcinols as bacterial signaling molecules

    PubMed Central

    Brameyer, Sophie; Kresovic, Darko; Bode, Helge B.; Heermann, Ralf

    2015-01-01

    It is well recognized that bacteria communicate via small diffusible molecules, a process termed quorum sensing. The best understood quorum sensing systems are those that use acylated homoserine lactones (AHLs) for communication. The prototype of those systems consists of a LuxI-like AHL synthase and a cognate LuxR receptor that detects the signal. However, many proteobacteria possess LuxR receptors, yet lack any LuxI-type synthase, and thus these receptors are referred to as LuxR orphans or solos. In addition to the well-known AHLs, little is known about the signaling molecules that are sensed by LuxR solos. Here, we describe a novel cell–cell communication system in the insect and human pathogen Photorhabdus asymbiotica. We identified the LuxR homolog PauR to sense dialkylresorcinols (DARs) and cyclohexanediones (CHDs) instead of AHLs as signals. The DarABC synthesis pathway produces the molecules, and the entire system emerged as important for virulence. Moreover, we have analyzed more than 90 different Photorhabdus strains by HPLC/MS and showed that these DARs and CHDs are specific to the human pathogen P. asymbiotica. On the basis of genomic evidence, 116 other bacterial species are putative DAR producers, among them many human pathogens. Therefore, we discuss the possibility of DARs as novel and widespread bacterial signaling molecules and show that bacterial cell–cell communication goes far beyond AHL signaling in nature. PMID:25550519

  18. Engineering crystals of dendritic molecules.

    PubMed

    Lukin, Oleg; Schubert, Dirk; Müller, Claudia M; Schweizer, W Bernd; Gramlich, Volker; Schneider, Julian; Dolgonos, Grygoriy; Shivanyuk, Alexander

    2009-07-01

    A detailed single-crystal X-ray study of conformationally flexible sulfonimide-based dendritic molecules with systematically varied molecular architectures was undertaken. Thirteen crystal structures reported in this work include 9 structures of the second-generation dendritic sulfonimides decorated with different aryl groups, 2 compounds bearing branches of both second and first generation, and 2 representatives of the first generation. Analysis of the packing patterns of 9 compounds bearing second-generation branches shows that despite their lack of strong directive functional groups there is a repeatedly reproduced intermolecular interaction mode consisting in an anchor-type packing of complementary second-generation branches of neighbouring molecules. The observed interaction tolerates a wide range of substituents in meta- and para-positions of the peripheral arylsulfonyl rings. Quantum chemical calculations of the molecule-molecule interaction energies agree at the qualitative level with the packing preferences found in the crystalline state. The calculations can therefore be used as a tool to rationalize and predict molecular structures with commensurate and non-commensurate branches for programming of different packing modes in crystal. PMID:19549870

  19. Engineering crystals of dendritic molecules

    PubMed Central

    Lukin, Oleg; Schubert, Dirk; Müller, Claudia M.; Schweizer, W. Bernd; Gramlich, Volker; Schneider, Julian; Dolgonos, Grygoriy; Shivanyuk, Alexander

    2009-01-01

    A detailed single-crystal X-ray study of conformationally flexible sulfonimide-based dendritic molecules with systematically varied molecular architectures was undertaken. Thirteen crystal structures reported in this work include 9 structures of the second-generation dendritic sulfonimides decorated with different aryl groups, 2 compounds bearing branches of both second and first generation, and 2 representatives of the first generation. Analysis of the packing patterns of 9 compounds bearing second-generation branches shows that despite their lack of strong directive functional groups there is a repeatedly reproduced intermolecular interaction mode consisting in an anchor-type packing of complementary second-generation branches of neighbouring molecules. The observed interaction tolerates a wide range of substituents in meta- and para-positions of the peripheral arylsulfonyl rings. Quantum chemical calculations of the molecule-molecule interaction energies agree at the qualitative level with the packing preferences found in the crystalline state. The calculations can therefore be used as a tool to rationalize and predict molecular structures with commensurate and non-commensurate branches for programming of different packing modes in crystal. PMID:19549870

  20. The Lyme Disease Spirochete Borrelia burgdorferi Utilizes Multiple Ligands, Including RNA, for Interferon Regulatory Factor 3-Dependent Induction of Type I Interferon-Responsive Genes ▿

    PubMed Central

    Miller, Jennifer C.; Maylor-Hagen, Heather; Ma, Ying; Weis, John H.; Weis, Janis J.

    2010-01-01

    We recently discovered a critical role for type I interferon (IFN) in the development of murine Lyme arthritis. Borrelia burgdorferi-mediated induction of IFN-responsive genes by bone marrow-derived macrophages (BMDMs) was dependent upon a functional type I IFN receptor but independent of Toll-like receptor 2 (TLR2), TLR4, TLR9, and the adapter molecule MyD88. We now demonstrate that induction of the IFN transcriptional profile in B. burgdorferi-stimulated BMDMs occurs independently of the adapter TRIF and of the cytoplasmic sensor NOD2. In contrast, B. burgdorferi-induced transcription of these genes was dependent upon a rapid STAT1 feedback amplification pathway. IFN profile gene transcription was IRF3 dependent but did not utilize B. burgdorferi-derived DNA or DNase-sensitive ligands. Instead, IFN-responsive gene expression could be induced by B. burgdorferi-derived RNA. Interferon regulatory factor 3 (IRF3)-dependent IFN profile gene transcription was also induced by sonicated bacteria, by the lipoprotein OspA, and by factors released into the BSKII medium during culture of B. burgdorferi. The IFN-stimulatory activity of B. burgdorferi culture supernatants was not destroyed by nuclease treatment. Nuclease digestion also had no effect on IFN profile induction mediated by sonicated B. burgdorferi. Thus, B. burgdorferi-derived RNA, OspA, and non-nucleic acid ligands present in both sonicated bacteria and B. burgdorferi culture medium contribute to type I IFN-responsive gene induction. These findings suggest that B. burgdorferi invasion of joint tissue and the resultant type I IFN induction associated with Lyme arthritis development may involve multiple triggering ligands. PMID:20404081

  1. Applying Adaptive Variables in Computerised Adaptive Testing

    ERIC Educational Resources Information Center

    Triantafillou, Evangelos; Georgiadou, Elissavet; Economides, Anastasios A.

    2007-01-01

    Current research in computerised adaptive testing (CAT) focuses on applications, in small and large scale, that address self assessment, training, employment, teacher professional development for schools, industry, military, assessment of non-cognitive skills, etc. Dynamic item generation tools and automated scoring of complex, constructed…

  2. Physiologic adaptation to space - Space adaptation syndrome

    NASA Technical Reports Server (NTRS)

    Vanderploeg, J. M.

    1985-01-01

    The adaptive changes of the neurovestibular system to microgravity, which result in space motion sickness (SMS), are studied. A list of symptoms, which range from vomiting to drowsiness, is provided. The two patterns of symptom development, rapid and gradual, and the duration of the symptoms are described. The concept of sensory conflict and rearrangements to explain SMS is being investigated.

  3. Retinal Imaging: Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Goncharov, A. S.; Iroshnikov, N. G.; Larichev, Andrey V.

    This chapter describes several factors influencing the performance of ophthalmic diagnostic systems with adaptive optics compensation of human eye aberration. Particular attention is paid to speckle modulation, temporal behavior of aberrations, and anisoplanatic effects. The implementation of a fundus camera with adaptive optics is considered.

  4. Uncertainty in adaptive capacity

    NASA Astrophysics Data System (ADS)

    Adger, W. Neil; Vincent, Katharine

    2005-03-01

    The capacity to adapt is a critical element of the process of adaptation: it is the vector of resources that represent the asset base from which adaptation actions can be made. Adaptive capacity can in theory be identified and measured at various scales, from the individual to the nation. The assessment of uncertainty within such measures comes from the contested knowledge domain and theories surrounding the nature of the determinants of adaptive capacity and the human action of adaptation. While generic adaptive capacity at the national level, for example, is often postulated as being dependent on health, governance and political rights, and literacy, and economic well-being, the determinants of these variables at national levels are not widely understood. We outline the nature of this uncertainty for the major elements of adaptive capacity and illustrate these issues with the example of a social vulnerability index for countries in Africa. To cite this article: W.N. Adger, K. Vincent, C. R. Geoscience 337 (2005).

  5. Water Resource Adaptation Program

    EPA Science Inventory

    The Water Resource Adaptation Program (WRAP) contributes to the U.S. Environmental Protection Agency’s (U.S. EPA) efforts to provide water resource managers and decision makers with the tools needed to adapt water resources to demographic and economic development, and future clim...

  6. Adaptive Sampling Proxy Application

    2012-10-22

    ASPA is an implementation of an adaptive sampling algorithm [1-3], which is used to reduce the computational expense of computer simulations that couple disparate physical scales. The purpose of ASPA is to encapsulate the algorithms required for adaptive sampling independently from any specific application, so that alternative algorithms and programming models for exascale computers can be investigated more easily.

  7. Adaptive Wavelet Transforms

    SciTech Connect

    Szu, H.; Hsu, C.

    1996-12-31

    Human sensors systems (HSS) may be approximately described as an adaptive or self-learning version of the Wavelet Transforms (WT) that are capable to learn from several input-output associative pairs of suitable transform mother wavelets. Such an Adaptive WT (AWT) is a redundant combination of mother wavelets to either represent or classify inputs.

  8. Toll-like receptor signaling in colorectal cancer: Carcinogenesis to cancer therapy

    PubMed Central

    Li, Ting-Ting; Ogino, Shuji; Qian, Zhi Rong

    2014-01-01

    Toll-like receptors (TLRs) are germ line encoded innate immune sensors that recognize conserved microbial structures and host alarmins, and signal expression of major histocompatibility complex proteins, costimulatory molecules, and inflammatory mediators by macrophages, neutrophils, dendritic cells, and other cell types. These protein receptors are characterized by their ability to respond to invading pathogens promptly by recognizing particular TLR ligands, including flagellin and lipopolysaccharide of bacteria, nucleic acids derived from viruses, and zymosan of fungi. There are 2 major TLR pathways; one is mediated by myeloid differentiation factor 88 (MYD88) adaptor proteins, and the other is independent of MYD88. The MYD88-dependent pathway involves early-phase activation of nuclear factor of kappa light polypeptide gene enhancer in B-cells 1 (NF-κB1) and all the TLRs, except TLR3, have been shown to activate this pathway. TLR3 and TLR4 act via MYD88-independent pathways with delayed activation of NF-κB signaling. TLRs play a vital role in activating immune responses. TLRs have been shown to mediate inflammatory responses and maintain epithelial barrier homeostasis, and are highly likely to be involved in the activation of a number of pathways following cancer therapy. Colorectal cancer (CRC) is one of the most common cancers, and accounts for almost half a million deaths annually worldwide. Inflammation is considered a risk factor for many common malignancies including cancers of the colorectum. The key molecules involved in inflammation-driven carcinogenesis include TLRs. As sensors of cell death and tissue remodeling, TLRs may have a universal role in cancer; stimulation of TLRs to activate the innate immune system has been a legitimate therapeutic strategy for some years. TLRs 3/4/7/8/9 are all validated targets for cancer therapy, and a number of companies are developing agonists and vaccine adjuvants. On the other hand, antagonists may favor inhibition

  9. Anti-Inflammatory Activity of Odina wodier Roxb, an Indian Folk Remedy, through Inhibition of Toll-Like Receptor 4 Signaling Pathway

    PubMed Central

    Ojha, Durbadal; Mukherjee, Hemanta; Mondal, Supriya; Jena, Aditya; Dwivedi, Ved Prakash; Mondal, Keshab C.; Malhotra, Bharti; Samanta, Amalesh; Chattopadhyay, Debprasad

    2014-01-01

    Inflammation is part of self-limiting non-specific immune response, which occurs during bodily injury. In some disorders the inflammatory process becomes continuous, leading to the development of chronic inflammatory diseases including cardiovascular diseases, diabetes, cancer etc. Several Indian tribes used the bark of Odina wodier (OWB) for treating inflammatory disorders. Thus, we have evaluated the immunotherapeutic potential of OWB methanol extract and its major constituent chlorogenic acid (CA), using three popular in vivo antiinflammatory models: Carrageenan- and Dextran-induced paw edema, Cotton pellet granuloma, and Acetic acid-induced vascular permeability. To elucidate the possible anti-inflammatory mechanism of action we determine the level of major inflammatory mediators (NO, iNOS, COX-2-dependent prostaglandin E2 or PGE2), and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-12). Further, we determine the toll-like receptor 4 (TLR4), Myeloid differentiation primary response gene 88 (MyD88), c-Jun N-terminal kinases (JNK), nuclear factor kappa-B cells (NF-κB), and NF-kB inhibitor alpha (IK-Bα) by protein and mRNA expression, and Western blot analysis in drug treated LPS-induced murine macrophage model. Moreover, we determined the acute and sub-acute toxicity of OWB extract in BALB/c mice. Our study demonstrated a significant anti-inflammatory activity of OWB extract and CA along with the inhibition of TNF-α, IL-1β, IL-6 and IL-12 expressions. Further, the expression of TLR4, NF-κBp65, MyD88, iNOS and COX-2 molecules were reduced in drug-treated groups, but not in the LPS-stimulated untreated or control groups, Thus, our results collectively indicated that the OWB extract and CA can efficiently inhibit inflammation through the down regulation of TLR4/MyD88/NF-kB signaling pathway. PMID:25153081

  10. Distinct Pathways of Humoral and Cellular Immunity Induced with the Mucosal Administration of a Nanoemulsion Adjuvant

    PubMed Central

    Makidon, Paul E.; Janczak, Katarzyna W.; Blanco, Luz P.; Swanson, Benjamin; Smith, Douglas M.; Pham, Tiffany; Szabo, Zsuzsanna; Kukowska-Latallo, Jolanta F.; Baker, James R.

    2014-01-01

    Nasal administration of an oil-in-water nanoemulsion (NE) adjuvant W805EC produces potent systemic and mucosal, Th-1– and Th-17–balanced cellular responses. However, its molecular mechanism of action has not been fully characterized and is of particular interest because NE does not contain specific ligands for innate immune receptors. In these studies, we demonstrate that W805EC NE adjuvant activates innate immunity, induces specific gene transcription, and modulates NF-κB activity via TLR2 and TLR4 by a mechanism that appears to be distinct from typical TLR agonists. Nasal immunization with NE-based vaccine showed that the TLR2, TLR4, and MyD88 pathways and IL-12 and IL-12Rβ1 expression are not required for an Ab response, but they are essential for the induction of balanced Th-1 polarization and Th-17 cellular immunity. NE adjuvant induces MHC class II, CD80, and CD86 costimulatory molecule expression and dendritic cell maturation. Further, upon immunization with NE, adjuvant mice deficient in the CD86 receptor had normal Ab responses but significantly reduced Th-1 cellular responses, whereas animals deficient in both CD80 and CD86 or lacking CD40 failed to produce either humoral or cellular immunity. Overall, our data show that intranasal administration of Ag with NE induces TLR2 and TLR4 activation along with a MyD88-independent Ab response and a MyD88-dependent Th-1 and Th-17 cell–mediated immune response. These findings suggest that the unique properties of NE adjuvant may offer novel opportunities for understanding previously unrecognized mechanisms of immune activation important for generating effective mucosal and systemic immune responses. PMID:24532579

  11. Mycobacterium indicus pranii and Mycobacterium bovis BCG lead to differential macrophage activation in Toll-like receptor-dependent manner.

    PubMed

    Kumar, Pawan; Tyagi, Rohit; Das, Gobardhan; Bhaskar, Sangeeta

    2014-10-01

    Mycobacterium indicus pranii (MIP) is an atypical mycobacterial species possessing strong immunomodulatory properties. It is a potent vaccine candidate against tuberculosis, promotes Th1 immune response and protects mice from tumours. In previous studies, we demonstrated higher protective efficacy of MIP against experimental tuberculosis as compared with bacillus Calmette-Guérin (BCG). Since macrophages play an important role in the pathology of mycobacterial diseases and cancer, in the present study, we evaluated the MIP in live and killed form for macrophage activation potential, compared it with BCG and investigated the underlying mechanisms. High levels of tumour necrosis factor-α, interleukin-12p40 (IL-12p40), IL-6 and nitric oxide were produced by MIP-stimulated macrophages as compared with BCG-stimulated macrophages. Prominent up-regulation of co-stimulatory molecules CD40, CD80 and CD86 was also observed in response to MIP. Loss of response in MyD88-deficient macrophages showed that both MIP and BCG activate the macrophages in a MyD88-dependent manner. MyD88 signalling pathway culminates in nuclear factor-κB/activator protein-1 (NF-κB/AP-1) activation and higher activation of NF-κB/AP-1 was observed in response to MIP. With the help of pharmacological inhibitors and Toll-like receptor (TLR) -deficient macrophages, we observed the role of TLR2, TLR4 and intracellular TLRs in MIP-mediated macrophage activation. Stimulation of HEK293 cells expressing TLR2 in homodimeric or heterodimeric form showed that MIP has a distinctly higher level of TLR2 agonist activity compared with BCG. Further experiments suggested that TLR2 ligands are well exposed in MIP whereas they are obscured in BCG. Our findings establish the higher macrophage activation potential of MIP compared with BCG and delineate the underlying mechanism. PMID:24766519

  12. Platelet-derived HMGB1 is a critical mediator of thrombosis

    PubMed Central

    Vogel, Sebastian; Bodenstein, Rebecca; Chen, Qiwei; Feil, Susanne; Feil, Robert; Rheinlaender, Johannes; Schäffer, Tilman E.; Bohn, Erwin; Frick, Julia-Stefanie; Borst, Oliver; Münzer, Patrick; Walker, Britta; Markel, Justin; Csanyi, Gabor; Pagano, Patrick J.; Loughran, Patricia; Jessup, Morgan E.; Watkins, Simon C.; Bullock, Grant C.; Sperry, Jason L.; Zuckerbraun, Brian S.; Billiar, Timothy R.; Lotze, Michael T.; Gawaz, Meinrad; Neal, Matthew D.

    2015-01-01

    Thrombosis and inflammation are intricately linked in several major clinical disorders, including disseminated intravascular coagulation and acute ischemic events. The damage-associated molecular pattern molecule high-mobility group box 1 (HMGB1) is upregulated by activated platelets in multiple inflammatory diseases; however, the contribution of platelet-derived HMGB1 in thrombosis remains unexplored. Here, we generated transgenic mice with platelet-specific ablation of HMGB1 and determined that platelet-derived HMGB1 is a critical mediator of thrombosis. Mice lacking HMGB1 in platelets exhibited increased bleeding times as well as reduced thrombus formation, platelet aggregation, inflammation, and organ damage during experimental trauma/hemorrhagic shock. Platelets were the major source of HMGB1 within thrombi. In trauma patients, HMGB1 expression on the surface of circulating platelets was markedly upregulated. Moreover, evaluation of isolated platelets revealed that HMGB1 is critical for regulating platelet activation, granule secretion, adhesion, and spreading. These effects were mediated via TLR4- and MyD88-dependent recruitment of platelet guanylyl cyclase (GC) toward the plasma membrane, followed by MyD88/GC complex formation and activation of the cGMP-dependent protein kinase I (cGKI). Thus, we establish platelet-derived HMGB1 as an important mediator of thrombosis and identify a HMGB1-driven link between MyD88 and GC/cGKI in platelets. Additionally, these findings suggest a potential therapeutic target for patients sustaining trauma and other inflammatory disorders associated with abnormal coagulation. PMID:26551681

  13. Anti-inflammatory activity of Odina wodier Roxb, an Indian folk remedy, through inhibition of toll-like receptor 4 signaling pathway.

    PubMed

    Ojha, Durbadal; Mukherjee, Hemanta; Mondal, Supriya; Jena, Aditya; Dwivedi, Ved Prakash; Mondal, Keshab C; Malhotra, Bharti; Samanta, Amalesh; Chattopadhyay, Debprasad

    2014-01-01

    Inflammation is part of self-limiting non-specific immune response, which occurs during bodily injury. In some disorders the inflammatory process becomes continuous, leading to the development of chronic inflammatory diseases including cardiovascular diseases, diabetes, cancer etc. Several Indian tribes used the bark of Odina wodier (OWB) for treating inflammatory disorders. Thus, we have evaluated the immunotherapeutic potential of OWB methanol extract and its major constituent chlorogenic acid (CA), using three popular in vivo antiinflammatory models: Carrageenan- and Dextran-induced paw edema, Cotton pellet granuloma, and Acetic acid-induced vascular permeability. To elucidate the possible anti-inflammatory mechanism of action we determine the level of major inflammatory mediators (NO, iNOS, COX-2-dependent prostaglandin E2 or PGE2), and pro-inflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-12). Further, we determine the toll-like receptor 4 (TLR4), Myeloid differentiation primary response gene 88 (MyD88), c-Jun N-terminal kinases (JNK), nuclear factor kappa-B cells (NF-κB), and NF-kB inhibitor alpha (IK-Bα) by protein and mRNA expression, and Western blot analysis in drug treated LPS-induced murine macrophage model. Moreover, we determined the acute and sub-acute toxicity of OWB extract in BALB/c mice. Our study demonstrated a significant anti-inflammatory activity of OWB extract and CA along with the inhibition of TNF-α, IL-1β, IL-6 and IL-12 expressions. Further, the expression of TLR4, NF-κBp65, MyD88, iNOS and COX-2 molecules were reduced in drug-treated groups, but not in the LPS-stimulated untreated or control groups, Thus, our results collectively indicated that the OWB extract and CA can efficiently inhibit inflammation through the down regulation of TLR4/MyD88/NF-kB signaling pathway. PMID:25153081

  14. Adaptation is automatic.

    PubMed

    Samuel, A G; Kat, D

    1998-04-01

    Two experiments were used to test whether selective adaptation for speech occurs automatically or instead requires attentional resources. A control condition demonstrated the usual large identification shifts caused by repeatedly presenting an adapting sound (/wa/, with listeners identifying members of a /ba/-/wa/ test series). Two types of distractor tasks were used: (1) Subjects did a rapid series of arithmetic problems during the adaptation periods (Experiments 1 and 2), or (2) they made a series of rhyming judgments, requiring phonetic coding (Experiment 2). A control experiment (Experiment 3) demonstrated that these tasks normally impose a heavy attentional cost on phonetic processing. Despite this, for both experimental conditions, the observed adaptation effect was just as large as in the control condition. This result indicates that adaptation is automatic, operating at an early, preattentive level. The implications of these results for current models of speech perception are discussed. PMID:9599999

  15. Unraveling Adaptation in Eukaryotic Pathways: Lessons from Protocells

    PubMed Central

    De Palo, Giovanna; Endres, Robert G.

    2013-01-01

    Eukaryotic adaptation pathways operate within wide-ranging environmental conditions without stimulus saturation. Despite numerous differences in the adaptation mechanisms employed by bacteria and eukaryotes, all require energy consumption. Here, we present two minimal models showing that expenditure of energy by the cell is not essential for adaptation. Both models share important features with large eukaryotic cells: they employ small diffusible molecules and involve receptor subunits resembling highly conserved G-protein cascades. Analyzing the drawbacks of these models helps us understand the benefits of energy consumption, in terms of adjustability of response and adaptation times as well as separation of cell-external sensing and cell-internal signaling. Our work thus sheds new light on the evolution of adaptation mechanisms in complex systems. PMID:24204235

  16. Unraveling adaptation in eukaryotic pathways: lessons from protocells.

    PubMed

    De Palo, Giovanna; Endres, Robert G

    2013-10-01

    Eukaryotic adaptation pathways operate within wide-ranging environmental conditions without stimulus saturation. Despite numerous differences in the adaptation mechanisms employed by bacteria and eukaryotes, all require energy consumption. Here, we present two minimal models showing that expenditure of energy by the cell is not essential for adaptation. Both models share important features with large eukaryotic cells: they employ small diffusible molecules and involve receptor subunits resembling highly conserved G-protein cascades. Analyzing the drawbacks of these models helps us understand the benefits of energy consumption, in terms of adjustability of response and adaptation times as well as separation of cell-external sensing and cell-internal signaling. Our work thus sheds new light on the evolution of adaptation mechanisms in complex systems. PMID:24204235

  17. Cold collisions between boson or fermion molecules

    SciTech Connect

    Kajita, Masatoshi

    2004-01-01

    We theoretically investigate collisions between electrostatically trapped cold polar molecules and compare boson and fermion isotopes. Evaporative cooling seems possible for fermion molecules as the ratio of the collision loss cross section to the elastic collision cross section (R) gets smaller as the molecular temperature T lowers. With boson molecules, R gets larger as T lowers, which makes evaporative cooling difficult. The elastic collision cross section between fermion molecules can be larger than that for boson molecules with certain conditions.

  18. Dissociation energy of molecules in dense gases

    NASA Technical Reports Server (NTRS)

    Kunc, J. A.

    1992-01-01

    A general approach is presented for calculating the reduction of the dissociation energy of diatomic molecules immersed in a dense (n = less than 10 exp 22/cu cm) gas of molecules and atoms. The dissociation energy of a molecule in a dense gas differs from that of the molecule in vacuum because the intermolecular forces change the intramolecular dynamics of the molecule, and, consequently, the energy of the molecular bond.

  19. Lectin-like ox-LDL receptor-1 (LOX-1)-Toll-like receptor 4 (TLR4) interaction and autophagy in CATH.a differentiated cells exposed to angiotensin II.

    PubMed

    Ding, Zufeng; Liu, Shijie; Wang, Xianwei; Khaidakov, Magomed; Dai, Yao; Deng, Xiaoyan; Fan, Yubo; Xiang, David; Mehta, Jawahar L

    2015-04-01

    Toll-like receptors (TLRs) play an essential role in innate immune response. Expression of TLRs has also been linked to autophagy. As the main receptor for oxidized low-density lipoprotein (ox-LDL) on the cell surface, lectin-like ox-LDL receptor-1 (LOX-1) is upregulated by proinflammatory cytokines and has been linked to the development of autophagy. However, the relationship between LOX-1, autophagy, and TLR4 in neurons has not been defined. Here, we show that Angiotensin II (Ang II) treatment of CATH.a differentiated neuronal cells resulted in the expression of TLR4 (and associated signals MyD88 and Toll/interleukin-1 receptor domain-containing adapter-inducing interferon (TRIF)), LOX-1 autophagy. LOX-1 knockdown (transfection with specific small interfering RNA (siRNA)) resulted in reduced expression of TLR4 (and associated signals MyD88 and TRIF) and P-P38 mitogen-activated protein kinase (MAPK) and autophagy. TLR4 knockdown with siRNA resulted in reduced LOX-1 expression and autophagy, indicating a positive feedback between LOX-1 and TLR4. Knockdown of TRIF as well as MyD88 or inhibition of P38 MAPK also inhibited the expression of LOX-1 and TLR4 and autophagy. Importantly, pretreatment with 3-methyladenine (autophagy inhibitor) enhanced while rapamycin (autophagy inducer) decreased the expression of LOX-1, TLR4, and P-P38 MAPK. These studies suggest the presence of a bidirectional link between LOX-1and TLR4 in cultured CATH.a differentiated cells exposed to Ang II with an important role for autophagy in this link. PMID:24902807

  20. Interleukin-1beta induces hyperpolarization and modulates synaptic inhibition in preoptic and anterior hypothalamic neurons.

    PubMed

    Tabarean, I V; Korn, H; Bartfai, T

    2006-09-15

    Most of the inflammatory effects of the cytokine interleukin 1beta (IL-1beta) are mediated by induction of cyclooxygenase (COX)2 and the subsequent synthesis and release of prostaglandin E2. This transcription-dependent process takes 45-60 min, but IL-1beta, a well-characterized endogenous pyrogen also exerts faster neuronal actions in the preoptic area/anterior hypothalamus. Here, we have studied the fast (1-3 min) signaling by IL-1beta using whole-cell patch clamp recordings in preoptic area/anterior hypothalamus neurons. Exposure to IL-1beta (0.1-1 nM) hyperpolarized a subset ( approximately 20%) of preoptic area/anterior hypothalamus neurons, decreased their input resistance and reduced their firing rate. These effects were associated with an increased frequency of bicuculline-sensitive spontaneous inhibitory postsynaptic currents and putative miniature inhibitory postsynaptic currents, strongly suggesting a presynaptic mechanism of action. These effects require the type 1 interleukin 1 receptor (IL-1R1), and the adapter protein myeloid differentiation primary response protein (MyD88), since they were not observed in cultures obtained from IL-1R1 (-/-) or from MyD88 (-/-) mice. Ceramide, a second messenger of the IL-1R1-dependent fast signaling cascade, is produced by IL-1R1-MyD88-mediated activation of the neutral sphingomyelinase. C2-ceramide, its cell penetrating analog, also increased the frequency of miniature inhibitory postsynaptic currents in a subset of cells. Both IL-1beta and ceramide reduced the delayed rectifier and the A-type K(+) currents in preoptic area/anterior hypothalamus neurons. The latter effect may account in part for the increased spontaneous inhibitory postsynaptic current frequency as suggested by experiments with the A-type K(+) channel blockers 4-aminopyridine. Taken together our data suggest that IL-1beta inhibits the activity of preoptic area/anterior hypothalamus neurons by increasing the presynaptic release of GABA. PMID

  1. Toll-Like Receptor Gene Expression during Trichinella spiralis Infection

    PubMed Central

    Kim, Sin; Park, Mi Kyung; Yu, Hak Sun

    2015-01-01

    In Trichinella spiralis infection, type 2 helper T (Th2) cell-related and regulatory T (Treg) cell-related immune responses are the most important immune events. In order to clarify which Toll-like receptors (TLRs) are closely associated with these responses, we analyzed the expression of mouse TLR genes in the small intestine and muscle tissue during T. spiralis infection. In addition, the expression of several chemokine- and cytokine-encoding genes, which are related to Th2 and Treg cell mediated immune responses, were analyzed in mouse embryonic fibroblasts (MEFs) isolated from myeloid differentiation factor 88 (MyD88)/TIR-associated proteins (TIRAP) and Toll receptor-associated activator of interferons (TRIF) adapter protein deficient and wild type (WT) mice. The results showed significantly increased TLR4 and TLR9 gene expression in the small intestine after 2 weeks of T. spiralis infection. In the muscle, TLR1, TLR2, TLR5, and TLR9 gene expression significantly increased after 4 weeks of infection. Only the expression of the TLR4 and TLR9 genes was significantly elevated in WT MEF cells after treatment with excretory-secretory (ES) proteins. Gene expression for Th2 chemokine genes were highly enhanced by ES proteins in WT MEF cells, while this elevation was slightly reduced in MyD88/TIRAP-/- MEF cells, and quite substantially decreased in TRIF-/- MEF cells. In contrast, IL-10 and TGF-β expression levels were not elevated in MyD88/TIRAP-/- MEF cells. In conclusion, we suggest that TLR4 and TLR9 might be closely linked to Th2 cell and Treg cell mediated immune responses, although additional data are needed to convincingly prove this observation. PMID:26323841

  2. Glatiramer acetate treatment negatively regulates type I interferon signaling

    PubMed Central

    Molnarfi, Nicolas; Prod'homme, Thomas; Schulze-Topphoff, Ulf; Spencer, Collin M.; Weber, Martin S.; Patarroyo, Juan C.; Lalive, Patrice H.

    2015-01-01

    Objective: Glatiramer acetate (GA; Copaxone), a disease-modifying therapy for multiple sclerosis (MS), promotes development of anti-inflammatory (M2, type II) monocytes that can direct differentiation of regulatory T cells. We investigated the innate immune signaling pathways that participate in GA-mediated M2 monocyte polarization. Methods: Monocytes were isolated from myeloid differentiation primary response gene 88 (MyD88)–deficient, Toll-IL-1 receptor domain–containing adaptor inducing interferon (IFN)–β (TRIF)–deficient, IFN-α/β receptor subunit 1 (IFNAR1)–deficient, and wild-type (WT) mice and human peripheral blood. GA-treated monocytes were stimulated with Toll-like receptor ligands, then evaluated for activation of kinases and transcription factors involved in innate immunity, and secretion of proinflammatory cytokines. GA-treated mice were evaluated for cytokine secretion and susceptibility to experimental autoimmune encephalomyelitis. Results: GA-mediated inhibition of proinflammatory cytokine production by monocytes occurred independently of MyD88 and nuclear factor–κB, but was blocked by TRIF deficiency. Furthermore, GA did not provide clinical benefit in TRIF-deficient mice. GA inhibited activation of p38 mitogen-activated protein kinase, an upstream regulator of activating transcription factor (ATF)–2, and c-Jun N-terminal kinase 1, which regulates IFN regulatory factor 3 (IRF3). Consequently, nuclear translocation of ATF-2 and IRF3, components of the IFN-β enhanceosome, was impaired. Consistent with these observations, GA inhibited production of IFN-β in vivo in WT mice, but did not modulate proinflammatory cytokine production by monocytes from IFNAR1-deficient mice. Conclusion: Our results demonstrate that GA inhibits the type I IFN pathway in M2 polarization of monocytes independently of MyD88, providing an important mechanism connecting innate and adaptive immune modulation in GA therapy and valuable insight regarding its

  3. Systems genetics of the nuclear factor-κB signal transduction network. I. Detection of several quantitative trait loci potentially relevant to aging.

    PubMed

    Diego, Vincent P; Curran, Joanne E; Charlesworth, Jac; Peralta, Juan M; Voruganti, V Saroja; Cole, Shelley A; Dyer, Thomas D; Johnson, Matthew P; Moses, Eric K; Göring, Harald H H; Williams, Jeff T; Comuzzie, Anthony G; Almasy, Laura; Blangero, John; Williams-Blangero, Sarah

    2012-01-01

    A theory of aging holds that senescence is caused by a dysregulated nuclear factor kappa B (NF-κB) signal transduction network (STN). We adopted a systems genetics approach in our study of the NF-κB STN. Ingenuity Pathways Analysis (IPA) was used to identify gene/gene product interactions between NF-κB and the genes in our transcriptional profiling array. Principal components factor analysis (PCFA) was performed on a sub-network of 19 genes, including two initiators of the toll-like receptor (TLR) pathway, myeloid differentiation primary response gene (88) (MyD88) and TIR (Toll/interleukin-1 receptor)-domain-containing adapter-inducing interferon-β (TRIF). TLR pathways are either MyD88-dependent or TRIF-dependent. Therefore, we also performed PCFA on a subset excluding the MyD88 transcript, and on another subset excluding two TRIF transcripts. Using linkage analysis we found that each set gave rise to at least one factor with a logarithm of the odds (LOD) score greater than 3, two on chromosome 15 at 15q12 and 15q22.2, and another two on chromosome 17 at 17p13.3 and 17q25.3. We also found several suggestive signals (2

  4. Anti-Inflammatory Activity of Tanshinone IIA in LPS-Stimulated RAW264.7 Macrophages via miRNAs and TLR4-NF-κB Pathway.

    PubMed

    Fan, Guanwei; Jiang, Xiaorui; Wu, Xiaoyan; Fordjour, Patrick Asare; Miao, Lin; Zhang, Han; Zhu, Yan; Gao, Xiumei

    2016-02-01

    Inflammation is a physiological response to infection or injury and involves the innate and adaptive immune system. Tanshinone IIA (Tan IIA) is a well-known flavonoid that elicits an important therapeutic effect by inhibiting inflammatory response. In this study, we examined whether Tan IIA exerts anti-inflammatory activity and investigated the possible mechanisms, including Toll-like receptor 4 (TLR4)-MyD88-nuclear factor kappa B (NF-κB) signaling pathway and microRNA expression in lipopolysaccharide (LPS)-induced RAW264.7 cells. Tan IIA could attenuate the inflammatory reaction via decreasing cytokine, chemokine, and acute-phase protein production, including GM-CSF, sICAM-1, cxcl-1, MIP-1α, and tumor necrosis factor alpha (TNF-α), analyzed by Proteome profile array in LPS-induced RAW264.7 cells. Concurrently, the messenger RNA (mRNA) expressions of IL-1β, TNF-α, and COX-2 were also significantly reduced by Tan IIA. Additionally, Tan IIA decreased LPS-induced NF-κB activation and downregulated TLR4 and MyD88 protein expression levels. We also observed reduced microRNA-155, miR-147, miR-184, miR-29b, and miR-34c expression levels, while LPS-induced microRNA-105, miR-145a, miR-194, miR-383, miR-132, and miR-451a expression levels were upregulated using microRNA (miRNA) qPCR array. Our results indicate that Tan IIA could exert an anti-inflammatory effect on LPS-induced RAW264.7 cells by decreasing TLR4-MyD88-NF-κB signaling pathway and regulating a series of cytokine production and miRNA expression. PMID:26639663

  5. Toll-Like Receptor Gene Expression during Trichinella spiralis Infection.

    PubMed

    Kim, Sin; Park, Mi Kyung; Yu, Hak Sun

    2015-08-01

    In Trichinella spiralis infection, type 2 helper T (Th2) cell-related and regulatory T (Treg) cell-related immune responses are the most important immune events. In order to clarify which Toll-like receptors (TLRs) are closely associated with these responses, we analyzed the expression of mouse TLR genes in the small intestine and muscle tissue during T. spiralis infection. In addition, the expression of several chemokine- and cytokine-encoding genes, which are related to Th2 and Treg cell mediated immune responses, were analyzed in mouse embryonic fibroblasts (MEFs) isolated from myeloid differentiation factor 88 (MyD88)/TIR-associated proteins (TIRAP) and Toll receptor-associated activator of interferons (TRIF) adapter protein deficient and wild type (WT) mice. The results showed significantly increased TLR4 and TLR9 gene expression in the small intestine after 2 weeks of T. spiralis infection. In the muscle, TLR1, TLR2, TLR5, and TLR9 gene expression significantly increased after 4 weeks of infection. Only the expression of the TLR4 and TLR9 genes was significantly elevated in WT MEF cells after treatment with excretory-secretory (ES) proteins. Gene expression for Th2 chemokine genes were highly enhanced by ES proteins in WT MEF cells, while this elevation was slightly reduced in MyD88/TIRAP(-/-) MEF cells, and quite substantially decreased in TRIF(-/-) MEF cells. In contrast, IL-10 and TGF-β expression levels were not elevated in MyD88/TIRAP(-/-) MEF cells. In conclusion, we suggest that TLR4 and TLR9 might be closely linked to Th2 cell and Treg cell mediated immune responses, although additional data are needed to convincingly prove this observation. PMID:26323841

  6. Microinjection of Francisella tularensis and Listeria monocytogenes reveals the importance of bacterial and host factors for successful replication.

    PubMed

    Meyer, Lena; Bröms, Jeanette E; Liu, Xijia; Rottenberg, Martin E; Sjöstedt, Anders

    2015-08-01

    Certain intracellular bacteria use the host cell cytosol as the replicative niche. Although it has been hypothesized that the successful exploitation of this compartment requires a unique metabolic adaptation, supportive evidence is lacking. For Francisella tularensis, many genes of the Francisella pathogenicity island (FPI) are essential for intracellular growth, and therefore, FPI mutants are useful tools for understanding the prerequisites of intracytosolic replication. We compared the growth of bacteria taken up by phagocytic or nonphagocytic cells with that of bacteria microinjected directly into the host cytosol, using the live vaccine strain (LVS) of F. tularensis; five selected FPI mutants thereof, i.e., ΔiglA, ΔiglÇ ΔiglG, ΔiglI, and ΔpdpE strains; and Listeria monocytogenes. After uptake in bone marrow-derived macrophages (BMDM), ASC(-/-) BMDM, MyD88(-/-) BMDM, J774 cells, or HeLa cells, LVS, ΔpdpE and ΔiglG mutants, and L. monocytogenes replicated efficiently in all five cell types, whereas the ΔiglA and ΔiglC mutants showed no replication. After microinjection, all 7 strains showed effective replication in J774 macrophages, ASC(-/-) BMDM, and HeLa cells. In contrast to the rapid replication in other cell types, L. monocytogenes showed no replication in MyD88(-/-) BMDM and LVS showed no replication in either BMDM or MyD88(-/-) BMDM after microinjection. Our data suggest that the mechanisms of bacterial uptake as well as the permissiveness of the cytosolic compartment per se are important factors for the intracytosolic replication. Notably, none of the investigated FPI proteins was found to be essential for intracytosolic replication after microinjection. PMID:26034213

  7. Microinjection of Francisella tularensis and Listeria monocytogenes Reveals the Importance of Bacterial and Host Factors for Successful Replication

    PubMed Central

    Meyer, Lena; Bröms, Jeanette E.; Liu, Xijia; Rottenberg, Martin E.

    2015-01-01

    Certain intracellular bacteria use the host cell cytosol as the replicative niche. Although it has been hypothesized that the successful exploitation of this compartment requires a unique metabolic adaptation, supportive evidence is lacking. For Francisella tularensis, many genes of the Francisella pathogenicity island (FPI) are essential for intracellular growth, and therefore, FPI mutants are useful tools for understanding the prerequisites of intracytosolic replication. We compared the growth of bacteria taken up by phagocytic or nonphagocytic cells with that of bacteria microinjected directly into the host cytosol, using the live vaccine strain (LVS) of F. tularensis; five selected FPI mutants thereof, i.e., ΔiglA, ΔiglÇ ΔiglG, ΔiglI, and ΔpdpE strains; and Listeria monocytogenes. After uptake in bone marrow-derived macrophages (BMDM), ASC−/− BMDM, MyD88−/− BMDM, J774 cells, or HeLa cells, LVS, ΔpdpE and ΔiglG mutants, and L. monocytogenes replicated efficiently in all five cell types, whereas the ΔiglA and ΔiglC mutants showed no replication. After microinjection, all 7 strains showed effective replication in J774 macrophages, ASC−/− BMDM, and HeLa cells. In contrast to the rapid replication in other cell types, L. monocytogenes showed no replication in MyD88−/− BMDM and LVS showed no replication in either BMDM or MyD88−/− BMDM after microinjection. Our data suggest that the mechanisms of bacterial uptake as well as the permissiveness of the cytosolic compartment per se are important factors for the intracytosolic replication. Notably, none of the investigated FPI proteins was found to be essential for intracytosolic replication after microinjection. PMID:26034213

  8. Antigen Presentation and T-Cell Activation Are Critical for RBP4-Induced Insulin Resistance.

    PubMed

    Moraes-Vieira, Pedro M; Castoldi, Angela; Aryal, Pratik; Wellenstein, Kerry; Peroni, Odile D; Kahn, Barbara B

    2016-05-01

    Adipose tissue (AT) inflammation contributes to impaired insulin action, which is a major cause of type 2 diabetes. RBP4 is an adipocyte- and liver-derived protein with an important role in insulin resistance, metabolic syndrome, and AT inflammation. RBP4 elevation causes AT inflammation by activating innate immunity, which elicits an adaptive immune response. RBP4-overexpressing mice (RBP4-Ox) are insulin resistant and glucose intolerant and have increased AT macrophages and T-helper 1 cells. We show that high-fat diet-fed RBP4(-/-) mice have reduced AT inflammation and improved insulin sensitivity versus wild type. We also elucidate the mechanism for RBP4-induced macrophage antigen presentation and subsequent T-cell activation. In RBP4-Ox, AT macrophages display enhanced c-Jun N-terminal kinase, extracellular signal-related kinase, and p38 phosphorylation. Inhibition of these pathways and of NF-κB reduces activation of macrophages and CD4 T cells. MyD88 is an adaptor protein involved in proinflammatory signaling. In macrophages from MyD88(-/-) mice, RBP4 fails to stimulate secretion of tumor necrosis factor, IL-12, and IL-6 and CD4 T-cell activation. In vivo blockade of antigen presentation by treating RBP4-Ox mice with CTLA4-Ig, which blocks costimulation of T cells, is sufficient to reduce AT inflammation and improve insulin resistance. Thus, MyD88 and downstream mitogen-activated protein kinase and NF-κB pathways are necessary for RBP4-induced macrophage antigen presentation and subsequent T-cell activation. Also, blocking antigen presentation with CTLA4-Ig improves RBP4-induced insulin resistance and macrophage-induced T-cell activation. PMID:26936962

  9. X(3872): charmonium or molecule?

    SciTech Connect

    Nefediev, A. V.

    2011-05-23

    A theoretical analysis of the recent experimental data from the Belle and BABAR Collaborations on the charmonium state X(3872) is performed. The analysis takes into account the proximity of an S-wave mesonic threshold and a possible presence of molecule component in the resonance wave function, finite width of the molecule constituents, and a possible interference in the final state. In particular, a model-independent approach is formulated, based on the Flatte parametrisation of near-threshold observables as well as on the Weinberg analysis of the nature of weakly bound systems generalised to the case of unstable constituents. Conclusion is made that the X(3872) is generated dynamically by a strong coupling of the bare {chi}{sub c1} charmonium to the DD-bar* hadronic channel, with a large admixture of the DD-bar* molecular component.

  10. Electrochemical detection of single molecules.

    PubMed

    Fan, F R; Bard, A J

    1995-02-10

    The electrochemical behavior of a single molecule can be observed by trapping a small volume of a dilute solution of the electroactive species between an ultramicroelectrode tip with a diameter of approximately 15 nanometers and a conductive substrate. A scanning electrochemical microscope was used to adjust the tip-substrate distance ( approximately 10 nanometers), and the oxidation of [(trimethylammonio)methyl] ferrocene (Cp(2)FeTMA(+)) to Cp(2)FeTMA(2+) was carried out. The response was stochastic, and anodic current peaks were observed as the molecule moved into and out of the electrode-substrate gap. Similar experiments were performed with a solution containing two redox species, ferrocene carboxylate (Cp(2)FeCOO(-)) and Os(bpy)(3)(2+) (bpy is 2,2'-bipyridyl). PMID:17813918

  11. Nanopore Device for Reversible Ion and Molecule Sensing or Migration

    NASA Technical Reports Server (NTRS)

    Pourmand, Nader (Inventor); Vilozny, Boaz (Inventor); Actis, Paolo (Inventor); Seger, R. Adam (Inventor); Singaram, Bakthan (Inventor)

    2015-01-01

    Disclosed are methods and devices for detection of ion migration and binding, utilizing a nanopipette adapted for use in an electrochemical sensing circuit. The nanopipette may be functionalized on its interior bore with metal chelators for binding and sensing metal ions or other specific binding molecules such as boronic acid for binding and sensing glucose. Such a functionalized nanopipette is comprised in an electrical sensor that detects when the nanopipette selectively and reversibly binds ions or small molecules. Also disclosed is a nanoreactor, comprising a nanopipette, for controlling precipitation in aqueous solutions by voltage-directed ion migration, wherein ions may be directed out of the interior bore by a repulsing charge in the bore.

  12. Quasi-Particle Self-Consistent GW for Molecules.

    PubMed

    Kaplan, F; Harding, M E; Seiler, C; Weigend, F; Evers, F; van Setten, M J

    2016-06-14

    We present the formalism and implementation of quasi-particle self-consistent GW (qsGW) and eigenvalue only quasi-particle self-consistent GW (evGW) adapted to standard quantum chemistry packages. Our implementation is benchmarked against high-level quantum chemistry computations (coupled-cluster theory) and experimental results using a representative set of molecules. Furthermore, we compare the qsGW approach for five molecules relevant for organic photovoltaics to self-consistent GW results (scGW) and analyze the effects of the self-consistency on the ground state density by comparing calculated dipole moments to their experimental values. We show that qsGW makes a significant improvement over conventional G0W0 and that partially self-consistent flavors (in particular evGW) can be excellent alternatives. PMID:27168352

  13. Bioactive molecules from sea hares.

    PubMed

    Kamiya, H; Sakai, R; Jimbo, M

    2006-01-01

    Sea hares, belonging to the order Opisthobranchia, subclass Gastropoda, are mollusks that have attracted many researchers who are interested in the chemical defense mechanisms of these soft and "shell-less" snails. Numbers of small molecules of dietary origin have been isolated from sea hares and some have ecologically relevant activities, such as fish deterrent activity or toxicity. Recently, however, greater attention has been paid to biomedically interesting sea hare isolates such as dolastatins, a series of antitumor peptide/macrolides isolated from Dolabella auricularia. Another series of bioactive peptide/macrolides, as represented by aplyronines, have been isolated from sea hares in Japanese waters. Although earlier studies indicated the potent antitumor activity of aplyronines, their clinical development has never been conducted because of the minute amount of compound available from the natural source. Recent synthetic studies, however, have made it possible to prepare these compounds and analogs for a structure-activity relationship study, and started to uncover their unique action mechanism towards their putative targets, microfilaments. Here, recent findings of small antitumor molecules isolated from Japanese sea hares are reviewed. Sea hares are also known to produce cytotoxic and antimicrobial proteins. In contrast to the small molecules of dietary origin, proteins are the genetic products of sea hares and they are likely to have some primary physiological functions in addition to ecological roles in the sea hare. Based on the biochemical properties and phylogenetic analysis of these proteins, we propose that they belong to one family of molecule, the "Aplysianin A family," although their molecular weights are apparently divided into two groups. Interestingly, the active principles in Aplysia species and Dolabella auricularia were shown to be L-amino acid oxidase (LAAO), a flavin enzyme that oxidizes an alpha-amino group of the substrate with

  14. Adhesion Molecules: Master Controllers of the Circulatory System.

    PubMed

    Schmidt, Eric P; Kuebler, Wolfgang M; Lee, Warren L; Downey, Gregory P

    2016-01-01

    This manuscript will review our current understanding of cellular adhesion molecules (CAMs) relevant to the circulatory system, their physiological role in control of vascular homeostasis, innate and adaptive immune responses, and their importance in pathophysiological (disease) processes such as acute lung injury, atherosclerosis, and pulmonary hypertension. This is a complex and rapidly changing area of research that is incompletely understood. By design, we will begin with a brief overview of the structure and classification of the major groups of adhesion molecules and their physiological functions including cellular adhesion and signaling. The role of specific CAMs in the process of platelet aggregation and hemostasis and leukocyte adhesion and transendothelial migration will be reviewed as examples of the complex and cooperative interplay between CAMs during physiological and pathophysiological processes. The role of the endothelial glycocalyx and the glycobiology of this complex system related to inflammatory states such as sepsis will be reviewed. We will then focus on the role of adhesion molecules in the pathogenesis of specific disease processes involving the lungs and cardiovascular system. The potential of targeting adhesion molecules in the treatment of immune and inflammatory diseases will be highlighted in the relevant sections throughout the manuscript. © 2016 American Physiological Society. Compr Physiol 6:945-973, 2016. PMID:27065171

  15. Autophagy proteins in antigen processing for presentation on MHC molecules.

    PubMed

    Münz, Christian

    2016-07-01

    Autophagy describes catabolic pathways that deliver cytoplasmic constituents for lysosomal degradation. Since major histocompatibility complex (MHC) molecules sample protein degradation products and present them to T cells for adaptive immunity, it is maybe not too surprising that autophagy contributes to this protein antigen processing for MHC presentation. However, the recently recognized breath of pathways, by which autophagy contributes to MHC antigen processing, is exciting. Macroautophagy does not only seem to deliver intracellular but facilitates also extracellular antigen processing by lysosomal hydrolysis for MHC class II presentation. Moreover, even MHC class I molecules that usually display proteasomal products are regulated by macroautophagy, probably using a pool of these molecules outside the endoplasmic reticulum, where MHC class I molecules are loaded with peptide during canonical MHC class I antigen processing. This review aims to summarize these recent developments and point out gaps of knowledge, which should be filled by further investigation, in order to harness the different antigen-processing pathways via autophagy for vaccine improvement. PMID:27319339

  16. Single molecule microscopy in 3D cell cultures and tissues.

    PubMed

    Lauer, Florian M; Kaemmerer, Elke; Meckel, Tobias

    2014-12-15

    From the onset of the first microscopic visualization of single fluorescent molecules in living cells at the beginning of this century, to the present, almost routine application of single molecule microscopy, the method has well-proven its ability to contribute unmatched detailed insight into the heterogeneous and dynamic molecular world life is composed of. Except for investigations on bacteria and yeast, almost the entire story of success is based on studies on adherent mammalian 2D cell cultures. However, despite this continuous progress, the technique was not able to keep pace with the move of the cell biology community to adapt 3D cell culture models for basic research, regenerative medicine, or drug development and screening. In this review, we will summarize the progress, which only recently allowed for the application of single molecule microscopy to 3D cell systems and give an overview of the technical advances that led to it. While initially posing a challenge, we finally conclude that relevant 3D cell models will become an integral part of the on-going success of single molecule microscopy. PMID:25453259

  17. Simple molecules as complex systems.

    PubMed

    Furtenbacher, Tibor; Arendás, Péter; Mellau, Georg; Császár, Attila G

    2014-01-01

    For individual molecules quantum mechanics (QM) offers a simple, natural and elegant way to build large-scale complex networks: quantized energy levels are the nodes, allowed transitions among the levels are the links, and transition intensities supply the weights. QM networks are intrinsic properties of molecules and they are characterized experimentally via spectroscopy; thus, realizations of QM networks are called spectroscopic networks (SN). As demonstrated for the rovibrational states of H2(16)O, the molecule governing the greenhouse effect on earth through hundreds of millions of its spectroscopic transitions (links), both the measured and first-principles computed one-photon absorption SNs containing experimentally accessible transitions appear to have heavy-tailed degree distributions. The proposed novel view of high-resolution spectroscopy and the observed degree distributions have important implications: appearance of a core of highly interconnected hubs among the nodes, a generally disassortative connection preference, considerable robustness and error tolerance, and an "ultra-small-world" property. The network-theoretical view of spectroscopy offers a data reduction facility via a minimum-weight spanning tree approach, which can assist high-resolution spectroscopists to improve the efficiency of the assignment of their measured spectra. PMID:24722221

  18. Molecules in the early universe

    SciTech Connect

    Lepp, S.; Shull, J.M.

    1984-05-15

    We present calculations of the formation of astrophysically interesting molecules (H/sub 2/, HD, LiH, and HeH/sup +/) by gas-phase reactions during the postrecombination epoch (redshifts z = 300-30). In standard Friedmann cosmological models, H/sub 2//Hroughly-equal10/sup -6/, HD/H/sub 2/roughly-equal10/sup -4.5/, and LiH/H/sub 2/roughly-equal10/sup -6.5/. These molecules may dominate the cooling and trigger the collapse of primordial gas clouds. The dipole rotational transitions of HD and LiH are particularly important at high density and low temperature. Additional molecules form during spherical collapse of these clouds, their rotational cooling keeps the gas temperature between 400 and 1500 K over 12 decades of density increase until the H/sub 2/ lines become optically thick. The existence of molecular coolants at high redshift has significant implications for the first generation of stars and for thermal instabilities in intergalactic matter.

  19. Simple molecules as complex systems

    PubMed Central

    Furtenbacher, Tibor; Árendás, Péter; Mellau, Georg; Császár, Attila G.

    2014-01-01

    For individual molecules quantum mechanics (QM) offers a simple, natural and elegant way to build large-scale complex networks: quantized energy levels are the nodes, allowed transitions among the levels are the links, and transition intensities supply the weights. QM networks are intrinsic properties of molecules and they are characterized experimentally via spectroscopy; thus, realizations of QM networks are called spectroscopic networks (SN). As demonstrated for the rovibrational states of H216O, the molecule governing the greenhouse effect on earth through hundreds of millions of its spectroscopic transitions (links), both the measured and first-principles computed one-photon absorption SNs containing experimentally accessible transitions appear to have heavy-tailed degree distributions. The proposed novel view of high-resolution spectroscopy and the observed degree distributions have important implications: appearance of a core of highly interconnected hubs among the nodes, a generally disassortative connection preference, considerable robustness and error tolerance, and an “ultra-small-world” property. The network-theoretical view of spectroscopy offers a data reduction facility via a minimum-weight spanning tree approach, which can assist high-resolution spectroscopists to improve the efficiency of the assignment of their measured spectra. PMID:24722221

  20. A single-molecule diode

    PubMed Central

    Elbing, Mark; Ochs, Rolf; Koentopp, Max; Fischer, Matthias; von Hänisch, Carsten; Weigend, Florian; Evers, Ferdinand; Weber, Heiko B.; Mayor, Marcel

    2005-01-01

    We have designed and synthesized a molecular rod that consists of two weakly coupled electronic π -systems with mutually shifted energy levels. The asymmetry thus implied manifests itself in a current–voltage characteristic with pronounced dependence on the sign of the bias voltage, which makes the molecule a prototype for a molecular diode. The individual molecules were immobilized by sulfur–gold bonds between both electrodes of a mechanically controlled break junction, and their electronic transport properties have been investigated. The results indeed show diode-like current–voltage characteristics. In contrast to that, control experiments with symmetric molecular rods consisting of two identical π -systems did not show significant asymmetries in the transport properties. To investigate the underlying transport mechanism, phenomenological arguments are combined with calculations based on density functional theory. The theoretical analysis suggests that the bias dependence of the polarizability of the molecule feeds back into the current leading to an asymmetric shape of the current–voltage characteristics, similar to the phenomena in a semiconductor diode. PMID:15956208