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Sample records for activates toll-like receptor

  1. DMPD: Proximal effects of Toll-like receptor activation in dendritic cells. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17142025 Proximal effects of Toll-like receptor activation in dendritic cells. Watt...) (.svg) (.html) (.csml) Show Proximal effects of Toll-like receptor activation in dendritic cells. PubmedID... 17142025 Title Proximal effects of Toll-like receptor activation in dendritic ce

  2. Activation of toll-like receptors and dendritic cells by a broad range of bacterial molecules

    NARCIS (Netherlands)

    Boele, L.C.L.; Bajramovic, J.J.; Vries, A.M.M.B.C. de; Voskamp-Visser, I.A.I.; Kaman, W.E.; Kleij, D. van der

    2009-01-01

    Activation of pattern recognition receptors such as Toll-like receptors (TLRs) by pathogens leads to activation and maturation of dendritic cells (DC), which orchestrate the development of the adaptive immune response. To create an overview of the effects of a broad range of pathogenic bacteria, the

  3. Glucose activation of islets of Langerhans up-regulates Toll-like receptor 5: possible mechanism of protection

    DEFF Research Database (Denmark)

    Weile, Christian Roar Andersen; Josefsen, Knud Elnegaard; Buschard, Karsten Stig

    2011-01-01

    Toll-like receptors are pattern-recognition receptors of the innate immune system that are activated during viral, bacterial or other infections, as well as during disease progression of type 1 and type 2 diabetes. Toll-like receptor 5 (TLR-5) specifically recognizes bacterial infection through b...

  4. The phosphoproteome of toll-like receptor-activated macrophages

    DEFF Research Database (Denmark)

    Weintz, Gabriele; Olsen, Jesper Velgaard; Frühauf, Katja;

    2010-01-01

    of primary macrophages using stable isotope labelling with amino acids in cell culture, phosphopeptide enrichment and high-resolution mass spectrometry. In parallel, nascent RNA was profiled to link transcription factor (TF) phosphorylation to TLR4-induced transcriptional activation. We reproducibly...

  5. DMPD: Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17502339 Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent pathways ...May 14. (.png) (.svg) (.html) (.csml) Show Crosstalk among Jak-STAT, Toll-like receptor, and ITAM-dependent path...T, Toll-like receptor, and ITAM-dependent pathways inmacrophage activation. Authors Hu X, Chen J, Wang L, Iv

  6. Murine retroviruses activate B cells via interaction with toll-like receptor 4

    OpenAIRE

    Rassa, John C.; Meyers, Jennifer L.; Zhang, Yuanming; Kudaravalli, Rama; Susan R Ross

    2002-01-01

    Although most retroviruses require activated cells as their targets for infection, it is not known how this is achieved in vivo. A candidate protein for the activation of B cells by either mouse mammary tumor virus (MMTV) or murine leukemia virus is the toll-like receptor 4 (TLR4), a component of the innate immune system. MMTV caused B cell activation in C3H/HeN mice but not in C3H/HeJ or BALB/c (C.C3H Tlr4lps-d) congenic mice, both of which have a mutant TLR4 gene. This activation was indepe...

  7. FATTY ACIDS MODULATE TOLL-LIKE RECEPTOR 4 ACTIVATION THROUGH REGULATION OF RECEPTOR DIMERIZATION AND RECRUITMENT INTO LIPID RAFTS

    Science.gov (United States)

    The saturated fatty acids acylated on Lipid A of lipopolysaccharide (LPS) or bacterial lipoproteins play critical roles in ligand recognition and receptor activation for Toll-like Receptor 4 (TLR4) and TLR2. The results from our previous studies (J Biol Chem 2003, 2004) demonstrated that saturated ...

  8. Proteolytic cleavage in an endolysosomal compartment is required for Toll-like receptor 9 activation

    OpenAIRE

    Park, Boyoun; Brinkmann, Melanie M.; Spooner, Eric; Lee, Clarissa C.; Kim, You-Me; Ploegh, Hidde L.

    2008-01-01

    Toll-like receptors (TLRs) activate the innate immune system in response to pathogens. Here we showed that TLR9 proteolytic cleavage is a prerequisite for TLR9 signaling. Inhibition of lysosomal proteolysis rendered TLR9 inactive. The C-terminal fragment of TLR9 thus generated included a portion of the TLR9 ectodomain, as well as the transmembrane and cytoplasmic domains. This cleavage fragment bound to the TLR9 ligand CpG, and, when expressed in Tlr9−/− dendritic cells, restored CpG-induced ...

  9. Toll-Like Receptor-Dependent Immune Complex Activation of B Cells and Dendritic Cells.

    Science.gov (United States)

    Moody, Krishna L; Uccellini, Melissa B; Avalos, Ana M; Marshak-Rothstein, Ann; Viglianti, Gregory A

    2016-01-01

    High titers of autoantibodies reactive with DNA/RNA molecular complexes are characteristic of autoimmune disorders such as systemic lupus erythematosus (SLE). In vitro and in vivo studies have implicated the endosomal Toll-like receptor 9 (TLR9) and Toll-like receptor 7 (TLR7) in the activation of the corresponding autoantibody producing B cells. Importantly, TLR9/TLR7-deficiency results in the inability of autoreactive B cells to proliferate in response to DNA/RNA-associated autoantigens in vitro, and in marked changes in the autoantibody repertoire of autoimmune-prone mice. Uptake of DNA/RNA-associated autoantigen immune complexes (ICs) also leads to activation of dendritic cells (DCs) through TLR9 and TLR7. The initial studies from our lab involved ICs formed by a mixture of autoantibodies and cell debris released from dying cells in culture. To better understand the nature of the mammalian ligands that can effectively activate TLR7 and TLR9, we have developed a methodology for preparing ICs containing defined DNA fragments that recapitulate the immunostimulatory activity of the previous "black box" ICs. As the endosomal TLR7 and TLR9 function optimally from intracellular acidic compartments, we developed a facile methodology to monitor the trafficking of defined DNA ICs by flow cytometry and confocal microscopy. These reagents reveal an important role for nucleic acid sequence, even when the ligand is mammalian DNA and will help illuminate the role of IC trafficking in the response.

  10. Nuclear Factor-κB: Activation and Regulation during Toll-like Receptor Signaling

    Institute of Scientific and Technical Information of China (English)

    Ruaidhrí J. Carmody; Youhai H. Chen

    2007-01-01

    Toll-like receptors (TLRs) recognize distinct microbial components to initiate the innate and adaptive immune responses. TLR activation culminates in the expression of appropriate pro-inflammatory and immunomodulatory factors to meet pathogenic challenges. The transcription factor NF-κB is the master regulator of all TLR-induced responses and its activation is the pivotal event in TLR-mediated activation of the innate immune response. Many of the key molecular events required for TLR-induced NF-κB activation have been elucidated. However, much remain to be learned about the ability of TLRs to generate pathogen-specific responses using a limited number of transcription factors. This review will focus on our current understanding of NF-κB activation by TLRs and potential mechanisms for achieving a signal-specific response through NF-κB.

  11. Murine retroviruses activate B cells via interaction with toll-like receptor 4

    Science.gov (United States)

    Rassa, John C.; Meyers, Jennifer L.; Zhang, Yuanming; Kudaravalli, Rama; Ross, Susan R.

    2002-01-01

    Although most retroviruses require activated cells as their targets for infection, it is not known how this is achieved in vivo. A candidate protein for the activation of B cells by either mouse mammary tumor virus (MMTV) or murine leukemia virus is the toll-like receptor 4 (TLR4), a component of the innate immune system. MMTV caused B cell activation in C3H/HeN mice but not in C3H/HeJ or BALB/c (C.C3H Tlr4lps-d) congenic mice, both of which have a mutant TLR4 gene. This activation was independent of viral gene expression, because it occurred after treatment of MMTV with ultraviolet light or 2,2′-dithiodipyridine and in azidothymidine-treated mice. Nuclear extracts prepared from the lymphocytes of MMTV-injected C3H/HeN but not C3H/HeJ mice showed increased nuclear factor κB activity. Additionally, the MMTV- and Moloney murine leukemia virus envelope proteins coimmunoprecipitated with TLR4 when expressed in 293T cells. The MMTV receptor failed to coimmunoprecipitate with TLR4, suggesting that MMTV/TLR4 interaction is independent of virus attachment and fusion. These results identify retroviral proteins that interact with a mammalian toll receptor and show that direct activation by such viruses may initiate in vivo infection pathways. PMID:11854525

  12. Toll-like receptors in neonatal sepsis.

    LENUS (Irish Health Repository)

    O'Hare, Fiona M

    2013-06-01

    Toll-like receptors are vital transmembrane receptors that initiate the innate immune response to many micro-organisms. The discovery of these receptors has improved our understanding of host-pathogen interactions, and these receptors play an important role in the pathogenesis of multiple neonatal conditions such as sepsis and brain injury. Toll-like receptors, especially TLRs 2 and 4, are associated with necrotizing enterocolitis, periventricular leukomalacia and sepsis.

  13. Improved Chemotherapeutic Activity by Morus alba Fruits through Immune Response of Toll-Like Receptor 4

    Directory of Open Access Journals (Sweden)

    Bo Yoon Chang

    2015-10-01

    Full Text Available Morus alba L. fruits have long been used in traditional medicine by many cultures. Their medicinal attributes include cardiovascular, hepatoprotective, neuroprotective and immunomodulatory actions. However, their mechanism of macrophage activation and anti-cancer effects remain unclear. The present study investigated the molecular mechanisms of immune stimulation and improved chemotherapeutic effect of M. alba L. fruit extract (MFE. MFE stimulated the production of cytokines, nitric oxide (NO and tumor necrosis factor-α (TNF-α and tumoricidal properties of macrophages. MFE activated macrophages through the mitogen-activated protein kinase (MAPKinase and nuclear factor-κB (NF-κB signaling pathways downstream from toll-like receptor (TLR 4. MFE was shown to exhibit cytotoxicity of CT26 cells via the activated macrophages, even though MFE did not directly affect CT26 cells. In a xenograft mouse model, MFE significantly enhanced anti-cancer activity combined with 5-fluorouracil and markedly promoted splenocyte proliferation, natural killer (NK cell activity, cytotoxic T lymphocyte (CTL activity and IFN-γ production. Immunoglobulin G (IgG antibody levels were significantly increased. These results indicate the indirect anti-cancer activity of MFE through improved immune response mediated by TLR4 signaling. M. alba L. fruit extract might be a potential anti-tumor immunomodulatory candidate chemotherapy agent.

  14. Improved Chemotherapeutic Activity by Morus alba Fruits through Immune Response of Toll-Like Receptor 4.

    Science.gov (United States)

    Chang, Bo Yoon; Kim, Seon Beom; Lee, Mi Kyeong; Park, Hyun; Kim, Sung Yeon

    2015-10-13

    Morus alba L. fruits have long been used in traditional medicine by many cultures. Their medicinal attributes include cardiovascular, hepatoprotective, neuroprotective and immunomodulatory actions. However, their mechanism of macrophage activation and anti-cancer effects remain unclear. The present study investigated the molecular mechanisms of immune stimulation and improved chemotherapeutic effect of M. alba L. fruit extract (MFE). MFE stimulated the production of cytokines, nitric oxide (NO) and tumor necrosis factor-α (TNF-α) and tumoricidal properties of macrophages. MFE activated macrophages through the mitogen-activated protein kinase (MAPKinase) and nuclear factor-κB (NF-κB) signaling pathways downstream from toll-like receptor (TLR) 4. MFE was shown to exhibit cytotoxicity of CT26 cells via the activated macrophages, even though MFE did not directly affect CT26 cells. In a xenograft mouse model, MFE significantly enhanced anti-cancer activity combined with 5-fluorouracil and markedly promoted splenocyte proliferation, natural killer (NK) cell activity, cytotoxic T lymphocyte (CTL) activity and IFN-γ production. Immunoglobulin G (IgG) antibody levels were significantly increased. These results indicate the indirect anti-cancer activity of MFE through improved immune response mediated by TLR4 signaling. M. alba L. fruit extract might be a potential anti-tumor immunomodulatory candidate chemotherapy agent.

  15. γ-Glutamyltranspeptidase is an endogenous activator of Toll-like receptor 4-mediated osteoclastogenesis

    Science.gov (United States)

    Moriwaki, Sawako; Into, Takeshi; Suzuki, Keiko; Miyauchi, Mutsumi; Takata, Takashi; Shibayama, Keigo; Niida, Shumpei

    2016-01-01

    Chronic inflammation-associated bone destruction, which is observed in rheumatoid arthritis (RA) and periodontitis, is mediated by excessive osteoclastogenesis. We showed previously that γ-glutamyltranspeptidase (GGT), an enzyme involved in glutathione metabolism, acts as an endogenous activator of such pathological osteoclastogenesis, independent of its enzymatic activity. GGT accumulation is clinically observed in the joints of RA patients, and, in animals, the administration of recombinant GGT to the gingival sulcus as an in vivo periodontitis model induces an increase in the number of osteoclasts. However, the underlying mechanisms of this process remain unclear. Here, we report that Toll-like receptor 4 (TLR4) recognizes GGT to activate inflammation-associated osteoclastogenesis. Unlike lipopolysaccharide, GGT is sensitive to proteinase K treatment and insensitive to polymyxin B treatment. TLR4 deficiency abrogates GGT-induced osteoclastogenesis and activation of NF-κB and MAPK signaling in precursor cells. Additionally, GGT does not induce osteoclastogenesis in cells lacking the signaling adaptor MyD88. The administration of GGT to the gingival sulcus induces increased osteoclastogenesis in wild-type mice, but does not induce it in TLR4-deficient mice. Our findings elucidate a novel mechanism of inflammation-associated osteoclastogenesis, which involves TLR4 recognition of GGT and subsequent activation of MyD88-dependent signaling. PMID:27775020

  16. Activation of Dendritic Cells by the Novel Toll-Like Receptor 3 Agonist RGC100

    Directory of Open Access Journals (Sweden)

    Kai Naumann

    2013-01-01

    Full Text Available Toll-like receptor (TLR 3 agonists emerged as attractive candidates for vaccination strategies against tumors and pathogens. An important mechanism of action of such agonists is based on the activation of TLR3-expressing dendritic cells (DCs, which display a unique capacity to induce and stimulate T-cell responses. In this context, it has been demonstrated that targeting of TLR3 by double-stranded RNA such as poly(I:C results in potent activation of DCs. Major disadvantages of poly(I:C comprise its undefined chemical structure and very poor homogeneity, with subsequent unpredictable pharmacokinetics and high toxicity. In the present study, we evaluated the physicochemical properties and biological activity of the novel TLR3 agonist RGC100. RGC100 has a defined chemical structure, with a defined length (100 bp and molecular weight (64.9 KDa and a good solubility. RGC100 is stable in serum and activates myeloid DCs through TLR3 targeting, as evidenced by gene silencing experiments. Activation of mouse and human myeloid CD1c+ DCs by RGC100 leads to secretion of several proinflammatory cytokines. In addition, RGC100 improves the ability of CD1c+ DCs to stimulate T-cell proliferation. Due to its physicochemical properties and its immunostimulatory properties, RGC100 may represent a promising adjuvant for prophylactic and therapeutic vaccination strategies.

  17. Starring role of toll-like receptor-4 activation in the gutliver axis

    Institute of Scientific and Technical Information of China (English)

    Simone; Carotti; Michele; Pier; Luca; Guarino; Umberto; Vespasiani-Gentilucci; Sergio; Morini

    2015-01-01

    Since the introduction of the term "gut-liver axis", many studies have focused on the functional links of intestinal microbiota, barrier function and immune responses to liver physiology. Intestinal and extra-intestinal diseases alter microbiota composition and lead to dysbiosis, which aggravates impaired intestinal barrier function via increased lipopolysaccharide translocation. The subsequent increased passage of gut-derived product from the intestinal lumen to the organ wall and bloodstream affects gut motility and liver biology. The activation of the toll-like receptor 4(TLR-4) likely plays a key role in both cases. This review analyzed the most recent literature on the gut-liver axis, with a particular focus on the role of TLR-4 activation. Findings that linked liver disease with dysbiosis are evaluated, and links between dysbiosis and alterations of intestinal permeability and motility are discussed. We also examine the mechanisms of translocated gut bacteria and/or the bacterial product activation of liver inflammation and fibrogenesis via activity on different hepatic cell types.

  18. Rice Bran Feruloylated Oligosaccharides Activate Dendritic Cells via Toll-Like Receptor 2 and 4 Signaling

    Directory of Open Access Journals (Sweden)

    Chi Chen Lin

    2014-04-01

    Full Text Available This work presents the effects of feruloylated oligosaccharides (FOs of rice bran on murine bone marrow-derived dendritic cells (BMDCs and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4 or TLR-2 but not DCs from mice with mutated TLR4 or TLR2. The mechanism of action of FOs may be mediated by increased phosphorylation of ERK, p38 and JNK mitogen-activated protein kinase (MAPKs and increased NF-kB activity, which are important signaling molecules downstream of TLR-4 and TLR-2. These data suggest that FOs induce DCs maturation through TLR-4 and/or TLR-2 and that FOs might have potential efficacy against tumor or virus infection or represent a candidate-adjuvant approach for application in immunotherapy and vaccination.

  19. Toll-like receptor 2 activation depends on lipopeptide shedding by bacterial surfactants

    Science.gov (United States)

    Hanzelmann, Dennis; Joo, Hwang-Soo; Franz-Wachtel, Mirita; Hertlein, Tobias; Stevanovic, Stefan; Macek, Boris; Wolz, Christiane; Götz, Friedrich; Otto, Michael; Kretschmer, Dorothee; Peschel, Andreas

    2016-01-01

    Sepsis caused by Gram-positive bacterial pathogens is a major fatal disease but its molecular basis remains elusive. Toll-like receptor 2 (TLR2) has been implicated in the orchestration of inflammation and sepsis but its role appears to vary for different pathogen species and clones. Accordingly, Staphylococcus aureus clinical isolates differ substantially in their capacity to activate TLR2. Here we show that strong TLR2 stimulation depends on high-level production of phenol-soluble modulin (PSM) peptides in response to the global virulence activator Agr. PSMs are required for mobilizing lipoproteins, the TLR2 agonists, from the staphylococcal cytoplasmic membrane. Notably, the course of sepsis caused by PSM-deficient S. aureus is similar in wild-type and TLR2-deficient mice, but TLR2 is required for protection of mice against PSM-producing S. aureus. Thus, a crucial role of TLR2 depends on agonist release by bacterial surfactants. Modulation of this process may lead to new therapeutic strategies against Gram-positive infections. PMID:27470911

  20. Rice bran feruloylated oligosaccharides activate dendritic cells via Toll-like receptor 2 and 4 signaling.

    Science.gov (United States)

    Lin, Chi Chen; Chen, Hua Han; Chen, Yu Kuo; Chang, Hung Chia; Lin, Ping Yi; Pan, I-Hong; Chen, Der-Yuan; Chen, Chuan Mu; Lin, Su Yi

    2014-01-01

    This work presents the effects of feruloylated oligosaccharides (FOs) of rice bran on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4) or TLR-2 but not DCs from mice with mutated TLR4 or TLR2. The mechanism of action of FOs may be mediated by increased phosphorylation of ERK, p38 and JNK mitogen-activated protein kinase (MAPKs) and increased NF-kB activity, which are important signaling molecules downstream of TLR-4 and TLR-2. These data suggest that FOs induce DCs maturation through TLR-4 and/or TLR-2 and that FOs might have potential efficacy against tumor or virus infection or represent a candidate-adjuvant approach for application in immunotherapy and vaccination. PMID:24762969

  1. Hypothermia Reduces Toll-Like Receptor 3-Activated Microglial Interferon-β and Nitric Oxide Production

    Directory of Open Access Journals (Sweden)

    Tomohiro Matsui

    2013-01-01

    Full Text Available Therapeutic hypothermia protects neurons after injury to the central nervous system (CNS. Microglia express toll-like receptors (TLRs that play significant roles in the pathogenesis of sterile CNS injury. To elucidate the possible mechanisms involved in the neuroprotective effect of therapeutic hypothermia, we examined the effects of hypothermic culture on TLR3-activated microglial release of interferon (IFN-β and nitric oxide (NO, which are known to be associated with neuronal cell death. When rat or mouse microglia were cultured under conditions of hypothermia (33°C and normothermia (37°C with a TLR3 agonist, polyinosinic-polycytidylic acid, the production of IFN-β and NO in TLR3-activated microglia at 48 h was decreased by hypothermia compared with that by normothermia. In addition, exposure to recombinant IFN-β and sodium nitroprusside, an NO donor, caused death of rat neuronal pheochromocytoma PC12 cells in a concentration-dependent manner after 24 h. Taken together, these results suggest that the attenuation of microglial production of IFN-β and NO by therapeutic hypothermia leads to the inhibition of neuronal cell death.

  2. Trichomonas vaginalis infection activates cells through toll-like receptor 4.

    Science.gov (United States)

    Zariffard, M Reza; Harwani, Sailesh; Novak, Richard M; Graham, Parrie J; Ji, Xin; Spear, Gregory T

    2004-04-01

    While Trichomonas vaginalis infection can cause inflammation and influx of leukocytes into the female genital tract, the molecular pathways important in inducing these effects are not known. This study determined if infection with T. vaginalis activates cells through toll-like receptor 4 (TLR4). Genital tract secretions from infected women stimulated TNF-alpha production by cells with functional TLR4 (350 pg/ml) but significantly less by cells that are unresponsive to TLR4 ligands (44 pg/ml, P = 0.001). Secretions collected after clearance of infection also induced significantly lower responses by cells with functional TLR4 (136 pg/ml, P = 0.008). TNF-alpha responses were not reduced by Polymyxin B and did not correlate with beta(2)-defensin levels, indicating that stimulation of cells was not through lipopolysaccharide or beta(2)-defensin. These studies show that T. vaginalis infection results in the appearance in the genital tract of substance(s) that stimulate cells through TLR4, suggesting a mechanism for the inflammation caused by this infection. PMID:15093558

  3. Toll-like receptor activation by helminths or helminth products to alleviate inflammatory bowel disease

    Directory of Open Access Journals (Sweden)

    Song YanXia

    2011-09-01

    Full Text Available Abstract Helminth infection may modulate the expression of Toll like receptors (TLR in dendritic cells (DCs and modify the responsiveness of DCs to TLR ligands. This may regulate aberrant intestinal inflammation in humans with helminthes and may thus help alleviate inflammation associated with human inflammatory bowel disease (IBD. Epidemiological and experimental data provide further evidence that reducing helminth infections increases the incidence rate of such autoimmune diseases. Fine control of inflammation in the TLR pathway is highly desirable for effective host defense. Thus, the use of antagonists of TLR-signaling and agonists of their negative regulators from helminths or helminth products should be considered for the treatment of IBD.

  4. Rice Bran Feruloylated Oligosaccharides Activate Dendritic Cells via Toll-Like Receptor 2 and 4 Signaling

    OpenAIRE

    Chi Chen Lin; Hua Han Chen; Yu Kuo Chen; Hung Chia Chang; Ping Yi Lin; I-Hong Pan; Der-Yuan Chen; Chuan Mu Chen; Su Yi Lin

    2014-01-01

    This work presents the effects of feruloylated oligosaccharides (FOs) of rice bran on murine bone marrow-derived dendritic cells (BMDCs) and the potential pathway through which the effects are mediated. We found that FOs induced phenotypic maturation of DCs, as shown by the increased expression of CD40, CD80/CD86 and MHC-I/II molecules. FOs efficiently induced maturation of DCs generated from C3H/HeN or C57BL/6 mice with normal toll-like receptor 4 (TLR-4) or TLR-2 but not DCs from mice with ...

  5. Toll-like receptor 9 is correlated to disease activity in Chinese systemic lupus erythematosus population

    Institute of Scientific and Technical Information of China (English)

    MU Rong; SUN Xiao-yun; Lik Thai Lim; XU Chuan-hui; DAI Chen-xian; SU Yin; JIA Ru-lin; LI Zhan-guo

    2012-01-01

    Background Toll like receptor (TLR) 9 has been shown to play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE) in animal models.Its pathogenic role in human SLE,however,was poorly elucidated.This study was performed to investigate the role of TLR9 involved in the aberrant signaling pathway and its correlation with disease activity in SLE.Methods mRNA level of TLR9 and interferon (IFN) regulatory factor 5 (IRF5) in peripheral blood mononuclear cells (PBMCs) were determined by real-time polymerase chain reaction (PCR).IFN-α expression was measured in the serum of the SLE patients by enzyme-linked immunosorbent assay (ELISA).Results TLR9 expression was significantly higher in SLE patients than that in health controls (P=-0.011).SLE patients with positive anti-dsDNA antibody had significantly higher expression of TLR9 than that with negative anti-dsDNA antibody (P=0.001).TLR9 expression was positively correlated with fever (P=0.017),alopecia (P=0.046),safety of estrogens in lupus erythematosus national assessment SLE disease activity index (SELENA-SLEDAI) score (rs=0.385,P=0.003),and the level of IRF5 (rs=0.35,P=0.027) and IFN-α (rs=0.627,P=0.001) in SLE patients.Conclusion TLR9 is associated with SLE disease activity and might be involved in the IFN-α pathway of SLE.

  6. Leishmania lipophosphoglycan (LPG) activates NK cells through toll-like receptor-2.

    Science.gov (United States)

    Becker, Ingeborg; Salaiza, Norma; Aguirre, Magdalena; Delgado, José; Carrillo-Carrasco, Nuria; Kobeh, Laila Gutiérrez; Ruiz, Adriana; Cervantes, Rocely; Torres, Armando Pérez; Cabrera, Nallely; González, Augusto; Maldonado, Carmen; Isibasi, Armando

    2003-08-31

    Toll-like receptors (TLRs) mediate the cellular response to conserved molecular patterns shared by microorganisms. We report that TLR-2 on human NK cells is upregulated and stimulated by Leishmania major lipophosphoglycan (LPG), a phosphoglycan belonging to a family of unique Leishmania glycoconjugates. We found that purified L. major LPG upregulates both mRNA and the membrane expression of TLR-2 in NK cells. Additionally, IFN-gamma and TNF-alpha production and nuclear translocation of NF-kappaB was enhanced. The activation effect was more intense with LPG purified from infectious metacyclic parasites than from noninfectious procyclic Leishmania. Since the difference between the molecules derived from these two stages of the parasite growth cycle lies exclusively in the number of phosphosaccharide repeat domains and in the composition of glycan side chains that branch off these domains, we propose that TLR-2 possibly distinguishes between phosphorylated glycan repeats on LPG molecules. The effect of LPG on cytokine production and on membrane expression of TLR-2 could be blocked with F(ab')2 fragments of the mAb against LPG (WIC 79.3). Confocal microscopy demonstrated the co-localization of LPG and TLR-2 on the NK cell membrane. Binding of LPG to TLR-2 in NK cells was demonstrated by immunoprecipitations done with anti-TLR-2 and anti-LPG mAb followed by immunoblotting with anti-LPG and anti-TLR-2, respectively. Both antibodies recognized the immune complexes. These results suggest that NK cells are capable of recognition of, and activation by, Leishmania LPG through TLR-2, enabling them to participate autonomously in the innate immune system and thereby increasing the effective destruction of the parasite. PMID:12946842

  7. S6K1 Negatively Regulates TAK1 Activity in the Toll-Like Receptor Signaling Pathway

    OpenAIRE

    Kim, So Yong; Baik, Kyung-Hwa; Baek, Kwan-Hyuck; Chah, Kyong-Hwa; Kim, Kyung Ah; Moon, Gyuyoung; Jung, Eunyu; Kim, Seong-Tae; Shim, Jae-Hyuck; Greenblatt, Matthew B.; Chun, Eunyoung; Lee, Ki-Young

    2014-01-01

    Transforming growth factor β (TGF-β)-activated kinase 1 (TAK1) is a key regulator in the signals transduced by proinflammatory cytokines and Toll-like receptors (TLRs). The regulatory mechanism of TAK1 in response to various tissue types and stimuli remains incompletely understood. Here, we show that ribosomal S6 kinase 1 (S6K1) negatively regulates TLR-mediated signals by inhibiting TAK1 activity. S6K1 overexpression causes a marked reduction in NF-κB and AP-1 activity induced by stimulation...

  8. DMPD: Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15031527 Toll-like receptor 3: a link between toll-like receptor, interferon and viruses... (.csml) Show Toll-like receptor 3: a link between toll-like receptor, interferon and viruses. PubmedID 1503...1527 Title Toll-like receptor 3: a link between toll-like receptor, interferon and viruses

  9. Evidence for Activation of Toll-Like Receptor and Receptor for Advanced Glycation End Products in Preterm Birth

    Directory of Open Access Journals (Sweden)

    Taketoshi Noguchi

    2010-01-01

    Full Text Available Objective. Individuals with inflammation have a myriad of pregnancy aberrations including increasing their preterm birth risk. Toll-like receptors (TLRs and receptor for advanced glycation end products (RAGE and their ligands were all found to play a key role in inflammation. In the present study, we reviewed TLR and RAGE expression, their ligands, and signaling in preterm birth. Research Design and Methods. A systematic search was performed in the electronic databases PubMed and ScienceDirect up to July 2010, combining the keywords “preterm birth,” “TLR”, “RAGE”, “danger signal”, “alarmin”, “genomewide,” “microarray,” and “proteomics” with specific expression profiles of genes and proteins. Results. This paper provides data on TLR and RAGE levels and critical downstream signaling events including NF-kappaB-dependent proinflammatory cytokine expression in preterm birth. About half of the genes and proteins specifically present in preterm birth have the properties of endogenous ligands “alarmin” for receptor activation. The interactions between the TLR-mediated acute inflammation and RAGE-mediated chronic inflammation have clear implications for preterm birth via the TLR and RAGE system, which may be acting collectively. Conclusions. TLR and RAGE expression and their ligands, signaling, and functional activation are increased in preterm birth and may contribute to the proinflammatory state.

  10. Analysis by Flow Cytometry of B-Cell Activation and Antibody Responses Induced by Toll-Like Receptors.

    Science.gov (United States)

    Pone, Egest J

    2016-01-01

    Toll-like receptors (TLRs) are expressed in B lymphocytes and contribute to B-cell activation, antibody responses, and their maturation. TLR stimulation of mouse B cells induces class switch DNA recombination (CSR) to isotypes specified by cytokines, and also induces formation of IgM(+) as well as class-switched plasma cells. B-cell receptor (BCR) signaling, while on its own inducing limited B-cell proliferation and no CSR, can enhance CSR driven by TLRs. Particular synergistic or antagonistic interactions among TLR pathways, BCR, and cytokine signaling can have important consequences for B-cell activation, CSR, and plasma cell formation. This chapter outlines protocols for the induction and analysis of B-cell activation and antibody production by TLRs with or without other stimuli. PMID:26803633

  11. Toll-Like Receptors in Angiogenesis

    Directory of Open Access Journals (Sweden)

    Karsten Grote

    2011-01-01

    Full Text Available Toll-like receptors (TLRs are known as pattern-recognition receptors related to the Toll protein of Drosophila. After recognition of pathogen-associated molecular patterns of microbial origin, the TLRs alert the immune system, and initiate innate and adaptive immune responses. The TLR system, though, is not confined solely to the leukocyte-mediated immune defense against exogenous pathogens. Besides myeloid cells, TLR expression has been reported in multiple tissues and cell types, including epithelial and endothelial cells. Moreover, despite the microbial patterns that are commonly accepted as TLR ligands, there is increasing evidence that TLRs also recognize host-derived molecules. In this regard, recent studies point to an involvement of TLRs in various chronic inflammatory disorders and cardiovascular diseases, including atherosclerosis, rheumatoid arthritis, systemic lupus erythematosus, and even cancer. A common feature of these disorders is an enhanced so-called inflammation-induced angiogenesis. However, inflammation-induced angiogenesis is not solely a key component of pathogen defense during acute infection or chronic inflammatory disorders, but also plays a critical role in repair mechanisms, e.g., wound healing and subsequent tissue regeneration. Interestingly, the latest research could coincidentally demonstrate that TLR activation promotes angiogenesis in various inflammatory settings in response to both exogenous and endogenous ligands, although the precise mode of action of TLRs in this context still remains ambiguous. The objective of this review is to present evidence for the implication of TLRs in angiogenesis during physiological and pathophysiological processes, and the potential clinical relevance for new treatment regimes involving TLR modulation.

  12. Microglia-Secreted Galectin-3 Acts as a Toll-like Receptor 4 Ligand and Contributes to Microglial Activation

    Directory of Open Access Journals (Sweden)

    Miguel Angel Burguillos

    2015-03-01

    Full Text Available Inflammatory response induced by microglia plays a critical role in the demise of neuronal populations in neuroinflammatory diseases. Although the role of toll-like receptor 4 (TLR4 in microglia’s inflammatory response is fully acknowledged, little is known about endogenous ligands that trigger TLR4 activation. Here, we report that galectin-3 (Gal3 released by microglia acts as an endogenous paracrine TLR4 ligand. Gal3-TLR4 interaction was further confirmed in a murine neuroinflammatory model (intranigral lipopolysaccharide [LPS] injection and in human stroke subjects. Depletion of Gal3 exerted neuroprotective and anti-inflammatory effects following global brain ischemia and in the neuroinflammatory LPS model. These results suggest that Gal3-dependent-TLR4 activation could contribute to sustained microglia activation, prolonging the inflammatory response in the brain.

  13. Activation of Toll-like Receptor-2 by Endogenous Matrix Metalloproteinase-2 Modulates Dendritic-Cell-Mediated Inflammatory Responses

    Directory of Open Access Journals (Sweden)

    Emmanuelle Godefroy

    2014-12-01

    Full Text Available Matrix metalloproteinase-2 (MMP-2 is involved in several physiological mechanisms, including wound healing and tumor progression. We show that MMP-2 directly stimulates dendritic cells (DCs to both upregulate OX40L on the cell surface and secrete inflammatory cytokines. The mechanism underlying DC activation includes physical association with Toll-like receptor-2 (TLR2, leading to NF-κB activation, OX40L upregulation on DCs, and ensuing TH2 differentiation. Significantly, MMP-2 polarizes T cells toward type 2 responses in vivo, in a TLR2-dependent manner. MMP-2-dependent type 2 polarization may represent a key immune regulatory mechanism for protection against a broad array of disorders, such as inflammatory, infectious, and autoimmune diseases, which can be hijacked by tumors to evade immunity.

  14. Activation of toll-like receptor-2 by endogenous matrix metalloproteinase-2 modulates dendritic-cell-mediated inflammatory responses.

    Science.gov (United States)

    Godefroy, Emmanuelle; Gallois, Anne; Idoyaga, Juliana; Merad, Miriam; Tung, Navpreet; Monu, Ngozi; Saenger, Yvonne; Fu, Yichun; Ravindran, Rajesh; Pulendran, Bali; Jotereau, Francine; Trombetta, Sergio; Bhardwaj, Nina

    2014-12-11

    Matrix metalloproteinase-2 (MMP-2) is involved in several physiological mechanisms, including wound healing and tumor progression. We show that MMP-2 directly stimulates dendritic cells (DCs) to both upregulate OX40L on the cell surface and secrete inflammatory cytokines. The mechanism underlying DC activation includes physical association with Toll-like receptor-2 (TLR2), leading to NF-κB activation, OX40L upregulation on DCs, and ensuing TH2 differentiation. Significantly, MMP-2 polarizes T cells toward type 2 responses in vivo, in a TLR2-dependent manner. MMP-2-dependent type 2 polarization may represent a key immune regulatory mechanism for protection against a broad array of disorders, such as inflammatory, infectious, and autoimmune diseases, which can be hijacked by tumors to evade immunity.

  15. Activation of Toll-like receptor-2 by endogenous matrix metalloproteinase-2 modulates dendritic cell-mediated inflammatory responses

    Science.gov (United States)

    Godefroy, Emmanuelle; Gallois, Anne; Idoyaga, Juliana; Merad, Miriam; Tung, Navpreet; Monu, Ngozi; Saenger, Yvonne; Fu, Yichun; Nair, Rajesh; Pulendran, Bali; Jotereau, Francine; Trombetta, Sergio; Bhardwaj, Nina

    2015-01-01

    SUMMARY Matrix metalloproteinase-2 (MMP-2) is involved in several physiological mechanisms, including wound healing and tumor progression. We show that MMP-2 directly stimulates dendritic cells (DCs) to both up-regulate OX40L on the cell surface and secrete inflammatory cytokines. The mechanism underlying DC activation includes physical association with Toll-like receptor-2 (TLR2), leading to NF-κB activation, OX40L up-regulation on DCs and ensuing TH2 differentiation. Significantly, MMP-2 polarizes T cells towards type-2 responses in vivo, in a TLR2-dependent manner. MMP-2-dependent type-2 polarization may represent a key immune regulatory mechanism to protect against a broad array of disorders, such as inflammatory, infectious and autoimmune diseases, which can be hijacked by tumors to evade immunity. PMID:25466255

  16. Glucuronic acid and the ethanol metabolite ethyl-glucuronide cause Toll-like receptor 4 activation and enhanced pain

    OpenAIRE

    Lewis, Susannah S.; Hutchinson, Mark R; Zhang, Yingning; Hund, Dana K.; Maier, Steven F.; Rice, Kenner C.; Watkins, Linda R

    2013-01-01

    We have previously observed that the non-opioid morphine metabolite, morphine-3-glucuronide, enhances pain via a toll-like receptor 4 (TLR4) dependent mechanism. The present studies were undertaken to determine whether TLR4-dependent pain enhancement generalizes to other classes of glucuronide metabolites. In silico modeling predicted that glucuronic acid alone and ethyl glucuronide, a minor but long-lasting ethanol metabolite, would dock to the same MD-2 portion of the TLR4 receptor complex ...

  17. Toll-Like Receptors and Myocardial Inflammation

    Directory of Open Access Journals (Sweden)

    Yan Feng

    2011-01-01

    Full Text Available Toll-like receptors (TLRs are a member of the innate immune system. TLRs detect invading pathogens through the pathogen-associated molecular patterns (PAMPs recognition and play an essential role in the host defense. TLRs can also sense a large number of endogenous molecules with the damage-associated molecular patterns (DAMPs that are produced under various injurious conditions. Animal studies of the last decade have demonstrated that TLR signaling contributes to the pathogenesis of the critical cardiac conditions, where myocardial inflammation plays a prominent role, such as ischemic myocardial injury, myocarditis, and septic cardiomyopathy. This paper reviews the animal data on (1 TLRs, TLR ligands, and the signal transduction system and (2 the important role of TLR signaling in these critical cardiac conditions.

  18. Mycoplasma lipoproteins and Toll-like receptors

    Institute of Scientific and Technical Information of China (English)

    Ling-ling ZUO; Yi-mou WU; Xiao-xing YOU

    2009-01-01

    Mycoplasmas, the smallest free-living, self-replicating bacteria with diameters of 200 to 800 nm, have been reported to be associated with human diseases. It is well known that the mycoplasma lipoprotein/peptide is able to modulate the host immune system, whose N-terminal structure is an important factor in inducing immunity and distinguishing Toll-like receptors (TLRs). However, there is still no clear elucidation about the pathogenic mechanism of mycoplasma lipoprotein/peptide and the signaling pathway. Some researchers have focused on understanding the structures of these proteins and the relationships between their structure and biological function. This review provides an update on the research in this field.

  19. Immune activation by medium-chain triglyceride-containing lipid emulsions is not modulated by n-3 lipids or toll-like receptor 4

    NARCIS (Netherlands)

    Olthof, E.D.; Gulich, A.F.; Renne, M.F.; Landman, S.; Joosten, L.A.B.; Roelofs, H.M.; Wanten, G.J.A.

    2015-01-01

    BACKGROUND: Saturated medium-chain triglycerides (MCT) as part of the parenteral lipid regimen (50% MCT and 50% long chain triglycerides (LCT)) activate the immune system in vitro. Fish oil (FO)-derived n-3 fatty acids (FA) inhibit saturated FA-induced immune activation via a toll-like receptor (TLR

  20. Toll-like receptor 4 is required for α-synuclein dependent activation of microglia and astroglia

    OpenAIRE

    Fellner, Lisa; Irschick, Regina; Schanda, Kathrin; Reindl, Markus; Klimaschewski, Lars; Poewe, Werner; Wenning, Gregor K; Stefanova, Nadia

    2013-01-01

    Alpha-synucleinopathies (ASP) are neurodegenerative disorders, characterized by accumulation of misfolded α-synuclein, selective neuronal loss, and extensive gliosis. It is accepted that microgliosis and astrogliosis contribute to the disease progression in ASP. Toll-like receptors (TLRs) are expressed on cells of the innate immune system, including glia, and TLR4 dysregulation may play a role in ASP pathogenesis. In this study we aimed to define the involvement of TLR4 in microglial and astr...

  1. Toll-like receptor 8 ligands activate a vitamin D mediated autophagic response that inhibits human immunodeficiency virus type 1.

    Directory of Open Access Journals (Sweden)

    Grant R Campbell

    Full Text Available Toll-like receptors (TLR are important in recognizing microbial pathogens and triggering host innate immune responses, including autophagy, and in the mediation of immune activation during human immunodeficiency virus type-1 (HIV infection. We report here that TLR8 activation in human macrophages induces the expression of the human cathelicidin microbial peptide (CAMP, the vitamin D receptor (VDR and cytochrome P450, family 27, subfamily B, polypeptide 1 (CYP27B1, which 1α-hydroxylates the inactive form of vitamin D, 25-hydroxycholecalciferol, into its biologically active metabolite. Moreover, we demonstrate using RNA interference, chemical inhibitors and vitamin D deficient media that TLR8 agonists inhibit HIV through a vitamin D and CAMP dependent autophagic mechanism. These data support an important role for vitamin D in the control of HIV infection, and provide a biological explanation for the benefits of vitamin D. These findings also provide new insights into potential novel targets to prevent and treat HIV infection.

  2. Toll-like Receptors and Prostate Cancer

    Directory of Open Access Journals (Sweden)

    Shu eZhao

    2014-07-01

    Full Text Available Prostate cancer is the second leading cause of cancer-related death in men after lung cancer. Immune responses clearly play a critical role in the tumorigenesis and in the efficacy of radiation therapy and chemotherapy in prostate cancer; however, the underlying molecular mechanisms are still poorly understood. Toll-like receptors (TLRs are a well-known family of pattern recognition receptors that play a key role in host immune system. Recent studies demonstrate that there are links between TLRs and cancer; however, the function and biological importance of TLRs in prostate cancer seems complex. To elucidate the role of TLRs and innate immunity in prostate cancer might provide us with a better understanding of the molecular mechanisms of this disease. Moreover, utilizing the agonists or antagonists of TLRs might represent a promising new strategy against prostate cancer. In this review, we summarize recent advances on the studies of association between TLR signaling and prostate cancer, TLR polymorphisms and prostate cancer risk, and provide some insights about TLRs as potential targets for prostate cancer immunotherapy.

  3. Role of Toll-like receptor 4 in inflammatory reactions of hippocampal neurons

    Institute of Scientific and Technical Information of China (English)

    Yae Hu; Jiahui Mao; Yu Zhang; Ailing Zhou

    2013-01-01

    Lipopolysaccharide stimulates Toll-like receptor 4 on immune cells to produce immune mediators. Toll-like receptor 4 is also expressed by non-immune cells, which can be stimulated by lipopolysaccharide. However, whether Toll-like receptor 4 is expressed by primary cultured hippocampal neurons and its specific role in lipopolysaccharide-induced neuroinflammation is currently undefined. In this study, Toll-like receptor 4 antibody blocking was used to analyze the Toll-like receptor 4 signaling pathway and changes in inflammation of lipopolysaccharide stimulated hippocampal neurons. Immunofluorescence showed that Toll-like receptor 4 protein was mainly located in the membrane of hippocampal neurons. Quantitative reverse transcription-PCR and western blot assay showed that after stimulation of lipopolysaccharide, the mRNA and protein levels of Toll-like receptor 4 and the mRNA levels of interleukin-1β and tumor necrosis factor-α were significantly increased. In addition, there was increased phosphorylation and degradation of kappa B α inhibitor in the cytosol and increased nuclear factor-κB p65 expression in the nuclei. Pretreatment with Toll-like receptor 4 antibody could almost completely block this increase. These experimental findings indicate that lipopolysaccharide participates in neuroinflammation by stimulating Toll-like receptor 4/nuclear factor-κB pathway in hippocampal neurons, which may be both "passive victims" and "activators" of neuroinflammation.

  4. MR imaging and T2 measurements in peripheral nerve repair with activation of Toll-like receptor 4 of neurotmesis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xiang; Zhang, Fang; Lu, Liejing; Li, Haojiang; Wen, Xuehua; Shen, Jun [Sun Yat-Sen University, Department of Radiology, Sun Yat-Sen Memorial Hospital, Guangzhou, Guangdong (China)

    2014-05-15

    To investigate the role of MR imaging in neurotmesis combined with surgical repair and Toll-like receptor 4 (TLR4) activation. Forty-eight rats received subepineurial microinjection of the TLR4 agonist lipopolysaccharide (LPS, n = 24) or phosphate buffered saline (PBS, n = 24) immediately after surgical repair of the transected sciatic nerve. Sequential fat-suppressed T2-weighted imaging and quantitative T2 measurements were obtained at 3, 7, 14 and 21 days after surgery, with histologic assessments performed at regular intervals. T2 relaxation times and histological quantification of the distal stumps were measured and compared. The distal stumps of transected nerves treated with LPS or PBS both showed persistent enlargement and hyperintense signal. T2 values of the distal stumps showed a rapid rise to peak level followed by a rapid decline pattern in nerves treated with LPS, while exhibiting a slow rise to peak value followed by a slow decline in nerves treated with PBS. Nerves treated with LPS exhibited more prominent macrophage recruitment, faster myelin debris clearance and more pronounced nerve regeneration. Nerves treated with TLR4 activation had a characteristic pattern of T2 value change over time. Longitudinal T2 measurements can be used to detect the enhanced repair effect associated with TLR4 activation in the surgical repair of neurotmesis. (orig.)

  5. CBLB502, an agonist of Toll-like receptor 5, has antioxidant and scavenging free radicals activities in vitro.

    Science.gov (United States)

    Li, Weiguang; Ge, Changhui; Yang, Liu; Wang, Ruixue; Lu, Yiming; Gao, Yan; Li, Zhihui; Wu, Yonghong; Zheng, Xiaofei; Wang, Zhaoyan; Zhang, Chenggang

    2016-01-01

    The bacterial protein flagellin is the known agonist of Toll-like receptor 5 (TLR5). It has been reported that CBLB502, a novel agonist of TLR5 derived from Salmonella flagellin, could reduce radiation toxicity in mouse and primate models, protect mice from dermatitis and oral mucositis caused by radiation, inhibit acute renal ischemic failure, and inhibit the growth of A549 lung cancer cell. The property of CBLB502 is able to bind to TLR5 and activates NF-κB signaling. In this study, we investigated the antioxidant potential and free radicals scavenging properties of CBLB502 in vitro. Interestingly, we found that CBLB502 has a direct and distinct antioxidant capacity and can efficiently scavenge a variety of free radicals, including superoxide anion, hydroxyl radical, and ABTS cation (ABTS(+)). Through wave scanning and kinetic evaluation of scavenging ABTS(+), we found that the ABTS(+) scavenging process of CBLB502 is relatively slow, and the ABTS(+) scavenging activity of CBLB502 has a consistently kinetics characteristics. In conclusion, our results suggested that CBLB502 has antioxidant and scavenging free radicals activities in vitro. It is implied that CBLB502 might partially promote the beneficial protective effect through its scavenging free radicals.

  6. Human Toll-like Receptor (TLR) 8-Specific Agonistic Activity in Substituted Pyrimidine-2,4-diamines.

    Science.gov (United States)

    Beesu, Mallesh; Salyer, Alex C D; Trautman, Kathryn L; Hill, Justin K; David, Sunil A

    2016-09-01

    Activation of human toll-like receptor-8 (TLR8) evokes a distinct cytokine profile favoring the generation of Type 1 helper T cells. A multiplexed high-throughput screen had led to the identification of N(4)-butyl-5-iodo-6-methylpyrimidine-2,4-diamine as a pure TLR8 agonist, and a detailed structure-activity relationship study of this chemotype was undertaken. A butyl substituent at N(4) was optimal, and replacement of the 5-iodo group with chloro, bromo, or fluoro groups led to losses in potency, as did the introduction of aromatic bulk. Drawing from our previous structure-based design, several 5-alkylamino derivatives were evaluated. Significant enhancement of potency was achieved in 5-(4-aminobutyl)-N(4)-butyl-6-methylpyrimidine-2,4-diamine. This compound potently induced Th1-biasing IFN-γ and IL-12 in human blood, but lower levels of the proinflammatory cytokines IL-1β, IL-6, and IL-8. These results suggest that the inflammatory and reactogenic propensities of this compound could be considerably more favorable than other TLR8 agonists under evaluation. PMID:27513008

  7. Lubricin/Proteoglycan 4 binds to and regulates the activity of Toll-Like Receptors In Vitro.

    Science.gov (United States)

    Iqbal, S M; Leonard, C; Regmi, S C; De Rantere, D; Tailor, P; Ren, G; Ishida, H; Hsu, Cy; Abubacker, S; Pang, D Sj; Salo, P T; Vogel, H J; Hart, D A; Waterhouse, C C; Jay, G D; Schmidt, T A; Krawetz, R J

    2016-01-01

    Proteoglycan 4 (PRG4/lubricin) is secreted by cells that reside in articular cartilage and line the synovial joint. Lubricin may play a role in modulating inflammatory responses through interaction with CD44. This led us to examine if lubricin could be playing a larger role in the modulation of inflammation/immunity through interaction with Toll-like receptors (TLRs). Human Embryonic Kidney (HEK) cells overexpressing TLRs 2, 4 or 5 and surface plasmon resonance were employed to determine if full length recombinant human lubricin was able to bind to and activate TLRs. Primary human synovial fibroblasts were also examined using flow cytometry and Luminex multiplex ELISA. A rat destabilization model of osteoarthritis (OA) was used to determine if lubricin injections were able to regulate pain and/or inflammation in vivo. Lubricin can bind to and regulate the activity of TLRs, leading to downstream changes in inflammatory signalling independent of HA. We confirmed these findings in vivo through intra-articular injections of lubricin in a rat OA model where the inhibition of systemic inflammatory signaling and reduction in pain were observed. Lubricin plays an important role in regulating the inflammatory environment under both homeostatic and tissue injury states. PMID:26752378

  8. Lubricin/Proteoglycan 4 binds to and regulates the activity of Toll-Like Receptors In Vitro.

    Science.gov (United States)

    Iqbal, S M; Leonard, C; Regmi, S C; De Rantere, D; Tailor, P; Ren, G; Ishida, H; Hsu, Cy; Abubacker, S; Pang, D Sj; Salo, P T; Vogel, H J; Hart, D A; Waterhouse, C C; Jay, G D; Schmidt, T A; Krawetz, R J

    2016-01-01

    Proteoglycan 4 (PRG4/lubricin) is secreted by cells that reside in articular cartilage and line the synovial joint. Lubricin may play a role in modulating inflammatory responses through interaction with CD44. This led us to examine if lubricin could be playing a larger role in the modulation of inflammation/immunity through interaction with Toll-like receptors (TLRs). Human Embryonic Kidney (HEK) cells overexpressing TLRs 2, 4 or 5 and surface plasmon resonance were employed to determine if full length recombinant human lubricin was able to bind to and activate TLRs. Primary human synovial fibroblasts were also examined using flow cytometry and Luminex multiplex ELISA. A rat destabilization model of osteoarthritis (OA) was used to determine if lubricin injections were able to regulate pain and/or inflammation in vivo. Lubricin can bind to and regulate the activity of TLRs, leading to downstream changes in inflammatory signalling independent of HA. We confirmed these findings in vivo through intra-articular injections of lubricin in a rat OA model where the inhibition of systemic inflammatory signaling and reduction in pain were observed. Lubricin plays an important role in regulating the inflammatory environment under both homeostatic and tissue injury states.

  9. Microbial Hijacking of Complement–Toll-like Receptor Crosstalk*

    OpenAIRE

    WANG Min; Krauss, Jennifer L.; Domon, Hisanori; Hosur, Kavita B.; Liang, Shuang; Magotti, Paola; Triantafilou, Martha; Triantafilou, Kathy; Lambris, John D.; Hajishengallis, George

    2010-01-01

    Recent evidence suggests that complement and Toll-like receptors (TLRs) crosstalk to coordinate innate immunity. We report a novel immune subversion mechanism involving microbial exploitation of the ability of complement and TLRs for communication. Porphyromonas gingivalis, a major oral and systemic pathogen expressing complement C5 convertase-like activity, was shown to synergize with C5a for cAMP elevation resulting in macrophage immunosuppression and enhanced pathogen survival in vitro and...

  10. Toll-like receptors of deuterostome invertebrates

    Directory of Open Access Journals (Sweden)

    Honoo eSatake

    2012-02-01

    Full Text Available Defensive systems against pathogens are responsible not only for survival or lifetime of an individual but also for the evolution of a species. Innate immunity is expected to be more important for invertebrates than mammals, given that adaptive immunity has not been acquired in the former. Toll-like receptors (TLRs have been shown to play a crucial role in host defense of pathogenic microbes in innate immunity of mammals. Recent genome-wide analyses have suggested that TLR or their related genes are conserved in invertebrates. In particular, numerous TLR-related gene candidates were detected in deuterostome invertebrates including a sea urchin (222 TLR-related gene candidates and amphioxus (72 TLR-related gene candidates. Molecular phylogenetic analysis verified that most of sea urchin or amphioxus TLR candidates are paralogous, suggesting that these organisms expanded TLR-related genes in a species-specific manner. In contrast, another deuterostome invertebrate, an ascidian, Ciona intestinalis, was found to possess only two TLR genes. Moreover, Ciona TLRs, Ci-TLR1 and -2, were shown to possess hybrid functionality of mammalian TLRs. Such functionality of Ci-TLRs could not be predicted by sequence comparison with vertebrate TLRs, indicating the confounding evolutionary lineages of deuterostome invertebrate TLRs or their candidates. In this review article, we present recent advances in studies of TLRs or their candidates of deuterostome invertebrates, and provide insight into an evolutionary process of TLRs.

  11. Toll-like receptor 2 or toll-like receptor 4 deficiency does not modify lupus in MRLlpr mice.

    Directory of Open Access Journals (Sweden)

    Simon J Freeley

    Full Text Available Systemic lupus erythematosus is an autoimmune disease with a high morbidity and nephritis is a common manifestation. Previous studies in murine lupus models have suggest a role for Toll-like receptor 2 and 4. We examined the role of these molecules in MRL lpr mice which is one of the most established and robust murine models. We compared disease parameters in Toll-like receptor 2 or Toll-like receptor 4 deficient mice with their littermate controls. We found no difference in the severity of glomerulonephritis as assessed by histology, serum creatinine and albuminuria when Toll-like receptor 2 or Toll-like receptor 4 deficient MRLlpr mice were compared with Toll-like receptor sufficient controls. We also found similar levels of anti-dsDNA and anti-ssDNA antibodies. These results show that Toll-like receptor 2 and Toll-like receptor 4 do not play a significant role in MRLlpr mice, and therefore they may not be important in human lupus.

  12. Prenatal activation of toll-like receptor-4 dampens adult hippocampal neurogenesis in an IL-6 dependent manner

    Directory of Open Access Journals (Sweden)

    Abdeslam eMouihate

    2016-06-01

    Full Text Available Prenatal immune challenge has been associated with alteration in brain development and plasticity that last into adulthood. We have previously shown that prenatal activation of toll-like receptor 4 by LPS induces IL-6-dependent STAT-3 signaling pathway in the fetal brain. Whether this IL-6-dependent activation of fetal brain results in long lasting impact in brain plasticity is still unknown. Furthermore, it has been shown that prenatal LPS heightens the hypothalamic-pituitary-adrenal (HPA response in adulthood. In the present study we tested whether LPS administration during pregnancy affects neurogenesis in adult male offspring. Because corticosterone, the end-product of HPA axis activity in rats, alters neurogenesis we tested whether this enhanced HPA axis responsiveness in adult male offspring played a role in the long lasting impact of LPS on neurogenesis during adulthood. Pregnant rats were given either LPS, or LPS and an IL-6 neutralizing antibody (IL-6Ab. The newly born neurons were monitored in the subventricular zone (SVZ and the dentate gyrus (DG of the hippocampus of adult male offspring by monitoring doublecortin and T-box brain protein 2 expression: two well-established markers of newly born neurons. Prenatal LPS decreased the number of newly born neurons in the DG, but not in the SVZ of adult offspring. This decreased number of newly born neurons in the DG was absent when IL-6Ab was co-injected with LPS during pregnancy. Furthermore, administration of a corticosterone receptor blocker, RU-486, to adult offspring blunted the prenatal LPS induced decrease in newly born neurons in the DG.These data suggest that maternally triggered IL-6 plays a crucial role in the long lasting impact of LPS on adult neurogenesis.

  13. Toll-like receptor expression and activation in astroglia: differential regulation by HIV-1 Tat, gp120, and morphine

    OpenAIRE

    El-Hage, Nazira; PODHAIZER, Elizabeth M.; Sturgill, Jamie; Hauser, Kurt F.

    2011-01-01

    In this study we determine whether morphine alone or in combination with HIV-1 Tat or gp120 affects the expression of Toll-like receptors (TLRs) by astrocytes and to assess whether TLRs expressed by astrocytes function in the release of inflammatory mediators in vitro. TLR profiling by immunofluorescence microscopy, flow cytometry, in-cell westerns, and RT-PCR showed that subpopulations of astrocytes possessed TLR 2, TLR3, TLR4, and TLR9 antigenicity. Exposure to HIV-1 Tat, gp120, and/or morp...

  14. Lactobacilli inhibit interleukin-8 production induced by Helicobacter pylori lipopolysaccharide-activated Toll-like receptor 4

    Institute of Scientific and Technical Information of China (English)

    Chao Zhou; Feng-Zhen Ma; Xue-Jie Deng; Hong Yuan; Hong-Sheng Ma

    2008-01-01

    AIM: To investigate the effect of Lactobacillus bulgaricus (LBG) on the Toll-like receptor 4 (TLR4) pathway and interleukin-8 (IL-8) production in SGC-7901 cells treated with Helicobacter pyloriSydney strain 1 lipopolysaccharide (H pyloriSS1-LPS).METHODS: SGC-7901 cells were treated with H pyIoriSS1-LPS in the presence or absence of pretreatment for 1 h with viable LBG or supematant recovered from LBG culture MRS broth (LBG-s). Cellular lysates were prepared for Western blot with anti-TLR4,anti-transforming growth factor β-activated kinase 1 (TAK1), anti-phospho-TAK1, anti-nuclear factor κB (NF-κB), anti-p38 mitogen-activated protein kinase (p38MAPK), and anti-phospho-p38MAPK antibodies.The amount of IL-8 in cell culture medium was measured by ELISA.RESULTS: H pyloriSS1-LPS up-regulated the expression of TLR4, stimulated the phosphorylation of TAK1, subsequently enhanced the activation of NFκB and the phosphorylation of p38MAPK in a timedependent manner, leading to augmentation of IL-8 production in SGC-7901 cells. Viable LBG or LBG-s pretreatment attenuated the expression of TLR4,inhibited the phosphorylation of TAK1 and p38MAPK,prevented the activation of NF-κB, and consequently blocked IL-8 production.CONCLUSION: H pyloriSS1-LPS induces IL-8production through activating TLR4 signaling in SGC-7901 cells and viable LBG or LBG-s prevents H pyloriSS1-LPS-mediated IL-8 production via inhibition of the TLR4 pathway.

  15. Lipid IVa incompletely activates MyD88-independent Toll-like receptor 4 signaling in mouse macrophage cell lines.

    Science.gov (United States)

    Ogura, Norihiko; Muroi, Masashi; Sugiura, Yuka; Tanamoto, Ken-ichi

    2013-04-01

    We investigated the difference in the effect of synthetic lipid A compounds on MyD88-dependent and -independent Toll-like receptor 4 (TLR4) signaling in mouse macrophage cells. At higher concentrations, Escherichia coli-type hexa-acylated lipid A 506, Salmonella-type hepta-acylated lipid A 516, the lipid A precursor lipid IVa and monophosphoryl lipid A induced similar levels of production of the MyD88-dependent cytokine IL-1β although their potencies varied, whereas the maximum production of the MyD88-independent cytokine RANTES induced by lipid IVa was less than 50% that of other lipid A compounds. A maximum level of NF-κB activation, which is involved in IL-1β gene transcription, was also induced to a similar level by these four lipid A compounds, while the maximum level of IFN-β promoter activity induced during MyD88-independent signaling was also less than 50% for lipid IVa stimulation compared with other lipid A compounds. Early IκBα phosphorylation activated by MyD88-dependent signaling was similarly induced by 506 and lipid IVa, whereas lipid IVa barely stimulated the phosphorylation of IRF3, a MyD88-independent transcription factor, although efficient phosphorylation was observed with 506 stimulation. These results indicate that lipid IVa has limited activity toward MyD88-independent signaling of TLR4, in macrophage cell lines, despite having efficient activity in the MyD88-dependent pathway.

  16. Differential cell reaction upon Toll-like receptor 4 and 9 activation in human alveolar and lung interstitial macrophages

    Directory of Open Access Journals (Sweden)

    Meyerhans Andreas

    2010-09-01

    Full Text Available Abstract Background Investigations on pulmonary macrophages (MΦ mostly focus on alveolar MΦ (AM as a well-defined cell population. Characteristics of MΦ in the interstitium, referred to as lung interstitial MΦ (IM, are rather ill-defined. In this study we therefore aimed to elucidate differences between AM and IM obtained from human lung tissue. Methods Human AM and IM were isolated from human non-tumor lung tissue from patients undergoing lung resection. Cell morphology was visualized using either light, electron or confocal microscopy. Phagocytic activity was analyzed by flow cytometry as well as confocal microscopy. Surface marker expression was measured by flow cytometry. Toll-like receptor (TLR expression patterns as well as cytokine expression upon TLR4 or TLR9 stimulation were assessed by real time RT-PCR and cytokine protein production was measured using a fluorescent bead-based immunoassay. Results IM were found to be smaller and morphologically more heterogeneous than AM, whereas phagocytic activity was similar in both cell types. HLA-DR expression was markedly higher in IM compared to AM. Although analysis of TLR expression profiles revealed no differences between the two cell populations, AM and IM clearly varied in cell reaction upon activation. Both MΦ populations were markedly activated by LPS as well as DNA isolated from attenuated mycobacterial strains (M. bovis H37Ra and BCG. Whereas AM expressed higher amounts of inflammatory cytokines upon activation, IM were more efficient in producing immunoregulatory cytokines, such as IL10, IL1ra, and IL6. Conclusion AM appear to be more effective as a non-specific first line of defence against inhaled pathogens, whereas IM show a more pronounced regulatory function. These dissimilarities should be taken into consideration in future studies on the role of human lung MΦ in the inflammatory response.

  17. Improved Chemotherapeutic Activity by Morus alba Fruits through Immune Response of Toll-Like Receptor 4

    OpenAIRE

    Bo Yoon Chang; Seon Beom Kim; Mi Kyeong Lee; Hyun Park; Sung Yeon Kim

    2015-01-01

    Morus alba L. fruits have long been used in traditional medicine by many cultures. Their medicinal attributes include cardiovascular, hepatoprotective, neuroprotective and immunomodulatory actions. However, their mechanism of macrophage activation and anti-cancer effects remain unclear. The present study investigated the molecular mechanisms of immune stimulation and improved chemotherapeutic effect of M. alba L. fruit extract (MFE). MFE stimulated the production of cytokines, nitric oxide (...

  18. Stimulation of Toll-like receptor 2 in human platelets induces a thromboinflammatory response through activation of phosphoinositide 3-kinase.

    Science.gov (United States)

    Blair, Price; Rex, Sybille; Vitseva, Olga; Beaulieu, Lea; Tanriverdi, Kahraman; Chakrabarti, Subrata; Hayashi, Chie; Genco, Caroline A; Iafrati, Mark; Freedman, Jane E

    2009-02-13

    Cells of the innate immune system use Toll-like receptors (TLRs) to initiate the proinflammatory response to microbial infection. Recent studies have shown acute infections are associated with a transient increase in the risk of vascular thrombotic events. Although platelets play a central role in acute thrombosis and accumulating evidence demonstrates their role in inflammation and innate immunity, investigations into the expression and functionality of platelet TLRs have been limited. In the present study, we demonstrate that human platelets express TLR2, TLR1, and TLR6. Incubation of isolated platelets with Pam(3)CSK4, a synthetic TLR2/TLR1 agonist, directly induced platelet aggregation and adhesion to collagen. These functional responses were inhibited in TLR2-deficient mice and, in human platelets, by pretreatment with TLR2-blocking antibody. Stimulation of platelet TLR2 also increased P-selectin surface expression, activation of integrin alpha(IIb)beta(3), generation of reactive oxygen species, and, in human whole blood, formation of platelet-neutrophil heterotypic aggregates. TLR2 stimulation also activated the phosphoinositide 3-kinase (PI3-K)/Akt signaling pathway in platelets, and inhibition of PI3-K significantly reduced Pam(3)CSK4-induced platelet responses. In vivo challenge with live Porphyromonas gingivalis, a Gram-negative pathogenic bacterium that uses TLR2 for innate immune signaling, also induced significant formation of platelet-neutrophil aggregates in wild-type but not TLR2-deficient mice. Together, these data provide the first demonstration that human platelets express functional TLR2 capable of recognizing bacterial components and activating the platelet thrombotic and/or inflammatory pathways. This work substantiates the role of platelets in the immune and inflammatory response and suggests a mechanism by which bacteria could directly activate platelets.

  19. Silencing of renal DNaseI in murine lupus nephritis imposes exposure of large chromatin fragments and activation of Toll like receptors and the Clec4e

    DEFF Research Database (Denmark)

    Thiyagarajan, Dhivya; Fismen, Silje; Seredkina, Natalya;

    2012-01-01

    Recent studies demonstrate that transformation of mild lupus nephritis into end-stage disease is imposed by silencing of renal DNaseI gene expression in (NZBxNZW)F1 mice. Down-regulation of DNaseI results in reduced chromatin fragmentation, and in deposition of extracellular chromatin-IgG complexes...... in glomerular basement membranes in individuals that produce IgG anti-chromatin antibodies. The main focus of the present study is to describe the biological consequences of renal DNaseI shut-down and reduced chromatin fragmentation with a particular focus on whether exposed large chromatin fragments activate...... Toll like receptors and the necrosis-related Clec4e receptor in murine and human lupus nephritis. Furthermore, analyses where performed to determine if matrix metalloproteases are up-regulated as a consequence of chromatin-mediated Toll like receptors/Clec4e stimulation. Mouse and human mRNA expression...

  20. Toll-like receptors:function and roles in asthma

    Institute of Scientific and Technical Information of China (English)

    周林福; 殷凯生

    2004-01-01

    @@ Asthma is a chronic airway inflammatory disease involved with multiple susceptible genes for atopy. Toll-like receptors (TLRs), an ancient though newly characterized and evolutionarily conserved immune receptor family, activate the mononuclear phagocyte system via both myeloid differentiation marker 88 (MyD88)-dependent and -independent signaling pathways. TLRs might play a key role in asthma by recognition of pathogenic microorganisms, activation of innate immunity, regulation of adaptive immunity, and induction of immune tolerance. For future immunotherapy of asthma, it is promising to develop novel immune regulators by selectively targeting blockade of TLRs.

  1. DMPD: Adaptor usage and Toll-like receptor signaling specificity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15876435 Adaptor usage and Toll-like receptor signaling specificity. Dunne A, O'Nei...sage and Toll-like receptor signaling specificity. PubmedID 15876435 Title Adaptor usage and Toll-like receptor signaling specific

  2. DMPD: Role of Toll-like receptor responses for sepsis pathogenesis. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18086373 Role of Toll-like receptor responses for sepsis pathogenesis. Weighardt H,... of Toll-like receptor responses for sepsis pathogenesis. PubmedID 18086373 Title Role of Toll-like receptor responses for sepsis pat

  3. Cracking the Toll-like receptor code in fungal infections

    OpenAIRE

    Cunha, Cristina; Romani, Luigina; Carvalho, Agostinho

    2010-01-01

    Innate control of fungal infection requires the specific recognition of invariant fungal molecular structures by a variety of innate immune receptors, including Toll-like receptors. In addition to the role in inducing protective immune responses, Toll-like receptor engagement may paradoxically favor fungal infections, by inducing inflammatory pathology and impairing antifungal immunity. Although the dissection of complex genetic traits modulating susceptibility to fungal infections is complex...

  4. The Expression of Toll-like Receptors in Dermatological Diseases and the Therapeutic Effect of Current and Newer Topical Toll-like Receptor Modulators

    OpenAIRE

    Valins, Whitney; Amini, Sadegh; Berman, Brian

    2010-01-01

    Toll-like receptors are a group of glycoproteins located mostly in cellular membranes, capable of recognizing certain molecules in exogenous microorganisms and initiating immune responses against them through the activation of several intracellular signaling pathways. Toll-like receptors can be stimulated when an inflammatory reaction is needed for the treatment of conditions, such as viral infections or skin cancer, or can be inhibited when a reduction of inflammation is necessary for the tr...

  5. Regulation of Toll-like receptor signaling in innate immunity

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Toll-like receptors sense invading pathogens by recognizing a wide variety of conserved pathogen-associated molecular patterns(PAMPs).The members of the TLR family selectively utilize adaptor proteins MyD88,TRIF,TIRAP and TRAM to activate overlapping but distinct signal transduction pathways which trigger production of different panels of mediators such as proinflammatory cytokines and type I interferon.These mediators not only control innate immunity but also direct subsequently developed adaptive immunity.TLR activation is strictly and finely regulated at multiple levels of the signal transduction pathways.

  6. Role of Toll-like receptor 4 and Janus kinase and signal transducer and activator of transcription signal transduction pathway in sepsis-induced brain damage

    Institute of Scientific and Technical Information of China (English)

    Haiyan Yin; Jianrui Wei; Rui Zhang; Xiaoling Ye; Youfeng Zhu

    2011-01-01

    The Janus kinase and signal transducer and activator of transcription (JAK/STAT) signal transduction pathway is involved in sepsis-induced functional damage to the heart, liver, kidney, and other organs.However, the cellular and molecular mechanisms underlying sepsis-induced brain damage remain elusive.In the present study, we found severe loss of neurons in the hippocampal CA1 region in rats with sepsis-induced brain damage following intraperitoneal injection of endotoxin, The expression of toll-like receptor 4, tumor necrosis factor α, and interleukin-6 was significantly increased in brain tissues following lipopolysaccharide exposure.AG490 (JAK2 antagonist) and rapamycin (STAT3 antagonist) significantly reduced neuronal loss and suppressed the increased expression of toll-like receptor 4, tumor necrosis factor α, and interleukin-6 in the hippocampal CA1 region in sepsis-induced brain damaged rats.Overall, these data suggest that blockade of the JAK/STAT signal transduction pathway is neuroprotective in sepsis-induced brain damage via the inhibition of toll-like receptor 4, tumor necrosis factor α, and interleukin-6 expression.

  7. Clinical Effects of a Topically Applied Toll-like Receptor 9 Agonist in Active Moderate-to-Severe Ulcerative Colitis

    Science.gov (United States)

    Atreya, Raja; Bloom, Stuart; Scaldaferri, Franco; Gerardi, Viviana; Admyre, Charlotte; Karlsson, Åsa; Knittel, Thomas; Kowalski, Jan; Lukas, Milan; Löfberg, Robert; Nancey, Stephane; Petryka, Robert; Rydzewska, Grazyna; Schnabel, Robert; Seidler, Ursula; Neurath, Markus F.

    2016-01-01

    Background and Aims: Toll-like receptors [TLRs] are potential drug targets for immunomodulation. We determined the safety and efficacy of the TLR-9 agonist DNA-based immunomodulatory sequence 0150 [DIMS0150] in ulcerative colitis [UC] patients refractory to standard therapy. Methods: In this randomized, double-blind, placebo-controlled trial, 131 patients with moderate-to-severe active UC were randomized to receive two single doses of the oligonucleotide DIMS0150 [30 mg] or placebo administered topically during lower GI endoscopy at baseline and Week 4. The primary endpoint was clinical remission, defined as Clinical Activity Index [CAI] ≤4, at Week 12. Secondary endpoints included mucosal healing and symptomatic remission of key patient-reported outcomes [absence of blood in stool and weekly stool frequency <35]. Results: There was no statistical significant difference between the groups in the induction of clinical remission at Week 12, with 44.4% in the DIMS0150 group vs. 46.5% in the placebo group. However, the proportion of patients who achieved symptomatic remission was 32.1% in the DIMS0150 group vs. 14.0% in the placebo group at Week 4 [p = 0.020], and 44.4% vs. 27.9% at Week 8 [p = 0.061]. More patients on DIMS0150 compared with those on placebo had mucosal healing [34.6% vs. 18.6%; p = 0.09] and histological improvement regarding the Geboes score [30.9% vs. 9.3%; p = 0.0073] at Week 4. Significantly more patients on DIMS0150 were in clinical remission with mucosal healing at Week 4: 21% vs. 4.7% in the placebo group [p = 0.02]. DIMS0150 was well tolerated, and no safety signals compared with placebo were evident. Conclusions: Therapy with the topically applied TLR-9 agonist DIMS0150 is a promising and well-tolerated novel therapeutic option for treatment-refractory, chronic active UC patients, warranting further clinical trials. PMID:27208386

  8. Toll-like receptor 4 modulates skeletal muscle substrate metabolism

    OpenAIRE

    Frisard, Madlyn I.; McMillan, Ryan P.; Marchand, Julie; Wahlberg, Kristin A.; Wu, Yaru; Voelker, Kevin A.; Heilbronn, Leonie; Haynie, Kimberly; Muoio, Brendan; Li, Liwu; Hulver, Matthew W.

    2010-01-01

    Toll-like receptor 4 (TLR4), a protein integral to innate immunity, is elevated in skeletal muscle of obese and type 2 diabetic humans and has been implicated in the development of lipid-induced insulin resistance. The purpose of this study was to examine the role of TLR4 as a modulator of basal (non-insulin-stimulated) substrate metabolism in skeletal muscle with the hypothesis that its activation would result in reduced fatty acid oxidation and increased partitioning of fatty acids toward n...

  9. Discovery and Structure-Activity Relationships of the Neoseptins: A New Class of Toll-like Receptor-4 (TLR4) Agonists.

    Science.gov (United States)

    Morin, Matthew D; Wang, Ying; Jones, Brian T; Su, Lijing; Surakattula, Murali M R P; Berger, Michael; Huang, Hua; Beutler, Elliot K; Zhang, Hong; Beutler, Bruce; Boger, Dale L

    2016-05-26

    Herein, we report studies leading to the discovery of the neoseptins and a comprehensive examination of the structure-activity relationships (SARs) of this new class of small-molecule mouse Toll-like receptor 4 (mTLR4) agonists. The compounds in this class, which emerged from screening an α-helix mimetic library, stimulate the immune response, act by a well-defined mechanism (mouse TLR4 agonist), are easy to produce and structurally manipulate, exhibit exquisite SARs, are nontoxic, and elicit improved and qualitatively different responses compared to lipopolysaccharide, even though they share the same receptor.

  10. DMPD: Translational mini-review series on Toll-like receptors: networks regulated byToll-like receptors mediate innate and adaptive immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available e receptors: networks regulated byToll-like receptors mediate innate and adaptive...ed byToll-like receptors mediate innate and adaptive immunity. Authors Parker LC, Prince LR, Sabroe I. Publi...d byToll-like receptors mediate innate and adaptive immunity. Parker LC, Prince LR, Sabroe I. Clin Exp Immun...17223959 Translational mini-review series on Toll-like receptors: networks regulate

  11. Glucuronic acid and the ethanol metabolite ethyl-glucuronide cause toll-like receptor 4 activation and enhanced pain.

    Science.gov (United States)

    Lewis, Susannah S; Hutchinson, Mark R; Zhang, Yingning; Hund, Dana K; Maier, Steven F; Rice, Kenner C; Watkins, Linda R

    2013-05-01

    We have previously observed that the non-opioid morphine metabolite, morphine-3-glucuronide, enhances pain via a toll-like receptor 4 (TLR4) dependent mechanism. The present studies were undertaken to determine whether TLR4-dependent pain enhancement generalizes to other classes of glucuronide metabolites. In silico modeling predicted that glucuronic acid alone and ethyl glucuronide, a minor but long-lasting ethanol metabolite, would dock to the same MD-2 portion of the TLR4 receptor complex previously characterized as the docking site for morphine-3-glucuronide. Glucuronic acid, ethyl glucuronide and ethanol all caused an increase in TLR4-dependent reporter protein expression in a cell line transfected with TLR4 and associated co-signaling molecules. Glucuronic acid-, ethyl glucuronide-, and ethanol-induced increases in TLR4 signaling were blocked by the TLR4 antagonists LPS-RS and (+)-naloxone. Glucuronic acid and ethyl glucuronide both caused allodynia following intrathecal injection in rats, which was blocked by intrathecal co-administration of the TLR4 antagonist LPS-RS. The finding that ethyl glucuronide can cause TLR4-dependent pain could have implications for human conditions such as hangover headache and alcohol withdrawal hyperalgesia, as well as suggesting that other classes of glucuronide metabolites could have similar effects. PMID:23348028

  12. Protection of Hippocampal Neurogenesis from Toll-Like Receptor 4-Dependent Innate Immune Activation by Ablation of Prostaglandin E2 Receptor Subtype EP1 or EP2

    Science.gov (United States)

    Keene, C. Dirk; Chang, Rubens; Stephen, Christina; Nivison, Mary; Nutt, Samuel E.; Look, Amy; Breyer, Richard M.; Horner, Phillip J.; Hevner, Robert; Montine, Thomas J.

    2009-01-01

    Prostaglandin E2 is one of several eicosanoid products of the cyclooxygenase isozymes and is a key regulator of innate immune responses; it also possesses paracrine effects on mature neurons. The prostaglandin E2 receptor family consists of four subtypes of which EP1 and EP2 are known to be expressed by microglia. Lipopolysaccharide (LPS)-induced innate immune activation leads to the degeneration of intermediate progenitor cells (IPCs) that are destined for neuronal maturation in the hippocampal subgranular zone (SGZ); these cells can be identified by the expression of the transcription factor T-box brain gene 2 (Tbr2). Importantly, depletion of LPS-induced IPCs from the SGZ is suppressed by cyclooxygenase inhibitors. We therefore tested the hypothesis that either EP1 or EP2 is critical to LPS-induced depletion of Tbr2+ IPCs from the SGZ. Expression of either EP1 or EP2 was necessary for Toll-like receptor 4-dependent innate immune-mediated depletion of these Tbr2+ IPCs in mice. Moreover, EP1 activation was directly toxic to murine adult hippocampal progenitor cells; EP2 was not expressed by these cells. Finally, EP1 modulated the response of murine primary microglia cultures to LPS but in a manner distinct from EP2. These results indicate that prostaglandin E2 signaling via either EP1 or EP2 is largely to completely necessary for Toll-like receptor 4-dependent depletion of IPCs from the SGZ and suggest further pharmacological strategies to protect this important neurogenic niche. PMID:19389932

  13. Systemic cancer immunotherapy with Toll-like receptor 7 agonists

    Science.gov (United States)

    Hotz, Christian; Bourquin, Carole

    2012-01-01

    Toll-like receptor (TLR) 7 agonists represent a promising strategy for the immunotherapy of cancer. We have recently investigated the influence of TLR tolerance on the efficacy of systemic tumor treatment with TLR7 ligands. We propose that considering the kinetics of receptor sensitivity highly improves the outcome of cancer immunotherapy. PMID:22720251

  14. Toll-like receptors as therapeutic targets in cystic fibrosis.

    LENUS (Irish Health Repository)

    Greene, Catherine M

    2008-12-01

    Background: Toll-like receptors (TLRs) are pattern recognition receptors that act as a first-line of defence in the innate immune response by recognising and responding to conserved molecular patterns in microbial factors and endogenous danger signals. Cystic fibrosis (CF)-affected airways represent a milieu potentially rich in TLR agonists and the chronic inflammatory phenotype evident in CF airway epithelial cells is probably due in large part to activation of TLRs. Objective\\/methods: To examine the prospects of developing novel therapies for CF by targeting TLRs. We outline the expression and function of TLRs and explore the therapeutic potential of naturally-occurring and synthetic TLR inhibitors for CF. Results\\/conclusion: Modulation of TLRs has therapeutic potential for the inflammatory lung manifestations of CF.

  15. Toll-Like Receptors, Their Ligands, and Atherosclerosis

    Directory of Open Access Journals (Sweden)

    Conrad P. Hodgkinson

    2011-01-01

    Full Text Available Atherosclerosis is a disease characterized by inflammation in the arterial wall. Atherogenesis is dependent on the innate immune response involving activation of Toll-like receptors (TLRs and the expression of inflammatory proteins. TLRs, which recognize various pathogen-associated molecular patterns, are expressed in various cell types within the atherosclerotic plaque. Microbial agents are associated with an increased risk of atherosclerosis and this is, in part, due to activation of TLRs. Recently considerable evidence has been provided suggesting that endogenous proteins promote atherosclerosis by binding to TLRs. In this review, we describe the role of TLRs in atherosclerosis with particular emphasis on those atherogenic endogenous proteins that have been implicated as TLR ligands.

  16. Toll-like receptors in brain development and homeostasis

    DEFF Research Database (Denmark)

    Larsen, Peter H; Holm, Thomas Hellesøe; Owens, Trevor

    2007-01-01

    Toll-like receptors (TLRs) are best known as initiators of the innate immune response to pathogens. Recent reports now reveal intriguing roles for TLRs in the central nervous system (CNS). These include the regulation of neuroinflammation and of neurite outgrowth. The archetypal Toll protein in...

  17. Toll-Like Receptors in Leishmania Infections: Guardians or Promoters?

    Directory of Open Access Journals (Sweden)

    Marilia S. Faria

    2012-01-01

    Full Text Available Protozoa of the genus Leishmania cause a wide variety of pathologies ranging from self-healing skin lesions to visceral damage, depending on the parasite species. The outcome of infection depends on the quality of the adaptive immune response, which is determined by parasite factors and the host genetic background. Innate responses, resulting in the generation of mediators with anti-leishmanial activity, contribute to parasite control and help the development of efficient adaptive responses. Among those, the potential contribution of members of the Toll-like receptors (TLRs family in the control of Leishmania infections started to be investigated about a decade ago. Although most studies appoint a protective role for TLRs, there is growing evidence that in some cases, TLRs facilitate infection. This review highlights recent advances in TLR function during Leishmania infections and discusses their potential role in restraining parasite growth versus yielding disease.

  18. Current Views of Toll-Like Receptor Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Masahiro Yamamoto

    2010-01-01

    Full Text Available On microbial invasion, the host immediately evokes innate immune responses. Recent studies have demonstrated that Toll-like receptors (TLRs play crucial roles in innate responses that lead not only to the clearance of pathogens but also to the efficient establishment of acquired immunity by directly detecting molecules from microbes. In terms of intracellular TLR-mediated signaling pathways, cytoplasmic adaptor molecules containing Toll/IL-1R (TIR domains play important roles in inflammatory immune responses through the production of proinflammatory cytokines, nitric oxide, and type I interferon, and upregulation of costimulatory molecules. In this paper, we will describe our current understanding of the relationship between TLRs and their ligands derived from pathogens such as viruses, bacteria, fungi, and parasites. Moreover, we will review the historical and current literature to describe the mechanisms behind TLR-mediated activation of innate immune responses.

  19. Recruitment of Cbl-b to B cell antigen receptor couples antigen recognition to Toll-like receptor 9 activation in late endosomes.

    Directory of Open Access Journals (Sweden)

    Margaret Veselits

    Full Text Available Casitas B-lineage lymphoma-b (Cbl-b is a ubiquitin ligase (E3 that modulates signaling by tagging molecules for degradation. It is a complex protein with multiple domains and binding partners that are not involved in ubiquitinating substrates. Herein, we demonstrate that Cbl-b, but not c-Cbl, is recruited to the clustered B cell antigen receptor (BCR and that Cbl-b is required for entry of endocytosed BCRs into late endosomes. The E3 activity of Cbl-b is not necessary for BCR endocytic trafficking. Rather, the ubiquitin associated (UBA domain is required. Furthermore, the Cbl-b UBA domain is sufficient to confer the receptor trafficking functions of Cbl-b on c-Cbl. Cbl-b is also required for entry of the Toll-like receptor 9 (TLR9 into late endosomes and for the in vitro activation of TLR9 by BCR-captured ligands. These data indicate that Cbl-b acts as a scaffolding molecule to coordinate the delivery of the BCR and TLR9 into subcellular compartments required for productively delivering BCR-captured ligands to TLR9.

  20. TGFβ activated kinase 1 (TAK1 at the crossroad of B cell receptor and Toll-like receptor 9 signaling pathways in human B cells.

    Directory of Open Access Journals (Sweden)

    Dániel Szili

    Full Text Available B cell development and activation are regulated by combined signals mediated by the B cell receptor (BCR, receptors for the B-cell activating factor of the tumor necrosis factor family (BAFF-R and the innate receptor, Toll-like receptor 9 (TLR9. However, the underlying mechanisms by which these signals cooperate in human B cells remain unclear. Our aim was to elucidate the key signaling molecules at the crossroads of BCR, BAFF-R and TLR9 mediated pathways and to follow the functional consequences of costimulation.Therefore we stimulated purified human B cells by combinations of anti-Ig, B-cell activating factor of the tumor necrosis factor family (BAFF and the TLR9 agonist, CpG oligodeoxynucleotide. Phosphorylation status of various signaling molecules, B cell proliferation, cytokine secretion, plasma blast generation and the frequency of IgG producing cells were investigated. We have found that BCR induced signals cooperate with BAFF-R- and TLR9-mediated signals at different levels of cell activation. BCR and BAFF- as well as TLR9 and BAFF-mediated signals cooperate at NFκB activation, while BCR and TLR9 synergistically costimulate mitogen activated protein kinases (MAPKs, ERK, JNK and p38. We show here for the first time that the MAP3K7 (TGF beta activated kinase, TAK1 is responsible for the synergistic costimulation of B cells by BCR and TLR9, resulting in an enhanced cell proliferation, plasma blast generation, cytokine and antibody production. Specific inhibitor of TAK1 as well as knocking down TAK1 by siRNA abrogates the synergistic signals. We conclude that TAK1 is a key regulator of receptor crosstalk between BCR and TLR9, thus plays a critical role in B cell development and activation.

  1. Rotavirus activates lymphocytes from non-obese diabetic mice by triggering toll-like receptor 7 signaling and interferon production in plasmacytoid dendritic cells.

    Directory of Open Access Journals (Sweden)

    Jessica A Pane

    2014-03-01

    Full Text Available It has been proposed that rotavirus infection promotes the progression of genetically-predisposed children to type 1 diabetes, a chronic autoimmune disease marked by infiltration of activated lymphocytes into pancreatic islets. Non-obese diabetic (NOD mice provide a model for the human disease. Infection of adult NOD mice with rhesus monkey rotavirus (RRV accelerates diabetes onset, without evidence of pancreatic infection. Rather, RRV spreads to the pancreatic and mesenteric lymph nodes where its association with antigen-presenting cells, including dendritic cells, induces cellular maturation. RRV infection increases levels of the class I major histocompatibility complex on B cells and proinflammatory cytokine expression by T cells at these sites. In autoimmunity-resistant mice and human mononuclear cells from blood, rotavirus-exposed plasmacytoid dendritic cells contribute to bystander polyclonal B cell activation through type I interferon expression. Here we tested the hypothesis that rotavirus induces bystander activation of lymphocytes from NOD mice by provoking dendritic cell activation and proinflammatory cytokine secretion. NOD mouse splenocytes were stimulated with rotavirus and assessed for activation by flow cytometry. This stimulation activated antigen-presenting cells and B cells independently of virus strain and replicative ability. Instead, activation depended on virus dose and was prevented by blockade of virus decapsidation, inhibition of endosomal acidification and interference with signaling through Toll-like receptor 7 and the type I interferon receptor. Plasmacytoid dendritic cells were more efficiently activated than conventional dendritic cells by RRV, and contributed to the activation of B and T cells, including islet-autoreactive CD8+ T cells. Thus, a double-stranded RNA virus can induce Toll-like receptor 7 signaling, resulting in lymphocyte activation. Our findings suggest that bystander activation mediated by type I

  2. Cross-talk between toll-like receptor 4 (TLR4) and proteinase-activated receptor 2 (PAR2) is involved in vascular function

    Science.gov (United States)

    Bucci, M; Vellecco, V; Harrington, L; Brancaleone, V; Roviezzo, F; Mattace Raso, G; Ianaro, A; Lungarella, G; De Palma, R; Meli, R; Cirino, G

    2013-01-01

    Background and Purpose Proteinase-activated receptors (PARs) and toll-like receptors (TLRs) are involved in innate immune responses. The aim of this study was to evaluate the possible cross-talk between PAR2 and TLR4 in vessels in physiological condition and how it varies following stimulation of TLR4 by using in vivo and ex vivo models. Experimental Approach Thoracic aortas were harvested from both naïve and endotoxaemic rats for in vitro studies. Arterial blood pressure was monitored in anaesthetized rats in vivo. LPS was used as a TLR4 agonist while PAR2 activating peptide (AP) was used as a PAR2 agonist. Aortas harvested from TLR4–/– mice were also used to characterize the PAR2 response. Key Results PAR2, but not TLR4, expression was enhanced in aortas of endotoxaemic rats. PAR2AP-induced vasorelaxation was increased in aortic rings of LPS-treated rats. TLR4 inhibitors, curcumine and resveratrol, reduced PAR2AP-induced vasorelaxation and PAR2AP-induced hypotension in both naïve and endotoxaemic rats. Finally, in aortic rings from TLR4–/– mice, the expression of PAR2 was reduced and the PAR2AP-induced vasodilatation impaired compared with those from wild-type mice and both resveratrol and curcumine were ineffective. Conclusions and Implications Cross-talk between PAR2 and TLR4 contributes to vascular homeostasis. PMID:22957757

  3. Computational Approaches to Toll-Like Receptor 4 Modulation.

    Science.gov (United States)

    Billod, Jean-Marc; Lacetera, Alessandra; Guzmán-Caldentey, Joan; Martín-Santamaría, Sonsoles

    2016-01-01

    Toll-like receptor 4 (TLR4), along with its accessory protein myeloid differentiation factor 2 (MD-2), builds a heterodimeric complex that specifically recognizes lipopolysaccharides (LPS), which are present on the cell wall of Gram-negative bacteria, activating the innate immune response. Some TLR4 modulators are undergoing preclinical and clinical evaluation for the treatment of sepsis, inflammatory diseases, cancer and rheumatoid arthritis. Since the relatively recent elucidation of the X-ray crystallographic structure of the extracellular domain of TLR4, research around this fascinating receptor has risen to a new level, and thus, new perspectives have been opened. In particular, diverse computational techniques have been applied to decipher some of the basis at the atomic level regarding the mechanism of functioning and the ligand recognition processes involving the TLR4/MD-2 system at the atomic level. This review summarizes the reported molecular modeling and computational studies that have recently provided insights into the mechanism regulating the activation/inactivation of the TLR4/MD-2 system receptor and the key interactions modulating the molecular recognition process by agonist and antagonist ligands. These studies have contributed to the design and the discovery of novel small molecules with promising activity as TLR4 modulators. PMID:27483231

  4. Brain interleukin-1β and the intrinsic receptor antagonist control peripheral Toll-like receptor 3-mediated suppression of spontaneous activity in rats.

    Directory of Open Access Journals (Sweden)

    Masanori Yamato

    Full Text Available During acute viral infections such as influenza, humans often experience not only transient fever, but also prolonged fatigue or depressive feelings with a decrease in social activity for days or weeks. These feelings are thought to be due to neuroinflammation in the brain. Recent studies have suggested that chronic neuroinflammation is a precipitating event of various neurological disorders, but the mechanism determining the duration of neuroinflammation has not been elucidated. In this study, neuroinflammation was induced by intraperitoneal injection of polyriboinosinic:polyribocytidylic acid (poly I:C, a Toll-like receptor-3 agonist that mimics viral infection in male Sprague-Dawley rats, and then investigated how the neuroinflammation shift from acute to the chronic state. The rats showed transient fever and prolonged suppression of spontaneous activity for several days following poly I:C injection. NS-398, a cyclooxygenase-2 inhibitor, completely prevented fever, but did not improve spontaneous activity, indicating that suppression of spontaneous activity was not induced by the arachidonate cascade that generated the fever. The animals overexpressed interleukin (IL-1β and IL-1 receptor antagonist (IL-1ra in the brain including the cerebral cortex. Blocking the IL-1 receptor in the brain by intracerebroventricular (i.c.v. infusion of recombinant IL-1ra completely blocked the poly I:C-induced suppression of spontaneous activity and attenuated amplification of brain interferon (IFN-α expression, which has been reported to produce fatigue-like behavior by suppressing the serotonergic system. Furthermore, i.c.v. infusion of neutralizing antibody for IL-1ra prolonged recovery from suppression of spontaneous activity. Our findings indicated that IL-1β is the key trigger of neuroinflammation and that IL-1ra prevents the neuroinflammation entering the chronic state.

  5. Suppressed Microglial E Prostanoid Receptor 1 Signaling Selectively Reduces TNFα and IL-6 Secretion from Toll-like Receptor 3 Activation

    Science.gov (United States)

    Li, Xianwu; Cudaback, Eiron; Keene, C. Dirk; Breyer, Richard M.; Montine, Thomas J.

    2010-01-01

    Activation of innate immunity via Toll-like receptors (TLRs) is associated with neurodegenerative diseases, and some effectors, like tumor necrosis factor alpha (TNFα) and interleukin 6 (IL-6), directly contribute to neurodegeneration. We tested the hypothesis that prostaglandin (PG) E2 receptor subtype 1 (EP1) was necessary for induction of microglial cytokines following activation of innate immunity. Primary murine microglia had cytokine secretion by activators of TLR3 > TLR9 >TLR4 > TLR2. TLR3 activation induced early expression of cyclooxygenase 2 (COX2) and delayed expression of membranous PGE synthase and secretion of PGE2. Non-selective and COX2-selective inhibitors blocked TLR3 induction of TNFα and IL-6. Moreover, of the eight out of twenty cytokines and chemokines induced by TLR3 activation, only TNFα and IL-6 were significantly dependent on EP1 signaling as determined using microglia from mice homozygous deficient for EP1 gene or wild type (WT) microglia co-incubated with an EP1 antagonist. These results were confirmed by blocking intracellular Ca2+ release with 2-aminoethoxy-diphenyl borate (2-APB) or Xestospongin C (XC), inhibitors of IP3 receptors. Our results show that suppression of microglial EP1 signaling achieves much of the desired effect of COX inhibitors by selectively blocking TLR3-induced microglial secretion of two major effectors of paracrine neuron damage. In combination with the ability of EP1 suppression to ameliorate excitotoxicity, these data point to blockade of EP1 as an attractive candidate therapeutic for neurodegenerative diseases. PMID:21319223

  6. Human herpesvirus 6 infection impairs Toll-like receptor signaling

    OpenAIRE

    Ochi Toshiki; Suemori Koichiro; An Jun; Fujiwara Hiroshi; Tanimoto Kazushi; Murakami Yuichi; Hasegawa Hitoshi; Yasukawa Masaki

    2010-01-01

    Abstract Human herpesvirus 6 (HHV-6) has a tropism for immunocompetent cells, including T lymphocytes, monocytes/macrophages, and dendritic cells (DCs) suggesting that HHV-6 infection affects the immunosurveillance system. Toll-like receptor (TLR) system plays an important role in innate immunity against various pathogens. In the present study, we investigated the effect of HHV-6 infection on the expression and intracellular signaling of TLRs in DCs. Although expression levels of TLRs were no...

  7. Pan-Vertebrate Toll-Like Receptors During Evolution

    OpenAIRE

    Oshiumi, Hiroyuki; Matsuo, Aya; Matsumoto, Misako; Seya, Tsukasa

    2008-01-01

    Human toll-like receptors (TLRs) recognize pathogen-associated molecular patterns (PAMPs) to raise innate immune responses. The human TLR family was discovered because of its sequence similarity to fruit fly (Drosophila) Toll, which is involved in an anti-fungal response. In this review, we focus on the origin of the vertebrate TLR family highlighted through functional and phylogenetic analyses of TLRs in non-mammalian vertebrates. Recent extensive genome projects revealed that teleosts conta...

  8. Intervention on toll-like receptors in pancreatic cancer

    OpenAIRE

    Vaz, Juan; Andersson, Roland

    2014-01-01

    Pancreatic ductal adenocarcinoma (PDA) is a devastating disease with pronounced morbidity and a high mortality rate. Currently available treatments lack convincing cost-efficiency determinations and are in most cases not associated with relevant success rate. Experimental stimulation of the immune system in murine PDA models has revealed some promising results. Toll-like receptors (TLRs) are pillars of the immune system that have been linked to several forms of malignancy, including lung, bre...

  9. Toll-like receptor sensing of human herpesvirus infection

    OpenAIRE

    John A West; Gregory, Sean M.; Damania, Blossom

    2012-01-01

    Toll-like receptors (TLRs) are evolutionarily conserved pathogen sensors that constitute the first line of defense in the human immune system. Herpesviruses are prevalent throughout the world and cause significant disease in the human population. Sensing of herpesviruses via TLRs has only been documented in the last 10 years and our understanding of the relationship between these sentinels of the immune system and herpesvirus infection has already provided great insight into how the host cell...

  10. The evolution of vertebrate Toll-like receptors

    OpenAIRE

    Roach, Jared C.; Glusman, Gustavo; Rowen, Lee; Kaur, Amardeep; Purcell, Maureen K.; Smith, Kelly D.; Hood, Leroy E.; Aderem, Alan

    2005-01-01

    The complete sequences of Takifugu Toll-like receptor (TLR) loci and gene predictions from many draft genomes enable comprehensive molecular phylogenetic analysis. Strong selective pressure for recognition of and response to pathogen-associated molecular patterns has maintained a largely unchanging TLR recognition in all vertebrates. There are six major families of vertebrate TLRs. This repertoire is distinct from that of invertebrates. TLRs within a family recognize a general class of pathog...

  11. Direct and Indirect Role of Toll-Like Receptors in T Cell Mediated Immunity

    Institute of Scientific and Technical Information of China (English)

    Damo Xu; Haiying Liu; Mousa Komai-Koma

    2004-01-01

    Toll-like receptors (TLR) are pathogen-associated molecular patterns (PAMPs) recognition receptors that play an important role in protective immunity against infection and inflammation. They act as central integrators of a wide variety of signals, responding to diverse agonists of microbial products. Stimulation of Toll-like receptors by microbial products leads to signaling pathways that activate not only innate, but also adaptive immunity by APC dependent or independent mechanisms. Recent evidence revealed that TLR signals played a determining role in the skewing of na(i)ve T cells towards either Th1 or Th2 responses. Activation of Toll-like receptors also directly or indirectly influences regulatory T cell functions. Therefore, TLRs are required in both immune activation and immune regulation. Study of TLRs has significantly enhanced our understanding of innate and adaptive immune responses and provides novel therapeutic approaches against infectious and inflammatory diseases.

  12. Direct and Indirect Role of Toll-Like Receptors in T Cell Mediated Immunity

    Institute of Scientific and Technical Information of China (English)

    DamoXu; HaiyingLiu; MousaKomai-Koma

    2004-01-01

    Toll-like receptors (TLR) are pathogen-associated molecular patterns (PAMPs) recognition receptors that play an important role in protective immunity against infection and inflammation. They act as central integrators of a wide variety of signals, responding to diverse agonists of microbial products. Stimulation of Toll-like receptors by microbial products leads to signaling pathways that activate not only innate, but also adaptive immunity by APC dependent or independent mechanisms. Recent evidence revealed that TLR signals played a determining role in the skewing of naive T cells towards either Thl or Th2 responses. Activation of Toll-like receptors also directly or indirectly influences regulatory T cell functions. Therefore, TLRs are required in both immune activation and immune regulation. Study of TLRs has significantly enhanced our understanding of innate and adaptive immune responses and provides novel therapeutic approaches against infectious and inflammatory diseases. Cellular & Molecular Immunology.

  13. Crosstalk between Complement and Toll-like Receptor Activation in Relation to Donor Brain Death and Renal Ischemia-Reperfusion Injury

    NARCIS (Netherlands)

    Damman, Jeffrey; Daha, Mohamed R.; van Son, Willem J.; Leuvenink, Henri G.; Ploeg, Rutger J.; Seelen, Marc A.

    2011-01-01

    Two central pathways of innate immunity, complement and Toll-like receptors (TLRs), play an important role in the pathogenesis of renal injury inherent to kidney transplantation. Recent findings indicate close crosstalk between complement and TLR signaling pathways. It is suggested that mitogen acti

  14. Neu1 desialylation of sialyl alpha-2,3-linked beta-galactosyl residues of TOLL-like receptor 4 is essential for receptor activation and cellular signaling.

    Science.gov (United States)

    Amith, Schammim Ray; Jayanth, Preethi; Franchuk, Susan; Finlay, Trisha; Seyrantepe, Volkan; Beyaert, Rudi; Pshezhetsky, Alexey V; Szewczuk, Myron R

    2010-02-01

    The ectodomain of TOLL-like receptors (TLR) is highly glycosylated with several N-linked gylcosylation sites located in the inner concave surface. The precise role of these sugar N-glycans in TLR receptor activation is unknown. Recently, we have shown that Neu1 sialidase and not Neu2, -3 and -4 forms a complex with TLR-2, -3 and -4 receptors on the cell-surface membrane of naïve and activated macrophage cells (Glycoconj J DOI 10.1007/s10719-009-9239-8). Activation of Neu1 is induced by TLR ligands binding to their respective receptors. Here, we show that endotoxin lipopolysaccharide (LPS)-induced MyD88/TLR4 complex formation and subsequent NFkappaB activation is dependent on the removal of alpha-2,3-sialyl residue linked to beta-galactoside of TLR4 by the Neu1 activity associated with LPS-stimulated live primary macrophage cells, macrophage and dendritic cell lines but not with primary Neu1-deficient macrophage cells. Exogenous alpha-2,3 sialyl specific neuraminidase (Streptoccocus pneumoniae) and wild-type T. cruzi trans-sialidase (TS) but not the catalytically inactive mutant TSAsp98-Glu mediate TLR4 dimerization to facilitate MyD88/TLR4 complex formation and NFkappaB activation similar to those responses seen with LPS. These same TLR ligand-induced NFkappaB responses are not observed in TLR deficient HEK293 cells, but are re-established in HEK293 cells stably transfected with TLR4/MD2, and are significantly inhibited by alpha-2,3-sialyl specific Maackia amurensis (MAL-2) lectin, alpha-2,3-sialyl specific galectin-1 and neuraminidase inhibitor Tamiflu but not by alpha-2,6-sialyl specific Sambucus nigra lectin (SNA). Taken together, the findings suggest that Neu1 desialylation of alpha-2,3-sialyl residues of TLR receptors enables in removing a steric hinderance to receptor association for TLR activation and cellular signaling. PMID:19796680

  15. Toll-Like Receptor 7-Targeted Therapy in Respiratory Disease.

    Science.gov (United States)

    Lebold, Katie M; Jacoby, David B; Drake, Matthew G

    2016-03-01

    Allergic asthma and allergic rhinitis are inflammatory diseases of the respiratory tract characterized by an excessive type-2 T helper cell (Th2) immune response. Toll-like receptor 7 (TLR7) is a single-stranded viral RNA receptor expressed in the airway that initiates a Th1 immune response and has garnered interest as a novel therapeutic target for treatment of allergic airway diseases. In animal models, synthetic TLR7 agonists reduce airway hyperreactivity, eosinophilic inflammation, and airway remodeling while decreasing Th2-associated cytokines. Furthermore, activation of TLR7 rapidly relaxes airway smooth muscle via production of nitric oxide. Thus, TLR7 has dual bronchodilator and anti-inflammatory effects. Two TLR7 ligands with promising pharmacologic profiles have entered clinical trials for the treatment of allergic rhinitis. Moreover, TLR7 agonists are potential antiviral therapies against respiratory viruses. TLR7 agonists enhance influenza vaccine efficacy and also reduce viral titers when given during an active airway infection. In this review, we examine the current data supporting TLR7 as a therapeutic target in allergic airway diseases. PMID:27226793

  16. DMPD: Viral recognition by Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17336545 Viral recognition by Toll-like receptors. Barton GM. Semin Immunol. 2007 F...eb;19(1):33-40. Epub 2007 Mar 2. (.png) (.svg) (.html) (.csml) Show Viral recognition by Toll-like receptors.... PubmedID 17336545 Title Viral recognition by Toll-like receptors. Authors Barton GM. Publication Semin Imm

  17. DMPD: A Toll-like receptor in horseshoe crabs. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15199958 A Toll-like receptor in horseshoe crabs. Inamori K, Ariki S, Kawabata S. I...mmunol Rev. 2004 Apr;198:106-15. (.png) (.svg) (.html) (.csml) Show A Toll-like receptor in horseshoe crabs.... PubmedID 15199958 Title A Toll-like receptor in horseshoe crabs. Authors Inamori K, Ariki S, Kawabata S. Pu

  18. DMPD: Endogenous ligands of Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15178705 Endogenous ligands of Toll-like receptors. Tsan MF, Gao B. J Leukoc Biol. ...2004 Sep;76(3):514-9. Epub 2004 Jun 3. (.png) (.svg) (.html) (.csml) Show Endogenous ligands of Toll-like re...ceptors. PubmedID 15178705 Title Endogenous ligands of Toll-like receptors. Authors Tsan MF, Gao B. Publicat

  19. DMPD: Signalling adaptors used by Toll-like receptors: an update. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18706831 Signalling adaptors used by Toll-like receptors: an update. Kenny EF, O'Ne...tors used by Toll-like receptors: an update. PubmedID 18706831 Title Signalling adaptors used by Toll-like receptors: an update

  20. DMPD: Toll-like receptors in atherosclerosis. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18031244 Toll-like receptors in atherosclerosis. Tobias PS, Curtiss LK. Biochem Soc... Trans. 2007 Dec;35(Pt 6):1453-5. (.png) (.svg) (.html) (.csml) Show Toll-like receptors in atherosclerosis.... PubmedID 18031244 Title Toll-like receptors in atherosclerosis. Authors Tobias PS, Curtiss LK. Publication

  1. DMPD: Toll like receptors and autoimmunity: a critical appraisal. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17959357 Toll like receptors and autoimmunity: a critical appraisal. Papadimitraki ...ml) Show Toll like receptors and autoimmunity: a critical appraisal. PubmedID 17959357 Title Toll like recep...tors and autoimmunity: a critical appraisal. Authors Papadimitraki ED, Bertsias G

  2. DMPD: Toll-like receptors regulation of viral infection and disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18280610 Toll-like receptors regulation of viral infection and disease. Thompson JM...how Toll-like receptors regulation of viral infection and disease. PubmedID 18280610 Title Toll-like recepto...rs regulation of viral infection and disease. Authors Thompson JM, Iwasaki A. Pub

  3. DMPD: Pathogen recognition with Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15950447 Pathogen recognition with Toll-like receptors. Kawai T, Akira S. Curr Opin... Immunol. 2005 Aug;17(4):338-44. (.png) (.svg) (.html) (.csml) Show Pathogen recognition with Toll-like rece...ptors. PubmedID 15950447 Title Pathogen recognition with Toll-like receptors. Authors Kawai T, Akira S. Publ

  4. Toll-like receptors in invertebrate innate immunity

    Directory of Open Access Journals (Sweden)

    L Zheng

    2005-08-01

    Full Text Available Among invertebrates, innate immunity is the only defense mechanism against harmful non-self agents.In response to recognition of microbial pattern molecules, Drosophila melanogaster activates either theToll or Imd pathway, leading to the translocation of NF-kB (or Rel transcription factors from the cytoplasmto the nucleus and the subsequent production of antimicrobial peptides, which provide systemic innateimmunity. Toll-like receptors (TLRs are characterized by an extracellular leucine rich repeat (LRRdomain and an intracellular Toll/interleukin-1 receptor (TIR domain. TLRs are found from cnidarians tomammals. Here we argue that TLR mediated innate immunity developed during an early stage ofevolution when organisms acquired a body cavity. This is supported by the distributions of TLR and Relgenes in the animal kingdom. Further, TLR mediated immunity appears to have developed independentlyin invertebrates and vertebrates. Recent studies have shown that microbial molecules, with the potentialto signal through TLR, can be beneficial to host survival. Studies on this signaling pathway could opendoors to a better understanding of the origins of innate immunity in invertebrates and potentialtransmission blocking strategies aimed at ameliorating vector-borne diseases.

  5. Toll-Like Receptor 9 Agonists for Cancer Therapy

    Directory of Open Access Journals (Sweden)

    Davide Melisi

    2014-08-01

    Full Text Available The immune system has acquired increasing importance as a key player in cancer maintenance and growth. Thus, modulating anti-tumor immune mediators has become an attractive strategy for cancer treatment. Toll-like receptors (TLRs have gradually emerged as potential targets of newer immunotherapies. TLR-9 is preferentially expressed on endosome membranes of B-cells and plasmacytoid dendritic cells (pDC and is known for its ability to stimulate specific immune reactions through the activation of inflammation-like innate responses. Several synthetic CpG oligonucleotides (ODNs have been developed as TLR-9 agonists with the aim of enhancing cancer immune surveillance. In many preclinical models, CpG ODNs were found to suppress tumor growth and proliferation both in monotherapy and in addition to chemotherapies or target therapies. TLR-9 agonists have been also tested in several clinical trials in patients with solid tumors. These agents showed good tolerability and usually met activity endpoints in early phase trials. However, they have not yet been demonstrated to significantly impact survival, neither as single agent treatments, nor in combination with chemotherapies or cancer vaccines. Further investigations in larger prospective studies are required.

  6. Synergic activation of toll-like receptor (TLR 2/6 and 9 in response to Ureaplasma parvum & urealyticum in human amniotic epithelial cells.

    Directory of Open Access Journals (Sweden)

    Martha Triantafilou

    Full Text Available Ureaplasma species are the most frequently isolated microorganisms inside the amniotic cavity and have been associated with spontaneous abortion, chorioamnionitis, premature rupture of the membranes (PROM, preterm labour (PL pneumonia in neonates and bronchopulmonary dysplasia in neonates. The mechanisms by which Ureaplasmas cause such diseases remain unclear, but it is believed that inappropriate induction of inflammatory responses is involved, triggered by the innate immune system. As part of its mechanism of activation, the innate immune system employs germ-lined encoded receptors, called pattern recognition receptors (PRRs in order to "sense" pathogens. One such family of PRRs are the Toll like receptor family (TLR. In the current study we aimed to elucidate the role of TLRs in Ureaplasma-induced inflammation in human amniotic epithelial cells. Using silencing, as well as human embryonic kidney (HEK transfected cell lines, we demonstrate that TLR2, TLR6 and TLR9 are involved in the inflammatory responses against Ureaplasma parvum and urealyticum serovars. Ureaplasma lipoproteins, such as Multiple Banded antigen (MBA, trigger responses via TLR2/TLR6, whereas the whole bacterium is required for TLR9 activation. No major differences were observed between the different serovars. Cell activation by Ureaplasma parvum and urealyticum seem to require lipid raft function and formation of heterotypic receptor complexes comprising of TLR2 and TLR6 on the cell surface and TLR9 intracellularly.

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

    OpenAIRE

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

    2015-01-01

    Scientific Reports | 5:13128 | DOI: 10.1038/srep13128 1 www.nature.com/scientificreports The Architecture of the TIR Domain Signalosome in the Toll-like Receptor-4 Signaling Pathway Emine Guven-Maiorov1,2, Ozlem Keskin1,2, Attila Gursoy2,3, Carter VanWaes4, Zhong Chen4, Chung-Jung Tsai5 & Ruth Nussinov5,6 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 understandin...

  8. Toll-Like Receptor Initiated Host Defense against Toxoplasma gondii

    Directory of Open Access Journals (Sweden)

    Eric Y. Denkers

    2010-01-01

    Full Text Available Toxoplasma gondii is an intracellular pathogen notable for its ability to establish a stable host-parasite relationship amongst a wide range of host species and in a large percentage of the human population. Toll-like receptor signaling through MyD88 is a critical pathway in initiating defense against this opportunistic protozoan and may also be a mediator of pathology during immune dysfunction. Other MyD88 independent signaling pathways are also involved in the host-parasite interaction. These responses can be triggered by the parasite itself, but interactions with the intestinal microbiota add additional complexity during enteric infection.

  9. Toll-Like Receptor 3 in Liver Diseases

    Directory of Open Access Journals (Sweden)

    Shi Yin

    2010-01-01

    Full Text Available Toll-like receptor 3 (TLR3 is a member of the TLR family that can recognize double-stranded RNA (dsRNA, playing an important role in antiviral immunity. Recent studies have shown that TLR3 is also expressed on parenchymal and nonparenchymal cells in the liver as well as on several types of immune cells. In this review, we summarize the role of TLR3 in liver injury, inflammation, regeneration, and liver fibrosis, and discuss the implication of TLR3 in the pathogenesis of human liver diseases including viral hepatitis and autoimmune liver disease.

  10. BURN-INDUCED ALTERATIONS IN TOLL-LIKE RECEPTOR-MEDIATED RESPONSES BY BRONCHOALVEOLAR LAVAGE CELLS

    OpenAIRE

    Richard F. Oppeltz; Rani, Meenakshi; Zhang, Qiong; Schwacha, Martin G.

    2011-01-01

    Burn is associated with profound inflammation and activation of the innate immune system in multiple organ beds, including the lung. Similarly, toll-like receptors (TLR) are associated with innate immune activation. Nonetheless, it is unclear what impact burn has on TLR-induced inflammatory responses in the lung.

  11. Toll-Like Receptor Gene Expression during Trichinella spiralis Infection.

    Science.gov (United States)

    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

  12. MyD88-dependent and independent pathways of Toll-Like Receptors are engaged in biological activity of Triptolide in ligand-stimulated macrophages

    Directory of Open Access Journals (Sweden)

    Dorn Ruth

    2010-04-01

    Full Text Available Abstract Background Triptolide is a diterpene triepoxide from the Chinese medicinal plant Tripterygium wilfordii Hook F., with known anti-inflammatory, immunosuppressive and anti-cancer properties. Results Here we report the expression profile of immune signaling genes modulated by triptolide in LPS induced mouse macrophages. In an array study triptolide treatment modulated expression of 22.5% of one hundred and ninety five immune signaling genes that included Toll-like receptors (TLRs. TLRs elicit immune responses through their coupling with intracellular adaptor molecules, MyD88 and TRIF. Although it is known that triptolide inhibits NFκB activation and other signaling pathways downstream of TLRs, involvement of TLR cascade in triptolide activity was not reported. In this study, we show that triptolide suppresses expression of proinflammatory downstream effectors induced specifically by different TLR agonists. Also, the suppressive effect of triptolide on TLR-induced NFκB activation was observed when either MyD88 or TRIF was knocked out, confirming that both MyD88 and TRIF mediated NFκB activation may be inhibited by triptolide. Within the TLR cascade triptolide downregulates TLR4 and TRIF proteins. Conclusions This study reveals involvement of TLR signaling in triptolide activity and further increases understanding of how triptolide activity may downregulate NFκB activation during inflammatory conditions.

  13. Toll-like receptor agonist augments virus-like particle-mediated protection from Ebola virus with transient immune activation.

    Directory of Open Access Journals (Sweden)

    Karen A O Martins

    Full Text Available Identifying safe and effective adjuvants is critical for the advanced development of protein-based vaccines. Pattern recognition receptor (PRR agonists are increasingly being explored as potential adjuvants, but there is concern that the efficacy of these molecules may be dependent on potentially dangerous levels of non-specific immune activation. The filovirus virus-like particle (VLP vaccine protects mice, guinea pigs, and nonhuman primates from viral challenge. In this study, we explored the impact of a stabilized dsRNA mimic, polyICLC, on VLP vaccination of C57BL/6 mice and Hartley guinea pigs. We show that at dose levels as low as 100 ng, the adjuvant increased the efficacy of the vaccine in mice. Antigen-specific, polyfunctional CD4 and CD8 T cell responses and antibody responses increased significantly upon inclusion of adjuvant. To determine whether the efficacy of polyICLC correlated with systemic immune activation, we examined serum cytokine levels and cellular activation in the draining lymph node. PolyICLC administration was associated with increases in TNFα, IL6, MCP1, MIP1α, KC, and MIP1β levels in the periphery and with the activation of dendritic cells (DCs, NK cells, and B cells. However, this activation resolved within 24 to 72 hours at efficacious adjuvant dose levels. These studies are the first to examine the polyICLC-induced enhancement of antigen-specific immune responses in the context of non-specific immune activation, and they provide a framework from which to consider adjuvant dose levels.

  14. Activation of epidermal toll-like receptor 2 enhances tight junction function – Implications for atopic dermatitis and skin barrier repair

    Science.gov (United States)

    Kuo, I-Hsin; Carpenter-Mendini, Amanda; Yoshida, Takeshi; McGirt, Laura Y.; Ivanov, Andrei I.; Barnes, Kathleen C.; Gallo, Richard L.; Borkowski, Andrew W.; Yamasaki, Kenshi; Leung, Donald Y.; Georas, Steve N.; De Benedetto, Anna; Beck, Lisa A.

    2012-01-01

    Atopic dermatitis (AD) is characterized by epidermal tight junction (TJ) defects and a propensity for Staphylococcus aureus (S. aureus) skin infections. S. aureus is sensed by many pattern recognition receptors including toll-like receptor (TLR) 2. We hypothesized that an effective innate immune response will include skin barrier repair and that this response is impaired in AD subjects. S. aureus-derived peptidoglycan (PGN) and synthetic TLR2 agonists enhanced TJ barrier and increased expression of TJ proteins, CLDN1, CLDN23, occludin and ZO-1 in primary human keratinocytes. A TLR2 agonist enhanced skin barrier recovery in human epidermis wounded by tape-stripping. Tlr2−/− mice had a delayed and incomplete barrier recovery following tape-stripping. AD subjects had reduced epidermal TLR2 expression as compared to nonatopic (NA) subjects, which inversely correlated (r= 0.654, P= 0.0004) with transepidermal water loss (TEWL). These observations indicate that TLR2 activation enhances skin barrier in murine and human skin and is an important part of a wound repair response. Reduced epidermal TLR2 expression observed in AD patients may play a role in their incompetent skin barrier. PMID:23223142

  15. Toll-like Receptors in Systemic Lupus Erythematosus Prospects for Therapeutic Intervention

    Science.gov (United States)

    Kim, Wan-Uk; Sreih, Antoine; Bucala, Richard

    2009-01-01

    Recent experimental and clinical studies have placed new emphasis on the role of the innate immune system in SLE. Nucleic acid-containing immune complexes activate the innate response by engaging specific Toll-like receptors (TLRs) and promote the generation of autoantibodies. Pharmacologic modulation of TLR-directed pathways may offer new therapeutic approaches for the treatment of SLE. PMID:18722558

  16. Crosstalk between complement and Toll-like receptor activation in relation to donor brain death and renal ischemia-reperfusion injury.

    Science.gov (United States)

    Damman, Jeffrey; Daha, Mohamed R; van Son, Willem J; Leuvenink, Henri G; Ploeg, Rutger J; Seelen, Marc A

    2011-04-01

    Two central pathways of innate immunity, complement and Toll-like receptors (TLRs), play an important role in the pathogenesis of renal injury inherent to kidney transplantation. Recent findings indicate close crosstalk between complement and TLR signaling pathways. It is suggested that mitogen activated protein kinases (MAPKs) might be the key molecules linking both the complement and TLR pathways together. Complement and TLRs are important mediators of renal ischemia-reperfusion injury (IRI). Besides IRI, complement C3 can also be upregulated and activated in the kidney before transplantation as a direct result of brain death (BD) in the donor. This local upregulation and activation of complement in the donor kidney has been proven to be detrimental for renal allograft outcome. Also TLR4 and several of its major ligands are upregulated by donor BD compared to living donors. Important and in line with the observations above, kidney transplant recipients have a benefit when receiving a kidney from a TLR4 Asp299Gly/Thr399Ile genotypic donor. The role of complement and TLRs and crosstalk between these two innate immune systems in relation to renal injury during donor BD and ischemia-reperfusion are focus of this review. Future strategies to target complement and TLR activation in kidney transplantation are considered.

  17. A bacterial carbohydrate links innate and adaptive responses through Toll-like receptor 2

    OpenAIRE

    Wang, Qun; McLoughlin, Rachel M.; Cobb, Brian A; Charrel-Dennis, Marie; Zaleski, Kathleen J.; Golenbock, Douglas; Tzianabos, Arthur O.; Kasper, Dennis L.

    2006-01-01

    Commensalism is critical to a healthy Th1/Th2 cell balance. Polysaccharide A (PSA), which is produced by the intestinal commensal Bacteroides fragilis, activates CD4+ T cells, resulting in a Th1 response correcting the Th2 cell skew of germ-free mice. We identify Toll-like receptors as crucial to the convergence of innate and adaptive responses stimulated by PSA. Optimization of the Th1 cytokine interferon-γ in PSA-stimulated dendritic cell–CD4+ T cell co-cultures depends on both Toll-like re...

  18. DMPD: Signal transduction by the lipopolysaccharide receptor, Toll-like receptor-4. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15379975 Signal transduction by the lipopolysaccharide receptor, Toll-like receptor... Signal transduction by the lipopolysaccharide receptor, Toll-like receptor-4. PubmedID 15379975 Title Signa...l transduction by the lipopolysaccharide receptor, Toll-like receptor-4. Authors

  19. Isolated Toll-like receptor transmembrane domains are capable of oligomerization.

    Directory of Open Access Journals (Sweden)

    James I Godfroy

    Full Text Available Toll-like receptors (TLRs act as the first line of defense against bacterial and viral pathogens by initiating critical defense signals upon dimer activation. The contribution of the transmembrane domain in the dimerization and signaling process has heretofore been overlooked in favor of the extracellular and intracellular domains. As mounting evidence suggests that the transmembrane domain is a critical region in several protein families, we hypothesized that this was also the case for Toll-like receptors. Using a combined biochemical and biophysical approach, we investigated the ability of isolated Toll-like receptor transmembrane domains to interact independently of extracellular domain dimerization. Our results showed that the transmembrane domains had a preference for the native dimer partners in bacterial membranes for the entire receptor family. All TLR transmembrane domains showed strong homotypic interaction potential. The TLR2 transmembrane domain demonstrated strong heterotypic interactions in bacterial membranes with its known interaction partners, TLR1 and TLR6, as well as with a proposed interaction partner, TLR10, but not with TLR4, TLR5, or unrelated transmembrane receptors providing evidence for the specificity of TLR2 transmembrane domain interactions. Peptides for the transmembrane domains of TLR1, TLR2, and TLR6 were synthesized to further study this subfamily of receptors. These peptides validated the heterotypic interactions seen in bacterial membranes and demonstrated that the TLR2 transmembrane domain had moderately strong interactions with both TLR1 and TLR6. Combined, these results suggest a role for the transmembrane domain in Toll-like receptor oligomerization and as such, may be a novel target for further investigation of new therapeutic treatments of Toll-like receptor mediated diseases.

  20. DMPD: Nuclear factor-kappaB: activation and regulation during toll-like receptorsignaling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17349209 Nuclear factor-kappaB: activation and regulation during toll-like receptor...signaling. Carmody RJ, Chen YH. Cell Mol Immunol. 2007 Feb;4(1):31-41. (.png) (.svg) (.html) (.csml) Show Nuclear... factor-kappaB: activation and regulation during toll-like receptorsignaling. PubmedID 17349209 Title Nuclear

  1. Sustained activation of toll-like receptor 9 induces an invasive phenotype in lung fibroblasts: possible implications in idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Kirillov, Varvara; Siler, Jonathan T; Ramadass, Mahalakshmi; Ge, Lingyin; Davis, James; Grant, Geraldine; Nathan, Steven D; Jarai, Gabor; Trujillo, Glenda

    2015-04-01

    Idiopathic pulmonary fibrosis (IPF) is characterized by excessive scarring of the lung parenchyma, resulting in a steady decline of lung function and ultimately respiratory failure. The disease course of IPF is extremely variable, with some patients exhibiting stability of symptoms for prolonged periods of time, whereas others exhibit rapid progression and loss of lung function. Viral infections have been implicated in IPF and linked to disease severity; however, whether they directly contribute to progression is unclear. We previously classified patients as rapid and slow progressors on the basis of clinical features and expression of the pathogen recognition receptor, Toll-like receptor 9 (TLR9). Activation of TLR9 in vivo exacerbated IPF in mice and induced differentiation of myofibroblasts in vitro, but the mechanism of TLR9 up-regulation and progression of fibrosis are unknown. Herein, we investigate whether transforming growth factor (TGF)-β, a pleiotropic cytokine central to IPF pathogenesis, regulates TLR9 in lung myofibroblasts. Results showed induction of TLR9 expression by TGF-β in lung myofibroblasts and a distinct profibrotic myofibroblast phenotype driven by stimulation with the TLR9 agonist, CpG-DNA. Chronic TLR9 stimulation resulted in stably differentiated α-smooth muscle actin(+)/platelet-derived growth factor receptor α(+)/CD44(+)/matrix metalloproteinase-14(+)/matrix metalloproteinase-2(+) myofibroblasts, which secrete inflammatory cytokines, invade Matrigel toward platelet-derived growth factor, and resist hypoxia-induced apoptosis. These results suggest a mechanism by which TGF-β and TLR9 responses in myofibroblasts collaborate to drive rapid progression of IPF.

  2. Toll-like receptor gene polymorphisms are associated with allergic rhinitis: a case control study

    OpenAIRE

    Nilsson Daniel; Andiappan Anand; Halldén Christer; Yun Wang; Säll Torbjörn; Tim Chew; Cardell Lars-Olaf

    2012-01-01

    Abstract Background The Toll-like receptor proteins are important in host defense and initiation of the innate and adaptive immune responses. A number of studies have identified associations between genetic variation in the Toll-like receptor genes and allergic disorders such as asthma and allergic rhinitis. The present study aim to search for genetic variation associated with allergic rhinitis in the Toll-like receptor genes. Methods A first association analysis genotyped 73 SNPs in 182 case...

  3. The application of Toll like receptors for cancer therapy

    Directory of Open Access Journals (Sweden)

    Eui Young So, Toru Ouchi

    2010-01-01

    Full Text Available Toll-like receptor (TLR proteins play key roles in immune responses against infection. Using TLR proteins, host can recognize the conserved molecular structures found in pathogens called pathogen-associated molecular patterns (PAMPs. At the same time, some TLRs are able to detect specific host molecules, such as high-mobility group box protein 1 (HMGB1 and heat shock proteins (hsp, and lead to inflammatory responses. Thus, it has been suggested that TLRs are involved in the development of many pathogenic conditions. Recent advances in TLR-related research not only provide us with scientific information, but also show the therapeutic potential against diseases, such as autoimmune disease and cancer. In this mini review, we demonstrate how TLRs pathways could be involved in cancer development and their therapeutic application, and discuss recent patentable subjects, in particular, that are targeting this unique pathway.

  4. Toll-like receptors as targets for immune disorders.

    LENUS (Irish Health Repository)

    Keogh, Brian

    2012-02-01

    Since the identification of the first Toll-like receptor (TLR) in humans in 1997, understanding of the molecular basis for innate immunity has increased significantly. The TLR family and downstream signalling pathways have been extensively characterised, There is now significant evidence suggesting a role for TLRs in human inflammatory and immune diseases such as rheumatoid arthritis, diabetes, allergy\\/asthma and atherosclerosis. Various approaches have been taken to identify novel therapeutic agents targeting TLRs including biologics, small molecules and nucleic acid-based drugs. Several are now being evaluated in the clinic and showing promise against various diseases. This review paper outlines the recent advances in the understanding of TLR biology and highlights novel TLR agonists and antagonists in development for the treatment of immune diseases.

  5. Penicillin binding proteins as danger signals: meningococcal penicillin binding protein 2 activates dendritic cells through Toll-like receptor 4.

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    Marcelo Hill

    Full Text Available Neisseria meningitidis is a human pathogen responsible for life-threatening inflammatory diseases. Meningococcal penicillin-binding proteins (PBPs and particularly PBP2 are involved in bacterial resistance to β-lactams. Here we describe a novel function for PBP2 that activates human and mouse dendritic cells (DC in a time and dose-dependent manner. PBP2 induces MHC II (LOGEC50 = 4.7 µg/ml ± 0.1, CD80 (LOGEC50 = 4.88 µg/ml ± 0.15 and CD86 (LOGEC50 = 5.36 µg/ml ± 0.1. This effect was abolished when DCs were co-treated with anti-PBP2 antibodies. PBP2-treated DCs displayed enhanced immunogenic properties in vitro and in vivo. Furthermore, proteins co-purified with PBP2 showed no effect on DC maturation. We show through different in vivo and in vitro approaches that this effect is not due to endotoxin contamination. At the mechanistic level, PBP2 induces nuclear localization of p65 NF-kB of 70.7 ± 5.1% cells versus 12 ± 2.6% in untreated DCs and needs TLR4 expression to mature DCs. Immunoprecipitation and blocking experiments showed thatPBP2 binds TLR4. In conclusion, we describe a novel function of meningococcal PBP2 as a pathogen associated molecular pattern (PAMP at the host-pathogen interface that could be recognized by the immune system as a danger signal, promoting the development of immune responses.

  6. The Therapeutic Potential of Toll-like Receptor 7 Stimulation in Asthma

    OpenAIRE

    Drake, Matthew G.; Kaufman, Elad H.; Fryer, Allison D.; Jacoby, David B.

    2012-01-01

    Asthma is an inflammatory disorder of the airways frequently characterized by an excessive Th2 adaptive immune response. Activation of Toll-like receptor (TLR)-7, a single-stranded viral RNA receptor that is highly expressed in the airways, triggers a rapid innate immune response and favors a subsequent Th1 response. Because of this role in pulmonary immunoregulation, TLR7 has gained considerable interest as a therapeutic target in asthma. Synthetic TLR7 ligands, including the imidazoquinolin...

  7. Maternal endotoxin-induced fetal growth restriction in rats: Fetal responses in toll-like receptor

    OpenAIRE

    Banun Kusumawardani; Marsetyawan HNE Soesatyo; Djaswadi Dasuki; Widya Asmara

    2012-01-01

    Background: Porphyromonas gingivalis as a major etiology of periodontal disease can produce virulence factor, lipopolysaccharide/LPS, which is expected to play a role in the intrauterine fetal growth. Trophoblast at the maternal-fetal interface actively participates in response to infection through the expression of a family of natural immune receptors, toll-like receptor (TLR). Purpose: the aims of study were to identify endotoxin concentration in maternal blood serum of Porphyromonas gingiv...

  8. A comprehensive map of the toll-like receptor signaling network

    OpenAIRE

    Oda, Kanae; Kitano, Hiroaki

    2006-01-01

    Recognition of pathogen-associated molecular signatures is critically important in proper activation of the immune system. The toll-like receptor (TLR) signaling network is responsible for innate immune response. In mammalians, there are 11 TLRs that recognize a variety of ligands from pathogens to trigger immunological responses. In this paper, we present a comprehensive map of TLRs and interleukin 1 receptor signaling networks based on papers published so far. The map illustrates the possib...

  9. DAT isn’t all that: cocaine reward and reinforcement requires Toll Like Receptor 4 signaling

    OpenAIRE

    Northcutt, A.L.; Hutchinson, M.R.; Wang, X.; Baratta, M.V.; Hiranita, T.; Cochran, T.A.; Pomrenze, M.B.; Galer, E.L.; Kopajtic, T.A.; Li, C.M.; AMAT, J.; Larson, G.; Cooper, D. C.; Huang, Y.; O’Neill, C.E.

    2015-01-01

    The initial reinforcing properties of drugs of abuse, such as cocaine, are largely attributed to their ability to activate the mesolimbic dopamine system. Resulting increases in extracellular dopamine in the nucleus accumbens (NAc) are traditionally thought to result from cocaine’s ability to block dopamine transporters (DATs). Here we demonstrate that cocaine also interacts with the immunosurveillance receptor complex, Toll-Like Receptor 4 (TLR4), on microglial cells to initiate central inna...

  10. Polygonum cuspidatum and its active components inhibit replication of the influenza virus through toll-like receptor 9-induced interferon beta expression.

    Directory of Open Access Journals (Sweden)

    Chao-Jen Lin

    Full Text Available Influenza virus infection is a global public health issue. The effectiveness of antiviral therapies for influenza has been limited by the emergence of drug-resistant viral strains. Therefore, there is an urgent need to identify novel antiviral therapies. Here we tested the effects of 300 traditional Chinese medicines on the replication of various influenza virus strains in a lung cell line, A549, using an influenza-specific luciferase reporter assay. Of the traditional medicines tested, Polygonum cuspidatum (PC and its active components, resveratrol and emodin, were found to attenuate influenza viral replication in A549 cells. Furthermore, they preferentially inhibited the replication of influenza A virus, including clinical strains isolated in 2009 and 2011 in Taiwan and the laboratory strain A/WSN/33 (H1N1. In addition to inhibiting the expression of hemagglutinin and neuraminidase, PC, emodin, and resveratrol also increased the expression of interferon beta (IFN-β through Toll-like receptor 9 (TLR9. Moreover, the anti-viral activity of IFN-β or resveratrol was reduced when the A549 cells were treated with neutralizing anti-IFN-β antibodies or a TLR9 inhibitor, suggesting that IFN-β likely acts synergistically with resveratrol to inhibit H1N1 replication. This potential antiviral mechanism, involving direct inhibition of virus replication and simultaneous activation of the host immune response, has not been previously described for a single antiviral molecule. In conclusion, our data support the use of PC, resveratrol or emodin for inhibiting influenza virus replication directly and via TLR-9-induced IFN-β production.

  11. Hyperglycemia Induces Toll-Like Receptor-2 and -4 Expression and Activity in Human Microvascular Retinal Endothelial Cells: Implications for Diabetic Retinopathy

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    Uthra Rajamani

    2014-01-01

    Full Text Available Diabetic retinopathy (DR causes visual impairment in working age adults and hyperglycemia-mediated inflammation is central in DR. Toll-like receptors (TLRs play a key role in innate immune responses and inflammation. However, scanty data is available on their role in DR. Hence, in this study, we examined TLR2 and TLR4 mRNA and protein expression and activity in hyperglycemic human retinal endothelial cells (HMVRECs. HMVRECs were treated with hyperglycemia (HG or euglycemia and mRNA and protein levels of TLR-2, TLR-4, MyD88, IRF3, and TRIF as well as NF-κB p65 activation were measured. IL-8, IL-1β, TNF-α and MCP-1, ICAM-1, and VCAM-1 as well as monocyte adhesion to HMVRECs were also assayed. HG (25 mM significantly induced TLR2 and TLR4 mRNA and protein in HMVRECs. It also increased both MyD88 and non-MyD88 pathways, nuclear factor-κB (NF-κB, biomediators, and monocyte adhesion. This inflammation was attenuated by TLR-4 or TLR-2 inhibition, and dual inhibition by a TLR inhibitory peptide as well as TLR2 and 4 siRNA. Additionally, antioxidant treatment reduced TLR-2 and TLR4 expression and downstream inflammatory markers. Collectively, our novel data suggest that hyperglycemia induces TLR-2 and TLR-4 activation and downstream signaling mediating increased inflammation possibly via reactive oxygen species (ROS and could contribute to DR.

  12. Mechanisms underlying the anti-inflammatory effects of Clinacanthus nutans Lindau extracts: inhibition of cytokine production and Toll-like receptor-4 activation

    Directory of Open Access Journals (Sweden)

    Chun Wai eMai

    2016-02-01

    Full Text Available Clinacanthus nutans has had a long history of use in folk medicine in Malaysia and Southeast Asia; mostly in the relief of inflammatory conditions. In this study, we investigated the effects of different extracts of C. nutans upon lipopolysaccharide (LPS induced inflammation in order to identify its mechanism of action. Extracts of leaves and stem bark of C. nutans were prepared using polar and non-polar solvents to produce four extracts, namely polar leaf extract (LP, non-polar leaf extract (LN, polar stem extract (SP and non-polar stem extracts (SN. The extracts were standardized by determining its total phenolic and total flavonoid contents. Its anti-inflammatory effects were assessed on LPS induced nitrite release in RAW264.7 macrophages and Toll-like receptor (TLR-4 activation in TLR-4 transfected human embryonic kidney cells (HEK-BlueTM-hTLR4 cells. The levels of inflammatory cytokines (TNF-α, IFN-γ, IL-1β, IL-6, IL-12p40 and IL-17 in treated RAW264.7 macrophages were quantified to verify its anti-inflammatory effects. Western blotting was used to investigate the effect of the most potent extract (LP on TLR-4 related inflammatory proteins (p65, p38, ERK, JNK, IRF3 in RAW264.7 macrophages. All four extracts produced a significant, concentration-dependent reduction in LPS-stimulated nitric oxide, LPS-induced TLR-4 activation in HEK-BlueTM-hTLR4 cells and LPS-stimulated cytokines production in RAW264.7 macrophages. The most potent extract, LP, also inhibited all LPS-induced TLR-4 inflammatory proteins. These results provide a basis for understanding the mechanisms underlying the previously demonstrated anti-inflammatory activity of C. nutans extracts.

  13. Mechanisms Underlying the Anti-Inflammatory Effects of Clinacanthus nutans Lindau Extracts: Inhibition of Cytokine Production and Toll-Like Receptor-4 Activation.

    Science.gov (United States)

    Mai, Chun W; Yap, Kok S I; Kho, Mee T; Ismail, Nor H; Yusoff, Khatijah; Shaari, Khozirah; Chin, Swee Y; Lim, Erin S H

    2016-01-01

    Clinacanthus nutans has had a long history of use in folk medicine in Malaysia and Southeast Asia; mostly in the relief of inflammatory conditions. In this study, we investigated the effects of different extracts of C. nutans upon lipopolysaccharide (LPS) induced inflammation in order to identify its mechanism of action. Extracts of leaves and stem bark of C. nutans were prepared using polar and non-polar solvents to produce four extracts, namely polar leaf extract (LP), non-polar leaf extract (LN), polar stem extract (SP), and non-polar stem extracts (SN). The extracts were standardized by determining its total phenolic and total flavonoid contents. Its anti-inflammatory effects were assessed on LPS induced nitrite release in RAW264.7 macrophages and Toll-like receptor (TLR-4) activation in TLR-4 transfected human embryonic kidney cells (HEK-Blue(TM)-hTLR4 cells). The levels of inflammatory cytokines (TNF-α, IFN-γ, IL-1β, IL-6, IL-12p40, and IL-17) in treated RAW264.7 macrophages were quantified to verify its anti-inflammatory effects. Western blotting was used to investigate the effect of the most potent extract (LP) on TLR-4 related inflammatory proteins (p65, p38, ERK, JNK, IRF3) in RAW264.7 macrophages. All four extracts produced a significant, concentration-dependent reduction in LPS-stimulated nitric oxide, LPS-induced TLR-4 activation in HEK-Blue(TM)-hTLR4 cells and LPS-stimulated cytokines production in RAW264.7 macrophages. The most potent extract, LP, also inhibited all LPS-induced TLR-4 inflammatory proteins. These results provide a basis for understanding the mechanisms underlying the previously demonstrated anti-inflammatory activity of C. nutans extracts. PMID:26869924

  14. Soluble markers of the Toll-like receptor 4 pathway differentiate between active and latent tuberculosis and are associated with treatment responses.

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    Siri L Feruglio

    Full Text Available BACKGROUND: Biomarkers to differentiate between active tuberculosis (TB and latent TB infection (LTBI and to monitor treatment responses are requested to complement TB diagnostics and control, particularly in patients with multi-drug resistant TB. We have studied soluble markers of the Toll-like-receptor 4 (TLR-4 pathway in various stages of TB disease and during anti-TB treatment. METHODS: Plasma samples from patients with culture confirmed drug-sensitive TB (n = 19 were collected before and after 2, 8 and 24 weeks of efficient anti-TB treatment and in a LTBI group (n = 6. Soluble (s CD14 and myeloid differentiation-2 (MD-2 were analyzed by the Enzyme-linked immunosorbent assay (ELISA. Lipopolysaccharide (LPS was analyzed by the Limulus Amebocyte Lysate colorimetric assay. Nonparametric statistics were applied. RESULTS: Plasma levels of sCD14 (p<0.001, MD-2 (p = 0.036 and LPS (p = 0.069 were elevated at baseline in patients with untreated active TB compared to the LTBI group. MD-2 concentrations decreased after 2 weeks of treatment (p = 0.011, while LPS levels decreased after 8 weeks (p = 0.005. In contrast, sCD14 levels increased after 2 weeks (p = 0.047 with a subsequent modest decrease throughout the treatment period. There was no significant difference in concentrations of any of these markers between patients with pulmonary and extrapulmonary TB or between patients with or without symptoms. CONCLUSION: Our data suggest that plasma levels of LPS, MD-2 and sCD14 can discriminate between active TB and LTBI. A decline in LPS and MD-2 concentrations was associated with response to anti-TB treatment. The clinical potential of these soluble TLR-4 pathway proteins needs to be further explored.

  15. The Role of Toll Like Receptors in Pregnancy

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    Elham Amirchaghmaghi

    2013-09-01

    Full Text Available For many years, the innate immunity was of less interest than the adaptive immunity because it was perceived to have secondary importance in the functionality of the immune system. During the past decades, with the advancement of knowledge about innate immune system, interest in innate immunity has grown dramatically and thus its function has been extensively studied. Innate immunity plays fundamental roles in the initiation and induction of adaptive immune responses. It consists of several cells and receptors including natural killer (NK cells, macrophages (MQs, dendritic cells (DCs and pattern recognition receptors (PRRs. Two decades ago, Toll like receptors (TLRs family was known as one of the important PRRs with unique functions especially in protection against invading pathogens. Since the female reproductive tract has access to the outside environment and has a unique interaction with different pathogens whether invading microorganisms or normal flora, allogenic sperm and semi allogenic fetus, it has an essential need for effective immune responses. It has therefore been suggested that TLRs may play important roles in the immune regulation of the female reproductive tract. In addition, it has been demonstrated that immune disturbance may be responsible for some adverse pregnancy outcomes such as preeclampsia (PE, recurrent spontaneous abortion (RSA and intrauterine growth restriction (IUGR. Our focus in this review is to show the importance of TLRs in pregnancy with emphasis on the expression of these receptors in different tissues related to pregnancy.

  16. Bordetella adenylate cyclase toxin differentially modulates toll-like receptor-stimulated activation, migration and T cell stimulatory capacity of dendritic cells.

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    Irena Adkins

    Full Text Available Adenylate cyclase toxin (CyaA is a key virulence factor of the whooping cough agent Bordetella pertussis. The toxin targets CD11b-expressing phagocytes and delivers into their cytosol an adenylyl cyclase (AC enzyme that subverts cellular signaling by increasing cAMP levels. In the present study, we analyzed the modulatory effects of CyaA on adhesive, migratory and antigen presenting properties of Toll-like receptor (TLR-activated murine and human dendritic cells (DCs. cAMP signaling of CyaA enhanced TLR-induced dissolution of cell adhesive contacts and migration of DCs towards the lymph node-homing chemokines CCL19 and CCL21 in vitro. Moreover, we examined in detail the capacity of toxin-treated DCs to induce CD4(+ and CD8(+ T cell responses. Exposure to CyaA decreased the capacity of LPS-stimulated DCs to present soluble protein antigen to CD4+ T cells independently of modulation of co-stimulatory molecules and cytokine production, and enhanced their capacity to promote CD4(+CD25(+Foxp3(+ T regulatory cells in vitro. In addition, CyaA decreased the capacity of LPS-stimulated DCs to induce CD8(+ T cell proliferation and limited the induction of IFN-γ producing CD8(+ T cells while enhancing IL-10 and IL-17-production. These results indicate that through activation of cAMP signaling, the CyaA may be mobilizing DCs impaired in T cell stimulatory capacity and arrival of such DCs into draining lymph nodes may than contribute to delay and subversion of host immune responses during B. pertussis infection.

  17. Penehyclidine hydrochloride: a potential drug for treating COPD by attenuating Toll-like receptors

    Directory of Open Access Journals (Sweden)

    Xiao HT

    2012-11-01

    Full Text Available Hong-Tao Xiao,1,* Zhi Liao,2,* Rong-Sheng Tong11Department of Pharmacy, 2Department of Gynecology and Obstetrics, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China*These authors contributed equally to this workBackground: The aim of this review was to evaluate and summarize the available scientific information on penehyclidine hydrochloride (PHC for the treatment of chronic obstructive pulmonary disease (COPD as a result of its ability to attenuate Toll-like receptors. Penehyclidine hydrochloride is an anticholinergic drug manufactured in China, with both antimuscarinic and antinicotinic activity. PHC is used widely in the clinic as a reversal agent in cases of organic phosphorus poisoning and soman poisoning, but also may also have an important role as a bronchodilator in the treatment of obstructive airway disease, including asthma and, in particular, COPD.Methods: Our bibliographic sources included the CAPLUS, MEDLINE, REGISTRY, CASREACT, CHEMLIST, CHEMCATS, and CNKI databases, updated to September 2012. In order to assess the data in detail, we used the search terms “penehyclidine hydrochloride,” “COPD,” “muscarinic receptor,” and “toll-like receptors.” Papers were restricted to those published in the English and Chinese languages, and to “paper” and “review” as the document type. Patents were also reviewed.Results: Our survey mainly yielded the results of research on PHC and the mechanisms of COPD. COPD is a preventable and treatable disease with some significant extrapulmonary manifestations that may contribute to its severity in some patients. Recently, it has been shown that muscarinic receptors may interact with Toll-like receptors. Basic and clinical studies of the relationship between the mechanism of action and the effects of PHC in the respiratory tract have been studied by a number of laboratories and institutions. The main advantages of PHC are that it has few M2

  18. Increased expression of Toll-like receptors 7 and 9 in myasthenia gravis thymus characterized by active Epstein-Barr virus infection.

    Science.gov (United States)

    Cavalcante, Paola; Galbardi, Barbara; Franzi, Sara; Marcuzzo, Stefania; Barzago, Claudia; Bonanno, Silvia; Camera, Giorgia; Maggi, Lorenzo; Kapetis, Dimos; Andreetta, Francesca; Biasiucci, Amelia; Motta, Teresio; Giardina, Carmelo; Antozzi, Carlo; Baggi, Fulvio; Mantegazza, Renato; Bernasconi, Pia

    2016-04-01

    Considerable data implicate the thymus as the main site of autosensitization to the acetylcholine receptor in myasthenia gravis (MG), a B-cell-mediated autoimmune disease affecting the neuromuscular junction. We recently demonstrated an active Epstein-Barr virus (EBV) infection in the thymus of MG patients, suggesting that EBV might contribute to the onset or maintenance of the autoimmune response within MG thymus, because of its ability to activate and immortalize autoreactive B cells. EBV has been reported to elicit and modulate Toll-like receptor (TLR) 7- and TLR9-mediated innate immune responses, which are known to favor B-cell dysfunction and autoimmunity. Aim of this study was to investigate whether EBV infection is associated with altered expression of TLR7 and TLR9 in MG thymus. By real-time PCR, we found that TLR7 and TLR9 mRNA levels were significantly higher in EBV-positive MG compared to EBV-negative normal thymuses. By confocal microscopy, high expression levels of TLR7 and TLR9 proteins were observed in B cells and plasma cells of MG thymic germinal centers (GCs) and lymphoid infiltrates, where the two receptors co-localized with EBV antigens. An increased frequency of Ki67-positive proliferating B cells was found in MG thymuses, where we also detected proliferating cells expressing TLR7, TLR9 and EBV antigens, thus supporting the idea that EBV-associated TLR7/9 signaling may promote abnormal B-cell activation and proliferation. Along with B cells and plasma cells, thymic epithelium, plasmacytoid dendritic cells and macrophages exhibited enhanced TLR7 and TLR9 expression in MG thymus; TLR7 was also increased in thymic myeloid dendritic cells and its transcriptional levels positively correlated with those of interferon (IFN)-β. We suggested that TLR7/9 signaling may be involved in antiviral type I IFN production and long-term inflammation in EBV-infected MG thymuses. Our overall findings indicate that EBV-driven TLR7- and TLR9-mediated innate immune

  19. Gain-of-function mutations in the Toll-like Receptor pathway: TPL2-mediated ERK1/ERK2 MAPK activation, a path to tumorigenesis in lymphoid neoplasms?

    Directory of Open Access Journals (Sweden)

    Simon eRousseau

    2016-05-01

    Full Text Available Lymphoid neoplasms form a family of cancers affecting B-cells, T-cells and NK cells. The Toll-Like Receptor (TLR signalling adapter molecule MYD88 is the most frequently mutated gene in these neoplasms. This signalling adaptor relays signals from TLRs to downstream effector pathways such as the Nuclear Factor kappa B (NFB and Mitogen Activated Protein Kinase (MAPK pathways to regulate innate immune responses (Kawai and Akira, 2010. Gain-of-function mutations such as MYD88[L265P] activate downstream signalling 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 HEK 293 cells led to ERK1/2 MAPK phosphorylation in addition to NFB activation. Moreover, this activation is dependent on the protein kinase Tumour Promoting Locus-2 (TPL-2, activated downstream of the IKK complex. Activation of ERK1/2 would then lead to activation, amongst others, of MYC and hnRNP A1, two proteins previously shown to contribute to tumour formation in lymphoid neoplasms. Taken together, this analysis suggests that TLR-mediated tumorigenesis occurs via the TPL2-mediated ERK1/2 activation. Therefore, the hypothesis proposed is that inhibition of ERK1/2 MAPK activation would prevent tumour growth downstream of MYD88[L265]. It will be interesting to test whether pharmacological inhibitors of this pathway show efficacy in primary tumour cells derived from hematologic malignancies such as Waldenstrom’s Macroglobulinemia, where the

  20. Role of toll-like receptor 2 and toll-like receptor 4 in post-ischemic coronary endothelial dysfunction in mice

    Institute of Scientific and Technical Information of China (English)

    J.FAVRE; P.MUSETTE; JPHENRY; C.THUILLEZ; V.RICHARD

    2004-01-01

    AIM: A growing body of evidence suggests a role of the toll-like receptors (TLR) in inflammatory processes. In addition to LPS,TLR are activated by many endogenous ligands such as heat shock proteins and oxygeil-derived free radicals which are both produced during cardiac ischemia-reperfusion (I/R). Among TLR,TLR-2 and TLR-4 are expressed in endothelial and myocardial cells and appear to regulate neutrophil-endothelial interactions.Since neutrophil adhesion is a critical event in endothelial injury

  1. Exploitation of the Toll-like receptor system in cancer: a doubled-edged sword?

    LENUS (Irish Health Repository)

    Killeen, S D

    2012-02-03

    The toll-like receptor (TLR) system constitutes a pylogenetically ancient, evolutionary conserved, archetypal pattern recognition system, which underpins pathogen recognition by and activation of the immune system. Toll-like receptor agonists have long been used as immunoadjuvants in anti cancer immunotherapy. However, TLRs are increasingly implicated in human disease pathogenesis and an expanding body of both clinical and experimental evidence suggests that the neoplastic process may subvert TLR signalling pathways to advance cancer progression. Recent discoveries in the TLR system open a multitude of potential therapeutic avenues. Extrapolation of such TLR system manipulations to a clinical oncological setting demands care to prevent potentially deleterious activation of TLR-mediated survival pathways. Thus, the TLR system is a double-edge sword, which needs to be carefully wielded in the setting of neoplastic disease.

  2. Toll-like receptors recognize distinct proteinase-resistant glycoconjugates in Campylobacter jejuni and Escherichia coli.

    Science.gov (United States)

    Phongsisay, Vongsavanh; Hara, Hiromitsu; Fujimoto, Shuji

    2015-03-01

    Campylobacter jejuni causes gastroenteritis and autoimmune neuropathy Guillain-Barré syndrome. The mechanism by which C. jejuni infection results in such the hyperimmunity is not completely understood. Host immunity plays an important role in the disease pathogenesis; however, little is known how immune system recognizes this human pathogen. In this study, we report that Toll-like receptors recognize distinct proteinase K-resistant glycoconjugates in C. jejuni and Escherichia coli. Lipopolysaccharide is solely proteinase-resistant glycoconjugate in E. coli. In contrast, C. jejuni possesses at least five different components that are resistant to proteinase digestion and are capable of inducing NF-κB activation through TLR2 and TLR4. Possession of multiple activators of Toll-like receptors may be the unique strategy of C. jejuni to trigger hyperimmunity.

  3. Substance P primes lipoteichoic acid- and Pam3CysSerLys4-mediated activation of human mast cells by up-regulating Toll-like receptor 2.

    Science.gov (United States)

    Tancowny, Brian P; Karpov, Victor; Schleimer, Robert P; Kulka, Marianna

    2010-10-01

    Substance P (SP) is a neuropeptide with neuroimmunoregulatory activity that may play a role in susceptibility to infection. Human mast cells, which are important in innate immune responses, were analysed for their responses to pathogen-associated molecules via Toll-like receptors (TLRs) in the presence of SP. Human cultured mast cells (LAD2) were activated by SP and TLR ligands including lipopolysaccharide (LPS), Pam3CysSerLys4 (Pam3CSK4) and lipoteichoic acid (LTA), and mast cell leukotriene and chemokine production was assessed by enzyme-linked immunosorbent assay (ELISA) and gene expression by quantitative PCR (qPCR). Mast cell degranulation was determined using a β-hexosaminidase (β-hex) assay. SP treatment of LAD2 up-regulated mRNA for TLR2, TLR4, TLR8 and TLR9 while anti-immunoglobulin E (IgE) stimulation up-regulated expression of TLR4 only. Flow cytometry and western blot confirmed up-regulation of TLR2 and TLR8. Pretreatment of LAD2 with SP followed by stimulation with Pam3CSK4 or LTA increased production of leukotriene C4 (LTC(4) ) and interleukin (IL)-8 compared with treatment with Pam3CSK4 or LTA alone (>2-fold; P<0·01). SP alone activated 5-lipoxygenase (5-LO) nuclear translocation but also augmented Pam3CSK4 and LTA-mediated 5-LO translocation. Pam3CSK4, LPS and LTA did not induce LAD2 degranulation. SP primed LTA and Pam3CSK4-mediated activation of JNK, p38 and extracellular-signal-regulated kinase (ERK) and activated the nuclear translocation of c-Jun, nuclear factor (NF)-κB, activating transcription factor 2 (ATF-2) and cyclic-AMP-responsive element binding protein (CREB) transcription factors. Pretreatment with SP followed by LTA stimulation synergistically induced production of chemokine (C-X-C motif) ligand 8 (CXCL8)/IL-8, chemokine (C-C motif) ligand 2 (CCL2)/monocyte chemotactic protein 1 (MCP-1), tumour necrosis factor (TNF) and IL-6 protein. SP primes TLR2-mediated activation of human mast cells by up-regulating TLR expression and

  4. Therapeutic Targeting of Toll-Like Receptors for Infectious and Inflammatory Diseases and Cancer

    OpenAIRE

    O'Neill, Luke A. J.; Bryant, Clare E.; Doyle, Sarah L

    2009-01-01

    Since first being described in the fruit fly Drosophila melanogaster, Toll-like receptors (TLRs) have proven to be of great interest to immunologists and investigators interested in the molecular basis to inflammation. They recognize pathogen-derived factors and also products of inflamed tissue, and trigger signaling pathways that lead to activation of transcription factors such as nuclear factor-κB and the interferon regulatory...

  5. Alcohol,nutrition and liver cancer:Role of Toll-like receptor signaling

    Institute of Scientific and Technical Information of China (English)

    Samuel; W; French; Joan; Oliva; Barbara; A; French; Fawzia; Bardag-Gorce

    2010-01-01

    This article reviews the evidence that ties the development of hepatocellular carcinoma (HCC) to the natural immune pro-inflammatory response to chronic liver disease, with a focus on the role of Toll-like receptor (TLR) signaling as the mechanism of liver stem cell/progenitor transformation to HCC. Two exemplary models of this phenomenon are reviewed in detail. One model applies chronic ethanol/lipopolysaccharide feeding to the activated TLR4 signaling pathway. The other applies chronic feeding of a carcin...

  6. Bupleurum Polysaccharides Attenuates Lipopolysaccharide-Induced Inflammation via Modulating Toll-Like Receptor 4 Signaling

    OpenAIRE

    Wu, Jian; Zhang, Yun-Yi; Guo, Li; LI Hong; Chen, Dao-Feng

    2013-01-01

    Background Bupleurum polysaccharides (BPs), isolated from Bupleurum smithii var. parvifolium, possesses immunomodulatory activity, particularly on inflammation. Bacterial endotoxin lipopolysaccharide (LPS) triggers innate immune responses through Toll-like receptor 4 (TLR4) on host cell membrane. The present study was performed to evaluate whether the therapeutic efficacy of BPs on suppression of LPS’s pathogenecity could be associated with the modulating of TLR4 signaling pathway. Methodolog...

  7. The co-stimulatory effects of MyD88-dependent Toll-like receptor signaling on activation of murine γδ T cells.

    Directory of Open Access Journals (Sweden)

    Jinping Zhang

    Full Text Available γδ T cells express several different toll-like receptor (TLRs. 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.

  8. Human herpesvirus 6 infection impairs Toll-like receptor signaling

    Directory of Open Access Journals (Sweden)

    Ochi Toshiki

    2010-05-01

    Full Text Available Abstract Human herpesvirus 6 (HHV-6 has a tropism for immunocompetent cells, including T lymphocytes, monocytes/macrophages, and dendritic cells (DCs suggesting that HHV-6 infection affects the immunosurveillance system. Toll-like receptor (TLR system plays an important role in innate immunity against various pathogens. In the present study, we investigated the effect of HHV-6 infection on the expression and intracellular signaling of TLRs in DCs. Although expression levels of TLRs were not decreased or slightly elevated following HHV-6 infection, the amounts of cytokines produced following stimulation with ligands for TLRs appeared to be dramatically decreased in HHV-6-infected DCs as compared to mock-infected DCs. Similarly, phosphorylation levels of TAK-1, IκB kinase, and IκB-α following stimulation of HHV-6-infected DCs with lipopolysaccharide, which is the ligand for TLR4, appeared to be decreased. These data show that HHV-6 impairs intracellular signaling through TLRs indicating the novel mechanism of HHV-6-mediated immunomodulation.

  9. Comparative studies of Toll-like receptor signalling using zebrafish.

    Science.gov (United States)

    Kanwal, Zakia; Wiegertjes, Geert F; Veneman, Wouter J; Meijer, Annemarie H; Spaink, Herman P

    2014-09-01

    Zebrafish model systems for infectious disease are increasingly used for the functional analysis of molecular pattern recognition processes. These studies benefit from the high conservation level of all innate immune factors in vertebrates. Zebrafish studies are strategically well positioned for this because of the ease of comparisons with studies in other fish species of which the immune system also has been intensively studied, but that are currently still less amendable to detailed genetic or microscopic studies. In this paper we focus on Toll-like receptor (TLR) signalling factors, which currently are the best characterized in mammalian systems. We review the knowledge on TLR signalling in the context of recent advances in zebrafish studies and discuss possibilities for future approaches that can complement studies in cell cultures and rodent models. A focus in these comparisons is the role of negative control mechanisms in immune responses that appear very important in a whole organism to keep adverse systemic responses in check. We also pay much attention to comparisons with studies in common carp that is highly related to zebrafish and that because of its large body mass can complement immune studies in zebrafish.

  10. Calpain Activity and Toll-Like Receptor 4 Expression in Platelet Regulate Haemostatic Situation in Patients Undergoing Cardiac Surgery and Coagulation in Mice

    Directory of Open Access Journals (Sweden)

    Jui-Chi Tsai

    2014-01-01

    Full Text Available Human platelets express Toll-like receptors (TLR 4. However, the mechanism by which TLR4 directly affects platelet aggregation and blood coagulation remains to be explored. Therefore, in this study, we evaluated the platelet TLR4 expression in patients who underwent CABG surgery; we explored the correlation between platelet TLR4 expression and the early outcomes in hospital of patients. Additionally, C57BL/6 and C57BL/6-TlrLPS−/− mice were used to explore the roles of platelet TLR4 in coagulation by platelet aggregometry and rotation thromboelastometry. In conclusion, our results highlight the important roles of TLR4 in blood coagulation and platelet function. Of clinical relevance, we also explored novel roles for platelet TLR4 that are associated with early outcomes in cardiac surgery.

  11. Expression of soluble Toll-like receptors in pleural effusions

    Institute of Scientific and Technical Information of China (English)

    YANG Hai-bo; XIE Kai-qing; DENG Jing-min; QIN Shou-ming

    2010-01-01

    Background The Toll-like receptors (TLRs) represent a group of single-pass transmembrane receptors expressed on sentinel cells that are central to innate immune responses.The aim of this study was to investigate the presence of soluble TLRs in pleural effusions, and the diagnostic values of TLRs for pleural effusion with various etiologies.Methods Pleural effusion and serum samples were collected from 102 patients (36 with malignant pleural effusion, 36with tuberculous pleural effusion, 18 with bacterial pleural effusion, and 12 with transudative pleural effusion).The concentrations of TLR1 to TLR10 were determined in effusion and serum samples by enzyme linked immunosorbent assay.Four classical parameters (protein, lactate dehydrogenase, glucose and C-reactive protein (CRP)) in the pleural fluid were also assessed.Receiver-operating characteristic curves were used to assess the sensitivity and specificity of pleural fluid TLRs and biochemical parameters for differentiating bacterial pleural effusion.Results The concentrations of TLR1, TLR3, TLR4, TLR7 and TLR9 in bacterial pleural effusion were significantly higher than those in malignant, tuberculous, and transudative groups, respectively.Analysis of receiver operating characteristic curves revealed that the area under the curves of TLR1, TLR3, TLR4, TLR7 and TLR9 were 0.831, 0.843,0.842, 0.883 and 0.786, respectively, suggesting that these TLRs play a role in the diagnosis of bacterial pleural effusion.Also, the diagnostic value of TLRs for bacterial pleural effusions was much better than that of biochemical parameters (protein, lactate dehydrogenase, glucose and CRP).Conclusions The concentrations of TLR1, TLR3, TLR4, TLR7 and TLR9 appeared to be increased in bacterial pleural effusion compared to non-bacterial pleural effusions.Determination of these pleural TLRs may improve the ability of clinicians to differentiate pleural effusion patients of bacterial origin from those with other etiologies.

  12. Anti-inflammatory activity of Odina wodier Roxb, an Indian folk remedy, through inhibition of toll-like receptor 4 signaling pathway.

    Directory of Open Access Journals (Sweden)

    Durbadal Ojha

    Full Text Available 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.

  13. Up-regulation of Toll-like receptors 2, 3 and 4 in allergic rhinitis

    Directory of Open Access Journals (Sweden)

    Uddman Rolf

    2005-09-01

    Full Text Available Abstract Background Toll-like receptors enable the host to recognize a large number of pathogen-associated molecular patterns such as bacterial lipopolysaccharide, viral RNA, CpG-containing DNA and flagellin. Toll-like receptors have also been shown to play a pivotal role in both innate and adaptive immune responses. The role of Toll-like receptors as a primary part of our microbe defense system has been shown in several studies, but their possible function as mediators in allergy and asthma remains to be established. The present study was designed to examine the expression of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with intermittent allergic rhinitis, focusing on changes induced by exposure to pollen. Methods 27 healthy controls and 42 patients with seasonal allergic rhinitis volunteered for the study. Nasal biopsies were obtained before and during pollen season as well as before and after allergen challenge. The seasonal material was used for mRNA quantification of Toll-like receptors 2, 3 and 4 with real-time polymerase chain reaction, whereas specimens achieved in conjunction with allergen challenge were used for immunohistochemical localization and quantification of corresponding proteins. Results mRNA and protein representing Toll-like receptors 2, 3 and 4 could be demonstrated in all specimens. An increase in protein expression for all three receptors could be seen following allergen challenge, whereas a significant increase of mRNA only could be obtained for Toll-like receptor 3 during pollen season. Conclusion The up-regulation of Toll-like receptors 2, 3 and 4 in the nasal mucosa of patients with symptomatic allergic rhinitis supports the idea of a role for Toll-like receptors in allergic airway inflammation.

  14. DMPD: Translational mini-review series on Toll-like receptors: recent advances inunderstanding the role of Toll-like receptors in anti-viral immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17223961 Translational mini-review series on Toll-like receptors: recent advances inunderstanding the role...ecent advances inunderstanding the role of Toll-like receptors in anti-viral immu...nity. PubmedID 17223961 Title Translational mini-review series on Toll-like receptors: recent advances inunderstanding the role

  15. Toll-like receptor 2 agonists inhibit human fibrocyte differentiation

    Directory of Open Access Journals (Sweden)

    Maharjan Anu S

    2010-11-01

    Full Text Available Abstract Background In healing wounds, some monocytes enter the wound and differentiate into fibroblast-like cells called fibrocytes. Since Toll-like receptors (TLRs are present on monocytes, and pathogens that can infect a wound have and/or release TLR agonists, we examined whether TLR agonists affect fibrocyte differentiation. Results When human peripheral blood mononuclear cells (PBMCs were cultured with TLR3, TLR4, TLR5, TLR7, TLR8 or TLR9 agonists, there was no significant effect on fibrocyte differentiation, even though enhanced extracellular tumor necrosis factor (TNF-α accumulation and/or increased cell surface CD86 or major histocompatibility complex (MHC class II levels were observed. However, all TLR2 agonists tested inhibited fibrocyte differentiation without any significant effect on cell survival. Adding TLR2 agonists to purified monocytes had no effect on fibrocyte differentiation. However, some TLR2 agonists caused PBMCs to secrete a factor that inhibits the differentiation of purified monocytes into fibrocytes. This factor is not interferon (IFN-α, IFN-γ, interleukin (IL-12, aggregated immunoglobulin G (IgG or serum amyloid P (SAP, factors known to inhibit fibrocyte differentiation. TLR2 agonist-treated PBMCs secrete low levels of IL-6, TNF-α, IFN-γ, granulocyte colony-stimulating factor and tumor growth factor β1, but combinations of these factors had no effect on fibrocyte differentiation from purified monocytes. Conclusions Our results indicate that TLR2 agonists indirectly inhibit fibrocyte differentiation and that, for some TLR2 agonists, this inhibition involves other cell types in the PBMC population secreting an unknown factor that inhibits fibrocyte differentiation. Together, these data suggest that the presence of some bacterial signals can inhibit fibrocyte differentiation and may thus slow wound closure.

  16. Toll-like receptor polymorphisms in malaria-endemic populations

    Directory of Open Access Journals (Sweden)

    Zimmerman Peter A

    2009-03-01

    Full Text Available Abstract Background Toll-like receptors (TLR and related downstream signaling pathways of innate immunity have been implicated in the pathogenesis of Plasmodium falciparum malaria. Because of their potential role in malaria pathogenesis, polymorphisms in these genes may be under selective pressure in populations where this infectious disease is endemic. Methods A post-PCR Ligation Detection Reaction-Fluorescent Microsphere Assay (LDR-FMA was developed to determine the frequencies of TLR2, TLR4, TLR9, MyD88-Adaptor Like Protein (MAL single nucleotide polymorphisms (SNPs, and TLR2 length polymorphisms in 170 residents of two regions of Kenya where malaria transmission is stable and high (holoendemic or episodic and low, 346 residents of a malaria holoendemic region of Papua New Guinea, and 261 residents of North America of self-identified ethnicity. Results The difference in historical malaria exposure between the two Kenyan sites has significantly increased the frequency of malaria protective alleles glucose-6-phoshpate dehydrogenase (G6PD and Hemoglobin S (HbS in the holoendemic site compared to the episodic transmission site. However, this study detected no such difference in the TLR2, TLR4, TLR9, and MAL allele frequencies between the two study sites. All polymorphisms were in Hardy Weinberg Equilibrium in the Kenyan and Papua New Guinean populations. TLR9 SNPs and length polymorphisms within the TLR2 5' untranslated region were the only mutant alleles present at a frequency greater than 10% in all populations. Conclusion Similar frequencies of TLR2, TLR4, TLR9, and MAL genetic polymorphisms in populations with different histories of malaria exposure suggest that these innate immune pathways have not been under strong selective pressure by malaria. Genotype frequencies are consistent with Hardy-Weinberg Equilibrium and the Neutral Theory, suggesting that genetic drift has influenced allele frequencies to a greater extent than selective

  17. DMPD: Innate immunity and toll-like receptors: clinical implications of basic scienceresearch. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15069387 Innate immunity and toll-like receptors: clinical implications of basic sc...te immunity and toll-like receptors: clinical implications of basic scienceresearch. PubmedID 15069387 Title... Innate immunity and toll-like receptors: clinical implications of basic sciencer

  18. DMPD: Toll-like receptors: novel pharmacological targets for the treatment ofneurological diseases. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17974478 Toll-like receptors: novel pharmacological targets for the treatment ofneu...png) (.svg) (.html) (.csml) Show Toll-like receptors: novel pharmacological targets for the treatment ofneur...ological diseases. PubmedID 17974478 Title Toll-like receptors: novel pharmacological targets for the trea...tment ofneurological diseases. Authors Marsh BJ, Stenzel-Poore MP. Publication Curr

  19. DMPD: Toll-like receptors: paving the path to T cell-driven autoimmunity? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17888644 Toll-like receptors: paving the path to T cell-driven autoimmunity? Marsla... Toll-like receptors: paving the path to T cell-driven autoimmunity? PubmedID 17888644 Title Toll-like receptors: paving the path

  20. DMPD: The negative regulation of Toll-like receptor and associated pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17621314 The negative regulation of Toll-like receptor and associated pathways. Lan...) Show The negative regulation of Toll-like receptor and associated pathways. PubmedID 17621314 Title The ne...gative regulation of Toll-like receptor and associated pathways. Authors Lang T,

  1. DMPD: Toll-like receptors are key participants in innate immune responses. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18064347 Toll-like receptors are key participants in innate immune responses. Aranc...Epub 2007 Nov 21. (.png) (.svg) (.html) (.csml) Show Toll-like receptors are key participants in innate immu...ne responses. PubmedID 18064347 Title Toll-like receptors are key participants in

  2. Toll-like receptors are potential therapeutic targets in rheumatoid arthritis

    Institute of Scientific and Technical Information of China (English)

    Siamak; Sandoghchian; Shotorbani

    2011-01-01

    Toll-like receptors (TLRs) are found on the membranes of pattern recognition receptors and not only play important roles in activating immune responses but are also involved in the pathogenesis of inflammatory disease, injury and cancer. Furthermore, TLRs are also able to recognize endogenous alarmins released by damaged tissue and necrosis and/or apoptotic cells and are present in numerous autoimmune diseases. Therefore, the release of endogenous TLR ligands plays an important role in initiating and driving inflammatory diseases. Increasing data suggest a role for TLR signaling in rheumatoid arthritis, which is an autoimmune disease. Although their involvement is not comprehensively understood, the TLRs signaling transducers may provide potential therapeutic targets.

  3. Ligands, cell-based models, and readouts required for Toll-like receptor action.

    LENUS (Irish Health Repository)

    Dellacasagrande, Jerome

    2012-02-01

    This chapter details the tools that are available to study Toll-like receptor (TLR) biology in vitro. This includes ligands, host cells, and readouts. The use of modified TLRs to circumvent some technical problems is also discussed.

  4. DMPD: The Toll-like receptors: analysis by forward genetic methods. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16001129 The Toll-like receptors: analysis by forward genetic methods. Beutler B. Immunogenetics...ods. Authors Beutler B. Publication Immunogenetics. 2005 Jul;57(6):385-92. Pathwa

  5. Anti-inflammatory effects of cordycepin in lipopolysaccharide-stimulated RAW 264.7 macrophages through Toll-like receptor 4-mediated suppression of mitogen-activated protein kinases and NF-κB signaling pathways

    Directory of Open Access Journals (Sweden)

    Choi YH

    2014-10-01

    Full Text Available Yung Hyun Choi,1,2 Gi-Young Kim,3 Hye Hyeon Lee4 1Department of Biochemistry, Dongeui University College of Korean Medicine, Busan, 2Anti-Aging Research Center and Blue-Bio Industry RIC, Dongeui University, Busan, 3Laboratory of Immunobiology, Department of Marine Life Sciences, Jeju National University, Jeju, 4Daegu Gyeongbuk Institute of Science and Technology, Daegu, Republic of Korea Abstract: Cordycepin is the main functional component of the Cordyceps species, which has been widely used in traditional Oriental medicine. This compound possesses many pharmacological properties, such as an ability to enhance immune function, as well as antioxidant, antiaging, and anticancer effects. In the present study, we investigated the anti-inflammatory effects of cordycepin using a murine macrophage RAW 264.7 cell model. Our data demonstrated that cordycepin suppressed production of proinflammatory mediators such as nitric oxide (NO and prostaglandin E2 by inhibiting inducible NO synthase and cyclooxygenase-2 gene expression. Cordycepin also inhibited the release of proinflammatory cytokines, including tumor necrosis factor-alpha and interleukin-1-beta, through downregulation of respective mRNA expression. In addition, pretreatment with cordycepin significantly inhibited lipopolysaccharide (LPS-induced phosphorylation of mitogen-activating protein kinases and attenuated nuclear translocation of NF-κB by LPS, which was associated with abrogation of inhibitor kappa B-alpha degradation. Furthermore, cordycepin potently inhibited the binding of LPS to macrophages and LPS-induced Toll-like receptor 4 and myeloid differentiation factor 88 expression. Taken together, the results suggest that the inhibitory effects of cordycepin on LPS-stimulated inflammatory responses in RAW 264.7 macrophages are associated with suppression of mitogen-activating protein kinases and activation of NF-κB by inhibition of the Toll-like receptor 4 signaling pathway. Keywords

  6. DMPD: Nucleic acid-sensing Toll-like receptors: beyond ligand search. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18321608 Nucleic acid-sensing Toll-like receptors: beyond ligand search. Miyake K. ...Adv Drug Deliv Rev. 2008 Apr 29;60(7):782-5. Epub 2008 Feb 15. (.png) (.svg) (.html) (.csml) Show Nucleic ac...id-sensing Toll-like receptors: beyond ligand search. PubmedID 18321608 Title Nucleic acid-sensing Toll-like

  7. Toll-Like Receptor 2- and 6-Mediated Stimulation by Macrophage-Activating Lipopeptide 2 Induces Lipopolysaccharide (LPS) Cross Tolerance in Mice, Which Results in Protection from Tumor Necrosis Factor Alpha but in Only Partial Protection from Lethal LPS Doses

    OpenAIRE

    Deiters, Ursula; Gumenscheimer, Marina; Galanos, Chris; Mühlradt, Peter F.

    2003-01-01

    Patients or experimental animals previously exposed to lipopolysaccharide (LPS) become tolerant to further LPS challenge. We investigated the potential of the macrophage-activating lipopeptide 2 (MALP-2) to induce in vivo cross tolerance to tumor necrosis factor alpha (TNF-α) and LPS. MALP-2-induced tolerance could be of practical interest, as MALP-2 proved much less pyrogenic in rabbits than LPS. Whereas LPS signals via Toll-like receptor 4 (TLR4), MALP-2 uses TLR2 and TLR6. LPS-mediated cyt...

  8. Anti-Inflammatory Activity of Fruit Fractions in Vitro, Mediated through Toll-Like Receptor 4 and 2 in the Context of Inflammatory Bowel Disease

    Directory of Open Access Journals (Sweden)

    Noha Ahmed Nasef

    2014-11-01

    Full Text Available Pattern recognition receptors such as Toll-Like Receptor 2 (TLR2 and 4 (TLR4 are important in detecting and responding to stress and bacterial stimuli. Defect or damage in the TLR2 and TLR4 pathways can lead to sustained inflammation, characteristic of inflammatory bowel disease (IBD. The goal of this study was to identify fruit fractions that can be tested further to develop them as complementary therapies for IBD. In order to do this, we identified fruit fractions that mediate their anti-inflammatory response through the TLR4 and TLR2 pathway. Human Embryonic Kidney (HEK-hTLR4 and hTLR2 cells were stimulated with their respective ligands to induce inflammation. These cells were treated with one of the 12 fractionated fruits and the inflammatory effect measured. 10 of the fruits came up as anti-inflammatory in the hTLR4 assay and nine in the hTLR2 assays. Many of the fruit fractions mediated their anti-inflammatory actions either mainly in their hydrophobic fractions (such as elderberry or hydrophilic fractions (such as red raspberry, or both. The strongest anti-inflammatory effects were seen for feijoa and blackberry. This study shows that fruits can have multiple fractions eliciting anti-inflammatory effects in a pathway specific manner. This suggests that the compounds found in fruits can act together to produce health benefits by way of reducing inflammation. Exploiting this property of fruits can help develop complimentary therapies for inflammatory diseases.

  9. Toll-like receptors and cancer: MYD88 mutation and inflammation

    Directory of Open Access Journals (Sweden)

    James Q Wang

    2014-07-01

    Full Text Available Pattern recognition receptors (PRRs expressed on immune cells are crucial for the early detection of invading pathogens, in initiating early innate immune response and in orchestrating the adaptive immune response. PRRs are activated by specific pathogen-associated molecular patterns (PAMPs that are present in pathogenic microbes or nucleic acids of viruses or bacteria. However, inappropriate activation of these PRRs, such as the Toll-like receptors (TLRs, due to genetic lesions or chronic inflammation has been demonstrated to be a major cause of many haematological malignancies. Gain-of-function mutations in the TLR adaptor protein MYD88 found in 39% of the activated B cell type of diffuse large B cell lymphomas (ABC-DLBCL and almost 100% of Waldenström’s macroglobulinemia (WM further highlight the involvement of TLRs in these malignancies. MYD88 mutations result in the chronic activation of TLR signalling pathways, thus the constitutive activation of the transcription factor NFκB to promote cell survival and proliferation. These recent insights into TLR pathway driven malignancies warrant the need for a better understanding of TLRs in cancers and the development of novel anti-cancer therapies targeting TLRs. This review focuses on Toll-like receptors function and signalling in normal or inflammatory conditions, and how mutations can also hijack the TLR signalling pathways to give rise to cancer. Lastly, we discuss how potential therapeutic agents could be used to restore normal responses to TLRs and have long lasting anti-tumour effects.

  10. Important role for Toll-like receptor 9 in host defense against meningococcal sepsis

    DEFF Research Database (Denmark)

    Sjölinder, Hong; Mogensen, Trine; Kilian, Mogens;

    2008-01-01

    Neisseria meningitidis is a leading cause of meningitis and sepsis. The pathogenesis of meningococcal disease is determined by both bacterial virulence factors and the host inflammatory response. Toll-like receptors (TLRs) are prominent activators of the inflammatory response, and TLR2, -4, and -9...... have been reported to be involved in the host response to N. meningitidis. While TLR4 has been suggested to play an important role in early containment of infection, the roles of TLR2 and TLR9 in meningococcal disease are not well described. Using a model for meningococcal sepsis, we report that TLR9...

  11. The role of Toll-like receptors in the pathogenesis of allergic diseases – where is the truth?

    OpenAIRE

    Anna Dębińska; Andrzej Boznański

    2014-01-01

    Toll-like receptors (TLRs) are pattern recognition receptors crucial for the innate and adaptive immune response to pathogen-associated molecular patterns (PAMPs). TLR stimulation via microbial products activates antigen-presenting cells, influences the function of T regulatory cells (Treg), determines the Th1/Th2 balance and Th17 cell differentiation, and controls cytokine production in mast cells and activation of eosinophils. The role of TLR receptors in pathogenesis of allergic diseases r...

  12. [Significance of Toll-like receptors in the pathophysiology of surgical sepsis].

    LENUS (Irish Health Repository)

    Romics, Laszlo Jr

    2012-02-03

    The discovery of Toll-like receptors has substantially changed our knowledge of pathogen recognition. 11 Toll-like receptors have so far been described in humans. These recognize distinct pathogen associated molecular patterns, as well as endogenous ligands and small molecular synthetic compounds. TLRs have a multifunctional role in pathogen-triggered immune responses and represent an important connection between the "innate" and "adaptive" immunity. The role of the TLRs in the recognition of pathogens renders them a key figure in the activation of the immune response during surgical sepsis. However, emerging evidence points to a fundamental role in tumorigenesis, transplantation, wound healing, atherogenesis and inflammatory bowel disease. The aim hence was to review experimental data pertaining to the activation of TLR signalling pathways in conditions associated with surgical sepsis. A systematic review of the literature was undertaken by searching the MEDLINE database for the period 1966-2004 without language restriction. The paper also analyses the possible therapeutic utilization of the TLR signalling pathways in surgical sepsis.

  13. Role of Toll-like receptors in regulatory functions of T and B cells

    Institute of Scientific and Technical Information of China (English)

    CHANG ZongLiang

    2008-01-01

    Pathogens can find their ways to most sites in the host. Pathogen sensors, such as Toll-like receptors (TLRs), must be equally and broadly distributed on immune cells to combat them through innate and adaptive immunity. Most classes of TLRs are found in innate immune cells to obtain an immediate re-sponse against pathogens, but recent studies indicate that a number of TLRs are wildly expressed in T and B cells, suggesting TLRs also directly regulate adaptive immune responses. Due to the rapid in-crease of new information on the multiple roles of TLRs, in this paper we aim to review several main properties of TLRs and their direct role in T and B cells. This review consists of 6 parts: (ⅰ) Characteris-tics of Toll-like receptors (TLRs) and signaling; (ⅱ) signalling pathways of TLRs; (ⅲ) TLR expressions on human leukocytes; (ⅳ) TLR expressions and functions in the Th1, CD4+CD45RO+ memory T cells and regulatory/suppressor T as well as B cell populations; (ⅴ) therapeutic potential of TLR agonists; (ⅵ) discussion and perspective. The latest findings and potential therapeutic applications are discussed. There is growing evidence supporting the concept that TLR activation contributes not only to innate immunity but also to adaptive immunity, including direct regulation of both T and B lymphocytes by TLRs.

  14. Malassezia-derived indoles activate the aryl hydrocarbon receptor and inhibit Toll-like receptor-induced maturation in monocyte-derived dendritic cells.

    NARCIS (Netherlands)

    Vlachos, C.; Schulte, B.M.; Magiatis, P.; Adema, G.J.; Gaitanis, G.

    2012-01-01

    Background The aryl hydrocarbon receptor (AhR) is a nuclear receptor and transcriptional regulator with pleiotropic effects. The production of potent AhR ligands by Malassezia yeasts, such as indirubin, indolo[3,2-b]carbazole (ICZ), tryptanthrin and malassezin, has been associated with the pathogene

  15. Structure–activity correlations of variant forms of the B pentamer of Escherichia coli type II heat-labile enterotoxin LT-IIb with Toll-like receptor 2 binding

    International Nuclear Information System (INIS)

    Structural data for the S74D variant of the pentameric B subunit of type II heat-labile enterotoxin of Escherichia coli reveal a smaller pore opening that may explain its reduced Toll-like receptor binding affinity compared to that of the wild type enterotoxin. The explanation for the enhanced Toll-like receptor binding affinity of the S74A variant is more complex than simply being attributed to the pore opening. The pentameric B subunit of the type II heat-labile enterotoxin of Escherichia coli (LT-IIb-B5) is a potent signaling molecule capable of modulating innate immune responses. It has previously been shown that LT-IIb-B5, but not the LT-IIb-B5 Ser74Asp variant [LT-IIb-B5(S74D)], activates Toll-like receptor (TLR2) signaling in macrophages. Consistent with this, the LT-IIb-B5(S74D) variant failed to bind TLR2, in contrast to LT-IIb-B5 and the LT-IIb-B5 Thr13Ile [LT-IIb-B5(T13I)] and LT-IIb-B5 Ser74Ala [LT-IIb-B5(S74A)] variants, which displayed the highest binding activity to TLR2. Crystal structures of the Ser74Asp, Ser74Ala and Thr13Ile variants of LT-IIb-B5 have been determined to 1.90, 1.40 and 1.90 Å resolution, respectively. The structural data for the Ser74Asp variant reveal that the carboxylate side chain points into the pore, thereby reducing the pore size compared with that of the wild-type or the Ser74Ala variant B pentamer. On the basis of these crystallographic data, the reduced TLR2-binding affinity of the LT-IIb-B5(S74D) variant may be the result of the pore of the pentamer being closed. On the other hand, the explanation for the enhanced TLR2-binding activity of the LT-IIb-B5(S74A) variant is more complex as its activity is greater than that of the wild-type B pentamer, which also has an open pore as the Ser74 side chain points away from the pore opening. Data for the LT-IIb-B5(T13I) variant show that four of the five variant side chains point to the outside surface of the pentamer and one residue points inside. These data are consistent with

  16. Role of toll-like receptors and inflammation in adrenal gland insufficiency.

    Science.gov (United States)

    Kanczkowski, Waldemar; Zacharowski, Kai; Bornstein, Stefan R

    2010-01-01

    Adrenal gland insufficiency - the clinical manifestation of deficient production or action of adrenal steroids - is a life-threatening disorder. Among many factors which can predispose to primary adrenal failure, an autoimmune adrenalitis and infectious agents play a major role. The initial host defense against bacterial infections is executed primarily by the pattern recognition receptors, e.g. Toll-like receptors (TLRs), expressed in cells from the innate immune system. Upon activation, TLRs have been found to regulate various levels of innate and adaptive immunity as well as control tissue inflammation. TLRs are implicated in adrenal cell turnover and steroidogenesis during inflammation. Therefore, TLRs play a crucial role in the activation of adrenal inflammation mediating adrenal gland dysfunction during septicemia.

  17. Toll-Like Receptor 2 as a Regulator of Oral Tolerance in the Gastrointestinal Tract

    Directory of Open Access Journals (Sweden)

    Matthew C. Tunis

    2014-01-01

    Full Text Available Food allergy, other adverse immune responses to foods, inflammatory bowel disease, and eosinophilic esophagitis have become increasingly common in the last 30 years. It has been proposed in the “hygiene hypothesis” that dysregulated immune responses to environmental microbial stimuli may modify the balance between tolerance and sensitization in some patients. Of the pattern recognition receptors that respond to microbial signals, toll-like receptors (TLRs represent the most investigated group. The relationship between allergy and TLR activation is currently at the frontier of immunology research. Although TLR2 is abundant in the mucosal environment, little is known about the complex relationship between bystander TLR2 activation by the commensal microflora and the processing of oral antigens. This review focuses on recent advances in our understanding of the relationship between TLR2 and oral tolerance, with an emphasis on regulatory T cells, eosinophils, B cells, IgA, intestinal regulation, and commensal microbes.

  18. Immune Modulation by Different Types of beta 2 -> 1-Fructans Is Toll-Like Receptor Dependent

    NARCIS (Netherlands)

    Vogt, L.; Ramasamy, U.; Meyer, Diederick; Pullens, G.; Venema, K.; Faas, M.M.; Schols, H.A.; de Vos, P.

    2013-01-01

    Introduction: beta 2 -> 1-fructans are dietary fibers. Main objectives of this study were 1) to demonstrate direct signalling of beta 2 -> 1-fructans on immune cells, 2) to study whether this is mediated by the pattern recognition receptors Toll-like receptors (TLRs) and nucleotide-binding oligomeri

  19. Reptile Toll-like receptor 5 unveils adaptive evolution of bacterial flagellin recognition

    NARCIS (Netherlands)

    Voogdt, Carlos G.P.; Bouwman, Lieneke I.; Kik, Marja J.L.; Wagenaar, Jaap A.; Putten, Van Jos P.M.

    2016-01-01

    Toll-like receptors (TLR) are ancient innate immune receptors crucial for immune homeostasis and protection against infection. TLRs are present in mammals, birds, amphibians and fish but have not been functionally characterized in reptiles despite the central position of this animal class in vert

  20. Systemic cancer immunotherapy with Toll-like receptor 7 agonists: Timing is everything.

    Science.gov (United States)

    Hotz, Christian; Bourquin, Carole

    2012-03-01

    Toll-like receptor (TLR) 7 agonists represent a promising strategy for the immunotherapy of cancer. We have recently investigated the influence of TLR tolerance on the efficacy of systemic tumor treatment with TLR7 ligands. We propose that considering the kinetics of receptor sensitivity highly improves the outcome of cancer immunotherapy. PMID:22720251

  1. Toll-like receptor-2 mediates mycobacteria-induced proinflammatory signaling in macrophages

    OpenAIRE

    Underhill, David M; Ozinsky, Adrian; Smith, Kelly D.; Aderem, Alan

    1999-01-01

    The recognition of mycobacterial cell wall components causes macrophages to secrete tumor necrosis factor α (TNF-α) and other cytokines that are essential for the development of a protective inflammatory response. We show that toll-like receptors are required for the induction of TNF-α in macrophages by Mycobacterium tuberculosis. Expression of a dominant negative form of MyD88 (a signaling component required for toll-like receptor signaling) in a mouse macrophage cell line blocks TNF-α produ...

  2. Toll-like receptors in inflammatory bowel disease-stepping into uncharted territory

    Institute of Scientific and Technical Information of China (English)

    Avi Levin; Oren Shibolet

    2008-01-01

    Ulcerative colitis and Crohn's disease are chronic relapsing-remitting inflammatory processes of the intestinaf tract.The etiology of these diseases is currently unknown.However,inflammation is hypothesized to result from inappropriate activation of mucosal immunity luminal antigens in genetically susceptible individuals.Toll-like receptors(TLRs)are a family of transmembrane proteins that act as microbial pattern recognition receptors.They are crucial initiators of innate immune responses.The role of TLRs in the pathogenesis of inflammatory bowel disease(IBD)has not been fully elucidated.In this review,we aim to analyze the available data connecting individual TLRs to intestinal inflammation and IBD.(C)2008 The WJG Press.All rights reserved.

  3. The role of Toll-like receptors in retinal ischemic diseases.

    Science.gov (United States)

    Xu, Wen-Qin; Wang, Yu-Sheng

    2016-01-01

    Toll-like receptors (TLRs) are commonly referred to a series of evolutionary conserved receptors which recognize and respond to various microbes and endogenous ligands. Growing evidence has demonstrated that the expression of TLRs in the retina is regulated during retinal ischemic diseases, including ischemia-reperfusion injury, glaucoma, diabetic retinopathy (DR) and retinopathy of prematurity (ROP). TLRs can be expressed in multiple cells in the retina, such as glial cells, retinal pigment epithelium (RPE), as well as photoreceptor cells and endothelium cells. Activation of TLRs in retina could initiate a complex signal transduction cascade, induce the production of inflammatory cytokines and regulate the level of co-stimulatory molecules, which play prominent roles in the pathogenesis of retinal ischemic diseases. In this review, we summarized current studies about the relationship between TLRs and ischemic retinopathy. A greater understanding of the effect of TLRs on ischemic injuries may contribute to the development of specific TLR targeted therapeutic strategies in these conditions. PMID:27672603

  4. A new Vitreoscilla filiformis extract grown on spa water-enriched medium activates endogenous cutaneous antioxidant and antimicrobial defenses through a potential Toll-like receptor 2/protein kinase C, zeta transduction pathway.

    Science.gov (United States)

    Mahe, Yann F; Perez, Marie-Jesus; Tacheau, Charlotte; Fanchon, Chantal; Martin, Richard; Rousset, Françoise; Seite, Sophie

    2013-01-01

    Vitreoscilla filiformis (VF) biomass (VFB) has been widely used in cosmetic preparations and shown to modulate the major inducible free-radical scavenger mitochondrial superoxide dismutase in skin cells. By adding La Roche-Posay (LRP) thermal spring water to the VF culture medium, we obtained a biomass (LRP-VFB) with a similar mitochondrial superoxide dismutase activation capacity to VF. Also, the new biomass more powerfully stimulated mRNA expression and antimicrobial peptides in reconstructed epidermis. Interestingly, a predictive computer model that analyzed transducing events within skin epidermal cells suggested that this protective activity may involve the Toll-like receptor 2/protein kinase C, zeta transduction pathway. Protein kinase C, zeta inhibition was effectively shown to abolish VFB-induced gene stimulation and confirmed this hypothesis. This thus opens new avenues for investigation into the improvement of skin homeostatic defense in relation to the control of its physiological microbiota and innate immunity. PMID:24039440

  5. Dynamic evolution of toll-like receptor multigene families in echinoderms

    Directory of Open Access Journals (Sweden)

    Katherine M Buckley

    2012-06-01

    Full Text Available The genome of the purple sea urchin, Strongylocentrotus purpuratus, was the first to be sequenced from a long-lived large invertebrate. Analysis of this genome uncovered a surprisingly complex immune system in which the moderately sized sets of pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR genes, more than 200 Nod-like receptors and 1095 scavenger receptor cysteine-rich domains, a ten-fold expansion relative to vertebrates. Given their stereotypic structure and simple intron-exon architecture, the TLRs are the most tractable of these families for more detailed analysis. An immune defense role for these receptors is suggested by their sequence diversity and expression in immunologically active tissues, including phagocytes. This complexity of the sea urchin TLR multigene families largely derives from expansions that are independent of those in vertebrates and protostomes, although a small family of TLRs with structure similar to that of Drosophila Toll likely originated in an ancient eumetazoan ancestor. Several other invertebrate deuterostome genomes have been sequenced, including the cephalochordate, Branchiostoma floridae and the sea urchin Lytechinus variegatus, as well as partial sequences from two other sea urchin species. Here, we present an analysis of the invertebrate deuterostome TLRs with emphasis on the echinoderms. Representatives of most of the S. purpuratus TLR subfamilies and homologs of the protostome-like sequences are found in L. variegatus. The phylogeny of these genes within sea urchins highlights lineage-specific expansions at higher resolution than is evident at the phylum level. These analyses identify quickly evolving TLR subfamilies that are likely to have novel functions and other, more stable, subfamilies that may function similarly to those of vertebrates.

  6. DMPD: A novel negative regulator for IL-1 receptor and Toll-like receptor 4. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15585304 A novel negative regulator for IL-1 receptor and Toll-like receptor 4. Lie...w FY, Liu H, Xu D. Immunol Lett. 2005 Jan 15;96(1):27-31. (.png) (.svg) (.html) (.csml) Show A novel negative... regulator for IL-1 receptor and Toll-like receptor 4. PubmedID 15585304 Title A novel negative regulator f

  7. Receptores similares a Toll en peces: el inicio de la divergencia Toll-like receptors in fish: the beginning divergence

    Directory of Open Access Journals (Sweden)

    IS Rondón-Barragán

    2009-06-01

    Full Text Available La inmunidad innata utiliza mecanismos de basados en el reconocimiento no clonal de componentes microbianos, denominados PAMPs, mediante el uso de receptores de reconocimiento de patrón genéticamente codificados (e.g. receptores similares a toll. Los PAMPs son estructuras esenciales para la fisiología y supervivencia de los microbios. Los receptores similares a Toll son una familia de receptores de transmembrana tipo I, con un dominio rico en leucina aminoterminal y una cola intracelular carboxiterminal; los cuales son expresados en diversas células incluyendo neutrófilos, macrófagos, células dendríticas, entre otras. Las vías de activación incluyen reclutamiento de proteínas citoplasmáticas adaptadoras que activan kinasas y factores asociados al factor de necrosis tumoral, conllevando a la activación de factores nucleares y a la producción de citoquinas y expresión de moléculas coestimuladoras de superficie en las células presentadoras de antígenos. El conocimiento acerca de los receptores similares a Toll permite el entendimiento de la dinámica de la respuesta inmune así como los procesos involucrados en el reconocimiento de los agentes microbianos. Esta revisión se enfoca en la identificación de los diversos receptores similares a Toll en peces, sus funciones e interacciones con otros así como la homología e identidad entre animales.Innate immunity initiates mechanisms based on the non-clonal recognition of microbial components, so-called PAMPs by using a variety of gene-encoded pattern recognition receptors (e.g. toll-like receptors. PAMPs are essential structures for the physiology and survival of the microbes. Toll-like receptors are transmembrane receptors family type I, with an aminoterminal leucin-rich repeat domain and a carboxiterminal intracellular tail; which are expressed in cells such as neutrophils, macrophages, dendritic cells, as well as others. Activation pathways including the recruitment of

  8. Toll-like receptor 2 activation by β2→1-fructans protects barrier function of t84 human intestinal epithelial cells in a chain length-dependent manner

    NARCIS (Netherlands)

    Vogt, L.M.; Meyer, D.; Pullens, G.; Faas, M.M.; Venema, K.; Ramasamy, U.; Schols, H.A.; Vos, P. de

    2014-01-01

    Dietary fiber intake is associated with lower incidence and mortality from disease, but the underlying mechanisms of these protective effects are unclear.We hypothesized that β2→1-fructan dietary fibers confer protection on intestinal epithelial cell barrier function via Toll-like receptor 2 (TLR2),

  9. The Role of Fatty Acids on Toll-like Receptor 4 Regulation of Substrate Metabolism with Obesity

    OpenAIRE

    McMillan, Ryan P

    2009-01-01

    Growing evidence suggests that obesity and associated metabolic dysregulation occurs in concert with chronic low-grade inflammation. Toll-like receptors (TLR) are transmembrane receptors that play an important role in innate immunity and the induction of inflammatory responses. Our laboratory has observed that TLR4 expression is elevated in the skeletal muscle of obese humans and is associated with reduced fatty acid (FA) oxidation and increased lipid synthesis. Additionally, activation of th...

  10. Toll-like receptor 4 is not targeted to the lysosome in cystic fibrosis airway epithelial cells

    OpenAIRE

    Kelly, Catriona; Canning, P.; Buchanan, Paul J.; Williams, Mark T.; Brown, V; Gruenert, Dieter C.; Elborn, Stuart; Ennis, M.; SCHOCK, BETTINA C.

    2013-01-01

    The innate immune response to bacterial infection is mediated through Toll-like receptors (TLRs), which trigger tightly regulated signaling cascades through transcription factors including NF-?B. LPS activation of TLR4 triggers internalization of the receptor-ligand complex which is directed toward lysosomal degradation or endocytic recycling. Cystic fibrosis (CF) patients display a robust and uncontrolled inflammatory response to bacterial infection, suggesting a defect in regulation. This s...

  11. Toll-like receptors and NOD-like receptors in rheumatic diseases.

    LENUS (Irish Health Repository)

    McCormack, William J

    2012-02-01

    The past 10 years have seen the description of families of receptors that drive proinflammatory cytokine production in infection and tissue injury. Two major classes have been examined in the context of inflammatory joint disease--the Toll-like receptors (TLRs) and NOD-like receptors (NLRs). TLRs such as TLR2 and TLR4 are being implicated in the pathology of rheumatoid arthritis, ankylosing spondylitis, lyme arthritis and osteoarthritis. Nalp3 has been identified as a key NLR for IL-1beta production and has been shown to have a particular role in gout. These findings present new therapeutic opportunities, possibly allowing for the replacement of biologics with small molecule inhibitors.

  12. DMPD: Toll-like receptors and RNA helicases: two parallel ways to trigger antiviralresponses. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16762830 Toll-like receptors and RNA helicases: two parallel ways to trigger antivi...-like receptors and RNA helicases: two parallel ways to trigger antiviralresponses. PubmedID 16762830 Title ...Toll-like receptors and RNA helicases: two parallel ways to trigger antiviralresp

  13. MECHANISMS OF ANTIINFECTIOUS FUNCTIONS OF INNATE IMMUNITY: ROLE OF TOLL-LIKE RECEPTORS

    Directory of Open Access Journals (Sweden)

    S. I. Suskov

    2012-01-01

    Full Text Available This review describes the main role of toll-like receptors of innate immunity for pathogen recognition; signaling; production of inflammatory response. Also Interrelation of innate and adaptive Immunity in conditions of pathology and organ transplantation were considered. 

  14. Intra-uterine Growth Restriction Downregulates the Hepatic Toll Like Receptor-4 Expression and Function

    OpenAIRE

    Ozlem Equils; Sapna Singh; Semra Karaburun; Daning Lu; Manikkavasagar Thamotharan; Devaskar, Sherin U.

    2005-01-01

    Maternal starvation is a significant cause of intrauterine growth restriction (IUGR) in the world and increases the risk of infection in the neonate. We examined the effect of maternal starvation on Toll like receptor (TLR)4 expression in hepatic, splenic and intestinal tissues obtained from the adult IUGR offspring of prenatal calorie restricted rats. The hepatic TLR4 protein concentration was undetectable in the...

  15. Toll-like Receptor 4 Signaling in Ventilator-induced Diaphragm Atrophy.

    NARCIS (Netherlands)

    Schellekens, W.J.M.; Hees, H.W.H. van; Vaneker, M.; Linkels, M.; Dekhuijzen, P.N.R.; Scheffer, G.J.; Hoeven, J.G. van der; Heunks, L.M.A.

    2012-01-01

    BACKGROUND:: Mechanical ventilation induces diaphragm muscle atrophy, which plays a key role in difficult weaning from mechanical ventilation. The signaling pathways involved in ventilator-induced diaphragm atrophy are poorly understood. The current study investigated the role of Toll-like receptor

  16. Relationship between Toll-Like Receptor 8 Gene Polymorphisms and Pediatric Pulmonary Tuberculosis

    Directory of Open Access Journals (Sweden)

    Nazan Dalgic

    2011-01-01

    Full Text Available Objectives: Genetic variants in Toll-like receptors (TLRs are considered a potential indicator for host susceptibility to and outcome of several infectious diseases including tuberculosis. The aim of this study was to determine whether −129 C/G and Met1Val polymorphisms of TLR8 were associated with pediatric pulmonary tuberculosis in Turkish population.

  17. Evolutionary patterns of Toll-like receptor signaling pathway genes in the Suidae

    NARCIS (Netherlands)

    Darfour-Oduro, K.A.; Megens, Hendrik Jan; Roca, A.L.; Groenen, M.A.M.; Schook, L.B.

    2016-01-01

    Background: The Toll-like receptor (TLR) signaling pathway constitutes an essential component of the innate immune system. Highly conserved proteins, indicative of their critical roles in host survival, characterize this pathway. Selective constraints could vary depending on the gene's position w

  18. Toll-like receptor 4 polymorphisms in dengue virus-infected children

    NARCIS (Netherlands)

    Djamiatun, K.; Ferwerda, B.; Netea, M.G.; Ven, A.J.A.M. van der; Dolmans, W.M.V.; Faradz, S.M.

    2011-01-01

    Differential viral recognition by cells bearing Toll-like receptor 4 (TLR4) polymorphisms Asp299Gly and Thr399Ile may influence susceptibility and severity of dengue virus infection. In central Java, Indonesia, we investigated 201 children with dengue hemorrhagic fever (DHF) and 179 healthy controls

  19. Toll-Like Receptor (TLR2 and TLR4) Polymorphisms and Chronic Obstructive Pulmonary Disease

    NARCIS (Netherlands)

    Budulac, S.E.; Boezen, H.M.; Hiemstra, Pieter S.; Lapperre, Therese S.; Vonk, Judith M.; Timens, W.; Postma, D.S.

    2012-01-01

    Toll-like receptors (TLRs) participate in the defence against bacterial infections that are common in patients with Chronic Obstructive Pulmonary Disease (COPD). We studied all tagging SNPs in TLR2 and TLR4 and their associations with the level and change over time of both FEV1 and sputum inflammato

  20. Expression of Toll-like receptors 2 and 4 in gingivitis and chronic periodontitis.

    Directory of Open Access Journals (Sweden)

    Sarah S

    2006-01-01

    Full Text Available Periodontal disease is the major cause of adult tooth loss and is commonly characterized by a chronic inflammation caused by infection by oral bacteria. Members of Toll-like receptor (TLR family recognize conserved microbial structures, such as bacterial lipopolysaccharides, and activate signaling pathways that result in immune responses against microbial infections. The aim of the present study was to assess the mRNA expression of TLR-2 and TLR-4 in gingivitis and chronic periodontitis. Gingival tissue samples were collected from patients with chronic periodontitis, gingivitis, and healthy controls. Total RNA was extracted and RT-PCR was done for TLR-2 and TLR-4. The results showed that TLR-2 was significantly increased in gingivitis compared to TLR-4 expression and decreased in chronic periodontitis.

  1. CPG-7909 (PF-3512676, ProMune): toll-like receptor-9 agonist in cancer therapy.

    Science.gov (United States)

    Murad, Yanal M; Clay, Timothy M; Lyerly, H Kim; Morse, Michael A

    2007-08-01

    Stimulation of toll-like receptor (TLR)9 activates human plasmacytoid dendritic cells and B cells, and induces potent innate immune responses in preclinical tumor models and in patients. CpG oligodeoxynucleotides (ODNs) are TLR9 agonists that show promising results as vaccine adjuvants and in the treatment of cancers, infections, asthma and allergy. PF-3512676 (ProMune) was developed as a TLR9 agonist for the treatment of cancer as monotherapy and as an adjuvant in combination with chemo- and immunotherapy. Phase I and II trials have tested this drug in several hematopoietic and solid tumors. Pfizer has initiated Phase III trials to test PF-3512676 in combination with standard chemotherapy for non-small-cell lung cancer. PMID:17696823

  2. Regulation of Toll-like receptors-dependent inflammatory response 

    Directory of Open Access Journals (Sweden)

    Ewa Kowalczyk

    2013-03-01

    Full Text Available Toll-like receptors (TLRs are a pivotal part of our innate immune response. They recognize a wide variety of pathogens and instigate an immune response, thus facilitating the removal of the disease-causing agent. Due to the intense nature of this response its strict control is of keyimportance, as a prolonged inflammatory signal leads to carcinogenesis and autoimmune disorders. The signaling cascade initiated by the activated TLR is complex and consists of multiple stages. It involves a variety of adaptor proteins, protein kinases and effector transcription factors. The number of stages in this process enables many possible checkpoints and ways of regulation. Signal modulation involves differentiated expression of TLRs, splicing variants of their adaptorproteins, enzymes modifying proteins engaged in the cascade and many more. This review focuses on endogenous factors responsible for controlling the TLR-dependent inflammatory response as well as on pharmacological therapies designed for regulating the innate immune response.  

  3. Toll-like receptors, a double-edged sword in immunity to malaria

    Institute of Scientific and Technical Information of China (English)

    Chen Jide; He Ying; Xu Wenyue; Huang Fusheng

    2009-01-01

    Toll-like receptors (TLRs) are a central component of innate immune system and play a major role as the initiator of the innate immune responses to defend against bacteria, viruses, parasite and other pathogens. During malaria infection, TLRs signaling pathways are initialed with the recognition of Plasmodium glycosylphosphatidylinositols (GPI) and hemozoin as pathogen-associated molecular patterns (PAMPs). And then, activation of TLRs signaling induces specific biological responses against malaria parasites invasion. However, TLRs are also involved in malaria pathogenesis and enhancement of immune tolerance and evasion for malaria infection. Moreover, malaria parasites regulate selectively TLRs expression on immune cells.Thus, these evidences indicated that TLRs have contrary roles on malaria infection. Understanding the complicated roles of TLRs on malaria infection will contribute us to design more effective anti-malaria drugs or vaccines.

  4. Role of Toll-like receptors in lung innate defense against invasive aspergillosis. Distinct impact in immunocompetent and immunocompromized hosts.

    Science.gov (United States)

    Chignard, Michel; Balloy, Viviane; Sallenave, Jean-Michel; Si-Tahar, Mustapha

    2007-09-01

    Toll-like receptors are key to pathogen recognition by a host and to the subsequent triggering of an innate immune response. Experimental and clinical evidence shows that defects in Toll-like receptors or in signaling pathways downstream from these receptors render hosts susceptible to various types of infection, including aspergillosis. Patients receiving an immunosuppressive regimen, including corticosteroid therapy or cytotoxic chemotherapy, are also susceptible to infections. Aspergillus fumigatus is an opportunistic pathogen that infects the lungs of immunosuppressed hosts. Here, we review the evidence that experimental inactivation of various Toll-like receptors and of their signaling pathways may worsen cases of invasive pulmonary aspergillosis. Moreover, the literature clearly indicates that the type of immunosuppression is very important, as it influences whether or not Toll-like receptors contribute to infection. The involvement of Toll-like receptors, based on the immunological status of the patient, should be considered if an immunosuppressive treatment must be administered. PMID:17604224

  5. A systematic review of CD14 and toll-like receptors in relation to asthma in Caucasian children.

    Science.gov (United States)

    Klaassen, Ester Mm; Thönissen, Brenda Ejt; van Eys, Guillaume; Dompeling, Edward; Jöbsis, Quirijn

    2013-03-15

    The aetiology of childhood asthma is complex. An early dysfunction in the immunological development of the innate immune system in combination with environmental factors possibly triggers asthma. CD14 and toll-like receptors are important components of the innate immune system. The aim of this systematic review was to obtain a better insight into the relation between CD14 and toll-like receptors and childhood asthma in Caucasians. We searched PubMed and EMBASE for relevant articles. In total, 44 articles were included. The quality of the selected studies was independently assessed by the first two authors using the Newcastle-Ottawa quality assessment scale. Toll-like receptor 2, toll-like receptor 6, toll-like receptor 9, and toll-like receptor 10 appear to have some association with childhood asthma in Caucasians. The evidence for a relation of CD14 with childhood asthma is limited. In conclusion, there is no convincing evidence yet for a role of CD14 and toll-like receptors in relation to childhood asthma. Future studies should include haplotype analysis and take environmental factors into account to further clarify the role of CD14 and toll-like receptors on childhood asthma.

  6. DMPD: The role of Toll-like receptors and Nod proteins in bacterial infection. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15476921 The role of Toll-like receptors and Nod proteins in bacterial infection. P...hilpott DJ, Girardin SE. Mol Immunol. 2004 Nov;41(11):1099-108. (.png) (.svg) (.html) (.csml) Show The role ...of Toll-like receptors and Nod proteins in bacterial infection. PubmedID 15476921 Title The role of Toll-lik

  7. DMPD: Innate recognition of lipopolysaccharide by Toll-like receptor 4-MD-2. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15051069 Innate recognition of lipopolysaccharide by Toll-like receptor 4-MD-2. Miy...ake K. Trends Microbiol. 2004 Apr;12(4):186-92. (.png) (.svg) (.html) (.csml) Show Innate recognition of lipopol...ysaccharide by Toll-like receptor 4-MD-2. PubmedID 15051069 Title Innate recognition of lipopolysacchari

  8. DMPD: Toll-like receptors. II. Distribution and pathways involved in TLR signalling. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16419614 Toll-like receptors. II. Distribution and pathways involved in TLR signall...ceptors. II. Distribution and pathways involved in TLR signalling. PubmedID 16419614 Title Toll-like recepto...rs. II. Distribution and pathways involved in TLR signalling. Authors Sandor F, B

  9. Neu1 sialidase and matrix metalloproteinase-9 cross-talk regulates nucleic acid-induced endosomal TOLL-like receptor-7 and -9 activation, cellular signaling and pro-inflammatory responses.

    Science.gov (United States)

    Abdulkhalek, Samar; Szewczuk, Myron R

    2013-11-01

    The precise mechanism(s) by which intracellular TOLL-like receptors (TLRs) become activated by their ligands remains unclear. Here, we report a molecular organizational G-protein coupled receptor (GPCR) signaling platform to potentiate a novel mammalian neuraminidase-1 (Neu1) and matrix metalloproteinase-9 (MMP-9) cross-talk in alliance with neuromedin B GPCR, all of which form a tripartite complex with TLR-7 and -9. siRNA silencing Neu1, MMP-9 and neuromedin-B GPCR in RAW-blue macrophage cells significantly reduced TLR7 imiquimod- and TLR9 ODN1826-induced NF-κB (NF-κB-pSer(536)) activity. Tamiflu, specific MMP-9 inhibitor, neuromedin B receptor specific antagonist BIM23127, and the selective inhibitor of whole heterotrimeric G-protein complex BIM-46174 significantly block nucleic acid-induced TLR-7 and -9 MyD88 recruitment, NF-κB activation and proinflammatory TNFα and MCP-1 cytokine responses. For the first time, Neu1 clearly plays a central role in mediating nucleic acid-induced intracellular TLR activation, and the interactions involving NMBR-MMP9-Neu1 cross-talk constitute a novel intracellular TLR signaling platform that is essential for NF-κB activation and pro-inflammatory responses. PMID:23827939

  10. Pleiotropic effects of Blastocystis spp. Subtypes 4 and 7 on ligand-specific toll-like receptor signaling and NF-κB activation in a human monocyte cell line.

    Directory of Open Access Journals (Sweden)

    Joshua D W Teo

    Full Text Available Blastocystis spp. is a common enteric stramenopile parasite that colonizes the colon of hosts of a diverse array of species, including humans. It has been shown to compromise intestinal epithelial cell barrier integrity and mediate the production of pro-inflammatory cytokines and chemokines. Mucosal epithelial surfaces, including the intestinal epithelium, are increasingly recognized to perform a vital surveillance role in the context of innate immunity, through the expression of pathogen recognition receptors, such as Toll-like receptors (TLRs. In this study, we use the human TLR reporter monocytic cell line, THP1-Blue, which expresses all human TLRs, to investigate effects of Blastocystis on TLR activation, more specifically the activation of TLR-2, -4 and -5. We have observed that live Blastocystis spp. parasites and whole cell lysate (WCL alone do not activate TLRs in THP1-Blue. Live ST4-WR1 parasites inhibited LPS-mediated NF-κB activation in THP1-Blue. In contrast, ST7-B WCL and ST4-WR1 WCL induced pleiotropic modulation of ligand-specific TLR-2 and TLR-4 activation, with no significant effects on flagellin-mediated TLR-5 activation. Real time-qPCR analysis on SEAP reporter gene confirmed the augmenting effect of ST7-B on LPS-mediated NF-κB activation in THP1-Blue. Taken together, this is the first study to characterize interactions between Blastocystis spp. and host TLR activation using an in vitro reporter model.

  11. Signal transducer and activator of transcription-3 licenses Toll-like receptor 4-dependent interleukin (IL)-6 and IL-8 production via IL-6 receptor-positive feedback in endometrial cells.

    Science.gov (United States)

    Cronin, J G; Kanamarlapudi, V; Thornton, C A; Sheldon, I M

    2016-09-01

    Interleukin 6 (IL-6), acting via the IL-6 receptor (IL6R) and signal transducer and activator of transcription-3 (STAT3), limits neutrophil recruitment once bacterial infections are resolved. Bovine endometritis is an exemplar mucosal disease, characterized by sustained neutrophil infiltration and elevated IL-6 and IL-8, a neutrophil chemoattractant, following postpartum Gram-negative bacterial infection. The present study examined the impact of the IL6R/STAT3 signaling pathway on IL-8 production by primary endometrial cells in response to short- or long-term exposure to lipopolysaccharide (LPS) from Gram-negative bacteria. Tyrosine phosphorylation of STAT3 is required for DNA binding and expression of specific targets genes. Immunoblotting indicated constitutive tyrosine phosphorylation of STAT3 in endometrial cells was impeded by acute exposure to LPS. After 24 h exposure to LPS, STAT3 returned to a tyrosine phosphorylated state, indicating cross-talk between the Toll-like receptor 4 (TLR4) and the IL6R/STAT3 signaling pathways. This was confirmed by short interfering RNA targeting the IL6R, which abrogated the accumulation of IL-6 and IL-8, induced by LPS. Furthermore, there was a differential endometrial cell response, as the accumulation of IL-6 and IL-8 was dependent on STAT3, suppressor of cytokine signaling 3, and Src kinase signaling in stromal cells, but not epithelial cells. In conclusion, positive feedback through the IL6R amplifies LPS-induced IL-6 and IL-8 production in the endometrium. These findings provide a mechanistic insight into how elevated IL-6 concentrations in the postpartum endometrium during bacterial infection leads to marked and sustained neutrophil infiltration. PMID:26813342

  12. Decreased Toll-like receptor 8 expression and lower TNF-alpha synthesis in infants with acute RSV infection

    OpenAIRE

    Gagro Alenka; Cepin-Bogovic Jasna; Aberle Neda; Vojvoda Valerija; Bendelja Kreso; Mlinaric-Galinovic Gordana; Rabatic Sabina

    2010-01-01

    Abstract Background Toll-like receptors (TLRs) are part of the innate immune system, able to recognize pathogen-associated molecular patterns and activate immune system upon pathogen challenge. Respiratory syncytial virus (RSV) is a RNA virus particularly detrimental in infancy. It could cause severe lower respiratory tract disease and recurrent infections related to inadequate development of anti-viral immunity. The reason could be inadequate multiple TLRs engagement, including TLR8 in recog...

  13. Interaction between Cannabinoid System and Toll-Like Receptors Controls Inflammation.

    Science.gov (United States)

    McCoy, Kathleen L

    2016-01-01

    Since the discovery of the endocannabinoid system consisting of cannabinoid receptors, endogenous ligands, and biosynthetic and metabolizing enzymes, interest has been renewed in investigating the promise of cannabinoids as therapeutic agents. Abundant evidence indicates that cannabinoids modulate immune responses. An inflammatory response is triggered when innate immune cells receive a danger signal provided by pathogen- or damage-associated molecular patterns engaging pattern-recognition receptors. Toll-like receptor family members are prominent pattern-recognition receptors expressed on innate immune cells. Cannabinoids suppress Toll-like receptor-mediated inflammatory responses. However, the relationship between the endocannabinoid system and innate immune system may not be one-sided. Innate immune cells express cannabinoid receptors and produce endogenous cannabinoids. Hence, innate immune cells may play a role in regulating endocannabinoid homeostasis, and, in turn, the endocannabinoid system modulates local inflammatory responses. Studies designed to probe the interaction between the innate immune system and the endocannabinoid system may identify new potential molecular targets in developing therapeutic strategies for chronic inflammatory diseases. This review discusses the endocannabinoid system and Toll-like receptor family and evaluates the interaction between them. PMID:27597805

  14. Toll-like receptor 4 decoy, TOY, attenuates gram-negative bacterial sepsis.

    Directory of Open Access Journals (Sweden)

    Keehoon Jung

    Full Text Available Lipopolysaccharide (LPS, the Gram-negative bacterial outer membrane glycolipid, induces sepsis through its interaction with myeloid differentiation protein-2 (MD-2 and Toll-like receptor 4 (TLR4. To block interaction between LPS/MD-2 complex and TLR4, we designed and generated soluble fusion proteins capable of binding MD-2, dubbed TLR4 decoy receptor (TOY using 'the Hybrid leucine-rich repeats (LRR technique'. TOY contains the MD-2 binding ectodomain of TLR4, the LRR motif of hagfish variable lymphocyte receptor (VLR, and the Fc domain of IgG1 to make it soluble, productive, and functional. TOY exhibited strong binding to MD-2, but not to the extracellular matrix (ECM, resulting in a favorable pharmacokinetic profile in vivo. TOY significantly extended the lifespan, when administered in either preventive or therapeutic manners, in both the LPS- and cecal ligation/puncture-induced sepsis models in mice. TOY markedly attenuated LPS-triggered NF-kappaB activation, secretion of proinflammatory cytokines, and thrombus formation in multiple organs. Taken together, the targeting strategy for sequestration of LPS/MD-2 complex using the decoy receptor TOY is effective in treating LPS- and bacteria-induced sepsis; furthermore, the strategy used in TOY development can be applied to the generation of other novel decoy receptor proteins.

  15. Dynamic Evolution of Toll-Like Receptor Multigene Families in Echinoderms

    OpenAIRE

    Buckley, Katherine M; Rast, Jonathan P.

    2012-01-01

    The genome sequence of the purple sea urchin, Strongylocentrotus purpuratus, a large and long-lived invertebrate, provides a new perspective on animal immunity. Analysis of this genome uncovered a highly complex immune system in which the gene families that encode homologs of the pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR) sequences, more than 200 Nod-like re...

  16. Differential expression of toll-like receptors in patients with irritable bowel syndrome.

    LENUS (Irish Health Repository)

    Brint, Elizabeth K

    2011-02-01

    The pathogenesis of irritable bowel syndrome (IBS) is poorly understood. One contributory factor may be low-grade mucosal inflammation, perhaps initiated by the microbiota. Toll-like receptors (TLRs) are a family of pathogen-recognition receptors of the innate immune system. The aim of this study was to evaluate the potential involvement of TLRs in IBS to further understand the involvement of the innate immune system in this complex disorder.

  17. Trypanosoma cruzi and its components as exogenous mediators of inflammation recognized through Toll-like receptors.

    OpenAIRE

    Gazzinelli, Ricardo T.; Campos, Marco A

    2004-01-01

    TRYPANOSOMA cruzi is the etiologic agent of Chagas' disease, a parasitic disease of enormous importance in Latin America. Herein we review the studies that revealed the receptors from innate immunity that are involved in the recognition of this protozoan parasite. We showed that the recognition of T. cruzi and its components occurs through Toll-like receptors (TLR) 2/CD14. Further, we showed in vivo the importance of the myeloid differentiation factor (MyD88), an adapter protein essential for...

  18. Toll-like receptor 4 gene polymorphism is associated with chronic periodontitis

    OpenAIRE

    Ding, Yuan-Sheng; Zhao, Yue; Xiao,Yuan-Yuan; Zhao, Gang

    2015-01-01

    Toll-like receptors (TLRs) contribute to the immune response by recognizing patterns presented by bacteria and other pathogens. These receptors have been implicated in the inflammatory response that contributes to gingivitis and periodontitis. Conflicting reports have suggested that variations in the genes encoding TLRs, particularly TLR2 and TLR4, may influence susceptibility to periodontitis. In this study, the contribution of variations in the genes encoding TLR2 and TLR4 in the context of...

  19. Structural relationship of the lipid A acyl groups to activation of murine Toll-like receptor 4 by lipopolysaccharides from pathogenic strains of Burkholderia mallei, Acinetobacter baumannii and Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Kirill V Korneev

    2015-11-01

    Full Text Available Toll-like receptor 4 (TLR4 is required for activation of innate immunity upon recognition of lipopolysaccharide (LPS of Gram-negative bacteria. The ability of TLR4 to respond to a particular LPS species is important since insufficient activation may not prevent bacterial growth while excessive immune reaction may lead to immunopathology associated with sepsis. Here we investigated the biological activity of LPS from Burkholderia mallei that causes glanders, and from the two well-known opportunistic pathogens Acinetobacter baumannii and Pseudomonas aeruginosa (causative agents of nosocomial infections. For each bacterial strain, R-form LPS preparations were purified by hydrophobic chromatography and the chemical structure of lipid A, an LPS structural component, was elucidated by HR-MALDI-TOF mass spectrometry. The biological activity of LPS samples was evaluated by their ability to induce production of proinflammatory cytokines, such as IL-6 and TNF, by bone marrow-derived macrophages (BMDM. Our results demonstrate direct correlation between the biological activity of LPS from these pathogenic bacteria and the extent of their lipid A acylation.

  20. Structural Relationship of the Lipid A Acyl Groups to Activation of Murine Toll-Like Receptor 4 by Lipopolysaccharides from Pathogenic Strains of Burkholderia mallei, Acinetobacter baumannii, and Pseudomonas aeruginosa

    Science.gov (United States)

    Korneev, Kirill V.; Arbatsky, Nikolay P.; Molinaro, Antonio; Palmigiano, Angelo; Shaikhutdinova, Rima Z.; Shneider, Mikhail M.; Pier, Gerald B.; Kondakova, Anna N.; Sviriaeva, Ekaterina N.; Sturiale, Luisa; Garozzo, Domenico; Kruglov, Andrey A.; Nedospasov, Sergei A.; Drutskaya, Marina S.; Knirel, Yuriy A.; Kuprash, Dmitry V.

    2015-01-01

    Toll-like receptor 4 (TLR4) is required for activation of innate immunity upon recognition of lipopolysaccharide (LPS) of Gram-negative bacteria. The ability of TLR4 to respond to a particular LPS species is important since insufficient activation may not prevent bacterial growth while excessive immune reaction may lead to immunopathology associated with sepsis. Here, we investigated the biological activity of LPS from Burkholderia mallei that causes glanders, and from the two well-known opportunistic pathogens Acinetobacter baumannii and Pseudomonas aeruginosa (causative agents of nosocomial infections). For each bacterial strain, R-form LPS preparations were purified by hydrophobic chromatography and the chemical structure of lipid A, an LPS structural component, was elucidated by HR-MALDI-TOF mass spectrometry. The biological activity of LPS samples was evaluated by their ability to induce production of proinflammatory cytokines, such as IL-6 and TNF, by bone marrow-derived macrophages. Our results demonstrate direct correlation between the biological activity of LPS from these pathogenic bacteria and the extent of their lipid A acylation. PMID:26635809

  1. Toll-like receptor-2 deficiency enhances non-alcoholic steatohepatitis

    Directory of Open Access Journals (Sweden)

    Brady Kristen

    2010-05-01

    Full Text Available Abstract Background Previously we reported that mice deficient in toll-like receptor 4 (TLR-4 signalling were protected from diet-induced non-alcoholic steatohepatitis (NASH. Another member of the toll-like receptor family, TLR-2, has been shown to play a role in lipid trafficking via uptake of diacylated lipoproteins. However, a role for TLR-2 in NASH has not been elucidated. The objectives of the current study were to examine the influence of dietary fat quality and TLR-2 on NASH pathogenesis. Methods Steatohepatitis was induced in male Db, C57BL/6 and TLR-2-/- mice by feeding an L-amino acid-defined diet that was deficient in methionine and choline (MCDD. Mice fed the base diet supplemented with methionine and choline (control diet; CD were used as controls. To determine the role of fat quality, MCDD was enriched with polyunsaturated corn oil (PUFA or coconut oil that is comprised mostly of saturated fat (SAFA; the total amount of each fat was 112.9 g/kg of diet. After 8 weeks of feeding CD or MCDD, hepatic steatosis, inflammation and necrosis were evaluated in histological sections. Total RNA was extracted from frozen liver samples and mRNA expression of TNFα, collagen α1, IL-10, peroxisome proliferator-activated receptor-γ (PPAR-γ, TLR-4, and CD14, was analyzed via real-time PCR. Protein levels of TLR-2 were analyzed by western blot. Results Panlobular macrovessicular steatosis and diffuse leukocyte infiltration were noted in PUFA-fed Db mice. Histological scores demonstrated significantly less steatosis, inflammation and necrosis in SAFA-fed mice of all mouse strains. However, compared to wild type mice, hepatocellular damage was notably more severe in TLR-2-/- mice. Consistent with histological findings, mRNA expression of TNFα was elevated by approximately 3-fold in TLR-2-/- mice; PPAR-γ expression was blunted in this strain compared to wild type. Expression of the matrix protein collagen αI was also significantly higher in TLR-2

  2. Toll-like receptors and cells migration%Toll样受体与细胞迁移

    Institute of Scientific and Technical Information of China (English)

    苏海英; 莫碧文

    2011-01-01

    The invasion of sensitive pathogens invade the body, and reproductive system encoded pattern recognition receptors recognize pathogens,thus start the innate immune system. Toll-like receptor (TLR) plays an important role in the immune system recognition of microbial pathogens thus is a regulating antigen receptor family. TLR are expressed on many immune and non immune cells while participate in a variety of cell migration, so they are closely related to movement and migration of cells.Activation of TLR induce a series of inflammatory mejiators,including cytokines,chemokines and so on,and result in strong biological effects. The most prominent biological function of TLR is on the one hand,they enhance the synthesis and release of cytokine and chemokine that trigger inflammation and cell effect,on the other hand, they promote the mature of antigen presenting cells that induce the acquired immune response. So TLR are the bridge of innate immunity and acquired immunity.%敏感性侵袭病原体侵入机体,生殖系编码模式识别受体识别病原体,由此启动先天免疫系统.Toll样受体家族(toll-like receptors,TLR)是在免疫系统特异性识别微生物病原体抗原中发挥重要调控作用的受体家族.TLR表达于许多的免疫和非免疫细胞,参与多种细胞迁移,与细胞的迁移性运动密切相关.活化TLR诱导产生一系列的炎症介质包括细胞因子、趋化因子等从而产生强有力的生物学效应.TLR最突出的生物学功能一方面促进细胞因子或趋化因子的合成与释放,引发炎症反应或细胞效应,另一方面是促进抗原递呈细胞的成熟,从而诱导机体的获得性免疫反应,因而是机体介导天然免疫转向获得性免疫的桥梁.

  3. Chapter 1. Overview of Toll-like receptors (TLRs) in the CNS

    OpenAIRE

    Kielian, Tammy

    2009-01-01

    Mammalian Toll-like receptors (TLRs) were first identified in 1997 based on their homology with Drosophila Toll, which mediates innate immunity in the fly. Over the past 8 years, the number of manuscripts describing TLR expression and function in the central nervous system (CNS) has been increasing steadily and expanding beyond their traditional roles in infectious diseases to neurodegenerative disorders and injury. Interest in the field serves as the impetus for this volume in the Current To...

  4. Novel Toll-like receptor-4 deficiency attenuates trastuzumab (Herceptin) induced cardiac injury in mice

    OpenAIRE

    Yousif Nasser; Al-amran Fadhil G

    2011-01-01

    Abstract Background Cardiac inflammation and generation of oxidative stress are known to contribute to trastuzumab (herceptin) induced cardiac toxicity. Toll-like receptors (TLRs) are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signaling, we investigated whether or not TLR4 is involved in trastuzumab induced cardiotoxicity. Methods Seven days after a single injection of herceptin (2 mg/kg; i.p.)...

  5. The role of toll-like receptor variants in acute anterior uveitis

    OpenAIRE

    Pratap, Divya S.; Lyndell L Lim; Wang, Jie Jin; Mackey, David A.; Kearns, Lisa S.; Stawell, Richard J.; ,; Kathryn P Burdon; Mitchell, Paul; Craig, Jamie E; Hall, Anthony J.; Hewitt, Alex W

    2011-01-01

    Purpose Acute anterior uveitis (AAU) is the most common form of uveitis; however, while it is presumed to have an immunological basis, the precise underlying etiology remains elusive. Toll-like receptors (TLRs) have a key role in linking innate and adaptive immunity, thereby forming a molecular bridge between microbial triggers and the development of AAU. The purpose of this study was to investigate the role of TLR2 and TLR4 gene polymorphisms in the pathogenesis of AAU. Methods The study com...

  6. Everolimus-Eluting Stents Reduce Monocyte Expression of Toll-Like Receptor 4

    OpenAIRE

    Mehriar Shokri; Bahador Bagheri; Alireza Garjani; Bahram Sohrabi; Afshin Habibzadeh; Babak Kazemi; Ali Akbar Movassaghpour

    2015-01-01

    Purpose: Toll-like receptors (TLR) are well known components of the innate immune system. Among them, TLR4 is related to the inflammatory processes involved in atherosclerotic plaque formation. Our purpose was to compare the monocytic expression of TLR4 following implantation of drug-eluting (DES) and bare stents (BMS). Methods: In this study, patients with chronic stable angina undergoing elective percutaneous coronary intervention (PCI) in ShahidMadani Heart Hospital, T...

  7. A conserved surface on Toll-like receptor 5 recognizes bacterial flagellin

    OpenAIRE

    Andersen-Nissen, Erica; Smith, Kelly D.; Bonneau, Richard; Strong, Roland K.; Aderem, Alan

    2007-01-01

    The molecular basis for Toll-like receptor (TLR) recognition of microbial ligands is unknown. We demonstrate that mouse and human TLR5 discriminate between different flagellins, and we use this difference to map the flagellin recognition site on TLR5 to 228 amino acids of the extracellular domain. Through molecular modeling of the TLR5 ectodomain, we identify two conserved surface-exposed regions. Mutagenesis studies demonstrate that naturally occurring amino acid variation in TLR5 residue 26...

  8. Toll-like receptor and tumour necrosis factor dependent endotoxin-induced acute lung injury

    Science.gov (United States)

    Togbe, Dieudonnée; Schnyder-Candrian, Silvia; Schnyder, Bruno; Doz, Emilie; Noulin, Nicolas; Janot, Laure; Secher, Thomas; Gasse, Pamela; Lima, Carla; Coelho, Fernando Rodrigues; Vasseur, Virginie; Erard, François; Ryffel, Bernhard; Couillin, Isabelle; Moser, Rene

    2007-01-01

    Recent studies on endotoxin/lipopolysaccharide (LPS)-induced acute inflammatory response in the lung are reviewed. The acute airway inflammatory response to inhaled endotoxin is mediated through Toll-like receptor 4 (TLR4) and CD14 signalling as mice deficient for TLR4 or CD14 are unresponsive to endotoxin. Acute bronchoconstriction, tumour necrosis factor (TNF), interleukin (IL)-12 and keratinocyte-derived chemokine (KC) production, protein leak and neutrophil recruitment in the lung are abrogated in mice deficient for the adaptor molecules myeloid differentiation factor 88 (MyD88) and Toll/Interleukin-1 receptor (TIR)-domain-containing adaptor protein (TIRAP), but independent of TIR-domain-containing adaptor-inducing interferon-beta (TRIF). In particular, LPS-induced TNF is required for bronchoconstriction, but dispensable for inflammatory cell recruitment. Lipopolysaccharide induces activation of the p38 mitogen-activated protein kinase (MAPK). Inhibition of pulmonary MAPK activity abrogates LPS-induced TNF production, bronchoconstriction, neutrophil recruitment into the lungs and broncho-alveolar space. In conclusion, TLR4-mediated, bronchoconstriction and acute inflammatory lung pathology to inhaled endotoxin are dependent on TLR4/CD14/MD2 expression using the adapter proteins TIRAP and MyD88, while TRIF, IL-1R1 or IL-18R signalling pathways are dispensable. Further downstream in this axis of signalling, TNF blockade reduces only acute bronchoconstriction, while MAPK inhibition abrogates completely endotoxin-induced inflammation. PMID:18039275

  9. Molecular and cellular dynamics of the Toll-like receptor 4 pathway.

    Directory of Open Access Journals (Sweden)

    Nick eGay

    2014-10-01

    Full Text Available As well as being the primary signaling receptor for bacterial endotoxin or lipopolysaccharide Toll-like receptor 4 function is modulated by numerous factors not only in the context of microbial pathogenesis but also autoimmune and allergic diseases. TLR4 is subject to multiple levels of endogenous control and regulation from biosynthesis and trafficking to signal transduction and degradation. On the other hand regulation of TLR4 activity breaks down during Gram –ve sepsis leading to systemic damage, multi organ failure and death. In this article we review how TLR4 traffics from the early secretory pathway, the cis/trans Golgi to the cell surface and endolysosomal compartments. We will present evidence about how these processes influence signaling and can potentially lead to ligand independent constitutive activation that may contribute to pathogenesis in sepsis. We will also discuss how sustained signaling may be coupled to endocytosis and consider the potential molecular mechanisms of immuno-modulators that modify TLR4 signalling function including the cat allergen FelD1 and endogenous protein ligands such as the extracellular matrix protein tenascin C and calprotectin (MRP8/14.

  10. Discovery of toll-like receptor 13 exists in the teleost fish: Miiuy croaker (Perciformes, Sciaenidae).

    Science.gov (United States)

    Wang, Yanjin; Bi, Xueyi; Chu, Qing; Xu, Tianjun

    2016-08-01

    Toll-like receptors (TLRs) play an indispensable role in the immune response for pathogen recognition and triggering not only innate immunity but also adaptive immunity. Here we report the TLR13 homologue, one member of TLRs, in Perciformes (especially Sciaenidae). And we used the miiuy croaker as represented species for further functional experiments. Former study reported the TLR13 only expressed in murine, and we are the first to report the teleost TLR13 (mmiTLR13). MmiTLR13 expressed highly in immune defense related tissues, such as the liver, spleen, and kidney, and Vibrio anguillarum or poly(I:C) infection showed the immune response of mmiTLR13. Further luciferase reporter assays showed the ability for activation of ISRE luciferase reporter, but it failed to active NF-κB. And further gene silence by short hairpin RNA (shRNA) confirmed the results. Immunofluorescence of mmiTLR13 presents the cytoplasmic distribution in Hela cell. In addition, the Toll/interleukin 1 receptor (TIR) domain of mammal TLR5 exhibits high identity with TLR13, which indicated the high homology between TLR5 and TLR13. These findings will lay the fundamental cornerstone for further research of teleost TLR13 and expand the horizon for better understand the teleost TLRs system. PMID:26952767

  11. Toll-like receptor cascade and gene polymorphism in host–pathogen interaction in Lyme disease

    Science.gov (United States)

    Rahman, Shusmita; Shering, Maria; Ogden, Nicholas H; Lindsay, Robbin; Badawi, Alaa

    2016-01-01

    Lyme disease (LD) risk occurs in North America and Europe where the tick vectors of the causal agent Borrelia burgdorferi sensu lato are found. It is associated with local and systemic manifestations, and has persistent posttreatment health complications in some individuals. The innate immune system likely plays a critical role in both host defense against B. burgdorferi and disease severity. Recognition of B. burgdorferi, activation of the innate immune system, production of proinflammatory cytokines, and modulation of the host adaptive responses are all initiated by Toll-like receptors (TLRs). A number of Borrelia outer-surface proteins (eg, OspA and OspB) are recognized by TLRs. Specifically, TLR1 and TLR2 were identified as the receptors most relevant to LD. Several functional single-nucleotide polymorphisms have been identified in TLR genes, and are associated with varying cytokines types and synthesis levels, altered pathogen recognition, and disruption of the downstream signaling cascade. These single-nucleotide polymorphism-related functional alterations are postulated to be linked to disease development and posttreatment persistent illness. Elucidating the role of TLRs in LD may facilitate a better understanding of disease pathogenesis and can provide an insight into novel therapeutic targets during active disease or postinfection and posttreatment stages. PMID:27330321

  12. DMPD: Toll-like receptors, RIG-I-like RNA helicases and the antiviral innate immuneresponse. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17667934 Toll-like receptors, RIG-I-like RNA helicases and the antiviral innate imm...g) (.svg) (.html) (.csml) Show Toll-like receptors, RIG-I-like RNA helicases and the antiviral innate immune...response. PubmedID 17667934 Title Toll-like receptors, RIG-I-like RNA helicases and the anti

  13. DMPD: Critical role of toll-like receptors and nucleotide oligomerisation domain inthe regulation of health and disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17535871 Critical role of toll-like receptors and nucleotide oligomerisation domain... Endocrinol. 2007 Jun;193(3):323-30. (.png) (.svg) (.html) (.csml) Show Critical role of toll-like receptors...bmedID 17535871 Title Critical role of toll-like receptors and nucleotide oligomerisation domain inthe regul

  14. DMPD: Toll-like receptors: from the discovery of NFkappaB to new insights intotranscriptional regulations in innate immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16930560 Toll-like receptors: from the discovery of NFkappaB to new insights intotr...2-13. Epub 2006 Aug 22. (.png) (.svg) (.html) (.csml) Show Toll-like receptors: from the discovery of NFkappaB to new...6930560 Title Toll-like receptors: from the discovery of NFkappaB to new insights intotranscriptional regula

  15. RNA Interference of Interferon Regulatory Factor-1 Gene Expression in THP-1 Cell Line Leads to Toll-Like Receptor-4 Overexpression/Activation As Well As Up-modulation of Annexin-II

    Directory of Open Access Journals (Sweden)

    Christos I. Maratheftis

    2007-12-01

    Full Text Available Interferon regulatory factor-1 (IRF-1 is a candidate transcription factor for the regulation of the Toll-like receptor-4 (TLR-4 gene. Using a small interfering RNAbased (siRNA process to silence IRF-1 gene expression in the leukemic monocytic cell line THP-1, we investigated whether such a modulation would alter TLR-4 expression and activation status in these cells. The siIRF-1 cells expressed elevated levels of TLR-4 mRNA and protein compared to controls by 90% and 77%, respectively. ICAM.1 protein expression and apoptosis levels were increased by 8.35- and 4.25-fold, respectively. The siIRF-1 cells overexpressed Bax mRNA compared to controls. Proteomic analysis revealed upmodulation of the Annexin-II protein in siIRF-1 THP-1 cells. Myelodysplastic syndrome (MDS patients with an absence of full-length IRF-1 mRNA also overexpressed Annexin-II. It is plausible that this overexpression may lead to the activation of TLR-4 contributing to the increased apoptosis characterizing MDS.

  16. Cervical Cancer Cell Supernatants Induce a Phenotypic Switch from U937-Derived Macrophage-Activated M1 State into M2-Like Suppressor Phenotype with Change in Toll-Like Receptor Profile

    Science.gov (United States)

    Sánchez-Reyes, Karina; Bravo-Cuellar, Alejandro; Hernández-Flores, Georgina; Lerma-Díaz, José Manuel; Jave-Suárez, Luis Felipe; Gómez-Lomelí, Paulina; de Celis, Ruth; Aguilar-Lemarroy, Adriana; Domínguez-Rodríguez, Jorge Ramiro; Ortiz-Lazareno, Pablo Cesar

    2014-01-01

    Cervical cancer (CC) is the second most common cancer among women worldwide. Infection with human papillomavirus (HPV) is the main risk factor for developing CC. Macrophages are important immune effector cells; they can be differentiated into two phenotypes, identified as M1 (classically activated) and M2 (alternatively activated). Macrophage polarization exerts profound effects on the Toll-like receptor (TLR) profile. In this study, we evaluated whether the supernatant of human CC cells HeLa, SiHa, and C-33A induces a shift of M1 macrophage toward M2 macrophage in U937-derived macrophages. Results. The results showed that soluble factors secreted by CC cells induce a change in the immunophenotype of macrophages from macrophage M1 into macrophage M2. U937-derived macrophages M1 released proinflammatory cytokines and nitric oxide; however, when these cells were treated with the supernatant of CC cell lines, we observed a turnover of M1 toward M2. These cells increased CD163 and IL-10 expression. The expression of TLR-3, -7, and -9 is increased when the macrophages were treated with the supernatant of CC cells. Conclusions. Our result strongly suggests that CC cells may, through the secretion of soluble factors, induce a change of immunophenotype M1 into M2 macrophages. PMID:25309919

  17. Cervical Cancer Cell Supernatants Induce a Phenotypic Switch from U937-Derived Macrophage-Activated M1 State into M2-Like Suppressor Phenotype with Change in Toll-Like Receptor Profile

    Directory of Open Access Journals (Sweden)

    Karina Sánchez-Reyes

    2014-01-01

    Full Text Available Cervical cancer (CC is the second most common cancer among women worldwide. Infection with human papillomavirus (HPV is the main risk factor for developing CC. Macrophages are important immune effector cells; they can be differentiated into two phenotypes, identified as M1 (classically activated and M2 (alternatively activated. Macrophage polarization exerts profound effects on the Toll-like receptor (TLR profile. In this study, we evaluated whether the supernatant of human CC cells HeLa, SiHa, and C-33A induces a shift of M1 macrophage toward M2 macrophage in U937-derived macrophages. Results. The results showed that soluble factors secreted by CC cells induce a change in the immunophenotype of macrophages from macrophage M1 into macrophage M2. U937-derived macrophages M1 released proinflammatory cytokines and nitric oxide; however, when these cells were treated with the supernatant of CC cell lines, we observed a turnover of M1 toward M2. These cells increased CD163 and IL-10 expression. The expression of TLR-3, -7, and -9 is increased when the macrophages were treated with the supernatant of CC cells. Conclusions. Our result strongly suggests that CC cells may, through the secretion of soluble factors, induce a change of immunophenotype M1 into M2 macrophages.

  18. A new Vitreoscilla filiformis extract grown on spa water-enriched medium activates endogenous cutaneous antioxidant and antimicrobial defenses through a potential Toll-like receptor 2/protein kinase C, zeta transduction pathway

    Directory of Open Access Journals (Sweden)

    Mahe YF

    2013-08-01

    Full Text Available Yann F Mahe,1 Marie-Jesus Perez,1 Charlotte Tacheau,1 Chantal Fanchon,2 Richard Martin,3 Françoise Rousset,1 Sophie Seite4 1L’Oreal Research and Innovation, Clichy, 2L’Oréal Research and Innovation, Chevilly Larue, 3L’Oréal Research and Innovation Tours, 4La Roche-Posay Pharmaceutical Laboratories, Asnières, France Abstract: Vitreoscilla filiformis (VF biomass (VFB has been widely used in cosmetic preparations and shown to modulate the major inducible free-radical scavenger mitochondrial superoxide dismutase in skin cells. By adding La Roche-Posay (LRP thermal spring water to the VF culture medium, we obtained a biomass (LRP-VFB with a similar mitochondrial superoxide dismutase activation capacity to VF. Also, the new biomass more powerfully stimulated mRNA expression and antimicrobial peptides in reconstructed epidermis. Interestingly, a predictive computer model that analyzed transducing events within skin epidermal cells suggested that this protective activity may involve the Toll-like receptor 2/protein kinase C, zeta transduction pathway. Protein kinase C, zeta inhibition was effectively shown to abolish VFB-induced gene stimulation and confirmed this hypothesis. This thus opens new avenues for investigation into the improvement of skin homeostatic defense in relation to the control of its physiological microbiota and innate immunity. Keywords: innate skin defenses, TLR2, PKCz, La Roche-Posay, mitochondrial superoxide dismutase, SOD2

  19. Toll-like receptor polymorphisms, inflammatory and infectious diseases, allergies, and cancer.

    Science.gov (United States)

    Medvedev, Andrei E

    2013-09-01

    Toll-like receptors (TLRs) are germ-line-encoded innate immune sensors that recognize conserved microbial structures and host alarmins and signal expression of MHC proteins, costimulatory molecules, and inflammatory mediators by macrophages, neutrophils, dendritic cells, and other cell types. These processes activate immediate and early mechanisms of innate host defense, as well as initiate and orchestrate adaptive immune responses. Several single-nucleotide polymorphisms (SNPs) within the TLR genes have been associated with altered susceptibility to infectious, inflammatory, and allergic diseases, and have been found to play a role in tumorigenesis. Critical advances in our understanding of innate immune functions and genome-wide association studies (GWAS) have uncovered complex interactions of genetic polymorphisms within TLRs and environmental factors. However, conclusions obtained in the course of such analyses are restricted by limited power of many studies that is likely to explain controversial findings. Further, linkages to certain ethnic backgrounds, gender, and the presence of multigenic effects further complicate the interpretations of how the TLR SNPs affect immune responses. For many TLRs, the molecular mechanisms by which SNPs impact receptor functions remain unknown. In this review, I have summarized current knowledge about the TLR polymorphisms, their impact on TLR signaling, and associations with various inflammatory, infectious, allergic diseases and cancers, and discussed the directions of future scientific research.

  20. Role of Toll-like receptors in Helicobacter pylori infection and immunity.

    Science.gov (United States)

    Smith, Sinéad M

    2014-08-15

    The gram-negative bacterium Helicobacter pylori (H. pylori) infects the stomachs of approximately half of the world's population. Although infection induces an immune response that contributes to chronic gastric inflammation, the response is not sufficient to eliminate the bacterium. H. pylori infection causes peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Disease outcome is linked to the severity of the host inflammatory response. Gastric epithelial cells represent the first line of innate immune defence against H. pylori, and respond to infection by initiating numerous cell signalling cascades, resulting in cytokine induction and the subsequent recruitment of inflammatory cells to the gastric mucosa. Pathogen recognition receptors of the Toll-like receptor (TLR) family mediate many of these cell signalling events. This review discusses recent findings on the role of various TLRs in the recognition of H. pylori in distinct cell types, describes the TLRs responsible for the recognition of individual H. pylori components and outlines the influence of innate immune activation on the subsequent development of the adaptive immune response. The mechanistic identification of host mediators of H. pylori-induced pathogenesis has the potential to reveal drug targets and opportunities for therapeutic intervention or prevention of H. pylori-associated disease by means of vaccines or immunomodulatory therapy. PMID:25133016

  1. Maternal endotoxin-induced fetal growth restriction in rats: Fetal responses in toll-like receptor

    Directory of Open Access Journals (Sweden)

    Banun Kusumawardani

    2012-09-01

    Full Text Available Background: Porphyromonas gingivalis as a major etiology of periodontal disease can produce virulence factor, lipopolysaccharide/LPS, which is expected to play a role in the intrauterine fetal growth. Trophoblast at the maternal-fetal interface actively participates in response to infection through the expression of a family of natural immune receptors, toll-like receptor (TLR. Purpose: the aims of study were to identify endotoxin concentration in maternal blood serum of Porphyromonas gingivalis-infected pregnant rats, to characterize the TLR-4 expression in trophoblast cells, and to determine its effect on fetal growth. Methods: Female rats were infected with live-Porphyromonas gingivalis at concentration of 2 x 109 cells/ml into subgingival sulcus area of the maxillary first molar before and/or during pregnancy. They were sacrified on 14th and 20th gestational day. Fetuses were evaluated for weight and length. Endotoxin was detected by limulus amebocyte lysate assay in the maternal blood serum. The TLR-4 expression in trophoblast cells was detected by immunohistochemistry. Inflammatory Role of Toll-Like Receptors in Human and Murine Adipose Tissue

    Directory of Open Access Journals (Sweden)

    Odile Poulain-Godefroy

    2010-01-01

    Full Text Available It was recently demonstrated that TLR4 activation via dietary lipids triggers inflammatory pathway and alters insulin responsiveness in the fat tissue during obesity. Here, we question whether other TLR family members could participate in the TLR-mediated inflammatory processes occurring in the obese adipose tissue. We thus studied the expression of TLR1, TLR2, TLR4, and TLR6 in adipose tissue. These receptors are expressed in omental and subcutaneous human fat tissue, the expression being higher in the omental tissue, independently of the metabolic status of the subject. We demonstrated a correlation of TLRs expression within and between each depot suggesting a coregulation. Murine 3T3-L1 preadipocyte cells stimulated with Pam3CSK4 induced the expression of some proinflammatory markers. Therefore, beside TLR4, other toll-like receptors are differentially expressed in human fat tissue, and functional in an adipocyte cell line, suggesting that they might participate omental adipose tissue-related inflammation that occurs in obesity.

  2. Role of Toll-like receptors in Helicobacter pylori infection and immunity

    Institute of Scientific and Technical Information of China (English)

    Sinéad; M; Smith

    2014-01-01

    The gram-negative bacterium Helicobacter pylori(H. pylori) infects the stomachs of approximately half of the world’s population. Although infection induces an immune response that contributes to chronic gastric inflammation, the response is not sufficient to eliminate the bacterium. H. pylori infection causes peptic ulcers, gastric cancer and mucosa-associated lymphoid tissue lymphoma. Disease outcome is linked to the severity of the host inflammatory response. Gastric epithelial cells represent the first line of innate immune defence against H. pylori, and respond to infection by initiating numerous cell signalling cascades, resulting in cytokine induction and the subsequent recruitment of inflamma-tory cells to the gastric mucosa. Pathogen recognition receptors of the toll-like receptor(TLR) family mediate many of these cell signalling events. This review dis-cusses recent findings on the role of various TLRs in the recognition of H. pylori in distinct cell types, describes the TLRs responsible for the recognition of individual H. pylori components and outlines the influence of innate immune activation on the subsequent development of the adaptive immune response. The mechanistic iden-tification of host mediators of H. pylori-induced patho-genesis has the potential to reveal drug targets and opportunities for therapeutic intervention or prevention of H. pylori-associated disease by means of vaccines or immunomodulatory therapy.

  3. Emerging role of Toll-like receptors in the control of pain and itch

    Institute of Scientific and Technical Information of China (English)

    Tong Liu; Yong-Jing Gao; Ru-Rong Ji

    2012-01-01

    Toll-like receptors (TLRs) are germline-encoded pattern-recognition receptors that initiate innate immune responses by recognizing molecular structures shared by a wide range of pathogens,known as pathogen-associated molecular patterns (PAMPs).After tissue injury or cellular stress,TLRs also detect endogenous ligands known as danger-associated molecular patterns (DAMPs).TLRs are expressed in both non-neuronal and neuronal cell types in the central nervous system (CNS) and contribute to both infectious and non-infectious disorders in the CNS.Following tissue insult and nerve injury,TLRs (such as TLR2,TLR3,and TLR4) induce the activation of microglia and astrocytes and the production of the proinflammatory cytokines in the spinal cord,leading to the development and maintenance of inflammatory pain and neuropathic pain.In particular,primary sensory neurons,such as nociceptors,express TLRs (e.g.,TLR4 and TLR7) to sense exogenous PAMPs and endogenous DAMPs released after tissue injury and cellular stress.These neuronal TLRs are new players in the processing of pain and itch by increasing the excitability of primary sensory neurons.Given the prevalence of chronic pain and itch and the suffering of affected people,insights into TLR signaling in the nervous system will open a new avenue for the management of clinical pain and itch.

  4. Role of Toll-like receptors in health and diseases of gastrointestinal tract

    Institute of Scientific and Technical Information of China (English)

    Greg Harris; Rhonda KuoLee; Wangxue Chen

    2006-01-01

    The human gastrointestinal (GI) tract is colonized by non-pathogenic commensal microflora and frequently exposed to many pathogenic organisms.For the maintenance of GI homeostasis, the host must discriminate between pathogenic and non-pathogenic organisms and initiate effective and appropriate immune and inflammatory responses. Mammalian toll-like receptors (TLRs) are members of the pattern-recognition receptor (PRR) family that plays a central role in the initiation of innate cellular immune responses and the subsequent adaptive immune responses to microbial pathogens. Recent studies have shown that gastrointestinal epithelial cells express almost all TLR subtypes characterized to date and that the expression and activation of TLRs in the GI tract are tightly and coordinately regulated. This review summarizes the current understanding of the crucial dual roles of TLRs in the development of host innate and adaptive immune responses to GI infections and the maintenance of the immune tolerance to commensal bacteria through down-regulation of surface expression of TLRs in intestinal epithelial cells.

  5. Role of Toll-like receptors in lung innate defense against invasive aspergillosis. Distinct impact in immunocompetent and immunocompromized hosts.

    OpenAIRE

    Chignard, Michel; Balloy, Viviane; Sallenave, Jean-Michel; Si-Tahar, Mustapha

    2007-01-01

    Toll-like receptors are key to pathogen recognition by a host and to the subsequent triggering of an innate immune response. Experimental and clinical evidence shows that defects in Toll-like receptors or in signaling pathways downstream from these receptors render hosts susceptible to various types of infection, including aspergillosis. Patients receiving an immunosuppressive regimen, including corticosteroid therapy or cytotoxic chemotherapy, are also susceptible to infections. Aspergillus ...

  6. H1 antihistamines in allergic rhinitis: The molecular pathways of interleukin and toll - like receptor systems

    Directory of Open Access Journals (Sweden)

    Jonny Karunia Fajar

    2016-03-01

    Full Text Available The complex interaction between inflammatory mediators in allergic rhinitis (AR is determined by the role of genetic polymorphisms, including interleukin (IL and toll-like receptor (TLR genes. This study aimed to discuss the effects of H1-antihistamines on IL and TLR systems. Several ILs involved in AR pathogenesis are: IL-4 (rs2243250, rs1800925, rs1801275, rs2227284, rs2070874, IL-6 (rs1800795, rs1800797, IL-10 (rs1800871, rs1800872, IL-12R (rs438421, IL-13 (rs1800925, rs20541, IL-17 (rs3819024, IL-18 (rs360721, rs360718, rs360717, rs187238, IL-23R (rs7517847, and IL-27 (rs153109, rs17855750. In the IL system, histamines stimulate the IL production in Type 2 helper T (Th2 cells through protein kinase A (PKA, janus kinase-signal transducer and activator of transcription (JAK-STAT pathway, and the activation of H1-histamine receptor and histidine decarboxylase (HDC genes. On contrary, antihistamines down-regulate the H1-histamine receptor gene expression through the transcription suppression of HDC and IL genes and suppress histamine basal signaling through the inverse agonistic activity. TLRs involved in AR pathogenesis are TLR2 (rs4696480, rs3804099, rs5743708, TLR4 (rs4986790, TLR6 (rs2381289, TLR7 (rs179008, rs5935438, TRL8 (rs2407992, rs5741883, rs17256081, rs4830805, rs3788935, rs178998, and TLR10 (rs11466651. In the TLR system, histamines trigger the TLR expression by stimulating interferon-γ (IFN-γ to up-regulate mast cells and by stimulating receptor-interacting protein (RIP to activate IκB kinase-β. Contrastingly, antihistamines suppress TIR-domain-containing adaptor protein inducing IFN-β (TRIF and RIP protein and thus inhibit the expression of TLR. In addition, several studies indicated that H1-antihistamines inhibit the IL and TLR systems indirectly.

  7. Nfkb1 activation by the E26 transformation-specific transcription factors PU.1 and Spi-B promotes Toll-like receptor-mediated splenic B cell proliferation.

    Science.gov (United States)

    Li, Stephen K H; Abbas, Ali K; Solomon, Lauren A; Groux, Gaëlle M N; DeKoter, Rodney P

    2015-05-01

    Generation of antibodies against T-independent and T-dependent antigens requires Toll-like receptor (TLR) engagement on B cells for efficient responses. However, the regulation of TLR expression and responses in B cells is not well understood. PU.1 and Spi-B (encoded by Sfpi1 and Spib, respectively) are transcription factors of the E26 transformation-specific (ETS) family and are important for B cell development and function. It was found that B cells from mice knocked out for Spi-B and heterozygous for PU.1 (Sfpi1(+/-) Spib(-/-) [PUB] mice) proliferated poorly in response to TLR ligands compared to wild-type (WT) B cells. The NF-κB family member p50 (encoded by Nfkb1) is required for lipopolysaccharide (LPS) responsiveness in mice. PUB B cells expressed reduced Nfkb1 mRNA transcripts and p50 protein. The Nfkb1 promoter was regulated directly by PU.1 and Spi-B, as shown by reporter assays and chromatin immunoprecipitation analysis. Occupancy of the Nfkb1 promoter by PU.1 was reduced in PUB B cells compared to that in WT B cells. Finally, infection of PUB B cells with a retroviral vector encoding p50 substantially restored proliferation in response to LPS. We conclude that Nfkb1 transcriptional activation by PU.1 and Spi-B promotes TLR-mediated B cell proliferation.

  8. Cloning, expression and functional analysis of the duck Toll-like receptor 5 (TLR5) gene.

    Science.gov (United States)

    Cheng, Yuqiang; Sun, Yingjie; Wang, Hengan; Shi, Shuduan; Yan, Yaxian; Li, Jing; Ding, Chan; Sun, Jianhe

    2015-01-01

    Toll-like receptor 5 (TLR5) is responsible for the recognition of bacterial flagellin in vertebrates. In the present study, the first TLR5 gene in duck was cloned. The open reading frame (ORF) of duck TLR5 (dTLR5) cDNA is 2580 bp and encodes a polypeptide of 859 amino acids. We also cloned partial sequences of myeloid differentiation factor 88, 2'-5'-oligoadenylate synthetase (OAS), and myxovirus resistance (Mx) genes from duck. dTLR5 mRNA was highly expressed in the bursa of Fabricius, spleen, trachea, lung, jejunum, rectum, and skin; moderately expressed in the muscular and glandular tissues, duodenum, ileum, caecum, and pancreas; and minimally expressed in the heart, liver, kidney, and muscle. DF-1 or HeLa cells transfected with DNA constructs encoding dTLR5 can activate NF-κB leading to the activation of interleukin-6 (IL-6) promoter. When we challenged ducks with a Herts33 Newcastle disease virus (NDV), mRNA transcription of the antiviral molecules Mx, Double stranded RNA activated protein kinase (PKR), and OAS was up-regulated in the liver, lung, and spleen 1 and 2 days post-inoculation. PMID:25269719

  9. Toll-like receptor 7 affects the pathogenesis of non-alcoholic fatty liver disease

    Science.gov (United States)

    Kim, Sokho; Park, Surim; Kim, Bumseok; Kwon, Jungkee

    2016-01-01

    Recently, a possible link between toll-like receptor 7 (TLR7) and liver disease was suggested, although it was limited to fibrosis. Based on this report, we investigated whether TLR7 has a pivotal role in non-alcoholic fatty liver disease (NAFLD). The TLR7 signaling pathway, which is activated by imiquimod (TLR7 ligand) naturally, induced autophagy and released insulin-like growth factor 1 (IGF-1) into medium from hepatocytes. Lipid accumulation induced by unsaturated fatty acid (UFA; arachidonic acid:oleic acid = 1:1) in hepatocytes, was attenuated in TLR7 and autophagy activation. Interestingly, TLR7 activation attenuated UFA-induced lipid peroxidation products, such as malondialdehyde (MDA) and 4-Hydroxy-2-Nonenal (4-HNE). To clarify a possible pathway between TLR7 and lipid peroxidation, we treated hepatocytes with MDA and 4-HNE. MDA and 4-HNE induced 2-folds lipid accumulation in UFA-treated hepatocytes via blockade of the TLR7 signaling pathway’s IGF-1 release compared to only UFA-treated hepatocytes. In vivo experiments carried out with TLR7 knockout mice produced results consistent with in vitro experiments. In conclusion, TLR7 prevents progression of NAFLD via induced autophagy and released IGF-1 from liver. These findings suggest a new therapeutic strategy for the treatment of NAFLD. PMID:27279075

  10. Bupleurum polysaccharides attenuates lipopolysaccharide-induced inflammation via modulating Toll-like receptor 4 signaling.

    Directory of Open Access Journals (Sweden)

    Jian Wu

    Full Text Available BACKGROUND: Bupleurum polysaccharides (BPs, isolated from Bupleurum smithii var. parvifolium, possesses immunomodulatory activity, particularly on inflammation. Bacterial endotoxin lipopolysaccharide (LPS triggers innate immune responses through Toll-like receptor 4 (TLR4 on host cell membrane. The present study was performed to evaluate whether the therapeutic efficacy of BPs on suppression of LPS's pathogenecity could be associated with the modulating of TLR4 signaling pathway. METHODOLOGY/PRINCIPAL FINDINGS: LPS stimulated expression and activation of factors in the TLR4 signaling system, including TLR4, CD14, IRAK4, TRAF6, NF-κB, and JNK, determined using immunocytochemical and/or Western blot assays. BPs significantly inhibited these effects of LPS. LPS increased pro-inflammatory cytokines (TNF-α, IL-6, IL-1β, IL-12p40, and IFN-β and NO production, evaluated using ELISA and Griess reaction assays, respectively. BPs antagonized these effects of LPS. Interestingly, BPs alone augmented secretion of some pro-inflammatory cytokines of non-LPS stimulated macrophages and enhanced phagocytic activity towards fluorescent E.coli bioparticles. In a rat model of acute lung injury (ALI with pulmonary hemorrhage and inflammation, BPs ameliorated lung injuries and suppressed TLR4 expression. SIGNIFICANCE: The therapeutic properties of BPs in alleviating inflammatory diseases could be attributed to its inhibitory effect on LPS-mediated TLR4 signaling.

  11. Dynamic evolution of toll-like receptor multigene families in echinoderms.

    Science.gov (United States)

    Buckley, Katherine M; Rast, Jonathan P

    2012-01-01

    The genome sequence of the purple sea urchin, Strongylocentrotus purpuratus, a large and long-lived invertebrate, provides a new perspective on animal immunity. Analysis of this genome uncovered a highly complex immune system in which the gene families that encode homologs of the pattern recognition receptors that form the core of vertebrate innate immunity are encoded in large multigene families. The sea urchin genome contains 253 Toll-like receptor (TLR) sequences, more than 200 Nod-like receptors and 1095 scavenger receptor cysteine-rich domains, a 10-fold expansion relative to vertebrates. Given their stereotypic protein structure and simple intron-exon architecture, the TLRs are the most tractable of these families for more detailed analysis. A role for these receptors in immune defense is suggested by their similarity to TLRs in other organisms, sequence diversity, and expression in immunologically active tissues, including phagocytes. The complexity of the sea urchin TLR multigene families is largely derived from expansions independent of those in vertebrates and protostomes, although a small family of TLRs with structure similar to that of Drosophila Toll can be traced to an ancient eumetazoan ancestor. Several other echinoderm sequences are now available, including Lytechinus variegatus, as well as partial sequences from two other sea urchin species. Here, we present an analysis of the invertebrate deuterostome TLRs with emphasis on the echinoderms. Representatives of most of the S. purpuratus TLR subfamilies and homologs of the mccTLR sequences are found in L. variegatus, although the L. variegatus TLR gene family is notably smaller (68 TLR sequences). The phylogeny of these genes within sea urchins highlights lineage-specific expansions at higher resolution than is evident at the phylum level. These analyses identify quickly evolving TLR subfamilies that are likely to have novel immune recognition functions and other, more stable, subfamilies that may

  12. Bovine colostrum enhances natural killer cell activity and immune response in a mouse model of influenza infection and mediates intestinal immunity through toll-like receptors 2 and 4.

    Science.gov (United States)

    Wong, Eric B; Mallet, Jean-François; Duarte, Jairo; Matar, Chantal; Ritz, Barry W

    2014-04-01

    Oral administration of bovine colostrum affects intestinal immunity, including an increased percentage of natural killer (NK) cells. However, effects on NK cell cytotoxic activity and resistance to infection as well as a potential mechanism remain unclear. Therefore, we investigated the effects of bovine colostrum (La Belle, Inc, Bellingham, WA) on the NK cytotoxic response to influenza infection and on toll-like receptor (TLR) activity in a primary intestinal epithelial cell culture. We hypothesized that colostrum would increase NK cell activity and that TLR-2 and TLR-4 blocking would reduce interleukin 6 production by epithelial cells in response to contact stimulation with colostrum. Four-month-old female C57BL/6 mice were supplemented with 1 g of colostrum per kilogram of body weight before and after infection with influenza A virus (H1N1). Animals were assessed for weight loss, splenic NK cell activity, and lung virus titers. Colostrum-supplemented mice demonstrated less reduction in body weight after influenza infection, indicating a less severe infection, increased NK cell cytotoxicity, and less virus burden in the lungs compared with controls. Colostrum supplementation enhanced NK cell cytotoxicity and improved the immune response to primary influenza virus infection in mice. To investigate a potential mechanism, a primary culture of small intestine epithelial cells was then stimulated with colostrum. Direct activation of epithelial cells resulted in increased interleukin 6 production, which was inhibited with TLR-2 and TLR-4 blocking antibodies. The interaction between colostrum and immunity may be dependent, in part, on the interaction of colostrum components with innate receptors at the intestinal epithelium, including TLR-2 and TLR-4. PMID:24774068

  13. The CNS role of Toll-like receptor 4 in innate neuroimmunity and painful neuropathy.

    Science.gov (United States)

    Tanga, Flobert Y; Nutile-McMenemy, Nancy; DeLeo, Joyce A

    2005-04-19

    Neuropathic pain remains a prevalent and persistent clinical problem because of our incomplete understanding of its pathogenesis. This study demonstrates for the first time, to our knowledge, a critical role for CNS innate immunity by means of microglial Toll-like receptor 4 (TLR4) in the induction phase of behavioral hypersensitivity in a mouse and rat model of neuropathy. We hypothesized that after L5 nerve transection, CNS neuroimmune activation and subsequent cytokine expression are triggered by the stimulation of microglial membrane-bound TLR4. To test this hypothesis, experiments were undertaken to assess tactile and thermal hypersensitivity in genetically altered (i.e., TLR4 knockout and point-mutant) mice after L5 nerve transection. In a complementary study, TLR4 antisense oligodeoxynucleotide (ODN) was administered intrathecally to L5 spinal nerve injured rats to reduce the expression of spinal TLR4. Both the genetically altered mice and the rats treated with TLR4 antisense ODN displayed significantly attenuated behavioral hypersensitivity and decreased expression of spinal microglial markers and proinflammatory cytokines as compared with their respective control groups. This finding shows that TLR4 contributes to the initiation of CNS neuroimmune activation after L5 nerve transection. Further understanding of this early, specific, innate CNS/microglial response and how it leads to sustained glial/neuronal hypersensitivity may point to new therapies for the prevention and treatment of neuropathic pain syndromes. PMID:15809417

  14. The emerging role of toll-like receptor pathways in surgical diseases.

    LENUS (Irish Health Repository)

    Romics, Laszlo Jr

    2012-02-03

    OBJECTIVE: To outline the emerging significance of Toll-like receptor (TLR) signaling pathways in surgical diseases. DATA SOURCES: A systematic review of the literature was undertaken by searching the MEDLINE database for the period 1966 to 2005 without language restriction. STUDY SELECTION: Original or review articles that described experimental data on the activation of TLR signaling pathways in surgically relevant diseases were selected for inclusion in this review. DATA EXTRACTION: Data were obtained from peer-reviewed articles and references. DATA SYNTHESIS: The role of TLRs in the recognition of pathogens renders them a key figure in the activation of both innate and adaptive immune responses during sepsis. However, emerging evidence points to fundamentally important roles in ulcerative colitis, Crohn disease, and Helicobacter pylori infection in the gastrointestinal tract and in the development of atherosclerotic plaques in the cardiovascular system. Furthermore, recent studies suggest that the regulation of the TLR pathway fulfills a central role in anticancer immunotherapy and in organ rejection after transplantation. CONCLUSION: Given the clinical significance of TLR pathways, the targeting of individual molecular components is likely to offer a broad range of future therapeutic modalities.

  15. The herpes simplex virus 1-encoded envelope glycoprotein B activates NF-κB through the Toll-like receptor 2 and MyD88/TRAF6-dependent signaling pathway.

    Directory of Open Access Journals (Sweden)

    Mingsheng Cai

    Full Text Available The innate immune response plays a critical role in the host defense against invading pathogens, and TLR2, a member of the Toll-like receptor (TLR family, has been implicated in the immune response and initiation of inflammatory cytokine secretion against several human viruses. Previous studies have demonstrated that infectious and ultraviolet-inactivated herpes simplex virus 1 (HSV-1 virions lead to the activation of nuclear factor kappa B (NF-κB and secretion of proinflammatory cytokines via TLR2. However, except for the envelope glycoprotein gH and gL, whether there are other determinants of HSV-1 responsible for TLR2 mediated biological effects is not known yet. Here, we demonstrated that the HSV-1-encoded envelope glycoprotein gB displays as molecular target recognized by TLR2. gB coimmunoprecipitated with TLR2, TLR1 and TLR6 in transfected and infected human embryonic kidney (HEK 293T cells. Treatment of TLR2-transfected HEK293T (HEK293T-TLR2 cells with purified gB results in the activation of NF-κB reporter, and this activation requires the recruitment of the adaptor molecules myeloid differentiation primary-response protein 88 (MyD88 and tumor necrosis factor receptor-associated factor 6 (TRAF6 but not CD14. Furthermore, activation of NF-κB was abrogated by anti-gB and anti-TLR2 blocking antibodies. In addition, the expression of interleukin-8 induced by gB was abrogated by the treatment of the human monocytic cell line THP-1 with anti-TLR2 blocking antibody or by the incubation of gB with anti-gB antibody. Taken together, these results indicate the importance and potency of HSV-1 gB as one of pathogen-associated molecular patterns (PAMPs molecule recognized by TLR2 with immediate kinetics.

  16. DMPD: Toll-like receptor 9 in murine lupus: more friend than foe! [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18241699 Toll-like receptor 9 in murine lupus: more friend than foe! Yu P, Musette P, Peng SL. Immunobiology...pus: more friend than foe! Authors Yu P, Musette P, Peng SL. Publication Immunobiology

  17. Space and time: New considerations about the relationship between Toll-like receptors (TLRs) and type I interferons (IFNs).

    Science.gov (United States)

    Perkins, Darren J; Vogel, Stefanie N

    2015-08-01

    The Toll like receptors (TLRs) and the type I interferons have critical roles to play in innate immunity. In this review we will discuss new developments relating to the important area of TLR/IFN cross regulation.

  18. DMPD: Toll-like receptors, Notch ligands, and cytokines drive the chronicity of lunginflammation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18073395 Toll-like receptors, Notch ligands, and cytokines drive the chronicity of lunginflammation. Raymond...ors, Notch ligands, and cytokines drive the chronicity of lunginflammation. Authors Raymond T, Schaller M, H

  19. Phylogeny of Toll-like receptor signaling: adapting the innate response.

    Directory of Open Access Journals (Sweden)

    Jeffrey M Roach

    Full Text Available The Toll-like receptors represent a largely evolutionarily conserved pathogen recognition machinery responsible for recognition of bacterial, fungal, protozoan, and viral pathogen associated microbial patterns and initiation of inflammatory response. Structurally the Toll-like receptors are comprised of an extracellular leucine rich repeat domain and a cytoplasmic Toll/Interleukin 1 receptor domain. Recognition takes place in the extracellular domain where as the cytoplasmic domain triggers a complex signal network required to sustain appropriate immune response. Signal transduction is regulated by the recruitment of different intracellular adaptors. The Toll-like receptors can be grouped depending on the usage of the adaptor, MyD88, into MyD88-dependent and MyD88 independent subsets. Herein, we present a unique phylogenetic analysis of domain regions of these receptors and their cognate signaling adaptor molecules. Although previously unclear from the phylogeny of full length receptors, these analyses indicate a separate evolutionary origin for the MyD88-dependent and MyD88-independent signaling pathway and provide evidence of a common ancestor for the vertebrate and invertebrate orthologs of the adaptor molecule MyD88. Together these observations suggest a very ancient origin of the MyD88-dependent pathway Additionally we show that early duplications gave rise to several adaptor molecule families. In some cases there is also strong pattern of parallel duplication between adaptor molecules and their corresponding TLR. Our results further support the hypothesis that phylogeny of specific domains involved in signaling pathway can shed light on key processes that link innate to adaptive immune response.

  1. DMPD: Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs andCTRPs. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17681884 Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs an...ng) (.svg) (.html) (.csml) Show Adipose tissue as an immunological organ: Toll-like receptors, C1q/TNFs andC...TRPs. PubmedID 17681884 Title Adipose tissue as an immunological organ: Toll-like

  2. Toll-like receptor 4 dependent responses to lung injury in a murine model of pulmonary contusion

    OpenAIRE

    Hoth, J. Jason; Wells, Jonathan D.; Brownlee, Noel A.; Hiltbold, Elizabeth M.; Meredith, J Wayne; McCall, Charles E.; Yoza, Barbara K.

    2009-01-01

    Blunt chest trauma resulting in pulmonary contusion with an accompanying acute inflammatory response is a common but poorly understood injury. We previously demonstrated that toll-like receptor 2 participates in the inflammatory response to lung injury. We hypothesized that the toll-like receptor 4, in a MyD88-dependent manner, may also participate in the response to lung injury. To investigate this, we used a model of pulmonary contusion in the mouse that is similar to that observed clinical...

  3. DMPD: Innate sensing of self and non-self RNAs by Toll-like receptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16530484 Innate sensing of self and non-self RNAs by Toll-like receptors. Sioud M. ...Trends Mol Med. 2006 Apr;12(4):167-76. Epub 2006 Mar 10. (.png) (.svg) (.html) (.csml) Show Innate sensing of self and non-self... RNAs by Toll-like receptors. PubmedID 16530484 Title Innate sensing of self and non-self

  4. Reduced expression of Toll-like receptor 4 inhibits human breast cancer cells proliferation and inflammatory cytokines secretion

    OpenAIRE

    Xie Xiaofang; Wen Huiyan; Zhou Xiaoni; Feng Ping; Zhou Huiqin; Yang Huan; Shen Haiying; Zhu Xueming

    2010-01-01

    Abstract Background Tumor cell expression of Toll-like receptors (TLRs) can promote inflammation and cell survival in the tumor microenvironment. Toll-like receptor 4 (TLR4) signaling in tumor cells can mediate tumor cell immune escape and tumor progression, and it is regarded as one of the mechanisms for chronic inflammation in tumorigenesis and progression. The expression of TLR4 in human breast cancer cell line MDA-MB-231 and its biological function in the development and progression of br...

  5. [Platelets "Toll-like receptor" engagement stimulates the release of immunomodulating molecules].

    Science.gov (United States)

    Cognasse, F; Hamzeh-Cognasse, H; Garraud, O

    2008-09-01

    Platelets are nonnucleated cellular elements that play a role in the process of haemostasis, and also in various ways in innate immunity and in inflammation. Platelets also contain numerous secretory products and can exert critical roles in several aspects of haemostasis. In addition, they house and secrete a variety of cytokines, chemokines and associated molecules which behave as ligands for receptors/counterparts displayed by endothelial cells lining tissue vessels and most leukocyte subsets. These latter studies show that platelets have an important role in innate as well as adaptive immunity; thus platelets can take part in an immune directive response. Moreover, platelets display receptors for several types of cytokines/chemokines along with FcgammaRII receptors. Finally, platelets not only express a variety of Toll-like receptors, with recently identified functions or not as-yet fully identified, but have also been demonstrated to express the key tandem pair of inflammatory and antigen presentation molecules (CD40 and CD40-ligand/CD154), this latter function making them the major purveyors of soluble CD40L in the plasma. It appears that platelets may be regarded as one of the neglected components of immune cell regulators, and platelets contribute to some interesting aspects in bridging innate and adaptive immunity. We propose that platelets discriminate danger signals and adapt the subsequent responses, with polarized cytokine secretion. Platelets may recognize several types of infectious pathogens and limit microbial colonization by sequestering these pathogens and releasing immunomodulatory factors. This review allows us to re-explore indications that platelets exert direct anti-infection immunity and we will present experimentally-driven arguments in favour of a role of platelet TLR in regulating certain immune activities.

  6. Toll-Like Receptor (TLR 2 and TLR4 Gene Expression in Canine Heart

    Directory of Open Access Journals (Sweden)

    A. Linde

    2007-01-01

    Full Text Available Toll-like receptors (TLRs are archetypal pattern recognition receptors of immediate importance for an efficacious innate immune response. TLRs exhibit marked differential tissue activity and their levels within a discrete cell type can be highly dynamic. Of 13 known mammalian paralogues, three TLRs have been identified in the dog. Although cardiac TLR expression has been reported in other species, this study is the first to present evidence that these innate immune receptors are expressed in the canine heart. Heart tissue samples from all four chambers were collected from healthy dogs immediately after euthanasia and stored at -80ºC until analysis. Total RNA was extracted with TRI Regent. Specific primers were designed for amplification of canine TLR2 and TLR4 based on previously reported sequences for these genes. Reverse transcription was performed with M-MLV reverse transcriptase. PCR amplification was performed and PCR products analyzed by agarose gel electrophoresis. Bands were excised from the gel and the DNA isolated and cloned using the TA Cloning® Kit. The correct sequence for each product was verified by nucleotide sequencing. TLR4 expression was detected in the left ventricle and right atrium; TLR2 was detectable at low levels in the right atrium only. Identity of the RT-PCR products was confirmed by sequencing. Our findings show that at least two TLR paralogues- namely TLR2 and TLR4 - are expressed in the canine heart. Additional studies are warranted to determine these immune receptors' potential implication in the development of naturally occurring heart disease in the dog.

  7. The role of Toll-like receptor 2 in inflammation and fibrosis during progressive renal injury.

    Directory of Open Access Journals (Sweden)

    Jaklien C Leemans

    Full Text Available Tissue fibrosis and chronic inflammation are common causes of progressive organ damage, including progressive renal disease, leading to loss of physiological functions. Recently, it was shown that Toll-like receptor 2 (TLR2 is expressed in the kidney and activated by endogenous danger signals. The expression and function of TLR2 during renal fibrosis and chronic inflammation has however not yet been elucidated. Therefore, we studied TLR2 expression in human and murine progressive renal diseases and explored its role by inducing obstructive nephropathy in TLR2(-/- or TLR2(+/+ mice. We found that TLR2 is markedly upregulated on tubular and tubulointerstitial cells in patients with chronic renal injury. In mice with obstructive nephropathy, renal injury was associated with a marked upregulation and change in distribution of TLR2 and upregulation of murine TLR2 danger ligands Gp96, biglycan, and HMGB1. Notably, TLR2 enhanced inflammation as reflected by a significantly reduced influx of neutrophils and production of chemokines and TGF-beta in kidneys of TLR2(-/- mice compared with TLR2(+/+ animals. Although, the obstructed kidneys of TLR2(-/- mice had less interstitial myofibroblasts in the later phase of obstructive nephropathy, tubular injury and renal matrix accumulation was similar in both mouse strains. Together, these data demonstrate that TLR2 can initiate renal inflammation during progressive renal injury and that the absence of TLR2 does not affect the development of chronic renal injury and fibrosis.

  8. Toll like receptor 4 mediates cell death in a mouse MPTP model of Parkinson disease

    Science.gov (United States)

    Noelker, Carmen; Morel, Lydie; Lescot, Thomas; Osterloh, Anke; Alvarez-Fischer, Daniel; Breloer, Minka; Henze, Carmen; Depboylu, Candan; Skrzydelski, Delphine; Michel, Patrick P.; Dodel, Richard C.; Lu, Lixia; Hirsch, Etienne C.; Hunot, Stéphane; Hartmann, Andreas

    2013-01-01

    In mammalians, toll-like receptors (TLR) signal-transduction pathways induce the expression of a variety of immune-response genes, including inflammatory cytokines. It is therefore plausible to assume that TLRs are mediators in glial cells triggering the release of cytokines that ultimately kill DA neurons in the substantia nigra in Parkinson disease (PD). Accordingly, recent data indicate that TLR4 is up-regulated by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treatment in a mouse model of PD. Here, we wished to evaluate the role of TLR4 in the acute mouse MPTP model of PD: TLR4-deficient mice and wild-type littermates control mice were used for the acute administration way of MPTP or a corresponding volume of saline. We demonstrate that TLR4-deficient mice are less vulnerable to MPTP intoxication than wild-type mice and display a decreased number of Iba1+ and MHC II+ activated microglial cells after MPTP application, suggesting that the TLR4 pathway is involved in experimental PD. PMID:23462811

  9. Methemoglobin Is an Endogenous Toll-Like Receptor 4 Ligand—Relevance to Subarachnoid Hemorrhage

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    Min Seong Kwon

    2015-03-01

    Full Text Available Neuroinflammation is a well-recognized consequence of subarachnoid hemorrhage (SAH, and may be responsible for important complications of SAH. Signaling by Toll-like receptor 4 (TLR4-mediated nuclear factor κB (NFκB in microglia plays a critical role in neuronal damage after SAH. Three molecules derived from erythrocyte breakdown have been postulated to be endogenous TLR4 ligands: methemoglobin (metHgb, heme and hemin. However, poor water solubility of heme and hemin, and lipopolysaccharide (LPS contamination have confounded our understanding of these molecules as endogenous TLR4 ligands. We used a 5-step process to obtain highly purified LPS-free metHgb, as confirmed by Fourier Transform Ion Cyclotron Resonance mass spectrometry and by the Limulus amebocyte lysate assay. Using this preparation, we show that metHgb is a TLR4 ligand at physiologically relevant concentrations. metHgb caused time- and dose-dependent secretion of the proinflammatory cytokine, tumor necrosis factor α (TNFα, from microglial and macrophage cell lines, with secretion inhibited by siRNA directed against TLR4, by the TLR4-specific inhibitors, Rs-LPS and TAK-242, and by anti-CD14 antibodies. Injection of purified LPS-free metHgb into the rat subarachnoid space induced microglial activation and TNFα upregulation. Together, our findings support the hypothesis that, following SAH, metHgb in the subarachnoid space can promote widespread TLR4-mediated neuroinflammation.

  10. Kidney Expression of Toll Like Receptors in Lupus Nephritis: Quantification and Clinicopathological Correlations

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    Fabrizio Conti

    2016-01-01

    Full Text Available Objective. The study aimed at locating and quantifying Toll Like Receptor (TLR 3, 7, 8, and 9 expression in kidney of patients with lupus nephritis (LN and correlating them with clinicopathological features. Methods. Kidney sections from 26 LN patients and 4 controls were analyzed by immunohistochemistry using anti-human TLR3, TLR7, TLR8, and TLR9 polyclonal antibodies; the number of TLR-positive nuclei/mm2 was evaluated on digitalized images. Results. Compared to controls, LN showed a significantly higher amount of glomerular and tubulointerstitial TLR9 (p=0.003 and p=0.007, whole and tubulointerstitial TLR3 (p=0.026 and p=0.031, and a higher tubulointerstitial TLR7 (p=0.022. TLR9 positively correlated with activity index (p=0.0063 and tubular TLR7 with chronicity index (p=0.026. TLR9 positively correlated with Renal-SLEDAI (p=0.01. Conclusions. This is the first study quantifying kidney expressions of TLRs in LN patients; the results show an overexpression of TLR3, TLR7, and TLR9 and demonstrate a correlation with clinicopathological indices supporting a role of these mediators in the pathogenesis of LN.

  11. Toll-Like Receptor 4 Engagement Mediates Prolyl Endopeptidase Release from Airway Epithelia via Exosomes.

    Science.gov (United States)

    Szul, Tomasz; Bratcher, Preston E; Fraser, Kyle B; Kong, Michele; Tirouvanziam, Rabindra; Ingersoll, Sarah; Sztul, Elizabeth; Rangarajan, Sunil; Blalock, J Edwin; Xu, Xin; Gaggar, Amit

    2016-03-01

    Proteases are important regulators of pulmonary remodeling and airway inflammation. Recently, we have characterized the enzyme prolyl endopeptidase (PE), a serine peptidase, as a critical protease in the generation of the neutrophil chemoattractant tripeptide Pro-Gly-Pro (PGP) from collagen. However, PE has been characterized as a cytosolic enzyme, and the mechanism mediating PE release extracellularly remains unknown. We examined the role of exosomes derived from airway epithelia as a mechanism for PE release and the potential extracellular signals that regulate the release of these exosomes. We demonstrate a specific regulatory pathway of exosome release from airway epithelia and identify PE as novel exosome cargo. LPS stimulation of airway epithelial cells induces release of PE-containing exosomes, which is significantly attenuated by small interfering RNA depletion of Toll-like receptor 4 (TLR4). These differences were recapitulated upon intratracheal LPS administration in mice competent versus deficient for TLR4 signaling. Finally, sputum samples from subjects with cystic fibrosis colonized with Pseudomonas aeruginosa demonstrate elevated exosome content and increased PE levels. This TLR4-based mechanism highlights the first report of nonstochastic release of exosomes in the lung and couples TLR4 activation with matrikine generation. The increased quantity of these proteolytic exosomes in the airways of subjects with chronic lung disease highlights a new mechanism of injury and inflammation in the pathogenesis of pulmonary disorders.

  12. Immune Adjuvant Effect of Molecularly-defined Toll-Like Receptor Ligands

    Directory of Open Access Journals (Sweden)

    Deana N. Toussi

    2014-04-01

    Full Text Available Vaccine efficacy is optimized by addition of immune adjuvants. However, although adjuvants have been used for over a century, to date, only few adjuvants are approved for human use, mostly aimed at improving vaccine efficacy and antigen-specific protective antibody production. The mechanism of action of immune adjuvants is diverse, depending on their chemical and molecular nature, ranging from non-specific effects (i.e., antigen depot at the immunization site to specific activation of immune cells leading to improved host innate and adaptive responses. Although the detailed molecular mechanism of action of many adjuvants is still elusive, the discovery of Toll-like receptors (TLRs has provided new critical information on immunostimulatory effect of numerous bacterial components that engage TLRs. These ligands have been shown to improve both the quality and the quantity of host adaptive immune responses when used in vaccine formulations targeted to infectious diseases and cancer that require both humoral and cell-mediated immunity. The potential of such TLR adjuvants in improving the design and the outcomes of several vaccines is continuously evolving, as new agonists are discovered and tested in experimental and clinical models of vaccination. In this review, a summary of the recent progress in development of TLR adjuvants is presented.

  13. Toll-like receptors gene polymorphisms may confer increased susceptibility to breast cancer development.

    Science.gov (United States)

    Theodoropoulos, George E; Saridakis, Vasilios; Karantanos, Theodoros; Michalopoulos, Nikolaos V; Zagouri, Flora; Kontogianni, Panagiota; Lymperi, Maria; Gazouli, Maria; Zografos, George C

    2012-08-01

    Toll-like receptor (TLR) activation may be an important event in tumor cell immune evasion. TLR2 and TLR4 gene polymorphisms have been related to increased susceptibility to cancer development in various organs. 261 patients and 480 health individuals were investigated for genotype and allelic frequencies of a 22-bp nucleotide deletion (-196 to -174del) in the promoter of TLR2 gene as well as two polymorphisms causing amino acid substitutions (Asp299Gly and Thr399Ile) in TLR4 gene. As far as (-196 to -174del) in TLR2 gene is concerned ins/del and del/del genotypes and del allele were significantly more frequent in breast cancer patients compared to healthy controls. Considering Asp299Gly replacement of TLR4 gene, Gly carriers (Asp/Gly & Gly/Gly genotype) and Gly allele were overrepresented among the breast cancer cases. The -174 to -196del of TLR2 gene and Asp299Gly of TLR4 gene polymorphisms may confer an increased susceptibility to breast cancer development.

  14. The complement system and toll-like receptors as integrated players in the pathophysiology of atherosclerosis.

    Science.gov (United States)

    Hovland, Anders; Jonasson, Lena; Garred, Peter; Yndestad, Arne; Aukrust, Pål; Lappegård, Knut T; Espevik, Terje; Mollnes, Tom E

    2015-08-01

    Despite recent medical advances, atherosclerosis is a global burden accounting for numerous deaths and hospital admissions. Immune-mediated inflammation is a major component of the atherosclerotic process, but earlier research focus on adaptive immunity has gradually switched towards the role of innate immunity. The complement system and toll-like receptors (TLRs), and the crosstalk between them, may be of particular interest both with respect to pathogenesis and as therapeutic targets in atherosclerosis. Animal studies indicate that inhibition of C3a and C5a reduces atherosclerosis. In humans modified LDL-cholesterol activate complement and TLRs leading to downstream inflammation, and histopathological studies indicate that the innate immune system is present in atherosclerotic lesions. Moreover, clinical studies have demonstrated that both complement and TLRs are upregulated in atherosclerotic diseases, although interventional trials have this far been disappointing. However, based on recent research showing an intimate interplay between complement and TLRs we propose a model in which combined inhibition of both complement and TLRs may represent a potent anti-inflammatory therapeutic approach to reduce atherosclerosis.

  15. Toll-like receptor-mediated immune response inhibits prion propagation.

    Science.gov (United States)

    Kang, Sang-Gyun; Kim, Chiye; Cortez, Leonardo M; Carmen Garza, María; Yang, Jing; Wille, Holger; Sim, Valerie L; Westaway, David; McKenzie, Debbie; Aiken, Judd

    2016-06-01

    Prion diseases are progressive neurodegenerative disorders affecting humans and various mammals. The prominent neuropathological change in prion diseases is neuroinflammation characterized by activation of neuroglia surrounding prion deposition. The cause and effect of this cellular response, however, is unclear. We investigated innate immune defenses against prion infection using primary mixed neuronal and glial cultures. Conditional prion propagation occurred in glial cultures depending on their immune status. Preconditioning of the cells with the toll-like receptor (TLR) ligand, lipopolysaccharide, resulted in a reduction in prion propagation, whereas suppression of the immune responses with the synthetic glucocorticoid, dexamethasone, increased prion propagation. In response to recombinant prion fibrils, glial cells up-regulated TLRs (TLR1 and TLR2) expression and secreted cytokines (tumor necrosis factor-α, interleukin-1β, interleukin-6, granulocyte-macrophage colony-stimulating factor, and interferon-β). Preconditioning of neuronal and glial cultures with recombinant prion fibrils inhibited prion replication and altered microglial and astrocytic populations. Our results provide evidence that, in early stages of prion infection, glial cells respond to prion infection through TLR-mediated innate immunity. GLIA 2016;64:937-951. PMID:26880394

  16. Involvement of Toll-like receptors on Helicobacter pylori-induced immunity.

    Directory of Open Access Journals (Sweden)

    Romy Käbisch

    Full Text Available Dendritic cells (DCs play a major role in the innate immune response since they recognize a broad repertoire of PAMPs mainly via Toll-like receptors (TLRs. During Helicobacter pylori (H. pylori infection, TLRs have been shown to be important to control cytokine response particularly in murine DCs. In the present study we analyzed the effect of blocking TLRs on human DCs. Co-incubation of human DCs with H. pylori resulted in the release of the pro-inflammatory cytokines IL-12p70, IL-6 and IL-10. Release of IL-12p70 and IL-10 was predominantly influenced when TLR4 signaling was blocked by adding specific antibodies, suggesting a strong influence on subsequent T cell responses through TLR4 activation on DCs. Co-incubation of H. pylori-primed DC with allogeneic CD4+ T cells resulted in the production of IFN-γ and IL-17A as well as the expression of Foxp3, validating a mixed Th1/Th17 and Treg response in vitro. Neutralization of TLR4 during H. pylori infection resulted in significantly decreased amounts of IL-17A and IFN-γ and reduced levels of Foxp3-expressing and IL-10-secreting T cells. Our findings suggest that DC cytokine secretion induced upon TLR4-mediated recognition of H. pylori influences inflammatory and regulatory T cell responses, which might facilitate the chronic bacterial persistence.

  17. In vitro inflammation inhibition model based on semi-continuous toll-like receptor biosensing.

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    Jin-Woo Jeon

    Full Text Available A chemical inhibition model of inflammation is proposed by semi-continuous monitoring the density of toll-like receptor 1 (TLR1 expressed on mammalian cells following bacterial infection to investigate an in vivo-mimicked drug screening system. The inflammation was induced by adding bacterial lysate (e.g., Pseudomonas aeruginosa to a mammalian cell culture (e.g., A549 cell line. The TLR1 density on the same cells was immunochemically monitored up to three cycles under optimized cyclic bacterial stimulation-and-restoration conditions. The assay was carried out by adopting a cell-compatible immunoanalytical procedure and signal generation method. Signal intensity relative to the background control obtained without stimulation was employed to plot the standard curve for inflammation. To suppress the inflammatory response, sodium salicylate, which inhibits nuclear factor-κB activity, was used to prepare the standard curve for anti-inflammation. Such measurement of differential TLR densities was used as a biosensing approach discriminating the anti-inflammatory substance from the non-effector, which was simulated by using caffeic acid phenethyl ester and acetaminophen as the two components, respectively. As the same cells exposed to repetitive bacterial stimulation were semi-continuously monitored, the efficacy and toxicity of the inhibitors may further be determined regarding persistency against time. Therefore, this semi-continuous biosensing model could be appropriate as a substitute for animal-based experimentation during drug screening prior to pre-clinical tests.

  18. Modulation of Female Genital Tract-Derived Dendritic Cell Migration and Activation in Response to Inflammatory Cytokines and Toll-Like Receptor Agonists.

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    Muki S Shey

    Full Text Available HIV transmission across the genital mucosa is a major mode of new HIV infections in women. The probability of infection may be influenced by several factors including recruitment and activation of HIV target cells, such as dendritic cells (DCs and cytokine production, associated with genital inflammation. We evaluated the role of inflammatory cytokines and TLR signaling in migration and activation of genital tract DCs in the human cervical explant model. Hysterectomy tissues from 10 HIV-negative and 7 HIV-positive donor women were separated into ecto- and endocervical explants, and incubated with inflammatory cytokines (TNF-α, IL-1β, IL-8, MIP-1β or agonists for TLR4 (LPS, TLR2/1 (PAM3 and TLR7/8 (R848. Migration (frequency and activation (HLA-DR expression of myeloid and plasmacytoid DCs and Langerhans cells were measured by flow cytometry. We observed that cytokines, LPS and PAM3 induced activation of migrating myeloid and plasmacytoid DCs. LPS induced a 3.6 fold lower levels of migration of plasmacytoid DCs from HIV-infected women compared with HIV-uninfected women (median activation indices of 2.932 vs 0.833. There was however a 4.5 fold increase in migration of Langerhans cells in HIV-infected compared with HIV-uninfected women in response to cytokines (median activation indices of 3.539 vs 0.77. Only TLR agonists induced migration and activation of DCs from endocervical explants. Hormonal contraception use was associated with an increase in activation of DC subsets in the endo and ectocervical explants. We conclude that inflammatory signals in the female genital tract induced DC migration and activation, with possible important implications for HIV susceptibility of cervical tissues.

  19. Live Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis activate the inflammatory response trhough Toll-like receptors 2, 4, and 9 in species-specific patterns

    DEFF Research Database (Denmark)

    Mogensen, T.H.; Paludan, Søren Riis; Kilian, Mogens;

    2006-01-01

    activation by live bacteria. Here, we demonstrate that live Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis, the three principal causes of bacterial meningitis, use distinct sets of TLRs to trigger the inflammatory response. Using human embryonic kidney 293 cell lines......, each overexpressing one type of TLR, we found that S. pneumoniae triggered activation of the transcription factor nuclear factor-kappaB and expression of interleukin-8, only in cells expressing TLR2 or -9. The same response was evoked by H. influenzae in cells expressing TLR2 or -4 and by N...... and confirmed the essential role of these TLRs and also identified differential functions of TLRs in activation of the inflammatory response. Collectively, we here demonstrate that S. pneumoniae, H. influenzae, and N. meningitidis each activate several TLRs in species-specific patterns and show that infection...

  20. Extracellular mtDNA activates NF-κB via toll-like receptor 9 and induces cell death in cardiomyocytes.

    Science.gov (United States)

    Bliksøen, Marte; Mariero, Lars Henrik; Torp, May Kristin; Baysa, Anton; Ytrehus, Kirsti; Haugen, Fred; Seljeflot, Ingebjørg; Vaage, Jarle; Valen, Guro; Stensløkken, Kåre-Olav

    2016-07-01

    Acute myocardial infarction (AMI) causes sterile inflammation, which exacerbates tissue injury. Elevated levels of circulating mitochondrial DNA (mtDNA) have been associated with AMI. We hypothesized that mtDNA triggers an innate immune response via TLR9 and NF-κB activation, causing cardiomyocyte injury. Murine cardiomyocytes express TLR9 mRNA and protein and were able to internalize fluorescently labeled mouse mtDNA. Incubation of human embryonic kidney cells with serum from AMI patients containing naturally elevated levels of mtDNA induced TLR9-dependent NF-κB activity. This effect was mimicked by isolated mtDNA. mtDNA activated NF-κB in reporter mice both in vivo and in isolated cardiomyocytes. Moreover, incubation of isolated cardiomyocytes with mtDNA induced cell death after 4 and 24 h. Laser confocal microscopy showed that incubation of cardiomyocytes with mtDNA accelerated mitochondrial depolarization induced by reactive oxygen species. In contrast to mtDNA, isolated total DNA did not activate NF-κB nor induce cell death. In conclusion, mtDNA can induce TLR9-dependent NF-κB activation in reporter cells and activate NF-κB in cardiomyocytes. In cardiomyocytes, mtDNA causes mitochondrial dysfunction and death. Endogenous mtDNA in the extracellular space is a danger signal with direct detrimental effects on cardiomyocytes. PMID:27164906

  1. Heat shock protein 60 stimulates the migration of vascular smooth muscle cells via Toll-like receptor 4 and ERK MAPK activation

    Science.gov (United States)

    Zhao, Ying; Zhang, Chenxu; Wei, Xuge; Li, Pei; Cui, Ying; Qin, Yuanhua; Wei, Xiaoqing; Jin, Minli; Kohama, Kazuhiro; Gao, Ying

    2015-01-01

    Accumulating evidence indicates that heat shock protein (HSP) 60 is strongly associated with the pathology of atherosclerosis (AS). However, the precise mechanisms by which HSP60 promotes atherosclerosis remain unclear. In the present study, we found that HSP60 mRNA and protein expression levels in the thoracic aorta are enhanced not only in a mouse model of AS but also in high-fat diet (HFD) mice. HSP60 expression and secretion was activated by platelet-derived growth factor-BB (PDGF-BB) and interleukin (IL)-8 in both human umbilical vein endothelial cells (HUVECs) and vascular smooth muscle cells (VSMCs). HSP60 was found to induce VSMC migration, and exposure to HSP60 activated ERK MAPK signaling. U0126, an inhibitor of ERK, reduced VSMC migration. The HSP60-stimulated VSMCs were found to express TLR4 mRNA but not TLR2 mRNA. Knockdown of TLR4 by siRNA reduced HSP60-induced VSMC migration and HSP60-induced ERK activation. Finally, HSP60 induced IL-8 secretion in VSMCs. Together these results suggest that HSP60 is involved in the stimulation of VSMC migration, via TLR4 and ERK MAPK activation. Meanwhile, activation of HSP60 is one of the most powerful methods of sending a ‘danger signal’ to the immune system to generate IL-8, which assists in the management of an infection or disease. PMID:26477505

  2. Heat shock protein 60 stimulates the migration of vascular smooth muscle cells via Toll-like receptor 4 and ERK MAPK activation

    OpenAIRE

    Ying Zhao; Chenxu Zhang; Xuge Wei; Pei Li; Ying Cui; Yuanhua Qin; Xiaoqing Wei; Minli Jin; Kazuhiro Kohama; Ying Gao

    2015-01-01

    Accumulating evidence indicates that heat shock protein (HSP) 60 is strongly associated with the pathology of atherosclerosis (AS). However, the precise mechanisms by which HSP60 promotes atherosclerosis remain unclear. In the present study, we found that HSP60 mRNA and protein expression levels in the thoracic aorta are enhanced not only in a mouse model of AS but also in high-fat diet (HFD) mice. HSP60 expression and secretion was activated by platelet-derived growth factor-BB (PDGF-BB) and...

  3. Extracts of Feijoa Inhibit Toll-Like Receptor 2 Signaling and Activate Autophagy Implicating a Role in Dietary Control of IBD.

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    Noha Ahmed Nasef

    Full Text Available Inflammatory bowel disease (IBD is a heterogeneous chronic inflammatory disease affecting the gut with limited treatment success for its sufferers. This suggests the need for better understanding of the different subtypes of the disease as well as nutritional interventions to compliment current treatments. In this study we assess the ability of a hydrophilic feijoa fraction (F3 to modulate autophagy a process known to regulate inflammation, via TLR2 using IBD cell lines.Mouse embryonic fibroblasts (MEF deleted for ATG5, and two intestinal epithelial cells HCT15 and HCT116, were used to test the anti-inflammatory effect of F3 after stimulating the cells with a TLR2 specific ligand PAM3CSK4.F3 was able to reduce TLR2 specific inflammation and stimulate autophagy in MEFs and HCT15 cells but not in HCT116 cells. The anti-inflammatory effect was reduced in the MEF cells deleted for ATG5. In addition, the activation of autophagy by F3 was enhanced by PAM3CSK4.F3 of feijoa can interact with cells via a TLR2 specific mechanism and reduce Nuclear factor kappa B (NF-κB activation in part due to stimulation of autophagy. These results suggest that there is potential benefit in using feijoa extracts as part of dietary interventions to manage IBD in patients.

  4. Minor modifications to the phosphate groups and the C3' acyl chain length of lipid A in two Bordetella pertussis strains, BP338 and 18-323, independently affect Toll-like receptor 4 protein activation.

    Science.gov (United States)

    Shah, Nita R; Albitar-Nehme, Sami; Kim, Emma; Marr, Nico; Novikov, Alexey; Caroff, Martine; Fernandez, Rachel C

    2013-04-26

    Lipopolysaccharides (LPS) of Bordetella pertussis are important modulators of the immune system. Interaction of the lipid A region of LPS with the Toll-like receptor 4 (TLR4) complex causes dimerization of TLR4 and activation of downstream nuclear factor κB (NFκB), which can lead to inflammation. We have previously shown that two strains of B. pertussis, BP338 (a Tohama I-derivative) and 18-323, display two differences in lipid A structure. 1) BP338 can modify the 1- and 4'-phosphates by the addition of glucosamine (GlcN), whereas 18-323 cannot, and 2) the C3' acyl chain in BP338 is 14 carbons long, but only 10 or 12 carbons long in 18-323. In addition, BP338 lipid A can activate TLR4 to a greater extent than 18-323 lipid A. Here we set out to determine the genetic reasons for the differences in these lipid A structures and the contribution of each structural difference to the ability of lipid A to activate TLR4. We show that three genes of the lipid A GlcN modification (Lgm) locus, lgmA, lgmB, and lgmC (previously locus tags BP0399-BP0397), are required for GlcN modification and a single amino acid difference in LpxA is responsible for the difference in C3' acyl chain length. Furthermore, by introducing lipid A-modifying genes into 18-323 to generate isogenic strains with varying penta-acyl lipid A structures, we determined that both modifications increase TLR4 activation, although the GlcN modification plays a dominant role. These results shed light on how TLR4 may interact with penta-acyl lipid A species.

  5. Toll-like receptor gene polymorphisms are associated with allergic rhinitis: a case control study

    Directory of Open Access Journals (Sweden)

    Nilsson Daniel

    2012-08-01

    Full Text Available Abstract Background The Toll-like receptor proteins are important in host defense and initiation of the innate and adaptive immune responses. A number of studies have identified associations between genetic variation in the Toll-like receptor genes and allergic disorders such as asthma and allergic rhinitis. The present study aim to search for genetic variation associated with allergic rhinitis in the Toll-like receptor genes. Methods A first association analysis genotyped 73 SNPs in 182 cases and 378 controls from a Swedish population. Based on these results an additional 24 SNPs were analyzed in one Swedish population with 352 cases and 709 controls and one Chinese population with 948 cases and 580 controls. Results The first association analysis identified 4 allergic rhinitis-associated SNPs in the TLR7-TLR8 gene region. Subsequent analysis of 24 SNPs from this region identified 7 and 5 significant SNPs from the Swedish and Chinese populations, respectively. The corresponding risk-associated haplotypes are significant after Bonferroni correction and are the most common haplotypes in both populations. The associations are primarily detected in females in the Swedish population, whereas it is seen in males in the Chinese population. Further independent support for the involvement of this region in allergic rhinitis was obtained from quantitative skin prick test data generated in both populations. Conclusions Haplotypes in the TLR7-TLR8 gene region were associated with allergic rhinitis in one Swedish and one Chinese population. Since this region has earlier been associated with asthma and allergic rhinitis in a Danish linkage study this speaks strongly in favour of this region being truly involved in the development of this disease.

  6. Toll-like receptor-4 pathway is required for the pathogenesis of human chronic endometritis.

    Science.gov (United States)

    Ju, Jinfen; Li, Liangpeng; Xie, Jingyan; Wu, Yan; Wu, Xi; Li, Weihon

    2014-12-01

    Toll-like receptor (TLR) signal transduction is a central component of the primary innate immune response to pathogenic challenge. TLR4, a member of the TLR family, is highly expressed in the endometrial cells of the uterus and could thus be a key link between human chronic endometritis (CE) and the immune system. However, the exact biological function of TLR4 in human CE remains largely unexplored. The present study aimed to examine the role of TLR4 in human CE. A comprehensive expression and activation analysis of TLR4 in the endometrial cells of the uterus from patients with human CE (n=25) and normal endometrial (NE) tissue (n=15) was performed. Western blot analyses demonstrated that compared with NE, the protein expression TLR4 markedly increased in human CE. Endometrial tissue scrapings were also used for total RNA extraction and were transcribed and amplified by reverse transcription quantitative polymerase chain reaction. The results showed that significant upregulation of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and downregulation of IL-10 mRNA was observed in CE compared with the NE group. Furthermore, the protein of the signaling adapter myeloid differentiation factor-88 and the accessory molecules (TNF receptor associated factor 6 and transforming growth factor-β-activated kinase 1) were also detected in all the assayed tissues. Of note, differential expression (CE versus NE) was observed by immunoblotting at each level of the nuclear factor-κB signaling cascade, including inhibitor κBα and P65 (all P<0.05). The altered TLR4 and its corresponding downstream signaling molecules in CE cells may be of relevance for the progression of the human CE. These findings indicate that the evaluation of expression patterns of TLR4 holds promise for the treatment of human CE. PMID:25371751

  7. Genetic diversity of Toll-like receptor 5 among pig populations

    OpenAIRE

    Xiuqin Yang; Haitao Li; Qingzhi Guan; Di Liu

    2013-01-01

    The Toll-like receptor 5 (TLR5) recognizes flagellin of Gram-positive and -negative bacteria and plays an important role in the host defense system. Here, we surveyed single nucleotide polymorphisms (SNPs) in the coding sequence of the porcine TLR5 gene in 83 individuals from five pig breeds, these including Chinese local populations and Western commercial pig breeds. A total of 19 medium polymorphic SNPs (0.25 < PIC < 0.5) were identified, three of which were missense mutations that clustere...

  8. Betaine inhibits Toll-like receptor 4 expression in rats with ethanol-induced liver injury

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    AIM:To test whether ethanol feeding could induce Toll-like receptor 4(TLR4)responses,assess the hepatoprotective effect of betaine and its inhibitive effect on TLR4 in animal models of alcoholic liver injury.METHODS:Forty-eight female Sprague-Dawley rats were randomly divided into four groups as control,model,low and high dose betaine groups.Except control group,all rats were fed with high fat-containing diet plus ethanol and fish oil gavages for 8 wk.Betaine was administered intragastrically after exposure...

  9. Virtual Screening Approaches towards the Discovery of Toll-Like Receptor Modulators

    Science.gov (United States)

    Pérez-Regidor, Lucía; Zarioh, Malik; Ortega, Laura; Martín-Santamaría, Sonsoles

    2016-01-01

    This review aims to summarize the latest efforts performed in the search for novel chemical entities such as Toll-like receptor (TLR) modulators by means of virtual screening techniques. This is an emergent research field with only very recent (and successful) contributions. Identification of drug-like molecules with potential therapeutic applications for the treatment of a variety of TLR-regulated diseases has attracted considerable interest due to the clinical potential. Additionally, the virtual screening databases and computational tools employed have been overviewed in a descriptive way, widening the scope for researchers interested in the field. PMID:27618029

  10. The complement system and toll-like receptors as integrated players in the pathophysiology of atherosclerosis

    DEFF Research Database (Denmark)

    Hovland, Anders; Jonasson, Lena; Garred, Peter;

    2015-01-01

    Despite recent medical advances, atherosclerosis is a global burden accounting for numerous deaths and hospital admissions. Immune-mediated inflammation is a major component of the atherosclerotic process, but earlier research focus on adaptive immunity has gradually switched towards the role...... of innate immunity. The complement system and toll-like receptors (TLRs), and the crosstalk between them, may be of particular interest both with respect to pathogenesis and as therapeutic targets in atherosclerosis. Animal studies indicate that inhibition of C3a and C5a reduces atherosclerosis. In humans...... to reduce atherosclerosis....

  11. Virtual Screening Approaches towards the Discovery of Toll-Like Receptor Modulators

    Directory of Open Access Journals (Sweden)

    Lucía Pérez-Regidor

    2016-09-01

    Full Text Available This review aims to summarize the latest efforts performed in the search for novel chemical entities such as Toll-like receptor (TLR modulators by means of virtual screening techniques. This is an emergent research field with only very recent (and successful contributions. Identification of drug-like molecules with potential therapeutic applications for the treatment of a variety of TLR-regulated diseases has attracted considerable interest due to the clinical potential. Additionally, the virtual screening databases and computational tools employed have been overviewed in a descriptive way, widening the scope for researchers interested in the field.

  12. Human Toll-like receptor 8 can be cool too: implications for foreign RNA sensing.

    Science.gov (United States)

    Sarvestani, Soroush T; Williams, Bryan R G; Gantier, Michael P

    2012-08-01

    Recent advances in our understanding of foreign nucleic acid sensing indicate an important role for the human Toll-like receptor (TLR) 8 in the initiation of immune responses to certain pathogens. However, TLR8, far too often grouped together with TLR7 for its common ability to detect RNA, has a function on its own in the initiation of specific proinflammatory responses to viruses and bacteria. Here, we present an overview of what is currently known of human TLR8 biology, from genetic regulation to its function in innate immunity, and discuss how TLR8 could present novel therapeutic opportunities in viral and cancer diseases. PMID:22817608

  13. Toll-like receptor 4, a novel signal transducer for lipopolysaccharide

    Institute of Scientific and Technical Information of China (English)

    杨清武; 朱佩芳; 王正国; 蒋建新

    2002-01-01

    LPS activation effect. Finally, for CD14 negative cells, the receptor combined LPS-LBP-sCD14 compound has not yet been identified. Some details indicated that a “co-receptor” for LPS signal transduction must exist. Although standard biochemical approaches, transfection assay, and immunologic tacties were all employed to search for this co-receptor, it has not yet been found. The find of Toll-like receptor 4 (TLR4) provides a new opportunity to study the mechanism of LPS action.

  14. Structural characterisation of Toll-like receptor 1 (TLR1) and Toll-like receptor 6 (TLR6) in elephant and harbor seals.

    Science.gov (United States)

    Woodman, Sally; Gibson, Amanda J; García, Ana Rubio; Contreras, Guillermo Sanchez; Rossen, John W; Werling, Dirk; Offord, Victoria

    2016-01-01

    Pinnipeds are a diverse clade of semi-aquatic mammals, which act as key indicators of ecosystem health. Their transition from land to marine environments provides a complex microbial milieu, making them vulnerable to both aquatic and terrestrial pathogens, thereby contributing to pinniped population decline. Indeed, viral pathogens such as influenza A virus and phocine distemper virus (PDV) have been identified as the cause of several of these mass mortality events. Furthermore, bacterial infection with mammalian Brucella sp. and methicillin-resistant Staphylococcus aureus strains have also been observed in marine mammals, posing further risk to both co-habiting endangered species and public health. During these disease outbreaks, mortality rates have varied amongst different pinniped species. Analyses of innate immune receptors at the host-pathogen interface have previously identified variants which may drive these species-specific responses. Through a combination of both sequence- and structure-based methods, this study characterises members of the Toll-like receptor (TLR) 1 superfamily from both harbour and elephant seals, identifying variations which will help us to understand these species-specific innate immune responses, potentially aiding the development of specific vaccine-adjuvants for these species. PMID:26827833

  15. N-acetylcysteine inhibits activation of toll-like receptor 2 and 4 gene expression in the liver and lung after partial hepatic ischemia-reper fusion injur y in mice

    Institute of Scientific and Technical Information of China (English)

    Xin Jin; Lin Wang; He-Shui Wu; Lei Zhang; Chun-You Wang; Yuan Tian; Jing-Hui Zhang

    2007-01-01

    BACKGROUND: Toll-like receptor 2 and 4 (TLR2/4) may play important roles in ischemia-reperfusion (I/R) injury, and N-acetylcysteine (NAC) can prevent the generation of reactive oxygen species (ROS) induced by I/R injury. This study aimed to investigate the changes in TLR2/4 gene expression in the liver and lung after I/R injury with or without NAC pretreatment. METHODS:BALB/c mice were used in a model of partial hepatic I/R injury and randomly assigned to a sham-operated control group (SH), a hepatic ischemia/reperfusion group (I/R) or a NAC pretreated, hepatic I/R group (I/R-NAC). The levels of TNF-α in the portal vein and plasma alanine aminotransferase (ALT) were measured at 1 and 3 hours after reperfusion. The lung wet-to-dry ratio was measured, and the expression of TLR2/4 mRNA and protein in the liver and lung were assessed with RT-PCR and Western blotting at the same time points. RESULTS: Compared with the I/R group, the expression of TLR2/4 mRNA and protein in the liver and lung in the I/R-NAC group was decreased at the same time point (P CONCLUSIONS:TLR2/4 was activated in the liver and lung in the process of partial hepatic I/R injury. NAC inhibited the activation of TLR2/4 and the induction of TNF-αresulting from I/R injury via modulating the redox state, thus it may mitigate liver and lung injury following partial hepatic I/R in mice.

  16. Fungal pathogens - a sweet and sour treat for toll-like receptors

    Directory of Open Access Journals (Sweden)

    Christelle eBourgeois

    2012-11-01

    Full Text Available Hundred-thousands of fungal species are present in our environment, including normal colonizers that constitute part of the human microbiota. The homeostasis of host-fungus interactions encompasses efficient fungal sensing, tolerance at mucosal surfaces, as well as antifungal defenses. Decrease in host immune fitness or increase in fungal burden may favor pathologies, ranging from superficial mucocutaneous diseases to invasive life-threatening fungal infections. Toll-like receptors (TLRs are essential players in this balance, due to their ability to control both inflammatory and anti-inflammatory processes upon recognition of fungal-specific pathogen-associated molecular patterns (PAMPs. Certain members of the TLR family participate to the initial recognition of fungal PAMPs on the cell surface, as well as inside phagosomes of innate immune cells. Active signaling cascades in phagocytes ultimately enable fungus clearance and the release of cytokines that shape and instruct other innate immune cells and the adaptive immune system. Some TLRs cooperate with other pattern recognition receptors (e.g., C-type lectins, Galectins, thus allowing for a tailored immune response. The spatio-temporal and physiological contributions of individual TLRs in fungal infections remains ill-defined, although in humans, TLR gene polymorphisms have been linked to increased susceptibility to fungal infections. This review focuses entirely on the role of TLRs that control the host susceptibility to environmental fungi (e.g., Aspergillus, Cryptoccocus, Coccidoides, as well as to the most frequent human fungal pathogens represented by the commensal Candida species. The emerging roles of TLRs in modulating host tolerance to fungi, and the strategies that evolved in some of these fungi to evade or use TLR recognition to their advantage will also be discussed, as well as their potential suitability as targets in vaccine therapies.

  17. Expression of toll-like receptors in hepatic cirrhosis and hepatocellular carcinoma.

    Science.gov (United States)

    Sun, L; Dai, J J; Hu, W F; Wang, J

    2016-01-01

    Toll-like receptors (TLRs) can specifically identify pathogen-associated molecular patterns (PAMPs) by recognizing structural patterns in diverse microbial molecules, and can provide an effective defense against multiple microbial infectious. A variety of TLRs can be expressed on the surface of liver parenchymal as well as nonparenchymal cells. Kupffer cells are a type of hepatic nonparenchymal macrophage, and are positively associated with the severity of liver fibrosis. They play an important role in the synthesis and deposition of the extracellular matrix by upregulating the expression of tissue inhibitor of metalloproteinases and downregulating the activity of matrix metalloproteinases. Cirrhosis, a chronic diffuse lesion usually accompanying extensive liver fibrosis and nodular regeneration, is caused by liver parenchymal cells repeating injury-repair following reconstruction of organizational structure in the hepatic lobules. Hepatocellular carcinoma is caused by repeated and persistent chronic severe liver injury, and partial hepatocytes can eventually transform into hepatoma cells. Multiple TLRs such as TLR2, TLR3, TLR4, and TLR9, as well as other receptors, can be expressed in cirrhosis and hepatocellular carcinoma. About 53 and 85% of hepatocellular carcinoma patients frequently express TLR3 and TLR9, respectively. The chronic and repeated liver injury caused by alcohol, and HBV, HCV, or other pathogens can be recognized by TLRs through the PAMP pathway, which directly increases the risk for hepatic cirrhosis and hepatocellular carcinoma. In this review, we briefly present evidence that the novel cellular molecular mechanisms of TLRs may provide more information about new therapeutics targets of the anti-inflammatory immune response.

  18. Lipoteichoic acid induces unique inflammatory responses when compared to other toll-like receptor 2 ligands.

    Directory of Open Access Journals (Sweden)

    Elizabeth M Long

    Full Text Available Toll-like receptors (TLRs recognize evolutionarily-conserved molecular patterns originating from invading microbes. In this study, we were interested in determining if microbial ligands, which use distinct TLR2-containing receptor complexes, represent unique signals to the cell and can thereby stimulate unique cellular responses. Using the TLR2 ligands, R-FSL1, S-FSL1, Pam2CSK4, Pam3CSK4, and lipoteichoic acid (LTA, we demonstrate that these ligands activate NF-kappaB and MAP Kinase pathways with ligand-specific differential kinetics in murine macrophages. Most strikingly, LTA stimulation of these pathways was substantially delayed when compared with the other TLR2 ligands. These kinetics differences were associated with a delay in the LTA-induced expression of a subset of genes as compared with another TLR2 ligand, R-FSL1. However, this did not translate to overall differences in gene expression patterns four hours following stimulation with different TLR2 ligands. We extended this study to evaluate the in vivo responses to distinct TLR2 ligands using a murine model of acute inflammation, which employs intravital microscopy to monitor leukocyte recruitment into the cremaster muscle. We found that, although R-FSL1, S-FSL1, Pam2CSK4, and Pam3CSK4 were all able to stimulate robust leukocyte recruitment in vivo, LTA remained functionally inert in this in vivo model. Therefore distinct TLR2 ligands elicit unique cellular responses, as evidenced by differences in the kinetic profiles of signaling and gene expression responses in vitro, as well as the physiologically relevant differences in the in vivo responses to these ligands.

  19. Targeting Toll-like receptor 4 prevents cobalt-mediated inflammation.

    Science.gov (United States)

    Lawrence, Helen; Mawdesley, Amy Elizabeth; Holland, James Patrick; Kirby, John Andrew; Deehan, David John; Tyson-Capper, Alison Jane

    2016-02-16

    Cobalt-chrome alloy is a widely used biomaterial in joint replacements, dental implants and spinal rods. Although it is an effective and biocompatible material, adverse reactions to metal debris (ARMD) have arisen in a minority of patients, particularly in those with metal-on-metal bearing hip replacements. There is currently no treatment for ARMD and once progressive, early revision surgery of the implant is necessary. Therapeutic agents to prevent, halt or reverse ARMD would therefore be advantageous. Cobalt ions activate Toll-like receptor 4 (TLR4), an innate immune receptor responsible for inflammatory responses to bacterial lipopolysaccharide (LPS) resulting in the production of pro-inflammatory cytokines and chemokines. We hypothesised that anti-TLR4 neutralising antibodies, reported to inhibit TLR4-mediated inflammation, could prevent the inflammatory response to cobalt ions in an in vitro macrophage cell culture model. This study shows that a monoclonal anti-TLR4 antibody inhibited cobalt-mediated increases in pro-inflammatory IL8, CCL20 and IL1A expression, as well as IL-8 secretion. In contrast, a polyclonal antibody did not prevent the effect of cobalt ions on either IL-8 or IL1A expression, although it did have a small effect on the CCL20 response. Interestingly, both antibodies inhibited cobalt-mediated neutrophil migration although the greater effect was observed with the monoclonal antibody. In summary our data shows that a monoclonal anti-TLR4 antibody can inhibit cobalt-mediated inflammatory responses while a polyclonal antibody only inhibits the effect of specific cytokines. Anti-TLR4 antibodies have therapeutic potential in ARMD although careful antibody design is required to ensure that the LPS response is preserved.

  20. Toll-Like Receptor 4 Is Essential in the Development of Abdominal Aortic Aneurysm.

    Directory of Open Access Journals (Sweden)

    Chao-Han Lai

    Full Text Available Toll-like receptor (TLR family plays a key role in innate immunity and various inflammatory responses. TLR4, one of the well-characterized pattern-recognition receptors, can be activated by endogenous damage-associated molecular pattern molecules such as high mobility group box 1 (HMGB1 to sustain sterile inflammation. Evidence suggested that blockade of TLR4 signaling may confer protection against abdominal aortic aneurysm (AAA. Herein we aimed to obtain further insight into the mechanism by which TLR4 might promote aneurysm formation. Characterization of the CaCl2-induced AAA model in mice revealed that upregulation of TLR4 expression, localized predominantly to vascular smooth muscle cells (VSMCs, was followed by a late decline during a 28-day period of AAA development. In vitro, TLR4 expression was increased in VSMCs treated with HMGB1. Knockdown of TLR4 by siRNA attenuated HMGB1-enhanced production of proinflammatory cytokines, specifically interleukin-6 and monocyte chemoattractant protein-1 (MCP-1, and matrix-degrading matrix metalloproteinase (MMP-2 from VSMCs. In vivo, two different strains of TLR4-deficient (C57BL/10ScNJ and C3H/HeJ mice were resistant to CaCl2-induced AAA formation compared to their respective controls (C57BL/10ScSnJ and C3H/HeN. Knockout of TLR4 reduced interleukin-6 and MCP-1 levels and HMGB1 expression, attenuated macrophage accumulation, and eventually suppressed MMP production, elastin destruction and VSMC loss. Finally, human AAA exhibited higher TLR4 expression that was localized to VSMCs. These data suggest that TLR4 signaling contributes to AAA formation by promoting a proinflammatory status of VSMCs and by inducing proteinase release from VSMCs during aneurysm initiation and development.

  1. Toll-like receptor signaling: a perspective to develop vaccine against leishmaniasis.

    Science.gov (United States)

    Singh, Rakesh K; Srivastava, Ankita; Singh, Nisha

    2012-09-01

    The toll-like receptors (TLRs) are the sentinel factor of the innate immunity, which are essential for host defense. These receptors detect the presence of conserved molecular patterns of potentially pathogenic microorganisms and contribute in both, cellular as well as humoral immune responses. Leishmania is an intracellular pathogen that silently invades host immune system. After phagocytosis, it divides and proliferates in the harmful environment of host macrophages by down-regulating its vital effector functions. In leishmaniasis, the outcome of the infection basically relies on the skewed balance between Th1/Th2 immune responses. Lots of work have been done and on progress but still characterization of either preventive or prophylactic candidate antigen/s is far from satisfactory. How does Leishmania regulate host innate immune system? Still it is unanswered. TLRs play very important role during inflammatory process of various diseases such as cancer, bacterial and viral infections but TLR signaling is comparatively less explained in leishmanial infection. In the context to Th1/Th2 dichotomy, identification of leishmanial antigens that modulate toll-like receptor signaling will certainly help in the development of future vaccine. This review will initially describe global properties of TLRs, and later will discuss their role in the pathogenesis of leishmaniasis.

  2. Intracellular expression of toll-like receptor 4 in neuroblastoma cells and their unresponsiveness to lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Mori Isamu

    2006-12-01

    Full Text Available Abstract Background Recently it has been reported that, toll-like receptors (TLRs are expressed on a series of tumor cells, such as colon cancer, breast cancer, prostate cancer, melanoma and lung cancer. Although some cancer cells like melanoma cells are known to respond to lipopolysaccharide (LPS via TLR4, not all cancer cells are positive for TLR4. There is little information on the expression and function of TLR4 in neuroblastoma cells. In this study, we investigated the expression of TLR4 in human neuroblastoma NB-1 cell line. Methods Expression and localization of TLR4 were detected by reverse transcription-polymerase chain reaction (RT-PCR and flow cytometric analysis, respectively. Activation of nuclear factor (NF-κB by LPS was detected by degradation of IκB-α and NF-κB luciferase assay. Activation and expression of mitogen-activated protein (MAP kinase and interferon regulatory factor (IRF-3 was detected by immunoblot analysis. Results Human NB-1 neuroblastoma cells expressed intracellular form of TLR4, but not the cell surface form. Further, NB-1 cells express CD14, MD2 and MyD88, which are required for LPS response. However, LPS did not significantly induce NF-κB activation in NB-1 cells although it slightly degraded IκB-α. NB-1 cells expressed no IRF-3, which plays a pivotal role on the MyD88-independent pathway of LPS signaling. Collectively, NB-1 cells are capable to avoid their response to LPS. Conclusion Although human NB-1 neuroblastoma cells possessed all the molecules required for LPS response, they did not respond to LPS. It might be responsible for intracellular expression of TLR4 or lack of IRF-3.

  3. Induction of bacterial lipoprotein tolerance is associated with suppression of toll-like receptor 2 expression.

    LENUS (Irish Health Repository)

    Wang, Jiang Huai

    2012-02-03

    Tolerance to bacterial cell wall components including lipopolysaccharide (LPS) may represent an essential regulatory mechanism during bacterial infection. Two members of the Toll-like receptor (TLR) family, TLR2 and TLR4, recognize the specific pattern of bacterial cell wall components. TLR4 has been found to be responsible for LPS tolerance. However, the role of TLR2 in bacterial lipoprotein (BLP) tolerance and LPS tolerance is unclear. Pretreatment of human THP-1 monocytic cells with a synthetic bacterial lipopeptide induced tolerance to a second BLP challenge with diminished tumor necrosis factor-alpha and interleukin-6 production, termed BLP tolerance. Furthermore, BLP-tolerized THP-1 cells no longer responded to LPS stimulation, indicating a cross-tolerance to LPS. Induction of BLP tolerance was CD14-independent, as THP-1 cells that lack membrane-bound CD14 developed tolerance both in serum-free conditions and in the presence of a specific CD14 blocking monoclonal antibody (MEM-18). Pre-exposure of THP-1 cells to BLP suppressed mitogen-activated protein kinase phosphorylation and nuclear factor-kappaB activation in response to subsequent BLP and LPS stimulation, which is comparable with that found in LPS-tolerized cells, indicating that BLP tolerance and LPS tolerance may share similar intracellular pathways. However, BLP strongly enhanced TLR2 expression in non-tolerized THP-1 cells, whereas LPS stimulation had no effect. Furthermore, a specific TLR2 blocking monoclonal antibody (2392) attenuated BLP-induced, but not LPS-induced, tumor necrosis factor-alpha and interleukin-6 production, indicating BLP rather than LPS as a ligand for TLR2 engagement and activation. More importantly, pretreatment of THP-1 cells with BLP strongly inhibited TLR2 activation in response to subsequent BLP stimulation. In contrast, LPS tolerance did not prevent BLP-induced TLR2 overexpression. These results demonstrate that BLP tolerance develops through down-regulation of TLR2

  4. Lack of Association between Toll Like Receptor-2 and Toll Like Receptor-4 Gene Polymorphisms and Other Feature in Iranian Asthmatics Patients.

    Directory of Open Access Journals (Sweden)

    Hamid Bahrami

    2015-02-01

    Full Text Available Asthma as a chronic inflammatory airway disease is considered to be the most common chronic disease that is involving genetic and environmental factors. Toll like receptors (TLRs and other inflammatory mediators are important in modulation of inflammation. In this study, we evaluated the role of TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms in the asthma susceptibility, progress, control levels and lung functions in Iranian patients. On 99 asthmatic patients and 120 normal subjects, TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms were evaluated by PCR-RFLP method recruiting Msp1 and Nco1 restriction enzymes, respectively. IgE serum levels by ELISA technique were determined and asthma diagnosis, treatment and control levels were considered using standard schemes and criteria. Our results indicated that the genotype and allele frequencies of the TLR2 Arg753Gln and TLR4 Asp299Gly polymorphisms were not significantly different between control subjects and asthmatics and were not related to in asthma features such as IgE levels, asthma history and pulmonary factors. Wherease some previous studies indicated TLRs and their polymorphisms might have some role in asthma incidence and features, our data demonstrated that TLR2 Arg753Gln and TLR4 Asp299Gly gene variants were not risk factors for asthma or its features in Iranian patients. Genetic complexity, ethnicity, influence of other genes or polymorphisms may overcome these polymorphisms in our asthmatics.

  5. Synthetic Toll like receptor-4 (TLR-4 agonist peptides as a novel class of adjuvants.

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    Arulkumaran Shanmugam

    Full Text Available BACKGROUND: Adjuvants serve as catalysts of the innate immune response by initiating a localized site of inflammation that is mitigated by the interactions between antigens and toll like receptor (TLR proteins. Currently, the majority of vaccines are formulated with aluminum based adjuvants, which are associated with various side effects. In an effort to develop a new class of adjuvants, agonists of TLR proteins, such as bacterial products, would be natural candidates. Lipopolysaccharide (LPS, a major structural component of gram negative bacteria cell walls, induces the systemic inflammation observed in septic shock by interacting with TLR-4. The use of synthetic peptides of LPS or TLR-4 agonists, which mimic the interaction between TLR-4 and LPS, can potentially regulate cellular signal transduction pathways such that a localized inflammatory response is achieved similar to that generated by adjuvants. METHODOLOGY/PRINCIPAL FINDINGS: We report the identification and activity of several peptides isolated using phage display combinatorial peptide technology, which functionally mimicked LPS. The activity of the LPS-TLR-4 interaction was assessed by NF-κB nuclear translocation analyses in HEK-BLUE™-4 cells, a cell culture model that expresses only TLR-4, and the murine macrophage cell line, RAW264.7. Furthermore, the LPS peptide mimics were capable of inducing inflammatory cytokine secretion from RAW264.7 cells. Lastly, ELISA analysis of serum from vaccinated BALB/c mice revealed that the LPS peptide mimics act as a functional adjuvant. CONCLUSIONS/SIGNIFICANCE: Our data demonstrate the identification of synthetic peptides that mimic LPS by interacting with TLR-4. This LPS mimotope-TLR-4 interaction will allow for the development and use of these peptides as a new class of adjuvants, namely TLR-4 agonists.

  6. The Toll-Like receptor adaptor TRIF contributes to otitis media pathogenesis and recovery

    Directory of Open Access Journals (Sweden)

    Pak Kwang

    2009-08-01

    Full Text Available Abstract Background Toll-like receptor (TLR signalling is crucial for innate immune responses to infection. The involvement of TLRs in otitis media (OM, the most prevalent childhood disease in developed countries, has been implicated by studies in middle ear cell lines, by association studies of TLR-related gene polymorphisms, and by altered OM in mice bearing mutations in TLR genes. Activated TLRs signal via two alternative intracellular signaling molecules with differing effects; MyD88 (Myeloid differentiation primary response gene 88 inducing primarily interleukin expression and TRIF (Tir-domain-containing adaptor inducing interferon β mediating type I interferon (IFN expression. We tested the hypothesis that TRIF and type I IFN signaling play a role in OM, using a murine model of OM induced by non-typeable Haemophilus influenzae (NTHi. The ME inflammatory response to NTHi was examined in wild-type (WT and TRIF-/- mice by qPCR, gene microarray, histopathology and bacterial culture. Results Expression of TRIF mRNA was only modesty enhanced during OM, but both type I IFN signalling genes and type I IFN-inducible genes were significantly up-regulated in WT mice. TRIF-deficient mice showed reduced but more persistent mucosal hyperplasia and less leukocyte infiltration into the ME in response to NTHi infection than did WT animals. Viable bacteria could be cultured from MEs of TRIF-/- mice for much longer in the course of disease than was the case for middle ears of WT mice. Conclusion Our results demonstrate that activation of TRIF/type I IFN responses is important in both the pathogenesis and resolution of NTHi-induced OM.

  7. Protective effect of Toll-like receptor 4 in pulmonary vaccinia infection.

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    Martha A Hutchens

    Full Text Available Innate immune responses are essential for controlling poxvirus infection. The threat of a bioterrorist attack using Variola major, the smallpox virus, or zoonotic transmission of other poxviruses has renewed interest in understanding interactions between these viruses and their hosts. We recently determined that TLR3 regulates a detrimental innate immune response that enhances replication, morbidity, and mortality in mice in response to vaccinia virus, a model pathogen for studies of poxviruses. To further investigate Toll-like receptor signaling in vaccinia infection, we first focused on TRIF, the only known adapter protein for TLR3. Unexpectedly, bioluminescence imaging showed that mice lacking TRIF are more susceptible to vaccinia infection than wild-type mice. We then focused on TLR4, the other Toll-like receptor that signals through TRIF. Following respiratory infection with vaccinia, mice lacking TLR4 signaling had greater viral replication, hypothermia, and mortality than control animals. The mechanism of TLR4-mediated protection was not due to increased release of proinflammatory cytokines or changes in total numbers of immune cells recruited to the lung. Challenge of primary bone marrow macrophages isolated from TLR4 mutant and control mice suggested that TLR4 recognizes a viral ligand rather than an endogenous ligand. These data establish that TLR4 mediates a protective innate immune response against vaccinia virus, which informs development of new vaccines and therapeutic agents targeted against poxviruses.

  8. Toll-like receptor-2 and -4 are associated with hyperlipidemia.

    Science.gov (United States)

    Zhu, Ya-Jun; Wang, Chao; Song, Guangyao; Zang, Sha-Sha; Liu, Yi-Xuan; Li, Ling

    2015-12-01

    Recent studies have suggested that toll-like receptors (TLRs) contribute to insulin resistance, and that fatty acids have a role in TLR activation. Other studies have found that TLR2 and TLR4 upregulation is consistent with an increase in serum lipid. Therefore, it was hypothesized that TLRs are associated with hyperlipidemia. The aim of the present study was to investigate whether TLR2 or TLR4 was associated with hyperlipidemia and to provide novel targets for hyperlipidemia therapy. Volunteers were selected at the Medical Examination Center of Hebei General Hospital (Shijiazhuang, China), including 43 patients with high triglyceride (TG) levels, 84 with high total cholesterol (TC) levels and 55 with high TG and high TC levels. In addition, 68 healthy volunteers were selected as a control group. For the animal study, the TLR gene and protein levels were assessed in the skeletal muscle of rats fed a high‑fat diet. As expected, TLR2 and TLR4 gene expression were upregulated when TC increased, TG increased, or TC and TG increased. In rats fed a high‑fat diet, the levels of gene and protein expression in the skeletal muscle of the two TLRs were all increased compared with the control group, this was consistent with an increase in TC and TG. In addition, in drug treatment groups the mRNA and protein expression levels of TLR in the skeletal muscle of rats fed a high fat diet were decreased, as were the TC and TG levels. In conclusion, these findings suggest that TLR2 and TLR4 are associated with hyperlipidemia.

  9. Association of bovine Toll-like receptor 4 with tick infestation rates and blood histamine concentration.

    Science.gov (United States)

    Zhao, G; Yu, M; Cui, Q-W; Zhou, X; Zhang, J-C; Li, H-X; Qu, K-X; Wang, G-L; Huang, B-Z

    2013-01-01

    We investigated a possible association between bovine Toll-like receptor 4 (TLR4) and resistance to tick infestation in 103 cattle, including BMY cattle (1/2 Brahman, 1/4 Murray Grey, and 1/4 Yunnan Yellow cattle), Brahman, and Red Angus grazing on improved pasture. The tick infestation weight and number of Rhipicephalus microplus and the blood histamine concentration were measured and compared with those of 32 Chinese Holsteins and 30 Simmentals. A 228-bp fragment was amplified and sequenced to analyze the polymorphisms of the TLR4 gene. After SSCP and sequencing analysis, 4 SNPs, i.e., 535(A>C), 546(T>C), 605(T>A), and 618(G>C), were identified, corresponding to GenBank accession Nos. AY297041 and NW_003104150; the latter two SNPs caused Leu→Gln and Gln→His substitutions, respectively. Genotype AA was completely predominant in the Chinese Holstein and Simmental; genotypes AA and AB were detected in Red Angus, while genotypes AA, AB, BB, and BC were detected in Brahman and in BMY cattle. A negative correlation was identified between blood histamine concentration and number of tick infestation; in BMY cattle this negative association was significant. The tick infestation in cattle with genotype BB was significantly lower than in those with genotype AA. Blood histamine concentration in cattle with genotype BB was significantly higher than in those with genotype AA. The TLR4 gene mutation could affect the blood histamine level and activate the immune reaction after tick infestation. Allele B has potential as a molecular marker for tick-resistance originated from Zebu cattle for use in cattle breeding programs. PMID:23479166

  10. Polymorphisms in Toll-like receptor genes are associated with vitiligo

    Directory of Open Access Journals (Sweden)

    Tanel eTraks

    2015-09-01

    Full Text Available Background: The family of Toll-like receptors (TLRs are responsible for recognising various molecular patterns associated with pathogens. Their expression is not confined to immune cells and have been detected in skin cells such as keratinocytes and melanocytes. As part of a generated response to pathogens, TLRs are involved in inducing inflammatory mediators to combat these threats. It is therefore not surprising that TLRs have been implicated in inflammatory skin diseases, including atopic dermatitis and psoriasis. Likewise, as key players in autoimmunity, they have been associated with a number of autoimmune diseases. Based on this, the role of TLRs in vitiligo could be suspected, but is yet to be clearly established.Methods: In order to conduct a genetic association analysis, 30 SNPs were selected from TLR1-TLR8 and TLR10 regions to be genotyped in Estonian case-control cohort consisting of 139 vitiligo patients and 307 healthy control individuals. The patients were further analysed in subgroups based on sex, age of onset, occurrence of vitiligo among relatives, extent of depigmented areas, vitiligo progression activity, appearance of Köbner’s phenomenon, existence of halo naevi, and incidence of spontaneous repigmentation.Results: The most notable finding came with SNP rs179020 situated in TLR7 gene, that was associated in entire vitiligo (Padj = 0.0065 and also several subgroup analyses. Other single marker and haplotype analyses pointed to TLR3, TLR4 and TLR10 genes.Conclusions: This study investigated the genetic regions of nine TLR genes in relation to vitiligo susceptibility. The main results were the associations of TLR7 SNPs with vitiligo, while several other associations were obtained from the remaining TLR gene regions. This suggests that in addition to other inflammatory skin diseases, TLRs affect the development of vitiligo, thus making them interesting targets for future research.

  11. Herpes simplex virus induces neural oxidative damage via microglial cell Toll-like receptor-2

    Directory of Open Access Journals (Sweden)

    Little Morgan R

    2010-06-01

    Full Text Available Abstract Background Using a murine model of herpes simplex virus (HSV-1 encephalitis, our laboratory has determined that induction of proinflammatory mediators in response to viral infection is largely mediated through a Toll-like receptor-2 (TLR2-dependent mechanism. Published studies have shown that, like other inflammatory mediators, reactive oxygen species (ROS are generated during viral brain infection. It is increasingly clear that ROS are responsible for facilitating secondary tissue damage during central nervous system infection and may contribute to neurotoxicity associated with herpes encephalitis. Methods Purified microglial cell and mixed neural cell cultures were prepared from C57B/6 and TLR2-/- mice. Intracellular ROS production in cultured murine microglia was measured via 2', 7'-Dichlorofluorescin diacetate (DCFH-DA oxidation. An assay for 8-isoprostane, a marker of lipid peroxidation, was utilized to measure free radical-associated cellular damage. Mixed neural cultures obtained from β-actin promoter-luciferase transgenic mice were used to detect neurotoxicity induced by HSV-infected microglia. Results Stimulation with HSV-1 elevated intracellular ROS in wild-type microglial cell cultures, while TLR2-/- microglia displayed delayed and attenuated ROS production following viral infection. HSV-infected TLR2-/- microglia produced less neuronal oxidative damage to mixed neural cell cultures in comparison to HSV-infected wild-type microglia. Further, HSV-infected TLR2-/- microglia were found to be less cytotoxic to cultured neurons compared to HSV-infected wild-type microglia. These effects were associated with decreased activation of p38 MAPK and p42/p44 ERK in TLR2-/- mice. Conclusions These studies demonstrate the importance of microglial cell TLR2 in inducing oxidative stress and neuronal damage in response to viral infection.

  12. Role of Toll-like receptor 4 and human defensin 5 in primary endocervical epithelial cells

    Institute of Scientific and Technical Information of China (English)

    MA Jing-mei; YANG Hui-xia

    2010-01-01

    Background Endocervical epithelial cells play early roles in the defense of upper female genital tract to pathogens. Toll-like receptors (TLRs) and human defensins (HD) have recently been identified as fundamental components of the innate immune responses to bacterial pathogens. We aimed to use in vitro model of human primary endocervical epithelial cells (HPECs) to investigate their roles in innate immune response of the endocervix.Methods TLR4 expression and distribution in HPECs and endocervix were investigated by immunofluorescence (IF). Cultured HPECs were divided into lipopolysaccharide (LPS) group which were treated by LPS for 0, 24 and 48 hours, and control group without treatment. At each time point, the levels of HD5, IL-6 and TNF-a in supernants were determined by ELISA. TLR4 and HD5 expressions of cells were detected by Western blotting simultaneously. HD5 expression pattern was also compared between the HeLa cell line and HPECs.Results Endocervix tissue surface and HPECs expressed TLR4. After incubated with LPS, HPECs expressed significantly higher levels of TLR4 than control group, especially after 24 hours (P <0.01), however decreased after 48 hours with a similar level of TLR4 expression compared with control group. LPS could upregulate the secretion of HD5, IL-6 and TNF-α in a time-dependent manner (24 hours: P <0.05; 48 hours: P <0.01, compared with control group). Intracellular HD5 expression levels decreased over time. HD5 expression patterns in HPECs were different from HeLa cell line.Conclusions To respond to LPS stimulation, HPECs may function in the mucosal immune defense through TLR4 activation and HD5 secretion. HPEC is considered a significant model for immunological study.

  13. Lipopolysaccharide and toll-like receptor 4 in dogs with congenital portosystemic shunts.

    Science.gov (United States)

    Tivers, M S; Lipscomb, V J; Smith, K C; Wheeler-Jones, C P D; House, A K

    2015-12-01

    Surgical attenuation of a congenital portosystemic shunt (CPSS) results in increased portal vein perfusion, liver growth and clinical improvement. Portal lipopolysaccharide (LPS) is implicated in liver regeneration via toll-like receptor (TLR) 4 mediated cytokine activation. The aim of this study was to investigate factors associated with LPS in dogs with CPSS. Plasma LPS concentrations were measured in the peripheral and portal blood using a limulus amoebocyte lysate (LAL) assay. LPS concentration was significantly greater in the portal blood compared to peripheral blood in dogs with CPSS (P = 0.046) and control dogs (P = 0.002). LPS concentrations in the peripheral (P = 0.012) and portal (P = 0.005) blood of dogs with CPSS were significantly greater than those of control dogs. The relative mRNA expression of cytokines and TLRs was measured in liver biopsies from dogs with CPSS using quantitative PCR. TLR4 expression significantly increased following partial CPSS attenuation (P = 0.020). TLR4 expression was significantly greater in dogs that tolerated complete CPSS attenuation (P = 0.011) and those with good portal blood flow on pre-attenuation (P = 0.004) and post-attenuation (P = 0.015) portovenography. Serum interleukin (IL)-6 concentration was measured using a canine specific ELISA and significantly increased 24 h following CPSS attenuation (P < 0.001). Portal LPS was increased in dogs with CPSS, consistent with decreased hepatic clearance. TLR4 mRNA expression was significantly associated with portal blood flow and increased following surgery. These findings support the concept that portal LPS delivery is important in the hepatic response to surgical attenuation. Serum IL-6 significantly increased following surgery, consistent with LPS stimulation via TLR4, although this increase might be non-specific. PMID:26383860

  14. Toll-like receptor 4 contributes to acute kidney injury after cardiopulmonary resuscitation in mice

    Science.gov (United States)

    Zhang, Qingsong; Li, Gang; Xu, Li; Li, Qian; Wang, Qianyan; Zhang, Yue; Zhang, Qing; Sun, Peng

    2016-01-01

    Toll-like receptor 4 (TLR4) activation mediates renal injury in regional ischemia and reperfusion (I/R) models generated by clamping renal pedicles. However, it remains unclear whether TLR4 is causal in the kidney injury following global I/R induced by cardiac arrest (CA) and cardiopulmonary resuscitation (CPR). The present study used wild-type (C3H/HeN) and TLR4-mutant (C3H/HeJ) mice to produce the CA/CPR model. CA was induced by injection of cold KCl and left untreated for different time periods. After resuscitation (72 h), the level of blood urea nitrogen (BUN) and serum creatinine (Scr), as well as histological changes in renal tissue were assessed to evaluate the severity of acute kidney injury (AKI). The expression of TLR4, intercellular adhesion molecule-1 (ICAM-1), myeloperoxidase (MPO) and growth-regulated oncogene-β (GRO-β) in kidney tissues was detected. The results demonstrated that the levels of Scr and BUN increased significantly in C3H/HeN and C3H/HeJ mice after CPR. CPR also resulted in increased expression of TLR4, ICAM-1, GRO-β and MPO in a CA-duration dependent manner. However, there was decreased expression of ICAM-1, GRO-β and MPO in C3H/HeJ mice compared with that in C3H/HeN mice. C3H/HeJ mice were resistant to AKI as demonstrated by the minor changes in renal histology and function following CPR. In conclusion, mice suffered from AKI after successful CPR and severe AKI occurred in mice with prolonged CA duration. TLR4 and its downstream signaling events that promote neutrophil infiltration via ICAM-1 and GRO-β may be important in mediating inflammatory responses to renal injury after CPR. PMID:27510583

  15. Bovine Viral Diarrhea Virus Type 2 Impairs Macrophage Responsiveness to Toll-Like Receptor Ligation with the Exception of Toll-Like Receptor 7.

    Directory of Open Access Journals (Sweden)

    Robert G Schaut

    Full Text Available Bovine viral diarrhea virus (BVDV is a member of the Flaviviridae family. BVDV isolates are classified into two biotypes based on the development of cytopathic (cp or non-cytopathic (ncp effects in epithelial cell culture. BVDV isolates are further separated into species, BVDV1 and 2, based on genetic differences. Symptoms of BVDV infection range from subclinical to severe, depending on strain virulence, and may involve multiple organ systems and induction of a generalized immunosuppression. During BVDV-induced immune suppression, macrophages, critical to innate immunity, may have altered pathogen recognition receptor (PRR signaling, including signaling through toll-like receptors (TLRs. Comparison of BVDV 2 strains with different biotypes and virulence levels is valuable to determining if there are differences in host macrophage cellular responses between viral phenotypes. The current study demonstrates that cytopathic (cp, noncytopathic (ncp, high (hv or low virulence (lv BVDV2 infection of bovine monocyte-derived macrophages (MDMΦ result in differential expression of pro-inflammatory cytokines compared to uninfected MDMΦ. A hallmark of cp BVDV2 infection is IL-6 production. In response to TLR2 or 4 ligation, as might be observed during secondary bacterial infection, cytokine secretion was markedly decreased in BVDV2-infected MDMΦ, compared to non-infected MDMΦ. Macrophages were hyporesponsive to viral TLR3 or TLR8 ligation. However, TLR7 stimulation of BVDV2-infected MDMΦ induced cytokine secretion, unlike results observed for other TLRs. Together, these data suggest that BVDV2 infection modulated mRNA responses and induced a suppression of proinflammatory cytokine protein responses to TLR ligation in MDMΦ with the exception of TLR7 ligation. It is likely that there are distinct differences in TLR pathways modulated following BVDV2 infection, which have implications for macrophage responses to secondary infections.

  16. Bovine Viral Diarrhea Virus Type 2 Impairs Macrophage Responsiveness to Toll-Like Receptor Ligation with the Exception of Toll-Like Receptor 7.

    Science.gov (United States)

    Schaut, Robert G; Ridpath, Julia F; Sacco, Randy E

    2016-01-01

    Bovine viral diarrhea virus (BVDV) is a member of the Flaviviridae family. BVDV isolates are classified into two biotypes based on the development of cytopathic (cp) or non-cytopathic (ncp) effects in epithelial cell culture. BVDV isolates are further separated into species, BVDV1 and 2, based on genetic differences. Symptoms of BVDV infection range from subclinical to severe, depending on strain virulence, and may involve multiple organ systems and induction of a generalized immunosuppression. During BVDV-induced immune suppression, macrophages, critical to innate immunity, may have altered pathogen recognition receptor (PRR) signaling, including signaling through toll-like receptors (TLRs). Comparison of BVDV 2 strains with different biotypes and virulence levels is valuable to determining if there are differences in host macrophage cellular responses between viral phenotypes. The current study demonstrates that cytopathic (cp), noncytopathic (ncp), high (hv) or low virulence (lv) BVDV2 infection of bovine monocyte-derived macrophages (MDMΦ) result in differential expression of pro-inflammatory cytokines compared to uninfected MDMΦ. A hallmark of cp BVDV2 infection is IL-6 production. In response to TLR2 or 4 ligation, as might be observed during secondary bacterial infection, cytokine secretion was markedly decreased in BVDV2-infected MDMΦ, compared to non-infected MDMΦ. Macrophages were hyporesponsive to viral TLR3 or TLR8 ligation. However, TLR7 stimulation of BVDV2-infected MDMΦ induced cytokine secretion, unlike results observed for other TLRs. Together, these data suggest that BVDV2 infection modulated mRNA responses and induced a suppression of proinflammatory cytokine protein responses to TLR ligation in MDMΦ with the exception of TLR7 ligation. It is likely that there are distinct differences in TLR pathways modulated following BVDV2 infection, which have implications for macrophage responses to secondary infections. PMID:27420479

  17. Role of toll-like receptors in acute gastrointestinal radiation syndrome

    International Nuclear Information System (INIS)

    Ionizing radiation induces various disorders according to the radiation sensitivity of each organ. Acute gastrointestinal radiation syndrome is a serious illness that is caused by exposure of gastrointestinal tract to high amounts of ionizing radiation in radiation accidents or radiation therapy in cancer treatment. Although the pathological mechanism have been well studied in human and animals, no effective treatments have been developed to date. The Toll-like receptor (TLR) family is one of the best-characterized families of innate immune receptors, which induce innate immune response against pathogen infection. However, contrary to their protective function, recent studies have suggested that immune responses triggered by TLRs play deleterious roles by aggravating tissue inflammation in some inflammatory and autoimmune diseases. This review describes recent advancement of our understanding of acute gastrointestinal radiation syndrome and the contributions of TLR to its pathological mechanisms. (author)

  18. T cells induce extended class II MHC compartments in dendritic cells in a Toll-like receptor-dependent manner.

    Science.gov (United States)

    Boes, Marianne; Bertho, Nicolas; Cerny, Jan; Op den Brouw, Marjolein; Kirchhausen, Tomas; Ploegh, Hidde

    2003-10-15

    Interaction of Ag-loaded dendritic cells with Ag-specific CD4 T cells induces the formation of long tubular class II MHC-positive compartments that polarize toward the T cell. We show involvement of a Toll-like receptor-mediated signal in this unusual form of intracellular class II MHC trafficking. First, wild-type dendritic cells loaded with LPS-free Ag failed to show formation of class II-positive tubules upon Ag-specific T cell engagement, but did so upon supplementation of the Ag with low concentrations of LPS. Second, Ag-loaded myeloid differentiation factor 88 -deficient dendritic cells failed to form these tubules upon interaction with T cells, regardless of the presence of LPS. Finally, inclusion of a cell-permeable peptide that blocks TNFR-associated factor 6 function, downstream of myeloid differentiation factor 88, blocked T cell-dependent tubulation. A Toll-like receptor-dependent signal is thus required to allow Ag-loaded dendritic cells to respond to T cell contact by formation of extended endosomal compartments. This activation does not result in massive translocation of class II MHC molecules to the cell surface.

  19. Inhibition of Toll-Like Receptor 2-Mediated Interleukin-8 Production in Cystic Fibrosis Airway Epithelial Cells via the α7-Nicotinic Acetylcholine Receptor

    OpenAIRE

    Shane J. O'Neill; McElvaney, Noel G; Wells, Robert J.; Hugh Ramsay; Greene, Catherine M

    2010-01-01

    Cystic Fibrosis (CF) is an inherited disorder characterised by chronic inflammation of the airways. The lung manifestations of CF include colonization with Pseudomonas aeruginosa and Staphylococcus aureus leading to neutrophil-dominated airway inflammation and tissue damage. Inflammation in the CF lung is initiated by microbial components which activate the innate immune response via Toll-like receptors (TLRs), increasing airway epithelial cell production of proinflammatory mediators such as ...

  20. Toll-like receptor 2 deficiency leads to delayed exacerbation of ischemic injury

    Directory of Open Access Journals (Sweden)

    Bohacek Ivan

    2012-08-01

    Full Text Available Abstract Background Using a live imaging approach, we have previously shown that microglia activation after stroke is characterized by marked and long-term induction of the Toll-like receptor (TLR 2 biophotonic signals. However, the role of TLR2 (and potentially other TLRs beyond the acute innate immune response and as early neuroprotection against ischemic injury is not well understood. Methods TLR2−/− mice were subjected to transient middle cerebral artery occlusion followed by different reperfusion times. Analyses assessing microglial activation profile/innate immune response were performed using in situ hybridization, immunohistochemistry analysis, flow cytometry and inflammatory cytokine array. The effects of the TLR2 deficiency on the evolution of ischemic brain injury were analyzed using a cresyl violet staining of brain sections with appropriate lesion size estimation. Results Here we report that TLR2 deficiency markedly affects post-stroke immune response resulting in delayed exacerbation of the ischemic injury. The temporal analysis of the microglia/macrophage activation profiles in TLR2−/− mice and age-matched controls revealed reduced microglia/macrophage activation after stroke, reduced capacity of resident microglia to proliferate as well as decreased levels of monocyte chemotactic protein-1 (MCP-1 and consequently lower levels of CD45high/CD11b+ expressing cells as shown by flow cytometry analysis. Importantly, although acute ischemic lesions (24 to 72 h were smaller in TLR2−/− mice, the observed alterations in innate immune response were more pronounced at later time points (at day 7 after initial stroke, which finally resulted in delayed exacerbation of ischemic lesion leading to larger chronic infarctions as compared with wild-type mice. Moreover, our results revealed that TLR2 deficiency is associated with significant decrease in the levels of neurotrophic/anti-apoptotic factor Insulin-like growth factor-1 (IGF-1

  1. DMPD: Inhibition of toll-like receptor and cytokine signaling--a unifying theme inischemic tolerance. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15545925 Inhibition of toll-like receptor and cytokine signaling--a unifying theme ...png) (.svg) (.html) (.csml) Show Inhibition of toll-like receptor and cytokine signaling--a unifying theme i...nischemic tolerance. PubmedID 15545925 Title Inhibition of toll-like receptor and... cytokine signaling--a unifying theme inischemic tolerance. Authors Kariko K, Weissman D, Welsh FA. Publicat

  2. DMPD: How Toll-like receptors signal: what we know and what we don't know. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16343886 How Toll-like receptors signal: what we know and what we don't know. O'Nei...ll LA. Curr Opin Immunol. 2006 Feb;18(1):3-9. Epub 2005 Dec 15. (.png) (.svg) (.html) (.csml) Show How Toll-...like receptors signal: what we know and what we don't know. PubmedID 16343886 Title How Toll-like receptors

  3. Toll-like receptors expressed by dermal fibroblasts contribute to hypertrophic scarring.

    Science.gov (United States)

    Wang, JianFei; Hori, Keijiro; Ding, Jie; Huang, Yue; Kwan, Peter; Ladak, Adil; Tredget, Edward E

    2011-05-01

    Hypertrophic scar (HTS), a fibroproliferative disorder (FPD), complicates burn wound healing. Although the pathogenesis is not understood, prolonged inflammation is a known contributing factor. Emerging evidence suggests that fibroblasts regulate immune/inflammatory responses through toll-like receptor 4 (TLR4) activated by lipopolysaccharide (LPS) through adaptor molecules, leading to nuclear factor kappa-light-chain-enhancer of activated B cells and mitogen-activated protein kinases activation, cytokine gene transcription and co-stimulatory molecule expression resulting in inflammation. This study explored the possible role of TLR4 in HTS formation. Paired normal and HTS tissue from burn patients was collected and dermal fibroblasts isolated and cultured. Immunohistochemical analysis of tissues demonstrated increased TLR4 staining in HTS tissue. Quantitative RT-PCR of three pairs of fibroblasts demonstrated mRNA levels for TLR4 and its legend myeloid differentiation factor 88 (MyD88) in HTS fibroblasts were increased significantly compared with normal fibroblasts. Flow cytometry showed increased TLR4 expression in HTS fibroblasts compared with normal. ELISA demonstrated protein levels for prostaglandin E2, interleukin (IL)-6, IL-8 and monocyte chemotactic protein-1 (MCP-1) were significantly increased in HTS fibroblasts compared to normal. When paired normal and HTS fibroblasts were stimulated with LPS, significant increases in mRNA and protein levels for MyD88, IL-6, IL-8, and MCP-1 were detected. However, when transfected with MyD88 small interfering RNA (siRNA), then stimulated with LPS, a significant decrease in mRNA and protein levels for these molecules compared to only LPS-stimulated fibroblasts was detected. In comparison, a scramble siRNA transfection did not affect mRNA or protein levels for these molecules. Results demonstrate LPS stimulates proinflammatory cytokine expression in dermal fibroblasts and MyD88 siRNA eliminates the expression. Therefore

  4. Toll-like receptor signaling in neonatal sepsis and inflammation: a matter of orchestration and conditioning.

    Science.gov (United States)

    Glaser, Kirsten; Speer, Christian P

    2013-12-01

    Altered neonatal Toll-like receptor (TLR) function is hypothesized to contribute to the heightened susceptibility to infection and perpetuated inflammation in term and preterm neonates, clinically evident in neonatal sepsis and increased rates of inflammatory disorders. Current data indicate that basal TLR expression in term neonates equals adult expression patterns, while expression in preterm infants seems to increase, depending on gestational age. Regarding TLR signaling, some studies suggest TLR incompetence in neonates associated with impaired pro-inflammatory responses, others describe neonatal TLR function well developed and allude to its hyper-inflammation tendency. We discuss the competing positions and considerable limitations of research approaches and conclude that neonatal innate immunity is not generally less able to respond to TLR stimulation. Moreover, we describe pre-conditioning factors other than immaturity having a comparable impact. In the long term, better understanding of the complex interplay of pre- and postnatal conditions and maturation-dependent neonatal TLR function may provide new therapeutic approaches.

  5. Modulation of Toll-like receptor signaling in innate immunity by natural products.

    Science.gov (United States)

    Chen, Luxi; Yu, Jianhua

    2016-08-01

    For centuries, natural products and their derivatives have provided a rich source of compounds for the development of new immunotherapies in the treatment of human disease. Many of these compounds are currently undergoing clinical trials, particularly as anti-oxidative, anti-microbial, and anti-cancer agents. However, the function and mechanism of natural products in how they interact with our immune system has yet to be extensively explored. Natural immune modulators may provide the key to control and ultimately defeat disorders affecting the immune system. They can either up- or down-regulate the immune response with few undesired adverse effects. In this review, we summarize the recent advancements made in utilizing natural products for immunomodulation and their important molecular targets, members of the Toll-like receptor (TLR) family, in the innate immune system. PMID:26899347

  6. Toll-like receptors in human papillomavirus infection-associated diseases%Toll样受体与HPV感染相关疾病研究进展

    Institute of Scientific and Technical Information of China (English)

    汤怡; 周强; 程浩

    2011-01-01

    Human papillomavirus (HPV) can cause verrucous hyperplasia of skin and mucosa,and is known as a causative factor of malignant tumors such as cervical cancer.By recognizing pathogen-associated molecular patterns,Toll-like receptors can trigger innate immune response and activate adaptive immunity.To the current knowledge,the expression of Toll-like receptors is abnormal in HPV-infected hosts,and Toll-like receptor agonists have proved to be effective for the treatment of HPV infection-associated diseases.This review states the relationship between Toll-like receptors and HPV infection-associated diseases as well as recent advances in Toll-like receptor agonists as a treatment choice for HPV infection-associated diseases.%人乳头瘤病毒感染引起皮肤、黏膜疣状增生,且与宫颈癌等恶性肿瘤的发生密切相关.Toll样受体能特异性识别微生物病原相关分子模式,启动天然免疫应答并激活获得性免疫反应.研究表明,某些Toll样受体在人乳头瘤病毒感染宿主表达异常,Toll样受体激动剂对人乳头瘤病毒感染相关疾病具有治疗作用.概述Toll样受体及其与人乳头瘤病毒感染相关疾病的关系以及Toll样受体激动剂在人乳头瘤病毒感染相关疾病治疗中的研究现状.

  7. Immune Modulation by Different Types of β2→1-Fructans Is Toll-Like Receptor Dependent

    NARCIS (Netherlands)

    Vogt, L.; Ramasamy, U.; Meyer, D.; Pullens, G.; Venema, K.; Faas, M.M.; Schols, H.A.; Vos, P. de

    2013-01-01

    Introduction:β2→1-fructans are dietary fibers. Main objectives of this study were 1) to demonstrate direct signalling of β2→1-fructans on immune cells, 2) to study whether this is mediated by the pattern recognition receptors Toll-like receptors (TLRs) and nucleotide-binding oligomerisation domain-c

  8. Immune Modulation by Different Types of ß2¿1-Fructans Is Toll-Like Receptor Dependent

    NARCIS (Netherlands)

    Vogt, L.; Ramasamy, U.; Meyer, D.; Pullens, G.; Venema, K.; Faas, M.M.; Schols, H.A.; Vos, de P.

    2013-01-01

    Introduction ß2¿1-fructans are dietary fibers. Main objectives of this study were 1) to demonstrate direct signalling of ß2¿1-fructans on immune cells, 2) to study whether this is mediated by the pattern recognition receptors Toll-like receptors (TLRs) and nucleotide-binding oligomerisation domain-c

  9. microRNA-26a modulates inflammatory response induced by toll-like receptor 4 stimulation in microglia.

    Science.gov (United States)

    Kumar, Asit; Bhatia, Harsharan Singh; de Oliveira, Antonio Carlos Pinheiro; Fiebich, Bernd L

    2015-12-01

    MiRNAs, a family of small non-coding RNAs, have emerged as novel post-transcriptional regulators of numerous cellular responses. Although the involvement of miRNAs in the regulation of neuroinflammation in various neurological diseases has been previously studied, their role in the production of inflammatory mediators during microglia activation is poorly understood. In this study, the role of miR-26a has been investigated in the modulation of inflammatory response in cultured microglia. Using real-time PCR, the expression of miR-26a was studied in toll-like receptors 4 stimulated primary mouse microglia. miR-26a expression was found to be rapidly reduced after the stimulation of toll-like receptors 4 in microglia. Over-expression of miR-26a significantly decreased the production of inflammatory cytokines such as tumor necrosis factor α and IL-6, whereas knockdown of miR-26a increased the expression of these mediators. Furthermore, using in silico analysis, we identified that the activating transcription factor (ATF) 2 is directly targeted by miR-26a. This finding was confirmed by loss and gain of function studies. Similar to the effect of miR-26a over-expression, knockdown of activating transcription factor 2 inhibited the production of proinflammatory cytokines, particularly IL-6. Taken together, our results suggest the involvement of miR-26a in the regulation of the production of proinflammatory cytokines in microglia. We proposed that in microglia, activation of toll-like receptor 4 (TLR4) by lipopolysaccharide (LPS) down-regulates miR-26a. The down-regulation of this miR increases expression of activating transcription factor 2 (ATF2). This event, in addition to the activation of ATF2 by c-Jun N-terminal kinase (JNK), increases interleukin-6 (IL-6) production. On the other hand, miR-26a also increases the production of tumor necrosis factor α (TNFα) by a mechanism independent of ATF2.

  10. Serine dipeptide lipids of Porphyromonas gingivalis inhibit osteoblast differentiation: Relationship to Toll-like receptor 2.

    Science.gov (United States)

    Wang, Yu-Hsiung; Nemati, Reza; Anstadt, Emily; Liu, Yaling; Son, Young; Zhu, Qiang; Yao, Xudong; Clark, Robert B; Rowe, David W; Nichols, Frank C

    2015-12-01

    Porphyromonas gingivalis is a periodontal pathogen strongly associated with loss of attachment and supporting bone for teeth. We have previously shown that the total lipid extract of P. gingivalis inhibits osteoblast differentiation through engagement of Toll-like receptor 2 (TLR2) and that serine dipeptide lipids of P. gingivalis engage both mouse and human TLR2. The purpose of the present investigation was to determine whether these serine lipids inhibit osteoblast differentiation in vitro and in vivo and whether TLR2 engagement is involved. Osteoblasts were obtained from calvaria of wild type or TLR2 knockout mouse pups that also express the Col2.3GFP transgene. Two classes of serine dipeptide lipids, termed Lipid 654 and Lipid 430, were tested. Osteoblast differentiation was monitored by cell GFP fluorescence and osteoblast gene expression and osteoblast function was monitored as von Kossa stained mineral deposits. Osteoblast differentiation and function were evaluated in calvarial cell cultures maintained for 21 days. Lipid 654 significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation and this inhibition was dependent on TLR2 engagement. Lipid 430 also significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation but these effects were only partially attributed to engagement of TLR2. More importantly, Lipid 430 stimulated TNF-α and RANKL gene expression in wild type cells but not in TLR2 knockout cells. Finally, osteoblast cultures were observed to hydrolyze Lipid 654 to Lipid 430 and this likely occurs through elevated PLA2 activity in the cultured cells. In conclusion, our results show that serine dipeptide lipids of P. gingivalis inhibit osteoblast differentiation and function at least in part through engagement of TLR2. The Lipid 430 serine class also increased the expression of genes that could increase osteoclast activity. We conclude that Lipid 654 and Lipid 430 have the potential

  11. Serine dipeptide lipids of Porphyromonas gingivalis inhibit osteoblast differentiation: Relationship to Toll-like receptor 2.

    Science.gov (United States)

    Wang, Yu-Hsiung; Nemati, Reza; Anstadt, Emily; Liu, Yaling; Son, Young; Zhu, Qiang; Yao, Xudong; Clark, Robert B; Rowe, David W; Nichols, Frank C

    2015-12-01

    Porphyromonas gingivalis is a periodontal pathogen strongly associated with loss of attachment and supporting bone for teeth. We have previously shown that the total lipid extract of P. gingivalis inhibits osteoblast differentiation through engagement of Toll-like receptor 2 (TLR2) and that serine dipeptide lipids of P. gingivalis engage both mouse and human TLR2. The purpose of the present investigation was to determine whether these serine lipids inhibit osteoblast differentiation in vitro and in vivo and whether TLR2 engagement is involved. Osteoblasts were obtained from calvaria of wild type or TLR2 knockout mouse pups that also express the Col2.3GFP transgene. Two classes of serine dipeptide lipids, termed Lipid 654 and Lipid 430, were tested. Osteoblast differentiation was monitored by cell GFP fluorescence and osteoblast gene expression and osteoblast function was monitored as von Kossa stained mineral deposits. Osteoblast differentiation and function were evaluated in calvarial cell cultures maintained for 21 days. Lipid 654 significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation and this inhibition was dependent on TLR2 engagement. Lipid 430 also significantly inhibited GFP expression, osteoblast gene expression and mineral nodule formation but these effects were only partially attributed to engagement of TLR2. More importantly, Lipid 430 stimulated TNF-α and RANKL gene expression in wild type cells but not in TLR2 knockout cells. Finally, osteoblast cultures were observed to hydrolyze Lipid 654 to Lipid 430 and this likely occurs through elevated PLA2 activity in the cultured cells. In conclusion, our results show that serine dipeptide lipids of P. gingivalis inhibit osteoblast differentiation and function at least in part through engagement of TLR2. The Lipid 430 serine class also increased the expression of genes that could increase osteoclast activity. We conclude that Lipid 654 and Lipid 430 have the potential

  12. Upregulated functional expression of Toll like receptor 4 in mesenchymal stem cells induced by lipopolysaccharide

    Institute of Scientific and Technical Information of China (English)

    SHI Liang; WANG Ji-shi; LIU Xing-mei; HU Xiao-yan; FANG Qin

    2007-01-01

    Background The coordinated change of haematopoietic supporting microenvironment in bone marrow (BM) is crucial for innate immunity and inflammation. As the precursors of marrow stroma, BM derived mesenchymal stem cells (MSCs)promote haematopoietic function, but their roles in innate immunity or inflammation have not been investigated. Here we investigated the expression of Toll like receptor 4 (TLR-4) and the effect of lipopolysaccharide (LPS) on its expression in BM MSCs in vitro.Methods MSCs were harvested from adult rat's BM cells by density gradient centrifugation and adhesive culture. The purity of MSCs were identified with the cell morphological feature and osteogenic capacity, the phenotypes were tested by flow cytometry. Cultured MSCs were treated by LPS (1 μg/ml, 10 μg/ml or 100 μg/ml) for 24 hours. The relative expression levels of TLR-4 mRNA were detected by semiquantitative reverse transcription polymerase chain reaction and costimulatory molecules (CD80, CD86 and MHC-Ⅱ) expressed on MSCs were analyzed by flow cytometry. The levels of tumor necrosis factor-α (TNF-α) in supernatants were determined by enzyme linked immunosorbent assay.Results After incubation with LPS, MSCs expressed the higher levels of TLR-4 mRNA, costimulatory molecules and TNF-α than the untreated group: LPS 10 μg/ml was the most effective (P<0.01); the levels of TLR-4 mRNA, costimulatory molecules and TNF-α decreased when MSCs were exposed to 100 μg/ml LPS. Except for MHC-Ⅱ and TNF-α (P>0.05),the levels of CD80, CD86 and TLR-4 mRNA were significantly lower than that in the treated group of 10 μg/ml (P<0.01).Conclusion MSCs expressed TLR-4 mRNA. LPS activated the functional expression levels of TLR-4 in MSCs although the activity may depend on the concentration of LPS.

  13. Antagonists of toll like receptor 4 maybe a new strategy to counteract opioid-induced hyperalgesia and opioid tolerance.

    Science.gov (United States)

    Li, Qian

    2012-12-01

    Long term opioid treatment results in hyperalgesia and tolerance, which is a troublesome phenomenon in clinic application. Recent studies have revealed a critical role of toll-like receptor 4 (TLR4) in the neuropathological process of opioid-induced hyperalgesia and tolerance. TLR4 is predominantly expressed by microglial cells and is a key modulator in the activation of the innate immune system. Activation of TLR4 may initiate the activation of microglia and hence a number of neurotransmitters and neuromodulators that could enhance neuronal excitability are released. Blockade of TLR4 activation by its antagonists alleviate neuropathic pain. We hypothesized that opioid antagonists such as naloxone and naltrexone, which were also demonstrated to be TLR4 antagonist, may have clinic application value in attenuation of opioid-induced hyperalgesia and tolerance.

  14. Molecular characterization of 10 Toll-like receptor genes in goat

    International Nuclear Information System (INIS)

    Toll-like receptors (TLR) play crucial roles in activating the innate immune system. To date, 10 human and 13 mice TLR have been identified to belong to the mammalian TLR family. In this study, we have cloned partial CDs of goat TLR, TLR1, TLR2, TLR5 for about 2kb, and the rest for more than 1kb. The cloned sequences were aligned to the corresponding regions of the relevant human, bovine and equip cabalas nucleotide sequences. As shown in Table I there is at least 79% identity between the relevant human and goat TLR nucleotide sequences. The identity of each cloned goat TLR to equus caballus and bovine reference sequence ranges between 81% and 98%. Translation of goat TLR nucleotide sequences and alignment to the human, bovine and Equus caballus TLR protein showed 69-97% of the amino acid sequence is conserved among the species. A broad pattern of tissue expression was obtained for goat TLR mRNA in heart, liver, spleen, lung, kidney, lymph node, muscle and small intestine. TLR1 was found to be expressed in spleen and lung. Goat TLR2 were expressed in most tissues except muscle and small intestine. We detected TLR3 in the goat spleen and lung. TLR6 and TLR2 had similar expression patterns except in heart, while TLR2 was expressed but not TLR6. TLR7 was expressed in the liver, spleen and kidney. Expression of goat TLR8 was similar to TLR3, which is found in the spleen and lung. Analysis of TLR10 expression pattern in goat revealed that this gene only expressed in the spleen. All of goat TLR mRNA were expressed at reasonably high levels in the spleen that is a tissue with an organized immune compartment. This also agrees with human in where TLR are mostly expressed in the spleen. To determine the overall role of goat TLR in mammal TLR evolution, a phylogenetic analysis was performed among mammal TLR (human, mouse, dog, cat, Pan-troglodytes, Macaca mulatta, Gallus gallus, equus caballus, bovine, pig, Mus musculus and Rattus norvegicus and goat). Phylogenetic and

  15. Potential of PEGylated Toll-Like Receptor 7 Ligands for Controlling Inflammation and Functional Changes in Mouse Models of Asthma and Silicosis

    OpenAIRE

    Ferreira, Tatiana Paula Teixeira; Mariano, Lívia Lacerda; Ghilosso-Bortolini, Roberta; de Arantes, Ana Carolina Santos; Fernandes, Andrey Junior; Berni, Michelle; Cecchinato, Valentina; Uguccioni, Mariagrazia; Maj, Roberto; Barberis, Alcide; Silva, Patricia Machado Rodrigues e; Martins, Marco Aurélio

    2016-01-01

    Prior investigations show that signaling activation through pattern recognition receptors can directly impact a number of inflammatory lung diseases. While toll-like receptor (TLR) 7 agonists have raised interest for their ability to inhibit allergen-induced pathological changes in experimental asthma conditions, the putative benefit of this treatment is limited by adverse effects. Our aim was to evaluate the therapeutic potential of two PEGylated purine-like compounds, TMX-302 and TMX-306, c...

  16. The role of MAPK in CD4{sup +} T cells toll-like receptor 9-mediated signaling following HHV-6 infection

    Energy Technology Data Exchange (ETDEWEB)

    Chi, Jing [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Wang, Fang [Department of Laboratory Medicine, the First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing 210029, Jiangsu Province (China); Li, Lingyun [Department of Developmental Genetics, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Feng, Dongju [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Qin, Jian [College of Foreign Languages, Hehai University, Nanjing 210029, Jiangsu Province (China); Xie, Fangyi; Zhou, Feng; Chen, Yun; Wang, Jinfeng [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China); Yao, Kun, E-mail: yaokun@njmu.edu.cn [Department of Microbiology and Immunology, Nanjing Medical University, Nanjing 210029, Jiangsu Province (China)

    2012-01-05

    Human herpesvirus-6 (HHV-6) is an important immunosuppressive and immunomodulatory virus that primarily infects immune cells (mainly CD4{sup +} T cells) and strongly suppresses the proliferation of infected cells. Toll-like receptors are pattern-recognition receptors essential for the development of an appropriate innate immune defense against infection. To understand the role of CD4{sup +} T cells in the innate response to HHV-6 infection and the involvement of TLRs, we used an in vitro infection model and observed that the infection of CD4{sup +} T cells resulted in the activation of JNK/SAPK via up-regulation of toll-like receptor 9 (TLR9). Associated with JNK activation, annexin V-PI staining indicated that HHV-6A was a strong inducer of apoptosis. Apoptotic response associated cytokines, IL-6 and TNF-{alpha} also induced by HHV-6A infection.

  17. Genetic Variation in TLR10, an Inhibitory Toll-Like Receptor, Influences Susceptibility to Complicated Skin and Skin Structure Infections.

    NARCIS (Netherlands)

    Stappers, M.H.T.; Oosting, M.; Ioana, M.; Reimnitz, P.; Mouton, J.W.; Netea, M.G.; Gyssens, I.C.J.; Joosten, L.A.B.

    2015-01-01

    BACKGROUND: Toll-like receptors (TLRs) play a central role in the innate immune response to complicated skin and skin structure infections (cSSSIs), with TLR10 being the first family member known to have an inhibitory function. This study assessed the role of TLR10 in recognition of cSSSI-related pa

  18. Comprehensive survey and genomic characterization of toll-like receptors in channel catfish, Ictalurus punctatus: identification of novel fish TLRs

    Science.gov (United States)

    A comprehensive survey of channel catfish Toll-Like Receptors (TLRs) was undertaken following a genomic PCR approach based on degenerate primers. Twenty different TLRs were identified in channel catfish. Channel catfish TLR sequences were characterized by phylogenetic analysis based on their conserv...

  19. Toll-like receptor 2 suppresses immunity against Candida albicans through induction of IL-10 and regulatory T cells.

    NARCIS (Netherlands)

    Netea, M.G.; Sutmuller, R.P.M.; Hermann, C.; Graaf, C.A.A. van der; Meer, J.W.M. van der; Krieken, J.H.J.M. van; Hartung, T.; Adema, G.J.; Kullberg, B.J.

    2004-01-01

    Toll-like receptor (TLR) 2 and TLR4 play a pivotal role in recognition of Candida albicans. We demonstrate that TLR2(-/-) mice are more resistant to disseminated Candida infection, and this is associated with increased chemotaxis and enhanced candidacidal capacity of TLR2(-/-) macrophages. Although

  20. GENES, IN ADDITION TO TOLL-LIKE RECEPTOR 2, PLAY A ROLE IN ANTIBACTERIAL DEFENSE TO STREPTOCOCCAL PNEUMONIA

    Science.gov (United States)

    Streptococcus infection in human populations continues to be a major cause of morbidity and mortality. To evaluate the effect of genetic background and toll-like receptor 2 (TLR2) on antibacterial defense to streptococcal infection, eight genetically diverse strains of mic...

  1. Single-nucleotide polymorphisms in the Toll-like receptor pathway increase susceptibility to infections in severely injured trauma patients

    NARCIS (Netherlands)

    M.W.G.A. Bronkhorst (Maarten); N.D.A. Boyé (Nicole); M.A.Z. Lomax (Miranda); R. Vossen (Rolf); J.F. Bakker (Jurriaan); P. Patka (Peter); E.M.M. van Lieshout (Esther)

    2013-01-01

    textabstractBackground: Sepsis and subsequent multiple-organ failure are the predominant causes of late mortality in trauma patients. Susceptibility and response to infection is, in part, heritable. Single-nucleotide polymorphisms (SNPs) in Toll-like receptor (TLR) and cluster of differentiation 14

  2. The role of toll-like receptors 2 and 4 in the pathogenesis of feline pyometra.

    Science.gov (United States)

    Jursza, E; Kowalewski, M P; Boos, A; Skarzynski, D J; Socha, P; Siemieniuch, M J

    2015-03-01

    Pyometra is the most common uterine disease in queens. To protect itself from infection, the female reproductive tract possesses several immune mechanisms that are based on germline-encoded pattern recognition receptors (toll-like receptors [TLRs]). The aim of our study was to examine endometrial immunolocalization of TLR2/4, study the influence of lipopolysaccharide (LPS) and tumor necrosis factor (TNF) α on messenger RNA expression of both receptors in pyometric queens, and compare these patterns between estrous cycling queens and those hormonally treated with medroxyprogesterone acetate (MPA). Thirty-six queens, ranging in age from 7 months to 11 years, were allocated into seven groups (anestrus, estrus, mid-diestrus and late diestrus, short-term and long-term hormonally treated queens, and pyometric queens). At the messenger RNA level, the real-time polymerase chain reaction was applied, whereas at the TLR2/4 protein level, the expression was tested by immunohistochemistry. In queens at estrus, gene expression of TLR2 was upregulated after stimulation of endometrial explants by TNF (P glandular epithelia. These data show that short-term and especially long-term administration of progesterone derivatives impairs TLRs in the endometrial epithelium, presumably enabling pathogens to break through this first natural barrier and thereby increase the risk of pyometra development. PMID:25481489

  3. Association of Toll-like receptor 2 Arg753Gln and Toll-like receptor 1 Ile602Ser single-nucleotide polymorphisms with leptospirosis in an Argentine population.

    Science.gov (United States)

    Cédola, Maia; Chiani, Yosena; Pretre, Gabriela; Alberdi, Lucrecia; Vanasco, Bibiana; Gómez, Ricardo M

    2015-06-01

    Toll-like receptor 2 (TLR2), a member of the Toll-like receptor family, plays an important role in the recognition of and subsequent immune response activation against leptospirosis in humans. The genetic polymorphism in TLR2 of an arginine to glutamine substitution at residue 753 (Arg753Gln) has been associated with a negative influence on TLR2 function, which may, in turn, determine the innate host response to Leptospira spp. This bacterium signals through TLR2/TLR1 heterodimers in human cells. The aim of the present study was to investigate the Arg753Gln single-nucleotide polymorphism (SNP) of the TLR2 gene, and the isoleucine to serine transversion at position 602 (Ile602Ser) of the TLR1 gene (previously associated with Lyme disease), in leptospirosis patients compared to healthy controls, carrying out a retrospective case/control study. The TLR2 polymorphism adenine (A) allele was observed in 7.3% of leptospirosis patients but was not found in the control group, whereas the guanine (G) allele of the TLR1 polymorphism was found in 63.6% of patients and 41.6% of controls. Susceptibility to leptospirosis disease was increased 10.57-fold for carriers of the TLR2 G/A genotype (P=0.0493) and 3.85-fold for carriers of the TLR1 G/G genotype (P=0.0428). Furthermore, the risk of developing hepatic insufficiency and jaundice was increased 18.86- and 27.60-fold for TLR2 G/A carriers, respectively. Similarly, the risk of developing jaundice was increased 12.67-fold for TLR1 G allele carriers (G/G and T/G genotypes). In conclusion, the present data suggest that the TLR2 Arg753Gln and TLR1 Ile602Ser SNPs influence the risk of developing leptospirosis and its severity.

  4. Intrathecal siRNA against Toll-like receptor 4 reduces nociception in a rat model of neuropathic pain

    Directory of Open Access Journals (Sweden)

    Fei-xiang Wu, Jin-jun Bian, Xue-rong Miao, Sheng-dong Huang, Xue-wu Xu, De-jun Gong, Yu-ming Sun, Zhi-jie Lu, Wei-feng Yu

    2010-01-01

    Full Text Available Background: Neuropathic pain is characterized by hyperalgesia, allodynia and spontaneous pain. It often occurs as a result of injury to peripheral nerves, dorsal root ganglions (DRG, spinal cord, or brain. Recent studies have suggested that Toll-like receptor 4 (TLR4 might play a role in neuropathic pain. Methodology/Principal Findings: In this study, we investigated the role of TLR4 in a rat chronic constriction injury (CCI model and explored the feasibility of treating neuropathic pain by inhibiting TLR4. Our results demonstrated that intrathecal siRNA-mediated suppression of TLR4 attenuated CCI-induced mechanical allodynia and thermal hyperalgesia through inhibiting the activation of NF-κB p65 and production of proinflammatory cytokines (e.g., TNF-α and IL-1β. Conclusions/Significance: These findings suggest that suppression of TLR4 mediated by intrathecally administered siRNA may be a new strategy for the treatment of neuropathic pain.

  5. DMPD: TICAM-1 and TICAM-2: toll-like receptor adapters that participate in inductionof type 1 interferons. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15618008 TICAM-1 and TICAM-2: toll-like receptor adapters that participate in induc... Mar;37(3):524-9. (.png) (.svg) (.html) (.csml) Show TICAM-1 and TICAM-2: toll-like receptor adapters that p...articipate in inductionof type 1 interferons. PubmedID 15618008 Title TICAM-1 and TICAM-2: toll

  6. Toll-Like Receptor 4 Wild Type Homozygozity of Polymorphisms +896 and +1196 Is Associated with High Gastrin Serum Levels and Peptic Ulcer Risk.

    Directory of Open Access Journals (Sweden)

    Vesa-Matti Pohjanen

    Full Text Available Toll-like receptor 4 is a part of the innate immune system and recognizes Helicobacter pylori lipopolysaccharide. The goal of this study was to analyze the role of Toll-like receptor 4 polymorphisms +896 (rs4986790 and +1196 (rs4986791 in the pathogenesis of Helicobacter pylori related gastroduodenal diseases in relation to gastric secretion and inflammation. Toll-like receptor 4 polymorphisms, serum gastrin-17 and pepsinogen I and II concentrations were determined, and gastroscopies with histopathological analyses were performed to 216 dyspeptic patients. As genotype controls, 179 controls and 61 gastric cancer patients were studied. In our study, the Toll-like receptor 4 +896 and +1196 polymorphisms were in total linkage disequilibrium. The homozygous wild types displayed higher gastrin-17 serum concentrations than the mutants (p = 0.001 and this effect was independent of Helicobacter pylori. The homozygous wild types also displayed an increased risk for peptic ulcers (OR: 4.390. Toll-like receptor 4 genotypes did not show any association with Helicobacter pylori positivity or the features of gastric inflammation. Toll-like receptor 4 expression was seen in gastrin and somatostatin expressing cells of antral mucosa by immunohistochemistry. Our results suggest a role for Toll-like receptor 4 in gastric acid regulation and that the Toll-like receptor 4 +896 and +1196 wild type homozygozity increases peptic ulcer risk via gastrin secretion.

  7. Toll-Like Receptor 4 Wild Type Homozygozity of Polymorphisms +896 and +1196 Is Associated with High Gastrin Serum Levels and Peptic Ulcer Risk

    Science.gov (United States)

    Pohjanen, Vesa-Matti; Koivurova, Olli-Pekka; Huhta, Heikki; Helminen, Olli; Mäkinen, Johanna M.; Karhukorpi, Jari M.; Joensuu, Tapio; Koistinen, Pentti O.; Valtonen, Jarno M.; Niemelä, Seppo E.; Karttunen, Riitta A.; Karttunen, Tuomo J.

    2015-01-01

    Toll-like receptor 4 is a part of the innate immune system and recognizes Helicobacter pylori lipopolysaccharide. The goal of this study was to analyze the role of Toll-like receptor 4 polymorphisms +896 (rs4986790) and +1196 (rs4986791) in the pathogenesis of Helicobacter pylori related gastroduodenal diseases in relation to gastric secretion and inflammation. Toll-like receptor 4 polymorphisms, serum gastrin-17 and pepsinogen I and II concentrations were determined, and gastroscopies with histopathological analyses were performed to 216 dyspeptic patients. As genotype controls, 179 controls and 61 gastric cancer patients were studied. In our study, the Toll-like receptor 4 +896 and +1196 polymorphisms were in total linkage disequilibrium. The homozygous wild types displayed higher gastrin-17 serum concentrations than the mutants (p = 0.001) and this effect was independent of Helicobacter pylori. The homozygous wild types also displayed an increased risk for peptic ulcers (OR: 4.390). Toll-like receptor 4 genotypes did not show any association with Helicobacter pylori positivity or the features of gastric inflammation. Toll-like receptor 4 expression was seen in gastrin and somatostatin expressing cells of antral mucosa by immunohistochemistry. Our results suggest a role for Toll-like receptor 4 in gastric acid regulation and that the Toll-like receptor 4 +896 and +1196 wild type homozygozity increases peptic ulcer risk via gastrin secretion. PMID:26161647

  8. DMPD: Toll-like receptors and the host defense against microbial pathogens: bringingspecificity to the innate-immune system. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15075354 Toll-like receptors and the host defense against microbial pathogens: brin... the host defense against microbial pathogens: bringingspecificity to the innate-...immune system. PubmedID 15075354 Title Toll-like receptors and the host defense against microbial pathogens:

  9. Colorectal irradiation induced immune response: 'toll like receptors' therapeutic manipulation

    International Nuclear Information System (INIS)

    Exposure of the abdomino-pelvic sphere to ionizing radiation is associated with a high incidence of complications. Radiation therapy may cause short and / or long-term harmful effects. In the most severe cases and in the absence of heavy treatments, the appearance of ulcers may induce the death of patients. Clinical trials are being conducted with Mesenchymal Stem Cells (MSC) to cure theses complications. Others studies indicate that the injection of bacterial motifs limits the radiotoxicity in the intestine. They stimulate receptors (Toll-Like- Receptors (TLR)) located on the surface of epithelial and intestinal immune cells. The first aim of this doctoral work is to characterize the effects of TLR stimulation on immunity and tissue repair using a model of localized colorectal irradiation at 20 Gy (acute effects of radiotherapy) on a rat. The thesis then aims to potentiate the effects of the MSC treatment when adding TLR ligands upon localized colorectal irradiation at 27 Gy (accidental complications). This work, using a 20 Gy exposure, show that TLR stimulation improves homeostasis (normalization of T cells, induction of regulatory T cells (Treg) and macrophages 'anti-inflammatory' M2). On the 27 Gy colorectal model, the injection of TLR ligand before CSM transplant improves the immune climate by reducing pro-inflammatory cytokines and inducting Treg and M2 cells. These modulations could contribute to improving the implantation and effectiveness of CSM. The observations have all shown that the stimulation of immunity is an approach to minimize radiation-induced lesions. (author)

  10. The evolution of bat nucleic acid-sensing Toll-like receptors.

    Science.gov (United States)

    Escalera-Zamudio, Marina; Zepeda-Mendoza, M Lisandra; Loza-Rubio, Elizabeth; Rojas-Anaya, Edith; Méndez-Ojeda, Maria L; Arias, Carlos F; Greenwood, Alex D

    2015-12-01

    We characterized the nucleic acid-sensing Toll-like receptors (TLR) of a New World bat species, the common vampire bat (Desmodus rotundus), and through a comparative molecular evolutionary approach searched for general adaptation patterns among the nucleic acid-sensing TLRs of eight different bats species belonging to three families (Pteropodidae, Vespertilionidae and Phyllostomidae). We found that the bat TLRs are evolving slowly and mostly under purifying selection and that the divergence pattern of such receptors is overall congruent with the species tree, consistent with the evolution of many other mammalian nuclear genes. However, the chiropteran TLRs exhibited unique mutations fixed in ligand-binding sites, some of which involved nonconservative amino acid changes and/or targets of positive selection. Such changes could potentially modify protein function and ligand-binding properties, as some changes were predicted to alter nucleic acid binding motifs in TLR 9. Moreover, evidence for episodic diversifying selection acting specifically upon the bat lineage and sublineages was detected. Thus, the long-term adaptation of chiropterans to a wide variety of environments and ecological niches with different pathogen profiles is likely to have shaped the evolution of the bat TLRs in an order-specific manner. The observed evolutionary patterns provide evidence for potential functional differences between bat and other mammalian TLRs in terms of resistance to specific pathogens or recognition of nucleic acids in general. PMID:26503258

  11. Macroscopic law of conservation revealed in the population dynamics of Toll-like receptor signaling

    Directory of Open Access Journals (Sweden)

    Selvarajoo Kumar

    2011-04-01

    Full Text Available Abstract Stimulating the receptors of a single cell generates stochastic intracellular signaling. The fluctuating response has been attributed to the low abundance of signaling molecules and the spatio-temporal effects of diffusion and crowding. At population level, however, cells are able to execute well-defined deterministic biological processes such as growth, division, differentiation and immune response. These data reflect biology as a system possessing microscopic and macroscopic dynamics. This commentary discusses the average population response of the Toll-like receptor (TLR 3 and 4 signaling. Without requiring detailed experimental data, linear response equations together with the fundamental law of information conservation have been used to decipher novel network features such as unknown intermediates, processes and cross-talk mechanisms. For single cell response, however, such simplicity seems far from reality. Thus, as observed in any other complex systems, biology can be considered to possess order and disorder, inheriting a mixture of predictable population level and unpredictable single cell outcomes.

  12. Are Toll-like receptor gene polymorphisms associated with prostate cancer?

    Directory of Open Access Journals (Sweden)

    Kutikhin AG

    2012-02-01

    Full Text Available Anton G Kutikhin, Arseniy E YuzhalinDepartment of Epidemiology, Kemerovo State Medical Academy, Kemerovo, Russian FederationAbstract: The suggestion that there is a connection between chronic intraprostatic inflammation and prostate cancer was declared some years ago. As Toll-like receptors (TLRs are the key players in the processes of chronic intraprostatic inflammation, there is a hypothesis that TLR gene polymorphisms may be associated with prostate cancer risk. Although a number of comprehensive studies have been conducted on large samples in various countries, reliable connections between these single nucleotide polymorphisms and prostate cancer risk, stage, grade, aggressiveness, ability to metastasize, and mortality have not been detected. Results have also varied slightly in different populations. The data obtained regarding the absence of connection between the polymorphisms of the genes encoding interleukin-1 receptor-associated kinases (IRAK1 and IRAK4 and prostate cancer risk might indicate a lack of association between inherited variation in the TLR signaling pathway and prostate cancer risk. It is possible to consider that polymorphisms of genes encoding TLRs and proteins of the TLR pathway also do not play a major role in the etiology and pathogenesis of prostate cancer. Feasibly, it would be better to focus research on associations between TLR single nucleotide polymorphisms and cancer risk in other infection-related cancer types.Keywords: TLRs, single nucleotide polymorphisms, genetic variation, inflammation, innate immunity

  13. Toll-Like Receptor 9 Promotes Cardiac Inflammation and Heart Failure during Polymicrobial Sepsis

    Directory of Open Access Journals (Sweden)

    Ralph Lohner

    2013-01-01

    Full Text Available Background. Aim was to elucidate the role of toll-like receptor 9 (TLR9 in cardiac inflammation and septic heart failure in a murine model of polymicrobial sepsis. Methods. Sepsis was induced via colon ascendens stent peritonitis (CASP in C57BL/6 wild-type (WT and TLR9-deficient (TLR9-D mice. Bacterial load in the peritoneal cavity and cardiac expression of inflammatory mediators were determined at 6, 12, 18, 24, and 36 h. Eighteen hours after CASP cardiac function was monitored in vivo. Sarcomere length of isolated cardiomyocytes was measured at 0.5 to 10 Hz after incubation with heat-inactivated bacteria. Results. CASP led to continuous release of bacteria into the peritoneal cavity, an increase of cytokines, and differential regulation of receptors of innate immunity in the heart. Eighteen hours after CASP WT mice developed septic heart failure characterised by reduction of end-systolic pressure, stroke volume, cardiac output, and parameters of contractility. This coincided with reduced cardiomyocyte sarcomere shortening. TLR9 deficiency resulted in significant reduction of cardiac inflammation and a sustained heart function. This was consistent with reduced mortality in TLR9-D compared to WT mice. Conclusions. In polymicrobial sepsis TLR9 signalling is pivotal to cardiac inflammation and septic heart failure.

  14. The Contributing Role of CD14 in Toll-Like Receptor 4 Dependent Neuropathic Pain

    Science.gov (United States)

    Cao, Ling; Tanga, Flobert Y; DeLeo, Joyce A.

    2009-01-01

    We have previously demonstrated that central nervous system (CNS) toll-like receptor 4 (TLR4) plays a key role in the development of behavioral hypersensitivity in a rodent model of neuropathic pain, spinal nerve L5 transection (L5Tx). TLR4 is a well-known receptor for lipopolysaccharide (LPS) in innate immune responses. In the current study, we further investigated the role of CD14, an accessory molecule in the LPS-TLR4 signaling pathway, in the development of L5Tx-induced neuropathic pain. CD14 knockout (KO) mice displayed significantly decreased behavioral sensitivity (mechanical allodynia and thermal hyperalgesia) as early as day 1 post-L5Tx, indicating a nociceptive role of CD14. By flow cytometric analyses, we observed significantly elevated microglial surface CD14 expression in the ipsilateral lumbar spinal cord 3 days post-L5Tx, as well as remarkable increases in microglial size (via forward scatter (FSC)) and granularity (via side scatter (SSC)). Further, intrathecal injection of soluble CD14 induced significantly greater mechanical hypersensitivity in wild type (C3H/HeN) mice compared to TLR4-deficient (C3H/HeJ) mice. Together, these data demonstrate that CD14 plays a contributing role in TLR4-dependent nerve injury-induced neuropathic pain. PMID:18976692

  15. Expression profiles and function of Toll-like receptors in human corneal epithelia

    Institute of Scientific and Technical Information of China (English)

    WU Xin-yi; GAO Jian-lu; REN Mei-yu

    2007-01-01

    Background Toll-like receptors play an important role in the human immune system. This study was conducted to investigate the expression profiles and function of Toll-like receptor (TLR)1-9 in human corneal epithelium.Methods The expression of TLR1-9 mRNA in 20 human donor corneal epithelia samples abraded during photorefractive keratotomy (PRK) and cultivated telomerase-immortalized human corneal epithelial cells (THCEs) was examined by semi-quantitative reverse-transcriptase polymerase chain reaction (RT-PCR) analysis. Human peripheral blood mononuclear cells (PBMCs) were used as positive controls. The expression of the TLR2 and TLR4 proteins was detected by Western analysis. ELISA was used to detect IL-8 secretion from THCEs challenged with ligands for TLR3 and TLR4 with and without antibody blockade.Results The expression of TLR1-9 at the mRNA level was detected in the epithelia of 20 patients and in THCE.Significant differences among individuals were observed. One patient was found to lack of the expression of TLR3, 4, 6 and 8, whereas another did not express TLR5. The expression of TLR2 and TLR4 protein was detected in human corneal epithelial cells. As THCE cells express TLR1-9, cells were challenged with lipopolysaccharides (LPS) and poly I:C to determine whether TLR4 and TLR3 were functional. The results showed that secretion of IL-8 by cells stimulated with LPS and Poly I:C was 7 to 10 fold greater than secretion by unchallenged cells. Blocking TLR4 with an anti-TLR4 antibody significantly inhibited the LPS-induced IL-8 production by THCE (P<0.05).Conclusion Human corneal epithelial cells express multiple TLRs and are able to recognize LPS and poly I:C. Different expression profiles among individuals suggest that differences in the susceptibilities and sensitivities to bacterial and viral infection in human populations relate to different patterns of TLR expression.

  16. Chandipura Virus infection in mice: the role of toll like receptor 4 in pathogenesis

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    Anukumar Balakrishnan

    2012-05-01

    Full Text Available Abstract Background The susceptibility of mice and humans to Chandipura virus infection is age-dependent. Upon experimental infection, mice secrete significant amounts of proinflammatory cytokines. Similarly, children who recover from natural infection with the virus show significant amounts of TNF-α production, suggesting that innate immunity plays a major role in the response to Chandipura virus. Toll-like receptors (TLR are key host molecules involved in innate immune responses in infections. Therefore, the aim of this study was to examine the role of TLR in the response to Chandipura virus infection. Methods The mouse monocyte-macrophage cell line, RAW 264.7, and C3H/HeJ mice were used as models. Micro array techniques were used to identify the type of TLR involved in the response to infection. The results were validated by examining TLR expression using flow cytometry and by measuring the levels of proinflammatory cytokines and nitric oxide (NO in the culture supernatants using bead assays and the Griess method, respectively. The pathogenic role of Toll-like receptor 4 (TLR4 was studied in a TLR4 mutant strain of mice -C3H/HeJ and the results compared with those from wild-type mice- C3H/CaJ. The pathogenic effects of NO were studied by treating experimentally infected mice with the NO inhibitor, aminoguanidine (AG. Results The micro array results showed that TLR4 was regulated after Chandipura virus infection. At high multiplicities of infection (10 MOI, RAW cells up- regulated cell surface expression of TLR4 and secreted significant amounts of TNF-α, MCP-1, IL-10 and IL-12 and NO. The survival rate of C3H/HeJ mice was higher than those of wild-type C3H/CaJ mice. The survived C3H/HeJ mice secreted significant quantity of MCP-1 and IFN-γ cytokines and cleared virus from brain. Similarly, the survival rate of AG-treated mice was higher than those of the untreated controls. Conclusions Chandipura virus regulates TLR4, which leads to the

  17. Neuroexcitatory effects of morphine-3-glucuronide are dependent on Toll-like receptor 4 signaling

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    Due Michael R

    2012-08-01

    Full Text Available Abstract Background Multiple adverse events are associated with the use of morphine for the treatment of chronic non-cancer pain, including opioid-induced hyperalgesia (OIH. Mechanisms of OIH are independent of opioid tolerance and may involve the morphine metabolite morphine-3-glucuronide (M3G. M3G exhibits limited affinity for opioid receptors and no analgesic effect. Previous reports suggest that M3G can act via the Toll-like receptor 4 (TLR4/myeloid differentiation protein-2 (MD-2 heterodimer in the central nervous system to elicit pain. Methods Immunoblot and immunocytochemistry methods were used to characterize the protein expression of TLR4 present in lumbar dorsal root ganglion (DRG. Using in vitro intracellular calcium and current clamp techniques, we determined whether TLR4 activation as elicited by the prototypical agonists of TLR4, lipopolysaccharide (LPS and M3G, contributed to changes in intracellular calcium and increased excitation. Rodents were also injected with M3G to determine the degree to which M3G-induced tactile hyperalgesia could be diminished using either a small molecule inhibitor of the MD-2/TLR4 complex in rats or TLR4 knockout mice. Whole cell voltage-clamp recordings were made from small- and medium-diameter DRG neurons (25 μm  Results We observed that TLR4 immunoreactivity was present in peptidergic and non-peptidergic sensory neurons in the DRG. Non-neuronal cells in the DRG lacked evidence of TLR4 expression. Approximately 15% of assayed small- and medium-diameter sensory neurons exhibited a change in intracellular calcium following LPS administration. Both nociceptive and non-nociceptive neurons were observed to respond, and approximately 40% of these cells were capsaicin-insensitive. Increased excitability observed in sensory neurons following LPS or M3G could be eliminated using Compound 15, a small molecule inhibitor of the TLR4/MD-2 complex. Likewise, systemic injection of M3G induced rapid tactile, but

  18. Specific Oligopeptides in Fermented Soybean Extract Inhibit NF-κB-Dependent iNOS and Cytokine Induction by Toll-Like Receptor Ligands

    OpenAIRE

    Lee, Woo Hyung; Wu, Hong Min; LEE, CHAN GYU; Sung, Dae Il; Song, Hye Jung; Matsui, Toshiro; Kim, Han Bok; Kim, Sang Geon

    2014-01-01

    The ethanol extract of fermented soybean from Glycine max (chungkookjang, CHU) has been claimed to have chemopreventive and cytoprotective effects. In the present study, we examined the inhibitory effect of CHU on inducible nitric oxide synthase (iNOS) and cytokine induction by toll-like receptor (TLR) ligands treatment and attempted to identify the responsible active components. Nitric oxide (NO) content and iNOS levels in the media or RAW264.7 cells were measured using the Griess reagent an...

  19. EPA and DHA exposure alters the inflammatory response but not the surface expression of toll-like receptor 4 in macrophages

    OpenAIRE

    Honda, Kaori L.; Lamon-Fava, Stefania; Matthan, Nirupa R.; Wu, Dayong; Lichtenstein, Alice H

    2014-01-01

    Dietary intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) and their respective enrichment in cell membranes have been negatively associated with atherosclerotic lesion development. This effect may be mediated, in part, by dampened inflammatory response of macrophages triggered by toll-like receptor 4 (TLR4) activation. This study investigated the influence of membrane fatty acid profile on TLR4-mediated inflammation in RAW 264.7 macrophages. Cells pretreated with myristic a...

  20. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor 1α

    OpenAIRE

    Alessio Paone; Roberta Galli; Chiara Gabellini; Dmitriy Lukashev; Donatella Starace; Agnes Gorlach; Paola De Cesaris; Elio Ziparo; Donatella Del Bufalo; Sitkovsky, Michail V.; Antonio Filippini; Anna Riccioli

    2010-01-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible...

  1. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor 1α1

    OpenAIRE

    Paone, Alessio; Galli, Roberta; Gabellini, Chiara; Lukashev, Dmitriy; Starace, Donatella; Gorlach, Agnes; Cesaris, Paola; Ziparo, Elio; Del Bufalo, Donatella; Sitkovsky, Michail V.; Filippini, Antonio; Riccioli, Anna

    2010-01-01

    Toll-like receptors (TLRs) recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C) induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-inducible...

  2. Placental Trophoblast Responses to Porphyromonas gingivalis Mediated by Toll-like Receptor-2 and -4

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    Banun Kusumawardani

    2013-09-01

    Full Text Available Trophoblast participates in preventing allorecognition and controlling pathogens that compromise fetal wellbeing. Toll-like receptors recognize conserved sequences on the pathogens surface and trigger effector cell functions. Porphyromonas gingivalis is thought to spread to the umbilical cord and cause fetal growth restriction. Objective: To characterize expression and function of TLR-2 and TLR-4 in trophoblast cells from Porphyromonas gingivalisinfected pregnant rats. Methods: Live Porphyromonas gingivalis were challenged into the maxillary first molar subgingival sulcus of female rats before and/or during pregnancy and sacrified on gestational day (GD 14 and 20. Porphyromonas gingivalis was detected by API-ZYM system in the maternal blood of the retro-orbital venous plexus and the umbilical cord. TLR-2 and TLR-4 expressions in trophoblast cells was detected by immunohistochemistry. Results: Porphyromonas gingivalis was first detected in the maternal blood and finally spread to the umbilical cord. Syncytiotrophoblast, spongitrophoblast and trophoblastic giant cell in treated groups had significantly higher expression of TLR-2 and TLR-4 than control group (p<0.05. Conclusion: Syncytiotrophoblast, spongitrophoblast and trophoblastic giant cell are able to recognize Porphyromonas gingivalis through TLR-2 and TLR-4 expression. The ligation of TLR-2 and TLR-4 promoted cytokine production and induced trophoblast cell death. These findings strengthen links between periodontal disease and fetal growth restriction.DOI: 10.14693/jdi.v20i2.150

  3. Polymorphisms of toll-like receptor 2 and 4 genes in Chagas disease

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    German Zafra

    2008-02-01

    Full Text Available The aim of this study was to test the possible implication of toll-like receptor 2 (TLR2 and TLR4 gene polymorphisms in determining the susceptibility to Chagas' disease. Genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism in 475 individuals from Colombia, 143 seropositive with chagasic cardiomyopathy, 132 seropositive asymptomatic and 200 seronegative. The TLR2 arginine to glutamine substitution at residue 753(Arg753Gln polymorphism was absent in the groups analyzed. The TLR4 Asp299Gly and Thr399Ile polymorphisms are in linkage disequilibrium and we observed a very low frequency of these polymorphisms in our study population (2.6% and 1.8% respectively. The overall TLR2 and TLR4 alleles and genotype distribution in seronegative and seropositive were not significantly different. We compared the frequencies between asymptomatic patients and those with chagasic cardiomyopathy and we did not observe any significant differences in the distribution of alleles or genotypes. In summary, this study corroborates the low frequency of TLR2 and TLR4 polymorphisms observed in other populations and suggest that these do not play an important role in Chagas' disease. The validation of these findings in independent cohorts is needed to firmly establish a role for TLR2 and TLR4 variants in Chagas' disease.

  4. Network Analysis of Neurodegenerative Disease Highlights a Role of Toll-Like Receptor Signaling

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    Thanh-Phuong Nguyen

    2014-01-01

    Full Text Available Despite significant advances in the study of the molecular mechanisms altered in the development and progression of neurodegenerative diseases (NDs, the etiology is still enigmatic and the distinctions between diseases are not always entirely clear. We present an efficient computational method based on protein-protein interaction network (PPI to model the functional network of NDs. The aim of this work is fourfold: (i reconstruction of a PPI network relating to the NDs, (ii construction of an association network between diseases based on proximity in the disease PPI network, (iii quantification of disease associations, and (iv inference of potential molecular mechanism involved in the diseases. The functional links of diseases not only showed overlap with the traditional classification in clinical settings, but also offered new insight into connections between diseases with limited clinical overlap. To gain an expanded view of the molecular mechanisms involved in NDs, both direct and indirect connector proteins were investigated. The method uncovered molecular relationships that are in common apparently distinct diseases and provided important insight into the molecular networks implicated in disease pathogenesis. In particular, the current analysis highlighted the Toll-like receptor signaling pathway as a potential candidate pathway to be targeted by therapy in neurodegeneration.

  5. Differential expression of Toll-like receptor 4 (TLR4) in healthy and infected canine endometrium.

    Science.gov (United States)

    Chotimanukul, S; Sirivaidyapong, S

    2011-10-01

    This study provides the first report into immunohistochemical localization of Toll-like receptor (TLR) in the canine reproductive tract. TLR4 was investigated in endometrium during the estrous cycle and in pyometra. Pyometra is the most important pathological condition of the uterus due to bacterial infection in dogs. To protect against invading pathogens, the female reproductive tract has evolved immune mechanisms. TLRs are the cellular components of the afferent arm of the innate immune system. The expression of TLR4 was significantly higher in the endometrial stroma compared to the endometrial surface epithelium and glandular epithelium in proestrus. The glandular epithelium and stroma at the diestrous stage expressed TLR4 significantly higher than surface epithelium. Furthermore, when compared to other healthy groups, the glandular epithelium at diestrus also higher expressed TLR4 than other stages. The expression of TLR4 in the surface epithelium was higher in dogs with pyometra compared with all other groups. And, the surface epithelium of dogs suffering from pyometra also expressed TLR4 more intensely than the glandular epithelium. The innate immunity of infected canine endometrium response to bacterial infection is intensely extremely increased by the expression of TLR4. Furthermore, the different levels of TLR4 expression seems related to physiological changes in distinct cell types of endometrium, leukocytes populations, cytokines and sex hormones. PMID:21752456

  6. Expression of antimicrobial peptides and toll-like receptors is increased in tinea and pityriasis versicolor.

    Science.gov (United States)

    Brasch, J; Mörig, A; Neumann, B; Proksch, E

    2014-03-01

    In superficial tinea and pityriasis versicolor, the causative fungi are for the most part confined to the stratum corneum which is barely reached by leukocytes. Therefore, a role of non-cellular components in the epidermal antifungal defence was suggested. To investigate the presence of such factors in these infections, the expression of human beta defensins 2 and 3 (hBD-2, hBD-3), RNase 7, psoriasin, toll-like receptors 2, 4 and 9 (TLR2, TLR4 and TLR9) and dectin 2 was analysed by use of immunostainings in skin biopsies. We found that hBD2, hBD3, psoriasin, RNase7, TLR2 and TLR4 were significantly more often expressed in distinct layers of lesional epidermis as compared with uninfected epidermis. In both infections but not in normal skin, hBD2 and hBD3 were commonly expressed within the stratum corneum and in the stratum granulosum. Similarly, psoriasin was seen more often in the upper skin layers of both infections as compared with normal skin. No significant differences between normal and infected skin were found for the expression of TLR9 and dectin 2. Our findings clearly show the expression of specific antimicrobial proteins and defence-related ligands in superficial tinea as well as in pityriasis versicolor, suggesting that these factors contribute to fungal containment.

  7. Expression of Toll-like receptor 4 in hippocampus of rat model with temporal lobe epilepsy

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    PAN Li-ping

    2013-12-01

    Full Text Available Objective To investigate the expression of Toll-like receptor 4 (TLR4 protein in hippocampus of rat model with temporal lobe epilepsy after status epilepticus (SE and explore its function in the pathogenesis of temporal lobe epilepsy. Methods Rat model with temporal lobe epilepsy was induced by lithium chloride (LiCl-pilocarpine. Total protein was extracted from hippocampus and rat brain slices were obtained at different time points (0, 1, 6, 12, 24, 48 h and 7, 10, 30, 50 d after SE. Western blotting and immunohistochemical staining were used for detection of the expression of TLR4 in the hippocampus. Results The results of Western blotting showed the TLR4 protein expression at 0, 1, 6, 12, 24, 48 h and 7, 10, 30 d after SE was higher than that in the control group (P 0.05. Conclusion TLR4 protein was mainly expressed in cytoplasm of pyramidal cells in CA3 area of hippocampus. TLR4 protein expression in the hippocampus was increased in varying degrees at different observation time points after SE, indicating that TLR4 may play an important role in the development of epilepsy.

  8. Characterization of promoter sequence of toll-like receptor genes in Vechur cattle

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    R. Lakshmi

    2016-06-01

    Full Text Available Aim: To analyze the promoter sequence of toll-like receptor (TLR genes in Vechur cattle, an indigenous breed of Kerala with the sequence of Bos taurus and access the differences that could be attributed to innate immune responses against bovine mastitis. Materials and Methods: Blood samples were collected from Jugular vein of Vechur cattle, maintained at Vechur cattle conservation center of Kerala Veterinary and Animal Sciences University, using an acid-citrate-dextrose anticoagulant. The genomic DNA was extracted, and polymerase chain reaction was carried out to amplify the promoter region of TLRs. The amplified product of TLR2, 4, and 9 promoter regions was sequenced by Sanger enzymatic DNA sequencing technique. Results: The sequence of promoter region of TLR2 of Vechur cattle with the B. taurus sequence present in GenBank showed 98% similarity and revealed variants for four sequence motifs. The sequence of the promoter region of TLR4 of Vechur cattle revealed 99% similarity with that of B. taurus sequence but not reveals significant variant in motifregions. However, two heterozygous loci were observed from the chromatogram. Promoter sequence of TLR9 gene also showed 99% similarity to B. taurus sequence and revealed variants for four sequence motifs. Conclusion: The results of this study indicate that significant variation in the promoter of TLR2 and 9 genes in Vechur cattle breed and may potentially link the influence the innate immunity response against mastitis diseases.

  9. Genomics in cardiovascular diseases: analysis of the importance of the toll-like receptor signaling pathway

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    Bustamante J

    2012-10-01

    Full Text Available J Bustamante,1 E Tamayo,2 J Herreros3,41Department of Cardiovascular Surgery, Hospital Universitario La Princesa, Madrid, 2Department of Anesthesiology and Intensive Care, Hospital Clinico Universitario de Valladolid, Valladolid, 3Department of Cardiovascular Surgery, Hospital Universitario Valdecilla, Santander, 4Biomedical Engineering Institute of Santander, Santander, SpainAbstract: The development of techniques for genomics study makes it possible for us to further our knowledge about the physiopathology of various immunological or infectious diseases. These techniques improve our understanding of the development and evolution of such diseases, including those of cardiovascular origin, whilst they help to bring about the design of new therapeutic strategies. We are reviewing the genetic alterations of immunity in said field, and focusing on the signaling pathway of toll-like receptors because not only does this play a decisive role in response to microorganisms, it is also heavily involved in modulating the inflammatory response to tissue damage, a side effect of numerous cardiovascular diseases. These alterations in tissue homeostasis are present under a wide range of circumstances, such as reperfusion ischemia (myocardial infarction phenomena, arteriosclerosis, or valvulopathy.Keywords: genome-wide association study, single-nucleotide polymorphism, innate immune system, ischemic/reperfusion, myocardial infarction

  10. Association of Toll-like receptors 2, 3, and 4 genes polymorphisms with periapical pathosis risk

    Science.gov (United States)

    Özan, Ülkü; Ocak, Zeynep; Özan, Fatih; Oktay, Elif-Aybala; Şahman, Halil; Yikilgan, İhsan; Oruçoğlu, Hasan; Er, Kürşat

    2016-01-01

    Background The aim of this study was to investigate the role of gene variations of Toll-like receptors (TLR) 2, 3, and 4 on genetic susceptibility to periapical pathosis. Material and Methods One hundred patients were included in the study and divided into two groups as follows; Control Group (n=50) that have root canal treatment and no periapical lesion, Patient Group (n=50) that have root canal treatment and periapical lesion. TLR2 Arg753Gln, TLR3 (c.1377C/T) and TLR4 Asp299Gly and Thr399Ile polymorphisms were genotyped by using PCR-RFLP. Genotypical analysis of control and patient groups were investigated to disclose whether there is any association between periapical lesions and gene variations. Results There are no significant statistical differences between control and patient groups according to TLR 2 and 4 gene sequence. On the contrary, CC allele detected 74% for TLR 3 in patient group, and this difference was found to be statistically significant (p endodontics. PMID:27031066

  11. Toll-like receptor 7 controls the anti-retroviral germinal center response.

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    Edward P Browne

    2011-10-01

    Full Text Available The development of vaccines that can enhance immunity to viral pathogens is an important goal. However, the innate molecular pathways that regulate the strength and quality of the immune response remain largely uncharacterized. To define the role of Toll-like receptor (TLR signaling in control of a model retroviral pathogen, Friend virus (FV, I generated mice in which the TLR signaling adapter Myd88 was selectively deleted in dendritic cell (DC or in B cell lineages. Deletion of Myd88 in DCs had little effect on immune control of FV, while B cell specific deletion of Myd88 caused a dramatic increase in viral infectious centers and a significantly reduced antibody response, indicating that B cell-intrinsic TLR signaling plays a crucial role, while TLR signaling in DCs is less important. I then identified the single-stranded RNA sensing protein TLR7 as being required for antibody-mediated control of FV by analyzing mice deficient in TLR7. Remarkably, B cells in infected TLR7-deficient mice upregulated CD69 and CD86 early in infection, but failed to develop into germinal center B cells. CD4 T cell responses were also attenuated in the absence of TLR7, but CD8 responses were TLR7 independent, suggesting the existence of additional pathways for detection of retroviral particles. Together these results demonstrate that the vertebrate immune system detects retroviruses in vivo via TLR7 and that this pathway regulates a key checkpoint controlling development of germinal center B cells.

  12. Toll-like receptor signalling in regenerative myogenesis: friend and foe.

    Science.gov (United States)

    Hindi, Sajedah M; Kumar, Ashok

    2016-06-01

    Skeletal muscle regeneration in normal and diseased muscle is regulated by multiple factors and cells present in the injured muscle micro-environment. In addition to muscle progenitor cells, several immunocytes participate in the regenerative response. Among them, macrophages are one of the most important components of the immune response that governs the step-wise progression of muscle regeneration. The initial role of macrophages is to phagocytose muscle cell debris and later, through their transition to an anti-inflammatory phenotype, they promote regeneration. However, in several genetic muscle disorders, continuous muscle injury disrupts the balance between pro-inflammatory and anti-inflammatory macrophages, leading to an overall inflammatory milieu and inhibition of muscle regeneration. Accumulating evidence suggests that Toll-like receptor (TLR)-mediated signalling plays an important role in the regulation of macrophage phenotypes during regenerative myogenesis in response to both acute and chronic muscle injury. Here, we discuss the role of TLR signalling in regulating macrophage phenotypes and skeletal muscle regeneration in healthy and diseased muscle. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:26956975

  13. Toll-like receptor-2 agonist functionalized biopolymer for mucosal vaccination.

    Science.gov (United States)

    Heuking, S; Iannitelli, A; Di Stefano, A; Borchard, G

    2009-11-01

    The objective of this study was to provide a new water-soluble chitosan derivative being functionalized with a Toll-like receptor-2 (TLR-2) agonist. At first, we synthesized the water-soluble TLR-2 agonist omega-amido-[N(alpha)-palmitoyl-oxy-S-[2,3-bis(palmitoyl-oxy)-(2R)-propyl]-[R]-cysteinyl]-alpha-amino poly(ethylene glycol) (Pam(3)Cys-PEG-NH(2)), which was characterized by (1)H and (13)C NMR as well as mass spectroscopy. Secondly, Pam(3)Cys-PEG-NH(2) was then successfully grafted to 6-O-carboxymethyl-N,N,N-trimethyl chitosan polymers (CM-TMC) using EDC/NHS as condensing agents. The copolymer was analysed by means of (1)H and (13)C NMR and FTIR spectroscopy. (13)C NMR spectroscopy did not deliver evidence that an amide bond was formed between CM-TMC and Pam(3)Cys-PEG-NH(2). However, (1)H NMR and FTIR spectroscopy demonstrated clearly that successful grafting took place. Based upon these results, this new TLR-2 functionalized biopolymer merits further investigations as material for vaccine delivery systems. PMID:19782879

  14. Novel Toll-like receptor-4 deficiency attenuates trastuzumab (Herceptin induced cardiac injury in mice

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    Yousif Nasser

    2011-10-01

    Full Text Available Abstract Background Cardiac inflammation and generation of oxidative stress are known to contribute to trastuzumab (herceptin induced cardiac toxicity. Toll-like receptors (TLRs are a part of the innate immune system and are involved in cardiac stress reactions. Since TLR4 might play a relevant role in cardiac inflammatory signaling, we investigated whether or not TLR4 is involved in trastuzumab induced cardiotoxicity. Methods Seven days after a single injection of herceptin (2 mg/kg; i.p., left ventricular pressure volume loops were measured in HeN compotent (TLR4+/+ and HeJ mutant (TLR4-/- treated with trastuzumab and control mice. Immunofluorescent staining for monocyte infiltration and analyses of plasma by (ELISAs for different chemokines including: MCP-1and tumor necrosis factor-α (TNF-α, Western immunoblotting assay for ICAM-1, and used troponin I for cardiac injury marker. Results Trastuzumab injection resulted in an impairment of left ventricular function in TLR-4 competent (HeN, in contrast TLR4-/- trastuzumab mice showed improved left ventricular function EF%, CO; p -/-; p -/-, marked reduction of myocardial troponin-I levels in TLR4-deficient mice. Data are presented as means ± SE; n = 8 in each group p Conclusions Treatment with trastuzumab induces an inflammatory response that contributes to myocardial tissue TLR4 mediates chemokine expression (TNF-α, MCP-1and ICAM-1, so in experimental animals TLR4 deficiency improves left ventricular function and attenuates pathophysiological key mechanisms in trastuzumab induced cardiomyopathy.

  15. Conservation of toll-like receptor signaling pathways in teleost fish

    Science.gov (United States)

    Purcell, M.K.; Smith, K.D.; Aderem, A.; Hood, L.; Winton, J.R.; Roach, J.C.

    2006-01-01

    In mammals, toll-like receptors (TLR) recognize ligands, including pathogen-associated molecular patterns (PAMPs), and respond with ligand-specific induction of genes. In this study, we establish evolutionary conservation in teleost fish of key components of the TLR-signaling pathway that act as switches for differential gene induction, including MYD88, TIRAP, TRIF, TRAF6, IRF3, and IRF7. We further explore this conservation with a molecular phylogenetic analysis of MYD88. To the extent that current genomic analysis can establish, each vertebrate has one ortholog to each of these genes. For molecular tree construction and phylogeny inference, we demonstrate a methodology for including genes with only partial primary sequences without disrupting the topology provided by the high-confidence full-length sequences. Conservation of the TLR-signaling molecules suggests that the basic program of gene regulation by the TLR-signaling pathway is conserved across vertebrates. To test this hypothesis, leukocytes from a model fish, rainbow trout (Oncorhynchus mykiss), were stimulated with known mammalian TLR agonists including: Diacylated and triacylated forms of lipoprotein, flagellin, two forms of LPS, synthetic double-stranded RNA, and two imidazoquinoline compounds (loxoribine and R848). Trout leukocytes responded in vitro to a number of these agonists with distinct patterns of cytokine expression that correspond to mammalian responses. Our results support the key prediction from our phylogenetic analyses that strong selective pressure of pathogenic microbes has preserved both TLR recognition and signaling functions during vertebrate evolution. ?? 2005 Elsevier Inc. All rights reserved.

  16. Intra-uterine Growth Restriction Downregulates the Hepatic Toll Like Receptor-4 Expression and Function

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    Ozlem Equils

    2005-01-01

    Full Text Available Maternal starvation is a significant cause of intrauterine growth restriction (IUGR in the world and increases the risk of infection in the neonate. We examined the effect of maternal starvation on Toll like receptor (TLR4 expression in hepatic, splenic and intestinal tissues obtained from the adult IUGR offspring of prenatal calorie restricted rats. The hepatic TLR4 protein concentration was undetectable in the IUGR rats that had restricted milk intake during the suckling period (SM/SP; n = 4, p < 0.05 as compared to the normal growth controls (CM/CP; n=4, and access to ad lib milk intake during the sucking period partially corrected the hepatic TLR4 expression (SM/CP; n = 4. IUGR had no effect on the splenic (n = 4 or intestinal (n = 4 TLR4 mRNA levels. In the liver, IUGR led to a 20% increase in baseline tumor necrosis factor (TNF-α mRNA expression ( p < 0.03 and a 70% increase in interleukin-1β (IL-1β mRNA expression ( p < 0.008 as compared to the control rats (CM/CP; n = 7. LPS-induced hepatic TNF-α release was significantly higher in SM/SP as compared to CM/CP. We propose that IUGR dysregulates TLR4 expression and function in the offspring, which may help explain the increased risk of Gram-negative sepsis and inflammatory diseases in this population.

  17. Expression of Toll-Like Receptors on Breast Tumors: Taking a Toll on Tumor Microenvironment

    International Nuclear Information System (INIS)

    Breast cancer remains a major cause of death in women in the developed world. As Toll-like receptors (TLRs) are widely expressed on tumor cells and play important roles in the initiation and progression of cancer, they may thus serve as important targets and have an effective perspective on breast cancer treatment. Expression of TLRs on breast cancer cells and mononuclear inflammatory cells can promote inflammation and cell survival in the tumor microenvironment. Inflammation and cancer are related. It is well known that persistent inflammatory conditions can induce cancer formation, due to production of cytokines and chemokines, which play a crucial role in promoting angiogenesis, metastasis, and subversion of adaptive immunity. TLR signaling in tumor cells can mediate tumor cell immune escape and tumor progression, and it is regarded as one of the mechanisms for chronic inflammation in tumorigenesis and progression. This paper delineates the expression of various TLRs in promotion of inflammation and development of mammary tumors. Understanding the mechanisms through which TLRs on breast cancer cells and inflammatory cells regulate growth, survival, and metastatic progression can make them potential targets for breast cancer therapy

  18. Drift, not selection, shapes toll-like receptor variation among oceanic island populations.

    Science.gov (United States)

    Gonzalez-Quevedo, Catalina; Spurgin, Lewis G; Illera, Juan Carlos; Richardson, David S

    2015-12-01

    Understanding the relative role of different evolutionary forces in shaping the level and distribution of functional genetic diversity among natural populations is a key issue in evolutionary and conservation biology. To do so accurately genetic data must be analysed in conjunction with an unambiguous understanding of the historical processes that have acted upon the populations. Here, we focused on diversity at toll-like receptor (TLR) loci, which play a key role in the vertebrate innate immune system and, therefore, are expected to be under pathogen-mediated selection. We assessed TLR variation within and among 13 island populations (grouped into three archipelagos) of Berthelot's pipit, Anthus berthelotii, for which detailed population history has previously been ascertained. We also compared the variation observed with that found in its widespread sister species, the tawny pipit, Anthus campestris. We found strong evidence for positive selection at specific codons in TLR1LA, TLR3 and TLR4. Despite this, we found that at the allele frequency level, demographic history has played the major role in shaping patterns of TLR variation in Berthelot's pipit. Levels of diversity and differentiation within and across archipelagos at all TLR loci corresponded very closely with neutral microsatellite variation and with the severity of the bottlenecks that occurred during colonization. Our study shows that despite the importance of TLRs in combating pathogens, demography can be the main driver of immune gene variation within and across populations, resulting in patterns of functional variation that can persist over evolutionary timescales.

  19. Expression of Toll-like receptors in nasal epithelium in allergic rhinitis.

    Science.gov (United States)

    Renkonen, Jutta; Toppila-Salmi, Sanna; Joenväärä, Sakari; Mattila, Pirkko; Parviainen, Ville; Hagström, Jaana; Haglund, Caj; Lehtonen, Mikko; Renkonen, Risto

    2015-08-01

    Toll-like receptors (TLRs) are important in barrier homeostasis, but their role in airborne allergies is not fully understood. The aim was to evaluate baseline and allergen-induced expression of TLR proteins in nasal epithelium during allergic rhinitis. Nineteen otherwise healthy non-smoking volunteers both allergic to birch pollen and non-allergic controls were enrolled. We took nasal biopsies before and after off-seasonal intranasal birch pollen or diluent challenge. The expression of epithelial TLR1-7, TLR9-10, and MyD88 proteins was immunohistochemically evaluated from the nasal biopsies. The TLR1-3 and TLR5-10 mRNAs were observed by RNA-microarray. Baseline epithelial expression of TLR proteins was wide and identical in controls and atopics. After off-seasonal intranasal birch pollen challenge, a negative change in the expression score of TLR1 and TLR6 proteins was detected in the atopic group. TLR mRNA expression was not affected by birch pollen challenge. Nasal epithelium seems to express all known TLRs. The mechanisms by which TLR1, and TLR6 proteins could affect pollen allergen transport need further studies.

  20. Association of Single Nucleotide Polymorphisms in Toll-like Receptors with Acinetobacter baumanii Infectionin a Chinese Population

    OpenAIRE

    He, Lei; Maohu LIN; Fan, Wensheng; Liu, Yunxi; SUO, Jijiang; Xing, Yubin; Jia, Ning

    2016-01-01

    Background: During recent years, infection of Acinetobacter baumanii showed a rapid growth in hospitals and community. Toll-like receptors (TLRs) are the most important pattern recognition receptors, which play a critical role during recognizing invading pathogens by the natural immune system. Our objective was to determine the associations of TLRs polymorphisms with the susceptibility to A. baumanii infection in a Chinese population. Methods: We carried out a case-control study, genotyping 1...

  1. Role of Toll-Like Receptors 2 and 4 in Pulmonary Inflammation and Injury Induced by Pneumolysin in Mice

    OpenAIRE

    Dessing, M C; Hirst, R. A.; De Vos; Poll, van der, T.

    2009-01-01

    Background: Pneumolysin (PLN) is an intracellular toxin of Streptococcus pneumoniae that has been implicated as a major virulence factor in infections caused by this pathogen. Conserved bacterial motifs are recognized by the immune system by pattern recognition receptors among which the family of Toll-like receptors (TLRs) prominently features. The primary objective of the present study was to determine the role of TLR2 and TLR4 in lung inflammation induced by intrapulmonary delivery of PLN. ...

  2. Crystal structure of Toll-like receptor adaptor MAL/TIRAP reveals the molecular basis for signal transduction and disease protection

    OpenAIRE

    Valkov, Eugene; Stamp, Anna; DiMaio, Frank; Baker, David; Verstak, Brett; Roversi, Pietro; Kellie, Stuart; Sweet, Matthew J.; Mansell, Ashley; Gay, Nicholas J.; Jennifer L Martin; Kobe, Bostjan

    2011-01-01

    Initiation of the innate immune response requires agonist recognition by pathogen-recognition receptors such as the Toll-like receptors (TLRs). Toll/interleukin-1 receptor (TIR) domain-containing adaptors are critical in orchestrating the signal transduction pathways after TLR and interleukin-1 receptor activation. Myeloid differentiation primary response gene 88 (MyD88) adaptor-like (MAL)/TIR domain-containing adaptor protein (TIRAP) is involved in bridging MyD88 to TLR2 and TLR4 in response...

  3. [The role of Toll-like receptors in the pathogenesis of allergic diseases - where is the truth?].

    Science.gov (United States)

    Dębińska, Anna; Boznański, Andrzej

    2014-01-01

    Toll-like receptors (TLRs) are pattern recognition receptors crucial for the innate and adaptive immune response to pathogen-associated molecular patterns (PAMPs). TLR stimulation via microbial products activates antigen-presenting cells, influences the function of T regulatory cells (Treg), determines the Th1/Th2 balance and Th17 cell differentiation, and controls cytokine production in mast cells and activation of eosinophils. The role of TLR receptors in pathogenesis of allergic diseases results from the biological function that they play in activation and regulation of the immune response. However, the exact role still remains a controversial area. Whereas numerous epidemiological studies mainly indicate a protective effect of microbial exposure, experiments show that innate immune stimulation via TLRs may be involved in both development of and protection against allergic diseases. Timing, dose, site and intensity of exposure to environmental factors and host genetic predisposition are clearly crucial to understanding the interaction between innate immune stimulation and allergy development.Furthermore, extensive clinical trials suggest that ligands for TLRs provide new therapeutic targets for protection against and treatment of asthma and allergic rhinitis. The aim of this review is to summarize the current knowledge about the role of TLRs in pathogenesis of allergic diseases. We will further discuss how we can reconcile inconsistencies in the results of existing studies and review information on the potential use of ligands for TLRs in allergy prevention and therapy. PMID:24662791

  4. The role of Toll-like receptors in the pathogenesis of allergic diseases – where is the truth?

    Directory of Open Access Journals (Sweden)

    Anna Dębińska

    2014-03-01

    Full Text Available Toll-like receptors (TLRs are pattern recognition receptors crucial for the innate and adaptive immune response to pathogen-associated molecular patterns (PAMPs. TLR stimulation via microbial products activates antigen-presenting cells, influences the function of T regulatory cells (Treg, determines the Th1/Th2 balance and Th17 cell differentiation, and controls cytokine production in mast cells and activation of eosinophils. The role of TLR receptors in pathogenesis of allergic diseases results from the biological function that they play in activation and regulation of the immune response. However, the exact role still remains a controversial area. Whereas numerous epidemiological studies mainly indicate a protective effect of microbial exposure, experiments show that innate immune stimulation via TLRs may be involved in both development of and protection against allergic diseases. Timing, dose, site and intensity of exposure to environmental factors and host genetic predisposition are clearly crucial to understanding the interaction between innate immune stimulation and allergy development.Furthermore, extensive clinical trials suggest that ligands for TLRs provide new therapeutic targets for protection against and treatment of asthma and allergic rhinitis. The aim of this review is to summarize the current knowledge about the role of TLRs in pathogenesis of allergic diseases. We will further discuss how we can reconcile inconsistencies in the results of existing studies and review information on the potential use of ligands for TLRs in allergy prevention and therapy.

  5. Characterization of Toll-like receptor gene expression in goldfish (Carassius auratus) during Dactylogyrus intermedius infection.

    Science.gov (United States)

    Tu, Xiao; Liu, Lei; Qi, Xiaozhou; Chen, Weichao; Wang, Gaoxue; Ling, Fei

    2016-10-01

    Toll-like receptors (TLRs), the first and best understood innate immune receptors, play a notable role in the innate immune system by sensing pathogenic agents and initiating appropriate immune responses. However, studies about the roles of fish TLRs in response to the infection of the ectoparasitic monogenean Dactylogyrus intermedius have been surprisingly vacant. In the present study, cDNA fragments of five members of TLRs family in goldfish (Carassius auratus) were cloned and the expression patterns of nine TLRs in five tissues at different time points during D. intermedius infection were subsequently investigated. We found that the expressions of TLR4, TLR5, TLR20 and TLR22 were significantly elevated after infection at some time points, of which the transcription of TLR5 was progressively increased nearly in all tissues, whereas the mRNA levels of other TLRs (TLR2, 3, 7, 9 and 21) were down-regulated or showed no significant change compared with the control at most time points. Additionally, this paper was also conducted to explore the expression of above TLRs after re-infected with D. intermedius. The results showed a significant upregulation of TLR4, TLR5 and TLR22 in all tested tissues at these two time points, especially the levels of TLR4 and TLR22 expression, were even higher comparing with the first infection. Besides, tissue-specific expression analysis revealed that spleen featured the highest expressions of almost all the TLR-encoding genes among detected tissues. The informations obtained here could be helpful towards understanding the functions of TLRs in response to parasitic infection in goldfish and provide new insights for the development of preventive and therapeutic approaches against D. intermedius infection.

  6. Characterization of Toll-like receptor gene expression in goldfish (Carassius auratus) during Dactylogyrus intermedius infection.

    Science.gov (United States)

    Tu, Xiao; Liu, Lei; Qi, Xiaozhou; Chen, Weichao; Wang, Gaoxue; Ling, Fei

    2016-10-01

    Toll-like receptors (TLRs), the first and best understood innate immune receptors, play a notable role in the innate immune system by sensing pathogenic agents and initiating appropriate immune responses. However, studies about the roles of fish TLRs in response to the infection of the ectoparasitic monogenean Dactylogyrus intermedius have been surprisingly vacant. In the present study, cDNA fragments of five members of TLRs family in goldfish (Carassius auratus) were cloned and the expression patterns of nine TLRs in five tissues at different time points during D. intermedius infection were subsequently investigated. We found that the expressions of TLR4, TLR5, TLR20 and TLR22 were significantly elevated after infection at some time points, of which the transcription of TLR5 was progressively increased nearly in all tissues, whereas the mRNA levels of other TLRs (TLR2, 3, 7, 9 and 21) were down-regulated or showed no significant change compared with the control at most time points. Additionally, this paper was also conducted to explore the expression of above TLRs after re-infected with D. intermedius. The results showed a significant upregulation of TLR4, TLR5 and TLR22 in all tested tissues at these two time points, especially the levels of TLR4 and TLR22 expression, were even higher comparing with the first infection. Besides, tissue-specific expression analysis revealed that spleen featured the highest expressions of almost all the TLR-encoding genes among detected tissues. The informations obtained here could be helpful towards understanding the functions of TLRs in response to parasitic infection in goldfish and provide new insights for the development of preventive and therapeutic approaches against D. intermedius infection. PMID:27238769

  7. Toll-like receptor 4-positive macrophages protect mice from Pasteurella pneumotropica-induced pneumonia

    Science.gov (United States)

    Hart, Marcia L.; Mosier, Derek A.; Chapes, Stephen K.

    2003-01-01

    This study investigates Toll-like receptor 4 (TLR4)-positive macrophages in early recognition and clearance of pulmonary bacteria. TLR4 is a trans-membrane receptor that is the primary recognition molecule for lipopolysaccharide of gram-negative bacteria. The TLR4(Lps-del) mouse strains C57BL10/ScN (B10) and STOCK Abb(tm1) TLR4(Lps-del) Slc11a1(s)(B10 x C2D) are susceptible to pulmonary infections and develop pneumonia when naturally or experimentally infected by the opportunistic bacterium Pasteurella pneumotropica. Since these mice have the TLR4(Lps-del) genotype, we hypothesized that reconstitution of mice with TLR4-positive macrophages would provide resistance to this bacterium. A cultured macrophage cell line (C2D macrophages) and bone marrow cells from C2D mice were adoptively transferred to B10 and B10 x C2D mice by intraperitoneal injection. C2D macrophages increased B10 and B10 x C2D mouse resistance to P. pneumotropica. In C2D-recipient mice there was earlier transcription of tumor necrosis factor alpha and chemokines JE and macrophage inflammatory protein 2 (MIP-2) in the lungs of B10 and B10 x C2D mice, and there was earlier transcription of KC and MIP-1alpha in B10 x C2D mice. In addition, the course of inflammation following experimental Pasteurella challenge was altered in C2D recipients. C2D macrophages also protected B10 x C2D mice, which lack CD4(+) T cells. These data indicate that macrophages are critical for pulmonary immunity and can provide host resistance to P. pneumotropica. This study indicates that TLR4-positive macrophages are important for early recognition and clearance of pulmonary bacterial infections.

  8. Functional Toll-like receptor 4 expressed in lactotrophs mediates LPS-induced proliferation in experimental pituitary hyperplasia

    Energy Technology Data Exchange (ETDEWEB)

    Sabatino, María Eugenia; Sosa, Liliana del Valle; Petiti, Juan Pablo; Mukdsi, Jorge Humberto [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina); Mascanfroni, Iván Darío; Pellizas, Claudia Gabriela [Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI-CONICET), Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Av. Haya de la Torre y Medina Allende, Ciudad Universitaria, CP 5000, Córdoba (Argentina); Gutiérrez, Silvina; Torres, Alicia Inés [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina); De Paul, Ana Lucía, E-mail: adepaul@cmefcm.uncor.edu [Centro de Microscopía Electrónica, Instituto de Investigaciones en Ciencias de la Salud (INICSA-CONICET), Facultad de Ciencias Médicas, Universidad Nacional de Córdoba, Av. Enrique Barros y Enfermera Gordillo, Ciudad Universitaria, CP 5000, Córdoba (Argentina)

    2013-11-15

    Toll like receptor 4 (TLR4) has been characterized for its ability to recognize bacterial endotoxin lipopolysaccharide (LPS). Considering that infections or inflammatory processes might contribute to the progression of pituitary tumors, we analyzed the TLR4 functional role by evaluating the LPS effect on lactotroph proliferation in primary cultures from experimental pituitary tumors, and examined the involvement of PI3K-Akt and NF-κB activation in this effect. In addition, the role of 17β-estradiol as a possible modulator of LPS-induced PRL cell proliferation was further investigated. In estrogen-induced hyperplasic pituitaries, LPS triggered lactotroph cell proliferation. However, endotoxin failed to increase the number of lactotrophs taking up BrdU in normal pituitaries. Moreover, incubation with anti-TLR4 antibody significantly reduced LPS-induced lactotroph proliferation, suggesting a functional role of this receptor. As a sign of TLR4 activation, an LPS challenge increased IL-6 release in normal and tumoral cells. By flow cytometry, TLR4 baseline expression was revealed at the plasma membrane of tumoral lactotrophs, without changes noted in the percentage of double PRL/TLR4 positive cells after LPS stimulus. Increases in TLR4 intracellular expression were detected as well as rises in CD14, p-Akt and NF-κB after an LPS challenge, as assessed by western blotting. The TLR4/PRL and PRL/NF-κB co-localization was also corroborated by immunofluorescence and the involvement of PI3K/Akt signaling in lactotroph proliferation and IL-6 release was revealed through the PI3K inhibitor Ly-294002. In addition, 17β-estradiol attenuated the LPS-evoked increase in tumoral lactotroph proliferation and IL-6 release. Collectively these results demonstrate the presence of functional TLR4 in lactotrophs from estrogen-induced hyperplasic pituitaries, which responded to the proliferative stimulation and IL-6 release induced by LPS through TLR4/CD14, with a contribution of the PI3K

  9. Comparative genomics of Toll-like receptor signalling in five species

    Directory of Open Access Journals (Sweden)

    Wu Chunhua

    2009-05-01

    Full Text Available Abstract Background Over the last decade, several studies have identified quantitative trait loci (QTL affecting variation of immune related traits in mammals. Recent studies in humans and mice suggest that part of this variation may be caused by polymorphisms in genes involved in Toll-like receptor (TLR signalling. In this project, we used a comparative approach to investigate the importance of TLR-related genes in comparison with other immunologically relevant genes for resistance traits in five species by associating their genomic location with previously published immune-related QTL regions. Results We report the genomic localisation of TLR1-10 and ten associated signalling molecules in sheep and pig using in-silico and/or radiation hybrid (RH mapping techniques and compare their positions with their annotated homologues in the human, cattle and mouse whole genome sequences. We also report medium-density RH maps for porcine chromosomes 8 and 13. A comparative analysis of the positions of previously published relevant QTLs allowed the identification of homologous regions that are associated with similar health traits in several species and which contain TLR related and other immunologically relevant genes. Additional evidence was gathered by examining relevant gene expression and association studies. Conclusion This comparative genomic approach identified eight genes as potentially causative genes for variations of health related traits. These include susceptibility to clinical mastitis in dairy cattle, general disease resistance in sheep, cattle, humans and mice, and tolerance to protozoan infection in cattle and mice. Four TLR-related genes (TLR1, 6, MyD88, IRF3 appear to be the most likely candidate genes underlying QTL regions which control the resistance to the same or similar pathogens in several species. Further studies are required to investigate the potential role of polymorphisms within these genes.

  10. Trichostatin A Protects Liver against Septic Injury through Inhibiting Toll-Like Receptor Signaling.

    Science.gov (United States)

    Kim, So-Jin; Park, Jin-Sook; Lee, Do-Won; Lee, Sun-Mee

    2016-07-01

    Sepsis, a serious clinical problem, is characterized by a systemic inflammatory response to infection and leads to organ failure. Toll-like receptor (TLR) signaling is intimately implicated in hyper-inflammatory responses and tissue injury during sepsis. Histone deacetylase (HDAC) inhibitors have been reported to exhibit anti-inflammatory properties. The aim of this study was to investigate the hepatoprotective mechanisms of trichostatin A (TSA), a HDAC inhibitor, associated with TLR signaling pathway during sepsis. The anti-inflammatory properties of TSA were assayed in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Polymicrobial sepsis was induced in mice by cecal ligation and puncture (CLP), a clinically relevant model of sepsis. The mice were intraperitoneally received TSA (1, 2 or 5 mg/kg) 30 min before CLP. The serum and liver samples were collected 6 and 24-h after CLP. TSA inhibited the increased production of tumor necrosis factor (TNF)-α and interleukin (IL)-6 in LPS-stimulated RAW264.7 cells. TSA improved sepsis-induced mortality, attenuated liver injury and decreased serum TNF-α and IL-6 levels. CLP increased the levels of TLR4, TLR2 and myeloid differentiation primary response protein 88 (MyD88) protein expression and association of MyD88 with TLR4 and TLR2, which were attenuated by TSA. CLP increased nuclear translocation of nuclear factor kappa B and decreased cytosolic inhibitor of kappa B (IκB) protein expression, which were attenuated by TSA. Moreover, CLP decreased acetylation of IκB kinase (IKK) and increased association of IKK with IκB and TSA attenuated these alterations. Our findings suggest that TSA attenuates liver injury by inhibiting TLR-mediated inflammatory response during sepsis. PMID:27068262

  11. Systemic Toll-like receptor stimulation suppresses experimental allergic asthma and autoimmune diabetes in NOD mice.

    Directory of Open Access Journals (Sweden)

    Aude Aumeunier

    Full Text Available BACKGROUND: Infections may be associated with exacerbation of allergic and autoimmune diseases. Paradoxically, epidemiological and experimental data have shown that some microorganisms can also prevent these pathologies. This observation is at the origin of the hygiene hypothesis according to which the decline of infections in western countries is at the origin of the increased incidence of both Th1-mediated autoimmune diseases and Th2-mediated allergic diseases over the last decades. We have tested whether Toll-like receptor (TLR stimulation can recapitulate the protective effect of infectious agents on allergy and autoimmunity. METHODS AND FINDINGS: Here, we performed a systematic study of the disease-modifying effects of a set of natural or synthetic TLR agonists using two experimental models, ovalbumin (OVA-induced asthma and spontaneous autoimmune diabetes, presenting the same genetic background of the non obese diabetic mouse (NOD that is highly susceptible to both pathologies. In the same models, we also investigated the effect of probiotics. Additionally, we examined the effect of the genetic invalidation of MyD88 on the development of allergic asthma and spontaneous diabetes. We demonstrate that multiple TLR agonists prevent from both allergy and autoimmunity when administered parenterally. Probiotics which stimulate TLRs also protect from these two diseases. The physiological relevance of these findings is further suggested by the major acceleration of OVA-induced asthma in MyD88 invalidated mice. Our results strongly indicate that the TLR-mediated effects involve immunoregulatory cytokines such as interleukin (IL-10 and transforming growth factor (TGF-beta and different subsets of regulatory T cells, notably CD4+CD25+FoxP3+ T cells for TLR4 agonists and NKT cells for TLR3 agonists. CONCLUSIONS/SIGNIFICANCE: These observations demonstrate that systemic administration of TLR ligands can suppress both allergic and autoimmune responses

  12. Regulation of angiogenesis, mural cell recruitment and adventitial macrophage behavior by Toll-like receptors.

    Science.gov (United States)

    Aplin, Alfred C; Ligresti, Giovanni; Fogel, Eric; Zorzi, Penelope; Smith, Kelly; Nicosia, Roberto F

    2014-01-01

    The angiogenic response to injury can be studied by culturing rat or mouse aortic explants in collagen gels. Gene expression studies show that aortic angiogenesis is preceded by an immune reaction with overexpression of Toll-like receptors (TLRs) and TLR-inducible genes. TLR1, 3, and 6 are transiently upregulated at 24 h whereas TLR2, 4, and 8 expression peaks at 24 h but remains elevated during angiogenesis and vascular regression. Expression of TLR5, 7 and 9 steadily increases over time and is highest during vascular regression. Studies with isolated cells show that TLRs are expressed at higher levels in aortic macrophages compared to endothelial or mural cells with the exception of TLR2 and TLR9 which are more abundant in the aortic endothelium. LPS and other TLR ligands dose dependently stimulate angiogenesis and vascular endothelial growth factor production. TLR9 ligands also influence the behavior of nonendothelial cell types by blocking mural cell recruitment and inducing formation of multinucleated giant cells by macrophages. TLR9-induced mural cell depletion is associated with reduced expression of the mural cell recruiting factor PDGFB. The spontaneous angiogenic response of the aortic rings to injury is reduced in cultures from mice deficient in myeloid differentiation primary response 88 (MyD88), a key adapter molecule of TLRs, and following treatment with an inhibitor of the NFκB pathway. These results suggest that the TLR system participates in the angiogenic response of the vessel wall to injury and may play an important role in the regulation of inflammatory angiogenesis in reactive and pathologic processes.

  13. Toll-Like Receptor 4 Signaling Pathway Mediates Inhalant Organic Dust-Induced Bone Loss.

    Science.gov (United States)

    Staab, Elizabeth; Thiele, Geoffrey M; Clarey, Dillon; Wyatt, Todd A; Romberger, Debra J; Wells, Adam D; Dusad, Anand; Wang, Dong; Klassen, Lynell W; Mikuls, Ted R; Duryee, Michael J; Poole, Jill A

    2016-01-01

    Agriculture workers have increased rates of airway and skeletal disease. Inhalant exposure to agricultural organic dust extract (ODE) induces bone deterioration in mice; yet, mechanisms underlying lung-bone crosstalk remain unclear. Because Toll-like receptor 2 (TLR2) and TLR4 are important in mediating the airway consequences of ODE, this study investigated their role in regulating bone responses. First, swine facility ODE stimulated wild-type (WT) bone marrow macrophages to form osteoclasts, and this finding was inhibited in TLR4 knock-out (KO), but not TLR2 KO cells. Next, using an established intranasal inhalation exposure model, WT, TLR2 KO and TLR4 KO mice were treated daily with ODE or saline for 3 weeks. ODE-induced airway neutrophil influx and cytokine/chemokine release were similarly reduced in TLR2 and TLR4 KO animals as compared to WT mice. Utilizing micro-computed tomography (CT), analysis of tibia showed loss of bone mineral density, volume and deterioration of bone micro-architecture and mechanical strength induced by ODE in WT mice were significantly reduced in TLR4 but not TLR2 KO animals. Bone marrow osteoclast precursor cell populations were analyzed by flow cytometry from exposed animals. In WT animals, exposure to inhalant ODE increased osteoclast precursor cell populations as compared to saline, an effect that was reduced in TLR4 but not TLR2 KO mice. These results show that TLR2 and TLR4 pathways mediate ODE-induced airway inflammation, but bone deterioration consequences following inhalant ODE treatment is strongly dependent upon TLR4. Thus, the TLR4 signaling pathway appears critical in regulating the lung-bone inflammatory axis to microbial component-enriched organic dust exposures. PMID:27479208

  14. Induction of IgG3 to LPS via Toll-like receptor 4 co-stimulation.

    Directory of Open Access Journals (Sweden)

    Francisco J Quintana

    Full Text Available B-cells integrate antigen-specific signals transduced via the B-cell receptor (BCR and antigen non-specific co-stimulatory signals provided by cytokines and CD40 ligation in order to produce IgG antibodies. Toll-like receptors (TLRs also provide co-stimulation, but the requirement for TLRs to generate T-cell independent and T-cell dependent antigen specific antibody responses is debated. Little is known about the role of B-cell expressed TLRs in inducing antigen-specific antibodies to antigens that also activate TLR signaling. We found that mice lacking functional TLR4 or its adaptor molecule MyD88 harbored significantly less IgG3 natural antibodies to LPS, and required higher amounts of LPS to induce anti-LPS IgG3. In vitro, BCR and TLR4 signaling synergized, lowering the threshold for production of T-cell independent IgG3 and IL-10. Moreover, BCR and TLR4 directly associate through the transmembrane domain of TLR4. Thus, in vivo, BCR/TLR synergism could facilitate the induction of IgG3 antibodies against microbial antigens that engage both innate and adaptive B-cell receptors. Vaccines might exploit BCR/TLR synergism to rapidly induce antigen-specific antibodies before significant T-cell responses arise.

  15. Vanadate from Air Pollutant Inhibits Hrs-Dependent Endosome Fusion and Augments Responsiveness to Toll-Like Receptors

    OpenAIRE

    Mojca Zelnikar; Mojca Benčina; Roman Jerala; Mateja Manček-Keber

    2014-01-01

    There is a well-established association between exposure to air pollutants and pulmonary injuries. For example, metals found in ROFA (residual oil fly ash) increase susceptibility of mice as well as humans to microbial infections. In our research, we have found that vanadate substantially increased the response of several Toll-like receptors (TLRs) to stimulation with their ligands. Although vanadate caused generation of reactive oxygen species (ROS), the addition of ROS scavenger N-acetyl cy...

  16. A novel model of common Toll-like receptor 4- and injury-induced transcriptional themes in human leukocytes

    OpenAIRE

    Haimovich, Beatrice; Reddell, Michael T; Calvano, Jacqueline E; Calvano, Steve E.; Macor, Marie A; Coyle, Susette M.; Lowry, Stephen F.

    2010-01-01

    Introduction An endotoxin challenge, sepsis, and injury/trauma, trigger significant changes in human peripheral blood leukocytes (PBL) gene expression. In this study, we have sought to test the hypothesis that the Toll-like receptor 4 (TLR4) induced transcription patterns elicited in humans exposed to in vivo endotoxin would parallel gene expression patterns observed in trauma patients with initial non-infectious injury. In addition, we sought to identify functional modules that are commonly ...

  17. Chronic Restraint Stress Promotes Immune Suppression through Toll-like Receptor 4-Mediated Phosphoinositide 3-kinase Signaling

    OpenAIRE

    Zhang, Yi; Zhang, Ying; Miao, JunYing; Hanley, Gregory; Stuart, Charles; Sun, Xiuli; Chen, Tingting; Yin, Deling

    2008-01-01

    Stress, either psychological or physical, can have a dramatic impact on the immune system. Toll-like receptors (TLRs) play a pivotal role in the induction of innate and adaptive immune response. We have reported that stress modulates the immune response in a TLR4-dependent manner. However, the mechanisms underlying TLR4-mediated signaling in stress modulation of immune system have not been identified. Here, we demonstrate an essential role for the TLR4-mediated phosphoinositide 3-kinase (PI3K...

  18. CD4+ T Cells and Toll-Like Receptors Recognize Salmonella Antigens Expressed in Bacterial Surface Organelles

    OpenAIRE

    Bergman, Molly A.; Cummings, Lisa A.; Barrett, Sara L. Rassoulian; Smith, Kelly D.; Lara, J. Cano; Aderem, Alan; Cookson, Brad T.

    2005-01-01

    A better understanding of immunity to infection is revealed from the characteristics of microbial ligands recognized by host immune responses. Murine infection with the intracellular bacterium Salmonella generates CD4+ T cells that specifically recognize Salmonella proteins expressed in bacterial surface organelles such as flagella and membrane vesicles. These natural Salmonella antigens are also ligands for Toll-like receptors (TLRs) or avidly associated with TLR ligands such as lipopolysacc...

  19. Colonic mucosal DNA methylation, immune response, and microbiome patterns in Toll-like receptor 2-knockout mice

    OpenAIRE

    Kellermayer, Richard; Dowd, Scot E.; Harris, R. Alan; Balasa, Alfred; Schaible, Tiffany D.; Wolcott, Randy D; Tatevian, Nina; Szigeti, Reka; Li, Zhijie; Versalovic, James; Smith, C. Wayne

    2011-01-01

    The connection between intestinal microbiota and host physiology is increasingly becoming recognized. The details of this dynamic interaction, however, remain to be explored. Toll-like receptor 2 (Tlr2) is important for its role in bacterial recognition, intestinal inflammation, and obesity-related metabolic changes. Therefore, we sought to determine the epigenomic and metagenomic consequences of Tlr2 deficiency in the colonic mucosa of mice to gain insights into biological pathways that shap...

  20. DMPD: Toll-like receptor signal transduction. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available M, Lee G, Choi S. Exp Mol Med. 2007 Aug 31;39(4):421-38. (.png) (.svg) (.html) (.csml) Show Toll-like recep... Selvarajoo K, Tsuchiya M, Lee G, Choi S. Publication Exp Mol Med. 2007 Aug 31;39

  1. Signatures of positive selection in Toll-like receptor (TLR genes in mammals

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    Areal Helena

    2011-12-01

    Full Text Available Abstract Background Toll-like receptors (TLRs are a major class of pattern recognition receptors (PRRs expressed in the cell surface or membrane compartments of immune and non-immune cells. TLRs are encoded by a multigene family and represent the first line of defense against pathogens by detecting foreigner microbial molecular motifs, the pathogen-associated molecular patterns (PAMPs. TLRs are also important by triggering the adaptive immunity in vertebrates. They are characterized by the presence of leucine-rich repeats (LRRs in the ectodomain, which are associated with the PAMPs recognition. The direct recognition of different pathogens by TLRs might result in different evolutionary adaptations important to understand the dynamics of the host-pathogen interplay. Ten mammal TLR genes, viral (TLR3, 7, 8, 9 and non-viral (TLR1-6, 10, were selected to identify signatures of positive selection that might have been imposed by interacting pathogens and to clarify if viral and non-viral TLRs might display different patterns of molecular evolution. Results By using Maximum Likelihood approaches, evidence of positive selection was found in all the TLRs studied. The number of positively selected codons (PSC ranged between 2-26 codons (0.25%-2.65% with the non-viral TLR4 as the receptor with higher percentage of positively selected codons (2.65%, followed by the viral TLR8 (2.50%. The results indicated that viral and non-viral TLRs are similarly under positive selection. Almost all TLRs have at least one PSC located in the LRR ectodomain which underlies the importance of the pathogen recognition by this region. Conclusions Our results are not in line with previous studies on primates and birds that identified more codons under positive selection in non-viral TLRs. This might be explained by the fact that both primates and birds are homogeneous groups probably being affected by only a restricted number of related viruses with equivalent motifs to be

  2. Stimulation of Toll-like receptor-1/2 combined with Velcade increases cytotoxicity to human multiple myeloma cells

    International Nuclear Information System (INIS)

    An increasing body of evidence supports the important role of adhesion to bone marrow microenvironment components for survival and drug resistance of multiple myeloma (MM) cells. Previous studies suggested that stimulation of Toll-like receptors by endogenous ligands released during inflammation and tissue damage may be pro-tumorigenic, but no studies have been performed in relation to modulation of cell adhesion and drug cytotoxicity. Here, we investigated the effect of TLR1/2 activation on adhesion of human myeloma cells to fibronectin, and their sensitivity to the proteasome inhibitor Velcade. It was found that TLR1/2 activation with Pam3CSK4 increased the cytotoxicity of Velcade in L363, OPM-2 and U266 human myeloma cells. This effect was not related to a decreased adhesion of the cells to fibronectin, but TLR1/2 activation stimulated the caspase-3 activity in Velcade-treated myeloma cells, which may be responsible for the enhanced cell death. Inhibitors of NF-κB and MAPK reduced the stimulatory effect. These findings indicate that TLR activation of MM cells could bypass protective effects of cell adhesion and suggest that TLR signaling may also have antitumorigenic potential

  3. A role for Toll-like receptor mediated signals in neutrophils in the pathogenesis of the anti-phospholipid syndrome.

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    Gerd Gladigau

    Full Text Available The anti-phospholipid syndrome (APS is characterized by recurrent thrombosis and occurrence of anti-phospholipid antibodies (aPL. aPL are necessary, but not sufficient for the clinical manifestations of APS. Growing evidence suggests a role of innate immune cells, in particular polymorphonuclear neutrophils (PMN and Toll-like receptors (TLR to be additionally involved. aPL activate endothelial cells and monocytes through a TLR4-dependent signalling pathway. Whether this is also relevant for PMN in a similar way is currently not known. To address this issue, we used purified PMN from healthy donors and stimulated them in the presence or absence of human monoclonal aPL and the TLR4 agonist LPS monitoring neutrophil effector functions, namely the oxidative burst, phagocytosis, L-Selectin shedding and IL-8 production. aPL alone were only able to induce minor activation of PMN effector functions at high concentrations. However, in the additional presence of LPS the activation threshold was markedly lower indicating a synergistic activation pathway of aPL and TLR in PMN. In summary, our results indicate that PMN effector functions are directly activated by aPL and boosted by the additional presence of microbial products. This highlights a role for PMN as important innate immune effector cells that contribute to the pathophysiology of APS.

  4. Molecular characterization and functional analysis of Toll-like receptor 3 gene in orange-spotted grouper (Epinephelus coioides).

    Science.gov (United States)

    Lin, Kebing; Ge, Hui; Lin, Qi; Wu, Jianshao; He, Libin; Fang, Qiongshan; Zhou, Chen; Sun, Minqiu; Huang, Zhongchi

    2013-09-15

    Toll-like receptor 3 (TLR3) plays an important role in activating innate immune responses during viral infection. In this report, TLR3 (EcTLR3) was characterized and analyzed for the first time in Epinephelus coioides. The full-length EcTLR3 cDNA is predicted to encode a 909 amino acid polypeptide that contains a signal peptide sequence, 18 leucine-rich repeat (LRR) motifs, a transmembrane region and a Toll/interleukin-1 receptor (TIR) domain. Quantitative real-time PCR revealed that the EcTLR3 mRNA was much more abundant in the liver than in other immune organs, and that the expression levels were very low in hemocyte and muscle. During development of the grouper, the levels of EcTLR3 transcripts increased with age, with very low expression levels at the early stages of development. EcTLR3 mRNA levels were examined in the liver at different times after treatment with polyriboinosinic polyribocytidylic acid (Poly I:C), and in nervous necrosis virus (NNV)-infected larval groupers. The results suggested that EcTLR3 plays an important role in a fish's defense against viral infection.

  5. The broad pattern recognition spectrum of the Toll-like receptor in mollusk Zhikong scallop Chlamys farreri.

    Science.gov (United States)

    Wang, Mengqiang; Wang, Lingling; Guo, Ying; Sun, Rui; Yue, Feng; Yi, Qilin; Song, Linsheng

    2015-10-01

    Toll-like receptors (TLRs) are among the most studied pattern recognition receptors (PRRs) playing essential roles in innate immune defenses. In the present study, the basic features of CfTLR in mollusk Zhikong scallop Chlamys farreri, including sequence homology, tissue distribution, subcellular localization and ligands spectrum, were investigated to elucidate its pattern recognition. The elements of extracellular domains (ECD) in CfTLR displayed high homology to the corresponding parts of the ECDs in TLRs from Homo sapiens. CfTLR protein was detected in hemocytes, mantle, gills, hepatopancreas, kidney and gonad of the scallops, and it was localized in both the plasma membranes and the lysosomes in HEK293T cells. CfTLR could activate NFκB in response to multiple HsTLR ligands including Pam3CSK4, glucan (GLU), peptidoglycan (PGN), polyriboinosinic:polyribocytidylic acid (poly I:C), Imiquimod and three types of CpG. Additionally, the scallop serum could enhance the induction of NFκB in the CfTLR expressing cells elicited by most PAMPs, including GLU, PGN, Imiquimod and four types of CpG. It could be concluded that this primitive mollusk TLR shared a hybrid function in pattern recognition and could recognize broader ligands than mammalian TLRs, and its mosaic capability of pathogen associated molecular pattern (PAMP) recognition might be based on the basic features of its structure, ligand properties and the assistance of some components in scallop serum.

  6. Effects of human Toll-like receptor 1 polymorphisms on ageing

    Directory of Open Access Journals (Sweden)

    Uciechowski Peter

    2013-02-01

    Full Text Available Abstract Background Advanced age results in crucial alterations of the innate and adaptive immune system leading to functional defects resulting in infection and chronic diseases. Toll-like receptors (TLR recognize pathogenic structures and are important in the immune response to infections and vaccination. However, the role of TLR single nucleotide polymorphisms (SNP is poorly understood in the setting of human ageing. This study investigated the impact of the TLR1 SNPs A743G and T1805G on ageing in different age groups from two European populations. Results The TLR1 genotypes 743AA/1805GG (TLR1neg are associated with a TLR1 negative phenotype, impaired function and susceptibility to tuberculosis. Carriers of heterozygous 743AG/1805TG and homozygous 743GG/1805TT genotypes (TLR1pos have a TLR1 positive phenotype. By comparing healthy young and old German donors, the old group showed a tendency to carry more TLR1neg and less homozygous TLR1pos genotypes. Anti-inflammatory Interleukin (IL-1 receptor antagonist (Ra was significantly elevated in supernatants of mononuclear cells from old German subjects with a TLR1pos genotype in contrast to those with the 743AA genotype. Healthy old individuals and nonagenarians from Italy displayed significantly higher frequencies of TLR1pos genotypes than the old group from Germany. The data show that tumor-necrosis-factor (TNFα, CXCL8 and CCL2 levels were higher in old donors from Germany than in plasma levels from old Italian donors. TNFα and CCL2 levels were significantly raised in old German individuals compared to Italian nonagenarians. German and Italian donors with the TLR1neg genotype basically produced more CCL2 than older European donors with TLR1pos genotypes. Conclusion The higher frequency of the TLR1pos genotype in elderly Italian subjects may result from different ethnic populations. Lower inflammatory mediator release of aged Italian individuals is probably due to different background in

  7. An Oligomeric Signaling Platform Formed by the Toll-like Receptor Signal Transducers MyD88 and IRAK-4*

    OpenAIRE

    Motshwene, Precious G.; Moncrieffe, Martin C.; Grossmann, J. Günter; KAO, CHENG; Ayaluru, Murali; Sandercock, Alan M.; Carol V Robinson; Latz, Eicke; Gay, Nicholas J.

    2009-01-01

    Toll-like receptors (TLRs) mediate responses to pathogen-associated molecules as part of the vertebrate innate immune response to infection. Receptor dimerization is coupled to downstream signal transduction by the recruitment of a post-receptor complex containing the adaptor protein MyD88 and the IRAK protein kinases. In this work, we show that the death domains of human MyD88 and IRAK-4 assemble into closed complexes having unusual stoichiometries of 7:4 and 8:4, the Myddosome. Formation of...

  8. Amino Acid-Dependent Attenuation of Toll-like Receptor Signaling by Peptide-Gold Nanoparticle Hybrids.

    Science.gov (United States)

    Yang, Hong; Fung, Shan-Yu; Xu, Shuyun; Sutherland, Darren P; Kollmann, Tobias R; Liu, Mingyao; Turvey, Stuart E

    2015-07-28

    Manipulation of immune responsiveness using nanodevices provides a potential approach to treat human diseases. Toll-like receptor (TLR) signaling plays a central role in the pathophysiology of many acute and chronic human inflammatory diseases, and pharmacological regulation of TLR responses is anticipated to be beneficial in many of these inflammatory conditions. Here we describe the discovery of a unique class of peptide-gold nanoparticle hybrids that exhibit a broad inhibitory activity on TLR signaling, inhibiting signaling through TLRs 2, 3, 4, and 5. As exemplified using TLR4, the nanoparticles were found to inhibit both arms of TLR4 signaling cascade triggered by the prototypical ligand, lipopolysaccharide (LPS). Through structure-activity relationship studies, we identified the key chemical components of the hybrids that contribute to their immunomodulatory activity. Specifically, the hydrophobicity and aromatic ring structure of the amino acids on the peptides were essential for modulating TLR4 responses. This work enhances our fundamental understanding of the role of nanoparticle surface chemistry in regulating innate immune signaling, and identifies specific nanoparticle hybrids that may represent a unique class of anti-inflammatory therapeutics for human inflammatory diseases.

  9. Lactobacillus casei prevents the development of dextran sulphate sodium-induced colitis in Toll-like receptor 4 mutant mice.

    Science.gov (United States)

    Chung, Y W; Choi, J H; Oh, T-Y; Eun, C S; Han, D S

    2008-01-01

    Probiotics, defined as live or attenuated bacteria or bacterial products, confer a significant health benefit to the host. Recently, they have been shown to be useful in the treatment of chronic inflammatory bowel disease and infectious colitis. In this study, we investigated the effect of probiotics on the development of experimental colitis using Toll-like receptor 4 (TLR-4) mutant (lps-/lps-) mice. TLR-4(lps-/lps-) and wild-type (WT) mice were given 2.5% dextran sulphate sodium (DSS) in drinking water to induce colitis with or without Lactobacillus casei pretreatment. Clinical and histological activity of DSS-colitis was attenuated markedly both in TLR-4(lps-/lps-) and WT mice pretreated with L. casei. Interestingly, histological activity was less severe in TLR-4(lps-/lps-) mice than in WT mice. The levels of myeloperoxidase activity and interleukin (IL)-12p40 were attenuated in pretreated TLR-4(lps-/lps-) mice after DSS administration. By contrast, transforming growth factor (TGF)-beta and IL-10 mRNA and protein expressions were increased markedly in pretreated TLR-4(lps-/lps-) mice. The current results suggest that L. casei has a preventive effect in the development of acute DSS-induced colitis and its action depends largely upon TLR-4 status. L. casei modulates the expression of inflammatory cytokines and down-regulates neutrophilic infiltration in the case of incomplete TLR-4 complex signalling. PMID:18005362

  10. The repertoire for pattern recognition of pathogens by the innate immune system is defined by cooperation between Toll-like receptors

    OpenAIRE

    Ozinsky, Adrian; Underhill, David M; Fontenot, Jason D.; Adeline M Hajjar; Smith, Kelly D.; Wilson, Christopher B.; Schroeder, Lea; Aderem, Alan

    2000-01-01

    Toll-like receptors (TLRs) have been shown to participate in the recognition of pathogens by the innate immune system, but it is not clear how a restricted family of receptors has the capacity to recognize the wide spectrum of TLR stimuli known to exist. We report here that two members of the TLR family, TLR2 and TLR6, together coordinate macrophage activation by Gram-positive bacteria and the yeast cell-wall particle, zymosan. TLR6 and TLR2 both are recruited to t...

  11. Herpes simplex virus infection is sensed by both Toll-like receptors and retinoic acid-inducible gene- like receptors, which synergize to induce type I interferon production

    DEFF Research Database (Denmark)

    Rasmussen, Simon Brandtoft; Jensen, Søren B; Nielsen, C;

    2009-01-01

    The innate antiviral response is initiated by pattern recognition receptors, which recognize viral pathogen-associated molecular patterns. Here we show that retinoic acid-inducible gene (RIG)-I-like receptors (RLRs) in cooperation with Toll-like receptor (TLR) 9 is required for expression of type...

  12. Toll-Like Receptor 9 Alternatively Spliced Isoform Negatively Regulates TLR9 Signaling in Teleost Fish

    Science.gov (United States)

    Chen, Nai-Yu; Nagarajan, Govindarajulu; Chiou, Pinwen Peter

    2015-01-01

    Toll-like receptor 9 (TLR9) recognizes and binds unmethylated CpG motifs in DNA, which are found in the genomes of bacteria and DNA viruses. In fish, Tlr9 is highly diverse, with the number of introns ranging from 0 to 4. A fish Tlr9 gene containing two introns has been reported to express two alternatively spliced isoforms, namely gTLR9A (full-length) and gTLR9B (with a truncated Cʹ-terminal signal transducing domain), whose regulation and function remain unclear. Here, we report a unique regulatory mechanism of gTLR9 signaling in orange-spotted grouper (Epinephelus coioides), whose gTlr9 sequence also contains two introns. We demonstrated that the grouper gTlr9 gene indeed has the capacity to produce two gTLR9 isoforms via alternative RNA splicing. We found that gTLR9B could function as a negative regulator to suppress gTLR9 signaling as demonstrated by the suppression of downstream gene expression. Following stimulation with CpG oligodeoxynucleotide (ODN), gTLR9A and gTLR9B were observed to translocate into endosomes and co-localize with ODN and the adaptor protein gMyD88. Both gTLR9A and gTLR9B could interact with gMyD88; however, gTLR9B could not interact with downstream IRAK4 and TRAF6. Further analysis of the expression profile of gTlr9A and gTlr9B upon immune-stimulation revealed that the two isoforms were differentially regulated in a time-dependent manner. Overall, these data suggest that fish TLR9B functions as a negative regulator, and that its temporal expression is mediated by alternative RNA splicing. This has not been observed in mammalian TLR9s and might have been acquired relatively recently in the evolution of fish. PMID:25955250

  13. Toll-Like Receptor 9 Alternatively Spliced Isoform Negatively Regulates TLR9 Signaling in Teleost Fish.

    Directory of Open Access Journals (Sweden)

    Frank Fang-Yao Lee

    Full Text Available Toll-like receptor 9 (TLR9 recognizes and binds unmethylated CpG motifs in DNA, which are found in the genomes of bacteria and DNA viruses. In fish, Tlr9 is highly diverse, with the number of introns ranging from 0 to 4. A fish Tlr9 gene containing two introns has been reported to express two alternatively spliced isoforms, namely gTLR9A (full-length and gTLR9B (with a truncated C'-terminal signal transducing domain, whose regulation and function remain unclear. Here, we report a unique regulatory mechanism of gTLR9 signaling in orange-spotted grouper (Epinephelus coioides, whose gTlr9 sequence also contains two introns. We demonstrated that the grouper gTlr9 gene indeed has the capacity to produce two gTLR9 isoforms via alternative RNA splicing. We found that gTLR9B could function as a negative regulator to suppress gTLR9 signaling as demonstrated by the suppression of downstream gene expression. Following stimulation with CpG oligodeoxynucleotide (ODN, gTLR9A and gTLR9B were observed to translocate into endosomes and co-localize with ODN and the adaptor protein gMyD88. Both gTLR9A and gTLR9B could interact with gMyD88; however, gTLR9B could not interact with downstream IRAK4 and TRAF6. Further analysis of the expression profile of gTlr9A and gTlr9B upon immune-stimulation revealed that the two isoforms were differentially regulated in a time-dependent manner. Overall, these data suggest that fish TLR9B functions as a negative regulator, and that its temporal expression is mediated by alternative RNA splicing. This has not been observed in mammalian TLR9s and might have been acquired relatively recently in the evolution of fish.

  14. Identification and expression analysis of cobia (Rachycentron canadum) Toll-like receptor 9 gene.

    Science.gov (United States)

    Byadgi, Omkar; Puteri, Dinda; Lee, Yan-Horn; Lee, Jai-Wei; Cheng, Ta-Chih

    2014-02-01

    Cobia culture is hindered by bacterial infection (Photobacterium damselae subsp. piscicida) and in order to study the effect of P. damselae subsp. piscicida challenge and CpG ODN stimulation on cobia Toll like receptor 9 (RCTLR9), we used PCR to clone RCTLR9 gene and qRT-PCR to quantify gene expression. The results indicated that RCTLR9 cDNA contains 3141 bp. It encodes 1047 amino acids containing 16 typical structures of leucine-rich repeats (LRRs) including an LRRTYP, LRRCT and a motif involved in PAMP binding was identified at position 240-253 amino acid. Broad expression of RCTLR9 was found in larval, juvenile and adult stages irrespective of the tissues. In larval stage, RCTLR9 mRNA expression decreased at 5 d and then increased at 10 dph. At juvenile stage cobia, the expression was significantly high (p < 0.05) in spleen and intestine compared to gill, kidney, liver and skin. However, at adult stage, the significant high expression was found in gill and intestine. Cobia challenged with P. damselae subsp. piscicida showed significant increase in RCTLR9 expression at 24 h post challenge in intestine, spleen and liver, while in kidney the expression was peak at 12 h and later it decreased at 24 h. The highest expression was 40 fold increase in spleen and the lowest expression was ∼3.6 fold increase in liver. Cobia stimulated with CpG oligonucleotides showed that the induction of these genes was CpG ODN type and time dependent. In spleen and liver, CpG ODNs 1668 and 2006 injected group showed high expression of RCTLR9, IL-1β, chemokine CC compared to other groups. Meanwhile, CpG ODN 2006 has induced high expression of IgM. The CpG ODNs 2395 have induced significant high expression of Mx in spleen and liver. These results demonstrates the potential of using CpG ODN to enhance cobia resistance to P. damselae subsp. piscicida infection and use as an adjuvant in vaccine development.

  15. Downstream Toll-like receptor signaling mediates adaptor-specific cytokine expression following focal cerebral ischemia

    Directory of Open Access Journals (Sweden)

    Bolanle Famakin

    2012-07-01

    Full Text Available Abstract Background Deletion of some Toll-like receptors (TLRs affords protection against cerebral ischemia, but disruption of their known major downstream adaptors does not. To determine whether compensation in the production of downstream effectors by one pathway when the other is disrupted can explain these findings, we examined cytokine/chemokine expression and inflammatory infiltrates in wild-type (WT, MyD88−/− and TRIF-mutant mice following permanent middle cerebral artery occlusion (pMCAO. Methods Cytokine/chemokine expression was measured with a 25-plex bead array in the serum and brains of all three groups of mice at baseline (no surgery/naïve and at 3 hours and 24 hours following pMCAO. Brain inflammatory and neutrophil infiltrates were examined 24 hours following pMCAO. Results IL-6, keratinocyte chemoattractant (KC, granulocyte colony-stimulating factor (G-CSF and IL-10 were significantly decreased in MyD88−/− mice compared to WT mice following pMCAO. Significantly, decreased levels of the neutrophil chemoattractants KC and G-CSF corresponded with a trend toward fewer neutrophils in the brains of MyD88−/− mice. IP-10 was significantly decreased when either pathway was disrupted. MIP-1α was significantly decreased in TRIF-mutant mice, consistent with TRIF-dependent production. MyD88−/− mice showed elevations of a number of Th2 cytokines, such as IL-13, at baseline, which became significantly decreased following pMCAO. Conclusions Both MyD88 and TRIF mediate pathway-specific cytokine production following focal cerebral ischemia. Our results also suggest a compensatory Th2-type skew at baseline in MyD88−/− mice and a paradoxical switch to a Th1 phenotype following focal cerebral ischemia. The MyD88 pathway directs the expression of neutrophil chemoattractants following cerebral ischemia.

  16. Toll-Like Receptor Mediated Modulation of T Cell Response by Commensal Intestinal Microbiota as a Trigger for Autoimmune Arthritis

    Directory of Open Access Journals (Sweden)

    Rebecca Rogier

    2015-01-01

    Full Text Available In autoimmune diseases, a disturbance of the balance between T helper 17 (Th17 and regulatory T cells (Tregs is often observed. This disturbed balance is also the case in rheumatoid arthritis (RA. Genetic predisposition to RA confers the presence of several polymorphisms mainly regulating activation of T lymphocytes. However, the presence of susceptibility factors is neither necessary nor sufficient to explain the disease development, emphasizing the importance of environmental factors. Multiple studies have shown that commensal gut microbiota is of great influence on immune homeostasis and can trigger the development of autoimmune diseases by favoring induction of Th17 cells over Tregs. However the mechanism by which intestinal microbiota influences the Th cell balance is not completely understood. Here we review the current evidence supporting the involvement of commensal intestinal microbiota in rheumatoid arthritis, along with a potential role of Toll-like receptors (TLRs in modulating the relevant Th cell responses to trigger autoimmunity. A better understanding of TLR triggering by intestinal microbiota and subsequent T cell activation might offer new perspectives for manipulating the T cell response in RA patients and may lead to the discovery of new therapeutic targets or even preventive measures.

  17. The involvement of hypoxia-inducible factor 1 alpha in Toll-like receptor 7/8-mediated inflammatory response

    Institute of Scientific and Technical Information of China (English)

    Sally A Nicholas; Vadim V Sumbayev

    2009-01-01

    Toll-like receptors (TLRs) 7 and 8 are crucial in host defence against single-stranded RNA (ssRNA) viruses. Such viruses cause severe illnesses, which remain a serious medical burden in both industrialised and developing countries. TLR7/8 downstream signaling leads to a dramatic cellular stress associated with energy consumption. However, the molecular mechanisms of cell survival and adaptation to TLR7/8-induced stress, which give the cells an opportunity to initiate proper inflammatory reactions, are not clear at all. Here we report for the first time that ligand-induced ac-tivation of TLR7/8 leads to the accumulation of hypoxia-inducible factor 1 alpha (HIF-1α) protein in THP-1 human myeloid macrophages via redox-and reactive nitrogen species-dependent mechanisms. MAP kinases and phosphoi-nositol-3K are not involved in TLR7/8-mediated HIF-1α accumulation. Experiments with HIF-la knockdown THP-1 cells have clearly demonstrated that HIF-1α is important for the protection of these cells against TLR7/8-induced depletion of ATP. Thus, HIF-1α might support both cell survival and the production of pro-inflammatory cytokines upon TLR7/8 activation.

  18. Toll-like receptors-2 and 4 are overexpressed in an experimental model of particle-induced osteolysis.

    Science.gov (United States)

    Valladares, Roberto D; Nich, Christophe; Zwingenberger, Stefan; Li, Chenguang; Swank, Katherine R; Gibon, Emmanuel; Rao, Allison J; Yao, Zhenyu; Goodman, Stuart B

    2014-09-01

    Aseptic loosening secondary to particle-associated periprosthetic osteolysis remains a major cause of failure of total joint replacements (TJR) in the mid- and long term. As sentinels of the innate immune system, macrophages are central to the recognition and initiation of the inflammatory cascade, which results in the activation of bone resorbing osteoclasts. Toll-like receptors (TLRs) are involved in the recognition of pathogen-associated molecular patterns and danger-associated molecular patterns. Experimentally, polymethylmethacrylate and polyethylene (PE) particles have been shown to activate macrophages via the TLR pathway. The specific TLRs involved in PE particle-induced osteolysis remain largely unknown. We hypothesized that TLR-2, -4, and -9 mediated responses play a critical role in the development of PE wear particle-induced osteolysis in the murine calvarium model. To test this hypothesis, we first demonstrated that PE particles caused observable osteolysis, visible by microCT and bone histomorphometry when the particles were applied to the calvarium of C57BL/6 mice. The number of TRAP positive osteoclasts was significantly greater in the PE-treated group when compared to the control group without particles. Finally, using immunohistochemistry, TLR-2 and TLR-4 were highly expressed in PE particle-induced osteolytic lesions, whereas TLR-9 was downregulated. TLR-2 and -4 may represent novel therapeutic targets for prevention of wear particle-induced osteolysis and accompanying TJR failure. PMID:24115330

  19. Immune modulation by different types of β2→1-fructans is toll-like receptor dependent.

    Directory of Open Access Journals (Sweden)

    Leonie Vogt

    Full Text Available INTRODUCTION: β2→1-fructans are dietary fibers. Main objectives of this study were 1 to demonstrate direct signalling of β2→1-fructans on immune cells, 2 to study whether this is mediated by the pattern recognition receptors Toll-like receptors (TLRs and nucleotide-binding oligomerisation domain-containing proteins (NODs, and 3 to relate the observed effects to the chain length differences in β2→1-fructans. METHODS: Four different β2→1-fructan formulations were characterised for their chain length profile. Human peripheral blood mononuclear cells (PBMCs were stimulated in vitro with β2→1-fructans, and production of IL-1Ra, IL-1β, IL-6, IL-10, IL-12p70, and TNF-α was analysed. Reporter cells for TLRs and NODs were incubated with β2→1-fructans and analysed for NF-κB/AP-1 activation. RESULTS: Cytokine production in human PBMCs was dose- and chain length-dependent. Strikingly, short chain enriched β2→1-fructans induced a regulatory cytokine balance compared to long chain enriched β2→1-fructans as measured by IL-10/IL-12 ratios. Activation of reporter cells showed that signalling was highly dependent on TLRs and their adapter, myeloid differentiation primary response protein 88 (MyD88. In human embryonic kidney reporter cells, TLR2 was prominently activated, while TLR4, 5, 7, 8, and NOD2 were mildly activated. CONCLUSIONS: β2→1-fructans possess direct signalling capacity on human immune cells. By activating primarily TLR2, and to a lesser extent TLR4, 5, 7, 8, and NOD2, β2→1-fructan stimulation results in NF-κB/AP-1 activation. Chain length of β2→1-fructans is important for the induced activation pattern and IL-10/IL-12 ratios.

  20. Toll-Like Receptor 4 Deficiency Causes Reduced Exploratory Behavior in Mice Under Approach-Avoidance Conflict.

    Science.gov (United States)

    Li, Chunlu; Yan, Yixiu; Cheng, Jingjing; Xiao, Gang; Gu, Jueqing; Zhang, Luqi; Yuan, Siyu; Wang, Junlu; Shen, Yi; Zhou, Yu-Dong

    2016-04-01

    Abnormal approach-avoidance behavior has been linked to deficits in the mesolimbic dopamine (DA) system of the brain. Recently, increasing evidence has indicated that toll-like receptor 4 (TLR4), an important pattern-recognition receptor in the innate immune system, can be directly activated by substances of abuse, resulting in an increase of the extracellular DA level in the nucleus accumbens. We thus hypothesized that TLR4-dependent signaling might regulate approach-avoidance behavior. To test this hypothesis, we compared the novelty-seeking and social interaction behaviors of TLR4-deficient (TLR4(-/-)) and wild-type (WT) mice in an approach-avoidance conflict situation in which the positive motivation to explore a novel object or interact with an unfamiliar mouse was counteracted by the negative motivation to hide in exposed, large spaces. We found that TLR4(-/-) mice exhibited reduced novelty-seeking and social interaction in the large open spaces. In less stressful test apparatuses similar in size to the mouse cage, however, TLR4(-/-) mice performed normally in both novelty-seeking and social interaction tests. The reduced exploratory behaviors under approach-avoidance conflict were not due to a high anxiety level or an enhanced fear response in the TLR4(-/-) mice, as these mice showed normal anxiety and fear responses in the open field and passive avoidance tests, respectively. Importantly, the novelty-seeking behavior in the large open field induced a higher level of c-Fos activation in the nucleus accumbens shell (NAcSh) in TLR4(-/-) mice than in WT mice. Partially inactivating the NAcSh via infusion of GABA receptor agonists restored the novelty-seeking behavior of TLR4(-/-) mice. These data suggested that TLR4 is crucial for positive motivational behavior under approach-avoidance conflict. TLR4-dependent activation of neurons in the NAcSh may contribute to this phenomenon.

  1. How the Intricate Interaction among Toll-Like Receptors, Microbiota, and Intestinal Immunity Can Influence Gastrointestinal Pathology.

    Science.gov (United States)

    Frosali, Simona; Pagliari, Danilo; Gambassi, Giovanni; Landolfi, Raffaele; Pandolfi, Franco; Cianci, Rossella

    2015-01-01

    The gut is able to maintain tolerance to microbial and food antigens. The intestine minimizes the number of harmful bacteria by shaping the microbiota through a symbiotic relationship. In healthy human intestine, a constant homeostasis is maintained by the perfect regulation of microbial load and the immune response generated against it. Failure of this balance may result in various pathological conditions. Innate immune sensors, such as Toll-like receptors (TLRs), may be considered an interface among intestinal epithelial barrier, microbiota, and immune system. TLRs pathway, activated by pathogens, is involved in the pathogenesis of several infectious and inflammatory diseases. The alteration of the homeostasis between physiologic and pathogenic bacteria of intestinal flora causes a condition called dysbiosis. The breakdown of homeostasis by dysbiosis may increase susceptibility to inflammatory bowel diseases. It is evident that environment, genetics, and host immunity form a highly interactive regulatory triad that controls TLR function. Imbalanced relationships within this triad may promote aberrant TLR signaling, critically contributing to acute and chronic intestinal inflammatory processes, such as in IBD, colitis, and colorectal cancer. The study of interactions between different components of the immune systems and intestinal microbiota will open new horizons in the knowledge of gut inflammation.

  2. How the Intricate Interaction among Toll-Like Receptors, Microbiota, and Intestinal Immunity Can Influence Gastrointestinal Pathology

    Directory of Open Access Journals (Sweden)

    Simona Frosali

    2015-01-01

    Full Text Available The gut is able to maintain tolerance to microbial and food antigens. The intestine minimizes the number of harmful bacteria by shaping the microbiota through a symbiotic relationship. In healthy human intestine, a constant homeostasis is maintained by the perfect regulation of microbial load and the immune response generated against it. Failure of this balance may result in various pathological conditions. Innate immune sensors, such as Toll-like receptors (TLRs, may be considered an interface among intestinal epithelial barrier, microbiota, and immune system. TLRs pathway, activated by pathogens, is involved in the pathogenesis of several infectious and inflammatory diseases. The alteration of the homeostasis between physiologic and pathogenic bacteria of intestinal flora causes a condition called dysbiosis. The breakdown of homeostasis by dysbiosis may increase susceptibility to inflammatory bowel diseases. It is evident that environment, genetics, and host immunity form a highly interactive regulatory triad that controls TLR function. Imbalanced relationships within this triad may promote aberrant TLR signaling, critically contributing to acute and chronic intestinal inflammatory processes, such as in IBD, colitis, and colorectal cancer. The study of interactions between different components of the immune systems and intestinal microbiota will open new horizons in the knowledge of gut inflammation.

  3. Elevated expression of the toll like receptors 2 and 4 in obese individuals: its significance for obesity-induced inflammation

    Directory of Open Access Journals (Sweden)

    Ahmad Rasheed

    2012-11-01

    Full Text Available Abstract Background Expression profile of the toll like receptors (TLRs on PBMCs is central to the regulation of proinflammatory markers. An imbalance in the TLRs expression may lead to several types of inflammatory disorders. Furthermore, the dynamic regulation of inflammatory activity and associated impaired production of cytokines by peripheral blood mononuclear cells (PBMCs in obese individulas remain poorly understood. Therefore, we determined the perturbation in TLRs (TLR2 and TLR4, their adaptor proteins (MyD88, IRAK1 and TRAF6 expression in PBMCs/subcutaneous adipose tissue (AT as well as inflammatory cytokines changes in obese individuals. Methods mRNA expression levels of TLR2, TLR4, IL-6, TNF-α and adaptor proteins were determined by RT-PCR. TLR2, TLR4 and adaptor proteins expression in AT was determined by immunohistochemistry. Results Obese and overweight individuals showed significantly increased expression of TLR2, TLR4 and MyD88 in both PBMCs and AT as compared with lean individuals (P  Conclusions TLRs and adapter proteins were overexpressed in PBMCs from obese subjects, which correlated with increased expression of TNF-α and IL-6. This association may explain a potential pathophysiological link between obesity and inflammation leading to insulin resistance.

  4. Role of Cytokines and Toll-Like Receptors in the Immunopathogenesis of Guillain-Barré Syndrome

    Directory of Open Access Journals (Sweden)

    Kishan Kumar Nyati

    2014-01-01

    Full Text Available Guillain-Barré syndrome (GBS is an autoimmune disease of the peripheral nervous system, mostly triggered by an aberrant immune response to an infectious pathogen. Although several infections have been implicated in the pathogenesis of GBS, not all such infected individuals develop this disease. Moreover, infection with a single agent might also lead to different subtypes of GBS emphasizing the role of host factors in the development of GBS. The host factors regulate a broad range of inflammatory processes that are involved in the pathogenesis of autoimmune diseases including GBS. Evidences suggest that systemically and locally released cytokines and their involvement in immune-mediated demyelination and axonal damage of peripheral nerves are important in the pathogenesis of GBS. Toll-like receptors (TLRs link innate and adaptive immunity through transcription of several proinflammatory cytokines. TLR genes may increase susceptibility to microbial infections; an attenuated immune response towards antigen and downregulation of cytokines occurs due to mutation in the gene. Herein, we discuss the crucial role of host factors such as cytokines and TLRs that activate the immune response and are involved in the pathogenesis of the disease.

  5. Downregulation of toll-like receptor 4 and IL-6 following irradiation of the rat urinary bladder.

    Science.gov (United States)

    Giglio, D; Wasén, C; Mölne, J; Suchy, D; Swanpalmer, J; Jabonero Valbuena, J; Tobin, G; Ny, L

    2016-07-01

    The pathophysiology behind radiation cystitis is poorly understood. Here we investigated whether bladder irradiation affects the immune system of the rat urinary bladder. Female rats were sedated and exposed to one single radiation dose of 20 Gy or only sedated (controls) and killed 16 h to 14 days later. Rats were placed in a metabolic cage at 16 h, 3 days, 7 days and 14 days following bladder irradiation. The urinary bladders were harvested and analysed with qPCR, immunohistochemistry and/or Western blot for the expression of interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-4, IL-5, IL-6, IL-10, IL-13, nitric oxide synthases (eNOS, iNOS and nNOS), tumour necrosis factor (TNF)-α and toll-like receptor 4 (TLR4). Urine was collected and analysed for IL-6 and nitrite (reflecting nitric oxide activity) with ELISA and the Griess reaction, respectively. Irradiation increased bladder frequency and decreased voiding volumes 14 days following bladder irradiation. Bladder irradiation increased the expression of IL-10 and collagen in the bladder, while TLR4 and IL-6 expressions were decreased in the urothelium concomitantly with a decrease in mast cells in the submucosa and urine levels of IL-6 and nitrite. The present findings show that bladder irradiation leads to urodynamic changes in the bladder and may suppress important immunoregulatory pathways in the urinary bladder. PMID:27117224

  6. Epigallocatechin-3-gallate suppresses proinflammatory cytokines and chemokines induced by Toll-like receptor 9 agonists in prostate cancer cells

    Directory of Open Access Journals (Sweden)

    Mukherjee S

    2014-06-01

    Full Text Available Sushovita Mukherjee, Mohammad Adnan Siddiqui, Shubham Dayal, Yasmine Zakaria Ayoub, Krishnamurthy Malathi Department of Biological Sciences, University of Toledo, Toledo, OH, USA Abstract: Chronic inflammation of the prostate contributes to the increased risk of prostate cancer. Microbial pathogens in the prostate cause inflammation that leads to prostatitis and proliferative inflammatory atrophy frequently associated with the development of prostate cancer. Bacterial lipopolysaccharides and DNA mediate immune responses by engaging Toll-like receptor (TLR 4 and 9, respectively. Synthetic oligodeoxynucleotides containing CpG motifs (CpG-ODN mimic bacterial DNA and signal through TLR9 to initiate innate immune responses. Here, we show that stimulation of DU145, PC3, or LnCap prostate cancer cells by the TLR9 agonists, CpG-ODN, induces mRNA expression of IL-6, IL-8, CXCL1, IP-10, CCL5, and TGFβ. In addition, activity of matrix metalloproteinase (MMP-9 and -2 and cell migration increased on CpG-ODN treatment. Induction of cytokines and chemokines was mediated by NF-ΚB activation and translocation to the nucleus. Treatment with epigallocatechin-3-gallate (EGCG, the major constituent of green tea, prior to CpG-ODN stimulation, inhibits cytokine and chemokine gene induction, activity of MMP-9 and -2, and cell migration. EGCG treatment sequesters the p65 subunit of transcription factor NF-ΚB in the cytoplasm and inhibits transcriptional activity of the NF-ΚB-driven promoter in response to CpG-ODN. Our results suggest that the ability of the TLR9 agonists, CpG-ODN, to induce cytokines, chemokines, and MMP activity, as well as suppression by EGCG are independent of the androgen receptor and p53 status of the cells. EGCG may provide protective effects against inflammation in the prostate and benefit prostate cancer treatment. Keywords: CpG-ODN, EGCG, inflammation, NF-ΚB

  7. Flagellin-induced tolerance of the Toll-like receptor 5 signaling pathway in polarized intestinal epithelial cells.

    Science.gov (United States)

    Sun, Jun; Fegan, Pamela E; Desai, Anjali S; Madara, James L; Hobert, Michael E

    2007-03-01

    Salmonella typhimurium is a gram-negative enteric pathogen that invades the mucosal epithelium and is associated with diarrheal illness in humans. Flagellin from S. typhimurium and other gram-negative bacteria has been shown to be the predominant proinflammatory mediator through activation of the basolateral Toll-like receptor 5 (TLR5). Recent evidence has shown that prior exposure can render immune cells tolerant to subsequent challenges by TLR ligands. Accordingly, we examined whether prior exposure to purified flagellin would render human intestinal epithelial cells insensitive to future contact. We found that flagellin-induced tolerance is common to polarized epithelial cells and prevents further activation of proinflammatory signaling cascades by both purified flagellin and Salmonella bacteria but does not affect TNF-alpha stimulation of the same pathways. Flagellin tolerance is a rapid process that does not require protein synthesis, and that occurs within 1 to 2 h of flagellin exposure. Prolonged flagellin exposure blocks activation of the NF-kappaB, MAPK, and phosphoinositol 3-kinase signaling pathways and results in the internalization of a fraction of the basolateral TLR5 without affecting the polarity or total expression of TLR5. After removal of flagellin, cells require more than 24 h to fully recover their ability to mount a normal proinflammatory response. We have found that activation of phosphoinositol 3-kinase and Akt by flagellin has a small damping effect in the early stages of flagellin signaling but is not responsible for tolerance. Our study indicates that inhibition of TLR5-associated IL-1 receptor-associated kinase-4 activity occurs during the development of flagellin tolerance and is likely to be the cause of tolerance. PMID:17138965

  8. Toll-like receptor 4 is not targeted to the lysosome in cystic fibrosis airway epithelial cells.

    Science.gov (United States)

    Kelly, Catriona; Canning, Paul; Buchanan, Paul J; Williams, Mark T; Brown, Vanessa; Gruenert, Dieter C; Elborn, J Stuart; Ennis, Madeleine; Schock, Bettina C

    2013-03-01

    The innate immune response to bacterial infection is mediated through Toll-like receptors (TLRs), which trigger tightly regulated signaling cascades through transcription factors including NF-κB. LPS activation of TLR4 triggers internalization of the receptor-ligand complex which is directed toward lysosomal degradation or endocytic recycling. Cystic fibrosis (CF) patients display a robust and uncontrolled inflammatory response to bacterial infection, suggesting a defect in regulation. This study examined the intracellular trafficking of TLR4 in CF and non-CF airway epithelial cells following stimulation with LPS. We employed cells lines [16hBE14o-, CFBE41o- (CF), and CFTR-complemented CFBE41o-] and confirmed selected experiments in primary nasal epithelial cells from non-CF controls and CF patients (F508del homozygous). In control cells, TLR4 expression (surface and cytoplasmic) was reduced after LPS stimulation but remained unchanged in CF cells and was accompanied by a heightened inflammatory response 24 h after stimulation. All cells expressed markers of the early (EEA1) and late (Rab7b) endosomes at basal levels. However, only CF cells displayed persistent expression of Rab7b following LPS stimulation. Rab7 variants may directly internalize bacteria to the Golgi for recycling or to the lysosome for degradation. TLR4 colocalized with the lysosomal marker LAMP1 in 16 hBE14o- cells, suggesting that TLR4 is targeted for lysosomal degradation in these cells. However, this colocalization was not observed in CFBE41o- cells, where persistent expression of Rab7 and release of proinflammatory cytokines was detected. Consistent with the apparent inability of CF cells to target TLR4 toward the lysosome for degradation, we observed persistent surface and cytoplasmic expression of this pathogen recognition receptor. This defect may account for the prolonged cycle of chronic inflammation associated with CF. PMID:23316065

  9. Toll-like receptor 4 regulates lipopolysaccharide-induced inflammation and lactation insufficiency in a mouse model of mastitis.

    Science.gov (United States)

    Glynn, Danielle J; Hutchinson, Mark R; Ingman, Wendy V

    2014-05-01

    Lactation mastitis is a debilitating inflammatory breast disease in postpartum women. Disease severity is associated with markers of inflammation rather than bacterial load, suggesting that immune-signaling pathways activated in the host are important in the disease pathology. The role of the innate pattern recognition receptor toll-like receptor 4 (TLR4) in progression and resolution of mastitislike disease was investigated in a mouse model. Lipopolysaccharide in Matrigel (10 μg/10 μl) was administered into the teat canal of lactating Tlr4 null mutant and wild-type mice to induce a localized area of inflammation. Mastitis induction resulted in a marked influx of RB6-positive neutrophils and F4/80-positive macrophages, which was higher in Tlr4(-/-) mice compared to wild-type mice. Tlr4 null mutation resulted in an altered immune-signaling fingerprint following induction of mastitis, with attenuated serum cytokines, including CXCL1, CCL2, interleukin 1 beta, and tumor necrosis factor alpha compared to wild-type mice. In both genotypes, the localized area of inflammation had resolved after 7 days, and milk protein was evident. However, the mammary glands of wild-type mice exhibited reduced capacity for milk production, with decreased percent area populated with glandular epithelium and decreased abundance of nuclear phosphorylated signal transducer and activator of transcription 5 compared to Tlr4 null mice. This study demonstrates that inflammatory pathways activated in the host are critically important in mastitis disease progression and suggests that lactation insufficiency associated with mastitis may be a consequence of TLR4-mediated inflammation, rather than the bacterial infection itself.

  10. Differential regulation of toll-like receptor-2, toll-like receptor-4, CD16 and human leucocyte antigen-DR on peripheral blood monocytes during mild and severe dengue fever.

    Science.gov (United States)

    Azeredo, Elzinandes L; Neves-Souza, Patrícia C; Alvarenga, Allan R; Reis, Sônia R N I; Torrentes-Carvalho, Amanda; Zagne, Sonia-Maris O; Nogueira, Rita M R; Oliveira-Pinto, Luzia M; Kubelka, Claire F

    2010-06-01

    Dengue fever (DF), a public health problem in tropical countries, may present severe clinical manifestations as result of increased vascular permeability and coagulation disorders. Dengue virus (DENV), detected in peripheral monocytes during acute disease and in in vitro infection, leads to cytokine production, indicating that virus-target cell interactions are relevant to pathogenesis. Here we investigated the in vitro and in vivo activation of human peripheral monocytes after DENV infection. The numbers of CD14(+) monocytes expressing the adhesion molecule intercellular adhesion molecule 1 (ICAM-1) were significantly increased during acute DF. A reduced number of CD14(+) human leucocyte antigen (HLA)-DR(+) monocytes was observed in patients with severe dengue when compared to those with mild dengue and controls; CD14(+) monocytes expressing toll-like receptor (TLR)2 and TLR4 were increased in peripheral blood from dengue patients with mild disease, but in vitro DENV-2 infection up-regulated only TLR2. Increased numbers of CD14(+) CD16(+) activated monocytes were found after in vitro and in vivo DENV-2 infection. The CD14(high) CD16(+) monocyte subset was significantly expanded in mild dengue, but not in severe dengue. Increased plasma levels of tumour necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma) and interleukin (IL)-18 in dengue patients were inversely associated with CD14(high) CD16(+), indicating that these cells might be involved in controlling exacerbated inflammatory responses, probably by IL-10 production. We showed here, for the first time, phenotypic changes on peripheral monocytes that were characteristic of cell activation. A sequential monocyte-activation model is proposed in which DENV infection triggers TLR2/4 expression and inflammatory cytokine production, leading eventually to haemorrhagic manifestations, thrombocytopenia, coagulation disorders, plasmatic leakage and shock development, but may also produce factors that act in

  11. Natural killer cell-dependent anti-fibrotic pathway in liver injury via Toll-like receptor-9.

    Directory of Open Access Journals (Sweden)

    Lina Abu-Tair

    Full Text Available The toll-like receptor-9 (TLR9 agonist cytosine phosphate guanine (CpG, activates hepatic stellate cells (HSCs and mediates fibrosis. We investigated the TLR9 effects on lymphocyte/HSCs interactions. Liver fibrosis was induced in wild-type (WT mice by intra-peritoneal carbon-tetrachloride (CCl4 induction for 6 weeks. Fibrotic groups were intravenously treated by a vehicle versus CpG along last 2 weeks. Compared to vehicle-treated fibrotic WT, the in-vivo CpG-treatment significantly attenuated hepatic fibrosis and inflammation, associated with decreased CD8 and increased NK liver cells. In-vitro, co-cultures with vehicle-treated fibrotic NK cells increased HSCs proliferation (P<0.001 while their CpG-treated counterparts achieved a significant decrease. To investigate the role of lymphocytes, TLR9(-/- mice induced-hepatic fibrosis were used. Although TLR9(-/- mice manifested lower fibrotic profile as compared to their wild-type (WT counterparts, senescence (SA-β-Gal activity in the liver and ALT serum levels were significantly greater. In an adoptive transfer model; irradiated WT and TLR9(-/- recipients were reconstituted with naïve WT or TLR9(-/- lymphocytes. The adoptive transfer of TLR9(-/- versus WT lymphocytes led to increased fibrosis of WT recipients. TLR9(-/- fibrotic recipients reconstituted with TLR9(-/- or WT lymphocytes showed no changes in hepatic fibrosis severity or ALT serum levels. TLR9 activation had inconsistent effects on lymphocytes and HSCs. The net balance of TLR9 activation in WT, displayed significant anti-fibrotic activity, accompanied by CD8 suppression and increased NK-cells, activity and adherence to HSCs. The pro-fibrotic and pro-inflammatory properties of TLR9(-/- lymphocytes fail to activate HSCs with an early senescence in TLR9(-/- mice.

  12. Characterization and functional analysis of toll-like receptor 4 in Chinese soft-shelled turtle Pelodiscus sinensis.

    Science.gov (United States)

    Zhou, Yingshan; Liang, Quan; Li, Weifen; Gu, Yuanxing; Liao, Xun; Fang, Weihuan; Li, Xiaoliang

    2016-10-01

    Mammalian Toll-like receptor 4 (TLR4) recognizes lipopolysaccharide (LPS) in initiating the innate immune responses. Early studies indicate that turtles are more resistant to LPS challenge than mammals. It remains unknown if turtles express TLR4 and why they are more resistant to LPS. In this study, TLR4 gene from Chinese soft-shelled turtle, Pelodiscus sinensis, was cloned and characterized. The full length cDNA of turtle TLR4 (tTLR4) consists of 3396 base pairs with an 2499-bp open reading frame, encoding 833 amino acids. Phylogenetic and syntenic analyses suggest that tTLR4 is to be orthologous to human TLR4. Its mRNA expression was up-regulated in spleen and blood of turtles upon Aeromonas hydrophila infection. Stimulation of turtle peripheral blood monocytes with LPS significantly upregulated tTLR4 mRNA and inflammation-related gene expression, such as Interleukin-1β (IL-1β) and cyclooxygenase-2 (COX-2). In tTLR4-expressing HEK293 cells, higher concentration of LPS exposure could enhance the activity of the NF-κB promoter, but not the INF-β promoter. Such activity required co-expression of turtle myeloid differentiation factor 2 (tMD2) and cluster of differentiation 14 (tCD14). These results provide evidence for a functional TLR4 in reptiles and, together with the syntenic analysis, support the idea that the TLR4 receptor for LPS recognition may have arisen after reptiles. PMID:27259833

  13. Comparison of Cellular Uptake and Inflammatory Response via Toll-Like Receptor 4 to Lipopolysaccharide and Titanium Dioxide Nanoparticles

    OpenAIRE

    Akiyoshi Taniguchi; Koki Kanehira; Sharmy Saimon Mano

    2013-01-01

    The innate immune response is the earliest cellular response to infectious agents and mediates the interactions between microbes and cells. Toll-like receptors (TLRs) play an important role in these interactions. We have already shown that TLRs are involved with the uptake of titanium dioxide nanoparticles (TiO2 NPs) and promote inflammatory responses. In this paper, we compared role of cellular uptake and inflammatory response via TLR 4 to lipopolysaccharide (LPS) and TiO2 NPs. In the case o...

  14. [TOLL-LIKE RECEPTORS IN COSMONAUT'S PERIPHERAL BLOOD CELLS AFTER LONG-DURATION MISSIONS TO THE INTERNATIONAL SPACE STATION].

    Science.gov (United States)

    Berendeeva, T A; Ponomarev, S A; Antropova, E N; Rykova, M P

    2015-01-01

    Studies of Toll-like receptors (TLR) in 20 cosmonauts-members of long-duration (124-199-day) missions to the International space station evidenced changes in relative and absolute counts of peripheral blood monocytes with TLR2, TLR4 and TLR6 on the surface, expression of TLR2 and TLR6 genes, and genes of molecules involved in the TLR signaling pathway and TLR-related NF-KB-, JNK/p38- and IRF pathways on the day of return to Earth. The observed changes displayed individual variability.

  15. Administration of a Toll-Like Receptor 9 Agonist Decreases the Proviral Reservoir in Virologically Suppressed HIV-Infected Patients

    OpenAIRE

    Winckelmann, Anni A.; Lærke V Munk-Petersen; Thomas A. Rasmussen; Jesper Melchjorsen; Thomas J Hjelholt; David Montefiori; Lars Østergaard; Søgaard, Ole S.; Martin Tolstrup

    2013-01-01

    Toll-like receptor (TLR) agonists can reactivate HIV from latently infected cells in vitro. We aimed to investigate the TLR-9 agonist, CPG 7909's in vivo effect on the proviral HIV reservoir and HIV-specific immunity. This was a post-hoc analysis of a double-blind randomized controlled vaccine trial. HIV-infected adults were randomized 1:1 to receive pneumococcal vaccines with or without 1 mg CPG 7909 as adjuvant at 0, 3 and 9 months. In patients on suppressive antiretroviral therapy we quant...

  16. Novel critical role of Toll-like receptor 4 in lung ischemia-reperfusion injury and edema

    OpenAIRE

    Zanotti, Giorgio; Casiraghi, Monica; Abano, John B.; Tatreau, Jason R.; Sevala, Mayura; Berlin, Hilary; Smyth, Susan; Funkhouser, William K.; Burridge, Keith; Randell, Scott H.; Egan, Thomas M.

    2009-01-01

    Toll-like receptors (TLRs) of the innate immune system contribute to noninfectious inflammatory processes. We employed a murine model of hilar clamping (1 h) with reperfusion times between 15 min and 3 h in TLR4-sufficient (C3H/OuJ) and TLR4-deficient (C3H/HeJ) anesthetized mice with additional studies in chimeric and myeloid differentiation factor 88 (MyD88)- and TLR4-deficient mice to determine the role of TLR4 in lung ischemia-reperfusion injury. Human pulmonary microvascular endothelial m...

  17. Hypoxia induced HMGB1 and mitochondrial DNA interactions mediate tumor growth in hepatocellular carcinoma through Toll Like Receptor 9

    Science.gov (United States)

    Liu, Yao; Yan, Wei; Tohme, Samer; Chen, Man; Fu, Yu; Tian, Dean; Lotze, Michael; Tang, Daolin; Tsung, Allan

    2015-01-01

    Background and aims The mechanisms of hypoxia-induced tumor growth remain unclear. Hypoxia induces intracellular translocation and release of a variety of damage associated molecular patterns (DAMPs) such as nuclear HMGB1 and mitochondrial DNA (mtDNA). In inflammation, Toll-like receptor (TLR)-9 activation by DNA-containing immune complexes has been shown to be mediated by HMGB1. We thus hypothesize that HMGB1 binds mtDNA in the cytoplasm of hypoxic tumor cells and promotes tumor growth through activating TLR9 signaling pathways. Methods C57BL6 mice were injected with Hepa1-6 cancer cells. TLR9 and HMGB1 were inhibited using shRNA or direct antagonists. Huh7 and Hepa1-6 cancer cells were investigated in vitro to investigate how the interaction of HMGB1 and mtDNA activates TLR9 signaling pathways. Results During hypoxia, HMGB1 translocates from the nucleus to the cytosol and binds to mtDNA released from damaged mitochondria. This complex subsequently activates TLR9 signaling pathways to promote tumor cell proliferation. Loss of HMGB1 or mtDNA leads to a defect in TLR9 signaling pathways in response to hypoxia, resulting in decreased tumor cell proliferation. Also, the addition of HMGB1 and mtDNA leads to the activation of TLR-9 and subsequent tumor cell proliferation. Moreover, TLR9 is overexpressed in both hypoxic tumor cells in vitro and in human hepatocellular cancer (HCC) specimens; and, knockdown of either HMGB1 or TLR9 from HCC cells suppressed tumor growth in vivo after injection in mice. Conclusions Our data reveals a novel mechanism by which the interactions of HMGB1 and mtDNA activate TLR9 signaling during hypoxia to induce tumor growth. PMID:25681553

  18. Extracellular heat-shock protein 70 aggravates cerulein-induced pancreatitis through toll-like receptor-4 in mice

    Institute of Scientific and Technical Information of China (English)

    SONG Jun-min; WANG Rong; LIU Hong-xiang; LI Yuan; ZENG Yu-jian; ZHOU Zong-guang; LIU Hai-yi; XU Bing; WANG Ling; ZHOU Bin

    2008-01-01

    Background In patients suffering from acute pancreatitis, the pathogenesis is not completely understood, and several recent studies in vitro suggested that heat shock proteins might play an important role in cell signaling. To investigate the possible role of extracellular heat shock protein 70 (Hsp70) in pancreatitis, toll-like receptor-4 (TLR4)-deficient and wild-type mice were administered with exogenous Hsp70 during the course of cerulein-induced pancreatitis (CIP).Methods Acute pancreatitis was induced by 5 intraperitoneal injections of cerulein at hourly intervals, and then treated with recombinant Hsp70 through the caudal vein 4 hours after the start of cerulein injections. Subsequently serum amylase and serum cytokines levels were detected. Histologic alteration of the pancreas was evaluated. Tumor necrosis factor alpha (TNF-a) concentrations and myeloperoxidase (MPO) activity in both pancreas and lungs were analyzed. The nuclear factor kappa B (NF-KB) activation in pancreatic tissue was measured using a sensitive RelA enzyme-linked immunosorbent assay.Results Treatment with recombinant Hsp70 to wild-type mice in CIP resulted in significant aggravation of inflammation in pancreas, elevated levels of serum cytokines, up-regulation of pulmonary MPO activity and increase of lung tissues TNF-α concentrations. In contrast, treatment with Hsp70 to TLR4-deficient mice had little effect on serum cytokines levels, pancreatic inflammation, pulmonary MPO activity and TNF-a concentrations.Conclusions The results suggest that extracellular HspTO might induce systemic inflammatory response syndrome (SIRS)-Iike response in vivo and TLR4 might be involved in the Hsp70-mediated activation of inflammatory reaction in the progression of CIP without infection.

  19. Toll-like receptor 3 agonist Poly I:C protects against simulated cerebral ischemia in vitro and in vivo

    Institute of Scientific and Technical Information of China (English)

    Lin-na PAN; Wei ZHU; Cai LI; Xu-lin XU; Lian-jun GUO; Qing LU

    2012-01-01

    Aim:To examine the neuroprotective effects of the Toll-like receptor 3 (TLR3) agonist Poly I:C in acute ischemic models in vitro and in vivo.Methods:Primary astrocyte cultures subjected to oxygen-glucose deprivation (OGD) were used as an in vitro simulated ischemic model.Poly I:C was administrated 2 h before OGD.Cell toxicity was measured using MTT assay and LDH leakage assay.The levels of TNFα,IL-6 and interferon-β (IFNβ) in the media were measured using ELISA.Toll/interleukin receptor domain-containing adaptor-inducing IFNβ (TRIF) protein levels were detected using Western blot analysis.A mouse middle cerebral artery occlusion (MCAO) model was used for in vivo study.The animals were administered Poly I:C (0.3 mg/kg,im) 2 h before MCAO,and examined with neurological deficit scoring and TTC staining.The levels of TNFα and IL-6 in ischemic brain were measured using ELISA.Results:Pretreatment with Poly I:C (10 and 20 μg/mL) markedly attenuated OGD-induced astrocyte injury,and significantly raised the cell viability and reduced the LDH leakage.Poly I:C significantly upregulated TRIF expression accompanied by increased downstream IFNβ production.Moreover,Poly I:C significantly suppressed the pro-inflammatory cytokines TNFα and IL-6 production.In mice subjected to MCAO,administration of Poly I:C significantly attenuated the neurological deficits,reduced infarction volume,and suppressed the increased levels of TNFα and IL-6 in the ischemic striatum and cortex.Conclusion:Poly I:C pretreatment exerts neuroprotective and anti-inflammatory effects in the simulated cerebral ischemia models,and the neuroprotection is at least in part due to the activation of the TLR3-TRIF pathway.

  20. Origin and consequences of brain Toll-like receptor 4 pathway stimulation in an experimental model of depression

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    Madrigal José LM

    2011-11-01

    Full Text Available Abstract Background There is a pressing need to identify novel pathophysiological pathways relevant to depression that can help to reveal targets for the development of new medications. Toll-like receptor 4 (TLR-4 has a regulatory role in the brain's response to stress. Psychological stress may compromise the intestinal barrier, and increased gastrointestinal permeability with translocation of lipopolysaccharide (LPS from Gram-negative bacteria may play a role in the pathophysiology of major depression. Methods Adult male Sprague-Dawley rats were subjected to chronic mild stress (CMS or CMS+intestinal antibiotic decontamination (CMS+ATB protocols. Levels of components of the TLR-4 signaling pathway, of LPS and of different inflammatory, oxidative/nitrosative and anti-inflammatory mediators were measured by RT-PCR, western blot and/or ELISA in brain prefrontal cortex. Behavioral despair was studied using Porsolt's test. Results CMS increased levels of TLR-4 and its co-receptor MD-2 in brain as well as LPS and LPS-binding protein in plasma. In addition, CMS also increased interleukin (IL-1β, COX-2, PGE2 and lipid peroxidation levels and reduced levels of the anti-inflammatory prostaglandin 15d-PGJ2 in brain tissue. Intestinal decontamination reduced brain levels of the pro-inflammatory parameters and increased 15d-PGJ2, however this did not affect depressive-like behavior induced by CMS. Conclusions Our results suggest that LPS from bacterial translocation is responsible, at least in part, for the TLR-4 activation found in brain after CMS, which leads to release of inflammatory mediators in the CNS. The use of Gram-negative antibiotics offers a potential therapeutic approach for the adjuvant treatment of depression.

  1. Comparative analysis of species-specific ligand recognition in Toll-like receptor 8 signaling: a hypothesis.

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    Rajiv Gandhi Govindaraj

    Full Text Available Toll-like receptors (TLRs play a central role in the innate immune response by recognizing conserved structural patterns in a variety of microbes. TLRs are classified into six families, of which TLR7 family members include TLR7, 8, and 9, which are localized to endolysosomal compartments recognizing viral infection in the form of foreign nucleic acids. In our current study, we focused on TLR8, which has been shown to recognize different types of ligands such as viral or bacterial ssRNA as well as small synthetic molecules. The primary sequences of rodent and non-rodent TLR8s are similar, but the antiviral compound (R848 that activates the TLR8 pathway is species-specific. Moreover, the factors underlying the receptor's species-specificity remain unknown. To this end, comparative homology modeling, molecular dynamics simulations refinement, automated docking and computational mutagenesis studies were employed to probe the intermolecular interactions between this anti-viral compound and TLR8. Furthermore, comparative analyses of modeled TLR8 (rodent and non-rodent structures have shown that the variation mainly occurs at LRR14-15 (undefined region; hence, we hypothesized that this variation may be the primary reason for the exhibited species-specificity. Our hypothesis was further bolstered by our docking studies, which clearly showed that this undefined region was in close proximity to the ligand-binding site and thus may play a key role in ligand recognition. In addition, the interface between the ligand and TLR8s varied depending upon the amino acid charges, free energy of binding, and interaction surface. Therefore, our current work provides a hypothesis for previous in vivo studies in the context of TLR signaling.

  2. Curcumin Modulates Macrophage Polarization Through the Inhibition of the Toll-Like Receptor 4 Expression and its Signaling Pathways

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    Yaoyao Zhou

    2015-05-01

    Full Text Available Background: Curcumin, the active ingredient in curcuma rhizomes, has a wide range of therapeutic effects. However, its atheroprotective activity in human acute monocytic leukemia THP-1 cells remains unclear. We investigated the activity and molecular mechanism of action of curcumin in polarized macrophages. Methods: Phorbol myristate acetate (PMA-treated THP-1 cells were differentiated to macrophages, which were further polarized to M1 cells by lipopolysaccharide (LPS; 1 µg/ml and interferon (IFN-γ (20 ng/ml and treated with varying curcumin concentrations. [3H]thymidine (3H-TdR incorporation assays were utilized to measure curcumin-induced growth inhibition. The expression of tumor necrosis factor-a (TNF-a, interleukin (IL-6, and IL-12B (p40 were measured by quantitative real-time polymerase chain reaction (PCR and enzyme-linked immunosorbent assay (ELISA. Macrophage polarization and its mechanism were evaluated by flow cytometry and western blot. Additionally, toll-like receptor 4 (TLR4 small interfering RNA and mitogen-activated protein kinase (MAPK inhibitors were used to further confirm the molecular mechanism of curcumin on macrophage polarization. Results: Curcumin dose-dependently inhibited M1 macrophage polarization and the production of TNF-a, IL-6, and IL-12B (p40. It also decreased TLR4 expression, which regulates M1 macrophage polarization. Furthermore, curcumin significantly inhibited the phosphorylation of ERK, JNK, p38, and nuclear factor (NF-γB. In contrast, SiTLR4 in combination with p-JNK, p-ERK, and p-p38 inhibition reduced the effect of curcumin on polarization. Conclusions: Curcumin can modulate macrophage polarization through TLR4-mediated signaling pathway inhibition, indicating that its effect on macrophage polarization is related to its anti-inflammatory and atheroprotective effects. Our data suggest that curcumin could be used as a therapeutic agent in atherosclerosis.

  3. Chronic treatment with metformin suppresses toll-like receptor 4 signaling and attenuates left ventricular dysfunction following myocardial infarction.

    Science.gov (United States)

    Soraya, Hamid; Clanachan, Alexander S; Rameshrad, Maryam; Maleki-Dizaji, Nasrin; Ghazi-Khansari, Mahmoud; Garjani, Alireza

    2014-08-15

    Acute treatment with metformin has a protective effect in myocardial infarction by suppression of inflammatory responses due to activation of AMP-activated protein kinase (AMPK). In the present study, the effect of chronic pre-treatment with metformin on cardiac dysfunction and toll-like receptor 4 (TLR4) activities following myocardial infarction and their relation with AMPK were assessed. Male Wistar rats were randomly assigned to one of 5 groups (n=6): normal control and groups were injected isoproterenol after chronic pre-treatment with 0, 25, 50, or 100mg/kg of metformin twice daily for 14 days. Isoproterenol (100mg/kg) was injected subcutaneously on the 13th and 14th days to induce acute myocardial infarction. Isoproterenol alone decreased left ventricular systolic pressure and myocardial contractility indexed as LVdp/dtmax and LVdp/dtmin. The left ventricular dysfunction was significantly lower in the groups treated with 25 and 50mg/kg of metformin. Metfromin markedly lowered isoproterenol-induced elevation in the levels of TLR4 mRNA, myeloid differentiation protein 88 (MyD88), tumor necrosis factor-alpha (TNF-α), and interleukin 6 (IL-6) in the heart tissues. Similar changes were also seen in the serum levels of TNF-α and IL-6. However, the lower doses of 25 and 50mg/kg were more effective than 100mg/kg. Phosphorylated AMPKα (p-AMPK) in the myocardium was significantly elevated by 25mg/kg of metformin, slightly by 50mg/kg, but not by 100mg/kg. Chronic pre-treatment with metformin reduces post-myocardial infarction cardiac dysfunction and suppresses inflammatory responses, possibly through inhibition of TLR4 activities. This mechanism can be considered as a target to protect infarcted myocardium.

  4. ROLE OF TOLL-LIKE RECEPTOR 4 IN AIRWAY INFLAMMA-TION OF CHRONIC OBSTRUCTIVE PULMONARY DISEASES

    Institute of Scientific and Technical Information of China (English)

    ZHOU Min; RONG Xia-jun; WAN Huan-ying; HUANG Shao-guang; LI Biao; LI Min

    2008-01-01

    Objective To confirm if pulmonary epithelial cells express Toll-like receptor 4 (TLR4) and investigate the role of TLR4 in airway inflammation of chronic obstructive pulmonary diseases (COPD). Methods The expressions of TLR4, IL-8 mRNA and NF-κB activation stimulated by differen factors [lipopolysacharides (LPS), interleukin-1β, cigarette smoking extract (CSE)] in pulmonary epithelial cells were investigated. Results LPS, CSE and IL-1β induced the production of IL-8 and activation of NF-κB. The levels of IL-8 mRNA and NF-κB protein in ElA+ cell were markedly higher than ElA-cell and A549 cell (P<0.05). The TLR4 mRNA of all the cells increased along with the increase of LPS' stimulated time. There was significant difference among different LPS' doses (12 h: P=0.039; 24 h: P=0.013). The TLR4 mRNA of ElA+ cell was higher than the other two groups (P<0.05). IL-1β induced all the cells expressing TLR4 mRNA. CSE had no effect on the expression of TLR4 mRNA. Conclusion Pulmonary epithelial cells express TLR4. LPS and IL-1β up-regulate IL-8 mediated via the activation of NF-κB induced by TLR4. But CSE up-regulates IL-8 mediated via the activation of NF-κB, which has no relation to TLR4 and may have another signal transduction pathway.

  5. Autoinmunidad y receptores tipo Toll = Autoimmunity and toll-like receptors

    Directory of Open Access Journals (Sweden)

    Ossa Giraldo, Ana Claudia

    2012-07-01

    Full Text Available La respuesta inmune innata está conformada por un conjunto de mecanismos que permiten reconocer los componentes propios del organismo y diferenciarlos de los microorganismos invasores para generar una primera línea de defensa. Este reconocimiento está mediado por diferentes receptores presentes en la superficie y en el interior de células inmunes y no inmunes; entre ellos se encuentran los siguientes: receptores tipo Toll (RTT, receptores de lectinas tipo C, receptores tipo GIR (genes inducibles por ácido retinoico y receptores tipo Nod y NALP, que reconocen patrones moleculares asociados a microorganismos (PMAM. Gracias a esta capacidad de discriminación, adquirida evolutivamente por la inmunidad innata, se ha aceptado tradicionalmente que los procesos autoinmunes no están relacionados con esta sino con la inmunidad adquirida. Sin embargo, varios estudios han demostrado que esa teoría no es totalmente cierta y que algunos mecanismos efectores de la inmunidad innata participan en la generación de las enfermedades autoinmunes o en la potenciación de su fisiopatología. En esta revisión se estudia la contribución de la inmunidad innata a la autoinmunidad con énfasis en el papel de los receptores tipo Toll.

  6. Regulation of Toll-like receptor 4-mediated immune responses through Pasteurella multocida toxin-induced G protein signalling

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    Hildebrand Dagmar

    2012-08-01

    Full Text Available Abstract Background Lipopolysaccharide (LPS-triggered Toll-like receptor (TLR 4-signalling belongs to the key innate defence mechanisms upon infection with Gram-negative bacteria and triggers the subsequent activation of adaptive immunity. There is an active crosstalk between TLR4-mediated and other signalling cascades to secure an effective immune response, but also to prevent excessive inflammation. Many pathogens induce signalling cascades via secreted factors that interfere with TLR signalling to modify and presumably escape the host response. In this context heterotrimeric G proteins and their coupled receptors have been recognized as major cellular targets. Toxigenic strains of Gram-negative Pasteurella multocida produce a toxin (PMT that constitutively activates the heterotrimeric G proteins Gαq, Gα13 and Gαi independently of G protein-coupled receptors through deamidation. PMT is known to induce signalling events involved in cell proliferation, cell survival and cytoskeleton rearrangement. Results Here we show that the activation of heterotrimeric G proteins through PMT suppresses LPS-stimulated IL-12p40 production and eventually impairs the T cell-activating ability of LPS-treated monocytes. This inhibition of TLR4-induced IL-12p40 expression is mediated by Gαi-triggered signalling as well as by Gβγ-dependent activation of PI3kinase and JNK. Taken together we propose the following model: LPS stimulates TLR4-mediated activation of the NFĸB-pathway and thereby the production of TNF-α, IL-6 and IL-12p40. PMT inhibits the production of IL-12p40 by Gαi-mediated inhibition of adenylate cyclase and cAMP accumulation and by Gβγ-mediated activation of PI3kinase and JNK activation. Conclusions On the basis of the experiments with PMT this study gives an example of a pathogen-induced interaction between G protein-mediated and TLR4-triggered signalling and illustrates how a bacterial toxin is able to interfere with the host’s immune

  7. High glucose induces inflammatory cytokine through protein kinase C-induced toll-like receptor 2 pathway in gingival fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Shao-Yun, E-mail: jiangshaoyun@yahoo.com [School of Dentistry, Tianjin Medical University, 12 Qi Xiang Tai Street, Heping District, Tianjin 300070 (China); Wei, Cong-Cong; Shang, Ting-Ting; Lian, Qi; Wu, Chen-Xuan [School of Dentistry, Tianjin Medical University, 12 Qi Xiang Tai Street, Heping District, Tianjin 300070 (China); Deng, Jia-Yin, E-mail: yazhou2991@126.com [School of Dentistry, Tianjin Medical University, 12 Qi Xiang Tai Street, Heping District, Tianjin 300070 (China)

    2012-10-26

    Highlights: Black-Right-Pointing-Pointer High glucose significantly induced TLR2 expression in gingival fibroblasts. Black-Right-Pointing-Pointer High glucose increased NF-{kappa}B p65 nuclear activity, IL-1{beta} and TNF-{alpha} levels. Black-Right-Pointing-Pointer PKC-{alpha}/{delta}-TLR2 pathway is involved in periodontal inflammation under high glucose. -- Abstract: Toll-like receptors (TLRs) play a key role in innate immune response and inflammation, especially in periodontitis. Meanwhile, hyperglycemia can induce inflammation in diabetes complications. However, the activity of TLRs in periodontitis complicated with hyperglycemia is still unclear. In the present study, high glucose (25 mmol/l) significantly induced TLR2 expression in gingival fibroblasts (p < 0.05). Also, high glucose increased nuclear factor kappa B (NF-{kappa}B) p65 nuclear activity, tumor necrosis factor-{alpha} (TNF-{alpha}) and interleukin-l{beta} (IL-1{beta}) levels. Protein kinase C (PKC)-{alpha} and {delta} knockdown with siRNA significantly decreased TLR2 and NF-{kappa}B p65 expression (p < 0.05), whereas inhibition of PKC-{beta} had no effect on TLR2 and NF-{kappa}B p65 under high glucose (p < 0.05). Additional studies revealed that TLR2 knockdown significantly abrogated high-glucose-induced NF-{kappa}B expression and inflammatory cytokine secretion. Collectively, these data suggest that high glucose stimulates TNF-{alpha} and IL-1{beta} secretion via inducing TLR2 through PKC-{alpha} and PKC-{delta} in human gingival fibroblasts.

  8. Intra-Peritoneal Administration of Mitochondrial DNA Provokes Acute Lung Injury and Systemic Inflammation via Toll-Like Receptor 9.

    Science.gov (United States)

    Zhang, Lemeng; Deng, Songyun; Zhao, Shuangping; Ai, Yuhang; Zhang, Lina; Pan, Pinhua; Su, Xiaoli; Tan, Hongyi; Wu, Dongdong

    2016-01-01

    The pathogenesis of sepsis is complex. Mitochondrial dysfunction, which is responsible for energy metabolism, intrinsic apoptotic pathway, oxidative stress, and systemic inflammatory responses, is closely related with severe sepsis induced death. Mitochondria DNA (mtDNA) contain un-methylated cytosine phosphate guanine (CpG) motifs, which exhibit immune stimulatory capacities. The aim of this study was to investigate the role and mechanism of mtDNA release on lipopolysaccharide (LPS) induced acute lung injury (ALI) and systemic inflammation. Following LPS injection, plasma mtDNA copies peak at 8 h. Compared with wild-type (WT) mice, mtDNA in toll like receptor 4 knockout (TLR4 KO) mice were significantly decreased. MtDNA intra-peritoneal administration causes apparent ALI as demonstrated by increased lung injury score, bronchoalveolar lavage fluid (BALF) total protein and wet/dry (W/D) ratio; mtDNA injection also directly provokes systemic inflammation, as demonstrated by increased IL-1β, IL-6, high-mobility group protein B1 (HMGB1) level; while nuclear DNA (nDNA) could not induce apparent ALI and systemic inflammation. However, compared with WT mice, TLR4 KO could not protect from mtDNA induced ALI and systemic inflammation. Specific TLR9 inhibitor, ODN 2088 pretreatment can significantly attenuate mtDNA induced ALI and systemic inflammation, as demonstrated by improved lung injury score, decreased lung wet/dry ratio, BALF total protein concentration, and decreased systemic level of IL-1β, IL-6 and HMGB1. MtDNA administration activates the expression of p-P38 mitogen-activated protein kinases (MAPK) in lung tissue and specific TLR9 inhibitor pretreatment can attenuate this activation. Thus, LPS-induced mtDNA release occurs in a TLR4-dependent manner, and mtDNA causes acute lung injury and systemic inflammation in a TLR9-dependent and TLR4-independent manner. PMID:27589725

  9. A flagellin-derived toll-like receptor 5 agonist stimulates cytotoxic lymphocyte-mediated tumor immunity.

    Directory of Open Access Journals (Sweden)

    Nicholas D Leigh

    Full Text Available Toll-like receptor (TLR mediated recognition of pathogen associated molecular patterns allows the immune system to rapidly respond to a pathogenic insult. The "danger context" elicited by TLR agonists allows an initially non-immunogenic antigen to become immunogenic. This ability to alter environment is highly relevant in tumor immunity, since it is inherently difficult for the immune system to recognize host-derived tumors as immunogenic. However, immune cells may have encountered certain TLR ligands associated with tumor development, yet the endogenous stimulation is typically not sufficient to induce spontaneous tumor rejection. Of special interest are TLR5 agonists, because there are no endogenous ligands that bind TLR5. CBLB502 is a pharmacologically optimized TLR5 agonist derived from Salmonella enterica flagellin. We examined the effect of CBLB502 on tumor immunity using two syngeneic lymphoma models, both of which do not express TLR5, and thus do not directly respond to CBLB502. Upon challenge with the T-cell lymphoma RMAS, CBLB502 treatment after tumor inoculation protects C57BL/6 mice from death caused by tumor growth. This protective effect is both natural killer (NK cell- and perforin-dependent. In addition, CBLB502 stimulates clearance of the B-cell lymphoma A20 in BALB/c mice in a CD8(+ T cell-dependent fashion. Analysis on the cellular level via ImageStream flow cytometry reveals that CD11b(+ and CD11c(+ cells, but neither NK nor T cells, directly respond to CBLB502 as determined by NFκB nuclear translocation. Our findings demonstrate that CBLB502 stimulates a robust antitumor response by directly activating TLR5-expressing accessory immune cells, which in turn activate cytotoxic lymphocytes.

  10. The Toll-Like Receptor 5 Agonist Entolimod Mitigates Lethal Acute Radiation Syndrome in Non-Human Primates.

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    Vadim I Krivokrysenko

    Full Text Available There are currently no approved medical radiation countermeasures (MRC to reduce the lethality of high-dose total body ionizing irradiation expected in nuclear emergencies. An ideal MRC would be effective even when administered well after radiation exposure and would counteract the effects of irradiation on the hematopoietic system and gastrointestinal tract that contribute to its lethality. Entolimod is a Toll-like receptor 5 agonist with demonstrated radioprotective/mitigative activity in rodents and radioprotective activity in non-human primates. Here, we report data from several exploratory studies conducted in lethally irradiated non-human primates (rhesus macaques treated with a single intramuscular injection of entolimod (in the absence of intensive individualized supportive care administered in a mitigative regimen, 1-48 hours after irradiation. Following exposure to LD50-70/40 of radiation, injection of efficacious doses of entolimod administered as late as 25 hours thereafter reduced the risk of mortality 2-3-fold, providing a statistically significant (P<0.01 absolute survival advantage of 40-60% compared to vehicle treatment. Similar magnitude of survival improvement was also achieved with drug delivered 48 hours after irradiation. Improved survival was accompanied by predominantly significant (P<0.05 effects of entolimod administration on accelerated morphological recovery of hematopoietic and immune system organs, decreased severity and duration of thrombocytopenia, anemia and neutropenia, and increased clonogenic potential of the bone marrow compared to control irradiated animals. Entolimod treatment also led to reduced apoptosis and accelerated crypt regeneration in the gastrointestinal tract. Together, these data indicate that entolimod is a highly promising potential life-saving treatment for victims of radiation disasters.

  11. Attenuation of Myocardial Injury by HMGB1 Blockade during Ischemia/Reperfusion Is Toll-Like Receptor 2-Dependent

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    Jan Mersmann

    2013-01-01

    Full Text Available Genetic or pharmacological ablation of toll-like receptor 2 (TLR2 protects against myocardial ischemia/reperfusion injury (MI/R. However, the endogenous ligand responsible for TLR2 activation has not yet been detected. The objective of this study was to identify HMGB1 as an activator of TLR2 signalling during MI/R. C57BL/6 wild-type (WT or TLR2−/−-mice were injected with vehicle, HMGB1, or HMGB1 BoxA one hour before myocardial ischemia (30 min and reperfusion (24 hrs. Infarct size, cardiac troponin T, leukocyte infiltration, HMGB1 release, TLR4-, TLR9-, and RAGE-expression were quantified. HMGB1 plasma levels were measured in patients undergoing coronary artery bypass graft (CABG surgery. HMGB1 antagonist BoxA reduced cardiomyocyte necrosis during MI/R in WT mice, accompanied by reduced leukocyte infiltration. Injection of HMGB1 did, however, not increase infarct size in WT animals. In TLR2−/−-hearts, neither BoxA nor HMGB1 affected infarct size. No differences in RAGE and TLR9 expression could be detected, while TLR2−/−-mice display increased TLR4 and HMGB1 expression. Plasma levels of HMGB1 were increased MI/R in TLR2−/−-mice after CABG surgery in patients carrying a TLR2 polymorphism (Arg753Gln. We here provide evidence that absence of TLR2 signalling abrogates infarct-sparing effects of HMGB1 blockade.

  12. Immunomodulatory Effect of Toll-Like Receptor-3 Ligand Poly I:C on Cortical Spreading Depression.

    Science.gov (United States)

    Ghaemi, Amir; Sajadian, Azadeh; Khodaie, Babak; Lotfinia, Ahmad Ali; Lotfinia, Mahmoud; Aghabarari, Afsaneh; Khaleghi Ghadiri, Maryam; Meuth, Sven; Gorji, Ali

    2016-01-01

    The release of inflammatory mediators following cortical spreading depression (CSD) is suggested to play a role in pathophysiology of CSD-related neurological disorders. Toll-like receptors (TLR) are master regulators of innate immune function and involved in the activation of inflammatory responses in the brain. TLR3 agonist poly I:C exerts anti-inflammatory effect and prevents cell injury in the brain. The aim of the present study was to examine the effect of systemic administration of poly I:C on the release of cytokines (TNF-α, IFN-γ, IL-4, TGF-β1, and GM-CSF) in the brain and spleen, splenic lymphocyte proliferation, expression of GAD65, GABAAα, GABAAβ as well as Hsp70, and production of dark neurons after induction of repetitive CSD in juvenile rats. Poly I:C significantly attenuated CSD-induced production of TNF-α and IFN-γ in the brain as well as TNF-α and IL-4 in the spleen. Poly I:C did not affect enhancement of splenic lymphocyte proliferation after CSD. Administration of poly I:C increased expression of GABAAα, GABAAβ as well as Hsp70 and decreased expression of GAD65 in the entorhinal cortex compared to CSD-treated tissues. In addition, poly I:C significantly prevented production of CSD-induced dark neurons. The data indicate neuroprotective and anti-inflammatory effects of TLR3 activation on CSD-induced neuroinflammation. Targeting TLR3 may provide a novel strategy for developing new treatments for CSD-related neurological disorders. PMID:25416860

  13. Human decidual macrophages and NK cells differentially express Toll-like receptors and display distinct cytokine profiles upon TLR stimulation.

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    Marion eDuriez

    2014-07-01

    Full Text Available Maternofetal pathogen transmission is partially controlled at the level of the maternal uterine mucosa at the fetal implantation site (the decidua basalis, where maternal and fetal cells are in close contact. Toll-like receptors (TLRs may play an important role in initiating rapid immune responses against pathogens in the decidua basalis, however the tolerant microenvironment should be preserved in order to allow fetal development. Here we investigated the expression and functionality of TLRs expressed by decidual macrophages (dMs and NK cells (dNKs, the major decidual immune cell populations.We report for the first time that both human dMs and dNK cells express mRNAs encoding TLRs 1-9, albeit with a higher expression level in dMs. TLR2, TLR3 and TLR4 protein expression checked by flow cytometry was positive for both dMs and dNK cells. In vitro treatment of primary dMs and dNK cells with specific TLR2, TLR3, TLR4, TLR7/8 and TLR9 agonists enhanced their secretion of pro- and anti-inflammatory cytokines, as well as cytokines and chemokines involved in immune cell crosstalk. Only dNK cells released IFN-γ, whereas only dMs released IL-1β, IL-10 and IL-12. TLR9 activation of dMs resulted in a distinct pattern of cytokine expression compared to the other TLRs. The cytokine profiles expressed by dMs and dNK cells upon TLR activation are compatible with maintenance of the fetotolerant immune environment during initiation of immune responses to pathogens at the maternofetal interface.

  14. Toll-Like Receptor Signalling Is Not Involved in Platelet Response to Streptococcus pneumoniae In Vitro or In Vivo

    Science.gov (United States)

    Schaap, Marianne C. L.; Hou, Baidong; van der Poll, Tom; Nieuwland, Rienk; van ‘t Veer, Cornelis

    2016-01-01

    Streptococcus (S.) pneumoniae strains vary considerably in their ability to cause invasive disease in humans, which is at least in part determined by the capsular serotype. Platelets have been implicated as sentinel cells in the circulation for host defence. One of their utensils for this function is the expression of Toll-like receptors (TLRs). We here aimed to investigate platelet response to S. pneumoniae and a role for TLRs herein. Platelets were stimulated using four serotypes of S. pneumonia including an unencapsulated mutant strain. In vitro aggregation and flow cytometry assays were performed using blood of healthy volunteers, or blood of TLR knock out and WT mice. For in vivo pneumonia experiments, platelet specific Myd88 knockout (Plt-Myd88-/-) mice were used. We found that platelet aggregation was induced by unencapsulated S. pneumoniae only. Whole blood incubation with all S. pneumoniae serotypes tested resulted in platelet degranulation and platelet-leukocyte complex formation. Platelet activation was TLR independent, as responses were not inhibited by TLR blocking antibodies, not induced by TLR agonists and were equally induced in wild-type and Tlr2-/-, Tlr4-/-, Tlr2/4-/-, Tlr9-/- and Myd88-/- blood. Plt-Myd88-/- and control mice displayed no differences in bacterial clearance or immune response to pneumonia by unencapsulated S. pneumoniae. In conclusion, S. pneumoniae activates platelets through a TLR-independent mechanism that is impeded by the bacterial capsule. Additionally, platelet MyD88-dependent TLR signalling is not involved in host defence to unencapsulated S. pneumoniae in vivo. PMID:27253707

  15. Toll-like receptor 4 promoter polymorphisms: common TLR4 variants may protect against severe urinary tract infection.

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    Bryndís Ragnarsdóttir

    Full Text Available BACKGROUND: Polymorphisms affecting Toll-like receptor (TLR structure appear to be rare, as would be expected due to their essential coordinator role in innate immunity. Here, we assess variation in TLR4 expression, rather than structure, as a mechanism to diversify innate immune responses. METHODOLOGY/PRINCIPAL FINDINGS: We sequenced the TLR4 promoter (4,3 kb in Swedish blood donors. Since TLR4 plays a vital role in susceptibility to urinary tract infection (UTI, promoter sequences were obtained from children with mild or severe disease. We performed a case-control study of pediatric patients with asymptomatic bacteriuria (ABU or those prone to recurrent acute pyelonephritis (APN. Promoter activity of the single SNPs or multiple allelic changes corresponding to the genotype patterns (GPs was tested. We then conducted a replication study in an independent cohort of adult patients with a history of childhood APN. Last, in vivo effects of the different GPs were examined after therapeutic intravesical inoculation of 19 patients with Escherichia coli 83972. We identified in total eight TLR4 promoter sequence variants in the Swedish control population, forming 19 haplotypes and 29 genotype patterns, some with effects on promoter activity. Compared to symptomatic patients and healthy controls, ABU patients had fewer genotype patterns, and their promoter sequence variants reduced TLR4 expression in response to infection. The ABU associated GPs also reduced innate immune responses in patients who were subjected to therapeutic urinary E. coli tract inoculation. CONCLUSIONS: The results suggest that genetic variation in the TLR4 promoter may be an essential, largely overlooked mechanism to influence TLR4 expression and UTI susceptibility.

  16. Toll-Like Receptor (TLR) and Nucleosome-binding Oligomerization Domain (NOD) gene polymorphisms and endometrial cancer risk

    International Nuclear Information System (INIS)

    Endometrial cancer is the most common gynaecological malignancy in women of developed countries. Many risk factors implicated in endometrial cancer trigger inflammatory events; therefore, alterations in immune response may predispose an individual to disease. Toll-like receptors (TLRs) and nucleosome-binding oligomerization domain (NOD) genes are integral to the recognition of pathogens and are highly polymorphic. For these reasons, the aim of the study was to assess the frequency of polymorphic variants in TLR and NOD genes in an Australian endometrial cancer population. Ten polymorphisms were genotyped in 191 endometrial cancer cases and 291 controls using real-time PCR: NOD1 (rs2075822, rs2907749, rs2907748), NOD2 (rs5743260, rs2066844, rs2066845), TLR2 (rs5743708), TLR4 (rs4986790) and TLR9 (rs5743836, rs187084). Haplotype analysis revealed that the combination of the variant alleles of the two TLR9 polymorphisms, rs5743836 and rs187084, were protective for endometrial cancer risk: OR 0.11, 95% CI (0.03-0.44), p = 0.002. This result remained highly significant after adjustment for endometrial cancer risk factors and Bonferroni correction for multiple testing. There were no other associations observed for the other polymorphisms in TLR2, TLR4, NOD1 and NOD2. The variant 'C' allele of rs5743836 causes greater TLR9 transcriptional activity compared to the 'T' allele, therefore, higher TLR9 activity may be related to efficient removal of microbial pathogens within the endometrium. Clearly, the association of these TLR9 polymorphisms and endometrial cancer risk must be further examined in an independent population. The results point towards the importance of examining immune response in endometrial tumourigenesis to understand new pathways that may be implicated in disease

  17. Effect of baicalin on toll-like receptor 4-mediated ischemia/reperfusion inflammatory responses in alcoholic fatty liver condition

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seok-Joo; Lee, Sun-Mee, E-mail: sunmee@skku.edu

    2012-01-01

    Alcoholic fatty liver is susceptible to secondary stresses such as ischemia/reperfusion (I/R). Baicalin is an active component extracted from Scutellaria baicalensis, which is widely used in herbal preparations for treatment of hepatic diseases and inflammatory disorders. This study evaluated the potential beneficial effect of baicalin on I/R injury in alcoholic fatty liver. Rats were fed an alcohol liquid diet or a control isocaloric diet for 5 weeks, and then subjected to 60 min of hepatic ischemia and 5 h of reperfusion. Baicalin (200 mg/kg) was intraperitoneally administered 24 and 1 h before ischemia. After reperfusion, baicalin attenuated the increases in serum alanine aminotransferase activity, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) levels in alcoholic fatty liver. The increased levels of TNF-α and IL-6 mRNA expression and inducible nitric oxide synthase and cyclooxygenase-2 protein and mRNA expressions increased after reperfusion, which were higher in ethanol-fed animals, were attenuated by baicalin. In ethanol-fed animals, baicalin attenuated the increases in toll-like receptor 4 (TLR4) and myeloid differentiation factor 88 protein expressions and the nuclear translocation of NF-κB after reperfusion. In conclusion, our findings suggest that baicalin ameliorates I/R-induced hepatocellular damage by suppressing TLR4-mediated inflammatory responses in alcoholic fatty liver. -- Highlights: ► Baicalin attenuates hepatic I/R-induced inflammation in alcoholic fatty liver. ► Baicalin downregulates TLR4, MyD88 expression during I/R in alcoholic fatty liver. ► Baicalin attenuates NF-κB nuclear translocation during I/R in alcoholic fatty liver.

  18. Human decidual macrophages and NK cells differentially express Toll-like receptors and display distinct cytokine profiles upon TLR stimulation.

    Science.gov (United States)

    Duriez, Marion; Quillay, Héloïse; Madec, Yoann; El Costa, Hicham; Cannou, Claude; Marlin, Romain; de Truchis, Claire; Rahmati, Mona; Barré-Sinoussi, Françoise; Nugeyre, Marie-Thérèse; Menu, Elisabeth

    2014-01-01

    Maternofetal pathogen transmission is partially controlled at the level of the maternal uterine mucosa at the fetal implantation site (the decidua basalis), where maternal and fetal cells are in close contact. Toll-like receptors (TLRs) may play an important role in initiating rapid immune responses against pathogens in the decidua basalis, however the tolerant microenvironment should be preserved in order to allow fetal development. Here we investigated the expression and functionality of TLRs expressed by decidual macrophages (dMs) and NK cells (dNKs), the major decidual immune cell populations. We report for the first time that both human dMs and dNK cells express mRNAs encoding TLRs 1-9, albeit with a higher expression level in dMs. TLR2, TLR3, and TLR4 protein expression checked by flow cytometry was positive for both dMs and dNK cells. In vitro treatment of primary dMs and dNK cells with specific TLR2, TLR3, TLR4, TLR7/8, and TLR9 agonists enhanced their secretion of pro- and anti-inflammatory cytokines, as well as cytokines and chemokines involved in immune cell crosstalk. Only dNK cells released IFN-γ, whereas only dMs released IL-1β, IL-10, and IL-12. TLR9 activation of dMs resulted in a distinct pattern of cytokine expression compared to the other TLRs. The cytokine profiles expressed by dMs and dNK cells upon TLR activation are compatible with maintenance of the fetotolerant immune environment during initiation of immune responses to pathogens at the maternofetal interface. PMID:25071732

  19. Microglia are required for astroglial toll-like receptor 4 response and for optimal TLR2 and TLR3 response

    DEFF Research Database (Denmark)

    Holm, Thomas Hellesøe; Draeby, Dina; Owens, Trevor

    2012-01-01

    Within the central nervous system, astrocytes and microglia are the primary responders to endogenous ligands released upon injury and stress, as well as to infectious pathogens. Toll-like receptors (TLRs) are implicated in recognition of both types of stimulus. Whether astrocytes respond as stron......Within the central nervous system, astrocytes and microglia are the primary responders to endogenous ligands released upon injury and stress, as well as to infectious pathogens. Toll-like receptors (TLRs) are implicated in recognition of both types of stimulus. Whether astrocytes respond...... as strongly as microglia to TLR agonists remains contentious. In this study, we have rigorously purified astrocytes to determine their capacity for autonomous TLR response, in absence of microglia. We used flow cytometry and differential adhesion as well as a myeloid lineage-specific suicide gene to purify...... astrocytes from mixed glial cultures and measured their response to TLR agonists. Our results show that the response of astrocytes to TLR2 and TLR3 agonists is greatly enhanced by, and response to TLR4 agonists is completely dependent on, the presence of functional microglia. In the case of the TLR4 response...

  20. Identification of soluble CD14 as an endogenous agonist for toll-like receptor 2 on human astrocytes by genome-scale functional screening of glial cell derived proteins

    NARCIS (Netherlands)

    Bsibsi, M.; Bajramovic, J.J.; Duijvenvoorden, E. van; Persoon, C.; Ravid, R.; Noort, J.M. van; Vogt, M.H.J.

    2007-01-01

    Human astrocytes express a limited repertoire of Toll-like receptor (TLR) family members including TLR1-4, which are expressed on the cell surface. Also, TLR3 but not TLR4 activation on astrocytes induces expression of several factors involved in neuroprotection and down-regulation of inflammation r

  1. Differential Constitutive and Cytokine-Modulated Expression of Human Toll-like Receptors in Primary Neutrophils, Monocytes, and Macrophages

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    D. Shane O'Mahony, Uyenvy Pham, Ramesh Iyer, Thomas R. Hawn, W. Conrad Liles

    2008-01-01

    Full Text Available Human Toll-like receptors (TLRs comprise a family of proteins that recognizes pathogen-associated molecular patterns (PAMPs and initiates host innate immune responses. Neutrophils, monocytes, and macrophages are critical cellular components of the human innate immune system. Proinflammatory cytokines, such as granulocyte colony-stimulating factor (G-CSF, granulocyte-macrophage colony-stimulating factor (GM-CSF, macrophage colony-stimulating factor (M-CSF, and interferon-γ (IFN-γ, have been shown to up-regulate microbicidal activity in these effector cells of innate immunity. Currently, the cellular and molecular mechanisms responsible for these effects are not completely understood. We hypothesized that these cytokines may up-regulate TLR expression as a mechanism to facilitate microbial recognition and augment the innate immune response. Using quantitative realtime rt-PCR technology, we examined constitutive expression of TLR2, TLR4, TLR5, and TLR9 mRNA and the effects of G-CSF, GM-CSF, M-CSF, and IFN-γ on TLR mRNA expression in purified populations of normal human neutrophils, monocytes, and monocyte-derived macrophages. Relative constitutive expression of TLR2, TLR4, and TLR9 was similar in neutrophils and monocytes. Constitutive expression of TLR5 was less in neutrophils compared to monocytes. Constitutive expression of TLR4 was greater and that of TLR9 lower in monocyte-derived macrophages compared to monocytes. Of the cytokines examined, IFN-γ and GM-CSF caused the greatest effects on TLR expression. IFN- γ up-regulated TLR2 and TLR4 in neutrophils and monocytes. GM-CSF up-regulated expression of TLR2 and TLR4 in neutrophils and TLR2 in monocytes. TLR5 was down-regulated by inflammatory cytokines in monocytes. These results suggest a potential role for IFN- γ and/or GM-CSF as therapeutic immunomodulators of the host defense to infection.

  2. Dysfunction in macrophage toll-like receptor signaling caused by an inborn error of cationic amino acid transport.

    Science.gov (United States)

    Kurko, Johanna; Vähä-Mäkilä, Mari; Tringham, Maaria; Tanner, Laura; Paavanen-Huhtala, Sari; Saarinen, Maiju; Näntö-Salonen, Kirsti; Simell, Olli; Niinikoski, Harri; Mykkänen, Juha

    2015-10-01

    Amino acids, especially arginine, are vital for the well-being and activity of immune cells, and disruption of amino acid balance may weaken immunity and predispose to infectious and autoimmune diseases. We present here a model of an inborn aminoaciduria, lysinuric protein intolerance (LPI), in which a single mutation in y(+)LAT1 cationic amino acid transporter gene SLC7A7 leads to a multisystem disease characterized by immunological complications, life-threatening pulmonary alveolar proteinosis and nephropathy. Macrophages are suggested to play a central role in LPI in the development of these severe secondary symptoms. We thus studied the effect of the Finnish y(+)LAT1 mutation on monocyte-derived macrophages where toll-like receptors (TLRs) act as the key molecules in innate immune response against external pathogens. The function of LPI patient and control macrophage TLR signaling was examined by stimulating the TLR2/1, TLR4 and TLR9 pathways with their associated pathogen-associated molecular patterns. Downregulation in expression of TLR9, IRF7, IRF3 and IFNB1 and in secretion of IFN-α was detected, suggesting an impaired response to TLR9 stimulation. In addition, secretion of TNF-α, IL-12 and IL-1RA by TLR2/1 stimulation and IL-12 and IL-1RA by TLR4 stimulation was increased in the LPI patients. LPI macrophages secreted significantly less nitric oxide than control macrophages, whereas plasma concentrations of inflammatory chemokines CXCL8, CXCL9 and CXCL10 were elevated in the LPI patients. In conclusion, our results strengthen the relevance of macrophages in the pathogenesis of LPI and, furthermore, suggest that cationic amino acid transport plays an important role in the regulation of innate immune responses. PMID:26210182

  3. Bacteria and Toll-like receptor and cytokine mRNA expression profiles associated with canine arthritis.

    Science.gov (United States)

    Riggio, Marcello P; Lappin, David F; Bennett, David

    2014-08-15

    The major forms of inflammatory canine arthritis are immune-mediated arthritis (IMA) and septic arthritis (SA), although some cases of cruciate disease (CD) are associated with significant levels of synovitis. In this study, the bacteria associated with canine arthritis were identified and mRNA expression levels of Toll-like receptors (TLRs) and pro-inflammatory cytokines determined. Of the 40 synovial fluid samples analysed, bacteria were isolated from 12 samples by culture (2 CD, 10 SA) and detected in 4 samples (3 CD, 1 SA) using culture-independent methods. Statistically significant increases in TLR2, tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and IL-12 mRNA expression were seen in all disease groups compared to normal controls. All disease groups had decreased mRNA expression of other TLRs compared to normal controls, but this did not reach statistical significance. Synovial fluid cell counts revealed that the highest number and proportion of mononuclear cells and neutrophils were found in the IMA and SA samples, respectively. Age had an effect on the TLR and cytokine mRNA expression profiles: TNF-α (p=0.043) and IL-12 (p=0.025) mRNA expression was increased and TLR4 mRNA expression was reduced (p=0.033) in dogs up to 4 years of age compared to older animals. In the 10 SA samples from which bacteria were isolated, statistically significant increases in TLR2, TLR7, TNF-α and IL-6 mRNA expression were observed. It is concluded that canine arthritis is associated with increased mRNA levels of pro-inflammatory cytokines, which could in some cases be mediated by bacteria through activation of TLR2.

  4. Toll-like receptor 2 -196 to -174 del polymorphism influences the susceptibility of Han Chinese people to Alzheimer's disease

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    Mao Cai-Xia

    2011-10-01

    Full Text Available Abstract Background Toll-like receptor 2 (TLR2 represents a reasonable functional and positional candidate gene for Alzheimer's disease (AD as it is located under the linkage region of AD on chromosome 4q, and functionally is involved in the microglia-mediated inflammatory response and amyloid-β clearance. The -196 to -174 del polymorphism affects the TLR2 gene and alters its promoter activity. Methods We recruited 800 unrelated Northern Han Chinese individuals comprising 400 late-onset AD (LOAD patients and 400 healthy controls matched for gender and age. The -196 to -174 del polymorphism in the TLR2 gene was genotyped using the polymerase chain reaction (PCR method. Results There were significant differences in genotype (P = 0.026 and allele (P = 0.009 frequencies of the -196 to -174 del polymorphism between LOAD patients and controls. The del allele was associated with an increased risk of LOAD (OR = 1.31, 95% CI = 1.07-1.60, Power = 84.9%. When these data were stratified by apolipoprotein E (ApoE ε4 status, the observed association was confined to ApoE ε4 non-carriers. Logistic regression analysis suggested an association of LOAD with the polymorphism in a recessive model (OR = 1.64, 95% CI = 1.13-2.39, Bonferroni corrected P = 0.03. Conclusions Our data suggest that the -196 to -174 del/del genotype of TLR2 may increase risk of LOAD in a Northern Han Chinese population.

  5. Divergent impact of Toll-like receptor 2 deficiency on repair mechanisms in healthy muscle versus Duchenne muscular dystrophy.

    Science.gov (United States)

    Mojumdar, Kamalika; Giordano, Christian; Lemaire, Christian; Liang, Feng; Divangahi, Maziar; Qureshi, Salman T; Petrof, Basil J

    2016-05-01

    Injury to skeletal muscle, whether acute or chronic, triggers macrophage-mediated innate immunity in a manner which can be either beneficial or harmful for subsequent repair. Endogenous ligands for Toll-like receptor 2 (TLR2) are released by damaged tissues and might play an important role in activating the innate immune system following muscle injury. To test this hypothesis, we compared macrophage behaviour and muscle repair mechanisms in mice lacking TLR2 under conditions of either acute (cardiotoxin-induced) or chronic (mdx mouse genetic model of Duchenne muscular dystrophy; DMD) muscle damage. In previously healthy muscle subjected to acute damage, TLR2 deficiency reduced macrophage numbers in the muscle post-injury but did not alter the expression pattern of the prototypical macrophage polarization markers iNOS and CD206. In addition, there was abnormal persistence of necrotic fibres and impaired regeneration in TLR2-/- muscles after acute injury. In contrast, TLR2 ablation in chronically diseased muscles of mdx mice not only resulted in significantly reduced macrophage numbers but additionally modified their phenotype by shifting from inflammatory (iNOS(pos) CD206(neg) ) to more anti-inflammatory (iNOS(neg) CD206(pos) ) characteristics. This decrease in macrophage-mediated inflammation was associated with ameliorated muscle histopathology and improved force-generating capacity of the dystrophic muscle. Our results suggest that the role of TLR2 in macrophage function and skeletal muscle repair depends greatly upon the muscle injury context, and raise the possibility that inhibition of TLR2 could serve as a useful therapeutic measure in DMD.

  6. Divergent impact of Toll-like receptor 2 deficiency on repair mechanisms in healthy muscle versus Duchenne muscular dystrophy.

    Science.gov (United States)

    Mojumdar, Kamalika; Giordano, Christian; Lemaire, Christian; Liang, Feng; Divangahi, Maziar; Qureshi, Salman T; Petrof, Basil J

    2016-05-01

    Injury to skeletal muscle, whether acute or chronic, triggers macrophage-mediated innate immunity in a manner which can be either beneficial or harmful for subsequent repair. Endogenous ligands for Toll-like receptor 2 (TLR2) are released by damaged tissues and might play an important role in activating the innate immune system following muscle injury. To test this hypothesis, we compared macrophage behaviour and muscle repair mechanisms in mice lacking TLR2 under conditions of either acute (cardiotoxin-induced) or chronic (mdx mouse genetic model of Duchenne muscular dystrophy; DMD) muscle damage. In previously healthy muscle subjected to acute damage, TLR2 deficiency reduced macrophage numbers in the muscle post-injury but did not alter the expression pattern of the prototypical macrophage polarization markers iNOS and CD206. In addition, there was abnormal persistence of necrotic fibres and impaired regeneration in TLR2-/- muscles after acute injury. In contrast, TLR2 ablation in chronically diseased muscles of mdx mice not only resulted in significantly reduced macrophage numbers but additionally modified their phenotype by shifting from inflammatory (iNOS(pos) CD206(neg) ) to more anti-inflammatory (iNOS(neg) CD206(pos) ) characteristics. This decrease in macrophage-mediated inflammation was associated with ameliorated muscle histopathology and improved force-generating capacity of the dystrophic muscle. Our results suggest that the role of TLR2 in macrophage function and skeletal muscle repair depends greatly upon the muscle injury context, and raise the possibility that inhibition of TLR2 could serve as a useful therapeutic measure in DMD. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. PMID:26800321

  7. Inosine-mediated modulation of RNA sensing by Toll-like receptor 7 (TLR7) and TLR8.

    Science.gov (United States)

    Sarvestani, Soroush T; Tate, Michelle D; Moffat, Jessica M; Jacobi, Ashley M; Behlke, Mark A; Miller, Alistair R; Beckham, Simone A; McCoy, Claire E; Chen, Weisan; Mintern, Justine D; O'Keeffe, Meredith; John, Matthias; Williams, Bryan R G; Gantier, Michael P

    2014-01-01

    RNA-specific adenosine deaminase (ADAR)-mediated adenosine-to-inosine (A-to-I) editing is a critical arm of the antiviral response. However, mechanistic insights into how A-to-I RNA editing affects viral infection are lacking. We posited that inosine incorporation into RNA facilitates sensing of nonself RNA by innate immune sensors and accordingly investigated the impact of inosine-modified RNA on Toll-like receptor 7 and 8 (TLR7/8) sensing. Inosine incorporation into synthetic single-stranded RNA (ssRNA) potentiated tumor necrosis factor alpha (TNF-α) or alpha interferon (IFN-α) production in human peripheral blood mononuclear cells (PBMCs) in a sequence-dependent manner, indicative of TLR7/8 recruitment. The effect of inosine incorporation on TLR7/8 sensing was restricted to immunostimulatory ssRNAs and was not seen with inosine-containing short double-stranded RNAs or with a deoxy-inosine-modified ssRNA. Inosine-mediated increase of self-secondary structure of an ssRNA resulted in potentiated IFN-α production in human PBMCs through TLR7 recruitment, as established through the use of a TLR7 antagonist and Tlr7-deficient cells. There was a correlation between hyperediting of influenza A viral ssRNA and its ability to stimulate TNF-α, independent of 5'-triphosphate residues, and involving Adar-1. Furthermore, A-to-I editing of viral ssRNA directly enhanced mouse Tlr7 sensing, when present in proportions reproducing biologically relevant levels of RNA editing. Thus, we demonstrate for the first time that inosine incorporation into immunostimulatory ssRNA can potentiate TLR7/8 activation. Our results suggest a novel function of A-to-I RNA editing, which is to facilitate TLR7/8 sensing of phagocytosed viral RNA. PMID:24227841

  8. Decreased Toll-like receptor 8 expression and lower TNF-alpha synthesis in infants with acute RSV infection

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    Gagro Alenka

    2010-10-01

    Full Text Available Abstract Background Toll-like receptors (TLRs are part of the innate immune system, able to recognize pathogen-associated molecular patterns and activate immune system upon pathogen challenge. Respiratory syncytial virus (RSV is a RNA virus particularly detrimental in infancy. It could cause severe lower respiratory tract disease and recurrent infections related to inadequate development of anti-viral immunity. The reason could be inadequate multiple TLRs engagement, including TLR8 in recognition of single-stranded viral RNA and diminished synthesis of inflammatory mediators due to a lower expression. Methods Intracellular TLR8 expression in peripheral blood monocytes from RSV-infected infants was profiled and compared to healthy adults and age matched controls. Whether the observed difference in TLR8 expression is a transitory effect, infants in convalescent phase (4-6 weeks later were retested. Specific TLR8-mediated TNF-α production in monocytes during an acute and convalescent phase was analyzed. Results RSV-infected and healthy infants had lower percentage of TLR8-expressing monocytes than healthy adults whereas decreased of TLR8 protein levels were detected only for RSV-infected infant group. Lower protein levels of TLR8 in monocytes from RSV-infected infants, compared to healthy infants, negatively correlated with respiratory frequency and resulted in lower TNF-α synthesis upon a specific TLR8 stimulation. In the convalescent phase, levels of TLR8 increased, accompanied by increased TNF-α synthesis compared to acute infection. Conclusions Lower TLR8 expression observed in monocytes, during an acute RSV infection, might have a dampening impact on early anti-viral cytokine production necessary to control RSV replication, and subsequently initiate an adaptive Th1 type immune response leading to severe disease in infected infants.

  9. Reduced expression of Toll-like receptor 4 inhibits human breast cancer cells proliferation and inflammatory cytokines secretion

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    Xie Xiaofang

    2010-07-01

    Full Text Available Abstract Background Tumor cell expression of Toll-like receptors (TLRs can promote inflammation and cell survival in the tumor microenvironment. Toll-like receptor 4 (TLR4 signaling in tumor cells can mediate tumor cell immune escape and tumor progression, and it is regarded as one of the mechanisms for chronic inflammation in tumorigenesis and progression. The expression of TLR4 in human breast cancer cell line MDA-MB-231 and its biological function in the development and progression of breast cancer have not been investigated. We sought to characterize the expression of TLR1-TLR10 in the established human breast cancer cell line MDA-MB-231, and to investigate the biological roles of TLR4 in breast cancer cells growth, survival, and its potential as a target for breast cancer therapy. Methods TLRs mRNA and protein expressions were detected in human breast cancer cell line MDA-MB-231 by RT-PCR, real-time PCR and flow cytometry (FCM. RNA interference was used to knockdown the expression of TLR4 in MDA-MB-231. MDA-MB-231 transfected with the vector pGenesil-1 and the vector containing a scrambled siRNA were as controls. Recombinant plasmids named TLR4AsiRNA, TLR4BsiRNA and TLR4CsiRNA specific to TLR4 were transfected into human breast cancer cell line MDA-MB-231 with Lipfectamine™2000 reagent. TLR4 mRNA and protein expressions were investigated by RT-PCR, real-time PCR, FCM and immunofluorescence after silence. MTT analysis was performed to detect cell proliferation and FCM was used to detect the secretion of inflammatory cytokines in supernatant of transfected cells. Results The human breast cancer cell line MDA-MB-231 was found to express TLR1-TLR10 at both the mRNA and protein levels. TLR4 was found to be the highest expressed TLR in MDA-MB-231. TLR4AsiRNA, TLR4BsiRNA and TLR4CsiRNA were found to significantly inhibit TLR4 expression in MDA-MB-231 at both mRNA and protein levels as compared to vector control(vector transfected cells. TLR4Asi

  10. Toll-like receptor 4 is involved in the cell cycle modulation and required for effective human cytomegalovirus infection in THP-1 macrophages

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    Arcangeletti, Maria-Cristina, E-mail: mariacristina.arcangeletti@unipr.it [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Germini, Diego; Rodighiero, Isabella [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Mirandola, Prisco [Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma (Italy); De Conto, Flora; Medici, Maria-Cristina [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy); Gatti, Rita [Department of Biomedical, Biotechnological and Translational Sciences, University of Parma, Parma (Italy); Chezzi, Carlo; Calderaro, Adriana [Department of Clinical and Experimental Medicine, University of Parma, Parma (Italy)

    2013-05-25

    Suitable host cell metabolic conditions are fundamental for the effective development of the human cytomegalovirus (HCMV) lytic cycle. Indeed, several studies have demonstrated the ability of this virus to interfere with cell cycle regulation, mainly by blocking proliferating cells in G1 or G1/S. In the present study, we demonstrate that HCMV deregulates the cell cycle of THP-1 macrophages (a cell line irreversibly arrested in G0) by pushing them into S and G2 phases. Moreover, we show that HCMV infection of THP-1 macrophages leads to Toll-like receptor 4 (TLR4) activation. Since various studies have indicated TLR4 to be involved in promoting cell proliferation, here we investigate the possible role of TLR4 in the observed HCMV-induced cell cycle perturbation. Our data strongly support TLR4 as a mediator of HCMV-triggered cell cycle activation in THP-1 macrophages favouring, in turn, the development of an efficient viral lytic cycle. - Highlights: ► We studied HCMV infection impact on THP-1 macrophage cell cycle. ► We analysed the role played by Toll-like receptor (TLR) 4 upon HCMV infection. ► HCMV pushes THP-1 macrophages (i.e. resting cells) to re-enter the cell cycle. ► TLR4 pathway inhibition strongly affects the effectiveness of HCMV replication. ► TLR4 pathway inhibition significantly decreases HCMV-induced cell cycle re-entry.

  11. Symbiotic Bacterial Metabolites Regulate Gastrointestinal Barrier Function via the Xenobiotic Sensor PXR and Toll-like Receptor 4

    Science.gov (United States)

    Venkatesh, Madhukumar; Mukherjee, Subhajit; Wang, Hongwei; Li, Hao; Sun, Katherine; Benechet, Alaxandre P.; Qiu, Zhijuan; Maher, Leigh; Redinbo, Matthew R.; Phillips, Robert S.; Fleet, James C.; Kortagere, Sandhya; Mukherjee, Paromita; Fasano, Alessio; Le Ven, Jessica; Nicholson, Jeremy K.; Dumas, Marc E.; Khanna, Kamal M.; Mani, Sridhar

    2014-01-01

    SUMMARY Intestinal microbial metabolites are conjectured to affect mucosal integrity through an incompletely characterized mechanism. Here we showed microbial-specific indoles regulated intestinal barrier function through the xenobiotic sensor, pregnane X receptor (PXR). Indole 3-propionic acid (IPA), in the context of indole, is as a ligand for PXR in vivo, and IPA down-regulated enterocyte TNF–α while up-regulated junctional protein-coding mRNAs. PXR-deficient (Nr1i2−/−) mice showed a distinctly “leaky” gut physiology coupled with up-regulation of the Toll-like receptor (TLR) signaling pathway. These defects in the epithelial barrier were corrected in Nr1i2−/−Tlr4−/− mice. Our results demonstrate that a direct chemical communication between the intestinal symbionts and PXR regulates mucosal integrity through a pathway which involves luminal sensing and signaling by TLR4. PMID:25065623

  12. Science Letters: A synthetic Toll-like receptor 2 ligand decreases allergic immune responses in a mouse rhinitis model sensitized to mite allergen

    Institute of Scientific and Technical Information of China (English)

    Cheng ZHOU; Xiao-dong KANG; Zhi CHEN

    2008-01-01

    It has been proposed that activation of Toll-like receptors (TLRs) plays crucial roles in the polarization of adaptive immune responses. A synthetic Toll-like receptor 2 (TLR2) ligand, Pam3CSK4, has been reported to modulate the balance of Thl/Tn2 responses. We evaluated the modulation effect of Pam3CSK4 on allergic immune response in a mouse rhinitis model sensitized to house dust mite allergen (HDM). Mice were sensitized and challenged with Dermatophagoides farinae allergen (Der f), and then the allergic mice were treated by Pam3CSK4. Nasal allergic symptoms and eosinophils were scored. Der f-specific cytokine responses were examined in the splenocytes and bronchoalveolar lavage fluid (BALF). Serum level of total IgE was also detected. After establishing a mouse allergic rhinitis model with HDM, we have showed that Pam3CSK4 treatment not only ameliorated the nasal allergic symptoms remarkably but also decreased the eosinophils and total inflammation cells in BALF significantly. Analysis of cytokine profile found that' IFN-γ released from either BALF or stimulated splenocytes increased markedly in Pam3CSK4-treated mice, while IL-13 decreased significantly. Moreover, serum level of total IgE was significantly lower in Pam3CSK4-treated mice than in the untreated. Thus, in an allergic rhinitis mouse model developed with HDM, Pam3CSK4 was shown to exhibit an antiallergic effect, indicating its potential application in allergic diseases.

  13. Enhanced antibody responses to a detoxified lipopolysaccharide-group B meningococcal outer membrane protein vaccine are due to synergistic engagement of Toll-like receptors.

    Science.gov (United States)

    Chen, Wilbur H; Basu, Subhendu; Bhattacharjee, Apurba K; Cross, Alan S

    2010-10-01

    When given passively or elicited actively, antibodies induced by a detoxified Escherichia coli Rc chemotype (J5) mutant lipopolysaccharide (J5dLPS)-group B meningococcal outer membrane protein (OMP) complex vaccine protected animals from lethal sepsis. The protection from sepsis is believed to be dependent on high levels of antibodies against the core glycolipid (CGL), a region of LPS that is rather conserved among Enterobacteriaceae. The addition of unmethylated deoxycytidyl-deoxyguanosine dinucleotide (CpG)-containing oligodeoxynucleotides (ODN) was used as an immuno-adjuvant to improve antibody responses. In preparation for a Phase I human trial, we elucidated potential contributions by which the sepsis vaccine (J5dLPS-OMP) and CpG ODN might enhance the antibody response and provide evidence that the generation of immune responses is Toll-like receptor (TLR) dependent. Toll-like receptor 2, TLR4, and TLR9 were each essential for generating robust cytokine and antibody responses. The signature cytokine of dendritic cells, interleukin-12, was one of the cytokines that demonstrated synergy with the optimal TLR ligand/ engagement combination. We conclude that the involvement of multiple TLRs upon immunization was critical for the generation of optimal antibody responses. These observations provide further evidence for the inclusion of innate immune-based adjuvants during the development of next-generation vaccines. PMID:19822632

  14. Garlic (Allium sativum) Extracts Inhibits Lipopolysaccharide-Induced Toll-Like Receptor 4 Dimerization

    Science.gov (United States)

    Garlic has been used as a folk medicine for a long history. Numerous studies demonstrated that garlic extracts and its sulfur-containing compounds inhibit nuclear factor-kappa B (NF-kB) activation induced by various receptor agonist including lipopolysaccharide (LPS). These effects suggest that garl...

  15. Cross talk between AT1 receptors and Toll-like receptor 4 in microglia contributes to angiotensin II-derived ROS production in the hypothalamic paraventricular nucleus.

    Science.gov (United States)

    Biancardi, Vinicia Campana; Stranahan, Alexis M; Krause, Eric G; de Kloet, Annette D; Stern, Javier E

    2016-02-01

    ANG II is thought to increase sympathetic outflow by increasing oxidative stress and promoting local inflammation in the paraventricular nucleus (PVN) of the hypothalamus. However, the relative contributions of inflammation and oxidative stress to sympathetic drive remain poorly understood, and the underlying cellular and molecular targets have yet to be examined. ANG II has been shown to enhance Toll-like receptor (TLR)4-mediated signaling on microglia. Thus, in the present study, we aimed to determine whether ANG II-mediated activation of microglial TLR4 signaling is a key molecular target initiating local oxidative stress in the PVN. We found TLR4 and ANG II type 1 (AT1) receptor mRNA expression in hypothalamic microglia, providing molecular evidence for the potential interaction between these two receptors. In hypothalamic slices, ANG II induced microglial activation within the PVN (∼65% increase, P microglia) to ANG II-driven ROS production in the PVN. Taken together, these results support functional interactions between AT1 receptors and TLR4 in mediating ANG II-dependent microglial activation and oxidative stress within the PVN. More broadly, our results support a functional interaction between the central renin-angiotensin system and innate immunity in the regulation of neurohumoral outflows from the PVN.

  16. Ontogeny of Toll-like and NOD-like receptor-mediated innate immune responses in Papua New Guinean infants.

    Science.gov (United States)

    Lisciandro, Joanne G; Prescott, Susan L; Nadal-Sims, Marie G; Devitt, Catherine J; Pomat, William; Siba, Peter M; Tulic, Meri C; Holt, Patrick G; Strickland, Deborah; van den Biggelaar, Anita H J

    2012-01-01

    Studies addressing the ontogeny of the innate immune system in early life have reported mainly on Toll-like receptor (TLR) responses in infants living in high-income countries, with little or even no information on other pattern recognition receptors or on early life innate immune responses in children living under very different environmental conditions in less-developed parts of the world. In this study, we describe whole blood innate immune responses to both Toll-like and nucleotide-binding oligomerization domain (NOD)-like receptor agonists including the widely used vaccine adjuvant 'alum' in a group of Papua New Guinean infants aged 1-3 (n = 18), 4-6 (n = 18), 7-12 (n = 21) and 13-18 (n = 10) months old. Depending on the ligands and cytokines studied, different age-related patterns were found: alum-induced IL-1β and CXCL8 responses were found to significantly decline with increasing age; inflammatory (IL-6, IL-1β, IFN-γ) responses to TLR2 and TLR3 agonists increased; and IL-10 responses remained constant or increased during infancy, while TNF-α responses either declined or remained the same. We report for the first time that whole blood innate immune responses to the vaccine adjuvant alum decrease with age in infancy; a finding that may imply that the adjuvant effect of alum in pediatric vaccines could be age-related. Our findings further suggest that patterns of innate immune development may vary between geographically diverse populations, which in line with the 'hygiene hypothesis' particularly involves persistence of innate IL-10 responses in populations experiencing higher infectious pressure. PMID:22649499

  17. Ontogeny of Toll-like and NOD-like receptor-mediated innate immune responses in Papua New Guinean infants.

    Directory of Open Access Journals (Sweden)

    Joanne G Lisciandro

    Full Text Available Studies addressing the ontogeny of the innate immune system in early life have reported mainly on Toll-like receptor (TLR responses in infants living in high-income countries, with little or even no information on other pattern recognition receptors or on early life innate immune responses in children living under very different environmental conditions in less-developed parts of the world. In this study, we describe whole blood innate immune responses to both Toll-like and nucleotide-binding oligomerization domain (NOD-like receptor agonists including the widely used vaccine adjuvant 'alum' in a group of Papua New Guinean infants aged 1-3 (n = 18, 4-6 (n = 18, 7-12 (n = 21 and 13-18 (n = 10 months old. Depending on the ligands and cytokines studied, different age-related patterns were found: alum-induced IL-1β and CXCL8 responses were found to significantly decline with increasing age; inflammatory (IL-6, IL-1β, IFN-γ responses to TLR2 and TLR3 agonists increased; and IL-10 responses remained constant or increased during infancy, while TNF-α responses either declined or remained the same. We report for the first time that whole blood innate immune responses to the vaccine adjuvant alum decrease with age in infancy; a finding that may imply that the adjuvant effect of alum in pediatric vaccines could be age-related. Our findings further suggest that patterns of innate immune development may vary between geographically diverse populations, which in line with the 'hygiene hypothesis' particularly involves persistence of innate IL-10 responses in populations experiencing higher infectious pressure.

  18. Involvement of Toll-like receptor 2 and epidermal growth factor receptor signaling in epithelial expression of airway remodeling factors.

    Science.gov (United States)

    Homma, Tetsuya; Kato, Atsushi; Sakashita, Masafumi; Norton, James E; Suh, Lydia A; Carter, Roderick G; Schleimer, Robert P

    2015-04-01

    Staphylococcus aureus (SA) colonization and infection is common, and may promote allergic or inflammatory airway diseases, such as asthma, cystic fibrosis, and chronic rhinosinusitis by interacting with airway epithelial cells. Airway epithelial cells not only comprise a physical barrier, but also play key roles in immune, inflammatory, repair, and remodeling responses upon encounters with pathogens. To elucidate the impact of SA on epithelial-mediated remodeling of allergic airways, we tested the hypothesis that SA can enhance the remodeling process. Normal human bronchial epithelial (NHBE) cells were stimulated with heat-killed SA (HKSA) or transforming growth factor (TGF) α. Cell extracts were collected to measure mRNA (real-time RT-PCR) and signaling molecules (Western blot); supernatants were collected to measure protein (ELISA) after 24 hours of stimulation. Epidermal growth factor receptor (EGFR) signaling inhibition experiments were performed using a specific EGFR kinase inhibitor (AG1478) and TGF-α was blocked with an anti-TGF-α antibody. HKSA induced both mRNA and protein for TGF-α and matrix metalloproteinase (MMP) 1 from NHBE cells by a Toll-like receptor 2-dependent mechanism. Recombinant human TGF-α also induced mRNA and protein for MMP-1 from NHBE cells; anti-TGF-α antibody inhibited HKSA-induced MMP-1, suggesting that endogenous TGF-α mediates the MMP-1 induction by HKSA. HKSA-induced MMP-1 expression was suppressed when a specific EGFR kinase inhibitor was added, suggesting that EGFR signaling was mediating the HKSA-induced MMP-1 release. Exposure or colonization by SA in the airway may enhance the remodeling of tissue through a TGF-α-dependent induction of MMP-1 expression, and may thereby promote remodeling in airway diseases in which SA is implicated, such as asthma and chronic rhinosinusitis. PMID:25180535

  19. Crucial role of Toll-like receptors in the zinc/nickel-induced inflammatory response in vascular endothelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Tsou, Tsui-Chun, E-mail: tctsou@nhri.org.tw [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 350, Taiwan (China); Liou, Saou-Hsing; Yeh, Szu-Ching; Tsai, Feng-Yuan [Division of Environmental Health and Occupational Medicine, National Health Research Institutes, Zhunan, Miaoli 350, Taiwan (China); Chao, How-Ran [Emerging Compounds Research Center, Department of Environmental Science and Engineering, National Pingtung University and Science and Technology, Neipu, Pingtung 912, Taiwan (China)

    2013-12-15

    Our previous studies indicated that zinc induced inflammatory response in both vascular endothelial cells and promonocytes. Here, we asked if other metals could cause the similar effect on vascular endothelial cells and tried to determine its underlying mechanism. Following screening of fifteen metals, zinc and nickel were identified with a marked proinflammatory effect, as determined by ICAM-1 and IL-8 induction, on human umbilical vein endothelial cells (HUVECs). Inhibiting protein expression of myeloid differentiation primary response protein-88 (MyD88), a Toll-like receptor (TLR) adaptor acting as a TLR-signaling transducer, significantly attenuated the zinc/nickel-induced inflammatory response, suggesting the critical roles of TLRs in the inflammatory response. Blockage of TLR-4 signaling by CLI-095, a TLR-4 inhibitor, completely inhibited the nickel-induced ICAM-1 and IL-8 expression and NFκB activation. The same CLI-095 treatment significantly blocked the zinc-induced IL-8 expression, however with no significant effect on the ICAM-1 expression and a minor inhibitory effect on the NFκB activation. The finding demonstrated the differential role of TLR-4 in regulation of the zinc/nickel-induced inflammatory response, where TLR-4 played a dominant role in NFκB activation by nickel, but not by zinc. Moreover, inhibition of NFκB by adenovirus-mediated IκBα expression and Bay 11-7025, an inhibitor of cytokine-induced IκB-α phosphorylation, significantly attenuated the zinc/nickel-induced inflammatory responses, indicating the critical of NFκB in the process. The study demonstrates the crucial role of TLRs in the zinc/nickel-induced inflammatory response in vascular endothelial cells and herein deciphers a potential important difference in NFκB activation via TLRs. The study provides a molecular basis for linkage between zinc/nickel exposure and pathogenesis of the metal-related inflammatory vascular disease. - Highlights: • Both zinc and nickel cause

  20. Hypoxia attenuates inflammatory mediators production induced by Acanthamoeba via Toll-like receptor 4 signaling in human corneal epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Hong [Department of Ophthalmology, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China); The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Public Health, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China); Wu, Xinyi, E-mail: xywu8868@163.com [Department of Ophthalmology, Qilu Hospital, Shandong University, 107, Wenhua Xi Road, Jinan 250012 (China)

    2012-04-13

    Highlights: Black-Right-Pointing-Pointer Hypoxia attenuates Acanthamoeba-induced the production of IL-8 and IFN-{beta}. Black-Right-Pointing-Pointer Hypoxia inhibits TLR4 expression in a time-dependent manner in HCECs. Black-Right-Pointing-Pointer Hypoxia inhibits Acanthamoeba-induced the activation of NF-{kappa}B and ERK1/2 in HCECs. Black-Right-Pointing-Pointer Hypoxia decreases Acanthamoeba-induced inflammatory response via TLR4 signaling. Black-Right-Pointing-Pointer LPS-induced the secretion of IL-6 and IL-8 is abated by hypoxia via TLR4 signaling. -- Abstract: Acanthamoeba keratitis (AK) is a vision-threatening corneal infection that is intimately associated with contact lens use which leads to hypoxic conditions on the corneal surface. However, the effect of hypoxia on the Acanthamoeba-induced host inflammatory response of corneal epithelial cells has not been studied. In the present study, we investigated the effect of hypoxia on the Acanthamoeba-induced production of inflammatory mediators interleukin-8 (IL-8) and interferon-{beta} (IFN-{beta}) in human corneal epithelial cells and then evaluated its effects on the Toll-like receptor 4 (TLR4) signaling, including TLR4 and myeloid differentiation primary response gene (88) (MyD88) expression as well as the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-{kappa}B) and extracellular signal-regulated kinases 1/2 (ERK1/2). We then studied the effect of hypoxia on a TLR4-specific inflammatory response triggered by the TLR4 ligand lipopolysaccharide (LPS). Our data showed that hypoxia significantly decreased the production of IL-8 and IFN-{beta}. Furthermore, hypoxia attenuated Acanthamoeba-triggered TLR4 expression as well as the activation of NF-{kappa}B and ERK1/2, indicating that hypoxia abated Acanthamoeba-induced inflammatory responses by affecting TLR4 signaling. Hypoxia also inhibited LPS-induced IL-6 and IL-8 secretion, myeloid differentiation primary response gene (88

  1. Toll-like receptor 4 knockout ameliorates neuroinflammation due to lung-brain interaction in mechanically ventilated mice.

    Science.gov (United States)

    Chen, Ting; Chen, Chang; Zhang, Zongze; Zou, Yufeng; Peng, Mian; Wang, Yanlin

    2016-08-01

    Toll-like receptor 4 (TLR4) is a crucial receptor in the innate immune system, and increasing evidence supports its role in inflammation, stress, and tissue injury, including injury to the lung and brain. We aimed to investigate the effects of TLR4 on neuroinflammation due to the lung-brain interaction in mechanically ventilated mice. Male wild-type (WT) C57BL/6 and TLR4 knockout (TLR4 KO) mice were divided into three groups: (1) control group (C): spontaneous breathing; (2) anesthesia group (A): spontaneous breathing under anesthesia; and (3) mechanical ventilation group (MV): 6h of MV under anesthesia. The behavioral responses of mice were tested with fear conditioning tests. The histological changes in the lung and brain were assessed using hematoxylin-eosin (HE) staining. The level of TLR4 mRNA in tissue was measured using reverse transcription-polymerase chain reaction (RT-PCR). The levels of inflammatory cytokines were measured with an enzyme-linked immunosorbent assay (ELISA). Microgliosis, astrocytosis, and the TLR4 immunoreactivity in the hippocampus were measured by double immunofluorescence. MV mice exhibited impaired cognition, and this impairment was less severe in TLR4 KO mice than in WT mice. In WT mice, MV increased TLR4 mRNA expression in the lung and brain. MV induced mild lung injury, which was prevented in TLR4 KO mice. MV mice exhibited increased levels of inflammatory cytokines, increased microglia and astrocyte activation. Microgliosis was alleviated in TLR4 KO mice. MV mice exhibited increased TLR4 immunoreactivity, which was expressed in microglia and astrocytes. These results demonstrate that TLR4 is involved in neuroinflammation due to the lung-brain interaction and that TLR4 KO ameliorates neuroinflammation due to lung-brain interaction after prolonged MV. In addition, Administration of a TLR4 antagonist (100μg/mice) to WT mice also significantly attenuated neuroinflammation of lung-brain interaction due to prolonged MV. TLR4 antagonism

  2. Induction of inflammatory cytokines and toll-like receptors in chickens infected with avian H9N2 influenza virus

    Directory of Open Access Journals (Sweden)

    Nang Nguyen

    2011-05-01

    Full Text Available Abstract H9N2 influenza virus is endemic in many Asian countries and is regarded as a candidate for the next human pandemic. Knowledge of the induction of inflammatory responses and toll-like receptors (TLRs in chickens infected with H9N2 is limited. Here, we show that H9N2 induces pro-inflammatory cytokines such as transforming growth factor-beta 3; tumor necrosis factor-alpha; interferon-alpha, -beta, and gamma; and TLR 1, 2, 3, 4, 5, 7, and 15 in trachea, lung, and intestine of infected chickens. In the lung, TLR-15 was dominantly induced. Taken together, it seems that H9N2 infections efficiently induce inflammatory cytokines and TLRs in trachea, lung and intestine of chickens.

  3. Toll-Like Receptors and Cytokines as Surrogate Biomarkers for Evaluating Vaginal Immune Response following Microbicide Administration

    Directory of Open Access Journals (Sweden)

    Sadhana M. Gupta

    2008-01-01

    Full Text Available Topical microbicides are intended for frequent use by women in reproductive age. Hence, it is essential to evaluate their impact on mucosal immune function in the vagina. In the present study, we evaluated nisin, a naturally occurring antimicrobial peptide (AMP, for its efficacy as an intravaginal microbicide. Its effect on the vaginal immune function was determined by localizing Toll-like receptors (TLRs-3, 9 and cytokines (IL-4, 6 , 10 and TNF-α in the rabbit cervicovaginal epithelium following intravaginal administration of high dose of nisin gel for 14 consecutive days. The results revealed no alteration in the expression of TLRs and cytokines at both protein and mRNA levels. However, in SDS gel-treated group, the levels were significantly upregulated with the induction of NF-κB signalling cascade. Thus, TLRs and cytokines appear as sensitive indicators for screening immunotoxic potential of candidate microbicides.

  4. Association of Toll-Like Receptor Signaling and Reactive Oxygen Species: A Potential Therapeutic Target for Posttrauma Acute Lung Injury

    Directory of Open Access Journals (Sweden)

    Meng Xiang

    2010-01-01

    Full Text Available Acute lung injury (ALI frequently occurs in traumatic patients and serves as an important component of systemic inflammatory response syndrome (SIRS. Hemorrhagic shock (HS that results from major trauma promotes the development of SIRS and ALI by priming the innate immune system for an exaggerated inflammatory response. Recent studies have reported that the mechanism underlying the priming of pulmonary inflammation involves the complicated cross-talk between Toll-like receptors (TLRs and interactions between neutrophils (PMNs and alveolar macrophages (AMϕ as well as endothelial cells (ECs, in which reactive oxygen species (ROS are the key mediator. This paper summarizes some novel mechanisms underlying HS-primed lung inflammation focusing on the role of TLRs and ROS, and therefore suggests a new therapeutic target for posttrauma ALI.

  5. Resistant starches differentially stimulate Toll-like receptors and attenuate proinflammatory cytokines in dendritic cells by modulation of intestinal epithelial cells

    NARCIS (Netherlands)

    Bermudez-Brito, Miriam; Rosch, Christiane; Schols, Henk A.; Faas, Marijke M.; de Vos, Paul

    2015-01-01

    Scope: Main objectives of this study were (1) to demonstrate direct signaling of starch on human dendritic cells (DCs), (2) to study whether this is mediated by the pattern recognition receptors such as Toll-like receptors (TLRs) and (3) to study whether intestinal epithelial cells (IECs) are involv

  6. Resistant starches differentially stimulate Toll-like receptors and attenuate proinflammatory cytokines in dendritic cells by modulation of intestinal epithelial cells

    NARCIS (Netherlands)

    Bermudez-Brito, M.; Rösch, C.; Schols, H.A.; Faas, M.M.; Vos, de P.

    2015-01-01

    Scope Main objectives of this study were (1) to demonstrate direct signaling of starch on human dendritic cells (DCs), (2) to study whether this is mediated by the pattern recognition receptors such as Toll-like receptors (TLRs) and (3) to study whether intestinal epithelial cells (IECs) are involve

  7. Increased expression of toll-like receptor 4 and inflammatory cytokines, interleukin-6 in particular, in islets from a mouse model of obesity and type 2 diabetes

    DEFF Research Database (Denmark)

    Ladefoged, Mette; Buschard, Karsten; Hansen, Ann Maria Kruse

    2013-01-01

    Toll-like receptor 4 (TLR4) has received much attention in the recent years due to its role in development of insulin resistance in type 2 diabetes mellitus. Its expression is elevated in fat and muscle from insulin-resistant mice. Several cells of the pancreatic islets, including β-cells and res......Toll-like receptor 4 (TLR4) has received much attention in the recent years due to its role in development of insulin resistance in type 2 diabetes mellitus. Its expression is elevated in fat and muscle from insulin-resistant mice. Several cells of the pancreatic islets, including β...

  8. Association of interacting genes in the toll-like receptor signaling pathway and the antibody response to pertussis vaccination.

    Directory of Open Access Journals (Sweden)

    Tjeerd G Kimman

    Full Text Available BACKGROUND: Activation of the Toll-like receptor (TLR signaling pathway through TLR4 may be important in the induction of protective immunity against Bordetella pertussis with TLR4-mediated activation of dendritic and B cells, induction of cytokine expression, and reversal of tolerance as crucial steps. We examined whether single nucleotide polymorphisms (SNPs in genes of the TLR4 pathway and their interaction are associated with the response to whole-cell vaccine (WCV pertussis vaccination in 490 one-year-old children. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed associations of 75 haplotype-tagging SNPs in genes in the TLR4 signaling pathway with pertussis toxin (PT-IgG titers. We found significant associations between the PT-IgG titer and SNPs in CD14, TLR4, TOLLIP, TIRAP, IRAK3, IRAK4, TICAM1, and TNFRSF4 in one or more of the analyses. The strongest evidence for association was found for two SNPs (rs5744034 and rs5743894 in TOLLIP that were almost completely in linkage disequilibrium, provided statistically significant associations in all tests with the lowest p-values, and displayed a dominant mode of inheritance. However, none of these single gene associations would withstand correction for multiple testing. In addition, Multifactor Dimensionality Reduction Analysis, an approach that does not need correction for multiple testing, showed significant and strong two and three locus interactions between SNPs in TOLLIP (rs4963060, TLR4 (rs6478317 and IRAK1 (rs1059703. CONCLUSIONS/SIGNIFICANCE: We have identified significant interactions between genes in the TLR pathway in the induction of vaccine-induced immunity. These interactions underline that these genes are functionally related and together form a true biological relationship in a protein-protein interaction network. Practically all our findings may be explained by genetic variation in directly or indirectly interacting proteins at the extra- and intracytoplasmic sites of the cell

  9. Toll-like receptor and pro-inflammatory cytokine expression during prolonged hyperinsulinaemia in horses: implications for laminitis.

    Science.gov (United States)

    de Laat, M A; Clement, C K; McGowan, C M; Sillence, M N; Pollitt, C C; Lacombe, V A

    2014-01-15

    Equine laminitis, a disease of the lamellar structure of the horse's hoof, can be incited by numerous factors that include inflammatory and metabolic aetiologies. However, the role of inflammation in hyperinsulinaemic laminitis has not been adequately defined. Toll-like receptor (TLR) activation results in up-regulation of inflammatory pathways and the release of pro-inflammatory cytokines, including interleukin-6 (IL-6) and tumour necrosis factor-alpha (TNF-α), and may be a pathogenic factor in laminitis. The aim of this study was to determine whether TLR4 expression and subsequent pro-inflammatory cytokine production is increased in lamellae and skeletal muscle during equine hyperinsulinaemia. Standardbred horses were treated with either a prolonged, euglycaemic hyperinsulinaemic clamp (p-EHC) or a prolonged, glucose infusion (p-GI), which induced marked and moderate hyperinsulinaemia, respectively. Age-matched control horses were treated simultaneously with a balanced electrolyte solution. Treated horses developed clinical (p-EHC) or subclinical (p-GI) laminitis, whereas controls did not. Skeletal muscle and lamellar protein extracts were analysed by Western blotting for TLR4, IL-6, TNF-α and suppressor of cytokine signalling 3 (SOCS3) expression. Lamellar protein expression of TLR4 and TNF-α, but not IL-6, was increased by the p-EHC, compared to control horses. A significant positive correlation was found between lamellar TLR4 and SOCS3. Skeletal muscle protein expression of TLR4 signalling parameters did not differ between control and p-EHC-treated horses. Similarly, the p-GI did not result in up-regulation of lamellar protein expression of any parameter. The results suggest that insulin-sensitive tissues may not accurately reflect lamellar pathology during hyperinsulinaemia. While TLR4 is present in the lamellae, its activation appears unlikely to contribute significantly to the developmental pathogenesis of hyperinsulinaemic laminitis. However

  10. Group X Secretory Phospholipase A2 Enhances Toll-Like Receptor 4 Signaling in Macrophages

    OpenAIRE

    Shridas, Preetha; Bailey, William M.; Talbott, Kayla R; Oslund, Rob C.; Gelb, Michael H; Webb, Nancy R.

    2011-01-01

    Secretory phospholipase A2’s (sPLA2) hydrolyze glycerophospholipids to liberate lysophospholipids and free fatty acids. Although Group X (GX) sPLA2 is recognized as the most potent mammalian sPLA2 in vitro, its precise physiological function(s) remain unclear. We recently reported that GX sPLA2 suppresses activation of the Liver X receptor (LXR) in macrophages, resulting in reduced expression of LXR-responsive genes including ABCA1 and ABCG1, and a consequent decrease in cellular cholesterol ...

  11. Toll-like receptor 4 knockout alleviates paraquat-induced cardiomyocyte contractile dysfunction through an autophagy-dependent mechanism.

    Science.gov (United States)

    Wang, Shuyi; Zhu, Xiaoling; Xiong, Lize; Zhang, Yingmei; Ren, Jun

    2016-08-22

    Paraquat, a quarternary nitrogen herbicide, is a toxic prooxidant leading to multi-organ failure including the heart although the underlying mechanism remains poorly understood. This study was designed to examine the role of the innate proinflammatory mediator toll-like receptor 4 (TLR4) in paraquat-induced cardiac contractile anomalies and the underlying mechanisms involved with a focus on autophagy, a conservative machinery governing protein and organelle degradation and recycling for cardiac homeostasis. Wild-type (WT) and TLR4 knockout (TLR4(-/-)) mice were challenged with paraquat (45mg/kg, i.p.) for 48h. Paraquat challenge did not affect mRNA levels of TLR2, TLR4 and TLR9 in WT mice nor did paraquat treatment alter TREM-1 levels. Paraquat challenge elicited cardiac mechanical defects including compromised cardiomyocyte contractile function, intracellular Ca(2+) handling, and overt autophagy as manifested by increased LC3BII-to-LC3BI ratio, Atg5, Atg7 and p62 levels. Interestingly, TLR4 knockout significantly attenuated paraquat-induced cardiac contractile and intracellular Ca(2+) derangement as well as alterations of autophagy markers. Paraquat-elicited changes in cardiac autophagy markers (LC3BII, LC3BII-to-LC3BI ratio and p62) were augmented by lysosomal inhibition using bafilomycin A1 in WT mice. TLR4 knockout significantly attenuated or negated paraquat-elicited increase in LC3BII, LC3BII-to-LC3BI ratio and p62 levels in the presence of lysosomal inhibition. In addition, paraquat challenge promoted phosphorylation of AMPK while suppressing the phosphorylation of mTOR and ULK1 (the autophagy inhibitory Ser(757)), the effects of which were significantly attenuated by TLR4 ablation. In vitro study revealed that AMPK activation using AICAR or mTOR inhibition using rapamycin effectively negated the beneficial cardiomyocyte mechanical effects of TLR4 inhibition (CLI-095) against paraquat toxicity, supporting a permissive role for AMPK-mTOR in TLR4 inhibition

  12. High-mobility group box 1 inhibits gastric ulcer healing through Toll-like receptor 4 and receptor for advanced glycation end products.

    Science.gov (United States)

    Nadatani, Yuji; Watanabe, Toshio; Tanigawa, Tetsuya; Ohkawa, Fumikazu; Takeda, Shogo; Higashimori, Akira; Sogawa, Mitsue; Yamagami, Hirokazu; Shiba, Masatsugu; Watanabe, Kenji; Tominaga, Kazunari; Fujiwara, Yasuhiro; Takeuchi, Koji; Arakawa, Tetsuo

    2013-01-01

    High-mobility group box 1 (HMGB1) was initially discovered as a nuclear protein that interacts with DNA as a chromatin-associated non-histone protein to stabilize nucleosomes and to regulate the transcription of many genes in the nucleus. Once leaked or actively secreted into the extracellular environment, HMGB1 activates inflammatory pathways by stimulating multiple receptors, including Toll-like receptor (TLR) 2, TLR4, and receptor for advanced glycation end products (RAGE), leading to tissue injury. Although HMGB1's ability to induce inflammation has been well documented, no studies have examined the role of HMGB1 in wound healing in the gastrointestinal field. The aim of this study was to evaluate the role of HMGB1 and its receptors in the healing of gastric ulcers. We also investigated which receptor among TLR2, TLR4, or RAGE mediates HMGB1's effects on ulcer healing. Gastric ulcers were induced by serosal application of acetic acid in mice, and gastric tissues were processed for further evaluation. The induction of ulcer increased the immunohistochemical staining of cytoplasmic HMGB1 and elevated serum HMGB1 levels. Ulcer size, myeloperoxidase (MPO) activity, and the expression of tumor necrosis factor α (TNFα) mRNA peaked on day 4. Intraperitoneal administration of HMGB1 delayed ulcer healing and elevated MPO activity and TNFα expression. In contrast, administration of anti-HMGB1 antibody promoted ulcer healing and reduced MPO activity and TNFα expression. TLR4 and RAGE deficiency enhanced ulcer healing and reduced the level of TNFα, whereas ulcer healing in TLR2 knockout (KO) mice was similar to that in wild-type mice. In TLR4 KO and RAGE KO mice, exogenous HMGB1 did not affect ulcer healing and TNFα expression. Thus, we showed that HMGB1 is a complicating factor in the gastric ulcer healing process, which acts through TLR4 and RAGE to induce excessive inflammatory responses.

  13. High-mobility group box 1 inhibits gastric ulcer healing through Toll-like receptor 4 and receptor for advanced glycation end products.

    Directory of Open Access Journals (Sweden)

    Yuji Nadatani

    Full Text Available High-mobility group box 1 (HMGB1 was initially discovered as a nuclear protein that interacts with DNA as a chromatin-associated non-histone protein to stabilize nucleosomes and to regulate the transcription of many genes in the nucleus. Once leaked or actively secreted into the extracellular environment, HMGB1 activates inflammatory pathways by stimulating multiple receptors, including Toll-like receptor (TLR 2, TLR4, and receptor for advanced glycation end products (RAGE, leading to tissue injury. Although HMGB1's ability to induce inflammation has been well documented, no studies have examined the role of HMGB1 in wound healing in the gastrointestinal field. The aim of this study was to evaluate the role of HMGB1 and its receptors in the healing of gastric ulcers. We also investigated which receptor among TLR2, TLR4, or RAGE mediates HMGB1's effects on ulcer healing. Gastric ulcers were induced by serosal application of acetic acid in mice, and gastric tissues were processed for further evaluation. The induction of ulcer increased the immunohistochemical staining of cytoplasmic HMGB1 and elevated serum HMGB1 levels. Ulcer size, myeloperoxidase (MPO activity, and the expression of tumor necrosis factor α (TNFα mRNA peaked on day 4. Intraperitoneal administration of HMGB1 delayed ulcer healing and elevated MPO activity and TNFα expression. In contrast, administration of anti-HMGB1 antibody promoted ulcer healing and reduced MPO activity and TNFα expression. TLR4 and RAGE deficiency enhanced ulcer healing and reduced the level of TNFα, whereas ulcer healing in TLR2 knockout (KO mice was similar to that in wild-type mice. In TLR4 KO and RAGE KO mice, exogenous HMGB1 did not affect ulcer healing and TNFα expression. Thus, we showed that HMGB1 is a complicating factor in the gastric ulcer healing process, which acts through TLR4 and RAGE to induce excessive inflammatory responses.

  14. Kinase RIP3 is dispensable for normal NF-kappa Bs, signaling by the B-cell and T-cell receptors, tumor necrosis factor receptor 1, and Toll-like receptors 2 and 4.

    Science.gov (United States)

    Newton, Kim; Sun, Xiaoqing; Dixit, Vishva M

    2004-02-01

    RIP3 is a member of the RIP kinase family. It is expressed in the embryo and in multiple adult tissues, including most hemopoietic cell lineages. Several studies have implicated RIP3 in the regulation of apoptosis and NF-kappa B signaling, but whether RIP3 promotes or attenuates activation of the NF-kappa B family of transcription factors has been controversial. We have generated RIP3-deficient mice by gene targeting and find RIP3 to be dispensable for normal mouse development. RIP3-deficient cells showed normal sensitivity to a variety of apoptotic stimuli and were indistinguishable from wild-type cells in their ability to activate NF-kappa B signaling in response to the following: human tumor necrosis factor (TNF), which selectively engages mouse TNF receptor 1; cross-linking of the B- or T-cell antigen receptors; peptidoglycan, which activates Toll-like receptor 2; and lipopolysaccharide (LPS), which stimulates Toll-like receptor 4. Consistent with these observations, RIP3-deficient mice exhibited normal antibody production after immunization with a T-dependent antigen and normal interleukin-1 beta (IL-1 beta), IL-6, and TNF production after LPS treatment. Thus, we can exclude RIP3 as an essential modulator of NF-kappa B signaling downstream of several receptor systems.

  15. Characterization of Toll-like receptors in primary lung epithelial cells: strong impact of the TLR3 ligand poly(I:C on the regulation of Toll-like receptors, adaptor proteins and inflammatory response

    Directory of Open Access Journals (Sweden)

    Weith Andreas

    2005-11-01

    Full Text Available Abstract Background Bacterial and viral exacerbations play a crucial role in a variety of lung diseases including COPD or asthma. Since the lung epithelium is a major source of various inflammatory mediators that affect the immune response, we analyzed the inflammatory reaction of primary lung epithelial cells to different microbial molecules that are recognized by Toll-like receptors (TLR. Methods The effects of TLR ligands on primary small airway epithelial cells were analyzed in detail with respect to cytokine, chemokine and matrix metalloproteinase secretion. In addition, the regulation of the expression of TLRs and their adaptor proteins in small airway epithelial cells was investigated. Results Our data demonstrate that poly(I:C, a synthetic analog of viral dsRNA, mediated the strongest proinflammatory effects among the tested ligands, including an increased secretion of IL-6, IL-8, TNF-α, GM-CSF, GRO-α, TARC, MCP-1, MIP-3α, RANTES, IFN-β, IP-10 and ITAC as well as an increased release of MMP-1, MMP-8, MMP-9, MMP-10 and MMP-13. Furthermore, our data show that poly(I:C as well as type-1 and type-2 cytokines have a pronounced effect on the expression of TLRs and molecules involved in TLR signaling in small airway epithelial cells. Poly(I:C induced an elevated expression of TLR1, TLR2 and TLR3 and increased the gene expression of the general TLR adaptor MyD88 and IRAK-2. Simultaneously, poly(I:C decreased the expression of TLR5, TLR6 and TOLLIP. Conclusion Poly(I:C, an analog of viral dsRNA and a TLR3 ligand, triggers a strong inflammatory response in small airway epithelial cells that is likely to contribute to viral exacerbations of pulmonary diseases like asthma or COPD. The pronounced effects of poly(I:C on the expression of Toll-like receptors and molecules involved in TLR signaling is assumed to influence the immune response of the lung epithelium to viral and bacterial infections. Likewise, the regulation of TLR expression by type

  16. Distinct uptake mechanisms but similar intracellular processing of two different toll-like receptor ligand-peptide conjugates in dendritic cells.

    NARCIS (Netherlands)

    Khan, S.; Bijker, M.S.; Weterings, J.J.; Tanke, H.J.; Adema, G.J.; Hall, T. van; Drijfhout, J.W.; Melief, C.J.; Overkleeft, H.S.; Marel, G.A. van der; Filippov, D.V.; Burg, S.H. van der; Ossendorp, F.

    2007-01-01

    Covalent conjugation of Toll-like receptor ligands (TLR-L) to synthetic antigenic peptides strongly improves antigen presentation in vitro and T lymphocyte priming in vivo. These molecularly well defined TLR-L-peptide conjugates, constitute an attractive vaccination modality, sharing the peptide ant

  17. DMPD: Signal transduction pathways mediated by the interaction of CpG DNA withToll-like receptor 9. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14751759 Signal transduction pathways mediated by the interaction of CpG DNA withTo...;16(1):17-22. (.png) (.svg) (.html) (.csml) Show Signal transduction pathways mediated by the interaction of... CpG DNA withToll-like receptor 9. PubmedID 14751759 Title Signal transduction pathways media

  18. Type I interferons might form the link between Toll-like receptor (TLR) 3/7 and TLR4-mediated synovial inflammation in rheumatoid arthritis (RA).

    NARCIS (Netherlands)

    Roelofs, M.F.; Wenink, M.H.; Brentano, F.; Abdollahi-Roodsaz, S.; Oppers-Walgreen, B.; Barrera, P.; Riel, P.L.C.M. van; Joosten, L.A.B.; Kyburz, D.; Berg, W.B. van den; Radstake, T.R.D.J.

    2009-01-01

    BACKGROUND: Rheumatoid arthritis (RA) has been associated with an increased risk of infections, but the underlying pathways have not yet been identified. Toll-like receptors (TLR) probably play a role in synovial inflammation and may also contribute to the understanding of the role of infections in

  19. Single nucleotide polymorphisms in genes encoding toll-like receptors 7, 8 and 9 in Danish patients with systemic lupus erythematosus

    DEFF Research Database (Denmark)

    Enevold, C; Nielsen, Claus Henrik; Jacobsen, Rasmus Sleimann;

    2014-01-01

    Several studies indicate a role for toll-like receptors (TLRs) in the pathogenesis of systemic lupus erythematosus (SLE). We aimed to investigate the risk of SLE and typical clinical and serological manifestations of SLE potentially conferred by selected single nucleotide polymorphisms (SNPs...

  20. Toll-like receptor 4 mutant and null mice retain morphine-induced tolerance, hyperalgesia, and physical dependence.

    Directory of Open Access Journals (Sweden)

    Theresa Alexandra Mattioli

    Full Text Available The innate immune system modulates opioid-induced effects within the central nervous system and one target that has received considerable attention is the toll-like receptor 4 (TLR4. Here, we examined the contribution of TLR4 in the development of morphine tolerance, hyperalgesia, and physical dependence in two inbred mouse strains: C3H/HeJ mice which have a dominant negative point mutation in the Tlr4 gene rendering the receptor non-functional, and B10ScNJ mice which are TLR4 null mutants. We found that neither acute antinociceptive response to a single dose of morphine, nor the development of analgesic tolerance to repeated morphine treatment, was affected by TLR4 genotype. Likewise, opioid induced hyperalgesia and opioid physical dependence (assessed by naloxone precipitated withdrawal were not altered in TLR4 mutant or null mice. We also examined the behavioural consequence of two stereoisomers of naloxone: (- naloxone, an opioid receptor antagonist, and (+ naloxone, a purported antagonist of TLR4. Both stereoisomers of naloxone suppressed opioid induced hyperalgesia in wild-type control, TLR4 mutant, and TLR4 null mice. Collectively, our data suggest that TLR4 is not required for opioid-induced analgesic tolerance, hyperalgesia, or physical dependence.