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Sample records for exacerbated innate host

  1. Exacerbated Innate Host Response to SARS-CoV in Aged Non-Human Primates

    Science.gov (United States)

    Smits, Saskia L.; de Lang, Anna; van den Brand, Judith M. A.; Leijten, Lonneke M.; van IJcken, Wilfred F.; Eijkemans, Marinus J. C.; van Amerongen, Geert; Kuiken, Thijs; Andeweg, Arno C.; Osterhaus, Albert D. M. E.; Haagmans, Bart L.

    2010-01-01

    The emergence of viral respiratory pathogens with pandemic potential, such as severe acute respiratory syndrome coronavirus (SARS-CoV) and influenza A H5N1, urges the need for deciphering their pathogenesis to develop new intervention strategies. SARS-CoV infection causes acute lung injury (ALI) that may develop into life-threatening acute respiratory distress syndrome (ARDS) with advanced age correlating positively with adverse disease outcome. The molecular pathways, however, that cause virus-induced ALI/ARDS in aged individuals are ill-defined. Here, we show that SARS-CoV-infected aged macaques develop more severe pathology than young adult animals, even though viral replication levels are similar. Comprehensive genomic analyses indicate that aged macaques have a stronger host response to virus infection than young adult macaques, with an increase in differential expression of genes associated with inflammation, with NF-κB as central player, whereas expression of type I interferon (IFN)-β is reduced. Therapeutic treatment of SARS-CoV-infected aged macaques with type I IFN reduces pathology and diminishes pro-inflammatory gene expression, including interleukin-8 (IL-8) levels, without affecting virus replication in the lungs. Thus, ALI in SARS-CoV-infected aged macaques developed as a result of an exacerbated innate host response. The anti-inflammatory action of type I IFN reveals a potential intervention strategy for virus-induced ALI. PMID:20140198

  2. Interplay between Candida albicans and the Mammalian Innate Host Defense

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    Cheng, Shih-Chin; Joosten, Leo A. B.; Kullberg, Bart-Jan

    2012-01-01

    Candida albicans is both the most common fungal commensal microorganism in healthy individuals and the major fungal pathogen causing high mortality in at-risk populations, especially immunocompromised patients. In this review, we summarize the interplay between the host innate system and C. albicans, ranging from how the host recognizes, responds, and clears C. albicans infection to how C. albicans evades, dampens, and escapes from host innate immunity. PMID:22252867

  3. RNA-virus proteases counteracting host innate immunity.

    Science.gov (United States)

    Lei, Jian; Hilgenfeld, Rolf

    2017-10-01

    Virus invasion triggers host immune responses, in particular, innate immune responses. Pathogen-associated molecular patterns of viruses (such as dsRNA, ssRNA, or viral proteins) released during virus replication are detected by the corresponding pattern-recognition receptors of the host, and innate immune responses are induced. Through production of type-I and type-III interferons as well as various other cytokines, the host innate immune system forms the frontline to protect host cells and inhibit virus infection. Not surprisingly, viruses have evolved diverse strategies to counter this antiviral system. In this review, we discuss the multiple strategies used by proteases of positive-sense single-stranded RNA viruses of the families Picornaviridae, Coronaviridae, and Flaviviridae, when counteracting host innate immune responses. © 2017 Federation of European Biochemical Societies.

  4. Pattern Recognition Receptors in Innate Immunity, Host Defense, and Immunopathology

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    Suresh, Rahul; Mosser, David M.

    2013-01-01

    Infection by pathogenic microbes initiates a set of complex interactions between the pathogen and the host mediated by pattern recognition receptors. Innate immune responses play direct roles in host defense during the early stages of infection, and they also exert a profound influence on the generation of the adaptive immune responses that ensue.…

  5. Soluble Host Defense Lectins in Innate Immunity to Influenza Virus

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    Ng, Wy Ching; Tate, Michelle D.; Brooks, Andrew G.; Reading, Patrick C.

    2012-01-01

    Host defenses against viral infections depend on a complex interplay of innate (nonspecific) and adaptive (specific) components. In the early stages of infection, innate mechanisms represent the main line of host defense, acting to limit the spread of virus in host tissues prior to the induction of the adaptive immune response. Serum and lung fluids contain a range of lectins capable of recognizing and destroying influenza A viruses (IAV). Herein, we review the mechanisms by which soluble endogenous lectins mediate anti-IAV activity, including their role in modulating IAV-induced inflammation and disease and their potential as prophylactic and/or therapeutic treatments during severe IAV-induced disease. PMID:22665991

  6. SARS coronavirus pathogenesis: host innate immune responses and viral antagonism of interferon.

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    Totura, Allison L; Baric, Ralph S

    2012-06-01

    SARS-CoV is a pathogenic coronavirus that emerged from a zoonotic reservoir, leading to global dissemination of the virus. The association SARS-CoV with aberrant cytokine, chemokine, and Interferon Stimulated Gene (ISG) responses in patients provided evidence that SARS-CoV pathogenesis is at least partially controlled by innate immune signaling. Utilizing models for SARS-CoV infection, key components of innate immune signaling pathways have been identified as protective factors against SARS-CoV disease, including STAT1 and MyD88. Gene transcription signatures unique to SARS-CoV disease states have been identified, but host factors that regulate exacerbated disease phenotypes still remain largely undetermined. SARS-CoV encodes several proteins that modulate innate immune signaling through the antagonism of the induction of Interferon and by avoidance of ISG effector functions. Copyright © 2012. Published by Elsevier B.V.

  7. Innate lymphoid cells contribute to allergic airway disease exacerbation by obesity.

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    Everaere, Laetitia; Ait-Yahia, Saliha; Molendi-Coste, Olivier; Vorng, Han; Quemener, Sandrine; LeVu, Pauline; Fleury, Sebastien; Bouchaert, Emmanuel; Fan, Ying; Duez, Catherine; de Nadai, Patricia; Staels, Bart; Dombrowicz, David; Tsicopoulos, Anne

    2016-11-01

    Epidemiologic and clinical observations identify obesity as an important risk factor for asthma exacerbation, but the underlying mechanisms remain poorly understood. Type 2 innate lymphoid cells (ILC2s) and type 3 innate lymphoid cells (ILC3s) have been implicated, respectively, in asthma and adipose tissue homeostasis and in obesity-associated airway hyperresponsiveness (AHR). We sought to determine the potential involvement of innate lymphoid cells (ILCs) in allergic airway disease exacerbation caused by high-fat diet (HFD)-induced obesity. Obesity was induced by means of HFD feeding, and allergic airway inflammation was subsequently induced by means of intranasal administration of house dust mite (HDM) extract. AHR, lung and visceral adipose tissue inflammation, humoral response, cytokines, and innate and adaptive lymphoid populations were analyzed in the presence or absence of ILCs. HFD feeding exacerbated allergic airway disease features, including humoral response, airway and tissue eosinophilia, AHR, and T H 2 and T H 17 pulmonary profiles. Notably, nonsensitized obese mice already exhibited increased lung ILC counts and tissue eosinophil infiltration compared with values in lean mice in the absence of AHR. The numbers of total and cytokine-expressing lung ILC2s and ILC3s further increased in HDM-challenged obese mice compared with those in HDM-challenged lean mice, and this was accompanied by high IL-33 and IL-1β levels and decreased ILC markers in visceral adipose tissue. Furthermore, depletion of ILCs with an anti-CD90 antibody, followed by T-cell reconstitution, led to a profound decrease in allergic airway inflammatory features in obese mice, including T H 2 and T H 17 infiltration. These results indicate that HFD-induced obesity might exacerbate allergic airway inflammation through mechanisms involving ILC2s and ILC3s. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  8. Activation of innate host defense mechanisms by Borrelia.

    NARCIS (Netherlands)

    Berende, A.; Oosting, M.; Kullberg, B.J.; Netea, M.G.; Joosten, L.A.B.

    2010-01-01

    Borrelia is the causative agent of Lyme disease, a widespread disease with important health consequences. Immune-mediated mechanisms are believed to play a major role in both host defense and in late complications of Lyme disease. Recognition of Borrelia and the initial activation of the innate

  9. Training innate immunity: the changing concept of immunological memory in innate host defence.

    Science.gov (United States)

    Netea, Mihai G

    2013-08-01

    The inability of innate immunity to build an immunological memory is considered a main difference with adaptive immunity. This concept has been challenged by studies in plants, invertebrates and mammals. Recently, a paradigm shift in our understanding host defence has been triggered by the mounting evidence for innate immune memory, leading to increased responses to secondary infections. Important differences between the cell populations and the molecular mechanisms exist between the adaptive traits of innate host defence on the one hand and immunological memory of adaptive immunity on the other hand. The lasting state of enhanced innate immunity termed 'trained immunity' is mediated by prototypical innate immune cells such as natural killer cells and monocytes/macrophages. It provides protection against reinfection in a T/B-cell-independent manner, with both specific mechanisms and nonspecific epigenetic reprogramming mediating these effects. This concept represents a paradigm change in immunity, and its putative role in resistance to reinfection may represent the next step in the design of future vaccines. © 2013 Stichting European Society for Clinical Investigation Journal Foundation. Published by John Wiley & Sons Ltd.

  10. Soluble Host Defense Lectins in Innate Immunity to Influenza Virus

    Directory of Open Access Journals (Sweden)

    Wy Ching Ng

    2012-01-01

    Full Text Available Host defenses against viral infections depend on a complex interplay of innate (nonspecific and adaptive (specific components. In the early stages of infection, innate mechanisms represent the main line of host defense, acting to limit the spread of virus in host tissues prior to the induction of the adaptive immune response. Serum and lung fluids contain a range of lectins capable of recognizing and destroying influenza A viruses (IAV. Herein, we review the mechanisms by which soluble endogenous lectins mediate anti-IAV activity, including their role in modulating IAV-induced inflammation and disease and their potential as prophylactic and/or therapeutic treatments during severe IAV-induced disease.

  11. Trained immunity: a memory for innate host defense.

    Science.gov (United States)

    Netea, Mihai G; Quintin, Jessica; van der Meer, Jos W M

    2011-05-19

    Immune responses in vertebrates are classically divided into innate and adaptive, with only the latter being able to build up immunological memory. However, although lacking adaptive immune responses, plants and invertebrates are protected against reinfection with pathogens, and invertebrates even display transplant rejection. In mammals, past "forgotten" studies demonstrate cross-protection between infections independently of T and B cells, and more recently memory properties for NK cells and macrophages, prototypical cells of innate immunity, have been described. We now posit that mammalian innate immunity also exhibits an immunological memory of past insults, for which we propose the term "trained immunity." Understanding trained immunity will revolutionize our view of host defense and immunological memory, and could lead to defining a new class of vaccines and immunotherapies. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. The innate host response in caries and periodontitis.

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    Meyle, Joerg; Dommisch, Henrik; Groeger, Sabine; Giacaman, Rodrigo A; Costalonga, Massimo; Herzberg, Mark

    2017-07-20

    Innate immunity rapidly defends the host against infectious insults. These reactions are of limited specificity and exhaust without providing long-term protection. Functional fluids and effector molecules contribute to the defence against infectious agents, drive the immune response, and direct the cellular players. To review the literature and present a summary of current knowledge about the function of tissues, cellular players and soluble mediators of innate immunity relevant to caries and periodontitis. Historical and recent literature was critically reviewed based on publications in peer-reviewed scientific journals. The innate immune response is vital to resistance against caries and periodontitis and rapidly attempts to protect against infectious agents in the dental hard and soft tissues. Soluble mediators include specialized proteins and lipids. They function to signal to immune and inflammatory cells, provide antimicrobial resistance, and also induce mechanisms for potential repair of damaged tissues. Far less investigated than adaptive immunity, innate immune responses are an emerging scientific and therapeutic frontier. Soluble mediators of the innate response provide a network of signals to organize the near immediate molecular and cellular response to infection, including direct and immediate antimicrobial activity. Further studies in human disease and animal models are generally needed. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Subversion and Utilization of Host Innate Defense by Leishmania amazonensis.

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    Soong, Lynn

    2012-01-01

    Infection with Leishmania amazonensis and other members of the Leishmania mexicana complex can lead to diverse clinical manifestations, some of which are relatively difficult to control, even with standard chemotherapy. Diffuse cutaneous leishmaniasis (CL) is a rare but severe form, and its clinical hallmark is excessive parasitic growth in infected cells accompanied by profound impairments in host immune responses to the parasites. Since these parasites also cause non-healing CL in most inbred strains of mice, these animals are valuable models for dissecting the mechanisms of persistent infection and disease pathogenesis. In comparison to other Leishmania species, L. amazonensis infections are most remarkable for their ability to repress the activation and effector functions of macrophages, dendritic cells, and CD4(+) T cells, implying discrete mechanisms at work. In addition to this multilateral suppression of host innate and adaptive immunity, the activation of types I and II interferon-mediated responses and autophagic/lipid metabolic pathways actually promotes rather than restrains L. amazonensis infection. These seemingly contradictory findings reflect the remarkable adaptation of the parasites to the ancient defense machinery of the host, as well as the complex parasite-host interactions at different stages of infection, which collectively contribute to non-healing leishmaniasis in the New World. This review article highlights new evidence that reveals the strategies utilized by L. amazonensis parasites to subvert or modulate host innate defense machinery in neutrophils and macrophages, as well as the regulatory roles of host innate responses in promoting parasite survival and replication within the huge parasitophorous vacuoles. A better understanding of unique features in host responses to these parasites at early and late stages of infection is important for the rational design of control strategies for non-healing leishmaniasis.

  14. Subversion and utilization of host innate defense by Leishmania amazonensis

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    Lynn eSoong

    2012-03-01

    Full Text Available Infection with Leishmania amazonensis and other members of the L. mexicana complex can lead to diverse clinical manifestations, some of which are relatively difficult to control, even with standard chemotherapy. Diffuse cutaneous leishmaniasis is a rare but severe form, and its clinical hallmark is excessive parasitic growth in infected cells accompanied by profound impairments in host immune responses to the parasites. Since these parasites also cause non-healing cutaneous leishmaniasis in most inbred strains of mice, these animals are valuable models for dissecting the mechanisms of persistent infection and disease pathogenesis. In comparison to other Leishmania species, L. amazonensis infections are most remarkable for their ability to repress the activation and effector functions of macrophages, dendritic cells and CD4+ T cells, implying discrete mechanisms at work. In addition to this multilateral suppression of host innate and adaptive immunity, the activation of types I and II interferon-mediated responses and autophagic/lipid metabolic pathways actually promotes rather than restrains L. amazonensis infection. These seemingly contradictory findings reflect the remarkable adaptation of the parasites to the ancient defense machinery of the host, as well as the complex parasite-host interactions at different stages of infection, which collectively contribute to non-healing leishmaniasis in the New World. This review article highlights new evidence that reveals the strategies utilized by L. amazonensis parasites to subvert or modulate host innate defense machinery in neutrophils and macrophages, as well as the regulatory roles of host innate responses in promoting parasite survival and replication within the huge parasitophorous vacuoles. A better understanding of unique features in host responses to these parasites at early and late stages of infection is important for the rational design of control strategies for non-healing leishmaniasis.

  15. Role of group 2 innate lymphocytes in aspirin-exacerbated respiratory disease pathogenesis.

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    White, Andrew A; Doherty, Taylor A

    2018-01-01

    Aspirin-exacerbated respiratory disease (AERD) is characterized by chronic eosinophilic nasal polyps, asthma, and airway reactions upon cyclooxygenase (COX) 1 inhibition. AERD is present in up to 7% of adult patients with asthma and the underlying pathogenesis remains largely elusive but prostaglandin D2, cysteinyl leukotrienes, mast cells, and type 2 cytokines are thought to contribute. A wealth of studies have recently implicated group 2 innate lymphoid cells (ILC2), a novel lineage-negative lymphocyte population that produces type 2 cytokines, in human allergic disease pathogenesis. Importantly, our recent work identified that ILC2s are recruited to the nasal mucosa of patients on AERD after COX-1 inhibitor administration. Here, we review the potential impact of ILC2s in the development and propagation of type 2 inflammation in AERD.

  16. Innate Immune B Cell Activation by Leishmania donovani Exacerbates Disease and Mediates Hypergammaglobulinemia.

    Science.gov (United States)

    Silva-Barrios, Sasha; Smans, Mélina; Duerr, Claudia U; Qureshi, Salman T; Fritz, Jörg H; Descoteaux, Albert; Stäger, Simona

    2016-06-14

    Participation of B cells in the immune response by various antibody-independent mechanisms has recently been uncovered. B cells producing cytokines have been described for several infections and appear to regulate the adaptive immune response. B cell activation by Leishmania donovani results in disease exacerbation. How Leishmania activates B cells is still unknown. We show that L. donovani amastigotes activate B cells by triggering endosomal TLRs; this activation leads to the induction of various cytokines. Cytokine expression is completely abrogated in B cells from Ifnar(-/-) mice upon exposure to L. donovani, suggesting an involvement of IFN-I in a positive feedback loop. IFN-I also appears to enhance the expression of endosomal TLRs following exposure to L. donovani. Cell-specific ablation of endosomal TLR signaling in B cells revealed that innate B cell activation by L. donovani is responsible for disease exacerbation through IL-10 and IFN-I production and for the promotion of hypergammaglobulinemia. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  17. Generalized selection to overcome innate immunity selects for host breadth in an RNA virus.

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    Wasik, Brian R; Muñoz-Rojas, Andrés R; Okamoto, Kenichi W; Miller-Jensen, Kathryn; Turner, Paul E

    2016-02-01

    Virus-host coevolution has selected for generalized host defense against viruses, exemplified by interferon production/signaling and other innate immune function in eukaryotes such as humans. Although cell-surface binding primarily limits virus infection success, generalized adaptation to counteract innate immunity across disparate hosts may contribute to RNA virus emergence potential. We examined this idea using vesicular stomatitis virus (VSV) populations previously evolved on strictly immune-deficient (HeLa) cells, strictly immune competent (MDCK) cells, or on alternating deficient/competent cells. By measuring viral fitness in unselected human cancer cells of differing innate immunity, we confirmed that HeLa-adapted populations were specialized for innate immune-deficient hosts, whereas MDCK-adapted populations were relatively more generalized for fitness on hosts of differing innate immune capacity and of different species origin. We also confirmed that HeLa-evolved populations maintained fitness in immune-deficient nonhuman primate cells. These results suggest that innate immunity is more prominent than host species in determining viral fitness at the host-cell level. Finally, our prediction was inexact that selection on alternating deficient/competent hosts should produce innate viral generalists. Rather, fitness differences among alternating host-evolved VSV populations indicated variable capacities to evade innate immunity. Our results suggest that the evolutionary history of innate immune selection can affect whether RNA viruses evolve greater host-breadth. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  18. INTERACTIONS OF PATHOGENIC BACTERIA WITH INNATE IMMUNE REACTIONS OF HOST

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    F. Yu. Garib

    2012-01-01

    Full Text Available Abstract. «Efficacy» of pathogens interaction with the immunity system is manifested by broad spreading of many bacterial infections including tuberculosis first of all and in activation of known and emergent pathogens. The refined mechanisms of avoiding of bacteria from recognizing by immune system as creation of obstacles for phagocytosis and intracellular killing, using of secretory systems like “syringe” for inoculation into host cells deregulated substances, suppression or enhancing of inflammatory response, activation of inhibitory receptors to suppress respiratory explosion in phagosome, decreasing of synthesis of proinflammatory cytokines by influences to inflammasomes, stimulation of cytokines production suppres sed of innate response, damage of key molecules on intracellular signal routes, manipulation with apoptosis and auto phagia with the aim of surviving and replication inside the host cells, blocking of processing and presentation of bacterial antigens have been evolutionary developed. The study of interaction between host and parasite allows to understand new facts characterized “logic of live being” on the pathogen level and to use their mechanisms of evasion for resolving of actual problems raised in human society, for example, development of original vaccines and principally new drugs for immune system correction in case of diseases such as oncogenic tumors, autoimmune and allergic diseases as well as infectious diseases which are difficult to prevent and treat. Moreover, it was proved that permanent interaction with microorganisms including pathogenic ones is useful for human being because bacterial substances “train” immune system of people and assist its evolutionary improvement.

  19. DMPD: Macrophage migration inhibitory factor and host innate immune responses tomicrobes. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 14620137 Macrophage migration inhibitory factor and host innate immune responses to...microbes. Calandra T. Scand J Infect Dis. 2003;35(9):573-6. (.png) (.svg) (.html) (.csml) Show Macrophage migration... inhibitory factor and host innate immune responses tomicrobes. PubmedID 14620137 Title Macrophage migration

  20. Innate Immune Interactions between Bacillus anthracis and Host Neutrophils

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    Janet Z. Liu

    2018-01-01

    Full Text Available Bacillus anthracis, the causative agent of anthrax, has been a focus of study in host-pathogen dynamics since the nineteenth century. While the interaction between anthrax and host macrophages has been extensively modeled, comparatively little is known about the effect of anthrax on the immune function of neutrophils, a key frontline effector of innate immune defense. Here we showed that depletion of neutrophils significantly enhanced mortality in a systemic model of anthrax infection in mice. Ex vivo, we found that freshly isolated human neutrophils can rapidly kill anthrax, with specific inhibitor studies showing that phagocytosis and reactive oxygen species (ROS generation contribute to this efficient bacterial clearance. Anthrax toxins, comprising lethal toxin (LT and edema toxin (ET, are known to have major roles in B. anthracis macrophage resistance and systemic toxicity. Employing isogenic wild-type and mutant toxin-deficient B. anthracis strains, we show that despite previous studies that reported inhibition of neutrophil function by purified LT or ET, endogenous production of these toxins by live vegetative B. anthracis failed to alter key neutrophil functions. The lack of alteration in neutrophil function is accompanied by rapid killing of B. anthracis by neutrophils, regardless of the bacteria's expression of anthrax toxins. Lastly, our study demonstrates for the first time that anthrax induced neutrophil extracellular trap (NET formation.

  1. Beneficial and Harmful Interactions of Antibiotics with Microbial Pathogens and the Host Innate Immune System

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    Ronald Anderson

    2010-05-01

    Full Text Available In general antibiotics interact cooperatively with host defences, weakening and decreasing the virulence of microbial pathogens, thereby increasing vulnerability to phagocytosis and eradication by the intrinsic antimicrobial systems of the host. Antibiotics, however, also interact with host defences by several other mechanisms, some harmful, others beneficial. Harmful activities include exacerbation of potentially damaging inflammatory responses, a property of cell-wall targeted agents, which promotes the release of pro-inflammatory microbial cytotoxins and cell-wall components. On the other hand, inhibitors of bacterial protein synthesis, especially macrolides, possess beneficial anti-inflammatory/cytoprotective activities, which result from interference with the production of microbial virulence factors/cytotoxins. In addition to these pathogen-directed, anti-inflammatory activities, some classes of antimicrobial agent possess secondary anti-inflammatory properties, unrelated to their conventional antimicrobial activities, which target cells of the innate immune system, particularly neutrophils. This is a relatively uncommon, potentially beneficial property of antibiotics, which has been described for macrolides, imidazole anti-mycotics, fluoroquinolones, and tetracyclines. Although of largely unproven significance in the clinical setting, increasing awareness of the pro-inflammatory and anti-inflammatory properties of antibiotics may contribute to a more discerning and effective use of these agents.

  2. Patterns of oligonucleotide sequences in viral and host cell RNA identify mediators of the host innate immune system.

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    Benjamin D Greenbaum

    Full Text Available The innate immune response provides a first line of defense against pathogens by targeting generic differential features that are present in foreign organisms but not in the host. These innate responses generate selection forces acting both in pathogens and hosts that further determine their co-evolution. Here we analyze the nucleic acid sequence fingerprints of these selection forces acting in parallel on both host innate immune genes and ssRNA viral genomes. We do this by identifying dinucleotide biases in the coding regions of innate immune response genes in plasmacytoid dendritic cells, and then use this signal to identify other significant host innate immune genes. The persistence of these biases in the orthologous groups of genes in humans and chickens is also examined. We then compare the significant motifs in highly expressed genes of the innate immune system to those in ssRNA viruses and study the evolution of these motifs in the H1N1 influenza genome. We argue that the significant under-represented motif pattern of CpG in an AU context--which is found in both the ssRNA viruses and innate genes, and has decreased throughout the history of H1N1 influenza replication in humans--is immunostimulatory and has been selected against during the co-evolution of viruses and host innate immune genes. This shows how differences in host immune biology can drive the evolution of viruses that jump into species with different immune priorities than the original host.

  3. Trained immunity: a memory for innate host defense

    NARCIS (Netherlands)

    Netea, M.G.; Quintin, J.; Meer, J.W.M. van der

    2011-01-01

    Immune responses in vertebrates are classically divided into innate and adaptive, with only the latter being able to build up immunological memory. However, although lacking adaptive immune responses, plants and invertebrates are protected against reinfection with pathogens, and invertebrates even

  4. Role of Innate Host Defenses in Susceptibility to Early Onset Neonatal Sepsis

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    Wynn, James L.; Levy, Ofer

    2010-01-01

    Neonatal sepsis continues to take a devastating toll globally. Although adequate to protect against invasive infection in most newborns, the distinct function of neonatal innate host defense coupled with impairments in adaptive immune responses, increases the likelihood of acquiring infection early in life with subsequent rapid dissemination and death. Unique differences exist between neonates and older populations with respect to the capacity, quantity, and quality of innate host responses to pathogens. Recent characterization of the age-dependent maturation of neonatal innate immune function has identified novel translational approaches that may lead to improved diagnostic, prophylactic and therapeutic modalities. PMID:20569810

  5. Cigarette smoke silences innate lymphoid cell function and facilitates an exacerbated type I interleukin-33-dependent response to infection.

    Science.gov (United States)

    Kearley, Jennifer; Silver, Jonathan S; Sanden, Caroline; Liu, Zheng; Berlin, Aaron A; White, Natalie; Mori, Michiko; Pham, Tuyet-Hang; Ward, Christine K; Criner, Gerard J; Marchetti, Nathaniel; Mustelin, Tomas; Erjefalt, Jonas S; Kolbeck, Roland; Humbles, Alison A

    2015-03-17

    Cigarette smoking is a major risk factor for chronic obstructive pulmonary disease and is presumed to be central to the altered responsiveness to recurrent infection in these patients. We examined the effects of smoke priming underlying the exacerbated response to viral infection in mice. Lack of interleukin-33 (IL-33) signaling conferred complete protection during exacerbation and prevented enhanced inflammation and exaggerated weight loss. Mechanistically, smoke was required to upregulate epithelial-derived IL-33 and simultaneously alter the distribution of the IL-33 receptor ST2. Specifically, smoke decreased ST2 expression on group 2 innate lymphoid cells (ILC2s) while elevating ST2 expression on macrophages and natural killer (NK) cells, thus altering IL-33 responsiveness within the lung. Consequently, upon infection and release, increased local IL-33 significantly amplified type I proinflammatory responses via synergistic modulation of macrophage and NK cell function. Therefore, in COPD, smoke alters the lung microenvironment to facilitate an alternative IL-33-dependent exaggerated proinflammatory response to infection, exacerbating disease. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Staphylococcus aureus Manipulates Innate Immunity through Own and Host-Expressed Proteases

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    Pietrocola, Giampiero; Nobile, Giulia; Rindi, Simonetta; Speziale, Pietro

    2017-01-01

    Neutrophils, complement system and skin collectively represent the main elements of the innate immune system, the first line of defense of the host against many common microorganisms. Bacterial pathogens have evolved strategies to counteract all these defense activities. Specifically, Staphylococcus aureus, a major human pathogen, secretes a variety of immune evasion molecules including proteases, which cleave components of the innate immune system or disrupt the integrity of extracellular matrix and intercellular connections of tissues. Additionally, S. aureus secretes proteins that can activate host zymogens which, in turn, target specific defense components. Secreted proteins can also inhibit the anti-bacterial function of neutrophils or complement system proteases, potentiating S. aureus chances of survival. Here, we review the current understanding of these proteases and modulators of host proteases in the functioning of innate immunity and describe the importance of these mechanisms in the pathology of staphylococcal diseases. PMID:28529927

  7. Evolution of host innate defence: insights from Caenorhabditis elegans and primitive invertebrates.

    Science.gov (United States)

    Irazoqui, Javier E; Urbach, Jonathan M; Ausubel, Frederick M

    2010-01-01

    The genetically tractable model organism Caenorhabditis elegans was first used to model bacterial virulence in vivo a decade ago. Since then, great strides have been made in identifying the host response pathways that are involved in its defence against infection. Strikingly, C. elegans seems to detect, and respond to, infection without the involvement of its homologue of Toll-like receptors, in contrast to the well-established role for these proteins in innate immunity in mammals. What, therefore, do we know about host defence mechanisms in C. elegans and what can they tell us about innate immunity in higher organisms?

  8. Evolution of host innate defence: insights from C. elegans and primitive invertebrates

    Science.gov (United States)

    Irazoqui, Javier E.; Urbach, Jonathan M.; Ausubel, Frederick M.

    2010-01-01

    Preface The genetically tractable model organism Caenorhabditis elegans was first used to model bacterial virulence in vivo a decade ago. Since then, great strides have been made in the identification of host response pathways that are involved in the defence against infection. Strikingly, C. elegans seems to detect and respond to infection without the involvement of its Toll-like receptor homologue, in contrast to the well-established role for these proteins in innate immunity in mammals. What, therefore, do we know about host defence mechanisms in C. elegans, and what can they tell us about innate immunity in higher organisms? PMID:20029447

  9. Lymphotoxin organizes contributions to host defense and metabolic illness from innate lymphoid cells.

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    Upadhyay, Vaibhav; Fu, Yang-Xin

    2014-04-01

    The lymphotoxin (LT)-pathway is a unique constituent branch of the Tumor Necrosis Superfamily (TNFSF). Use of LT is a critical mechanism by which fetal innate lymphoid cells regulate lymphoid organogenesis. Within recent years, adult innate lymphoid cells have been discovered to utilize this same pathway to regulate IL-22 and IL-23 production for host defense. Notably, genetic studies have linked polymorphisms in the genes encoding LTα to several phenotypes contributing to metabolic syndrome. The role of the LT-pathway may lay the foundation for a bridge between host immune response, microbiota, and metabolic syndrome. The contribution of the LT-pathway to innate lymphoid cell function and metabolic syndrome will be visited in this review. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. Innate Immunity Evasion by Enteroviruses: Insights into Virus-Host Interaction

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    Xiaobo Lei

    2016-01-01

    Full Text Available Enterovirus genus includes multiple important human pathogens, such as poliovirus, coxsackievirus, enterovirus (EV A71, EV-D68 and rhinovirus. Infection with EVs can cause numerous clinical conditions including poliomyelitis, meningitis and encephalitis, hand-foot-and-mouth disease, acute flaccid paralysis, diarrhea, myocarditis and respiratory illness. EVs, which are positive-sense single-stranded RNA viruses, trigger activation of the host antiviral innate immune responses through pathogen recognition receptors such as retinoic acid-inducible gene (RIG-I-likeand Toll-like receptors. In turn, EVs have developed sophisticated strategies to evade host antiviral responses. In this review, we discuss the interplay between the host innate immune responses and EV infection, with a primary focus on host immune detection and protection against EV infection and viral strategies to evade these antiviral immune responses.

  11. Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning

    Science.gov (United States)

    Segura, Diego F.; Nussenbaum, Ana L.; Viscarret, Mariana M.; Devescovi, Francisco; Bachmann, Guillermo E.; Corley, Juan C.; Ovruski, Sergio M.; Cladera, Jorge L.

    2016-01-01

    Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host) represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively) could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach) using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging. PMID:27007298

  12. Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning.

    Directory of Open Access Journals (Sweden)

    Diego F Segura

    Full Text Available Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats. Under this scenario, chemical cues from the host habitat (not related to the host represent poor indicators of host location. Hence, it is unlikely that naïve females show a strong response to host habitat cues, which would become important only if the parasitoids learn to associate such cues to the host presence. This concept does not consider that habitats can vary in profitability or host nutritional quality, which according to the optimal foraging theory and the preference-performance hypothesis (respectively could shape the way in which parasitoids make use of chemical cues from the host habitat. We assessed innate preference in the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues from four host habitats (apple, fig, orange and peach using a Y-tube olfactometer. Contrary to what was predicted, we found a hierarchic pattern of preference. The parasitism rate realized on these fruit species and the weight of the host correlates positively, to some extent, with the preference pattern, whereas preference did not correlate with survival and fecundity of the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preference changed markedly depending on their previous experience and the abundance of hosts. These findings suggest that the pattern of preference for host habitats is attributable to differences in encounter rate and host quality. Host habitat preference seems to be, however, quite plastic and easily modified according to the information obtained during foraging.

  13. Subversion and Utilization of Host Innate Defense by Leishmania amazonensis

    OpenAIRE

    Soong, Lynn

    2012-01-01

    Infection with Leishmania amazonensis and other members of the Leishmania mexicana complex can lead to diverse clinical manifestations, some of which are relatively difficult to control, even with standard chemotherapy. Diffuse cutaneous leishmaniasis (CL) is a rare but severe form, and its clinical hallmark is excessive parasitic growth in infected cells accompanied by profound impairments in host immune responses to the parasites. Since these parasites also cause non-healing CL in most inbr...

  14. Host DNA released by NETosis promotes rhinovirus-induced type-2 allergic asthma exacerbation.

    Science.gov (United States)

    Toussaint, Marie; Jackson, David J; Swieboda, Dawid; Guedán, Anabel; Tsourouktsoglou, Theodora-Dorita; Ching, Yee Man; Radermecker, Coraline; Makrinioti, Heidi; Aniscenko, Julia; Edwards, Michael R; Solari, Roberto; Farnir, Frédéric; Papayannopoulos, Venizelos; Bureau, Fabrice; Marichal, Thomas; Johnston, Sebastian L

    2017-06-01

    Respiratory viral infections represent the most common cause of allergic asthma exacerbations. Amplification of the type-2 immune response is strongly implicated in asthma exacerbation, but how virus infection boosts type-2 responses is poorly understood. We report a significant correlation between the release of host double-stranded DNA (dsDNA) following rhinovirus infection and the exacerbation of type-2 allergic inflammation in humans. In a mouse model of allergic airway hypersensitivity, we show that rhinovirus infection triggers dsDNA release associated with the formation of neutrophil extracellular traps (NETs), known as NETosis. We further demonstrate that inhibiting NETosis by blocking neutrophil elastase or by degrading NETs with DNase protects mice from type-2 immunopathology. Furthermore, the injection of mouse genomic DNA alone is sufficient to recapitulate many features of rhinovirus-induced type-2 immune responses and asthma pathology. Thus, NETosis and its associated extracellular dsDNA contribute to the pathogenesis and may represent potential therapeutic targets of rhinovirus-induced asthma exacerbations.

  15. Cross-Species Virus-Host Protein-Protein Interactions Inhibiting Innate Immunity

    Science.gov (United States)

    2016-07-01

    virus families with know or suspected histories of changes in host-species tropism from animal to humans. In the Paramyxoviridae family, Hendra ...8725 John J. Kingman Road, MS 6201 Fort Belvoir, VA 22060-6201 T E C H N IC A L R E P O R T DTRA-TR-16-79 Cross-species virus -host...Cross-species virus -host protein-protein interactions inhibiting innate immunity What are the major goals of the project? List the major goals of

  16. Local innate host response and filamentous fungi in patients with cystic fibrosis.

    Science.gov (United States)

    Roilides, Emmanuel; Simitsopoulou, Maria

    2010-11-01

    Filamentous fungi especially Aspergillus spp. and Scedosporium spp. can colonize the lungs of cystic fibrosis (CF) patients. Persistent infection by these organisms may cause deterioration of lung function, mycetomas or local invasive disease. Although CF patients exert an excessive inflammatory response to inhaled bacteria, very little is known about the local innate immune response to filamentous fungi. In this paper, we review the innate immune response of respiratory tract of healthy individuals to filamentous fungi with some inference to CF patients and link the latter to existing data. We also report some preliminary findings on the in vitro antifungal responses of human phagocytes against Aspergillus spp. isolated from CF patients. Translation of these in vitro findings to appropriate in vivo systems and into clinical trials of immunomodulatory treatments may lead to improved strategies for appropriate innate host defenses in CF patients persistently infected with filamentous fungi.

  17. Structural modifications of bacterial lipopolysaccharide that facilitate Gram-negative bacteria evasion of host innate immunity

    Directory of Open Access Journals (Sweden)

    Motohiro eMatsuura

    2013-05-01

    Full Text Available Bacterial lipopolysaccharide (LPS, a cell wall component characteristic of Gram-negative bacteria, is a representative pathogen-associated molecular pattern that allows mammalian cells to recognize bacterial invasion and trigger innate immune responses. The polysaccharide moiety of LPS primary plays protective roles for bacteria such as prevention from complement attacks or camouflage with common host carbohydrate residues. The lipid moiety, termed lipid A, is recognized by the Toll-like receptor 4 (TLR4/MD-2 complex, which transduces signals for activation of host innate immunity. The basic structure of lipid A is a glucosamine disaccharide substituted by phosphate groups and acyl groups. Lipid A with 6 acyl groups (hexa-acylated form has been indicated to be a strong stimulator of the TLR4/MD-2 complex. This type of lipid A is conserved among a wide variety of Gram-negative bacteria, and those bacteria are easily recognized by host cells for activation of defensive innate immune responses. Modifications of the lipid A structure to less-acylated forms have been observed in some bacterial species, and those forms are poor stimulators of the TLR4/MD-2 complex. Such modifications are thought to facilitate bacterial evasion of host innate immunity, thereby enhancing pathogenicity. This hypothesis is supported by studies of Yersinia pestis LPS, which contains hexa-acylated lipid A when the bacterium grows at 27ºC (the temperature of the vector flea, and shifts to contain less-acylated forms when grown at the human body temperature of 37ºC. This alteration of lipid A forms following transmission of Y. pestis from fleas to humans contributes predominantly to the virulence of this bacterium over other virulence factors. A similar role for less-acylated lipid A forms has been indicated in some other bacterial species, such as Francisella tularensis, Helicobacter pylori, and Porphyromonas gingivalis, and further studies to explore this concept are

  18. Infection of goats with goatpox virus triggers host antiviral defense through activation of innate immune signaling.

    Science.gov (United States)

    Zeng, Xiancheng; Wang, Song; Chi, Xiaojuan; Chen, Shi-long; Huang, Shile; Lin, Qunqun; Xie, Baogui; Chen, Ji-Long

    2016-02-01

    Goatpox, caused by goatpox virus (GTPV), is one of the most serious infectious diseases associated with high morbidity and mortality in goats. However, little is known about involvement of host innate immunity during the GTPV infection. For this, goats were experimentally infected with GTPV. The results showed that GTPV infection significantly induced mRNA expression of type I interferon (IFN)-α and IFN-β in peripheral blood lymphocytes, spleen and lung. In addition, GTPV infection enhanced expression of several inflammatory cytokines, including interleukin (IL)-1β, IL-6, IL-18; and tumor necrosis factor-α (TNF-α). Strikingly, infection with GTPV activated signal transducers and activators of transcription 3 (STAT3), a critical cytokine signaling molecule. Interestingly, the virus infection induced expression of suppressor of cytokine signaling (SOCS)-1. Importantly, the infection resulted in an increased expression of some critical interferon-stimulated genes, such as interferon-induced transmembrane protein (IFITM) 1, IFITM3, interferon stimulated gene (ISG) 15 and ISG20. Furthermore, we found that infection with GTPV up-regulated expression of Toll-like receptor (TLR) 2 and TLR9. These results revealed that GTPV infection activated host innate immune signaling and thereby triggered antiviral innate immunity. The findings provide novel insights into complex mechanisms underlying GTPV-host interaction and pathogenesis of GTPV. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Interplay between Human Cytomegalovirus and Intrinsic/Innate Host Responses: A Complex Bidirectional Relationship

    Science.gov (United States)

    Rossini, Giada; Cerboni, Cristina; Santoni, Angela; Landini, Maria Paola; Landolfo, Santo; Gatti, Deborah; Gribaudo, Giorgio; Varani, Stefania

    2012-01-01

    The interaction between human cytomegalovirus (HCMV) and its host is a complex process that begins with viral attachment and entry into host cells, culminating in the development of a specific adaptive response that clears the acute infection but fails to eradicate HCMV. We review the viral and cellular partners that mediate early host responses to HCMV with regard to the interaction between structural components of virions (viral glycoproteins) and cellular receptors (attachment/entry receptors, toll-like receptors, and other nucleic acid sensors) or intrinsic factors (PML, hDaxx, Sp100, viperin, interferon inducible protein 16), the reactions of innate immune cells (antigen presenting cells and natural killer cells), the numerous mechanisms of viral immunoevasion, and the potential exploitation of events that are associated with early phases of virus-host interplay as a therapeutic strategy. PMID:22701276

  20. Cellular stress response and innate immune signaling: integrating pathways in host defense and inflammation

    Science.gov (United States)

    Muralidharan, Sujatha; Mandrekar, Pranoti

    2013-01-01

    Extensive research in the past decade has identified innate immune recognition receptors and intracellular signaling pathways that culminate in inflammatory responses. Besides its role in cytoprotection, the importance of cell stress in inflammation and host defense against pathogens is emerging. Recent studies have shown that proteins in cellular stress responses, including the heat shock response, ER stress response, and DNA damage response, interact with and regulate signaling intermediates involved in the activation of innate and adaptive immune responses. The effect of such regulation by cell stress proteins may dictate the inflammatory profile of the immune response during infection and disease. In this review, we describe the regulation of innate immune cell activation by cell stress pathways, present detailed descriptions of the types of stress response proteins and their crosstalk with immune signaling intermediates that are essential in host defense, and illustrate the relevance of these interactions in diseases characteristic of aberrant immune responses, such as chronic inflammatory diseases, autoimmune disorders, and cancer. Understanding the crosstalk between cellular stress proteins and immune signaling may have translational implications for designing more effective regimens to treat immune disorders. PMID:23990626

  1. SAMHD1 host restriction factor: a link with innate immune sensing of retrovirus infection.

    Science.gov (United States)

    Sze, Alexandre; Olagnier, David; Lin, Rongtuan; van Grevenynghe, Julien; Hiscott, John

    2013-12-13

    SAMHD1 [sterile alpha motif and histidine-aspartic domain (HD) containing protein 1] is the most recent addition to a unique group of host restriction factors that limit retroviral replication at distinct stages of the viral life cycle. SAMHD1 is a deoxynucleoside triphosphate triphosphohydrolase that degrades the intracellular pool of deoxynucleoside triphosphates available during early reverse transcription. SAMHD1 activity is blocked by the Vpx accessory function present in human immunodeficiency virus type 2 and SIVsm. Mutations in SAMHD1 are associated with the autoimmune disorder Aicardi-Goutières syndrome, thus emphasizing its role in regulation of the immune response. SAMHD1 antiretroviral activity is modulated by post-translational modifications, cell-cycle-dependent functions and cytokine-mediated changes. Innate receptors that sense retroviral DNA intermediates are the focus of intense study, and recent studies have established a link among SAMHD1 restriction, innate sensing of DNA and protective immune responses. Cell-cycle-dependent regulation of SAMHD1 by phosphorylation and the increasingly broad range of viruses inhibited by SAMHD1 further emphasize the importance of these mechanisms of host restriction. This review highlights current knowledge regarding SAMHD1 regulation and its impact on innate immune signaling and retroviral restriction. © 2013.

  2. Salidroside exhibits anti-dengue virus activity by upregulating host innate immune factors.

    Science.gov (United States)

    Sharma, Navita; Mishra, K P; Ganju, Lilly

    2016-12-01

    Dengue is an arboviral disease with no effective therapy available. Therefore, there is an urgent need to find a potent antiviral agent against dengue virus (DENV). In the present study, salidroside, a main bioactive compound of Rhodiola rosea, was evaluated for its antiviral potential against DENV serotype-2 infection and its effect on host innate immune factors. Antiviral effects of salidroside were examined in DENV-infected cells by western blotting, flow cytometry and real-time PCR. Its underlying mechanism involved in antiviral action was determined by evaluating expression of host innate immune factors including RIG-I, IRF-3, IRF-7, PKR, P-eIF2α and NF-κB. Salidroside potently inhibited DENV infection by decreasing DENV envelope protein expression more than tenfold. Salidroside exerts its antiviral activity by increasing expression of RNA helicases such as RIG-I, thereby initiating a downstream signaling cascade that induces upregulation of IRF-3 and IRF-7. It prevents viral protein synthesis by increasing the expression of PKR and P-eIF2α while decreasing NF-κB expression. It was also found to induce the expression of IFN-α. In addition, the number of NK cells and CD8(+) T cells were also found to be increased by salidroside treatment in human PBMCs, which are important in limiting DENV replication during early stages of infection. The findings presented here suggest that salidroside exhibits antiviral activity against DENV by inhibiting viral protein synthesis and boosting host immunity by increasing the expression of host innate immune factors and hence could be considered for the development of an effective therapeutic agent against DENV infection.

  3. The Listeria monocytogenes ChiA chitinase enhances virulence through suppression of host innate immunity.

    Science.gov (United States)

    Chaudhuri, Swarnava; Gantner, Benjamin N; Ye, Richard D; Cianciotto, Nicholas P; Freitag, Nancy E

    2013-03-19

    Environmental pathogens survive and replicate within the outside environment while maintaining the capacity to infect mammalian hosts. For some microorganisms, mammalian infection may be a relatively rare event. Understanding how environmental pathogens retain their ability to cause disease may provide insight into environmental reservoirs of disease and emerging infections. Listeria monocytogenes survives as a saprophyte in soil but is capable of causing serious invasive disease in susceptible individuals. The bacterium secretes virulence factors that promote cell invasion, bacterial replication, and cell-to-cell spread. Recently, an L. monocytogenes chitinase (ChiA) was shown to enhance bacterial infection in mice. Given that mammals do not synthesize chitin, the function of ChiA within infected animals was not clear. Here we have demonstrated that ChiA enhances L. monocytogenes survival in vivo through the suppression of host innate immunity. L. monocytogenes ΔchiA mutants were fully capable of establishing bacterial replication within target organs during the first 48 h of infection. By 72 to 96 h postinfection, however, numbers of ΔchiA bacteria diminished, indicative of an effective immune response to contain infection. The ΔchiA-associated virulence defect could be complemented in trans by wild-type L. monocytogenes, suggesting that secreted ChiA altered a target that resulted in a more permissive host environment for bacterial replication. ChiA secretion resulted in a dramatic decrease in inducible nitric oxide synthase (iNOS) expression, and ΔchiA mutant virulence was restored in NOS2(-/-) mice lacking iNOS. This work is the first to demonstrate modulation of a specific host innate immune response by a bacterial chitinase. Bacterial chitinases have traditionally been viewed as enzymes that either hydrolyze chitin as a food source or serve as a defense mechanism against organisms containing structural chitin (such as fungi). Recent evidence indicates

  4. The gut microbiota and host innate immunity: Regulators of host metabolism and metablic diseases in poultry?

    Science.gov (United States)

    The gut microbiota represents the multitudes of microbes residing in the intestine and is integral in multiple physiological processes of the host. The endogenous intestinal microflora together with other environmental factors, such as diet, play a central role in immune homeostasis. Moreover, the...

  5. Bacterial Nucleotidyl Cyclase Inhibits the Host Innate Immune Response by Suppressing TAK1 Activation.

    Science.gov (United States)

    He, Chenxi; Zhou, Yilong; Liu, Feng; Liu, Haipeng; Tan, Hao; Jin, Shouguang; Wu, Weihui; Ge, Baoxue

    2017-09-01

    Exoenzyme Y (ExoY) is a type III secretion system effector found in 90% of the Pseudomonas aeruginosa isolates. Although it is known that ExoY is a soluble nucleotidyl cyclase that increases the cytoplasmic levels of nucleoside 3',5'-cyclic monophosphates (cNMPs) to mediate endothelial Tau phosphorylation and permeability, its functional role in the innate immune response is still poorly understood. Transforming growth factor β-activated kinase 1 (TAK1) is critical for mediating Toll-like receptor (TLR) signaling and subsequent activation of NF-κB and AP-1, which are transcriptional activators of innate immunity. Here, we report that ExoY inhibits proinflammatory cytokine production through suppressing the activation of TAK1 as well as downstream NF-κB and mitogen-activated protein (MAP) kinases. Mice infected with ExoY-deficient P. aeruginosa had higher levels of tumor necrosis factor (TNF) and interleukin-6 (IL-6), more neutrophil recruitment, and a lower bacterial load in lung tissue than mice infected with wild-type P. aeruginosa Taken together, our findings identify a previously unknown mechanism by which P. aeruginosa ExoY inhibits the host innate immune response. Copyright © 2017 American Society for Microbiology.

  6. Innate immune recognition of the microbiota promotes host-microbial symbiosis.

    Science.gov (United States)

    Chu, Hiutung; Mazmanian, Sarkis K

    2013-07-01

    Pattern-recognition receptors (PRRs) are traditionally known to sense microbial molecules during infection to initiate inflammatory responses. However, ligands for PRRs are not exclusive to pathogens and are abundantly produced by the resident microbiota during normal colonization. Mechanism(s) that underlie this paradox have remained unclear. Recent studies reveal that gut bacterial ligands from the microbiota signal through PRRs to promote development of host tissue and the immune system, and protection from disease. Evidence from both invertebrate and vertebrate models reveals that innate immune receptors are required to promote long-term colonization by the microbiota. This emerging perspective challenges current models in immunology and suggests that PRRs may have evolved, in part, to mediate the bidirectional cross-talk between microbial symbionts and their hosts.

  7. Dengue virus targets the adaptor protein MITA to subvert host innate immunity.

    Directory of Open Access Journals (Sweden)

    Chia-Yi Yu

    Full Text Available Dengue is one of the most important arboviral diseases caused by infection of four serotypes of dengue virus (DEN. We found that activation of interferon regulatory factor 3 (IRF3 triggered by viral infection and by foreign DNA and RNA stimulation was blocked by DEN-encoded NS2B3 through a protease-dependent mechanism. The key adaptor protein in type I interferon pathway, human mediator of IRF3 activation (MITA but not the murine homologue MPYS, was cleaved in cells infected with DEN-1 or DEN-2 and with expression of the enzymatically active protease NS2B3. The cleavage site of MITA was mapped to LRR↓(96G and the function of MITA was suppressed by dengue protease. DEN replication was reduced with overexpression of MPYS but not with MITA, while DEN replication was enhanced by MPYS knockdown, indicating an antiviral role of MITA/MPYS against DEN infection. The involvement of MITA in DEN-triggered innate immune response was evidenced by reduction of IRF3 activation and IFN induction in cells with MITA knockdown upon DEN-2 infection. NS2B3 physically interacted with MITA, and the interaction and cleavage of MITA could be further enhanced by poly(dA:dT stimulation. Thus, we identified MITA as a novel host target of DEN protease and provide the molecular mechanism of how DEN subverts the host innate immunity.

  8. Modulation of host innate and adaptive immune defenses by cytomegalovirus: timing is everything

    Science.gov (United States)

    Loewendorf, A.; Benedict, C. A.

    2010-01-01

    Loewendorf A, Benedict CA (La Jolla Institute for Allergy and Immunology, La Jolla, CA, USA). Modulation of host innate and adaptive immune defenses by cytomegalovirus: timing is everything (Symposium). Human cytomegalovirus (HCMV) (HHV-5, a β-herpesvirus) causes the vast majority of infection-related congenital birth defects, and can trigger severe disease in immune suppressed individuals. The high prevalence of societal infection, the establishment of lifelong persistence and the growing number of immune-related diseases where HCMV is touted as a potential promoter is slowly heightening public awareness to this virus. The millions of years of co-evolution between CMV and the immune system of its host provides for a unique opportunity to study immune defense strategies, and pathogen counterstrategies. Dissecting the timing of the cellular and molecular processes that regulate innate and adaptive immunity to this persistent virus has revealed a complex defense network that is shaped by CMV immune modulation, resulting in a finely tuned host–pathogen relationship. PMID:20433576

  9. HIV Exploits Antiviral Host Innate GCN2-ATF4 Signaling for Establishing Viral Replication Early in Infection.

    Science.gov (United States)

    Jiang, Guochun; Santos Rocha, Clarissa; Hirao, Lauren A; Mendes, Erica A; Tang, Yuyang; Thompson, George R; Wong, Joseph K; Dandekar, Satya

    2017-05-02

    Antiviral innate host defenses against acute viral infections include suppression of host protein synthesis to restrict viral protein production. Less is known about mechanisms by which viral pathogens subvert host antiviral innate responses for establishing their replication and dissemination. We investigated early innate defense against human immunodeficiency virus (HIV) infection and viral evasion by utilizing human CD4 + T cell cultures in vitro and a simian immunodeficiency virus (SIV) model of AIDS in vivo Our data showed that early host innate defense against the viral infection involves GCN2-ATF4 signaling-mediated suppression of global protein synthesis, which is exploited by the virus for supporting its own replication during early viral infection and dissemination in the gut mucosa. Suppression of protein synthesis and induction of protein kinase GCN2-ATF4 signaling were detected in the gut during acute SIV infection. These changes diminished during chronic viral infection. HIV replication induced by serum deprivation in CD4 + T cells was linked to the induction of ATF4 that was recruited to the HIV long terminal repeat (LTR) to promote viral transcription. Experimental inhibition of GCN2-ATF4 signaling either by a specific inhibitor or by amino acid supplementation suppressed the induction of HIV expression. Enhancing ATF4 expression through selenium administration resulted in reactivation of latent HIV in vitro as well as ex vivo in the primary CD4 + T cells isolated from patients receiving suppressive antiretroviral therapy (ART). In summary, HIV/SIV exploits the early host antiviral response through GCN2-ATF4 signaling by utilizing ATF4 for activating the viral LTR transcription to establish initial viral replication and is a potential target for HIV prevention and therapy. IMPORTANCE Understanding how HIV overcomes host antiviral innate defense response in order to establish infection and dissemination is critical for developing prevention and

  10. Ceftaroline modulates the innate immune and host defense responses of immunocompetent cells exposed to cigarette smoke.

    Science.gov (United States)

    Bruno, A; Cipollina, C; Di Vincenzo, S; Siena, L; Dino, P; Di Gaudio, F; Gjomarkaj, M; Pace, E

    2017-09-05

    Cigarette smoke, the principal risk factor for chronic obstructive pulmonary disease (COPD), negatively influences the effectiveness of the immune system's response to a pathogen. The antibiotic ceftaroline exerts immune-modulatory effects in bronchial epithelial cells exposed to cigarette smoke. The present study aims to assess the effects of ceftaroline on TLR2 and TLR4 expression, LPS binding and TNF-α and human beta defensin (HBD2) release in an undifferentiated and PMA-differentiated human monocyte cell line (THP-1) exposed or not to cigarette smoke extracts (CSE). TLR2, TLR4, and LPS binding were assessed by flow cytometry, TNF-α and HBD2 release were evaluated by ELISA. The constitutive expression of TLR2 and TLR4 and LPS binding were higher in differentiated compared to undifferentiated THP-1 cells. In undifferentiated THP-1 cells, CSE increased TLR2 and TLR4 protein levels, LPS binding and TNF-α release and reduced HBD2 release and ceftaroline counteracted all these effects. In differentiated THP-1, CSE did not significantly affect TLR2 and TLR4 expression and LPS binding but reduced HBD2 release and increased TNF-α release. Ceftaroline counteracted the effects of CSE on HBD2 release in differentiated THP-1. Ceftaroline counteracts the effect of CSE in immune cells by increasing the effectiveness of the innate immune system. This effect may also assist in reducing pathogen activity and recurrent exacerbations in COPD patients. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. 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 gingspecificity to the innate-immune system. Netea MG, van der Graaf C, Van der Meer JW, Kullberg BJ. J Leuk... the host defense against microbial pathogens: bringingspecificity to the innate-immune system... bringingspecificity to the innate-immune system. Authors Netea MG, van der Graaf C, Van der Meer JW, Kullbe

  12. Pathobiology of Salmonella, intestinal microbiota, and the host innate immune response

    Directory of Open Access Journals (Sweden)

    Renato Lima Santos

    2014-05-01

    Full Text Available Salmonella is a relevant pathogen under a clinical and public health perspective. Therefore, there has been a significant scientific effort to learn about pathogenic determinants of this pathogen. The clinical relevance of the disease, associated with the molecular tools available to study Salmonella as well as suitable animal models for salmonellosis, have provided optimal conditions to drive the scientific community to generate a large expansion of our knowledge about the pathogenesis of Salmonella-induced enterocolitis that took place during the past two decades. This research effort has also generated a wealth of information on the host immune mechanisms that complements gaps in the fundamental research in this area. This review focus on how the interaction between Salmonella, the microbiota and intestinal innate immunity leads to disease manifestation. As a highly successful enteropathogen, Salmonella actively elicits a robust acute intestinal inflammatory response from the host, which could theoretically lead to the pathogen demise. However, Salmonella has evolved redundant molecular machineries that renders this pathogen highly adapted to the inflamed intestinal environment, in which Salmonella is capable of outcompete resident commensal organisms. The adaptation of Salmonella to the inflamed intestinal lumen associated with the massive inflammatory response that leads to diarrhea, generate perfect conditions for transmission of the pathogen. These conditions illustrate the complexity of the co-evolution and ecology of the pathogen, commensals and the host.

  13. Pathobiology of salmonella, intestinal microbiota, and the host innate immune response.

    Science.gov (United States)

    Santos, Renato Lima

    2014-01-01

    Salmonella is a relevant pathogen under a clinical and public health perspective. Therefore, there has been a significant scientific effort to learn about pathogenic determinants of this pathogen. The clinical relevance of the disease, associated with the molecular tools available to study Salmonella as well as suitable animal models for salmonellosis, have provided optimal conditions to drive the scientific community to generate a large expansion of our knowledge about the pathogenesis of Salmonella-induced enterocolitis that took place during the past two decades. This research effort has also generated a wealth of information on the host immune mechanisms that complements gaps in the fundamental research in this area. This review focus on how the interaction between Salmonella, the microbiota and intestinal innate immunity leads to disease manifestation. As a highly successful enteropathogen, Salmonella actively elicits a robust acute intestinal inflammatory response from the host, which could theoretically lead to the pathogen demise. However, Salmonella has evolved redundant molecular machineries that renders this pathogen highly adapted to the inflamed intestinal environment, in which Salmonella is capable of outcompete resident commensal organisms. The adaptation of Salmonella to the inflamed intestinal lumen associated with the massive inflammatory response that leads to diarrhea, generate perfect conditions for transmission of the pathogen. These conditions illustrate the complexity of the co-evolution and ecology of the pathogen, commensals, and the host.

  14. Burkholderia pseudomallei Differentially Regulates Host Innate Immune Response Genes for Intracellular Survival in Lung Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Kumutha Malar Vellasamy

    2016-07-01

    Full Text Available Burkholderia pseudomallei, the causative agent of melioidosis poses a serious threat to humankind. B. pseudomallei secretes numerous virulence proteins that alter host cell functions to escape from intracellular immune sensors. However, the events underlying disease pathogenesis are poorly understood.We determined the ability of B. pseudomallei to invade and survive intracellularly in A549 human lung epithelial cells, and also investigated the early transcriptional responses using an Illumina HumanHT-12 v4 microarray platform, after three hours of exposure to live B. pseudomallei (BCMS and its secreted proteins (CCMS.We found that the ability of B. pseudomallei to invade and survive intracellularly correlated with increase of multiplicity of infection and duration of contact. Activation of host carbohydrate metabolism and apoptosis as well as suppression of amino acid metabolism and innate immune responses both by live bacteria and its secreted proteins were evident. These early events might be linked to initial activation of host genes directed towards bacterial dissemination from lungs to target organs (via proposed in vivo mechanisms or to escape potential sensing by macrophages.Understanding the early responses of A549 cells toward B. pseudomallei infection provide preliminary insights into the likely pathogenesis mechanisms underlying melioidosis, and could contribute to development of novel intervention strategies to combat B. pseudomallei infections.

  15. Microbial Mitigation-Exacerbation Continuum: A novel framework for microbiome effects on hosts in the face of stress.

    Science.gov (United States)

    David, Aaron S; Thapa-Magar, Khum B; Afkhami, Michelle E

    2018-01-18

    A key challenge to understanding microbiomes and their role in ecological processes is contextualizing their effects on host organisms, particularly when faced with environmental stress. One influential theory, the Stress Gradient Hypothesis, might predict that the frequency of positive interactions increases with stressful conditions such that microbial taxa would mitigate harmful effects on host performance. Yet, equally plausible is that microbial taxa could exacerbate these effects. Here, we introduce the "Mitigation-Exacerbation Continuum" as a novel framework to conceptualize microbial mediation of stress. We (1) use this continuum to quantify microbial mediation of stress for six plant species, and (2) test the association between these continuum values and natural species abundance. We factorially manipulated a common stress (allelopathy) and the presence of soil microbes to quantify microbial effects in benign and stressed environments for two critical early life-history metrics, seed germination and seedling biomass. Although we found evidence of both mitigation and exacerbation among the six species, exacerbation was more common. Across species, the degree of microbial-mediated effects on germination explained >80% of the variation of natural field abundances. Our results suggest a critical role of soil microbes in mediating plant stress responses, and a potential microbial mechanism underlying species abundance. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  16. Spitting Image: Tick Saliva Assists the Causative Agent of Lyme Disease in Evading Host Skin's Innate Immune Response

    NARCIS (Netherlands)

    Hovius, Joppe W. R.

    2009-01-01

    Lyme disease is caused by the spirochete Borrelia burgdorferi and is transmitted through ticks. Inhibition of host skin's innate immune response might be instrumental to both tick feeding and B. burgdorferi transmission. The article by Marchal et al. describes how tick saliva suppresses B.

  17. Cross-species Virus-host Protein-Protein Interactions Inhibiting Innate Immunity

    Science.gov (United States)

    2016-07-01

    protein- protein interactions inhibiting innate immunity Distribution Statement A. Approved for public release; distribution is unlimited. July 2016...protein interactions inhibiting innate immunity Sb. GRANT NUMBER HDTRA1-13-1-0017 Sc. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER Timothy...first-line innate immunity response against viral infection. The inhibition or avoidance of this initial innate immune response is a commonly occurring

  18. The Serine Protease Autotransporter Pic Modulates Citrobacter rodentium Pathogenesis and Its Innate Recognition by the Host.

    Science.gov (United States)

    Bhullar, Kirandeep; Zarepour, Maryam; Yu, Hongbing; Yang, Hong; Croxen, Matthew; Stahl, Martin; Finlay, B Brett; Turvey, Stuart E; Vallance, Bruce A

    2015-07-01

    Bacterial pathogens produce a number of autotransporters that possess diverse functions. These include the family of serine protease autotransporters of Enterobacteriaceae (SPATEs) produced by enteric pathogens such as Shigella flexneri and enteroaggregative Escherichia coli. Of these SPATEs, one termed "protein involved in colonization," or Pic, has been shown to possess mucinase activity in vitro, but to date, its role in in vivo enteric pathogenesis is unknown. Testing a pic null (ΔpicC) mutant in Citrobacter rodentium, a natural mouse pathogen, found that the C. rodentium ΔpicC strain was impaired in its ability to degrade mucin in vitro compared to the wild type. Upon infection of mice, the ΔpicC mutant exhibited a hypervirulent phenotype with dramatically heavier pathogen burdens found in intestinal crypts. ΔpicC mutant-infected mice suffered greater barrier disruption and more severe colitis and weight loss, necessitating their euthanization between 10 and 14 days postinfection. Notably, the virulence of the ΔpicC mutant was normalized when the picC gene was restored; however, a PicC point mutant causing loss of mucinase activity did not replicate the ΔpicC phenotype. Exploring other aspects of PicC function, the ΔpicC mutant was found to aggregate to higher levels in vivo than wild-type C. rodentium. Moreover, unlike the wild type, the C. rodentium ΔpicC mutant had a red, dry, and rough (RDAR) morphology in vitro and showed increased activation of the innate receptor Toll-like receptor 2 (TLR2). Interestingly, the C. rodentium ΔpicC mutant caused a degree of pathology similar to that of wild-type C. rodentium when infecting TLR2-deficient mice, showing that despite its mucinase activity, PicC's major role in vivo may be to limit C. rodentium's stimulation of the host's innate immune system.

  19. HMGB1 exacerbates experimental mouse colitis by enhancing innate lymphoid cells 3 inflammatory responses via promoted IL-23 production.

    Science.gov (United States)

    Chen, Xiangyu; Li, Lingyun; Khan, Muhammad Noman; Shi, Lifeng; Wang, Zhongyan; Zheng, Fang; Gong, Feili; Fang, Min

    2016-11-01

    In inflammatory bowel diseases (IBD), high mobility group box 1 (HMGB1), as an endogenous inflammatory molecule, can promote inflammatory cytokines secretion by acting on TLR2/4 resulting in tissue damage. The underlying mechanisms remain unclear. Here we report a novel role of HMGB1 in controlling the maintenance and function of intestine-resident group-3 innate lymphoid cells (ILC3s) that are important innate effector cells implicated in mucosal homeostasis and IBD pathogenesis. We showed that mice treated with anti-HMGB1 Ab, or genetically deficient for TLR2 -/- or TLR4 -/- mice, displayed reduced intestinal inflammation. In these mice, the numbers of colonic ILC3s were significantly reduced, and the levels of IL-17 and IL-22 that can be secreted by ILC3s were also decreased in the colon tissues. Furthermore, HMGB1 promoted DCs via TLR2/4 signaling to produce IL-23, activating ILC3s to produce IL-17 and IL-22. Our data thus indicated that the HMGB1-TLR2/4-DCs-IL-23 cascade pathway enhances the functions of ILC3s to produce IL-17 and IL-22, and this signal way might play a vital role in the development of IBD.

  20. Scabies mite peritrophins are potential targets of human host innate immunity.

    Directory of Open Access Journals (Sweden)

    Angela Mika

    2011-09-01

    lectin pathway of the complement cascade. These initial findings indicate a novel role of scabies mite peritrophins in triggering a host innate immune response within the mite gut.

  1. Innate immune memory: towards a better understanding of host defense mechanisms

    NARCIS (Netherlands)

    Quintin, J.; Cheng, S.C.; Meer, J.W. van der; Netea, M.G.

    2014-01-01

    Innate immunity is classically defined as unable to build up immunological memory. Recently however, the assumption of the lack of immunological memory within innate immune responses has been reconsidered. Plants and invertebrates lacking adaptive immune system can be protected against secondary

  2. Innate immune memory: towards a better understanding of host defense mechanisms.

    Science.gov (United States)

    Quintin, Jessica; Cheng, Shih-Chin; van der Meer, Jos W M; Netea, Mihai G

    2014-08-01

    Innate immunity is classically defined as unable to build up immunological memory. Recently however, the assumption of the lack of immunological memory within innate immune responses has been reconsidered. Plants and invertebrates lacking adaptive immune system can be protected against secondary infections. It has been shown that mammals can build cross-protection to secondary infections independently of T-lymphocytes and B-lymphocytes. Moreover, recent studies have demonstrated that innate immune cells such as NK cells and monocytes can display adaptive characteristics, a novel concept for which the term trained immunity has been proposed. Several mechanisms are involved in mediating innate immune memory, among which epigenetic histone modifications and modulation of recognition receptors on the surface of innate immune cells are likely to play a central role. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. The Mla pathway is critical for Pseudomonas aeruginosa resistance to outer membrane permeabilization and host innate immune clearance.

    Science.gov (United States)

    Munguia, Jason; LaRock, Doris L; Tsunemoto, Hannah; Olson, Joshua; Cornax, Ingrid; Pogliano, Joseph; Nizet, Victor

    2017-10-01

    Pseudomonas aeruginosa is an important opportunistic pathogen that has become a serious problem due to increased rates of antibiotic resistance. Due to this along with a dearth in novel antibiotic development, especially against Gram-negative pathogens, new therapeutic strategies are needed to prevent a post-antibiotic era. Here, we describe the importance of the vacJ/Mla pathway in resisting bactericidal actions of the host innate immune response. P. aeruginosa tn5 transposon mutants in genes from the VacJ/Mla pathway showed increased susceptibility to killing by the host cathelicidin antimicrobial peptide, LL-37, when compared to the wild-type parent strain. The P. aeruginosa vacJ - mutant demonstrated increased membrane permeability upon damage as well as sensitivity to killing in the presence of the detergent sodium dodecyl sulfate and the divalent cation chelator EDTA. When exposed to human whole blood and serum complement, the vacJ - mutant was killed more rapidly when compared to the wild-type parent strain and complemented mutant. Finally, in an in vivo mouse lung infection model, infection with the vacJ - mutant resulted in reduced mortality, lower bacterial burden, and reduced lung damage when compared to the wild-type strain. This study highlights the potential in therapeutically targeting the VacJ/Mla pathway in sensitizing P. aeruginosa to killing by the host innate immune response. • The Mla pathway regulates outer membrane dynamics in human pathogen Pseudomonas aeruginosa (PA). • Disruption of Mla pathway gene vacJ sensitizes PA to host cathelicidin antimicrobial peptide LL-37. • Loss of vacJ expression renders PA more sensitive to human whole blood and serum killing. • Loss of vacJ expression reduces PA survival and virulence in a murine lung infection model. • The Mla pathway merits exploration as a pharmacologic target to sensitize PA to host innate immunity.

  4. Innate immune memory: Implications for host responses to damage-associated molecular patterns

    NARCIS (Netherlands)

    Crisan, T.O.; Netea, M.G.; Joosten, L.A.B.

    2016-01-01

    Cells of the innate immune system build immunological memory via epigenetic reprogramming after stimulations with microbial ligands. This functional readjustment allows for enhanced nonspecific inflammatory responses upon secondary challenges, a process termed "trained immunity." The epigenomic

  5. Innate and adaptive immunity cooperate flexibly to maintain host-microbiota mutualism.

    OpenAIRE

    Slack Emma; Hapfelmeier Siegfried; Stecher Bärbel; Velykoredko Yuliya; Stoel Maaike; Lawson Melissa A E; Geuking Markus B; Beutler Bruce; Tedder Thomas F; Hardt Wolf-Dietrich; Bercik Premysl; Verdu Elena F; McCoy Kathy D; Macpherson Andrew J

    2009-01-01

    Commensal bacteria in the lower intestine of mammals are 10 times as numerous as the body's cells. We investigated the relative importance of different immune mechanisms in limiting the spread of the intestinal microbiota. Here we reveal a flexible continuum between innate and adaptive immune function in containing commensal microbes. Mice deficient in critical innate immune functions such as Toll like receptor signaling or oxidative burst production spontaneously produce high titer serum ant...

  6. Interaction of Bovine Peripheral Blood Polymorphonuclear Cells and Leptospira Species; Innate Responses in the Natural Bovine Reservoir Host

    Science.gov (United States)

    Wilson-Welder, Jennifer H.; Frank, Ami T.; Hornsby, Richard L.; Olsen, Steven C.; Alt, David P.

    2016-01-01

    Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and can also be reservoir hosts of other Leptospira species such as L. kirschneri, and Leptospira interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murine neutrophils have shown activation of neutrophil extracellular trap or NET formation, and upregulation of inflammatory mediators by neutrophils in the presence of Leptospira. Humans, companion animals and most widely studied models of Leptospirosis are of acute infection, hallmarked by systemic inflammatory response, neutrophilia, and septicemia. In contrast, cattle exhibit chronic infection with few outward clinical signs aside from reproductive failure. Taking into consideration that there is host species variation in innate immunity, especially in pathogen recognition and response, the interaction of bovine peripheral blood polymorphonuclear cells (PMNs) and several Leptospira strains was evaluated. Studies including bovine-adapted strains, human pathogen strains, a saprophyte and inactivated organisms. Incubation of PMNs with Leptospira did induce slight activation of neutrophil NETs, greater than unstimulated cells but less than the quantity from E. coli P4 stimulated PMNs. Very low but significant from non-stimulated, levels of reactive oxygen peroxides were produced in the presence of all Leptospira strains and E. coli P4. Similarly, significant levels of reactive nitrogen intermediaries (NO2) was produced from PMNs when incubated with the Leptospira strains and greater quantities in the presence of E. coli P4. PMNs incubated with Leptospira induced RNA transcripts of IL-1β, MIP-1α, and TNF-α, with greater amounts induced by live organisms when compared to heat-inactivated leptospires. Transcript for inflammatory cytokine IL-8 was also induced, at similar levels regardless of Leptospira strain or viability. However, incubation of Leptospira strains

  7. Stress-inducible gene Atf3 in the noncancer host cells contributes to chemotherapy-exacerbated breast cancer metastasis.

    Science.gov (United States)

    Chang, Yi Seok; Jalgaonkar, Swati P; Middleton, Justin D; Hai, Tsonwin

    2017-08-22

    Chemotherapy is a double-edged sword. It is anticancer because of its cytotoxicity. Paradoxically, by increasing chemoresistance and cancer metastasis, it is also procancer. However, the underlying mechanisms for chemotherapy-induced procancer activities are not well understood. Here we describe the ability of paclitaxel (PTX), a frontline chemotherapeutic agent, to exacerbate metastasis in mouse models of breast cancer. We demonstrate that, despite the apparent benefit of reducing tumor size, PTX increased the circulating tumor cells in the blood and enhanced the metastatic burden at the lung. At the primary tumor, PTX increased the abundance of the tumor microenvironment of metastasis, a landmark microanatomical structure at the microvasculature where cancer cells enter the blood stream. At the metastatic lung, PTX improved the tissue microenvironment (the "soil") for cancer cells (the "seeds") to thrive; these changes include increased inflammatory monocytes and reduced cytotoxicity. Importantly, these changes in the primary tumor and the metastatic lung were all dependent on Atf3, a stress-inducible gene, in the noncancer host cells. Together, our data provide mechanistic insights into the procancer effect of chemotherapy, explaining its paradox in the context of the seed-and-soil theory. Analyses of public datasets suggest that our data may have relevance to human cancers. Thus, ATF3 in the host cells links a chemotherapeutic agent-a stressor-to immune modulation and cancer metastasis. Dampening the effect of ATF3 may improve the efficacy of chemotherapy.

  8. Lipooligosaccharide structure is an important determinant in the resistance of Neisseria gonorrhoeae to antimicrobial agents of innate host defense

    Directory of Open Access Journals (Sweden)

    Jacqueline T Balthazar

    2011-02-01

    Full Text Available The strict human pathogen Neisseria gonorrhoeae has caused the sexually transmitted infection termed gonorrhea for thousands of years. Over the millennia, the gonococcus has likely evolved mechanisms to evade host defense systems that operate on the genital mucosal surfaces in both males and females. Past research has shown that the presence or modification of certain cell envelope structures can significantly impact levels of gonococcal susceptibility to host-derived antimicrobial compounds that bathe genital mucosal surfaces and participate in innate host defense against invading pathogens. In order to facilitate the identification of gonococcal genes that are important in determining levels of bacterial susceptibility to mediators of innate host defense, we used the Himar I mariner in vitro mutagenesis system to construct a transposon insertion library in strain F62. As proof of principle that this strategy would be suitable for this purpose, we screened the library for mutants expressing decreased susceptibility to the bacteriolytic action of normal human serum (NHS. We found that a transposon insertion in the lgtD gene, which encodes an N-acetylgalactosamine transferase involved in the extension of the α-chain of lipooligosaccharide (LOS, could confer decreased susceptibility of strain F62 to complement-mediated killing by NHS. By complementation and chemical analyses, we demonstrated both linkage of the transposon insertion to the NHS-resistance phenotype and chemical changes in LOS structure that resulted from loss of LgtD production. Further truncation of the LOS α-chain or loss of phosphoethanolamine (PEA from the lipid A region of LOS also impacted levels of NHS-resistance. PEA decoration of lipid A also increased gonococcal resistance to the model cationic antimicrobial polymyxin B. Taken together, we conclude that the Himar I mariner in vitro mutagenesis procedure can facilitate studies on structures involved in gonococcal

  9. New concepts in immunity to Neisseria gonorrhoeae: innate responses and suppression of adaptive immunity favor the pathogen, not the host

    Directory of Open Access Journals (Sweden)

    Yingru eLiu

    2011-03-01

    Full Text Available It is well known that gonorrhea can be acquired repeatedly with no apparent development of protective immunity arising from previous episodes of infection. Symptomatic infection is characterized by a purulent exudate, but the host response mechanisms are poorly understood. While the remarkable antigenic variability displayed by Neisseria gonorrhoeae and its capacity to inhibit complement activation allow it to evade destruction by the host’s immune defenses, we propose that it also has the capacity to avoid inducing specific immune responses. In a mouse model of vaginal gonococcal infection, N. gonorrhoeae elicits Th17-driven inflammatory- immune responses, which recruit innate defense mechanisms including an influx of neutrophils. Concomitantly, N. gonorrhoeae suppresses Th1- and Th2-dependent adaptive immunity, including specific antibody responses, through a mechanism involving TGF-β and regulatory T cells. Blockade of TGF-β alleviates the suppression of specific anti-gonococcal responses and allows Th1 and Th2 responses to emerge with the generation of immune memory and protective immunity. Genital tract tissues are naturally rich in TGF-β, which fosters an immunosuppressive environment that is important in reproduction. In exploiting this niche, N. gonorrhoeae exemplifies a well-adapted pathogen that proactively elicits from its host innate responses that it can survive and concomitantly suppresses adaptive immunity. Comprehension of these mechanisms of gonococcal pathogenesis should allow the development of novel approaches to therapy and facilitate the development of an effective vaccine.

  10. The role of innate Immunity and host specificity in Salmonella infection in vitro

    OpenAIRE

    Walk, Nicole

    2012-01-01

    Salmonella serovars are important zoonotic pathogens, and can cause severe infections in both humans and animals. In the study presented here, comparative in vitro infection studies were performed in two, established cell types (epithelia and macrophage) derived from three different host species origins (porcine, murine and human). Both host-adapted and broad host-range S. enterica spp. enterica serovars (S. Typhimurium, S. Choleraesius, S. Dublin und S. Enteritidis) were used for the infecti...

  11. Interaction of bovine peripheral blood polymorphonuclear cells and Leptospira species; innate responses in the natural bovine reservoir host.

    Directory of Open Access Journals (Sweden)

    Jennifer H Wilson-Welder

    2016-07-01

    Full Text Available Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and can also be reservoir hosts of other Leptospira species such as L. kirschneri, and L. interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murine neutrophils have shown activation of neutrophil extracellular trap or NET formation, and upregulation of inflammatory mediators by neutrophils in the presence of Leptospira. Humans, companion animals and most widely studied models of Leptospirosis are of acute infection, hallmarked by systemic inflammatory response, neutrophilia and septicemia. In contrast, cattle exhibit chronic infection with few outward clinical signs aside from reproductive failure. Taking into consideration that there is host species variation in innate immunity, especially in pathogen recognition and response, the interaction of bovine peripheral blood polymorphonuclear cells (PMNs and several Leptospira strains was evaluated. Studies including bovine-adapted strains, human pathogen strains, a saprophyte and inactivated organisms. Incubation of PMNs with Leptospira did induce slight activation of neutrophil NETs, greater than unstimulated cells but less than the quantity from E. coli P4 stimulated PMNs. Very low but significant from non-stimulated, levels of reactive oxygen peroxides were produced in the presence of all Leptospira strains and E. coli P4. Similarly, significant levels of reactive nitrogen intermediaries (NO2 was produced from PMNs when incubated with the Leptospira strains and greater quantities in the presence of E. coli P4. PMNs incubated with Leptospira induced RNA transcripts of IL-1β, MIP-1α, and TNF-α, with greater amounts induced by live organisms when compared to heat-inactivated leptospires. Transcript for inflammatory cytokine IL-8 was also induced, at similar levels regardless of Leptospira strain or viability. However, incubation of

  12. A Systems Biology Approach to the Coordination of Defensive and Offensive Molecular Mechanisms in the Innate and Adaptive Host-Pathogen Interaction Networks.

    Science.gov (United States)

    Wu, Chia-Chou; Chen, Bor-Sen

    2016-01-01

    Infected zebrafish coordinates defensive and offensive molecular mechanisms in response to Candida albicans infections, and invasive C. albicans coordinates corresponding molecular mechanisms to interact with the host. However, knowledge of the ensuing infection-activated signaling networks in both host and pathogen and their interspecific crosstalk during the innate and adaptive phases of the infection processes remains incomplete. In the present study, dynamic network modeling, protein interaction databases, and dual transcriptome data from zebrafish and C. albicans during infection were used to infer infection-activated host-pathogen dynamic interaction networks. The consideration of host-pathogen dynamic interaction systems as innate and adaptive loops and subsequent comparisons of inferred innate and adaptive networks indicated previously unrecognized crosstalk between known pathways and suggested roles of immunological memory in the coordination of host defensive and offensive molecular mechanisms to achieve specific and powerful defense against pathogens. Moreover, pathogens enhance intraspecific crosstalk and abrogate host apoptosis to accommodate enhanced host defense mechanisms during the adaptive phase. Accordingly, links between physiological phenomena and changes in the coordination of defensive and offensive molecular mechanisms highlight the importance of host-pathogen molecular interaction networks, and consequent inferences of the host-pathogen relationship could be translated into biomedical applications.

  13. TNF-dependent regulation and activation of innate immune cells are essential for host protection against cerebral tuberculosis.

    Science.gov (United States)

    Francisco, Ngiambudulu M; Hsu, Nai-Jen; Keeton, Roanne; Randall, Philippa; Sebesho, Boipelo; Allie, Nasiema; Govender, Dhirendra; Quesniaux, Valerie; Ryffel, Bernhard; Kellaway, Lauriston; Jacobs, Muazzam

    2015-06-26

    Tuberculosis (TB) affects one third of the global population, and TB of the central nervous system (CNS-TB) is the most severe form of tuberculosis which often associates with high mortality. The pro-inflammatory cytokine tumour necrosis factor (TNF) plays a critical role in the initial and long-term host immune protection against Mycobacterium tuberculosis (M. tuberculosis) which involves the activation of innate immune cells and structure maintenance of granulomas. However, the contribution of TNF, in particular neuron-derived TNF, in the control of cerebral M. tuberculosis infection and its protective immune responses in the CNS were not clear. We generated neuron-specific TNF-deficient (NsTNF(-/-)) mice and compared outcomes of disease against TNF(f/f) control and global TNF(-/-) mice. Mycobacterial burden in brains, lungs and spleens were compared, and cerebral pathology and cellular contributions analysed by microscopy and flow cytometry after M. tuberculosis infection. Activation of innate immune cells was measured by flow cytometry and cell function assessed by cytokine and chemokine quantification using enzyme-linked immunosorbent assay (ELISA). Intracerebral M. tuberculosis infection of TNF(-/-) mice rendered animals highly susceptible, accompanied by uncontrolled bacilli replication and eventual mortality. In contrast, NsTNF(-/-) mice were resistant to infection and presented with a phenotype similar to that in TNF(f/f) control mice. Impaired immunity in TNF(-/-) mice was associated with altered cytokine and chemokine synthesis in the brain and characterised by a reduced number of activated innate immune cells. Brain pathology reflected enhanced inflammation dominated by neutrophil influx. Our data show that neuron-derived TNF has a limited role in immune responses, but overall TNF production is necessary for protective immunity against CNS-TB.

  14. Individual Members of the Microbiota Disproportionately Modulate Host Innate Immune Responses.

    Science.gov (United States)

    Rolig, Annah S; Parthasarathy, Raghuveer; Burns, Adam R; Bohannan, Brendan J M; Guillemin, Karen

    2015-11-11

    Predicting host health status based on microbial community structure is a major goal of microbiome research. An implicit assumption of microbiome profiling for diagnostic purposes is that the proportional representation of different taxa determine host phenotypes. To test this assumption, we colonized gnotobiotic zebrafish with zebrafish-derived bacterial isolates and measured bacterial abundance and host neutrophil responses. Surprisingly, combinations of bacteria elicited immune responses that do not reflect the numerically dominant species. These data are consistent with a quantitative model in which the host responses to commensal species are additive but where various species have different per capita immunostimulatory effects. For example, one species has a high per capita immunosuppression that is mediated through a potent secreted factor. We conclude that the proportional representation of bacteria in a community does not necessarily predict its functional capacities; however, characterizing specific properties of individual species offers predictive insights into multi-species community function. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Differences in Host Innate Responses among Coccidioides Isolates in a Murine Model of Pulmonary Coccidioidomycosis.

    Science.gov (United States)

    Lewis, Eric R G; David, Victoria R; Doyle, Adina L; Rajabi, Khadijeh; Kiefer, Jeffrey A; Pirrotte, Patrick; Barker, Bridget M

    2015-10-01

    Coccidioides immitis and Coccidioides posadasii are soil-dwelling fungi and the causative agents of coccidioidomycosis, a mycosis endemic to certain semiarid regions in the Americas. The most common route of infection is by inhalation of airborne Coccidioides arthroconidia. Once a susceptible host inhales the conidia, a transition to mature endosporulated spherules can occur within the first 5 days of infection. For this study, we examined the host response in a murine model of coccidioidomycosis during a time period of infection that has not been well characterized. We collected lung tissue and bronchoalveolar lavage fluid (BALF) from BALB/c mice that were infected with a C. immitis pure strain, a C. immitis hybrid strain, or a C. posadasii strain as well as uninfected mice. We compared the host responses to the Coccidioides strains used in this study by assessing the level of transcription of selected cytokine genes in lung tissues and characterized host and fungal proteins present in BALF. Host response varied depending on the Coccidioides strain that was used and did not appear to be overly robust. This study provides a foundation to begin to dissect the host immune response early in infection, to detect abundant Coccidioides proteins, and to develop diagnostics that target these early time points of infection. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Comparison of innate and Th1-type host immune responses inOesophagostomum dentatumandTrichuris suisinfections in pigs

    DEFF Research Database (Denmark)

    Andreasen, Annette; Skovgaard, Kerstin; Klaver, Elsenoor J.

    2016-01-01

    The present study investigated details of the innate and Th1/Treg type associated host immune responses in Trichuris suis and Oesophagostomum dentatum mono- and co-infected pigs and in vitro in stimulated porcine dendritic cell cultures. Forty-eight pigs were allocated into a 2-factorial design...... with two groups trickle inoculated with 10 T. suis eggs/kg/day (Group T) or 20 O. dentatum L3/kg/day (O). Another group (OT) was infected with both parasites. Group C remained uninfected. Expression of innate and Th1/Treg cell associated genes in gut mucosa and associated lymph nodes was determined by q......PCR at necropsy day 35 and 71. Gene expression showed suppressed/inhibited Th1 and Treg type immune reactions, in accordance with previous findings of a predominant Th2 type immune response to both nematodes. The in vitro part examined production of TNF-α in porcine dendritic cells (DC) exposed to T. suis and...

  17. The Human Cytomegalovirus Major Immediate-Early Proteins as Antagonists of Intrinsic and Innate Antiviral Host Responses

    Directory of Open Access Journals (Sweden)

    Michael Nevels

    2009-11-01

    Full Text Available The major immediate-early (IE gene of human cytomegalovirus (CMV is believed to have a decisive role in acute infection and its activity is an important indicator of viral reactivation from latency. Although a variety of gene products are expressed from this region, the 72-kDa IE1 and the 86-kDa IE2 nuclear phosphoproteins are the most abundant and important. Both proteins have long been recognized as promiscuous transcriptional regulators. More recently, a critical role of the IE1 and IE2 proteins in counteracting nonadaptive host cell defense mechanisms has been revealed. In this review we will briefly summarize the available literature on IE1- and IE2-dependent mechanisms contributing to CMV evasion from intrinsic and innate immune responses.

  18. Achyrocline satureioides (Lam. D.C. Hydroalcoholic Extract Inhibits Neutrophil Functions Related to Innate Host Defense

    Directory of Open Access Journals (Sweden)

    Eric Diego Barioni

    2013-01-01

    Full Text Available Achyrocline satureioides (Lam. D.C. is a herb native to South America, and its inflorescences are popularly employed to treat inflammatory diseases. Here, the effects of the in vivo actions of the hydroalcoholic extract obtained from inflorescences of A. satureioides on neutrophil trafficking into inflamed tissue were investigated. Male Wistar rats were orally treated with A. satureioides extract, and inflammation was induced one hour later by lipopolysaccharide injection into the subcutaneous tissue. The number of leukocytes and the amount of chemotactic mediators were quantified in the inflammatory exudate, and adhesion molecule and toll-like receptor 4 (TLR-4 expressions and phorbol-myristate-acetate- (PMA- stimulated oxidative burst were quantified in circulating neutrophils. Leukocyte-endothelial interactions were quantified in the mesentery tissue. Enzymes and tissue morphology of the liver and kidney were evaluated. Treatment with A. satureioides extract reduced neutrophil influx and secretion of leukotriene B4 and CINC-1 in the exudates, the number of rolling and adhered leukocytes in the mesentery postcapillary venules, neutrophil L-selectin, β2-integrin and TLR-4 expression, and oxidative burst, but did not cause an alteration in the morphology and activities of liver and kidney. Together, the data show that A. satureioides extract inhibits neutrophil functions related to the innate response and does not cause systemic toxicity.

  19. Innate immune recognition of the microbiota promotes host-microbial symbiosis

    OpenAIRE

    Chu, Hiutung; Mazmanian, Sarkis K.

    2013-01-01

    Pattern recognition receptors (PRRs) are traditionally known to recognize microbial molecules during infection to initiate inflammatory responses. However, ligands for PRRs are not exclusive to pathogens, and are abundantly produced by the resident microbiota during normal colonization. Mechanism(s) that underlie this paradox have remained unclear. Recent studies reveal that gut bacterial ligands from the microbiota signal through PRRs to promote host tissue and immune development, and protec...

  20. Asynchrony between Host Plant and Insects-Defoliator within a Tritrophic System: The Role of Herbivore Innate Immunity.

    Directory of Open Access Journals (Sweden)

    Vyacheslav V Martemyanov

    Full Text Available The effects of asynchrony in the phenology of spring-feeding insect-defoliators and their host plants on insects' fitness, as well as the importance of this effect for the population dynamics of outbreaking species of insects, is a widespread and well-documented phenomenon. However, the spreading of this phenomenon through the food chain, and especially those mechanisms operating this spreading, are still unclear. In this paper, we study the effect of seasonally declined leafquality (estimated in terms of phenolics and nitrogen content on herbivore fitness, immune parameters and resistance against pathogen by using the silver birch Betula pendula--gypsy moth Lymantria dispar--nucleopolyhedrovirus as the tritrophic system. We show that a phenological mismatch induced by the delay in the emergence of gypsy moth larvae and following feeding on mature leaves has negative effects on the female pupal weight, on the rate of larval development and on the activity of phenoloxidase in the plasma of haemolymph. In addition, the larval susceptibility to exogenous nucleopolyhydrovirus infection as well as covert virus activation were both enhanced due to the phenological mismatch. The observed effects of phenological mismatch on insect-baculovirus interaction may partially explain the strong and fast fluctuations in the population dynamics of the gypsy moth that is often observed in the studied part of the defoliator area. This study also reveals some indirect mechanisms of effect related to host plant quality, which operate through the insect innate immune status and affect resistance to both exogenous and endogenous virus.

  1. HDAC Inhibitor Panobinostat Engages Host Innate Immune Defenses to Promote the Tumoricidal Effects of Trastuzumab in HER2(+) Tumors.

    Science.gov (United States)

    Medon, Mikolaj; Vidacs, Eva; Vervoort, Stephin J; Li, Jason; Jenkins, Misty R; Ramsbottom, Kelly M; Trapani, Joseph A; Smyth, Mark J; Darcy, Phillip K; Atadja, Peter W; Henderson, Michael A; Johnstone, Ricky W; Haynes, Nicole M

    2017-05-15

    Histone deacetylase inhibitors (HDACi) may engage host immunity as one basis for their antitumor effects. Herein, we demonstrate an application of this concept using the HDACi panobinostat to augment the antitumor efficacy of trastuzumab (anti-HER2) therapy, through both tumor cell autonomous and nonautonomous mechanisms. In HER2(+) tumors that are inherently sensitive to the cytostatic effects of trastuzumab, cotreatment with panobinostat abrogated AKT signaling and triggered tumor regression in mice that lacked innate and/or adaptive immune effector cells. However, the cooperative ability of panobinostat and trastuzumab to harness host anticancer immune defenses was essential for their curative activity in trastuzumab-refractory HER2(+) tumors. In trastuzumab-resistant HER2(+) AU565(pv) xenografts and BT474 tumors expressing constitutively active AKT, panobinostat enhanced the antibody-dependent cell-mediated cytotoxicity function of trastuzumab. IFNγ-mediated, CXCR3-dependent increases in tumor-associated NK cells underpinned the combined curative activity of panobinostat and trastuzumab in these tumors. These data highlight the immune-enhancing effects of panobinostat and provide compelling evidence that this HDACi can license trastuzumab to evoke NK-cell-mediated responses capable of eradicating trastuzumab-refractory HER2(+) tumors. Cancer Res; 77(10); 2594-606. ©2017 AACR. ©2017 American Association for Cancer Research.

  2. An evolutionary history of defensins: a role for copy number variation in maximizing host innate and adaptive immune responses.

    Directory of Open Access Journals (Sweden)

    Lee R Machado

    2015-03-01

    Full Text Available Defensins represent an evolutionary ancient family of antimicrobial peptides that play diverse roles in human health and disease. Defensins are cationic cysteine-containing multifunctional peptides predominantly expressed by epithelial cells or neutrophils. Defensins play a key role in host innate immune responses to infection and, in addition to their classically described role as antimicrobial peptides, have also been implicated in immune modulation, fertility, development and wound healing. Aberrant expression of defensins is important in a number of inflammatory diseases as well as modulating host immune responses to bacteria, unicellular pathogens and viruses. In parallel with their role in immunity, in other species, defensins have evolved alternative functions, including the control of coat color in dogs. Defensin genes reside in complex genomic regions that are prone to structural variations and some defensin family members exhibit copy number variation (CNV. Structural variations have mediated, and continue to influence, the diversification and expression of defensin family members. This review highlights the work currently being done to better understand the genomic architecture of the β-defensin locus. It evaluates current evidence linking defensin copy number variation to autoimmune disease (i.e. Crohn’s disease and psoriasis as well as the contribution CNV has in influencing immune responses to HIV infection.

  3. Clostridium difficile modulates host innate immunity via toxin-independent and dependent mechanism(s.

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    Nazila V Jafari

    Full Text Available Clostridium difficile infection (CDI is the leading cause of hospital and community-acquired antibiotic-associated diarrhoea and currently represents a significant health burden. Although the role and contribution of C. difficile toxins to disease pathogenesis is being increasingly understood, at present other facets of C. difficile-host interactions, in particular, bacterial-driven effects on host immunity remain less studied. Using an ex-vivo model of infection, we report that the human gastrointestinal mucosa elicits a rapid and significant cytokine response to C. difficile. Marked increase in IFN-γ with modest increase in IL-22 and IL-17A was noted. Significant increase in IL-8 suggested potential for neutrophil influx while presence of IL-12, IL-23, IL-1β and IL-6 was indicative of a cytokine milieu that may modulate subsequent T cell immunity. Majority of C. difficile-driven effects on murine bone-marrow-derived dendritic cell (BMDC activation were toxin-independent; the toxins were however responsible for BMDC inflammasome activation. In contrast, human monocyte-derived DCs (mDCs released IL-1β even in the absence of toxins suggesting host-specific mediation. Infected DC-T cell crosstalk revealed the ability of R20291 and 630 WT strains to elicit a differential DC IL-12 family cytokine milieu which culminated in significantly greater Th1 immunity in response to R20291. Interestingly, both strains induced a similar Th17 response. Elicitation of mucosal IFN-γ/IL-17A and Th1/Th17 immunity to C. difficile indicates a central role for this dual cytokine axis in establishing antimicrobial immunity to CDI.

  4. Innate Immunity Correlates with Host Fitness in Wild Boar (Sus scrofa) Exposed to Classical Swine Fever

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    Rossi, Sophie; Doucelin, Anaïs; Le Potier, Marie-Frédérique; Eraud, Cyril; Gilot-Fromont, Emmanuelle

    2013-01-01

    Constitutive humoral immunity (CHI) is thought to be a first-line of protection against pathogens invading vertebrate hosts. However, clear evidence that CHI correlates with host fitness in natural conditions is still lacking. This study explores the relationship between CHI, measured using a haemagglutination-haemolysis assay (HAHL), and resistance to classical swine fever virus (CSFV) among wild boar piglets. The individual dynamics of HAHL during piglet growth was analysed, using 423 serum samples from 92 piglets repeatedly captured in the absence of CSFV (in 2006) within two areas showing contrasting food availability. Natural antibody levels increased with age, but, in the youngest piglets antibody levels were higher in individuals from areas with the highest food availability. Complement activity depended on natural antibody levels and piglets' body condition. In the presence of CSFV (i.e., in 2005 within one area), serum samples from piglets that were repeatedly captured were used to assess whether piglet HAHL levels affected CSFV status at a later capture. The correlation between CHI and resistance to CSFV was tested using 79 HAHL measures from 23 piglets captured during a CSFV outbreak. Both natural antibodies and complement activity levels measured at a given time correlated negatively to the subsequent probability of becoming viremic. Finally, capture-mark-recapture models showed that piglets with medium/high average complement activity, independently of their age, were significantly less at risk of becoming viremic and more likely to develop a specific immune response than piglets with low complement activity. Additionally, piglets with high average complement activity showed the highest survival prospects. This study provides evidence linking CHI to individual fitness within a natural mammal population. The results also highlight the potential of HAHL assays to explore the dynamics and co-evolution between wildlife mammal hosts and blood

  5. Transcriptional responses of Leptospira interrogans to host innate immunity: significant changes in metabolism, oxygen tolerance, and outer membrane.

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    Feng Xue

    Full Text Available BACKGROUND: Leptospira interrogans is the major causative agent of leptospirosis. Phagocytosis plays important roles in the innate immune responses to L. interrogans infection, and L. interrogans can evade the killing of phagocytes. However, little is known about the adaptation of L. interrogans during this process. METHODOLOGY/PRINCIPAL FINDINGS: To better understand the interaction of pathogenic Leptospira and innate immunity, we employed microarray and comparative genomics analyzing the responses of L. interrogans to macrophage-derived cells. During this process, L. interrogans altered expressions of many genes involved in carbohydrate and lipid metabolism, energy production, signal transduction, transcription and translation, oxygen tolerance, and outer membrane proteins. Among them, the catalase gene expression was significantly up-regulated, suggesting it may contribute to resisting the oxidative pressure of the macrophages. The expressions of several major outer membrane protein (OMP genes (e.g., ompL1, lipL32, lipL41, lipL48 and ompL47 were dramatically down-regulated (10-50 folds, consistent with previous observations that the major OMPs are differentially regulated in vivo. The persistent down-regulations of these major OMPs were validated by immunoblotting. Furthermore, to gain initial insight into the gene regulation mechanisms in L. interrogans, we re-defined the transcription factors (TFs in the genome and identified the major OmpR TF gene (LB333 that is concurrently regulated with the major OMP genes, suggesting a potential role of LB333 in OMPs regulation. CONCLUSIONS/SIGNIFICANCE: This is the first report on global responses of pathogenic Leptospira to innate immunity, which revealed that the down-regulation of the major OMPs may be an immune evasion strategy of L. interrogans, and a putative TF may be involved in governing these down-regulations. Alterations of the leptospiral OMPs up interaction with host antigen

  6. Transcriptional responses of Leptospira interrogans to host innate immunity: significant changes in metabolism, oxygen tolerance, and outer membrane.

    Science.gov (United States)

    Xue, Feng; Dong, Haiyan; Wu, Jinyu; Wu, Zuowei; Hu, Weilin; Sun, Aihua; Troxell, Bryan; Yang, X Frank; Yan, Jie

    2010-10-26

    Leptospira interrogans is the major causative agent of leptospirosis. Phagocytosis plays important roles in the innate immune responses to L. interrogans infection, and L. interrogans can evade the killing of phagocytes. However, little is known about the adaptation of L. interrogans during this process. To better understand the interaction of pathogenic Leptospira and innate immunity, we employed microarray and comparative genomics analyzing the responses of L. interrogans to macrophage-derived cells. During this process, L. interrogans altered expressions of many genes involved in carbohydrate and lipid metabolism, energy production, signal transduction, transcription and translation, oxygen tolerance, and outer membrane proteins. Among them, the catalase gene expression was significantly up-regulated, suggesting it may contribute to resisting the oxidative pressure of the macrophages. The expressions of several major outer membrane protein (OMP) genes (e.g., ompL1, lipL32, lipL41, lipL48 and ompL47) were dramatically down-regulated (10-50 folds), consistent with previous observations that the major OMPs are differentially regulated in vivo. The persistent down-regulations of these major OMPs were validated by immunoblotting. Furthermore, to gain initial insight into the gene regulation mechanisms in L. interrogans, we re-defined the transcription factors (TFs) in the genome and identified the major OmpR TF gene (LB333) that is concurrently regulated with the major OMP genes, suggesting a potential role of LB333 in OMPs regulation. This is the first report on global responses of pathogenic Leptospira to innate immunity, which revealed that the down-regulation of the major OMPs may be an immune evasion strategy of L. interrogans, and a putative TF may be involved in governing these down-regulations. Alterations of the leptospiral OMPs up interaction with host antigen-presenting cells (APCs) provide critical information for selection of vaccine candidates. In

  7. CD36 is essential for regulation of the host innate response to Staphylococcus aureus alpha-toxin-mediated dermonecrosis

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    Castleman, Moriah J.; Febbraio, Maria; Hall, Pamela R.

    2015-01-01

    Staphylococcus aureus is the primary cause of skin and skin structure infections (SSSI) in the USA. Alpha-hemolysin (Hla), a pore-forming toxin secreted by S. aureus and a major contributor to tissue necrosis, prompts recruitment of neutrophils critical for host defense against S. aureus infections. However, the failure to clear apoptotic neutrophils can result in damage to host tissues, suggesting that mechanisms of neutrophil clearance are essential to limiting Hla-mediated dermonecrosis. We hypothesized that CD36, a scavenger receptor which facilitates recognition of apoptosing cells, would play a significant role in regulating Hla-mediated inflammation and tissue injury during S. aureus SSSI. Here we show that CD36 on macrophages negatively regulates dermonecrosis caused by Hla-producing S. aureus. This regulation is independent of bacterial burden, as CD36 also limits dermonecrosis caused by intoxication with sterile bacterial supernatant or purified Hla. Dermonecrotic lesions of supernatant intoxicated CD36−/− mice are significantly larger, with increased neutrophil accumulation and IL-1β expression, compared to CD36+/+ (wild-type) mice. Neutrophil depletion of CD36−/− mice prevents this phenotype, demonstrating the contribution of neutrophils to tissue injury in this model. Furthermore, administration of CD36+/+, but not CD36−/−, macrophages near the site of intoxication reduces dermonecrosis, IL-1β production and neutrophil accumulation to levels seen in wild-type mice. This therapeutic effect is reversed by inhibiting actin polymerization in the CD36+/+ macrophages, supporting a mechanism of action whereby CD36-dependent macrophage phagocytosis of apoptotic neutrophils regulates Hla-mediated dermonecrosis. Together, these data demonstrate that CD36 is essential for controlling the host innate response to S. aureus skin infection. PMID:26223653

  8. Lipid Bodies: Inflammatory Organelles Implicated in Host-Trypanosoma cruzi Interplay during Innate Immune Responses

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    Heloisa D'Avila

    2012-01-01

    Full Text Available The flagellated protozoa Trypanosoma cruzi is the causal agent of Chagas' disease, a significant public health issue and still a major cause of morbidity and mortality in Latin America. Acute Chagas' disease elicits a strong inflammatory response. In order to control the parasite multiplication, cells of the monocytic lineage are highly mobilized. Monocyte differentiation leads to the formation of phagocytosing macrophages, which are strongly activated and direct host defense. A distinguishing feature of Chagas' disease-triggered macrophages is the presence of increased numbers of distinct cytoplasmic organelles termed lipid bodies or lipid droplets. These organelles are actively formed in response to the parasite and are sites for synthesis and storage of inflammatory mediators. This review covers current knowledge on lipid bodies elicited by the acute Chagas' disease within inflammatory macrophages and discusses the role of these organelles in inflammation. The increased knowledge of lipid bodies in pathogenic mechanisms of infections may not only contribute to the understanding of pathogen-host interactions but may also identify new targets for intervention.

  9. Modulation of Host Immunity by Human Respiratory Syncytial Virus Virulence Factors: A Synergic Inhibition of Both Innate and Adaptive Immunity

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    Gisela Canedo-Marroquín

    2017-08-01

    Full Text Available The Human Respiratory Syncytial Virus (hRSV is a major cause of acute lower respiratory tract infections (ARTIs and high rates of hospitalizations in children and in the elderly worldwide. Symptoms of hRSV infection include bronchiolitis and pneumonia. The lung pathology observed during hRSV infection is due in part to an exacerbated host immune response, characterized by immune cell infiltration to the lungs. HRSV is an enveloped virus, a member of the Pneumoviridae family, with a non-segmented genome and negative polarity-single RNA that contains 10 genes encoding for 11 proteins. These include the Fusion protein (F, the Glycoprotein (G, and the Small Hydrophobic (SH protein, which are located on the virus surface. In addition, the Nucleoprotein (N, Phosphoprotein (P large polymerase protein (L part of the RNA-dependent RNA polymerase complex, the M2-1 protein as a transcription elongation factor, the M2-2 protein as a regulator of viral transcription and (M protein all of which locate inside the virion. Apart from the structural proteins, the hRSV genome encodes for the non-structural 1 and 2 proteins (NS1 and NS2. HRSV has developed different strategies to evade the host immunity by means of the function of some of these proteins that work as virulence factors to improve the infection in the lung tissue. Also, hRSV NS-1 and NS-2 proteins have been shown to inhibit the activation of the type I interferon response. Furthermore, the hRSV nucleoprotein has been shown to inhibit the immunological synapsis between the dendritic cells and T cells during infection, resulting in an inefficient T cell activation. Here, we discuss the hRSV virulence factors and the host immunological features raised during infection with this virus.

  10. Inhibition of antiviral innate immunity by birnavirus VP3 protein via blockage of viral double-stranded RNA binding to the host cytoplasmic RNA detector MDA5.

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    Ye, Chengjin; Jia, Lu; Sun, Yanting; Hu, Boli; Wang, Lun; Lu, Xingmeng; Zhou, Jiyong

    2014-10-01

    Chicken MDA5 (chMDA5), the sole known pattern recognition receptor for cytoplasmic viral RNA in chickens, initiates type I interferon (IFN) production. Infectious bursal disease virus (IBDV) evades host innate immunity, but the mechanism is unclear. We report here that IBDV inhibited antiviral innate immunity via the chMDA5-dependent signaling pathway. IBDV infection did not induce efficient type I interferon (IFN) production but antagonized the antiviral activity of beta interferon (IFN-β) in DF-1 cells pretreated with IFN-α/β. Dual-luciferase assays and inducible expression systems demonstrated that IBDV protein VP3 significantly inhibited IFN-β expression stimulated by naked IBDV genomic double-stranded RNA (dsRNA). The VP3 protein competed strongly with chMDA5 to bind IBDV genomic dsRNA in vitro and in vivo, and VP3 from other birnaviruses also bound dsRNA. Site-directed mutagenesis confirmed that deletion of the VP3 dsRNA binding domain restored IFN-β expression. Our data demonstrate that VP3 inhibits antiviral innate immunity by blocking binding of viral genomic dsRNA to MDA5. MDA5, a known pattern recognition receptor and cytoplasmic viral RNA sensor, plays a critical role in host antiviral innate immunity. Many pathogens escape or inhibit the host antiviral immune response, but the mechanisms involved are unclear for most pathogens. We report here that birnaviruses inhibit host antiviral innate immunity via the MDA5-dependent signaling pathway. The antiviral innate immune system involving IFN-β did not function effectively during birnavirus infection, and the viral protein VP3 significantly inhibited IFN-β expression stimulated by naked viral genomic dsRNA. We also show that VP3 blocks MDA5 binding to viral genomic dsRNA in vitro and in vivo. Our data reveal that birnavirus-encoded viral protein VP3 is an inhibitor of the antiviral innate immune response and inhibits the antiviral innate immune response via the MDA5-dependent signaling pathway

  11. Modulation of Innate Host Factors by Mycobacterium avium Complex in Human Macrophages Includes Interleukin 17

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    Vázquez, Nancy; Rekka, Sofia; Gliozzi, Maria; Feng, Carl G.; Amarnath, Shoba; Orenstein, Jan M.; Wahl, Sharon M.

    2012-01-01

    Background. Although opportunistic infections due to Mycobacterium avium complex (MAC) have been less common since the introduction of highly active antiretroviral therapy, globally, human immunodeficiency virus-1 (HIV-1)–positive patients remain predisposed to these infections. Absence of a properly functioning acquired immune response allows MAC persistence within macrophages localized in lymph nodes coinfected with HIV and MAC. Although a deficiency in interferon γ appears to play a part in the ability of MAC to deflect the macrophage-associated antimicrobial attack, questions about this process remain. Our study examines the ability of MAC to regulate interleukin 17 (IL-17), a proinflammatory cytokine involved in host cell recruitment. Methods. Coinfected lymph nodes were examined for IL-17 by immunohistochemical analysis. In vitro, macrophages exposed to mycobacteria were evaluated for transcription activities, proteins, and signaling pathways responsible for IL-17 expression. Infected macrophages were also analyzed for expression of interleukin 21 (IL-21) and negative regulators of immune responses. Results. Infection of macrophages triggered synthesis of IL-17, correlating with IL-17 expression by macrophages in coinfected lymph nodes. Infected macrophages exposed to exogenous IL-17 expressed CXCL10, which favors recruitment of new macrophages as targets for infection. Blockade of nuclear factor κ-light-chain-enhancer of activated B cells and mitogen-activated protein kinase pathways suppressed mycobacteria-induced IL-17 expression. MAC triggered expression of IL-21, IRF4, and STAT3 genes related to IL-17 regulation, as well as expression of the negative immunoregulators CD274(PD-L1) and suppressors of cytokine signaling. Conclusions. MAC-infected macrophages can provide an alternative source for IL-17 that favors accumulation of new targets for perpetuating bacterial and viral infection while suppressing host antimicrobial immune responses. PMID

  12. Innate immunity kinase TAK1 phosphorylates Rab1 on a hotspot for posttranslational modifications by host and pathogen.

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    Levin, Rebecca S; Hertz, Nicholas T; Burlingame, Alma L; Shokat, Kevan M; Mukherjee, Shaeri

    2016-08-16

    TGF-β activated kinase 1 (TAK1) is a critical signaling hub responsible for translating antigen binding signals to immune receptors for the activation of the AP-1 and NF-κB master transcriptional programs. Despite its importance, known substrates of TAK1 are limited to kinases of the MAPK and IKK families and include no direct effectors of biochemical processes. Here, we identify over 200 substrates of TAK1 using a chemical genetic kinase strategy. We validate phosphorylation of the dynamic switch II region of GTPase Rab1, a mediator of endoplasmic reticulum to Golgi vesicular transport, at T75 to be regulated by TAK1 in vivo. TAK1 preferentially phosphorylates the inactive (GDP-bound) state of Rab1. Phosphorylation of Rab1 disrupts interaction with GDP dissociation inhibitor 1 (GDI1), but not guanine exchange factor (GEF) or GTPase-activating protein (GAP) enzymes, and is exclusive to membrane-localized Rab1, suggesting phosphorylation may stimulate Rab1 membrane association. Furthermore, we found phosphorylation of Rab1 at T75 to be essential for Rab1 function. Previous studies established that the pathogen Legionella pneumophila is capable of hijacking Rab1 function through posttranslational modifications of the switch II region. Here, we present evidence that Rab1 is regulated by the host in a similar fashion, and that the innate immunity kinase TAK1 and Legionella effectors compete to regulate Rab1 by switch II modifications during infection.

  13. Borna disease virus encoded phosphoprotein inhibits host innate immunity by regulating miR-155.

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    Zhai, Aixia; Qian, Jun; Kao, Wenping; Li, Aimei; Li, Yujun; He, Junming; Zhang, Qingmeng; Song, Wuqi; Fu, Yingmei; Wu, Jing; Chen, Xiaobei; Li, Hui; Zhong, Zhaohua; Ling, Hong; Zhang, Fengmin

    2013-04-01

    It has been reported that the Borna disease virus (BDV) encoded phosphoprotein (P protein) can inhibit the activity of Traf family member-associated NF-kappaB activator (TANK)-binding kinase 1 (TBK-1), thus preventing the induction of type I interferon (IFN). However, the effects of microRNA on the regulation of BDV infection and the host's immune response have not been characterized. miR-155 was predicted to be complementary to the BDV P mRNA by RNAhybrid software. Here, we showed that miR-155 was down-regulated in BDV persistently infected human oligodendroglial (OL/BDV) cells and that the BDV P protein, but not the X protein, directly inhibited miR-155 expression in cells. When miR-155 was over-expressed, the inhibition of type I IFNs by BDV in cells was reversed, and the expression of type I IFNs was increased. When miR-155 expression was specifically blocked, cellular IFN expression and the induction of IFN by poly I:C treatment were suppressed. Furthermore, miR-155 promoted type I IFN production by targeting suppressor of cytokine signaling 1 (SOCS1) and SOCS3. Mutations in the nt1138-nt1158 region of SOCS3 abandoned the impact of miR-155 on the expression of SOCS3-enhanced green fluorescent protein (EGFP). The levels of BDV P mRNA and protein were significantly decreased in OL/BDV cells when miR-155 was over-expressed; however, miR-155-mutation did not affect the expression of BDV P-EGFP. Thus, BDV persistent infection inhibited the expression of type I IFNs through the suppression of miR-155, and miR-155 played an important immune regulatory role in BDV persistent infection. Copyright © 2013 Elsevier B.V. All rights reserved.

  14. Mutations in fetal genes involved in innate immunity and host defense against microbes increase risk of preterm premature rupture of membranes (PPROM).

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    Modi, Bhavi P; Teves, Maria E; Pearson, Laurel N; Parikh, Hardik I; Haymond-Thornburg, Hannah; Tucker, John L; Chaemsaithong, Piya; Gomez-Lopez, Nardhy; York, Timothy P; Romero, Roberto; Strauss, Jerome F

    2017-11-01

    Twin studies have revealed a significant contribution of the fetal genome to risk of preterm birth. Preterm premature rupture of membranes (PPROM) is the leading identifiable cause of preterm delivery. Infection and inflammation of the fetal membranes is commonly found associated with PPROM. We carried out whole exome sequencing (WES) of genomic DNA from neonates born of African-American mothers whose pregnancies were complicated by PPROM (76) or were normal term pregnancies (N = 43) to identify mutations in 35 candidate genes involved in innate immunity and host defenses against microbes. Targeted genotyping of mutations in the candidates discovered by WES was conducted on an additional 188 PPROM cases and 175 controls. We identified rare heterozygous nonsense and frameshift mutations in several of the candidate genes, including CARD6, CARD8, DEFB1, FUT2, MBL2, NLP10, NLRP12, and NOD2. We discovered that some mutations (CARD6, DEFB1, FUT2, MBL2, NLRP10, NOD2) were present only in PPROM cases. We conclude that rare damaging mutations in innate immunity and host defense genes, the majority being heterozygous, are more frequent in neonates born of pregnancies complicated by PPROM. These findings suggest that the risk of preterm birth in African-Americans may be conferred by mutations in multiple genes encoding proteins involved in dampening the innate immune response or protecting the host against microbial infection and microbial products. © 2017 The Authors. Molecular Genetics & Genomic Medicine published by Wiley Periodicals, Inc.

  15. Entamoeba histolytica-Induced Mucin Exocytosis Is Mediated by VAMP8 and Is Critical in Mucosal Innate Host Defense.

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    Cornick, Steve; Moreau, France; Gaisano, Herbert Y; Chadee, Kris

    2017-10-03

    Intestinal mucus secretion is critical in maintaining mucosal host defense against a myriad of pathogens by preventing direct association with the epithelium. Entamoeba histolytica specifically binds colonic MUC2 mucin and also induces potent hypersecretion from goblet cells; however, characterization of the nature of the mechanisms controlling mucus release remains elusive. In this report, we identify vesicle SNARE vesicle-associated membrane protein 8 (VAMP8) present on mucin granules as orchestrating regulated exocytosis in human goblet cells in response to the presence of E. histolytica VAMP8 was specifically activated during E. histolytica infection, and ablation of VAMP8 led to impaired mucin secretion. As a consequence, loss of VAMP8 increased E. histolytica adherence to epithelial cells associated with enhanced cell death through apoptosis characterized by caspase 3 and 9 cleavages and DNA fragmentation. With the mucosal barrier compromised in Vamp8-/- animals, E. histolytica induced an aggressive proinflammatory response with elevated levels of interleukin-1 alpha (IL-1α), IL-1β, and tumor necrosis factor alpha (TNF-α) secretion. This report is the first to characterize regulated mucin exocytosis in intestinal goblet cells in response to a pathogen and the downstream consequences of improper mucin secretion in mucosal barrier defense.IMPORTANCE The intestinal tract is exposed to countless substances and pathogens, and yet homeostasis is maintained, in part by the mucus layer that houses the microbiota and spatially separates potential threats from the underlying single layer of epithelium. Despite the critical role of mucus in innate host defense, characterization of the mechanisms by which mucus is secreted from specialized goblet cells in the gut remains elusive. Here, we describe the machinery that regulates mucus secretion as well as the consequence during infection with the colonic pathogen Entamoeba histolytica Abolishment of the key machinery

  16. Induction of innate host responses in the lungs of chickens following infection with a very virulent strain of Marek's disease virus.

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    Abdul-Careem, Mohamed Faizal; Haq, Kamran; Shanmuganathan, Sangitha; Read, Leah R; Schat, Karel A; Heidari, Mohammad; Sharif, Shayan

    2009-10-25

    The natural route of entry of Marek's disease virus (MDV) is via the respiratory system. However, little is known about host-virus interactions in the lungs. The objective of the present study was to examine MDV replication and induction of innate host responses in the lungs of chickens infected through inhalation. Replication of MDV in lungs was detectable as early as 12 hours post-infection (hpi). The expression of Toll-like receptor (TLR)3 and TLR7 genes was enhanced in response to MDV infection in the lungs. This was associated with the up-regulation of interleukin (IL)-1beta and IL-8 genes. In response to MDV infection, the number of macrophages in lungs of infected chickens was significantly higher compared to uninfected control chickens. The expression of inducible nitric oxide synthase (iNOS) gene was also significantly higher in the lungs at 72 hpi following MDV infection. In conclusion, the present study demonstrates induction of innate host responses to MDV infection in the respiratory system. Further studies are needed to characterize other host responses generated in the lungs following MDV infection.

  17. Shifts in Host Mucosal Innate Immune Function Are Associated with Ruminal Microbial Succession in Supplemental Feeding and Grazing Goats at Different Ages

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    Jinzhen Jiao

    2017-08-01

    Full Text Available Gastrointestinal microbiota may play an important role in regulating host mucosal innate immune function. This study was conducted to test the hypothesis that age (non-rumination, transition and rumination and feeding type [Supplemental feeding (S vs. Grazing (G] could alter ruminal microbial diversity and maturation of host mucosal innate immune system in goat kids. MiSeq sequencing was applied to investigate ruminal microbial composition and diversity, and RT-PCR was used to test expression of immune-related genes in ruminal mucosa. Results showed that higher (P < 0.05 relative abundances of Prevotella, Butyrivibrio, Pseudobutyrivibrio, Methanobrevibacter.gottschalkii, Neocallimastix, Anoplodinium–Diplodinium, and Polyplastron, and lower relative abundance of Methanosphaera (P = 0.042 were detected in the rumen of S kids when compared to those in G kids. The expression of genes encoding TLRs, IL1α, IL1β and TICAM2 was down-regulated (P < 0.01, while expression of genes encoding tight junction proteins was up-regulated (P < 0.05 in the ruminal mucosa of S kids when compared to that in G kids. Moreover, irrespective of feeding type, relative abundances of ruminal Prevotella, Fibrobacter, Ruminococcus, Butyrivibrio, Methanobrevibacter, Neocallimastix, and Entodinium increased with age. The expression of most genes encoding TLRs and cytokines increased (P < 0.05 from day 0 to 7, while expression of genes encoding tight junction proteins declined with age (P < 0.05. This study revealed that the composition of each microbial domain changed as animals grew, and these changes might be associated with variations in host mucosal innate immune function. Moreover, supplementing goat kids with concentrate could modulate ruminal microbial composition, enhance barrier function and decrease local inflammation. The findings provide useful information in interpreting microbiota and host interactions, and developing nutritional strategies to improve the

  18. Influence of Foot-and-Mouth Disease Virus O/CHN/Mya98/33-P Strain Leader Protein on Viral Replication and Host Innate Immunity.

    Science.gov (United States)

    Jiang, Shaodong; Bai, Xingwen; Li, Pinghua; Zhang, Meng; Bao, Huifang; Sun, Pu; Lu, Zengjun; Cao, Yimei; Chen, Yingli; Li, Dong; Fu, Yuanfang; Liu, Zaixin

    2015-09-01

    Foot-and-mouth disease virus (FMDV) O/CHN/Mya98/33-P strain was isolated from the esophageal-pharyngeal fluid sample of cattle, and was shown to cause persistent infection. Its leader protein contains 200 amino acids with one amino acid deletion, which is upstream and next to the second initiation codon compared with the majority of FMDV Mya98 strains. The FMDV genome includes two initiation codons that can produce two different leader proteins, Lab (from the first AUG) and Lb (from the second AUG). For convenience, the inter-AUG region was named as La. Previously, it was found that a recombinant virus with Lab of FMDV O/CHN/Mya98/33-P strain had higher proliferation efficiency, and better ability to inhibit the host innate immune response. Three full-length infectious cDNA clones-rHN33-Lb, rHN33-La, and rHNGSLX-Lb-containing the FMDV O/CHN/Mya98/33-P strain leader proteins Lb, La, or the FMDV O/GSLX/2010 strain leader protein Lb, respectively, were constructed based on an established infectious clone r-HN rescued from FMDV O/HN/CHN/93 strain. After infecting pig kidney primary cells, rHN33-La showed higher replication efficiency than r-HN, and rHN33-Lb displayed better ability to resist host innate immunity than rHNGSLX-Lb. These results demonstrated that the inter-AUG region of FMDV strain O/CHN/Mya98/33-P leader protein must be involved in increasing viral replication efficiency. Additionally, the Lb of FMDV O/CHN/Mya98/33-P must be involve in increasing its ability to inhibit host innate immune response, and the distinctive amino acids G56 and/or R118 of FMDV leader protein may play essential roles in it.

  19. Interaction of bovine peripheral blood polymorphonuclear cells and Leptospira species; innate responses in the natural bovine reservoir host.

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    Cattle are the reservoir hosts of Leptospira borgpetersenii serovar Hardjo, and also be reservoir hosts of other Leptospira species such as L. kirschneri, and L. interrogans. As a reservoir host, cattle shed Leptospira, infecting other animals, including humans. Previous studies with human and murin...

  20. The Varicella-Zoster Virus ORF47 Kinase Interferes with Host Innate Immune Response by Inhibiting the Activation of IRF3

    Science.gov (United States)

    Vandevenne, Patricia; Lebrun, Marielle; El Mjiyad, Nadia; Ote, Isabelle; Di Valentin, Emmanuel; Habraken, Yvette; Dortu, Estelle; Piette, Jacques; Sadzot-Delvaux, Catherine

    2011-01-01

    The innate immune response constitutes the first line of host defence that limits viral spread and plays an important role in the activation of adaptive immune response. Viral components are recognized by specific host pathogen recognition receptors triggering the activation of IRF3. IRF3, along with NF-κB, is a key regulator of IFN-β expression. Until now, the role of IRF3 in the activation of the innate immune response during Varicella-Zoster Virus (VZV) infection has been poorly studied. In this work, we demonstrated for the first time that VZV rapidly induces an atypical phosphorylation of IRF3 that is inhibitory since it prevents subsequent IRF3 homodimerization and induction of target genes. Using a mutant virus unable to express the viral kinase ORF47p, we demonstrated that (i) IRF3 slower-migrating form disappears; (ii) IRF3 is phosphorylated on serine 396 again and recovers the ability to form homodimers; (iii) amounts of IRF3 target genes such as IFN-β and ISG15 mRNA are greater than in cells infected with the wild-type virus; and (iv) IRF3 physically interacts with ORF47p. These data led us to hypothesize that the viral kinase ORF47p is involved in the atypical phosphorylation of IRF3 during VZV infection, which prevents its homodimerization and subsequent induction of target genes such as IFN-β and ISG15. PMID:21347389

  1. Emerging Concepts in Innate Immunity.

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    Pelka, Karin; De Nardo, Dominic

    2018-01-01

    This review introduces recent concepts in innate immunity highlighting some of the latest exciting findings. These include: the discovery of the initiator of pyroptosis, Gasdermin D, and mechanisms of inflammatory caspases in innate immune signaling; the formation of oligomeric signalosomes downstream of innate immune receptors; mechanisms that shape innate immune responses, such as cellular homeostasis, cell metabolism, and pathogen viability; rapid methods of cell-to-cell communication; the interplay between the host and its microbiome and the concept of innate immunological memory. Furthermore, we discuss open questions and illustrate how technological advances, such as CRISPR/Cas9, may provide important answers for outstanding questions in the field of innate immunity.

  2. Kidney and innate immunity.

    Science.gov (United States)

    Wang, Ying-Hui; Zhang, Yu-Gen

    2017-03-01

    Innate immune system is an important modulator of the inflammatory response during infection and tissue injury/repair. The kidney as a vital organ with high energy demand plays a key role in regulating the disease related metabolic process. Increasing research interest has focused on the immune pathogenesis of many kidney diseases. However, innate immune cells such as dendritic cells, macrophages, NK cells and a few innate lymphocytes, as well as the complement system are essential for renal immune homeostasis and ensure a coordinated balance between tissue injury and regeneration. The innate immune response provides the first line of host defense initiated by several classes of pattern recognition receptors (PRRs), such as membrane-bound Toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), together with inflammasomes responsible for early innate immune response. Although the innate immune system is well studied, the research on the detailed relationship between innate immunity and kidney is still very limited. In this review, we will focus on the innate immune sensing system in renal immune homeostasis, as well as the corresponding pathogenesis of many kidney diseases. The pivotal roles of innate immunity in renal injury and regeneration with special emphasis on kidney disease related immunoregulatory mechanism are also discussed. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  3. Glycosylation of the Hemagglutinin Protein of H5N1 Influenza Virus Increases Its Virulence in Mice by Exacerbating the Host Immune Response.

    Science.gov (United States)

    Zhao, Dongming; Liang, Libin; Wang, Shuai; Nakao, Tomomi; Li, Yanbing; Liu, Liling; Guan, Yuntao; Fukuyama, Satoshi; Bu, Zhigao; Kawaoka, Yoshihiro; Chen, Hualan

    2017-04-01

    productivity, exacerbated the host response, and thereby contributed to the high pathogenicity of H5N1 virus in mice. Copyright © 2017 Zhao et al.

  4. Innate and adaptive host responses and their genetic control in tuberculosis : studies in Indonesia, a highly TB endemic setting

    NARCIS (Netherlands)

    Sahiratmadja, Edhyana Kusumastuti

    2007-01-01

    Tuberculosis (TB) is an infectious disease, caused by Mycobacterium tuberculosis. MTB infection does not necessarily progress to TB. Only 5-10% of exposed individuals develop clinical signs and symptoms of TB. Given the impact of mycobacterial exposure and the immunoregulatory consequences for host

  5. Complement component C3 – The “Swiss Army Knife” of innate immunity and host defense

    NARCIS (Netherlands)

    Ricklin, Daniel; Reis, Edimara S.; Mastellos, Dimitrios C.; Gros, Piet; Lambris, John D.

    2016-01-01

    As a preformed defense system, complement faces a delicate challenge in providing an immediate, forceful response to pathogens even at first encounter, while sparing host cells in the process. For this purpose, it engages a tightly regulated network of plasma proteins, cell surface receptors, and

  6. Microbial metalloproteinases mediate sensing of invading pathogens and activate innate immune responses in the lepidopteran model host Galleria mellonella.

    Science.gov (United States)

    Altincicek, Boran; Linder, Monica; Linder, Dietmar; Preissner, Klaus T; Vilcinskas, Andreas

    2007-01-01

    Thermolysin-like metalloproteinases such as aureolysin, pseudolysin, and bacillolysin represent virulence factors of diverse bacterial pathogens. Recently, we discovered that injection of thermolysin into larvae of the greater wax moth, Galleria mellonella, mediated strong immune responses. Thermolysin-mediated proteolysis of hemolymph proteins yielded a variety of small-sized (protein fragments (protfrags) that are potent elicitors of innate immune responses. In this study, we report the activation of a serine proteinase cascade by thermolysin, as described for bacterial lipopolysaccharides (LPS), that results in subsequent prophenoloxidase activation leading to melanization, an elementary immune defense reaction of insects. Quantitative real-time reverse transcription-PCR analyses of the expression of immune-related genes encoding the inducible metalloproteinase inhibitor, gallerimycin, and lysozyme demonstrated increased transcriptional rates after challenge with purified protfrags similar to rates after challenge with LPS. Additionally, we determined the induction of a similar spectrum of immune-responsive proteins that were secreted into the hemolymph by using comparative proteomic analyses of hemolymph proteins from untreated larvae and from larvae that were challenged with either protfrags or LPS. Since G. mellonella was recently established as a valuable pathogenicity model for Cryptococcus neoformans infection, the present results add to our understanding of the mechanisms of immune responses in G. mellonella. The obtained results support the proposed danger model, which suggests that the immune system senses endogenous alarm signals during infection besides recognition of microbial pattern molecules.

  7. Mutation of the Enterohemorrhagic Escherichia coli Core LPS Biosynthesis Enzyme RfaD Confers Hypersusceptibility to Host Intestinal Innate Immunity In vivo.

    Science.gov (United States)

    Kuo, Cheng-Ju; Chen, Jenn-Wei; Chiu, Hao-Chieh; Teng, Ching-Hao; Hsu, Tai-I; Lu, Pei-Jung; Syu, Wan-Jr; Wang, Sin-Tian; Chou, Ting-Chen; Chen, Chang-Shi

    2016-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O157:H7 is an important foodborne pathogen causing severe diseases in humans worldwide. Currently, there is no specific treatment available for EHEC infection and the use of conventional antibiotics is contraindicated. Therefore, identification of potential therapeutic targets and development of effective measures to control and treat EHEC infection are needed. Lipopolysaccharides (LPS) are surface glycolipids found on the outer membrane of gram-negative bacteria, including EHEC, and LPS biosynthesis has long been considered as potential anti-bacterial target. Here, we demonstrated that the EHEC rfaD gene that functions in the biosynthesis of the LPS inner core is required for the intestinal colonization and pathogenesis of EHEC in vivo. Disruption of the EHEC rfaD confers attenuated toxicity in Caenorhabditis elegans and less bacterial colonization in the intestine of C. elegans and mouse. Moreover, rfaD is also involved in the control of susceptibility of EHEC to antimicrobial peptides and host intestinal immunity. It is worth noting that rfaD mutation did not interfere with the growth kinetics when compared to the wild-type EHEC cells. Taken together, we demonstrated that mutations of the EHEC rfaD confer hypersusceptibility to host intestinal innate immunity in vivo, and suggested that targeting the RfaD or the core LPS synthesis pathway may provide alternative therapeutic regimens for EHEC infection.

  8. Toll-like receptor 2-independent host innate immune response against an epidemic strain of Streptococcus suis that causes a toxic shock-like syndrome in humans.

    Directory of Open Access Journals (Sweden)

    Claude Lachance

    Full Text Available Streptococcus suis is an emerging zoonotic agent causing meningitis and septicemia. Outbreaks in humans in China with atypical cases of streptococcal toxic shock-like syndrome have been described to be caused by a clonal epidemic S. suis strain characterized as sequence type (ST 7 by multilocus sequence typing, different from the classical ST1 usually isolated in Europe. Previous in vitro studies showed that Toll-like receptor (TLR 2 plays a major role in S. suis ST1 interactions with host cells. In the present study, the in vivo role of TLR2 in systemic infections caused by S. suis ST1 or ST7 strains using TLR2 deficient (TLR2(-/- mice was evaluated. TLR2-mediated recognition significantly contributes to the acute disease caused by the highly virulent S. suis ST1 strain, since the TLR2(-/- mice remained unaffected when compared to wild type (WT mice. The lack of mortality could not be associated with a lower bacterial burden; however, a significant decrease in the induction of pro-inflammatory mediators, as evaluated by microarray, real-time PCR and protein assays, was observed. On the other hand, TLR2(-/- mice infected with the epidemic ST7 strain presented no significant differences regarding survival and expression of pro-inflammatory mediators when compared to the WT mice. Together, these results show a TLR2-independent host innate immune response to S. suis that depends on the strain.

  9. Foot-and-mouth disease virus 5'-terminal S fragment is required for replication and modulation of the innate immune response in host cells.

    Science.gov (United States)

    Kloc, Anna; Diaz-San Segundo, Fayna; Schafer, Elizabeth A; Rai, Devendra K; Kenney, Mary; de Los Santos, Teresa; Rieder, Elizabeth

    2017-12-01

    The S fragment of the FMDV 5' UTR is predicted to fold into a long stem-loop structure and it has been implicated in virus-host protein interactions. In this study, we report the minimal S fragment sequence required for virus viability and show a direct correlation between the extent of the S fragment deletion mutations and attenuated phenotypes. Furthermore, we provide novel insight into the role of the S fragment in modulating the host innate immune response. Importantly, in an FMDV mouse model system, all animals survive the inoculation with the live A 24 FMDV-S 4 mutant, containing a 164 nucleotide deletion in the upper S fragment loop, at a dose 1000 higher than the one causing lethality by parental A 24 FMDV, indicating that the A 24 FMDV-S 4 virus is highly attenuated in vivo. Additionally, mice exposed to high doses of live A 24 FMDV-S 4 virus are fully protected when challenged with parental A 24 FMDV virus. Published by Elsevier Inc.

  10. Infection with host-range mutant adenovirus 5 suppresses innate immunity and induces systemic CD4+ T cell activation in rhesus macaques.

    Directory of Open Access Journals (Sweden)

    Huma Qureshi

    Full Text Available Ad5 is a common cause of respiratory disease and an occasional cause of gastroenteritis and conjunctivitis, and seroconversion before adolescence is common in humans. To gain some insight into how Ad5 infection affects the immune system of rhesus macaques (RM 18 RM were infected with a host-range mutant Ad5 (Ad5hr by 3 mucosal inoculations. There was a delay of 2 to 6 weeks after the first inoculation before plasmacytoid dendritic cell (pDC frequency and function increased in peripheral blood. Primary Ad5hr infection suppressed IFN-γ mRNA expression, but the second Ad5hr exposure induced a rapid increase in IFN-gamma mRNA in peripheral blood mononuclear cells (PBMC. Primary Ad5hr infection suppressed CCL20, TNF and IL-1 mRNA expression in PBMC, and subsequent virus exposures further dampened expression of these pro-inflammatory cytokines. Primary, but not secondary, Ad5hr inoculation increased the frequency of CXCR3+ CD4+ T cells in blood, while secondary, but not primary, Ad5hr infection transiently increased the frequencies of Ki67+, HLADR+ and CD95+/CCR5+ CD4+ T cells in blood. Ad5hr infection induced polyfunctional CD4 and CD8+ T cells specific for the Ad5 hexon protein in all of the animals. Thus, infection with Ad5hr induced a complex pattern of innate and adaptive immunity in RM that included transient systemic CD4+ T cell activation and suppressed innate immunity on re-exposure to the virus. The complex effects of adenovirus infection on the immune system may help to explain the unexpected results of testing Ad5 vector expressing HIV antigens in Ad5 seropositive people.

  11. Complexity of the Microglial Activation Pathways that Drive Innate Host Responses During Lethal Alphavirus Encephalitis in Mice

    Directory of Open Access Journals (Sweden)

    Nilufer Esen

    2012-04-01

    Full Text Available Microglia express multiple TLRs (Toll-like receptors and provide important host defence against viruses that invade the CNS (central nervous system. Although prior studies show these cells become activated during experimental alphavirus encephalitis in mice to generate cytokines and chemokines that influence virus replication, tissue inflammation and neuronal survival, the specific PRRs (pattern recognition receptors and signalling intermediates controlling microglial activation in this setting remain unknown. To investigate these questions directly in vivo, mice ablated of specific TLR signalling molecules were challenged with NSV (neuroadapted Sindbis virus and CNS viral titres, inflammatory responses and clinical outcomes followed over time. To approach this problem specifically in microglia, the effects of NSV on primary cells derived from the brains of wild-type and mutant animals were characterized in vitro. From the standpoint of the virus, microglial activation required viral uncoating and an intact viral genome; inactivated virus particles did not elicit measurable microglial responses. At the level of the target cell, NSV triggered multiple PRRs in microglia to produce a broad range of inflammatory mediators via non-overlapping signalling pathways. In vivo, disease survival was surprisingly independent of TLR-driven responses, but still required production of type-I IFN (interferon to control CNS virus replication. Interestingly, the ER (endoplasmic reticulum protein UNC93b1 facilitated host survival independent of its known effects on endosomal TLR signalling. Taken together, these data show that alphaviruses activate microglia via multiple PRRs, highlighting the complexity of the signalling networks by which CNS host responses are elicited by these infections.

  12. Novel Bat Influenza Virus NS1 Proteins Bind Double-Stranded RNA and Antagonize Host Innate Immunity.

    Science.gov (United States)

    Turkington, Hannah L; Juozapaitis, Mindaugas; Kerry, Philip S; Aydillo, Teresa; Ayllon, Juan; García-Sastre, Adolfo; Schwemmle, Martin; Hale, Benjamin G

    2015-10-01

    We demonstrate that novel bat HL17NL10 and HL18NL11 influenza virus NS1 proteins are effective interferon antagonists but do not block general host gene expression. Solving the RNA-binding domain structures revealed the canonical NS1 symmetrical homodimer, and RNA binding required conserved basic residues in this domain. Interferon antagonism was strictly dependent on RNA binding, and chimeric bat influenza viruses expressing NS1s defective in this activity were highly attenuated in interferon-competent cells but not in cells unable to establish antiviral immunity. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  13. P58(IPK: a novel "CIHD" member of the host innate defense response against pathogenic virus infection.

    Directory of Open Access Journals (Sweden)

    Alan G Goodman

    2009-05-01

    Full Text Available To support their replication, viruses take advantage of numerous cellular factors and processes. Recent large-scale screens have identified hundreds of such factors, yet little is known about how viruses exploit any of these. Influenza virus infection post-translationally activates P58(IPK, a cellular inhibitor of the interferon-induced, dsRNA-activated eIF2alpha kinase, PKR. Here, we report that infection of P58(IPK knockout mice with influenza virus resulted in increased lung pathology, immune cell apoptosis, PKR activation, and mortality. Analysis of lung transcriptional profiles, including those induced by the reconstructed 1918 pandemic virus, revealed increased expression of genes associated with the cell death, immune, and inflammatory responses. These experiments represent the first use of a mammalian infection model to demonstrate the role of P58(IPK in the antiviral response. Our results suggest that P58(IPK represents a new class of molecule, a cellular inhibitor of the host defense (CIHD, as P58(IPK is activated during virus infection to inhibit virus-induced apoptosis and inflammation to prolong host survival, even while prolonging viral replication.

  14. Differences in Acinetobacter baumannii strains and host innate immune response determine morbidity and mortality in experimental pneumonia.

    Directory of Open Access Journals (Sweden)

    Anna de Breij

    Full Text Available Despite many reports documenting its epidemicity, little is known on the interaction of Acinetobacter baumannii with its host. To deepen our insight into this relationship, we studied persistence of and host response to different A. baumannii strains including representatives of the European (EU clones I-III in a mouse pneumonia model. Neutropenic mice were inoculated intratracheally with five A. baumannii strains and an A. junii strain and at several days morbidity, mortality, bacterial counts, airway inflammation, and chemo- and cytokine production in lungs and blood were determined. A. baumannii RUH875 and RUH134 (EU clone I and II, respectively and sporadic strain LUH8326 resulted in high morbidity/mortality, whereas A. baumannii LUH5875 (EU clone III, which is less widespread than clone I and II caused less symptoms. A. baumannii type strain RUH3023(T and A. junii LUH5851 did not cause disease. All strains, except A. baumannii RUH3023(T and A. junii LUH5851, survived and multiplied in the lungs for several days. Morbidity and mortality were associated with the severity of lung pathology and a specific immune response characterized by low levels of anti-inflammatory (IL-10 and specific pro-inflammatory (IL-12p40 and IL-23 cytokines at the first day of infection. Altogether, a striking difference in behaviour among the A. baumannii strains was observed with the clone I and II strains being most virulent, whereas the A. baumannii type strain, which is frequently used in virulence studies appeared harmless.

  15. Ambient ozone and pulmonary innate immunity

    Science.gov (United States)

    Al-Hegelan, Mashael; Tighe, Robert M.; Castillo, Christian; Hollingsworth, John W.

    2013-01-01

    Ambient ozone is a criteria air pollutant that impacts both human morbidity and mortality. The effect of ozone inhalation includes both toxicity to lung tissue and alteration of the host immunologic response. The innate immune system facilitates immediate recognition of both foreign pathogens and tissue damage. Emerging evidence supports that ozone can modify the host innate immune response and that this response to inhaled ozone is dependent on genes of innate immunity. Improved understanding of the complex interaction between environmental ozone and host innate immunity will provide fundamental insight into the pathogenesis of inflammatory airways disease. We review the current evidence supporting that environmental ozone inhalation: (1) modifies cell types required for intact innate immunity, (2) is partially dependent on genes of innate immunity, (3) primes pulmonary innate immune responses to LPS, and (4) contributes to innate-adaptive immune system cross-talk. PMID:21132467

  16. Host transcriptomic responses to pneumonic plague reveal that Yersinia pestis inhibits both the initial adaptive and innate immune responses in mice.

    Science.gov (United States)

    Yang, Huiying; Wang, Tong; Tian, Guang; Zhang, Qingwen; Wu, Xiaohong; Xin, Youqian; Yan, Yanfeng; Tan, Yafang; Cao, Shiyang; Liu, Wanbing; Cui, Yujun; Yang, Ruifu; Du, Zongmin

    2017-01-01

    Pneumonic plague is the most deadly form of infection caused by Yersinia pestis and can progress extremely fast. However, our understanding on the host transcriptomic response to pneumonic plague is insufficient. Here, we used RNA-sequencing technology to analyze transcriptomic responses in mice infected with fully virulent strain 201 or EV76, a live attenuated vaccine strain lacking the pigmentation locus. Approximately 600 differentially expressed genes (DEGs) were detected in lungs from both 201- and EV76-infected mice at 12h post-infection (hpi). DEGs in lungs of 201-infected mice exceeded 2000 at 48hpi, accompanied by sustained large numbers of DEGs in the liver and spleen; however, limited numbers of DEGs were detected in those organs of EV-infected mice. Remarkably, DEGs in lungs were significantly enriched in critical immune responses pathways in EV76-infected but not 201-infected mice, including antigen processing and presentation, T cell receptor signaling among others. Pathological and bacterial load analyses confirmed the rapid systemic dissemination of 201-infection and the confined EV76-infection in lungs. Our results suggest that fully virulent Y. pestis inhibits both the innate and adaptive immune responses that are substantially stimulated in a self-limited infection, which update our holistic views on the transcriptomic response to pneumonic plague. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Specific mtDNA mutations in mouse carcinoma cells suppress their tumor formation via activation of the host innate immune system.

    Directory of Open Access Journals (Sweden)

    Hirotake Imanishi

    Full Text Available In mammalian species, mitochondrial DNA (mtDNA with pathogenic mutations that induce mitochondrial respiration defects has been proposed to be involved in tumor phenotypes via induction of enhanced glycolysis under normoxic conditions (the Warburg effects. However, because both nuclear DNA and mtDNA control mitochondrial respiratory function, it is difficult to exclude the possible contribution of nuclear DNA mutations to mitochondrial respiration defects and the resultant expression of tumor phenotypes. Therefore, it is important to generate transmitochondrial cybrids sharing the same nuclear DNA background but carrying mtDNA with and without the mutations by using intercellular mtDNA transfer technology. Our previous studies isolated transmitochondrial cybrids and showed that specific mtDNA mutations enhanced tumor progression as a consequence of overproduction of reactive oxygen species (ROS. This study assessed whether mtDNA mutations inducing ROS overproduction always enhance tumor progression. We introduced mtDNA from senescence-accelerated mice P1 (SAMP1 into C57BL/6J (B6 mice-derived Lewis lung carcinoma P29 cells, and isolated new transmitochondrial cybrids (P29mtSAMP1 cybrids that overproduced ROS. The inoculation of the cybrids into B6 mice unexpectedly showed that mtDNA from SAMP1 mice conversely induced tumor suppression. Moreover, the tumor suppression of P29mtSAMP1 cybrids in B6 mice occurred as a consequence of innate immune responses of the host B6 mice. Enzyme pretreatment experiments of P29mtSAMP1 cybrids revealed that some peptides encoded by mtDNA and expressed on the cell surface of P29mtSAMP1 cybrids induce increased IL-6 production from innate immune cells (dendritic cells of B6 mice, and mediate augmented inflammatory responses around the tumor-inoculated environment. These observations indicate presence of a novel role of mtDNA in tumor phenotype, and provide new insights into the fields of mitochondrial tumor biology

  18. Novel murine infection models provide deep insights into the "ménage à trois" of Campylobacter jejuni, microbiota and host innate immunity.

    Directory of Open Access Journals (Sweden)

    Stefan Bereswill

    Full Text Available BACKGROUND: Although Campylobacter jejuni-infections have a high prevalence worldwide and represent a significant socioeconomic burden, it is still not well understood how C. jejuni causes intestinal inflammation. Detailed investigation of C. jejuni-mediated intestinal immunopathology is hampered by the lack of appropriate vertebrate models. In particular, mice display colonization resistance against this pathogen. METHODOLOGY/PRINCIPAL FINDINGS: To overcome these limitations we developed a novel C. jejuni-infection model using gnotobiotic mice in which the intestinal flora was eradicated by antibiotic treatment. These animals could then be permanently associated with a complete human (hfa or murine (mfa microbiota. After peroral infection C. jejuni colonized the gastrointestinal tract of gnotobiotic and hfa mice for six weeks, whereas mfa mice cleared the pathogen within two days. Strikingly, stable C. jejuni colonization was accompanied by a pro-inflammatory immune response indicated by increased numbers of T- and B-lymphocytes, regulatory T-cells, neutrophils and apoptotic cells, as well as increased concentrations of TNF-α, IL-6, and MCP-1 in the colon mucosa of hfa mice. Analysis of MyD88(-/-, TRIF(-/-, TLR4(-/-, and TLR9(-/- mice revealed that TLR4- and TLR9-signaling was essential for immunopathology following C. jejuni-infection. Interestingly, C. jejuni-mutant strains deficient in formic acid metabolism and perception induced less intestinal immunopathology compared to the parental strain infection. In summary, the murine gut flora is essential for colonization resistance against C. jejuni and can be overcome by reconstitution of gnotobiotic mice with human flora. Detection of C. jejuni-LPS and -CpG-DNA by host TLR4 and TLR9, respectively, plays a key role in immunopathology. Finally, the host immune response is tightly coupled to bacterial formic acid metabolism and invasion fitness. CONCLUSION/SIGNIFICANCE: We conclude that

  19. Innate Immune Recognition of EBV.

    Science.gov (United States)

    Lünemann, Anna; Rowe, Martin; Nadal, David

    2015-01-01

    The ability of Epstein-Barr virus (EBV) to establish latency despite specific immune responses and to successfully persist lifelong in the human host shows that EBV has developed powerful strategies and mechanisms to exploit, evade, abolish, or downsize otherwise effective immune responses to ensure its own survival. This chapter focuses on current knowledge on innate immune responses against EBV and its evasion strategies for own benefit and summarizes the questions that remain to be tackled. Innate immune reactions against EBV originate both from the main target cells of EBV and from nontarget cells, which are elements of the innate immune system. Thus, we structured our review accordingly but with a particular focus on the innate recognition of EBV in its two stages in its life cycle, latent state and lytic replication. Specifically, we discuss (I) innate sensing and resulting innate immune responses against EBV by its main target cells, focusing on (i) EBV transmission between epithelial cells and B cells and their life cycle stages; and (ii) elements of innate immunity in EBV's target cells. Further, we debate (II) the innate recognition and resulting innate immune responses against EBV by cells other than the main target cells, focusing on (iii) myeloid cells: dendritic cells, monocytes, macrophages, and neutrophil granulocytes; and (iv) natural killer cells. Finally, we address (III) how EBV counteracts or exploits innate immunity in its latent and lytic life cycle stages, concentrating on (v) TLRs; (vi) EBERs; and (vii) microRNAs.

  20. Intercellular communication for innate immunity.

    Science.gov (United States)

    Nguyen, Tan A; Pang, Ken C; Masters, Seth L

    2017-06-01

    An effective innate immune response relies on the detection of pathogen associated molecular patterns (PAMPs) by various host pattern recognition receptors (PRRs) that result in the production of pro-inflammatory cytokines and chemokines. Viruses and bacteria have co-evolved with the immune system and developed multiple strategies to usurp or circumvent host machinery and blunt the innate immune response in infected cells. Recently, it has become apparent that infected or dying cells can transmit PAMPs and host PRR signalling proteins to uninfected bystander cells to thereby bypass pathogen evasion strategies, and potentiate innate immune signalling. This bystander activation of innate immunity represents an alternative method by which the host can control infections via cell-to-cell communication. In this review, we discuss what is currently known about the intercellular transfer of pathogen- or host-derived RNA, DNA and proteins from infected cells to neighbouring cells and how this impacts on host innate immunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Self-consuming innate immunity in Arabidopsis

    DEFF Research Database (Denmark)

    Hofius, Daniel; Mundy, John; Petersen, Morten

    2009-01-01

    Programmed cell death (PCD) associated with the pathogen-induced hypersensitive response (HR) is a hallmark of plant innate immunity. HR PCD is triggered upon recognition of pathogen effector molecules by host immune receptors either directly or indirectly via effector modulation of host targets....... However, it has been unclear by which molecular mechanisms plants execute PCD during innate immune responses. We recently examined HR PCD in autophagy-deficient Arabidopsis knockout mutants (atg) and find that PCD conditioned by one class of plant innate immune receptors is suppressed in atg mutants...... with innate immune responses in eukaryotes as well as of prodeath functions for the autophagy pathway in plants....

  2. Innate immunity

    African Journals Online (AJOL)

    not listed in Table 1, epithelial cells and endothelial cells, and to a lesser extent other types of structural cells such as fibroblasts and smooth-muscle cells, are critically involved in promoting both innate and adaptive immune responses. In the case of epithelial cells, this is achieved via production of pro-inflammatory.

  3. Rhinovirus-Induced Exacerbations of Asthma and COPD

    Science.gov (United States)

    Hershenson, Marc B.

    2013-01-01

    Over the past two decades, increasing evidence has shown that, in patients with chronic airways disease, viral infection is the most common cause of exacerbation. This review will examine the evidence for viral-induced exacerbations of asthma and chronic obstructive lung disease and the potential mechanisms by which viruses cause exacerbations. Attention will be focused on rhinovirus, the most common cause of respiratory exacerbations. Exacerbations due to rhinovirus, which infects relatively few cells in the airway and does not cause the cytotoxicity of other viruses such as influenza or respiratory syncytial virus, are particularly poorly understood. While the innate immune response likely plays a role in rhinovirus-induced exacerbations, its precise role, either adaptive or maladaptive, is debated. Because current treatment strategies are only partially effective, further research examining the cellular and molecular mechanisms underlying viral-induced exacerbations of chronic airways diseases is warranted. PMID:24278777

  4. Innate Pathways of Immune Activation in Transplantation

    OpenAIRE

    Brennan, Todd V.; Lunsford, Keri E.; Kuo, Paul C.

    2010-01-01

    Studies of the immune mechanisms of allograft rejection have predominantly focused on the adaptive immune system that includes T cells and B cells. Recent investigations into the innate immune system, which recognizes foreign antigens through more evolutionarily primitive pathways, have demonstrated a critical role of the innate immune system in the regulation of the adaptive immune system. Innate immunity has been extensively studied in its role as the host's first-line defense against micro...

  5. CD4+ lymphoid tissue inducer cells promote innate immunity in the gut

    Science.gov (United States)

    Sonnenberg, Gregory F.; Monticelli, Laurel A.; Elloso, M. Merle; Fouser, Lynette A.; Artis, David

    2010-01-01

    SUMMARY Fetal CD4+ lymphoid tissue inducer (LTi) cells play a critical role in the development of lymphoid-tissues. Recent studies identified that LTi cells persist in adults and are related to a heterogeneous population of innate lymphoid cells that have been implicated in inflammatory responses. However, whether LTi cells contribute to protective immunity remains poorly defined. We demonstrate that following infection with Citrobacter rodentium, CD4+ LTi cells were a dominant source of interleukin-22 (IL-22) early during infection. Infection-induced CD4+ LTi cell responses were IL-23-dependent, and ablation of IL-23 impaired innate immunity. Further, depletion of CD4+ LTi cells abrogated infection-induced expression of IL-22 and anti-microbial peptides, resulting in exacerbated host mortality. LTi cells were also found to be essential for host protective immunity in lymphocyte-replete hosts. Collectively these data demonstrate that adult CD4+ LTi cells are a critical source of IL-22 and identify a previously unrecognized function for CD4+ LTi cells in promoting innate immunity in the intestine. PMID:21194981

  6. Innate immune response to Burkholderia mallei

    OpenAIRE

    Kamal U Saikh; Mott, Tiffany M.

    2017-01-01

    Purpose of review Burkholderia mallei is a facultative intracellular pathogen that causes the highly contagious and often the fatal disease, glanders. With its high rate of infectivity via aerosol and recalcitrance toward antibiotics, this pathogen is considered a potential biological threat agent. This review focuses on the most recent literature highlighting host innate immune response to B. mallei. Recent findings Recent studies focused on elucidating host innate immune responses to the no...

  7. Alcohol, aging, and innate immunity.

    Science.gov (United States)

    Boule, Lisbeth A; Kovacs, Elizabeth J

    2017-07-01

    The global population is aging: in 2010, 8% of the population was older than 65 y, and that is expected to double to 16% by 2050. With advanced age comes a heightened prevalence of chronic diseases. Moreover, elderly humans fair worse after acute diseases, namely infection, leading to higher rates of infection-mediated mortality. Advanced age alters many aspects of both the innate and adaptive immune systems, leading to impaired responses to primary infection and poor development of immunologic memory. An often overlooked, yet increasingly common, behavior in older individuals is alcohol consumption. In fact, it has been estimated that >40% of older adults consume alcohol, and evidence reveals that >10% of this group is drinking more than the recommended limit by the National Institute on Alcohol Abuse and Alcoholism. Alcohol consumption, at any level, alters host immune responses, including changes in the number, phenotype, and function of innate and adaptive immune cells. Thus, understanding the effect of alcohol ingestion on the immune system of older individuals, who are already less capable of combating infection, merits further study. However, there is currently almost nothing known about how drinking alters innate immunity in older subjects, despite innate immune cells being critical for host defense, resolution of inflammation, and maintenance of immune homeostasis. Here, we review the effects of aging and alcohol consumption on innate immune cells independently and highlight the few studies that have examined the effects of alcohol ingestion in aged individuals. © Society for Leukocyte Biology.

  8. Tick innate immunity.

    Science.gov (United States)

    Kopácek, Petr; Hajdusek, Ondrej; Buresová, Veronika; Daffre, Sirlei

    2010-01-01

    Ticks are blood feeding parasites transmitting a wide variety of pathogens to their vertebrate hosts. The vector competence of ticks is tightly linked with their immune system. Despite its importance, our knowledge of tick innate immunity is still inadequate and the limited number of sufficiently characterized immune molecules and cellular reactions are dispersed across numerous tick species. The phagocytosis of microbes by tick hemocytes seems to be coupled with a primitive complement-like system, which possibly involves self/nonself recognition by fibrinogen-related lectins and the action of thioester-containing proteins. Ticks do not seem to possess a pro-phenoloxidase system leading to melanization and also coagulation of tick hemolymph has not been experimentally proven. They are capable of defending themselves against microbial infection with a variety of antimicrobial peptides comprising lysozymes, defensins and molecules not found in other invertebrates. Virtually nothing is known about the signaling cascades involved in the regulation of tick antimicrobial immune responses. Midgut immunity is apparently the decisive factor of tick vector competence. The gut content is a hostile environment for ingested microbes, which is mainly due to the antimicrobial activity of hemoglobin fragments generated by the digestion of the host blood as well as other antimicrobial peptides. Reactive oxygen species possibly also play an important role in the tick-pathogen interaction. The recent release of the Ixodes scapularis genome and the feasibility of RNA interference in ticks promise imminent and substantial progress in tick innate immunity research.

  9. Foot-and-mouth disease virus 5’-terminal S fragment is required for replication and modulation of the innate immune response in host cells

    Science.gov (United States)

    The foot-and-mouth disease virus (FMDV) contains a 5’ untranslated region (5’UTR) with multiple structural domains that regulate viral genome replication, translation, and virus-host interactions. At its 5’terminus, the S fragment of over 360 bp is predicted to form a stable stem-loop that is separ...

  10. Determinants of host susceptibility to murine respiratory syncytial virus (RSV) disease identify a role for the innate immunity scavenger receptor MARCO gene in human infants.

    Science.gov (United States)

    High, Monica; Cho, Hye-Youn; Marzec, Jacqui; Wiltshire, Tim; Verhein, Kirsten C; Caballero, Mauricio T; Acosta, Patricio L; Ciencewicki, Jonathan; McCaw, Zackary R; Kobzik, Lester; Miller-DeGraff, Laura; Gladwell, Wes; Peden, David B; Serra, M Elina; Shi, Min; Weinberg, Clarice; Suzuki, Oscar; Wang, Xuting; Bell, Douglas A; Polack, Fernando P; Kleeberger, Steven R

    2016-09-01

    Respiratory syncytial virus (RSV) is the global leading cause of lower respiratory tract infection in infants. Nearly 30% of all infected infants develop severe disease including bronchiolitis, but susceptibility mechanisms remain unclear. We infected a panel of 30 inbred strains of mice with RSV and measured changes in lung disease parameters 1 and 5days post-infection and they were used in genome-wide association (GWA) studies to identify quantitative trait loci (QTL) and susceptibility gene candidates. GWA identified QTLs for RSV disease phenotypes, and the innate immunity scavenger receptor Marco was a candidate susceptibility gene; targeted deletion of Marco worsened murine RSV disease. We characterized a human MARCO promoter SNP that caused loss of gene expression, increased in vitro cellular response to RSV infection, and associated with increased risk of disease severity in two independent populations of children infected with RSV. Translational integration of a genetic animal model and in vitro human studies identified a role for MARCO in human RSV disease severity. Because no RSV vaccines are approved for clinical use, genetic studies have implications for diagnosing individuals who are at risk for severe RSV disease, and disease prevention strategies (e.g. RSV antibodies). Published by Elsevier B.V.

  11. Plant innate immunity induced by flagellin suppresses the hypersensitive response in non-host plants elicited by Pseudomonas syringae pv. averrhoi.

    Science.gov (United States)

    Wei, Chia-Fong; Hsu, Shih-Tien; Deng, Wen-Ling; Wen, Yu-Der; Huang, Hsiou-Chen

    2012-01-01

    A new pathogen, Pseudomonas syringae pv. averrhoi (Pav), which causes bacterial spot disease on carambola was identified in Taiwan in 1997. Many strains of this pathovar have been isolated from different locations and several varieties of hosts. Some of these strains, such as HL1, are nonmotile and elicit a strong hypersensitive response (HR) in nonhost tobacco leaves, while other strains, such as PA5, are motile and elicit a weak HR. Based on the image from a transmission electron microscope, the results showed that HL1 is flagellum-deficient and PA5 has normal flagella. Here we cloned and analyzed the fliC gene and glycosylation island from Pav HL1 and PA5. The amino acid sequences of FliC from HL1 and PA5 are identical to P. s. pvs. tabaci (Pta), glycinea and phaseolicola and share very high similarity with other pathovars of P. syringae. In contrast to the flagellin mutant PtaΔfliC, PA5ΔfliC grows as well as wild type in the host plant, but it elicits stronger HR than wild type does in non-host plants. Furthermore, the purified Pav flagellin, but not the divergent flagellin from Agrobacterium tumefaciens, is able to impair the HR induced by PA5ΔfliC. PA5Δfgt1 possessing nonglycosylated flagella behaved as its wild type in both bacterial growth in host and HR elicitation. Flagellin was infiltrated into tobacco leaves either simultaneously with flagellum-deficient HL1 or prior to the inoculation of wild type HL1, and both treatments impaired the HR induced by HL1. Moreover, the HR elicited by PA5 and PA5ΔfliC was enhanced by the addition of cycloheximide, suggesting that the flagellin is one of the PAMPs (pathogen-associated molecular patterns) contributed to induce the PAMP-triggered immunity (PTI). Taken together, the results shown in this study reveal that flagellin in Pav is capable of suppressing HR via PTI induction during an incompatible interaction.

  12. Plant innate immunity induced by flagellin suppresses the hypersensitive response in non-host plants elicited by Pseudomonas syringae pv. averrhoi.

    Directory of Open Access Journals (Sweden)

    Chia-Fong Wei

    Full Text Available A new pathogen, Pseudomonas syringae pv. averrhoi (Pav, which causes bacterial spot disease on carambola was identified in Taiwan in 1997. Many strains of this pathovar have been isolated from different locations and several varieties of hosts. Some of these strains, such as HL1, are nonmotile and elicit a strong hypersensitive response (HR in nonhost tobacco leaves, while other strains, such as PA5, are motile and elicit a weak HR. Based on the image from a transmission electron microscope, the results showed that HL1 is flagellum-deficient and PA5 has normal flagella. Here we cloned and analyzed the fliC gene and glycosylation island from Pav HL1 and PA5. The amino acid sequences of FliC from HL1 and PA5 are identical to P. s. pvs. tabaci (Pta, glycinea and phaseolicola and share very high similarity with other pathovars of P. syringae. In contrast to the flagellin mutant PtaΔfliC, PA5ΔfliC grows as well as wild type in the host plant, but it elicits stronger HR than wild type does in non-host plants. Furthermore, the purified Pav flagellin, but not the divergent flagellin from Agrobacterium tumefaciens, is able to impair the HR induced by PA5ΔfliC. PA5Δfgt1 possessing nonglycosylated flagella behaved as its wild type in both bacterial growth in host and HR elicitation. Flagellin was infiltrated into tobacco leaves either simultaneously with flagellum-deficient HL1 or prior to the inoculation of wild type HL1, and both treatments impaired the HR induced by HL1. Moreover, the HR elicited by PA5 and PA5ΔfliC was enhanced by the addition of cycloheximide, suggesting that the flagellin is one of the PAMPs (pathogen-associated molecular patterns contributed to induce the PAMP-triggered immunity (PTI. Taken together, the results shown in this study reveal that flagellin in Pav is capable of suppressing HR via PTI induction during an incompatible interaction.

  13. Immune Responses in Rhinovirus-Induced Asthma Exacerbations.

    Science.gov (United States)

    Steinke, John W; Borish, Larry

    2016-11-01

    Acute asthma exacerbations are responsible for urgent care visits and hospitalizations; they interfere with school and work productivity, thereby driving much of the morbidity and mortality associated with asthma. Approximately 80 to 85 % of asthma exacerbations in children, adolescents, and less frequently adults are associated with viral upper respiratory tract viral infections, and rhinovirus (RV) accounts for ∼60-70 % of these virus-associated exacerbations. Evidence suggests that it is not the virus itself but the nature of the immune response to RV that drives this untoward response. In particular, evidence supports the concept that RV acts to exacerbate an ongoing allergic inflammatory response to environmental allergens present at the time of the infection. The interaction of the ongoing IgE- and T cell-mediated response to allergen superimposed on the innate and adaptive immune responses to the virus and how this leads to triggering of an asthma exacerbation is discussed.

  14. Innate Immunity and the 2011 Nobel Prize

    Indian Academy of Sciences (India)

    IAS Admin

    It may be important to point out that the innate response is useful to the host to initiate responses that protect it from microbes, microbial constituents, dead host cells, endogenous cholesterol, uric acid, etc.; however, an unregulated response may be harmful due to the excessive production of free radicals and cytokines.

  15. Prevention of COPD exacerbations

    DEFF Research Database (Denmark)

    Vestbo, Jørgen; Lange, Peter

    2015-01-01

    Exacerbations have significant impact on the morbidity and mortality of patients with chronic obstructive pulmonary disease. Most guidelines emphasise prevention of exacerbations by treatment with long-acting bronchodilators and/or anti-inflammatory drugs. Whereas most of this treatment is eviden...

  16. Innate immune sensing of HIV-1 infection.

    Science.gov (United States)

    Jakobsen, Martin R; Olagnier, David; Hiscott, John

    2015-03-01

    The innate immune system plays a critical role in the control of viral infections. Although the mechanisms involved in sensing and response to viral pathogens has progressed tremendously in the last decade, an understanding of the innate antiviral response to human retroviruses lagged behind. Recent studies now demonstrate that human retroviruses such as human immunodeficiency virus type 1 (HIV-1) and human T-lymphotropic virus 1 (HTLV-1) trigger a type I interferon antiviral response through novel cytosolic sensors that detect DNA intermediates of reverse transcription; in addition, these early host-pathogen interactions may trigger cell death pathways depending on the activation state of the target cell. The purpose of this review is to summarize the recent progress in the understanding of innate immune sensing of human retroviruses. Innate immune sensing of HIV-1 and HTLV-1 is influenced by the target cell phenotype, viral replicative intermediates, and host restriction factors that limit retroviral replication. Macrophages and dendritic cells detect HIV-DNA intermediates, whereas CD4 T cells differentially sense HIV DNA depending on the level of T-cell activation. Furthermore, the structure of the viral capsid and interplay between innate DNA sensors and host restriction factors all contribute to the magnitude of the ensuing innate immune response. The interplay between HIV infection and the innate immune system has emerged as an important component of HIV pathogenesis, linked to both induction of innate immunity and stimulation of cell death mechanisms. Ultimately, an in-depth knowledge of the mechanisms of innate immune control of human retrovirus infection may facilitate the development of novel treatment strategies to control retrovirus-induced immunopathology.

  17. Small Heterodimer Partner and Innate Immune Regulation

    Directory of Open Access Journals (Sweden)

    Jae-Min Yuk

    2016-03-01

    Full Text Available The nuclear receptor superfamily consists of the steroid and non-steroid hormone receptors and the orphan nuclear receptors. Small heterodimer partner (SHP is an orphan family nuclear receptor that plays an essential role in the regulation of glucose and cholesterol metabolism. Recent studies reported a previously unidentified role for SHP in the regulation of innate immunity and inflammation. The innate immune system has a critical function in the initial response against a variety of microbial and danger signals. Activation of the innate immune response results in the induction of inflammatory cytokines and chemokines to promote anti-microbial effects. An excessive or uncontrolled inflammatory response is potentially harmful to the host, and can cause tissue damage or pathological threat. Therefore, the innate immune response should be tightly regulated to enhance host defense while preventing unwanted immune pathologic responses. In this review, we discuss recent studies showing that SHP is involved in the negative regulation of toll-like receptor-induced and NLRP3 (NACHT, LRR and PYD domains-containing protein 3-mediated inflammatory responses in innate immune cells. Understanding the function of SHP in innate immune cells will allow us to prevent or modulate acute and chronic inflammation processes in cases where dysregulated innate immune activation results in damage to normal tissues.

  18. [Innate immunity primary immunodeficiencies and infections].

    Science.gov (United States)

    Duchamp, M; Miot, C; Bustamante, J C; Picard, C

    2016-07-01

    The diagnosis of primary immunodeficiency diseases (PIDs) is important for the early and adaptive care of patients and their families. Among the various known PIDs, a number of them concern the innate immune system, which involve a set of cells and mechanisms involved in the host defense by a nonspecific and fast response. The majority of patients with innate immunity defects have a predisposition to one isolated type of infection (bacterial, viral, or fungal), dependent on the genetic defect involved. This article describes the different PIDs involving innate immunity and the immunological investigations allowing for their diagnosis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Seasonal Risk Factors for Asthma Exacerbations among Inner City Children

    Science.gov (United States)

    Teach, Stephen J.; Gergen, Peter J.; Szefler, Stanley J.; Mitchell, Herman E.; Calatroni, Agustin; Wildfire, Jeremy; Bloomberg, Gordon; Kercsmar, Carolyn; Liu, Andrew H.; Makhija, Melanie; Matsui, Elizabeth; Morgan, Wayne; O'Connor, George; Busse, William W.

    2015-01-01

    Background Exacerbations of asthma remain common even in children and adolescents despite optimal medical management. Identification of host risk factors for exacerbations is incomplete, particularly for seasonal episodes. Objective Define host risk factors for asthma exacerbations unique to their season of occurrence. Methods This is a retrospective analysis of patients aged 6-20 years who comprised the control groups of the Asthma Control Evaluation trial and the Inner City Anti-IgE Therapy for Asthma trial. Univariate and multivariate models were constructed to determine if patient demographic and historical factors, allergic sensitization, fractional exhaled nitric oxide, spirometric measurements, asthma control, and treatment requirements were associated with seasonal exacerbations. Results The analysis included 400 patients (54.5% male; 59.0% African American; median age 13 years). Exacerbations occurred in 37.5% of participants over the periods of observation and were most common in the fall (28.8% of participants). In univariate analysis, impaired pulmonary function was significantly associated with greater odds of exacerbations for all seasons, as was an exacerbation in the previous season for all seasons except spring. In multivariate analysis, exacerbation in the previous season was the strongest predictor in fall and winter while a higher requirement for inhaled corticosteroids was the strongest predictor in spring and summer. The multivariate models had the best predictive power for fall exacerbations (30.5% variance attributed). Conclusions Among a large cohort of inner city children with asthma, patient risk factors for exacerbations vary by season. Thus, individual patient information may be beneficial in strategies to prevent these seasonal events. Clinical Implications Inner city children remain at risk for asthma exacerbations despite appropriate therapy. Because their risk factors vary by season, strategies to prevent them may need to differ as

  20. Tumour viruses and innate immunity.

    Science.gov (United States)

    Hopcraft, Sharon E; Damania, Blossom

    2017-10-19

    Host cells sense viral infection through pattern recognition receptors (PRRs), which detect pathogen-associated molecular patterns (PAMPs) and stimulate an innate immune response. PRRs are localized to several different cellular compartments and are stimulated by viral proteins and nucleic acids. PRR activation initiates signal transduction events that ultimately result in an inflammatory response. Human tumour viruses, which include Kaposi's sarcoma-associated herpesvirus, Epstein-Barr virus, human papillomavirus, hepatitis C virus, hepatitis B virus, human T-cell lymphotropic virus type 1 and Merkel cell polyomavirus, are detected by several different PRRs. These viruses engage in a variety of mechanisms to evade the innate immune response, including downregulating PRRs, inhibiting PRR signalling, and disrupting the activation of transcription factors critical for mediating the inflammatory response, among others. This review will describe tumour virus PAMPs and the PRRs responsible for detecting viral infection, PRR signalling pathways, and the mechanisms by which tumour viruses evade the host innate immune system.This article is part of the themed issue 'Human oncogenic viruses'. © 2017 The Author(s).

  1. Incidence and risk factors for exacerbations of asthma during pregnancy

    Directory of Open Access Journals (Sweden)

    Ali Z

    2013-05-01

    Full Text Available Zarqa Ali, Charlotte Suppli UlrikDepartment of Pulmonary Medicine, Hvidovre Hospital and University of Copenhagen, Copenhagen, DenmarkBackground: Asthma is one of the most common chronic diseases among pregnant women. Acute exacerbations of asthma during pregnancy have an unfavorable impact on pregnancy outcome. This review provides an overview of current knowledge of incidence, mechanisms, and risk factors for acute exacerbations of asthma during pregnancy.Methods: A narrative literature review was carried out using the PubMed database.Results: During pregnancy, up to 6% of women with asthma are hospitalized for an acute exacerbation. The maternal immune system is characterized by a very high T-helper-2:T-helper-1 cytokine ratio during pregnancy and thereby provides an environment essential for fetal survival but one that may aggravate asthma. Cells of the innate immune system such as monocytes and neutrophils are also increased during pregnancy, and this too can exacerbate maternal asthma. Severe or difficult-to-control asthma appears to be the major risk factor for exacerbations during pregnancy, but studies also suggest that nonadherence with controller medication and viral infections are important triggers of exacerbations during pregnancy. So far, inconsistent findings have been reported regarding the effect of fetal sex on exacerbations during pregnancy. Other risk factors for exacerbation during pregnancy include obesity, ethnicity, and reflux, whereas atopy does not appear to be a risk factor.Discussion: The incidence of asthma exacerbations during pregnancy is disturbingly high. Severe asthma – better described as difficult-to-control asthma – nonadherence with controller therapy, viral infections, obesity, and ethnicity are likely to be important risk factors for exacerbations of asthma during pregnancy, whereas inconsistent findings have been reported with regard to the importance of sex of the fetus.Keywords: acute exacerbations

  2. Dietary Salt Exacerbates Experimental Colitis.

    Science.gov (United States)

    Tubbs, Alan L; Liu, Bo; Rogers, Troy D; Sartor, R Balfour; Miao, Edward A

    2017-08-01

    The Western diet is characterized by high protein, sugar, fat, and low fiber intake, and is widely believed to contribute to the incidence and pathogenesis of inflammatory bowel disease (IBD). However, high sodium chloride salt content, a defining feature of processed foods, has not been considered as a possible environmental factor that might drive IBD. We set out to bridge this gap. We examined murine models of colitis on either a high salt diet (HSD) or a low salt diet. We demonstrate that an HSD exacerbates inflammatory pathology in the IL-10-deficient murine model of colitis relative to mice fed a low salt diet. This was correlated with enhanced expression of numerous proinflammatory cytokines. Surprisingly, sodium accumulated in the colons of mice on an HSD, suggesting a direct effect of salt within the colon. Similar to the IL-10-deficient model, an HSD also enhanced cytokine expression during infection by Salmonella typhimurium This occurred in the first 3 d of infection, suggesting that an HSD potentiates an innate immune response. Indeed, in cultured dendritic cells we found that high salt media potentiates cytokine expression downstream of TLR4 activation via p38 MAPK and SGK1. A third common colitis model, administration of dextran sodium sulfate, was hopelessly confounded by the high sodium content of the dextran sodium sulfate. Our results raise the possibility that high dietary salt is an environmental factor that drives increased inflammation in IBD. Copyright © 2017 by The American Association of Immunologists, Inc.

  3. Taste Receptors in Innate Immunity

    Science.gov (United States)

    Lee, Robert J.

    2014-01-01

    Taste receptors were first identified on the tongue, where they initiate a signaling pathway that communicates information to the brain about the nutrient content or potential toxicity of ingested foods. However, recent research has shown that taste receptors are also expressed in a myriad of other tissues, from the airway and gastrointestinal epithelia to the pancreas and brain. The functions of many of these extraoral taste receptors remain unknown, but emerging evidence suggests that bitter and sweet taste receptors in the airway are important sentinels of innate immunity. This review discusses taste receptor signaling, focusing on the G-protein coupled–receptors that detect bitter, sweet, and savory tastes, followed by an overview of extraoral taste receptors and in-depth discussion of studies demonstrating the roles of taste receptors in airway innate immunity. Future research on extraoral taste receptors has significant potential for identification of novel immune mechanisms and insights into host-pathogen interactions. PMID:25323130

  4. Innate Immune Effectors in Mycobacterial Infection

    Directory of Open Access Journals (Sweden)

    Hiroyuki Saiga

    2011-01-01

    Full Text Available Tuberculosis, which is caused by infection with Mycobacterium tuberculosis (Mtb, remains one of the major bacterial infections worldwide. Host defense against Mtb is mediated by a combination of innate and adaptive immune responses. In the last 15 years, the mechanisms for activation of innate immunity have been elucidated. Toll-like receptors (TLRs have been revealed to be critical for the recognition of pathogenic microorganisms including mycobacteria. Subsequent studies further revealed that NOD-like receptors and C-type lectin receptors are responsible for the TLR-independent recognition of mycobacteria. Several molecules, such as active vitamin D3, secretary leukocyte protease inhibitor, and lipocalin 2, all of which are induced by TLR stimulation, have been shown to direct innate immune responses to mycobacteria. In addition, Irgm1-dependent autophagy has recently been demonstrated to eliminate intracellular mycobacteria. Thus, our understanding of the mechanisms for the innate immune response to mycobacteria is developing.

  5. Activation of the Innate Immune Receptors: Guardians of the Micro Galaxy : Activation and Functions of the Innate Immune Receptors.

    Science.gov (United States)

    De Nardo, Dominic

    2017-01-01

    The families of innate immune receptors are the frontline responders to danger. These superheroes of the host immune systems populate innate immune cells, surveying the extracellular environment and the intracellular endolysosomal compartments and cytosol for exogenous and endogenous danger signals. As a collective the innate immune receptors recognise a wide array of stimuli, and in response they initiate specific signalling pathways leading to activation of transcriptional or proteolytic pathways and the production of inflammatory molecules to destroy foreign pathogens and/or resolve tissue injury. In this review, I will give an overview of the innate immune system and the activation and effector functions of the families of receptors it comprises. Current key concepts will be described throughout, including innate immune memory, formation of innate immune receptor signalosomes, inflammasome formation and pyroptosis, methods of extrinsic cell communication and examples of receptor cooperation. Finally, several open questions and future directions in the field of innate immunity will be presented and discussed.

  6. The innate and adaptive immune response to avian influenza virus

    Science.gov (United States)

    Protective immunity against viruses is mediated by the early innate immune responses and later on by the adaptive immune responses. The early innate immunity is designed to contain and limit virus replication in the host, primarily through cytokine and interferon production. Most all cells are cap...

  7. The Epitranscriptome and Innate Immunity.

    Directory of Open Access Journals (Sweden)

    Mary A O'Connell

    2015-12-01

    Full Text Available Our knowledge of the variety and abundances of RNA base modifications is rapidly increasing. Modified bases have critical roles in tRNAs, rRNAs, translation, splicing, RNA interference, and other RNA processes, and are now increasingly detected in all types of transcripts. Can new biological principles associated with this diversity of RNA modifications, particularly in mRNAs and long non-coding RNAs, be identified? This review will explore this question by focusing primarily on adenosine to inosine (A-to-I RNA editing by the adenine deaminase acting on RNA (ADAR enzymes that have been intensively studied for the past 20 years and have a wide range of effects. Over 100 million adenosine to inosine editing sites have been identified in the human transcriptome, mostly in embedded Alu sequences that form potentially innate immune-stimulating dsRNA hairpins in transcripts. Recent research has demonstrated that inosine in the epitranscriptome and ADAR1 protein establish innate immune tolerance for host dsRNA formed by endogenous sequences. Innate immune sensors that detect viral nucleic acids are among the readers of epitranscriptome RNA modifications, though this does preclude a wide range of other modification effects.

  8. Dark chocolate exacerbates acne.

    Science.gov (United States)

    Vongraviopap, Saivaree; Asawanonda, Pravit

    2016-05-01

    The effects of chocolate on acne exacerbations have recently been reevaluated. For so many years, it was thought that it had no role in worsening acne. To investigate whether 99% dark chocolate, when consumed in regular daily amounts, would cause acne to worsen in acne-prone male subjects, twenty-five acne prone male subjects were asked to consume 25 g of 99% dark chocolate daily for 4 weeks. Assessments which included Leeds revised acne scores as well as lesion counts took place weekly. Food frequency questionnaire was used, and daily activities were recorded. Statistically significant changes of acne scores and numbers of comedones and inflammatory papules were detected as early as 2 weeks into the study. At 4 weeks, the changes remained statistically significant compared to baseline. Dark chocolate when consumed in normal amounts for 4 weeks can exacerbate acne in male subjects with acne-prone skin. © 2015 The International Society of Dermatology.

  9. Aspirin-Exacerbated Asthma

    OpenAIRE

    Varghese, Mathew; Lockey, Richard F

    2008-01-01

    This review focuses on aspirin-exacerbated asthma (AEA). The review includes historical perspective of aspirin, prevalence, pathogenesis, clinical features and treatment of AEA. The pathogenesis of AEA involves the cyclooxygenase and lipooxygenase pathway. Aspirin affects both of these pathways by inhibiting the enzyme cycooxygenase-1 (COX-1). Inhibition of COX-1 leads to a decrease in prostaglandin E2 (PGE2). The decrease in PGE2 results in an increase in cysteinyl leukotrienes by the lipoo...

  10. Post-Translational Modification Control of Innate Immunity.

    Science.gov (United States)

    Liu, Juan; Qian, Cheng; Cao, Xuetao

    2016-07-19

    A coordinated balance between the positive and negative regulation of pattern-recognition receptor (PRR)-initiated innate inflammatory responses is required to ensure the most favorable outcome for the host. Post-translational modifications (PTMs) of innate sensors and downstream signaling molecules influence their activity and function by inducing their covalent linkage to new functional groups. PTMs including phosphorylation and polyubiquitination have been shown to potently regulate innate inflammatory responses through the activation, cellular translocation, and interaction of innate receptors, adaptors, and downstream signaling molecules in response to infectious and dangerous signals. Other PTMs such as methylation, acetylation, SUMOylation, and succinylation are increasingly implicated in the regulation of innate immunity and inflammation. In this review, we focus on the roles of PTMs in controlling PRR-triggered innate immunity and inflammatory responses. The emerging roles of PTMs in the pathogenesis and potential treatment of infectious and inflammatory immune diseases are also discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. A prime time for trained immunity: innate immune memory in newborns and infants.

    Science.gov (United States)

    Levy, Ofer; Wynn, James L

    2014-01-01

    The newborn and infant periods of early life are associated with heightened vulnerability to infection. Limited antigen exposure and distinct adaptive immune function compared to the adult places a greater burden on innate immunity for host defense to microbial challenge during this time. Trained immunity describes the phenomenon of augmented innate immune function following a stimulus that is not specific to the original stimulus. We review the concept of trained immunity in the context of the newborn's unique innate immune system function, the preclinical and clinical evidence that supports the tenet of innate immune memory in early life, and potential consequences of altered innate immune host responses. © 2013 S. Karger AG, Basel.

  12. A Prime Time for Trained Immunity: Innate Immune Memory in Newborns & Infants

    Science.gov (United States)

    Levy, Ofer; Wynn, James L.

    2014-01-01

    The newborn and infant periods of early life are associated with heightened vulnerability to infection. Limited antigen exposure and distinct adaptive immune function compared to the adult places a greater burden on innate immunity for host defense to microbial challenge during this time. Trained immunity describes the phenomenon of augmented innate immune function following a stimulus that is not specific to the original stimulus. We review the concept of trained immunity in the context of the newborn’s unique innate immune system function, the preclinical and clinical evidence that support the tenet of innate immune memory in early life, and potential consequences of altered innate immune host responses. PMID:24356292

  13. Human innate lymphoid cells

    NARCIS (Netherlands)

    Hazenberg, Mette D.; Spits, Hergen

    2014-01-01

    Innate lymphoid cells (ILCs) are lymphoid cells that do not express rearranged receptors and have important effector and regulatory functions in innate immunity and tissue remodeling. ILCs are categorized into 3 groups based on their distinct patterns of cytokine production and the requirement of

  14. Innate immune response to Burkholderia mallei.

    Science.gov (United States)

    Saikh, Kamal U; Mott, Tiffany M

    2017-06-01

    Burkholderia mallei is a facultative intracellular pathogen that causes the highly contagious and often the fatal disease, glanders. With its high rate of infectivity via aerosol and recalcitrance toward antibiotics, this pathogen is considered a potential biological threat agent. This review focuses on the most recent literature highlighting host innate immune response to B. mallei. Recent studies focused on elucidating host innate immune responses to the novel mechanisms and virulence factors employed by B. mallei for survival. Studies suggest that pathogen proteins manipulate various cellular processes, including host ubiquitination pathways, phagosomal escape, and actin-cytoskeleton rearrangement. Immune-signaling molecules such as Toll-like receptors, nucleotode-binding oligomerization domain, myeloid differentiation primary response protein 88, and proinflammatory cytokines such as interferon-gamma and tumor necrosis factor-α, play key roles in the induction of innate immune responses. Modifications in B. mallei lipopolysaccharide, in particular, the lipid A acyl groups, stimulate immune responses via Toll-like receptor4 activation that may contribute to persistent infection. Mortality is high because of septicemia and immune pathogenesis with B. mallei exposure. An effective innate immune response is critical to controlling the acute phase of the infection. Both vaccination and therapeutic approaches are necessary for complete protection against B. mallei.

  15. Salmonella enterica serovar Typhimurium ΔmsbB Triggers Exacerbated Inflammation in Nod2 Deficient Mice

    Science.gov (United States)

    Claes, Anne-Kathrin; Steck, Natalie; Schultz, Dorothee; Zähringer, Ulrich; Lipinski, Simone; Rosenstiel, Philip; Geddes, Kaoru; Philpott, Dana J.; Heine, Holger; Grassl, Guntram A.

    2014-01-01

    The intracellular pathogen Salmonella enterica serovar Typhimurium causes intestinal inflammation characterized by edema, neutrophil influx and increased pro-inflammatory cytokine expression. A major bacterial factor inducing pro-inflammatory host responses is lipopolysaccharide (LPS). S. Typhimurium ΔmsbB possesses a modified lipid A, has reduced virulence in mice, and is being considered as a potential anti-cancer vaccine strain. The lack of a late myristoyl transferase, encoded by MsbB leads to attenuated TLR4 stimulation. However, whether other host receptor pathways are also altered remains unclear. Nod1 and Nod2 are cytosolic pattern recognition receptors recognizing bacterial peptidoglycan. They play important roles in the host's immune response to enteric pathogens and in immune homeostasis. Here, we investigated how deletion of msbB affects Salmonella's interaction with Nod1 and Nod2. S. Typhimurium Δ msbB-induced inflammation was significantly exacerbated in Nod2−/− mice compared to C57Bl/6 mice. In addition, S. Typhimurium ΔmsbB maintained robust intestinal colonization in Nod2−/− mice from day 2 to day 7 p.i., whereas colonization levels significantly decreased in C57Bl/6 mice during this time. Similarly, infection of Nod1−/− and Nod1/Nod2 double-knockout mice revealed that both Nod1 and Nod2 play a protective role in S. Typhimurium ΔmsbB-induced colitis. To elucidate why S. Typhimurium ΔmsbB, but not wild-type S. Typhimurium, induced an exacerbated inflammatory response in Nod2−/− mice, we used HEK293 cells which were transiently transfected with pathogen recognition receptors. Stimulation of TLR2-transfected cells with S. Typhimurium ΔmsbB resulted in increased IL-8 production compared to wild-type S. Typhimurium. Our results indicate that S. Typhimurium ΔmsbB triggers exacerbated colitis in the absence of Nod1 and/or Nod2, which is likely due to increased TLR2 stimulation. How bacteria with “genetically detoxified” LPS

  16. COPD exacerbation: Lost in translation

    Directory of Open Access Journals (Sweden)

    Bouros Demosthenes

    2009-01-01

    Full Text Available Abstract The introduction and acceptance of a standard definition for exacerbations of COPD can be helpful in prompt diagnosis and management of these events. The latest GOLD executive committee recognised this necessity and it has now included a definition of exacerbation in the guidelines for COPD which is an important step forward in the management of the disease. This definition is pragmatic and compromises the different approaches for exacerbation. However, the inclusion of the "healthcare utilisation" approach (".. may warrant a change in regular medication" in the definition may introduce in the diagnosis of exacerbation factors related to the access to health care services which may not be related to the underlying pathophysiologal process which characterizes exacerbations. It should be also noted that the aetiology of COPD exacerbations has not yet been included in the current definition. In this respect, the definition does not acknowledge the fact that many patients with COPD may suffer from additional conditions (i.e. congestive cardiac failure or pulmonary embolism that can masquerade as exacerbations but they should not be considered as causes of them. The authors therefore suggest that an inclusion of the etiologic factors of COPD exacerbations in the definition. Moreover, COPD exacerbations are characterized by increased airway and systemic inflammation and significant deterioration in lung fuction. These fundamental aspects should be accounted in diagnosis/definition of exacerbations. This could be done by the introduction of a "laboratory" marker in the diagnosis of these acute events. The authors acknowledge that the use of a test or a biomarker in the diagnosis of exacerbations meets certain difficulties related to performing lung function tests or to sampling during exacerbations. However, the introduction of a test that reflects airway or systemic inflammation in the diagnosis of exacerbations might be another step forward

  17. Induction of innate immunity and its perturbation by influenza viruses.

    Science.gov (United States)

    Goraya, Mohsan Ullah; Wang, Song; Munir, Muhammad; Chen, Ji-Long

    2015-10-01

    Influenza A viruses (IAV) are highly contagious pathogens causing dreadful losses to human and animal, around the globe. IAVs first interact with the host through epithelial cells, and the viral RNA containing a 5'-triphosphate group is thought to be the critical trigger for activation of effective innate immunity via pattern recognition receptors-dependent signaling pathways. These induced immune responses establish the antiviral state of the host for effective suppression of viral replication and enhancing viral clearance. However, IAVs have evolved a variety of mechanisms by which they can invade host cells, circumvent the host immune responses, and use the machineries of host cells to synthesize and transport their own components, which help them to establish a successful infection and replication. In this review, we will highlight the molecular mechanisms of how IAV infection stimulates the host innate immune system and strategies by which IAV evades host responses.

  18. Osteopontin That Is Elevated in the Airways during COPD Impairs the Antibacterial Activity of Common Innate Antibiotics.

    Directory of Open Access Journals (Sweden)

    Anele Gela

    Full Text Available Bacterial infections of the respiratory tract contribute to exacerbations and disease progression in chronic obstructive pulmonary disease (COPD. There is also an increased risk of invasive pneumococcal disease in COPD. The underlying mechanisms are not fully understood but include impaired mucociliary clearance and structural remodeling of the airways. In addition, antimicrobial proteins that are constitutively expressed or induced during inflammatory conditions are an important part of the airway innate host defense. In the present study, we show that osteopontin (OPN, a multifunctional glycoprotein that is highly upregulated in the airways of COPD patients co-localizes with several antimicrobial proteins expressed in the airways. In vitro, OPN bound lactoferrin, secretory leukocyte peptidase inhibitor (SLPI, midkine, human beta defensin-3 (hBD-3, and thymic stromal lymphopoietin (TSLP but showed low or no affinity for lysozyme and LL-37. Binding of OPN impaired the antibacterial activity against the important bacterial pathogens Streptococcus pneumoniae and Pseudomonas aeruginosa. Interestingly, OPN reduced lysozyme-induced killing of S. pneumoniae, a finding that could be explained by binding of OPN to the bacterial surface, thereby shielding the bacteria. A fragment of OPN generated by elastase of P. aeruginosa retained some inhibitory effect. Some antimicrobial proteins have additional functions. However, the muramidase-activity of lysozyme and the protease inhibitory function of SLPI were not affected by OPN. Taken together, OPN can contribute to the impairment of innate host defense by interfering with the function of antimicrobial proteins, thus increasing the vulnerability to acquire infections during COPD.

  19. Corruption of innate immunity by bacterial proteases.

    Science.gov (United States)

    Potempa, Jan; Pike, Robert N

    2009-01-01

    The innate immune system of the human body has developed numerous mechanisms to control endogenous and exogenous bacteria and thus prevent infections by these microorganisms. These mechanisms range from physical barriers such as the skin or mucosal epithelium to a sophisticated array of molecules and cells that function to suppress or prevent bacterial infection. Many bacteria express a variety of proteases, ranging from non-specific and powerful enzymes that degrade many proteins involved in innate immunity to proteases that are extremely precise and specific in their mode of action. Here we have assembled a comprehensive picture of how bacterial proteases affect the host's innate immune system to gain advantage and cause infection. This picture is far from being complete since the numbers of mechanisms utilized are as astonishing as they are diverse, ranging from degradation of molecules vital to innate immune mechanisms to subversion of the mechanisms to allow the bacterium to hide from the system or take advantage of it. It is vital that such mechanisms are elucidated to allow strategies to be developed to aid the innate immune system in controlling bacterial infections.

  20. Activation of innate immunity during systemic Candida infections

    NARCIS (Netherlands)

    Ifrim, D.C.

    2015-01-01

    Despite the increased knowledge on the mechanisms of Candida recognition and the networks of innate and adaptive host defense activated during infection, much remains to be learned regarding the distinctive modulatory effects of Candida spp on host immune responses. We showed that the chronic

  1. Interplay of innate lymphoid cells and the microbiota.

    Science.gov (United States)

    Britanova, Liudmila; Diefenbach, Andreas

    2017-09-01

    Innate lymphoid cells (ILC) are a recently identified group of innate lymphocytes that are preferentially located at barrier surfaces. Barrier surfaces are in direct contact with complex microbial ecosystems, collectively referred to as the microbiota. It is now believed that the interplay of the microbiota with host components (i.e. epithelial cells and immune cells) promotes host fitness by regulating organ homeostasis, metabolism, and host defense against pathogens. In this review, we will give an overview of this multifaceted interplay between ILC and components of the microbiota. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Exacerbations of asthma during pregnancy

    DEFF Research Database (Denmark)

    Ali, Z; Hansen, A V; Ulrik, C S

    2016-01-01

    that asthma exacerbations during pregnancy increase the risk of pre-eclampsia, gestational diabetes, placental abruption and placenta praevia. Furthermore, these women also have higher risk for breech presentation, haemorrhage, pulmonary embolism, caesarean delivery, maternal admission to the intensive care...... to these outcomes. In conclusion, asthma exacerbations during pregnancy are associated with complications of pregnancy, labour and delivery. Prevention of exacerbations is essential to reduce the risk of complications and poor outcome....

  3. Exacerbations of asthma - A descriptive study of 425 severe exacerbations

    NARCIS (Netherlands)

    Tattersfield, AE; Postma, DS; Barnes, PJ; Svensson, K; Bauer, CA; O'Byrne, PM; Lofdahl, CG; Pauwels, RA; Ullman, A

    The identification, prevention, and prompt treatment of exacerbations are major objectives of asthma management. We looked at change in PEF, symptoms, and use of rescue p-agonists during the 425 severe exacerbations that occurred during a 12-mo parallel group study (FACET) in which low and high

  4. Innate Immune Activation in Intestinal Homeostasis

    OpenAIRE

    Harrison, Oliver J.; Maloy, Kevin J.

    2011-01-01

    Loss of intestinal immune regulation leading to aberrant immune responses to the commensal microbiota are believed to precipitate the chronic inflammation observed in the gastrointestinal tract of patients with inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis. Innate immune receptors that recognize conserved components derived from the microbiota are widely expressed by both epithelial cells and leucocytes of the gastrointestinal tract and play a key role in host prot...

  5. T cells exacerbate Lyme borreliosis in TLR2-deficient mice

    Directory of Open Access Journals (Sweden)

    Carrie E. Lasky

    2016-11-01

    Full Text Available Infection of humans with the spirochete, Borrelia burgdorferi, causes Lyme borreliosis and can lead to clinical manifestations such as, arthritis, carditis and neurological conditions. Experimental infection of mice recapitulates many of these symptoms and serves as a model system for the investigation of disease pathogenesis and immunity. Innate immunity is known to drive the development of Lyme arthritis and carditis, but the mechanisms driving this response remain unclear. Innate immune cells recognize B. burgdorferi surface lipoproteins primarily via Toll-like receptor (TLR2; however, previous work has demonstrated TLR2-/- mice had exacerbated disease and increased bacterial burden. We demonstrate increased CD4 and CD8 T cell infiltrates in B. burgdorferi-infected joints and hearts of C3H TLR2-/- mice. In vivo depletion of either CD4 or CD8 T cells reduced Borrelia-induced joint swelling and lowered tissue spirochete burden, while depletion of CD8 T cells alone reduced disease severity scores. Exacerbation of Lyme arthritis correlated with increased production of CXCL9 by synoviocytes and this was reduced with CD8 T cell depletion. These results demonstrate T cells can exacerbate Lyme disease pathogenesis and prolong disease resolution possibly through dysregulation of inflammatory responses and inhibition of bacterial clearance.

  6. Toll-like receptor 3 blockade in rhinovirus-induced experimental asthma exacerbations

    DEFF Research Database (Denmark)

    Silkoff, Philip E; Flavin, Susan; Gordon, Robert

    2017-01-01

    BACKGROUND: Human rhinoviruses (HRVs) commonly precipitate asthma exacerbations. Toll-like receptor 3, an innate pattern recognition receptor, is triggered by HRV, driving inflammation that can worsen asthma. OBJECTIVE: We sought to evaluate an inhibitory mAb to Toll-like receptor 3, CNTO3157, on...

  7. TLR3 Blockade in Rhinovirus-Induced Experimental Asthma Exacerbations: A Randomized Controlled Study

    NARCIS (Netherlands)

    Silkoff, Philip E.; Flavin, Susan; Gordon, Robert; Loza, Mathew J.; Sterk, Peter J.; Lutter, Rene; Diamant, Zuzana; Turner, Ronald B.; Lipworth, Brian J.; Proud, David; Singh, Dave; Eich, Andreas; Backer, Vibeke; Gern, James E.; Herzmann, Christian; Halperin, Scott A.; Mensinga, Tjeert T.; del Vecchio, Alfred M.; Branigan, Patrick; San Mateo, Lani; Baribaud, Frédéric; Barnathan, Elliot S.; Johnston, Sebastian L.

    2017-01-01

    Human rhinoviruses (HRV) commonly precipitate asthma exacerbations. TLR3, an innate pattern-recognition receptor, is triggered by HRV driving inflammation that may worsen asthma. To evaluate an inhibitory monoclonal antibody to TLR3, CNTO3157, on experimental HRV-16 inoculation in healthy and

  8. [Innate immunity and transplantation].

    Science.gov (United States)

    Ponticelli, Claudio

    2015-01-01

    Innate immunity is the first barrier against pathogen infection and has also the important function of activating the adaptive immunity. The receptors of innate immunity, such as toll-like receptors and other receptors, recognize as danger signals the molecular patterns of pathogens as well as those of endogenous molecules released by dying cells. The information is transmitted to adapter proteins that, through a chain of kinases that translate the signal to transcription factors regulating inflammatory genes. In the inflammatory milieu dendritic cells become mature, intercept the antigen and migrate to lymphoid organs where they present the antigen to naïve T cells. Complement also exerts an important role of bridge between innate and adaptive immunity. In donor-deceased kidney transplantation, the innate immunity is triggered in the donor by brain death and is aggravated by the cold ischemia and even more by reperfusion. Once activated, innate immunity produces a local inflammatory environment leading to dendritic cell maturation and complement activation. Dendritic cells present the alloantigen to T cells and induce their differentiation towards effector Th1 and Th17 while inhibiting Th2 and T regulatory cells. A main goal of the current research in transplantation is to obtain an immunological tolerance. Experimental studies showed the possibility of inducing operative tolerance in murine models and even in primates with the infusion of regulatory dendritic cells. However, there are no data with this technique in clinical transplantation.

  9. Regulation of Intestinal Homeostasis by Innate Immune Cells

    OpenAIRE

    Kayama, Hisako; Nishimura, Junichi; Takeda, Kiyoshi

    2013-01-01

    The intestinal immune system has an ability to distinguish between the microbiota and pathogenic bacteria, and then activate pro-inflammatory pathways against pathogens for host defense while remaining unresponsive to the microbiota and dietary antigens. In the intestine, abnormal activation of innate immunity causes development of several inflammatory disorders such as inflammatory bowel diseases (IBD). Thus, activity of innate immunity is finely regulated in the intestine. To date, multiple...

  10. Aspirin-Exacerbated Asthma

    Directory of Open Access Journals (Sweden)

    Varghese Mathew

    2008-06-01

    Full Text Available This review focuses on aspirin-exacerbated asthma (AEA. The review includes historical perspective of aspirin, prevalence, pathogenesis, clinical features and treatment of AEA. The pathogenesis of AEA involves the cyclooxygenase and lipooxygenase pathway. Aspirin affects both of these pathways by inhibiting the enzyme cycooxygenase-1 (COX-1. Inhibition of COX-1 leads to a decrease in prostaglandin E2 (PGE2. The decrease in PGE2 results in an increase in cysteinyl leukotrienes by the lipooxygenase pathway involving the enzyme 5-lipooxygenase (5-LO. Leukotriene C4 (LTC4 synthase is the enzyme responsible for the production of leukotriene C4, the chief cysteinyl leukotriene responsible for AEA. There have been familial occurences of AEA. An allele of the LTC4 synthase gene in AEA is known as allele C. Allele C has a higher frequency in AEA. Clinical presentation includes a history of asthma after ingestion of aspirin, nasal congestion, watery rhinorrhea and nasal polyposis. Treatment includes leukotriene receptor antagonists, leukotriene inhibitors, aspirin desinsitaztion and surgery. AEA is the most well-defined phenotype of asthma. Although AEA affects adults and children with physician-diagnosed asthma, in some cases there is no history of asthma and AEA often goes unrecognized and underdiagnosed.

  11. Oral innate immunity in HIV infection in HAART era.

    Science.gov (United States)

    Nittayananta, Wipawee; Tao, Renchuan; Jiang, Lanlan; Peng, Yuanyuan; Huang, Yuxiao

    2016-01-01

    Oral innate immunity, an important component in host defense and immune surveillance in the oral cavity, plays a crucial role in the regulation of oral health. As part of the innate immune system, epithelial cells lining oral mucosal surfaces not only provide a physical barrier but also produce different antimicrobial peptides, including human β-defensins (hBDs), secretory leukocyte protease inhibitor (SLPI), and various cytokines. These innate immune mediators help in maintaining oral homeostasis. When they are impaired either by local or systemic causes, various oral infections and malignancies may be developed. Human immunodeficiency virus (HIV) infection and other co-infections appear to have both direct and indirect effects on systemic and local innate immunity leading to the development of oral opportunistic infections and malignancies. Highly active antiretroviral therapy (HAART), the standard treatment of HIV infection, contributed to a global reduction of HIV-associated oral lesions. However, prolonged use of HAART may lead to adverse effects on the oral innate immunity resulting in the relapse of oral lesions. This review article focused on the roles of oral innate immunity in HIV infection in HAART era. The following five key questions were addressed: (i) What are the roles of oral innate immunity in health and disease?, (ii) What are the effects of HIV infection on oral innate immunity?, (iii) What are the roles of oral innate immunity against other co-infections?, (iv) What are the effects of HAART on oral innate immunity?, and (v) Is oral innate immunity enhanced by HAART? © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  12. Influenza A virus protein PB1-F2 exacerbates IFN-beta expression of human respiratory epithelial cells.

    Science.gov (United States)

    Le Goffic, Ronan; Bouguyon, Edwige; Chevalier, Christophe; Vidic, Jasmina; Da Costa, Bruno; Leymarie, Olivier; Bourdieu, Christiane; Decamps, Laure; Dhorne-Pollet, Sophie; Delmas, Bernard

    2010-10-15

    The PB1-F2 protein of the influenza A virus (IAV) contributes to viral pathogenesis by a mechanism that is not well understood. PB1-F2 was shown to modulate apoptosis and to be targeted by the CD8(+) T cell response. In this study, we examined the downstream effects of PB1-F2 protein during IAV infection by measuring expression of the cellular genes in response to infection with wild-type WSN/33 and PB1-F2 knockout viruses in human lung epithelial cells. Wild-type virus infection resulted in a significant induction of genes involved in innate immunity. Knocking out the PB1-F2 gene strongly decreased the magnitude of expression of cellular genes implicated in antiviral response and MHC class I Ag presentation, suggesting that PB1-F2 exacerbates innate immune response. Biological network analysis revealed the IFN pathway as a link between PB1-F2 and deregulated genes. Using quantitative RT-PCR and IFN-β gene reporter assay, we determined that PB1-F2 mediates an upregulation of IFN-β expression that is dependent on NF-κB but not on AP-1 and IFN regulatory factor-3 transcription factors. Recombinant viruses knocked out for the PB1-F2 and/or the nonstructural viral protein 1 (the viral antagonist of the IFN response) genes provide further evidence that PB1-F2 increases IFN-β expression and that nonstructural viral protein 1 strongly antagonizes the effect of PB1-F2 on the innate response. Finally, we compared the effect of PB1-F2 variants taken from several IAV strains on IFN-β expression and found that PB1-F2-mediated IFN-β induction is significantly influenced by its amino acid sequence, demonstrating its importance in the host cell response triggered by IAV infection.

  13. Human innate lymphoid cells

    NARCIS (Netherlands)

    Mjösberg, Jenny; Spits, Hergen

    2016-01-01

    Innate lymphoid cells (ILCs) are increasingly acknowledged as important mediators of immune homeostasis and pathology. ILCs act as early orchestrators of immunity, responding to epithelium-derived signals by expressing an array of cytokines and cell-surface receptors, which shape subsequent immune

  14. Human innate lymphoid cells.

    Science.gov (United States)

    Mjösberg, Jenny; Spits, Hergen

    2016-11-01

    Innate lymphoid cells (ILCs) are increasingly acknowledged as important mediators of immune homeostasis and pathology. ILCs act as early orchestrators of immunity, responding to epithelium-derived signals by expressing an array of cytokines and cell-surface receptors, which shape subsequent immune responses. As such, ILCs make up interesting therapeutic targets for several diseases. In patients with allergy and asthma, group 2 innate lymphoid cells produce high amounts of IL-5 and IL-13, thereby contributing to type 2-mediated inflammation. Group 3 innate lymphoid cells are implicated in intestinal homeostasis and psoriasis pathology through abundant IL-22 production, whereas group 1 innate lymphoid cells are accumulated in chronic inflammation of the gut (inflammatory bowel disease) and lung (chronic obstructive pulmonary disease), where they contribute to IFN-γ-mediated inflammation. Although the ontogeny of mouse ILCs is slowly unraveling, the development of human ILCs is far from understood. In addition, the growing complexity of the human ILC family in terms of previously unrecognized functional heterogeneity and plasticity has generated confusion within the field. Here we provide an updated view on the function and plasticity of human ILCs in tissue homeostasis and disease. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  15. Crosstalk between microbiota, pathogens and the innate immune responses.

    Science.gov (United States)

    Günther, Claudia; Josenhans, Christine; Wehkamp, Jan

    2016-08-01

    Research in the last decade has convincingly demonstrated that the microbiota is crucial in order to prime and orchestrate innate and adaptive immune responses of their host and influence barrier function as well as multiple developmental and metabolic parameters of the host. Reciprocally, host reactions and immune responses instruct the composition of the microbiota. This review summarizes recent evidence from experimental and human studies which supports these arms of mutual relationship and crosstalk between host and resident microbiota, with a focus on innate immune responses in the gut, the role of cell death pathways and antimicrobial peptides. We also provide some recent examples on how dysbiosis and pathogens can act in concert to promote intestinal infection, inflammatory pathologies and cancer. The future perspectives of these combined research efforts include the discovery of protective species within the microbiota and specific traits and factors of microbes that weaken or enforce host intestinal homeostasis. Copyright © 2016 Elsevier GmbH. All rights reserved.

  16. The Innate Immune Database (IIDB

    Directory of Open Access Journals (Sweden)

    Zak Daniel

    2008-03-01

    Full Text Available Abstract Background As part of a National Institute of Allergy and Infectious Diseases funded collaborative project, we have performed over 150 microarray experiments measuring the response of C57/BL6 mouse bone marrow macrophages to toll-like receptor stimuli. These microarray expression profiles are available freely from our project web site http://www.innateImmunity-systemsbiology.org. Here, we report the development of a database of computationally predicted transcription factor binding sites and related genomic features for a set of over 2000 murine immune genes of interest. Our database, which includes microarray co-expression clusters and a host of web-based query, analysis and visualization facilities, is available freely via the internet. It provides a broad resource to the research community, and a stepping stone towards the delineation of the network of transcriptional regulatory interactions underlying the integrated response of macrophages to pathogens. Description We constructed a database indexed on genes and annotations of the immediate surrounding genomic regions. To facilitate both gene-specific and systems biology oriented research, our database provides the means to analyze individual genes or an entire genomic locus. Although our focus to-date has been on mammalian toll-like receptor signaling pathways, our database structure is not limited to this subject, and is intended to be broadly applicable to immunology. By focusing on selected immune-active genes, we were able to perform computationally intensive expression and sequence analyses that would currently be prohibitive if applied to the entire genome. Using six complementary computational algorithms and methodologies, we identified transcription factor binding sites based on the Position Weight Matrices available in TRANSFAC. For one example transcription factor (ATF3 for which experimental data is available, over 50% of our predicted binding sites coincide with genome

  17. Plant innate immunity – sunny side up?

    Science.gov (United States)

    Stael, Simon; Kmiecik, Przemyslaw; Willems, Patrick; Van Der Kelen, Katrien; Coll, Nuria S.; Teige, Markus; Van Breusegem, Frank

    2016-01-01

    Reactive oxygen species (ROS)- and calcium- dependent signaling pathways play well-established roles during plant innate immunity. Chloroplasts host major biosynthetic pathways and have central roles in energy production, redox homeostasis, and retrograde signaling. However, the organelle’s importance in immunity has been somehow overlooked. Recent findings suggest that the chloroplast also has an unanticipated function as a hub for ROS- and calcium-signaling that affects immunity responses at an early stage after pathogen attack. In this opinion article, we discuss a chloroplastic calcium-ROS signaling branch of plant innate immunity. We propose that this chloroplastic branch acts as a light-dependent rheostat that, through the production of ROS, influences the severity of the immune response. PMID:25457110

  18. Is Logic Innate?

    Directory of Open Access Journals (Sweden)

    Stephen Crain

    2007-12-01

    Full Text Available Arguments are presented supporting logical nativism: the conjecture that humans have an innate logic faculty. In making a case for logical nativism, this article concentrates on children’s acquisition of the logical concept of disjunction. Despite the widespread belief to the contrary, the interpretation of disjunction in human languages is arguably the same as it is in classical logic, namely inclusive–or. The argument proceeds with empirical support for the view that the inclusive–or is the meaning of disjunction in human languages, from studies of child language development and from cross-linguistic research. Evidence is presented showing that young children adhere to universal semantic principles that characterize adult linguistic competence across languages. Several a priori arguments are also offered in favour of logical nativism. These arguments show that logic, like Socratic virtue and like certain aspects of language, is not learned and cannot be taught — thus supporting a strong form of innateness.

  19. Innate and intrinsic antiviral immunity in skin.

    Science.gov (United States)

    Kawamura, Tatsuyoshi; Ogawa, Youichi; Aoki, Rui; Shimada, Shinji

    2014-09-01

    As the body's most exposed interface with the environment, the skin is constantly challenged by potentially pathogenic microbes, including viruses. To sense the invading viruses, various types of cells resident in the skin express many different pattern-recognition receptors (PRRs) such as C-type lectin receptors (CLRs), Toll-like receptors (TLRs), nucleotide-binding oligomerization domain (NOD)-like receptors (NLRs), retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs) and cytosolic DNA sensors, that can detect the pathogen-associated molecular patterns (PAMPs) of the viruses. The detection of viral PAMPs initiates two major innate immune signaling cascades: the first involves the activation of the downstream transcription factors, such as interferon regulatory factors (IRFs), nuclear factor kappa B (NF-κB) and activator protein 1 (AP-1), which cooperate to induce the transcription of type I interferons and pro-inflammatory cytokines. The second signaling pathway involves the caspase-1-mediated processing of IL-1β and IL-18 through the formation of an inflammasome complex. Cutaneous innate immunity including the production of the innate cytokines constitutes the first line of host defence that limits the virus dissemination from the skin, and also plays an important role in the activation of adaptive immune response, which represents the second line of defence. More recently, the third immunity "intrinsic immunity" has emerged, that provides an immediate and direct antiviral defense mediated by host intrinsic restriction factors. This review focuses on the recent advances regarding the antiviral immune systems, highlighting the innate and intrinsic immunity against the viral infections in the skin, and describes how viral components are recognized by cutaneous immune systems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  20. Insights into innate immune signalling in controlling cardiac remodelling.

    Science.gov (United States)

    Zhang, Yaxing; Huang, Zan; Li, Hongliang

    2017-11-01

    Canonical innate immune signalling involves complex cascades: multiple germline-encoded pattern recognition receptors rapidly recognize pathogen-associated or damage-associated molecular patterns to induce the production of cytokines, which bind to their corresponding receptors to orchestrate subsequent host defense phases. Inflammation is a healthy response to pathogenic signals, which are typically rapid and specific, and they terminate once the threat has passed. However, excessive activation or suppression of innate immune or inflammatory responses can lead to considerable human suffering, such as cardiac remodelling. Interestingly, recent studies have revealed that innate immune molecules in the parenchymal cells of the heart influence cardiac homeostasis not only by directly regulating innate immune responses but also through reprogrammed signalling pathways, which are independent of conventional innate immune signalling. Elucidating 'innate immune signalling reprogramming' events will help us better understand the functions of innate immune molecules and, moreover, the pathogenesis of cardiac diseases. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

  1. Is Logic Innate?

    OpenAIRE

    Stephen Crain; Drew Khlentzos

    2007-01-01

    Arguments are presented supporting logical nativism: the conjecture that humans have an innate logic faculty. In making a case for logical nativism, this article concentrates on children’s acquisition of the logical concept of disjunction. Despite the widespread belief to the contrary, the interpretation of disjunction in human languages is arguably the same as it is in classical logic, namely inclusive–or. The argument proceeds with empirical support for the view that the inclusive–or is the...

  2. Curating the innate immunity interactome

    Science.gov (United States)

    2010-01-01

    Background The innate immune response is the first line of defence against invading pathogens and is regulated by complex signalling and transcriptional networks. Systems biology approaches promise to shed new light on the regulation of innate immunity through the analysis and modelling of these networks. A key initial step in this process is the contextual cataloguing of the components of this system and the molecular interactions that comprise these networks. InnateDB (http://www.innatedb.com) is a molecular interaction and pathway database developed to facilitate systems-level analyses of innate immunity. Results Here, we describe the InnateDB curation project, which is manually annotating the human and mouse innate immunity interactome in rich contextual detail, and present our novel curation software system, which has been developed to ensure interactions are curated in a highly accurate and data-standards compliant manner. To date, over 13,000 interactions (protein, DNA and RNA) have been curated from the biomedical literature. Here, we present data, illustrating how InnateDB curation of the innate immunity interactome has greatly enhanced network and pathway annotation available for systems-level analysis and discuss the challenges that face such curation efforts. Significantly, we provide several lines of evidence that analysis of the innate immunity interactome has the potential to identify novel signalling, transcriptional and post-transcriptional regulators of innate immunity. Additionally, these analyses also provide insight into the cross-talk between innate immunity pathways and other biological processes, such as adaptive immunity, cancer and diabetes, and intriguingly, suggests links to other pathways, which as yet, have not been implicated in the innate immune response. Conclusions In summary, curation of the InnateDB interactome provides a wealth of information to enable systems-level analysis of innate immunity. PMID:20727158

  3. Group 2 innate lymphoid cells and asthma

    Directory of Open Access Journals (Sweden)

    Hiroki Kabata

    2015-07-01

    Full Text Available Group 2 innate lymphoid cells (ILC2s are recently identified cell populations that produce type 2 cytokines such as IL-5 and IL-13 in response to epithelial cell-derived cytokines. Although ILC2s were initially reported to play a key role in the anti-helminth innate immunity, we now have greater interest in their role in asthma and other allergic diseases. In various asthma mouse models, ILC2s provoke eosinophilic inflammation accompanied by airway hyperresponsiveness independent of acquired immunity. Moreover, recent mouse studies show that ILC2s also promote acquired immunity and Th2 polarization, and various cytokines and lipid mediators influence the functions of ILC2s. Although ILC2s have also been identified in humans, studies on the role of human ILC2s in asthma are very limited. Thus far, human studies have shown that there is a slight difference in responsiveness and production of cytokines between mouse and human ILC2s, and it has been suggested that ILC2s are involved in allergic-type asthma and the exacerbation of asthma. In this review, we focus on mouse and human ILC2s, and discuss their role in asthma.

  4. Manipulation of innate immunity by a bacterial secreted peptide: Lantibiotic nisin Z is selectively immunomodulatory

    NARCIS (Netherlands)

    Kindrachuk, J.; Jenssen, H.; Elliott, M.; Breukink, E.J.|info:eu-repo/dai/nl/120305100; Hancock, R.E.W.; et al., [No Value

    2013-01-01

    Innate immunity is triggered by a variety of bacterial molecules, resulting in both protective and potentially harmful proinflammatory responses. Further, innate immunity also provides a mechanism for the maintenance of homeostasis between the host immune system and symbiotic or non-pathogenic

  5. The Activation and Suppression of Plant Innate Immunity by Parasitic Nematodes

    NARCIS (Netherlands)

    Goverse, A.; Smant, G.

    2014-01-01

    Plant-parasitic nematodes engage in prolonged and intimate relationships with their host plants, often involving complex alterations in host cell morphology and function. It is puzzling how nematodes can achieve this, seemingly without activating the innate immune system of their hosts. Secretions

  6. Adaptation in the innate immune system and heterologous innate immunity.

    Science.gov (United States)

    Martin, Stefan F

    2014-11-01

    The innate immune system recognizes deviation from homeostasis caused by infectious or non-infectious assaults. The threshold for its activation seems to be established by a calibration process that includes sensing of microbial molecular patterns from commensal bacteria and of endogenous signals. It is becoming increasingly clear that adaptive features, a hallmark of the adaptive immune system, can also be identified in the innate immune system. Such adaptations can result in the manifestation of a primed state of immune and tissue cells with a decreased activation threshold. This keeps the system poised to react quickly. Moreover, the fact that the innate immune system recognizes a wide variety of danger signals via pattern recognition receptors that often activate the same signaling pathways allows for heterologous innate immune stimulation. This implies that, for example, the innate immune response to an infection can be modified by co-infections or other innate stimuli. This "design feature" of the innate immune system has many implications for our understanding of individual susceptibility to diseases or responsiveness to therapies and vaccinations. In this article, adaptive features of the innate immune system as well as heterologous innate immunity and their implications are discussed.

  7. Activation of innate immunity during systemic Candida infections

    OpenAIRE

    Ifrim, D.C.

    2015-01-01

    Despite the increased knowledge on the mechanisms of Candida recognition and the networks of innate and adaptive host defense activated during infection, much remains to be learned regarding the distinctive modulatory effects of Candida spp on host immune responses. We showed that the chronic exposure of primary human immune cells to C. albicans primes them for subsequent stimulation with different microorganisms, mechanism that could explain the potential stimulatory effects of the fungus in...

  8. Innate immune signaling in defense against intestinal microbes

    Science.gov (United States)

    Kinnebrew, Melissa A.; Pamer, Eric G.

    2015-01-01

    Summary The gastrointestinal system is a common entry point for pathogenic microbes to access the inner environment of the body. Antimicrobial factors produced by the intestinal mucosa limit the translocation of both commensal and pathogenic microbes across the intestinal epithelial cell barrier. The regulation of these host defense mechanisms largely depends on the activation of innate immune receptors by microbial molecules. Under steady-state conditions, the microbiota provides constitutive signals to the innate immune system, which helps to maintain a healthy inflammatory tone within the intestinal mucosa and, thus, enhances resistance to infection with enteric pathogens. During an acute infection, the intestinal epithelial cell barrier is breached, and the detection of microbial molecules in the intestinal lamina propria rapidly stimulates innate immune signaling pathways that coordinate early defense mechanisms. Herein, we review how microbial molecules shed by both commensal and pathogenic microbes direct host defenses at the intestinal mucosa. We highlight the signaling pathways, effector molecules, and cell populations that are activated by microbial molecule recognition and, thereby, are involved in the maintenance of homeostatic levels of host defense and in the early response to acute enteric infection. Finally, we discuss how manipulation of these host defense pathways by stimulating innate immune receptors is a potential therapeutic strategy to prevent or alleviate intestinal disease. PMID:22168416

  9. Innate, adaptive and regulatory responses in schistosomiasis: Relationship to allergy

    NARCIS (Netherlands)

    Hartgers, F.C.; Smits, H.H.; Kleij, D. van der; Yazdanbakhsh, M.

    2006-01-01

    Helminth infections have profound effects on the immune system. Here, recent insights in the molecular interactions between schistosomes and the host are described with respect to adaptive but also with respect to innate immune responses. Furthermore, the different mechanisms of immune

  10. Innate immune factors associated with HIV-1 transmission

    NARCIS (Netherlands)

    Pollakis, Georgios; Stax, Martijn J.; Paxton, William A.

    2011-01-01

    Relatively little is known with regards to the mechanisms of HIV-1 transmission across a mucosal surface and more specifically what effects host factors have on influencing infection and early viral dissemination. The purpose of this review is to summarize which factors of the innate immune response

  11. Developmental acquisition of regulomes underlies innate lymphoid cell functionality

    Science.gov (United States)

    Innate lymphoid cells (ILCs) play key roles in host defense, barrier integrity, and homeostasis, and they mirror adaptive CD4+ T helper (Th) cell subtypes in both usages of effector molecules and ·transcription factors. To better understand ILC subsets and their relationship with Th cells, we measur...

  12. Innate immunity networks during infection with Borrelia burgdorferi

    NARCIS (Netherlands)

    Oosting, M.; Buffen, K.; Meer, J.W. van der; Netea, M.G.; Joosten, L.A.

    2016-01-01

    The recognition of Borrelia species represents a complex process in which multiple components of the immune system are involved. In this review, we summarize the interplay between the host innate system and Borrelia spp., from the recognition by pattern recognition receptors (PRRs) to the induction

  13. Innate immunity networks during infection with Borrelia burgdorferi

    NARCIS (Netherlands)

    Oosting, M.; Buffen, K.; Meer, J.W.M. van der; Netea, M.G.; Joosten, L.A.B.

    2014-01-01

    Abstract The recognition of Borrelia species represents a complex process in which multiple components of the immune system are involved. In this review, we summarize the interplay between the host innate system and Borrelia spp., from the recognition by pattern recognition receptors (PRRs) to the

  14. Acute asthma exacerbations: an overview

    Directory of Open Access Journals (Sweden)

    Domenico Lorenzo Urso

    2014-07-01

    Full Text Available Asthma is a chronic inflammatory disease of the airways. All patient with asthma are at risk of having exacerbations characterized by worsening symptoms, airflow obstruction, and an increased requirement for rescue bronchodilators. Asthma exacerbations can be classified as mild, moderate, severe, or life threatening. The goals of treatment are correction of severe hypoxemia, rapid reversal of airflow obstruction, and reduction of the risk of relapse.http://dx.doi.org/10.7175/rhc.v5i3.932

  15. Curating the innate immunity interactome.

    LENUS (Irish Health Repository)

    Lynn, David J

    2010-01-01

    The innate immune response is the first line of defence against invading pathogens and is regulated by complex signalling and transcriptional networks. Systems biology approaches promise to shed new light on the regulation of innate immunity through the analysis and modelling of these networks. A key initial step in this process is the contextual cataloguing of the components of this system and the molecular interactions that comprise these networks. InnateDB (http:\\/\\/www.innatedb.com) is a molecular interaction and pathway database developed to facilitate systems-level analyses of innate immunity.

  16. Cellular transcriptional profiling in influenza A virus-infected lung epithelial cells: The role of the nonstructural NS1 protein in the evasion of the host innate defense and its potential contribution to pandemic influenza

    Science.gov (United States)

    Geiss, Gary K.; Salvatore, Mirella; Tumpey, Terrence M.; Carter, Victoria S.; Wang, Xiuyan; Basler, Christopher F.; Taubenberger, Jeffery K.; Bumgarner, Roger E.; Palese, Peter; Katze, Michael G.; García-Sastre, Adolfo

    2002-08-01

    The NS1 protein of influenza A virus contributes to viral pathogenesis, primarily by enabling the virus to disarm the host cell type IFN defense system. We examined the downstream effects of NS1 protein expression during influenza A virus infection on global cellular mRNA levels by measuring expression of over 13,000 cellular genes in response to infection with wild-type and mutant viruses in human lung epithelial cells. Influenza A/PR/8/34 virus infection resulted in a significant induction of genes involved in the IFN pathway. Deletion of the viral NS1 gene increased the number and magnitude of expression of cellular genes implicated in the IFN, NF-B, and other antiviral pathways. Interestingly, different IFN-induced genes showed different sensitivities to NS1-mediated inhibition of their expression. A recombinant virus with a C-terminal deletion in its NS1 gene induced an intermediate cellular mRNA expression pattern between wild-type and NS1 knockout viruses. Most significantly, a virus containing the 1918 pandemic NS1 gene was more efficient at blocking the expression of IFN-regulated genes than its parental influenza A/WSN/33 virus. Taken together, our results suggest that the cellular response to influenza A virus infection in human lung cells is significantly influenced by the sequence of the NS1 gene, demonstrating the importance of the NS1 protein in regulating the host cell response triggered by virus infection.

  17. RNA viruses can hijack vertebrate microRNAs to suppress innate immunity

    Science.gov (United States)

    Trobaugh, Derek W.; Gardner, Christina L.; Sun, Chengqun; Haddow, Andrew D.; Wang, Eryu; Chapnik, Elik; Mildner, Alexander; Weaver, Scott C.; Ryman, Kate D.; Klimstra, William B.

    2014-02-01

    Currently, there is little evidence for a notable role of the vertebrate microRNA (miRNA) system in the pathogenesis of RNA viruses. This is primarily attributed to the ease with which these viruses mutate to disrupt recognition and growth suppression by host miRNAs. Here we report that the haematopoietic-cell-specific miRNA miR-142-3p potently restricts the replication of the mosquito-borne North American eastern equine encephalitis virus in myeloid-lineage cells by binding to sites in the 3' non-translated region of its RNA genome. However, by limiting myeloid cell tropism and consequent innate immunity induction, this restriction directly promotes neurologic disease manifestations characteristic of eastern equine encephalitis virus infection in humans. Furthermore, the region containing the miR-142-3p binding sites is essential for efficient virus infection of mosquito vectors. We propose that RNA viruses can adapt to use antiviral properties of vertebrate miRNAs to limit replication in particular cell types and that this restriction can lead to exacerbation of disease severity.

  18. Mechanisms and pathways of innate immune activation and regulation in health and cancer.

    Science.gov (United States)

    Cui, Jun; Chen, Yongjun; Wang, Helen Y; Wang, Rong-Fu

    2014-01-01

    Research on innate immune signaling and regulation has recently focused on pathogen recognition receptors (PRRs) and their signaling pathways. Members of PRRs sense diverse microbial invasions or danger signals, and initiate innate immune signaling pathways, leading to proinflammatory cytokines production, which, in turn, instructs adaptive immune response development. Despite the diverse functions employed by innate immune signaling to respond to a variety of different pathogens, the innate immune response must be tightly regulated. Otherwise, aberrant, uncontrolled immune responses will lead to harmful, or even fatal, consequences. Therefore, it is essential to better discern innate immune signaling and many regulators, controlling various signaling pathways, have been identified. In this review, we focus on the recent advances in our understanding of the activation and regulation of innate immune signaling in the host response to pathogens and cancer.

  19. Role of innate immunity in the pathogenesis of type 1 and type 2 diabetes.

    Science.gov (United States)

    Lee, Myung-Shik

    2014-08-01

    The importance of innate immunity in host defense is becoming clear after discovery of innate immune receptors such as Toll-like receptor or Nod-like receptor. Innate immune system plays an important role in diverse pathological situations such as autoimmune diseases. Role of innate immunity in the pathogenesis of metabolic disorders such as type 2 diabetes, metabolic syndrome or atherosclerosis that has not been previously considered as inflammatory disorders, is also being appreciated. Here, the role of innate immunity in the development of type 1 diabetes, a classical organ-specific autoimmune disease, and type 2 diabetes will be discussed, focusing on the role of specific innate immune receptors involved in these disease processes.

  20. INNATE IMMUNITY AND CKD PROGRESSION

    Directory of Open Access Journals (Sweden)

    Mallamaci F

    2012-06-01

    Conclusions: Plasma procalcitonin is a more sensitive biomarker of innate immunity than CRP in CKD patients and in part reflects excessive adiposity. High PCT in CKD patients predicts progression toward kidney failure. These results are compatible with the hypothesis that alterations in innate immunity play a role in the progression of CKD in humans.

  1. Innate immune functions of microglia isolated from human glioma patients

    Directory of Open Access Journals (Sweden)

    Grimm Elizabeth

    2006-03-01

    Full Text Available Abstract Background Innate immunity is considered the first line of host defense and microglia presumably play a critical role in mediating potent innate immune responses to traumatic and infectious challenges in the human brain. Fundamental impairments of the adaptive immune system in glioma patients have been investigated; however, it is unknown whether microglia are capable of innate immunity and subsequent adaptive anti-tumor immune responses within the immunosuppressive tumor micro-environment of human glioma patients. We therefore undertook a novel characterization of the innate immune phenotype and function of freshly isolated human glioma-infiltrating microglia (GIM. Methods GIM were isolated by sequential Percoll purification from patient tumors immediately after surgical resection. Flow cytometry, phagocytosis and tumor cytotoxicity assays were used to analyze the phenotype and function of these cells. Results GIM expressed significant levels of Toll-like receptors (TLRs, however they do not secrete any of the cytokines (IL-1β, IL-6, TNF-α critical in developing effective innate immune responses. Similar to innate macrophage functions, GIM can mediate phagocytosis and non-MHC restricted cytotoxicity. However, they were statistically less able to mediate tumor cytotoxicity compared to microglia isolated from normal brain. In addition, the expression of Fas ligand (FasL was low to absent, indicating that apoptosis of the incoming lymphocyte population may not be a predominant mode of immunosuppression by microglia. Conclusion We show for the first time that despite the immunosuppressive environment of human gliomas, GIM are capable of innate immune responses such as phagocytosis, cytotoxicity and TLR expression but yet are not competent in secreting key cytokines. Further understanding of these innate immune functions could play a critical role in understanding and developing effective immunotherapies to malignant human gliomas.

  2. The Interface between Fungal Biofilms and Innate Immunity

    Science.gov (United States)

    Kernien, John F.; Snarr, Brendan D.; Sheppard, Donald C.; Nett, Jeniel E.

    2018-01-01

    Fungal biofilms are communities of adherent cells surrounded by an extracellular matrix. These biofilms are commonly found during infection caused by a variety of fungal pathogens. Clinically, biofilm infections can be extremely difficult to eradicate due to their resistance to antifungals and host defenses. Biofilm formation can protect fungal pathogens from many aspects of the innate immune system, including killing by neutrophils and monocytes. Altered immune recognition during this phase of growth is also evident by changes in the cytokine profiles of monocytes and macrophages exposed to biofilm. In this manuscript, we review the host response to fungal biofilms, focusing on how these structures are recognized by the innate immune system. Biofilms formed by Candida, Aspergillus, and Cryptococcus have received the most attention and are highlighted. We describe common themes involved in the resilience of fungal biofilms to host immunity and give examples of biofilm defenses that are pathogen-specific. PMID:29375581

  3. The Interface between Fungal Biofilms and Innate Immunity

    Directory of Open Access Journals (Sweden)

    John F. Kernien

    2018-01-01

    Full Text Available Fungal biofilms are communities of adherent cells surrounded by an extracellular matrix. These biofilms are commonly found during infection caused by a variety of fungal pathogens. Clinically, biofilm infections can be extremely difficult to eradicate due to their resistance to antifungals and host defenses. Biofilm formation can protect fungal pathogens from many aspects of the innate immune system, including killing by neutrophils and monocytes. Altered immune recognition during this phase of growth is also evident by changes in the cytokine profiles of monocytes and macrophages exposed to biofilm. In this manuscript, we review the host response to fungal biofilms, focusing on how these structures are recognized by the innate immune system. Biofilms formed by Candida, Aspergillus, and Cryptococcus have received the most attention and are highlighted. We describe common themes involved in the resilience of fungal biofilms to host immunity and give examples of biofilm defenses that are pathogen-specific.

  4. ID'ing innate and innate-like lymphoid cells.

    Science.gov (United States)

    Verykokakis, Mihalis; Zook, Erin C; Kee, Barbara L

    2014-09-01

    The immune system can be divided into innate and adaptive components that differ in their rate and mode of cellular activation, with innate immune cells being the first responders to invading pathogens. Recent advances in the identification and characterization of innate lymphoid cells have revealed reiterative developmental programs that result in cells with effector fates that parallel those of adaptive lymphoid cells and are tailored to effectively eliminate a broad spectrum of pathogenic challenges. However, activation of these cells can also be associated with pathologies such as autoimmune disease. One major distinction between innate and adaptive immune system cells is the constitutive expression of ID proteins in the former and inducible expression in the latter. ID proteins function as antagonists of the E protein transcription factors that play critical roles in lymphoid specification as well as B- and T-lymphocyte development. In this review, we examine the transcriptional mechanisms controlling the development of innate lymphocytes, including natural killer cells and the recently identified innate lymphoid cells (ILC1, ILC2, and ILC3), and innate-like lymphocytes, including natural killer T cells, with an emphasis on the known requirements for the ID proteins. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  5. ID’ing Innate and Innate-like Lymphoid Cells

    Science.gov (United States)

    Verykokakis, Mihalis; Zook, Erin C.; Kee, Barbara L.

    2014-01-01

    Summary The immune system can be divided into innate and adaptive components that differ in their rate and mode of cellular activation, with innate immune cells being the first responders to invading pathogens. Recent advances in the identification and characterization of innate lymphoid cells have revealed reiterative developmental programs that result in cells with effector fates that parallel those of adaptive lymphoid cells and are tailored to effectively eliminate a broad spectrum of pathogenic challenges. However, activation of these cells can also be associated with pathologies such as autoimmune disease. One major distinction between innate and adaptive immune system cells is the constitutive expression of ID proteins in the former and inducible expression in the latter. ID proteins function as antagonists of the E protein transcription factors that play critical roles in lymphoid specification as well as B and T-lymphocyte development. In this review, we examine the transcriptional mechanisms controlling the development of innate lymphocytes, including natural killer cells and the recently identified innate lymphoid cells (ILC1, ILC2, and ILC3), and innate-like lymphocytes, including natural killer T cells, with an emphasis on the known requirements for the ID proteins. PMID:25123285

  6. Toward a Consensus Definition for COPD Exacerbations

    National Research Council Canada - National Science Library

    Roberto Rodriguez-Roisin

    2000-01-01

    .... Exacerbations are associated with a significant increase in mortality, hospitalization, and health-care utilization, but there is currently no widely accepted definition of what constitutes an exacerbation of COPD...

  7. MicroRNA in innate immunity and autophagy during mycobacterial infection.

    Science.gov (United States)

    Kim, Jin Kyung; Kim, Tae Sung; Basu, Joyoti; Jo, Eun-Kyeong

    2017-01-01

    The fine-tuning of innate immune responses is an important aspect of host defenses against mycobacteria. MicroRNAs (miRNAs), small non-coding RNAs, play essential roles in regulating multiple biological pathways including innate host defenses against various infections. Accumulating evidence shows that many miRNAs regulate the complex interplay between mycobacterial survival strategies and host innate immune pathways. Recent studies have contributed to understanding the role of miRNAs, the levels of which can be modulated by mycobacterial infection, in tuning host autophagy to control bacterial survival and innate effector function. Despite considerable efforts devoted to miRNA profiling over the past decade, further work is needed to improve the selection of appropriate biomarkers for tuberculosis. Understanding the roles and mechanisms of miRNAs in regulating innate immune signaling and autophagy may provide insights into new therapeutic modalities for host-directed anti-mycobacterial therapies. Here, we present a comprehensive review of the recent literature regarding miRNA profiling in tuberculosis and the roles of miRNAs in modulating innate immune responses and autophagy defenses against mycobacterial infections. © 2016 John Wiley & Sons Ltd.

  8. Exacerbating factors of itch in atopic dermatitis.

    Science.gov (United States)

    Murota, Hiroyuki; Katayama, Ichiro

    2017-01-01

    Atopic dermatitis (AD) displays different clinical symptoms, progress, and response to treatment during early infancy and after childhood. After the childhood period, itch appears first, followed by formation of well-circumscribed plaque or polymorphous dermatoses at the same site. When accompanied with dermatitis and dry skin, treatment of skin lesions should be prioritized. When itch appears first, disease history, such as causes and time of appearance of itch should be obtained by history taking. In many cases, itch increases in the evening when the sympathetic nerve activity decreased. Treatment is provided considering that hypersensitivity to various external stimulations can cause itch. Heat and sweating are thought to especially exacerbate itch. Factors causing itch, such as cytokines and chemical messengers, also induce itch mainly by stimulating the nerve. Scratching further aggravates dermatitis. Skin hypersensibility, where other non-itch senses, such as pain and heat, are felt as itch, sometimes occurs in AD. Abnormal elongation of the sensory nerve into the epidermis, as well as sensitizing of the peripheral/central nerve, are possible causes of hypersensitivity, leading to itch. To control itch induced by environmental factors such as heat, treatment for dermatitis is given priority. In the background of itch exacerbated by sweating, attention should be given to the negative impact of sweat on skin homeostasis due to 1) leaving excess sweat on the skin, and 2) heat retention due to insufficient sweating. Excess sweat on the skin should be properly wiped off, and dermatitis should be controlled so that appropriate amount of sweat can be produced. Not only stimulation from the skin surface, but also visual and auditory stimulation can induce new itch. This "contagious itch" can be notably observed in patients with AD. This article reviews and introduces causes of aggravation of itch and information regarding how to cope with such causes. Copyright

  9. Regulatory Innate Lymphoid Cells Control Innate Intestinal Inflammation.

    Science.gov (United States)

    Wang, Shuo; Xia, Pengyan; Chen, Yi; Qu, Yuan; Xiong, Zhen; Ye, Buqing; Du, Ying; Tian, Yong; Yin, Zhinan; Xu, Zhiheng; Fan, Zusen

    2017-09-21

    An emerging family of innate lymphoid cells (termed ILCs) has an essential role in the initiation and regulation of inflammation. However, it is still unclear how ILCs are regulated in the duration of intestinal inflammation. Here, we identify a regulatory subpopulation of ILCs (called ILCregs) that exists in the gut and harbors a unique gene identity that is distinct from that of ILCs or regulatory T cells (Tregs). During inflammatory stimulation, ILCregs can be induced in the intestine and suppress the activation of ILC1s and ILC3s via secretion of IL-10, leading to protection against innate intestinal inflammation. Moreover, TGF-β1 is induced by ILCregs during the innate intestinal inflammation, and autocrine TGF-β1 sustains the maintenance and expansion of ILCregs. Therefore, ILCregs play an inhibitory role in the innate immune response, favoring the resolution of intestinal inflammation. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Innate Immune Signaling Activated by MDR Bacteria in the Airway

    Science.gov (United States)

    Parker, Dane; Ahn, Danielle; Cohen, Taylor; Prince, Alice

    2015-01-01

    Health care-associated bacterial pneumonias due to multiple-drug resistant (MDR) pathogens are an important public health problem and are major causes of morbidity and mortality worldwide. In addition to antimicrobial resistance, these organisms have adapted to the milieu of the human airway and have acquired resistance to the innate immune clearance mechanisms that normally prevent pneumonia. Given the limited efficacy of antibiotics, bacterial clearance from the airway requires an effective immune response. Understanding how specific airway pathogens initiate and regulate innate immune signaling, and whether this response is excessive, leading to host-induced pathology may guide future immunomodulatory therapy. We will focus on three of the most important causes of health care-associated pneumonia, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae, and review the mechanisms through which an inappropriate or damaging innate immune response is stimulated, as well as describe how airway pathogens cause persistent infection by evading immune activation. PMID:26582515

  11. Innate lymphoid cells and asthma.

    Science.gov (United States)

    Yu, Sanhong; Kim, Hye Young; Chang, Ya-Jen; DeKruyff, Rosemarie H; Umetsu, Dale T

    2014-04-01

    Asthma is a complex and heterogeneous disease with several phenotypes, including an allergic asthma phenotype characterized by TH2 cytokine production and associated with allergen sensitization and adaptive immunity. Asthma also includes nonallergic asthma phenotypes, such as asthma associated with exposure to air pollution, infection, or obesity, that require innate rather than adaptive immunity. These innate pathways that lead to asthma involve macrophages, neutrophils, natural killer T cells, and innate lymphoid cells, newly described cell types that produce a variety of cytokines, including IL-5 and IL-13. We review the recent data regarding innate lymphoid cells and their role in asthma. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  12. Innate immune memory in plants.

    Science.gov (United States)

    Reimer-Michalski, Eva-Maria; Conrath, Uwe

    2016-08-01

    The plant innate immune system comprises local and systemic immune responses. Systemic plant immunity develops after foliar infection by microbial pathogens, upon root colonization by certain microbes, or in response to physical injury. The systemic plant immune response to localized foliar infection is associated with elevated levels of pattern-recognition receptors, accumulation of dormant signaling enzymes, and alterations in chromatin state. Together, these systemic responses provide a memory to the initial infection by priming the remote leaves for enhanced defense and immunity to reinfection. The plant innate immune system thus builds immunological memory by utilizing mechanisms and components that are similar to those employed in the trained innate immune response of jawed vertebrates. Therefore, there seems to be conservation, or convergence, in the evolution of innate immune memory in plants and vertebrates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. HIV-1 evades innate immune recognition through specific cofactor recruitment

    Science.gov (United States)

    Rasaiyaah, Jane; Tan, Choon Ping; Fletcher, Adam J.; Price, Amanda J.; Blondeau, Caroline; Hilditch, Laura; Jacques, David A.; Selwood, David L.; James, Leo C.; Noursadeghi, Mahdad; Towers, Greg J.

    2013-11-01

    Human immunodeficiency virus (HIV)-1 is able to replicate in primary human macrophages without stimulating innate immunity despite reverse transcription of genomic RNA into double-stranded DNA, an activity that might be expected to trigger innate pattern recognition receptors. We reasoned that if correctly orchestrated HIV-1 uncoating and nuclear entry is important for evasion of innate sensors then manipulation of specific interactions between HIV-1 capsid and host factors that putatively regulate these processes should trigger pattern recognition receptors and stimulate type 1 interferon (IFN) secretion. Here we show that HIV-1 capsid mutants N74D and P90A, which are impaired for interaction with cofactors cleavage and polyadenylation specificity factor subunit 6 (CPSF6) and cyclophilins (Nup358 and CypA), respectively, cannot replicate in primary human monocyte-derived macrophages because they trigger innate sensors leading to nuclear translocation of NF-κB and IRF3, the production of soluble type 1 IFN and induction of an antiviral state. Depletion of CPSF6 with short hairpin RNA expression allows wild-type virus to trigger innate sensors and IFN production. In each case, suppressed replication is rescued by IFN-receptor blockade, demonstrating a role for IFN in restriction. IFN production is dependent on viral reverse transcription but not integration, indicating that a viral reverse transcription product comprises the HIV-1 pathogen-associated molecular pattern. Finally, we show that we can pharmacologically induce wild-type HIV-1 infection to stimulate IFN secretion and an antiviral state using a non-immunosuppressive cyclosporine analogue. We conclude that HIV-1 has evolved to use CPSF6 and cyclophilins to cloak its replication, allowing evasion of innate immune sensors and induction of a cell-autonomous innate immune response in primary human macrophages.

  14. Targeting Innate Immunity for Type 1 Diabetes Prevention.

    Science.gov (United States)

    Needell, James C; Zipris, Danny

    2017-09-27

    Despite immense research efforts, type 1 diabetes (T1D) remains an autoimmune disease without a known trigger or approved intervention. Over the last three decades, studies have primarily focused on delineating the role of the adaptive immune system in the mechanism of T1D. The discovery of Toll-like receptors in the 1990s has advanced the knowledge on the role of the innate immune system in host defense as well as mechanisms that regulate adaptive immunity including the function of autoreactive T cells. Recent investigations suggest that inflammation plays a key role in promoting a large number of autoimmune disorders including T1D. Data from the LEW1.WR1 rat model of virus-induced disease and the RIP-B7.1 mouse model of diabetes suggest that innate immune signaling plays a key role in triggering disease progression. There is also evidence that innate immunity may be involved in the course of T1D in humans; however, a small number of clinical trials have shown that interfering with the function of the innate immune system following disease onset exerts only a modest effect on β-cell function. The data implying that innate immune pathways are linked with mechanisms of islet autoimmunity hold great promise for the identification of novel disease pathways that may be harnessed for clinical intervention. Nevertheless, more work needs to be done to better understand mechanisms by which innate immunity triggers β-cell destruction and assess the therapeutic value in blocking innate immunity for diabetes prevention.

  15. Probiotic Modulation of Innate Cell Pathogen Sensing and Signaling Events

    Directory of Open Access Journals (Sweden)

    Amy Llewellyn

    2017-10-01

    Full Text Available There is a growing body of evidence documenting probiotic bacteria to have a beneficial effect to the host through their ability to modulate the mucosal immune system. Many probiotic bacteria can be considered to act as either immune activators or immune suppressors, which have appreciable influence on homeostasis, inflammatory- and suppressive-immunopathology. What is becoming apparent is the ability of these probiotics to modulate innate immune responses via direct or indirect effects on the signaling pathways that drive these activatory or suppressive/tolerogenic mechanisms. This review will focus on the immunomodulatory role of probiotics on signaling pathways in innate immune cells: from positive to negative regulation associated with innate immune cells driving gut mucosal functionality. Research investigations have shown probiotics to modulate innate functionality in many ways including, receptor antagonism, receptor expression, binding to and expression of adaptor proteins, expression of negative regulatory signal molecules, induction of micro-RNAs, endotoxin tolerisation and finally, the secretion of immunomodulatory proteins, lipids and metabolites. The detailed understanding of the immunomodulatory signaling effects of probiotic strains will facilitate strain-specific selective manipulation of innate cell signal mechanisms in the modulation of mucosal adjuvanticity, immune deviation and tolerisation in both healthy subjects and patients with inflammatory and suppressive pathology.

  16. Trained immunity: A smart way to enhance innate immune defence.

    Science.gov (United States)

    van der Meer, Jos W M; Joosten, Leo A B; Riksen, Niels; Netea, Mihai G

    2015-11-01

    The innate arm of the immune system is generally viewed as primitive and non-specific and - in contrast to the adaptive immune arm - not to possess memory. However in plants and invertebrate animals that lack adaptive immunity, innate immunity will exhibit a prolonged enhanced functional state after adequate priming. A similar enhancement of function of the innate immunity has occasionally been described in vertebrates, including humans. Over the past few years we have studied this phenomenon in greater detail and we have coined the term 'Trained (innate) immunity' (TI). TI can be induced by a variety of stimuli, of which we have studied BCG and β-glucan in greater detail. The non-specific protective effects of BCG that have been observed in vaccination studies in the literature are probably due to TI. Monocytes and macrophages are among the main cells of the innate immune arm that can be trained. We have discovered that both BCG (via NOD2 signalling) and β-glucan (via dectin-1) induce epigenetic reprogramming, in particular stable changes in histone trimethylation at H3K4. These epigenetic changes lead to cellular activation, enhanced cytokine production and a change in the metabolic state of the cell with a shift from oxidative phosphorylation to aerobic glycolysis. TI is not only important for host defence and vaccine responses, but most probably also for diseases like atherosclerosis. Modulation of TI is a promising area for new treatments. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. 'Towards a Conceptual Framework for Innate Immunity'

    OpenAIRE

    Twycross, Jamie; Aickelin, Uwe

    2005-01-01

    Innate immunity now occupies a central role in immunology. However, artificial immune system models have largely been inspired by adaptive not innate immunity. This paper reviews the biological principles and properties of innate immunity and, adopting a conceptual framework, asks how these can be incorporated into artificial models. The aim is to outline a meta-framework for models of innate immunity.

  18. Innate immune cell response upon Candida albicans infection

    Science.gov (United States)

    Qin, Yulin; Zhang, Lulu; Xu, Zheng; Zhang, Jinyu; Jiang, Yuan-ying; Cao, Yongbing; Yan, Tianhua

    2016-01-01

    abstract Candida albicans is a polymorphic fungus which is the predominant cause of superficial and deep tissue fungal infections. This microorganism has developed efficient strategies to invade the host and evade host defense systems. However, the host immune system will be prepared for defense against the microbe by recognition of receptors, activation of signal transduction pathways and cooperation of immune cells. As a consequence, C. albicans could either be eliminated by immune cells rapidly or disseminate hematogenously, leading to life-threatening systemic infections. The interplay between Candida albicans and the host is complex, requiring recognition of the invaded pathogens, activation of intricate pathways and collaboration of various immune cells. In this review, we will focus on the effects of innate immunity that emphasize the first line protection of host defense against invaded C. albicans including the basis of receptor-mediated recognition and the mechanisms of cell-mediated immunity. PMID:27078171

  19. Memory T Cell-Derived interferon-γ Instructs Potent Innate Cell Activation For Protective Immunity

    Science.gov (United States)

    Soudja, Saidi M’Homa; Chandrabos, Ceena; Yakob, Ernest; Veenstra, Mike; Palliser, Deborah; Lauvau, Grégoire

    2014-01-01

    SUMMARY Cells of the innate immune system are essential for host defenses against primary microbial pathogen infections, yet their involvement in effective memory responses of vaccinated individuals has been poorly investigated. Here we show that memory T cells instruct innate cells to become potent effector cells in a systemic and a mucosal model of infection. Memory T cells controlled phagocyte, dendritic cell and NK or NK T cell mobilization and induction of a strong program of differentiation, which included their expression of effector cytokines and microbicidal pathways, all of which were delayed in non-vaccinated hosts. Disruption of IFN-γ-signaling in Ly6C+ monocytes, dendritic cells and macrophages impaired these processes and the control of pathogen growth. These results reveal how memory T cells, through rapid secretion of IFN-γ, orchestrate extensive modifications of host innate immune responses that are essential for effective protection of vaccinated hosts. PMID:24931122

  20. Innate immunomodulation to trypanosomatid parasite infections.

    Science.gov (United States)

    Dos-Santos, A L A; Carvalho-Kelly, L F; Dick, C F; Meyer-Fernandes, J R

    2016-08-01

    The recognition of invading pathogens by the innate immune system is essential for host protection against human parasites and the initiation of an effective adaptive immune response. Innate immune cells such as macrophages and dendritic cells (DCs) are involved in the first line of defense against protozoan parasites via sensing the invaders through pattern recognition receptors (PRRs), such as Toll-like receptors (TLRs). Activation of macrophages and dendritic cells starts with the interaction between microbial ligands (pathogen-associated molecular patterns - PAMPs) and PRRs, and these activated cells influence the overall immune response. Trypanosomatid PAMPs are sensed by TLRs; for example, TLR2 recognizes alkylacylglycerol and lipophosphoglycan in Trypanosoma cruzi and Leishmania, respectively; TLR2/TLR4 recognize glycoisnositolphospholipids and glycosylphosphatidyl inositol in Trypanosoma species; and TLR9 recognizes genomic DNA in Trypanosoma. TLR signaling includes the recruitment of different adaptor molecules that activate various transcription factors, such as NF-kB, IRF3/7, and MAP kinases, to induce the production of pro-inflammatory cytokines and type I interferons. Moreover, activated macrophages and dendritic cells produce ROS and NOS, which limit pathogen survival, and large amounts of cytokines; additionally, antigen presentation enhances the adaptive immune response. In this review, we highlight the recent findings on PAMP recognition in trypanosomatid infections and the signaling pathways activated by PRRs. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Innate immune control of West Nile virus infection.

    Science.gov (United States)

    Arjona, Alvaro; Wang, Penghua; Montgomery, Ruth R; Fikrig, Erol

    2011-11-01

    West Nile virus (WNV), from the Flaviviridae family, is a re-emerging zoonotic pathogen of medical importance. In humans, WNV infection may cause life-threatening meningoencephalitis or long-term neurologic sequelae. WNV is transmitted by Culex spp. mosquitoes and both the arthropod vector and the mammalian host are equipped with antiviral innate immune mechanisms sharing a common phylogeny. As far as the current evidence is able to demonstrate, mosquitoes primarily rely on RNA interference, Toll, Imd and JAK-STAT signalling pathways for limiting viral infection, while mammals are provided with these and other more complex antiviral mechanisms involving antiviral effectors, inflammatory mediators, and cellular responses triggered by highly specialized pathogen detection mechanisms that often resemble their invertebrate ancestry. This mini-review summarizes our current understanding of how the innate immune systems of the vector and the mammalian host react to WNV infection and shape its pathogenesis. © 2011 Blackwell Publishing Ltd.

  2. Functions of innate immune cells and commensal bacteria in gut homeostasis.

    Science.gov (United States)

    Kayama, Hisako; Takeda, Kiyoshi

    2016-02-01

    The intestinal immune system remains unresponsive to beneficial microbes and dietary antigens while activating pro-inflammatory responses against pathogens for host defence. In intestinal mucosa, abnormal activation of innate immunity, which directs adaptive immune responses, causes the onset and/or progression of inflammatory bowel diseases. Thus, innate immunity is finely regulated in the gut. Multiple innate immune cell subsets have been identified in both murine and human intestinal lamina propria. Some innate immune cells play a key role in the maintenance of gut homeostasis by preventing inappropriate adaptive immune responses while others are associated with the pathogenesis of intestinal inflammation through development of Th1 and Th17 cells. In addition, intestinal microbiota and their metabolites contribute to the regulation of innate/adaptive immune responses. Accordingly, perturbation of microbiota composition can trigger intestinal inflammation by driving inappropriate immune responses. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

  3. MAP kinase cascades in Arabidopsis innate immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt; Roux, Milena Edna; Petersen, Morten

    2012-01-01

    Plant mitogen-activated protein kinase (MAPK) cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs) by host transmembrane pattern recognition receptors which trigger MAPK-dependent innate...... immune responses. In the model Arabidopsis, molecular genetic evidence implicates a number of MAPK cascade components in PAMP signaling, and in responses to immunity-related phytohormones such as ethylene, jasmonate, and salicylate. In a few cases, cascade components have been directly linked...... to the transcription of target genes or to the regulation of phytohormone synthesis. Thus MAPKs are obvious targets for bacterial effector proteins and are likely guardees of resistance proteins, which mediate defense signaling in response to the action of effectors, or effector-triggered immunity. This mini...

  4. Interactions between Innate Immunity, Microbiota, and Probiotics.

    Science.gov (United States)

    Giorgetti, GianMarco; Brandimarte, Giovanni; Fabiocchi, Federica; Ricci, Salvatore; Flamini, Paolo; Sandri, Giancarlo; Trotta, Maria Cristina; Elisei, Walter; Penna, Antonio; Lecca, Piera Giuseppina; Picchio, Marcello; Tursi, Antonio

    2015-01-01

    The term "microbiota" means genetic inheritance associated with microbiota, which is about 100 times larger than the guest. The tolerance of the resident bacterial flora is an important key element of immune cell function. A key role in the interaction between the host and the microbiota is played by Paneth cell, which is able to synthesize and secrete proteins and antimicrobial peptides, such as α/β defensins, cathelicidin, 14 β-glycosidases, C-type lectins, and ribonuclease, in response to various stimuli. Recent studies found probiotics able to preserve intestinal homeostasis by downmodulating the immune response and inducing the development of T regulatory cells. Specific probiotic strain, as well as probiotic-driven metabolic products called "postbiotics," has been recently recognized and it is able to influence innate immunity. New therapeutic approaches based on probiotics are now available, and further treatments based on postbiotics will come in the future.

  5. Interactions between Innate Immunity, Microbiota, and Probiotics

    Directory of Open Access Journals (Sweden)

    GianMarco Giorgetti

    2015-01-01

    Full Text Available The term “microbiota” means genetic inheritance associated with microbiota, which is about 100 times larger than the guest. The tolerance of the resident bacterial flora is an important key element of immune cell function. A key role in the interaction between the host and the microbiota is played by Paneth cell, which is able to synthesize and secrete proteins and antimicrobial peptides, such as α/β defensins, cathelicidin, 14 β-glycosidases, C-type lectins, and ribonuclease, in response to various stimuli. Recent studies found probiotics able to preserve intestinal homeostasis by downmodulating the immune response and inducing the development of T regulatory cells. Specific probiotic strain, as well as probiotic-driven metabolic products called “postbiotics,” has been recently recognized and it is able to influence innate immunity. New therapeutic approaches based on probiotics are now available, and further treatments based on postbiotics will come in the future.

  6. Hepatitis C, Innate Immunity and Alcohol: Friends or Foes?

    Directory of Open Access Journals (Sweden)

    Natalia A. Osna

    2015-02-01

    Full Text Available Hepatitis C and alcohol are the most widespread causes of liver disease worldwide. Approximately 80% of patients with a history of hepatitis C and alcohol abuse develop chronic liver injury. Alcohol consumption in hepatitis C virus (HCV-infected patients exacerbates liver disease leading to rapid progression of fibrosis, cirrhosis and even hepatocellular carcinoma. Hepatocytes are the main sites of HCV-infection and ethanol metabolism, both of which generate oxidative stress. Oxidative stress levels affect HCV replication and innate immunity, resulting in a greater susceptibility for HCV-infection and virus spread in the alcoholic patients. In this review paper, we analyze the effects of ethanol metabolism and other factors on HCV replication. In addition, we illustrate the mechanisms of how HCV hijacks innate immunity and how ethanol exposure regulates this process. We also clarify the effects of HCV and ethanol metabolism on interferon signaling—a crucial point for activation of anti-viral genes to protect cells from virus—and the role that HCV- and ethanol-induced impairments play in adaptive immunity which is necessary for recognition of virally-infected hepatocytes. In conclusion, ethanol exposure potentiates the suppressive effects of HCV on innate immunity, which activates viral spread in the liver and finally, leads to impairments in adaptive immunity. The dysregulation of immune response results in impaired elimination of HCV-infected cells, viral persistence, progressive liver damage and establishment of chronic infection that worsens the outcomes of chronic hepatitis C in alcoholic patients.

  7. Infective Exacerbation of Pasteurella multocida

    Directory of Open Access Journals (Sweden)

    Mayumi Hamada

    2016-01-01

    Full Text Available An 89-year-old lady presented with a one-day history of shortness of breath as well as a cough productive of brown sputum. Her medical history was significant for chronic obstructive pulmonary disease (COPD. She was in severe type one respiratory failure and blood tests revealed markedly raised inflammatory markers; however her chest X-ray was clear. On examination there was bronchial breathing with widespread crepitations and wheeze. She was treated as per an infective exacerbation of COPD. Subsequent blood cultures grew Pasteurella multocida, a common commensal in the oropharynx of domesticated animals. The patient was then asked about any contact with animals, after which she revealed she had a dog and was bitten on her left hand the day before admission. We should not forget to enquire about recent history of injuries or animal bites when patients present acutely unwell. She made a complete recovery after treatment with penicillin.

  8. Innate immune responses of calves during transient infection with a noncytopathic strain of bovine viral diarrhea virus

    DEFF Research Database (Denmark)

    Muller-Doblies, D.; Arquint, A.; Schaller, P.

    2004-01-01

    In this study, six immunocompetent calves were experimentally infected with a noncytopathic strain of bovine viral diarrhea virus (BVDV), and the effects of the viral infection on parameters of the innate immune response of the host were analyzed. Clinical and virological data were compared...... 2 to 15. In the context of this study with BVDV, the level of Mx protein expression in WBC provided the most telling diagnostic window to monitor the host's ongoing innate immune response....

  9. Asthma exacerbation prediction: recent insights.

    Science.gov (United States)

    Fleming, Louise

    2018-04-01

    Asthma attacks are frequent in children with asthma and can lead to significant adverse outcomes including time off school, hospital admission and death. Identifying children at risk of an asthma attack affords the opportunity to prevent attacks and improve outcomes. Clinical features, patient behaviours and characteristics, physiological factors, environmental data and biomarkers are all associated with asthma attacks and can be used in asthma exacerbation prediction models. Recent studies have better characterized children at risk of an attack: history of a severe exacerbation in the previous 12 months, poor adherence and current poor control are important features which should alert healthcare professionals to the need for remedial action. There is increasing interest in the use of biomarkers. A number of novel biomarkers, including patterns of volatile organic compounds in exhaled breath, show promise. Biomarkers are likely to be of greatest utility if measured frequently and combined with other measures. To date, most prediction models are based on epidemiological data and population-based risk. The use of digital technology affords the opportunity to collect large amounts of real-time data, including clinical and physiological measurements and combine these with environmental data to develop personal risk scores. These developments need to be matched by changes in clinical guidelines away from a focus on current asthma control and stepwise escalation in drug therapy towards inclusion of personal risk scores and tailored management strategies including nonpharmacological approaches. There have been significant steps towards personalized prediction models of asthma attacks. The utility of such models needs to be tested in the ability not only to predict attacks but also to reduce them.

  10. Insect Innate Immunity Database (IIID): An Annotation Tool for Identifying Immune Genes in Insect Genomes

    OpenAIRE

    Brucker, Robert M; Lisa J Funkhouser; Shefali Setia; Rini Pauly; Bordenstein, Seth R.

    2012-01-01

    The innate immune system is an ancient component of host defense. Since innate immunity pathways are well conserved throughout many eukaryotes, immune genes in model animals can be used to putatively identify homologous genes in newly sequenced genomes of non-model organisms. With the initiation of the "i5k" project, which aims to sequence 5,000 insect genomes by 2016, many novel insect genomes will soon become publicly available, yet few annotation resources are currently available for insec...

  11. A Prime Time for Trained Immunity: Innate Immune Memory in Newborns & Infants

    OpenAIRE

    Levy, Ofer; Wynn, James L.

    2013-01-01

    The newborn and infant periods of early life are associated with heightened vulnerability to infection. Limited antigen exposure and distinct adaptive immune function compared to the adult places a greater burden on innate immunity for host defense to microbial challenge during this time. Trained immunity describes the phenomenon of augmented innate immune function following a stimulus that is not specific to the original stimulus. We review the concept of trained immunity in the context of t...

  12. HIV-1 infection of macrophages is dependent on evasion of innate immune cellular activation.

    Science.gov (United States)

    Tsang, Jhen; Chain, Benjamin M; Miller, Robert F; Webb, Benjamin L J; Barclay, Wendy; Towers, Greg J; Katz, David R; Noursadeghi, Mahdad

    2009-11-13

    The cellular innate immune response to HIV-1 is poorly characterized. In view of HIV-1 tropism for macrophages, which can be activated via pattern recognition receptors to trigger antimicrobial defences, we investigated innate immune responses to HIV-1 by monocyte-derived macrophages. In a model of productive HIV-1 infection, cellular innate immune responses to HIV-1 were investigated, at the level of transcription factor activation, specific gene expression and genome-wide transcriptional profiling. In addition, the viral determinants of macrophage responses and the physiological effect of innate immune cellular activation on HIV-1 replication were assessed. Productive HIV-1 infection did not activate nuclear factor-kappaB and interferon regulatory factor 3 transcription factors or interferon gene expression (IFN) and caused remarkably small changes to the host-cell transcriptome, with no evidence of inflammatory or IFN signatures. Evasion of IFN induction was not dependent on HIV-1 envelope-mediated cellular entry, inhibition by accessory proteins or reverse transcription of ssRNA that may reduce innate immune cellular activation by viral RNA. Furthermore, IFNbeta priming did not sensitize responses to HIV-1. Importantly, exogenous IFNbeta or stimulation with the RNA analogue poly I:C to simulate innate immune activation invoked HIV-1 restriction. We conclude that macrophages lack functional pattern recognition receptors for this virus and that HIV-1 tropism for macrophages helps to establish a foothold in the host without triggering innate immune cellular activation, which would otherwise block viral infection effectively.

  13. The Innate Lymphoid Cell Precursor.

    Science.gov (United States)

    Ishizuka, Isabel E; Constantinides, Michael G; Gudjonson, Herman; Bendelac, Albert

    2016-05-20

    The discovery of tissue-resident innate lymphoid cell populations effecting different forms of type 1, 2, and 3 immunity; tissue repair; and immune regulation has transformed our understanding of mucosal immunity and allergy. The emerging complexity of these populations along with compounding issues of redundancy and plasticity raise intriguing questions about their precise lineage relationship. Here we review advances in mapping the emergence of these lineages from early lymphoid precursors. We discuss the identification of a common innate lymphoid cell precursor characterized by transient expression of the transcription factor PLZF, and the lineage relationships of innate lymphoid cells with conventional natural killer cells and lymphoid tissue inducer cells. We also review the rapidly growing understanding of the network of transcription factors that direct the development of these lineages.

  14. Generalized immune activation and innate immune responses in simian immunodeficiency virus infection.

    Science.gov (United States)

    Bosinger, Steven E; Sodora, Donald L; Silvestri, Guido

    2011-09-01

    Chronic immune activation is a key factor driving the immunopathogenesis of AIDS. During pathogenic HIV/simian immunodeficiency virus (SIV) infections, innate and adaptive antiviral immune responses contribute to chronic immune activation. In contrast, nonpathogenic SIV infections of natural hosts such as sooty mangabeys and African green monkeys (AGMs) are characterized by low immune activation despite similarly high viremia. This review focuses on the role of innate immune responses in SIV infection. Several studies have examined the role of innate immune responses to SIV as potential drivers of immune activation. The key result of these studies is that both pathogenic SIV infection of macaques and nonpathogenic SIV infections of natural hosts are associated with strong innate immune responses to the virus, high production of type I interferons by plasmacytoid dendritic cells, and upregulation of interferon-stimulated genes (ISGs). However, SIV-infected sooty mangabeys and AGMs (but not SIV-infected macaques) rapidly downmodulate the interferon response within 4-6 weeks of infection, thus resulting in a state of limited immune activation during chronic infection. Studies in nonhuman primates suggest that chronic innate/interferon responses may contribute to AIDS pathogenesis. Further, the ability of natural host species to resolve innate immune responses after infection provides a novel avenue for potential immunotherapy.

  15. Are Evolution and the Intracellular Innate Immune System Key Determinants in HIV Transmission?

    Science.gov (United States)

    Sumner, Rebecca P.; Thorne, Lucy G.; Fink, Doug L.; Khan, Hataf; Milne, Richard S.; Towers, Greg J.

    2017-01-01

    HIV-1 is the single most important sexually transmitted disease in humans from a global health perspective. Among human lentiviruses, HIV-1 M group has uniquely achieved pandemic levels of human-to-human transmission. The requirement to transmit between hosts likely provides the strongest selective forces on a virus, as without transmission, there can be no new infections within a host population. Our perspective is that evolution of all of the virus–host interactions, which are inherited and perpetuated from host-to-host, must be consistent with transmission. For example, CXCR4 use, which often evolves late in infection, does not favor transmission and is therefore lost when a virus transmits to a new host. Thus, transmission inevitably influences all aspects of virus biology, including interactions with the innate immune system, and dictates the biological niche in which the virus exists in the host. A viable viral niche typically does not select features that disfavor transmission. The innate immune response represents a significant selective pressure during the transmission process. In fact, all viruses must antagonize and/or evade the mechanisms of the host innate and adaptive immune systems that they encounter. We believe that viewing host–virus interactions from a transmission perspective helps us understand the mechanistic details of antiviral immunity and viral escape. This is particularly true for the innate immune system, which typically acts from the very earliest stages of the host–virus interaction, and must be bypassed to achieve successful infection. With this in mind, here we review the innate sensing of HIV, the consequent downstream signaling cascades and the viral restriction that results. The centrality of these mechanisms to host defense is illustrated by the array of countermeasures that HIV deploys to escape them, despite the coding constraint of a 10 kb genome. We consider evasion strategies in detail, in particular the role of the

  16. Insights into antiviral innate immunity revealed by studying hepatitis C virus.

    Science.gov (United States)

    Horner, Stacy M

    2015-08-01

    Experimental studies on the interactions of the positive strand RNA virus hepatitis C virus (HCV) with the host have contributed to several discoveries in the field of antiviral innate immunity. These include revealing the antiviral sensing pathways that lead to the induction of type I interferon (IFN) during HCV infection and also the importance of type III IFNs in the antiviral immune response to HCV. These studies on HCV/host interactions have contributed to our overall understanding of viral sensing and viral evasion of the antiviral intracellular innate immune response. In this review, I will highlight how these studies of HCV/host interactions have led to new insights into antiviral innate immunity. Overall, I hope to emphasize that studying antiviral immunity in the context of virus infection is necessary to fully understand antiviral immunity and how it controls the outcome of viral infection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Blood Coagulation and Asthma Exacerbation in Children.

    Science.gov (United States)

    Manuyakorn, Wiparat; Mairiang, Dara; Sirachainan, Nongnuch; Kadegasem, Praguywan; Kamchaisatian, Wasu; Benjaponpitak, Suwat; Chuansumrit, Ampaiwan

    2016-01-01

    Recent studies have demonstrated the activation of coagulation pathways in asthmatic airways. This study aimed to determine systemic blood coagulation during asthma exacerbation compared with the stable state in children. Pediatric patients (aged between 5 and 15 years) suffering from asthma exacerbation were enrolled. von Willebrand factor (vWF), plasminogen activator inhibitor type-1 (PAI-1), protein C, D-dimer, prothrombin fragment 1 + 2 (F1 + 2), thrombin-antithrombin complex (TAT), and C-reactive protein (CRP) levels were measured during asthma exacerbation and stable state. A total of 22 patients were enrolled. The median vWF, PAI-1, and CRP during asthma exacerbation were significantly higher than those of the stable state: 147.5% (interquartile range, IQR: 111.05-196.57) versus 94% (IQR: 69.72-109.62, p coagulation in asthma exacerbation. © 2016 S. Karger AG, Basel.

  18. [Treatment and prevention of COPD exacerbation].

    Science.gov (United States)

    Yamaya, Mutsuo; Yasuda, Hiroyasu; Yoshida, Motoki; Nishimura, Hidekazu; Nakayama, Katsutoshi

    2007-04-01

    Airway inflammation, mucosal edema, epithelial hyperpermeability, mucus secretion and airway smooth muscle contraction induced by airway bacterial, virus infection and exposure to air pollution may be associated with COPD exacerbation. Severity of COPD exacerbation is estimated by blood gas analysis, serum CRP values and the chest radiograph. Patients with COPD exacerbations are recommended to be treated with additional inhalations of beta-2 agonists and anti -cholinergic agents, systemic administered glucocorticosteroids, oxygen inhalation, and, in cases with purulent sputum, antibiotics. Glucocorticosteroids, beta-2 agonists and anti-cholinergic agents reduce the frequency of COPD exacerbation. We reported the inhibitory effects of glucocorticosteroids on rhinovirus infection, the major cause of common colds, and the inhibitory effects of L-carbocisteine and erythromycin on COPD exacerbations and rhinovirus infection.

  19. Optimizing antibiotic selection in treating COPD exacerbations

    Directory of Open Access Journals (Sweden)

    Attiya Siddiqi

    2008-03-01

    Full Text Available Attiya Siddiqi, Sanjay SethiDivision of Pulmonary, Critical Care and Sleep Medicine, Department of Medicine, Veterans Affairs Western New York Health Care System and University of Buffalo, State University of New York, Buffalo, New York, USAAbstract: Our understanding of the etiology, pathogenesis and consequences of acute exacerbations of chronic obstructive pulmonary disease (COPD has increased substantially in the last decade. Several new lines of evidence demonstrate that bacterial isolation from sputum during acute exacerbation in many instances reflects a cause-effect relationship. Placebo-controlled antibiotic trials in exacerbations of COPD demonstrate significant clinical benefits of antibiotic treatment in moderate and severe episodes. However, in the multitude of antibiotic comparison trials, the choice of antibiotics does not appear to affect the clinical outcome, which can be explained by several methodological limitations of these trials. Recently, comparison trials with nontraditional end-points have shown differences among antibiotics in the treatment of exacerbations of COPD. Observational studies that have examined clinical outcome of exacerbations have repeatedly demonstrated certain clinical characteristics to be associated with treatment failure or early relapse. Optimal antibiotic selection for exacerbations has therefore incorporated quantifying the risk for a poor outcome of the exacerbation and choosing antibiotics differently for low risk and high risk patients, reserving the broader spectrum drugs for the high risk patients. Though improved outcomes in exacerbations with antibiotic choice based on such risk stratification has not yet been demonstrated in prospective controlled trials, this approach takes into account concerns of disease heterogeneity, antibiotic resistance and judicious antibiotic use in exacerbations.Keywords: COPD, exacerbation, bronchitis, antibiotics

  20. Hypoxia, innate immunity and infection in the lung.

    LENUS (Irish Health Repository)

    Schaible, Bettina

    2012-02-01

    The mucosal surface of the lung is the key interface between the external atmosphere and the bloodstream. Normally, this well oxygenated tissue is maintained in state of sterility by a number of innate immune processes. These include a physical and dynamic mucus barrier, the production of microbiocidal peptides and the expression of specific pattern recognition receptors on alveolar epithelial cells and resident macrophages and dendritic cells which recognise microbial structures and initiate innate immune responses which promote the clearance of potentially infectious agents. In a range of diseases, the mucosal surface of the lung experiences decreased oxygen tension leading to localised areas of prominent hypoxia which can impact upon innate immune and subsequent infectious and inflammatory processes. Under these conditions, the lung is generally more susceptible to infection and subsequent inflammation. In the current review, we will discuss recent data pertaining to the role of hypoxia in regulating both host and pathogen in the lung during pulmonary disease and how this contributes to innate immunity, infection and inflammation.

  1. Role of innate immunity in the pathogenesis of otitis media.

    Science.gov (United States)

    Mittal, Rahul; Kodiyan, Joyson; Gerring, Robert; Mathee, Kalai; Li, Jian-Dong; Grati, M'hamed; Liu, Xue Zhong

    2014-12-01

    Otitis media (OM) is a public health problem in both developed and developing countries. It is the leading cause of hearing loss and represents a significant healthcare burden. In some cases, acute OM progresses to chronic suppurative OM (CSOM), characterized by effusion and discharge, despite antimicrobial therapy. The emergence of antibiotic resistance and potential ototoxicity of antibiotics has created an urgent need to design non-conventional therapeutic strategies against OM based on modern insights into its pathophysiology. In this article, we review the role of innate immunity as it pertains to OM and discuss recent advances in understanding the role of innate immune cells in protecting the middle ear. We also discuss the mechanisms utilized by pathogens to subvert innate immunity and thereby overcome defensive responses. A better knowledge about bacterial virulence and host resistance promises to reveal novel targets to design effective treatment strategies against OM. The identification and characterization of small natural compounds that can boost innate immunity may provide new avenues for the treatment of OM. There is also a need to design novel methods for targeted delivery of these compounds into the middle ear, allowing higher therapeutic doses and minimizing systemic side effects. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Innate and adaptive T cells in influenza disease.

    Science.gov (United States)

    Nüssing, Simone; Sant, Sneha; Koutsakos, Marios; Subbarao, Kanta; Nguyen, Thi H O; Kedzierska, Katherine

    2018-02-01

    Influenza is a major global health problem, causing infections of the respiratory tract, often leading to acute pneumonia, life-threatening complications and even deaths. Over the last seven decades, vaccination strategies have been utilized to protect people from complications of influenza, especially groups at high risk of severe disease. While current vaccination regimens elicit strain-specific antibody responses, they fail to generate cross-protection against seasonal, pandemic and avian viruses. Moreover, vaccines designed to generate influenza-specific T-cell responses are yet to be optimized. During natural infection, viral replication is initially controlled by innate immunity before adaptive immune responses (T cells and antibody-producing B cells) achieve viral clearance and host recovery. Adaptive T and B cells maintain immunological memory and provide protection against subsequent infections with related influenza viruses. Recent studies also shed light on the role of innate T-cells (MAIT cells, γδ cells, and NKT cells) in controlling influenza and linking innate and adaptive immune mechanisms, thus making them attractive targets for vaccination strategies. We summarize the current knowledge on influenza-specific innate MAIT and γδ T cells as well as adaptive CD8 + and CD4 + T cells, and discuss how these responses can be harnessed by novel vaccine strategies to elicit cross-protective immunity against different influenza strains and subtypes.

  3. Psoriasis: dysregulation of innate immunity

    NARCIS (Netherlands)

    Bos, J. D.; de Rie, M. A.; Teunissen, M. B. M.; Piskin, G.

    2005-01-01

    The current understanding of the function of natural killer (NK) T cells in innate immunity and their potential to control acquired specific immunity, as well as the remarkable efficacy of antitumour necrosis factor-alpha biological treatments in psoriasis, forces us to refine the current T-cell

  4. Innate immune signaling in CLL.

    Science.gov (United States)

    Maus, Marcela V

    2016-01-28

    In this issue of Blood, Wagner et al describe a complex signaling model that explains the mechanism of action of a long-known prognostic marker in chronic lymphocytic leukemia (CLL) and integrates its function with the innate immune system and B-cell receptor signaling.

  5. Opinion: Interactions of innate and adaptive lymphocytes

    Science.gov (United States)

    Gasteiger, Georg; Rudensky, Alexander Y.

    2015-01-01

    Innate lymphocytes, including natural killer (NK) cells and the recently discovered innate lymphoid cells (ILCs) have crucial roles during infection, tissue injury and inflammation. Innate signals regulate the activation and homeostasis of innate lymphocytes. Less well understood is the contribution of the adaptive immune system to the orchestration of innate lymphocyte responses. We review our current understanding of the interactions between adaptive and innate lymphocytes, and propose a model in which adaptive T cells function as antigen-specific sensors for the activation of innate lymphocytes to amplify and instruct local immune responses. We highlight the potential role of regulatory and helper T cells in these processes and discuss major questions in the emerging area of crosstalk between adaptive and innate lymphocytes. PMID:25132095

  6. Can we predict fall asthma exacerbations? Validation of the seasonal asthma exacerbation index.

    Science.gov (United States)

    Hoch, Heather E; Calatroni, Agustin; West, Joseph B; Liu, Andrew H; Gergen, Peter J; Gruchalla, Rebecca S; Khurana Hershey, Gurjit K; Kercsmar, Carolyn M; Kim, Haejin; Lamm, Carin I; Makhija, Melanie M; Mitchell, Herman E; Teach, Stephen J; Wildfire, Jeremy J; Busse, William W; Szefler, Stanley J

    2017-10-01

    A Seasonal Asthma Exacerbation Predictive Index (saEPI) was previously reported based on 2 prior National Institute of Allergy and Infectious Diseases Inner City Asthma Consortium trials. This study sought to validate the saEPI in a separate trial designed to prevent fall exacerbations with omalizumab therapy. The saEPI and its components were analyzed to characterize those who had an asthma exacerbation during the Preventative Omalizumab or Step-Up Therapy for Fall Exacerbations (PROSE) study. We characterized those inner-city children with and without asthma exacerbations in the fall period treated with guidelines-based therapy (GBT) in the absence and presence of omalizumab. A higher saEPI was associated with an exacerbation in both the GBT alone (P asthma exacerbation in both groups. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. All rights reserved.

  7. Inhibitor of apoptosis (IAP) proteins in regulation of inflammation and innate immunity

    DEFF Research Database (Denmark)

    Damgaard, Rune B; Gyrd-Hansen, Mads

    2011-01-01

    Inflammatory and innate immune signaling in response to recognition of pathogens is essential for immunity and host survival. However, deregulation may lead to detrimental pathologies including immunodeficiency, inflammatory diseases, and cancer. Inhibitor of apoptosis (IAP) proteins have emerged...... as promising targets for anti-inflammatory therapies in PRR-dependent inflammatory diseases including Crohn's disease, Blau syndrome, and septic shock.......Inflammatory and innate immune signaling in response to recognition of pathogens is essential for immunity and host survival. However, deregulation may lead to detrimental pathologies including immunodeficiency, inflammatory diseases, and cancer. Inhibitor of apoptosis (IAP) proteins have emerged...

  8. E. fischeriana Root Compound Dpo Activates Antiviral Innate Immunity

    Directory of Open Access Journals (Sweden)

    Jingxuan Chen

    2017-10-01

    Full Text Available E. fischeriana has long been used as a traditional Chinese medicine. Recent studies reported that some compounds of E. fischeriana exhibited antimicrobial and immune enhance activity. Innate immune system is essential for the immune surveillance of inner and outer threats, initial host defense responses and immune modulation. The role of natural drug compounds, including E. fischeriana, in innate immune regulation is largely unknown. Here we demonstrated that E. fischeriana compound Dpo is involved in antiviral signaling. The genome wide RNA-seq analysis revealed that the induction of ISGs by viral infection could be synergized by Dpo. Consistently, Dpo enhanced the antiviral immune responses and protected the mice from death during viral infection. Dpo however was not able to rescue STING deficient mice lethality caused by HSV-1 infection. The enhancement of ISG15 by Dpo was also impaired in STING, IRF3, IRF7, or ELF4 deficient cells, demonstrating that Dpo activates innate immune responses in a STING/IRFs/ELF4 dependent way. The STING/IRFs/ELF4 axis is therefore important for Dpo induced ISGs expression, and can be used by host to counteract infection.

  9. Human innate lymphoid cells (ILCs) in filarial infections.

    Science.gov (United States)

    Bonne-Année, S; Nutman, T B

    2018-02-01

    Filarial infections are characteristically chronic and can cause debilitating diseases governed by parasite-induced innate and adaptive immune responses. Filarial parasites traverse or establish niches in the skin (migrating infective larvae), in nonmucosal tissues (adult parasite niche) and in the blood or skin (circulating microfilariae) where they intersect with the host immune response. While several studies have demonstrated that filarial parasites and their antigens can modulate myeloid cells (monocyte, macrophage and dendritic cell subsets), T- and B-lymphocytes and skin resident cell populations, the role of innate lymphoid cells during filarial infections has only recently emerged. Despite the identification and characterization of innate lymphoid cells (ILCs) in murine helminth infections, little is actually known about the role of human ILCs during parasitic infections. The focus of this review will be to highlight the composition of ILCs in the skin, lymphatics and blood; where the host-parasite interaction is well-defined and to examine the role of ILCs during filarial infections. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  10. Asthma Exacerbation in Children: A Practical Review

    Directory of Open Access Journals (Sweden)

    Lin-Shien Fu

    2014-04-01

    Full Text Available Asthma is the most common chronic lower respiratory tract disease in childhood throughout the world. Despite advances in asthma management, acute exacerbations continue to be a major problem in patients and they result in a considerable burden on direct/indirect health care providers. A severe exacerbation occurring within 1 year is an independent risk factor. Respiratory tract viruses have emerged as the most frequent triggers of exacerbations in children. It is becoming increasingly clear that interactions may exist between viruses and other triggers, increasing the likelihood of an exacerbation. In this study, we provide an overview of current knowledge about asthma exacerbations, including its definition, impact on health care providers, and associated factors. Prevention management in intermittent asthma as well as intermittent wheeze in pre-school children and those with persistent asthma are discussed. Our review findings support the importance of controlling persistent asthma, as indicated in current guidelines. In addition, we found that early episodic intervention appeared to be crucial in preventing severe attacks and future exacerbations. Besides the use of medication, timely education after an exacerbation along with a comprehensive plan in follow up is also vitally important.

  11. Prevention of exacerbations of COPD with pharmacotherapy.

    Science.gov (United States)

    Miravitlles, M

    2010-06-01

    Exacerbations are a frequent event in the evolution of chronic obstructive pulmonary disease (COPD) patients. Individuals with COPD have a mean of 1-3 episodes per year, some of which lead to hospital admission and may even be a cause of death. The importance of COPD exacerbations has become increasingly apparent due to the impact these episodes have on the natural history of disease. It is now known that frequent exacerbations can adversely affect health-related quality of life and short- and long-term pulmonary function. Optimising treatment for stable COPD will help to reduce exacerbations. Long-acting bronchodilators, alone or combined with inhaled corticosteroids, have demonstrated efficacy in reducing the rate of exacerbations in patients with COPD. Other innovative approaches are being investigated, such as the long-term use of macrolides or the use of antibiotics in an effort to suppress bronchial colonisation and consequent exacerbations. Other drugs, such as mucolytics and immunomodulators, have recently provided positive results. Non-pharmacological interventions such as rehabilitation, self-management plans and the maintenance of high levels of physical activity in daily life are also useful strategies to prevent exacerbations in patients with COPD and should be implemented in regular clinical practice.

  12. Prevention of exacerbations of COPD with pharmacotherapy

    Directory of Open Access Journals (Sweden)

    M. Miravitlles

    2010-06-01

    Full Text Available Exacerbations are a frequent event in the evolution of chronic obstructive pulmonary disease (COPD patients. Individuals with COPD have a mean of 1–3 episodes per year, some of which lead to hospital admission and may even be a cause of death. The importance of COPD exacerbations has become increasingly apparent due to the impact these episodes have on the natural history of disease. It is now known that frequent exacerbations can adversely affect health-related quality of life and short- and long-term pulmonary function. Optimising treatment for stable COPD will help to reduce exacerbations. Long-acting bronchodilators, alone or combined with inhaled corticosteroids, have demonstrated efficacy in reducing the rate of exacerbations in patients with COPD. Other innovative approaches are being investigated, such as the long-term use of macrolides or the use of antibiotics in an effort to suppress bronchial colonisation and consequent exacerbations. Other drugs, such as mucolytics and immunomodulators, have recently provided positive results. Non-pharmacological interventions such as rehabilitation, self-management plans and the maintenance of high levels of physical activity in daily life are also useful strategies to prevent exacerbations in patients with COPD and should be implemented in regular clinical practice.

  13. Prevention of exacerbations of COPD with pharmacotherapy

    OpenAIRE

    M. Miravitlles

    2010-01-01

    Exacerbations are a frequent event in the evolution of chronic obstructive pulmonary disease (COPD) patients. Individuals with COPD have a mean of 1–3 episodes per year, some of which lead to hospital admission and may even be a cause of death. The importance of COPD exacerbations has become increasingly apparent due to the impact these episodes have on the natural history of disease. It is now known that frequent exacerbations can adversely affect health-related quality of life and short- an...

  14. IL-33–Dependent Type 2 Inflammation during Rhinovirus-induced Asthma Exacerbations In Vivo

    Science.gov (United States)

    Jackson, David J.; Makrinioti, Heidi; Rana, Batika M. J.; Shamji, Betty W. H.; Trujillo-Torralbo, Maria-Belen; Footitt, Joseph; Jerico del-Rosario; Telcian, Aurica G.; Nikonova, Alexandra; Zhu, Jie; Aniscenko, Julia; Gogsadze, Leila; Bakhsoliani, Eteri; Traub, Stephanie; Dhariwal, Jaideep; Porter, James; Hunt, Duncan; Hunt, Toby; Hunt, Trevor; Stanciu, Luminita A.; Khaitov, Musa; Bartlett, Nathan W.; Edwards, Michael R.; Kon, Onn Min; Mallia, Patrick; Papadopoulos, Nikolaos G.; Akdis, Cezmi A.; Westwick, John; Edwards, Matthew J.; Cousins, David J.; Walton, Ross P.

    2014-01-01

    Rationale: Rhinoviruses are the major cause of asthma exacerbations; however, its underlying mechanisms are poorly understood. We hypothesized that the epithelial cell–derived cytokine IL-33 plays a central role in exacerbation pathogenesis through augmentation of type 2 inflammation. Objectives: To assess whether rhinovirus induces a type 2 inflammatory response in asthma in vivo and to define a role for IL-33 in this pathway. Methods: We used a human experimental model of rhinovirus infection and novel airway sampling techniques to measure IL-4, IL-5, IL-13, and IL-33 levels in the asthmatic and healthy airways during a rhinovirus infection. Additionally, we cultured human T cells and type 2 innate lymphoid cells (ILC2s) with the supernatants of rhinovirus-infected bronchial epithelial cells (BECs) to assess type 2 cytokine production in the presence or absence of IL-33 receptor blockade. Measurements and Main Results: IL-4, IL-5, IL-13, and IL-33 are all induced by rhinovirus in the asthmatic airway in vivo and relate to exacerbation severity. Further, induction of IL-33 correlates with viral load and IL-5 and IL-13 levels. Rhinovirus infection of human primary BECs induced IL-33, and culture of human T cells and ILC2s with supernatants of rhinovirus-infected BECs strongly induced type 2 cytokines. This induction was entirely dependent on IL-33. Conclusions: IL-33 and type 2 cytokines are induced during a rhinovirus-induced asthma exacerbation in vivo. Virus-induced IL-33 and IL-33–responsive T cells and ILC2s are key mechanistic links between viral infection and exacerbation of asthma. IL-33 inhibition is a novel therapeutic approach for asthma exacerbations. PMID:25350863

  15. IL-33-dependent type 2 inflammation during rhinovirus-induced asthma exacerbations in vivo.

    Science.gov (United States)

    Jackson, David J; Makrinioti, Heidi; Rana, Batika M J; Shamji, Betty W H; Trujillo-Torralbo, Maria-Belen; Footitt, Joseph; Jerico Del-Rosario; Telcian, Aurica G; Nikonova, Alexandra; Zhu, Jie; Aniscenko, Julia; Gogsadze, Leila; Bakhsoliani, Eteri; Traub, Stephanie; Dhariwal, Jaideep; Porter, James; Hunt, Duncan; Hunt, Toby; Hunt, Trevor; Stanciu, Luminita A; Khaitov, Musa; Bartlett, Nathan W; Edwards, Michael R; Kon, Onn Min; Mallia, Patrick; Papadopoulos, Nikolaos G; Akdis, Cezmi A; Westwick, John; Edwards, Matthew J; Cousins, David J; Walton, Ross P; Johnston, Sebastian L

    2014-12-15

    Rhinoviruses are the major cause of asthma exacerbations; however, its underlying mechanisms are poorly understood. We hypothesized that the epithelial cell-derived cytokine IL-33 plays a central role in exacerbation pathogenesis through augmentation of type 2 inflammation. To assess whether rhinovirus induces a type 2 inflammatory response in asthma in vivo and to define a role for IL-33 in this pathway. We used a human experimental model of rhinovirus infection and novel airway sampling techniques to measure IL-4, IL-5, IL-13, and IL-33 levels in the asthmatic and healthy airways during a rhinovirus infection. Additionally, we cultured human T cells and type 2 innate lymphoid cells (ILC2s) with the supernatants of rhinovirus-infected bronchial epithelial cells (BECs) to assess type 2 cytokine production in the presence or absence of IL-33 receptor blockade. IL-4, IL-5, IL-13, and IL-33 are all induced by rhinovirus in the asthmatic airway in vivo and relate to exacerbation severity. Further, induction of IL-33 correlates with viral load and IL-5 and IL-13 levels. Rhinovirus infection of human primary BECs induced IL-33, and culture of human T cells and ILC2s with supernatants of rhinovirus-infected BECs strongly induced type 2 cytokines. This induction was entirely dependent on IL-33. IL-33 and type 2 cytokines are induced during a rhinovirus-induced asthma exacerbation in vivo. Virus-induced IL-33 and IL-33-responsive T cells and ILC2s are key mechanistic links between viral infection and exacerbation of asthma. IL-33 inhibition is a novel therapeutic approach for asthma exacerbations.

  16. IL-22 Defect During Streptococcus pneumoniae Infection Triggers Exacerbation of Chronic Obstructive Pulmonary Disease.

    Science.gov (United States)

    Pichavant, Muriel; Sharan, Riti; Le Rouzic, Olivier; Olivier, Cécile; Hennegrave, Florence; Rémy, Gaëlle; Pérez-Cruz, Magdiel; Koné, Bachirou; Gosset, Pierre; Just, Nicolas; Gosset, Philippe

    2015-11-01

    Progression of chronic obstructive pulmonary disease (COPD) is linked to episodes of exacerbations caused by bacterial infections due to Streptococcus pneumoniae. Our objective was to identify during COPD, factors of susceptibility to bacterial infections among cytokine network and their role in COPD exacerbations. S. pneumoniae was used to sub-lethally challenge mice chronically exposed to air or cigarette smoke (CS) and to stimulate peripheral blood mononuclear cells (PBMC) from non-smokers, smokers and COPD patients. The immune response and the cytokine production were evaluated. Delayed clearance of the bacteria and stronger lung inflammation observed in infected CS-exposed mice were associated with an altered production of IL-17 and IL-22 by innate immune cells. This defect was related to a reduced production of IL-1β and IL-23 by antigen presenting cells. Importantly, supplementation with recombinant IL-22 restored bacterial clearance in CS-exposed mice and limited lung alteration. In contrast with non-smokers, blood NK and NKT cells from COPD patients failed to increase IL-17 and IL-22 levels in response to S. pneumoniae, in association with a defect in IL-1β and IL-23 secretion. This study identified IL-17 and IL-22 as susceptibility factors in COPD exacerbation. Therefore targeting such cytokines could represent a potent strategy to control COPD exacerbation.

  17. Osteopontin Bridging Innate and Adaptive Immunity in Autoimmune Diseases

    Directory of Open Access Journals (Sweden)

    Nausicaa Clemente

    2016-01-01

    Full Text Available Osteopontin (OPN regulates the immune response at multiple levels. Physiologically, it regulates the host response to infections by driving T helper (Th polarization and acting on both innate and adaptive immunity; pathologically, it contributes to the development of immune-mediated and inflammatory diseases. In some cases, the mechanisms of these effects have been described, but many aspects of the OPN function remain elusive. This is in part ascribable to the fact that OPN is a complex molecule with several posttranslational modifications and it may act as either an immobilized protein of the extracellular matrix or a soluble cytokine or an intracytoplasmic molecule by binding to a wide variety of molecules including crystals of calcium phosphate, several cell surface receptors, and intracytoplasmic molecules. This review describes the OPN structure, isoforms, and functions and its role in regulating the crosstalk between innate and adaptive immunity in autoimmune diseases.

  18. Boosting innate immunity to sustainably control diseases in crops.

    Science.gov (United States)

    Nicaise, Valerie

    2017-10-01

    Viruses cause epidemics in all major crops, threatening global food security. The development of efficient and durable resistance able to withstand viral attacks represents a major challenge for agronomy, and relies greatly on the understanding of the molecular dialogue between viral pathogens and their hosts. Research over the last decades provided substantial advances in the field of plant-virus interactions. Remarkably, the advent of studies of plant innate immunity has recently offered new strategies exploitable in the field. This review summarizes the recent breakthroughs that define the mechanisms underlying antiviral innate immunity in plants, and emphasizes the importance of integrating that knowledge into crop improvement actions, particularly by exploiting the insights related to immune receptors. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Osteopontin Bridging Innate and Adaptive Immunity in Autoimmune Diseases

    Science.gov (United States)

    Raineri, Davide; Boggio, Elena; Favero, Francesco; Soluri, Maria Felicia

    2016-01-01

    Osteopontin (OPN) regulates the immune response at multiple levels. Physiologically, it regulates the host response to infections by driving T helper (Th) polarization and acting on both innate and adaptive immunity; pathologically, it contributes to the development of immune-mediated and inflammatory diseases. In some cases, the mechanisms of these effects have been described, but many aspects of the OPN function remain elusive. This is in part ascribable to the fact that OPN is a complex molecule with several posttranslational modifications and it may act as either an immobilized protein of the extracellular matrix or a soluble cytokine or an intracytoplasmic molecule by binding to a wide variety of molecules including crystals of calcium phosphate, several cell surface receptors, and intracytoplasmic molecules. This review describes the OPN structure, isoforms, and functions and its role in regulating the crosstalk between innate and adaptive immunity in autoimmune diseases. PMID:28097158

  20. Exposure to particulate hexavalent chromium exacerbates allergic asthma pathology

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Brent C. [Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC 20037 (United States); Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037 (United States); Constant, Stephanie L. [Department of Microbiology, Immunology and Tropical Medicine, The George Washington University, Washington, DC 20037 (United States); Patierno, Steven R. [Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037 (United States); GW Cancer Institute, The George Washington University, Washington, DC 20037 (United States); Jurjus, Rosalyn A. [Department of Anatomy and Regenerative Biology, The George Washington University, Washington, DC 20037 (United States); Ceryak, Susan M., E-mail: phmsmc@gwumc.edu [Department of Pharmacology and Physiology, The George Washington University, Washington, DC 20037 (United States)

    2012-02-15

    Airborne hexavalent chromate, Cr(VI), has been identified by the Environmental Protection Agency as a possible health threat in urban areas, due to the carcinogenic potential of some of its forms. Particulate chromates are produced in many different industrial settings, with high levels of aerosolized forms historically documented. Along with an increased risk of lung cancer, a high incidence of allergic asthma has been reported in workers exposed to certain inhaled particulate Cr(VI) compounds. However, a direct causal association between Cr(VI) and allergic asthma has not been established. We recently showed that inhaled particulate Cr(VI) induces an innate neutrophilic inflammatory response in BALB/c mice. In the current studies we investigated how the inflammation induced by inhaled particulate Cr(VI) might alter the pathology of an allergic asthmatic response. We used a well-established mouse model of allergic asthma. Groups of ovalbumin protein (OVA)-primed mice were challenged either with OVA alone, or with a combination of OVA and particulate zinc chromate, and various parameters associated with asthmatic responses were measured. Co-exposure to particulate Cr(VI) and OVA mediated a mixed form of asthma in which both eosinophils and neutrophils are present in airways, tissue pathology is markedly exacerbated, and airway hyperresponsiveness is significantly increased. Taken together these findings suggest that inhalation of particulate forms of Cr(VI) may augment the severity of ongoing allergic asthma, as well as alter its phenotype. Such findings may have implications for asthmatics in settings in which airborne particulate Cr(VI) compounds are present at high levels. -- Highlights: ► Allergic asthma correlated with exposure to certain inhaled particulate chromates. ► Direct causal association between Cr(VI) and allergic asthma not established. ► Cr exacerbated pathology and airway hyperresponsiveness in an OVA-challenged mouse. ► Particulate Cr

  1. Adiponectin: a versatile player of innate immunity.

    Science.gov (United States)

    Luo, Yan; Liu, Meilian

    2016-04-01

    Adiponectin acts as a key regulator of the innate immune system and plays a major role in the progression of inflammation and metabolic disorders. Macrophages and monocytes are representative components of the innate immune system, and their proliferation, plasticity, and polarization are a key component of metabolic adaption. Innate-like lymphocytes such as group 2 innate lymphoid cells (ILC2s), natural killer T (NKT) cells, and gamma delta T (γδ T) cells are also members of the innate immune system and play important roles in the development of obesity and its related diseases. Adiponectin senses metabolic stress and modulates metabolic adaption by targeting the innate immune system under physiological and pathological conditions. Defining the mechanisms underlying the role of adiponectin in regulating innate immunity is crucial to adiponectin-based therapeutic intervention. © The Author (2016). Published by Oxford University Press on behalf of Journal of Molecular Cell Biology, IBCB, SIBS, CAS. All rights reserved.

  2. Emerging roles of orphan nuclear receptors in regulation of innate immunity.

    Science.gov (United States)

    Jin, Hyo Sun; Kim, Tae Sung; Jo, Eun-Kyeong

    2016-11-01

    Innate immunity constitutes the first line of defense against pathogenic and dangerous insults. However, it is a double-edged sword, as it functions in both clearance of infection and inflammatory damage. It is therefore important that innate immune responses are tightly controlled to prevent harmful excessive inflammation. Nuclear receptors (NRs) are a family of transcription factors that play critical roles in various physiological responses. Orphan NRs are a subset of NRs for which the ligands and functions are unclear. Accumulating evidence has revealed that orphan NRs play essential roles in innate immune responses to prevent pathogenic inflammatory responses and to enhance antimicrobial host defenses. In this review, we describe current knowledge on the roles and mechanisms of orphan NRs in the regulation of innate immune responses. Discovery of new functions of orphan NRs would facilitate development of novel preventive and therapeutic strategies against human inflammatory diseases.

  3. Acute exacerbations of fibrotic interstitial lung disease.

    Science.gov (United States)

    Churg, Andrew; Wright, Joanne L; Tazelaar, Henry D

    2011-03-01

    An acute exacerbation is the development of acute lung injury, usually resulting in acute respiratory distress syndrome, in a patient with a pre-existing fibrosing interstitial pneumonia. By definition, acute exacerbations are not caused by infection, heart failure, aspiration or drug reaction. Most patients with acute exacerbations have underlying usual interstitial pneumonia, either idiopathic or in association with a connective tissue disease, but the same process has been reported in patients with fibrotic non-specific interstitial pneumonia, fibrotic hypersensitivity pneumonitis, desquamative interstitial pneumonia and asbestosis. Occasionally an acute exacerbation is the initial manifestation of underlying interstitial lung disease. On biopsy, acute exacerbations appear as diffuse alveolar damage or bronchiolitis obliterans organizing pneumonia (BOOP) superimposed upon the fibrosing interstitial pneumonia. Biopsies may be extremely confusing, because the acute injury pattern can completely obscure the underlying disease; a useful clue is that diffuse alveolar damage and organizing pneumonia should not be associated with old dense fibrosis and peripheral honeycomb change. Consultation with radiology can also be extremely helpful, because the fibrosing disease may be evident on old or concurrent computed tomography scans. The aetiology of acute exacerbations is unknown, and the prognosis is poor; however, some patients survive with high-dose steroid therapy. © 2010 Blackwell Publishing Limited.

  4. Vitamin D deficiency and adult asthma exacerbations.

    Science.gov (United States)

    Salas, Natalie Mariam; Luo, Li; Harkins, Michelle S

    2014-11-01

    There is growing evidence indicating a connection between vitamin D deficiency and the severity of asthma exacerbations. This study seeks to assess the relationship between vitamin D deficiency and the number and severity of asthma exacerbation in adults. A retrospective analysis was conducted in 92 patients being treated for asthma at the University of New Mexico Adult Asthma Clinic. Serum 25-hydroxyvitamin D3 levels were analyzed in adults with mild to severe persistent asthma. Using multi-variant modeling, the relationship was examined between serum vitamin D levels and the odds of asthma exacerbations ranging in severity from moderate to severe over the span of five years. This study demonstrates that vitamin D sufficiency was significantly associated with a decreased total number of asthma exacerbations (incidence rate ratio [IRR]: 0.61, 95% confidence interval [CI]: 0.44-0.84, p = 0.002), decreased total severe asthma exacerbations (IRR: 0.41, 95% CI: 0.24-0.72, p = 0.002) and decreased emergency room visits (IRR: 0.42, 95% CI: 0.20-0.88, p = 0.023). Vitamin D deficiency may be linked to the risk of severe asthma exacerbations in adults.

  5. Host-pathogen interactions in typhoid fever

    NARCIS (Netherlands)

    de Jong, H.K.

    2015-01-01

    This thesis focuses on host-pathogen interactions in Salmonella Typhi and Burkholderia pseudomallei infections and explores the interplay between these bacteria and the innate immune system. Typhoid fever is one of the most common causes of bacterial infection in low-income countries. With adequate

  6. RIP3-dependent necrosis induced inflammation exacerbates atherosclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Lingjun, E-mail: menglingjun@nibs.ac.cn [College of Biological Sciences, China Agricultural University, Beijing 100094 (China); National Institute of Biological Sciences, Beijing 102206 (China); Jin, Wei [Institute for Immunology, Tsinghua University, Beijing 100084 (China); Wang, Yuhui [Institute of Cardiovascular Sciences, Health Science Center, Peking University, Beijing 100191 (China); Huang, Huanwei; Li, Jia; Zhang, Cai [National Institute of Biological Sciences, Beijing 102206 (China)

    2016-04-29

    Atherothrombotic vascular disease is already the leading cause of mortality worldwide. Atherosclerosis shares features with diseases caused by chronic inflammation. More attention should concentrates on the innate immunity effect atherosclerosis progress. RIP3 (receptor-interacting protein kinase 3) act through the transcription factor named Nr4a3 (Nuclear orphan receptors) to regulate cytokine production. Deletion RIP3 decreases IL-1α production. Injection of anti-IL-1α antibody protects against the progress of atherosclerosis in ApoE −/− mice. RIP3 as a molecular switch in necrosis, controls macrophage necrotic death caused inflammation. Inhibiting necrosis will certainly reduce atherosclerosis through limit inflammation. Necrotic cell death caused systemic inflammation exacerbated cardiovascular disease. Inhibition of necrosis may yield novel therapeutic targets for treatment in years to come. - Highlights: • RIP3 regulate the Nr4a3 to control cytokine production. • Deletion RIP3 decreases IL-1a production. • Injection anti-IL-1a antibody protects against the progress of atherosclerosis. • RIP3 controls macrophage necrotic dead caused inflammation.

  7. A haptoglobin-hemoglobin receptor conveys innate immunity to Trypanosoma brucei in humans

    DEFF Research Database (Denmark)

    Vanhollebeke, Benoit; De Muylder, Géraldine; Nielsen, Marianne J

    2008-01-01

    receptor also recognized the complex between hemoglobin and haptoglobin-related protein, which explains its ability to capture trypanolytic HDLs. Thus, in humans the presence of haptoglobin-related protein has diverted the function of the trypanosome haptoglobin-hemoglobin receptor to elicit innate host...... immunity against the parasite....

  8. Modelling the innate immune response against avian influenza virus in chicken

    NARCIS (Netherlands)

    Hagenaars, T.J.; Fischer, E.A.J.; Jansen, C.A.; Rebel, J.M.J.; Spekreijse, D.; Vervelde, L.; Backer, J.A.; Jong, de M.C.M.; Koets, A.P.

    2016-01-01

    At present there is limited understanding of the host immune response to (low pathogenic) avian influenza virus infections in poultry. Here we develop a mathematical model for the innate immune response to avian influenza virus in chicken lung, describing the dynamics of viral load,

  9. On the modulation of innate immunity by plant-parasitic cyst nematodes

    NARCIS (Netherlands)

    Postma, W.J.

    2013-01-01

    Plant-parasitic cyst nematodes are major agricultural pests worldwide. These obligate endoparasites invade the roots of host plants where they transform cells near the vascular cylinder into a permanent feeding site. Plants possess a multilayered innate immune system consisting of different types of

  10. Innate immune responses to Chlamydia pneumoniae infection: Role of TLRs, NLRs, and the Inflammasome

    Science.gov (United States)

    Shimada, Kenichi; Crother, Timothy R.; Arditi, Moshe

    2012-01-01

    Chlamydiae are important human pathogens that are responsible for a wide rage of diseases with a significant impact on public health. In this review article we highlight how recent studies have increased our knowledge of Chlamydia pneumoniae pathogenesis and mechanisms of innate immunity directed host defense against Chlamydia pneumoniae infection. PMID:22985781

  11. Diffferential innate responses of chickens and ducks to low pathogenic avian influenza virus

    NARCIS (Netherlands)

    Cornelissen, J.B.W.J.; Post, J.; Peeters, B.P.H.; Vervelde, L.; Rebel, J.M.J.

    2012-01-01

    Ducks and chickens are hosts of avian influenza virus, each with distinctive responses to infection. To understand these differences, we characterized the innate immune response to low pathogenicity avian influenza virus H7N1 infection in chickens and ducks. Viral RNA was detected in the lungs of

  12. Bacterial Immune Evasion through Manipulation of Host Inhibitory Immune Signaling

    NARCIS (Netherlands)

    Van Avondt, Kristof; van Sorge, Nina M.|info:eu-repo/dai/nl/279926812; Meyaard, Linde|info:eu-repo/dai/nl/13444972X

    An innate immune response is essential for survival of the host upon infection, yet excessive inflammation can result in harmful complications [1]. Inhibitory signaling evolved to limit host responses and prevent inflammatory pathology [2,3]. Given the significance of inhibitory pathways for

  13. Recall features and allorecognition in innate immunity.

    Science.gov (United States)

    Uehara, Hirofumi; Minami, Koichiro; Quante, Markus; Nian, Yeqi; Heinbokel, Timm; Azuma, Haruhito; Khal, Abdala El; Tullius, Stefan G

    2017-09-19

    Alloimmunity traditionally distinguishes short-lived, rapid and nonspecific innate immune responses from adaptive immune responses that are characterized by a highly specific response initiated in a delayed fashion. Key players of innate immunity such as natural killer (NK) cells and macrophages present the first-line defence of immunity. The concept of unspecific responses in innate immunity has recently been challenged. The discovery of pattern recognition receptors (PRRs) has demonstrated that innate immune cells respond in a semi-specific fashion through the recognition of pathogen-associated molecular patterns (PAMPs) representing conserved molecular structures shared by large groups of microorganisms. Although immunological memory has generally been considered as exclusive to adaptive immunity, recent studies have demonstrated that innate immune cells have the potential to acquire memory. Here, we discuss allospecific features of innate immunity and their relevance in transplantation. © 2017 Steunstichting ESOT.

  14. Innate immunity in the pathogenesis of psoriasis.

    LENUS (Irish Health Repository)

    Sweeney, Cheryl M

    2011-12-01

    Psoriasis is a common, immune-mediated inflammatory skin disorder. T helper(h)1 and Th17 lymphocytes contribute to the pathogenesis of psoriasis through the release of inflammatory cytokines that promote further recruitment of immune cells, keratinocyte proliferation and sustained inflammation. The innate immune system is the first line of defence against infection and plays a crucial role in the initiation of the adaptive immune response. The presence of innate immune cells and their products in psoriatic skin plaques suggests a role for innate immunity in this disease. In addition, the innate immune system can direct the development of pathogenic Th cells in psoriasis. In this article, we will summarise the role of the innate immune system in psoriasis with particular emphasis on the role of cytokines, signalling pathways and cells of the innate immune system.

  15. Innate Immunity and Breast Milk

    Science.gov (United States)

    Cacho, Nicole Theresa; Lawrence, Robert M.

    2017-01-01

    Human milk is a dynamic source of nutrients and bioactive factors; unique in providing for the human infant’s optimal growth and development. The growing infant’s immune system has a number of developmental immune deficiencies placing the infant at increased risk of infection. This review focuses on how human milk directly contributes to the infant’s innate immunity. Remarkable new findings clarify the multifunctional nature of human milk bioactive components. New research techniques have expanded our understanding of the potential for human milk’s effect on the infant that will never be possible with milk formulas. Human milk microbiome directly shapes the infant’s intestinal microbiome, while the human milk oligosaccharides drive the growth of these microbes within the gut. New techniques such as genomics, metabolomics, proteomics, and glycomics are being used to describe this symbiotic relationship. An expanded role for antimicrobial proteins/peptides within human milk in innate immune protection is described. The unique milieu of enhanced immune protection with diminished inflammation results from a complex interaction of anti-inflammatory and antioxidative factors provided by human milk to the intestine. New data support the concept of mucosal-associated lymphoid tissue and its contribution to the cellular content of human milk. Human milk stem cells (hMSCs) have recently been discovered. Their direct role in the infant for repair and regeneration is being investigated. The existence of these hMSCs could prove to be an easily harvested source of multilineage stem cells for the study of cancer and tissue regeneration. As the infant’s gastrointestinal tract and immune system develop, there is a comparable transition in human milk over time to provide fewer immune factors and more calories and nutrients for growth. Each of these new findings opens the door to future studies of human milk and its effect on the innate immune system and the developing

  16. Innate Immunity and Breast Milk

    Directory of Open Access Journals (Sweden)

    Nicole Theresa Cacho

    2017-05-01

    Full Text Available Human milk is a dynamic source of nutrients and bioactive factors; unique in providing for the human infant’s optimal growth and development. The growing infant’s immune system has a number of developmental immune deficiencies placing the infant at increased risk of infection. This review focuses on how human milk directly contributes to the infant’s innate immunity. Remarkable new findings clarify the multifunctional nature of human milk bioactive components. New research techniques have expanded our understanding of the potential for human milk’s effect on the infant that will never be possible with milk formulas. Human milk microbiome directly shapes the infant’s intestinal microbiome, while the human milk oligosaccharides drive the growth of these microbes within the gut. New techniques such as genomics, metabolomics, proteomics, and glycomics are being used to describe this symbiotic relationship. An expanded role for antimicrobial proteins/peptides within human milk in innate immune protection is described. The unique milieu of enhanced immune protection with diminished inflammation results from a complex interaction of anti-inflammatory and antioxidative factors provided by human milk to the intestine. New data support the concept of mucosal-associated lymphoid tissue and its contribution to the cellular content of human milk. Human milk stem cells (hMSCs have recently been discovered. Their direct role in the infant for repair and regeneration is being investigated. The existence of these hMSCs could prove to be an easily harvested source of multilineage stem cells for the study of cancer and tissue regeneration. As the infant’s gastrointestinal tract and immune system develop, there is a comparable transition in human milk over time to provide fewer immune factors and more calories and nutrients for growth. Each of these new findings opens the door to future studies of human milk and its effect on the innate immune system

  17. Acute bacterial exacerbations in bronchitis and asthma.

    Science.gov (United States)

    Chodosh, S

    1987-04-27

    Symptomatic exacerbations are frequent problems in the management of chronic bronchitis and bronchial asthma. Identification of a bacterial etiology as the cause of specific exacerbations should be based on changes in clinical symptoms and documentation of significant bronchial bacterial flora and a neutrophilic inflammatory response. Most acute bacterial exacerbations in patients with bronchitis or asthma are caused by Hemophilus influenzae, Streptococcus pneumoniae, or Branhamella catarrhalis. Treatment with ampicillins, synthetic tetracyclines, or trimethoprim/sulfamethoxazole is successful in 80 to 90 percent of bacterial exacerbations. Emergence of resistant Hemophilus species and pneumococci motivates development of new orally administered antimicrobial drugs. Appropriate treatment depends on the prompt recognition that bacterial infection is present. Once instituted, antimicrobial therapy should be continued for a minimum of 10 to 14 days, which should increase the duration of the infection-free period until the next bacterial exacerbation. Adequate response should be evaluated by the return of symptoms to pre-infectious levels and by decreased sputum bacterial flora and neutrophilic inflammation.

  18. Innate Immunity against Leishmania Infections

    Science.gov (United States)

    Gurung, Prajwal; Kanneganti, Thirumala-Devi

    2015-01-01

    Leishmaniasis is a major health problem that affects more than 300 million people throughout the world. The morbidity associated with the disease causes serious economic burden in Leishmania endemic regions. Despite the morbidity and economic burden associated with Leishmaniasis, this disease rarely gets noticed and is still categorized under neglected tropical diseases. The lack of research combined with the ability of Leishmania to evade immune recognition has rendered our efforts to design therapeutic treatments or vaccines challenging. Herein, we review the literature on Leishmania from innate immune perspective and discuss potential problems as well as solutions and future directions that could aid in identifying novel therapeutic targets to eliminate this parasite. PMID:26249747

  19. Shaping Innate Lymphoid Cell Diversity

    Directory of Open Access Journals (Sweden)

    Qiutong Huang

    2017-11-01

    Full Text Available Innate lymphoid cells (ILCs are a key cell type that are enriched at mucosal surfaces and within tissues. Our understanding of these cells is growing rapidly. Paradoxically, these cells play a role in maintaining tissue integrity but they also function as key drivers of allergy and inflammation. We present here the most recent understanding of how genomics has provided significant insight into how ILCs are generated and the enormous heterogeneity present within the canonical subsets. This has allowed the generation of a detailed blueprint for ILCs to become highly sensitive and adaptive sensors of environmental changes and therefore exquisitely equipped to protect immune surfaces.

  20. Innate lymphoid cells and the skin

    OpenAIRE

    Salimi, Maryam; Ogg, Graham

    2014-01-01

    Innate lymphoid cells are an emerging family of effector cells that contribute to lymphoid organogenesis, metabolism, tissue remodelling and protection against infections. They maintain homeostatic immunity at barrier surfaces such as lung, skin and gut (Nature 464:1367?1371, 2010, Nat Rev Immunol 13: 145?149, 2013). Several human and mouse studies suggest a role for innate lymphoid cells in inflammatory skin conditions including atopic eczema and psoriasis. Here we review the innate lymphoid...

  1. Interactions between the microbiota and innate and innate-like lymphocytes.

    Science.gov (United States)

    Constantinides, Michael G

    2018-03-01

    The microbiota, which consists of commensal bacteria, fungi, and viruses, limits the colonization of pathogens at barrier tissues and promotes immune homeostasis. The latter is accomplished through the induction and regulation of both innate and adaptive immune responses. Innate lymphocytes, which include the type-1 innate lymphoid cell (ILC1), NK cell, type-2 innate lymphoid cell (ILC2), type-3 innate lymphoid cell (ILC3), and lymphoid tissue inducer (LTi) cell populations, and innate-like lymphocytes, such as NKT cells, mucosal-associated invariant T (MAIT) cells, and γδ T cells, are uniquely capable of responding to the microbiota due to their tissue localization and rapid primary responses. In turn, through their effector functions, these lymphocyte populations modulate the composition of the microbiota and maintain the segregation of commensals. This review will focus on how innate and innate-like lymphocytes mediate the crosstalk with the microbiome. ©2017 Society for Leukocyte Biology.

  2. Innate immune recognition and activation during HIV infection

    Science.gov (United States)

    2010-01-01

    The pathogenesis of HIV infection, and in particular the development of immunodeficiency, remains incompletely understood. Whichever intricate molecular mechanisms are at play between HIV and the host, it is evident that the organism is incapable of restricting and eradicating the invading pathogen. Both innate and adaptive immune responses are raised, but they appear to be insufficient or too late to eliminate the virus. Moreover, the picture is complicated by the fact that the very same cells and responses aimed at eliminating the virus seem to play deleterious roles by driving ongoing immune activation and progressive immunodeficiency. Whereas much knowledge exists on the role of adaptive immunity during HIV infection, it has only recently been appreciated that the innate immune response also plays an important part in HIV pathogenesis. In this review, we present current knowledge on innate immune recognition and activation during HIV infection based on studies in cell culture, non-human primates, and HIV-infected individuals, and discuss the implications for the understanding of HIV immunopathogenesis. PMID:20569472

  3. Interactions between bile salts, gut microbiota, and hepatic innate immunity.

    Science.gov (United States)

    Schubert, Kristin; Olde Damink, Steven W M; von Bergen, Martin; Schaap, Frank G

    2017-09-01

    Bile salts are the water-soluble end products of hepatic cholesterol catabolism that are released into the duodenum and solubilize lipids due to their amphipathic structure. Bile salts also act as endogenous ligands for dedicated nuclear receptors that exert a plethora of biological processes, mostly related to metabolism. Bile salts are actively reclaimed in the distal part of the small intestine, released into the portal system, and subsequently extracted by the liver. This enterohepatic cycle is critically dependent on dedicated bile salt transporters. In the intestinal lumen, bile salts exert direct antimicrobial activity based on their detergent property and shape the gut microbiota. Bile salt metabolism by gut microbiota serves as a mechanism to counteract this toxicity and generates bile salt species that are distinct from those of the host. Innate immune cells of the liver play an important role in the early recognition and effector response to invading microbes. Bile salts signal primarily via the membrane receptor TGR5 and the intracellular farnesoid-x receptor, both present in innate immune cells. In this review, the interactions between bile salts, gut microbiota, and hepatic innate immunity are discussed. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Plant scents modify innate colour preference in foraging swallowtail butterflies.

    Science.gov (United States)

    Yoshida, Mina; Itoh, Yuki; Ômura, Hisashi; Arikawa, Kentaro; Kinoshita, Michiyo

    2015-07-01

    Flower-visiting insects exhibit innate preferences for particular colours. A previous study demonstrated that naive Papilio xuthus females prefer yellow and red, whereas males are more attracted to blue. Here, we demonstrate that the innate colour preference can be modified by olfactory stimuli in a sexually dimorphic manner. Naive P. xuthus were presented with four coloured discs: blue, green, yellow and red. The innate colour preference (i.e. the colour first landed on) of the majority of individuals was blue. When scent from essential oils of either orange flower or lily was introduced to the room, females' tendency to select the red disc increased. Scents of lavender and flowering potted Hibiscus rosa-sinensis, however, were less effective. Interestingly, the odour of the non-flowering larval host plant, Citrus unshiu, shifted the preference to green in females. In males, however, all plant scents were less effective than in females, such that blue was always the most favoured colour. These observations indicate that interactions between visual and olfactory cues play a more prominent role in females. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  5. Innate lymphoid cells in tissue homeostasis and diseases.

    Science.gov (United States)

    Ignacio, Aline; Breda, Cristiane Naffah Souza; Camara, Niels Olsen Saraiva

    2017-08-18

    Innate lymphoid cells (ILCs) are the most recently discovered family of innate immune cells. They are a part of the innate immune system, but develop from the lymphoid lineage. They lack pattern-recognition receptors and rearranged receptors, and therefore cannot directly mediate antigen specific responses. The progenitors specifically associated with the ILCs lineage have been uncovered, enabling the distinction between ILCs and natural killer cells. Based on the requirement of specific transcription factors and their patterns of cytokine production, ILCs are categorized into three subsets (ILC1, ILC2 and ILC3). First observed in mucosal surfaces, these cell populations interact with hematopoietic and non-hematopoietic cells throughout the body during homeostasis and diseases, promoting immunity, commensal microbiota tolerance, tissue repair and inflammation. Over the last 8 years, ILCs came into the spotlight as an essential cell type able to integrate diverse host immune responses. Recently, it became known that ILC subsets play a key role in immune responses at barrier surfaces, interacting with the microbiota, nutrients and metabolites. Since the liver receives the venous blood directly from the intestinal vein, the intestine and liver are essential to maintain tolerance and can rapidly respond to infections or tissue damage. Therefore, in this review, we discuss recent findings regarding ILC functions in homeostasis and disease, with a focus on the intestine and liver.

  6. Innate immune recognition and activation during HIV infection

    Directory of Open Access Journals (Sweden)

    Larsen Carsten S

    2010-06-01

    Full Text Available Abstract The pathogenesis of HIV infection, and in particular the development of immunodeficiency, remains incompletely understood. Whichever intricate molecular mechanisms are at play between HIV and the host, it is evident that the organism is incapable of restricting and eradicating the invading pathogen. Both innate and adaptive immune responses are raised, but they appear to be insufficient or too late to eliminate the virus. Moreover, the picture is complicated by the fact that the very same cells and responses aimed at eliminating the virus seem to play deleterious roles by driving ongoing immune activation and progressive immunodeficiency. Whereas much knowledge exists on the role of adaptive immunity during HIV infection, it has only recently been appreciated that the innate immune response also plays an important part in HIV pathogenesis. In this review, we present current knowledge on innate immune recognition and activation during HIV infection based on studies in cell culture, non-human primates, and HIV-infected individuals, and discuss the implications for the understanding of HIV immunopathogenesis.

  7. Periodontal innate immune mechanisms relevant to atherosclerosis.

    Science.gov (United States)

    Amar, S; Engelke, M

    2015-06-01

    Atherosclerosis is a common cardiovascular disease in the USA where it is a leading cause of illness and death. Atherosclerosis is the most common cause for heart attack and stroke. Most commonly, people develop atherosclerosis as a result of diabetes, genetic risk factors, high blood pressure, a high-fat diet, obesity, high blood cholesterol levels, and smoking. However, a sizable number of patients suffering from atherosclerosis do not harbor the classical risk factors. Ongoing infections have been suggested to play a role in this process. Periodontal disease is perhaps the most common chronic infection in adults with a wide range of clinical variability and severity. Research in the past decade has shed substantial light on both the initiating infectious agents and host immunological responses in periodontal disease. Up to 46% of the general population harbors the microorganism(s) associated with periodontal disease, although many are able to limit the progression of periodontal disease or even clear the organism(s) if infected. In the last decade, several epidemiological studies have found an association between periodontal infection and atherosclerosis. This review focuses on exploring the molecular consequences of infection by pathogens that exacerbate atherosclerosis, with the focus on infections by the periodontal bacterium Porphyromonas gingivalis as a running example. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Acute exacerbation of asthma: a case report

    Directory of Open Access Journals (Sweden)

    Domenico Lorenzo Urso

    2011-09-01

    Full Text Available Asthma is a chronic inflammatory disease of the airways with a worldwide prevalence ranging from 1% to 18%. We report the case of a 43-year-old man with acute asthma exacerbation admitted to Emergency Department. All patients with asthma are at risk of having exacerbations characterised by worsening symptoms, airflow obstruction, and an increased requirement for rescue bronchodilators. Patients should be evaluated and triaged quickly to assess the presence of exacerbations and the need for urgent intervention. The goals of treatment may be summarised as maintenance of adequate oxygen saturation with supplemental oxygen, relief of airway obstruction with repetitive administration of rapid-acting inhaled bronchodilators, and treatment of airway inflammation with systemic corticosteroids.

  9. [Asthmatic exacerbations: specific features in children].

    Science.gov (United States)

    Carsin, A; Pham-Thi, N

    2011-12-01

    Asthma concerns more than 10% of 10-year-old children. Despite the similarities between adult and childhood asthma, the pediatric population presents some specific characteristics, notably in relation to exacerbations. Asthma in the newborn infant is a specific entity, the definition of which has recently been officially recognized. In exacerbations, the most important trigger factors are respiratory virus infections, the strain having prognostic importance. The indoor and outdoor environments are risk factors, particularly high levels of atmospheric pollution. Nutrients seem to play a prognostic role through vitamin D or food allergy. Measurement of exhaled nitric oxide and examination of induced sputum may help in diagnosis and adjustment of treatment but these tools are not yet effective as predictive factors in asthma exacerbations. Prevention, early management and continued education of children and their families remain the best methods to improve asthma control. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  10. Expanding the universe of cytokines and pattern recognition receptors: galectins and glycans in innate immunity.

    Science.gov (United States)

    Cerliani, Juan P; Stowell, Sean R; Mascanfroni, Iván D; Arthur, Connie M; Cummings, Richard D; Rabinovich, Gabriel A

    2011-02-01

    Effective immunity relies on the recognition of pathogens and tumors by innate immune cells through diverse pattern recognition receptors (PRRs) that lead to initiation of signaling processes and secretion of pro- and anti-inflammatory cytokines. Galectins, a family of endogenous lectins widely expressed in infected and neoplastic tissues have emerged as part of the portfolio of soluble mediators and pattern recognition receptors responsible for eliciting and controlling innate immunity. These highly conserved glycan-binding proteins can control immune cell processes through binding to specific glycan structures on pathogens and tumors or by acting intracellularly via modulation of selective signaling pathways. Recent findings demonstrate that various galectin family members influence the fate and physiology of different innate immune cells including polymorphonuclear neutrophils, mast cells, macrophages, and dendritic cells. Moreover, several pathogens may actually utilize galectins as a mechanism of host invasion. In this review, we aim to highlight and integrate recent discoveries that have led to our current understanding of the role of galectins in host-pathogen interactions and innate immunity. Challenges for the future will embrace the rational manipulation of galectin-glycan interactions to instruct and shape innate immunity during microbial infections, inflammation, and cancer.

  11. Human Respiratory Syncytial Virus: Role of Innate Immunity in Clearance and Disease Progression.

    Science.gov (United States)

    Farrag, Mohamed A; Almajhdi, Fahad N

    2016-01-01

    Human respiratory syncytial virus (HRSV) infections have worldwide records. The virus is responsible for bronchiolitis, pneumonia, and asthma in humans of different age groups. Premature infants, young children, and immunocompromised individuals are prone to severe HRSV infection that may lead to death. Based on worldwide estimations, millions of cases were reported in both developed and developing countries. In fact, HRSV symptoms develop mainly as a result of host immune response. Due to inability to establish long lasting adaptive immunity, HRSV infection is recurrent and hence impairs vaccine development. Once HRSV attached to the airway epithelia, interaction with the host innate immune components starts. HRSV interaction with pulmonary innate defenses is crucial in determining the disease outcome. Infection of alveolar epithelial cells triggers a cascade of events that lead to recruitment and activation of leukocyte populations. HRSV clearance is mediated by a number of innate leukocytes, including macrophages, natural killer cells, eosinophils, dendritic cells, and neutrophils. Regulation of these cells is mediated by cytokines, chemokines, and other immune mediators. Although the innate immune system helps to clear HRSV infection, it participates in disease progression such as bronchiolitis and asthma. Resolving the mechanisms by which HRSV induces pathogenesis, different possible interactions between the virus and immune components, and immune cells interplay are essential for developing new effective vaccines. Therefore, the current review focuses on how the pulmonary innate defenses mediate HRSV clearance and to what extent they participate in disease progression. In addition, immune responses associated with HRSV vaccines will be discussed.

  12. Trauma: the role of the innate immune system

    Directory of Open Access Journals (Sweden)

    Rijkers GT

    2006-05-01

    Full Text Available Abstract Immune dysfunction can provoke (multiple organ failure in severely injured patients. This dysfunction manifests in two forms, which follow a biphasic pattern. During the first phase, in addition to the injury by trauma, organ damage is caused by the immune system during a systemic inflammatory response. During the second phase the patient is more susceptible for sepsis due to host defence failure (immune paralysis. The pathophysiological model outlined in this review encompasses etiological factors and the contribution of the innate immune system in the end organ damage. The etiological factors can be divided into intrinsic (genetic predisposition and physiological status and extrinsic components (type of injury or "traumaload" and surgery or "intervention load". Of all the factors, the intervention load is the only one which, can be altered by the attending emergency physician. Adjustment of the therapeutic approach and choice of the most appropriate treatment strategy can minimize the damage caused by the immune response and prevent the development of immunological paralysis. This review provides a pathophysiological basis for the damage control concept, in which a staged approach of surgery and post-traumatic immunomonitoring have become important aspects of the treatment protocol. The innate immune system is the main objective of immunomonitoring as it has the most prominent role in organ failure after trauma. Polymorphonuclear phagocytes and monocytes are the main effector-cells of the innate immune system in the processes that lead to organ failure. These cells are controlled by cytokines, chemokines, complement factors and specific tissue signals. The contribution of tissue barrier integrity and its interaction with the innate immune system is further evaluated.

  13. Distinct Populations of Innate CD8+ T Cells Revealed in a CXCR3 Reporter Mouse

    Science.gov (United States)

    Oghumu, Steve; Dong, Ran; Varikuti, Sanjay; Shawler, Todd; Kampfrath, Thomas; Terrazas, Cesar A.; Lezama-Davila, Claudio; Ahmer, Brian M. M.; Whitacre, Caroline C.; Rajagopalan, Sanjay; Locksley, Richard; Sharpe, Arlene H.; Satoskar, Abhay R.

    2013-01-01

    CXCR3, expressed mainly on activated T and NK cells, is implicated in a host of immunological conditions and can contribute either to disease resolution or pathology. We report the generation and characterization of a novel CXCR3 internal ribosome entry site bicistronic enhanced GFP reporter (CIBER) mouse in which enhanced GFP expression correlates with surface levels of CXCR3. Using CIBER mice, we identified two distinct populations of innate CD8+ T cells based on constitutive expression of CXCR3. We demonstrate that CXCR3+ innate CD8+ T cells preferentially express higher levels of Ly6C and CD122, but lower levels of CCR9 compared with CXCR3− innate CD8+ T cells. Furthermore, we show that CXCR3+ innate CD8+ T cells express higher transcript levels of antiapoptotic but lower levels of proapoptotic factors, respond more robustly to IL-2 and IL-15, and produce significantly more IFN-γ and granzyme B. Interestingly, CXCR3+ innate CD8+ T cells do not respond to IL-12 or IL-18 alone, but produce significant amounts of IFN-γ on stimulation with a combination of these cytokines. Taken together, these findings demonstrate that CXCR3+ and CXCR3− innate CD8+ T cells are phenotypically and functionally distinct. These newly generated CIBER mice provide a novel tool for studying the role of CXCR3 and CXCR3-expressing cells in vivo. PMID:23338236

  14. Ambivalent role of the innate immune response in rabies virus pathogenesis.

    Science.gov (United States)

    Chopy, Damien; Pothlichet, Julien; Lafage, Mireille; Mégret, Françoise; Fiette, Laurence; Si-Tahar, Mustapha; Lafon, Monique

    2011-07-01

    The neurotropic rabies virus (RABV) has developed several evasive strategies, including immunoevasion, to successfully infect the nervous system (NS) and trigger a fatal encephalomyelitis. Here we show that expression of LGP2, a protein known as either a positive or negative regulator of the RIG-I-mediated innate immune response, is restricted in the NS. We used a new transgenic mouse model (LGP2 TG) overexpressing LGP2 to impair the innate immune response to RABV and thus revealed the role of the RIG-I-mediated innate immune response in RABV pathogenesis. After infection, LGP2 TG mice exhibited reduced expression of inflammatory/chemoattractive molecules, beta interferon (IFN-β), and IFN-stimulated genes in their NS compared to wild-type (WT) mice, demonstrating the inhibitory function of LGP2 in the innate immune response to RABV. Surprisingly, LGP2 TG mice showed more viral clearance in the brain and lower morbidity than WT mice, indicating that the host innate immune response, paradoxically, favors RABV neuroinvasiveness and morbidity. LGP2 TG mice exhibited similar neutralizing antibodies and microglia activation to those of WT mice but showed a reduction of infiltrating CD4(+) T cells and less disappearance of infiltrating CD8(+) T cells. This occurred concomitantly with reduced neural expression of the IFN-inducible protein B7-H1, an immunoevasive protein involved in the elimination of infiltrated CD8(+) T cells. Our study shows that the host innate immune response favors the infiltration of T cells and, at the same time, promotes CD8(+) T cell elimination. Thus, to a certain extent, RABV exploits the innate immune response to develop its immunoevasive strategy.

  15. Ubiquitin in Influenza Virus Entry and Innate Immunity.

    Science.gov (United States)

    Rudnicka, Alina; Yamauchi, Yohei

    2016-10-24

    Viruses are obligatory cellular parasites. Their mission is to enter a host cell, to transfer the viral genome, and to replicate progeny whilst diverting cellular immunity. The role of ubiquitin is to regulate fundamental cellular processes such as endocytosis, protein degradation, and immune signaling. Many viruses including influenza A virus (IAV) usurp ubiquitination and ubiquitin-like modifications to establish infection. In this focused review, we discuss how ubiquitin and unanchored ubiquitin regulate IAV host cell entry, and how histone deacetylase 6 (HDAC6), a cytoplasmic deacetylase with ubiquitin-binding activity, mediates IAV capsid uncoating. We also discuss the roles of ubiquitin in innate immunity and its implications in the IAV life cycle.

  16. In vivo Ebola virus infection leads to a strong innate response in circulating immune cells.

    Science.gov (United States)

    Caballero, Ignacio S; Honko, Anna N; Gire, Stephen K; Winnicki, Sarah M; Melé, Marta; Gerhardinger, Chiara; Lin, Aaron E; Rinn, John L; Sabeti, Pardis C; Hensley, Lisa E; Connor, John H

    2016-09-05

    Ebola virus is the causative agent of a severe syndrome in humans with a fatality rate that can approach 90 %. During infection, the host immune response is thought to become dysregulated, but the mechanisms through which this happens are not entirely understood. In this study, we analyze RNA sequencing data to determine the host response to Ebola virus infection in circulating immune cells. Approximately half of the 100 genes with the strongest early increases in expression were interferon-stimulated genes, such as ISG15, OAS1, IFIT2, HERC5, MX1 and DHX58. Other highly upregulated genes included cytokines CXCL11, CCL7, IL2RA, IL2R1, IL15RA, and CSF2RB, which have not been previously reported to change during Ebola virus infection. Comparing this response in two different models of exposure (intramuscular and aerosol) revealed a similar signature of infection. The strong innate response in the aerosol model was seen not only in circulating cells, but also in primary and secondary target tissues. Conversely, the innate immune response of vaccinated macaques was almost non-existent. This suggests that the innate response is a major aspect of the cellular response to Ebola virus infection in multiple tissues. Ebola virus causes a severe infection in humans that is associated with high mortality. The host immune response to virus infection is thought to be an important aspect leading to severe pathology, but the components of this overactive response are not well characterized. Here, we analyzed how circulating immune cells respond to the virus and found that there is a strong innate response dependent on active virus replication. This finding is in stark contrast to in vitro evidence showing a suppression of innate immune signaling, and it suggests that the strong innate response we observe in infected animals may be an important contributor to pathogenesis.

  17. Cerebral Innate Immunity in Drosophila Melanogaster

    Directory of Open Access Journals (Sweden)

    Brian P. Leung

    2015-03-01

    Full Text Available Modeling innate immunity in Drosophila melanogaster has a rich history that includes ground-breaking discoveries in pathogen detection and signaling. These studies revealed the evolutionary conservation of innate immune pathways and mechanisms of pathogen detection, resulting in an explosion of findings in the innate immunity field. In D. melanogaster, studies have focused primarily on responses driven by the larval fat body and hemocytes, analogs to vertebrate liver and macrophages, respectively. Aside from pathogen detection, many recent mammalian studies associate innate immune pathways with development and disease pathogenesis. Importantly, these studies stress that the innate immune response is integral to maintain central nervous system (CNS health. Microglia, which are the vertebrate CNS mononuclear phagocytes, drive vertebrate cerebral innate immunity. The invertebrate CNS contains microglial-like cells-ensheathing glia and reticular glia-that could be used to answer basic questions regarding the evolutionarily conserved innate immune processes in CNS development and health. A deeper understanding of the relationship between D. melanogaster phagocytic microglial-like cells and vertebrate microglia will be key to answering basic and translational questions related to cerebral innate immunity.

  18. [Role of innate immunity in tolerance induction].

    Science.gov (United States)

    Dolgikh, M S

    2015-01-01

    This review considers the role of innate immunity in mechanisms of transplant tolerance and rejection, analyse the role of innate immunity cells (dendritic cells-DC, NK, must and other cells) in these processes, and the pathes of creation of tolerogenic DC for transplant rejection therapy and tolerance.

  19. Psoriasis, innate immunity, and gene pools

    NARCIS (Netherlands)

    Bos, Jan D.

    2007-01-01

    Recently, emphasis has shifted from T cells to innate (natural) immunity as the possible major culprit in psoriasis. All known elements of innate immune responses are up-regulated in psoriasis lesions, which must have a polygenetic origin. We hypothesize that urbanized populations have been under

  20. Neonatal innate immunity - A translational perspective

    NARCIS (Netherlands)

    Belderbos, M.E.

    2012-01-01

    Human newborns are highly susceptible to infections, which appears to be due to immaturity of the neonatal innate immune system. At birth, neonatal innate immune responses are characterized by decreased Th1-polarizing responses, whereas generation of Th2-polarizing and regulatory responses is

  1. Interplay Between Innate Immunity and the Plant Microbiota.

    Science.gov (United States)

    Hacquard, Stéphane; Spaepen, Stijn; Garrido-Oter, Ruben; Schulze-Lefert, Paul

    2017-08-04

    The innate immune system of plants recognizes microbial pathogens and terminates their growth. However, recent findings suggest that at least one layer of this system is also engaged in cooperative plant-microbe interactions and influences host colonization by beneficial microbial communities. This immune layer involves sensing of microbe-associated molecular patterns (MAMPs) by pattern recognition receptors (PRRs) that initiate quantitative immune responses to control host-microbial load, whereas diversification of MAMPs and PRRs emerges as a mechanism that locally sculpts microbial assemblages in plant populations. This suggests a more complex microbial management role of the innate immune system for controlled accommodation of beneficial microbes and in pathogen elimination. The finding that similar molecular strategies are deployed by symbionts and pathogens to dampen immune responses is consistent with this hypothesis but implies different selective pressures on the immune system due to contrasting outcomes on plant fitness. The reciprocal interplay between microbiota and the immune system likely plays a critical role in shaping beneficial plant-microbiota combinations and maintaining microbial homeostasis.

  2. Microbiota activation and regulation of innate and adaptive immunity.

    Science.gov (United States)

    Alexander, Katie L; Targan, Stephan R; Elson, Charles O

    2014-07-01

    The human host has coevolved with the collective of bacteria species, termed microbiota, in a complex fashion that affects both innate and adaptive immunity. Differential regulation of regulatory T-cell and effector T-cell responses are a direct result of specific microbial species present within the gut, and this relationship is subject to dysregulation during inflammation and disease. The microbiota varies widely between individuals and has a profound effect on how one reacts to various environmental stimuli, particularly if a person is genetically predisposed to an immune-mediated inflammatory disorder such as inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC). Approximately, half of all CD patients have elevated antibodies to CBir1, a microbiota flagellin common to mice and humans, demonstrating flagellins as immunodominant antigens in the intestines. This review focuses on the use of flagellins as probes to study microbiota-specific responses in the context of health and disease as well as probes of innate and adaptive responses employed by the host to deal with the overwhelming bacterial presence of the microbiota. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Hantaan virus triggers TLR4-dependent innate immune responses.

    Science.gov (United States)

    Yu, Hai-Tao; Jiang, Hong; Zhang, Ye; Nan, Xue-Ping; Li, Yu; Wang, Wei; Jiang, Wei; Yang, Dong-Qiang; Su, Wen-Jing; Wang, Jiu-Ping; Wang, Ping-Zhong; Bai, Xue-Fan

    2012-10-01

    The innate immune response induced by Hantavirus is responsible for endothelial cell dysfunction and viral pathogenicity. Recent studies demonstrate that TLR4 expression is upregulated and mediates the secretion of several cytokines in Hantaan virus (HTNV)-infected endothelial cells. To examine viral interactions with host endothelial cells and characterize the innate antiviral responses associated with Toll-like receptors, we selected TLR4 as the target molecule to investigate anti-hantavirus immunity. TLR4 mRNA-silenced EVC-304 (EVC-304 TLR4-) cells and EVC-304 cells were used to investigate signaling molecules downstream of TLR4. The expression of the adaptor protein TRIF was higher in HTNV-infected EVC-304 cells than in EVC-304 TLR4- cells. However, there was no apparent difference in the expression of MyD88 in either cell line. The transcription factors for NF-κB and IRF-3 were translocated from the cytoplasm into the nucleus in HTNV-infected EVC-304 cells, but not in HTNV-infected EVC-304 TLR4- cells. Our results demonstrate that TLR4 may play an important role in the antiviral immunity of the host against HTNV infection through an MyD88-independent signaling pathway.

  4. Avian Bornaviruses Escape Recognition by the Innate Immune System

    Directory of Open Access Journals (Sweden)

    Antje Reuter

    2010-04-01

    Full Text Available Like other pathogens that readily persist in animal hosts, members of the Bornaviridae family have evolved effective mechanisms to evade the innate immune response. The prototype of this virus family, Borna disease virus employs an unusual replication strategy that removes the triphosphates from the 5’ termini of the viral RNA genome. This strategy allows the virus to avoid activation of RIG-I and other innate immune response receptors in infected cells. Here we determined whether the newly discovered avian bornaviruses (ABV might use a similar strategy to evade the interferon response. We found that de novo infection of QM7 and CEC32 quail cells with two different ABV strains was efficiently inhibited by exogenous chicken IFN-α. IFN-α also reduced the viral load in QM7 and CEC32 cells persistently infected with both ABV strains, suggesting that ABV is highly sensitive to type I IFN. Although quail cells persistently infected with ABV contained high levels of viral RNA, the supernatants of infected cultures did not contain detectable levels of biologically active type I IFN. RNA from cells infected with ABV failed to induce IFN-β synthesis if transfected into human cells. Furthermore, genomic RNA of ABV was susceptible to 5’-monophosphate-specific RNase, suggesting that it lacks 5’-triphospates like BDV. These results indicate that bornaviruses of mammals and birds use similar strategies to evade the host immune response.

  5. Avian Bornaviruses Escape Recognition by the Innate Immune System

    Science.gov (United States)

    Reuter, Antje; Ackermann, Andreas; Kothlow, Sonja; Rinder, Monika; Kaspers, Bernd; Staeheli, Peter

    2010-01-01

    Like other pathogens that readily persist in animal hosts, members of the Bornaviridae family have evolved effective mechanisms to evade the innate immune response. The prototype of this virus family, Borna disease virus employs an unusual replication strategy that removes the triphosphates from the 5′ termini of the viral RNA genome. This strategy allows the virus to avoid activation of RIG-I and other innate immune response receptors in infected cells. Here we determined whether the newly discovered avian bornaviruses (ABV) might use a similar strategy to evade the interferon response. We found that de novo infection of QM7 and CEC32 quail cells with two different ABV strains was efficiently inhibited by exogenous chicken IFN-α. IFN-α also reduced the viral load in QM7 and CEC32 cells persistently infected with both ABV strains, suggesting that ABV is highly sensitive to type I IFN. Although quail cells persistently infected with ABV contained high levels of viral RNA, the supernatants of infected cultures did not contain detectable levels of biologically active type I IFN. RNA from cells infected with ABV failed to induce IFN-β synthesis if transfected into human cells. Furthermore, genomic RNA of ABV was susceptible to 5′-monophosphate-specific RNase, suggesting that it lacks 5′-triphospates like BDV. These results indicate that bornaviruses of mammals and birds use similar strategies to evade the host immune response. PMID:21994661

  6. Acute exacerbation of airspace enlargement with fibrosis

    Directory of Open Access Journals (Sweden)

    Tomoyuki Kakugawa

    2014-01-01

    Full Text Available In 2008, Kawabata et al. described a lesion which they termed “airspace enlargement with fibrosis” that could be included on the spectrum of smoking-related interstitial lung diseases. This group also reported that patients with airspace enlargement with fibrosis but without coexisting interstitial pneumonia of another type had no acute exacerbations and favorable prognoses on clinical follow-up. Here we describe the first case, to our knowledge, of acute exacerbation of airspace enlargement with fibrosis without coexisting interstitial pneumonia of another type. An 82-year-old man was referred to our department for worsening dyspnea and new alveolar opacities on chest radiograph following left pulmonary segmentectomy (S6 for cancer. A diagnosis of acute exacerbation of airspace enlargement with fibrosis without coexisting interstitial pneumonia of other types was made, based on pathological evidence of airspace enlargement with fibrosis and organizing diffuse alveolar damage. Treatment with high-dose methylprednisolone followed by tapered oral prednisolone resulted in gradual improvement of the clinical condition and chest radiographic findings. Clinicians should be aware that patients with airspace enlargement with fibrosis may experience acute exacerbation.

  7. Prevention of Acute Exacerbations of COPD

    Science.gov (United States)

    Bourbeau, Jean; Diekemper, Rebecca L.; Ouellette, Daniel R.; Goodridge, Donna; Hernandez, Paul; Curren, Kristen; Balter, Meyer S.; Bhutani, Mohit; Camp, Pat G.; Celli, Bartolome R.; Dechman, Gail; Dransfield, Mark T.; Fiel, Stanley B.; Foreman, Marilyn G.; Hanania, Nicola A.; Ireland, Belinda K.; Marchetti, Nathaniel; Marciniuk, Darcy D.; Mularski, Richard A.; Ornelas, Joseph; Stickland, Michael K.

    2015-01-01

    BACKGROUND: COPD is a major cause of morbidity and mortality in the United States as well as throughout the rest of the world. An exacerbation of COPD (periodic escalations of symptoms of cough, dyspnea, and sputum production) is a major contributor to worsening lung function, impairment in quality of life, need for urgent care or hospitalization, and cost of care in COPD. Research conducted over the past decade has contributed much to our current understanding of the pathogenesis and treatment of COPD. Additionally, an evolving literature has accumulated about the prevention of acute exacerbations. METHODS: In recognition of the importance of preventing exacerbations in patients with COPD, the American College of Chest Physicians (CHEST) and Canadian Thoracic Society (CTS) joint evidence-based guideline (AECOPD Guideline) was developed to provide a practical, clinically useful document to describe the current state of knowledge regarding the prevention of acute exacerbations according to major categories of prevention therapies. Three key clinical questions developed using the PICO (population, intervention, comparator, and outcome) format addressed the prevention of acute exacerbations of COPD: nonpharmacologic therapies, inhaled therapies, and oral therapies. We used recognized document evaluation tools to assess and choose the most appropriate studies and to extract meaningful data and grade the level of evidence to support the recommendations in each PICO question in a balanced and unbiased fashion. RESULTS: The AECOPD Guideline is unique not only for its topic, the prevention of acute exacerbations of COPD, but also for the first-in-kind partnership between two of the largest thoracic societies in North America. The CHEST Guidelines Oversight Committee in partnership with the CTS COPD Clinical Assembly launched this project with the objective that a systematic review and critical evaluation of the published literature by clinical experts and researchers in

  8. Innate immunity in vertebrates: an overview.

    Science.gov (United States)

    Riera Romo, Mario; Pérez-Martínez, Dayana; Castillo Ferrer, Camila

    2016-06-01

    Innate immunity is a semi-specific and widely distributed form of immunity, which represents the first line of defence against pathogens. This type of immunity is critical to maintain homeostasis and prevent microbe invasion, eliminating a great variety of pathogens and contributing with the activation of the adaptive immune response. The components of innate immunity include physical and chemical barriers, humoral and cell-mediated components, which are present in all jawed vertebrates. The understanding of innate defence mechanisms in non-mammalian vertebrates is the key to comprehend the general picture of vertebrate innate immunity and its evolutionary history. This is also essential for the identification of new molecules with applications in immunopharmacology and immunotherapy. In this review, we describe and discuss the main elements of vertebrate innate immunity, presenting core findings in this field and identifying areas that need further investigation. © 2016 John Wiley & Sons Ltd.

  9. Blurring Borders: Innate Immunity with Adaptive Features

    Directory of Open Access Journals (Sweden)

    K. Kvell

    2007-01-01

    Full Text Available Adaptive immunity has often been considered the penultimate of immune capacities. That system is now being deconstructed to encompass less stringent rules that govern its initiation, actual effector activity, and ambivalent results. Expanding the repertoire of innate immunity found in all invertebrates has greatly facilitated the relaxation of convictions concerning what actually constitutes innate and adaptive immunity. Two animal models, incidentally not on the line of chordate evolution (C. elegans and Drosophila, have contributed enormously to defining homology. The characteristics of specificity and memory and whether the antigen is pathogenic or nonpathogenic reveal considerable information on homology, thus deconstructing the more fundamentalist view. Senescence, cancer, and immunosuppression often associated with mammals that possess both innate and adaptive immunity also exist in invertebrates that only possess innate immunity. Strict definitions become blurred casting skepticism on the utility of creating rigid definitions of what innate and adaptive immunity are without considering overlaps.

  10. The role of innate immune signaling in the pathogenesis of atopic dermatitis and consequences for treatments.

    Science.gov (United States)

    Skabytska, Yuliya; Kaesler, Susanne; Volz, Thomas; Biedermann, Tilo

    2016-01-01

    The skin is the largest organ at the interface between the environment and the host. Consequently, the skin plays a central role in mounting effective host defense. In addition to pathogens, the microbiota and the host immune system are in permanent contact and communication via the skin. Consequences of this permanent interaction are a unique and partly symbiotic relationship, a tight interdependence between these partners, and also a functional "setting the clock," in which, in the healthy steady state, an induction of protective responses to pathogens is guaranteed. At the same time, commensal microbes contribute to the alertness of the immune system and to the maintenance of immune tolerance. Atopic dermatitis (AD) is a chronic inflammatory skin disease based on a complex genetic trait with defects in cutaneous barrier, in stabilizing skin integrity. Most of AD patients develop deviated innate and adaptive immune responses. As a result, increased susceptibility to cutaneous infection is found in AD patients, and the interactions between these microbes and the skin participate in the development of chronic cutaneous inflammation. The role of the adaptive immune system was characterized in much detail, less though the contribution of innate immunity to AD pathogenesis. It is rather recent evidence that demonstrates a dominant role of components of the innate immune system not only for protecting from microbial invasion but also by orchestrating chronic skin inflammation. In this review we discuss the role of innate immune signaling and consecutive immune networks important for the pathogenesis and management of AD.

  11. Innate immunity to Candida albicans

    Directory of Open Access Journals (Sweden)

    Yusuke Kiyoura

    2015-08-01

    Full Text Available Candida albicans is not a pathogen in healthy individuals, but can cause severe systemic candidiasis in immunocompromised patients. C. albicans has various virulence factors and activates the innate immune system. Specifically, C. albicans induces proinflammatory cytokine production in various cell types via many receptors, such as Toll-like receptors (TLRs and C-type lectin receptors (CLRs. This microorganism also promotes phagocytosis via CLRs on macrophages. In a previous study, we found that C. albicans induces the production of galectin-3, which is a known CLR that kills C. albicans. This review indicates that the use of mouthwash containing an antimicrobial peptide or protein might be a useful new oral care method for the prevention of oral candidiasis.

  12. Innate lymphoid cells in atherosclerosis.

    Science.gov (United States)

    Engelbertsen, Daniel; Lichtman, Andrew H

    2017-12-05

    The family of innate lymphoid cells (ILCs) consisting of NK cells, lymphoid tissue inducer cells and the 'helper'-like ILC subsets ILC1, ILC2 and ILC3 have been shown to have important roles in protection against microbes, regulation of inflammatory diseases and involved in allergic reactions. ILC1s produce IFN-γ upon stimulation with IL-12 and IL-18, ILC2s produce IL-5 and IL-13 responding to IL-33 and IL-25 while ILC3s produce IL-17 and IL-22 after stimulation with IL-23 or IL-1. Although few studies have directly investigated the role for ILCs in atherosclerosis, several studies have investigated transcription factors and cytokines shared by ILCs and T helper cells. In this review we summarize our current understanding of the role of ILC in atherosclerosis and discuss future directions. Copyright © 2017. Published by Elsevier B.V.

  13. Trained innate immunity and atherosclerosis.

    Science.gov (United States)

    Bekkering, Siroon; Joosten, Leo A B; van der Meer, Jos W M; Netea, Mihai G; Riksen, Niels P

    2013-12-01

    Monocytes/macrophages play a decisive role in the development and progression of atherosclerosis. It is currently unknown what stimuli initiate and orchestrate the activation of these cells in atherogenesis. In this review, we postulate that the novel concept of 'trained immunity' modulates the development and progression of atherosclerosis. Recently, results from our laboratory challenged the current paradigm that innate immunity is static and does not have an immunological memory. Stimulation by various microbial products, including Candida albicans and bacille Calmette-Guérin, appeared to bring monocytes into a long-term enhanced functional state, showing a stronger proinflammatory response to a second stimulus. This 'trained immunity' was mediated by increased and stable histone methylation. We describe the hypothesis that this functional reprogramming of monocytes, either by microbial products or by metabolic products, contributes to atherogenesis and propose epigenetic reprogramming of monocytes as a novel pharmacological target for preventing or treating atherosclerosis in the future.

  14. Recent progress in understanding host immunity to Avian Coccidiosis: Role of IL-17 Family Cytokines

    Science.gov (United States)

    Host-pathogen interaction leading to protection against coccidiosis is complex, involving many aspects of innate and adaptive immunity to intracellular parasites. Recent application of global gene expression microarray analysis to investigate gut innate immune response to Eimeria infections led to t...

  15. Distinct patterns of innate immune activation by clinical isolates of respiratory syncytial virus.

    Science.gov (United States)

    Levitz, Ruth; Gao, Yajing; Dozmorov, Igor; Song, Ran; Wakeland, Edward K; Kahn, Jeffrey S

    2017-01-01

    Respiratory syncytial virus (RSV) is a major respiratory pathogen of infants and young children. Multiple strains of both subgroup A and B viruses circulate during each seasonal epidemic. Genetic heterogeneity among RSV genomes, in large part due to the error prone RNA-dependent, RNA polymerase, could mediate variations in pathogenicity. We evaluated clinical strains of RSV for their ability to induce the innate immune response. Subgroup B viruses were used to infect human pulmonary epithelial cells (A549) and primary monocyte-derived human macrophages (MDM) from a variety of donors. Secretions of IL-6 and CCL5 (RANTES) from infected cells were measured following infection. Host and viral transcriptome expression were assessed using RNA-SEQ technology and the genomic sequences of several clinical isolates were determined. There were dramatic differences in the induction of IL-6 and CCL5 in both A549 cells and MDM infected with a variety of clinical isolates of RSV. Transcriptome analyses revealed that the pattern of innate immune activation in MDM was virus-specific and host-specific. Specifically, viruses that induced high levels of secreted IL-6 and CCL5 tended to induce cellular innate immune pathways whereas viruses that induced relatively low level of IL-6 or CCL5 did not induce or suppressed innate immune gene expression. Activation of the host innate immune response mapped to variations in the RSV G gene and the M2-1 gene. Viral transcriptome data indicated that there was a gradient of transcription across the RSV genome though in some strains, RSV G was the expressed in the highest amounts at late times post-infection. Clinical strains of RSV differ in cytokine/chemokine induction and in induction and suppression of host genes expression suggesting that these viruses may have inherent differences in virulence potential. Identification of the genetic elements responsible for these differences may lead to novel approaches to antiviral agents and vaccines.

  16. Distinct patterns of innate immune activation by clinical isolates of respiratory syncytial virus

    Science.gov (United States)

    Levitz, Ruth; Wakeland, Edward K.

    2017-01-01

    Respiratory syncytial virus (RSV) is a major respiratory pathogen of infants and young children. Multiple strains of both subgroup A and B viruses circulate during each seasonal epidemic. Genetic heterogeneity among RSV genomes, in large part due to the error prone RNA-dependent, RNA polymerase, could mediate variations in pathogenicity. We evaluated clinical strains of RSV for their ability to induce the innate immune response. Subgroup B viruses were used to infect human pulmonary epithelial cells (A549) and primary monocyte-derived human macrophages (MDM) from a variety of donors. Secretions of IL-6 and CCL5 (RANTES) from infected cells were measured following infection. Host and viral transcriptome expression were assessed using RNA-SEQ technology and the genomic sequences of several clinical isolates were determined. There were dramatic differences in the induction of IL-6 and CCL5 in both A549 cells and MDM infected with a variety of clinical isolates of RSV. Transcriptome analyses revealed that the pattern of innate immune activation in MDM was virus-specific and host-specific. Specifically, viruses that induced high levels of secreted IL-6 and CCL5 tended to induce cellular innate immune pathways whereas viruses that induced relatively low level of IL-6 or CCL5 did not induce or suppressed innate immune gene expression. Activation of the host innate immune response mapped to variations in the RSV G gene and the M2-1 gene. Viral transcriptome data indicated that there was a gradient of transcription across the RSV genome though in some strains, RSV G was the expressed in the highest amounts at late times post-infection. Clinical strains of RSV differ in cytokine/chemokine induction and in induction and suppression of host genes expression suggesting that these viruses may have inherent differences in virulence potential. Identification of the genetic elements responsible for these differences may lead to novel approaches to antiviral agents and vaccines

  17. 25-hydroxyvitamin D deficiency, exacerbation frequency and human rhinovirus exacerbations in chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Quint Jennifer K

    2012-06-01

    Full Text Available Abstract Background 25-hydroxyvitamin D deficiency is associated with COPD and increased susceptibility to infection in the general population. Methods We investigated whether COPD patients deficient in 25-hydroxyvitamin D were more likely to be frequent exacerbators, had reduced outdoor activity and were more susceptible to human rhinovirus (HRV exacerbations than those with insufficient and normal levels. We also investigated whether the frequency of FokI, BsmI and TaqIα 25-hydroxyvitamin D receptor (VDR polymorphisms differed between frequent and infrequent exacerbators. Results There was no difference in 25-hydroxyvitamin D levels between frequent and infrequent exacerbators in the summer; medians 44.1nmol/L (29.1 – 68.0 and 39.4nmol/L (22.3 – 59.2 or winter; medians 24.9nmol/L (14.3 – 43.1 and 27.1nmol/L (19.9 – 37.6. Patients who spent less time outdoors in the 14 days prior to sampling had lower 25-hydroxyvitamin D levels (p = 0.02. Day length was independently associated with 25-hydroxyvitamin D levels (p = 0.02. There was no difference in 25-hydroxyvitamin D levels between baseline and exacerbation; medians 36.2nmol/L (IQR 22.4-59.4 and 33.3nmol/L (23.0-49.7; p = 0.43. HRV positive exacerbations were not associated with lower 25-hydroxyvitamin D levels at exacerbation than exacerbations that did not test positive for HRV; medians 30.0nmol/L (20.4 – 57.8 and 30.6nmol/L (19.4 – 48.7. There was no relationship between exacerbation frequency and any VDR polymorphisms (all p > 0.05. Conclusions Low 25-hydroxyvitamin D levels in COPD are not associated with frequent exacerbations and do not increase susceptibility to HRV exacerbations. Independent of day length, patients who spend less time outdoors have lower 25-hydroxyvitamin D concentration.

  18. Pilot study of lithium to restore intestinal barrier function in severe graft-versus-host disease

    NARCIS (Netherlands)

    Steinbach, G.; Hockenbery, D.M.; Huls, G.A.; Furlong, T.; Myerson, D.; Loeb, K.R.; Fann, J.R.; Castilla-Llorente, C.; McDonald, G.B.; Martin, P.J.

    2017-01-01

    Severe intestinal graft-vs-host disease (GVHD) after allogeneic hematopoietic cell transplantation (HCT) causes mucosal ulceration and induces innate and adaptive immune responses that amplify and perpetuate GVHD and the associated barrier dysfunction. Pharmacological agents to target mucosal

  19. Mannose-binding lectin deficiency and acute exacerbations of chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Woodruff PG

    2012-11-01

    Full Text Available Richard K Albert,1 John Connett,2 Jeffrey L Curtis,3,4 Fernando J Martinez,3 MeiLan K Han,3 Stephen C Lazarus,5 Prescott G Woodruff51Medicine Service, Denver Health and Department of Medicine, University of Colorado Denver, Denver, CO, 2Division of Biostatistics, School of Public Health, University of Minnesota, Minneapolis, MN, 3Pulmonary and Critical Care Medicine, Department of Medicine, University of Michigan, Ann Arbor, MI, 4Pulmonary and Critical Care Medicine, VA Medical Center, Ann Arbor, MI, 5Pulmonary and Critical Care Medicine, Department of Medicine, and Cardiovascular Research Institute, University of California, San Francisco, CA, USABackground: Mannose-binding lectin is a collectin involved in host defense against infection. Whether mannose-binding lectin deficiency is associated with acute exacerbations of chronic obstructive pulmonary disease is debated.Methods: Participants in a study designed to determine if azithromycin taken daily for one year decreased acute exacerbations had serum mannose-binding lectin concentrations measured at the time of enrollment.Results: Samples were obtained from 1037 subjects (91% in the trial. The prevalence of mannose-binding lectin deficiency ranged from 0.5% to 52.2%, depending on how deficiency was defined. No differences in the prevalence of deficiency were observed with respect to any demographic variable assessed, and no differences were observed in time to first exacerbation, rate of exacerbations, or percentage of subjects requiring hospitalization for exacerbations in those with deficiency versus those without, regardless of how deficiency was defined.Conclusion: In a large sample of subjects with chronic obstructive pulmonary disease selected for having an increased risk of experiencing an acute exacerbation of chronic obstructive pulmonary disease, only 1.9% had mannose-binding lectin concentrations below the normal range and we found no association between mannose-binding lectin

  20. Addiction, adolescence, and innate immune gene induction

    Directory of Open Access Journals (Sweden)

    Fulton T Crews

    2011-04-01

    Full Text Available Repeated drug use/abuse amplifies psychopathology, progressively reducing frontal lobe behavioral control and cognitive flexibility while simultaneously increasing limbic temporal lobe negative emotionality. The period of adolescence is a neurodevelopmental stage characterized by poor behavioral control as well as strong limbic reward and thrill seeking. Repeated drug abuse and/or stress during this stage increase the risk of addiction and elevate activator innate immune signaling in the brain. Nuclear factor-kappa-light-chain-enhancer of activated B cells (NF-κB is a key glial transcription factor that regulates proinflammatory chemokines, cytokines, oxidases, proteases, and other innate immune genes. Induction of innate brain immune gene expression (e.g., NF-κB facilitates negative affect, depression-like behaviors, and inhibits hippocampal neurogenesis. In addition, innate immune gene induction alters cortical neurotransmission consistent with loss of behavioral control. Studies with anti-oxidant, anti-inflammatory, and anti-depressant drugs as well as opiate antagonists link persistent innate immune gene expression to key behavioral components of addiction, e.g. negative affect-anxiety and loss of frontal cortical behavioral control. This review suggests that persistent and progressive changes in innate immune gene expression contribute to the development of addiction. Innate immune genes may represent a novel new target for addiction therapy.

  1. InnateDB: systems biology of innate immunity and beyond—recent updates and continuing curation

    Science.gov (United States)

    Breuer, Karin; Foroushani, Amir K.; Laird, Matthew R.; Chen, Carol; Sribnaia, Anastasia; Lo, Raymond; Winsor, Geoffrey L.; Hancock, Robert E. W.; Brinkman, Fiona S. L.; Lynn, David J.

    2013-01-01

    InnateDB (http://www.innatedb.com) is an integrated analysis platform that has been specifically designed to facilitate systems-level analyses of mammalian innate immunity networks, pathways and genes. In this article, we provide details of recent updates and improvements to the database. InnateDB now contains >196 000 human, mouse and bovine experimentally validated molecular interactions and 3000 pathway annotations of relevance to all mammalian cellular systems (i.e. not just immune relevant pathways and interactions). In addition, the InnateDB team has, to date, manually curated in excess of 18 000 molecular interactions of relevance to innate immunity, providing unprecedented insight into innate immunity networks, pathways and their component molecules. More recently, InnateDB has also initiated the curation of allergy- and asthma-related interactions. Furthermore, we report a range of improvements to our integrated bioinformatics solutions including web service access to InnateDB interaction data using Proteomics Standards Initiative Common Query Interface, enhanced Gene Ontology analysis for innate immunity, and the availability of new network visualizations tools. Finally, the recent integration of bovine data makes InnateDB the first integrated network analysis platform for this agriculturally important model organism. PMID:23180781

  2. InnateDB: systems biology of innate immunity and beyond--recent updates and continuing curation.

    Science.gov (United States)

    Breuer, Karin; Foroushani, Amir K; Laird, Matthew R; Chen, Carol; Sribnaia, Anastasia; Lo, Raymond; Winsor, Geoffrey L; Hancock, Robert E W; Brinkman, Fiona S L; Lynn, David J

    2013-01-01

    InnateDB (http://www.innatedb.com) is an integrated analysis platform that has been specifically designed to facilitate systems-level analyses of mammalian innate immunity networks, pathways and genes. In this article, we provide details of recent updates and improvements to the database. InnateDB now contains >196 000 human, mouse and bovine experimentally validated molecular interactions and 3000 pathway annotations of relevance to all mammalian cellular systems (i.e. not just immune relevant pathways and interactions). In addition, the InnateDB team has, to date, manually curated in excess of 18 000 molecular interactions of relevance to innate immunity, providing unprecedented insight into innate immunity networks, pathways and their component molecules. More recently, InnateDB has also initiated the curation of allergy- and asthma-related interactions. Furthermore, we report a range of improvements to our integrated bioinformatics solutions including web service access to InnateDB interaction data using Proteomics Standards Initiative Common Query Interface, enhanced Gene Ontology analysis for innate immunity, and the availability of new network visualizations tools. Finally, the recent integration of bovine data makes InnateDB the first integrated network analysis platform for this agriculturally important model organism.

  3. Periodontal innate immune mechanisms relevant to obesity.

    Science.gov (United States)

    Amar, S; Leeman, S

    2013-10-01

    Obesity affects over 35% of the adult population of the USA, and obesity-related illnesses have emerged as the leading cause of preventable death worldwide, according to the World Health Organization. Obesity's secondary morbidities include increased risk of cardiovascular disease, type II diabetes, and cancer, in addition to increased occurrence and severity of infections. Sedentary lifestyle and weight gain caused by consumption of a high-fat diet contribute to the development of obesity, with individuals having a body mass index (BMI) score > 30 being considered obese. Genetic models of obesity (ob/ob mice, db/db mice, and fa/fa rats) have been insufficient to study human obesity because of the overall lack of genetic causes for obesity in human populations. To date, the diet-induced obese (DIO) mouse model best serves research studies relevant to human health. Periodontal disease presents with a wide range of clinical variability and severity. Research in the past decade has shed substantial light on both the initiating infectious agents and host immunological responses in periodontal disease. Up to 46% of the general population harbors the microorganism(s) associated with periodontal disease, although many are able to limit the progression of periodontal disease or even clear the organism(s) if infected. In the last decade, several epidemiological studies have found an association between obesity and increased incidence of periodontal disease. This review focuses on exploring the immunological consequences of obesity that exacerbate effects of infection by pathogens, with focus on infection by the periodontal bacterium Porphyromonas gingivalis as a running example. 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd

  4. Activation and pathogenic manipulation of the sensors of the innate immune system.

    Science.gov (United States)

    Odendall, Charlotte; Kagan, Jonathan C

    The innate immune system detects the presence of microbes through different families of pattern-recognition receptors (PRRs). PRRs detect pathogens of all origins and trigger signaling events that activate innate and adaptive immunity. These events need to be tightly regulated in order to ensure optimal activation when required, and minimal signaling in the absence of microbial encounters. This regulation is achieved, at least in part, through the precise subcellular positioning of receptors and downstream signaling proteins. Consequently, mislocalization of these proteins inhibits innate immune pathways, and pathogens have evolved to alter host protein localization as a strategy to evade immune detection. This review describes the importance of subcellular localization of various PRR families and their adaptors, and highlights pathogenic immune evasion strategies that operate by altering immune protein localization. Copyright © 2017. Published by Elsevier Masson SAS.

  5. Antimicrobial peptides in innate immune responses

    DEFF Research Database (Denmark)

    Sorensen, O.E.; Borregaard, N.; Cole, A.M.

    2008-01-01

    Antimicrobial peptides (AMPs) are ancient effector molecules in the innate immune response of eukaryotes. These peptides are important for the antimicrobial efficacy of phagocytes and for the innate immune response mounted by epithelia of humans and other mammals. AMPs are generated either by de...... novo synthesis or by proteolytic cleavage from antimicrobially inactive proproteins. Studies of human diseases and animal studies have given important clues to the in vivo role of AMPs. It is now evident that dysregulation of the generation of AMPs in innate immune responses plays a role in certain...

  6. Innate immune cells in inflammation and cancer.

    Science.gov (United States)

    Nowarski, Roni; Gagliani, Nicola; Huber, Samuel; Flavell, Richard A

    2013-08-01

    The innate immune system has evolved in multicellular organisms to detect and respond to situations that compromise tissue homeostasis. It comprises a set of tissue-resident and circulating leukocytes primarily designed to sense pathogens and tissue damage through hardwired receptors and eliminate noxious sources by mediating inflammatory processes. While indispensable to immunity, the inflammatory mediators produced in situ by activated innate cells during injury or infection are also associated with increased cancer risk and tumorigenesis. Here, we outline basic principles of innate immune cell functions in inflammation and discuss how these functions converge upon cancer development. ©2013 AACR.

  7. Innate lymphoid cells in inflammatory bowel diseases.

    Science.gov (United States)

    Peters, C P; Mjösberg, J M; Bernink, J H; Spits, H

    2016-04-01

    It is generally believed that inflammatory bowel diseases (IBD) are caused by an aberrant immune response to environmental triggers in genetically susceptible individuals. The exact contribution of the adaptive and innate immune system has not been elucidated. However, recent advances in treatments targeting key inflammatory mediators such as tumour necrosis factor highlight the crucial role of the innate immune system in IBD. Innate lymphoid cells (ILCs) have recently been identified to play an important role in immune mediated inflammatory diseases. In this review we recapitulate the current knowledge on ILCs in IBD. Copyright © 2015 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  8. Pneumonic vs nonpneumonic acute exacerbations of COPD.

    Science.gov (United States)

    Lieberman, David; Lieberman, Devora; Gelfer, Yevgenia; Varshavsky, Raiesa; Dvoskin, Bella; Leinonen, Maija; Friedman, Maureen G

    2002-10-01

    To describe and compare the background, clinical manifestations, disease course, and infectious etiologies of pneumonic acute exacerbations (PNAE) vs nonpneumonic acute exacerbations (NPAE) of COPD. A prospective, observational study. A tertiary university medical center in southern Israel. Twenty-three hospitalizations for PNAE and 217 hospitalizations for NPAE were included in the study. Paired sera were obtained for each of the hospitalizations and were tested serologically for 12 pathogens. Only a significant change in antibody titers or levels was considered diagnostic. No significant differences were found between the two groups for any of the parameters related to COPD or comorbidity. The clinical type of the exacerbation was not significantly different between the groups. Compared to NPAE, patients with PNAE had lower PO(2) values at hospital admission (p = 0.004) but higher rates of abrupt onset (p = 0.005), ICU admissions (p = 0.006), invasive mechanical ventilation (p = 0.01), mortality (p = 0.007), and longer hospital stay (p = 0.001). In 22 PNAE hospitalizations (96%) and in 153 NPAE hospitalizations (71%), at least one infectious etiology was identified (p = 0.001). Mixed infection was found in 13 patients with PNAE (59%) and in 59 patients with NPAE (39%; not significant [NS]). Viral etiology was identified in 18 patients with PNAE (78%) compared with 99 patients with NPAE (46%; p = 0.003). Pneumococcal etiology was found in 10 patients with PNAE (43%) and in 38 patients with NPAE (18%; p = 0.006). An atypical etiology was identified in 8 patients with PNAE (35%) and 64 patients with NPAE (30%; NS). Community-acquired pneumonia is common among patients hospitalized for an acute exacerbation of COPD and is generally manifested by more severe clinical and laboratory parameters. In PNAE, compared to NPAE, viral and pneumococcal etiologies are more common, but the rate of atypical pathogens is similar. The therapeutic significance of these findings

  9. Biomarkers Predictive of Exacerbations in the SPIROMICS and COPDGene Cohorts.

    Science.gov (United States)

    Keene, Jason D; Jacobson, Sean; Kechris, Katerina; Kinney, Gregory L; Foreman, Marilyn G; Doerschuk, Claire M; Make, Barry J; Curtis, Jeffrey L; Rennard, Stephen I; Barr, R Graham; Bleecker, Eugene R; Kanner, Richard E; Kleerup, Eric C; Hansel, Nadia N; Woodruff, Prescott G; Han, MeiLan K; Paine, Robert; Martinez, Fernando J; Bowler, Russell P; O'Neal, Wanda K

    2017-02-15

    Chronic obstructive pulmonary disease exacerbations are associated with disease progression, higher healthcare cost, and increased mortality. Published predictors of future exacerbations include previous exacerbation, airflow obstruction, poor overall health, home oxygen use, and gastroesophageal reflux. To determine the value of adding blood biomarkers to clinical variables to predict exacerbations. Subjects from the SPIROMICS (Subpopulations and Intermediate Outcomes Measures in COPD Study) (n = 1,544) and COPDGene (Genetic Epidemiology of COPD) (n = 602) cohorts had 90 plasma or serum candidate proteins measured on study entry using Myriad-RBM multiplex panels. We defined total exacerbations as subject-reported worsening in respiratory health requiring therapy with corticosteroids and/or antibiotics, and severe exacerbations as those leading to hospitalizations or emergency room visits. We assessed retrospective exacerbations during the 12 months before enrollment and then documented prospective exacerbations in each cohort. Exacerbations were modeled for biomarker associations with negative binomial regression including clinical covariates (age, sex, percent predicted FEV1, self-reported gastroesophageal reflux, St. George's Respiratory Questionnaire score, smoking status). We used the Stouffer-Liptak test to combine P values for metaanalysis. Between the two cohorts, 3,471 total exacerbations (1,044 severe) were reported. We identified biomarkers within each cohort that were significantly associated with a history of exacerbation and with a future exacerbation, but there was minimal replication between the cohorts. Although established clinical features were predictive of exacerbations, of the blood biomarkers only decorin and α2-macroglobulin increased predictive value for future severe exacerbations. Blood biomarkers were significantly associated with the occurrence of exacerbations but were not robust between cohorts and added little to the

  10. Fine particulate pollution and asthma exacerbations.

    Science.gov (United States)

    Bouazza, Naïm; Foissac, Frantz; Urien, Saik; Guedj, Romain; Carbajal, Ricardo; Tréluyer, Jean-Marc; Chappuy, Hélène

    2017-12-19

    As the results from epidemiological studies about the impact of outdoor air pollution on asthma in children are heterogeneous, our objective was to investigate the association between asthma exacerbation in children and exposure to air pollutants. A database of 1 264 585 paediatric visits during the 2010-2015 period to the emergency rooms from 20 emergency departments (EDs) of 'Assistance Publique Hôpitaux de Paris (APHP)', the largest hospital group in Europe, was used. A total of 47 107 visits were classified as asthma exacerbations. Concentration of air pollutants (nitrogen dioxide, ozone, fine particulate matter (PM) with an aerodynamic diameter smaller than 10  µm (PM10) and 2.5 µm (PM2.5)), as well as meteorological data, evolution of respiratory syncytial virus infection and pollen exposition, were collected on an hourly or daily basis for the same period using institutional databases. To assess the association between air pollution and asthma, mixed-effects quasi-Poisson regression modelling was performed. The only compound independently associated with ED visits for asthma was PM2.5 (Peffect, was estimated at 13.5 µg/m3. We found an association between daily asthma exacerbation in paediatric visits to the ED and fine particulate air pollutants. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. [Prevention of COPD exacerbation: a fundamental challenge].

    Science.gov (United States)

    Roche, N; Aguilaniu, B; Burgel, P-R; Durand-Zaleski, I; Dusser, D; Escamilla, R; Perez, T; Raherison, C; Similowski, T

    2012-06-01

    Acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a cause of suffering for patients and a burden for healthcare systems and society. Their prevention represents individual and collective challenge. The present article is based on the work of a group of experts who met on 5th and 6th May 2011 and seeks to highlight the importance of AECOPD. In the absence of easily quantifiable criteria, the definition of AECOPD varies in the literature, making identification difficult and affecting interpretation of study results. Exacerbations increase mortality and risk of cardiovascular disease. They also increase the risk of developing further exacerbations, accelerate the decline in lung function and contribute to reduction in muscle mass. By limiting physical activity and affecting mental state (anxiety, depression), AECOPD are disabling and impair quality of life. They increase work absenteeism and are responsible for about 60% of the global cost of COPD. Earlier identification with simple criteria, possibly associated to patient phenotyping, could be helpful in preventing hospitalization. Given their immediate and delayed impact, AECOPD should not be trivialized or neglected. Their prevention is a fundamental issue. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  12. Biofilm-Induced Type 2 Innate Immunity in a Cystic Fibrosis Model of Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Kenny Bielen

    2017-06-01

    Full Text Available Biofilm-producing strains of Pseudomonas aeruginosa are a major cause of morbidity and mortality in cystic fibrosis (CF patients. In these patients, increased levels of IL-17 as well as of IL-5 and IL-13 along with arginase (Arg-positive macrophages have been observed in bronchoalveolar lavage fluid. While IL-17 is a strong proinflammatory cytokine associated with host defense against bacterial and fungal infections and is also elevated in several autoimmune diseases, IL-5/IL-13 and Arg1-positive M2 macrophages are part of the anti-inflammatory type 2 (Th2 immunity. To study whether increased IL-5 and IL-13 levels are related to biofilm formation, which is frequently observed in CF patients colonized by P. aeruginosa, we utilized an agarose bead-embedded P. aeruginosa rat model commonly employed in in vivo biofilm studies. We showed that “sterile” agarose bead instillation in rat notably increased lung transcript levels of IL-5 and IL-13 at two post-instillation study-points, day 1 and day 3. Concurrently, increased infiltration of type 2 innate cells such as eosinophils and Arg1 positive M2 activated macrophages (Arg1+CD68+ was also observed both at day 1 and day 3 while the proportion of M1 activated macrophages (iNOS+CD68+ at these time-points decreased. In contrast, P. aeruginosa-loaded beads caused a drastic elevation of proinflammatory Th1 (IFNγ, TNFα, IL-12a and antibacterial Th17 (IL-17a, IL-17f, IL-22, IL-23a cytokines along with a high influx of neutrophils and M1 macrophages, while Th2 cytokines (IL-5 and IL-13 drastically declined at day 1 post-infection. Interestingly, at day 3 post-infection, both Th1 and Th17 cytokines sharply declined and corroborated with decreased M1 and increased M2 macrophages. These data suggest that while IL-17 is linked to episodes of acute exacerbations of infection in CF patients, the increased Th2 cytokines and M2 macrophages observed in these patients are largely due to the biofilm matrix. The

  13. Innate Immune Detection of Flagellin Positively and Negatively Regulates Salmonella Infection

    Science.gov (United States)

    Lai, Marvin A.; Quarles, Ellen K.; López-Yglesias, Américo H.; Zhao, Xiaodan; Hajjar, Adeline M.; Smith, Kelly D.

    2013-01-01

    Salmonella enterica serovar Typhimurium is a flagellated bacterium and one of the leading causes of gastroenteritis in humans. Bacterial flagellin is required for motility and also a prime target of the innate immune system. Innate immune recognition of flagellin is mediated by at least two independent pathways, TLR5 and Naip5-Naip6/NlrC4/Caspase-1. The functional significance of each of the two independent flagellin recognition systems for host defense against wild type Salmonella infection is complex, and innate immune detection of flagellin contributes to both protection and susceptibility. We hypothesized that efficient modulation of flagellin expression in vivo permits Salmonella to evade innate immune detection and limit the functional role of flagellin-specific host innate defenses. To test this hypothesis, we used Salmonella deficient in the anti-sigma factor flgM, which overproduce flagella and are attenuated in vivo. In this study we demonstrate that flagellin recognition by the innate immune system is responsible for the attenuation of flgM− S. Typhimurium, and dissect the contribution of each flagellin recognition pathway to bacterial clearance and inflammation. We demonstrate that caspase-1 controls mucosal and systemic infection of flgM− S. Typhimurium, and also limits intestinal inflammation and injury. In contrast, TLR5 paradoxically promotes bacterial colonization in the cecum and systemic infection, but attenuates intestinal inflammation. Our results indicate that Salmonella evasion of caspase-1 dependent flagellin recognition is critical for establishing infection and that evasion of TLR5 and caspase-1 dependent flagellin recognition helps Salmonella induce intestinal inflammation and establish a niche in the inflamed gut. PMID:23977202

  14. Genomic Signatures of Selective Pressures and Introgression from Archaic Hominins at Human Innate Immunity Genes.

    Science.gov (United States)

    Deschamps, Matthieu; Laval, Guillaume; Fagny, Maud; Itan, Yuval; Abel, Laurent; Casanova, Jean-Laurent; Patin, Etienne; Quintana-Murci, Lluis

    2016-01-07

    Human genes governing innate immunity provide a valuable tool for the study of the selective pressure imposed by microorganisms on host genomes. A comprehensive, genome-wide study of how selective constraints and adaptations have driven the evolution of innate immunity genes is missing. Using full-genome sequence variation from the 1000 Genomes Project, we first show that innate immunity genes have globally evolved under stronger purifying selection than the remainder of protein-coding genes. We identify a gene set under the strongest selective constraints, mutations in which are likely to predispose individuals to life-threatening disease, as illustrated by STAT1 and TRAF3. We then evaluate the occurrence of local adaptation and detect 57 high-scoring signals of positive selection at innate immunity genes, variation in which has been associated with susceptibility to common infectious or autoimmune diseases. Furthermore, we show that most adaptations targeting coding variation have occurred in the last 6,000-13,000 years, the period at which populations shifted from hunting and gathering to farming. Finally, we show that innate immunity genes present higher Neandertal introgression than the remainder of the coding genome. Notably, among the genes presenting the highest Neandertal ancestry, we find the TLR6-TLR1-TLR10 cluster, which also contains functional adaptive variation in Europeans. This study identifies highly constrained genes that fulfill essential, non-redundant functions in host survival and reveals others that are more permissive to change-containing variation acquired from archaic hominins or adaptive variants in specific populations-improving our understanding of the relative biological importance of innate immunity pathways in natural conditions. Copyright © 2016 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  15. Genomic Signatures of Selective Pressures and Introgression from Archaic Hominins at Human Innate Immunity Genes

    Science.gov (United States)

    Deschamps, Matthieu; Laval, Guillaume; Fagny, Maud; Itan, Yuval; Abel, Laurent; Casanova, Jean-Laurent; Patin, Etienne; Quintana-Murci, Lluis

    2016-01-01

    Human genes governing innate immunity provide a valuable tool for the study of the selective pressure imposed by microorganisms on host genomes. A comprehensive, genome-wide study of how selective constraints and adaptations have driven the evolution of innate immunity genes is missing. Using full-genome sequence variation from the 1000 Genomes Project, we first show that innate immunity genes have globally evolved under stronger purifying selection than the remainder of protein-coding genes. We identify a gene set under the strongest selective constraints, mutations in which are likely to predispose individuals to life-threatening disease, as illustrated by STAT1 and TRAF3. We then evaluate the occurrence of local adaptation and detect 57 high-scoring signals of positive selection at innate immunity genes, variation in which has been associated with susceptibility to common infectious or autoimmune diseases. Furthermore, we show that most adaptations targeting coding variation have occurred in the last 6,000–13,000 years, the period at which populations shifted from hunting and gathering to farming. Finally, we show that innate immunity genes present higher Neandertal introgression than the remainder of the coding genome. Notably, among the genes presenting the highest Neandertal ancestry, we find the TLR6-TLR1-TLR10 cluster, which also contains functional adaptive variation in Europeans. This study identifies highly constrained genes that fulfill essential, non-redundant functions in host survival and reveals others that are more permissive to change—containing variation acquired from archaic hominins or adaptive variants in specific populations—improving our understanding of the relative biological importance of innate immunity pathways in natural conditions. PMID:26748513

  16. Myasthenia gravis exacerbation and diarrhea associated with erythromycin treatment

    Directory of Open Access Journals (Sweden)

    Sora Yasr

    2017-02-01

    Full Text Available An important problem in management of the case with myasthenia gravis (MG is the control of exacerbation. There are several possible causes of exacerbation of MG including the use of drug. Here, the authors report a case of MG exacerbation and diarrhea associated with erythromycin treatment.

  17. Innate preference or opportunism: mosquitoes feeding on birds of prey at the Southeastern Raptor Center.

    Science.gov (United States)

    Burkett-Cadena, Nathan D; Bingham, Andrea M; Porterfield, Christopher; Unnasch, Thomas R

    2014-06-01

    The amplification of mosquito-borne pathogens is driven by patterns of host use by vectors. While each mosquito species is innately adapted to feed upon a particular group of hosts, this "preference" is difficult to assess in field-based studies, because factors such as host defenses and spatial and temporal overlap of mosquitoes and hosts affect which host animals actually get bitten. Here we examined patterns of host use by mosquitoes feeding on caged raptors at a rehabilitation and education center for birds of prey in Alabama, U.S.A. PCR-based techniques were used to determine the host species fed upon. Of 19 raptor species at the facility, seven were found to be fed upon by mosquitoes. Feeding indices and linear regression indicated that no species or family of raptor were significantly preferred over another (R(2)=0.46). Relative abundance adjusted for bird size explained a statistically significant amount of the variation in relative host use (R(2)=0.71), suggesting that bird size is an important component of host selection by mosquitoes. These findings support the hypothesis that traits of host animals drive patterns of host use by mosquitoes in nature, an interaction that leads to amplification of mosquito-borne viruses. © 2014 The Society for Vector Ecology.

  18. Roles for Innate Immunity in Combination Immunotherapies.

    Science.gov (United States)

    Moynihan, Kelly D; Irvine, Darrell J

    2017-10-01

    Immunity to infectious agents involves a coordinated response of innate and adaptive immune cells working in concert, with many feed-forward and regulatory interactions between both arms of the immune system. In contrast, many therapeutic strategies to augment immunity against tumors have focused predominantly on stimulation of adaptive immunity. However, a growing appreciation of the potential contributions of innate immune effectors to antitumor immunity, especially in the context of combination immunotherapy, is leading to novel strategies to elicit a more integrated immune response against cancer. Here we review antitumor activities of innate immune cells, mechanisms of their synergy with adaptive immune responses against tumors, and discuss recent studies highlighting the potential of combination therapies recruiting both innate and adaptive immune effectors to eradicate established tumors. Cancer Res; 77(19); 5215-21. ©2017 AACR. ©2017 American Association for Cancer Research.

  19. Innate intelligence: its origins and problems

    Science.gov (United States)

    Morgan, Lon

    1998-01-01

    Animal Magnetism and Radionics were among several occult practices used during the 19th century for the treatment of disease. D.D. Palmer was exposed to these teachings and derived many of his ideas about health from the folk medicine practices of his time. As a ‘magnetic healer’ Palmer believed he was correcting an undefined fifth force in the body that is otherwise unknown to science. Palmer believed he could influence this fifth force, termed Innate Intelligence, and that it was the explanation for the presence or absence of health. Today, Innate Intelligence remains an untestable enigma that isolates chiropractic and impedes its acceptance as a legitimate health science. The concept of Innate is derived directly from the occult practices of another era. It carries a high penalty in divisiveness and lack of logical coherence. The chiropractic profession must decide whether the concept of Innate should be retained.

  20. Cholangiopathy with Respect to Biliary Innate Immunity

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    Kenichi Harada

    2012-01-01

    Full Text Available Biliary innate immunity is involved in the pathogenesis of cholangiopathies in cases of biliary disease. Cholangiocytes possess Toll-like receptors (TLRs which recognize pathogen-associated molecular patterns (PAMPs and play a pivotal role in the innate immune response. Tolerance to bacterial PAMPs such as lipopolysaccharides is also important to maintain homeostasis in the biliary tree, but tolerance to double-stranded RNA (dsRNA is not found. Moreover, in primary biliary cirrhosis (PBC and biliary atresia, biliary innate immunity is closely associated with the dysregulation of the periductal cytokine milieu and the induction of biliary apoptosis and epithelial-mesenchymal transition (EMT, forming in disease-specific cholangiopathy. Biliary innate immunity is associated with the pathogenesis of various cholangiopathies in biliary diseases as well as biliary defense systems.

  1. Impact of cigarette smoke exposure on innate immunity: a Caenorhabditis elegans model.

    Directory of Open Access Journals (Sweden)

    Rebecca M Green

    Full Text Available BACKGROUND: Cigarette smoking is the major cause of chronic obstructive pulmonary disease (COPD and lung cancer. Respiratory bacterial infections have been shown to be involved in the development of COPD along with impaired airway innate immunity. METHODOLOGY/PRINCIPAL FINDINGS: To address the in vivo impact of cigarette smoke (CS exclusively on host innate defense mechanisms, we took advantage of Caenorhabditis elegans (C. elegans, which has an innate immune system but lacks adaptive immune function. Pseudomonas aeruginosa (PA clearance from intestines of C. elegans was dampened by CS. Microarray analysis identified 6 candidate genes with a 2-fold or greater reduction after CS exposure, that have a human orthologue, and that may participate in innate immunity. To confirm a role of CS-down-regulated genes in the innate immune response to PA, RNA interference (RNAi by feeding was carried out in C. elegans to inhibit the gene of interest, followed by PA infection to determine if the gene affected innate immunity. Inhibition of lbp-7, which encodes a lipid binding protein, resulted in increased levels of intestinal PA. Primary human bronchial epithelial cells were shown to express mRNA of human Fatty Acid Binding Protein 5 (FABP-5, the human orthologue of lpb-7. Interestingly, FABP-5 mRNA levels from human smokers with COPD were significantly lower (p = 0.036 than those from smokers without COPD. Furthermore, FABP-5 mRNA levels were up-regulated (7-fold after bacterial (i.e., Mycoplasma pneumoniae infection in primary human bronchial epithelial cell culture (air-liquid interface culture. CONCLUSIONS: Our results suggest that the C. elegans model offers a novel in vivo approach to specifically study innate immune deficiencies resulting from exposure to cigarette smoke, and that results from the nematode may provide insight into human airway epithelial cell biology and cigarette smoke exposure.

  2. Impact of cigarette smoke exposure on innate immunity: a Caenorhabditis elegans model.

    Science.gov (United States)

    Green, Rebecca M; Gally, Fabienne; Keeney, Jonathon G; Alper, Scott; Gao, Bifeng; Han, Min; Martin, Richard J; Weinberger, Andrew R; Case, Stephanie R; Minor, Maisha N; Chu, Hong Wei

    2009-08-31

    Cigarette smoking is the major cause of chronic obstructive pulmonary disease (COPD) and lung cancer. Respiratory bacterial infections have been shown to be involved in the development of COPD along with impaired airway innate immunity. To address the in vivo impact of cigarette smoke (CS) exclusively on host innate defense mechanisms, we took advantage of Caenorhabditis elegans (C. elegans), which has an innate immune system but lacks adaptive immune function. Pseudomonas aeruginosa (PA) clearance from intestines of C. elegans was dampened by CS. Microarray analysis identified 6 candidate genes with a 2-fold or greater reduction after CS exposure, that have a human orthologue, and that may participate in innate immunity. To confirm a role of CS-down-regulated genes in the innate immune response to PA, RNA interference (RNAi) by feeding was carried out in C. elegans to inhibit the gene of interest, followed by PA infection to determine if the gene affected innate immunity. Inhibition of lbp-7, which encodes a lipid binding protein, resulted in increased levels of intestinal PA. Primary human bronchial epithelial cells were shown to express mRNA of human Fatty Acid Binding Protein 5 (FABP-5), the human orthologue of lpb-7. Interestingly, FABP-5 mRNA levels from human smokers with COPD were significantly lower (p = 0.036) than those from smokers without COPD. Furthermore, FABP-5 mRNA levels were up-regulated (7-fold) after bacterial (i.e., Mycoplasma pneumoniae) infection in primary human bronchial epithelial cell culture (air-liquid interface culture). Our results suggest that the C. elegans model offers a novel in vivo approach to specifically study innate immune deficiencies resulting from exposure to cigarette smoke, and that results from the nematode may provide insight into human airway epithelial cell biology and cigarette smoke exposure.

  3. The Innate Immune System in Demyelinating Disease

    OpenAIRE

    Mayo, Lior; Quintana, Francisco J.; Weiner, Howard L

    2012-01-01

    Demyelinating diseases such as multiple sclerosis are chronic inflammatory autoimmune diseases with a heterogeneous clinical presentation and course. Both the adaptive and the innate immune systems have been suggested to contribute to their pathogenesis and recovery. In this review, we discuss the role of the innate immune system in mediating demyelinating diseases. In particular, we provide an overview of the anti-inflammatory or pro-inflammatory functions of dendritic cells, mast cells, nat...

  4. Histomorphology and innate immunity during the progression of osteoarthritis: Does synovitis affect cartilage degradation?

    Science.gov (United States)

    Wang, Huan; Wang, Qingguo; Yang, Meijuan; Yang, Lili; Wang, Weili; Ding, Haobin; Zhang, Dong; Xu, Jing; Tang, Xuezhang; Ding, Haitao; Wang, Qingfu

    2018-02-01

    Osteoarthritis (OA) is a common chronic degenerative disease that affects all joints. At present, the pathological processes and mechanisms of OA are still unclear. Innate immunity, a key player in damage to the structure of the joint and the mechanism by which the host attempts to repair OA, affects all pathological stages of the disease. In the present study, our aim was to assess changes in innate immunity during the pathological processes of OA in articular cartilage (AC) and the synovial membrane (SM), which are the major structures in joints, and to systematically examine the histological changes in AC and SM in mild, moderate and severe cases of OA, in order to further speculate about the manner in which the interactions of AC and SM are facilitated by innate immunity. Histological methods (including HE and Safranin O-fast green staining), immunofluorescent double staining, TUNEL stain, and Western blots were used to assess the morphological changes within AC and SM tissues in healthy and mild, moderate, or severe OA rats. Our results showed that the damage to AC and SM within the joints progressively worsened in different degrees during the course of the disease, and that the innate immune system was closely involved in the AC and SM during each stage of OA. These findings also confirmed that SM may affect the pathological changes in AC through the innate immune system, and therefore affect the progress of OA. © 2017 Wiley Periodicals, Inc.

  5. Lgt processing is an essential step in Streptococcus suis lipoprotein mediated innate immune activation.

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    Paul J Wichgers Schreur

    Full Text Available BACKGROUND: Streptococcus suis causes invasive infections in pigs and occasionally in humans. The host innate immune system plays a major role in counteracting S. suis infections. The main components of S. suis able to activate the innate immune system likely include cell wall constituents that may be released during growth or after cell wall integrity loss, however characterization of these components is still limited. METHODOLOGY/PRINCIPAL FINDINGS: [corrected] A concentrated very potent innate immunity activating supernatant of penicillin-treated S. suis was SDS-PAGE fractionated and tested for porcine peripheral blood mononucleated cell (PBMC stimulating activity using cytokine gene transcript analysis. More than half of the 24 tested fractions increased IL-1β and IL-8 cytokine gene transcript levels in porcine PBMCs. Mass spectrometry of the active fractions indicated 24 proteins including 9 lipoproteins. Genetic inactivation of a putative prolipoprotein diacylglyceryl transferase (Lgt gene resulted in deficient lipoprotein synthesis as evidenced by palmitate labeling. The Lgt mutant showed strongly reduced activation of porcine PBMCs, indicating that lipoproteins are dominant porcine PBMC activating molecules of S. suis. CONCLUSION/SIGNIFICANCE: This study for the first time identifies and characterizes lipoproteins of S. suis as major activators of the innate immune system of the pig. In addition, we provide evidence that Lgt processing of lipoproteins is required for lipoprotein mediated innate immune activation.

  6. The innate immune response affects the development of the autoimmune response in Theiler's virus-induced demyelinating disease.

    Science.gov (United States)

    Olson, Julie K; Miller, Stephen D

    2009-05-01

    Multiple sclerosis (MS) is a human CNS autoimmune demyelinating disease. Epidemiological evidence has suggested a role for virus infection in the initiation and/or exacerbation of MS. Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease serves as a relevant mouse model for MS. TMEV-infected mice develop a demyelinating disease with clinical symptoms beginning around 35 days after infection, which is associated with development of myelin-specific, PLP(139-151), CD4(+) T cell responses. Viruses have been suggested to initiate autoimmune disease through bystander activation of immune cells or through bystander damage to tissue during infection. We examined the effect of the innate immune response on development of autoimmune demyelinating disease by altering the innate immune response through administration of innate immune cytokines, IFN-alpha or IFN-beta, or antiserum against the type I IFNs during the innate immune response to TMEV. Administration of IFN-beta, but not IFN-alpha, to TMEV- infected mice led to reduced myelin-specific CD4(+) T cell responses and reduced demyelinating disease, which was associated with decreased immune cell infiltration into the CNS and increased expression of IL-10 in the CNS. Conversely, administration of antiserum to IFN-beta led to a more severe demyelinating disease. In addition, administration of poly(I:C), which is an innate immune agonist, to TMEV-infected mice during the innate immune response resulted in decreased myelin-specific CD4(+) T cell responses and reduced demyelinating disease. These results demonstrate that activating or enhancing the innate immune response can reduce the subsequent initiation and progression of the autoimmune response and demyelinating disease.

  7. The innate immune response affects the development of the autoimmune response in Theiler’s virus- induced demyelinating disease

    Science.gov (United States)

    Olson, Julie K.; Miller, Stephen D.

    2010-01-01

    Multiple sclerosis (MS) is a human CNS autoimmune demyelinating disease. Epidemiological evidence has suggested a role for virus infection in the initiation and/or exacerbation of MS. Theiler’s murine encephalomyelitis virus (TMEV)- induced demyelinating disease serves as a relevant mouse model for MS. TMEV- infected mice develop a demyelinating disease with clinical symptoms beginning around 35 days post infection which is associated with development of myelin- specific, PLP139–151, CD4+ T cell responses. Viruses have been suggested to initiate autoimmune disease through bystander activation of immune cells or through bystander damage to tissue during infection. We examined the effect of the innate immune response on development of autoimmune demyelinating disease by altering the innate immune response through administration of innate immune cytokines, IFNα or IFNβ, or antiserum against the type I interferons during the innate immune response to TMEV. Administration of IFNβ, but not IFNα, to TMEV- infected mice led to reduced myelin-specific CD4+ T cell responses and reduced demyelinating disease which was associated with decreased immune cell infiltration into the CNS and increased expression of IL-10 in the CNS. Conversely, administration of antiserum to IFNβ led to a more severe demyelinating disease. In addition, administration of polyI:C, which is an innate immune agonist, to TMEV- infected mice during the innate immune response resulted in decreased myelin-specific CD4+ T cell responses and reduced demyelinating disease. These results demonstrate that activating or enhancing the innate immune response can reduce the subsequent initiation and progression of the autoimmune response and demyelinating disease. PMID:19380818

  8. Mycobacterium tuberculosis inhibits human innate immune responses via the production of TLR2 antagonist glycolipids.

    Science.gov (United States)

    Blanc, Landry; Gilleron, Martine; Prandi, Jacques; Song, Ok-Ryul; Jang, Mi-Seon; Gicquel, Brigitte; Drocourt, Daniel; Neyrolles, Olivier; Brodin, Priscille; Tiraby, Gérard; Vercellone, Alain; Nigou, Jérôme

    2017-10-17

    Mycobacterium tuberculosis is a major human pathogen that is able to survive inside host cells and resist immune clearance. Most particularly, it inhibits several arms of the innate immune response, including phagosome maturation or cytokine production. To better understand the molecular mechanisms by which M. tuberculosis circumvents host immune defenses, we used a transposon mutant library generated in a virulent clinical isolate of M. tuberculosis of the W/Beijing family to infect human macrophages, utilizing a cell line derivative of THP-1 cells expressing a reporter system for activation of the transcription factor NF-κB, a key regulator of innate immunity. We identified several M. tuberculosis mutants inducing a NF-κB activation stronger than that of the wild-type strain. One of these mutants was found to be deficient for the synthesis of cell envelope glycolipids, namely sulfoglycolipids, suggesting that the latter can interfere with innate immune responses. Using natural and synthetic molecular variants, we determined that sulfoglycolipids inhibit NF-κB activation and subsequent cytokine production or costimulatory molecule expression by acting as competitive antagonists of Toll-like receptor 2, thereby inhibiting the recognition of M. tuberculosis by this receptor. Our study reveals that producing glycolipid antagonists of pattern recognition receptors is a strategy used by M. tuberculosis to undermine innate immune defense. Sulfoglycolipids are major and specific lipids of M. tuberculosis, considered for decades as virulence factors of the bacilli. Our study uncovers a mechanism by which they may contribute to M. tuberculosis virulence.

  9. Innate immune activation of NFκB and its antagonism by poxviruses.

    Science.gov (United States)

    Brady, Gareth; Bowie, Andrew G

    2014-10-01

    In recent years there has been an acceleration of discovery in the field of innate anti-viral immunity to the point that many of the key events in early virus sensing and the discrete anti-viral responses they trigger have been elucidated in detail. In particular, pattern recognition receptors (PRRs) that detect viruses at the plasma membrane, in endosomes, and within the cytosol have been characterized. Upon stimulation by viruses, most of these PRRs trigger signal transduction pathways culminating in NFκB activation. NFκB contributes both to type I interferon induction, and to production of pro-inflammatory cytokines from infected cells. Our understanding of host anti-viral innate immunity has been greatly aided by an appreciation of the ways in which poxviruses have evolved strategies to inhibit both innate sensing and effector responses. A recurring feature of poxviral immunomodulation is the apparent necessity for poxviruses to evolve multiple, non-redundant inhibitors of NFκB activation which often appear to act on the same innate signalling pathway. The reason for such apparent over-targeting of one transcription factor is not clear. Here we describe the current understanding of how host cells sense poxvirus infection to trigger signalling pathways leading to NFκB activation and pro-inflammatory cytokine induction, and the ways in which poxviruses have evolved to concisely antagonize these systems. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. A bite to fight: front-line innate immune defenses against malaria parasites.

    Science.gov (United States)

    Tannous, Stephanie; Ghanem, Esther

    2018-01-29

    Malaria infection caused by Plasmodium parasites remains a major health burden worldwide especially in the tropics and subtropics. Plasmodium exhibits a complex life cycle whereby it undergoes a series of developmental stages in the Anopheles mosquito vector and the vertebrate human host. Malaria severity is mainly attributed to the genetic complexity of the parasite which is reflected in the sophisticated mechanisms of invasion and evasion that allow it to overcome the immune responses of both its invertebrate and vertebrate hosts. In this review, we aim to provide an updated, clear and concise summary of the literature focusing on the interactions of the vertebrate innate immune system with Plasmodium parasites, namely sporozoites, merozoites, and trophozoites. The roles of innate immune factors, both humoral and cellular, in anti-Plasmodium defense are described with particular emphasis on the contribution of key innate players including neutrophils, macrophages, and natural killer cells to the clearance of liver and blood stage parasites. A comprehensive understanding of the innate immune responses to malaria parasites remains an important goal that would dramatically help improve the design of original treatment strategies and vaccines, both of which are urgently needed to relieve the burden of malaria especially in endemic countries.

  11. Innate Immune Function of Mitochondrial Metabolism.

    Science.gov (United States)

    Sancho, David; Enamorado, Michel; Garaude, Johan

    2017-01-01

    Sensing of microbe-associated molecular patterns or danger signals by innate immune receptors drives a complex exchange of information. Innate receptor signaling not only triggers transcriptional events but also induces profound changes in metabolic fluxes, redox balance, and metabolite abundance thereby influencing immune cell function. Mitochondria are at the core of metabolic adaptation to the changing environment. The close interaction between mitochondrial metabolism and immune signaling has emerged as a central regulator of innate sensing. Metabolic processes generate a constant flow of electrons that eventually end up in the mitochondrial electron transport chain (ETC). Two electron carriers and four respiratory complexes that can assemble as larger molecular supercomplexes compose the ETC in the mitochondrial inner membrane. While the meaning and biological relevance of such structural organization is a matter of passionate debates, recent data support that innate stimuli remodel the ETC. We will review the function of mitochondrial metabolism and ETC dynamics as innate rheostats that regulate signaling, transcription, and epigenetics to orchestrate innate immune responses.

  12. Innate Immune Sensing and Response to Influenza

    Science.gov (United States)

    Pulendran, Bali; Maddur, Mohan S.

    2015-01-01

    Influenza viruses pose a substantial threat to human and animal health worldwide. Recent studies in mouse models have revealed an indispensable role for the innate immune system in defense against influenza virus. Recognition of the virus by innate immune receptors in a multitude of cell types activates intricate signaling networks, functioning to restrict viral replication. Downstream effector mechanisms include activation of innate immune cells and, induction and regulation of adaptive immunity. However, uncontrolled innate responses are associated with exaggerated disease, especially in pandemic influenza virus infection. Despite advances in the understanding of innate response to influenza in the mouse model, there is a large knowledge gap in humans, particularly in immunocom-promised groups such as infants and the elderly. We propose here, the need for further studies in humans to decipher the role of innate immunity to influenza virus, particularly at the site of infection. These studies will complement the existing work in mice and facilitate the quest to design improved vaccines and therapeutic strategies against influenza. PMID:25078919

  13. Mitochondria-Endoplasmic Reticulum Contact Sites Mediate Innate Immune Responses.

    Science.gov (United States)

    Misawa, Takuma; Takahama, Michihiro; Saitoh, Tatsuya

    2017-01-01

    Mitochondria and the endoplasmic reticulum (ER) are fundamental organelles that coordinate high-order cell functions. Mitochondria are centers of energy production, whereas the ER is responsible for folding, transport, and degradation of proteins. In addition to their specific functions, mitochondria and ER actively communicate with each other to promote a variety of cellular events, such as material transfer and signal transduction. Recent studies have shown the critical involvement of these organelles in regulation of the innate immune system, which functions in host defense. The innate immune system utilizes a wide range of germ-line-encoded pattern recognition receptors (PRRs) to recognize pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) and induces inflammatory and antiviral responses. Contact sites between mitochondria and the ER function in assembly of the NLR family pyrin domain containing 3 (NLRP3)-inflammasome to promote the inflammatory response. The NLRP3-inflammasome is a protein complex composed of the receptor NLRP3 on the ER side and the adaptor apoptosis-associated speck-like protein containing a CARD on the mitochondrial side; it induces caspase-1-dependent maturation of proinflammatory cytokines such as interleukin (IL)-1β and IL-18. Furthermore, ER-mitochondria contact sites function in initiation and mediation of signal transduction pathways downstream of intracellular PRRs, such as retinoic acid-inducible gene I-like receptor and cyclic GMP-AMP synthase, to promote the antiviral response. Therefore, ER-mitochondria contact sites, also known as mitochondria-associated membranes, play key roles in regulation of innate immune responses.

  14. Medically treated exacerbations in COPD by GOLD 1-4

    DEFF Research Database (Denmark)

    Ingebrigtsen, Truls S.; Marott, Jacob L.; Lange, Peter

    2015-01-01

    -up. Construct validity of this definition of medically treated exacerbations was assessed by studying baseline determinants as well as by studying the association between GOLD 1 through 4 grades and time to first exacerbation during follow-up. RESULTS: Among individuals with COPD, 964 individuals (7.1%) had...... definition of exacerbations was robust and without major biases. CONCLUSIONS: Compared to individuals with GOLD 1, the risk of exacerbations was 17-fold for GOLD 4, 5-fold for GOLD 3, and 2-fold for GOLD 2. Medically treated exacerbations defined by register linkage seem a valid, robust, and low...

  15. Prognostic factors for clinical failure of exacerbations in elderly outpatients with moderate-to-severe COPD

    Directory of Open Access Journals (Sweden)

    Wilson R

    2015-06-01

    Full Text Available Robert Wilson,1 Antonio Anzueto,2 Marc Miravitlles,3 Pierre Arvis,4 Daniel Haverstock,5 Mila Trajanovic,6 Sanjay Sethi7 1Host Defence Unit, Royal Brompton Hospital, London, UK; 2University of Texas Health Science Center, South Texas Veterans Health Care System, San Antonio, TX, USA; 3Pneumology Department, Hospital Universitari Vall d’Hebron, CIBER de Enfermedades Respiratorias (CIBERES, Barcelona, Spain; 4Bayer HealthCare Pharmaceuticals, Loos, France; 5Bayer HealthCare Pharmaceuticals, Whippany, NJ, USA; 6Bayer HealthCare Pharmaceuticals, Toronto, ON, Canada; 7University at Buffalo, Buffalo, NY, USA Background: Acute exacerbations represent a significant burden for patients with moderate-to-severe chronic obstructive pulmonary disease. Each exacerbation episode is frequently associated with a lengthy recovery and impaired quality of life. Prognostic factors for outpatients that may predict poor outcome after treatment with antibiotics recommended in the guidelines, are not fully understood. We aimed to identify pretherapy factors predictive of clinical failure in elderly (≥60 years old outpatients with acute Anthonisen type 1 exacerbations.Trial registration: NCT00656747.Methods: Based on the moxifloxacin in AECOPDs (acute exacerbations of chronic obstructive pulmonary disease trial (MAESTRAL database, this study evaluated pretherapy demographic, clinical, sputum bacteriological factors using multivariate logistic regression analysis, with internal validation by bootstrap replicates, to investigate their possible association with clinical failure at end of therapy (EOT and 8 weeks posttherapy.Results: The analyses found that the independent factors predicting clinical failure at EOT were more frequent exacerbations, increased respiratory rate and lower body temperature at exacerbation, treatment with long-acting anticholinergic drugs, and in vitro bacterial resistance to study drug. The independent factors predicting poor outcome at 8

  16. Stability of the frequent COPD exacerbator in the general population

    DEFF Research Database (Denmark)

    Reilev, Mette; Lykkegaard, Jesper; Halling, Anders

    2017-01-01

    Exacerbation frequency is central in treatment strategies for chronic obstructive pulmonary disease. However, whether chronic obstructive pulmonary disease patients from the general population with frequent exacerbations continue to have frequent exacerbations over an extended period of time...... is currently unknown. In this study, we aimed to investigate the stability of the frequent exacerbator in a population-based setting. To this end, we conducted a nationwide register-based descriptive study with a 10-year follow-up period of chronic obstructive pulmonary disease patients with at least one...... medically treated exacerbation in 2003. Each subsequent year, we divided the population into frequent, infrequent and non-exacerbators and quantified the flow between categories. Further, we estimated the percentage of frequent exacerbators at baseline who stayed in this category each year during a 5-year...

  17. The suppression of innate immune response by human rhinovirus C.

    Science.gov (United States)

    Pang, Li-Li; Yuan, Xin-Hui; Shao, Chang-Sheng; Li, Mao-Zhong; Wang, Ying; Wang, Hui-Min; Xie, Guang-Cheng; Xie, Zhi-Ping; Yuan, Yue; Zhou, Dong-Mei; Sun, Xiao-Man; Zhang, Qing; Xin, Yan; Li, Dan-di; Duan, Zhao-Jun

    2017-08-12

    Rhinovirus C (RV-C), a newly identified group of human rhinoviruses (RVs), is associated with exacerbation of severe asthma. The type I interferon (IFN) response induced by this virus and the mechanisms of evasion of IFN-mediated innate immunity for RV-C remain unclear. In this study, we constructed a full-length cDNA clone of RV-C (LZ651) from a clinical sample. IFN-β mRNA and protein levels were not elevated in differentiated Human bronchial epithelial (HBE) cells at the air-liquid interface infected with RV-C, except in the early stage of infection. The ability to attenuate IFN-β activation was ascribed to 3C(pro) of RV-C, and the 40-His site of 3C(pro) played an important role. Furthermore, RIG-I was degraded by 3C(pro) in a caspase-dependent manner and 3C(pro) cleaved MAVS at 148 Q/A, which inhibited IFN signaling. Taken together, our results demonstrate the mechanism by which RV-C circumvents the production of type I IFN in infected cells. Copyright © 2017. Published by Elsevier Inc.

  18. Insect antiviral innate immunity: pathways, effectors, and connections.

    Science.gov (United States)

    Kingsolver, Megan B; Huang, Zhijing; Hardy, Richard W

    2013-12-13

    Insects are infected by a wide array of viruses some of which are insect restricted and pathogenic, and some of which are transmitted by biting insects to vertebrates. The medical and economic importance of these viruses heightens the need to understand the interaction between the infecting pathogen and the insect immune system in order to develop transmission interventions. The interaction of the virus with the insect host innate immune system plays a critical role in the outcome of infection. The major mechanism of antiviral defense is the small, interfering RNA pathway that responds through the detection of virus-derived double-stranded RNA to suppress virus replication. However, other innate antimicrobial pathways such as Imd, Toll, and Jak-STAT and the autophagy pathway have also been shown to play important roles in antiviral immunity. In this review, we provide an overview of the current understanding of the main insect antiviral pathways and examine recent findings that further our understanding of the roles of these pathways in facilitating a systemic and specific response to infecting viruses. © 2013.

  19. Nipah and hendra virus interactions with the innate immune system.

    Science.gov (United States)

    Basler, Christopher F

    2012-01-01

    Nipah virus and Hendra virus are related, highly pathogenic paramyxoviruses with unusually broad host ranges. Henipaviruses encode several proteins that block innate immune responses, and these are likely to serve as virulence factors. Specfically, four virus-encoded proteins, the phosphoprotein (P), the V protein, the W protein, and the C protein have each been demonstrated to counteract aspects of the interferon (IFN)-α/β response, a key component of the innate immune response to virus infection. The available data indicate that V and W can inhibit the production of IFNα/β in response to various stimuli, while the P, V, and W proteins also block the ability of IFNs to signal and induce an antiviral state in cells. The C protein also inhibits the antiviral effects of IFNα/β by a poorly characterized mechanism. Reverse genetics systems, which allow the generation of recombinant viruses bearing specific mutations, have demonstrated the importance of the viral IFN-antagonists for replication. With these systems in hand, the field is now poised to define how specific viral IFN-antagonist functions influence viral pathogenesis.

  20. Review: Gp-340/DMBT1 in mucosal innate immunity.

    Science.gov (United States)

    Madsen, Jens; Mollenhauer, Jan; Holmskov, Uffe

    2010-06-01

    Deleted in Malignant Brain Tumour 1 (DMBT1) is a gene that encodes alternatively spliced proteins involved in mucosal innate immunity. It also encodes a glycoprotein with a molecular mass of 340 kDa, and is referred to as gp-340 (DMBT1(gp340)) and salivary agglutinin (DMBT1(SAG)). DMBT1(gp340) is secreted into broncho-alveolar surface lining fluid whereas DMBT(SAG) is present in the saliva. The two molecules were shown to be identical and both interact with and agglutinate several Gram-negative and Gram-positive bacteria including Streptococcus mutans, a bacterium responsible for caries in the oral cavity. DMBT1(gp340) interacts with surfactant proteins A and D (SP-D). DMBT1(gp340) and SP-D can individually and together interact and agglutinate influenza A virus. DMBT1(gp340) also binds to HIV-1 and facilitates transcytosis of the virus into epithelial cells. DMBT1 binds to a variety of other host proteins, including serum and secretory IgA, C1q, lactoferrin, MUC5B and trefoil factor 2 (TFF2), all molecules with involvement in innate immunity and/or wound-healing processes. Recent generation of Dmbt1-deficient mice has provided the research field of DMBT1 with a model that allows research to progress from in vitro studies to in vivo functional studies of the multifunctional proteins encoded by the DMBT1 gene.

  1. Xenobiotic Receptor-Mediated Regulation of Intestinal Barrier Function and Innate Immunity

    Directory of Open Access Journals (Sweden)

    Harmit S. Ranhotra

    2016-07-01

    Full Text Available The molecular basis for the regulation of the intestinal barrier is a very fertile research area. A growing body of knowledge supports the targeting of various components of intestinal barrier function as means to treat a variety of diseases, including the inflammatory bowel diseases. Herein, we will summarize the current state of knowledge of key xenobiotic receptor regulators of barrier function, highlighting recent advances, such that the field and its future are succinctly reviewed. We posit that these receptors confer an additional dimension of host-microbe interaction in the gut, by sensing and responding to metabolites released from the symbiotic microbiota, in innate immunity and also in host drug metabolism. The scientific evidence for involvement of the receptors and its molecular basis for the control of barrier function and innate immunity regulation would serve as a rationale towards development of non-toxic probes and ligands as drugs.

  2. Co-ordinating innate and adaptive immunity to viral infection: mobility is the key

    DEFF Research Database (Denmark)

    Wern, Jeanette Erbo; Thomsen, Allan Randrup

    2009-01-01

    The host counters a viral infection through a complex response made up of components belonging to both the innate and the adaptive immune system. In this report, we review the mechanisms underlying this response, how it is induced and how it is co-ordinated. As cell-cell communication represents......-ordinated recruitment of different cell types intended to work in concert, cellular co-operation is optimized particularly under conditions that may involve rare cells. Consequently, a major focus is placed on presenting an overview of the co-operative events and the associated cell migration, which is essential...... in mounting an efficient host response and co-ordinating innate and adaptive immunity during a primary viral infection....

  3. Innate Defense against Influenza A Virus: Activity of Human Neutrophil Defensins and Interactions of Defensins with Surfactant Protein D

    DEFF Research Database (Denmark)

    Hartshorn, Kevan L.; White, Mitchell R.; Tecle, Tesfaldet

    2006-01-01

    Surfactant protein D (SP-D) plays important roles in innate host defense against influenza A virus (IAV) infection, in part by modifying interactions with neutrophils. Human neutrophil defensins (HNPs) inhibit infectivity of enveloped viruses, including IAV. Our goal in this study...

  4. Long-term olive oil-based parenteral nutrition sustains innate immune function in home patients without active underlying disease

    NARCIS (Netherlands)

    Olthof, E.D.; Roelofs, H.M.J.; Versleijen, M.W.J.; Morsche, R.H.M. te; Simonetti, E.R.; Hermans, P.W.M.; Wanten, G.J.A.

    2013-01-01

    BACKGROUND & AIMS: It remains unclear whether impaired host defenses contribute to the increased risk for infectious complications seen in patients on home parenteral nutrition (HPN). The aim of this study was to compare the innate immune function of patients on olive oil-based HPN with that of

  5. Colonization and effector functions of innate lymphoid cells in mucosal tissues

    Science.gov (United States)

    Kim, Myunghoo; Kim, Chang H.

    2016-01-01

    Innate lymphoid cells (ILCs) protect mucosal barrier tissues to fight infection and maintain tissue integrity. ILCs and their progenitors are developmentally programmed to migrate, differentiate and populate various mucosal tissues and associated lymphoid tissues. Functionally mature ILC subsets respond to diverse pathogens such as bacteria, viruses, fungi and parasites in subset-specific manners. In this review, we will discuss how ILCs populate mucosal tissues and regulate immune responses to distinct pathogens to protect the host and maintain tissue integrity. PMID:27365193

  6. The Role of Hyaluronan in Innate Defense Responses of the Intestine

    Directory of Open Access Journals (Sweden)

    Carol A. de la Motte

    2015-01-01

    Full Text Available Hyaluronan is an abundant extracellular matrix component prevalent in the vertebrate intestinal tract. Here we discuss what is known about hyaluronan distribution during homeostasis and inflammatory diseases of the gut and discuss ways in which this glycosaminoglycan can participate in regulating innate host defense mechanisms. These natural responses include mechanisms promoting rapid leukocyte recruitment after bacterial challenge/colon tissue damage as well as promoting epithelial defense mechanisms in the intestine.

  7. Nasal Acai Polysaccharides Potentiate Innate Immunity to Protect against Pulmonary Francisella tularensis and Burkholderia pseudomallei Infections

    OpenAIRE

    Skyberg, Jerod A.; Rollins, MaryClare F.; Holderness, Jeff S.; Marlenee, Nicole L.; Schepetkin, Igor A.; Goodyear, Andrew; Dow, Steven W.; Jutila, Mark A.; Pascual, David W.

    2012-01-01

    Pulmonary Francisella tularensis and Burkholderia pseudomallei infections are highly lethal in untreated patients, and current antibiotic regimens are not always effective. Activating the innate immune system provides an alternative means of treating infection and can also complement antibiotic therapies. Several natural agonists were screened for their ability to enhance host resistance to infection, and polysaccharides derived from the Acai berry (Acai PS) were found to have potent abilitie...

  8. Role of microbiota and innate immunity in recurrent Clostridium difficile infection.

    Science.gov (United States)

    Bibbò, Stefano; Lopetuso, Loris Riccardo; Ianiro, Gianluca; Di Rienzo, Teresa; Gasbarrini, Antonio; Cammarota, Giovanni

    2014-01-01

    Recurrent Clostridium difficile infection represents a burdensome clinical issue whose epidemiology is increasing worldwide. The pathogenesis is not yet completely known. Recent observations suggest that the alteration of the intestinal microbiota and impaired innate immunity may play a leading role in the development of recurrent infection. Various factors can cause dysbiosis. The causes most involved in the process are antibiotics, NSAIDs, acid suppressing therapies, and age. Gut microbiota impairment can favor Clostridium difficile infection through several mechanisms, such as the alteration of fermentative metabolism (especially SCFAs), the alteration of bile acid metabolism, and the imbalance of antimicrobial substances production. These factors alter the intestinal homeostasis promoting the development of an ecological niche for Clostridium difficile and of the modulation of immune response. Moreover, the intestinal dysbiosis can promote a proinflammatory environment, whereas Clostridium difficile itself modulates the innate immunity through both toxin-dependent and toxin-independent mechanisms. In this narrative review, we discuss how the intestinal microbiota modifications and the modulation of innate immune response can lead to and exacerbate Clostridium difficile infection.

  9. Innate lymphoid cells: the role in respiratory infections and lung tissue damage.

    Science.gov (United States)

    Głobińska, Anna; Kowalski, Marek L

    2017-10-01

    Innate lymphoid cells (ILCs) represent a diverse family of cells of the innate immune system, which play an important role in regulation of tissue homeostasis, immunity and inflammation. Emerging evidence has highlighted the importance of ILCs in both protective immunity to respiratory infections and their pathological roles in the lungs. Therefore, the aim of this review is to summarize the current knowledge, interpret and integrate it into broader perspective, enabling greater insight into the role of ILCs in respiratory diseases. Areas covered: In this review we highlighted the role of ILCs in the lungs, citing the most recent studies in this area. PubMed searches (2004- July 2017) were conducted using the term 'innate lymphoid cells respiratory viral infections' in combination with other relevant terms including various respiratory viruses. Expert commentary: Since studies of ILCs have opened new areas of investigation, understanding the role of ILCs in respiratory infections may help to clarify the mechanisms underlying viral-induced exacerbations of lung diseases, providing the basis for novel therapeutic strategies. Potential therapeutic targets have already been identified. So far, the most promising strategy is cytokine-targeting, although further clinical trials are needed to verify its effectiveness.

  10. Vitally important - does early innate immunity predict recruitment and adult innate immunity?

    Science.gov (United States)

    Vermeulen, Anke; Müller, Wendt; Eens, Marcel

    2016-03-01

    The immune system is one of the most important adaptations that has evolved to protect animals from a wide range of pathogens they encounter from early life onwards. During the early developmental period this is particularly true for the innate immunity, as other components of the immune system are, as yet, poorly developed. But innate immunity may not only be crucial for early life survival, but may also have long-lasting effects, for example if early life immunity reflects the functioning of the immune system as a whole. For this reason, we investigated the importance of four constitutive innate immune parameters (natural antibodies, complement activity, concentrations of haptoglobin, and concentrations of nitric oxide) for recruitment in free-living great tits. We compared nestling immunity of recruits with nestling immunity of their nonrecruited siblings. We also investigated within individual consistency of these innate immune parameters for those individuals that recruited, which may be taken as a measure of immune capacity. In accordance with previous studies, we found a clear effect of tarsus length and a trend for body mass on the likelihood to recruit. Nevertheless, we found no evidence that higher levels of constitutive innate immunity as a nestling facilitated local recruitment. Furthermore, individual innate immunity was not consistent across life stages, that is to say, nestling immune parameters did not determine, or respectively, reflect adult innate immune parameters. This plasticity in innate immune components may explain why we did not find long-lasting survival benefits.

  11. Divergent Roles of Interferon-γ and Innate Lymphoid Cells in Innate and Adaptive Immune Cell-Mediated Intestinal Inflammation.

    Science.gov (United States)

    Brasseit, Jennifer; Kwong Chung, Cheong K C; Noti, Mario; Zysset, Daniel; Hoheisel-Dickgreber, Nina; Genitsch, Vera; Corazza, Nadia; Mueller, Christoph

    2018-01-01

    Aberrant interferon gamma (IFNγ) expression is associated with the pathogenesis of numerous autoimmune- and inflammatory disorders, including inflammatory bowel diseases (IBD). However, the requirement of IFNγ for the pathogenesis of chronic intestinal inflammation remains controversial. The aim of this study was thus to investigate the role of IFNγ in experimental mouse models of innate and adaptive immune cell-mediated intestinal inflammation using genetically and microbiota-stabilized hosts. While we find that IFNγ drives acute intestinal inflammation in the anti-CD40 colitis model in an innate lymphoid cell (ILC)-dependent manner, IFNγ secreted by both transferred CD4 T cells and/or cells of the lymphopenic Rag1 -/- recipient mice was dispensable for CD4 T cell-mediated colitis. In the absence of IFNγ, intestinal inflammation in CD4 T cell recipient mice was associated with enhanced IL17 responses; consequently, targeting IL17 signaling in IFNγ-deficient mice reduced T cell-mediated colitis. Intriguingly, in contrast to the anti-CD40 model of colitis, depletion of ILC in the Rag1 -/- recipients of colitogenic CD4 T cells did not prevent induction of colonic inflammation. Together, our findings demonstrate that IFNγ represents an essential, or a redundant, pro-inflammatory cytokine for the induction of intestinal inflammation, depending on the experimental mouse model used and on the nature of the critical disease inducing immune cell populations involved.

  12. Role of heat shock protein 70 in innate alloimmunity

    Directory of Open Access Journals (Sweden)

    Walter G. eLand

    2012-01-01

    Full Text Available This article briefly describes our own experience with the proven demonstration of heat shock protein 70 in reperfused renal allografts from brain-deaddonors and reflects about its potential role as a typical damage-associated molecular pattern (DAMP in the setting of innate alloimmunity. In fact, our group was able to demonstrate a dramatic up-regulation of heat shock protein 70 expression after postischemic reperfusion of renal allografts. Of note, up-regulation of this stress protein expression, although to a lesser extent, was already observed after cold storage of the organ indicating that this molecule is already induced in the stressed organism of a brain-dead donor. However, whether or not the dramatic up-regulation of heat shock protein 70 expression contributes to mounting an innate alloimmune response cannot be judged in view of these clinical findings.Nevertheless, heat shock protein 70, since generated in association with postischemic reperfusion-induced allograft injury, can be called a typical DAMP - as can everymolecule be termed a DAMP that is generated in associationwith any stressful tissue injury regardless of its final positive or negative regulatory function within the innate immune response elicited by it.In fact, as we discuss in this article, the context-dependent, even contradistinctive activities of heat shock protein 70 reflect the biological phenomenon that, throughout evolution, mammals have developed an elaborate network of positive and negative regulatory mechanisms, which provide balance between defensive and protective measures against unwarranted destruction of the host. In this sense, up-regulated expression of heat shock protein 70 in an injured allograft might reflect a pure protective response against the severe oxidative injury of a reperfused donor organ. On the other hand, up-regulated expression of this stress protein in an injured allograft might reflect a(futile attempt of the innate immune system to

  13. Dynamics of innate immunity are key to chronic immune activation in AIDS.

    Science.gov (United States)

    Benecke, Arndt; Gale, Michael; Katze, Michael G

    2012-01-01

    We propose here that the dynamics rather than the structure of cellular and viral networks play a determining role in chronic immune activation of HIV-infected individuals. A number of novel avenues of experimental analysis and modeling strategies are discussed to conclusively address these network dynamics in the future. Recent insights into the molecular dynamics of immune activation and its control following simian immunodeficiency virus (SIV) infection in natural host primates has provided possible alternate interpretations of SIV and HIV pathogenesis. Concomitant with insights gained in other host-pathogen systems, as well as an increased understanding of innate immune activation mechanisms, these observations lead to a new model for the timing of innate HIV immune responses and a possible primordial role of this timing in programming chronic immune activation. Chronic immune activation is today considered the leading cause of AIDS in HIV-infected individuals. Systems biology has recently lent arguments for considering chronic immune activation a result of untimely innate immune responses by the host to the infection. Future strategies for the analysis, comprehension, and incorporation of the dynamic component of immune activation into HIV vaccination strategies are discussed.

  14. The role of rare innate immune cells in Type 2 immune activation against parasitic helminths.

    Science.gov (United States)

    Webb, Lauren M; Tait Wojno, Elia D

    2017-09-01

    The complexity of helminth macroparasites is reflected in the intricate network of host cell types that participate in the Type 2 immune response needed to battle these organisms. In this context, adaptive T helper 2 cells and the Type 2 cytokines interleukin (IL)-4, IL-5, IL-9 and IL-13 have been the focus of research for years, but recent work has demonstrated that the innate immune system plays an essential role. Some innate immune cells that promote Type 2 immunity are relatively abundant, such as macrophages and eosinophils. However, we now appreciate that more rare cell types including group 2 innate lymphoid cells, basophils, mast cells and dendritic cells make significant contributions to these responses. These cells are found at low frequency but they are specialized to their roles - located at sites such as the skin, lung and gut, where the host combats helminth parasites. These cells respond rapidly and robustly to worm antigens and worm-induced damage to produce essential cytokines, chemokines, eicosanoids and histamine to activate damaged epithelium and to recruit other effectors. Thus, a greater understanding of how these cells operate is essential to understand how the host protects itself during helminth infection.

  15. Molecular Mechanisms of Innate Immune Inhibition by Non-Segmented Negative-Sense RNA Viruses

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Srirupa; Basler, Christopher F.; Amarasinghe, Gaya K.; Leung, Daisy W.

    2016-08-01

    The host innate immune system serves as the first line of defense against viral infections. Germline-encoded pattern recognition receptors detect molecular patterns associated with pathogens and activate innate immune responses. Of particular relevance to viral infections are those pattern recognition receptors that activate type I interferon responses, which establish an antiviral state. The order Mononegavirales is composed of viruses that possess single-stranded, non-segmented negative-sense (NNS) RNA genomes and are important human pathogens that consistently antagonize signaling related to type I interferon responses. NNS viruses have limited encoding capacity compared to many DNA viruses, and as a likely consequence, most open reading frames encode multifunctional viral proteins that interact with host factors in order to evade host cell defenses while promoting viral replication. In this review, we will discuss the molecular mechanisms of innate immune evasion by select NNS viruses. A greater understanding of these interactions will be critical in facilitating the development of effective therapeutics and viral countermeasures.

  16. UVRAG Deficiency Exacerbates Doxorubicin-Induced Cardiotoxicity

    Science.gov (United States)

    An, Lin; Hu, Xiao-wen; Zhang, Shasha; Hu, Xiaowen; Song, Zongpei; Naz, Amber; Zi, Zhenguo; Wu, Jian; Li, Can; Zou, Yunzeng; He, Lin; Zhu, Hongxin

    2017-01-01

    Doxorubicin (DOX) is an effective chemotherapeutic drug in the treatment of various types of cancers. However, its clinical application has been largely limited by potential development of cardiotoxicity. Previously we have shown that ultra-violet radiation resistance-associated gene (UVRAG), an autophagy-related protein, is essential for the maintenance of autophagic flux in the heart under physiological conditions. Here, we sought to determine the role of UVRAG-mediated autophagy in DOX-induced cardiotoxicity. Mouse models of acute or chronic DOX-induced cardiotoxicity were established. UVRAG deficiency exacerbated DOX-induced mortality and cardiotoxicity manifested by increased cytoplasmic vacuolization, enhanced collagen accumulation, elevated serum activities of lactate dehydrogenase and myocardial muscle creatine kinase, higher ROS levels, aggravated apoptosis and more depressed cardiac function. Autophagic flux was impaired in DOX-induced cardiotoxicity. UVRAG deficiency aggravated impaired autophagic flux in DOX-induced cardiotoxicity. Intermittent fasting restored autophagy and ameliorated pathological alterations of DOX-induced cardiotoxicity. Collectively, our data suggest that UVRAG deficiency exacerbates DOX-induced cardiotoxicity, at least in part, through aggravation of DOX-induced impaired autophagic flux. Intermittent fasting, which restores blunted autophagic flux and ameliorates pathology in the mouse models of DOX-induced cardiotoxicity, may be used as a potential preventive or therapeutic approach for DOX cardiotoxicity. PMID:28225086

  17. Neonatal innate immunity in allergy development.

    Science.gov (United States)

    Belderbos, Mirjam; Levy, Ofer; Bont, Louis

    2009-12-01

    The neonate is born with a distinct immune system that is biased against the production of T-helper cell 1 (Th1) cytokines. Birth imposes a great challenge on the neonatal immune system, which is confronted with an outside world rich in foreign antigens. Exposure to these antigens shapes the developing neonatal immune system. Inducing Th-1 or Th-2 polarized responses that may extend beyond the neonatal age and counteract or promote allergic sensitization. This review describes how engagement of the innate immune system might contribute to the development of allergy in children. The exact role of innate immune stimulation in the development of allergies is a controversial area. Epidemiological literature suggests that microbial exposure in early childhood protects against the development of allergies, whereas a large amount of experimental data demonstrates that innate immune stimulation enhances Th2 responses upon primary and secondary antigen exposure. Dose, site and timing of allergen exposure are likely to modulate the innate immune response, polarizing the maturing neonatal immune system towards Th1 or Th2-type responses, thereby protecting from or predisposing to asthma and allergies. Modulation of neonatal innate immune responses may be a novel approach to prevent asthma and allergies.

  18. Innate Immunity and BK Virus: Prospective Strategies.

    Science.gov (United States)

    Kariminik, Ashraf; Yaghobi, Ramin; Dabiri, Shahriar

    2016-03-01

    Recent information demonstrated that BK virus reactivation is a dominant complication after kidney transplantation, which occurs because of immunosuppression. BK virus reactivation is the main reason of transplanted kidney losing. Immune response against BK virus is the major inhibitor of the virus reactivation. Therefore, improving our knowledge regarding the main parameters that fight against BK viruses can shed light on to direct new treatment strategies to suppress BK infection. Innate immunity consists of numerous cell systems and also soluble molecules, which not only suppress virus replication, but also activate adaptive immunity to eradicate the infection. Additionally, it appears that immune responses against reactivated BK virus are the main reasons for induction of BK virus-associated nephropathy (BKAN). Thus, improving our knowledge regarding the parameters and detailed mechanisms of innate immunity and also the status of innate immunity of the patients with BK virus reactivation and its complications can introduce new prospective strategies to either prevent or as therapy of the complication. Therefore, this review was aimed to collate the most recent data regarding the roles played by innate immunity against BK virus and also the status of innate immunity in the patients with reactivation BK virus and BKAN.

  19. Expression of innate immune genes, proteins and microRNAs in lung tissue of pigs infected experimentally with influenza virus (H1N2)

    DEFF Research Database (Denmark)

    Skovgaard, Kerstin; Cirera, Susanna; Vasby, Ditte

    2013-01-01

    This study aimed at providing a better understanding of the involvement of innate immune factors, including miRNA, in the local host response to influenza virus infection. Twenty pigs were challenged by influenza A virus subtype H1N2. Expression of microRNA (miRNA), mRNA and proteins were...... results suggest that, in addition to a wide range of innate immune factors, miRNAs may also be involved in controlling acute influenza infection in pigs....

  20. Innate Immune Activation and Subversion of Mammalian Functions by Leishmania Lipophosphoglycan

    Directory of Open Access Journals (Sweden)

    Luis H. Franco

    2012-01-01

    Full Text Available Leishmania promastigotes express several prominent glycoconjugates, either secreted or anchored to the parasite surface. Of these lipophosphoglycan (LPG is the most abundant, and along with other phosphoglycan-bearing molecules, plays important roles in parasite infectivity and pathogenesis in both the sand fly and the mammalian host. Besides its contribution for parasite survival in the sand fly vector, LPG is important for modulation the host immune responses to favor the establishment of mammalian infection. This review will summarize the current knowledge regarding the role of LPG in Leishmania infectivity, focusing on the interaction of LPG and innate immune cells and in the subversion of mammalian functions by this molecule.

  1. The Genetics of Urinary Tract Infections and the Innate Defense of the Kidney and Urinary tract

    Science.gov (United States)

    Ambite, Ines; Rydstrom, Gustav; Schwaderer, Andrew L.; Hains, David S.

    2015-01-01

    The urinary tract is a sterile organ system. Urinary tract infections (UTIs) are common and often serious infections. Research has focused on uropathogen, environment, and host factors leading to UTI pathogenesis. A growing body of evidence exists implicating genetic factors that can contribute to UTI risks. In this review, we highlight genetic variations in aspects of the innate immune system critical to the host response to uropathogens. This overview includes genetic variations in pattern recognition receptor molecules, chemokines/cytokines, and neutrophil activation. We also comprehensively cover murine knockout models of UTI, genetic variations involved in renal scarring as a result of ascending UTIs, and asymptomatic bacteriuria. PMID:27617139

  2. Innate B cells: oxymoron or validated concept? [v1; ref status: indexed, http://f1000r.es/T4CAVP

    Directory of Open Access Journals (Sweden)

    Carl F Ware

    2012-08-01

    Full Text Available B lymphocytes promote the initial innate interferon response to viral pathogens without the need for antigen receptor activation. B cell dependent IFN production requires the cytokine, lymphotoxin-β. The LTβ pathway is well known to regulate lymphoid organogenesis and homeostasis by differentiating stromal cells and macrophages. However, in response to viral pathogens these same B cell-regulated populations rapidly produce type 1 interferons. Thus, B cells act as innate effector cells via LTβ homeostatic pathways, which serve as innate host barriers to viral pathogens.

  3. Thioredoxin-1 protects against neutrophilic inflammation and emphysema progression in a mouse model of chronic obstructive pulmonary disease exacerbation.

    Science.gov (United States)

    Tanabe, Naoya; Hoshino, Yuma; Marumo, Satoshi; Kiyokawa, Hirofumi; Sato, Susumu; Kinose, Daisuke; Uno, Kazuko; Muro, Shigeo; Hirai, Toyohiro; Yodoi, Junji; Mishima, Michiaki

    2013-01-01

    Exacerbations of chronic obstructive pulmonary disease (COPD) are characterized by acute enhancement of airway neutrophilic inflammation under oxidative stress and can be involved in emphysema progression. However, pharmacotherapy against the neutrophilic inflammation and emphysema progression associated with exacerbation has not been established. Thioredoxin-1 has anti-oxidative and anti-inflammatory properties and it can ameliorate neutrophilic inflammation through anti-chemotactic effects and prevent cigarette smoke (CS)-induced emphysema. We aimed to determine whether thioredoxin-1 can suppress neutrophilic inflammation and emphysema progression in a mouse model of COPD exacerbation and if so, to reveal the underlying mechanisms. Mice were exposed to CS and then challenged with polyinosine-polycytidylic acid [poly(I:C)], an agonist for virus-induced innate immunity. Airway neutrophilic inflammation, oxidative stress and lung apoptosis were enhanced in smoke-sensitive C57Bl/6, but not in smoke-resistant NZW mice. Exposure to CS and poly(I:C) challenge accelerated emphysema progression in C57Bl/6 mice. Thioredoxin-1 suppressed neutrophilic inflammation and emphysema progression. Poly(I:C) caused early neutrophilic inflammation through keratinocyte-derived chemokine and granulocyte-macrophage colony-stimulating factor (GM-CSF) release in the lung exposed to CS. Late neutrophilic inflammation was caused by persistent GM-CSF release, which thioredoxin-1 ameliorated. Thioredoxin-1 enhanced pulmonary mRNA expression of MAP kinase phosphatase 1 (MKP-1), and the suppressive effects of thioredoxin-1 on prolonged GM-CSF release and late neutrophilic inflammation disappeared by inhibiting MKP-1. Using a mouse model of COPD exacerbation, we demonstrated that thioredoxin-1 ameliorated neutrophilic inflammation by suppressing GM-CSF release, which prevented emphysema progression. Our findings deepen understanding of the mechanisms underlying the regulation of neutrophilic

  4. Thioredoxin-1 protects against neutrophilic inflammation and emphysema progression in a mouse model of chronic obstructive pulmonary disease exacerbation.

    Directory of Open Access Journals (Sweden)

    Naoya Tanabe

    Full Text Available BACKGROUND: Exacerbations of chronic obstructive pulmonary disease (COPD are characterized by acute enhancement of airway neutrophilic inflammation under oxidative stress and can be involved in emphysema progression. However, pharmacotherapy against the neutrophilic inflammation and emphysema progression associated with exacerbation has not been established. Thioredoxin-1 has anti-oxidative and anti-inflammatory properties and it can ameliorate neutrophilic inflammation through anti-chemotactic effects and prevent cigarette smoke (CS-induced emphysema. We aimed to determine whether thioredoxin-1 can suppress neutrophilic inflammation and emphysema progression in a mouse model of COPD exacerbation and if so, to reveal the underlying mechanisms. RESULTS: Mice were exposed to CS and then challenged with polyinosine-polycytidylic acid [poly(I:C], an agonist for virus-induced innate immunity. Airway neutrophilic inflammation, oxidative stress and lung apoptosis were enhanced in smoke-sensitive C57Bl/6, but not in smoke-resistant NZW mice. Exposure to CS and poly(I:C challenge accelerated emphysema progression in C57Bl/6 mice. Thioredoxin-1 suppressed neutrophilic inflammation and emphysema progression. Poly(I:C caused early neutrophilic inflammation through keratinocyte-derived chemokine and granulocyte-macrophage colony-stimulating factor (GM-CSF release in the lung exposed to CS. Late neutrophilic inflammation was caused by persistent GM-CSF release, which thioredoxin-1 ameliorated. Thioredoxin-1 enhanced pulmonary mRNA expression of MAP kinase phosphatase 1 (MKP-1, and the suppressive effects of thioredoxin-1 on prolonged GM-CSF release and late neutrophilic inflammation disappeared by inhibiting MKP-1. CONCLUSION: Using a mouse model of COPD exacerbation, we demonstrated that thioredoxin-1 ameliorated neutrophilic inflammation by suppressing GM-CSF release, which prevented emphysema progression. Our findings deepen understanding of the mechanisms

  5. HERP Binds TBK1 To Activate Innate Immunity and Repress Virus Replication in Response to Endoplasmic Reticulum Stress.

    Science.gov (United States)

    Ge, Maolin; Luo, Zhen; Qiao, Zhi; Zhou, Yao; Cheng, Xin; Geng, Qibin; Cai, Yanyan; Wan, Pin; Xiong, Ying; Liu, Fang; Wu, Kailang; Liu, Yingle; Wu, Jianguo

    2017-11-01

    Host innate immunity is crucial for cellular responses against viral infection sensed by distinct pattern recognition receptors and endoplasmic reticulum (ER) stress. Enterovirus 71 (EV71) is a causative agent of hand, foot, and mouth disease and neurological diseases. However, the exact mechanism underlying the link between ER stress induced by EV71 infection and host innate immunity is largely unknown. In this study, we demonstrated that EV71 infection induces the homocysteine-induced ER protein (HERP), a modulator of the ER stress response which is dependent on the participation of MAVS. Virus-induced HERP subsequently stimulates host innate immunity to repress viral replication by promoting type-I IFNs (IFN-α and IFN-β) and type-III IFN (IFN-λ1) expression. Through interacting with TANK-binding kinase 1, HERP amplifies the MAVS signaling and facilitates the phosphorylation and nuclear translocation of IFN regulatory factor 3 and NF-κB to enhance the expression of IFNs, which leads to a broad inhibition of the replication of RNA viruses, including EV71, Sendai virus, influenza A virus, and vesicular stomatitis virus. Therefore, we demonstrated that HERP plays an important role in the regulation of host innate immunity in response to ER stress during the infection of RNA viruses. These findings provide new insights into the mechanism underlying the replication of RNA viruses and the production of IFNs, and also demonstrate a new role of HERP in the regulation of host innate immunity in response to viral infection. Copyright © 2017 by The American Association of Immunologists, Inc.

  6. Stimulator of Interferon Genes Deficiency in Acute Exacerbation of Idiopathic Pulmonary Fibrosis

    Directory of Open Access Journals (Sweden)

    Hui Qiu

    2017-12-01

    Full Text Available The stimulator of interferon genes (STING is a key adaptor protein mediating innate immune defense against DNA viruses. To investigate the role of STING in acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF, we isolated primary peripheral blood mononuclear cells (PBMCs from patients and healthy controls (HCs. Raw264.7 and A549 cells were infected with herpes simplex virus type 1 (HSV-1. Mice with bleomycin-induced lung fibrosis were infected with HSV-1 to stimulate acute exacerbation of the lung fibrosis. Global gene expression profiling revealed a substantial downregulation of interferon-regulated genes (downstream of STING in the AE-IPF group compared with the HC and stable IPF groups. The PBMCs of the AE-IPF group showed significantly reduced STING protein levels, increased levels of endoplasmic reticulum (ER stress markers, and elevated apoptosis. HSV-1 infection decreased STING expression and stimulated the ER stress pathways in Raw264.7 and A549 cells in a time- and dose-dependent manner. HSV-1 infection exacerbated the bleomycin-induced lung injury in mice. In the primary bone marrow-derived macrophages of mice treated with bleomycin and HSV-1, STING protein expression was substantially reduced; ER stress was stimulated. Tauroursodeoxycholic acid, a known inhibitor of ER stress, partially reversed those HSV-1-mediated adverse effects in mice with bleomycin-induced lung injury. STING levels in PBMCs increased after treatment in patients showing improvement but remained at low levels in patients with deterioration. Viral infection may trigger ER stress, resulting in STING deficiency and AE-IPF onset.

  7. Characterization of the effect of Cr(VI) on humoral innate immunity using Drosophila melanogaster.

    Science.gov (United States)

    Pragya, P; Shukla, A K; Murthy, R C; Abdin, M Z; Kar Chowdhuri, D

    2015-11-01

    With the advancement of human race, different anthropogenic activities have heaped the environment with chemicals that can cause alteration in the immune system of exposed organism. As a first line of barrier, the evolutionary conserved innate immunity is crucial for the health of an organism. However, there is paucity of information regarding in vivo assessment of the effect of environmental chemicals on innate immunity. Therefore, we examined the effect of a widely used environmental chemical, Cr(VI), on humoral innate immune response using Drosophila melanogaster. The adverse effect of Cr(VI) on host humoral response was characterized by decreased gene expression of antimicrobial peptides (AMPs) in the exposed organism. Concurrently, a significantly decreased transcription of humoral pathway receptors (Toll and PGRP) and triglyceride level along with inhibition of antioxidant enzyme activities were observed in exposed organism. This in turn weakened the immune response of exposed organism that was manifested by their reduced resistance against bacterial infection. In addition, overexpression of the components of humoral immunity particularly Diptericin benefits Drosophila from Cr(VI)-induced humoral immune-suppressive effect. To our knowledge, this is the first report regarding negative impact of an environmental chemical on humoral innate immune response of Drosophila along with subsequent protection by AMPs, which may provide novel insight into host-chemical interactions. Also, our data validate the utility and sensitivity of Drosophila as a model that could be used for screening the possible risk of environmental chemicals on innate immunity with minimum ethical concern that can be further extrapolated to higher organisms. © 2014 Wiley Periodicals, Inc.

  8. Obligate brood parasites show more functionally effective innate immune responses: an eco-immunological hypothesis

    Science.gov (United States)

    Hahn, D. Caldwell; Summers, Scott G.; Genovese, Kenneth J.; He, Haiqi; Kogut, Michael H.

    2013-01-01

    Immune adaptations of obligate brood parasites attracted interest when three New World cowbird species (Passeriformes, Icteridae, genus Molothrus) proved unusually resistant to West Nile virus. We have used cowbirds as models to investigate the eco-immunological hypothesis that species in parasite-rich environments characteristically have enhanced immunity as a life history adaptation. As part of an ongoing program to understand the cowbird immune system, in this study we measured degranulation and oxidative burst, two fundamental responses of the innate immune system. Innate immunity provides non-specific, fast-acting defenses against a variety of invading pathogens, and we hypothesized that innate immunity experiences particularly strong selection in cowbirds, because their life history strategy exposes them to diverse novel and unpredictable parasites. We compared the relative effectiveness of degranulation and oxidative burst responses in two cowbird species and one related, non-parasitic species. Both innate immune defenses were significantly more functionally efficient in the two parasitic cowbird species than in the non-parasitic red-winged blackbird (Icteridae, Agelaius phoeniceus). Additionally, both immune defenses were more functionally efficient in the brown-headed cowbird (M. ater), an extreme host-generalist brood parasite, than in the bronzed cowbird (M. aeneus), a moderate host-specialist with lower exposure to other species and their parasites. Thus the relative effectiveness of these two innate immune responses corresponds to the diversity of parasites in the niche of each species and to their relative resistance to WNV. This study is the first use of these two specialized assays in a comparative immunology study of wild avian species.

  9. Innate immunity in lophotrochozoans: the annelids.

    Science.gov (United States)

    Salzet, Michel; Tasiemski, Aurélie; Cooper, Edwin

    2006-01-01

    Innate immunity plays a major role as a first defense against microbes. Effectors of the innate response include pattern recognition receptors (PRR), phagocytic cells, proteolytic cascades and peptides/proteins with antimicrobial properties. Each element of these events has been well studied in vertebrates and in some invertebrates such as annelids. From these different researches, it appears that mammalian innate immunity could be considered as a mosaic of invertebrate immune responses. Annelids belonging to the lophotrochozoans' group are primitive coelomates that possess specially developed cellular immunity against pathogens including phagocytosis, encapsulation and spontaneous cytotoxicity of coelomocytes against allogenic or xenogenic cells. They have also developed an important humoral immunity that is based on antimicrobial, hemolytic and clotting properties of their body fluid. In the present review, we will emphasize the different immunodefense strategies that adaptation has taken during the course of evolution of two classes of annelids i.e. oligochaetes and achaetes.

  10. The innate immune system in demyelinating disease.

    Science.gov (United States)

    Mayo, Lior; Quintana, Francisco J; Weiner, Howard L

    2012-07-01

    Demyelinating diseases such as multiple sclerosis are chronic inflammatory autoimmune diseases with a heterogeneous clinical presentation and course. Both the adaptive and the innate immune systems have been suggested to contribute to their pathogenesis and recovery. In this review, we discuss the role of the innate immune system in mediating demyelinating diseases. In particular, we provide an overview of the anti-inflammatory or pro-inflammatory functions of dendritic cells, mast cells, natural killer (NK) cells, NK-T cells, γδ T cells, microglial cells, and astrocytes. We emphasize the interaction of astroctyes with the immune system and how this interaction relates to the demyelinating pathologies. Given the pivotal role of the innate immune system, it is possible that targeting these cells may provide an effective therapeutic approach for demyelinating diseases. © 2012 John Wiley & Sons A/S.

  11. Vaccine Adjuvants: Putting Innate Immunity to Work

    Science.gov (United States)

    Coffman, Robert L.; Sher, Alan; Seder, Robert A.

    2012-01-01

    Adjuvants enhance immunity to vaccines and experimental antigens by a variety of mechanisms. In the past decade, many receptors and signaling pathways in the innate immune system have been defined and these innate responses strongly influence the adaptive immune response. The focus of this review is to delineate the innate mechanisms by which adjuvants mediate their effects. We highlight how adjuvants can be used to influence the magnitude and alter the quality of the adaptive response in order to provide maximum protection against specific pathogens. Despite the impressive success of currently approved adjuvants for generating immunity to viral and bacterial infections, there remains a need for improved adjuvants that enhance protective antibody responses, especially in populations that respond poorly to current vaccines. However, the larger challenge is to develop vaccines that generate strong T cell immunity with purified or recombinant vaccine antigens. PMID:21029960

  12. Six host-range restricted poxviruses from three genera induce distinct gene expression profiles in an in vivo mouse model

    National Research Council Canada - National Science Library

    Offerman, Kristy; Deffur, Armin; Carulei, Olivia; Wilkinson, Robert; Douglass, Nicola; Williamson, Anna-Lise

    2015-01-01

    .... An understanding of the host innate immune responses produced by different poxvirus vectors would aid in the assessment, selection and rational design of improved vaccines for human and veterinary applications...

  13. A novel study design for antibiotic trials in acute exacerbations of COPD: MAESTRAL methodology

    Directory of Open Access Journals (Sweden)

    Wilson R

    2011-06-01

    Full Text Available Robert Wilson1, Antonio Anzueto2, Marc Miravitlles3, Pierre Arvis4, Geneviève Faragó5, Daniel Haverstock6, Mila Trajanovic5, Sanjay Sethi71Host Defence Unit, Royal Brompton Hospital, London, England, UK; 2University of Texas Health Science Center at San Antonio, South Texas Veterans HealthCare System, San Antonio, TX, USA; 3Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS, Ciber de Enfermedades Respiratorias (CIBERES, Hospital Clinic, Barcelona, Spain; 4Bayer HealthCare, Loos, France; 5Bayer Inc, Toronto, ON, Canada; 6Bayer HealthCare Pharmaceuticals, Montville, NJ, USA; 7Division of Pulmonary, Critical Care and Sleep Medicine, University at Buffalo, State University of New York, Buffalo, NY, USAAbstract: Antibiotics, along with oral corticosteroids, are standard treatments for acute exacerbations of chronic obstructive pulmonary disease (AECOPD. The ultimate aims of treatment are to minimize the impact of the current exacerbation, and by ensuring complete resolution, reduce the risk of relapse. In the absence of superiority studies of antibiotics in AECOPD, evidence of the relative efficacy of different drugs is lacking, and so it is difficult for physicians to select the most effective antibiotic. This paper describes the protocol and rationale for MAESTRAL (moxifloxacin in AECBs [acute exacerbation of chronic bronchitis] trial; www.clinicaltrials.gov: NCT00656747, one of the first antibiotic comparator trials designed to show superiority of one antibiotic over another in AECOPD. It is a prospective, multinational, multicenter, randomized, double-blind controlled study of moxifloxacin (400 mg PO [per os] once daily for 5 days vs amoxicillin/clavulanic acid (875/125 mg PO twice daily for 7 days in outpatients with COPD and chronic bronchitis suffering from an exacerbation. MAESTRAL uses an innovative primary endpoint of clinical failure: the requirement for additional or alternate treatment for the exacerbation at 8 weeks

  14. Innate immunity modulation in virus entry.

    Science.gov (United States)

    Faure, Mathias; Rabourdin-Combe, Chantal

    2011-07-01

    Entry into a cell submits viruses to detection by pattern recognition receptors (PRRs) leading to an early innate anti-viral response. Several viruses evolved strategies to avoid or subvert PRR recognition at the step of virus entry to promote infection. Whereas viruses mostly escape from soluble PRR detection, endocytic/phagocytic PRRs, such as the mannose receptor or DC-SIGN, are commonly used for virus entry. Moreover, virion-incorporated proteins may also offer viruses a way to dampen anti-viral innate immunity upon virus entry, and entering viruses might usurp autophagy to improve their own infectivity. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. MECHANISMS OF MICROBE-HOST-INTERACTION IN CROHN'S DISEASE: DYSBIOSIS VS. PATHOBIONT SELECTION

    Directory of Open Access Journals (Sweden)

    Ludovica F. Buttó

    2015-11-01

    Full Text Available Crohn’s disease (CD is a systemic chronic inflammatory condition mainly characterized by discontinuous transmural pathology of the gastrointestinal tract and frequent extra-intestinal manifestations with intermittent episodes of remission and relapse. Genome-wide association studies identified a number of risk loci that, catalyzed by environmental triggers, result in the loss of tolerance towards commensal bacteria based on dysregulated innate effector functions and anti-microbial defense, leading to exacerbated adaptive immune responses responsible for chronic immune-mediated tissue damage. In this review, we discuss the interrelated role of changes in the intestinal microbiota, epithelial barrier integrity and immune cell functions on the pathogenesis of CD, describing the current approaches available to investigate the molecular mechanisms underlying the disease. Substantial effort has been dedicated to define disease-associated changes in the intestinal microbiota (dysbiosis and to link pathobionts to the aetiology of IBD. A cogent definition of dysbiosis is lacking, as well as an agreement of whether pathobionts or complex shifts in the microbiota trigger inflammation in the host. Among the rarely available animal models, SAMP/Yit and TNFdeltaARE mice are the best known displaying a transmural CD-like phenotype. New hypothesis-driven mouse models e.g. epithelial-specific Caspase8-/-, ATG16L1-/- and XBP-1-/- mice validate pathway-focused function of specific CD-associated risk genes highlighting the role of Paneth cells in antimicrobial defense. To study the causal role of bacteria in initiating inflammation in the host, the use of germfree mouse models is indispensable. Unraveling the interactions of genes, immune cells and microbes constitute a criterion for the development of safe, reliable and effective treatment options for CD.

  16. Pidotimod activity against chronic bronchitis exacerbations.

    Science.gov (United States)

    Ciaccia, A

    1994-12-01

    The efficacy of pidotimod ((R)-3-[(S)-(5-oxo-2-pyrrolidinyl) carbonyl]-thiazolidine-4-carboxylic acid, PGT/1A, CAS 121808-62-6) in the management of infectious exacerbations of chronic bronchitis was evaluated in a double-blind, placebo-controlled study in parallel groups over 5 months (60 days of treatment and 90 days of follow-up). The study enrolled 580 patients, of whom 514 could be evaluated. The pidotimod group had fewer and shorter infectious episodes, fewer days of antibiotic therapy and fewer days unable to undertake normal activities. The difference vs. placebo was significant during the follow-up period and, in those subjects with a less severe history, during the treatment period also. Pidotimod was well tolerated.

  17. Role of antileukotrienes in acute asthma exacerbations

    Directory of Open Access Journals (Sweden)

    Domenico Lorenzo Urso

    2012-04-01

    Full Text Available Acute asthma exacerbations are one of the most frequent reasons to visit the emergency department or general practitioner. Although current standard treatments for acute asthma – including supplemental oxygen, short-acting β2-agonists, systemic corticosteroids and anticholinergics – are quite effective in most patients, they are inadequate for rapid and sustained improvement in a significant proportion. The antileukotrienes, a relatively new class of drugs, have a role in the treatment of chronic asthma. Their relatively rapid onset of action after endovenous or oral administration and their additive effect to β2-agonists led to the hypothesis that they might be of benefit in acute asthma. This review examines the efficacy of antileukotrienes in the treatment of acute asthma.

  18. [Treatment of multiple sclerosis symptoms and exacerbations].

    Science.gov (United States)

    Prieto González, José María

    2014-12-01

    In the last few years, there has been an explosion of new drugs acting on the clinical course of multiple sclerosis (MS) but less attention has been paid to better knowledge of the symptoms of this disease and their pathogenesis and treatment, which is essential to improve patients' quality of life. Because many patients have numerous concurrent symptoms during their clinical course, their management is complex and consequently it is important to know which symptoms are a direct result of the degenerative lesions of MS. The present article describes all the therapeutic options available for spasticity and its associated pain, paroxystic symptoms, fatigue, genitourinary disorders and sexual dysfunction, tremor, ataxia, gait disorder and cognitive impairment, with special emphasis on novel treatments. The article also defines exacerbations, how to recognize them and the available treatments, mainly oral administration of high-dose methylprednisolone and plasmapheresis. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  19. Genetic control of the variable innate immune response to asymptomatic bacteriuria.

    Directory of Open Access Journals (Sweden)

    Jenny Grönberg-Hernández

    Full Text Available The severity of urinary tract infection (UTI reflects the quality and magnitude of the host response. While strong local and systemic innate immune activation occurs in patients with acute pyelonephritis, the response to asymptomatic bacteriuria (ABU is low. The immune response repertoire in ABU has not been characterized, due to the inherent problem to distinguish bacterial differences from host-determined variation. In this study, we investigated the host response to ABU and genetic variants affecting innate immune signaling and UTI susceptibility. Patients were subjected to therapeutic urinary tract inoculation with E. coli 83972 to ensure that they were exposed to the same E. coli strain. The innate immune response repertoire was characterized in urine samples, collected from each patient before and after inoculation with bacteria or PBS, if during the placebo arm of the study. Long-term E. coli 83972 ABU was established in 23 participants, who were followed for up to twelve months and the innate immune response was quantified in 233 urine samples. Neutrophil numbers increased in all but two patients and in an extended urine cytokine/chemokine analysis (31 proteins, the chemoattractants IL-8 and GRO-α, RANTES, Eotaxin-1 and MCP-1, the T cell chemoattractant and antibacterial peptide IP-10, inflammatory regulators IL-1-α and sIL-1RA and the T lymphocyte/dendritic cell product sIL-2Rα were detected and variably increased, compared to sterile samples. IL-6, which is associated with symptomatic UTI, remained low and numerous specific immune mediators were not detected. The patients were also genotyped for UTI-associated IRF3 and TLR4 promoter polymorphisms. Patients with ABU associated TLR4 polymorphisms had low neutrophil numbers, IL-6, IP-10, MCP-1 and sIL-2Rα concentrations. Patients with the ABU-associated IRF3 genotype had lower neutrophils, IL-6 and MCP-1 responses than the remaining group. The results suggest that the host

  20. Exacerbating factors of itch in atopic dermatitis

    Directory of Open Access Journals (Sweden)

    Hiroyuki Murota

    2017-01-01

    Full Text Available Atopic dermatitis (AD displays different clinical symptoms, progress, and response to treatment during early infancy and after childhood. After the childhood period, itch appears first, followed by formation of well-circumscribed plaque or polymorphous dermatoses at the same site. When accompanied with dermatitis and dry skin, treatment of skin lesions should be prioritized. When itch appears first, disease history, such as causes and time of appearance of itch should be obtained by history taking. In many cases, itch increases in the evening when the sympathetic nerve activity decreased. Treatment is provided considering that hypersensitivity to various external stimulations can cause itch. Heat and sweating are thought to especially exacerbate itch. Factors causing itch, such as cytokines and chemical messengers, also induce itch mainly by stimulating the nerve. Scratching further aggravates dermatitis. Skin hypersensibility, where other non-itch senses, such as pain and heat, are felt as itch, sometimes occurs in AD. Abnormal elongation of the sensory nerve into the epidermis, as well as sensitizing of the peripheral/central nerve, are possible causes of hypersensitivity, leading to itch. To control itch induced by environmental factors such as heat, treatment for dermatitis is given priority. In the background of itch exacerbated by sweating, attention should be given to the negative impact of sweat on skin homeostasis due to 1 leaving excess sweat on the skin, and 2 heat retention due to insufficient sweating. Excess sweat on the skin should be properly wiped off, and dermatitis should be controlled so that appropriate amount of sweat can be produced. Not only stimulation from the skin surface, but also visual and auditory stimulation can induce new itch. This “contagious itch” can be notably observed in patients with AD. This article reviews and introduces causes of aggravation of itch and information regarding how to cope with such

  1. Targeting the Innate Immune Response to Improve Cardiac Graft Recovery after Heart Transplantation: Implications for the Donation after Cardiac Death

    Directory of Open Access Journals (Sweden)

    Stefano Toldo

    2016-06-01

    Full Text Available Heart transplantation (HTx is the ultimate treatment for end-stage heart failure. The number of patients on waiting lists for heart transplants, however, is much higher than the number of available organs. The shortage of donor hearts is a serious concern since the population affected by heart failure is constantly increasing. Furthermore, the long-term success of HTx poses some challenges despite the improvement in the management of the short-term complications and in the methods to limit graft rejection. Myocardial injury occurs during transplantation. Injury initiated in the donor as result of brain or cardiac death is exacerbated by organ procurement and storage, and is ultimately amplified by reperfusion injury at the time of transplantation. The innate immune system is a mechanism of first-line defense against pathogens and cell injury. Innate immunity is activated during myocardial injury and produces deleterious effects on the heart structure and function. Here, we briefly discuss the role of the innate immunity in the initiation of myocardial injury, with particular focus on the Toll-like receptors and inflammasome, and how to potentially expand the donor population by targeting the innate immune response.

  2. Alum Adjuvant Enhances Protection against Respiratory Syncytial Virus but Exacerbates Pulmonary Inflammation by Modulating Multiple Innate and Adaptive Immune Cells.

    Science.gov (United States)

    Kim, Ki-Hye; Lee, Young-Tae; Hwang, Hye Suk; Kwon, Young-Man; Jung, Yu-Jin; Lee, Youri; Lee, Jong Seok; Lee, Yu-Na; Park, Soojin; Kang, Sang-Moo

    2015-01-01

    Respiratory syncytial virus (RSV) is well-known for inducing vaccine-enhanced respiratory disease after vaccination of young children with formalin-inactivated RSV (FI-RSV) in alum formulation. Here, we investigated alum adjuvant effects on protection and disease after FI-RSV immunization with or without alum in comparison with live RSV reinfections. Despite viral clearance, live RSV reinfections caused weight loss and substantial pulmonary inflammation probably due to high levels of RSV specific IFN-γ+IL4-, IFN-γ-TNF-α+, IFN-γ+TNF-α- effector CD4 and CD8 T cells. Alum adjuvant significantly improved protection as evidenced by effective viral clearance compared to unadjuvanted FI-RSV. However, in contrast to unadjuvanted FI-RSV, alum-adjuvanted FI-RSV (FI-RSV-A) induced severe vaccine-enhanced RSV disease including weight loss, eosinophilia, and lung histopathology. Alum adjuvant in the FI-RSV-A was found to be mainly responsible for inducing high levels of RSV-specific IFN-γ-IL4+, IFN-γ-TNF-α+ CD4+ T cells, and proinflammatory cytokines IL-6 and IL-4 as well as B220+ plasmacytoid and CD4+ dendritic cells, and inhibiting the induction of IFN-γ+CD8 T cells. This study suggests that alum adjuvant in FI-RSV vaccines increases immunogenicity and viral clearance but also induces atypical T helper CD4+ T cells and multiple inflammatory dendritic cell subsets responsible for vaccine-enhanced severe RSV disease.

  3. Alum Adjuvant Enhances Protection against Respiratory Syncytial Virus but Exacerbates Pulmonary Inflammation by Modulating Multiple Innate and Adaptive Immune Cells.

    Directory of Open Access Journals (Sweden)

    Ki-Hye Kim

    Full Text Available Respiratory syncytial virus (RSV is well-known for inducing vaccine-enhanced respiratory disease after vaccination of young children with formalin-inactivated RSV (FI-RSV in alum formulation. Here, we investigated alum adjuvant effects on protection and disease after FI-RSV immunization with or without alum in comparison with live RSV reinfections. Despite viral clearance, live RSV reinfections caused weight loss and substantial pulmonary inflammation probably due to high levels of RSV specific IFN-γ+IL4-, IFN-γ-TNF-α+, IFN-γ+TNF-α- effector CD4 and CD8 T cells. Alum adjuvant significantly improved protection as evidenced by effective viral clearance compared to unadjuvanted FI-RSV. However, in contrast to unadjuvanted FI-RSV, alum-adjuvanted FI-RSV (FI-RSV-A induced severe vaccine-enhanced RSV disease including weight loss, eosinophilia, and lung histopathology. Alum adjuvant in the FI-RSV-A was found to be mainly responsible for inducing high levels of RSV-specific IFN-γ-IL4+, IFN-γ-TNF-α+ CD4+ T cells, and proinflammatory cytokines IL-6 and IL-4 as well as B220+ plasmacytoid and CD4+ dendritic cells, and inhibiting the induction of IFN-γ+CD8 T cells. This study suggests that alum adjuvant in FI-RSV vaccines increases immunogenicity and viral clearance but also induces atypical T helper CD4+ T cells and multiple inflammatory dendritic cell subsets responsible for vaccine-enhanced severe RSV disease.

  4. Dynamic regulation of innate immune responses in Drosophila by Senju-mediated glycosylation.

    Science.gov (United States)

    Yamamoto-Hino, Miki; Muraoka, Masatoshi; Kondo, Shu; Ueda, Ryu; Okano, Hideyuki; Goto, Satoshi

    2015-05-05

    The innate immune system is the first line of defense encountered by invading pathogens. Delayed and/or inadequate innate immune responses can result in failure to combat pathogens, whereas excessive and/or inappropriate responses cause runaway inflammation. Therefore, immune responses are tightly regulated from initiation to resolution and are repressed during the steady state. It is well known that glycans presented on pathogens play important roles in pathogen recognition and the interactions between host molecules and microbes; however, the function of glycans of host organisms in innate immune responses is less well known. Here, we show that innate immune quiescence and strength of the immune response are controlled by host glycosylation involving a novel UDP-galactose transporter called Senju. In senju mutants, reduced expression of galactose-containing glycans resulted in hyperactivation of the Toll signaling pathway in the absence of immune challenges. Genetic epistasis and biochemical analyses revealed that Senju regulates the Toll signaling pathway at a step that converts Toll ligand Spatzle to its active form. Interestingly, Toll activation in immune-challenged wild type (WT) flies reduced the expression of galactose-containing glycans. Suppression of the degalactosylation by senju overexpression resulted in reduced induction of Toll-dependent expression of an antimicrobial peptide, Drosomycin, and increased susceptibility to infection with Gram-positive bacteria. These data suggest that Senju-mediated galactosylation suppresses undesirable Toll signaling activation during the steady state; however, Toll activation in response to infection leads to degalactosylation, which raises the immune response to an adequate level and contributes to the prompt elimination of pathogens.

  5. Are the innate and adaptive immune systems setting hypertension on fire?

    Science.gov (United States)

    Bomfim, Gisele F; Rodrigues, Fernanda Luciano; Carneiro, Fernando S

    2017-03-01

    Hypertension is the most common chronic cardiovascular disease and is associated with several pathological states, being an important cause of morbidity and mortality around the world. Low-grade inflammation plays a key role in hypertension and the innate and adaptive immune systems seem to contribute to hypertension development and maintenance. Hypertension is associated with vascular inflammation, increased vascular cytokines levels and infiltration of immune cells in the vasculature, kidneys and heart. However, the mechanisms that trigger inflammation and immune system activation in hypertension are completely unknown. Cells from the innate immune system express pattern recognition receptors (PRR), which detect conserved pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) that induce innate effector mechanisms to produce endogenous signals, such as inflammatory cytokines and chemokines, to alert the host about danger. Additionally, antigen-presenting cells (APC) act as sentinels that are activated by PAMPs and DAMPs to sense the presence of the antigen/neoantigen, which ensues the adaptive immune system activation. In this context, different lymphocyte types are activated and contribute to inflammation and end-organ damage in hypertension. This review will focus on experimental and clinical evidence demonstrating the contribution of the innate and adaptive immune systems to the development of hypertension. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Are you experienced? Understanding bladder innate immunity in the context of recurrent urinary tract infection

    Science.gov (United States)

    O’Brien, Valerie P.; Hannan, Thomas J.; Schaeffer, Anthony J.; Hultgren, Scott J.

    2015-01-01

    Purpose of review Recurrent urinary tract infection (rUTI) is a serious clinical problem, yet effective therapeutic options are limited, especially against multidrug-resistant uropathogens. In this review, we explore the development of a clinically relevant model of rUTI in previously infected mice and review recent developments in bladder innate immunity that may affect susceptibility to rUTI. Recent findings Chronic bladder inflammation during prolonged bacterial cystitis in mice causes bladder mucosal remodelling that sensitizes the host to rUTI. Although constitutive defenses help prevent bacterial colonization of the urinary bladder, once infection occurs, induced cytokine and myeloid cell responses predominate and the balance of immune cell defense and bladder immunopathology is critical for determining disease outcome, in both naïve and experienced mice. In particular, the maintenance of the epithelial barrier appears to be essential for preventing severe infection. Summary The innate immune response plays a key role in determining susceptibility to rUTI. Future studies should be directed towards understanding how the innate immune response changes as a result of bladder mucosal remodelling in previously infected mice, and validating these findings in human clinical specimens. New therapeutics targeting the immune response should selectively target the induced innate responses that cause bladder immunopathology, while leaving protective defenses intact. PMID:25517222

  7. Innate Immunity and the 2011 Nobel Prize

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 17; Issue 10. Innate Immunity and the 2011 Nobel Prize. Mukta Deobagkar Lele Chetana Bhaskarla Rajkumar Dhanaraju Manikandan Ponnusamy Dipankar Nandi. General Article Volume 17 Issue 10 October 2012 pp 974-995 ...

  8. Innate immune functions in kidney transplantation

    NARCIS (Netherlands)

    Berger, Stefan Philip

    2009-01-01

    The innate immune system plays an important role in solid organ transplantation. This thesis focuses on the role of the lectin pathway of complement activation in kidney and simultaneous pancreas-kidney transplantation (SPKT) and describes the role of properdin in tubular complement activation and

  9. Monotheism versus an innate bias towards mentalizing.

    Science.gov (United States)

    Costello, Fintan John

    2016-01-01

    Norenzayan et al.'s account for the spread of monotheistic "Big God" religions sees these religions originating as by-products of innate cognitive biases. These biases produce polytheistic rather than monotheistic systems, however, and so do not explain the origin of monotheism. Accounts where monotheism arises from polytheism (for political reasons, for example) appear better able to explain the spread of monotheism.

  10. Biliary Innate Immunity: Function and Modulation

    Directory of Open Access Journals (Sweden)

    Kenichi Harada

    2010-01-01

    Full Text Available Biliary innate immunity is involved in the pathogenesis of cholangiopathies in patients with primary biliary cirrhosis (PBC and biliary atresia. Biliary epithelial cells possess an innate immune system consisting of the Toll-like receptor (TLR family and recognize pathogen-associated molecular patterns (PAMPs. Tolerance to bacterial PAMPs such as lipopolysaccharides is also important to maintain homeostasis in the biliary tree, but tolerance to double-stranded RNA (dsRNA is not found. In PBC, CD4-positive Th17 cells characterized by the secretion of IL-17 are implicated in the chronic inflammation of bile ducts and the presence of Th17 cells around bile ducts is causally associated with the biliary innate immune responses to PAMPs. Moreover, a negative regulator of intracellular TLR signaling, peroxisome proliferator-activated receptor-γ (PPARγ, is involved in the pathogenesis of cholangitis. Immunosuppression using PPARγ ligands may help to attenuate the bile duct damage in PBC patients. In biliary atresia characterized by a progressive, inflammatory, and sclerosing cholangiopathy, dsRNA viruses are speculated to be an etiological agent and to directly induce enhanced biliary apoptosis via the expression of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL. Moreover, the epithelial-mesenchymal transition (EMT of biliary epithelial cells is also evoked by the biliary innate immune response to dsRNA.

  11. The biology of innate lymphoid cells

    NARCIS (Netherlands)

    Artis, David; Spits, Hergen

    2015-01-01

    The innate immune system is composed of a diverse array of evolutionarily ancient haematopoietic cell types, including dendritic cells, monocytes, macrophages and granulocytes. These cell populations collaborate with each other, with the adaptive immune system and with non-haematopoietic cells to

  12. Innate lymphoid cells in inflammatory bowel diseases

    NARCIS (Netherlands)

    Peters, C. P.; Mjösberg, J. M.; Bernink, J. H.; Spits, H.

    2016-01-01

    It is generally believed that inflammatory bowel diseases (IBD) are caused by an aberrant immune response to environmental triggers in genetically susceptible individuals. The exact contribution of the adaptive and innate immune system has not been elucidated. However, recent advances in treatments

  13. The Role of Innate Immunity in Autoimmunity

    Science.gov (United States)

    Bach, Jean-François; Bendelac, Albert; Brenner, Michael B.; Cantor, Harvey; De Libero, Gennaro; Kronenberg, Mitchell; Lanier, Lewis L.; Raulet, David H.; Shlomchik, Mark J.; von Herrath, Matthias G.

    2004-01-01

    During the 2004 International Congress of Immunology in Montreal, a panel of experts gathered for an “Ideashop” discussion on the potential role of innate immunity in autoimmunity and the ways in which this might be targeted in future therapies. PMID:15611284

  14. Innate immune signalling of the zebrafish embryo

    NARCIS (Netherlands)

    Stockhammer, Oliver W.

    2010-01-01

    In the last decade the study of the innate immune system has gained renewed scientific momentum as a result of the discovery of essential receptor families, such as the Toll-like receptor (TLR) family, that are required for pathogen recognition. These receptors detect specific molecular structures

  15. Innate immunity and the new forward genetics.

    Science.gov (United States)

    Beutler, Bruce

    2016-12-01

    As it is a hard-wired system for responses to microbes, innate immunity is particularly susceptible to classical genetic analysis. Mutations led the way to the discovery of many of the molecular elements of innate immune sensing and signaling pathways. In turn, the need for a faster way to find the molecular causes of mutation-induced phenotypes triggered a huge transformation in forward genetics. During the 1980s and 1990s, many heritable phenotypes were ascribed to mutations through positional cloning. In mice, this required three steps. First, a genetic mapping step was used to show that a given phenotype emanated from a circumscribed region of the genome. Second, a physical mapping step was undertaken, in which all of the region was cloned and its gene content determined. Finally, a concerted search for the mutation was performed. Such projects usually lasted for several years, but could produce breakthroughs in our understanding of biological processes. Publication of the annotated mouse genome sequence in 2002 made physical mapping unnecessary. More recently we devised a new technology for automated genetic mapping, which eliminated both genetic mapping and the search for mutations among candidate genes. The cause of phenotype can now be determined instantaneously. We have created more than 100,000 coding/splicing mutations. And by screening for defects of innate and adaptive immunity we have discovered many "new" proteins needed for innate immune function. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Kawasaki disease: a matter of innate immunity.

    Science.gov (United States)

    Hara, T; Nakashima, Y; Sakai, Y; Nishio, H; Motomura, Y; Yamasaki, S

    2016-11-01

    Kawasaki disease (KD) is an acute systemic vasculitis of childhood that does not have a known cause or aetiology. The epidemiological features (existence of epidemics, community outbreaks and seasonality), unique age distribution and clinical symptoms and signs of KD suggest that the disease is caused by one or more infectious environmental triggers. However, KD is not transmitted person-to-person and does not occur in clusters within households, schools or nurseries. KD is a self-limited illness that is not associated with the production of autoantibodies or the deposition of immune complexes, and it rarely recurs. Regarding the underlying pathophysiology of KD, innate immune activity (the inflammasome) is believed to play a role in the development of KD vasculitis, based on the results of studies with animal models and the clinical and laboratory findings of KD patients. Animal studies have demonstrated that innate immune pathogen-associated molecular patterns (PAMPs) can cause vasculitis independently of acquired immunity and have provided valuable insights regarding the underlying mechanisms of this phenomenon. To validate this concept, we recently searched for KD-specific PAMPs and identified such molecules with high specificity and sensitivity. These molecules have structures similar to those of microbe-associated molecular patterns (MAMPs), as shown by liquid chromatography-tandem mass spectrometry. We propose herein that KD is an innate immune disorder resulting from the exposure of a genetically predisposed individual to microbe-derived innate immune stimulants and that it is not a typical infectious disease. © 2016 British Society for Immunology.

  17. Innate immune responses to environmental allergens

    NARCIS (Netherlands)

    Kauffman, HF

    Aero-allergens, including plant pollens, house dust mite particles, fungal spores, and mycelium fragments, are continuously inhaled and deposited on the airway mucosa. These particles and their soluble components actively interact with innate recognition systems present in the mucosal layer (e.g.,

  18. Innate lymphoid cells in inflammation and immunity

    NARCIS (Netherlands)

    McKenzie, Andrew N. J.; Spits, Hergen; Eberl, Gerard

    2014-01-01

    Innate lymphoid cells (ILCs) were first described as playing important roles in the development of lymphoid tissues and more recently in the initiation of inflammation at barrier surfaces in response to infection or tissue damage. It has now become apparent that ILCs play more complex roles

  19. Improving microphage innate immunity by modulating protein ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Improving microphage innate immunity by modulating protein tyrosine phosphatases: The complete mouse and human PTPomes. Diseases that result from an infection are most often resolved by cells that use an immune response to clear foreign agents. These cells include macrophages, which are the predominant type of ...

  20. Is there an innate need for children

    NARCIS (Netherlands)

    R. Veenhoven (Ruut)

    1974-01-01

    textabstractABSTRACT It is commonly assumed that we have an innate need for children, in particular, that women have a 'mother instinct'. This belief lives in the general public as well as among scientists. In this paper that theory is criticized on two grounds: Firstly, it is argued that the theory

  1. Metabolic signals and innate immune activation in obesity and exercise

    National Research Council Canada - National Science Library

    Ringseis, Robert; Eder, Klaus; Mooren, Frank C; Krüger, Karsten

    2015-01-01

    ... being indicative of activation of the innate immune system. Recent evidence suggests that activation of the innate immune system in the course of obesity is mediated by metabolic signals, such as free fatty acids (FFAs...

  2. Regulation of Innate Lymphoid Cells by Aryl Hydrocarbon Receptor

    Directory of Open Access Journals (Sweden)

    Shiyang Li

    2018-01-01

    Full Text Available With striking similarity to their adaptive T helper cell counterparts, innate lymphoid cells (ILCs represent an emerging family of cell types that express signature transcription factors, including T-bet+ Eomes+ natural killer cells, T-bet+ Eomes− group 1 ILCs, GATA3+ group 2 ILCs, RORγt+ group 3 ILCs, and newly identified Id3+ regulatory ILC. ILCs are abundantly present in barrier tissues of the host (e.g., the lung, gut, and skin at the interface of host–environment interactions. Active research has been conducted to elucidate molecular mechanisms underlying the development and function of ILCs. The aryl hydrocarbon receptor (Ahr is a ligand-dependent transcription factor, best known to mediate the effects of xenobiotic environmental toxins and endogenous microbial and dietary metabolites. Here, we review recent progresses regarding Ahr function in ILCs. We focus on the Ahr-mediated cross talk between ILCs and other immune/non-immune cells in host tissues especially in the gut. We discuss the molecular mechanisms of the action of Ahr expression and activity in regulation of ILCs in immunity and inflammation, and the interaction between Ahr and other pathways/transcription factors in ILC development and function with their implication in disease.

  3. Regulation of Innate Lymphoid Cells by Aryl Hydrocarbon Receptor

    Science.gov (United States)

    Li, Shiyang; Bostick, John W.; Zhou, Liang

    2018-01-01

    With striking similarity to their adaptive T helper cell counterparts, innate lymphoid cells (ILCs) represent an emerging family of cell types that express signature transcription factors, including T-bet+ Eomes+ natural killer cells, T-bet+ Eomes− group 1 ILCs, GATA3+ group 2 ILCs, RORγt+ group 3 ILCs, and newly identified Id3+ regulatory ILC. ILCs are abundantly present in barrier tissues of the host (e.g., the lung, gut, and skin) at the interface of host–environment interactions. Active research has been conducted to elucidate molecular mechanisms underlying the development and function of ILCs. The aryl hydrocarbon receptor (Ahr) is a ligand-dependent transcription factor, best known to mediate the effects of xenobiotic environmental toxins and endogenous microbial and dietary metabolites. Here, we review recent progresses regarding Ahr function in ILCs. We focus on the Ahr-mediated cross talk between ILCs and other immune/non-immune cells in host tissues especially in the gut. We discuss the molecular mechanisms of the action of Ahr expression and activity in regulation of ILCs in immunity and inflammation, and the interaction between Ahr and other pathways/transcription factors in ILC development and function with their implication in disease. PMID:29354125

  4. Modulation of the innate immune responses in the striped ...

    African Journals Online (AJOL)

    It is well-known that the innate immune mechanisms in fish serve as the first line of defence against wide variety of pathogens. In most of the situations, innate responses get induced and enhanced after the pathogen invasion. It would be interesting to look into the inducibility of various innate immune mechanisms and the ...

  5. DMPD: Antiviral innate immunity pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16474426 Antiviral innate immunity pathways. Seth RB, Sun L, Chen ZJ. Cell Res. 200...6 Feb;16(2):141-7. (.png) (.svg) (.html) (.csml) Show Antiviral innate immunity pathways. PubmedID 16474426 ...Title Antiviral innate immunity pathways. Authors Seth RB, Sun L, Chen ZJ. Publication Cell Res. 2006 Feb;16

  6. Determinants of low risk of asthma exacerbation during pregnancy

    DEFF Research Database (Denmark)

    Ali, Zarqa; Nilas, Lisbeth; Ulrik, Charlotte Suppli

    2017-01-01

    BACKGROUND: Assessment of asthma control every 4-6 weeks during pregnancy is recommended to reduce risk of exacerbation, and by that improve outcome. OBJECTIVE: To identify determinants of pregnancies with low risk of asthma exacerbation. METHODS: All pregnant women enrolled into the Management o...... is protected by copyright. All rights reserved....

  7. Inflammatory biomarkers and exacerbations in chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Thomsen, Mette; Ingebrigtsen, Truls Sylvan; Marott, Jacob Louis

    2013-01-01

    Exacerbations of respiratory symptoms in chronic obstructive pulmonary disease (COPD) have profound and long-lasting adverse effects on patients.......Exacerbations of respiratory symptoms in chronic obstructive pulmonary disease (COPD) have profound and long-lasting adverse effects on patients....

  8. Blood Eosinophils and Exacerbations in Chronic Obstructive Pulmonary Disease

    DEFF Research Database (Denmark)

    Vedel-Krogh, Signe; Nielsen, Sune F; Lange, Peter

    2016-01-01

    RATIONALE: Whether high blood eosinophils are associated with COPD exacerbations among individuals with COPD in the general population is largely unknown. OBJECTIVES: To test the hypothesis that high blood eosinophils predict COPD exacerbations. METHODS: Among 81,668 individuals from the Copenhag...

  9. Detection of rhinovirus-associated asthma exacerbations using ...

    African Journals Online (AJOL)

    Ehab

    INTRODUCTION. Acute asthma exacerbation is a cause of strong concern among children and parents and represents a challenge for pediatric healthcare providers1. Studies reported the issue of “virus-induced exacerbation in asthma and chronic obstructive pulmonary disease” and evidence of viral infection is found in ...

  10. Factors associated with change in exacerbation frequency in COPD

    DEFF Research Database (Denmark)

    Donaldson, Gavin C; Müllerova, Hanna; Locantore, Nicholas

    2013-01-01

    Patients with chronic obstructive pulmonary disease (COPD) can be categorized as having frequent (FE) or infrequent (IE) exacerbations depending on whether they respectively experience two or more, or one or zero exacerbations per year. Although most patients do not change category from year...

  11. Prevalence and pattern of asthma exacerbation in children seen at ...

    African Journals Online (AJOL)

    Background: Acute exacerbation is a major cause of morbidity in asthmatic children. It can occur even in well controlled asthma. Aim: To determine the prevalence and pattern of acute exacerbation of asthma in children seen at the emergency room of the University of Nigeria Teaching Hospital (UNTH), Enugu. Materials ...

  12. Incidence and risk factors for exacerbations of asthma during pregnancy

    DEFF Research Database (Denmark)

    Ali, Zarqa; Ulrik, Charlotte Suppli

    2013-01-01

    Asthma is one of the most common chronic diseases among pregnant women. Acute exacerbations of asthma during pregnancy have an unfavorable impact on pregnancy outcome. This review provides an overview of current knowledge of incidence, mechanisms, and risk factors for acute exacerbations of asthma...

  13. Increased neutrophil expression of pattern recognition receptors during COPD exacerbations

    NARCIS (Netherlands)

    Pouwels, Simon D.; Van Geffen, Wouter H.; Jonker, Marnix R.; Kerstjens, Huib A. M.; Nawijn, Martijn C.; Heijink, Irene H.

    Previously, we observed increased serum levels of damage-associated molecular patterns (DAMPs) during COPD exacerbations. Here, gene expression of DAMP receptors was measured in peripheral blood neutrophils of COPD patients during stable disease and severe acute exacerbation. The expression of

  14. Acute exacerbations and pulmonary hypertension in advanced idiopathic pulmonary fibrosis.

    LENUS (Irish Health Repository)

    Judge, Eoin P

    2012-07-01

    The aim of this study was to evaluate the risk factors for and outcomes of acute exacerbations in patients with advanced idiopathic pulmonary fibrosis (IPF), and to examine the relationship between disease severity and neovascularisation in explanted IPF lung tissue. 55 IPF patients assessed for lung transplantation were divided into acute (n=27) and non-acute exacerbation (n=28) groups. Haemodynamic data was collected at baseline, at the time of acute exacerbation and at lung transplantation. Histological analysis and CD31 immunostaining to quantify microvessel density (MVD) was performed on the explanted lung tissue of 13 transplanted patients. Acute exacerbations were associated with increased mortality (p=0.0015). Pulmonary hypertension (PH) at baseline and acute exacerbations were associated with poor survival (p<0.01). PH at baseline was associated with a significant risk of acute exacerbations (HR 2.217, p=0.041). Neovascularisation (MVD) was significantly increased in areas of cellular fibrosis and significantly decreased in areas of honeycombing. There was a significant inverse correlation between mean pulmonary artery pressure and MVD in areas of honeycombing. Acute exacerbations were associated with significantly increased mortality in patients with advanced IPF. PH was associated with the subsequent development of an acute exacerbation and with poor survival. Neovascularisation was significantly decreased in areas of honeycombing, and was significantly inversely correlated with mean pulmonary arterial pressure in areas of honeycombing.

  15. Impairment of innate immune responses in cirrhotic patients and treatment by branched-chain amino acids

    Science.gov (United States)

    Nakamura, Ikuo

    2014-01-01

    It has been reported that host defense responses, such as phagocytic function of neutrophils and natural killer (NK) cell activity of lymphocytes, are impaired in cirrhotic patients. This review will concentrate on the impairment of innate immune responses in decompensated cirrhotic patients and the effect of the treatment by branched-chain amino acids (BCAA) on innate immune responses. We already reported that phagocytic function of neutrophils was significantly improved by 3-mo BCAA supplementation. In addition, the changes of NK activity were also significant at 3 mo of supplementation compared with before supplementation. Also, Fisher’s ratios were reported to be significantly increased at 3 mo of BCAA supplementation compared with those before oral supplementation. Therefore, administration of BCAA could reduce the risk of bacterial and viral infection in patients with decompensated cirrhosis by restoring impaired innate immune responses of the host. In addition, it was also revealed that BCAA oral supplementation could reduce the risk of development of hepatocellular carcinoma in cirrhotic patients. The mechanisms of the effects will also be discussed in this review article. PMID:24966600

  16. Encephalitis due to emerging viruses: CNS innate immunity and potential therapeutic targets.

    Science.gov (United States)

    Denizot, M; Neal, J W; Gasque, P

    2012-07-01

    The emerging viruses represent a group of pathogens that are intimately connected to a diverse range of animal vectors. The recent escalation of air travel climate change and urbanization has meant humans will have increased risk of contacting these pathogens resulting in serious CNS infections. Many RNA viruses enter the CNS by evading the BBB due to axonal transport from the periphery. The systemic adaptive and CNS innate immune systems express pattern recognition receptors PRR (TLRs, RiG-1 and MDA-5) that detect viral nucleic acids and initiate host antiviral response. However, several emerging viruses (West Nile Fever, Influenza A, Enterovirus 71 Ebola) are recognized and internalized by host cell receptors (TLR, MMR, DC-SIGN, CD162 and Scavenger receptor B) and escape immuno surveillance by the host systemic and innate immune systems. Many RNA viruses express viral proteins WNF (E protein), Influenza A (NS1), EV71 (protein 3C), Rabies (Glycoprotein), Ebola proteins (VP24 and VP 35) that inhibit the host cell anti-virus Interferon type I response promoting virus replication and encephalitis. The therapeutic use of RNA interference methodologies to silence gene expression of viral peptides and treat emerging virus infection of the CNS is discussed. Copyright © 2012. Published by Elsevier Ltd.

  17. Exacerbation of colon carcinogenesis by Blastocystis sp.

    Science.gov (United States)

    Kumar, Suresh

    2017-01-01

    Colorectal cancer (CRC) is one the most commonly diagnosed cancers worldwide and the number is increasing every year. Despite advances in screening programs, CRC remains as the second leading cause of cancer deaths in the United States. Oxidative stress plays an important role in the molecular mechanisms of colorectal cancer (CRC) and has been shown to be associated with Blastocystis sp., a common intestinal microorganism. In the present study, we aimed to identify a role for Blastocystis sp. in exacerbating carcinogenesis using in vivo rat model. Methylene blue staining was used to identify colonic aberrant crypt foci (ACF) and adenomas formation in infected rats whilst elevation of oxidative stress biomarker levels in the urine and serum samples were evaluated using biochemical assays. Histological changes of the intestinal mucosa were observed and a significant number of ACF was found in Blastocystis sp. infected AOM-rats compared to the AOM-controls. High levels of urinary oxidative indices including advanced oxidative protein products (AOPP) and hydrogen peroxide were observed in Blastocystis sp. infected AOM-rats compared to the uninfected AOM-rats. Our study provides evidence that Blastocystis sp. has a significant role in enhancing AOM-induced carcinogenesis by resulting damage to the intestinal epithelium and promoting oxidative damage in Blastocystis sp. infected rats. PMID:28859095

  18. Crosstalk between the intestinal microbiota and the innate immune system in intestinal homeostasis and inflammatory bowel disease.

    Science.gov (United States)

    Dupaul-Chicoine, Jeremy; Dagenais, Maryse; Saleh, Maya

    2013-09-01

    : Inflammatory bowel diseases are a set of complex and chronic disorders that arise in genetically predisposed individuals due to a lack of tolerance to the gut microflora. Although the intestinal microbiota is required for the proper development of the host and the maintenance of intestinal homeostasis, its dysbiosis is associated with inflammatory bowel diseases pathogenesis. In this review, we focus the discussion on the crosstalk between the innate immune system and the microbiota. We examine new findings from genetic and functional studies investigating the critical role of the intestinal epithelial cell layer and the processes that maintain its integrity in health and disease. We further explore the mechanisms of the mucosal innate immune system including dendritic cells, macrophages, and innate-like lymphocytes in mediating immunological tolerance at the steady state or pathogenic inflammatory responses in inflammatory bowel diseases.

  19. The interplay between neuroendocrine activity and psychological stress-induced exacerbation of allergic asthma.

    Science.gov (United States)

    Miyasaka, Tomomitsu; Dobashi-Okuyama, Kaori; Takahashi, Tomoko; Takayanagi, Motoaki; Ohno, Isao

    2018-01-01

    Psychological stress is recognized as a key factor in the exacerbation of allergic asthma, whereby brain responses to stress act as immunomodulators for asthma. In particular, stress-induced enhanced type 2 T-helper (Th2)-type lung inflammation is strongly associated with asthma pathogenesis. Psychological stress leads to eosinophilic airway inflammation through activation of the hypothalamic-pituitary-adrenal pathway and autonomic nervous system. This is followed by the secretion of stress hormones into the blood, including glucocorticoids, epinephrine, and norepinephrine, which enhance Th2 and type 17 T-helper (Th17)-type asthma profiles in humans and rodents. Recent evidence has shown that a defect of the μ-opioid receptor in the brain along with a defect of the peripheral glucocorticoid receptor signaling completely disrupted stress-induced airway inflammation in mice. This suggests that the stress response facilitates events in the central nervous and endocrine systems, thus exacerbating asthma. In this review, we outline the recent findings on the interplay between stress and neuroendocrine activities followed by stress-induced enhanced Th2 and Th17 immune responses and attenuated regulatory T (Treg) cell responses that are closely linked with asthma exacerbation. We will place a special focus on our own data that has emphasized the continuity from central sensing of psychological stress to enhanced eosinophilic airway inflammation. The mechanism that modulates psychological stress-induced exacerbation of allergic asthma through neuroendocrine activities is thought to involve a series of consecutive pathological events from the brain to the lung, which implies there to be a "neuropsychiatry phenotype" in asthma. Copyright © 2017 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

  20. Emerging Mechanisms of Innate Immunity and Their Translational Potential in Inflammatory Bowel Disease

    Directory of Open Access Journals (Sweden)

    Daniele Corridoni

    2018-02-01

    Full Text Available Activation of the innate immune system through pattern-recognition receptor (PRR signaling plays a pivotal role in the early induction of host defense following exposure to pathogens. Loss of intestinal innate immune regulation leading aberrant immune responses has been implicated in the pathogenesis of inflammatory bowel disease (IBD. The precise role of PRRs in gut inflammation is not well understood, but considering their role as bacterial sensors and their genetic association with IBD, they likely contribute to dysregulated immune responses to the commensal microbiota. The purpose of this review is to evaluate the emerging functions of PRRs including their functional cross-talk, how they respond to mitochondrial damage, induce mitophagy or autophagy, and influence adaptive immune responses by interacting with the antigen presentation machinery. The review also summarizes some of the recent attempts to harness these pathways for therapeutic approaches in intestinal inflammation.

  1. Innate immune signalling at the intestinal epithelium in homeostasis and disease

    Science.gov (United States)

    Pott, Johanna; Hornef, Mathias

    2012-01-01

    The intestinal epithelium—which constitutes the interface between the enteric microbiota and host tissues—actively contributes to the maintenance of mucosal homeostasis and defends against pathogenic microbes. The recognition of conserved microbial products by cytosolic or transmembrane pattern recognition receptors in epithelial cells initiates signal transduction and influences effector cell function. However, the signalling pathways, effector molecules and regulatory mechanisms involved are not yet fully understood, and the functional outcome is poorly defined. This review analyses the complex and dynamic role of intestinal epithelial innate immune recognition and signalling, on the basis of results in intestinal epithelial cell-specific transgene or gene-deficient animals. This approach identifies specific epithelial cell functions within the diverse cellular composition of the mucosal tissue, in the presence of the complex and dynamic gut microbiota. These insights have thus provided a more comprehensive understanding of the role of the intestinal epithelium in innate immunity during homeostasis and disease. PMID:22801555

  2. Innate immune evasion by hepatitis C virus and West Nile virus

    Science.gov (United States)

    Keller, Brian C; Johnson, Cynthia L.; Erickson, Andrea Kaup; Gale, Michael

    2009-01-01

    Antiviral immunity in mammals involves several levels of surveillance and effector actions by host factors to detect viral pathogens, trigger α/β interferon production, and to mediate innate defenses within infected cells. Our studies have focused on understanding how these processes are regulated during infection by hepatitis C virus (HCV) and West Nile virus (WNV). Both viruses are members of the Flaviviridae and are human pathogens but they each mediate a very different disease and course of infection. Our results demonstrate common and unique innate immune interactions of each virus that govern antiviral immunity, and demonstrate the central role of α/β interferon immune defenses in controlling the outcome of infection. PMID:17702639

  3. Pathological and therapeutic roles of innate lymphoid cells in diverse diseases.

    Science.gov (United States)

    Kim, Jisu; Kim, Geon; Min, Hyeyoung

    2017-11-01

    Innate lymphoid cells (ILCs) are a recently defined type of innate-immunity cells that belong to the lymphoid lineage and have lymphoid morphology but do not express an antigen-specific B cell or T-cell receptor. ILCs regulate immune functions prior to the formation of adaptive immunity and exert effector functions through a cytokine release. ILCs have been classified into three groups according to the transcription factors that regulate their development and function and the effector cytokines they produce. Of note, ILCs resemble T helper (Th) cells, such as Th1, Th2, and Th17 cells, and show a similar dependence on transcription factors and distinct cytokine production. Despite their short history in immunology, ILCs have received much attention, and numerous studies have revealed biological functions of ILCs including host defense against pathogens, inflammation, tissue repair, and metabolic homeostasis. Here, we describe recent findings about the roles of ILCs in the pathogenesis of various diseases and potential therapeutic targets.

  4. Toward immunogenetic studies of amphibian chytridiomycosis: Linking innate and acquired immunity

    Science.gov (United States)

    Richmond, J.Q.; Savage, Anna E.; Zamudio, Kelly R.; Rosenblum, E.B.

    2009-01-01

    Recent declines in amphibian diversity and abundance have contributed significantly to the global loss of biodiversity. The fungal disease chytridiomycosis is widely considered to be a primary cause of these declines, yet the critical question of why amphibian species differ in susceptibility remains unanswered. Considerable evidence links environmental conditions and interspecific variability of the innate immune system to differential infection responses, but other sources of individual, population, or species-typical variation may also be important. In this article we review the preliminary evidence supporting a role for acquired immune defenses against chytridiomycosis, and advocate for targeted investigation of genes controlling acquired responses, as well as those that functionally bridge the innate and acquired immune systems. Immunogenetic data promise to answer key questions about chytridiomycosis susceptibility and host-pathogen coevolution, and will draw much needed attention to the importance of considering evolutionary processes in amphibian conservation management and practice. ?? 2009 by American Institute of Biological Sciences.

  5. Nucleic acid sensing and innate immunity: signaling pathways controlling viral pathogenesis and autoimmunity

    Science.gov (United States)

    Ahlers, Laura R. H.; Goodman, Alan G.

    2016-01-01

    Innate immunity refers to the body’s initial response to curb infection upon exposure to invading organisms. While the detection of pathogen-associated molecules is an ancient form of host defense, if dysfunctional, autoimmune disease may result. The innate immune response during pathogenic infection is initiated through the activation of receptors recognizing conserved molecular patterns, such as nucleic acids from a virus’ genome or replicative cycle. Additionally, the host’s own nucleic acids are capable of activating an immune response. Therefore, it follows that the nucleic acid-sensing pathways must be tightly controlled to avoid an autoimmune response from recognition of self, yet still be unimpeded to respond to viral infections. In this review, we will describe the nucleic acid sensing pathways and how they respond to virus infection. Moreover, we will discuss autoimmune diseases that develop when these pathways fail to signal properly and identify knowledge gaps that are prime for interrogation. PMID:27857881

  6. Innate immunity to H5N1 influenza viruses in humans.

    Science.gov (United States)

    Ramos, Irene; Fernandez-Sesma, Ana

    2012-12-01

    Avian influenza virus infections in the human population are rare due to their inefficient direct human-to-human transmission. However, when humans are infected, a strong inflammatory response is usually induced, characterized by elevated levels of cytokines and chemokines in serum, believed to be important in the severe pathogenesis that develops in a high proportion of these patients. Extensive research has been performed to understand the molecular viral mechanisms involved in the H5N1 pathogenesis in humans, providing interesting insights about the virus-host interaction and the regulation of the innate immune response by these highly pathogenic viruses. In this review we summarize and discuss the most important findings in this field, focusing mainly on H5N1 virulence factors and their impact on the modulation of the innate immunity in humans.

  7. Innate immune responses to gut microbiota differ between oceanic and freshwater threespine stickleback populations.

    Science.gov (United States)

    Milligan-Myhre, Kathryn; Small, Clayton M; Mittge, Erika K; Agarwal, Meghna; Currey, Mark; Cresko, William A; Guillemin, Karen

    2016-02-01

    Animal hosts must co-exist with beneficial microbes while simultaneously being able to mount rapid, non-specific, innate immune responses to pathogenic microbes. How this balance is achieved is not fully understood, and disruption of this relationship can lead to disease. Excessive inflammatory responses to resident microbes are characteristic of certain gastrointestinal pathologies such as inflammatory bowel disease (IBD). The immune dysregulation of IBD has complex genetic underpinnings that cannot be fully recapitulated with single-gene-knockout models. A deeper understanding of the genetic regulation of innate immune responses to resident microbes requires the ability to measure immune responses in the presence and absence of the microbiota using vertebrate models with complex genetic variation. Here, we describe a new gnotobiotic vertebrate model to explore the natural genetic variation that contributes to differences in innate immune responses to microbiota. Threespine stickleback, Gasterosteus aculeatus, has been used to study the developmental genetics of complex traits during the repeated evolution from ancestral oceanic to derived freshwater forms. We established methods to rear germ-free stickleback larvae and gnotobiotic animals monoassociated with single bacterial isolates. We characterized the innate immune response of these fish to resident gut microbes by quantifying the neutrophil cells in conventionally reared monoassociated or germ-free stickleback from both oceanic and freshwater populations grown in a common intermediate salinity environment. We found that oceanic and freshwater fish in the wild and in the laboratory share many intestinal microbial community members. However, oceanic fish mount a strong immune response to residential microbiota, whereas freshwater fish frequently do not. A strong innate immune response was uniformly observed across oceanic families, but this response varied among families of freshwater fish. The gnotobiotic

  8. Innate immune responses to gut microbiota differ between oceanic and freshwater threespine stickleback populations

    Directory of Open Access Journals (Sweden)

    Kathryn Milligan-Myhre

    2016-02-01

    Full Text Available Animal hosts must co-exist with beneficial microbes while simultaneously being able to mount rapid, non-specific, innate immune responses to pathogenic microbes. How this balance is achieved is not fully understood, and disruption of this relationship can lead to disease. Excessive inflammatory responses to resident microbes are characteristic of certain gastrointestinal pathologies such as inflammatory bowel disease (IBD. The immune dysregulation of IBD has complex genetic underpinnings that cannot be fully recapitulated with single-gene-knockout models. A deeper understanding of the genetic regulation of innate immune responses to resident microbes requires the ability to measure immune responses in the presence and absence of the microbiota using vertebrate models with complex genetic variation. Here, we describe a new gnotobiotic vertebrate model to explore the natural genetic variation that contributes to differences in innate immune responses to microbiota. Threespine stickleback, Gasterosteus aculeatus, has been used to study the developmental genetics of complex traits during the repeated evolution from ancestral oceanic to derived freshwater forms. We established methods to rear germ-free stickleback larvae and gnotobiotic animals monoassociated with single bacterial isolates. We characterized the innate immune response of these fish to resident gut microbes by quantifying the neutrophil cells in conventionally reared monoassociated or germ-free stickleback from both oceanic and freshwater populations grown in a common intermediate salinity environment. We found that oceanic and freshwater fish in the wild and in the laboratory share many intestinal microbial community members. However, oceanic fish mount a strong immune response to residential microbiota, whereas freshwater fish frequently do not. A strong innate immune response was uniformly observed across oceanic families, but this response varied among families of freshwater fish

  9. Budesonide and formoterol reduce early innate anti-viral immune responses in vitro.

    Directory of Open Access Journals (Sweden)

    Janet M Davies

    Full Text Available Asthma is a chronic inflammatory airways disease in which respiratory viral infections frequently trigger exacerbations. Current treatment of asthma with combinations of inhaled corticosteroids and long acting beta2 agonists improves asthma control and reduces exacerbations but what impact this might have on innate anti-viral immunity is unclear. We investigated the in vitro effects of asthma drugs on innate anti-viral immunity. Peripheral blood mononuclear cells (PBMC from healthy and asthmatic donors were cultured for 24 hours with the Toll-like receptor 7 agonist, imiquimod, or rhinovirus 16 (RV16 in the presence of budesonide and/or formoterol. Production of proinflammatory cytokines and expression of anti-viral intracellular signalling molecules were measured by ELISA and RT-PCR respectively. In PBMC from healthy donors, budesonide alone inhibited IP-10 and IL-6 production induced by imiquimod in a concentration-dependent manner and the degree of inhibition was amplified when budesonide and formoterol were used in combination. Formoterol alone had little effect on these parameters, except at high concentrations (10⁻⁶ M when IL-6 production increased. In RV16 stimulated PBMC, the combination of budesonide and formoterol inhibited IFNα and IP-10 production in asthmatic as well as healthy donors. Combination of budesonide and formoterol also inhibited RV16-stimulated expression of the type I IFN induced genes myxovirus protein A and 2', 5' oligoadenylate synthetise. Notably, RV16 stimulated lower levels of type Myxovirus A and oligoadenylate synthase in PBMC of asthmatics than control donors. These in vitro studies demonstrate that combinations of drugs commonly used in asthma therapy inhibit both early pro-inflammatory cytokines and key aspects of the type I IFN pathway. These findings suggest that budesonide and formoterol curtail excessive inflammation induced by rhinovirus infections in patients with asthma, but whether this inhibits

  10. Innate lymphoid cells and the MHC.

    Science.gov (United States)

    Robinette, M L; Colonna, M

    2016-01-01

    Innate lymphoid cells (ILCs) are a new class of immune cells that include natural killer (NK) cells and appear to be the innate counterparts to CD4(+) helper T cells and CD8(+) cytotoxic T cells based on developmental and functional similarities. Like T cells, both NK cells and other ILCs also show connections to the major histocompatibility complex (MHC). In human and mouse, NK cells recognize and respond to classical and nonclassical MHC I molecules as well as structural homologues, whereas mouse ILCs have recently been shown to express MHC II. We describe the history of MHC I recognition by NK cells and discuss emerging roles for MHC II expression by ILC subsets, making comparisons between both mouse and human when possible. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. Neutrophils: Cinderella of innate immune system.

    Science.gov (United States)

    Kumar, V; Sharma, A

    2010-11-01

    Neutrophils are the first line of innate immune defense against infectious diseases. However, since their discovery by Elie Metchnikoff, they have always been considered tissue-destructive cells responsible for inflammatory tissue damage occurring during acute infections. Now, extensive research in the field of neutrophil cell biology and their role skewing the immune response in various infections or inflammatory disorders revealed their importance in the regulation of immune response. Along with releasing various antimicrobial molecules, neutrophils also release neutrophil extracellular traps (NETs) for the containment of infection and inflammation. Activated neutrophils provide signals for the activation and maturation of macrophages as well as dendritic cells. Neutrophils are also involved in the regulation of T-cell immune response against various pathogens and tumor antigens. Thus, the present review is intended to highlight the emerging role of neutrophils in the regulation of both innate and adaptive immunity during acute infectious or inflammatory conditions. Copyright © 2010 Elsevier B.V. All rights reserved.

  12. Innate immunity in Sjögren's syndrome.

    Science.gov (United States)

    Kiripolsky, Jeremy; McCabe, Liam G; Kramer, Jill M

    2017-09-01

    Sjögren's syndrome (SS) is an autoimmune disease of exocrine tissue that primarily affects women. Although patients typically experience xerostomia and xerophthalmia, numerous systemic disease manifestations are seen. Innate immune hyperactivity is integral to many autoimmune diseases, including SS. Results from SS mouse models suggest that innate immune dysregulation drives disease and this is a seminal event in SS pathogenesis. Findings in SS patients corroborate those in mouse models, as innate immune cells and pathways are dysregulated both in exocrine tissue and in peripheral blood. We will review the role of the innate immune system in SS pathogenesis. We will discuss the etiology of SS with an emphasis on innate immune dysfunction. Moreover, we will review the innate cells that mediate inflammation in SS, the pathways implicated in disease, and the potential mechanisms governing their dysregulation. Finally, we will discuss emerging therapeutic approaches to target dysregulated innate immune signaling in SS. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. The Dynamic Interplay between HIV-1, SAMHD1, and the Innate Antiviral Response

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    Jenna M. Antonucci

    2017-11-01

    Full Text Available The innate immune response constitutes the first cellular line of defense against initial HIV-1 infection. Immune cells sense invading virus and trigger signaling cascades that induce antiviral defenses to control or eliminate infection. Professional antigen-presenting cells located in mucosal tissues, including dendritic cells and macrophages, are critical for recognizing HIV-1 at the site of initial exposure. These cells are less permissive to HIV-1 infection compared to activated CD4+ T-cells, which is mainly due to host restriction factors that serve an immediate role in controlling the establishment or spread of viral infection. However, HIV-1 can exploit innate immune cells and their cellular factors to avoid detection and clearance by the host immune system. Sterile alpha motif and HD-domain containing protein 1 (SAMHD1 is the mammalian deoxynucleoside triphosphate triphosphohydrolase responsible for regulating intracellular dNTP pools and restricting the replication of HIV-1 in non-dividing myeloid cells and quiescent CD4+ T-cells. Here, we review and analyze the latest literature on the antiviral function of SAMHD1, including the mechanism of HIV-1 restriction and the ability of SAMHD1 to regulate the innate immune response to viral infection. We also provide an overview of the dynamic interplay between HIV-1, SAMHD1, and the cell-intrinsic antiviral response to elucidate how SAMHD1 modulates HIV-1 infection in non-dividing immune cells. A more complete understanding of SAMHD1’s role in the innate immune response to HIV-1 infection may help develop stratagems to enhance its antiviral effects and to more efficiently block HIV-1 replication and avoid the pathogenic result of viral infection.

  14. Innate Immunity Dysregulation in Myelodysplastic Syndromes

    Science.gov (United States)

    2015-12-01

    formed by Toll-like receptor and the histone demethylase JMJD3 in the bone marrow hematopoietic stem/ progenitor cells (HSPCs) of MDS. The objective...U c. THIS PAGE U UU 10 19b. TELEPHONE NUMBER (include area code ) 2 [SF298] Note: An abstract is required to be provided in Block 14 Abstract...We recently identified the deregulation of an innate immune signaling axis formed by Toll-like receptor and the histone demethylase JMJD3 in the bone

  15. Virus-induced exacerbations in asthma and COPD

    Directory of Open Access Journals (Sweden)

    Daisuke eKurai

    2013-10-01

    Full Text Available Chronic obstructive pulmonary disease (COPD is characterized by chronic airway inflammation and/or airflow limitation due to pulmonary emphysema. Chronic bronchitis, pulmonary emphysema, and bronchial asthma may all be associated with airflow limitation; therefore, exacerbation of asthma may be associated with the pathophysiology of COPD. Furthermore, recent studies have suggested that the exacerbation of asthma, namely virus-induced asthma, may be associated with a wide variety of respiratory viruses.COPD and asthma have different underlying pathophysiological processes and thus require individual therapies. Exacerbation of both COPD and asthma, which are basically defined and diagnosed by clinical symptoms, is associated with a rapid decline in lung function and increased mortality. Similar pathogens, including human rhinovirus, respiratory syncytial virus, influenza virus, parainfluenza virus and coronavirus, are also frequently detected during exacerbation of asthma and/or COPD. Immune response to respiratory viral infections, which may be related to the severity of exacerbation in each disease, varies in patients with both COPD and asthma. In this regard, it is crucial to recognize and understand both the similarities and differences of clinical features in patients with COPD and/or asthma associated with respiratory viral infections, especially in the exacerbative stage.In relation to definition, epidemiology, and pathophysiology, this review aims to summarize current knowledge concerning exacerbation of both COPD and asthma by focusing on the clinical significance of associated respiratory virus infections.

  16. Can meteorological factors forecast asthma exacerbation in a paediatric population?

    Science.gov (United States)

    Hervás, D; Utrera, J F; Hervás-Masip, J; Hervás, J A; García-Marcos, L

    2015-01-01

    Asthma exacerbations attended in emergency departments show a marked seasonality in the paediatric age. This seasonal pattern can change from one population to another and the factors involved are poorly understood. To evaluate the association between meteorological factors and schooling with asthma exacerbations in children attended in the paediatric emergency department of a district hospital. We conducted a retrospective review of the medical records of children 5-14 years of age attended for asthma exacerbations during a 4-year period (2007-2011). Climatic data were obtained from a weather station located very close to the population studied. The number of asthma exacerbations was correlated to temperature, barometric pressure, relative humidity, rainfall, wind speed, wind distance, solar radiation, water vapour pressure and schooling, using regression analyses. During the study period, 371 children were attended for asthma exacerbations; median age was eight years (IQR: 6-11), and 59% were males. Asthma exacerbations showed a bimodal pattern with peaks in spring and summer. Maximum annual peak occurred in week 39, within 15 days from school beginning after the summer holidays. A regression model with mean temperature, water vapour pressure, relative humidity, maximum wind speed and schooling could explain 98.4% (pschooling could predict asthma exacerbations in children attended in a paediatric emergency department. Copyright © 2013 SEICAP. Published by Elsevier Espana. All rights reserved.

  17. Characteristic of innate lymphoid cells (ILC

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    Mateusz Adamiak

    2014-12-01

    Full Text Available Innate lymphoid cells (ILC is a newly described family of immune cells that are part of the natural immunity which is important not only during infections caused by microorganisms, but also in the formation of lymphoid tissue, tissue remodeling after damage due to injury and homeostasis tissue stromal cells. Family ILC cells form NK cells (natural killer and lymphoid tissue inducer T cells (LTi, which, although they have different functions, are evolutionarily related. NK cells are producing mainly IFN-γ, whereas LTi cells as NKR+LTi like, IL-17 and/or IL-22, which suggests that the last two cells, can also represent the innate versions of helper T cell - TH17 and TH22. Third population of ILC is formed by cells with characteristics such as NK cells and LTi (ILC22 - which are named NK22 cells, natural cytotoxicity receptor 22 (NCR22 cells or NK receptor-positive (LTi NKR+ LTi cells. Fourth population of ILC cells are ILC17 - producing IL-17, while the fifth is formed by natural helper type 2 T cells (nTH2, nuocyte, innate type 2 helper cells (IH2 and multi-potent progenitor type 2 cells (MPPtype2. Cells of the last population synthesize IL-5 and IL-13. It is assumed that an extraordinary functional diversity of ILC family, resembles T cells, probably because they are under the control of the corresponding transcription factors - as direct regulation factors, such as the family of lymphocytes T.

  18. Innate immunity in alcoholic liver disease

    Science.gov (United States)

    Seki, Ekihiro; Brenner, David A.; Friedman, Scott; Cohen, Jessica I.; Nagy, Laura; Szabo, Gyongyi; Zakhari, Samir

    2011-01-01

    Excessive alcohol consumption is a leading cause of chronic liver disease in the Western world. Alcohol-induced hepatotoxicity and oxidative stress are important mechanisms contributing to the pathogenesis of alcoholic liver disease. However, emerging evidence suggests that activation of innate immunity involving TLR4 and complement also plays an important role in initiating alcoholic steatohepatitis and fibrosis, but the role of adaptive immunity in the pathogenesis of alcoholic liver disease remains obscure. Activation of a TLR4-mediated MyD88-independent (TRIF/IRF-3) signaling pathway in Kupffer cells contributes to alcoholic steatohepatitis, whereas activation of TLR4 signaling in hepatic stellate cells promotes liver fibrosis. Alcohol consumption activates the complement system in the liver by yet unidentified mechanisms, leading to alcoholic steatohepatitis. In contrast to activation of TLR4 and complement, alcohol consumption can inhibit natural killer cells, another important innate immunity component, contributing to alcohol-mediated acceleration of viral infection and liver fibrosis in patients with chronic viral hepatitis. Understanding of the role of innate immunity in the pathogenesis of alcoholic liver disease may help us identify novel therapeutic targets to treat this disease. PMID:21252049

  19. Heme on innate immunity and inflammation

    Directory of Open Access Journals (Sweden)

    Fabianno Ferreira Dutra

    2014-05-01

    Full Text Available Heme is an essential molecule expressed ubiquitously all through our tissues. Heme plays major functions in cellular physiology and metabolism as the prostetic group of diverse proteins. Once released from cells and from hemeproteins free heme causes oxidative damage and inflammation, thus acting as a prototypic damage-associated molecular pattern. In this context, free heme is a critical component of the pathological process of sterile and infectious hemolytic conditions including malaria, hemolytic anemias, ischemia-reperfusion and hemorrhage. The plasma scavanger proteins hemopexin and albumin reduce heme toxicity and are responsible for transporting free heme to intracellular compartments where it is catabolized by heme-oxygenase enzymes. Upon hemolysis or severe cellular damage the serum capacity to scavange heme may saturate and increase free heme to sufficient amounts to cause tissue damage in various organs. The mechanism by which heme causes reactive oxygen generation, activation of cells of the innate immune system and cell death are not fully understood. Although heme can directly promote lipid peroxidation by its iron atom, heme can also induce ROS generation and production of inflammatory mediators through the activation of selective signaling pathways. Heme activates innate immune cells such as macrophages and neutrophils through activation of innate immune receptors. The importance of these events has been demonstrated in infectious and non-infectious diseases models. In this review we will discuss the mechanisms behind heme-induced citotoxicity and inflammation and the consequences of these events on different tissues and diseases.

  20. siRNA and innate immunity.

    Science.gov (United States)

    Robbins, Marjorie; Judge, Adam; MacLachlan, Ian

    2009-06-01

    Canonical small interfering RNA (siRNA) duplexes are potent activators of the mammalian innate immune system. The induction of innate immunity by siRNA is dependent on siRNA structure and sequence, method of delivery, and cell type. Synthetic siRNA in delivery vehicles that facilitate cellular uptake can induce high levels of inflammatory cytokines and interferons after systemic administration in mammals and in primary human blood cell cultures. This activation is predominantly mediated by immune cells, normally via a Toll-like receptor (TLR) pathway. The siRNA sequence dependency of these pathways varies with the type and location of the TLR involved. Alternatively nonimmune cell activation may also occur, typically resulting from siRNA interaction with cytoplasmic RNA sensors such as RIG1. As immune activation by siRNA-based drugs represents an undesirable side effect due to the considerable toxicities associated with excessive cytokine release in humans, understanding and abrogating this activity will be a critical component in the development of safe and effective therapeutics. This review describes the intracellular mechanisms of innate immune activation by siRNA, the design of appropriate sequences and chemical modification approaches, and suitable experimental methods for studying their effects, with a view toward reducing siRNA-mediated off-target effects.

  1. Epigenomic Views of Innate Lymphoid Cells.

    Science.gov (United States)

    Sciumè, Giuseppe; Shih, Han-Yu; Mikami, Yohei; O'Shea, John J

    2017-01-01

    The discovery of innate lymphoid cells (ILCs) with selective production of cytokines typically attributed to subsets of T helper cells forces immunologists to reassess the mechanisms by which selective effector functions arise. The parallelism between ILCs and T cells extends beyond these two cell types and comprises other innate-like T lymphocytes. Beyond the recognition of specialized effector functionalities in diverse lymphocytes, features typical of T cells, such as plasticity and memory, are also relevant for innate lymphocytes. Herein, we review what we have learned in terms of the molecular mechanisms underlying these shared functions, focusing on insights provided by next generation sequencing technologies. We review data on the role of lineage-defining- and signal-dependent transcription factors (TFs). ILC regulomes emerge developmentally whereas the much of the open chromatin regions of T cells are generated acutely, in an activation-dependent manner. And yet, these regions of open chromatin in T cells and ILCs have remarkable overlaps, suggesting that though accessibility is acquired by distinct modes, the end result is that convergent signaling pathways may be involved. Although much is left to be learned, substantial progress has been made in understanding how TFs and epigenomic status contribute to ILC biology in terms of differentiation, specification, and plasticity.

  2. Innate lymphoid cells and their stromal microenvironments.

    Science.gov (United States)

    Kellermayer, Zoltán; Vojkovics, Dóra; Balogh, Péter

    2017-09-01

    In addition to the interaction between antigen presenting cells, T and B lymphocytes, recent studies have revealed important roles for a diverse set of auxiliary cells that profoundly influence the induction and regulation of immune responses against pathogens. Of these the stromal cells composed of various non-hematopoietic constituents are crucial for the creation and maintenance of specialized semi-static three-dimensional lymphoid tissue microenvironment, whereas the more recently described innate lymphoid cells are generated by the diversification of committed lymphoid precursor cells independently from clonally rearranged antigen receptor genes. Recent findings have revealed important contributions by innate lymphoid cells in inflammation and protection against pathogens in a tissue-specific manner. Importantly, lymphoid stromal cells also influence the onset of immune responses in tissue-specific fashion, raising the possibility of tissue-specific stromal - innate lymphoid cell collaboration. In this review we summarize the main features and interactions between these two cells types, with particular emphasis on ILC type 3 cells and their microenvironmental partners. Copyright © 2017 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  3. Distinct mechanisms of the newborn innate immunity.

    Science.gov (United States)

    Kumar, S Kingsley Manoj; Bhat, B Vishnu

    2016-05-01

    The ontogeny of immunity during early life is of high importance as it shapes the immune system for the entire course of life. The microbiome and the environment contribute to the development of immunity in newborns. As immune responses in newborns are predominantly less experienced they are increasingly susceptible to infections. Though the immune cells in newborns are in 'naïve' state, they have been shown to mount adult-like responses in several circumstances. The innate immunity plays a vital role in providing protection during the neonatal period. Various stimulants have been shown to enhance the potential and functioning of the innate immune cells in newborns. They are biased against the production of pro-inflammatory cytokines and this makes them susceptible to wide variety of intracellular pathogens. The adaptive immunity requires prior antigenic experience which is very limited in newborns. This review discusses in detail the characteristics of innate immunity in newborns and the underlying developmental and functional mechanisms involved in the immune response. A better understanding of the immunological milieu in newborns could help the medical fraternity to find novel methods for prevention and treatment of infection in newborns. Copyright © 2016 European Federation of Immunological Societies. Published by Elsevier B.V. All rights reserved.

  4. Acute kidney injury in stable COPD and at exacerbation

    Directory of Open Access Journals (Sweden)

    Barakat MF

    2015-09-01

    Full Text Available MF Barakat,1 HI McDonald,1 TJ Collier,1 L Smeeth,1 D Nitsch,1 JK Quint1,2 1Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, 2Department of Respiratory Epidemiology, Occupational Medicine and Public Health, National Heart and Lung Institute, Imperial College London, London, UK Background: While acute kidney injury (AKI alone is associated with increased mortality, the incidence of hospital admission with AKI among stable and exacerbating COPD patients and the effect of concurrent AKI at COPD exacerbation on mortality is not known.Methods: A total of 189,561 individuals with COPD were identified from the Clinical Practice Research Datalink. Using Poisson and logistic regressions, we explored which factors predicted admission for AKI (identified in Hospital Episode Statistics in this COPD cohort and concomitant AKI at a hospitalization for COPD exacerbation. Using survival analysis, we investigated the effect of concurrent AKI at exacerbation on mortality (n=36,107 and identified confounding factors.Results: The incidence of AKI in the total COPD cohort was 128/100,000 person-years. The prevalence of concomitant AKI at exacerbation was 1.9%, and the mortality rate in patients with AKI at exacerbation was 521/1,000 person-years. Male sex, older age, and lower glomerular filtration rate predicted higher risk of AKI or death. There was a 1.80 fold (95% confidence interval: 1.61, 2.03 increase in adjusted mortality within the first 6 months post COPD exacerbation in patients suffering from AKI and COPD exacerbation compared to those who were AKI free.Conclusion: In comparison to previous studies on general populations and hospitalizations, the incidence and prevalence of AKI is relatively high in COPD patients. Coexisting AKI at exacerbation is prognostic of poor outcome. Keywords: acute renal failure, mortality, emphysema, chronic bronchitis, prognosis

  5. Influenza Virus Coinfection with Bordetella bronchiseptica Enhances Bacterial Colonization and Host Responses Exacerbating Pulmonary Lesions

    Science.gov (United States)

    Influenza virus (Flu) infection and secondary complications are a leading cause of morbidity and mortality worldwide. The increasing number of annual Flu cases, coupled with the recent Flu pandemic, has amplified concerns about the impact of Flu on human and animal health. Similar to humans, Flu i...

  6. Crohn's Disease Exacerbation Induced by Edwardsiella tarda Gastroenteritis.

    Science.gov (United States)

    Arya, Aman V; Rostom, Alaa; Dong, Wei-Feng; Flynn, Andrew N

    2011-09-01

    Exacerbations of Crohn's disease are not infrequently associated with bacterial gastroenteritis. The recognition of synchronous infections in such patients is vital for the initiation of appropriate antimicrobial therapy. Furthermore, the detection of active bacterial infections may lead the clinician to delay starting biological therapy. We report here a man presenting with an exacerbation of his Crohn's disease during a trip to Thailand. Stool cultures were positive for the unusual gut pathogen Edwardsiella tarda. The patient's symptoms resolved with concurrent antibiotic and steroid therapy. This finding demonstrates the value of performing stool culture in all patients presenting with exacerbations of inflammatory bowel diseases.

  7. Crohn’s Disease Exacerbation Induced by Edwardsiella tarda Gastroenteritis

    Directory of Open Access Journals (Sweden)

    Aman V. Arya

    2011-10-01

    Full Text Available Exacerbations of Crohn’s disease are not infrequently associated with bacterial gastroenteritis. The recognition of synchronous infections in such patients is vital for the initiation of appropriate antimicrobial therapy. Furthermore, the detection of active bacterial infections may lead the clinician to delay starting biological therapy. We report here a man presenting with an exacerbation of his Crohn’s disease during a trip to Thailand. Stool cultures were positive for the unusual gut pathogen Edwardsiella tarda. The patient’s symptoms resolved with concurrent antibiotic and steroid therapy. This finding demonstrates the value of performing stool culture in all patients presenting with exacerbations of inflammatory bowel diseases.

  8. Long-term in vitro and in vivo effects of γ-irradiated BCG on innate and adaptive immunity.

    Science.gov (United States)

    Arts, Rob J W; Blok, Bastiaan A; Aaby, Peter; Joosten, Leo A B; de Jong, Dirk; van der Meer, Jos W M; Benn, Christine Stabell; van Crevel, Reinout; Netea, Mihai G

    2015-12-01

    BCG vaccination is associated with a reduced mortality from nonmycobacterial infections. This is likely to be mediated by a combination of innate-immune memory ("trained immunity") and heterologous effects on adaptive immunity. As such, BCG could be used to boost host immunity but not in immunocompromised hosts, as it is a live, attenuated vaccine. Therefore, we assessed whether killed γBCG has similar potentiating effects. In an in vitro model of trained immunity, human monocytes were incubated with γBCG for 24 h and restimulated after 6 d. Cytokine production and the role of pattern recognition receptors and histone methylation markers were assessed. The in vivo effects of γBCG vaccination were studied in a proof-of-principle trial in 15 healthy volunteers. γBCG induced trained immunity in vitro via the NOD2 receptor pathway and up-regulation of H3K4me3 histone methylation. However, these effects were less strong than those induced by live BCG. γBCG vaccination in volunteers had only minimal effects on innate immunity, whereas a significant increase in heterologous Th1/Th17 immunity was observed. Our results indicate that γBCG induces long-term training of innate immunity in vitro. In vivo, γBCG induces mainly heterologous effects on the adaptive-immune system, whereas effects on innate cytokine production are limited. © Society for Leukocyte Biology.

  9. Brief exposure to cigarette smoke impairs airway epithelial cell innate anti-viral defence.

    Science.gov (United States)

    Logan, Jayden; Chen, Linping; Gangell, Catherine; Sly, Peter D; Fantino, Emmanuelle; Liu, Kenneth

    2014-12-01

    Human rhinovirus (hRV) infections commonly cause acute upper respiratory infections and asthma exacerbations. Environmental cigarette smoke exposure is associated with a significant increase in the risk for these infections in children. To determine the impact of short-term exposure to cigarette smoke on innate immune responses of airway epithelial cells infected with hRV. A human bronchial epithelial cell line (HBEC-3KT) was exposed to cigarette smoke extract (CSE) for 30 min and subsequently infected with hRV serotype 1B. Viral-induced cytokine release was measured with AlphaLISA and viral replication quantified by shed viral titer and intracellular viral copy number 24h post-infection. CSE induced a concentration-dependent decrease in CXCL10 (peffects were maintained when infection was delayed up to 24h post CSE exposure. Exogenous IFN-β treatment at t=0 after infection blunts the effects of CSE on viral replication (pexposure of 30 min to cigarette smoke has a lasting impact on epithelial innate defence providing a plausible mechanism for the increase in respiratory infections seen in children exposed to second-hand tobacco smoke. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Host defences against Giardia lamblia.

    Science.gov (United States)

    Lopez-Romero, G; Quintero, J; Astiazarán-García, H; Velazquez, C

    2015-08-01

    Giardia spp. is a protozoan parasite that inhabits the upper small intestine of mammals and other species and is the aetiological agent of giardiasis. It has been demonstrated that nitric oxide, mast cells and dendritic cells are the first line of defence against Giardia. IL-6 and IL-17 play an important role during infection. Several cytokines possess overlapping functions in regulating innate and adaptive immune responses. IgA and CD4(+) T cells are fundamental to the process of Giardia clearance. It has been suggested that CD4(+) T cells play a double role during the anti-Giardia immune response. First, they activate and stimulate the differentiation of B cells to generate Giardia-specific antibodies. Second, they act through a B-cell-independent mechanism that is probably mediated by Th17 cells. Several Giardia proteins that stimulate humoral and cellular immune responses have been described. Variant surface proteins, α-1 giardin, and cyst wall protein 2 can induce host protective responses to future Giardia challenges. The characterization and evaluation of the protective potential of the immunogenic proteins that are associated with Giardia will offer new insights into host-parasite interactions and may aid in the development of an effective vaccine against the parasite. © 2015 John Wiley & Sons Ltd.

  11. Interactions between Innate Lymphoid Cells and Cells of the Innate and Adaptive Immune System.

    Science.gov (United States)

    Symowski, Cornelia; Voehringer, David

    2017-01-01

    Type 2 innate lymphoid cells (ILC2s) are a major source of cytokines, which are also produced by Th2 cells and several cell types of the innate immune system. Work over the past few years indicates that ILC2s play a central role in regulating type 2 immune responses against allergens and helminths. ILC2s can interact with a variety of cells types of the innate and adaptive immune system by cell-cell contacts or by communication via soluble factors. In this review, we provide an overview about recent advances in our understanding how ILC2s orchestrate type 2 immune responses with focus on direct interactions between ILC2s and other cells of the immune system.

  12. Innate immunity drives the initiation of a murine model of primary biliary cirrhosis.

    Directory of Open Access Journals (Sweden)

    Chao-Hsuan Chang

    Full Text Available Invariant natural killer T (iNKT cells play complex roles in bridging innate and adaptive immunity by engaging with glycolipid antigens presented by CD1d. Our earlier work suggested that iNKT cells were involved in the initiation of the original loss of tolerance in primary biliary cirrhosis (PBC. To address this issue in more detail and, in particular, to focus on whether iNKT cells activated by a Th2-biasing agonist (2s,3s,4r-1-O-(α-D-galactopyranosyl-N-tetracosanoyl-2-amino-1,3,4-nonanetriol (OCH, can influence the development of PBC in a xenobiotic-induced PBC murine model. Groups of mice were treated with either OCH or, as a control, α-galactosylceramide (α-GalCer and thence serially followed for cytokine production, markers of T cell activation, liver histopathology and anti-mitochondrial antibody responses. Further, additional groups of CD1d deleted mice were similarly studied. Our data indicate that administration of OCH has a dramatic influence with exacerbation of portal inflammation and hepatic fibrosis similar to mice treated with α-GalCer. Further, iNKT cell deficient CD1d knockout mice have decreased inflammatory portal cell infiltrates and reduced anti-mitochondrial antibody responses. We submit that activation of iNKT cells can occur via overlapping and/or promiscuous pathways and highlight the critical role of innate immunity in the natural history of autoimmune cholangitis. These data have implications for humans with PBC and emphasize that therapeutic strategies must focus not only on suppressing adaptive responses, but also innate immunity.

  13. Interactions between intestinal microbiota and innate immune system in pediatric inflammatory bowel disease.

    Science.gov (United States)

    Cucchiara, Salvatore; Stronati, Laura; Aloi, Marina

    2012-10-01

    Inflammatory bowel disease (IBD) is the result of an altered immune homeostasis within the intestinal mucosa against the gut microbiota, leading to chronic inflammation in genetically predisposed individuals. Under normal conditions, the immune system defends against pathogens and prevents the passage of excessive intestinal bacteria; regulatory pathways must maintain a low-grade, controlled inflammation in a healthy gut, but also induce a protective response against pathogens. The innate immune system is the first-line defense from microbes; dendritic cells, macrophages, and epithelial cells produce an initial, immediate response. The immune system constantly controls commensal bacteria and utilizes constitutive antimicrobial mechanisms to sustain immune homeostasis. The discovery that several genes linked to IBD modulate microbial recognition and innate immune pathways, such as nucleotide oligomerization domain 2 (Nod2), and genes that mediate autophagy (ie, ATG16L1, IRGM), has highlighted the critical role of host-microbe interactions in controlling intestinal immune homeostasis. Commensal microorganisms actively interact with the intestinal mucosa and influence the activity of the immune system as well as the amplitude of the immune response. In contrast, host factors can influence microbes, which in turn modulate disease susceptibility. In this paper, we focus on the mechanisms that mediate host-microbe interactions and how the disruption of this balance leads to chronic intestinal inflammation in IBD.

  14. Phenytoin induced Stevens-Johnson syndrome exacerbated by cefepime

    OpenAIRE

    Prabhu, Varsha A.; Doddapaneni, Sahiti; Thunga, Girish; Thiyagu, Rajakannan; Prabhu, M. Mukyaprana; Naha, Kushal

    2013-01-01

    Steven Johnson syndrome (SJS) is a rare drug induced mucocutaneous reaction. Here, we present an elaborate report of a 28-year-old female patient who developed Phenytoin induced SJS, which was exacerbated by cefepime.

  15. Phenytoin induced Stevens-Johnson syndrome exacerbated by cefepime.

    Science.gov (United States)

    Prabhu, Varsha A; Doddapaneni, Sahiti; Thunga, Girish; Thiyagu, Rajakannan; Prabhu, M Mukyaprana; Naha, Kushal

    2013-10-01

    Steven Johnson syndrome (SJS) is a rare drug induced mucocutaneous reaction. Here, we present an elaborate report of a 28-year-old female patient who developed Phenytoin induced SJS, which was exacerbated by cefepime.

  16. Susceptibility to exacerbation in chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Hurst, John R; Vestbo, Jørgen; Anzueto, Antonio

    2010-01-01

    BACKGROUND: Although we know that exacerbations are key events in chronic obstructive pulmonary disease (COPD), our understanding of their frequency, determinants, and effects is incomplete. In a large observational cohort, we tested the hypothesis that there is a frequent-exacerbation phenotype...... of follow-up were 0.85 per person for patients with stage 2 COPD (with stage defined in accordance with Global Initiative for Chronic Obstructive Lung Disease [GOLD] stages), 1.34 for patients with stage 3, and 2.00 for patients with stage 4. Overall, 22% of patients with stage 2 disease, 33% with stage 3...... of COPD that is independent of disease severity. METHODS: We analyzed the frequency and associations of exacerbation in 2138 patients enrolled in the Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE) study. Exacerbations were defined as events that led a care provider...

  17. Childhood obesity in relation to poor asthma control and exacerbations

    NARCIS (Netherlands)

    Ahmadizar, Fariba; Vijverberg, Susanne; Arets, Hubertus; De Boer, Anthonius; Lang, Jason; Kattan, Meyer; Palmer, Colin; Mukhopadhyay, Somnath; Turner, Steve; Van Der Zee, Anke-Hilse Maitland

    2016-01-01

    Background: The relationship between obesity and asthma severity in children is inconsistent across studies. Objectives: To estimate the association between obesity and poor asthma control/ risk of exacerbations in asthmatic children and adolescents, and to assess whether these associations are

  18. Age-Specific Characteristics of Inpatients with Severe Asthma Exacerbation

    Directory of Open Access Journals (Sweden)

    Kiyoshi Sekiya

    2013-01-01

    Conclusions: The characteristics of inpatients with severe asthma vary depending on age. We need to establish countermeasures for asthma exacerbation according to the characteristics of patients depending on age.

  19. Chemical modulators of the innate immune response alter gypsy moth larval susceptibility to Bacillus thuringiensis.

    Science.gov (United States)

    Broderick, Nichole A; Raffa, Kenneth F; Handelsman, Jo

    2010-04-27

    The gut comprises an essential barrier that protects both invertebrate and vertebrate animals from invasion by microorganisms. Disruption of the balanced relationship between indigenous gut microbiota and their host can result in gut bacteria eliciting host responses similar to those caused by invasive pathogens. For example, ingestion of Bacillus thuringiensis by larvae of some species of susceptible Lepidoptera can result in normally benign enteric bacteria exerting pathogenic effects. We explored the potential role of the insect immune response in mortality caused by B. thuringiensis in conjunction with gut bacteria. Two lines of evidence support such a role. First, ingestion of B. thuringiensis by gypsy moth larvae led to the depletion of their hemocytes. Second, pharmacological agents that are known to modulate innate immune responses of invertebrates and vertebrates altered larval mortality induced by B. thuringiensis. Specifically, Gram-negative peptidoglycan pre-treated with lysozyme accelerated B. thuringiensis-induced killing of larvae previously made less susceptible due to treatment with antibiotics. Conversely, several inhibitors of the innate immune response (eicosanoid inhibitors and antioxidants) increased the host's survival time following ingestion of B. thuringiensis. This study demonstrates that B. thuringiensis infection provokes changes in the cellular immune response of gypsy moth larvae. The effects of chemicals known to modulate the innate immune response of many invertebrates and vertebrates, including Lepidoptera, also indicate a role of this response in B. thuringiensis killing. Interactions among B. thuringiensis toxin, enteric bacteria, and aspects of the gypsy moth immune response may provide a novel model to decipher mechanisms of sepsis associated with bacteria of gut origin.

  20. Chemical modulators of the innate immune response alter gypsy moth larval susceptibility to Bacillus thuringiensis

    Directory of Open Access Journals (Sweden)

    Broderick Nichole A

    2010-04-01

    Full Text Available Abstract Background The gut comprises an essential barrier that protects both invertebrate and vertebrate animals from invasion by microorganisms. Disruption of the balanced relationship between indigenous gut microbiota and their host can result in gut bacteria eliciting host responses similar to those caused by invasive pathogens. For example, ingestion of Bacillus thuringiensis by larvae of some species of susceptible Lepidoptera can result in normally benign enteric bacteria exerting pathogenic effects. Results We explored the potential role of the insect immune response in mortality caused by B. thuringiensis in conjunction with gut bacteria. Two lines of evidence support such a role. First, ingestion of B. thuringiensis by gypsy moth larvae led to the depletion of their hemocytes. Second, pharmacological agents that are known to modulate innate immune responses of invertebrates and vertebrates altered larval mortality induced by B. thuringiensis. Specifically, Gram-negative peptidoglycan pre-treated with lysozyme accelerated B. thuringiensis-induced killing of larvae previously made less susceptible due to treatment with antibiotics. Conversely, several inhibitors of the innate immune response (eicosanoid inhibitors and antioxidants increased the host's survival time following ingestion of B. thuringiensis. Conclusions This study demonstrates that B. thuringiensis infection provokes changes in the cellular immune response of gypsy moth larvae. The effects of chemicals known to modulate the innate immune response of many invertebrates and vertebrates, including Lepidoptera, also indicate a role of this response in B. thuringiensis killing. Interactions among B. thuringiensis toxin, enteric bacteria, and aspects of the gypsy moth immune response may provide a novel model to decipher mechanisms of sepsis associated with bacteria of gut origin.

  1. Fibrinogen and α1-antitrypsin in COPD exacerbations

    DEFF Research Database (Denmark)

    Ingebrigtsen, Truls S; Marott, Jacob L; Rode, Line

    2015-01-01

    BACKGROUND: We tested the hypotheses that fibrinogen and α1-antitrypsin are observationally and genetically associated with exacerbations in COPD. METHODS: We studied 13,591 individuals with COPD from the Copenhagen General Population Study (2003-2013), of whom 6857 were genotyped for FGB -455 (rs...... in instrumental variable analyses. RESULTS: Elevated fibrinogen and α1-antitrypsin levels were associated with increased risk of exacerbations in COPD, HR=1.14 (1.07 to 1.22, p

  2. Oxygen therapy in acute exacerbations of chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Ringbaek, T.; Lange, P.; Mogensen, T.

    2008-01-01

    Acute exacerbation of COPD is a major cause of hospitalisation in Denmark. Most of the patients require supplemental oxygen in the acute phase and some patients continue oxygen therapy at home after discharge. In this paper we discuss the physiological mechanisms of respiratory failure seen...... in acute exacerbations of COPD. The principles for oxygen therapy in the acute phase are described and recommendations for oxygen therapy are suggested Udgivelsesdato: 2008/5/5...

  3. Beta Blockers for the Prevention of Acute Exacerbations of COPD

    Science.gov (United States)

    2016-10-01

    40%.21 22 ▸ Current therapy with ocular β-blocker medications. ▸ Critical ischaemia related to peripheral arterial disease . ▸ Other diseases that are...exacerbations of chronic obstructive pulmonary disease (βLOCK COPD): a randomised controlled study protocol. Bhatt, SP; Connett, JE; Voelker, H...acute exacerbations of chronic obstructive pulmonary disease (βLOCK COPD): a randomised controlled study protocol Surya P Bhatt,1 John E Connett,2 Helen

  4. [Risk factors for acute exacerbation in patients with bronchiectasis].

    Science.gov (United States)

    Jiao, Rui; Liu, Shuang

    2015-01-27

    To evaluate the risk factors for patients with an acute exacerbation of bronchiectasis. Retrospective analyses were conducted for 228 patients diagnosed with acute exacerbation of bronchiectasis at Affiliated Beijing Anzhen Hospital, Capital Medical University from January 2008 to December 2012. Depending on whether there were recurrences with exacerbation within one year after discharge, they were divided into two groups. Their basic profiles, clinical symptoms and signs, blood tests, sputum culture, dyspnea score (mMRC) and imaging data were analyzed. There were 110 males and 118 females with an average age of (64.5+14.5) years. The incidence of the recurrence of acute exacerbation was 55.7% (127/228) within one year after discharge. Multivariate Logistic regression analysis showed that age ≥ 60 years (OR = 2.583, 95%CI: 1.188-5.613), body mass index (BMI)resolution computed tomography (CT) displayed bronchiectasis involving ≥ 3 lobes (OR = 3.179, 95%CI: 1.449-6.976) and staying in intensive care unit (ICU) (OR = 2.499, 95%CI: 1.301-4.801) were associated with the acute exacerbation of bronchiectasis (all P < 0.05). There are multiple risk factors of acute exacerbation in patients with bronchiectasis. And their proper identification and management shall improve the prognosis of bronchiectasis patients.

  5. The causes and consequences of seasonal variation in COPD exacerbations

    Directory of Open Access Journals (Sweden)

    Donaldson GC

    2014-10-01

    Full Text Available Gavin C Donaldson, Jadwiga A Wedzicha Airways Disease Section, National Heart and Lung Institute, Imperial College London, London, UK Abstract: The time of year when patients experience exacerbations of chronic obstructive pulmonary disease is a much-overlooked feature of the disease. The higher incidence of exacerbations in winter has important consequences for patients in terms of increased morbidity and mortality. The seasonality also imposes a considerable burden on already-overloaded health care services, with both primary care consultations and hospital admissions increasing in number. The seasonality of exacerbations varies with latitude, and is greater in more temperate climates, where there may be less protection from outdoor and indoor cold exposure. The precise causes of the seasonality are unknown, but thought to be partly due to the increased prevalence of respiratory viral infections circulating in cold, damp conditions. Increased susceptibility to viral infection may also be a mechanism mediated through increased airway inflammation or possibly reduced vitamin D levels. The seasonality of exacerbations informs us about the triggers of exacerbations and suggests possible strategies to reduce their number. Keywords: exacerbations of COPD, seasonality, winter mortality, winter morbidity

  6. Antibiotics usefulness and choice in BPCO acute exacerbation

    Directory of Open Access Journals (Sweden)

    Bruno Tartaglino

    2005-10-01

    Full Text Available Although the debate on the role of bacterial infections and antibiotic treatment in AE-COPD remains open, there is evidence that the persistence of bacteria after acute exacerbation (residual bacterial colony influences the frequency and severity of subsequent acute exacerbation and that antibiotic treatment that induces faster and more complete eradication produces better clinical outcomes. New aspects must now be considered, given that COPD is a chronic illness subject to acute exacerbations of varying frequencies and that acute exacerbations correspond to functional respiratory deterioration. One of the parameters that is currently acquiring clinical relevance is the interval free of infection (IFI, the period that elapses between one acute exacerbation and the next, caused by bacterial infection. Another guiding concept in the choice of antibiotic treatment is that not all patients benefit in the same way; those requiring more aggressive treatment are most likely to be those with FEV1 < 50%, frequent exacerbations (> 3/year treated with antibiotics, relevant co-morbidity, under chronic steroid treatment, etc., for these patients it is recommended to administer antibiotics active on the three most common pathogens (in particular H. influenzae, considering the resistance acquired in recent years, and on Pseudomomias aeruginosa.

  7. Expression of innate immune genes, proteins and microRNAs in lung tissue and leukocytes of pigs infected with influenza virus

    DEFF Research Database (Denmark)

    Skovgaard, Kerstin; Cirera, Susanna; Vasby, Ditte

    This study aimed at providing a better understanding of the involvement of innate immune factors including microRNA (miRNA) in the local and systemic host response to influenza virus infection. Twenty pigs were challenged by influenza A virus subtype H1N2. Expression of miRNA, mRNA and proteins w...

  8. ALV-J strain SCAU-HN06 induces innate immune responses in chicken primary monocyte-derived macrophages.

    Science.gov (United States)

    Feng, Min; Dai, Manman; Cao, Weisheng; Tan, Yan; Li, Zhenhui; Shi, Meiqing; Zhang, Xiquan

    2017-01-01

    Avian leucosis virus subgroup J (ALV-J) can cause lifelong infection and can escape from the host immune defenses in chickens. Since macrophages act as the important defense line against invading pathogens in host innate immunity, we investigated the function and innate immune responses of chicken primary monocyte-derived macrophages (MDM) after ALV-J infection in this study. Our results indicated that ALV-J was stably maintained in MDM cells but that the viral growth rate was significantly lower than that in DF-1 cells. We also found that ALV-J infection significantly increased nitric oxide (NO) production, but had no effect on MDM phagocytic capacity. Interestingly, infection with ALV-J rapidly promoted the expression levels of Myxovirus resistance 1 (Mx) (3 h, 6 h), ISG12 (6 h), and interleukin-1β (IL-1β) (3 h, 12 h) at an early infection stage, whereas it sharply decreased the expression of Mx (24 h, 36 h), ISG12 (36 h), and made little change on IL-1β (24 h, 36 h) production at a late infection stage in MDM cells. Moreover, the protein levels of interferon-β (IFN-β) and interleukin-6 (IL-6) had sharply increased in infected MDM cells from 3 to 36 h post infection (hpi) of ALV-J. And, the protein level of interleukin-10 (IL-10) was dramatically decreased at 36 hpi in MDM cells infected with ALV-J. These results demonstrate that ALV-J can induce host innate immune responses and we hypothesize that macrophages play an important role in host innate immune attack and ALV-J immune escape. © The Author 2016. Published by Oxford University Press on behalf of Poultry Science Association.

  9. The role of pattern recognition receptors in the innate recognition of Candida albicans

    Science.gov (United States)

    Zheng, Nan-Xin; Wang, Yan; Hu, Dan-Dan; Yan, Lan; Jiang, Yuan-Ying

    2015-01-01

    Candida albicans is both a commensal microorganism in healthy individuals and a major fungal pathogen causing high mortality in immunocompromised patients. Yeast-hypha morphological transition is a well known virulence trait of C. albicans. Host innate immunity to C. albicans critically requires pattern recognition receptors (PRRs). In this review, we summarize the PRRs involved in the recognition of C. albicans in epithelial cells, endothelial cells, and phagocytic cells separately. We figure out the differential recognition of yeasts and hyphae, the findings on PRR-deficient mice, and the discoveries on human PRR-related single nucleotide polymorphisms (SNPs). PMID:25714264

  10. Infectious Disease: Connecting Innate Immunity to Biocidal Polymers.

    Science.gov (United States)

    Gabriel, Gregory J; Som, Abhigyan; Madkour, Ahmad E; Eren, Tarik; Tew, Gregory N

    2007-08-01

    Infectious disease is a critically important global healthcare issue. In the U.S. alone there are 2 million new cases of hospital-acquired infections annually leading to 90,000 deaths and 5 billion dollars of added healthcare costs. Couple these numbers with the appearance of new antibiotic resistant bacterial strains and the increasing occurrences of community-type outbreaks, and clearly this is an important problem. Our review attempts to bridge the research areas of natural host defense peptides (HDPs), a component of the innate immune system, and biocidal cationic polymers. Recently discovered peptidomimetics and other synthetic mimics of HDPs, that can be short oligomers as well as polymeric macromolecules, provide a unique link between these two areas. An emerging class of these mimics are the facially amphiphilic polymers that aim to emulate the physicochemical properties of HDPs but take advantage of the synthetic ease of polymers. These mimics have been designed with antimicrobial activity and, importantly, selectivity that rivals natural HDPs. In addition to providing some perspective on HDPs, selective mimics, and biocidal polymers, focus is given to the arsenal of biophysical techniques available to study their mode of action and interactions with phospholipid membranes. The issue of lipid type is highlighted and the important role of negative curvature lipids is illustrated. Finally, materials applications (for instance, in the development of permanently antibacterial surfaces) are discussed as this is an important part of controlling the spread of infectious disease.

  11. Coronavirus infection, ER stress, apoptosis and innate immunity

    Science.gov (United States)

    Fung, To S.; Liu, Ding X.

    2014-01-01

    The replication of coronavirus, a family of important animal and human pathogens, is closely associated with the cellular membrane compartments, especially the endoplasmic reticulum (ER). Coronavirus infection of cultured cells was previously shown to cause ER stress and induce the unfolded protein response (UPR), a process that aims to restore the ER homeostasis by global translation shutdown and increasing the ER folding capacity. However, under prolonged ER stress, UPR can also induce apoptotic cell death. Accumulating evidence from recent studies has shown that induction of ER stress and UPR may constitute a major aspect of coronavirus–host interaction. Activation of the three branches of UPR modulates a wide variety of signaling pathways, such as mitogen-activated protein (MAP) kinase activation, autophagy, apoptosis, and innate immune response. ER stress and UPR activation may therefore contribute significantly to the viral replication and pathogenesis during coronavirus infection. In this review, we summarize the current knowledge on coronavirus-induced ER stress and UPR activation, with emphasis on their cross-talking to apoptotic signaling. PMID:24987391

  12. The humoral pattern recognition molecule PTX3 is a key component of innate immunity against urinary tract infection.

    Science.gov (United States)

    Jaillon, Sébastien; Moalli, Federica; Ragnarsdottir, Bryndis; Bonavita, Eduardo; Puthia, Manoj; Riva, Federica; Barbati, Elisa; Nebuloni, Manuela; Cvetko Krajinovic, Lidija; Markotic, Alemka; Valentino, Sonia; Doni, Andrea; Tartari, Silvia; Graziani, Giorgio; Montanelli, Alessandro; Delneste, Yves; Svanborg, Catharina; Garlanda, Cecilia; Mantovani, Alberto

    2014-04-17

    Immunity in the urinary tract has distinct and poorly understood pathophysiological characteristics and urinary tract infections (UTIs) are important causes of morbidity and mortality. We investigated the role of the soluble pattern recognition molecule pentraxin 3 (PTX3), a key component of the humoral arm of innate immunity, in UTIs. PTX3-deficient mice showed defective control of UTIs and exacerbated inflammation. Expression of PTX3 was induced in uroepithelial cells by uropathogenic Escherichia coli (UPEC) in a Toll-like receptor 4 (TLR4)- and MyD88-dependent manner. PTX3 enhanced UPEC phagocytosis and phagosome maturation by neutrophils. PTX3 was detected in urine of UTI patients and amounts correlated with disease severity. In cohorts of UTI-prone patients, PTX3 gene polymorphisms correlated with susceptibility to acute pyelonephritis and cystitis. These results suggest that PTX3 is an essential component of innate resistance against UTIs. Thus, the cellular and humoral arms of innate immunity exert complementary functions in mediating resistance against UTIs. Copyright © 2014 Elsevier Inc. All rights reserved.

  13. An Evolutionarily Conserved Innate Immunity Protein Interaction Network*

    Science.gov (United States)

    De Arras, Lesly; Seng, Amara; Lackford, Brad; Keikhaee, Mohammad R.; Bowerman, Bruce; Freedman, Jonathan H.; Schwartz, David A.; Alper, Scott

    2013-01-01

    The innate immune response plays a critical role in fighting infection; however, innate immunity also can affect the pathogenesis of a variety of diseases, including sepsis, asthma, cancer, and atherosclerosis. To identify novel regulators of innate immunity, we performed comparative genomics RNA interference screens in the nematode Caenorhabditis elegans and mouse macrophages. These screens have uncovered many candidate regulators of the response to lipopolysaccharide (LPS), several of which interact physically in multiple species to form an innate immunity protein interaction network. This protein interaction network contains several proteins in the canonical LPS-responsive TLR4 pathway as well as many novel interacting proteins. Using RNAi and overexpression studies, we show that almost every gene in this network can modulate the innate immune response in mouse cell lines. We validate the importance of this network in innate immunity regulation in vivo using available mutants in C. elegans and mice. PMID:23209288

  14. Host response mechanisms in periodontal diseases

    Directory of Open Access Journals (Sweden)

    Nora SILVA

    2015-06-01

    Full Text Available Periodontal diseases usually refer to common inflammatory disorders known as gingivitis and periodontitis, which are caused by a pathogenic microbiota in the subgingival biofilm, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola that trigger innate, inflammatory, and adaptive immune responses. These processes result in the destruction of the tissues surrounding and supporting the teeth, and eventually in tissue, bone and finally, tooth loss. The innate immune response constitutes a homeostatic system, which is the first line of defense, and is able to recognize invading microorganisms as non-self, triggering immune responses to eliminate them. In addition to the innate immunity, adaptive immunity cells and characteristic cytokines have been described as important players in the periodontal disease pathogenesis scenario, with a special attention to CD4+ T-cells (T-helper cells. Interestingly, the T cell-mediated adaptive immunity development is highly dependent on innate immunity-associated antigen presenting cells, which after antigen capture undergo into a maturation process and migrate towards the lymph nodes, where they produce distinct patterns of cytokines that will contribute to the subsequent polarization and activation of specific T CD4+ lymphocytes. Skeletal homeostasis depends on a dynamic balance between the activities of the bone-forming osteoblasts (OBLs and bone-resorbing osteoclasts (OCLs. This balance is tightly controlled by various regulatory systems, such as the endocrine system, and is influenced by the immune system, an osteoimmunological regulation depending on lymphocyte- and macrophage-derived cytokines. All these cytokines and inflammatory mediators are capable of acting alone or in concert, to stimulate periodontal breakdown and collagen destruction via tissue-derived matrix metalloproteinases, a characterization of the progression of periodontitis as

  15. Host response mechanisms in periodontal diseases

    Science.gov (United States)

    SILVA, Nora; ABUSLEME, Loreto; BRAVO, Denisse; DUTZAN, Nicolás; GARCIA-SESNICH, Jocelyn; VERNAL, Rolando; HERNÁNDEZ, Marcela; GAMONAL, Jorge

    2015-01-01

    Periodontal diseases usually refer to common inflammatory disorders known as gingivitis and periodontitis, which are caused by a pathogenic microbiota in the subgingival biofilm, including Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Tannerella forsythia and Treponema denticola that trigger innate, inflammatory, and adaptive immune responses. These processes result in the destruction of the tissues surrounding and supporting the teeth, and eventually in tissue, bone and finally, tooth loss. The innate immune response constitutes a homeostatic system, which is the first line of defense, and is able to recognize invading microorganisms as non-self, triggering immune responses to eliminate them. In addition to the innate immunity, adaptive immunity cells and characteristic cytokines have been described as important players in the periodontal disease pathogenesis scenario, with a special attention to CD4+ T-cells (T-helper cells). Interestingly, the T cell-mediated adaptive immunity development is highly dependent on innate immunity-associated antigen presenting cells, which after antigen capture undergo into a maturation process and migrate towards the lymph nodes, where they produce distinct patterns of cytokines that will contribute to the subsequent polarization and activation of specific T CD4+ lymphocytes. Skeletal homeostasis depends on a dynamic balance between the activities of the bone-forming osteoblasts (OBLs) and bone-resorbing osteoclasts (OCLs). This balance is tightly controlled by various regulatory systems, such as the endocrine system, and is influenced by the immune system, an osteoimmunological regulation depending on lymphocyte- and macrophage-derived cytokines. All these cytokines and inflammatory mediators are capable of acting alone or in concert, to stimulate periodontal breakdown and collagen destruction via tissue-derived matrix metalloproteinases, a characterization of the progression of periodontitis as a stage that

  16. Innate Lymphoid Cells in Tumor Immunity.

    Science.gov (United States)

    van Beek, Jasper J P; Martens, Anne W J; Bakdash, Ghaith; de Vries, I Jolanda M

    2016-02-25

    Innate lymphoid cells (ILCs) are a group of immune cells of the lymphoid lineage that do not possess antigen specificity. The group includes natural killer (NK) cells, lymphoid tissue inducer (LTi) cells and the recently identified ILC1s, ILC2s and ILC3s. Although the role of NK cells in the context of cancer has been well established, the involvement of other ILC subsets in cancer progression and resistance is just emerging. Here, we review the literature on the role of the different ILC subsets in tumor immunity and discuss its implications for cancer treatment and monitoring.

  17. The Development of Adult Innate Lymphoid Cells

    Science.gov (United States)

    Yang, Qi; Bhandoola, Avinash

    2016-01-01

    Innate lymphoid cells (ILC) are a specialized family of effector lymphocytes that transcriptionally and functionally mirror effector subsets of T cells, but differ from T cells in that they lack clonally-distributed adaptive antigen receptors. Our understanding of this family of lymphocytes is still in its infancy. In this review, we summarize current understanding and discuss recent insights into the cellular and molecular events that occur during early ILC development in adult mice. We discuss how these events overlap and diverge with the early development of adaptive T cells, and how they may influence the molecular and functional properties of mature ILC. PMID:26871595

  18. Regulation of the Host Antiviral State by Intercellular Communications

    Directory of Open Access Journals (Sweden)

    Sonia Assil

    2015-08-01

    Full Text Available Viruses usually induce a profound remodeling of host cells, including the usurpation of host machinery to support their replication and production of virions to invade new cells. Nonetheless, recognition of viruses by the host often triggers innate immune signaling, preventing viral spread and modulating the function of immune cells. It conventionally occurs through production of antiviral factors and cytokines by infected cells. Virtually all viruses have evolved mechanisms to blunt such responses. Importantly, it is becoming increasingly recognized that infected cells also transmit signals to regulate innate immunity in uninfected neighboring cells. These alternative pathways are notably mediated by vesicular secretion of various virus- and host-derived products (miRNAs, RNAs, and proteins and non-infectious viral particles. In this review, we focus on these newly-described modes of cell-to-cell communications and their impact on neighboring cell functions. The reception of these signals can have anti- and pro-viral impacts, as well as more complex effects in the host such as oncogenesis and inflammation. Therefore, these “broadcasting” functions, which might be tuned by an arms race involving selective evolution driven by either the host or the virus, constitute novel and original regulations of viral infection, either highly localized or systemic.

  19. Interaction of entomopathogenic fungi with the host immune system.

    Science.gov (United States)

    Qu, Shuang; Wang, Sibao

    2018-02-02

    Entomopathogenic fungi can invade wide range of insect hosts in the natural world and have been used as environmentally friendly alternatives to chemical insecticides for pest control. Studies of host-pathogen interactions provide valuable insights into the coevolutionay arms race between fungal pathogens and their hosts. Entomopathogenic fungi have evolved a series of sophisticated strategies to counter insect immune defenses. In response to fungal infection, insect hosts rely on behavior avoidance, physical barrier and innate immune defenses in the fight against invading pathogens. The insect cuticle acts as the first physical barrier against pathogens. It is an inhospitable physiological environment that contains chemicals (e.g., antimicrobial peptides and reactive oxygen species), which inhibit fungal growth. In addition, innate immune responses, including cellular immunity and humoral immunity, play critical roles in preventing fungal infection. In this review, we outline the current state of our knowledge of insect defenses to fungal infection and discuss the strategies by which entomopathogenic fungi counter the host immune system. Increased knowledge regarding the molecular interactions between entomopathogenic fungi and the insect host could provide new strategies for pest management. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Hepatitis C and Innate Immunity – Recent Advances

    OpenAIRE

    Szabo, Gyongyi; Dolganiuc, Angela

    2008-01-01

    Eradication of HCV infection requires a complex and coordinated interplay between innate and adaptive immune responses that, when it fails, leads to chronic infection. Increasing evidence suggest that defects in innate immune recognition and in innate immunity-induced activation of adaptive immune responses play a critical role in failure of HCV clearance. The evolutionarily preserved receptors of viral recognition in immune cells and in hepatocytes sense invading pathogens that results in in...