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Sample records for innate immune defenses

  1. Personality and innate immune defenses in a wild bird

    NARCIS (Netherlands)

    Jacques-Hamilton, Rowan; Hall, Michelle L.; Buttemer, William A.; Matson, Kevin D.; Gonçalves da Silva, Anders; Mulder, Raoul A.; Peters, Anne

    2017-01-01

    We tested the two main evolutionary hypotheses for an association between immunity and personality. The risk-of-parasitism hypothesis predicts that more proactive (bold, exploratory, risk-taking) individuals have more vigorous immune defenses because of increased risk of parasite exposure. In

  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. Extraribosomal l13a is a specific innate immune factor for antiviral defense.

    Science.gov (United States)

    Mazumder, Barsanjit; Poddar, Darshana; Basu, Abhijit; Kour, Ravinder; Verbovetskaya, Valentina; Barik, Sailen

    2014-08-01

    We report a novel extraribosomal innate immune function of mammalian ribosomal protein L13a, whereby it acts as an antiviral agent. We found that L13a is released from the 60S ribosomal subunit in response to infection by respiratory syncytial virus (RSV), an RNA virus of the Pneumovirus genus and a serious lung pathogen. Unexpectedly, the growth of RSV was highly enhanced in L13a-knocked-down cells of various lineages as well as in L13a knockout macrophages from mice. In all L13a-deficient cells tested, translation of RSV matrix (M) protein was specifically stimulated, as judged by a greater abundance of M protein and greater association of the M mRNA with polyribosomes, while general translation was unaffected. In silico RNA folding analysis and translational reporter assays revealed a putative hairpin in the 3'untranslated region (UTR) of M mRNA with significant structural similarity to the cellular GAIT (gamma-activated inhibitor of translation) RNA hairpin, previously shown to be responsible for assembling a large, L13a-containing ribonucleoprotein complex that promoted translational silencing in gamma interferon (IFN-γ)-activated myeloid cells. However, RNA-protein interaction studies revealed that this complex, which we named VAIT (respiratory syncytial virus-activated inhibitor of translation) is functionally different from the GAIT complex. VAIT is the first report of an extraribosomal L13a-mediated, IFN-γ-independent innate antiviral complex triggered in response to virus infection. We provide a model in which the VAIT complex strongly hinders RSV replication by inhibiting the translation of the rate-limiting viral M protein, which is a new paradigm in antiviral defense. The innate immune mechanisms of host cells are diverse in nature and act as a broad-spectrum cellular defense against viruses. Here, we report a novel innate immune mechanism functioning against respiratory syncytial virus (RSV), in which the cellular ribosomal protein L13a is released

  4. Innate immunity

    African Journals Online (AJOL)

    Ronnie Anderson is Director of the Medical Research Council Unit for Inflammation and Immunity. ... field have included macrophage, T cell, cytokine and cytokine activated killer cell interactions .... monocytes, mast cells, lymphocytes, eccrine.

  5. Skin innate immune system

    Directory of Open Access Journals (Sweden)

    Berna Aksoy

    2013-06-01

    Full Text Available All multicellular organisms protect themselves from external universe and microorganisms by innate immune sytem that is constitutively present. Skin innate immune system has several different components composed of epithelial barriers, humoral factors and cellular part. In this review information about skin innate immune system and its components are presented to the reader. Innate immunity, which wasn’t adequately interested in previously, is proven to provide a powerfull early protection system, control many infections before the acquired immunity starts and directs acquired immunity to develop optimally

  6. Ironing Out the Wrinkles in Host Defense: Interactions between Iron Homeostasis and Innate Immunity

    Science.gov (United States)

    Wang, Lijian; Cherayil, Bobby J.

    2009-01-01

    Iron is an essential micronutrient for both microbial pathogens and their mammalian hosts. Changes in iron availability and distribution have significant effects on pathogen virulence and on the immune response to infection. Recent advances in our understanding of the molecular regulation of iron metabolism have shed new light on how alterations in iron homeostasis both contribute to and influence innate immunity. In this article, we review what is currently known about the role of iron in the response to infection. PMID:20375603

  7. Personality and innate immune defenses in a wild bird: Evidence for the pace-of-life hypothesis.

    Science.gov (United States)

    Jacques-Hamilton, Rowan; Hall, Michelle L; Buttemer, William A; Matson, Kevin D; Gonҫalves da Silva, Anders; Mulder, Raoul A; Peters, Anne

    2017-02-01

    We tested the two main evolutionary hypotheses for an association between immunity and personality. The risk-of-parasitism hypothesis predicts that more proactive (bold, exploratory, risk-taking) individuals have more vigorous immune defenses because of increased risk of parasite exposure. In contrast, the pace-of-life hypothesis argues that proactive behavioral styles are associated with shorter lifespans and reduced investment in immune function. Mechanistically, associations between immunity and personality can arise because personality differences are often associated with differences in condition and stress responsiveness, both of which are intricately linked with immunity. Here we investigate the association between personality (measured as proactive exploration of a novel environment) and three indices of innate immune function (the non-specific first line of defense against parasites) in wild superb fairy-wrens Malurus cyaneus. We also quantified body condition, hemoparasites (none detected), chronic stress (heterophil:lymphocyte ratio) and circulating corticosterone levels at the end of the behavioral test (CORT, in a subset of birds). We found that fast explorers had lower titers of natural antibodies. This result is consistent with the pace-of-life hypothesis, and with the previously documented higher mortality of fast explorers in this species. There was no interactive effect of exploration score and duration in captivity on immune indices. This suggests that personality-related differences in stress responsiveness did not underlie differences in immunity, even though behavioral style did modulate the effect of captivity on CORT. Taken together these results suggest reduced constitutive investment in innate immune function in more proactive individuals. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. 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.

  9. Innate immune defense in the inner ear - mucines are expressed by the human endolymphatic sac

    DEFF Research Database (Denmark)

    Møller, Martin N; Kirkeby, Svend; Cayé-Thomasen, Per

    2017-01-01

    The human endolymphatic sac has been shown recently to have immunological capacities and has thus been proposed as the main entity protecting the inner ear from pathogen invasion, equivalent to mucosa-associated lymphoid tissue (MALT). Although the sac expresses molecules of the innate immune...... system, the potential expression of members of the important mucin family has not been detailed. Thus, this paper explores endolymphatic sac expression of a number of mucins and mucin precursors. Twelve fresh tissue samples from the human endolymphatic sac were obtained during translabyrinthine surgery...... immunological tissue structure of the inner ear, equivalent to MALT in other organs. The mucins may also play a role in the formation and continuous homeostasis of the inner ear fluids, as well as the pathogenesis of Meniere's disease....

  10. Host-pathogen interactions between the human innate immune system and Candida albicans - Understanding and modeling defense and evasion strategies

    Directory of Open Access Journals (Sweden)

    Sybille eDühring

    2015-06-01

    Full Text Available The diploid, polymorphic yeast Candida albicans is one of the most important humanpathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within thehuman host for a long time. Alterations in the host environment, however, can render C. albicansvirulent. In this review, we describe the immunological cross-talk between C. albicans and thehuman innate immune system. We give an overview in form of pairs of human defense strategiesincluding immunological mechanisms as well as general stressors such as nutrient limitation,pH, fever etc. and the corresponding fungal response and evasion mechanisms. FurthermoreComputational Systems Biology approaches to model and investigate these complex interactionare highlighted with a special focus on game-theoretical methods and agent-based models. Anoutlook on interesting questions to be tackled by Systems Biology regarding entangled defenseand evasion mechanisms is given.

  11. Tick Innate Immunity.

    Czech Academy of Sciences Publication Activity Database

    Kopáček, Petr; Hajdušek, Ondřej; Burešová, Veronika; Daffre, S.

    2010-01-01

    Roč. 708, - (2010), 137-162 ISSN 0065-2598 R&D Projects: GA ČR GAP506/10/2136; GA MŠk(CZ) LC06009 Institutional research plan: CEZ:AV0Z60220518 Keywords : tick * pathogen transmission * innate immunity Subject RIV: EC - Immunology Impact factor: 1.379, year: 2010

  12. 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.

  13. Isonitrosoacetophenone drives transcriptional reprogramming in Nicotiana tabacum cells in support of innate immunity and defense.

    Directory of Open Access Journals (Sweden)

    Arnaud T Djami-Tchatchou

    Full Text Available Plants respond to various stress stimuli by activating broad-spectrum defense responses both locally as well as systemically. As such, identification of expressed genes represents an important step towards understanding inducible defense responses and assists in designing appropriate intervention strategies for disease management. Genes differentially expressed in tobacco cell suspensions following elicitation with isonitrosoacetophenone (INAP were identified using mRNA differential display and pyro-sequencing. Sequencing data produced 14579 reads, which resulted in 198 contigs and 1758 singletons. Following BLAST analyses, several inducible plant defense genes of interest were identified and classified into functional categories including signal transduction, transcription activation, transcription and protein synthesis, protein degradation and ubiquitination, stress-responsive, defense-related, metabolism and energy, regulation, transportation, cytoskeleton and cell wall-related. Quantitative PCR was used to investigate the expression of 17 selected target genes within these categories. Results indicate that INAP has a sensitising or priming effect through activation of salicylic acid-, jasmonic acid- and ethylene pathways that result in an altered transcriptome, with the expression of genes involved in perception of pathogens and associated cellular re-programming in support of defense. Furthermore, infection assays with the pathogen Pseudomonas syringae pv. tabaci confirmed the establishment of a functional anti-microbial environment in planta.

  14. Regulation of intestinal homeostasis by innate immune cells.

    Science.gov (United States)

    Kayama, Hisako; Nishimura, Junichi; Takeda, Kiyoshi

    2013-12-01

    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 innate immune cells have been shown to maintain gut homeostasis by preventing inadequate adaptive immune responses in the murine intestine. Additionally, several innate immune subsets, which promote Th1 and Th17 responses and are implicated in the pathogenesis of IBD, have recently been identified in the human intestinal mucosa. The demonstration of both murine and human intestinal innate immune subsets contributing to regulation of adaptive immunity emphasizes the conserved innate immune functions across species and might promote development of the intestinal innate immunity-based clinical therapy.

  15. Salt, chloride, bleach, and innate host defense

    Science.gov (United States)

    Wang, Guoshun; Nauseef, William M.

    2015-01-01

    Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense. PMID:26048979

  16. Salt, chloride, bleach, and innate host defense.

    Science.gov (United States)

    Wang, Guoshun; Nauseef, William M

    2015-08-01

    Salt provides 2 life-essential elements: sodium and chlorine. Chloride, the ionic form of chlorine, derived exclusively from dietary absorption and constituting the most abundant anion in the human body, plays critical roles in many vital physiologic functions, from fluid retention and secretion to osmotic maintenance and pH balance. However, an often overlooked role of chloride is its function in innate host defense against infection. Chloride serves as a substrate for the generation of the potent microbicide chlorine bleach by stimulated neutrophils and also contributes to regulation of ionic homeostasis for optimal antimicrobial activity within phagosomes. An inadequate supply of chloride to phagocytes and their phagosomes, such as in CF disease and other chloride channel disorders, severely compromises host defense against infection. We provide an overview of the roles that chloride plays in normal innate immunity, highlighting specific links between defective chloride channel function and failures in host defense. © Society for Leukocyte Biology.

  17. 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.

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

    Science.gov (United States)

    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.

  19. Host-pathogen interactions between the human innate immune system and Candida albicans—understanding and modeling defense and evasion strategies

    Science.gov (United States)

    Dühring, Sybille; Germerodt, Sebastian; Skerka, Christine; Zipfel, Peter F.; Dandekar, Thomas; Schuster, Stefan

    2015-01-01

    The diploid, polymorphic yeast Candida albicans is one of the most important human pathogenic fungi. C. albicans can grow, proliferate and coexist as a commensal on or within the human host for a long time. However, alterations in the host environment can render C. albicans virulent. In this review, we describe the immunological cross-talk between C. albicans and the human innate immune system. We give an overview in form of pairs of human defense strategies including immunological mechanisms as well as general stressors such as nutrient limitation, pH, fever etc. and the corresponding fungal response and evasion mechanisms. Furthermore, Computational Systems Biology approaches to model and investigate these complex interactions are highlighted with a special focus on game-theoretical methods and agent-based models. An outlook on interesting questions to be tackled by Systems Biology regarding entangled defense and evasion mechanisms is given. PMID:26175718

  20. Plant innate immunity

    Indian Academy of Sciences (India)

    Plants are invaded by an array of pathogens of which only a few succeed in causing disease. The attack by others is countered by a sophisticated immune system possessed by the plants. The plant immune system is broadly divided into two, viz. microbial-associated molecular-patterns-triggered immunity (MTI) and ...

  1. Innate immune defenses exhibit circadian rhythmicity and differential temporal sensitivity to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus)

    DEFF Research Database (Denmark)

    Lazado, Carlo Cabacang; Skov, Peter Vilhelm; Pedersen, Per Bovbjerg

    2016-01-01

    The present study investigated the daily dynamics of humoral immune defenses and the temporal influence in the sensitivity of these responses to a bacterial endotoxin in Nile tilapia (Oreochromis niloticus). The first experiment subjected the fish to two photoperiod conditions, 12L:12D (LD) and 0L...... experiment, fish were injected with bacterial endotoxin lipopolysaccharide (LPS) either at ZT3 (day) or at ZT15 (night) to evaluate the temporal sensitivity of humoral immunity to a pathogen-associated molecular pattern. The results demonstrated that responses to LPS were gated by the time of day. LPS...... significantly modulated serum ALP and ANTI activities but only when the endotoxin was administered at ZT3. Serum LYZ and PER were stimulated at both injection times but with differing response profiles. Modulated LYZ activity was persistent when injected at ZT3 but transient when LPS was applied at ZT15...

  2. 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.

  3. Innate Immune Responses in Leprosy

    Science.gov (United States)

    Pinheiro, Roberta Olmo; Schmitz, Veronica; Silva, Bruno Jorge de Andrade; Dias, André Alves; de Souza, Beatriz Junqueira; de Mattos Barbosa, Mayara Garcia; de Almeida Esquenazi, Danuza; Pessolani, Maria Cristina Vidal; Sarno, Euzenir Nunes

    2018-01-01

    Leprosy is an infectious disease that may present different clinical forms depending on host immune response to Mycobacterium leprae. Several studies have clarified the role of various T cell populations in leprosy; however, recent evidences suggest that local innate immune mechanisms are key determinants in driving the disease to its different clinical manifestations. Leprosy is an ideal model to study the immunoregulatory role of innate immune molecules and its interaction with nervous system, which can affect homeostasis and contribute to the development of inflammatory episodes during the course of the disease. Macrophages, dendritic cells, neutrophils, and keratinocytes are the major cell populations studied and the comprehension of the complex networking created by cytokine release, lipid and iron metabolism, as well as antimicrobial effector pathways might provide data that will help in the development of new strategies for leprosy management. PMID:29643852

  4. 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 infant.

  5. 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

  6. Effects of kefir fractions on innate immunity.

    Science.gov (United States)

    Vinderola, Gabriel; Perdigon, Gabriela; Duarte, Jairo; Thangavel, Deepa; Farnworth, Edward; Matar, Chantal

    2006-01-01

    Innate immunity that protects against pathogens in the tissues and circulation is the first line of defense in the immune reaction, where macrophages have a critical role in directing the fate of the infection. We recently demonstrated that kefir modulates the immune response in mice, increasing the number of IgA+ cells in the intestinal and bronchial mucosa and the phagocytic activity of peritoneal and pulmonary macrophages. The aim of this study was to further characterize the immunomodulating capacity of the two fractions of kefir (F1: solids including bacteria and F2: liquid supernatant), by studying the cytokines produced by cells from the innate immune system: peritoneal macrophages and the adherent cells from Peyer's patches. BALB/c mice were fed either kefir solid fraction (F1) or kefir supernatant (F2) for 2, 5 or 7 consecutive days. The number of cytokine (IL-1alpha, IFNgamma, TNFalpha, IL-6 and IL-10) producing cells was determined on peritoneal macrophages and adherent cells from Peyer's patches. Both kefir fractions (F1 and F2) induced similar cytokine profiles on peritoneal macrophages (only TNFalpha and IL-6 were up-regulated). All cytokines studied on adherent cells from Peyer's patches were enhanced after F1 and F2 feeding, except for IFNgamma after F2 administration. Moreover, the percentage of IL-10+cells induced by fraction F2 on adherent cells from Peyer's patches was significantly higher than the one induced by fraction F1. Different components of kefir have an in vivo role as oral biotherapeutic substances capable of stimulating immune cells of the innate immune system, to down-regulate the Th2 immune phenotype or to promote cell-mediated immune responses against tumours and also against intracellular pathogenic infections.

  7. Effects of engineered nanoparticles on the innate immune system.

    Science.gov (United States)

    Liu, Yuanchang; Hardie, Joseph; Zhang, Xianzhi; Rotello, Vincent M

    2017-12-01

    Engineered nanoparticles (NPs) have broad applications in industry and nanomedicine. When NPs enter the body, interactions with the immune system are unavoidable. The innate immune system, a non-specific first line of defense against potential threats to the host, immediately interacts with introduced NPs and generates complicated immune responses. Depending on their physicochemical properties, NPs can interact with cells and proteins to stimulate or suppress the innate immune response, and similarly activate or avoid the complement system. NPs size, shape, hydrophobicity and surface modification are the main factors that influence the interactions between NPs and the innate immune system. In this review, we will focus on recent reports about the relationship between the physicochemical properties of NPs and their innate immune response, and their applications in immunotherapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. 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.

  9. 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.

  10. 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

  11. Immune defense in leaf-cutting ants

    DEFF Research Database (Denmark)

    Armitage, Sophie A O; Broch, Jens F; Marín, Hermogenes Fernández

    2011-01-01

    To ameliorate the impact of disease, social insects combine individual innate immune defenses with collective social defenses. This implies that there are different levels of selection acting on investment in immunity, each with their own trade-offs. We present the results of a cross......-fostering experiment designed to address the influences of genotype and social rearing environment upon individual and social immune defenses. We used a multiply mating leaf-cutting ant, enabling us to test for patriline effects within a colony, as well as cross-colony matriline effects. The worker's father influenced...... both individual innate immunity (constitutive antibacterial activity) and the size of the metapleural gland, which secretes antimicrobial compounds and functions in individual and social defense, indicating multiple mating could have important consequences for both defense types. However, the primarily...

  12. DMPD: Toll-like receptors and the host defense against microbial pathogens: bringingspecificity to the innate-immune system. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15075354 Toll-like receptors and the host defense against microbial pathogens: brin...oc Biol. 2004 May;75(5):749-55. Epub 2004 Jan 14. (.png) (.svg) (.html) (.csml) Show Toll-like receptors and the host defense again...immune system. PubmedID 15075354 Title Toll-like receptors and the host defense against microbial pathogens:

  13. Innate immune system and preeclampsia

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    Alejandra ePerez-Sepulveda

    2014-05-01

    Full Text Available Normal pregnancy is considered as a Th2 type immunological state that favors an immune-tolerance environment in order to prevent fetal rejection. PE has been classically described as a Th1/Th2 imbalance; however, the Th1/Th2 paradigm has proven insufficient to fully explain the functional and molecular changes observed during normal/pathological pregnancies. Recent studies have expanded the Th1/Th2 into a Th1⁄Th2⁄Th17 and regulatory T (Treg cells paradigm and where dendritic cells could have a crucial role. Recently, some evidence has emerged supporting the idea that mesenchymal stem cells might be part of the feto-maternal tolerance environment. This review will discuss the involvement of the innate immune system in the establishment of a physiological environment that favors pregnancy and possible alterations related to the development of preeclampsia.

  14. 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.

  15. SUMO-, MAPK- and resistance protein-signaling converge at transcription complexes that regulate plant innate immunity

    NARCIS (Netherlands)

    Burg, van den H.A.; Takken, F.L.W.

    2010-01-01

    Upon pathogen perception plant innate immune receptors activate various signaling pathways that trigger host defenses. PAMP-triggered defense signaling requires mitogen-activated protein kinase (MAPK) pathways, which modulate the activity of transcription factors through phosphorylation. Here, we

  16. SUMO-, MAPK-, and resistance protein-signaling converge at transcription complexes that regulate plant innate immunity

    NARCIS (Netherlands)

    van den Burg, H.A.; Takken, F.L.W.

    2010-01-01

    Upon pathogen perception plant innate immune receptors activate various signaling pathways that trigger host defenses. PAMP-triggered defense signaling requires mitogen-activated protein kinase (MAPK) pathways, which modulate the activity of transcription factors through phosphorylation. Here, we

  17. Glycoconjugates as elicitors or suppressors of plant innate immunity

    DEFF Research Database (Denmark)

    Silipo, Alba; Erbs, Gitte; Shinya, Tomonori

    2010-01-01

    Innate immunity is the first line of defense against invading microorganisms in vertebrates and the only line of defense in invertebrates and plants. Bacterial glyco-conjugates, such as lipopolysaccharides (LPS) from the outer membrane of Gram-negative bacteria and peptidoglycan (PGN) from the cell...... walls of both Gram-positive and Gram-negative bacteria, and fungal and oomycete glycoconjugates such as oligosaccharides derived from the cell wall components ß-glucan, chitin and chitosan, have been found to act as elicitors of plant innate immunity. These conserved indispensable microbe......-specific molecules are also referred to as microbe-associated molecular patterns (MAMPs). Other glyco-conjugates such as bacterial extracellular polysaccharides (EPS) and cyclic glucan have been shown to suppress innate immune responses, thus conversely promoting pathogenesis. MAMPs are recognized by the plant...

  18. Cerebral Innate Immunity in Drosophila Melanogaster

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    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.

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

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    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.

  20. Infectious Agents as Stimuli of Trained Innate Immunity

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    Paulina Rusek

    2018-02-01

    Full Text Available The discoveries made over the past few years have modified the current immunological paradigm. It turns out that innate immunity cells can mount some kind of immunological memory, similar to that observed in the acquired immunity and corresponding to the defense mechanisms of lower organisms, which increases their resistance to reinfection. This phenomenon is termed trained innate immunity. It is based on epigenetic changes in innate immune cells (monocytes/macrophages, NK cells after their stimulation with various infectious or non-infectious agents. Many infectious stimuli, including bacterial or fungal cells and their components (LPS, β-glucan, chitin as well as viruses or even parasites are considered potent inducers of innate immune memory. Epigenetic cell reprogramming occurring at the heart of the phenomenon may provide a useful basis for designing novel prophylactic and therapeutic strategies to prevent and protect against multiple diseases. In this article, we present the current state of art on trained innate immunity occurring as a result of infectious agent induction. Additionally, we discuss the mechanisms of cell reprogramming and the implications for immune response stimulation/manipulation.

  1. The Interface between Fungal Biofilms and Innate Immunity

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    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.

  2. 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.

  3. 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...

  4. The innate immune response during urinary tract infection and pyelonephritis.

    Science.gov (United States)

    Spencer, John David; Schwaderer, Andrew L; Becknell, Brian; Watson, Joshua; Hains, David S

    2014-07-01

    Despite its proximity to the fecal flora, the urinary tract is considered sterile. The precise mechanisms by which the urinary tract maintains sterility are not well understood. Host immune responses are critically important in the antimicrobial defense of the urinary tract. During recent years, considerable advances have been made in our understanding of the mechanisms underlying immune homeostasis of the kidney and urinary tract. Dysfunctions in these immune mechanisms may result in acute disease, tissue destruction and overwhelming infection. The objective of this review is to provide an overview of the innate immune response in the urinary tract in response to microbial assault. In doing so, we focus on the role of antimicrobial peptides-a ubiquitous component of the innate immune response.

  5. Tweaking Innate Immunity: The Promise of Innate Immunologicals as Anti-Infectives

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    Kenneth L Rosenthal

    2006-01-01

    Full Text Available New and exciting insights into the importance of the innate immune system are revolutionizing our understanding of immune defense against infections, pathogenesis, and the treatment and prevention of infectious diseases. The innate immune system uses multiple families of germline-encoded pattern recognition receptors (PRRs to detect infection and trigger a variety of antimicrobial defense mechanisms. PRRs are evolutionarily highly conserved and serve to detect infection by recognizing pathogen-associated molecular patterns that are unique to microorganisms and essential for their survival. Toll-like receptors (TLRs are transmembrane signalling receptors that activate gene expression programs that result in the production of proinflammatory cytokines and chemokines, type I interferons and antimicrobial factors. Furthermore, TLR activation facilitates and guides activation of adaptive immune responses through the activation of dendritic cells. TLRs are localized on the cell surface and in endosomal/lysosomal compartments, where they detect bacterial and viral infections. In contrast, nucleotide-binding oligomerization domain proteins and RNA helicases are located in the cell cytoplasm, where they serve as intracellular PRRs to detect cytoplasmic infections, particularly viruses. Due to their ability to enhance innate immune responses, novel strategies to use ligands, synthetic agonists or antagonists of PRRs (also known as 'innate immunologicals' can be used as stand-alone agents to provide immediate protection or treatment against bacterial, viral or parasitic infections. Furthermore, the newly appreciated importance of innate immunity in initiating and shaping adaptive immune responses is contributing to our understanding of vaccine adjuvants and promises to lead to improved next-generation vaccines.

  6. 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...

  7. Sublethal Heavy Metal Stress Stimulates Innate Immunity in Tomato

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    Nilanjan Chakraborty

    2015-01-01

    Full Text Available Effect of sublethal heavy metal stress as plant biotic elicitor for triggering innate immunity in tomato plant was investigated. Copper in in vivo condition induced accumulation of defense enzymes like peroxidase (PO, polyphenol oxidase (PPO, phenylalanine ammonia-lyase (PAL, and β-1,3 glucanase along with higher accumulation of total phenol, antioxidative enzymes (catalase and ascorbate peroxidase, and total chlorophyll content. Furthermore, the treatment also induced nitric oxide (NO production which was confirmed by realtime visualization of NO burst using a fluorescent probe 4,5-diaminofluorescein diacetate (DAF-2DA and spectrophotometric analysis. The result suggested that the sublethal dose of heavy metal can induce an array of plant defense responses that lead to the improvement of innate immunity in plants.

  8. 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.

  9. Innate Immune Responses of Drosophila melanogaster Are Altered by Spaceflight

    Science.gov (United States)

    Marcu, Oana; Lera, Matthew P.; Sanchez, Max E.; Levic, Edina; Higgins, Laura A.; Shmygelska, Alena; Fahlen, Thomas F.; Nichol, Helen; Bhattacharya, Sharmila

    2011-01-01

    Alterations and impairment of immune responses in humans present a health risk for space exploration missions. The molecular mechanisms underpinning innate immune defense can be confounded by the complexity of the acquired immune system of humans. Drosophila (fruit fly) innate immunity is simpler, and shares many similarities with human innate immunity at the level of molecular and genetic pathways. The goals of this study were to elucidate fundamental immune processes in Drosophila affected by spaceflight and to measure host-pathogen responses post-flight. Five containers, each containing ten female and five male fruit flies, were housed and bred on the space shuttle (average orbit altitude of 330.35 km) for 12 days and 18.5 hours. A new generation of flies was reared in microgravity. In larvae, the immune system was examined by analyzing plasmatocyte number and activity in culture. In adults, the induced immune responses were analyzed by bacterial clearance and quantitative real-time polymerase chain reaction (qPCR) of selected genes following infection with E. coli. The RNA levels of relevant immune pathway genes were determined in both larvae and adults by microarray analysis. The ability of larval plasmatocytes to phagocytose E. coli in culture was attenuated following spaceflight, and in parallel, the expression of genes involved in cell maturation was downregulated. In addition, the level of constitutive expression of pattern recognition receptors and opsonins that specifically recognize bacteria, and of lysozymes, antimicrobial peptide (AMP) pathway and immune stress genes, hallmarks of humoral immunity, were also reduced in larvae. In adults, the efficiency of bacterial clearance measured in vivo following a systemic infection with E. coli post-flight, remained robust. We show that spaceflight altered both cellular and humoral immune responses in Drosophila and that the disruption occurs at multiple interacting pathways. PMID:21264297

  10. Innate immune responses of Drosophila melanogaster are altered by spaceflight.

    Directory of Open Access Journals (Sweden)

    Oana Marcu

    2011-01-01

    Full Text Available Alterations and impairment of immune responses in humans present a health risk for space exploration missions. The molecular mechanisms underpinning innate immune defense can be confounded by the complexity of the acquired immune system of humans. Drosophila (fruit fly innate immunity is simpler, and shares many similarities with human innate immunity at the level of molecular and genetic pathways. The goals of this study were to elucidate fundamental immune processes in Drosophila affected by spaceflight and to measure host-pathogen responses post-flight. Five containers, each containing ten female and five male fruit flies, were housed and bred on the space shuttle (average orbit altitude of 330.35 km for 12 days and 18.5 hours. A new generation of flies was reared in microgravity. In larvae, the immune system was examined by analyzing plasmatocyte number and activity in culture. In adults, the induced immune responses were analyzed by bacterial clearance and quantitative real-time polymerase chain reaction (qPCR of selected genes following infection with E. coli. The RNA levels of relevant immune pathway genes were determined in both larvae and adults by microarray analysis. The ability of larval plasmatocytes to phagocytose E. coli in culture was attenuated following spaceflight, and in parallel, the expression of genes involved in cell maturation was downregulated. In addition, the level of constitutive expression of pattern recognition receptors and opsonins that specifically recognize bacteria, and of lysozymes, antimicrobial peptide (AMP pathway and immune stress genes, hallmarks of humoral immunity, were also reduced in larvae. In adults, the efficiency of bacterial clearance measured in vivo following a systemic infection with E. coli post-flight, remained robust. We show that spaceflight altered both cellular and humoral immune responses in Drosophila and that the disruption occurs at multiple interacting pathways.

  11. Initiation of innate immune responses by surveillance of homeostasis perturbations.

    Science.gov (United States)

    Colaço, Henrique G; Moita, Luis F

    2016-07-01

    Pathogen recognition, signaling transduction pathways, and effector mechanisms are necessary steps of innate immune responses that play key roles in the early phase of defense and in the stimulation of the later specific response of adaptive immunity. Here, we argue that in addition to the direct recognition of conserved common structural and functional molecular signatures of microorganisms using pattern recognition receptors, hosts can mount an immune response following the sensing of disruption in homeostasis as proximal reporters for infections. Surveillance of disruption of core cellular activities leading to defense responses is a flexible strategy that requires few additional components and that can effectively detect relevant threats. It is likely to be evolutionarily very conserved and ancient because it is operational in organisms that lack pattern recognition triggered immunity. A homeostasis disruption model of immune response initiation and modulation has broad implications for pathophysiology and treatment of disease and might constitute an often overlooked but central component of a comprehensive conceptual framework for innate immunity. © 2016 Federation of European Biochemical Societies.

  12. Pathogen recognition in the innate immune response.

    Science.gov (United States)

    Kumar, Himanshu; Kawai, Taro; Akira, Shizuo

    2009-04-28

    Immunity against microbial pathogens primarily depends on the recognition of pathogen components by innate receptors expressed on immune and non-immune cells. Innate receptors are evolutionarily conserved germ-line-encoded proteins and include TLRs (Toll-like receptors), RLRs [RIG-I (retinoic acid-inducible gene-I)-like receptors] and NLRs (Nod-like receptors). These receptors recognize pathogens or pathogen-derived products in different cellular compartments, such as the plasma membrane, the endosomes or the cytoplasm, and induce the expression of cytokines, chemokines and co-stimulatory molecules to eliminate pathogens and instruct pathogen-specific adaptive immune responses. In the present review, we will discuss the recent progress in the study of pathogen recognition by TLRs, RLRs and NLRs and their signalling pathways.

  13. Differential activity of innate defense antimicrobial peptides against Nocardia species.

    Science.gov (United States)

    Rieg, Siegbert; Meier, Benjamin; Fähnrich, Eva; Huth, Anja; Wagner, Dirk; Kern, Winfried V; Kalbacher, Hubert

    2010-02-23

    Members of the genus Nocardia are ubiquitous environmental saprophytes capable to cause human pulmonary, disseminated and cutaneous nocardiosis or bovine mastitis. Innate immunity appears to play an important role in early defense against Nocardia species. To elucidate the contribution of antimicrobial peptides (AMPs) in innate defense against Nocardia, the activity of human alpha-defensins human neutrophil peptides (HNPs) 1-3, human beta-defensin (hBD)-3 and cathelicidin LL-37 as well as bovine beta-defensins lingual and tracheal antimicrobial peptides (LAP, TAP) and bovine neutrophil-derived indolicidin against four important Nocardia species was investigated. Whereas N. farcinica ATCC 3318 and N. nova ATCC 33726 were found to be susceptible to all investigated human and bovine AMPs, N. asteroides ATCC 19247 was killed exclusively by neutrophil-derived human alpha-defensins HNP 1-3 and bovine indolicidin. N. brasiliensis ATCC 19296 was found to exhibit complete resistance to investigated human AMPs and to be susceptible only to bovine indolicidin. Selected AMPs are capable to contribute to the first line of defense against Nocardia, yet, susceptibility appears to vary across different Nocardia species. Obtained results of neutrophil-derived AMPs to possess the broadest antinocardial spectrum are remarkable, since nocardiosis is characterized by a neutrophil-rich infiltrate in vivo.

  14. Differential activity of innate defense antimicrobial peptides against Nocardia species

    Directory of Open Access Journals (Sweden)

    Wagner Dirk

    2010-02-01

    Full Text Available Abstract Background Members of the genus Nocardia are ubiquitous environmental saprophytes capable to cause human pulmonary, disseminated and cutaneous nocardiosis or bovine mastitis. Innate immunity appears to play an important role in early defense against Nocardia species. To elucidate the contribution of antimicrobial peptides (AMPs in innate defense against Nocardia, the activity of human α-defensins human neutrophil peptides (HNPs 1-3, human β-defensin (hBD-3 and cathelicidin LL-37 as well as bovine β-defensins lingual and tracheal antimicrobial peptides (LAP, TAP and bovine neutrophil-derived indolicidin against four important Nocardia species was investigated. Results Whereas N. farcinica ATCC 3318 and N. nova ATCC 33726 were found to be susceptible to all investigated human and bovine AMPs, N. asteroides ATCC 19247 was killed exclusively by neutrophil-derived human α-defensins HNP 1-3 and bovine indolicidin. N. brasiliensis ATCC 19296 was found to exhibit complete resistance to investigated human AMPs and to be susceptible only to bovine indolicidin. Conclusion Selected AMPs are capable to contribute to the first line of defense against Nocardia, yet, susceptibility appears to vary across different Nocardia species. Obtained results of neutrophil-derived AMPs to possess the broadest antinocardial spectrum are remarkable, since nocardiosis is characterized by a neutrophil-rich infiltrate in vivo.

  15. 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.

  16. 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

  17. Xanthomonas campestris lipooligosaccharides trigger innate immunity and oxidative burst in Arabidopsis

    NARCIS (Netherlands)

    Proietti, S; Giangrande, C; Amoresano, A; Pucci, P; Molinaro, A; Bertini, L; Caporale, C; Caruso, C

    2014-01-01

    Plants lack the adaptive immunity mechanisms of jawed vertebrates, so they rely on innate immune responses to defense themselves from pathogens. The plant immune system perceives the presence of pathogens by recognition of molecules known as pathogen-associated molecular patterns (PAMPs). PAMPs have

  18. Necroptotic signaling in adaptive and innate immunity.

    Science.gov (United States)

    Lu, Jennifer V; Chen, Helen C; Walsh, Craig M

    2014-11-01

    The vertebrate immune system is highly dependent on cell death for efficient responsiveness to microbial pathogens and oncogenically transformed cells. Cell death pathways are vital to the function of many immune cell types during innate, humoral and cellular immune responses. In addition, cell death regulation is imperative for proper adaptive immune self-tolerance and homeostasis. While apoptosis has been found to be involved in several of these roles in immunity, recent data demonstrate that alternative cell death pathways are required. Here, we describe the involvement of a programmed form of cellular necrosis called "necroptosis" in immunity. We consider the signaling pathways that promote necroptosis downstream of death receptors, type I transmembrane proteins of the tumor necrosis factor (TNF) receptor family. The involvement of necroptotic signaling through a "RIPoptosome" assembled in response to innate immune stimuli or genotoxic stress is described. We also characterize the induction of necroptosis following antigenic stimulation in T cells lacking caspase-8 or FADD function. While necroptotic signaling remains poorly understood, it is clear that this pathway is an essential component to effective vertebrate immunity. Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. 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.

  20. Role of innate T cells in anti-bacterial immunity

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    Yifang eGao

    2015-06-01

    Full Text Available Innate T cells are a heterogeneous group of αβ and γδ T cells that respond rapidly (<2 hours upon activation. These innate T cells also share a non MHC class I or II restriction requirement for antigen recognition. Three major populations within the innate T cell group are recognized, namely Invariant NKT cells (iNKT; Mucosal associated invariant T cells (MAIT and gamma delta T cells. These cells recognize foreign/self-lipid presented by non-classical MHC molecules, such as CD1d, MR1 and CD1a.They are activated during the early stages of bacterial infection and act as a bridge between the innate and adaptive immune systems. In this review we focus on the functional properties of these 3 innate T cell populations and how they are purposed for antimicrobial defense. Furthermore we address the mechanisms through which their effector functions are targeted for bacterial control and compare this in human and murine systems. Lastly we speculate on future roles of these cell types in therapeutic settings such as vaccination.

  1. Indispensable Role of Proteases in Plant Innate Immunity.

    Science.gov (United States)

    Balakireva, Anastasia V; Zamyatnin, Andrey A

    2018-02-23

    Plant defense is achieved mainly through the induction of microbe-associated molecular patterns (MAMP)-triggered immunity (MTI), effector-triggered immunity (ETI), systemic acquired resistance (SAR), induced systemic resistance (ISR), and RNA silencing. Plant immunity is a highly complex phenomenon with its own unique features that have emerged as a result of the arms race between plants and pathogens. However, the regulation of these processes is the same for all living organisms, including plants, and is controlled by proteases. Different families of plant proteases are involved in every type of immunity: some of the proteases that are covered in this review participate in MTI, affecting stomatal closure and callose deposition. A large number of proteases act in the apoplast, contributing to ETI by managing extracellular defense. A vast majority of the endogenous proteases discussed in this review are associated with the programmed cell death (PCD) of the infected cells and exhibit caspase-like activities. The synthesis of signal molecules, such as salicylic acid, jasmonic acid, and ethylene, and their signaling pathways, are regulated by endogenous proteases that affect the induction of pathogenesis-related genes and SAR or ISR establishment. A number of proteases are associated with herbivore defense. In this review, we summarize the data concerning identified plant endogenous proteases, their effect on plant-pathogen interactions, their subcellular localization, and their functional properties, if available, and we attribute a role in the different types and stages of innate immunity for each of the proteases covered.

  2. Innate Immunity Dysregulation in Myelodysplastic Syndromes

    Science.gov (United States)

    2013-10-01

    by the Regional Ministry of Education of Castilla-la Mancha, Spain, supported by the European Social Fund (ESF). We are thankful for the efforts...consistent with previous reports that aber rant activation of innate immune signals in MDS, including overcxpression of several TLRs (36) and loss...281: 1652- 1659. 14. Loiarro M, Set te C , Gallo G. Ciacc.i A, Fa nto N, et al. (2005) Peptide- media ted interference of T JR domain dimeri7.ation

  3. 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.

  4. [The role of the innate immune system in atopic dermatitis].

    Science.gov (United States)

    Volz, T; Kaesler, S; Skabytska, Y; Biedermann, T

    2015-02-01

    The mechanisms how the innate immune system detects microbes and mounts a rapid immune response have been more and more elucidated in the past years. Subsequently it has been shown that innate immunity also shapes adaptive immune responses and determines their quality that can be either inflammatory or tolerogenic. As atopic dermatitis is characterized by disturbances of innate and adaptive immune responses, colonization with pathogens and defects in skin barrier function, insight into mechanisms of innate immunity has helped to understand the vicious circle of ongoing skin inflammation seen in atopic dermatitis patients. Elucidating general mechanisms of the innate immune system and its functions in atopic dermatitis paves the way for developing new therapies. Especially the novel insights into the human microbiome and potential functional consequences make the innate immune system a very fundamental and promising target. As a result atopic dermatitis manifestations can be attenuated or even resolved. These currently developed strategies will be introduced in the current review.

  5. Fish innate immunity against intestinal helminths.

    Science.gov (United States)

    Dezfuli, B S; Bosi, G; DePasquale, J A; Manera, M; Giari, L

    2016-03-01

    Most individual fish in farmed and wild populations are infected with parasites. Upon dissection of fish, helminths from gut are often easily visible. Enteric helminths include several species of digeneans, cestodes, acanthocephalans and nematodes. Some insights into biology, morphology and histopathological effects of the main fish enteric helminths taxa will be described here. The immune system of fish, as that of other vertebrates, can be subdivided into specific and aspecific types, which in vivo act in concert with each other and indeed are interdependent in many ways. Beyond the small number of well-described models that exist, research focusing on innate immunity in fish against parasitic infections is lacking. Enteric helminths frequently cause inflammation of the digestive tract, resulting in a series of chemical and morphological changes in the affected tissues and inducing leukocyte migration to the site of infection. This review provides an overview on the aspecific defence mechanisms of fish intestine against helminths. Emphasis will be placed on the immune cellular response involving mast cells, neutrophils, macrophages, rodlet cells and mucous cells against enteric helminths. Given the relative importance of innate immunity in fish, and the magnitude of economic loss in aquaculture as a consequence of disease, this area deserves considerable attention and support. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Acquired and innate immunity to polyaromatic hydrocarbons

    International Nuclear Information System (INIS)

    Yusuf, Nabiha; Timares, Laura; Seibert, Megan D.; Xu Hui; Elmets, Craig A.

    2007-01-01

    Polyaromatic hydrocarbons are ubiquitous environmental pollutants that are potent mutagens and carcinogens. Researchers have taken advantage of these properties to investigate the mechanisms by which chemicals cause cancer of the skin and other organs. When applied to the skin of mice, several carcinogenic polyaromatic hydrocarbons have also been shown to interact with the immune system, stimulating immune responses and resulting in the development of antigen-specific T-cell-mediated immunity. Development of cell-mediated immunity is strain-specific and is governed by Ah receptor genes and by genes located within the major histocompatibility complex. CD8 + T cells are effector cells in the response, whereas CD4 + T cells down-regulate immunity. Development of an immune response appears to have a protective effect since strains of mice that develop a cell-mediated immune response to carcinogenic polyaromatic hydrocarbons are less likely to develop tumors when subjected to a polyaromatic hydrocarbon skin carcinogenesis protocol than mice that fail to develop an immune response. With respect to innate immunity, TLR4-deficient C3H/HeJ mice are more susceptible to polyaromatic hydrogen skin tumorigenesis than C3H/HeN mice in which TLR4 is normal. These findings support the hypothesis that immune responses, through their interactions with chemical carcinogens, play an active role in the prevention of chemical skin carcinogenesis during the earliest stages. Efforts to augment immune responses to the chemicals that cause tumors may be a productive approach to the prevention of tumors caused by these agents

  7. A Role for PML in Innate Immunity

    Science.gov (United States)

    Lunardi, Andrea; Gaboli, Mirella; Giorgio, Marco; Rivi, Roberta; Bygrave, Anne; Antoniou, Michael; Drabek, Dubravka; Dzierzak, Elaine; Fagioli, Marta; Salmena, Leonardo; Botto, Marina; Cordon-Cardo, Carlos; Luzzatto, Lucio; Pelicci, Pier Giuseppe; Grosveld, Frank; Pandolfi, Pier Paolo

    2011-01-01

    The promyelocytic leukemia gene (PML) of acute promyelocytic leukemia is an established tumor suppressor gene with critical functions in growth suppression, induction of apoptosis, and cellular senescence. Interestingly, although less studied, PML seems to play a key role also in immune response to viral infection. Herein, we report that Pml −/− mice spontaneously develop an atypical invasive and lethal granulomatous lesion known as botryomycosis (BTM). In Pml −/− mice, BTM is the result of impaired function of macrophages, whereby they fail to become activated and are thus unable to clear pathogenic microorganisms. Accordingly, Pml −/− mice are resistant to lipopolysaccharide (LPS)–induced septic shock as a result of an ineffective production of cytokines and chemokines, suggesting a role for PML in the innate immune Toll-like receptor (TLR)/NF-κB prosurvival pathway. These results not only shed light on a new fundamental function of PML in innate immunity, but they also point to a proto-oncogenic role for PML in certain cellular and pathological contexts. PMID:21779477

  8. Modulation of the innate immune responses in the striped ...

    African Journals Online (AJOL)

    Thus, most of the innate non-specific immune responses are inducible though they are constitutive of fish immune system exhibiting a basal level of activity even in the absence of pathogen challenge. Keywords: Aeromonas hydrophila, Experimental challenge, Innate immune response, Striped snakehead murrel ...

  9. Glucosinolate metabolites required for an Arabidopsis innate immune response.

    Science.gov (United States)

    Clay, Nicole K; Adio, Adewale M; Denoux, Carine; Jander, Georg; Ausubel, Frederick M

    2009-01-02

    The perception of pathogen or microbe-associated molecular pattern molecules by plants triggers a basal defense response analogous to animal innate immunity and is defined partly by the deposition of the glucan polymer callose at the cell wall at the site of pathogen contact. Transcriptional and metabolic profiling in Arabidopsis mutants, coupled with the monitoring of pathogen-triggered callose deposition, have identified major roles in pathogen response for the plant hormone ethylene and the secondary metabolite 4-methoxy-indol-3-ylmethylglucosinolate. Two genes, PEN2 and PEN3, are also necessary for resistance to pathogens and are required for both callose deposition and glucosinolate activation, suggesting that the pathogen-triggered callose response is required for resistance to microbial pathogens. Our study shows that well-studied plant metabolites, previously identified as important in avoiding damage by herbivores, are also required as a component of the plant defense response against microbial pathogens.

  10. Glucosinolate Metabolites Required for an Arabidopsis Innate Immune Response*

    Science.gov (United States)

    Clay, Nicole K.; Adio, Adewale M.; Denoux, Carine; Jander, Georg; Ausubel, Frederick M.

    2008-01-01

    Summary The perception of pathogen or microbe-associated molecular pattern molecules by plants triggers a basal defense response analogous to animal innate immunity, and is defined in part by the deposition of the glucan polymer callose at the cell wall at the site of pathogen contact. Transcriptional and metabolic profiling in Arabidopsis mutants, coupled with the monitoring of pathogen triggered callose deposition, have identified major roles in pathogen response for the plant hormone ethylene and the secondary metabolite 4-methoxy-indol-3-ylmethylglucosinolate. Two genes, PEN2 and PEN3, are also necessary for resistance to pathogens and are required for both callose deposition and glucosinolate activation, suggesting that the pathogen triggered callose response is required for resistance to microbial pathogens. Our study shows that well-studied plant metabolites, previously identified as important in avoiding damage by herbivores, are also required as a component of the plant defense response against microbial pathogens. PMID:19095898

  11. 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.

  12. Innate immune response development in nestling tree swallows

    Science.gov (United States)

    Stambaugh, T.; Houdek, B.J.; Lombardo, M.P.; Thorpe, P.A.; Caldwell, Hahn D.

    2011-01-01

    We tracked the development of innate immunity in nestling Tree Swallows (Tachycineta bicolor) and compared it to that of adults using blood drawn from nestlings during days 6, 12, and 18 of the ???20-day nestling period and from adults. Innate immunity was characterized using an in vitro assay of the ability of whole blood to kill Escherichia coli. The ability of whole blood to kill E. coli increased as nestlings matured. Neither this component of innate immunity nor right wing chord length on day18 were as developed as in adults indicating that development of the innate immune system and growth both continued after fledging. Narrow sense heritability analyses suggest that females with strong immune responses produced nestlings with strong immune responses. These data suggest nestling Tree Swallows allocated sufficient energy to support rapid growth to enable fledging by day 18, but that further development of innate immunity occurred post-fledging. ?? 2011 by the Wilson Ornithological Society.

  13. Organ system view of the hepatic innate immunity in HCV infection.

    Science.gov (United States)

    Bang, Bo-Ram; Elmasry, Sandra; Saito, Takeshi

    2016-12-01

    An orchestration of innate and adaptive immunity determines the infection outcome and whether the host achieves clearance or allows the pathogen to establish persistent infection. The robust activation of the innate immune response plays the most critical role in both limiting viral replication and halting the spread of the pathogen immediately after infection. The magnitude of innate immune activation is coupled with the efficient mounting of the adaptive immunity. Although immunity against HCV infection is known to be inadequate as most cases transitions to chronicity, approximately 25% of acute infection cases result in spontaneous clearance. The exact immune mechanisms that govern the infection outcome remain largely unknown; recent discoveries suggest that the innate immune system facilitates this event. Both infected hepatocytes and local innate immune cells trigger the front line defense program of the liver as well as the recruitment of diverse adaptive immune cells to the site of infection. Although hepatocyte is the target of HCV infection, nearly all cell types that exist in the liver are involved in the innate defense and contribute to the pathophysiology of hepatic inflammation. The main focus of this comprehensive review is to discuss the current knowledge on how each hepatic cell type contributes to the organ system level innate immunity against HCV infection as well as interplays with the viral evasion program. Furthermore, this review article also aims to synchronize the observations from both molecular biological studies and clinical studies with the ultimate goal of improving our understanding of HCV mediated hepatitis. J. Med. Virol. 88:2025-2037, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  14. Innate immunity orchestrates adipose tissue homeostasis.

    Science.gov (United States)

    Lin, Yi-Wei; Wei, Li-Na

    2017-06-23

    Obesity is strongly associated with multiple diseases including insulin resistance, type 2 diabetes, cardiovascular diseases, fatty liver disease, neurodegenerative diseases and cancers, etc. Adipose tissue (AT), mainly brown AT (BAT) and white AT (WAT), is an important metabolic and endocrine organ that maintains whole-body homeostasis. BAT contributes to non-shivering thermogenesis in a cold environment; WAT stores energy and produces adipokines that fine-tune metabolic and inflammatory responses. Obesity is often characterized by over-expansion and inflammation of WAT where inflammatory cells/mediators are abundant, especially pro-inflammatory (M1) macrophages, resulting in chronic low-grade inflammation and leading to insulin resistance and metabolic complications. Macrophages constitute the major component of innate immunity and can be activated as a M1 or M2 (anti-inflammatory) phenotype in response to environmental stimuli. Polarized M1 macrophage causes AT inflammation, whereas polarized M2 macrophage promotes WAT remodeling into the BAT phenotype, also known as WAT browning/beiging, which enhances insulin sensitivity and metabolic health. This review will discuss the regulation of AT homeostasis in relation to innate immunity.

  15. Are innate immune signaling pathways in plants and animals conserved?

    Science.gov (United States)

    Ausubel, Frederick M

    2005-10-01

    Although adaptive immunity is unique to vertebrates, the innate immune response seems to have ancient origins. Common features of innate immunity in vertebrates, invertebrate animals and plants include defined receptors for microbe-associated molecules, conserved mitogen-associated protein kinase signaling cascades and the production of antimicrobial peptides. It is commonly reported that these similarities in innate immunity represent a process of divergent evolution from an ancient unicellular eukaryote that pre-dated the divergence of the plant and animal kingdoms. However, at present, data suggest that the seemingly analogous regulatory modules used in plant and animal innate immunity are a consequence of convergent evolution and reflect inherent constraints on how an innate immune system can be constructed.

  16. Yersinia type III effectors perturb host innate immune responses

    Science.gov (United States)

    Pha, Khavong; Navarro, Lorena

    2016-01-01

    The innate immune system is the first line of defense against invading pathogens. Innate immune cells recognize molecular patterns from the pathogen and mount a response to resolve the infection. The production of proinflammatory cytokines and reactive oxygen species, phagocytosis, and induced programmed cell death are processes initiated by innate immune cells in order to combat invading pathogens. However, pathogens have evolved various virulence mechanisms to subvert these responses. One strategy utilized by Gram-negative bacterial pathogens is the deployment of a complex machine termed the type III secretion system (T3SS). The T3SS is composed of a syringe-like needle structure and the effector proteins that are injected directly into a target host cell to disrupt a cellular response. The three human pathogenic Yersinia spp. (Y. pestis, Y. enterocolitica, and Y. pseudotuberculosis) are Gram-negative bacteria that share in common a 70 kb virulence plasmid which encodes the T3SS. Translocation of the Yersinia effector proteins (YopE, YopH, YopT, YopM, YpkA/YopO, and YopP/J) into the target host cell results in disruption of the actin cytoskeleton to inhibit phagocytosis, downregulation of proinflammatory cytokine/chemokine production, and induction of cellular apoptosis of the target cell. Over the past 25 years, studies on the Yersinia effector proteins have unveiled tremendous knowledge of how the effectors enhance Yersinia virulence. Recently, the long awaited crystal structure of YpkA has been solved providing further insights into the activation of the YpkA kinase domain. Multisite autophosphorylation by YpkA to activate its kinase domain was also shown and postulated to serve as a mechanism to bypass regulation by host phosphatases. In addition, novel Yersinia effector protein targets, such as caspase-1, and signaling pathways including activation of the inflammasome were identified. In this review, we summarize the recent discoveries made on Yersinia

  17. γ-Oryzanol-Rich Black Rice Bran Extract Enhances the Innate Immune Response.

    Science.gov (United States)

    Shin, Soon Young; Kim, Heon-Woong; Jang, Hwan-Hee; Hwang, Yu-Jin; Choe, Jeong-Sook; Lim, Yoongho; Kim, Jung-Bong; Lee, Young Han

    2017-09-01

    The innate immune response is an important host primary defense system against pathogens. γ-Oryzanol is one of the nutritionally important phytoceutical components in rice bran oil. The goal of this study was to investigate the effect of γ-oryzanol-rich extract from black rice bran (γORE) on the activation of the innate immune system. In this study, we show that γORE increased the expression of CD14 and Toll-like receptor 4 and enhanced the phagocytic activity of RAW264.7 macrophages. Furthermore, γORE and its active ingredient γ-oryzanol promoted the secretion of innate cytokines, interleukin-8, and CCL2, which facilitate phagocytosis by RAW264.7 cells. These findings suggest that γ-oryzanol in the γORE enhances innate immune responses.

  18. Effector-triggered immunity: from pathogen perception to robust defense.

    Science.gov (United States)

    Cui, Haitao; Tsuda, Kenichi; Parker, Jane E

    2015-01-01

    In plant innate immunity, individual cells have the capacity to sense and respond to pathogen attack. Intracellular recognition mechanisms have evolved to intercept perturbations by pathogen virulence factors (effectors) early in host infection and convert it to rapid defense. One key to resistance success is a polymorphic family of intracellular nucleotide-binding/leucine-rich-repeat (NLR) receptors that detect effector interference in different parts of the cell. Effector-activated NLRs connect, in various ways, to a conserved basal resistance network in order to transcriptionally boost defense programs. Effector-triggered immunity displays remarkable robustness against pathogen disturbance, in part by employing compensatory mechanisms within the defense network. Also, the mobility of some NLRs and coordination of resistance pathways across cell compartments provides flexibility to fine-tune immune outputs. Furthermore, a number of NLRs function close to the nuclear chromatin by balancing actions of defense-repressing and defense-activating transcription factors to program cells dynamically for effective disease resistance.

  19. Innate immune defences in the human endometrium

    Directory of Open Access Journals (Sweden)

    Kelly Rodney W

    2003-11-01

    Full Text Available Abstract The human endometrium is an important site of innate immune defence, giving protection against uterine infection. Such protection is critical to successful implantation and pregnancy. Infection is a major cause of preterm birth and can also cause infertility and ectopic pregnancy. Natural anti-microbial peptides are key mediators of the innate immune system. These peptides, between them, have anti-bacterial, anti-fungal and anti-viral activity and are expressed at epithelial surfaces throughout the female genital tract. Two families of natural anti-microbials, the defensins and the whey acidic protein (WAP motif proteins, appear to be prominent in endometrium. The human endometrial epithelium expresses beta-defensins 1–4 and the WAP motif protein, secretory leukocyte protease inhibitor. Each beta-defensin has a different expression profile in relation to the stage of the menstrual cycle, providing potential protection throughout the cycle. Secretory leukocyte protease inhibitor is expressed during the secretory phase of the cycle and has a range of possible roles including anti-protease and anti-microbial activity as well as having effects on epithelial cell growth. The leukocyte populations in the endometrium are also a source of anti-microbial production. Neutrophils are a particularly rich source of alpha-defensins, lactoferrin, lysozyme and the WAP motif protein, elafin. The presence of neutrophils during menstruation will enhance anti-microbial protection at a time when the epithelial barrier is disrupted. Several other anti-microbials including the natural killer cell product, granulysin, are likely to have a role in endometrium. The sequential production of natural anti-microbial peptides by the endometrium throughout the menstrual cycle and at other sites in the female genital tract will offer protection from many pathogens, including those that are sexually transmitted.

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

    Science.gov (United States)

    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

  1. 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.

  2. 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

  3. Viral evasion of DNA-stimulated innate immune responses

    Science.gov (United States)

    Christensen, Maria H; Paludan, Søren R

    2017-01-01

    Cellular sensing of virus-derived nucleic acids is essential for early defenses against virus infections. In recent years, the discovery of DNA sensing proteins, including cyclic GMP–AMP synthase (cGAS) and gamma-interferon-inducible protein (IFI16), has led to understanding of how cells evoke strong innate immune responses against incoming pathogens carrying DNA genomes. The signaling stimulated by DNA sensors depends on the adaptor protein STING (stimulator of interferon genes), to enable expression of antiviral proteins, including type I interferon. To facilitate efficient infections, viruses have evolved a wide range of evasion strategies, targeting host DNA sensors, adaptor proteins and transcription factors. In this review, the current literature on virus-induced activation of the STING pathway is presented and we discuss recently identified viral evasion mechanisms targeting different steps in this antiviral pathway. PMID:26972769

  4. Viral evasion of DNA-stimulated innate immune responses.

    Science.gov (United States)

    Christensen, Maria H; Paludan, Søren R

    2017-01-01

    Cellular sensing of virus-derived nucleic acids is essential for early defenses against virus infections. In recent years, the discovery of DNA sensing proteins, including cyclic GMP-AMP synthase (cGAS) and gamma-interferon-inducible protein (IFI16), has led to understanding of how cells evoke strong innate immune responses against incoming pathogens carrying DNA genomes. The signaling stimulated by DNA sensors depends on the adaptor protein STING (stimulator of interferon genes), to enable expression of antiviral proteins, including type I interferon. To facilitate efficient infections, viruses have evolved a wide range of evasion strategies, targeting host DNA sensors, adaptor proteins and transcription factors. In this review, the current literature on virus-induced activation of the STING pathway is presented and we discuss recently identified viral evasion mechanisms targeting different steps in this antiviral pathway.

  5. Contrasting invertebrate immune defense behaviors caused by a single gene, the Caenorhabditis elegans neuropeptide receptor gene npr-1

    NARCIS (Netherlands)

    Nakad, Rania; Snoek, Basten; Yang, Wentao; Ellendt, S.; Schneider, Franziska; Mohr, T.G.; Rösingh, Lone; Masche, Anna C.; Rosenstiel, P.C.; Dierking, K.; Kammenga, Jan E.; Schulenburg, Hinrich

    2016-01-01

    Background: The invertebrate immune system comprises physiological mechanisms, physical barriers and also behavioral responses. It is generally related to the vertebrate innate immune system and widely believed to provide
    nonspecific defense against pathogens, whereby the response to different

  6. Contrasting invertebrate immune defense behaviors caused by a single gene, the Caenorhabditis elegans neuropeptide receptor gene npr-1

    NARCIS (Netherlands)

    Nakad, Rania; Snoek, L.B.; Yang, Wentao; Ellendt, S.; Schneider, Franziska; Mohr, T.G.; Rösingh, Lone; Masche, Anna C.; Rosenstiel, P.C.; Dierking, K.; Kammenga, J.E.; Schulenburg, Hinrich

    2016-01-01

    Background The invertebrate immune system comprises physiological mechanisms, physical barriers and also behavioral responses. It is generally related to the vertebrate innate immune system and widely believed to provide nonspecific defense against pathogens, whereby the response to different

  7. Contrasting invertebrate immune defense behaviors caused by a single gene, the Caenorhabditis elegans neuropeptide receptor gene npr-1

    NARCIS (Netherlands)

    Nakad, Rania; Snoek, L Basten; Yang, Wentao; Ellendt, Sunna; Schneider, Franziska; Mohr, Timm G; Rösingh, Lone; Masche, Anna C; Rosenstiel, Philip C; Dierking, Katja; Kammenga, Jan E; Schulenburg, Hinrich

    2016-01-01

    BACKGROUND: The invertebrate immune system comprises physiological mechanisms, physical barriers and also behavioral responses. It is generally related to the vertebrate innate immune system and widely believed to provide nonspecific defense against pathogens, whereby the response to different

  8. Stress Hyperglycemia, Insulin Treatment, and Innate Immune Cells

    Directory of Open Access Journals (Sweden)

    Fangming Xiu

    2014-01-01

    Full Text Available Hyperglycemia (HG and insulin resistance are the hallmarks of a profoundly altered metabolism in critical illness resulting from the release of cortisol, catecholamines, and cytokines, as well as glucagon and growth hormone. Recent studies have proposed a fundamental role of the immune system towards the development of insulin resistance in traumatic patients. A comprehensive review of published literatures on the effects of hyperglycemia and insulin on innate immunity in critical illness was conducted. This review explored the interaction between the innate immune system and trauma-induced hypermetabolism, while providing greater insight into unraveling the relationship between innate immune cells and hyperglycemia. Critical illness substantially disturbs glucose metabolism resulting in a state of hyperglycemia. Alterations in glucose and insulin regulation affect the immune function of cellular components comprising the innate immunity system. Innate immune system dysfunction via hyperglycemia is associated with a higher morbidity and mortality in critical illness. Along with others, we hypothesize that reduction in morbidity and mortality observed in patients receiving insulin treatment is partially due to its effect on the attenuation of the immune response. However, there still remains substantial controversy regarding moderate versus intensive insulin treatment. Future studies need to determine the integrated effects of HG and insulin on the regulation of innate immunity in order to provide more effective insulin treatment regimen for these patients.

  9. Rorγt+ innate lymphoid cells in intestinal homeostasis and immunity.

    Science.gov (United States)

    Aparicio-Domingo, Patricia; Cupedo, Tom

    2011-01-01

    Innate lymphoid cells (ILC) combine innate and adaptive immune functions and are part of the first line of defense against mucosal infections. ILC are set apart from adaptive lymphocytes by their independence on RAG genes and the resulting absence of specific antigen receptors. In this review, we will discuss the biology and function of intestinal ILC that express the nuclear hormone receptor Rorγt (encoded by the Rorc gene) and highlight their role in intestinal homeostasis and immunity. Copyright © 2011 S. Karger AG, Basel.

  10. PKA/KIN-1 mediates innate immune responses to bacterial pathogens in Caenorhabditis elegans.

    Science.gov (United States)

    Xiao, Yi; Liu, Fang; Zhao, Pei-Ji; Zou, Cheng-Gang; Zhang, Ke-Qin

    2017-11-01

    The genetically tractable organism Caenorhabditis elegans is a powerful model animal for the study of host innate immunity. Although the intestine and the epidermis of C. elegans that is in contact with pathogens are likely to function as sites for the immune function, recent studies indicate that the nervous system could control innate immunity in C. elegans. In this report, we demonstrated that protein kinase A (PKA)/KIN-1 in the neurons contributes to resistance against Salmonella enterica infection in C. elegans. Microarray analysis revealed that PKA/KIN-1 regulates the expression of a set of antimicrobial effectors in the non-neuron tissues, which are required for innate immune responses to S. enterica. Furthermore, PKA/KIN-1 regulated the expression of lysosomal genes during S. enterica infection. Our results suggest that the lysosomal signaling molecules are involved in autophagy by controlling autophagic flux, rather than formation of autophagosomes. As autophagy is crucial for host defense against S. enterica infection in a metazoan, the lysosomal pathway also acts as a downstream effector of the PKA/KIN-1 signaling for innate immunity. Our data indicate that the PKA pathway contributes to innate immunity in C. elegans by signaling from the nervous system to periphery tissues to protect the host against pathogens.

  11. Evolution and Function of Thioester-Containing Proteins and the Complement System in the Innate Immune Response

    Directory of Open Access Journals (Sweden)

    Upasana Shokal

    2017-06-01

    Full Text Available The innate immune response is evolutionary conserved among organisms. The complement system forms an important and efficient immune defense mechanism. It consists of plasma proteins that participate in microbial detection, which ultimately results in the production of various molecules with antimicrobial activity. Thioester-containing proteins (TEPs are a superfamily of secreted effector proteins. In vertebrates, certain TEPs act in the innate immune response by promoting recruitment of immune cells, phagocytosis, and direct lysis of microbial invaders. Insects are excellent models for dissecting the molecular basis of innate immune recognition and response to a wide range of microbial infections. Impressive progress in recent years has generated crucial information on the role of TEPs in the antibacterial and antiparasite response of the tractable model insect Drosophila melanogaster and the mosquito malaria vector Anopheles gambiae. This knowledge is critical for better understanding the evolution of TEPs and their involvement in the regulation of the host innate immune system.

  12. Morphological and Cellular Features of Innate Immune Reaction in Helicobacter pylori Gastritis: A Brief Review

    Directory of Open Access Journals (Sweden)

    Antonio Ieni

    2016-01-01

    Full Text Available Innate and adaptive immunity are both involved in acute and chronic inflammatory processes. The main cellular players in the innate immune system are macrophages, mast cells, dendritic cells, neutrophils, eosinophils, and natural killer (NK, which offer antigen-independent defense against infection. Helicobacter pylori (H. pylori infection presents peculiar characteristics in gastric mucosa infrequently occurring in other organs; its gastric colonization determines a causal role in both gastric carcinomas and mucosa-associated lymphoid tissue lymphoma. In contrast, an active role for Epstein-Barr virus (EBV has been identified only in 9% of gastric carcinomas. The aim of the present review is to discuss the role of cellular morphological effectors in innate immunity during H. pylori infection and gastric carcinogenesis.

  13. Evolution and integration of innate immune systems from fruit flies to man: lessons and questions.

    Science.gov (United States)

    Martinelli, Cosimo; Reichhart, Jean-Marc

    2005-01-01

    Despite broad differences in morphology, ecology and behavior, the fruit fly Drosophila melanogaster and humans show a remarkably high degree of conservation for many molecular, cellular, and developmental aspects of their biology. During the last decade, similarities have also been discovered in some of the mechanisms regulating their innate immune system. These parallels regard mainly the Toll-like receptor family and the intracellular signaling pathways involved in the control of the immune response. However, if the overall similarities are important, the detailed pathogen recognition mechanisms differ significantly between fly and humans, highlighting a complicated evolutionary history of the metazoan innate defenses. In this review, we will discuss the main similarities and differences between the two types of organisms. We hope that this current knowledge will be used as a starting point for a more comprehensive view of innate immunity within the broad variety of metazoan phyla.

  14. Retinoic Acid and Its Role in Modulating Intestinal Innate Immunity

    Directory of Open Access Journals (Sweden)

    Paulo Czarnewski

    2017-01-01

    Full Text Available Vitamin A (VA is amongst the most well characterized food-derived nutrients with diverse immune modulatory roles. Deficiency in dietary VA has not only been associated with immune dysfunctions in the gut, but also with several systemic immune disorders. In particular, VA metabolite all-trans retinoic acid (atRA has been shown to be crucial in inducing gut tropism in lymphocytes and modulating T helper differentiation. In addition to the widely recognized role in adaptive immunity, increasing evidence identifies atRA as an important modulator of innate immune cells, such as tolerogenic dendritic cells (DCs and innate lymphoid cells (ILCs. Here, we focus on the role of retinoic acid in differentiation, trafficking and the functions of innate immune cells in health and inflammation associated disorders. Lastly, we discuss the potential involvement of atRA during the plausible crosstalk between DCs and ILCs.

  15. Dissecting Phaseolus vulgaris innate immune system against Colletotrichum lindemuthianum infection.

    Directory of Open Access Journals (Sweden)

    Paula Rodrigues Oblessuc

    Full Text Available BACKGROUND: The genus Colletotrichum is one of the most economically important plant pathogens, causing anthracnose on a wide range of crops including common beans (Phaseolus vulgaris L.. Crop yield can be dramatically decreased depending on the plant cultivar used and the environmental conditions. This study aimed to identify potential genetic components of the bean immune system to provide environmentally friendly control measures against this fungus. METHODOLOGY AND PRINCIPAL FINDINGS: As the common bean is not amenable to reverse genetics to explore functionality and its genome is not fully curated, we used putative Arabidopsis orthologs of bean expressed sequence tag (EST to perform bioinformatic analysis and experimental validation of gene expression to identify common bean genes regulated during the incompatible interaction with C. lindemuthianum. Similar to model pathosystems, Gene Ontology (GO analysis indicated that hormone biosynthesis and signaling in common beans seem to be modulated by fungus infection. For instance, cytokinin and ethylene responses were up-regulated and jasmonic acid, gibberellin, and abscisic acid responses were down-regulated, indicating that these hormones may play a central role in this pathosystem. Importantly, we have identified putative bean gene orthologs of Arabidopsis genes involved in the plant immune system. Based on experimental validation of gene expression, we propose that hypersensitive reaction as part of effector-triggered immunity may operate, at least in part, by down-regulating genes, such as FLS2-like and MKK5-like, putative orthologs of the Arabidopsis genes involved in pathogen perception and downstream signaling. CONCLUSIONS/SIGNIFICANCE: We have identified specific bean genes and uncovered metabolic processes and pathways that may be involved in the immune response against pathogens. Our transcriptome database is a rich resource for mining novel defense-related genes, which enabled us to

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

    Science.gov (United States)

    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.

  17. Innate immunity and effector and regulatory mechanisms involved in allergic contact dermatitis.

    Science.gov (United States)

    Silvestre, Marilene Chaves; Sato, Maria Notomi; Reis, Vitor Manoel Silva Dos

    2018-03-01

    Skin's innate immunity is the initial activator of immune response mechanisms, influencing the development of adaptive immunity. Some contact allergens are detected by Toll-like receptors (TLRs) and inflammasome NLR3. Keratinocytes participate in innate immunity and, in addition to functioning as an anatomical barrier, secrete cytokines, such as TNF, IL-1β, and IL-18, contributing to the development of Allergic Contact Dermatitis. Dendritic cells recognize and process antigenic peptides into T cells. Neutrophils cause pro-inflammatory reactions, mast cells induce migration/maturation of skin DCs, the natural killer cells have natural cytotoxic capacity, the γδ T cells favor contact with hapten during the sensitization phase, and the innate lymphoid cells act in the early stages by secreting cytokines, as well as act in inflammation and tissue homeostasis. The antigen-specific inflammation is mediated by T cells, and each subtype of T cells (Th1/Tc1, Th2/Tc2, and Th17/Tc17) activates resident skin cells, thus contributing to inflammation. Skin's regulatory T cells have a strong ability to inhibit the proliferation of hapten-specific T cells, acting at the end of the Allergic Contact Dermatitis response and in the control of systemic immune responses. In this review, we report how cutaneous innate immunity is the first line of defense and focus its role in the activation of the adaptive immune response, with effector response induction and its regulation.

  18. Innate immunity and effector and regulatory mechanisms involved in allergic contact dermatitis*

    Science.gov (United States)

    Silvestre, Marilene Chaves; Sato, Maria Notomi; dos Reis, Vitor Manoel Silva

    2018-01-01

    Skin's innate immunity is the initial activator of immune response mechanisms, influencing the development of adaptive immunity. Some contact allergens are detected by Toll-like receptors (TLRs) and inflammasome NLR3. Keratinocytes participate in innate immunity and, in addition to functioning as an anatomical barrier, secrete cytokines, such as TNF, IL-1β, and IL-18, contributing to the development of Allergic Contact Dermatitis. Dendritic cells recognize and process antigenic peptides into T cells. Neutrophils cause pro-inflammatory reactions, mast cells induce migration/maturation of skin DCs, the natural killer cells have natural cytotoxic capacity, the γδ T cells favor contact with hapten during the sensitization phase, and the innate lymphoid cells act in the early stages by secreting cytokines, as well as act in inflammation and tissue homeostasis. The antigen-specific inflammation is mediated by T cells, and each subtype of T cells (Th1/Tc1, Th2/Tc2, and Th17/Tc17) activates resident skin cells, thus contributing to inflammation. Skin's regulatory T cells have a strong ability to inhibit the proliferation of hapten-specific T cells, acting at the end of the Allergic Contact Dermatitis response and in the control of systemic immune responses. In this review, we report how cutaneous innate immunity is the first line of defense and focus its role in the activation of the adaptive immune response, with effector response induction and its regulation. PMID:29723367

  19. Bruton's Tyrosine Kinase: An Emerging Key Player in Innate Immunity.

    Science.gov (United States)

    Weber, Alexander N R; Bittner, Zsofia; Liu, Xiao; Dang, Truong-Minh; Radsak, Markus Philipp; Brunner, Cornelia

    2017-01-01

    Bruton's tyrosine kinase (BTK) was initially discovered as a critical mediator of B cell receptor signaling in the development and functioning of adaptive immunity. Growing evidence also suggests multiple roles for BTK in mononuclear cells of the innate immune system, especially in dendritic cells and macrophages. For example, BTK has been shown to function in Toll-like receptor-mediated recognition of infectious agents, cellular maturation and recruitment processes, and Fc receptor signaling. Most recently, BTK was additionally identified as a direct regulator of a key innate inflammatory machinery, the NLRP3 inflammasome. BTK has thus attracted interest not only for gaining a more thorough basic understanding of the human innate immune system but also as a target to therapeutically modulate innate immunity. We here review the latest developments on the role of BTK in mononuclear innate immune cells in mouse versus man, with specific emphasis on the sensing of infectious agents and the induction of inflammation. Therapeutic implications for modulating innate immunity and critical open questions are also discussed.

  20. Innate immune reconstitution with suppression of HIV-1.

    Science.gov (United States)

    Scully, Eileen P; Lockhart, Ainsley; Garcia-Beltran, Wilfredo; Palmer, Christine D; Musante, Chelsey; Rosenberg, Eric; Allen, Todd M; Chang, J Judy; Bosch, Ronald J; Altfeld, Marcus

    2016-03-17

    Progressive HIV-1 infection leads to both profound immune suppression and pathologic inflammation in the majority of infected individuals. While adaptive immune dysfunction, as evidenced by CD4 + T cell depletion and exhaustion, has been extensively studied, less is known about the functional capacity of innate immune cell populations in the context of HIV-1 infection. Given the broad susceptibility to opportunistic infections and the dysregulated inflammation observed in progressive disease, we hypothesized that there would be significant changes in the innate cellular responses. Using a cohort of patients with multiple samplings before and after antiretroviral therapy (ART) initiation, we demonstrated increased responses to innate immune stimuli following viral suppression, as measured by the production of inflammatory cytokines. Plasma viral load itself had the strongest association with this change in innate functional capacity. We further identified epigenetic modifications in the TNFA promoter locus in monocytes that are associated with viremia, suggesting a molecular mechanism for the observed changes in innate immune function following initiation of ART. These data indicate that suppression of HIV-1 viremia is associated with changes in innate cellular function that may in part determine the restoration of protective immune responses.

  1. 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.

  2. Evasion of host immune defenses by human papillomavirus.

    Science.gov (United States)

    Westrich, Joseph A; Warren, Cody J; Pyeon, Dohun

    2017-03-02

    A majority of human papillomavirus (HPV) infections are asymptomatic and self-resolving in the absence of medical interventions. Various innate and adaptive immune responses, as well as physical barriers, have been implicated in controlling early HPV infections. However, if HPV overcomes these host immune defenses and establishes persistence in basal keratinocytes, it becomes very difficult for the host to eliminate the infection. The HPV oncoproteins E5, E6, and E7 are important in regulating host immune responses. These oncoproteins dysregulate gene expression, protein-protein interactions, posttranslational modifications, and cellular trafficking of critical host immune modulators. In addition to the HPV oncoproteins, sequence variation and dinucleotide depletion in papillomavirus genomes has been suggested as an alternative strategy for evasion of host immune defenses. Since anti-HPV host immune responses are also considered to be important for antitumor immunity, immune dysregulation by HPV during virus persistence may contribute to immune suppression essential for HPV-associated cancer progression. Here, we discuss cellular pathways dysregulated by HPV that allow the virus to evade various host immune defenses. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  3. Toxin-mediated effects on the innate mucosal defenses: implications for enteric vaccines

    DEFF Research Database (Denmark)

    Glenn, Gregory M; Francis, David H; Danielsen, E Michael

    2009-01-01

    mucosal barrier as a key step in enteric pathogen survival. We review key observations relevant to the roles of LT and cholera toxin in protective immunity and the effects of these toxins on innate mucosal defenses. We suggest either that toxin-mediated fluid secretion mechanically disrupts the mucus...... layer or that toxins interfere with innate mucosal defenses by other means. Such a breach gives pathogens access to the enterocyte, leading to binding and pathogenicity by enterotoxigenic E. coli (ETEC) and other organisms. Given the common exposure to LT(+) ETEC by humans visiting or residing...... unexpectedly broad protective effects against LT(+) ETEC and mixed infections when using a toxin-based enteric vaccine. If toxins truly exert barrier-disruptive effects as a key step in pathogenesis, then a return to classic toxin-based vaccine strategies for enteric disease is warranted and can be expected...

  4. Salivary innate defense system in type 1 diabetes mellitus in children with mixed and permanent dentition.

    Science.gov (United States)

    Zalewska, Anna; Knaś, Małgorzata; Kuźmiuk, Anna; Waszkiewicz, Napoleon; Niczyporuk, Marek; Waszkiel, Danuta; Zwierz, Krzysztof

    2013-11-01

    It should be expected that type 1 diabetes mellitus may disturb innate and acquired immunity. There are no data on type 1 diabetes mellitus-related changes in the salivary flow and the protein output responsible for the innate immunity of saliva depending on the quality of dentition reflecting the age of child. The aim of this work was the evaluation of parameters responsible for the innate immunity of saliva in children and adolescents with type 1 diabetes mellitus. In diabetic children, adolescent and healthy volunteers, the salivary flow, the output and the concentration of the activity of peroxidase (colorimetry), lysozyme (radial immunodiffusion) and lactoferrin (ELISA) were determined. In children with mixed and permanent dentition, type 1 diabetes mellitus significantly decreases (as compared with the appropriate controls) the unstimulated salivary flow, the output, concentration of peroxidase and the output of the lysozyme and lactoferrin. In conclusion, it may be stated that type 1 diabetes mellitus causes functional changes in the salivary glands, resulting in a decrease of the salivary flow and weakening of the salivary innate defense system, thus creating a threat to the oral and general health of type 1 diabetes mellitus children. The results showed that the salivary glands of younger children, when compared to adolescents with type 1 diabetes mellitus, are more susceptible to the injurious effects of the disease.

  5. Cheetahs have a stronger constitutive innate immunity than leopards.

    Science.gov (United States)

    Heinrich, Sonja K; Hofer, Heribert; Courtiol, Alexandre; Melzheimer, Jörg; Dehnhard, Martin; Czirják, Gábor Á; Wachter, Bettina

    2017-03-23

    As a textbook case for the importance of genetics in conservation, absence of genetic variability at the major histocompatibility complex (MHC) is thought to endanger species viability, since it is considered crucial for pathogen resistance. An alternative view of the immune system inspired by life history theory posits that a strong response should evolve in other components of the immune system if there is little variation in the MHC. In contrast to the leopard (Panthera pardus), the cheetah (Acinonyx jubatus) has a relatively low genetic variability at the MHC, yet free-ranging cheetahs are healthy. By comparing the functional competence of the humoral immune system of both species in sympatric populations in Namibia, we demonstrate that cheetahs have a higher constitutive innate but lower induced innate and adaptive immunity than leopards. We conclude (1) immunocompetence of cheetahs is higher than previously thought; (2) studying both innate and adaptive components of immune systems will enrich conservation science.

  6. Alternatives to conventional vaccines--mediators of innate immunity.

    Science.gov (United States)

    Eisen, D P; Liley, H G; Minchinton, R M

    2004-01-01

    Vaccines have been described as "weapons of mass protection". The eradication of many diseases is testament to their utility and effectiveness. Nevertheless, many vaccine preventable diseases remain prevalent because of political and economic barriers. Additionally, the effects of immaturity and old age, therapies that incapacitate the adaptive immune system and the multitude of strategies evolved by pathogens to evade immediate or sustained recognition by the mammalian immune system are barriers to the effectiveness of existing vaccines or development of new vaccines. In the front line of defence against the pervasiness of infection are the elements of the innate immune system. Innate immunity is under studied and poorly appreciated. However, in the first days after entry of a pathogen into the body, our entire protective response is dependant upon the various elements of our innate immune repertoire. In spite of its place as our initial defence against infection, attention is only now turning to strategies which enhance or supplement innate immunity. This review examines the need for and potential of innate immune therapies.

  7. Early life innate immune signatures of persistent food allergy.

    Science.gov (United States)

    Neeland, Melanie R; Koplin, Jennifer J; Dang, Thanh D; Dharmage, Shyamali C; Tang, Mimi L; Prescott, Susan L; Saffery, Richard; Martino, David J; Allen, Katrina J

    2017-11-14

    Food allergy naturally resolves in a proportion of food-allergic children without intervention; however the underlying mechanisms governing the persistence or resolution of food allergy in childhood are not understood. This study aimed to define the innate immune profiles associated with egg allergy at age 1 year, determine the phenotypic changes that occur with the development of natural tolerance in childhood, and explore the relationship between early life innate immune function and serum vitamin D. This study used longitudinally collected PBMC samples from a population-based cohort of challenge-confirmed egg-allergic infants with either persistent or transient egg allergy outcomes in childhood to phenotype and quantify the functional innate immune response associated with clinical phenotypes of egg allergy. We show that infants with persistent egg allergy exhibit a unique innate immune signature, characterized by increased numbers of circulating monocytes and dendritic cells that produce more inflammatory cytokines both at baseline and following endotoxin exposure when compared with infants with transient egg allergy. Follow-up analysis revealed that this unique innate immune signature continues into childhood in those with persistent egg allergy and that increased serum vitamin D levels correlate with changes in innate immune profiles observed in children who developed natural tolerance to egg. Early life innate immune dysfunction may represent a key immunological driver and predictor of persistent food allergy in childhood. Serum vitamin D may play an immune-modulatory role in the development of natural tolerance. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  8. 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 ...

  9. Breakdown of the innate immune system by bacterial proteases

    NARCIS (Netherlands)

    Laarman, A.J.

    2011-01-01

    Bacteria have developed many strategies to circumvent our immune system to survive and colonize human tissues. One of these strategies is by secreting proteases that specifically target the innate immune system. Aureolysin is a metalloprotease from Staphylococcus aureus which target the main

  10. DMPD: Innate immunity minireview series: making biochemical sense of nucleic acidsensors that trigger antiviral innate immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17395579 Innate immunity minireview series: making biochemical sense of nucleic aci...007 Mar 29. (.png) (.svg) (.html) (.csml) Show Innate immunity minireview series: making biochemical sense o...itle Innate immunity minireview series: making biochemical sense of nucleic acidsensors that trigger antivir

  11. Viral degradasome hijacks mitochondria to suppress innate immunity

    Science.gov (United States)

    Goswami, Ramansu; Majumdar, Tanmay; Dhar, Jayeeta; Chattopadhyay, Saurabh; Bandyopadhyay, Sudip K; Verbovetskaya, Valentina; Sen, Ganes C; Barik, Sailen

    2013-01-01

    The balance between the innate immunity of the host and the ability of a pathogen to evade it strongly influences pathogenesis and virulence. The two nonstructural (NS) proteins, NS1 and NS2, of respiratory syncytial virus (RSV) are critically required for RSV virulence. Together, they strongly suppress the type I interferon (IFN)-mediated innate immunity of the host cells by degrading or inhibiting multiple cellular factors required for either IFN induction or response pathways, including RIG-I, IRF3, IRF7, TBK1 and STAT2. Here, we provide evidence for the existence of a large and heterogeneous degradative complex assembled by the NS proteins, which we named “NS-degradasome” (NSD). The NSD is roughly ∼300-750 kD in size, and its degradative activity was enhanced by the addition of purified mitochondria in vitro. Inside the cell, the majority of the NS proteins and the substrates of the NSD translocated to the mitochondria upon RSV infection. Genetic and pharmacological evidence shows that optimal suppression of innate immunity requires mitochondrial MAVS and mitochondrial motility. Together, we propose a novel paradigm in which the mitochondria, known to be important for the innate immune activation of the host, are also important for viral suppression of the innate immunity. PMID:23877405

  12. 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

  13. Interleukin-1 and cutaneous inflammation: a crucial link between innate and acquired immunity.

    Science.gov (United States)

    Murphy, J E; Robert, C; Kupper, T S

    2000-03-01

    As our primary interface with the environment, the skin is constantly subjected to injury and invasion by pathogens. The fundamental force driving the evolution of the immune system has been the need to protect the host against overwhelming infection. The ability of T and B cells to recombine antigen receptor genes during development provides an efficient, flexible, and powerful immune system with nearly unlimited specificity for antigen. The capacity to expand subsets of antigen-specific lymphocytes that become activated by environmental antigens (memory response) is termed "acquired" immunity. Immunologic memory, although a fundamental aspect of mammalian biology, is a relatively recent evolutionary event that permits organisms to live for years to decades. "Innate" immunity, mediated by genes that remain in germ line conformation and encode for proteins that recognize conserved structural patterns on microorganisms, is a much more ancient system of host defense. Defensins and other antimicrobial peptides, complement and opsonins, and endocytic receptors are all considered components of the innate immune system. None of these, however, are signal-transducing receptors. Most recently, a large family of cell surface receptors that mediate signaling through the NF-kappaB transcription factor has been identified. This family of proteins shares striking homology with plant and Drosophila genes that mediate innate immunity. In mammals, this family includes the type I interleukin-1 receptor, the interleukin-18 receptor, and a growing family of Toll-like receptors, two of which were recently identified as signal-transducing receptors for bacterial endotoxin. In this review, we discuss how interleukin-1 links the innate and acquired immune systems to provide synergistic host defense activities in skin.

  14. Injury to Allografts: innate immune pathways to acute and chronic rejection

    International Nuclear Information System (INIS)

    Land, W. G.

    2005-01-01

    An emerging body of evidence suggests that innate immunity, as the first line of host defense against invading pathogens or their components [pathogen-associated molecular patterns, (PAMPs)], plays also a critical role in acute and chronic allograft rejection. Injury to the donor organ induces an inflammatory milieu in the allograft, which appears to be the initial key event for activation of the innate immune system. Injury-induced generation of putative endogenous molecular ligand, in terms of damaged/danger-associated molecular patterns (DAMPs) such as heat shock proteins, are recognized by Toll-like receptors (TLRs), a family of pattern recognition receptors on cells of innate immunity. Acute allograft injury (e.g. oxidative stress during donor brain-death condition, post-ischemic reperfusion injury in the recipient) includes DAMPs which may interact with, and activate, innate TLR-bearing dendritic cells (DCs) which, in turn, via direct allo-recognition through donor-derived DCs and indirect allo-recogntion through recipient-derived DCs, initiate the recipient's adaptive alloimmune response leading to acute allograft rejection. Chronic injurious events in the allograft (e.g. hypertension, hyperlipidemia, CMV infection, administration of cell-toxic drugs [calcineurin-inhibitors]) induce the generation of D AMPs , which may interact with and activate innate TLR-bearing vascular cells (endothelial cells, smooth muscle cells) which, in turn, contribute to the development of atherosclerosis of donor organ vessels (alloatherosclerosis), thus promoting chronic allograft rejection. (author)

  15. Innate Immunity and Saliva in Candida albicans–mediated Oral Diseases

    Science.gov (United States)

    Salvatori, O.; Puri, S.; Tati, S.; Edgerton, M.

    2016-01-01

    The oral cavity is a unique niche where Candida albicans infections occur in immunocompetent as well as immunosuppressed individuals. Here we critically review the significance of human innate immune response in preventing oral candidiasis. One important line of defense against oropharyngeal candidiasis is the oral microbiota that prevents infection by competing for space and nutrients as well as by secreting antagonistic molecules and triggering local inflammatory responses. C. albicans is able to induce mucosal defenses through activation of immune cells and production of cytokines. Also, saliva contains various proteins that affect C. albicans growth positively by promoting mucosal adherence and negatively through immune exclusion and direct fungicidal activity. We further discuss the role of saliva in unifying host innate immune defenses against C. albicans as a communicating medium and how C. albicans overgrowth in the oral cavity may be a result of aberrations ranging from microbial dysbiosis and salivary dysfunction to epithelial damage. Last we underscore select oral diseases in which C. albicans is a contributory microorganism in immune-competent individuals. PMID:26747422

  16. Postnatal Innate Immune Development: From Birth to Adulthood

    Directory of Open Access Journals (Sweden)

    Anastasia Georgountzou

    2017-08-01

    Full Text Available It is well established that adaptive immune responses are deficient in early life, contributing to increased mortality and morbidity. The developmental trajectories of different components of innate immunity are only recently being explored. Individual molecules, cells, or pathways of innate recognition and signaling, within different compartments/anatomical sites, demonstrate variable maturation patterns. Despite some discrepancies among published data, valuable information is emerging, showing that the developmental pattern of cytokine responses during early life is age and toll-like receptor specific, and may be modified by genetic and environmental factors. Interestingly, specific environmental exposures have been linked both to innate function modifications and the occurrence of chronic inflammatory disorders, such as respiratory allergies. As these conditions are on the rise, our knowledge on innate immune development and its modulating factors needs to be expanded. Improved understanding of the sequence of events associated with disease onset and persistence will lead toward meaningful interventions. This review describes the state-of-the-art on normal postnatal innate immune ontogeny and highlights research areas that are currently explored or should be further addressed.

  17. Convergence of the innate and adaptive immunity during human aging

    Directory of Open Access Journals (Sweden)

    Branca Isabel Pereira

    2016-11-01

    Full Text Available Aging is associated with profound changes in the human immune system, a phenomenon referred to as immunosenescence. This complex immune remodeling affects the adaptive immune system and the CD8+ T cell compartment in particular, leading to the accumulation of terminally differentiated T cells, which can rapidly exert their effector functions at the expenses of a limited proliferative potential. In this review we will discuss evidence suggesting that senescent αβCD8+ T cells acquire the hallmarks of innate-like T cells and use recently acquired NK cell receptors as an alternative mechanism to mediate rapid effector functions. These cells concomitantly lose expression of co-stimulatory receptors and exhibit decreased TCR signaling suggesting a functional shift away from antigen specific activation. The convergence of innate and adaptive features in senescent T cells challenges the classic division between innate and adaptive immune systems. Innate-like T cells are particularly important for stress and tumor surveillance and we propose a new role for these cells in aging, where the acquisition of innate-like functions may represent a beneficial adaptation to an increased burden of malignancy with age, although it may also pose a higher risk of autoimmune disorders.

  18. Cannabinoids and Innate Immunity: Taking a Toll on Neuroinflammation

    Directory of Open Access Journals (Sweden)

    Eric J. Downer

    2011-01-01

    Full Text Available The biologically active components of cannabis have therapeutic potential in neuroinflammatory disorders due to their anti-inflammatory propensity. Cannabinoids influence immune function in both the peripheral and the central nervous system (CNS, and the components of the cannabinoid system, the cannabinoid receptors and their endogenous ligands (endocannabinoids, have been detected on immune cells as well as in brain glia. Neuroinflammation is the complex innate immune response of neural tissue to control infection and eliminate pathogens, and Toll-like receptors (TLRs, a major family of pattern recognition receptors (PRRs that mediate innate immunity, have emerged as players in the neuroinflammatory processes underpinning various CNS diseases. This review will highlight evidence that cannabinoids interact with the immune system by impacting TLR-mediated signaling events, which may provide cues for devising novel therapeutic approaches for cannabinoid ligands.

  19. Mechanisms of innate immune evasion in re-emerging RNA viruses.

    Science.gov (United States)

    Ma, Daphne Y; Suthar, Mehul S

    2015-06-01

    Recent outbreaks of Ebola, West Nile, Chikungunya, Middle Eastern Respiratory and other emerging/re-emerging RNA viruses continue to highlight the need to further understand the virus-host interactions that govern disease severity and infection outcome. As part of the early host antiviral defense, the innate immune system mediates pathogen recognition and initiation of potent antiviral programs that serve to limit virus replication, limit virus spread and activate adaptive immune responses. Concordantly, viral pathogens have evolved several strategies to counteract pathogen recognition and cell-intrinsic antiviral responses. In this review, we highlight the major mechanisms of innate immune evasion by emerging and re-emerging RNA viruses, focusing on pathogens that pose significant risk to public health. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. 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.

  1. Vitamin D signaling in intestinal innate immunity and homeostasis.

    Science.gov (United States)

    Dimitrov, Vassil; White, John H

    2017-09-15

    The lumen of the gut hosts a plethora of microorganisms that participate in food assimilation, inactivation of harmful particles and in vitamin synthesis. On the other hand, enteric flora, a number of food antigens, and toxins are capable of triggering immune responses causing inflammation, which, when unresolved, may lead to chronic conditions such as inflammatory bowel disease (IBD). It is important, therefore, to contain the gut bacteria within the lumen, control microbial load and composition, as well as ensure adequate innate and adaptive immune responses to pathogenic threats. There is growing evidence that vitamin D signaling has impacts on all these aspects of intestinal physiology, contributing to healthy enteric homeostasis. VD was first discovered as the curative agent for nutritional rickets, and its classical actions are associated with calcium absorption and bone health. However, vitamin D exhibits a number of extra-skeletal effects, particularly in innate immunity. Notably, it stimulates production of pattern recognition receptors, anti-microbial peptides, and cytokines, which are at the forefront of innate immune responses. They play a role in sensing the microbiota, in preventing excessive bacterial overgrowth, and complement the actions of vitamin D signaling in enhancing intestinal barrier function. Vitamin D also favours tolerogenic rather than inflammogenic T cell differentiation and function. Compromised innate immune function and overactive adaptive immunity, as well as defective intestinal barrier function, have been associated with IBD. Importantly, observational and intervention studies support a beneficial role of vitamin D supplementation in patients with Crohn's disease, a form of IBD. This review summarizes the effects of vitamin D signaling on barrier integrity and innate and adaptive immunity in the gut, as well as on microbial load and composition. Collectively, studies to date reveal that vitamin D signaling has widespread effects

  2. Improving microphage innate immunity by modulating protein ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Diseases that result from an infection are most often resolved by cells that use an immune response to clear foreign agents. ... The authors hypothesize that certain PTPs favour the generation of the pro-inflammatory M1 macrophages, thereby regulating the functions leading to promoting immune surveillance and killing of ...

  3. Distinct innate immune phagocyte responses to Aspergillus fumigatus conidia and hyphae in zebrafish larvae.

    Science.gov (United States)

    Knox, Benjamin P; Deng, Qing; Rood, Mary; Eickhoff, Jens C; Keller, Nancy P; Huttenlocher, Anna

    2014-10-01

    Aspergillus fumigatus is the most common filamentous fungal pathogen of immunocompromised hosts, resulting in invasive aspergillosis (IA) and high mortality rates. Innate immunity is known to be the predominant host defense against A. fumigatus; however, innate phagocyte responses to A. fumigatus in an intact host and their contributions to host survival remain unclear. Here, we describe a larval zebrafish A. fumigatus infection model amenable to real-time imaging of host-fungal interactions in live animals. Following infection with A. fumigatus, innate phagocyte populations exhibit clear preferences for different fungal morphologies: macrophages rapidly phagocytose conidia and form aggregates around hyphae, while the neutrophil response is dependent upon the presence of hyphae. Depletion of macrophages rendered host larvae susceptible to invasive disease. Moreover, a zebrafish model of human leukocyte adhesion deficiency with impaired neutrophil function also resulted in invasive disease and impaired host survival. In contrast, macrophage-deficient but not neutrophil-deficient larvae exhibited attenuated disease following challenge with a less virulent (ΔlaeA) strain of A. fumigatus, which has defects in secondary metabolite production. Taking these results together, we have established a new vertebrate model for studying innate immune responses to A. fumigatus that reveals distinct roles for neutrophils and macrophages in mediating host defense against IA. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  4. Specific gene expression responses to parasite genotypes reveal redundancy of innate immunity in vertebrates.

    Directory of Open Access Journals (Sweden)

    David Haase

    Full Text Available Vertebrate innate immunity is the first line of defense against an invading pathogen and has long been assumed to be largely unspecific with respect to parasite/pathogen species. However, recent phenotypic evidence suggests that immunogenetic variation, i.e. allelic variability in genes associated with the immune system, results in host-parasite genotype-by-genotype interactions and thus specific innate immune responses. Immunogenetic variation is common in all vertebrate taxa and this reflects an effective immunological function in complex environments. However, the underlying variability in host gene expression patterns as response of innate immunity to within-species genetic diversity of macroparasites in vertebrates is unknown. We hypothesized that intra-specific variation among parasite genotypes must be reflected in host gene expression patterns. Here we used high-throughput RNA-sequencing to examine the effect of parasite genotypes on gene expression patterns of a vertebrate host, the three-spined stickleback (Gasterosteus aculeatus. By infecting naïve fish with distinct trematode genotypes of the species Diplostomum pseudospathaceum we show that gene activity of innate immunity in three-spined sticklebacks depended on the identity of an infecting macroparasite genotype. In addition to a suite of genes indicative for a general response against the trematode we also find parasite-strain specific gene expression, in particular in the complement system genes, despite similar infection rates of single clone treatments. The observed discrepancy between infection rates and gene expression indicates the presence of alternative pathways which execute similar functions. This suggests that the innate immune system can induce redundant responses specific to parasite genotypes.

  5. Innate and Adaptive Immunity to Mucorales.

    Science.gov (United States)

    Ghuman, Harlene; Voelz, Kerstin

    2017-09-05

    Mucormycosis is an invasive fungal infection characterised by rapid filamentous growth, which leads to angioinvasion, thrombosis, and tissue necrosis. The high mortality rates (50-100%) associated with mucormycosis are reflective of not only the aggressive nature of the infection and the poor therapeutics currently employed, but also the failure of the human immune system to successfully clear the infection. Immune effector interaction with Mucorales is influenced by the developmental stage of the mucormycete spore. In a healthy immune environment, resting spores are resistant to phagocytic killing. Contrarily, swollen spores and hyphae are susceptible to damage and degradation by macrophages and neutrophils. Under the effects of immune suppression, the recruitment and efficacy of macrophage and neutrophil activity against mucormycetes is considerably reduced. Following penetration of the endothelial lining, Mucorales encounter platelets. Platelets adhere to both mucormycete spores and hyphae, and exhibit germination suppression and hyphal damage capacity in vitro. Dendritic cells are activated in response to Mucorales hyphae only, and induce adaptive immunity. It is crucial to further knowledge regarding our immune system's failure to eradicate resting spores under intact immunity and inhibit fungal growth under immunocompromised conditions, in order to understand mucormycosis pathogenicity and enhance therapeutic strategies for mucormycosis.

  6. Immune defense and host life history.

    Science.gov (United States)

    Zuk, Marlene; Stoehr, Andrew M

    2002-10-01

    Recent interest has focused on immune response in an evolutionary context, with particular attention to disease resistance as a life-history trait, subject to trade-offs against other traits such as reproductive effort. Immune defense has several characteristics that complicate this approach, however; for example, because of the risk of autoimmunity, optimal immune defense is not necessarily maximum immune defense. Two important types of cost associated with immunity in the context of life history are resource costs, those related to the allocation of essential but limited resources, such as energy or nutrients, and option costs, those paid not in the currency of resources but in functional or structural components of the organism. Resource and option costs are likely to apply to different aspects of resistance. Recent investigations into possible trade-offs between reproductive effort, particularly sexual displays, and immunity have suggested interesting functional links between the two. Although all organisms balance the costs of immune defense against the requirements of reproduction, this balance works out differently for males than it does for females, creating sex differences in immune response that in turn are related to ecological factors such as the mating system. We conclude that immune response is indeed costly and that future work would do well to include invertebrates, which have sometimes been neglected in studies of the ecology of immune defense.

  7. 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.

  8. Mitochondrial contribution to innate immune pathways | IDRC ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    ... that alert neighbouring cells to the infection, particularly cells of the immune system. ... Bello (Chile), and the National Institute of Biological Sciences (China). ... research competition of the Joint Canada-Israel Health Research Program, ...

  9. 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.

  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. MAMPs/PAMPs - elicitors of innate immunity in plants

    DEFF Research Database (Denmark)

    Erbs, Gitte; Newman, Mari-Anne

    2009-01-01

    Patterns (MAMPs or PAMPs), are recognised by the plant innate immune systems Pattern Recognition Receptors (PRRs). General bacterial elicitors, like lipopolysaccharides (LPS), flagellin (Flg), elongation factor Tu (EF-Tu), cold shock protein (CSP), peptidoglycan (PGN) and the enzyme superoxide dismutase...

  12. Lipoprotein Lipase Maintains Microglial Innate Immunity in Obesity

    NARCIS (Netherlands)

    Gao, Yuanqing; Vidal-Itriago, Andrés; Kalsbeek, Martin J; Layritz, Clarita; García-Cáceres, Cristina; Tom, Robby Zachariah; Eichmann, Thomas O; Vaz, Frédéric M; Houtkooper, Riekelt H; van der Wel, Nicole; Verhoeven, Arthur J; Yan, Jie; Kalsbeek, A.; Eckel, Robert H; Hofmann, Susanna M; Yi, Chun-Xia

    2017-01-01

    Consumption of a hypercaloric diet upregulates microglial innate immune reactivity along with a higher expression of lipoprotein lipase (Lpl) within the reactive microglia in the mouse brain. Here, we show that knockdown of the Lpl gene specifically in microglia resulted in deficient microglial

  13. Hepatitis C, innate immunity and alcohol: friends or foes?

    Science.gov (United States)

    Osna, Natalia A; Ganesan, Murali; Kharbanda, Kusum K

    2015-02-05

    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.

  14. 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.

  15. Peptidoglycan and muropeptides from pathogens Agrobacterium and Xanthomonas elicit plant innate immunity

    DEFF Research Database (Denmark)

    Erbs, Gitte; Silipo, Alba; Aslam, Shazia

    2008-01-01

    Peptidoglycan (PGN) is a unique and essential structural part of the bacterial cell wall. PGNs from two contrasting Gram-negative plant pathogenic bacteria elicited components characteristic of the innate immune system in Arabidopsis thaliana, such as transcription of the defense gene PR1, oxidat...

  16. DMPD: IRAK1: a critical signaling mediator of innate immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17890055 IRAK1: a critical signaling mediator of innate immunity. Gottipati S, Rao ...IRAK1: a critical signaling mediator of innate immunity. PubmedID 17890055 Title IRAK1: a critical signaling mediator

  17. Anthrax Lethal Toxin Impairs Innate Immune Functions of Alveolar Macrophages and Facilitates Bacillus anthracis Survival

    National Research Council Canada - National Science Library

    Ribot, Wilson J; Panchal, Rekha G; Brittingham, Katherine C; Ruthel, Gordon; Kenny, Tara A; Lane, Douglas; Curry, Bob; Hoover, Timothy A; Friedlander, Arthur M; Bavari, Sina

    2006-01-01

    Alveolar macrophages (AM) are very important for pulmonary innate immune responses against invading inhaled pathogens because they directly kill the organisms and initiate a cascade of innate and adaptive immune responses...

  18. 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.

  19. Initiation of Antiviral B Cell Immunity Relies on Innate Signals from Spatially Positioned NKT Cells.

    Science.gov (United States)

    Gaya, Mauro; Barral, Patricia; Burbage, Marianne; Aggarwal, Shweta; Montaner, Beatriz; Warren Navia, Andrew; Aid, Malika; Tsui, Carlson; Maldonado, Paula; Nair, Usha; Ghneim, Khader; Fallon, Padraic G; Sekaly, Rafick-Pierre; Barouch, Dan H; Shalek, Alex K; Bruckbauer, Andreas; Strid, Jessica; Batista, Facundo D

    2018-01-25

    B cells constitute an essential line of defense from pathogenic infections through the generation of class-switched antibody-secreting cells (ASCs) in germinal centers. Although this process is known to be regulated by follicular helper T (TfH) cells, the mechanism by which B cells initially seed germinal center reactions remains elusive. We found that NKT cells, a population of innate-like T lymphocytes, are critical for the induction of B cell immunity upon viral infection. The positioning of NKT cells at the interfollicular areas of lymph nodes facilitates both their direct priming by resident macrophages and the localized delivery of innate signals to antigen-experienced B cells. Indeed, NKT cells secrete an early wave of IL-4 and constitute up to 70% of the total IL-4-producing cells during the initial stages of infection. Importantly, the requirement of this innate immunity arm appears to be evolutionarily conserved because early NKT and IL-4 gene signatures also positively correlate with the levels of neutralizing antibodies in Zika-virus-infected macaques. In conclusion, our data support a model wherein a pre-TfH wave of IL-4 secreted by interfollicular NKT cells triggers the seeding of germinal center cells and serves as an innate link between viral infection and B cell immunity. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  20. Memory CD8+ T Cells: Orchestrators and Key Players of Innate Immunity?

    Directory of Open Access Journals (Sweden)

    Grégoire Lauvau

    2016-09-01

    Full Text Available Over the past decades, the dichotomy between innate and adaptive immune responses has largely dominated our understanding of immunology. Upon primary encounter with microbial pathogens, differentiation of adaptive immune cells into functional effectors usually takes several days or even longer, making them contribute to host protection only late during primary infection. However, once generated, antigen-experienced T lymphocytes can persist in the organism and constitute a pool of memory cells that mediate fast and effective protection to a recall infection with the same microbial pathogen. Herein, we challenge this classical paradigm by highlighting the "innate nature" of memory CD8+ T cells. First, within the thymus or in the periphery, naïve CD8+ T cells may acquire phenotypic and functional characteristics of memory CD8+ T cells independently of challenge with foreign antigens. Second, both the "unconventional" and the "conventional" memory cells can rapidly express protective effector functions in response to sets of inflammatory cytokines and chemokines signals, independent of cognate antigen triggering. Third, memory CD8+ T cells can act by orchestrating the recruitment, activation, and licensing of innate cells, leading to broad antimicrobial states. Thus, collectively, memory CD8+ T cells may represent important actors of innate immune defenses.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. MAPK-triggered chromatin reprogramming by histone deacetylase in plant innate immunity

    KAUST Repository

    Latrasse, David; Jé gu, Teddy; Li, Huchen; Zé licourt, Axel de; Raynaud, Cé cile; Legras, Sté phanie; Gust, Andrea; Samajova, Olga; Veluchamy, Alaguraj; Rayapuram, Naganand; Ramirez Prado, Juan Sebastian; Kulikova, Olga; Colcombet, Jean; Bigeard, Jean; Genot, Baptiste; Bisseling, Ton; Benhamed, Moussa; Hirt, Heribert

    2017-01-01

    Microbial-associated molecular patterns activate several MAP kinases, which are major regulators of the innate immune response in Arabidopsis thaliana that induce large-scale changes in gene expression. Here, we determine whether microbial-associated molecular pattern-triggered gene expression involves modifications at the chromatin level.Histone acetylation and deacetylation are major regulators of microbial-associated molecular pattern-triggered gene expression and implicate the histone deacetylase HD2B in the reprogramming of defence gene expression and innate immunity. The MAP kinase MPK3 directly interacts with and phosphorylates HD2B, thereby regulating the intra-nuclear compartmentalization and function of the histone deacetylase.By studying a number of gene loci that undergo microbial-associated molecular pattern-dependent activation or repression, our data reveal a mechanistic model for how protein kinase signaling directly impacts chromatin reprogramming in plant defense.

  3. MAPK-triggered chromatin reprogramming by histone deacetylase in plant innate immunity

    KAUST Repository

    Latrasse, David

    2017-07-06

    Microbial-associated molecular patterns activate several MAP kinases, which are major regulators of the innate immune response in Arabidopsis thaliana that induce large-scale changes in gene expression. Here, we determine whether microbial-associated molecular pattern-triggered gene expression involves modifications at the chromatin level.Histone acetylation and deacetylation are major regulators of microbial-associated molecular pattern-triggered gene expression and implicate the histone deacetylase HD2B in the reprogramming of defence gene expression and innate immunity. The MAP kinase MPK3 directly interacts with and phosphorylates HD2B, thereby regulating the intra-nuclear compartmentalization and function of the histone deacetylase.By studying a number of gene loci that undergo microbial-associated molecular pattern-dependent activation or repression, our data reveal a mechanistic model for how protein kinase signaling directly impacts chromatin reprogramming in plant defense.

  4. A role for PML in innate immunity

    NARCIS (Netherlands)

    A. Lunardi (Andrea); M. Gaboli (Mirella); M. Giorgio (Marco); R. Rivi (Roberta); A. Bygrave (Anne); D.D. Drabek (Dubravka); E.A. Dzierzak (Elaine); M. Fagioli (Marta); L. Salmena (Leonardo); M. Antoniou (Michael); M. Botto (Marina); C. Cordon-Cardo (Carlos); L. Luzzatto (Lucio); P.G. Pelicci; F.G. Grosveld (Frank); P.P. Pandolfi

    2011-01-01

    textabstractThe promyelocytic leukemia gene (PML) of acute promyelocytic leukemia is an established tumor suppressor gene with critical functions in growth suppression, induction of apoptosis, and cellular senescence. Interestingly, although less studied, PML seems to play a key role also in immune

  5. The Role of Innate Immune System Receptors in Epilepsy Research.

    Science.gov (United States)

    Cordero-Arreola, Jessica; West, Rachel M; Mendoza-Torreblanca, Julieta; Mendez-Hernandez, Edna; Salas-Pacheco, Jose; Menendez-Gonzalez, Manuel; Freire, Rafael C; Machado, Sergio; Murillo-Rodriguez, Eric; Nardi, Antonio E; Arias-Carrion, Oscar

    2017-01-01

    Epilepsy is one of the most complex neurological disorders and its study requires a broad knowledge of neurology and neuroscience. It comprises a diverse group of neurological disorders that share the central feature of spontaneous recurrent seizures, and are often accompanied by cognitive deficits and mood disorder. This condition is one of the most common neurological disorders. Until recently, alterations of neuronal activities had been the focus of epilepsy research. This neurocentric emphasis did not address issues that arise in more complex models of epileptogenesis. An important factor in epilepsy that is not regulated directly by neurons is inflammation and the immune response of the brain. Recent evidence obtained in rodent epilepsy models supports the role of immune responses in the initiation and maintenance of epilepsy. Recognition of exogenous pathogens by the innate immune system is mediated by some pattern recognition receptors such as Toll-like receptors leading to cell activation and cytokine production. Currently, these receptors have been the focus of epilepsy studies looking to determine whether the innate immune activation is neuroprotective or neurotoxic for the brain. Here, we present the evidence in the literature of the involvement of key innate immune receptors in the development of epilepsy. We address some of the contradictory findings in these studies and also mention possible avenues for research into epilepsy treatments that target these receptors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  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. Innate Immune Evasion Mediated by Flaviviridae Non-Structural Proteins.

    Science.gov (United States)

    Chen, Shun; Wu, Zhen; Wang, Mingshu; Cheng, Anchun

    2017-10-07

    Flaviviridae-caused diseases are a critical, emerging public health problem worldwide. Flaviviridae infections usually cause severe, acute or chronic diseases, such as liver damage and liver cancer resulting from a hepatitis C virus (HCV) infection and high fever and shock caused by yellow fever. Many researchers worldwide are investigating the mechanisms by which Flaviviridae cause severe diseases. Flaviviridae can interfere with the host's innate immunity to achieve their purpose of proliferation. For instance, dengue virus (DENV) NS2A, NS2B3, NS4A, NS4B and NS5; HCV NS2, NS3, NS3/4A, NS4B and NS5A; and West Nile virus (WNV) NS1 and NS4B proteins are involved in immune evasion. This review discusses the interplay between viral non-structural Flaviviridae proteins and relevant host proteins, which leads to the suppression of the host's innate antiviral immunity.

  8. Characterization of innate immune activity in Phrynops geoffroanus (Testudines: Chelidae

    Directory of Open Access Journals (Sweden)

    Bruno O. Ferronato

    2009-12-01

    Full Text Available The innate immune activity of the freshwater turtle Phrynops geoffroanus (Schweigger, 1812 was investigated, using a sheep-red-blood cell hemolysis assay. The time- and concentration-dependent hemolytic activity of the turtle plasma was low compared to that reported for other reptiles. However the plasma of P. geoffroanus exhibited higher activity at elevated temperatures, resulting in temperature-dependent hemolysis. The sensitivity of turtle plasma to temperature could be interpreted as a mechanism by which freshwater turtles use basking behavior to elevate body temperature, thus enhancing the innate immune response. However, we cannot discard the possibility that environmental contaminants could be affecting the turtle's immune response, since the animals in this investigation were captured in a polluted watercourse.

  9. 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.

  10. DMPD: Innate immune recognition of, and regulation by, DNA. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16979939 Innate immune recognition of, and regulation by, DNA. Ishii KJ, Akira S. T...rends Immunol. 2006 Nov;27(11):525-32. Epub 2006 Sep 18. (.png) (.svg) (.html) (.csml) Show Innate immune recognition... of, and regulation by, DNA. PubmedID 16979939 Title Innate immune recognition of, and regulation b

  11. DMPD: Innate immune responses: crosstalk of signaling and regulation of genetranscription. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16753195 Innate immune responses: crosstalk of signaling and regulation of genetran...l) (.csml) Show Innate immune responses: crosstalk of signaling and regulation of genetranscription. PubmedI...D 16753195 Title Innate immune responses: crosstalk of signaling and regulation o

  12. Innate immunity in the lung regulates the development of asthma.

    Science.gov (United States)

    DeKruyff, Rosemarie H; Yu, Sanhong; Kim, Hye Young; Umetsu, Dale T

    2014-07-01

    The lung, while functioning as a gas exchange organ, encounters a large array of environmental factors, including particulate matter, toxins, reactive oxygen species, chemicals, allergens, and infectious microbes. To rapidly respond to and counteract these elements, a number of innate immune mechanisms have evolved that can lead to lung inflammation and asthma, which is the focus of this review. These innate mechanisms include a role for two incompletely understood cell types, invariant natural killer T (iNKT) cells and innate lymphoid cells (ILCs), which together produce a wide range of cytokines, including interleukin-4 (IL-4), IL-5, IL-13, interferon-γ, IL-17, and IL-22, independently of adaptive immunity and conventional antigens. The specific roles of iNKT cells and ILCs in immunity are still being defined, but both cell types appear to play important roles in the lungs, particularly in asthma. As we gain a better understanding of these innate cell types, we will acquire great insight into the mechanisms by which allergic and non-allergic asthma phenotypes develop. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Enhancing crop innate immunity: new promising trends

    Directory of Open Access Journals (Sweden)

    Pin-Yao eHuang

    2014-11-01

    Full Text Available Plants are constantly exposed to potentially pathogenic microbes present in their surrounding environment. Due to the activation of the pattern-triggered immunity (PTI response that largely relies on accurate detection of pathogen- or microbe-associated molecular patterns by pattern-recognition receptors (PRRs, plants are resistant to the majority of potential pathogens. However, adapted pathogens may avoid recognition or repress plant PTI and resulting diseases significantly affect crop yield worldwide. PTI provides protection against a wide range of pathogens. Reinforcement of PTI through genetic engineering may thus generate crops with broad-spectrum field resistance. In this review, new approaches based on fundamental discoveries in PTI to improve crop immunity are discussed. Notably, we highlight recent studies describing the interfamily transfer of PRRs or key regulators of PTI signalling.

  14. Shigella infection of intestinal epithelium and circumvention of the host innate defense system.

    Science.gov (United States)

    Ashida, Hiroshi; Ogawa, Michinaga; Mimuro, Hitomi; Sasakawa, Chihiro

    2009-01-01

    Shigella, Gram-negative bacteria closely related to Escherichia coli, are highly adapted human pathogens that cause bacillary dysentery. Although Shigella have neither adherence factors nor flagella required for attaching or accessing the intestinal epithelium, Shigella are capable of colonizing the intestinal epithelium by exploiting epithelial-cell functions and circumventing the host innate immune response. During Shigella infection, they deliver many numbers of effectors through the type III secretion system into the surrounding space and directly into the host-cell cytoplasm. The effectors play pivotal roles from the onset of bacterial infection through to the establishment of the colonization of the intestinal epithelium, such as bacterial invasion, intracellular survival, subversion of the host immune defense response, and maintenance of the infectious foothold. These examples suggest that Shigella have evolved highly sophisticated infectious and intracellular strategies to establish replicative niches in the intestinal epithelium.

  15. Effect of the Ketone Body Beta-Hydroxybutyrate on the Innate Defense Capability of Primary Bovine Mammary Epithelial Cells

    OpenAIRE

    Hillreiner, Maria;Flinspach, Claudia;Pfaffl, Michael W.;Kliem, Heike

    2017-01-01

    Negative energy balance and ketosis are thought to cause impaired immune function and to increase the risk of clinical mastitis in dairy cows. The present in vitro study aimed to investigate the effect of elevated levels of the predominant ketone body β-hydroxybutyrate on the innate defense capability of primary bovine mammary epithelial cells (pbMEC) challenged with the mastitis pathogen Escherichia coli (E. coli). Therefore, pbMEC of healthy dairy cows in mid- lactation were isolated from m...

  16. Work stress and innate immune response.

    Science.gov (United States)

    Boscolo, P; Di Gioacchino, M; Reale, M; Muraro, R; Di Giampaolo, L

    2011-01-01

    Several reports highlight the relationship between blood NK cytotoxic activity and life style. Easy life style, including physical activity, healthy dietary habits as well as good mental health are characterized by an efficient immune response. Life style is related to the type of occupational activity since work has a central part in life either as source of income or contributing to represent the social identity. Not only occupational stress, but also job loss or insecurity are thus considered serious stressful situations, inducing emotional disorders which may affect both neuroendocrine and immune systems; reduced reactivity to mitogens and/or decreased blood NK cytotoxic activity was reported in unemployed workers or in those with a high perception of job insecurity and/or job stress. Although genetic factors have a key role in the pathogenesis of autoimmune disorders, occupational stress (as in night shifts) was reported associated to an increased incidence of autoimmune disorders. Monitoring blood NK response may thus be included in the health programs as an indirect index of stressful job and/or poor lifestyle.

  17. Pathogen Pressure Puts Immune Defense into Perspective

    NARCIS (Netherlands)

    Horrocks, Nicholas P. C.; Matson, Kevin D.; Tieleman, B. Irene

    2011-01-01

    The extent to which organisms can protect themselves from disease depends on both the immune defenses they maintain and the pathogens they face. At the same time, immune systems are shaped by the antigens they encounter, both over ecological and evolutionary time. Ecological immunologists often

  18. FOXO-dependent regulation of innate immune homeostasis.

    Science.gov (United States)

    Becker, Thomas; Loch, Gerrit; Beyer, Marc; Zinke, Ingo; Aschenbrenner, Anna C; Carrera, Pilar; Inhester, Therese; Schultze, Joachim L; Hoch, Michael

    2010-01-21

    The innate immune system represents an ancient host defence mechanism that protects against invading microorganisms. An important class of immune effector molecules to fight pathogen infections are antimicrobial peptides (AMPs) that are produced in plants and animals. In Drosophila, the induction of AMPs in response to infection is regulated through the activation of the evolutionarily conserved Toll and immune deficiency (IMD) pathways. Here we show that AMP activation can be achieved independently of these immunoregulatory pathways by the transcription factor FOXO, a key regulator of stress resistance, metabolism and ageing. In non-infected animals, AMP genes are activated in response to nuclear FOXO activity when induced by starvation, using insulin signalling mutants, or by applying small molecule inhibitors. AMP induction is lost in foxo null mutants but enhanced when FOXO is overexpressed. Expression of AMP genes in response to FOXO activity can also be triggered in animals unable to respond to immune challenges due to defects in both the Toll and IMD pathways. Molecular experiments at the Drosomycin promoter indicate that FOXO directly binds to its regulatory region, thereby inducing its transcription. In vivo studies in Drosophila, but also studies in human lung, gut, kidney and skin cells indicate that a FOXO-dependent regulation of AMPs is evolutionarily conserved. Our results indicate a new mechanism of cross-regulation of metabolism and innate immunity by which AMP genes can be activated under normal physiological conditions in response to the oscillating energy status of cells and tissues. This regulation seems to be independent of the pathogen-responsive innate immunity pathways whose activation is often associated with tissue damage and repair. The sparse production of AMPs in epithelial tissues in response to FOXO may help modulating the defence reaction without harming the host tissues, in particular when animals are suffering from energy shortage

  19. Transmission of innate immune signaling by packaging of cGAMP in viral particles.

    Science.gov (United States)

    Gentili, Matteo; Kowal, Joanna; Tkach, Mercedes; Satoh, Takeshi; Lahaye, Xavier; Conrad, Cécile; Boyron, Marilyn; Lombard, Bérangère; Durand, Sylvère; Kroemer, Guido; Loew, Damarys; Dalod, Marc; Théry, Clotilde; Manel, Nicolas

    2015-09-11

    Infected cells detect viruses through a variety of receptors that initiate cell-intrinsic innate defense responses. Cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase (cGAS) is a cytosolic sensor for many DNA viruses and HIV-1. In response to cytosolic viral DNA, cGAS synthesizes the second messenger 2'3'-cyclic GMP-AMP (cGAMP), which activates antiviral signaling pathways. We show that in cells producing virus, cGAS-synthesized cGAMP can be packaged in viral particles and extracellular vesicles. Viral particles efficiently delivered cGAMP to target cells. cGAMP transfer by viral particles to dendritic cells activated innate immunity and antiviral defenses. Finally, we show that cell-free murine cytomegalovirus and Modified Vaccinia Ankara virus contained cGAMP. Thus, transfer of cGAMP by viruses may represent a defense mechanism to propagate immune responses to uninfected target cells. Copyright © 2015, American Association for the Advancement of Science.

  20. Genetic adaptation of the antibacterial human innate immunity network

    Directory of Open Access Journals (Sweden)

    Lazarus Ross

    2011-07-01

    Full Text Available Abstract Background Pathogens have represented an important selective force during the adaptation of modern human populations to changing social and other environmental conditions. The evolution of the immune system has therefore been influenced by these pressures. Genomic scans have revealed that immune system is one of the functions enriched with genes under adaptive selection. Results Here, we describe how the innate immune system has responded to these challenges, through the analysis of resequencing data for 132 innate immunity genes in two human populations. Results are interpreted in the context of the functional and interaction networks defined by these genes. Nucleotide diversity is lower in the adaptors and modulators functional classes, and is negatively correlated with the centrality of the proteins within the interaction network. We also produced a list of candidate genes under positive or balancing selection in each population detected by neutrality tests and showed that some functional classes are preferential targets for selection. Conclusions We found evidence that the role of each gene in the network conditions the capacity to evolve or their evolvability: genes at the core of the network are more constrained, while adaptation mostly occurred at particular positions at the network edges. Interestingly, the functional classes containing most of the genes with signatures of balancing selection are involved in autoinflammatory and autoimmune diseases, suggesting a counterbalance between the beneficial and deleterious effects of the immune response.

  1. Genetic adaptation of the antibacterial human innate immunity network.

    Science.gov (United States)

    Casals, Ferran; Sikora, Martin; Laayouni, Hafid; Montanucci, Ludovica; Muntasell, Aura; Lazarus, Ross; Calafell, Francesc; Awadalla, Philip; Netea, Mihai G; Bertranpetit, Jaume

    2011-07-11

    Pathogens have represented an important selective force during the adaptation of modern human populations to changing social and other environmental conditions. The evolution of the immune system has therefore been influenced by these pressures. Genomic scans have revealed that immune system is one of the functions enriched with genes under adaptive selection. Here, we describe how the innate immune system has responded to these challenges, through the analysis of resequencing data for 132 innate immunity genes in two human populations. Results are interpreted in the context of the functional and interaction networks defined by these genes. Nucleotide diversity is lower in the adaptors and modulators functional classes, and is negatively correlated with the centrality of the proteins within the interaction network. We also produced a list of candidate genes under positive or balancing selection in each population detected by neutrality tests and showed that some functional classes are preferential targets for selection. We found evidence that the role of each gene in the network conditions the capacity to evolve or their evolvability: genes at the core of the network are more constrained, while adaptation mostly occurred at particular positions at the network edges. Interestingly, the functional classes containing most of the genes with signatures of balancing selection are involved in autoinflammatory and autoimmune diseases, suggesting a counterbalance between the beneficial and deleterious effects of the immune response.

  2. Effect of the Ketone Body Beta-Hydroxybutyrate on the Innate Defense Capability of Primary Bovine Mammary Epithelial Cells.

    Directory of Open Access Journals (Sweden)

    Maria Hillreiner

    Full Text Available Negative energy balance and ketosis are thought to cause impaired immune function and to increase the risk of clinical mastitis in dairy cows. The present in vitro study aimed to investigate the effect of elevated levels of the predominant ketone body β-hydroxybutyrate on the innate defense capability of primary bovine mammary epithelial cells (pbMEC challenged with the mastitis pathogen Escherichia coli (E. coli. Therefore, pbMEC of healthy dairy cows in mid- lactation were isolated from milk and challenged in culture with 3 mM BHBA and E. coli. pbMEC stimulated with E. coli for 6 h or 30 h showed an up-regulation of several innate immune genes, whereas co-stimulation of pbMEC with 3 mM BHBA and E. coli resulted in the down-regulation of CCL2, SAA3, LF and C3 gene expression compared to the challenge with solely the bacterial stimulus. These results indicated that increased BHBA concentrations may be partially responsible for the higher mastitis susceptibility of dairy cows in early lactation. Elevated levels of BHBA in blood and milk during negative energy balance and ketosis are likely to impair innate immune function in the bovine mammary gland by attenuating the expression of a broad range of innate immune genes.

  3. Effect of the Ketone Body Beta-Hydroxybutyrate on the Innate Defense Capability of Primary Bovine Mammary Epithelial Cells.

    Science.gov (United States)

    Hillreiner, Maria; Flinspach, Claudia; Pfaffl, Michael W; Kliem, Heike

    2016-01-01

    Negative energy balance and ketosis are thought to cause impaired immune function and to increase the risk of clinical mastitis in dairy cows. The present in vitro study aimed to investigate the effect of elevated levels of the predominant ketone body β-hydroxybutyrate on the innate defense capability of primary bovine mammary epithelial cells (pbMEC) challenged with the mastitis pathogen Escherichia coli (E. coli). Therefore, pbMEC of healthy dairy cows in mid- lactation were isolated from milk and challenged in culture with 3 mM BHBA and E. coli. pbMEC stimulated with E. coli for 6 h or 30 h showed an up-regulation of several innate immune genes, whereas co-stimulation of pbMEC with 3 mM BHBA and E. coli resulted in the down-regulation of CCL2, SAA3, LF and C3 gene expression compared to the challenge with solely the bacterial stimulus. These results indicated that increased BHBA concentrations may be partially responsible for the higher mastitis susceptibility of dairy cows in early lactation. Elevated levels of BHBA in blood and milk during negative energy balance and ketosis are likely to impair innate immune function in the bovine mammary gland by attenuating the expression of a broad range of innate immune genes.

  4. 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

  5. Repurposed transcriptomic data facilitate discovery of innate immunity toll-like receptor (TLR) Genes across Lophotrochozoa.

    Science.gov (United States)

    Halanych, Kenneth M; Kocot, Kevin M

    2014-10-01

    The growing volume of genomic data from across life represents opportunities for deriving valuable biological information from data that were initially collected for another purpose. Here, we use transcriptomes collected for phylogenomic studies to search for toll-like receptor (TLR) genes in poorly sampled lophotrochozoan clades (Annelida, Mollusca, Brachiopoda, Phoronida, and Entoprocta) and one ecdysozoan clade (Priapulida). TLR genes are involved in innate immunity across animals by recognizing potential microbial infection. They have an extracellular leucine-rich repeat (LRR) domain connected to a transmembrane domain and an intracellular toll/interleukin-1 receptor (TIR) domain. Consequently, these genes are important in initiating a signaling pathway to trigger defense. We found at least one TLR ortholog in all but two taxa examined, suggesting that a broad array of lophotrochozoans may have innate immune systems similar to those observed in vertebrates and arthropods. Comparison to the SMART database confirmed the presence of both the LRR and the TIR protein motifs characteristic of TLR genes. Because we looked at only one transcriptome per species, discovery of TLR genes was limited for most taxa. However, several TRL-like genes that vary in the number and placement of LRR domains were found in phoronids. Additionally, several contigs contained LRR domains but lacked TIR domains, suggesting they were not TLRs. Many of these LRR-containing contigs had other domains (e.g., immunoglobin) and are likely involved in innate immunity. © 2014 Marine Biological Laboratory.

  6. Innate immune receptor Toll-like receptor 4 signalling in neuropsychiatric diseases.

    Science.gov (United States)

    García Bueno, B; Caso, J R; Madrigal, J L M; Leza, J C

    2016-05-01

    The innate immunity is a stereotyped first line of defense against pathogens and unspecified damage signals. One of main actors of innate immunity are the Toll-like receptors (TLRs), and one of the better characterized members of this family is TLR-4, that it is mainly activated by Gram-negative bacteria lipopolysaccharide. In brain, TLR-4 organizes innate immune responses against infections or cellular damage, but also possesses other physiological functions. In the last years, some evidences suggest a role of TLR-4 in stress and stress-related neuropsychiatric diseases. Peripheral and brain TLR-4 activation triggers sickness behavior, and its expression is a risk factor of depression. Some elements of the TLR-4 signaling pathway are up-regulated in peripheral samples and brain post-mortem tissue from depressed and suicidal patients. The "leaky gut" hypothesis of neuropsychiatric diseases is based on the existence of an increase of the intestinal permeability which results in bacterial translocation able to activate TLR-4. Enhanced peripheral TLR-4 expression/activity has been described in subjects diagnosed with schizophrenia, bipolar disorder and in autistic children. A role for TLR-4 in drugs abuse has been also proposed. The therapeutic potential of pharmacological/genetic modulation of TLRs signaling pathways in neuropsychiatry is promising, but a great preclinical/clinical scientific effort is still needed. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. A conserved p38 MAP kinase pathway in Caenorhabditis elegans innate immunity.

    Science.gov (United States)

    Kim, Dennis H; Feinbaum, Rhonda; Alloing, Geneviève; Emerson, Fred E; Garsin, Danielle A; Inoue, Hideki; Tanaka-Hino, Miho; Hisamoto, Naoki; Matsumoto, Kunihiro; Tan, Man-Wah; Ausubel, Frederick M

    2002-07-26

    A genetic screen for Caenorhabditis elegans mutants with enhanced susceptibility to killing by Pseudomonas aeruginosa led to the identification of two genes required for pathogen resistance: sek-1, which encodes a mitogen-activated protein (MAP) kinase kinase, and nsy-1, which encodes a MAP kinase kinase kinase. RNA interference assays and biochemical analysis established that a p38 ortholog, pmk-1, functions as the downstream MAP kinase required for pathogen defense. These data suggest that this MAP kinase signaling cassette represents an ancient feature of innate immune responses in evolutionarily diverse species.

  8. 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.

  9. Analysis of Thioester-Containing Proteins during the Innate Immune Response of Drosophila melanogaster

    Science.gov (United States)

    Bou Aoun, Richard; Hetru, Charles; Troxler, Laurent; Doucet, Daniel; Ferrandon, Dominique; Matt, Nicolas

    2010-01-01

    Thioester-containing proteins (TEPs) are conserved proteins among insects that are thought to be involved in innate immunity. In Drosophila, the Tep family is composed of 6 genes named Tep1–Tep6. In this study, we investigated the phylogeny, expression pattern and roles of these genes in the host defense of Drosophila. Protostomian Tep genes are clustered in 3 distinct branches, 1 of which is specific to mosquitoes. Most D. melanogaster Tep genes are expressed in hemocytes, can be induced in the fat body, and are expressed in specific regions of the hypodermis. This expression pattern is consistent with a role in innate immunity. However, we find that TEP1, TEP2, and TEP4 are not strictly required in the body cavity to fight several bacterial and fungal infections. One possibility is that Drosophila TEPs act redundantly or that their absence can be compensated by other components of the immune response. TEPs may thus provide a subtle selective advantage during evolution. Alternatively, they may be required in host defense against specific as yet unidentified natural pathogens of Drosophila. PMID:21063077

  10. Human Milk Hyaluronan Enhances Innate Defense of the Intestinal Epithelium*

    Science.gov (United States)

    Hill, David R.; Rho, Hyunjin K.; Kessler, Sean P.; Amin, Ripal; Homer, Craig R.; McDonald, Christine; Cowman, Mary K.; de la Motte, Carol A.

    2013-01-01

    Breast-feeding is associated with enhanced protection from gastrointestinal disease in infants, mediated in part by an array of bioactive glycan components in milk that act through molecular mechanisms to inhibit enteric pathogen infection. Human milk contains hyaluronan (HA), a glycosaminoglycan polymer found in virtually all mammalian tissues. We have shown that synthetic HA of a specific size range promotes expression of antimicrobial peptides in intestinal epithelium. We hypothesize that hyaluronan from human milk also enhances innate antimicrobial defense. Here we define the concentration of HA in human milk during the first 6 months postpartum. Importantly, HA isolated from milk has a biological function. Treatment of HT-29 colonic epithelial cells with human milk HA at physiologic concentrations results in time- and dose-dependent induction of the antimicrobial peptide human β-defensin 2 and is abrogated by digestion of milk HA with a specific hyaluronidase. Milk HA induction of human β-defensin 2 expression is also reduced in the presence of a CD44-blocking antibody and is associated with a specific increase in ERK1/2 phosphorylation, suggesting a role for the HA receptor CD44. Furthermore, oral administration of human milk-derived HA to adult, wild-type mice results in induction of the murine Hβ D2 ortholog in intestinal mucosa and is dependent upon both TLR4 and CD44 in vivo. Finally, treatment of cultured colonic epithelial cells with human milk HA enhances resistance to infection by the enteric pathogen Salmonella typhimurium. Together, our observations suggest that maternally provided HA stimulates protective antimicrobial defense in the newborn. PMID:23950179

  11. 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

  12. Regulation of intestinal homeostasis by innate and adaptive immunity.

    Science.gov (United States)

    Kayama, Hisako; Takeda, Kiyoshi

    2012-11-01

    The intestine is a unique tissue where an elaborate balance is maintained between tolerance and immune responses against a variety of environmental factors such as food and the microflora. In a healthy individual, the microflora stimulates innate and adaptive immune systems to maintain gut homeostasis. However, the interaction of environmental factors with particular genetic backgrounds can lead to dramatic changes in the composition of the microflora (i.e. dysbiosis). Many of the specific commensal-bacterial products and the signaling pathways they trigger have been characterized. The role of T(h)1, T(h)2 and T(h)17 cells in inflammatory bowel disease has been widely investigated, as has the contribution of epithelial cells and subsets of dendritic cells and macrophages. To date, multiple regulatory cells in adaptive immunity, such as regulatory T cells and regulatory B cells, have been shown to maintain gut homeostasis by preventing inappropriate innate and adaptive immune responses to commensal bacteria. Additionally, regulatory myeloid cells have recently been identified that prevent intestinal inflammation by inhibiting T-cell proliferation. An increasing body of evidence has shown that multiple regulatory mechanisms contribute to the maintenance of gut homeostasis.

  13. New Players in Immunity to Tuberculosis: The Host Microbiome, Lung Epithelium, and Innate Immune Cells

    Science.gov (United States)

    Gupta, Nancy; Kumar, Rakesh; Agrawal, Babita

    2018-01-01

    Tuberculosis (TB) is a highly contagious infection and devastating chronic disease, causing 10.4 million new infections and 1.8 million deaths every year globally. Efforts to control and eradicate TB are hampered by the rapid emergence of drug resistance and limited efficacy of the only available vaccine, BCG. Immunological events in the airways and lungs are of major importance in determining whether exposure to Mycobacterium tuberculosis (Mtb) results in successful infection or protective immunity. Several studies have demonstrated that the host microbiota is in constant contact with the immune system, and thus continually directs the nature of immune responses occurring during new infections. However, little is known about its role in the eventual outcome of the mycobacterial infection. In this review, we highlight the changes in microbial composition in the respiratory tract and gut that have been linked to the alteration of immune responses, and to the risk, prevention, and treatment of TB. In addition, we summarize our current understanding of alveolar epithelial cells and the innate immune system, and their interaction with Mtb during early infection. Extensive studies are warranted to fully understand the all-inclusive role of the lung microbiota, its interaction with epithelium and innate immune responses and resulting adaptive immune responses, and in the pathogenesis and/or protection from Mtb infection. Novel interventions aimed at influencing the microbiota, the alveolar immune system and innate immunity will shape future strategies of prevention and treatment for TB. PMID:29692778

  14. Candesartan ameliorates impaired fear extinction induced by innate immune activation.

    Science.gov (United States)

    Quiñones, María M; Maldonado, Lizette; Velazquez, Bethzaly; Porter, James T

    2016-02-01

    Patients with post-traumatic stress disorder (PTSD) tend to show signs of a relatively increased inflammatory state suggesting that activation of the immune system may contribute to the development of PTSD. In the present study, we tested whether activation of the innate immune system can disrupt acquisition or recall of auditory fear extinction using an animal model of PTSD. Male adolescent rats received auditory fear conditioning in context A. The next day, an intraperitoneal injection of lipopolysaccharide (LPS; 100 μg/kg) prior to auditory fear extinction in context B impaired acquisition and recall of extinction. LPS (100 μg/kg) given after extinction training did not impair extinction recall suggesting that LPS did not affect consolidation of extinction. In contrast to cued fear extinction, contextual fear extinction was not affected by prior injection of LPS (100 μg/kg). Although LPS also reduced locomotion, we could dissociate the effects of LPS on extinction and locomotion by using a lower dose of LPS (50 μg/kg) which impaired locomotion without affecting extinction. In addition, 15 h after an injection of 250 μg/kg LPS in adult rats, extinction learning and recall were impaired without affecting locomotion. A sub-chronic treatment with candesartan, an angiotensin II type 1 receptor blocker, prevented the LPS-induced impairment of extinction in adult rats. Our results demonstrate that activation of the innate immune system can disrupt auditory fear extinction in adolescent and adult animals. These findings also provide direction for clinical studies of novel treatments that modulate the innate immune system for stress-related disorders like PTSD. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Immunity, suicide or both? Ecological determinants for the combined evolution of anti-pathogen defense systems.

    Science.gov (United States)

    Iranzo, Jaime; Lobkovsky, Alexander E; Wolf, Yuri I; Koonin, Eugene V

    2015-03-13

    Parasite-host arms race is one of the key factors in the evolution of life. Most cellular life forms, in particular prokaryotes, possess diverse forms of defense against pathogens including innate immunity, adaptive immunity and programmed cell death (altruistic suicide). Coevolution of these different but interacting defense strategies yields complex evolutionary regimes. We develop and extensively analyze a computational model of coevolution of different defense strategies to show that suicide as a defense mechanism can evolve only in structured populations and when the attainable degree of immunity against pathogens is limited. The general principle of defense evolution seems to be that hosts do not evolve two costly defense mechanisms when one is sufficient. Thus, the evolutionary interplay of innate immunity, adaptive immunity and suicide, leads to an equilibrium state where the combination of all three defense strategies is limited to a distinct, small region of the parameter space. The three strategies can stably coexist only if none of them are highly effective. Coupled adaptive immunity-suicide systems, the existence of which is implied by the colocalization of genes for the two types of defense in prokaryotic genomes, can evolve either when immunity-associated suicide is more efficacious than other suicide systems or when adaptive immunity functionally depends on the associated suicide system. Computational modeling reveals a broad range of outcomes of coevolution of anti-pathogen defense strategies depending on the relative efficacy of different mechanisms and population structure. Some of the predictions of the model appear compatible with recent experimental evolution results and call for additional experiments.

  16. 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.

  17. New insights into innate immune control of systemic candidiasis

    Science.gov (United States)

    Lionakis, Michail S.

    2014-01-01

    Systemic infection caused by Candida species is the fourth leading cause of nosocomial bloodstream infection in modern hospitals and carries high morbidity and mortality despite antifungal therapy. A recent surge of immunological studies in the mouse models of systemic candidiasis and the parallel discovery and phenotypic characterization of inherited genetic disorders in antifungal immune factors that are associated with enhanced susceptibility or resistance to the infection have provided new insights into the cellular and molecular basis of protective innate immune responses against Candida. In this review, the new developments in our understanding of how the mammalian immune system responds to systemic Candida challenge are synthesized and important future research directions are highlighted. PMID:25023483

  18. Immune regulation by pericytes: modulating innate and adaptive immunity

    DEFF Research Database (Denmark)

    Navarro, Rocio; Compte, Marta; Álvarez-Vallina, Luis

    2016-01-01

    Pericytes (PC) are mural cells that surround endothelial cells (EC) in small blood vessels. PC have traditionally been endowed with structural functions, being essential for vessel maturation and stabilization. However, accumulating evidence suggest that PC also display immune properties. They ca...

  19. S1P dependent inter organ trafficking of group 2 innate lymphoid cells suppots host defense

    Science.gov (United States)

    Innate lymphoid cells (ILCs) are considered to be the innate counterparts of adaptive T lymphocytes and play important roles in host defense, tissue repair, metabolic homeostasis, and inflammatory diseases. ILCs are generally thought of as tissue-resident cells, but whether ILCs strictly behave in a...

  20. Innate Immune Responses of Bat and Human Cells to Filoviruses: Commonalities and Distinctions.

    Science.gov (United States)

    Kuzmin, Ivan V; Schwarz, Toni M; Ilinykh, Philipp A; Jordan, Ingo; Ksiazek, Thomas G; Sachidanandam, Ravi; Basler, Christopher F; Bukreyev, Alexander

    2017-04-15

    filoviruses remains unknown. The outcome of a virus-host interaction depends on the ability of the host immune system to suppress viral replication and the ability of a virus to counteract the host defenses. Our study is a comparative analysis of the host innate immune response to either MARV or EBOV infection in bat and human cells and the role of viral interferon-inhibiting domains in the host innate immune responses. The data are useful for understanding the interactions of filoviruses with natural and accidental hosts and for identification of factors that influence filovirus evolution. Copyright © 2017 American Society for Microbiology.

  1. Candida albicans infection of Caenorhabditis elegans induces antifungal immune defenses.

    Directory of Open Access Journals (Sweden)

    Read Pukkila-Worley

    2011-06-01

    Full Text Available Candida albicans yeast cells are found in the intestine of most humans, yet this opportunist can invade host tissues and cause life-threatening infections in susceptible individuals. To better understand the host factors that underlie susceptibility to candidiasis, we developed a new model to study antifungal innate immunity. We demonstrate that the yeast form of C. albicans establishes an intestinal infection in Caenorhabditis elegans, whereas heat-killed yeast are avirulent. Genome-wide, transcription-profiling analysis of C. elegans infected with C. albicans yeast showed that exposure to C. albicans stimulated a rapid host response involving 313 genes (124 upregulated and 189 downregulated, ~1.6% of the genome many of which encode antimicrobial, secreted or detoxification proteins. Interestingly, the host genes affected by C. albicans exposure overlapped only to a small extent with the distinct transcriptional responses to the pathogenic bacteria Pseudomonas aeruginosa or Staphylococcus aureus, indicating that there is a high degree of immune specificity toward different bacterial species and C. albicans. Furthermore, genes induced by P. aeruginosa and S. aureus were strongly over-represented among the genes downregulated during C. albicans infection, suggesting that in response to fungal pathogens, nematodes selectively repress the transcription of antibacterial immune effectors. A similar phenomenon is well known in the plant immune response, but has not been described previously in metazoans. Finally, 56% of the genes induced by live C. albicans were also upregulated by heat-killed yeast. These data suggest that a large part of the transcriptional response to C. albicans is mediated through "pattern recognition," an ancient immune surveillance mechanism able to detect conserved microbial molecules (so-called pathogen-associated molecular patterns or PAMPs. This study provides new information on the evolution and regulation of the innate

  2. HSV-1 ICP0: An E3 Ubiquitin Ligase That Counteracts Host Intrinsic and Innate Immunity

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    Mirna Perusina Lanfranca

    2014-05-01

    Full Text Available The herpes simplex virus type 1 (HSV-1 encoded E3 ubiquitin ligase, infected cell protein 0 (ICP0, is required for efficient lytic viral replication and regulates the switch between the lytic and latent states of HSV-1. As an E3 ubiquitin ligase, ICP0 directs the proteasomal degradation of several cellular targets, allowing the virus to counteract different cellular intrinsic and innate immune responses. In this review, we will focus on how ICP0’s E3 ubiquitin ligase activity inactivates the host intrinsic defenses, such as nuclear domain 10 (ND10, SUMO, and the DNA damage response to HSV-1 infection. In addition, we will examine ICP0’s capacity to impair the activation of interferon (innate regulatory mediators that include IFI16 (IFN γ-inducible protein 16, MyD88 (myeloid differentiation factor 88, and Mal (MyD88 adaptor-like protein. We will also consider how ICP0 allows HSV-1 to evade activation of the NF-κB (nuclear factor kappa B inflammatory signaling pathway. Finally, ICP0’s paradoxical relationship with USP7 (ubiquitin specific protease 7 and its roles in intrinsic and innate immune responses to HSV-1 infection will be discussed.

  3. Autophagy, Innate Immunity and Tissue Repair in Acute Kidney Injury

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    Pu Duann

    2016-05-01

    Full Text Available Kidney is a vital organ with high energy demands to actively maintain plasma hemodynamics, electrolytes and water homeostasis. Among the nephron segments, the renal tubular epithelium is endowed with high mitochondria density for their function in active transport. Acute kidney injury (AKI is an important clinical syndrome and a global public health issue with high mortality rate and socioeconomic burden due to lack of effective therapy. AKI results in acute cell death and necrosis of renal tubule epithelial cells accompanied with leakage of tubular fluid and inflammation. The inflammatory immune response triggered by the tubular cell death, mitochondrial damage, associative oxidative stress, and the release of many tissue damage factors have been identified as key elements driving the pathophysiology of AKI. Autophagy, the cellular mechanism that removes damaged organelles via lysosome-mediated degradation, had been proposed to be renoprotective. An in-depth understanding of the intricate interplay between autophagy and innate immune response, and their roles in AKI pathology could lead to novel therapies in AKI. This review addresses the current pathophysiology of AKI in aspects of mitochondrial dysfunction, innate immunity, and molecular mechanisms of autophagy. Recent advances in renal tissue regeneration and potential therapeutic interventions are also discussed.

  4. Feliform carnivores have a distinguished constitutive innate immune response

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    Sonja K. Heinrich

    2016-05-01

    Full Text Available Determining the immunological phenotype of endangered and threatened populations is important to identify those vulnerable to novel pathogens. Among mammals, members of the order Carnivora are particularly threatened by diseases. We therefore examined the constitutive innate immune system, the first line of protection against invading microbes, of six free-ranging carnivore species; the black-backed jackal (Canis mesomelas, the brown hyena (Hyena brunnea, the caracal (Caracal caracal, the cheetah (Acinonyx jubatus, the leopard (Panthera pardus and the lion (Panthera leo using a bacterial killing assay. The differences in immune responses amongst the six species were independent of their foraging behaviour, body mass or social organisation but reflected their phylogenetic relatedness. The bacterial killing capacity of black-backed jackals, a member of the suborder Caniformia, followed the pattern established for a wide variety of vertebrates. In contrast, the five representatives of the suborder Feliformia demonstrated a killing capacity at least an order of magnitude higher than any species reported previously, with a particularly high capacity in caracals and cheetahs. Our results suggest that the immunocompetence of threatened felids such as the cheetah has been underestimated and its assessment ought to consider both innate and adaptive components of the immune system.

  5. Verneuil's disease, innate immunity and vitamin D: a pilot study.

    Science.gov (United States)

    Guillet, A; Brocard, A; Bach Ngohou, K; Graveline, N; Leloup, A-G; Ali, D; Nguyen, J-M; Loirat, M-J; Chevalier, C; Khammari, A; Dreno, B

    2015-07-01

    Verneuil's disease is a chronic inflammatory skin disease of the follicles in apocrine glands rich area of the skin (axillary, inguinal, anogenital) and is associated with a deficient skin innate immunity. It is characterized by the occurrence of nodules, abscesses, fistulas, scars. Recently, vitamin D has been shown to stimulate skin innate immunity. The primary objective of the study was to assess whether Verneuil's disease was associated with vitamin D deficiency. The secondary objective was to determine whether vitamin D supplementation could improve inflammatory lesions. First, 25(OH) vitamin D3 serum levels in patients with Verneuil's disease followed at Nantes University Hospital were compared to those of healthy donors from the French Blood Bank. Then, a pilot study was conducted in 14 patients supplemented with vitamin D according to their vitamin D level at baseline at months 3 and 6. The endpoints at 6 months were decreased by at least 20% in the number of nodules and in the frequency of flare-ups. Twenty-two patients (100%) had vitamin D deficiency (level vitamin D deficiency (91%) of whom 14% were severely deficient. In 14 patients, the supplementation significantly decreased the number of nodules at 6 months (P = 0.01133), and the endpoints were achieved in 79% of these patients. A correlation between the therapeutic success and the importance of the increase in vitamin D level after supplementation was observed (P = 0.01099). Our study shows that Verneuil's disease is associated with a major vitamin D deficiency, correlated with the disease severity. It suggests that vitamin D could significantly improve the inflammatory nodules, probably by stimulating the skin innate immunity. A larger randomized study is needed to confirm these findings. © 2014 European Academy of Dermatology and Venereology.

  6. 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.; 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

  7. Learning from the Messengers: Innate Sensing of Viruses and Cytokine Regulation of Immunity — Clues for Treatments and Vaccines

    Directory of Open Access Journals (Sweden)

    Jesper Melchjorsen

    2013-01-01

    Full Text Available Virus infections are a major global public health concern, and only via substantial knowledge of virus pathogenesis and antiviral immune responses can we develop and improve medical treatments, and preventive and therapeutic vaccines. Innate immunity and the shaping of efficient early immune responses are essential for control of viral infections. In order to trigger an efficient antiviral defense, the host senses the invading microbe via pattern recognition receptors (PRRs, recognizing distinct conserved pathogen-associated molecular patterns (PAMPs. The innate sensing of the invading virus results in intracellular signal transduction and subsequent production of interferons (IFNs and proinflammatory cytokines. Cytokines, including IFNs and chemokines, are vital molecules of antiviral defense regulating cell activation, differentiation of cells, and, not least, exerting direct antiviral effects. Cytokines shape and modulate the immune response and IFNs are principle antiviral mediators initiating antiviral response through induction of antiviral proteins. In the present review, I describe and discuss the current knowledge on early virus–host interactions, focusing on early recognition of virus infection and the resulting expression of type I and type III IFNs, proinflammatory cytokines, and intracellular antiviral mediators. In addition, the review elucidates how targeted stimulation of innate sensors, such as toll-like receptors (TLRs and intracellular RNA and DNA sensors, may be used therapeutically. Moreover, I present and discuss data showing how current antimicrobial therapies, including antibiotics and antiviral medication, may interfere with, or improve, immune response.

  8. Emerging Role of D-Amino Acid Metabolism in the Innate Defense

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    Jumpei Sasabe

    2018-05-01

    Full Text Available Mammalian innate and adaptive immune systems use the pattern recognition receptors, such as toll-like receptors, to detect conserved bacterial and viral components. Bacteria synthesize diverse D-amino acids while eukaryotes and archaea generally produce two D-amino acids, raising the possibility that many of bacterial D-amino acids are bacteria-specific metabolites. Although D-amino acids have not been identified to bind to any known pattern recognition receptors, D-amino acids are enantioselectively recognized by some other receptors and enzymes including a flavoenzyme D-amino acid oxidase (DAO in mammals. At host–microbe interfaces in the neutrophils and intestinal mucosa, DAO catalyzes oxidation of bacterial D-amino acids, such as D-alanine, and generates H2O2, which is linked to antimicrobial activity. Intestinal DAO also modifies the composition of microbiota through modulation of growth for some bacteria that are dependent on host nutrition. Furthermore, regulation and recognition of D-amino acids in mammals have additional meanings at various host–microbe interfaces; D-phenylalanine and D-tryptophan regulate chemotaxis of neutrophils through a G-coupled protein receptor, D-serine has a bacteriostatic role in the urinary tract, D-phenylalanine and D-leucine inhibit innate immunity through the sweet taste receptor in the upper airway, and D-tryptophan modulates immune tolerance in the lower airway. This mini-review highlights recent evidence supporting the hypothesis that D-amino acids are utilized as inter-kingdom communication at host–microbe interface to modulate bacterial colonization and host defense.

  9. Lipoprotein Lipase Maintains Microglial Innate Immunity in Obesity

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    Yuanqing Gao

    2017-09-01

    Full Text Available Consumption of a hypercaloric diet upregulates microglial innate immune reactivity along with a higher expression of lipoprotein lipase (Lpl within the reactive microglia in the mouse brain. Here, we show that knockdown of the Lpl gene specifically in microglia resulted in deficient microglial uptake of lipid, mitochondrial fuel utilization shifting to glutamine, and significantly decreased immune reactivity. Mice with knockdown of the Lpl gene in microglia gained more body weight than control mice on a high-carbohydrate high-fat (HCHF diet. In these mice, microglial reactivity was significantly decreased in the mediobasal hypothalamus, accompanied by downregulation of phagocytic capacity and increased mitochondrial dysmorphologies. Furthermore, HCHF-diet-induced POMC neuronal loss was accelerated. These results show that LPL-governed microglial immunometabolism is essential to maintain microglial function upon exposure to an HCHF diet. In a hypercaloric environment, lack of such an adaptive immunometabolic response has detrimental effects on CNS regulation of energy metabolism.

  10. Early Subretinal Allograft Rejection Is Characterized by Innate Immune Activity.

    Science.gov (United States)

    Kennelly, Kevin P; Holmes, Toby M; Wallace, Deborah M; O'Farrelly, Cliona; Keegan, David J

    2017-06-09

    Successful subretinal transplantation is limited by considerable early graft loss despite pharmacological suppression of adaptive immunity. We postulated that early innate immune activity is a dominant factor in determining graft survival and chose a nonimmunosuppressed mouse model of retinal pigment epithelial (RPE) cell transplantation to explore this. Expression of almost all measured cytokines by DH01 RPE cells increased significantly following graft preparation, and the neutrophil chemoattractant KC/GRO/CINC was most significantly increased. Subretinal allografts of DH01 cells (C57BL/10 origin) into healthy, nonimmunosuppressed C57BL/6 murine eyes were harvested and fixed at 1, 3, 7, and 28 days postoperatively and subsequently cryosectioned and stained. Graft cells were detected using SV40 large T antigen (SV40T) immunolabeling and apoptosis/necrosis by terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL). Sections were also immunolabeled for macrophage (CD11b and F4/80), neutrophil (Gr1 Ly-6G), and T-lymphocyte (CD3-ɛ) infiltration. Images captured with an Olympus FV1000 confocal microscope were analyzed using the Imaris software. The proportion of the subretinal bolus comprising graft cells (SV40T+) was significantly (p < 0.001) reduced between postoperative day (POD) 3 (90 ± 4%) and POD 7 (20 ± 7%). CD11b+, F4/80+, and Gr1 Ly-6G+ cells increased significantly (p < 0.05) from POD 1 and predominated over SV40T+ cells by POD 7. Colabeling confocal microscopic analysis demonstrated graft engulfment by neutrophils and macrophages at POD 7, and reconstruction of z-stacked confocal images confirmed SV40T inside Gr1 Ly-6G+ cells. Expression of CD3-ɛ was low and did not differ significantly between time points. By POD 28, no graft cells were detectable and few inflammatory cells remained. These studies reveal, for the first time, a critical role for innate immune mechanisms early in subretinal graft rejection. The future success

  11. Lipopolysaccharide O-antigen delays plant innate immune recognition of Xylella fastidiosa.

    Science.gov (United States)

    Rapicavoli, Jeannette N; Blanco-Ulate, Barbara; Muszyński, Artur; Figueroa-Balderas, Rosa; Morales-Cruz, Abraham; Azadi, Parastoo; Dobruchowska, Justyna M; Castro, Claudia; Cantu, Dario; Roper, M Caroline

    2018-01-26

    Lipopolysaccharides (LPS) are among the known pathogen-associated molecular patterns (PAMPs). LPSs are potent elicitors of PAMP-triggered immunity (PTI), and bacteria have evolved intricate mechanisms to dampen PTI. Here we demonstrate that Xylella fastidiosa (Xf), a hemibiotrophic plant pathogenic bacterium, possesses a long chain O-antigen that enables it to delay initial plant recognition, thereby allowing it to effectively skirt initial elicitation of innate immunity and establish itself in the host. Lack of the O-antigen modifies plant perception of Xf and enables elicitation of hallmarks of PTI, such as ROS production specifically in the plant xylem tissue compartment, a tissue not traditionally considered a spatial location of PTI. To explore translational applications of our findings, we demonstrate that pre-treatment of plants with Xf LPS primes grapevine defenses to confer tolerance to Xf challenge.

  12. GSL-enriched membrane microdomains in innate immune responses.

    Science.gov (United States)

    Nakayama, Hitoshi; Ogawa, Hideoki; Takamori, Kenji; Iwabuchi, Kazuhisa

    2013-06-01

    Many pathogens target glycosphingolipids (GSLs), which, together with cholesterol, GPI-anchored proteins, and various signaling molecules, cluster on host cell membranes to form GSL-enriched membrane microdomains (lipid rafts). These GSL-enriched membrane microdomains may therefore be involved in host-pathogen interactions. Innate immune responses are triggered by the association of pathogens with phagocytes, such as neutrophils, macrophages and dendritic cells. Phagocytes express a diverse array of pattern-recognition receptors (PRRs), which sense invading microorganisms and trigger pathogen-specific signaling. PRRs can recognize highly conserved pathogen-associated molecular patterns expressed on microorganisms. The GSL lactosylceramide (LacCer, CDw17), which binds to various microorganisms, including Candida albicans, is expressed predominantly on the plasma membranes of human mature neutrophils and forms membrane microdomains together with the Src family tyrosine kinase Lyn. These LacCer-enriched membrane microdomains can mediate superoxide generation, migration, and phagocytosis, indicating that LacCer functions as a PRR in innate immunity. Moreover, the interactions of GSL-enriched membrane microdomains with membrane proteins, such as growth factor receptors, are important in mediating the physiological properties of these proteins. Similarly, we recently found that interactions between LacCer-enriched membrane microdomains and CD11b/CD18 (Mac-1, CR3, or αMβ2-integrin) are significant for neutrophil phagocytosis of non-opsonized microorganisms. This review describes the functional role of LacCer-enriched membrane microdomains and their interactions with CD11b/CD18.

  13. Antagonism of Innate Immunity by Paramyxovirus Accessory Proteins

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    Raychel Chambers

    2009-10-01

    Full Text Available Paramyxovirinae, a subfamily of Paramyxoviridae, are negative strand RNA viruses comprised of many important human and animal pathogens, which share a high degree of genetic and structural homology. The accessory proteins expressed from the P/V/C gene are major factors in the pathogenicity of the viruses, because of their ability to abrogate various facets of type I interferon (IFN induction and signaling. Most of the paramyxoviruses exhibit a commonality in their ability to antagonize innate immunity by blocking IFN induction and the Jak/STAT pathway. However, the manner in which the accessory proteins inhibit the pathway differs among viruses. Similarly, there are variations in the capability of the viruses to counteract intracellular detectors (RNA helicases, mda-5 and RIG-I. Furthermore, a functional specificity in the antagonism of the IFN response has been reported, suggesting that specificity in the circumvention of innate immunity restricts viral host range. Available evidence indicates that paramyxoviruses employ specific strategies to antagonize the IFN response of their specific hosts, which is one of the major factors that determine viral pathogenicity and host range.

  14. Hematopoietic Stem and Progenitor Cells as Effectors in Innate Immunity

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    Jennifer L. Granick

    2012-01-01

    Full Text Available Recent research has shed light on novel functions of hematopoietic stem and progenitor cells (HSPC. While they are critical for maintenance and replenishment of blood cells in the bone marrow, these cells are not limited to the bone marrow compartment and function beyond their role in hematopoiesis. HSPC can leave bone marrow and circulate in peripheral blood and lymph, a process often manipulated therapeutically for the purpose of transplantation. Additionally, these cells preferentially home to extramedullary sites of inflammation where they can differentiate to more mature effector cells. HSPC are susceptible to various pathogens, though they may participate in the innate immune response without being directly infected. They express pattern recognition receptors for detection of endogenous and exogenous danger-associated molecular patterns and respond not only by the formation of daughter cells but can themselves secrete powerful cytokines. This paper summarizes the functional and phenotypic characterization of HSPC, their niche within and outside of the bone marrow, and what is known regarding their role in the innate immune response.

  15. Network topologies and dynamics leading to endotoxin tolerance and priming in innate immune cells.

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    Yan Fu

    Full Text Available The innate immune system, acting as the first line of host defense, senses and adapts to foreign challenges through complex intracellular and intercellular signaling networks. Endotoxin tolerance and priming elicited by macrophages are classic examples of the complex adaptation of innate immune cells. Upon repetitive exposures to different doses of bacterial endotoxin (lipopolysaccharide or other stimulants, macrophages show either suppressed or augmented inflammatory responses compared to a single exposure to the stimulant. Endotoxin tolerance and priming are critically involved in both immune homeostasis and the pathogenesis of diverse inflammatory diseases. However, the underlying molecular mechanisms are not well understood. By means of a computational search through the parameter space of a coarse-grained three-node network with a two-stage Metropolis sampling approach, we enumerated all the network topologies that can generate priming or tolerance. We discovered three major mechanisms for priming (pathway synergy, suppressor deactivation, activator induction and one for tolerance (inhibitor persistence. These results not only explain existing experimental observations, but also reveal intriguing test scenarios for future experimental studies to clarify mechanisms of endotoxin priming and tolerance.

  16. An Overview of Pathogen Recognition Receptors for Innate Immunity in Dental Pulp

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    Ji-Hyun Jang

    2015-01-01

    Full Text Available Pathogen recognition receptors (PRRs are a class of germ line-encoded receptors that recognize pathogen-associated molecular patterns (PAMPs. The activation of PRRs is crucial for the initiation of innate immunity, which plays a key role in first-line defense until more specific adaptive immunity is developed. PRRs differ in the signaling cascades and host responses activated by their engagement and in their tissue distribution. Currently identified PRR families are the Toll-like receptors (TLRs, the C-type lectin receptors (CLRs, the nucleotide-binding oligomerization domain-like receptors (NLRs, the retinoic acid-inducible gene-I-like receptors (RLRs, and the AIM2-like receptor (ALR. The environment of the dental pulp is substantially different from that of other tissues of the body. Dental pulp resides in a low compliance root canal system that limits the expansion of pulpal tissues during inflammatory processes. An understanding of the PRRs in dental pulp is important for immunomodulation and hence for developing therapeutic targets in the field of endodontics. Here we comprehensively review recent finding on the PRRs and the mechanisms by which innate immunity is activated. We focus on the PRRs expressed on dental pulp and periapical tissues and their role in dental pulp inflammation.

  17. HMGB1 and cord blood: its role as immuno-adjuvant factor in innate immunity.

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    Alessandra Ciucci

    Full Text Available In newborn the innate immune system provides essential protection during primary infections before the generation of an appropriate adaptive immune response that is initially not fully operative. Innate immune response is evoked and perpetuated by molecules derived from microorganisms or by the damage/death of host cells. These are collectively known as damage-associated molecular-pattern (DAMP molecules. High-mobility group box 1 protein (HMGB1 or amphoterin, which previously was considered to be only a nuclear factor, has been recently identified as a DAMP molecule. When it is actively secreted by inflammatory cells or passively released from necrotic cells, HMGB1 mediates the response to infection, injury and inflammation, inducing dendritic cells maturation and T helper-1-cell responses. To characterize the role of HMGB1 in the innate and immature defense mechanisms in newborns, human cord blood (CB mononuclear cells, in comparison to adult peripheral blood (PB mononuclear cells, have been analyzed for its expression. By flow cytometry and western blot analysis, we observed that in CB and PB cells: i HMGB1 is expressed on cell surface membranes of myeloid dendritic cell precursors, mostly, and lymphocytes (gamma/delta and CD4(+ T cells to a lesser extent; ii different pro-inflammatory stimuli or molecules that mimic infection increased cell surface expression of HMGB1 as well as its secretion into extracellular environment; iii the treatment with synthetic molecules such as aminobisphosphonates (ABs, identified to be γδ T cell antigens, triggered up-regulation of HMGB1 expression on mononuclear cells, as well γδ T lymphocytes, inducing its secretion. The modulation of its secretion and the HMGB1-mediated migration of monocytes indicated HMGB1 as regulator of immune response in an immature system, like CB, through engagement of γδ T lymphocytes and myeloid dendritic cell precursors, essential components of innate immunity. In addition

  18. Arthropod Innate Immune Systems and Vector-Borne Diseases.

    Science.gov (United States)

    Baxter, Richard H G; Contet, Alicia; Krueger, Kathryn

    2017-02-21

    Arthropods, especially ticks and mosquitoes, are the vectors for a number of parasitic and viral human diseases, including malaria, sleeping sickness, Dengue, and Zika, yet arthropods show tremendous individual variation in their capacity to transmit disease. A key factor in this capacity is the group of genetically encoded immune factors that counteract infection by the pathogen. Arthropod-specific pattern recognition receptors and protease cascades detect and respond to infection. Proteins such as antimicrobial peptides, thioester-containing proteins, and transglutaminases effect responses such as lysis, phagocytosis, melanization, and agglutination. Effector responses are initiated by damage signals such as reactive oxygen species signaling from epithelial cells and recognized by cell surface receptors on hemocytes. Antiviral immunity is primarily mediated by siRNA pathways but coupled with interferon-like signaling, antimicrobial peptides, and thioester-containing proteins. Molecular mechanisms of immunity are closely linked to related traits of longevity and fertility, and arthropods have the capacity for innate immunological memory. Advances in understanding vector immunity can be leveraged to develop novel control strategies for reducing the rate of transmission of both ancient and emerging threats to global health.

  19. Innate Immune Response to Rift Valley Fever Virus in Goats

    Science.gov (United States)

    Nfon, Charles K.; Marszal, Peter; Zhang, Shunzhen; Weingartl, Hana M.

    2012-01-01

    Rift Valley fever (RVF), a re-emerging mosquito-borne disease of ruminants and man, was endemic in Africa but spread to Saudi Arabia and Yemen, meaning it could spread even further. Little is known about innate and cell-mediated immunity to RVF virus (RVFV) in ruminants, which is knowledge required for adequate vaccine trials. We therefore studied these aspects in experimentally infected goats. We also compared RVFV grown in an insect cell-line and that grown in a mammalian cell-line for differences in the course of infection. Goats developed viremia one day post infection (DPI), which lasted three to four days and some goats had transient fever coinciding with peak viremia. Up to 4% of peripheral blood mononuclear cells (PBMCs) were positive for RVFV. Monocytes and dendritic cells in PBMCs declined possibly from being directly infected with virus as suggested by in vitro exposure. Infected goats produced serum IFN-γ, IL-12 and other proinflammatory cytokines but not IFN-α. Despite the lack of IFN-α, innate immunity via the IL-12 to IFN-γ circuit possibly contributed to early protection against RVFV since neutralising antibodies were detected after viremia had cleared. The course of infection with insect cell-derived RVFV (IN-RVFV) appeared to be different from mammalian cell-derived RVFV (MAM-RVFV), with the former attaining peak viremia faster, inducing fever and profoundly affecting specific immune cell subpopulations. This indicated possible differences in infections of ruminants acquired from mosquito bites relative to those due to contact with infectious material from other animals. These differences need to be considered when testing RVF vaccines in laboratory settings. PMID:22545170

  20. Immune-Modulating Perspectives for Low Frequency Electromagnetic Fields in Innate Immunity

    Directory of Open Access Journals (Sweden)

    Maria Manuela Rosado

    2018-03-01

    Full Text Available In recent years, the effects of electromagnetic fields (EMFs on the immune system have received a considerable interest, not only to investigate possible negative health impact but also to explore the possibility to favorably modulate immune responses. To generate beneficial responses, the immune system should eradicate pathogens while “respecting” the organism and tolerating irrelevant antigens. According to the current view, damage-associated molecules released by infected or injured cells, or secreted by innate immune cells generate danger signals activating an immune response. These signals are also relevant to the subsequent activation of homeostatic mechanisms that control the immune response in pro- or anti-inflammatory reactions, a feature that allows modulation by therapeutic treatments. In the present review, we describe and discuss the effects of extremely low frequency (ELF-EMF and pulsed EMF on cell signals and factors relevant to the activation of danger signals and innate immunity cells. By discussing the EMF modulating effects on cell functions, we envisage the use of EMF as a therapeutic agent to regulate immune responses associated with wound healing.

  1. Microarray expression analysis of genes involved in innate immune memory in peritoneal macrophages

    Directory of Open Access Journals (Sweden)

    Keisuke Yoshida

    2016-03-01

    Full Text Available Immunological memory has been believed to be a feature of the adaptive immune system for long period, but recent reports suggest that the innate immune system also exhibits memory-like reaction. Although evidence of innate immune memory is accumulating, no in vivo experimental data has clearly implicated a molecular mechanism, or even a cell-type, for this phenomenon. In this study of data deposited into Gene Expression Omnibus (GEO under GSE71111, we analyzed the expression profile of peritoneal macrophages isolated from mice pre-administrated with toll-like receptor (TLR ligands, mimicking pathogen infection. In these macrophages, increased expression of a group of innate immunity-related genes was sustained over a long period of time, and these genes overlapped with ATF7-regulated genes. We conclude that ATF7 plays an important role in innate immune memory in macrophages. Keywords: Macrophage, ATF7, Innate immune memory, Microarray

  2. The innate immune signaling in cancer and cardiometabolic diseases: Friends or foes?

    Science.gov (United States)

    Wang, Weijun; Zhang, Yaxing; Yang, Ling; Li, Hongliang

    2017-02-28

    The innate immune system is responsible for sensing pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs) by several types of germline-encoded pattern-recognition receptors (PRRs). It has the capacity to help the human body maintain homeostasis under normal conditions. However, in pathological conditions, PAMPs or DAMPs trigger aberrant innate immune and inflammatory responses and thus negatively or positively influence the progression of cancer and cardiometabolic diseases. Interestingly, we found that some elements of innate immune signaling are involved in these diseases partially via immune-independent manners, indicating a deeper understanding of the function of innate immune signaling in these diseases is urgent. In this review, we summarize the primary innate immune signaling pathways and their association with cancer and cardiometabolic diseases, with the aim of providing effective therapies for these diseases. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  3. 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.

  4. Depletion of dendritic cells enhances innate anti-bacterial host defense through modulation of phagocyte homeostasis.

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    Stella E Autenrieth

    2012-02-01

    Full Text Available Dendritic cells (DCs as professional antigen-presenting cells play an important role in the initiation and modulation of the adaptive immune response. However, their role in the innate immune response against bacterial infections is not completely defined. Here we have analyzed the role of DCs and their impact on the innate anti-bacterial host defense in an experimental infection model of Yersinia enterocolitica (Ye. We used CD11c-diphtheria toxin (DT mice to deplete DCs prior to severe infection with Ye. DC depletion significantly increased animal survival after Ye infection. The bacterial load in the spleen of DC-depleted mice was significantly lower than that of control mice throughout the infection. DC depletion was accompanied by an increase in the serum levels of CXCL1, G-CSF, IL-1α, and CCL2 and an increase in the numbers of splenic phagocytes. Functionally, splenocytes from DC-depleted mice exhibited an increased bacterial killing capacity compared to splenocytes from control mice. Cellular studies further showed that this was due to an increased production of reactive oxygen species (ROS by neutrophils. Adoptive transfer of neutrophils from DC-depleted mice into control mice prior to Ye infection reduced the bacterial load to the level of Ye-infected DC-depleted mice, suggesting that the increased number of phagocytes with additional ROS production account for the decreased bacterial load. Furthermore, after incubation with serum from DC-depleted mice splenocytes from control mice increased their bacterial killing capacity, most likely due to enhanced ROS production by neutrophils, indicating that serum factors from DC-depleted mice account for this effect. In summary, we could show that DC depletion triggers phagocyte accumulation in the spleen and enhances their anti-bacterial killing capacity upon bacterial infection.

  5. Aberrant innate immune activation following tissue injury impairs pancreatic regeneration.

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    Alexandra E Folias

    Full Text Available Normal tissue architecture is disrupted following injury, as resident tissue cells become damaged and immune cells are recruited to the site of injury. While injury and inflammation are critical to tissue remodeling, the inability to resolve this response can lead to the destructive complications of chronic inflammation. In the pancreas, acinar cells of the exocrine compartment respond to injury by transiently adopting characteristics of progenitor cells present during embryonic development. This process of de-differentiation creates a window where a mature and stable cell gains flexibility and is potentially permissive to changes in cellular fate. How de-differentiation can turn an acinar cell into another cell type (such as a pancreatic β-cell, or a cell with cancerous potential (as in cases of deregulated Kras activity is of interest to both the regenerative medicine and cancer communities. While it is known that inflammation and acinar de-differentiation increase following pancreatic injury, it remains unclear which immune cells are involved in this process. We used a combination of genetically modified mice, immunological blockade and cellular characterization to identify the immune cells that impact pancreatic regeneration in an in vivo model of pancreatitis. We identified the innate inflammatory response of macrophages and neutrophils as regulators of pancreatic regeneration. Under normal conditions, mild innate inflammation prompts a transient de-differentiation of acinar cells that readily dissipates to allow normal regeneration. However, non-resolving inflammation developed when elevated pancreatic levels of neutrophils producing interferon-γ increased iNOS levels and the pro-inflammatory response of macrophages. Pancreatic injury improved following in vivo macrophage depletion, iNOS inhibition as well as suppression of iNOS levels in macrophages via interferon-γ blockade, supporting the impairment in regeneration and the

  6. Oxidative stress, innate immunity, and age-related macular degeneration

    Science.gov (United States)

    Shaw, Peter X.; Stiles, Travis; Douglas, Christopher; Ho, Daisy; Fan, Wei; Du, Hongjun; Xiao, Xu

    2016-01-01

    Age-related macular degeneration (AMD) is a leading cause of vision loss affecting tens of millions of elderly worldwide. Early AMD is characterized by the appearance of soft drusen, as well as pigmentary changes in the retinal pigment epithelium (RPE). These soft, confluent drusen can progress into two forms of advanced AMD: geographic atrophy (GA, or dry AMD) or choroidal neovascularization (CNV, or wet AMD). Both forms of AMD result in a similar clinical progression in terms of loss of central vision. The exact mechanism for developing early AMD, as well as triggers responsible for progressing to advanced stage of disease, is still largely unknown. However, significant evidence exists demonstrating a complex interplay of genetic and environmental factors as causes of AMD progression. Multiple genes and/or single nucleotide polymorphisms (SNPs) have been found associated with AMD, including various genes involved in the complement pathway, lipid metabolism and extracellular matrix (ECM) remodeling. Of the known genetic contributors to disease risk, the CFH Y402H and HTRA1/ARMS polymorphisms contribute to more than 50% of the genetic risk for AMD. Environmentally, oxidative stress plays a critical role in many aging diseases including cardiovascular disease, cancer, Alzheimer’s disease and AMD. Due to the exposure to sunlight and high oxygen concentration, the oxidative stress burden is higher in the eye than other tissues, which can be further complicated by additional oxidative stressors such as smoking. Increasingly, evidence is accumulating suggesting that functional abnormalities of the innate immune system incurred via high risk genotypes may be contributing to the pathogenesis of AMD by altering the inflammatory homeostasis in the eye, specifically in the handling of oxidation products. As the eye in non-pathological instances maintains a low level of inflammation despite the presence of a relative abundance of potentially inflammatory molecules, we have

  7. The Quantitative Basis of the Arabidopsis Innate Immune System to Endemic Pathogens Depends on Pathogen Genetics.

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    Jason A Corwin

    2016-02-01

    Full Text Available The most established model of the eukaryotic innate immune system is derived from examples of large effect monogenic quantitative resistance to pathogens. However, many host-pathogen interactions involve many genes of small to medium effect and exhibit quantitative resistance. We used the Arabidopsis-Botrytis pathosystem to explore the quantitative genetic architecture underlying host innate immune system in a population of Arabidopsis thaliana. By infecting a diverse panel of Arabidopsis accessions with four phenotypically and genotypically distinct isolates of the fungal necrotroph B. cinerea, we identified a total of 2,982 genes associated with quantitative resistance using lesion area and 3,354 genes associated with camalexin production as measures of the interaction. Most genes were associated with resistance to a specific Botrytis isolate, which demonstrates the influence of pathogen genetic variation in analyzing host quantitative resistance. While known resistance genes, such as receptor-like kinases (RLKs and nucleotide-binding site leucine-rich repeat proteins (NLRs, were found to be enriched among associated genes, they only account for a small fraction of the total genes associated with quantitative resistance. Using publically available co-expression data, we condensed the quantitative resistance associated genes into co-expressed gene networks. GO analysis of these networks implicated several biological processes commonly connected to disease resistance, including defense hormone signaling and ROS production, as well as novel processes, such as leaf development. Validation of single gene T-DNA knockouts in a Col-0 background demonstrate a high success rate (60% when accounting for differences in environmental and Botrytis genetic variation. This study shows that the genetic architecture underlying host innate immune system is extremely complex and is likely able to sense and respond to differential virulence among pathogen

  8. Training modifies innate immune responses in blood monocytes and in pulmonary alveolar macrophages.

    Science.gov (United States)

    Frellstedt, Linda; Waldschmidt, Ingrid; Gosset, Philippe; Desmet, Christophe; Pirottin, Dimitri; Bureau, Fabrice; Farnir, Frédéric; Franck, Thierry; Dupuis-Tricaud, Marie-Capucine; Lekeux, Pierre; Art, Tatiana

    2014-07-01

    In humans, strenuous exercise causes increased susceptibility to respiratory infections associated with down-regulated expression of Toll-like receptors (TLRs) and costimulatory and antigen-presenting molecules. Lower airway diseases are also a common problem in sport and racing horses. Because innate immunity plays an essential role in lung defense mechanisms, we assessed the effect of acute exercise and training on innate immune responses in two different compartments. Blood monocytes and pulmonary alveolar macrophages (PAMs) were collected from horses in untrained, moderately trained, intensively trained, and deconditioned states before and after a strenuous exercise test. The cells were analyzed for TLR messenger ribonucleic acid (mRNA) expression by real-time PCR in vitro, and cytokine production after in vitro stimulation with TLR ligands was measured by ELISA. Our results showed that training, but not acute exercise, modified the innate immune responses in both compartments. The mRNA expression of TLR3 was down-regulated by training in both cell types, whereas the expression of TLR4 was up-regulated in monocytes. Monocytes treated with LPS and a synthetic diacylated lipoprotein showed increased cytokine secretion in trained and deconditioned subjects, indicating the activation of cells at the systemic level. The production of TNF-α and IFN-β in nonstimulated and stimulated PAMs was decreased in trained and deconditioned horses and might therefore explain the increased susceptibility to respiratory infections. Our study reports a dissociation between the systemic and the lung response to training that is probably implicated in the systemic inflammation and in the pulmonary susceptibility to infection.

  9. Ontogenetic profile of innate immune related genes and their tissue-specific expression in brown trout, Salmo trutta (Linnaeus, 1758).

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    Cecchini, Stefano; Paciolla, Mariateresa; Biffali, Elio; Borra, Marco; Ursini, Matilde V; Lioi, Maria B

    2013-09-01

    The innate immune system is a fundamental defense weapon of fish, especially during early stages of development when acquired immunity is still far from being completely developed. The present study aims at looking into ontogeny of innate immune system in the brown trout, Salmo trutta, using RT-PCR based approach. Total RNA extracted from unfertilized and fertilized eggs and hatchlings at 0, 1 h and 1, 2, 3, 4, 5, 6, 7 weeks post-fertilization was subjected to RT-PCR using self-designed primers to amplify some innate immune relevant genes (TNF-α, IL-1β, TGF-β and lysozyme c-type). The constitutive expression of β-actin was detected in all developmental stages. IL-1β and TNF-α transcripts were detected from 4 week post-fertilization onwards, whereas TGF-β transcript was detected only from 7 week post-fertilization onwards. Lysozyme c-type transcript was detected early from unfertilized egg stage onwards. Similarly, tissues such as muscle, ovary, heart, brain, gill, testis, liver, intestine, spleen, skin, posterior kidney, anterior kidney and blood collected from adult brown trout were subjected to detection of all selected genes by RT-PCR. TNF-α and lysozyme c-type transcripts were expressed in all tissues. IL-1β and TGF-β transcripts were expressed in all tissues except for the brain and liver, respectively. Taken together, our results show a spatial-temporal expression of some key innate immune-related genes, improving the basic knowledge of the function of innate immune system at early stage of brown trout. Copyright © 2013 Elsevier Ltd. All rights reserved.

  10. The RNA uridyltransferase Zcchc6 is expressed in macrophages and impacts innate immune responses.

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    Elyse Kozlowski

    Full Text Available Alveolar macrophages orchestrate pulmonary innate immunity and are essential for early immune surveillance and clearance of microorganisms in the airways. Inflammatory signaling must be sufficiently robust to promote host defense but limited enough to prevent excessive tissue injury. Macrophages in the lungs utilize multiple transcriptional and post-transcriptional mechanisms of inflammatory gene expression to delicately balance the elaboration of immune mediators. RNA terminal uridyltransferases (TUTs, including the closely homologous family members Zcchc6 (TUT7 and Zcchc11 (TUT4, have been implicated in the post-transcriptional regulation of inflammation from studies conducted in vitro. In vivo, we observed that Zcchc6 is expressed in mouse and human primary macrophages. Zcchc6-deficient mice are viable and born in Mendelian ratios and do not exhibit an observable spontaneous phenotype under basal conditions. Following an intratracheal challenge with S. pneumoniae, Zcchc6 deficiency led to a modest but significant increase in the expression of select cytokines including IL-6, CXCL1, and CXCL5. These findings were recapitulated in vitro whereby Zcchc6-deficient macrophages exhibited similar increases in cytokine expression due to bacterial stimulation. Although loss of Zcchc6 also led to increased neutrophil emigration to the airways during pneumonia, these responses were not sufficient to impact host defense against infection.

  11. Innate immune system capabilities of the Asian citrus psyllid, Diaphorina citri.

    Science.gov (United States)

    Arp, Alex P; Martini, Xavier; Pelz-Stelinski, Kirsten S

    2017-09-01

    Citrus production worldwide is currently threatened by Huanglongbing, or citrus greening disease. The associated pathogen, Candidatus Liberibacter asiaticus (CLas), is transmitted by the Asian citrus psyllid, Diaphorina citri. Annotation of the D. citri genome revealed a reduced innate immune system lacking a number of antimicrobial peptides and the Imd pathway associated with defense against Gram-negative bacteria. We characterized this apparent immune reduction in survival assays in which D. citri were exposed to Gram-negative or Gram-positive bacteria. D. citri experienced significant mortality when exposed to Serratia marcescens (Gram-negative) through oral ingestion or by septic injury. Escherichia coli (Gram-negative) also caused significant D. citri mortality, but only when inoculated at high concentrations through oral ingestion or by septic injury. Neither Micrococcus luteus (Gram-positive) or Bacillus subtilis (Gram-positive) caused significant mortality as compared to controls in any experiment. E. coli titers increased rapidly following exposure, while M. luteus titer remained stable for 72 h. We demonstrate that D. citri is capable of defending against E. coli, a Gram-negative bacterium, despite lacking the Imd defense pathway. The tolerance of D. citri to M. luteus infection, yet inability to effectively clear infections, presents questions to efficacy of D. citri immune response to effectively clear Gram-positive infections. Copyright © 2017. Published by Elsevier Inc.

  12. Reduced innate immunity of Cuban Treefrogs at leading edge of range expansion.

    Science.gov (United States)

    Goetz, Scott M; Romagosa, Christina M; Appel, Arthur G; Guyer, Craig; Mendonça, Mary T

    2017-12-01

    During geographic range expansion, populations of non-indigenous species at the invasion front may benefit from directing resources away from immune defense. To test this hypothesis, we investigated the strength of two innate immune components in populations of invasive Cuban Treefrogs (Osteopilus septentrionalis) in a long-colonized area (core region) and at the invasion front (leading-edge region). First, we compared the region-specific metabolic response of frogs injected with an endotoxin that induces systemic inflammation (lipopolysaccharide, LPS) to sham-injected control frogs pooled from both regions. Males and females were analyzed independently because we detected a sex-related difference in mass-independent metabolism of control frogs, with males exhibiting a significantly higher metabolic rate (F 1, 21  = 29.02, P leading-edge populations, there was no significant difference in the metabolic rate of LPS-injected and control frogs (males, P  = 0.195; females, P  = 0.132). Second, we directly compared bacterial killing ability of frog blood plasma between regions. Bactericidal ability of plasma was significantly greater in frogs from the core region in comparison with those at the leading edge (F 1, 26   = 28.67, P < 0.001). For both immune components that we examined, populations from the core exhibited stronger immune responses. Our findings support hypotheses predicting an inverse relationship between immunity and range expansion. © 2018 Wiley Periodicals, Inc.

  13. DMPD: Cytosolic DNA recognition for triggering innate immune responses. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18280611 Cytosolic DNA recognition for triggering innate immune responses. Takaoka ...A, Taniguchi T. Adv Drug Deliv Rev. 2008 Apr 29;60(7):847-57. Epub 2007 Dec 31. (.png) (.svg) (.html) (.csml) Show Cytosol...ic DNA recognition for triggering innate immune responses. PubmedID 18280611 Title Cytosolic D

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

    Directory of Open Access Journals (Sweden)

    S. I. Suskov

    2012-01-01

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

  15. DMPD: Peptidoglycan signaling in innate immunity and inflammatory disease. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 15802263 Peptidoglycan signaling in innate immunity and inflammatory disease. McDon...ald C, Inohara N, Nunez G. J Biol Chem. 2005 May 27;280(21):20177-80. Epub 2005 Mar 31. (.png) (.svg) (.html) (.csml) Show Peptidog...lycan signaling in innate immunity and inflammatory disease. PubmedID 15802263 Title Peptidog

  16. 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

  17. DMPD: Innate immune responses during infection. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available va Correia J. Vaccine. 2004 Dec 6;22 Suppl 1:S25-30. (.png) (.svg) (.html) (.csml) Show Innate immune responses during infection. Pub...medID 15576198 Title Innate immune responses during infection. Authors Ulevitch RJ,

  18. Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans

    NARCIS (Netherlands)

    Kox, M.; Eijk, L.T.G.J. van; Zwaag, J.; Wildenberg, J. van den; Sweep, F.C.; Hoeven, J.G. van der; Pickkers, P.

    2014-01-01

    Excessive or persistent proinflammatory cytokine production plays a central role in autoimmune diseases. Acute activation of the sympathetic nervous system attenuates the innate immune response. However, both the autonomic nervous system and innate immune system are regarded as systems that cannot

  19. The role of intracellular thyroid hormone metabolism in innate immune cells

    NARCIS (Netherlands)

    van der Spek, A.H.

    2018-01-01

    Innate immune cells have recently been identified as important thyroid hormone target cells. This thesis studies the role of intracellular thyroid hormone metabolism in the function of neutrophils and macrophages, two essential cell types of the innate immune system. Neutrophils, monocytes and

  20. The molecular mechanisms of signaling by cooperative assembly formation in innate immunity pathways.

    Science.gov (United States)

    Vajjhala, Parimala R; Ve, Thomas; Bentham, Adam; Stacey, Katryn J; Kobe, Bostjan

    2017-06-01

    The innate immune system is the first line of defense against infection and responses are initiated by pattern recognition receptors (PRRs) that detect pathogen-associated molecular patterns (PAMPs). PRRs also detect endogenous danger-associated molecular patterns (DAMPs) that are released by damaged or dying cells. The major PRRs include the Toll-like receptor (TLR) family members, the nucleotide binding and oligomerization domain, leucine-rich repeat containing (NLR) family, the PYHIN (ALR) family, the RIG-1-like receptors (RLRs), C-type lectin receptors (CLRs) and the oligoadenylate synthase (OAS)-like receptors and the related protein cyclic GMP-AMP synthase (cGAS). The different PRRs activate specific signaling pathways to collectively elicit responses including the induction of cytokine expression, processing of pro-inflammatory cytokines and cell-death responses. These responses control a pathogenic infection, initiate tissue repair and stimulate the adaptive immune system. A central theme of many innate immune signaling pathways is the clustering of activated PRRs followed by sequential recruitment and oligomerization of adaptors and downstream effector enzymes, to form higher-order arrangements that amplify the response and provide a scaffold for proximity-induced activation of the effector enzymes. Underlying the formation of these complexes are co-operative assembly mechanisms, whereby association of preceding components increases the affinity for downstream components. This ensures a rapid immune response to a low-level stimulus. Structural and biochemical studies have given key insights into the assembly of these complexes. Here we review the current understanding of assembly of immune signaling complexes, including inflammasomes initiated by NLR and PYHIN receptors, the myddosomes initiated by TLRs, and the MAVS CARD filament initiated by RIG-1. We highlight the co-operative assembly mechanisms during assembly of each of these complexes. Copyright

  1. Nitric oxide-mediated maintenance of redox homeostasis contributes to NPR1-dependent plant innate immunity triggered by lipopolysaccharides.

    Science.gov (United States)

    Sun, Aizhen; Nie, Shengjun; Xing, Da

    2012-10-01

    The perception of lipopolysaccharides (LPS) by plant cells can lead to nitric oxide (NO) production and defense gene induction. However, the signaling cascades underlying these cellular responses have not yet been resolved. This work investigated the biosynthetic origin of NO and the role of NONEXPRESSOR OF PATHOGENESIS-RELATED GENES1 (NPR1) to gain insight into the mechanism involved in LPS-induced resistance of Arabidopsis (Arabidopsis thaliana). Analysis of inhibitors and mutants showed that LPS-induced NO synthesis was mainly mediated by an arginine-utilizing source of NO generation. Furthermore, LPS-induced NO caused transcript accumulation of alternative oxidase genes and increased antioxidant enzyme activity, which enhanced antioxidant capacity and modulated redox state. We also analyzed the subcellular localization of NPR1 to identify the mechanism for protein-modulated plant innate immunity triggered by LPS. LPS-activated defense responses, including callose deposition and defense-related gene expression, were found to be regulated through an NPR1-dependent pathway. In summary, a significant NO synthesis induced by LPS contributes to the LPS-induced defense responses by up-regulation of defense genes and modulation of cellular redox state. Moreover, NPR1 plays an important role in LPS-triggered plant innate immunity.

  2. Complex interplay of body condition, life history, and prevailing environment shapes immune defenses of garter snakes in the wild.

    Science.gov (United States)

    Palacios, Maria G; Cunnick, Joan E; Bronikowski, Anne M

    2013-01-01

    The immunocompetence "pace-of-life" hypothesis proposes that fast-living organisms should invest more in innate immune defenses and less in adaptive defenses compared to slow-living ones. We found some support for this hypothesis in two life-history ecotypes of the snake Thamnophis elegans; fast-living individuals show higher levels of innate immunity compared to slow-living ones. Here, we optimized a lymphocyte proliferation assay to assess the complementary prediction that slow-living snakes should in turn show stronger adaptive defenses. We also assessed the "environmental" hypothesis that predicts that slow-living snakes should show lower levels of immune defenses (both innate and adaptive) given the harsher environment they live in. Proliferation of B- and T-lymphocytes of free-living individuals was on average higher in fast-living than slow-living snakes, opposing the pace-of-life hypothesis and supporting the environmental hypothesis. Bactericidal capacity of plasma, an index of innate immunity, did not differ between fast-living and slow-living snakes in this study, contrasting the previously documented pattern and highlighting the importance of annual environmental conditions as determinants of immune profiles of free-living animals. Our results do not negate a link between life history and immunity, as indicated by ecotype-specific relationships between lymphocyte proliferation and body condition, but suggest more subtle nuances than those currently proposed.

  3. Immune system development during early childhood in tropical Latin America: evidence for the age-dependent down regulation of the innate immune response.

    Science.gov (United States)

    Teran, Rommy; Mitre, Edward; Vaca, Maritza; Erazo, Silvia; Oviedo, Gisela; Hübner, Marc P; Chico, Martha E; Mattapallil, Joseph J; Bickle, Quentin; Rodrigues, Laura C; Cooper, Philip J

    2011-03-01

    The immune response that develops in early childhood underlies the development of inflammatory diseases such as asthma and there are few data from tropical Latin America (LA). This study investigated the effects of age on the development of immunity during the first 5 years of life by comparing innate and adaptive immune responses in Ecuadorian children aged 6-9 months, 22-26 months, and 48-60 months. Percentages of naïve CD4+ T cells declined with age while those of memory CD4(+) and CD8(+) T cells increased indicating active development of the immune system throughout the first five years. Young infants had greater innate immune responses to TLR agonists compared to older children while regulatory responses including SEB-induced IL-10 and percentages of FoxP3(+) T-regulatory cells decreased with age. Enhanced innate immunity in early life may be important for host defense against pathogens but may increase the risk of immunopathology. Copyright © 2010 Elsevier Inc. All rights reserved.

  4. BACH transcription factors in innate and adaptive immunity.

    Science.gov (United States)

    Igarashi, Kazuhiko; Kurosaki, Tomohiro; Roychoudhuri, Rahul

    2017-07-01

    BTB and CNC homology (BACH) proteins are transcriptional repressors of the basic region leucine zipper (bZIP) transcription factor family. Recent studies indicate widespread roles of BACH proteins in controlling the development and function of the innate and adaptive immune systems, including the differentiation of effector and memory cells of the B and T cell lineages, CD4 + regulatory T cells and macrophages. Here, we emphasize similarities at a molecular level in the cell-type-specific activities of BACH factors, proposing that competitive interactions of BACH proteins with transcriptional activators of the bZIP family form a common mechanistic theme underlying their diverse actions. The findings contribute to a general understanding of how transcriptional repressors shape lineage commitment and cell-type-specific functions through repression of alternative lineage programmes.

  5. 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.

  6. Autophagy, inflammation and innate immunity in inflammatory myopathies.

    Directory of Open Access Journals (Sweden)

    Cristina Cappelletti

    Full Text Available Autophagy has a large range of physiological functions and its dysregulation contributes to several human disorders, including autoinflammatory/autoimmune diseases such as inflammatory myopathies (IIMs. In order to better understand the pathogenetic mechanisms of these muscular disorders, we sought to define the role of autophagic processes and their relation with the innate immune system in the three main subtypes of IIM, specifically sporadic inclusion body myositis (sIBM, polymyositis (PM, dermatomyositis (DM and juvenile dermatomyositis (JDM. We found that although the mRNA transcript levels of the autophagy-related genes BECN1, ATG5 and FBXO32 were similar in IIM and controls, autophagy activation in all IIM subgroups was suggested by immunoblotting results and confirmed by immunofluorescence. TLR4 and TLR3, two potent inducers of autophagy, were highly increased in IIM, with TLR4 transcripts significantly more expressed in PM and DM than in JDM, sIBM and controls, and TLR3 transcripts highly up-regulated in all IIM subgroups compared to controls. Co-localization between autophagic marker, LC3, and TLR4 and TLR3 was observed not only in sIBM but also in PM, DM and JDM muscle tissues. Furthermore, a highly association with the autophagic processes was observed in all IIM subgroups also for some TLR4 ligands, endogenous and bacterial HSP60, other than the high-mobility group box 1 (HMGB1. These findings indicate that autophagic processes are active not only in sIBM but also in PM, DM and JDM, probably in response to an exogenous or endogenous 'danger signal'. However, autophagic activation and regulation, and also interaction with the innate immune system, differ in each type of IIM. Better understanding of these differences may lead to new therapies for the different IIM types.

  7. Metabolic signals and innate immune activation in obesity and exercise.

    Science.gov (United States)

    Ringseis, Robert; Eder, Klaus; Mooren, Frank C; Krüger, Karsten

    2015-01-01

    The combination of a sedentary lifestyle and excess energy intake has led to an increased prevalence of obesity which constitutes a major risk factor for several co-morbidities including type 2 diabetes and cardiovascular diseases. Intensive research during the last two decades has revealed that a characteristic feature of obesity linking it to insulin resistance is the presence of chronic low-grade inflammation 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), being elevated in many obese subjects, through activation of pattern recognition receptors thereby leading to stimulation of critical inflammatory signaling cascades, like IκBα kinase/nuclear factor-κB (IKK/NF- κB), endoplasmic reticulum (ER) stress-induced unfolded protein response (UPR) and NOD-like receptor P3 (NLRP3) inflammasome pathway, that interfere with insulin signaling. Exercise is one of the main prescribed interventions in obesity management improving insulin sensitivity and reducing obesity- induced chronic inflammation. This review summarizes current knowledge of the cellular recognition mechanisms for FFAs, the inflammatory signaling pathways triggered by excess FFAs in obesity and the counteractive effects of both acute and chronic exercise on obesity-induced activation of inflammatory signaling pathways. A deeper understanding of the effects of exercise on inflammatory signaling pathways in obesity is useful to optimize preventive and therapeutic strategies to combat the increasing incidence of obesity and its comorbidities. Copyright © 2015 International Society of Exercise and Immunology. All rights reserved.

  8. Trained innate immunity as underlying mechanism for the long-term, nonspecific effects of vaccines

    DEFF Research Database (Denmark)

    Blok, Bastiaan A; Arts, Rob J W; van Crevel, Reinout

    2015-01-01

    An increasing body of evidence shows that the innate immune system has adaptive characteristics that involve a heterologous memory of past insults. Both experimental models and proof-of-principle clinical trials show that innate immune cells, such as monocytes, macrophages, and NK cells, can...... provide protection against certain infections in vaccination models independently of lymphocytes. This process is regulated through epigenetic reprogramming of innate immune cells and has been termed "trained immunity." It has been hypothesized that induction of trained immunity is responsible...... for the protective, nonspecific effects induced by vaccines, such as BCG, measles vaccination, and other whole-microorganism vaccines. In this review, we will present the mechanisms of trained immunity responsible for the long-lasting effects of vaccines on the innate immune system....

  9. Fungal Innate Immunity Induced by Bacterial Microbe-Associated Molecular Patterns (MAMPs

    Directory of Open Access Journals (Sweden)

    Simon Ipcho

    2016-06-01

    Full Text Available Plants and animals detect bacterial presence through Microbe-Associated Molecular Patterns (MAMPs which induce an innate immune response. The field of fungal–bacterial interaction at the molecular level is still in its infancy and little is known about MAMPs and their detection by fungi. Exposing Fusarium graminearum to bacterial MAMPs led to increased fungal membrane hyperpolarization, a putative defense response, and a range of transcriptional responses. The fungus reacted with a different transcript profile to each of the three tested MAMPs, although a core set of genes related to energy generation, transport, amino acid production, secondary metabolism, and especially iron uptake were detected for all three. Half of the genes related to iron uptake were predicted MirA type transporters that potentially take up bacterial siderophores. These quick responses can be viewed as a preparation for further interactions with beneficial or pathogenic bacteria, and constitute a fungal innate immune response with similarities to those of plants and animals.

  10. Role of Interleukin-33 in Innate-Type Immune Cells in Allergy

    Directory of Open Access Journals (Sweden)

    Susumu Nakae

    2013-01-01

    Full Text Available Interleukin-33 (IL-33, a member of the IL-1 cytokine family, is preferentially and constitutively expressed in epithelial cells, and it is especially localized in the cells' nucleus. The nuclear IL-33 is released by necrotic cells after tissue injury and/or trauma, and subsequently provokes local inflammation as an alarmin, like high-mobility group box protein-1 (HMGB-1 and IL-1α. IL-33 mainly activates Th2 cells and such innate-type immune cells as mast cells, basophils, eosinophils and natural helper cells that express IL-33R (a heterodimer of IL-1 receptor-like 1 [IL-1RL1; also called ST2, T1, Der4, fit-1] and IL-1 receptor accessory protein [IL-1RAcP]. That activation causes the cells to produce Th2 cytokines, which contribute to host defense against nematodes. On the other hand, excessive and/or inappropriate production of IL-33 is also considered to be involved in the development of such disorders as allergy. In this review, we summarize current knowledge regarding the pathogenic roles of IL-33 in the development of allergic inflammation by focusing on its effects on innate-type immune cells.

  11. Antagonism of the Phosphatase PP1 by the Measles Virus V Protein Is Required for Innate Immune Escape of MDA5

    NARCIS (Netherlands)

    Davis, Meredith E.; Wang, May K.; Rennick, Linda J.; Full, Florian; Gableske, Sebastian; Mesman, Annelies W.; Gringhuis, Sonja I.; Geijtenbeek, Teunis B. H.; Duprex, W. Paul; Gack, Michaela U.

    2014-01-01

    The cytosolic sensor MDA5 is crucial for antiviral innate immune defense against various RNA viruses including measles virus; as such, many viruses have evolved strategies to antagonize the antiviral activity of MDA5. Here, we show that measles virus escapes MDA5 detection by targeting the

  12. Innate defense regulator peptide 1018 in wound healing and wound infection.

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    Lars Steinstraesser

    Full Text Available Innate defense regulators (IDRs are synthetic immunomodulatory versions of natural host defense peptides (HDP. IDRs mediate protection against bacterial challenge in the absence of direct antimicrobial activity, representing a novel approach to anti-infective and anti-inflammatory therapy. Previously, we reported that IDR-1018 selectively induced chemokine responses and suppressed pro-inflammatory responses. As there has been an increasing appreciation for the ability of HDPs to modulate complex immune processes, including wound healing, we characterized the wound healing activities of IDR-1018 in vitro. Further, we investigated the efficacy of IDR-1018 in diabetic and non-diabetic wound healing models. In all experiments, IDR-1018 was compared to the human HDP LL-37 and HDP-derived wound healing peptide HB-107. IDR-1018 was significantly less cytotoxic in vitro as compared to either LL-37 or HB-107. Furthermore, administration of IDR-1018 resulted in a dose-dependent increase in fibroblast cellular respiration. In vivo, IDR-1018 demonstrated significantly accelerated wound healing in S. aureus infected porcine and non-diabetic but not in diabetic murine wounds. However, no significant differences in bacterial colonization were observed. Our investigation demonstrates that in addition to previously reported immunomodulatory activities IDR-1018 promotes wound healing independent of direct antibacterial activity. Interestingly, these effects were not observed in diabetic wounds. It is anticipated that the wound healing activities of IDR-1018 can be attributed to modulation of host immune pathways that are suppressed in diabetic wounds and provide further evidence of the multiple immunomodulatory activities of IDR-1018.

  13. Immune evasion strategies of ranaviruses and innate immune responses to these emerging pathogens.

    Science.gov (United States)

    Grayfer, Leon; Andino, Francisco De Jesús; Chen, Guangchun; Chinchar, Gregory V; Robert, Jacques

    2012-07-01

    Ranaviruses (RV, Iridoviridae) are large double-stranded DNA viruses that infect fish, amphibians and reptiles. For ecological and commercial reasons, considerable attention has been drawn to the increasing prevalence of ranaviral infections of wild populations and in aquacultural settings. Importantly, RVs appear to be capable of crossing species barriers of numerous poikilotherms, suggesting that these pathogens possess a broad host range and potent immune evasion mechanisms. Indeed, while some of the 95-100 predicted ranavirus genes encode putative evasion proteins (e.g., vIFα, vCARD), roughly two-thirds of them do not share significant sequence identity with known viral or eukaryotic genes. Accordingly, the investigation of ranaviral virulence and immune evasion strategies is promising for elucidating potential antiviral targets. In this regard, recombination-based technologies are being employed to knock out gene candidates in the best-characterized RV member, Frog Virus (FV3). Concurrently, by using animal infection models with extensively characterized immune systems, such as the African clawed frog, Xenopus laevis, it is becoming evident that components of innate immunity are at the forefront of virus-host interactions. For example, cells of the macrophage lineage represent important combatants of RV infections while themselves serving as targets for viral infection, maintenance and possibly dissemination. This review focuses on the recent advances in the understanding of the RV immune evasion strategies with emphasis on the roles of the innate immune system in ranaviral infections.

  14. Innate immune memory: implications for development of pediatric immunomodulatory agents and adjuvanted vaccines

    NARCIS (Netherlands)

    Levy, O.; Netea, M.G.

    2014-01-01

    Unique features of immunity early in life include a distinct immune system particularly reliant on innate immunity, with weak T helper (Th)1-polarizing immune responses, and impaired responses to certain vaccines leading to a heightened susceptibility to infection. To these important aspects, we now

  15. Innate immunity and the sensing of infection, damage and danger in the female genital tract.

    Science.gov (United States)

    Sheldon, Iain Martin; Owens, Siân-Eleri; Turner, Matthew Lloyd

    2017-02-01

    Tissue homeostasis in the female genital tract is challenged by infection, damage, and even physiological events during reproductive cycles. We propose that the evolutionarily ancient system of innate immunity is sufficient to sense and respond to danger in the non-pregnant female genital tract. Innate immunity produces a rapidly inducible, non-specific response when cells sense danger. Here we provide a primer on innate immunity and discuss what is known about how danger signals are sensed in the endometrium and ovary, the impact of inflammatory responses on reproduction, and how endocrinology and innate immunity are integrated. Endometrial epithelial and stromal cells, and ovarian granulosa cells express pattern recognition receptors, similar to cells of the innate immune system. These pattern recognition receptors, such as the Toll-like receptors, bind pathogen-associated or damage-associated molecular patterns. Activation of pattern recognition receptors leads to inflammation, recruitment of immune cells from the peripheral circulation, and phagocytosis. Although the inflammatory response helps maintain or restore endometrial health, there may also be negative consequences for fertility, including perturbation of oocyte competence. The intensity of the inflammatory response reflects the balance between the level of danger and the systems that regulate innate immunity, including the endocrine environment. Understanding innate immunity is important because disease and inappropriate inflammatory responses in the endometrium or ovary cause infertility. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  16. The Innate Immune System in Alzheimer’s Disease

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    Allal Boutajangout

    2013-01-01

    Full Text Available Alzheimer’s disease (AD is the leading cause for dementia in the world. It is characterized by two biochemically distinct types of protein aggregates: amyloid β (Aβ peptide in the forms of parenchymal amyloid plaques and congophilic amyloid angiopathy (CAA and aggregated tau protein in the form of intraneuronal neurofibrillary tangles (NFT. Several risk factors have been discovered that are associated with AD. The most well-known genetic risk factor for late-onset AD is apolipoprotein E4 (ApoE4 (Potter and Wisniewski (2012, and Verghese et al. (2011. Recently, it has been reported by two groups independently that a rare functional variant (R47H of TREM2 is associated with the late-onset risk of AD. TREM2 is expressed on myeloid cells including microglia, macrophages, and dendritic cells, as well as osteoclasts. Microglia are a major part of the innate immune system in the CNS and are also involved in stimulating adaptive immunity. Microglia express several Toll-like receptors (TLRs and are the resident macrophages of the central nervous system (CNS. In this review, we will focus on the recent advances regarding the role of TREM2, as well as the effects of TLRs 4 and 9 on AD.

  17. Innate lymphoid cells and their role in immune response regulation

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    Bibiana Patricia Ruiz-Sánchez

    2017-10-01

    Full Text Available Innate lymphoid cells (ILCs are lymphocytes lacking antigen recognition receptors and become activated in response to cytokines and through microbe-associated molecular pattern (MAMP receptors. ILCs are found mainly in mucosal tissues and participate in the immune response against infections and in chronic inflammatory conditions. ILCs are divided in ILC-1, ILC-2 and ILC-3, and these cells have analogue functions to those of immune adaptive response lymphocytes Th1, Th2 and Th17. ILC-1 express T-bet, produce IFNγ, protect against infections with intracellular microorganisms and are related to inflammatory bowel disease immunopathology. ILC-2 express GATA3, produce IL-4, IL-5, IL-13 and amphiregulin, protect against parasitic infections and related to allergy and obesity immunopathology. ILC-3 express ROR(γt, produce IL-17 and IL-22, protect against fungal infections and contribute to tolerance to intestinal microbiota and intestinal repair. They are related to inflammatory bowel disease and psoriasis immunopathology. In general terms, ILCs maintain homeostasis and coadjuvate in the protection against infections.

  18. Hiding the evidence: two strategies for innate immune evasion by hemorrhagic fever viruses.

    Science.gov (United States)

    Hastie, Kathryn M; Bale, Shridhar; Kimberlin, Christopher R; Saphire, Erica Ollmann

    2012-04-01

    The innate immune system is one of the first lines of defense against invading pathogens. Pathogens have, in turn, evolved different strategies to counteract these responses. Recent studies have illuminated how the hemorrhagic fever viruses Ebola and Lassa fever prevent host sensing of double-stranded RNA (dsRNA), a key hallmark of viral infection. The ebolavirus protein VP35 adopts a unique bimodal configuration to mask key cellular recognition sites on dsRNA. Conversely, the Lassa fever virus nucleoprotein actually digests the dsRNA signature. Collectively, these structural and functional studies shed new light on the mechanisms of pathogenesis of these viruses and provide new targets for therapeutic intervention. Copyright © 2012. Published by Elsevier B.V.

  19. Soluble CD14 in human breast milk and its role in innate immune responses.

    Science.gov (United States)

    Vidal, K; Labéta, M O; Schiffrin, E J; Donnet-Hughes, A

    2001-10-01

    Immune factors secreted in milk are important for health in the neonatal gut. We have detected the bacterial pattern recognition receptor, soluble CD14 (sCD14) in human breast milk at different times during lactation. The molecule occurs in a single form in milk, in contrast to human serum, in which there are two isoforms. Produced by mammary epithelial cells, milk sCD14 mediates secretion of innate immune response molecules such as interleukin-8, tumor necrosis factor-alpha, and epithelial neutrophil activator-78 by CD14-negative intestinal epithelial cells exposed to lipopolysaccharide (LPS) or bacteria. Although present at low concentrations in milk, LPS-binding protein may be implicated in the biological effects observed. Our findings support the premise that milk sCD14 acts as a 'sentinel' molecule and immune modulator in homeostasis and in the defense of the neonatal intestine. In so doing, it may prevent the immune and inflammatory conditions of the gut to which non-breastfed infants are predisposed.

  20. DMPD: Glucocorticoids and the innate immune system: crosstalk with the toll-likereceptor signaling network. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17576036 Glucocorticoids and the innate immune system: crosstalk with the toll-like...07 May 13. (.png) (.svg) (.html) (.csml) Show Glucocorticoids and the innate immune system: crosstalk with t...nd the innate immune system: crosstalk with the toll-likereceptor signaling network. Authors Chinenov Y, Rog

  1. DMPD: Nod1 and Nod2 in innate immunity and human inflammatory disorders. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18031249 Nod1 and Nod2 in innate immunity and human inflammatory disorders. Le Bour...w Nod1 and Nod2 in innate immunity and human inflammatory disorders. PubmedID 18031249 Title Nod1 and Nod2 in innate immunity and hum...an inflammatory disorders. Authors Le Bourhis L, Benko S

  2. DMPD: Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18406369 Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins...svg) (.html) (.csml) Show Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins. ...PubmedID 18406369 Title Regulation of innate immunity by suppressor of cytokine signaling (SOCS)proteins

  3. DMPD: Innate immune sensing of pathogens and danger signals by cell surface Toll-likereceptors. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17275324 Innate immune sensing of pathogens and danger signals by cell surface Toll... Show Innate immune sensing of pathogens and danger signals by cell surface Toll-likereceptors. PubmedID 172...75324 Title Innate immune sensing of pathogens and danger signals by cell surface

  4. Evasion of adaptive and innate immune response mechanisms by γ-herpesviruses

    Science.gov (United States)

    Feng, Pinghui; Moses, Ashlee; Früh, Klaus

    2015-01-01

    γ-Herpesviral immune evasion mechanisms are optimized to support the acute, lytic and the longterm, latent phase of infection. During acute infection, specific immune modulatory proteins limit, but also exploit, the antiviral activities of cell intrinsic innate immune responses as well as those of innate and adaptive immune cells. During latent infection, a restricted gene expression program limits immune targeting and cis-acting mechanisms to reduce the antigen presentation as well as antigenicity of latency-associated proteins. Here, we will review recent progress in our understanding of γ-herpesviral immune evasion strategies. PMID:23735334

  5. Induced ER-chaperones regulate a novel receptor-like kinase to mediate a viral innate immune response

    Science.gov (United States)

    Caplan, Jeffrey L.; Zhu, Xiaohong; Mamillapalli, Padmavathi; Marathe, Rajendra; Anandalakshmi, Radhamani; Dinesh-Kumar, S. P.

    2009-01-01

    Summary The plant innate immune response requires a rapid, global reprogramming of cellular processes. Here we employed two complementary proteomic methods, two-dimensional differential in-gel electrophoresis (2D-DIGE) and iTRAQ, to identify differentially regulated proteins early during a defense response. Besides defense-related proteins, the constituents of the largest category of up-regulated proteins were cytoplasmic- and endoplasmic reticulum (ER)-residing molecular chaperones. Silencing of ER-resident protein disulfide isomerases, NbERp57 and NbP5, and the calreticulins, NbCRT2 and NbCRT3, lead to a partial loss of N immune receptor-mediated defense against Tobacco mosaic virus (TMV). Furthermore, NbCRT2 and NbCRT3 are required for the expression of a novel induced receptor-like kinase (IRK). IRK is a plasma membrane-localized protein required for the N-mediated hypersensitive response programmed cell death (HR-PCD) and resistance to TMV. These data support a model in which ER-resident chaperones are required for the accumulation of membrane bound or secreted proteins that are necessary for innate immunity. PMID:19917500

  6. Evolutionary perspectives on innate immunity from the study of Caenorhabditis elegans.

    Science.gov (United States)

    Kim, Dennis H; Ausubel, Frederick M

    2005-02-01

    Genetic and functional genomic approaches have begun to define the molecular determinants of pathogen resistance in Caenorhabditis elegans. Conserved signal transduction components are required for pathogen resistance, including a Toll/IL-1 receptor domain adaptor protein that functions upstream of a conserved p38 MAP kinase pathway. We suggest that this pathway is an ancestral innate immune signaling pathway present in the common ancestor of nematodes, arthropods and vertebrates, which is likely to predate the involvement of canonical Toll signaling pathways in innate immunity. We anticipate that the study of pathogen resistance in C. elegans will continue to provide evolutionary and mechanistic insights into the signal transduction and physiology of innate immunity.

  7. The G protein-coupled receptor FSHR-1 is required for the Caenorhabditis elegans innate immune response.

    Science.gov (United States)

    Powell, Jennifer R; Kim, Dennis H; Ausubel, Frederick M

    2009-02-24

    Innate immunity is an ancient defense system used by both vertebrates and invertebrates. Previously characterized innate immune responses in plants and animals are triggered by detection of pathogens using specific receptors, which typically use a leucine-rich repeat (LRR) domain to bind molecular patterns associated with infection. The nematode Caenorhabditis elegans uses defense pathways conserved with vertebrates; however, the mechanism by which C. elegans detects pathogens is unknown. We screened all LRR-containing transmembrane receptors in C. elegans and identified the G protein-coupled receptor FSHR-1 as an important component of the C. elegans immune response to Gram-negative and Gram-positive bacterial pathogens. FSHR-1 acts in the C. elegans intestine, the primary site of exposure to ingested pathogens. FSHR-1 signals in parallel to the known p38 MAPK pathway but converges to regulate the transcriptional induction of an overlapping but nonidentical set of antimicrobial effectors. FSHR-1 may act generally to boost the nematode immune response, or it may function as a pathogen receptor.

  8. Targeting innate immunity to downmodulate adaptive immunity and reverse type 1 diabetes

    Directory of Open Access Journals (Sweden)

    Itoh A

    2017-05-01

    Full Text Available Arata Itoh, William M Ridgway Division of Immunology, Allergy and Rheumatology, University of Cincinnati College of Medicine, Cincinnati, OH, USA Abstract: Type 1 diabetes (T1D is characterized by specific destruction of pancreatic insulin-producing beta cells accompanied by evidence of beta-cell-directed autoimmunity such as autoreactive T cells and islet autoantibodies (IAAs. Currently, T1D cannot be prevented or reversed in humans. T1D is easy to prevent in the nonobese diabetic (NOD spontaneous mouse model but reversing new-onset T1D in mice is more difficult. Since the discovery of the T-cell receptor in the 1980s and the subsequent identification of autoreactive T cells directed toward beta-cell antigens (eg, insulin, glutamic acid decarboxylase, the dream of antigen-specific immunotherapy has dominated the field with its promise of specificity and limited side effects. While such approaches have worked in the NOD mouse, however, dozens of human trials have failed. Broader immunosuppressive approaches (originally cyclosporine, subsequently anti-CD3 antibody have shown partial successes (e.g., prolonged C peptide preservation but no major therapeutic efficacy or disease reversal. Human prevention trials have failed, despite the ease of such approaches in the NOD mouse. In the past 50 years, the incidence of T1D has increased dramatically, and one explanation is the “hygiene hypothesis”, which suggests that decreased exposure of the innate immune system to environmental immune stimulants (e.g., bacterial products such as Toll-like receptor (TLR 4-stimulating lipopolysaccharide [LPS] dramatically affects the adaptive immune system and increases subsequent autoimmunity. We have tested the role of innate immunity in autoimmune T1D by treating acute-onset T1D in NOD mice with anti-TLR4/MD-2 agonistic antibodies and have shown a high rate of disease reversal. The TLR4 antibodies do not directly stimulate T cells but induce tolerogenic

  9. Regulation of aeroallergen immunity by the innate immune system: laboratory evidence for a new paradigm.

    Science.gov (United States)

    Horner, Anthony A

    2010-01-01

    Over the last decade, it has become increasingly clear that innate responses to microbes are mediated largely by toll-like receptors (TLRs), which recognize a diverse family of molecules produced by viruses, bacteria and fungi. This article will present evidence that TLRs also play a dominant role in innate responses to non-infectious immunostimulatory materials present in house dust extracts (HDEs) and the living environments they represent. However, our investigations challenge the commonly held view that microbial products in ambient air protect against the allergic march by promoting protective Th1 biased responses to inspired aeroallergens. Instead, all HDEs studied to date have preferentially promoted the development of Th2 biased airway hypersensitivities when used as adjuvants for intranasal (i.n.) vaccination. In contrast, daily low dose i.n. HDE delivery was found to promote the development of aeroallergen tolerance. This article will review these experimental findings as evidence to propose a new paradigm by which airborne TLR ligands and other stimulants of innate immunity may influence aeroallergen specific immunity and the genesis of allergic respiratory diseases.

  10. Age-dependent changes in innate immune phenotype and function in rhesus macaques (Macaca mulatta

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    Mark Asquith

    2012-06-01

    Full Text Available Aged individuals are more susceptible to infections due to a general decline in immune function broadly referred to as immune senescence. While age-related changes in the adaptive immune system are well documented, aging of the innate immune system remains less well understood, particularly in nonhuman primates. A more robust understanding of age-related changes in innate immune function would provide mechanistic insight into the increased susceptibility of the elderly to infection. Rhesus macaques have proved a critical translational model for aging research, and present a unique opportunity to dissect age-dependent modulation of the innate immune system. We examined age-related changes in: (i innate immune cell frequencies; (ii expression of pattern recognition receptors (PRRs and innate signaling molecules; (iii cytokine responses of monocytes and dendritic cells (DC following stimulation with PRR agonists; and (iv plasma cytokine levels in this model. We found marked changes in both the phenotype and function of innate immune cells. This included an age-associated increased frequency of myeloid DC (mDC. Moreover, we found toll-like receptor (TLR agonists lipopolysaccharide (TLR4, fibroblast stimulating ligand-1 (TLR2/6, and ODN2006 (TLR7/9 induced reduced cytokine responses in aged mDC. Interestingly, with the exception of the monocyte-derived TNFα response to LPS, which increased with age, TNFα, IL-6, and IFNα responses declined with age. We also found that TLR4, TLR5, and innate negative regulator, sterile alpha and TIR motif containing protein (SARM, were all expressed at lower levels in young animals. By contrast, absent in melanoma 2 and retinoic acid-inducible gene I expression was lowest in aged animals. Together, these observations indicate that several parameters of innate immunity are significantly modulated by age and contribute to differential immune function in aged macaques.

  11. Duox2-induced innate immune responses in the respiratory epithelium and intranasal delivery of Duox2 DNA using polymer that mediates immunization.

    Science.gov (United States)

    Jeon, Yung Jin; Kim, Hyun Jik

    2018-05-01

    Respiratory mucosa especially nasal epithelium is well known as the first-line barrier of air-borne pathogens. High levels of reactive oxygen species (ROS) are detected in in vitro cultured human epithelial cells and in vivo lung. With identification of NADPH oxidase (Nox) system of respiratory epithelium, the antimicrobial role of ROS has been studied. Duox2 is the most abundant Nox isoform and produces the regulated amount of ROS in respiratory epithelium. Duox2-derived ROS are involved in antiviral innate immune responses but more studies are needed to verify the mechanism. In respiratory epithelium, Duox2-derived ROS is critical for recognition of virus through families retinoic acid-inducible gene-I (RIG-I) and melanoma differentiation-associated protein 5 (MDA5) at the early stage of antiviral innate immune responses. Various secreted interferons (IFNs) play essential roles for antiviral host defense by downstream cell signaling, and transcription of IFN-stimulated genes is started to suppress viral replication. Type I and type III IFNs are verified more responsible for influenza A virus (IAV) infection in respiratory epithelium and Duox2 is required to regulate IFN-related immune responses. Transient overexpression of Duox2 using cationic polymer polyethylenimine (PEI) induces secretion of type I and type III IFNs and significantly attenuated IAV replication in respiratory epithelium. Here, we discuss Duox2-mediated antiviral innate immune responses and the role of Duox2 as a mucosal vaccine to resist respiratory viral infection.

  12. Mechanisms for eco-immunity in a changing enviroment: how does the coral innate immune system contend with climate change?

    Science.gov (United States)

    Traylor-Knowles, N. G.

    2016-02-01

    Innate immunity plays a central role in maintaining homeostasis, and within the context of impending climate change scenarios, understanding how this system works is critical. However, the actual mechanisms involved in the evolution of the innate immune system are largely unknown. Cnidaria (including corals, sea anemones and jellyfish) are well suited for studying the fundamental functions of innate immunity because they share a common ancestor with bilaterians. This study will highlight the transcriptomic changes during a heat shock in the coral Acropora hyacinthus of American Samoa, examining the temporal changes, every half an hour for 5 hours. We hypothesize that genes involved in innate immunity, and extracellular matrix maintenance will be key components to the heat stress response. This presentation will highlight the novel role of the tumor necrosis factor receptor gene family as a responder to heat stress and present future directions for this developing field in coral reef research.

  13. Mechanisms by which Porphyromonas gingivalis evades innate immunity.

    Directory of Open Access Journals (Sweden)

    Kaveh Abdi

    Full Text Available The oral cavity is home to unique resident microbial communities whose interactions with host immunity are less frequently studied than those of the intestinal microbiome. We examined the stimulatory capacity and the interactions of two oral bacteria, Porphyromonas gingivalis (P. gingivalis and Fusobacterium nucleatum (F. nucleatum, on Dendritic Cell (DC activation, comparing them to the effects of the well-studied intestinal microbe Escherichia coli (E. coli. Unlike F. nucleatum and E. coli, P. gingivalis failed to activate DCs, and in fact silenced DC responses induced by F. nucleatum or E. coli. We identified a variant strain of P. gingivalis (W50 that lacked this immunomodulatory activity. Using biochemical approaches and whole genome sequencing to compare the two substrains, we found a point mutation in the hagA gene. This protein is though to be involved in the alteration of the PorSS/gingipain pathway, which regulates protein secretion into the extracellular environment. A proteomic comparison of the secreted products of the two substrains revealed enzymatic differences corresponding to this phenotype. We found that P. gingivalis secretes gingipain(s that inactivate several key proinflammatory mediators made by DCs and/or T cells, but spare Interleukin-1 (IL-1 and GM-CSF, which can cause capillary leaks that serve as a source of the heme that P. gingivalis requires for its survival, and GM-CSF, which can cause epithelial-cell growth. Taken together, our results suggest that P. gingivalis has evolved potent mechanisms to modulate its virulence factors and dampen the innate immune response by selectively inactivating most proinflammatory cytokines.

  14. The role of innate immunity in the development of chronic rhinosinusitis and perspectives of its conservative management

    Directory of Open Access Journals (Sweden)

    V. I. Egorov

    2016-01-01

    Full Text Available Chronic rhinosinusitis (CRS is a heterogeneous, multifactorial disease of unknown etiology, with an underlying deficient immune response to infectious and other triggers, leading to their incomplete elimination and persistence of inflammation. Development of CRS is made possible by a deficient response of the innate immunity of nasal and paranasal sinus mucosa. The main factors of non-specific defense system of nasal and paranasal mucosa are the function of cell junctions between epithelial cells, mucociliary clearance, pattern recognition receptors (PRRs, antigen presenting cells, and phagocytosis. The multirowed ciliate epithelium of nasal and paranasal sinus mucosa is covered by a thick layer of mucus containing more than 200 proteins. Changes in the qualitative composition of the nasal mucus in CRS manifests in overexpression of the main mucins MUC5AC and MUC5B and decreased synthesis of lactoferrin and lyzocin. Ciliary dyskinesia or abnormalities in their microstructure lead to decreased efficacy of mucociliary clearance. Diminished expression of proteins of tight junctions (TJ ZO-1 and occluding results in decreased density of intercellular contacts and increased permeability of epithelial barrier. In addition, CRS is characterized by deficient Tolllike receptors (TLR 9, 2 and 4, as well as increased counts of M2 macrophages in the mucosa. This results in suppressed phagocytosis and antimicrobial mucosal defense. Lower levels of STAT3 protein causes an imbalanced reaction of innate and adaptive immune response and disordered reparation processes. With abnormal functioning of all the above mentioned mechanisms, no immune elimination of infectious agents can take place, with increased susceptibility to viral and bacterial infections of the upper respiratory tract. This opens the door to development of CRS, including that with polyps. Investigation of the innate immunity factors would allow for predicting of inflammation in a given patient

  15. Another Armament in Gut Immunity: Lymphotoxin-Mediated Crosstalk between Innate Lymphoid and Dendritic Cells

    NARCIS (Netherlands)

    Spits, H.

    2011-01-01

    Innate lymphoid cells (ILCs) are novel players in innate immunity. Tumanov et al. (Tumanov et al., 2011) demonstrate that crosstalk between ILCs and dendritic cells involving membrane-bound lymphotoxin in ILCs and its receptor is critical for protection against colitogenic bacteria

  16. Meningococcal outer membrane vesicle composition-dependent activation of the innate immune response

    NARCIS (Netherlands)

    Zariri, Afshin; Beskers, Joep; van de Waterbeemd, Bas; Hamstra, Hendrik Jan; Bindels, Tim H E; van Riet, Elly; van Putten, Jos P M; van der Ley, Peter

    2016-01-01

    Meningococcal outer membrane vesicles (OMVs) have been extensively investigated and successfully implemented as vaccines. They contain pathogen associated molecular patterns including lipopolysaccharide (LPS), capable of triggering innate immunity. However, Neisseria meningitidis contains an

  17. Silencing the alarms: innate immune antagonism by rotavirus NSP1 and VP3

    Science.gov (United States)

    Morelli, Marco; Ogden, Kristen M.; Patton, John T.

    2016-01-01

    The innate immune response involves a broad array of pathogen sensors that stimulate the production of interferons (IFN) to induce an antiviral state. Rotavirus, a significant cause of childhood gastroenteritis and a member of the Reoviridae family of segmented, double-stranded RNA viruses, encodes at least two direct antagonists of host innate immunity: NSP1 and VP3. NSP1, a putative E3 ubiquitin ligase, mediates the degradation of cellular factors involved in both IFN induction and downstream signaling. VP3, the viral capping enzyme, utilizes a 2H-phosphodiesterase domain to prevent activation of the cellular oligoadenylate synthase (OAS)-RNase L pathway. Computational, molecular, and biochemical studies have provided key insights into the structural and mechanistic basis of innate immune antagonism by NSP1 and VP3 of group A rotaviruses (RVA). Future studies with non-RVA isolates will be essential to understand how other RV species evade host innate immune responses. PMID:25724417

  18. The Basic Immune Simulator: An agent-based model to study the interactions between innate and adaptive immunity

    Directory of Open Access Journals (Sweden)

    Orosz Charles G

    2007-09-01

    Full Text Available Abstract Background We introduce the Basic Immune Simulator (BIS, an agent-based model created to study the interactions between the cells of the innate and adaptive immune system. Innate immunity, the initial host response to a pathogen, generally precedes adaptive immunity, which generates immune memory for an antigen. The BIS simulates basic cell types, mediators and antibodies, and consists of three virtual spaces representing parenchymal tissue, secondary lymphoid tissue and the lymphatic/humoral circulation. The BIS includes a Graphical User Interface (GUI to facilitate its use as an educational and research tool. Results The BIS was used to qualitatively examine the innate and adaptive interactions of the immune response to a viral infection. Calibration was accomplished via a parameter sweep of initial agent population size, and comparison of simulation patterns to those reported in the basic science literature. The BIS demonstrated that the degree of the initial innate response was a crucial determinant for an appropriate adaptive response. Deficiency or excess in innate immunity resulted in excessive proliferation of adaptive immune cells. Deficiency in any of the immune system components increased the probability of failure to clear the simulated viral infection. Conclusion The behavior of the BIS matches both normal and pathological behavior patterns in a generic viral infection scenario. Thus, the BIS effectively translates mechanistic cellular and molecular knowledge regarding the innate and adaptive immune response and reproduces the immune system's complex behavioral patterns. The BIS can be used both as an educational tool to demonstrate the emergence of these patterns and as a research tool to systematically identify potential targets for more effective treatment strategies for diseases processes including hypersensitivity reactions (allergies, asthma, autoimmunity and cancer. We believe that the BIS can be a useful addition to

  19. Innate immune genes including a mucin-like gene, mul-1, induced by ionizing radiation in Caenorhabditis elegans.

    Science.gov (United States)

    Kimura, Takafumi; Takanami, Takako; Sakashita, Tetsuya; Wada, Seiichi; Kobayashi, Yasuhiko; Higashitani, Atsushi

    2012-10-01

    The effect of radiation on the intestine has been studied for more than one hundred years. It remains unclear, however, whether this organ uses specific defensive mechanisms against ionizing radiation. The infection with Pseudomonas aeruginosa (PA14) in Caenorhabditis elegans induces up-regulation of innate immune response genes. Here, we found that exposure to ionizing radiation also induces certain innate immune response genes such as F49F1.6 (termed mul-1), clec-4, clec-67, lys-1 and lys-2 in the intestine. Moreover, pre-treatment with ionizing radiation before seeding on PA14 lawn plate significantly increased survival rate in the nematode. We also studied transcription pathway of the mul-1 in response to ionizing radiation. Induction of mul-1 gene was highly dependent on the ELT-2 transcription factor and p38 MAPK. Moreover, the insulin/IGF-1 signal pathway works to enhance induction of this gene. The mul-1 gene showed a different induction pattern from the DNA damage response gene, ced-13, which implies that the expression of this gene might be triggered as an indirect effect of radiation. Silencing of the mul-1 gene led to growth retardation after treatment with ionizing radiation. We describe the cross-tolerance between the response to radiation exposure and the innate immune system.

  20. Experimental in vitro and in vivo systems for studying the innate immune response during dengue virus infections.

    Science.gov (United States)

    Kitab, Bouchra; Kohara, Michinori; Tsukiyama-Kohara, Kyoko

    2018-03-08

    Dengue is the most prevalent arboviral disease in humans and leads to significant morbidity and socioeconomic burden in tropical and subtropical areas. Dengue is caused by infection with any of the four closely related serotypes of dengue virus (DENV1-4) and usually manifests as a mild febrile illness, but may develop into fatal dengue hemorrhagic fever and shock syndrome. There are no specific antiviral therapies against dengue because understanding of DENV biology is limited. A tetravalent chimeric dengue vaccine, Dengvaxia, has finally been licensed for use, but its efficacy was significantly lower against DENV-2 infections and in dengue-naïve individuals. The identification of mechanisms underlying the interactions between DENV and immune responses will help to determine efficient therapeutic and preventive options. It has been well established how the innate immune system responds to DENV infection and how DENV overcomes innate antiviral defenses, however further progress in this field remains hampered by the absence of appropriate experimental dengue models. Herein, we review the available in vitro and in vivo approaches to study the innate immune responses to DENV.

  1. MicroRNAs, Innate Immunity and Ventricular Rupture in Human Myocardial Infarction

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    Nina Zidar

    2011-01-01

    Full Text Available MicroRNAs are non-coding RNAs, functionioning as post-transcriptional regulators of gene expression. Some microRNAs have been demonstrated to play a role in regulation of innate immunity. After myocardial infarction (MI, innate immunity is activated leading to an acute inflammatory reaction. There is evidence that an intense inflammatory reaction might contribute to the development of ventricular rupture (VR after MI.

  2. Abiotic elicitors mediated elicitation of innate immunity in tomato: an ex vivo comparison.

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    Chakraborty, Nilanjan; Ghosh, Sudeepa; Chandra, Swarnendu; Sengupta, Sarban; Acharya, Krishnendu

    2016-07-01

    Improvement of the host resistance by using hazard free chemical elicitors is emerging as an alternative approach in the field of plant disease management. In our present work, we have screened the efficacy and possible mechanism of abiogenic elicitors like Dipotassium hydrogen orthophosphate ( K 2 HPO 4 ), Oxalic acid (OA), Isonicotinic acid (INA), Salicylic acid (SA), Acetylsalicylate (AS), Arachidonic acid (AA) and Calcium chloride (CaCl 2 ) to stimulate innate immune responses in Lycopersicum esculentum Mill. Excised tomato leaves, treated with elicitors at three different concentrations, were found to stimulate defense and antioxidative enzymes, total phenol and flavonoid content after 24 h of incubation. CaCl 2 (0.5 %) followed by INA (2.5 mM) were found most effective in activation of all such defense molecules in tomato leaves. Furthermore, nitric oxide (NO), a key gaseous mediator in plant defense signaling, was also measured after subsequent elicitor application. Higher doses of elicitors showed an elevated level of reactive oxygen species (ROS) generation, enhanced lipid peroxidation rate and proline content, which indicates the extent of abiotic stress generation on the leaves. However, ROS production, lipid peroxidation rate and proline concentration remain significantly reduced as a result of CaCl 2 (0.5 %) and INA (2.5 mM) application. A sharp increase of total chlorophyll content was also recorded due to treatment of CaCl 2 (0.5 %). These results demonstrate the effects of different abiogenic elicitors to regulate the production of defense molecules. Results also suggest that among all such chemicals, CaCl 2 (0.5 %) and INA (2.5 mM) can be used as a potential elicitor in organic farming of tomato.

  3. Bruton’s Tyrosine Kinase: An Emerging Key Player in Innate Immunity

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    Alexander N. R. Weber

    2017-11-01

    Full Text Available Bruton’s tyrosine kinase (BTK was initially discovered as a critical mediator of B cell receptor signaling in the development and functioning of adaptive immunity. Growing evidence also suggests multiple roles for BTK in mononuclear cells of the innate immune system, especially in dendritic cells and macrophages. For example, BTK has been shown to function in Toll-like receptor-mediated recognition of infectious agents, cellular maturation and recruitment processes, and Fc receptor signaling. Most recently, BTK was additionally identified as a direct regulator of a key innate inflammatory machinery, the NLRP3 inflammasome. BTK has thus attracted interest not only for gaining a more thorough basic understanding of the human innate immune system but also as a target to therapeutically modulate innate immunity. We here review the latest developments on the role of BTK in mononuclear innate immune cells in mouse versus man, with specific emphasis on the sensing of infectious agents and the induction of inflammation. Therapeutic implications for modulating innate immunity and critical open questions are also discussed.

  4. The evolutionarily conserved mediator subunit MDT-15/MED15 links protective innate immune responses and xenobiotic detoxification.

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    Read Pukkila-Worley

    2014-05-01

    Full Text Available Metazoans protect themselves from environmental toxins and virulent pathogens through detoxification and immune responses. We previously identified a small molecule xenobiotic toxin that extends survival of Caenorhabditis elegans infected with human bacterial pathogens by activating the conserved p38 MAP kinase PMK-1 host defense pathway. Here we investigate the cellular mechanisms that couple activation of a detoxification response to innate immunity. From an RNAi screen of 1,420 genes expressed in the C. elegans intestine, we identified the conserved Mediator subunit MDT-15/MED15 and 28 other gene inactivations that abrogate the induction of PMK-1-dependent immune effectors by this small molecule. We demonstrate that MDT-15/MED15 is required for the xenobiotic-induced expression of p38 MAP kinase PMK-1-dependent immune genes and protection from Pseudomonas aeruginosa infection. We also show that MDT-15 controls the induction of detoxification genes and functions to protect the host from bacteria-derived phenazine toxins. These data define a central role for MDT-15/MED15 in the coordination of xenobiotic detoxification and innate immune responses.

  5. The evolutionarily conserved mediator subunit MDT-15/MED15 links protective innate immune responses and xenobiotic detoxification.

    Science.gov (United States)

    Pukkila-Worley, Read; Feinbaum, Rhonda L; McEwan, Deborah L; Conery, Annie L; Ausubel, Frederick M

    2014-05-01

    Metazoans protect themselves from environmental toxins and virulent pathogens through detoxification and immune responses. We previously identified a small molecule xenobiotic toxin that extends survival of Caenorhabditis elegans infected with human bacterial pathogens by activating the conserved p38 MAP kinase PMK-1 host defense pathway. Here we investigate the cellular mechanisms that couple activation of a detoxification response to innate immunity. From an RNAi screen of 1,420 genes expressed in the C. elegans intestine, we identified the conserved Mediator subunit MDT-15/MED15 and 28 other gene inactivations that abrogate the induction of PMK-1-dependent immune effectors by this small molecule. We demonstrate that MDT-15/MED15 is required for the xenobiotic-induced expression of p38 MAP kinase PMK-1-dependent immune genes and protection from Pseudomonas aeruginosa infection. We also show that MDT-15 controls the induction of detoxification genes and functions to protect the host from bacteria-derived phenazine toxins. These data define a central role for MDT-15/MED15 in the coordination of xenobiotic detoxification and innate immune responses.

  6. 'Omics investigations of HIV and SIV pathogenesis and innate immunity.

    Science.gov (United States)

    Palermo, Robert E; Fuller, Deborah H

    2013-01-01

    investigations as applied to understanding of HIV pathogenesis and innate immunity, drawing from our own research as well as the literature examples that utilized in vitro cell-based models or studies in nonhuman primates. We will also discuss the potential for systems biology to help guide strategies for HIV vaccines that offer significant protection by either preventing acquisition or strongly suppressing viral replication levels post-infection.

  7. Cyclic GMP-AMP as an Endogenous Second Messenger in Innate Immune Signaling by Cytosolic DNA.

    Science.gov (United States)

    Kato, Kazuki; Omura, Hiroki; Ishitani, Ryuichiro; Nureki, Osamu

    2017-06-20

    The innate immune system functions as the first line of defense against invading bacteria and viruses. In this context, the cGAS/STING [cyclic guanosine monophosphate (GMP)-adenosine monophosphate (AMP) synthase/STING] signaling axis perceives the nonself DNA associated with bacterial and viral infections, as well as the leakage of self DNA by cellular dysfunction and stresses, to elicit the host's immune responses. In this pathway, the noncanonical cyclic dinucleotide 2',3'-cyclic GMP-AMP (2',3'-cGAMP) functions as a second messenger for signal transduction: 2',3'-cGAMP is produced by the enzyme cGAS upon its recognition of double-stranded DNA, and then the 2',3'-cGAMP is recognized by the receptor STING to induce the phosphorylation of downstream factors, including TBK1 (TANK binding kinase 1) and IRF3 (interferon regulatory factor 3). Numerous crystal structures of the components of this cGAS/STING signaling axis have been reported and these clarify the structural basis for their signal transduction mechanisms. In this review, we summarize recent progress made in the structural dissection of this signaling pathway and indicate possible directions of forthcoming research.

  8. Adenylate Cyclases of Trypanosoma brucei, Environmental Sensors and Controllers of Host Innate Immune Response.

    Science.gov (United States)

    Salmon, Didier

    2018-04-25

    Trypanosoma brucei , etiological agent of Sleeping Sickness in Africa, is the prototype of African trypanosomes, protozoan extracellular flagellate parasites transmitted by saliva ( Salivaria ). In these parasites the molecular controls of the cell cycle and environmental sensing are elaborate and concentrated at the flagellum. Genomic analyses suggest that these parasites appear to differ considerably from the host in signaling mechanisms, with the exception of receptor-type adenylate cyclases (AC) that are topologically similar to receptor-type guanylate cyclase (GC) of higher eukaryotes but control a new class of cAMP targets of unknown function, the cAMP response proteins (CARPs), rather than the classical protein kinase A cAMP effector (PKA). T. brucei possesses a large polymorphic family of ACs, mainly associated with the flagellar membrane, and these are involved in inhibition of the innate immune response of the host prior to the massive release of immunomodulatory factors at the first peak of parasitemia. Recent evidence suggests that in T. brucei several insect-specific AC isoforms are involved in social motility, whereas only a few AC isoforms are involved in cytokinesis control of bloodstream forms, attesting that a complex signaling pathway is required for environmental sensing. In this review, after a general update on cAMP signaling pathway and the multiple roles of cAMP, I summarize the existing knowledge of the mechanisms by which pathogenic microorganisms modulate cAMP levels to escape immune defense.

  9. Adenylate Cyclases of Trypanosoma brucei, Environmental Sensors and Controllers of Host Innate Immune Response

    Directory of Open Access Journals (Sweden)

    Didier Salmon

    2018-04-01

    Full Text Available Trypanosoma brucei, etiological agent of Sleeping Sickness in Africa, is the prototype of African trypanosomes, protozoan extracellular flagellate parasites transmitted by saliva (Salivaria. In these parasites the molecular controls of the cell cycle and environmental sensing are elaborate and concentrated at the flagellum. Genomic analyses suggest that these parasites appear to differ considerably from the host in signaling mechanisms, with the exception of receptor-type adenylate cyclases (AC that are topologically similar to receptor-type guanylate cyclase (GC of higher eukaryotes but control a new class of cAMP targets of unknown function, the cAMP response proteins (CARPs, rather than the classical protein kinase A cAMP effector (PKA. T. brucei possesses a large polymorphic family of ACs, mainly associated with the flagellar membrane, and these are involved in inhibition of the innate immune response of the host prior to the massive release of immunomodulatory factors at the first peak of parasitemia. Recent evidence suggests that in T. brucei several insect-specific AC isoforms are involved in social motility, whereas only a few AC isoforms are involved in cytokinesis control of bloodstream forms, attesting that a complex signaling pathway is required for environmental sensing. In this review, after a general update on cAMP signaling pathway and the multiple roles of cAMP, I summarize the existing knowledge of the mechanisms by which pathogenic microorganisms modulate cAMP levels to escape immune defense.

  10. Wallerian degeneration: the innate-immune response to traumatic nerve injury

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    Rotshenker Shlomo

    2011-08-01

    Full Text Available Abstract Traumatic injury to peripheral nerves results in the loss of neural functions. Recovery by regeneration depends on the cellular and molecular events of Wallerian degeneration that injury induces distal to the lesion site, the domain through which severed axons regenerate back to their target tissues. Innate-immunity is central to Wallerian degeneration since innate-immune cells, functions and molecules that are produced by immune and non-immune cells are involved. The innate-immune response helps to turn the peripheral nerve tissue into an environment that supports regeneration by removing inhibitory myelin and by upregulating neurotrophic properties. The characteristics of an efficient innate-immune response are rapid onset and conclusion, and the orchestrated interplay between Schwann cells, fibroblasts, macrophages, endothelial cells, and molecules they produce. Wallerian degeneration serves as a prelude for successful repair when these requirements are met. In contrast, functional recovery is poor when injury fails to produce the efficient innate-immune response of Wallerian degeneration.

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

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    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.

  12. Adenovirus Vector-Derived VA-RNA-Mediated Innate Immune Responses

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    Hiroyuki Mizuguchi

    2011-07-01

    Full Text Available The major limitation of the clinical use of replication-incompetent adenovirus (Ad vectors is the interference by innate immune responses, including induction of inflammatory cytokines and interferons (IFN, following in vivo application of Ad vectors. Ad vector-induced production of inflammatory cytokines and IFNs also results in severe organ damage and efficient induction of acquired immune responses against Ad proteins and transgene products. Ad vector-induced innate immune responses are triggered by the recognition of Ad components by pattern recognition receptors (PRRs. In order to reduce the side effects by Ad vector-induced innate immune responses and to develop safer Ad vectors, it is crucial to clarify which PRRs and which Ad components are involved in Ad vector-induced innate immune responses. Our group previously demonstrated that myeloid differentiating factor 88 (MyD88 and toll-like receptor 9 (TLR9 play crucial roles in the Ad vector-induced inflammatory cytokine production in mouse bone marrow-derived dendritic cells. Furthermore, our group recently found that virus associated-RNAs (VA-RNAs, which are about 160 nucleotide-long non-coding small RNAs encoded in the Ad genome, are involved in IFN production through the IFN-β promoter stimulator-1 (IPS-1-mediated signaling pathway following Ad vector transduction. The aim of this review is to highlight the Ad vector-induced innate immune responses following transduction, especially VA-RNA-mediated innate immune responses. Our findings on the mechanism of Ad vector-induced innate immune responses should make an important contribution to the development of safer Ad vectors, such as an Ad vector lacking expression of VA-RNAs.

  13. Forkhead, a new cross regulator of metabolism and innate immunity downstream of TOR in Drosophila.

    Science.gov (United States)

    Varma, Disha; Bülow, Margret H; Pesch, Yanina-Yasmin; Loch, Gerrit; Hoch, Michael

    2014-10-01

    Antimicrobial peptides (AMPs) are conserved cationic peptides which act both as defense molecules of the host immune system and as regulators of the commensal microbiome. Expression of AMPs is induced in response to infection by the Toll and Imd pathway. Under non-infected conditions, the transcription factor dFOXO directly regulates a set of AMP expression at low levels when nutrients are limited. Here we have analyzed whether target of rapamycin (TOR), another major regulator of growth and metabolism, also modulates AMP responses in Drosophila. We found that downregulation of TOR by feeding the drug rapamycin or by overexpressing the negative TOR regulators TSC1/TSC2, resulted in a specific induction of the AMPs Diptericin (Dpt) and Metchnikowin (Mtk). In contrast, overexpression of Rheb, which positively regulates TOR led to a repression of the two AMPs. Genetic and pharmacological experiments indicate that Dpt and Mtk activation is controlled by the transcription factor Forkhead (FKH), the founding member of the FoxO family. Shuttling of FKH from the cytoplasm to the nucleus is induced in the fat body and in the posterior midgut in response to TOR downregulation. The FKH-dependent induction of Dpt and Mtk can be triggered in dFOXO null mutants and in immune-compromised Toll and IMD pathway mutants indicating that FKH acts in parallel to these regulators. Together, we have discovered that FKH is the second conserved member of the FoxO family cross-regulating metabolism and innate immunity. dFOXO and FKH, which are activated upon downregulation of insulin or TOR activities, respectively, act in parallel to induce different sets of AMPs, thereby modulating the immune status of metabolic tissues such as the fat body or the gut in response to the oscillating energy status of the organism. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Homeostatic migration and distribution of innate immune cells in primary and secondary lymphoid organs with ageing.

    Science.gov (United States)

    Nikolich-Žugich, J; Davies, J S

    2017-03-01

    Ageing of the innate and adaptive immune system, collectively termed immune senescence, is a complex process. One method to understand the components of ageing involves dissociating the effects of ageing on the cells of the immune system, on the microenvironment in lymphoid organs and tissues where immune cells reside and on the circulating factors that interact with both immune cells and their microenvironment. Heterochronic parabiosis, a surgical union of two organisms of disparate ages, is ideal for this type of study, as it has the power to dissociate the age of the cell and the age of the microenvironment into which the cell resides or is migrating. So far, however, it has been used sparingly to study immune ageing. Here we review the limited literature on homeostatic innate immune cell trafficking in ageing in the absence of chronic inflammation. We also review our own recent data on trafficking of innate immune subsets between primary and secondary lymphoid organs in heterochronic parabiosis. We found no systemic bias in retention or acceptance of neutrophils, macrophages, dendritic cells or natural killer cells with ageing in primary and secondary lymphoid organs. We conclude that these four innate immune cell types migrate to and populate lymphoid organs (peripheral lymph nodes, spleen and bone marrow), regardless of their own age and of the age of lymphoid organs. © 2017 British Society for Immunology.

  15. Intermittent Metronomic Drug Schedule Is Essential for Activating Antitumor Innate Immunity and Tumor Xenograft Regression

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    Chong-Sheng Chen

    2014-01-01

    Full Text Available Metronomic chemotherapy using cyclophosphamide (CPA is widely associated with antiangiogenesis; however, recent studies implicate other immune-based mechanisms, including antitumor innate immunity, which can induce major tumor regression in implanted brain tumor models. This study demonstrates the critical importance of drug schedule: CPA induced a potent antitumor innate immune response and tumor regression when administered intermittently on a 6-day repeating metronomic schedule but not with the same total exposure to activated CPA administered on an every 3-day schedule or using a daily oral regimen that serves as the basis for many clinical trials of metronomic chemotherapy. Notably, the more frequent metronomic CPA schedules abrogated the antitumor innate immune and therapeutic responses. Further, the innate immune response and antitumor activity both displayed an unusually steep dose-response curve and were not accompanied by antiangiogenesis. The strong recruitment of innate immune cells by the 6-day repeating CPA schedule was not sustained, and tumor regression was abolished, by a moderate (25% reduction in CPA dose. Moreover, an ~20% increase in CPA dose eliminated the partial tumor regression and weak innate immune cell recruitment seen in a subset of the every 6-day treated tumors. Thus, metronomic drug treatment must be at a sufficiently high dose but also sufficiently well spaced in time to induce strong sustained antitumor immune cell recruitment. Many current clinical metronomic chemotherapeutic protocols employ oral daily low-dose schedules that do not meet these requirements, suggesting that they may benefit from optimization designed to maximize antitumor immune responses.

  16. Induction of innate immune genes in brain create the neurobiology of addiction.

    Science.gov (United States)

    Crews, F T; Zou, Jian; Qin, Liya

    2011-06-01

    Addiction occurs through repeated abuse of drugs that progressively reduce behavioral control and cognitive flexibility while increasing limbic negative emotion. Recent discoveries indicate neuroimmune signaling underlies addiction and co-morbid depression. Low threshold microglia undergo progressive stages of innate immune activation involving astrocytes and neurons with repeated drug abuse, stress, and/or cell damage signals. Increased brain NF-κB transcription of proinflammatory chemokines, cytokines, oxidases, proteases, TLR and other genes create loops amplifying NF-κB transcription and innate immune target gene expression. Human post-mortem alcoholic brain has increased NF-κB and NF-κB target gene message, increased microglial markers and chemokine-MCP1. Polymorphisms of human NF-κB1 and other innate immune genes contribute to genetic risk for alcoholism. Animal transgenic and genetic studies link NF-κB innate immune gene expression to alcohol drinking. Human drug addicts show deficits in behavioral flexibility modeled pre-clinically using reversal learning. Binge alcohol, chronic cocaine, and lesions link addiction neurobiology to frontal cortex, neuroimmune signaling and loss of behavioral flexibility. Addiction also involves increasing limbic negative emotion and depression-like behavior that is reflected in hippocampal neurogenesis. Innate immune activation parallels loss of neurogenesis and increased depression-like behavior. Protection against loss of neurogenesis and negative affect by anti-oxidant, anti-inflammatory, anti-depressant, opiate antagonist and abstinence from ethanol dependence link limbic affect to changes in innate immune signaling. The hypothesis that innate immune gene induction underlies addiction and affective disorders creates new targets for therapy. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. A key requirement for CD300f in innate immune responses of eosinophils in colitis.

    Science.gov (United States)

    Moshkovits, I; Reichman, H; Karo-Atar, D; Rozenberg, P; Zigmond, E; Haberman, Y; Ben Baruch-Morgenstern, N; Lampinen, M; Carlson, M; Itan, M; Denson, L A; Varol, C; Munitz, A

    2017-01-01

    Eosinophils are traditionally studied in the context of type 2 immune responses. However, recent studies highlight key innate immune functions for eosinophils especially in colonic inflammation. Surprisingly, molecular pathways regulating innate immune activities of eosinophil are largely unknown. We have recently shown that the CD300f is highly expressed by colonic eosinophils. Nonetheless, the role of CD300f in governing innate immune eosinophil activities is ill-defined. RNA sequencing of 162 pediatric Crohn's disease patients revealed upregulation of multiple Cd300 family members, which correlated with the presence of severe ulcerations and inflammation. Increased expression of CD300 family receptors was also observed in active ulcerative colitis (UC) and in mice following induction of experimental colitis. Specifically, the expression of CD300f was dynamically regulated in monocytes and eosinophils. Dextran sodium sulfate (DSS)-treated Cd300f -/- mice exhibit attenuated disease activity and histopathology in comparison with DSS-treated wild type (WT). Decreased disease activity in Cd300f -/- mice was accompanied with reduced inflammatory cell infiltration and nearly abolished production of pro-inflammatory cytokines. Monocyte depletion and chimeric bone marrow transfer experiments revealed a cell-specific requirement for CD300f in innate immune activation of eosinophils. Collectively, we uncover a new pathway regulating innate immune activities of eosinophils, a finding with significant implications in eosinophil-associated gastrointestinal diseases.

  18. Long-term in vitro and in vivo effects of γ-irradiated BCG on innate and adaptive immunity

    DEFF Research Database (Denmark)

    Arts, Rob J W; Blok, Bastiaan A; Aaby, Peter

    2015-01-01

    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, γ......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...

  19. The Memories of NK Cells: Innate-Adaptive Immune Intrinsic Crosstalk.

    Science.gov (United States)

    Gabrielli, Sara; Ortolani, Claudio; Del Zotto, Genny; Luchetti, Francesca; Canonico, Barbara; Buccella, Flavia; Artico, Marco; Papa, Stefano; Zamai, Loris

    2016-01-01

    Although NK cells are considered part of the innate immune system, a series of evidences has demonstrated that they possess characteristics typical of the adaptive immune system. These NK adaptive features, in particular their memory-like functions, are discussed from an ontogenetic and evolutionary point of view.

  20. The Memories of NK Cells: Innate-Adaptive Immune Intrinsic Crosstalk

    Directory of Open Access Journals (Sweden)

    Sara Gabrielli

    2016-01-01

    Full Text Available Although NK cells are considered part of the innate immune system, a series of evidences has demonstrated that they possess characteristics typical of the adaptive immune system. These NK adaptive features, in particular their memory-like functions, are discussed from an ontogenetic and evolutionary point of view.

  1. 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,

  2. TLR4 links podocytes with the innate immune system to mediate glomerular injury

    DEFF Research Database (Denmark)

    Banas, Miriam C; Banas, Bernhard; Hudkins, Kelly L

    2008-01-01

    profile of chemokines. In conclusion, it was demonstrated that TLR4 is constitutively expressed by podocytes and is upregulated in MPGN, where it may mediate glomerular injury by modulating expression of chemokines; therefore, TLR4 may link podocytes with the innate immune system to mediate MPGN triggered...... by the deposition of immune complexes....

  3. Stimulation of the innate immune system of carp: role of Toll-like receptors

    NARCIS (Netherlands)

    Pietretti, D.

    2013-01-01

    Toll-like receptors (TLRs), named after the Toll gene identified in fruit flies, are a family of evolutionary conserved proteins that play a key role in the innate immune system. TLRs are found inside or on the surface of immune cells of virtually all-living animals and recognize integral parts

  4. 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; de Jong, 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, interferon-α, -β

  5. No genetic tradeoffs between hygienic behaviour and individual innate immunity in the honey bee, Apis mellifera.

    Science.gov (United States)

    Harpur, Brock A; Chernyshova, Anna; Soltani, Arash; Tsvetkov, Nadejda; Mahjoorighasrodashti, Mohammad; Xu, Zhixing; Zayed, Amro

    2014-01-01

    Many animals have individual and social mechanisms for combating pathogens. Animals may exhibit short-term physiological tradeoffs between social and individual immunity because the latter is often energetically costly. Genetic tradeoffs between these two traits can also occur if mutations that enhance social immunity diminish individual immunity, or vice versa. Physiological tradeoffs between individual and social immunity have been previously documented in insects, but there has been no study of genetic tradeoffs involving these traits. There is strong evidence that some genes influence both innate immunity and behaviour in social insects--a prerequisite for genetic tradeoffs. Quantifying genetic tradeoffs is critical for understanding the evolution of immunity in social insects and for devising effective strategies for breeding disease-resistant pollinator populations. We conducted two experiments to test the hypothesis of a genetic tradeoff between social and individual immunity in the honey bee, Apis mellifera. First, we estimated the relative contribution of genetics to individual variation in innate immunity of honey bee workers, as only heritable traits can experience genetic tradeoffs. Second, we examined if worker bees with hygienic sisters have reduced individual innate immune response. We genotyped several hundred workers from two colonies and found that patriline genotype does not significantly influence the antimicrobial activity of a worker's hemolymph. Further, we did not find a negative correlation between hygienic behaviour and the average antimicrobial activity of a worker's hemolymph across 30 honey bee colonies. Taken together, our work indicates no genetic tradeoffs between hygienic behaviour and innate immunity in honey bees. Our work suggests that using artificial selection to increase hygienic behaviour of honey bee colonies is not expected to concurrently compromise individual innate immunity of worker bees.

  6. No genetic tradeoffs between hygienic behaviour and individual innate immunity in the honey bee, Apis mellifera.

    Directory of Open Access Journals (Sweden)

    Brock A Harpur

    Full Text Available Many animals have individual and social mechanisms for combating pathogens. Animals may exhibit short-term physiological tradeoffs between social and individual immunity because the latter is often energetically costly. Genetic tradeoffs between these two traits can also occur if mutations that enhance social immunity diminish individual immunity, or vice versa. Physiological tradeoffs between individual and social immunity have been previously documented in insects, but there has been no study of genetic tradeoffs involving these traits. There is strong evidence that some genes influence both innate immunity and behaviour in social insects--a prerequisite for genetic tradeoffs. Quantifying genetic tradeoffs is critical for understanding the evolution of immunity in social insects and for devising effective strategies for breeding disease-resistant pollinator populations. We conducted two experiments to test the hypothesis of a genetic tradeoff between social and individual immunity in the honey bee, Apis mellifera. First, we estimated the relative contribution of genetics to individual variation in innate immunity of honey bee workers, as only heritable traits can experience genetic tradeoffs. Second, we examined if worker bees with hygienic sisters have reduced individual innate immune response. We genotyped several hundred workers from two colonies and found that patriline genotype does not significantly influence the antimicrobial activity of a worker's hemolymph. Further, we did not find a negative correlation between hygienic behaviour and the average antimicrobial activity of a worker's hemolymph across 30 honey bee colonies. Taken together, our work indicates no genetic tradeoffs between hygienic behaviour and innate immunity in honey bees. Our work suggests that using artificial selection to increase hygienic behaviour of honey bee colonies is not expected to concurrently compromise individual innate immunity of worker bees.

  7. Viral Inhibition of PRR-Mediated Innate Immune Response: Learning from KSHV Evasion Strategies.

    Science.gov (United States)

    Lee, Hye-Ra; Choi, Un Yung; Hwang, Sung-Woo; Kim, Stephanie; Jung, Jae U

    2016-11-30

    The innate immune system has evolved to detect and destroy invading pathogens before they can establish systemic infection. To successfully eradicate pathogens, including viruses, host innate immunity is activated through diverse pattern recognition receptors (PRRs) which detect conserved viral signatures and trigger the production of type I interferon (IFN) and pro-inflammatory cytokines to mediate viral clearance. Viral persistence requires that viruses co-opt cellular pathways and activities for their benefit. In particular, due to the potent antiviral activities of IFN and cytokines, viruses have developed various strategies to meticulously modulate intracellular innate immune sensing mechanisms to facilitate efficient viral replication and persistence. In this review, we highlight recent advances in the study of viral immune evasion strategies with a specific focus on how Kaposi's sarcoma-associated herpesvirus (KSHV) effectively targets host PRR signaling pathways.

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

    Lifescience Database Archive (English)

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

  9. Alcohol resistance in Drosophila is modulated by the Toll innate immune pathway.

    Science.gov (United States)

    Troutwine, B R; Ghezzi, A; Pietrzykowski, A Z; Atkinson, N S

    2016-04-01

    A growing body of evidence has shown that alcohol alters the activity of the innate immune system and that changes in innate immune system activity can influence alcohol-related behaviors. Here, we show that the Toll innate immune signaling pathway modulates the level of alcohol resistance in Drosophila. In humans, a low level of response to alcohol is correlated with increased risk of developing an alcohol use disorder. The Toll signaling pathway was originally discovered in, and has been extensively studied in Drosophila. The Toll pathway is a major regulator of innate immunity in Drosophila, and mammalian Toll-like receptor signaling has been implicated in alcohol responses. Here, we use Drosophila-specific genetic tools to test eight genes in the Toll signaling pathway for effects on the level of response to ethanol. We show that increasing the activity of the pathway increases ethanol resistance whereas decreasing the pathway activity reduces ethanol resistance. Furthermore, we show that gene products known to be outputs of innate immune signaling are rapidly induced following ethanol exposure. The interaction between the Toll signaling pathway and ethanol is rooted in the natural history of Drosophila melanogaster. © 2016 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

  10. A systems biology approach reveals that tissue tropism to West Nile virus is regulated by antiviral genes and innate immune cellular processes.

    Directory of Open Access Journals (Sweden)

    Mehul S Suthar

    2013-02-01

    Full Text Available The actions of the RIG-I like receptor (RLR and type I interferon (IFN signaling pathways are essential for a protective innate immune response against the emerging flavivirus West Nile virus (WNV. In mice lacking RLR or IFN signaling pathways, WNV exhibits enhanced tissue tropism, indicating that specific host factors of innate immune defense restrict WNV infection and dissemination in peripheral tissues. However, the immune mechanisms by which the RLR and IFN pathways coordinate and function to impart restriction of WNV infection are not well defined. Using a systems biology approach, we defined the host innate immune response signature and actions that restrict WNV tissue tropism. Transcriptional profiling and pathway modeling to compare WNV-infected permissive (spleen and nonpermissive (liver tissues showed high enrichment for inflammatory responses, including pattern recognition receptors and IFN signaling pathways, that define restriction of WNV replication in the liver. Assessment of infected livers from Mavs(-/- × Ifnar(-/- mice revealed the loss of expression of several key components within the natural killer (NK cell signaling pathway, including genes associated with NK cell activation, inflammatory cytokine production, and NK cell receptor signaling. In vivo analysis of hepatic immune cell infiltrates from WT mice demonstrated that WNV infection leads to an increase in NK cell numbers with enhanced proliferation, maturation, and effector action. In contrast, livers from Mavs(-/- × Ifnar(-/- infected mice displayed reduced immune cell infiltration, including a significant reduction in NK cell numbers. Analysis of cocultures of dendritic and NK cells revealed both cell-intrinsic and -extrinsic roles for the RLR and IFN signaling pathways to regulate NK cell effector activity. Taken together, these observations reveal a complex innate immune signaling network, regulated by the RLR and IFN signaling pathways, that drives tissue

  11. Ebola Virus Altered Innate and Adaptive Immune Response Signalling Pathways: Implications for Novel Therapeutic Approaches.

    Science.gov (United States)

    Kumar, Anoop

    2016-01-01

    Ebola virus (EBOV) arise attention for their impressive lethality by the poor immune response and high inflammatory reaction in the patients. It causes a severe hemorrhagic fever with case fatality rates of up to 90%. The mechanism underlying this lethal outcome is poorly understood. In 2014, a major outbreak of Ebola virus spread amongst several African countries, including Leone, Sierra, and Guinea. Although infections only occur frequently in Central Africa, but the virus has the potential to spread globally. Presently, there is no vaccine or treatment is available to counteract Ebola virus infections due to poor understanding of its interaction with the immune system. Accumulating evidence indicates that the virus actively alters both innate and adaptive immune responses and triggers harmful inflammatory responses. In the literature, some reports have shown that alteration of immune signaling pathways could be due to the ability of EBOV to interfere with dendritic cells (DCs), which link innate and adaptive immune responses. On the other hand, some reports have demonstrated that EBOV, VP35 proteins act as interferon antagonists. So, how the Ebola virus altered the innate and adaptive immune response signaling pathways is still an open question for the researcher to be explored. Thus, in this review, I try to summarize the mechanisms of the alteration of innate and adaptive immune response signaling pathways by Ebola virus which will be helpful for designing effective drugs or vaccines against this lethal infection. Further, potential targets, current treatment and novel therapeutic approaches have also been discussed.

  12. Genes of the major histocompatibility complex highlight interactions of the innate and adaptive immune system

    Directory of Open Access Journals (Sweden)

    Barbara Lukasch

    2017-08-01

    Full Text Available Background A well-functioning immune defence is crucial for fitness, but our knowledge about the immune system and its complex interactions is still limited. Major histocompatibility complex (MHC molecules are involved in T-cell mediated adaptive immune responses, but MHC is also highly upregulated during the initial innate immune response. The aim of our study was therefore to determine to what extent the highly polymorphic MHC is involved in interactions of the innate and adaptive immune defence and if specific functional MHC alleles (FA or heterozygosity at the MHC are more important. Methods To do this we used captive house sparrows (Passer domesticus to survey MHC diversity and immune function controlling for several environmental factors. MHC class I alleles were identified using parallel amplicon sequencing and to mirror immune function, several immunological tests that correspond to the innate and adaptive immunity were conducted. Results Our results reveal that MHC was linked to all immune tests, highlighting its importance for the immune defence. While all innate responses were associated with one single FA, adaptive responses (cell-mediated and humoral were associated with several different alleles. Discussion We found that repeated injections of an antibody in nestlings and adults were linked to different FA and hence might affect different areas of the immune system. Also, individuals with a higher number of different FA produced a smaller secondary response, indicating a disadvantage of having numerous MHC alleles. These results demonstrate the complexity of the immune system in relation to the MHC and lay the foundation for other studies to further investigate this topic.

  13. Genes of the major histocompatibility complex highlight interactions of the innate and adaptive immune system.

    Science.gov (United States)

    Lukasch, Barbara; Westerdahl, Helena; Strandh, Maria; Winkler, Hans; Moodley, Yoshan; Knauer, Felix; Hoi, Herbert

    2017-01-01

    A well-functioning immune defence is crucial for fitness, but our knowledge about the immune system and its complex interactions is still limited. Major histocompatibility complex (MHC) molecules are involved in T-cell mediated adaptive immune responses, but MHC is also highly upregulated during the initial innate immune response. The aim of our study was therefore to determine to what extent the highly polymorphic MHC is involved in interactions of the innate and adaptive immune defence and if specific functional MHC alleles (FA) or heterozygosity at the MHC are more important. To do this we used captive house sparrows ( Passer domesticus ) to survey MHC diversity and immune function controlling for several environmental factors. MHC class I alleles were identified using parallel amplicon sequencing and to mirror immune function, several immunological tests that correspond to the innate and adaptive immunity were conducted. Our results reveal that MHC was linked to all immune tests, highlighting its importance for the immune defence. While all innate responses were associated with one single FA, adaptive responses (cell-mediated and humoral) were associated with several different alleles. We found that repeated injections of an antibody in nestlings and adults were linked to different FA and hence might affect different areas of the immune system. Also, individuals with a higher number of different FA produced a smaller secondary response, indicating a disadvantage of having numerous MHC alleles. These results demonstrate the complexity of the immune system in relation to the MHC and lay the foundation for other studies to further investigate this topic.

  14. Antimicrobial activity of innate immune molecules against Streptococcus pneumoniae, Moraxella catarrhalis and nontypeable Haemophilus influenzae

    Directory of Open Access Journals (Sweden)

    Teufert Karen

    2004-05-01

    Full Text Available Abstract Background Despite its direct connection to the nasopharynx which harbors otitis media pathogens as part of its normal flora, the middle ear cavity is kept free of these bacteria by as yet unknown mechanisms. Respiratory mucosal epithelia, including those of the middle ear and eustachian tube, secrete antimicrobial effectors including lysozyme, lactoferrin and β defensins-1 and -2. To elucidate the role of these innate immune molecules in the normal defense and maintenance of sterility of respiratory mucosa such as that of the middle ear, we assessed their effect on the respiratory pathogens nontypeable Haemophilus influenzae (NTHi 12, Moraxella catarrhalis 035E, and Streptococcus pneumoniae 3, and 6B. Methods Two assay methods, the radial assay and the liquid broth assay, were employed for testing the antimicrobial activity of the molecules. This was done in order to minimize the possibility that the observed effects were artifacts of any single assay system employed. Also, transmission electron microscopy (TEM was employed to evaluate the effect of antimicrobial innate immune molecules on OM pathogens. For the statistical analysis of the data, Student's t-test was performed. Results Results of the radial diffusion assay showed that β defensin-2 was active against all four OM pathogens tested, while treatment with β defensin-1 appeared to only affect M. catarrhalis. The radial assay results also showed that lysozyme was quite effective against S. pneumoniae 3 and 6B and was partially bacteriostatic/bactericidal against M. catarrhalis. Lysozyme however, appeared not to affect the growth of NTHi. Thus, lysozyme seems to have a more pronounced impact on the growth of the Gram-positive S. pneumoniae as compared to that of Gram-negative pathogens. Lactoferrin on the other hand, enhanced the growth of the bacteria tested. The results of the radial assays were confirmed using liquid broth assays for antimicrobial activity, and showed that

  15. Innate immune responses in central nervous system inflammation

    DEFF Research Database (Denmark)

    Finsen, Bente; Owens, Trevor

    2011-01-01

    In autoimmune diseases of the central nervous system (CNS), innate glial cell responses play a key role in determining the outcome of leukocyte infiltration. Access of leukocytes is controlled via complex interactions with glial components of the blood-brain barrier that include angiotensin II...

  16. 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

  17. 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.

  18. Regulation of innate and adaptive immunity by the commensal microbiota

    OpenAIRE

    Jarchum, Irene; Pamer, Eric G.

    2011-01-01

    The microbial communities that inhabit the intestinal tract are essential for mammalian health. Communication between the microbiota and the host establishes and maintains immune homeostasis, enabling protective immune responses against pathogens while preventing adverse inflammatory responses to harmless commensal microbes. Specific bacteria, such as segmented filamentous bacteria, Clostridium species, and Bacteroides fragilis, are key contributors to immune homeostasis in the gut. The cellu...

  19. The fungal quorum-sensing molecule farnesol activates innate immune cells but suppresses cellular adaptive immunity.

    Science.gov (United States)

    Leonhardt, Ines; Spielberg, Steffi; Weber, Michael; Albrecht-Eckardt, Daniela; Bläss, Markus; Claus, Ralf; Barz, Dagmar; Scherlach, Kirstin; Hertweck, Christian; Löffler, Jürgen; Hünniger, Kerstin; Kurzai, Oliver

    2015-03-17

    Farnesol, produced by the polymorphic fungus Candida albicans, is the first quorum-sensing molecule discovered in eukaryotes. Its main function is control of C. albicans filamentation, a process closely linked to pathogenesis. In this study, we analyzed the effects of farnesol on innate immune cells known to be important for fungal clearance and protective immunity. Farnesol enhanced the expression of activation markers on monocytes (CD86 and HLA-DR) and neutrophils (CD66b and CD11b) and promoted oxidative burst and the release of proinflammatory cytokines (tumor necrosis factor alpha [TNF-α] and macrophage inflammatory protein 1 alpha [MIP-1α]). However, this activation did not result in enhanced fungal uptake or killing. Furthermore, the differentiation of monocytes to immature dendritic cells (iDC) was significantly affected by farnesol. Several markers important for maturation and antigen presentation like CD1a, CD83, CD86, and CD80 were significantly reduced in the presence of farnesol. Furthermore, farnesol modulated migrational behavior and cytokine release and impaired the ability of DC to induce T cell proliferation. Of major importance was the absence of interleukin 12 (IL-12) induction in iDC generated in the presence of farnesol. Transcriptome analyses revealed a farnesol-induced shift in effector molecule expression and a down-regulation of the granulocyte-macrophage colony-stimulating factor (GM-CSF) receptor during monocytes to iDC differentiation. Taken together, our data unveil the ability of farnesol to act as a virulence factor of C. albicans by influencing innate immune cells to promote inflammation and mitigating the Th1 response, which is essential for fungal clearance. Farnesol is a quorum-sensing molecule which controls morphological plasticity of the pathogenic yeast Candida albicans. As such, it is a major mediator of intraspecies communication. Here, we investigated the impact of farnesol on human innate immune cells known to be

  20. The Role of Sphingolipids on Innate Immunity to Intestinal Salmonella Infection.

    Science.gov (United States)

    Huang, Fu-Chen

    2017-08-07

    Salmonella spp. remains a major public health problem for the whole world. To reduce the use of antimicrobial agents and drug-resistant Salmonella , a better strategy is to explore alternative therapy rather than to discover another antibiotic. Sphingolipid- and cholesterol-enriched lipid microdomains attract signaling proteins and orchestrate them toward cell signaling and membrane trafficking pathways. Recent studies have highlighted the crucial role of sphingolipids in the innate immunity against infecting pathogens. It is therefore mandatory to exploit the role of the membrane sphingolipids in the innate immunity of intestinal epithelia infected by this pathogen. In the present review, we focus on the role of sphingolipids in the innate immunity of intestinal epithelia against Salmonella infection, including adhesion, autophagy, bactericidal effect, barrier function, membrane trafficking, cytokine and antimicrobial peptide expression. The intervention of sphingolipid-enhanced foods to make our life healthy or pharmacological agents regulating sphingolipids is provided at the end.

  1. Cyclic GMP-AMP synthase is an innate immune sensor of HIV and other retroviruses.

    Science.gov (United States)

    Gao, Daxing; Wu, Jiaxi; Wu, You-Tong; Du, Fenghe; Aroh, Chukwuemika; Yan, Nan; Sun, Lijun; Chen, Zhijian J

    2013-08-23

    Retroviruses, including HIV, can activate innate immune responses, but the host sensors for retroviruses are largely unknown. Here we show that HIV infection activates cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS) to produce cGAMP, which binds to and activates the adaptor protein STING to induce type I interferons and other cytokines. Inhibitors of HIV reverse transcriptase, but not integrase, abrogated interferon-β induction by the virus, suggesting that the reverse-transcribed HIV DNA triggers the innate immune response. Knockout or knockdown of cGAS in mouse or human cell lines blocked cytokine induction by HIV, murine leukemia virus, and simian immunodeficiency virus. These results indicate that cGAS is an innate immune sensor of HIV and other retroviruses.

  2. Microglia and Beyond: Innate Immune Cells As Regulators of Brain Development and Behavioral Function

    Directory of Open Access Journals (Sweden)

    Kathryn M. Lenz

    2018-04-01

    Full Text Available Innate immune cells play a well-documented role in the etiology and disease course of many brain-based conditions, including multiple sclerosis, Alzheimer’s disease, traumatic brain and spinal cord injury, and brain cancers. In contrast, it is only recently becoming clear that innate immune cells, primarily brain resident macrophages called microglia, are also key regulators of brain development. This review summarizes the current state of knowledge regarding microglia in brain development, with particular emphasis on how microglia during development are distinct from microglia later in life. We also summarize the effects of early life perturbations on microglia function in the developing brain, the role that biological sex plays in microglia function, and the potential role that microglia may play in developmental brain disorders. Finally, given how new the field of developmental neuroimmunology is, we highlight what has yet to be learned about how innate immune cells shape the development of brain and behavior.

  3. Microglia and Beyond: Innate Immune Cells As Regulators of Brain Development and Behavioral Function.

    Science.gov (United States)

    Lenz, Kathryn M; Nelson, Lars H

    2018-01-01

    Innate immune cells play a well-documented role in the etiology and disease course of many brain-based conditions, including multiple sclerosis, Alzheimer's disease, traumatic brain and spinal cord injury, and brain cancers. In contrast, it is only recently becoming clear that innate immune cells, primarily brain resident macrophages called microglia, are also key regulators of brain development. This review summarizes the current state of knowledge regarding microglia in brain development, with particular emphasis on how microglia during development are distinct from microglia later in life. We also summarize the effects of early life perturbations on microglia function in the developing brain, the role that biological sex plays in microglia function, and the potential role that microglia may play in developmental brain disorders. Finally, given how new the field of developmental neuroimmunology is, we highlight what has yet to be learned about how innate immune cells shape the development of brain and behavior.

  4. PTX3, a Humoral Pattern Recognition Molecule, in Innate Immunity, Tissue Repair, and Cancer.

    Science.gov (United States)

    Garlanda, Cecilia; Bottazzi, Barbara; Magrini, Elena; Inforzato, Antonio; Mantovani, Alberto

    2018-04-01

    Innate immunity includes a cellular and a humoral arm. PTX3 is a fluid-phase pattern recognition molecule conserved in evolution which acts as a key component of humoral innate immunity in infections of fungal, bacterial, and viral origin. PTX3 binds conserved microbial structures and self-components under conditions of inflammation and activates effector functions (complement, phagocytosis). Moreover, it has a complex regulatory role in inflammation, such as ischemia/reperfusion injury and cancer-related inflammation, as well as in extracellular matrix organization and remodeling, with profound implications in physiology and pathology. Finally, PTX3 acts as an extrinsic oncosuppressor gene by taming tumor-promoting inflammation in murine and selected human tumors. Thus evidence suggests that PTX3 is a key homeostatic component at the crossroad of innate immunity, inflammation, tissue repair, and cancer. Dissecting the complexity of PTX3 pathophysiology and human genetics paves the way to diagnostic and therapeutic exploitation.

  5. Cyclic GMP-AMP Synthase Is an Innate Immune DNA Sensor for Mycobacterium tuberculosis.

    Science.gov (United States)

    Collins, Angela C; Cai, Haocheng; Li, Tuo; Franco, Luis H; Li, Xiao-Dong; Nair, Vidhya R; Scharn, Caitlyn R; Stamm, Chelsea E; Levine, Beth; Chen, Zhijian J; Shiloh, Michael U

    2015-06-10

    Activation of the DNA-dependent cytosolic surveillance pathway in response to Mycobacterium tuberculosis infection stimulates ubiquitin-dependent autophagy and inflammatory cytokine production, and plays an important role in host defense against M. tuberculosis. However, the identity of the host sensor for M. tuberculosis DNA is unknown. Here we show that M. tuberculosis activated cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS) in macrophages to produce cGAMP, a second messenger that activates the adaptor protein stimulator of interferon genes (STING) to induce type I interferons and other cytokines. cGAS localized with M. tuberculosis in mouse and human cells and in human tuberculosis lesions. Knockdown or knockout of cGAS in human or mouse macrophages blocked cytokine production and induction of autophagy. Mice deficient in cGAS were more susceptible to lethality caused by infection with M. tuberculosis. These results demonstrate that cGAS is a vital innate immune sensor of M. tuberculosis infection. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. PAR-1 contributes to the innate immune response during viral infection

    Science.gov (United States)

    Antoniak, Silvio; Owens, A. Phillip; Baunacke, Martin; Williams, Julie C.; Lee, Rebecca D.; Weithäuser, Alice; Sheridan, Patricia A.; Malz, Ronny; Luyendyk, James P.; Esserman, Denise A.; Trejo, JoAnn; Kirchhofer, Daniel; Blaxall, Burns C.; Pawlinski, Rafal; Beck, Melinda A.; Rauch, Ursula; Mackman, Nigel

    2013-01-01

    Coagulation is a host defense system that limits the spread of pathogens. Coagulation proteases, such as thrombin, also activate cells by cleaving PARs. In this study, we analyzed the role of PAR-1 in coxsackievirus B3–induced (CVB3-induced) myocarditis and influenza A infection. CVB3-infected Par1–/– mice expressed reduced levels of IFN-β and CXCL10 during the early phase of infection compared with Par1+/+ mice that resulted in higher viral loads and cardiac injury at day 8 after infection. Inhibition of either tissue factor or thrombin in WT mice also significantly increased CVB3 levels in the heart and cardiac injury compared with controls. BM transplantation experiments demonstrated that PAR-1 in nonhematopoietic cells protected mice from CVB3 infection. Transgenic mice overexpressing PAR-1 in cardiomyocytes had reduced CVB3-induced myocarditis. We found that cooperative signaling between PAR-1 and TLR3 in mouse cardiac fibroblasts enhanced activation of p38 and induction of IFN-β and CXCL10 expression. Par1–/– mice also had decreased CXCL10 expression and increased viral levels in the lung after influenza A infection compared with Par1+/+ mice. Our results indicate that the tissue factor/thrombin/PAR-1 pathway enhances IFN-β expression and contributes to the innate immune response during single-stranded RNA viral infection. PMID:23391721

  7. Houttuynia cordata modulates oral innate immune mediators: potential role of herbal plant on oral health.

    Science.gov (United States)

    Satthakarn, S; Chung, W O; Promsong, A; Nittayananta, W

    2015-05-01

    Epithelial cells play an active role in oral innate immunity by producing various immune mediators. Houttuynia cordata Thunb (H. cordata), a herbal plant found in Asia, possesses many activities. However, its impacts on oral innate immunity have never been reported. The aim of this study was to determine the effects of H. cordata extract on the expression of innate immune mediators produced by oral epithelial cells. Primary gingival epithelial cells (GECs) were treated with various concentrations of the extract for 18 h. The gene expression of hBD2, SLPI, cytokines, and chemokines was measured using quantitative real-time RT-PCR. The secreted proteins in the culture supernatants were detected by ELISA or Luminex assay. Cytotoxicity of the extract was assessed using CellTiter-Blue Assay. H. cordata significantly induced the expression of hBD2, SLPI, IL-8, and CCL20 in a dose-dependent manner without cytotoxicity. The secreted hBD2 and SLPI proteins were modulated, and the levels of IL-2, IL-6, IL-8, and IFN-γ were significantly induced by the extract. Our data indicated that H. cordata can modulate oral innate immune mediators. These findings may lead to the development of new topical agents from H. cordata for the prevention and treatment of immune-mediated oral diseases. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. Quantitative Methods for Measuring Repair Rates and Innate-Immune Cell Responses in Wounded Mouse Skin.

    Science.gov (United States)

    Li, Zhi; Gothard, Elizabeth; Coles, Mark C; Ambler, Carrie A

    2018-01-01

    In skin wounds, innate-immune cells clear up tissue debris and microbial contamination, and also secrete cytokines and other growth factors that impact repair process such as re-epithelialization and wound closure. After injury, there is a rapid influx and efflux of immune cells at wound sites, yet the function of each innate cell population in skin repair is still under investigation. Flow cytometry is a valuable research tool for detecting and quantifying immune cells; however, in mouse back skin, the difficulty in extracting immune cells from small area of skin due to tissue complexity has made cytometric analysis an underutilized tool. In this paper, we provide detailed methods on the digestion of lesion-specific skin without disrupting antigen expression followed by multiplex cell staining that allows for identification of seven innate-immune populations, including rare subsets such as group-3 innate lymphoid cells (ILC3s), by flow-cytometry analysis. Furthermore, when studying the functions of immune cells to tissue repair an important metric to monitor is size of the wound opening. Normal wounds close steadily albeit at non-linear rates, while slow or stalled wound closure can indicate an underlying problem with the repair process. Calliper measurements are difficult and time-consuming to obtain and can require repeated sedation of experimental animals. We provide advanced methods for measuring of wound openness; digital 3D image capture and semi-automated image processing that allows for unbiased, reliable measurements that can be taken repeatedly over time.

  9. Group 2 Innate Lymphoid Cells in Pulmonary Immunity and Tissue Homeostasis

    Directory of Open Access Journals (Sweden)

    Barbara C. Mindt

    2018-04-01

    Full Text Available Group 2 innate lymphoid cells (ILC2 represent an evolutionary rather old but only recently identified member of the family of innate lymphoid cells and have received much attention since their detailed description in 2010. They can orchestrate innate as well as adaptive immune responses as they interact with and influence several immune and non-immune cell populations. Moreover, ILC2 are able to rapidly secrete large amounts of type 2 cytokines that can contribute to protective but also detrimental host immune responses depending on timing, location, and physiological context. Interestingly, ILC2, despite their scarcity, are the dominant innate lymphoid cell population in the lung, indicating a key role as first responders and amplifiers upon immune challenge at this site. In addition, the recently described tissue residency of ILC2 further underlines the importance of their respective microenvironment. In this review, we provide an overview of lung physiology including a description of the most prominent pulmonary resident cells together with a review of known and potential ILC2 interactions within this unique environment. We will further outline recent observations regarding pulmonary ILC2 during immune challenge including respiratory infections and discuss different models and approaches to study ILC2 biology in the lung.

  10. Group 2 Innate Lymphoid Cells in Pulmonary Immunity and Tissue Homeostasis.

    Science.gov (United States)

    Mindt, Barbara C; Fritz, Jörg H; Duerr, Claudia U

    2018-01-01

    Group 2 innate lymphoid cells (ILC2) represent an evolutionary rather old but only recently identified member of the family of innate lymphoid cells and have received much attention since their detailed description in 2010. They can orchestrate innate as well as adaptive immune responses as they interact with and influence several immune and non-immune cell populations. Moreover, ILC2 are able to rapidly secrete large amounts of type 2 cytokines that can contribute to protective but also detrimental host immune responses depending on timing, location, and physiological context. Interestingly, ILC2, despite their scarcity, are the dominant innate lymphoid cell population in the lung, indicating a key role as first responders and amplifiers upon immune challenge at this site. In addition, the recently described tissue residency of ILC2 further underlines the importance of their respective microenvironment. In this review, we provide an overview of lung physiology including a description of the most prominent pulmonary resident cells together with a review of known and potential ILC2 interactions within this unique environment. We will further outline recent observations regarding pulmonary ILC2 during immune challenge including respiratory infections and discuss different models and approaches to study ILC2 biology in the lung.

  11. Innate immunity is not related to the sex of adult Tree Swallows during the nestling period

    Science.gov (United States)

    Houdek, Bradley J.; Lombardo, Michael P.; Thorpe, Patrick A.; Hahn, D. Caldwell

    2011-01-01

    Evolutionary theory predicts that exposure to more diverse pathogens will result in the evolution of a more robust immune response. We predicted that during the breeding season the innate immune function of female Tree Swallows (Tachycineta bicolor) should be more effective than that of males because (1) the transmission of sexually transmitted microbes during copulation puts females at greater risk because ejaculates move from males to females, (2) females copulate with multiple males, exposing them to the potentially pathogenic microbes in semen, and (3) females spend more time in the nest than do males so may be more exposed to nest microbes and ectoparasites that can be vectors of bacterial and viral pathogens. In addition, elevated testosterone in males may suppress immune function. We tested our prediction during the 2009 breeding season with microbicidal assays in vitro to assess the ability of the innate immune system to kill Escherichia coli. The sexes did not differ in the ability of their whole blood to kill E. coli. We also found no significant relationships between the ability of whole blood to kill E. coli and the reproductive performance or the physical condition of males or females. These results indicate that during the nestling period there are no sexual differences in this component of the innate immune system. In addition, they suggest that there is little association between this component of innate immunity and the reproductive performance and physical condition during the nestling period of adult Tree Swallows.

  12. Innate Immune Cytokines, Fibroblast Phenotypes, and Regulation of Extracellular Matrix in Lung.

    Science.gov (United States)

    Richards, Carl D

    2017-02-01

    Chronic inflammation can be caused by adaptive immune responses in autoimmune and allergic conditions, driven by a T lymphocyte subset balance (TH1, TH2, Th17, Th22, and/or Treg) and skewed cellular profiles in an antigen-specific manner. However, several chronic inflammatory diseases have no clearly defined adaptive immune mechanisms that drive chronicity. These conditions include those that affect the lung such as nonatopic asthma or idiopathic pulmonary fibrosis comprising significant health problems. The remodeling of extracellular matrix (ECM) causes organ dysfunction, and it is largely generated by fibroblasts as the major cell controlling net ECM. As such, these are potential targets of treatment approaches in the context of ECM pathology. Fibroblast phenotypes contribute to ECM and inflammatory cell accumulation, and they are integrated into chronic disease mechanisms including cancer. Evidence suggests that innate cytokine responses may be critical in nonallergic/nonautoimmune disease, and they enable environmental agent exposure mechanisms that are independent of adaptive immunity. Innate immune cytokines derived from macrophage subsets (M1/M2) and innate lymphoid cell (ILC) subsets can directly regulate fibroblast function. We also suggest that STAT3-activating gp130 cytokines can sensitize fibroblasts to the innate cytokine milieu to drive phenotypes and exacerbate existing adaptive responses. Here, we review evidence exploring innate cytokine regulation of fibroblast behavior.

  13. 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.

  14. Both live and dead Enterococci activate Caenorhabditis elegans host defense via immune and stress pathways.

    Science.gov (United States)

    Yuen, Grace J; Ausubel, Frederick M

    2018-12-31

    The innate immune response of the nematode Caenorhabditis elegans has been extensively studied and a variety of Toll-independent immune response pathways have been identified. Surprisingly little, however, is known about how pathogens activate the C. elegans immune response. Enterococcus faecalis and Enterococcus faecium are closely related enterococcal species that exhibit significantly different levels of virulence in C. elegans infection models. Previous work has shown that activation of the C. elegans immune response by Pseudomonas aeruginosa involves P. aeruginosa-mediated host damage. Through ultrastructural imaging, we report that infection with either E. faecalis or E. faecium causes the worm intestine to become distended with proliferating bacteria in the absence of extensive morphological changes and apparent physical damage. Genetic analysis, whole-genome transcriptional profiling, and multiplexed gene expression analysis demonstrate that both enterococcal species, whether live or dead, induce a rapid and similar transcriptional defense response dependent upon previously described immune signaling pathways. The host response to E. faecium shows a stricter dependence upon stress response signaling pathways than the response to E. faecalis. Unexpectedly, we find that E. faecium is a C. elegans pathogen and that an active wild-type host defense response is required to keep an E. faecium infection at bay. These results provide new insights into the mechanisms underlying the C. elegans immune response to pathogen infection.

  15. Contrasting patterns of diversity and population differentiation at the innate immunity gene toll-like receptor 2 (TLR2) in two sympatric rodent species.

    Science.gov (United States)

    Tschirren, Barbara; Andersson, Martin; Scherman, Kristin; Westerdahl, Helena; Råberg, Lars

    2012-03-01

    Comparing patterns of diversity and divergence between populations at immune genes and neutral markers can give insights into the nature and geographic scale of parasite-mediated selection. To date, studies investigating such patterns of selection in vertebrates have primarily focused on the acquired branch of the immune system, whereas it remains largely unknown how parasite-mediated selection shapes innate immune genes both within and across vertebrate populations. Here, we present a study on the diversity and population differentiation at the innate immune gene Toll-like receptor 2 (TLR2) across nine populations of yellow-necked mice (Apodemus flavicollis) and bank voles (Myodes glareolus) in southern Sweden. In yellow-necked mice, TLR2 diversity was very low, as was TLR2 population differentiation compared to neutral loci. In contrast, several TLR2 haplotypes co-occurred at intermediate frequencies within and across bank vole populations, and pronounced isolation by distance between populations was observed. The diversity and differentiation at neutral loci was similar in the two species. These results indicate that parasite-mediated selection has been acting in dramatically different ways on a given immune gene in ecologically similar and sympatric species. Furthermore, the finding of TLR2 population differentiation at a small geographical scale in bank voles highlights that vertebrate innate immune defense may be evolutionarily more dynamic than has previously been appreciated. © 2011 The Author(s). Evolution© 2011 The Society for the Study of Evolution.

  16. Interleukin-21 receptor signalling is important for innate immune protection against HSV-2 infections.

    Directory of Open Access Journals (Sweden)

    Sine K Kratholm

    Full Text Available Interleukin (IL -21 is produced by Natural Killer T (NKT cells and CD4(+ T cells and is produced in response to virus infections, where IL-21 has been shown to be essential in adaptive immune responses. Cells from the innate immune system such as Natural Killer (NK cells and macrophages are also important in immune protection against virus. These cells express the IL-21 receptor (IL-21R and respond to IL-21 with increased cytotoxicity and cytokine production. Currently, however it is not known whether IL-21 plays a significant role in innate immune responses to virus infections. The purpose of this study was to investigate the role of IL-21 and IL-21R in the innate immune response to a virus infection. We used C57BL/6 wild type (WT and IL-21R knock out (KO mice in a murine vaginal Herpes Simplex Virus type 2 (HSV-2 infection model to show that IL-21 - IL-21R signalling is indeed important in innate immune responses against HSV-2. We found that the IL-21R was expressed in the vaginal epithelium in uninfected (u.i WT mice, and expression increased early after HSV-2 infection. IL-21R KO mice exhibited increased vaginal viral titers on day 2 and 3 post infection (p.i. and subsequently developed significantly higher disease scores and a lower survival rate compared to WT mice. In addition, WT mice infected with HSV-2 receiving intra-vaginal pre-treatment with murine recombinant IL-21 (mIL-21 had decreased vaginal viral titers on day 2 p.i., significantly lower disease scores, and a higher survival rate compared to infected untreated WT controls. Collectively our data demonstrate the novel finding that the IL-21R plays a critical role in regulating innate immune responses against HSV-2 infection.

  17. Delicate regulation of the cGAS-MITA-mediated innate immune response.

    Science.gov (United States)

    Luo, Wei-Wei; Shu, Hong-Bing

    2018-02-19

    Although it has long been demonstrated that cytosolic DNA is a potent immune stimulant, it is only in recent years that the molecular mechanisms of DNA-stimulated innate immune responses have emerged. Studies have established critical roles for the DNA sensor cyclic GMP-AMP synthase (cGAS) and the adapter protein MITA/STING in the innate immune response to cytosolic DNA or DNA viruses. Although the regulation of cGAS-MITA/STING-mediated signaling remains to be fully investigated, understanding the processes involved may help to explain the mechanisms of innate immune signaling events and perhaps autoinflammatory diseases and to provide potential therapeutic targets for drug intervention. In this review, we summarize recent progress on the regulation of the cGAS-MITA/STING-mediated innate immune response to DNA viruses at the organelle-trafficking, post-translational and transcriptional levels.Cellular & Molecular Immunology advance online publication, 19 February 2018; doi:10.1038/cmi.2016.51.

  18. Muscles provide protection during microbial infection by activating innate immune response pathways in Drosophila and zebrafish

    Directory of Open Access Journals (Sweden)

    Arunita Chatterjee

    2016-06-01

    Full Text Available Muscle contraction brings about movement and locomotion in animals. However, muscles have also been implicated in several atypical physiological processes including immune response. The role of muscles in immunity and the mechanism involved has not yet been deciphered. In this paper, using Drosophila indirect flight muscles (IFMs as a model, we show that muscles are immune-responsive tissues. Flies with defective IFMs are incapable of mounting a potent humoral immune response. Upon immune challenge, the IFMs produce anti-microbial peptides (AMPs through the activation of canonical signaling pathways, and these IFM-synthesized AMPs are essential for survival upon infection. The trunk muscles of zebrafish, a vertebrate model system, also possess the capacity to mount an immune response against bacterial infections, thus establishing that immune responsiveness of muscles is evolutionarily conserved. Our results suggest that physiologically fit muscles might boost the innate immune response of an individual.

  19. Functional comparison of innate immune signaling pathways in primates.

    Directory of Open Access Journals (Sweden)

    Luis B Barreiro

    2010-12-01

    Full Text Available Humans respond differently than other primates to a large number of infections. Differences in susceptibility to infectious agents between humans and other primates are probably due to inter-species differences in immune response to infection. Consistent with that notion, genes involved in immunity-related processes are strongly enriched among recent targets of positive selection in primates, suggesting that immune responses evolve rapidly, yet providing only indirect evidence for possible inter-species functional differences. To directly compare immune responses among primates, we stimulated primary monocytes from humans, chimpanzees, and rhesus macaques with lipopolysaccharide (LPS and studied the ensuing time-course regulatory responses. We find that, while the universal Toll-like receptor response is mostly conserved across primates, the regulatory response associated with viral infections is often lineage-specific, probably reflecting rapid host-virus mutual adaptation cycles. Additionally, human-specific immune responses are enriched for genes involved in apoptosis, as well as for genes associated with cancer and with susceptibility to infectious diseases or immune-related disorders. Finally, we find that chimpanzee-specific immune signaling pathways are enriched for HIV-interacting genes. Put together, our observations lend strong support to the notion that lineage-specific immune responses may help explain known inter-species differences in susceptibility to infectious diseases.

  20. Focusing on Ciona intestinalis (Tunicata) innate immune system. Evolutionary implications

    OpenAIRE

    N Parrinello

    2009-01-01

    Phylogenetic analyses based on molecular data provide compelling evidence that ascidians are of critical importance for studying chordate immune system evolution. The Ciona intestinalis draft genome sequence allows searches for phylogenetic relationships, gene cloning and expression of immunorelevant molecules. Acidians lack of the pivotal components of the vertebrate recombinatory adaptive immunity, i.e., MHC, TCRs and dimeric immunoglobulins. However, bioinformatic sequence analyses recogni...

  1. Innate immunity is sufficient for the clearance of Chlamydia trachomatis from the female mouse genital tract.

    Science.gov (United States)

    Sturdevant, Gail L; Caldwell, Harlan D

    2014-10-01

    Chlamydia muridarum and Chlamydia trachomatis, mouse and human strains, respectively, have been used to study immunity in a murine model of female genital tract infection. Despite evidence that unique genes of these otherwise genomically similar strains could play a role in innate immune evasion in their respective mouse and human hosts, there have been no animal model findings to directly support this conclusion. Here, we infected C57BL/6 and adaptive immune-deficient Rag1(-/-) female mice with these strains and evaluated their ability to spontaneously resolve genital infection. Predictably, C57BL/6 mice spontaneously cleared infection caused by both chlamydial strains. In contrast, Rag1(-/-) mice which lack mature T and B cell immunity but maintain functional innate immune effectors were incapable of resolving C. muridarum infection but spontaneously cleared C. trachomatis infection. This distinct dichotomy in adaptive and innate immune-mediated clearance between mouse and human strains has important cautionary implications for the study of natural immunity and vaccine development in the mouse model. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  2. Alveolar macrophage–derived type I interferons orchestrate innate immunity to RSV through recruitment of antiviral monocytes

    Science.gov (United States)

    Goritzka, Michelle; Makris, Spyridon; Kausar, Fahima; Durant, Lydia R.; Pereira, Catherine; Kumagai, Yutaro; Culley, Fiona J.; Mack, Matthias; Akira, Shizuo

    2015-01-01

    Type I interferons (IFNs) are important for host defense from viral infections, acting to restrict viral production in infected cells and to promote antiviral immune responses. However, the type I IFN system has also been associated with severe lung inflammatory disease in response to respiratory syncytial virus (RSV). Which cells produce type I IFNs upon RSV infection and how this directs immune responses to the virus, and potentially results in pathological inflammation, is unclear. Here, we show that alveolar macrophages (AMs) are the major source of type I IFNs upon RSV infection in mice. AMs detect RSV via mitochondrial antiviral signaling protein (MAVS)–coupled retinoic acid–inducible gene 1 (RIG-I)–like receptors (RLRs), and loss of MAVS greatly compromises innate immune restriction of RSV. This is largely attributable to loss of type I IFN–dependent induction of monocyte chemoattractants and subsequent reduced recruitment of inflammatory monocytes (infMo) to the lungs. Notably, the latter have potent antiviral activity and are essential to control infection and lessen disease severity. Thus, infMo recruitment constitutes an important and hitherto underappreciated, cell-extrinsic mechanism of type I IFN–mediated antiviral activity. Dysregulation of this system of host antiviral defense may underlie the development of RSV-induced severe lung inflammation. PMID:25897172

  3. GENETIC SUSCEPTIBILITY TO RESPIRATORY SYNCYTIAL VIRUS BRONCHIOLITIS IN PRETERM CHILDREN IS ASSOCIATED WITH AIRWAY REMODELING GENES AND INNATE IMMUNE GENES

    NARCIS (Netherlands)

    Siezen, Christine L. E.; Bont, Louis; Hodemaekers, Hennie M.; Ermers, Marieke J.; Doornbos, Gerda; van't Slot, Ruben; Wijmenga, Ciska; van Hottwelingen, Hans C.; Kimpen, Jan L. L.; Kimman, Tjeerd G.; Hoebee, Barbara; Janssen, Riny

    Prematurity is a risk factor for severe respiratory syncytial virus bronchiolitis. We show that genetic factors in innate immune genes (IFNA13, IFNAR2, STAT2. IL27, NFKBIA, C3, IL1RN, TLR5), in innate and adaptive immunity (IFNG), and in airway remodeling genes (ADAM33 and TGFBR1), affect disease

  4. 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.

  5. Immune defense mechanisms in the Caenorhabditis elegans intestinal epithelium.

    Science.gov (United States)

    Pukkila-Worley, Read; Ausubel, Frederick M

    2012-02-01

    Intestinal epithelial cells provide an essential line of defense for Caernohabditis elegans against ingested pathogens. Because nematodes consume microorganisms as their food source, there has presumably been selection pressure to evolve and maintain immune defense mechanisms within the intestinal epithelium. Here we review recent advances that further define the immune signaling network within these cells and suggest mechanisms used by the nematode to monitor for infection. In reviewing studies of pathogenesis that use this simple model system, we hope to illustrate some of the basic principles of epithelial immunity that may also be of relevance in higher order hosts. Copyright © 2012. Published by Elsevier Ltd.

  6. Estimating Herd Immunity to Amphibian Chytridiomycosis in Madagascar Based on the Defensive Function of Amphibian Skin Bacteria

    OpenAIRE

    Bletz, Molly C.; Myers, Jillian; Woodhams, Douglas C.; Rabemananjara, Falitiana C. E.; Rakotonirina, Angela; Weldon, Che; Edmonds, Devin; Vences, Miguel; Harris, Reid N.

    2017-01-01

    For decades, Amphibians have been globally threatened by the still expanding infectious disease, chytridiomycosis. Madagascar is an amphibian biodiversity hotspot where Batrachochytrium dendrobatidis (Bd) has only recently been detected. While no Bd-associated population declines have been reported, the risk of declines is high when invasive virulent lineages become involved. Cutaneous bacteria contribute to host innate immunity by providing defense against pathogens for numerous animals, inc...

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

    Directory of Open Access Journals (Sweden)

    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.

  8. The Role of Innate Lymphoid Cells in Immune-Mediated Liver Diseases

    Science.gov (United States)

    Liu, Meifang; Zhang, Cai

    2017-01-01

    Innate lymphoid cells (ILCs) are a recently identified group of innate immune cells lacking antigen-specific receptors that can mediate immune responses and regulate tissue homeostasis and inflammation. ILCs comprise group 1 ILCs, group 2 ILCs, and group 3 ILCs. These ILCs usually localize at mucosal surfaces and combat pathogens by the rapid release of certain cytokines. However, the uncontrolled activation of ILCs can also lead to damaging inflammation, especially in the gut, lung, and skin. Although the physiological and pathogenic roles of ILCs in liver diseases have been attracting increasing attention recently, there has been no systematic review regarding the roles of ILCs in immune-mediated liver diseases. Here, we review the relationships between the ILC subsets and their functions in immune-mediated liver diseases, and discuss their therapeutic potential based on current knowledge about the functional roles of these cells in liver diseases. PMID:28659927

  9. Development and function of human innate immune cells in a humanized mouse model.

    Science.gov (United States)

    Rongvaux, Anthony; Willinger, Tim; Martinek, Jan; Strowig, Till; Gearty, Sofia V; Teichmann, Lino L; Saito, Yasuyuki; Marches, Florentina; Halene, Stephanie; Palucka, A Karolina; Manz, Markus G; Flavell, Richard A

    2014-04-01

    Mice repopulated with human hematopoietic cells are a powerful tool for the study of human hematopoiesis and immune function in vivo. However, existing humanized mouse models cannot support development of human innate immune cells, including myeloid cells and natural killer (NK) cells. Here we describe two mouse strains called MITRG and MISTRG, in which human versions of four genes encoding cytokines important for innate immune cell development are knocked into their respective mouse loci. The human cytokines support the development and function of monocytes, macrophages and NK cells derived from human fetal liver or adult CD34(+) progenitor cells injected into the mice. Human macrophages infiltrated a human tumor xenograft in MITRG and MISTRG mice in a manner resembling that observed in tumors obtained from human patients. This humanized mouse model may be used to model the human immune system in scenarios of health and pathology, and may enable evaluation of therapeutic candidates in an in vivo setting relevant to human physiology.

  10. Transcriptional Innate Immune Response of the Developing Chicken Embryo to Newcastle Disease Virus Infection

    Science.gov (United States)

    Schilling, Megan A.; Katani, Robab; Memari, Sahar; Cavanaugh, Meredith; Buza, Joram; Radzio-Basu, Jessica; Mpenda, Fulgence N.; Deist, Melissa S.; Lamont, Susan J.; Kapur, Vivek

    2018-01-01

    Traditional approaches to assess the immune response of chickens to infection are through animal trials, which are expensive, require enhanced biosecurity, compromise welfare, and are frequently influenced by confounding variables. Since the chicken embryo becomes immunocompetent prior to hatch, we here characterized the transcriptional response of selected innate immune genes to Newcastle disease virus (NDV) infection in chicken embryos at days 10, 14, and 18 of embryonic development. The results suggest that the innate immune response 72 h after challenge of 18-day chicken embryo is both consistent and robust. The expression of CCL5, Mx1, and TLR3 in lung tissues of NDV challenged chicken embryos from the outbred Kuroiler and Tanzanian local ecotype lines showed that their expression was several orders of magnitude higher in the Kuroiler than in the local ecotypes. Next, the expression patterns of three additional innate-immunity related genes, IL-8, IRF-1, and STAT1, were examined in the highly congenic Fayoumi (M5.1 and M15.2) and Leghorn (Ghs6 and Ghs13) sublines that differ only at the microchromosome bearing the major histocompatibility locus. The results show that the Ghs13 Leghorn subline had a consistently higher expression of all genes except IL-8 and expression seemed to be subline-dependent rather than breed-dependent, suggesting that the innate immune response of chicken embryos to NDV infection may be genetically controlled by the MHC-locus. Taken together, the results suggest that the chicken embryo may represent a promising model to studying the patterns and sources of variation of the avian innate immune response to infection with NDV and related pathogens. PMID:29535762

  11. Transcriptional Innate Immune Response of the Developing Chicken Embryo to Newcastle Disease Virus Infection

    Directory of Open Access Journals (Sweden)

    Megan A. Schilling

    2018-02-01

    Full Text Available Traditional approaches to assess the immune response of chickens to infection are through animal trials, which are expensive, require enhanced biosecurity, compromise welfare, and are frequently influenced by confounding variables. Since the chicken embryo becomes immunocompetent prior to hatch, we here characterized the transcriptional response of selected innate immune genes to Newcastle disease virus (NDV infection in chicken embryos at days 10, 14, and 18 of embryonic development. The results suggest that the innate immune response 72 h after challenge of 18-day chicken embryo is both consistent and robust. The expression of CCL5, Mx1, and TLR3 in lung tissues of NDV challenged chicken embryos from the outbred Kuroiler and Tanzanian local ecotype lines showed that their expression was several orders of magnitude higher in the Kuroiler than in the local ecotypes. Next, the expression patterns of three additional innate-immunity related genes, IL-8, IRF-1, and STAT1, were examined in the highly congenic Fayoumi (M5.1 and M15.2 and Leghorn (Ghs6 and Ghs13 sublines that differ only at the microchromosome bearing the major histocompatibility locus. The results show that the Ghs13 Leghorn subline had a consistently higher expression of all genes except IL-8 and expression seemed to be subline-dependent rather than breed-dependent, suggesting that the innate immune response of chicken embryos to NDV infection may be genetically controlled by the MHC-locus. Taken together, the results suggest that the chicken embryo may represent a promising model to studying the patterns and sources of variation of the avian innate immune response to infection with NDV and related pathogens.

  12. Accelerated evolution of innate immunity proteins in social insects: adaptive evolution or relaxed constraint?

    Science.gov (United States)

    Harpur, Brock A; Zayed, Amro

    2013-07-01

    The genomes of eusocial insects have a reduced complement of immune genes-an unusual finding considering that sociality provides ideal conditions for disease transmission. The following three hypotheses have been invoked to explain this finding: 1) social insects are attacked by fewer pathogens, 2) social insects have effective behavioral or 3) novel molecular mechanisms for combating pathogens. At the molecular level, these hypotheses predict that canonical innate immune pathways experience a relaxation of selective constraint. A recent study of several innate immune genes in ants and bees showed a pattern of accelerated amino acid evolution, which is consistent with either positive selection or a relaxation of constraint. We studied the population genetics of innate immune genes in the honey bee Apis mellifera by partially sequencing 13 genes from the bee's Toll pathway (∼10.5 kb) and 20 randomly chosen genes (∼16.5 kb) sequenced in 43 diploid workers. Relative to the random gene set, Toll pathway genes had significantly higher levels of amino acid replacement mutations segregating within A. mellifera and fixed between A. mellifera and A. cerana. However, levels of diversity and divergence at synonymous sites did not differ between the two gene sets. Although we detect strong signs of balancing selection on the pathogen recognition gene pgrp-sa, many of the genes in the Toll pathway show signatures of relaxed selective constraint. These results are consistent with the reduced complement of innate immune genes found in social insects and support the hypothesis that some aspect of eusociality renders canonical innate immunity superfluous.

  13. Innate immune responses to obesity in cloned and wild-type domestic pig

    DEFF Research Database (Denmark)

    Højbøge, Tina Rødgaard; Skovgaard, Kerstin; Stagsted, Jan

    as a refined pig model for obesity-induced innate host responses by reducing pig-to-pig biological variation compared to wild-type (WT) pigs (n=19). Pigs were fed ad libitum with a high fat/high sucrose diet to induce obesity or kept lean on a restricted diet (60% of ad libitum intake) beginning at three...... months of age. mRNA expression levels were determined for 39 innate immune factors on a high-throughput qPCR system in samples from liver, abdominal fat, mesenteric fat and subcutaneous fat. Previous findings have suggested that cloning may affect certain phenotypic traits of pigs including basic...... concentrations and responsiveness of components of the innate immune system. Terminal body weights at 7½ - 9½ months of age were significantly higher for both (WT and cloned) obese groups compared to the lean groups. However, obese WT pigs weighed significantly more than obese cloned pigs (P

  14. Staphylococcus aureus innate immune evasion is lineage-specific: a bioinfomatics study.

    Science.gov (United States)

    McCarthy, Alex J; Lindsay, Jodi A

    2013-10-01

    Staphylococcus aureus is a major human pathogen, and is targeted by the host innate immune system. In response, S. aureus genomes encode dozens of secreted proteins that inhibit complement, chemotaxis and neutrophil activation resulting in successful evasion of innate immune responses. These proteins include immune evasion cluster proteins (IEC; Chp, Sak, Scn), staphylococcal superantigen-like proteins (SSLs), phenol soluble modulins (PSMs) and several leukocidins. Biochemical studies have indicated that genetic variants of these proteins can have unique functions. To ascertain the scale of genetic variation in secreted immune evasion proteins, whole genome sequences of 88 S. aureus isolates, representing 25 clonal complex (CC) lineages, in the public domain were analysed across 43 genes encoding 38 secreted innate immune evasion protein complexes. Twenty-three genes were variable, with between 2 and 15 variants, and the variants had lineage-specific distributions. They include genes encoding Eap, Ecb, Efb, Flipr/Flipr-like, Hla, Hld, Hlg, Sbi, Scin-B/C and 13 SSLs. Most of these protein complexes inhibit complement, chemotaxis and neutrophil activation suggesting that isolates from each S. aureus lineage respond to the innate immune system differently. In contrast, protein complexes that lyse neutrophils (LukSF-PVL, LukMF, LukED and PSMs) were highly conserved, but can be carried on mobile genetic elements (MGEs). MGEs also encode proteins with narrow host-specificities arguing that their acquisition has important roles in host/environmental adaptation. In conclusion, this data suggests that each lineage of S. aureus evades host immune responses differently, and that isolates can adapt to new host environments by acquiring MGEs and the immune evasion protein complexes that they encode. Cocktail therapeutics that targets multiple variant proteins may be the most appropriate strategy for controlling S. aureus infections. Copyright © 2013 Elsevier B.V. All rights

  15. Photoperiod but not food restriction modulates innate immunity in an opportunistic breeder, Loxia curvirostra.

    Science.gov (United States)

    Schultz, Elizabeth M; Hahn, Thomas P; Klasing, Kirk C

    2017-02-15

    An organism's investment in immune function often varies seasonally but understanding of how fluctuations in environmental conditions directly modulate investment remains limited. This experiment investigated how changes in photoperiod and food availability affect investment in constitutive innate immunity and the acute phase response induced by lipopolysaccharide (LPS) injections in captive red crossbills ( Loxia curvirostra ). Crossbills are reproductively flexible songbirds that specialize on an unpredictably available food resource and display temporal variation in immunity in the wild. Birds were separated into four treatments and exposed to long or short day lengths for 6 weeks before continuing on an ad libitum diet or experiencing a 20% food reduction for 10 days. Birds were un-injected or injected with LPS both before and after diet change. Innate immunity was quantified throughout the experiment to assess effects of photoperiod, food availability and their interactions on hemolysis-hemagglutination, haptoglobin, bacterial killing ability and leukocyte counts. Overall, increasing day length significantly increased both bacterial killing ability and leukocyte counts. Surprisingly, food restriction had little effect on the immune parameters, potentially owing to the 'low-cost' environment of captivity and suggesting that investment in innate immunity is prioritized and maintained whenever possible. LPS injections induced stereotypical sickness behaviors and increased bacterial killing ability in short day birds and complement activity (hemolysis) both before and after food restriction. These results demonstrate robust seasonal modulation of immune investment and an ability to maintain innate immunity in the face of limited resources in these temporally flexible songbirds. © 2017. Published by The Company of Biologists Ltd.

  16. Modulation of innate immune responses by Yersinia type III secretion system translocators and effectors.

    Science.gov (United States)

    Bliska, James B; Wang, Xiaoying; Viboud, Gloria I; Brodsky, Igor E

    2013-10-01

    The innate immune system of mammals responds to microbial infection through detection of conserved molecular determinants called 'pathogen-associated molecular patterns' (PAMPs). Pathogens use virulence factors to counteract PAMP-directed responses. The innate immune system can in turn recognize signals generated by virulence factors, allowing for a heightened response to dangerous pathogens. Many Gram-negative bacterial pathogens encode type III secretion systems (T3SSs) that translocate effector proteins, subvert PAMP-directed responses and are critical for infection. A plasmid-encoded T3SS in the human-pathogenic Yersinia species translocates seven effectors into infected host cells. Delivery of effectors by the T3SS requires plasma membrane insertion of two translocators, which are thought to form a channel called a translocon. Studies of the Yersinia T3SS have provided key advances in our understanding of how innate immune responses are generated by perturbations in plasma membrane and other signals that result from translocon insertion. Additionally, studies in this system revealed that effectors function to inhibit innateimmune responses resulting from insertion of translocons into plasma membrane. Here, we review these advances with the goal of providing insight into how a T3SS can activate and inhibit innate immune responses, allowing a virulent pathogen to bypass host defences. © 2013 John Wiley & Sons Ltd.

  17. The role of innate signaling in the homeostasis of tolerance and immunity in the intestine.

    NARCIS (Netherlands)

    Wells, J.; Loonen, L.M.P.; Karczewski, J.

    2010-01-01

    In the intestine innate recognition of microbes is achieved through pattern recognition receptor (PRR) families expressed in immune cells and different cell lineages of the intestinal epithelium. Toll-like receptor (TLR) and nucleotide-binding and oligomerization domain-like receptor (NLR) families

  18. Fungal innate immunity induced by bacterial microbe-associated molecular patterns (MAMPs)

    DEFF Research Database (Denmark)

    Ip Cho, Simon; Sundelin, Thomas; Erbs, Gitte

    2016-01-01

    Plants and animals detect bacterial presence through Microbe-Associated Molecular Patterns (MAMPs) which induce an innate immune response. The field of fungal-bacterial interaction at the molecular level is still in its infancy and little is known about MAMPs and their detection by fungi. Exposin...

  19. Innate immunity based cancer immunotherapy: B16-F10 murine melanoma model

    Czech Academy of Sciences Publication Activity Database

    Caisová, V.; Vieru, A.; Kumžáková, Z.; Glaserová, S.; Husniková, H.; Vácová, N.; Krejčová, G.; Paďouková, L.; Jochmanová, I.; Wolf, K. I.; Chmelař, J.; Kopecký, Jan; Ženka, J.

    2016-01-01

    Roč. 16, č. 1 (2016), č. článku 940. ISSN 1471-2407 Institutional support: RVO:60077344 Keywords : cancer immunotherapy * innate immunity * melanoma * neutrophils * resiquimod * mannan * phagocytosis Subject RIV: EC - Immunology Impact factor: 3.288, year: 2016

  20. Exosome RNA Released by Hepatocytes Regulates Innate Immune Responses to Hepatitis B Virus Infection

    Directory of Open Access Journals (Sweden)

    Takahisa Kouwaki

    2016-08-01

    Full Text Available The innate immune system is essential for controlling viral infection. Hepatitis B virus (HBV persistently infects human hepatocytes and causes hepatocellular carcinoma. However, the innate immune response to HBV infection in vivo remains unclear. Using a tree shrew animal model, we showed that HBV infection induced hepatic interferon (IFN-γ expression during early infection. Our in vitro study demonstrated that hepatic NK cells produced IFN-γ in response to HBV only in the presence of hepatic F4/80+ cells. Moreover, extracellular vesicles released from HBV-infected hepatocytes contained viral nucleic acids and induced NKG2D ligand expression in macrophages by stimulating MyD88, TICAM-1, and MAVS-dependent pathways. In addition, depletion of exosomes from extracellular vesicles markedly reduced NKG2D ligand expression, suggesting the importance of exosomes for NK cell activation. In contrast, infection of hepatocytes with HBV increased immunoregulatory microRNA levels in extracellular vesicles and exosomes, which were transferred to macrophages, thereby suppressing IL-12p35 mRNA expression in macrophages to counteract the host innate immune response. IFN-γ increased the hepatic expression of DDX60 and augmented the DDX60-dependent degradation of cytoplasmic HBV RNA. Our results elucidated the crucial role of exosomes in antiviral innate immune response against HBV.

  1. 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

  2. Bipolar and panic disorders may be associated with hereditary defects in the innate immune system

    DEFF Research Database (Denmark)

    Foldager, Leslie; Köhler, Karl Ole; Steffensen, Rudi Nora

    2014-01-01

    Background: Mannan-binding lectin (MBL) and mannan-binding lectin-associated serine protease-2 (MASP-2) represent important arms of the innate immune system, and different deficiencies may result in infections or autoimmune diseases. Both bipolar and panic disorders are associated with increased...

  3. Synergy between ficolin-2 and pentraxin 3 boosts innate immune recognition and complement deposition

    DEFF Research Database (Denmark)

    Ma, Ying Jie; Doni, Andrea; Hummelshøj, Tina

    2009-01-01

    The long pentraxin 3 (PTX3) is a multifunctional soluble pattern recognition molecule that is crucial in innate immune protection against opportunistic fungal pathogens such as Aspergillus fumigatus. The mechanisms that mediate downstream effects of PTX3 are largely unknown. However, PTX3 interac...

  4. Salmonella Typhimurium type III secretion effectors stimulate innate immune responses in cultured epithelial cells.

    Directory of Open Access Journals (Sweden)

    Vincent M Bruno

    2009-08-01

    Full Text Available Recognition of conserved bacterial products by innate immune receptors leads to inflammatory responses that control pathogen spread but that can also result in pathology. Intestinal epithelial cells are exposed to bacterial products and therefore must prevent signaling through innate immune receptors to avoid pathology. However, enteric pathogens are able to stimulate intestinal inflammation. We show here that the enteric pathogen Salmonella Typhimurium can stimulate innate immune responses in cultured epithelial cells by mechanisms that do not involve receptors of the innate immune system. Instead, S. Typhimurium stimulates these responses by delivering through its type III secretion system the bacterial effector proteins SopE, SopE2, and SopB, which in a redundant fashion stimulate Rho-family GTPases leading to the activation of mitogen-activated protein (MAP kinase and NF-kappaB signaling. These observations have implications for the understanding of the mechanisms by which Salmonella Typhimurium induces intestinal inflammation as well as other intestinal inflammatory pathologies.

  5. In Vivo Screening of Chemically Modified RNA duplexes for their Ability to Induce Innate Immune Responses

    DEFF Research Database (Denmark)

    Schyth, Brian Dall; Bramsen, Jesper Bertram; Kjems, Jørgen

    RNAs include the 2´-5´ oligoadenylate synthetase system, the protein kinase R, RIG-I and Toll-like receptor activated pathways all resulting in antiviral defence mechanism. We have previously shown that antiviral innate immune reactions against double stranded RNAs could be detected in vivo as partial...

  6. Waves of change: immunomodulation of the innate immune response by low frequency electromagnetic field exposure

    NARCIS (Netherlands)

    Golbach, L.A.

    2015-01-01

    In this thesis we investigated possible modulatory roles of low frequency electromagnetic fields (LF EMFs) exposure on the innate immune system. Recent decades have seen a huge increase in the use of electronic devices that nowadays enable us to communicate with distant family, enjoy

  7. MAP Kinase 4 Substrates and Plant Innate Immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt

    . For example, Arabidopsis MPK4 regulates the expression of a subset of defense genes via at least one WRKY transcription factor. We report here that MPK4 is found in complexes in vivo with (i) PAT1, component of the mRNA decapping machinery, (ii) AOC3, a component in the biosynthesis pathway of JA and (iii) e...

  8. Innate lymphoid cells: models of plasticity for immune homeostasis and rapid responsiveness in protection.

    Science.gov (United States)

    Almeida, F F; Belz, G T

    2016-09-01

    Innate lymphoid cells (ILCs) have stormed onto the immune landscape as "newly discovered" cell types. These tissue-resident sentinels are enriched at mucosal surfaces and engage in complex cross talk with elements of the adaptive immune system and microenvironment to orchestrate immune homeostasis. Many parallels exist between innate cells and T cells leading to the initial partitioning of ILCs into rather rigid subsets that reflect their "adaptive-like" effector cytokines profiles. ILCs themselves, however, have unique attributes that are only just beginning to be elucidated. These features result in complementarity with, rather than complete duplication of, functions of the adaptive immune system. Key transcription factors determine the pathway of differentiation of progenitors towards an ILC1, ILC2, or ILC3 subset. Once formed, flexibility in the responses of these subsets to stimuli unexpectedly allows transdifferentation between the different subsets and the acquisition of altered phenotypes and function. This provides a mechanism for rapid innate immune responsiveness. Here, we discuss the models of differentiation for maintenance and activation of tissue-resident ILCs in maintaining immune homeostasis and protection.

  9. TAM receptor tyrosine kinases as emerging targets of innate immune checkpoint blockade for cancer therapy.

    Science.gov (United States)

    Akalu, Yemsratch T; Rothlin, Carla V; Ghosh, Sourav

    2017-03-01

    Cancer immunotherapy utilizing T-cell checkpoint inhibitors has shown tremendous clinical success. Yet, this mode of treatment is effective in only a subset of patients. Unresponsive patients tend to have non-T-cell-inflamed tumors that lack markers associated with the activation of adaptive anti-tumor immune responses. Notably, elimination of cancer cells by T cells is critically dependent on the optimal activity of innate immune cells. Therefore, identifying new targets that regulate innate immune cell function and promote the engagement of adaptive tumoricidal responses is likely to lead to the development of improved therapies against cancer. Here, we review the TAM receptor tyrosine kinases-TYRO3, AXL, and MERTK-as an emerging class of innate immune checkpoints that participate in key steps of anti-tumoral immunity. Namely, TAM-mediated efferocytosis, negative regulation of dendritic cell activity, and dysregulated production of chemokines collectively favor the escape of malignant cells. Hence, disabling TAM signaling may promote engagement of adaptive immunity and complement T-cell checkpoint blockade. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  10. The CD47-SIRPα signaling axis as an innate immune checkpoint in cancer.

    Science.gov (United States)

    Matlung, Hanke L; Szilagyi, Katka; Barclay, Neil A; van den Berg, Timo K

    2017-03-01

    Immune checkpoint inhibitors, including those targeting CTLA-4/B7 and the PD-1/PD-L1 inhibitory pathways, are now available for clinical use in cancer patients, with other interesting checkpoint inhibitors being currently in development. Most of these have the purpose to promote adaptive T cell-mediated immunity against cancer. Here, we review another checkpoint acting to potentiate the activity of innate immune cells towards cancer. This innate immune checkpoint is composed of what has become known as the 'don't-eat me' signal CD47, which is a protein broadly expressed on normal cells and often overexpressed on cancer cells, and its counter-receptor, the myeloid inhibitory immunoreceptor SIRPα. Blocking CD47-SIRPα interactions has been shown to promote the destruction of cancer cells by phagocytes, including macrophages and neutrophils. Furthermore, there is growing evidence that targeting of the CD47-SIRPα axis may also promote antigen-presenting cell function and thereby stimulate adaptive T cell-mediated anti-cancer immunity. The development of CD47-SIRPα checkpoint inhibitors and the potential side effects that these may have are discussed. Collectively, this identifies the CD47-SIRPα axis as a promising innate immune checkpoint in cancer, and with data of the first clinical studies with CD47-SIRPα checkpoint inhibitors expected within the coming years, this is an exciting and rapidly developing field. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. FORMATION OF INNATE AND ADAPTIVE IMMUNE RESPONSE UNDER THE INFLUENCE OF DIFFERENT FLAVIVIRUS VACCINES

    Directory of Open Access Journals (Sweden)

    N. V. Krylova

    2015-01-01

    Full Text Available The review examines in a comparative perspective the key moments of formation of innate and adaptive immune responses to different types of current flavivirus vaccines: live attenuated against yellow fever virus and inactivated whole virus against tick-borne encephalitis virus. Particular attention is paid to the ability of these different vaccines, containing exogenous pathogen-associated molecular structures, to stimulate innate immunity. Live attenuated vaccine by infecting several subtypes of dendritic cells activates them through various pattern-recognition receptors, such as Tolland RIG-I-like receptors, which leads to significant production of proinflammatory cytokines, including interferon-α primary mediator of innate antiviral immunity. By simulating natural viral infection, this vaccine quickly spreads over the vascular network, and the dendritic cells, activated by it, migrate to the draining lymph nodes and trigger multiple foci of Tand B-cell activation. Inactivated vaccine stimulates the innate immunity predominantly at the injection site, and for the sufficient activation requires the presence in its composition of an adjuvant (aluminum hydroxide, which effects the formation and activation of inflammasomes, ensuring the formation and secretion of IL-1β and IL-18 that, in turn, trigger a cascade of cellular and humoral innate immune responses. We demonstrated the possibility of involvement in the induction of innate immunity, mediated by the inactivated vaccine, endogenous pathogenassociated molecular patterns (uric acid and host cell DNA, forming at the vaccine injection site. We discuss the triggering of Band T-cell responses by flavivirus vaccines that determine various duration of protection against various pathogens. A single injection of the live vaccine against yellow fever virus induces polyvalent adaptive immune response, including the production of cytotoxic T-lymphocytes, Th1and Th2-cells and neutralizing antibodies

  12. A method for high purity intestinal epithelial cell culture from adult human and murine tissues for the investigation of innate immune function.

    Science.gov (United States)

    Graves, Christina L; Harden, Scott W; LaPato, Melissa; Nelson, Michael; Amador, Byron; Sorenson, Heather; Frazier, Charles J; Wallet, Shannon M

    2014-12-01

    Intestinal epithelial cells (IECs) serve as an important physiologic barrier between environmental antigens and the host intestinal immune system. Thus, IECs serve as a first line of defense and may act as sentinel cells during inflammatory insults. Despite recent renewed interest in IEC contributions to host immune function, the study of primary IEC has been hindered by lack of a robust culture technique, particularly for small intestinal and adult tissues. Here, a novel adaptation for culture of primary IEC is described for human duodenal organ donor tissue as well as duodenum and colon of adult mice. These epithelial cell cultures display characteristic phenotypes and are of high purity. In addition, the innate immune function of human primary IEC, specifically with regard to Toll-like receptor (TLR) expression and microbial ligand responsiveness, is contrasted with a commonly used intestinal epithelial cell line (HT-29). Specifically, TLR expression at the mRNA level and production of cytokine (IFNγ and TNFα) in response to TLR agonist stimulation is assessed. Differential expression of TLRs as well as innate immune responses to ligand stimulation is observed in human-derived cultures compared to that of HT-29. Thus, use of this adapted method to culture primary epithelial cells from adult human donors and from adult mice will allow for more appropriate studies of IECs as innate immune effectors. Published by Elsevier B.V.

  13. Differences in innate immune response gene regulation in the middle ear of children who are otitis prone and in those not otitis prone

    Science.gov (United States)

    Casey, Janet; Pichichero, Michael

    2016-01-01

    Objective: Acute otitis media (AOM) causes an inflammatory response in the middle ear. We assessed differences in innate immune responses involved in bacterial defense at onset of AOM in children who were stringently defined as otitis prone (sOP) and children not otitis prone (NOP). Study Design: Innate immune genes analysis from middle ear fluid (MEF) samples of children. Methods: Genes of toll-like receptors (TLR), nod-like and retinoic acid-inducible gene-I-like receptors, downstream effectors important for inflammation and apoptosis, including cytokines and chemokines, were studied from MEF samples by using a real-time polymerase chain reaction array. Protein levels of differentially regulated genes were measured by Luminex. Results: Gene expression in MEF among children who were sOP was significantly different in upregulation of interleukin 8, secretory leukocyte peptidase inhibitor, and chemokine (C-C motif) ligand 3, and in downregulation of interferon regulatory factor 7 and its related signaling molecules interferon alpha, Toll-like receptor adaptor molecule 2, chemokine (C-C motif) ligand 5, and mitogen-activated protein kinase 8 compared with children who were NOP. Differences in innate gene regulation were similar when AOM was caused by Streptococcus pneumoniae or nontypeable Haemophilus influenzae. Conclusion: Innate-immune response genes are differentially regulated in children who were sOP compared with children with NOP. PMID:28124644

  14. Role of Soluble Innate Effector Molecules in Pulmonary Defense against Fungal Pathogens

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    Soledad R. Ordonez

    2017-10-01

    Full Text Available Fungal infections of the lung are life-threatening but rarely occur in healthy, immunocompetent individuals, indicating efficient clearance by pulmonary defense mechanisms. Upon inhalation, fungi will first encounter the airway surface liquid which contains several soluble effector molecules that form the first barrier of defense against fungal infections. These include host defense peptides, like LL-37 and defensins that can neutralize fungi by direct killing of the pathogen, and collectins, such as surfactant protein A and D, that can aggregate fungi and stimulate phagocytosis. In addition, these molecules have immunomodulatory activities which can aid in fungal clearance from the lung. However, existing observations are based on in vitro studies which do not reflect the complexity of the lung and its airway surface liquid. Ionic strength, pH, and the presence of mucus can have strong detrimental effects on antifungal activity, while the potential synergistic interplay between soluble effector molecules is largely unknown. In this review, we describe the current knowledge on soluble effector molecules that contribute to antifungal activity, the importance of environmental factors and discuss the future directions required to understand the innate antifungal defense in the lung.

  15. Role of Soluble Innate Effector Molecules in Pulmonary Defense against Fungal Pathogens

    Science.gov (United States)

    Ordonez, Soledad R.; Veldhuizen, Edwin J. A.; van Eijk, Martin; Haagsman, Henk P.

    2017-01-01

    Fungal infections of the lung are life-threatening but rarely occur in healthy, immunocompetent individuals, indicating efficient clearance by pulmonary defense mechanisms. Upon inhalation, fungi will first encounter the airway surface liquid which contains several soluble effector molecules that form the first barrier of defense against fungal infections. These include host defense peptides, like LL-37 and defensins that can neutralize fungi by direct killing of the pathogen, and collectins, such as surfactant protein A and D, that can aggregate fungi and stimulate phagocytosis. In addition, these molecules have immunomodulatory activities which can aid in fungal clearance from the lung. However, existing observations are based on in vitro studies which do not reflect the complexity of the lung and its airway surface liquid. Ionic strength, pH, and the presence of mucus can have strong detrimental effects on antifungal activity, while the potential synergistic interplay between soluble effector molecules is largely unknown. In this review, we describe the current knowledge on soluble effector molecules that contribute to antifungal activity, the importance of environmental factors and discuss the future directions required to understand the innate antifungal defense in the lung. PMID:29163395

  16. What vaccination studies tell us about immunological memory within the innate immune system of cultured shrimp and crayfish.

    Science.gov (United States)

    Chang, Yu-Hsuan; Kumar, Ramya; Ng, Tze Hann; Wang, Han-Ching

    2018-03-01

    The possibility of immunological memory in invertebrates is a topic that has recently attracted a lot of attention. Today, even vertebrates are known to exhibit innate immune responses that show memory-like properties, and since these responses are triggered by cells that are involved in the innate immune system, it seems that immune specificity and immune memory do not necessarily require the presence of B cells and T cells after all. This kind of immune response has been called "immune priming" or "trained immunity". In this report, we review recent observations and our current understanding of immunological memory within the innate immune system in cultured shrimp and crayfish after vaccination with live vaccine, killed vaccine and subunit vaccines. We also discuss the possible mechanisms involved in this immune response. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Innate immune responses against foot-and-mouth disease virus: current understanding and future directions.

    Science.gov (United States)

    Summerfield, Artur; Guzylack-Piriou, Laurence; Harwood, Lisa; McCullough, Kenneth C

    2009-03-15

    Foot-and-mouth disease (FMD) represents one of the most economically important diseases of farm animals. The basis for the threat caused by this virus is the high speed of replication, short incubation time, high contagiousness, and high mutation rate resulting in constant antigenic changes. Thus, although protective immune responses against FMD virus (FMDV) can be efficacious, the rapidity of virus replication and spread can outpace immune defence development and overrun the immune system. FMDV can also evade innate immune responses through its ability to shut down cellular protein synthesis, including IFN type I, in susceptible epithelial cells. This is important for virus evolution, as FMDV is quite sensitive to the action of IFN. Despite this, innate immune responses are probably induced in vivo, although detailed studies on this subject are lacking. Accordingly, this interaction of FMDV with cells of the innate immune system is of particular interest. Dendritic cells (DC) can be infected by FMDV and support viral RNA replication, and viral protein synthesis but the latter is inefficient or abortive, leading most often to incomplete replication and progeny virus release. As a result DC can be activated, and particularly in the case of plasmacytoid DC (pDC), this is manifest in terms of IFN-alpha release. Our current state of knowledge on innate immune responses induced by FMDV is still only at a relatively early stage of understanding. As we progress, the investigations in this area will help to improve the design of current vaccines and the development of novel control strategies against FMD.

  18. IL-36/LXR axis modulates cholesterol metabolism and immune defense to Mycobacterium tuberculosis.

    Science.gov (United States)

    Ahsan, Fadhil; Maertzdorf, Jeroen; Guhlich-Bornhof, Ute; Kaufmann, Stefan H E; Moura-Alves, Pedro

    2018-01-24

    Mycobacterium tuberculosis (Mtb) is a life-threatening pathogen in humans. Bacterial infection of macrophages usually triggers strong innate immune mechanisms, including IL-1 cytokine secretion. The newer member of the IL-1 family, IL-36, was recently shown to be involved in cellular defense against Mtb. To unveil the underlying mechanism of IL-36 induced antibacterial activity, we analyzed its role in the regulation of cholesterol metabolism, together with the involvement of Liver X Receptor (LXR) in this process. We report that, in Mtb-infected macrophages, IL-36 signaling modulates cholesterol biosynthesis and efflux via LXR. Moreover, IL-36 induces the expression of cholesterol-converting enzymes and the accumulation of LXR ligands, such as oxysterols. Ultimately, both IL-36 and LXR signaling play a role in the regulation of antimicrobial peptides expression and in Mtb growth restriction. These data provide novel evidence for the importance of IL-36 and cholesterol metabolism mediated by LXR in cellular host defense against Mtb.

  19. 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

  20. Ebola Virus Glycoprotein Induces an Innate Immune Response In vivo via TLR4

    Directory of Open Access Journals (Sweden)

    Chih-Yun Lai

    2017-08-01

    Full Text Available Ebola virus (EBOV, a member of the Filoviridae family, causes the most severe form of viral hemorrhagic fever. Although no FDA licensed vaccine or treatment against Ebola virus disease (EVD is currently available, Ebola virus glycoprotein (GP is the major antigen used in all candidate Ebola vaccines. Recent reports of protection as quickly as within 6 days of administration of the rVSV-based vaccine expressing EBOV GP before robust humoral responses were generated suggests that the innate immune responses elicited early after vaccination may contribute to the protection. However, the innate immune responses induced by EBOV GP in the absence of viral vectors or adjuvants have not been fully characterized in vivo. Our recent studies demonstrated that immunization with highly purified recombinant GP in the absence of adjuvants induced a robust IgG response and partial protection against EBOV infection suggesting that GP alone can induce protective immunity. In this study we investigated the early immune response to purified EBOV GP alone in vitro and in vivo. We show that GP was efficiently internalized by antigen presenting cells and subsequently induced production of key inflammatory cytokines. In vivo, immunization of mice with EBOV GP triggered the production of key Th1 and Th2 innate immune cytokines and chemokines, which directly governed the recruitment of CD11b+ macrophages and CD11c+ dendritic cells to the draining lymph nodes (DLNs. Pre-treatment of mice with a TLR4 antagonist inhibited GP-induced cytokine production and recruitment of immune cells to the DLN. EBOV GP also upregulated the expression of costimulatory molecules in bone marrow derived macrophages suggesting its ability to enhance APC stimulatory capacity, which is critical for the induction of effective antigen-specific adaptive immunity. Collectively, these results provide the first in vivo evidence that early innate immune responses to EBOV GP are mediated via the TLR4

  1. Subversion of innate defenses by the interplay between DENV and pre-existing enhancing antibodies: TLRs signaling collapse.

    Directory of Open Access Journals (Sweden)

    Naphak Modhiran

    defense resulting in suppression of an array of innate immune responses. Interestingly, this phenomenon specifically occurred during the severe form of DENV infection but not in the mild form of disease.

  2. Mycobacterial growth inhibition is associated with trained innate immunity.

    Science.gov (United States)

    Joosten, Simone A; van Meijgaarden, Krista E; Arend, Sandra M; Prins, Corine; Oftung, Fredrik; Korsvold, Gro Ellen; Kik, Sandra V; Arts, Rob Jw; van Crevel, Reinout; Netea, Mihai G; Ottenhoff, Tom Hm

    2018-05-01

    The lack of defined correlates of protection hampers development of vaccines against tuberculosis (TB). In vitro mycobacterial outgrowth assays are thought to better capture the complexity of the human host/Mycobacterium tuberculosis (Mtb) interaction. Here, we used a mycobacterial growth inhibition assay (MGIA) based on peripheral blood mononuclear cells to investigate the capacity to control outgrowth of bacille Calmette-Guérin (BCG). Interestingly, strong control of BCG outgrowth was observed almost exclusively in individuals with recent exposure to Mtb, but not in (long-term) latent TB infection, and only modestly in BCG vaccinees. Mechanistically, control of mycobacterial outgrowth strongly correlated with the presence of a CD14dim monocyte population, but also required the presence of T cells. The nonclassical monocytes produced CXCL10, and CXCR3 receptor blockade inhibited the capacity to control BCG outgrowth. Expression of CXCR3 splice variants was altered in recently Mtb-exposed individuals. Cytokines previously associated with trained immunity were detected in MGIA supernatants, and CXCL9, CXCL10, and CXCL11 represent new markers of trained immunity. These data indicate that CXCR3 ligands are associated with trained immunity and are critical factors in controlling mycobacterial outgrowth. In conclusion, control of mycobacterial outgrowth early after exposure to Mtb is the result of trained immunity mediated by a CXCL10-producing nonclassical CD14dim monocyte subset.

  3. Strategies to Improve Vaccine Efficacy against Tuberculosis by Targeting Innate Immunity

    Directory of Open Access Journals (Sweden)

    Ulrich E. Schaible

    2017-12-01

    Full Text Available The global tuberculosis epidemic is the most common cause of death after infectious disease worldwide. Increasing numbers of infections with multi- and extensively drug-resistant variants of the Mycobacterium tuberculosis complex, resistant even to newly discovered and last resort antibiotics, highlight the urgent need for an efficient vaccine. The protective efficacy to pulmonary tuberculosis in adults of the only currently available vaccine, M. bovis BCG, is unsatisfactory and geographically diverse. More importantly, recent clinical studies on new vaccine candidates did not prove to be better than BCG, yet. Here, we propose and discuss novel strategies to improve efficacy of existing anti-tuberculosis vaccines. Modulation of innate immune responses upon vaccination already provided promising results in animal models of tuberculosis. For instance, neutrophils have been shown to influence vaccine efficacy, both, positively and negatively, and stimulate specific antibody secretion. Modulating immune regulatory properties after vaccination such as induction of different types of innate immune cell death, myeloid-derived suppressor or regulatory T cells, production of anti-inflammatory cytokines such as IL-10 may have beneficial effects on protection efficacy. Incorporation of lipid antigens presented via CD1 molecules to T cells have been discussed as a way to enhance vaccine efficacy. Finally, concepts of dendritic cell-based immunotherapies or training the innate immune memory may be exploitable for future vaccination strategies against tuberculosis. In this review, we put a spotlight on host immune networks as potential targets to boost protection by old and new tuberculosis vaccines.

  4. Fluorescent nanodiamonds engage innate immune effector cells: A potential vehicle for targeted anti-tumor immunotherapy.

    Science.gov (United States)

    Suarez-Kelly, Lorena P; Campbell, Amanda R; Rampersaud, Isaac V; Bumb, Ambika; Wang, Min S; Butchar, Jonathan P; Tridandapani, Susheela; Yu, Lianbo; Rampersaud, Arfaan A; Carson, William E

    2017-04-01

    Fluorescent nanodiamonds (FNDs) are nontoxic, infinitely photostable, and emit fluorescence in the near infrared region. Natural killer (NK) cells and monocytes are part of the innate immune system and are crucial to the control of carcinogenesis. FND-mediated stimulation of these cells may serve as a strategy to enhance anti-tumor activity. FNDs were fabricated with a diameter of 70±28 nm. Innate immune cell FND uptake, viability, surface marker expression, and cytokine production were evaluated in vitro. Evaluation of fluorescence emission from the FNDs was conducted in an animal model. In vitro results demonstrated that treatment of immune cells with FNDs resulted in significant dose-dependent FND uptake, no compromise in cell viability, and immune cell activation. FNDs were visualized in an animal model. Hence, FNDs may serve as novel agents with "track and trace" capabilities to stimulate innate immune cell anti-tumor responses, especially as FNDs are amenable to surface-conjugation with immunomodulatory molecules. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Innate lymphoid cells as regulators of immunity, inflammation and tissue homeostasis.

    Science.gov (United States)

    Klose, Christoph S N; Artis, David

    2016-06-21

    Research over the last 7 years has led to the formal identification of innate lymphoid cells (ILCs), increased the understanding of their tissue distribution and has established essential functions of ILCs in diverse physiological processes. These include resistance to pathogens, the regulation of autoimmune inflammation, tissue remodeling, cancer and metabolic homeostasis. Notably, many ILC functions appear to be regulated by mechanisms distinct from those of other innate and adaptive immune cells. In this Review, we focus on how group 2 ILC (ILC2) and group 3 ILC (ILC3) responses are regulated and how these cells interact with other immune and non-immune cells to mediate their functions. We highlight experimental evidence from mouse models and patient-based studies that have elucidated the effects of ILCs on the maintenance of tissue homeostasis and the consequences for health and disease.

  6. Low-dose radiation induces drosophila innate immunity through toll pathway activation

    International Nuclear Information System (INIS)

    Seong, Ki Moon; Kim, Cha Soon; Lee, Byung-Sub; Nam, Seon Young; Yang, Kwang Hee; Kim, Ji-Young; Jin, Young-Woo; Park, Joong-Jean; Min, Kyung-Jin

    2012-01-01

    Numerous studies report that exposing certain organisms to low-dose radiation induces beneficial effects on lifespan, tumorigenesis, and immunity. By analyzing survival after bacterial infection and antimicrobial peptide gene expression in irradiated flies, we demonstrate that low-dose irradiation of Drosophila enhances innate immunity. Low-dose irradiation of flies significantly increased resistance against gram-positive and gram-negative bacterial infections, as well as expression of several antimicrobial peptide genes. Additionally, low-dose irradiation also resulted in a specific increase in expression of key proteins of the Toll signaling pathway and phosphorylated forms of p38 and N-terminal kinase (JNK). These results indicate that innate immunity is activated after low-dose irradiation through Toll signaling pathway in Drosophila. (author)

  7. MiRNAs at the Crossroads between Innate Immunity and Cancer: Focus on Macrophages

    Directory of Open Access Journals (Sweden)

    Graziella Curtale

    2018-02-01

    Full Text Available Innate immune cells form an integrative component of the tumor microenvironment (TME, which can control or prevent tumor initiation and progression, due to the simultaneous processing of both anti- and pro-growth signals. This decision-making process is a consequence of gene expression changes, which are in part dependent on post-transcriptional regulatory mechanisms. In this context, microRNAs have been shown to regulate both recruitment and activation of specific tumor-associated immune cells in the TME. This review aims to describe the most important microRNAs that target cancer-related innate immune pathways. The role of exosomal microRNAs in tumor progression and microRNA-based therapeutic strategies are also discussed.

  8. Crosstalk between Innate Lymphoid Cells and Other Immune Cells in the Tumor Microenvironment

    Directory of Open Access Journals (Sweden)

    Fabian Flores-Borja

    2016-01-01

    Full Text Available Our knowledge and understanding of the tumor microenvironment (TME have been recently expanded with the recognition of the important role of innate lymphoid cells (ILC. Three different groups of ILC have been described based on their ability to produce cytokines that mediate the interactions between innate and adaptive immune cells in a variety of immune responses in infection, allergy, and autoimmunity. However, recent evidence from experimental models and clinical studies has demonstrated that ILC contribute to the mechanisms that generate suppressive or tolerant environments that allow tumor regression or progression. Defining the complex network of interactions and crosstalk of ILC with other immune cells and understanding the specific contributions of each type of ILC leading to tumor development will allow the manipulation of their function and will be important to develop new interventions and therapeutic strategies.

  9. Crosstalk between Innate Lymphoid Cells and Other Immune Cells in the Tumor Microenvironment

    Science.gov (United States)

    Irshad, Sheeba; Gordon, Peter; Wong, Felix; Sheriff, Ibrahim; Tutt, Andrew; Ng, Tony

    2016-01-01

    Our knowledge and understanding of the tumor microenvironment (TME) have been recently expanded with the recognition of the important role of innate lymphoid cells (ILC). Three different groups of ILC have been described based on their ability to produce cytokines that mediate the interactions between innate and adaptive immune cells in a variety of immune responses in infection, allergy, and autoimmunity. However, recent evidence from experimental models and clinical studies has demonstrated that ILC contribute to the mechanisms that generate suppressive or tolerant environments that allow tumor regression or progression. Defining the complex network of interactions and crosstalk of ILC with other immune cells and understanding the specific contributions of each type of ILC leading to tumor development will allow the manipulation of their function and will be important to develop new interventions and therapeutic strategies. PMID:27882334

  10. Genetic and phenotypic relationships between immune defense, melanism and life-history traits at different temperatures and sexes in Tenebrio molitor.

    Science.gov (United States)

    Prokkola, J; Roff, D; Kärkkäinen, T; Krams, I; Rantala, M J

    2013-08-01

    Insect cuticle melanism is linked to a number of life-history traits, and a positive relationship is hypothesized between melanism and the strength of immune defense. In this study, the phenotypic and genetic relationships between cuticular melanization, innate immune defense, individual development time and body size were studied in the mealworm beetle (Tenebrio molitor) using three different temperatures with a half-sib breeding design. Both innate immune defense and cuticle darkness were higher in females than males, and a positive correlation between the traits was found at the lowest temperature. The effect of temperature on all the measured traits was strong, with encapsulation ability and development time decreasing and cuticle darkness increasing with a rise in temperature, and body size showing a curved response. The analysis showed a highly integrated system sensitive to environmental change involving physiological, morphological and life-history traits.

  11. I-L-C-2 it: type 2 immunity and group 2 innate lymphoid cells in homeostasis.

    Science.gov (United States)

    von Moltke, Jakob; Locksley, Richard M

    2014-12-01

    Innate type 2 immune cells are activated in response to helminths, allergens, and certain types of proteases and particulates. Recently, innate type 2 immune pathways have also been implicated in protective host responses to homeostatic perturbations, such as metabolic dysfunction, atherosclerosis, and tissue injury. In this context, innate type 2 cytokines stimulate local tissues, recruit eosinophils, and alternatively activate macrophages to restore homeostasis. As the major source of innate interleukin (IL)-5 and IL-13, group 2 innate lymphoid cells are positioned to initiate and maintain homeostatic type 2 responses. The absence of exogenous stimuli in these processes implicates endogenous pathways in the activation of type 2 immunity and suggests an alternative evolutionary trajectory for type 2 immunity, apart from its role in response to helminths and allergens. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. The Role of Quinine-Responsive Taste Receptor Family 2 in Airway Immune Defense and Chronic Rhinosinusitis

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    Alan D. Workman

    2018-03-01

    Full Text Available BackgroundBitter (T2R and sweet (T1R taste receptors in the airway are important in innate immune defense, and variations in taste receptor functionality in one T2R (T2R38 correlate with disease status and disease severity in chronic rhinosinusitis (CRS. Quinine is a bitter compound that is an agonist for several T2Rs also expressed on sinonasal cells, but not for T2R38. Because of this property, quinine may stimulate innate immune defense mechanisms in the airway, and functional differences in quinine perception may be reflective of disease status in CRS.MethodsDemographic and taste intensity data were collected prospectively from CRS patients and non-CRS control subjects. Sinonasal tissue from patients undergoing rhinologic surgery was also collected and grown at an air–liquid interface (ALI. Nitric oxide (NO production and dynamic regulation of ciliary beat frequency in response to quinine stimulation were assessed in vitro.ResultsQuinine reliably increased ciliary beat frequency and NO production in ALI cultures in a manner consistent with T2R activation (p < 0.01. Quinine taste intensity rating was performed in 328 CRS patients and 287 control subjects demonstrating that CRS with nasal polyps (CRSwNP patients rated quinine as significantly less intense than did control subjects.ConclusionQuinine stimulates airway innate immune defenses by increasing ciliary beat frequency and stimulating NO production in a manner fitting with T2R activation. Patient variability in quinine sensitivity is observed in taste intensity ratings, and gustatory quinine “insensitivity” is associated with CRSwNP status. Thus, taste tests for quinine may be a biomarker for CRSwNP, and topical quinine has therapeutic potential as a stimulant of innate defenses.

  13. Innate and adaptive immune traits are differentially affected by genetic and environmental factors

    Science.gov (United States)

    Mangino, Massimo; Roederer, Mario; Beddall, Margaret H.; Nestle, Frank O.; Spector, Tim D.

    2017-01-01

    The diversity and activity of leukocytes is controlled by genetic and environmental influences to maintain balanced immune responses. However, the relative contribution of environmental compared with genetic factors that affect variations in immune traits is unknown. Here we analyse 23,394 immune phenotypes in 497 adult female twins. 76% of these traits show a predominantly heritable influence, whereas 24% are mostly influenced by environment. These data highlight the importance of shared childhood environmental influences such as diet, infections or microbes in shaping immune homeostasis for monocytes, B1 cells, γδ T cells and NKT cells, whereas dendritic cells, B2 cells, CD4+ T and CD8+ T cells are more influenced by genetics. Although leukocyte subsets are influenced by genetics and environment, adaptive immune traits are more affected by genetics, whereas innate immune traits are more affected by environment. PMID:28054551

  14. Immune modules shared by innate lymphoid cells and T cells.

    Science.gov (United States)

    Robinette, Michelle L; Colonna, Marco

    2016-11-01

    In recent years, innate lymphoid cells (ILCs) have emerged as innate correlates to T cells. The similarities between ILCs and T cells indicate that lymphocytes of fundamentally distinct lineages can share core "immune modules" that encompass transcriptional circuitry and effector functions while using nonredundant complementary mechanisms of pattern recognition to enact these functions. We review modules currently recognized to be shared between ILCs and T cells. Copyright © 2016 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  15. Age-associated changes in monocyte and innate immune activation markers occur more rapidly in HIV infected women.

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    Genevieve E Martin

    Full Text Available Aging is associated with immune dysfunction and the related development of conditions with an inflammatory pathogenesis. Some of these immune changes are also observed in HIV infection, but the interaction between immune changes with aging and HIV infection are unknown. Whilst sex differences in innate immunity are recognized, little research into innate immune aging has been performed on women.This cross-sectional study of HIV positive and negative women used whole blood flow cytometric analysis to characterize monocyte and CD8(+ T cell subsets. Plasma markers of innate immune activation were measured using standard ELISA-based assays.HIV positive women exhibited elevated plasma levels of the innate immune activation markers CXCL10 (p<0.001, soluble CD163 (sCD163, p = 0.001, sCD14 (p = 0.022, neopterin (p = 0.029 and an increased proportion of CD16(+ monocytes (p = 0.009 compared to uninfected controls. Levels of the innate immune aging biomarkers sCD163 and the proportion of CD16(+ monocytes were equivalent to those observed in HIV negative women aged 14.5 and 10.6 years older, respectively. CXCL10 increased with age at an accelerated rate in HIV positive women (p = 0.002 suggesting a synergistic effect between HIV and aging on innate immune activation. Multivariable modeling indicated that age-related increases in innate immune biomarkers CXCL10 and sCD163 are independent of senescent changes in CD8(+ T lymphocytes.Quantifying the impact of HIV on immune aging reveals that HIV infection in women confers the equivalent of a 10-14 year increase in the levels of innate immune aging markers. These changes may contribute to the increased risk of inflammatory age-related diseases in HIV positive women.

  16. Age-associated changes in monocyte and innate immune activation markers occur more rapidly in HIV infected women.

    Science.gov (United States)

    Martin, Genevieve E; Gouillou, Maelenn; Hearps, Anna C; Angelovich, Thomas A; Cheng, Allen C; Lynch, Fiona; Cheng, Wan-Jung; Paukovics, Geza; Palmer, Clovis S; Novak, Richard M; Jaworowski, Anthony; Landay, Alan L; Crowe, Suzanne M

    2013-01-01

    Aging is associated with immune dysfunction and the related development of conditions with an inflammatory pathogenesis. Some of these immune changes are also observed in HIV infection, but the interaction between immune changes with aging and HIV infection are unknown. Whilst sex differences in innate immunity are recognized, little research into innate immune aging has been performed on women. This cross-sectional study of HIV positive and negative women used whole blood flow cytometric analysis to characterize monocyte and CD8(+) T cell subsets. Plasma markers of innate immune activation were measured using standard ELISA-based assays. HIV positive women exhibited elevated plasma levels of the innate immune activation markers CXCL10 (p<0.001), soluble CD163 (sCD163, p = 0.001), sCD14 (p = 0.022), neopterin (p = 0.029) and an increased proportion of CD16(+) monocytes (p = 0.009) compared to uninfected controls. Levels of the innate immune aging biomarkers sCD163 and the proportion of CD16(+) monocytes were equivalent to those observed in HIV negative women aged 14.5 and 10.6 years older, respectively. CXCL10 increased with age at an accelerated rate in HIV positive women (p = 0.002) suggesting a synergistic effect between HIV and aging on innate immune activation. Multivariable modeling indicated that age-related increases in innate immune biomarkers CXCL10 and sCD163 are independent of senescent changes in CD8(+) T lymphocytes. Quantifying the impact of HIV on immune aging reveals that HIV infection in women confers the equivalent of a 10-14 year increase in the levels of innate immune aging markers. These changes may contribute to the increased risk of inflammatory age-related diseases in HIV positive women.

  17. Microbial environment affects innate immunity in two closely related earthworm species Eisenia andrei and Eisenia fetida.

    Directory of Open Access Journals (Sweden)

    Jiří Dvořák

    Full Text Available Survival of earthworms in the environment depends on their ability to recognize and eliminate potential pathogens. This work is aimed to compare the innate defense mechanisms of two closely related earthworm species, Eisenia andrei and Eisenia fetida, that inhabit substantially different ecological niches. While E. andrei lives in a compost and manure, E. fetida can be found in the litter layer in forests. Therefore, the influence of environment-specific microbiota on the immune response of both species was followed. Firstly, a reliable method to discern between E. andrei and E. fetida based on species-specific primers for cytochrome c oxidase I (COI and stringent PCR conditions was developed. Secondly, to analyze the immunological profile in both earthworm species, the activity and expression of lysozyme, pattern recognition protein CCF, and antimicrobial proteins with hemolytic function, fetidin and lysenins, have been assessed. Whereas, CCF and lysozyme showed only slight differences in the expression and activity, fetidin/lysenins expression as well as the hemolytic activity was considerably higher in E. andrei as compared to E. fetida. The expression of fetidin/lysenins in E. fetida was not affected upon the challenge with compost microbiota, suggesting more substantial changes in the regulation of the gene expression. Genomic DNA analyses revealed significantly higher level of fetidin/lysenins (determined using universal primer pairs in E. andrei compared to E. fetida. It can be hypothesized that E. andrei colonizing compost as a new habitat acquired an evolutionary selection advantage resulting in a higher expression of antimicrobial proteins.

  18. Quantitative Methods for Measuring Repair Rates and Innate-Immune Cell Responses in Wounded Mouse Skin

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    Zhi Li

    2018-02-01

    Full Text Available In skin wounds, innate-immune cells clear up tissue debris and microbial contamination, and also secrete cytokines and other growth factors that impact repair process such as re-epithelialization and wound closure. After injury, there is a rapid influx and efflux of immune cells at wound sites, yet the function of each innate cell population in skin repair is still under investigation. Flow cytometry is a valuable research tool for detecting and quantifying immune cells; however, in mouse back skin, the difficulty in extracting immune cells from small area of skin due to tissue complexity has made cytometric analysis an underutilized tool. In this paper, we provide detailed methods on the digestion of lesion-specific skin without disrupting antigen expression followed by multiplex cell staining that allows for identification of seven innate-immune populations, including rare subsets such as group-3 innate lymphoid cells (ILC3s, by flow-cytometry analysis. Furthermore, when studying the functions of immune cells to tissue repair an important metric to monitor is size of the wound opening. Normal wounds close steadily albeit at non-linear rates, while slow or stalled wound closure can indicate an underlying problem with the repair process. Calliper measurements are difficult and time-consuming to obtain and can require repeated sedation of experimental animals. We provide advanced methods for measuring of wound openness; digital 3D image capture and semi-automated image processing that allows for unbiased, reliable measurements that can be taken repeatedly over time.

  19. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system

    Directory of Open Access Journals (Sweden)

    Enrique Montalvillo

    2014-05-01

    Full Text Available The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on innate lymphoid cells, a newly discovered, heterogeneous set of cells that derive from an Id2-dependent lymphoid progenitor cell population. These cells have been categorized on the basis of the pattern of cytokines that they secrete, and the transcription factors that regulate their development and functions. Innate lymphoid cells play a role in the early response to pathogens, the anatomical contention of the commensal flora, and the maintenance of epithelial integrity. Amongst the various innate lymphoid cells we shall lay emphasis on a subpopulation with several peculiarities, namely that of natural killer T cells, a subset of T lymphocytes that express both T-cell and NK-cell receptors. The most numerous fraction of the NKT population are the so-called invariant NKT or iNKT cells. These iNKT cells have an invariant TCR and recognize the glycolipidic structures presented by the CD1d molecule, a homolog of class-I MHC molecules. Following activation they rapidly acquire cytotoxic activity and secrete both Th1 and Th2 cytokines, including IL-17. While their specific role is not yet established, iNKT cells take part in a great variety of intestinal immune responses ranging from oral tolerance to involvement in a number of gastrointestinal conditions.

  20. Innate lymphoid cells and natural killer T cells in the gastrointestinal tract immune system.

    Science.gov (United States)

    Montalvillo, Enrique; Garrote, José Antonio; Bernardo, David; Arranz, Eduardo

    2014-05-01

    The gastrointestinal tract is equipped with a highly specialized intrinsic immune system. However, the intestine is exposed to a high antigenic burden that requires a fast, nonspecific response -so-called innate immunity- to maintain homeostasis and protect the body from incoming pathogens. In the last decade multiple studies helped to unravel the particular developmental requirements and specific functions of the cells that play a role in innate immunity. In this review we shall focus on innate lymphoid cells, a newly discovered, heterogeneous set of cells that derive from an Id2-dependent lymphoid progenitor cell population. These cells have been categorized on the basis of the pattern of cytokines that they secrete, and the transcription factors that regulate their development and functions. Innate lymphoid cells play a role in the early response to pathogens, the anatomical contention of the commensal flora, and the maintenance of epithelial integrity.Amongst the various innate lymphoid cells we shall lay emphasis on a subpopulation with several peculiarities, namely that of natural killer T cells, a subset of T lymphocytes that express both T-cell and NK-cell receptors. The most numerous fraction of the NKT population are the so-called invariant NKT or iNKT cells. These iNKT cells have an invariant TCR and recognize the glycolipidic structures presented by the CD1d molecule, a homolog of class-I MHC molecules. Following activation they rapidly acquire cytotoxic activity and secrete both Th1 and Th2 cytokines, including IL-17. While their specific role is not yet established, iNKT cells take part in a great variety of intestinal immune responses ranging from oral tolerance to involvement in a number of gastrointestinal conditions.

  1. Stealth proteins: in silico identification of a novel protein family rendering bacterial pathogens invisible to host immune defense.

    Directory of Open Access Journals (Sweden)

    Peter Sperisen

    2005-11-01

    Full Text Available There are a variety of bacterial defense strategies to survive in a hostile environment. Generation of extracellular polysaccharides has proved to be a simple but effective strategy against the host's innate immune system. A comparative genomics approach led us to identify a new protein family termed Stealth, most likely involved in the synthesis of extracellular polysaccharides. This protein family is characterized by a series of domains conserved across phylogeny from bacteria to eukaryotes. In bacteria, Stealth (previously characterized as SacB, XcbA, or WefC is encoded by subsets of strains mainly colonizing multicellular organisms, with evidence for a protective effect against the host innate immune defense. More specifically, integrating all the available information about Stealth proteins in bacteria, we propose that Stealth is a D-hexose-1-phosphoryl transferase involved in the synthesis of polysaccharides. In the animal kingdom, Stealth is strongly conserved across evolution from social amoebas to simple and complex multicellular organisms, such as Dictyostelium discoideum, hydra, and human. Based on the occurrence of Stealth in most Eukaryotes and a subset of Prokaryotes together with its potential role in extracellular polysaccharide synthesis, we propose that metazoan Stealth functions to regulate the innate immune system. Moreover, there is good reason to speculate that the acquisition and spread of Stealth could be responsible for future epidemic outbreaks of infectious diseases caused by a large variety of eubacterial pathogens. Our in silico identification of a homologous protein in the human host will help to elucidate the causes of Stealth-dependent virulence. At a more basic level, the characterization of the molecular and cellular function of Stealth proteins may shed light on fundamental mechanisms of innate immune defense against microbial invasion.

  2. Stealth Proteins: In Silico Identification of a Novel Protein Family Rendering Bacterial Pathogens Invisible to Host Immune Defense.

    Directory of Open Access Journals (Sweden)

    2005-11-01

    Full Text Available There are a variety of bacterial defense strategies to survive in a hostile environment. Generation of extracellular polysaccharides has proved to be a simple but effective strategy against the host's innate immune system. A comparative genomics approach led us to identify a new protein family termed Stealth, most likely involved in the synthesis of extracellular polysaccharides. This protein family is characterized by a series of domains conserved across phylogeny from bacteria to eukaryotes. In bacteria, Stealth (previously characterized as SacB, XcbA, or WefC is encoded by subsets of strains mainly colonizing multicellular organisms, with evidence for a protective effect against the host innate immune defense. More specifically, integrating all the available information about Stealth proteins in bacteria, we propose that Stealth is a D-hexose-1-phosphoryl transferase involved in the synthesis of polysaccharides. In the animal kingdom, Stealth is strongly conserved across evolution from social amoebas to simple and complex multicellular organisms, such as Dictyostelium discoideum, hydra, and human. Based on the occurrence of Stealth in most Eukaryotes and a subset of Prokaryotes together with its potential role in extracellular polysaccharide synthesis, we propose that metazoan Stealth functions to regulate the innate immune system. Moreover, there is good reason to speculate that the acquisition and spread of Stealth could be responsible for future epidemic outbreaks of infectious diseases caused by a large variety of eubacterial pathogens. Our in silico identification of a homologous protein in the human host will help to elucidate the causes of Stealth-dependent virulence. At a more basic level, the characterization of the molecular and cellular function of Stealth proteins may shed light on fundamental mechanisms of innate immune defense against microbial invasion.

  3. Arthropod Innate Immune Systems and Vector-Borne Diseases

    OpenAIRE

    Baxter, Richard H. G.; Contet, Alicia; Krueger, Kathryn

    2017-01-01

    Arthropods, especially ticks and mosquitoes, are the vectors for a number of parasitic and viral human diseases, including malaria, sleeping sickness, Dengue, and Zika, yet arthropods show tremendous individual variation in their capacity to transmit disease. A key factor in this capacity is the group of genetically encoded immune factors that counteract infection by the pathogen. Arthropod-specific pattern recognition receptors and protease cascades detect and respond to infection. Proteins ...

  4. Innate Immunity and Biomaterials at the Nexus: Friends or Foes.

    Science.gov (United States)

    Christo, Susan N; Diener, Kerrilyn R; Bachhuka, Akash; Vasilev, Krasimir; Hayball, John D

    2015-01-01

    Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical "antigen." In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a "combined" immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.

  5. Innate Immunity and Biomaterials at the Nexus: Friends or Foes

    Directory of Open Access Journals (Sweden)

    Susan N. Christo

    2015-01-01

    Full Text Available Biomaterial implants are an established part of medical practice, encompassing a broad range of devices that widely differ in function and structural composition. However, one common property amongst biomaterials is the induction of the foreign body response: an acute sterile inflammatory reaction which overlaps with tissue vascularisation and remodelling and ultimately fibrotic encapsulation of the biomaterial to prevent further interaction with host tissue. Severity and clinical manifestation of the biomaterial-induced foreign body response are different for each biomaterial, with cases of incompatibility often associated with loss of function. However, unravelling the mechanisms that progress to the formation of the fibrotic capsule highlights the tightly intertwined nature of immunological responses to a seemingly noncanonical “antigen.” In this review, we detail the pathways associated with the foreign body response and describe possible mechanisms of immune involvement that can be targeted. We also discuss methods of modulating the immune response by altering the physiochemical surface properties of the biomaterial prior to implantation. Developments in these areas are reliant on reproducible and effective animal models and may allow a “combined” immunomodulatory approach of adapting surface properties of biomaterials, as well as treating key immune pathways to ultimately reduce the negative consequences of biomaterial implantation.

  6. Manipulation of Innate and Adaptive Immunity by Staphylococcal Superantigens

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    Stephen W. Tuffs

    2018-05-01

    Full Text Available Staphylococcal superantigens (SAgs constitute a family of potent exotoxins secreted by Staphylococcus aureus and other select staphylococcal species. SAgs function to cross-link major histocompatibility complex (MHC class II molecules with T cell receptors (TCRs to stimulate the uncontrolled activation of T lymphocytes, potentially leading to severe human illnesses such as toxic shock syndrome. The ubiquity of SAgs in clinical S. aureus isolates suggests that they likely make an important contribution to the evolutionary fitness of S. aureus. Although the apparent redundancy of SAgs in S. aureus has not been explained, the high level of sequence diversity within this toxin family may allow for SAgs to recognize an assorted range of TCR and MHC class II molecules, as well as aid in the avoidance of humoral immunity. Herein, we outline the major diseases associated with the staphylococcal SAgs and how a dysregulated immune system may contribute to pathology. We then highlight recent research that considers the importance of SAgs in the pathogenesis of S. aureus infections, demonstrating that SAgs are more than simply an immunological diversion. We suggest that SAgs can act as targeted modulators that drive the immune response away from an effective response, and thus aid in S. aureus persistence.

  7. The Role of Mast Cells in Tuberculosis: Orchestrating Innate Immune Crosstalk?

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    Karen M. Garcia-Rodriguez

    2017-10-01

    Full Text Available Tuberculosis causes more annual deaths globally than any other infectious disease. However, progress in developing novel vaccines, diagnostics, and therapies has been hampered by an incomplete understanding of the immune response to Mycobacterium tuberculosis (Mtb. While the role of many immune cells has been extensively explored, mast cells (MCs have been relatively ignored. MCs are tissue resident cells involved in defense against bacterial infections playing an important role mediating immune cell crosstalk. This review discusses specific interactions between MCs and Mtb, their contribution to both immunity and disease pathogenesis, and explores their role in orchestrating other immune cells against infections.

  8. Functions of Calcium-Dependent Protein Kinases in Plant Innate Immunity

    Directory of Open Access Journals (Sweden)

    Xiquan Gao

    2014-03-01

    Full Text Available An increase of cytosolic Ca2+ is generated by diverse physiological stimuli and stresses, including pathogen attack. Plants have evolved two branches of the immune system to defend against pathogen infections. The primary innate immune response is triggered by the detection of evolutionarily conserved pathogen-associated molecular pattern (PAMP, which is called PAMP-triggered immunity (PTI. The second branch of plant innate immunity is triggered by the recognition of specific pathogen effector proteins and known as effector-triggered immunity (ETI. Calcium (Ca2+ signaling is essential in both plant PTI and ETI responses. Calcium-dependent protein kinases (CDPKs have emerged as important Ca2+ sensor proteins in transducing differential Ca2+ signatures, triggered by PAMPs or effectors and activating complex downstream responses. CDPKs directly transmit calcium signals by calcium binding to the elongation factor (EF-hand domain at the C-terminus and substrate phosphorylation by the catalytic kinase domain at the N-terminus. Emerging evidence suggests that specific and overlapping CDPKs phosphorylate distinct substrates in PTI and ETI to regulate diverse plant immune responses, including production of reactive oxygen species, transcriptional reprogramming of immune genes, and the hypersensitive response.

  9. The 3 major types of innate and adaptive cell-mediated effector immunity.

    Science.gov (United States)

    Annunziato, Francesco; Romagnani, Chiara; Romagnani, Sergio

    2015-03-01

    The immune system has tailored its effector functions to optimally respond to distinct species of microbes. Based on emerging knowledge on the different effector T-cell and innate lymphoid cell (ILC) lineages, it is clear that the innate and adaptive immune systems converge into 3 major kinds of cell-mediated effector immunity, which we propose to categorize as type 1, type 2, and type 3. Type 1 immunity consists of T-bet(+) IFN-γ-producing group 1 ILCs (ILC1 and natural killer cells), CD8(+) cytotoxic T cells (TC1), and CD4(+) TH1 cells, which protect against intracellular microbes through activation of mononuclear phagocytes. Type 2 immunity consists of GATA-3(+) ILC2s, TC2 cells, and TH2 cells producing IL-4, IL-5, and IL-13, which induce mast cell, basophil, and eosinophil activation, as well as IgE antibody production, thus protecting against helminthes and venoms. Type 3 immunity is mediated by retinoic acid-related orphan receptor γt(+) ILC3s, TC17 cells, and TH17 cells producing IL-17, IL-22, or both, which activate mononuclear phagocytes but also recruit neutrophils and induce epithelial antimicrobial responses, thus protecting against extracellular bacteria and fungi. On the other hand, type 1 and 3 immunity mediate autoimmune diseases, whereas type 2 responses can cause allergic diseases. Copyright © 2014 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  10. Functions of Calcium-Dependent Protein Kinases in Plant Innate Immunity

    Science.gov (United States)

    Gao, Xiquan; Cox, Kevin L.; He, Ping

    2014-01-01

    An increase of cytosolic Ca2+ is generated by diverse physiological stimuli and stresses, including pathogen attack. Plants have evolved two branches of the immune system to defend against pathogen infections. The primary innate immune response is triggered by the detection of evolutionarily conserved pathogen-associated molecular pattern (PAMP), which is called PAMP-triggered immunity (PTI). The second branch of plant innate immunity is triggered by the recognition of specific pathogen effector proteins and known as effector-triggered immunity (ETI). Calcium (Ca2+) signaling is essential in both plant PTI and ETI responses. Calcium-dependent protein kinases (CDPKs) have emerged as important Ca2+ sensor proteins in transducing differential Ca2+ signatures, triggered by PAMPs or effectors and activating complex downstream responses. CDPKs directly transmit calcium signals by calcium binding to the elongation factor (EF)-hand domain at the C-terminus and substrate phosphorylation by the catalytic kinase domain at the N-terminus. Emerging evidence suggests that specific and overlapping CDPKs phosphorylate distinct substrates in PTI and ETI to regulate diverse plant immune responses, including production of reactive oxygen species, transcriptional reprogramming of immune genes, and the hypersensitive response. PMID:27135498

  11. Synthetic RNAs Mimicking Structural Domains in the Foot-and-Mouth Disease Virus Genome Elicit a Broad Innate Immune Response in Porcine Cells Triggered by RIG-I and TLR Activation.

    Science.gov (United States)

    Borrego, Belén; Rodríguez-Pulido, Miguel; Revilla, Concepción; Álvarez, Belén; Sobrino, Francisco; Domínguez, Javier; Sáiz, Margarita

    2015-07-17

    The innate immune system is the first line of defense against viral infections. Exploiting innate responses for antiviral, therapeutic and vaccine adjuvation strategies is being extensively explored. We have previously described, the ability of small in vitro RNA transcripts, mimicking the sequence and structure of different domains in the non-coding regions of the foot-and-mouth disease virus (FMDV) genome (ncRNAs), to trigger a potent and rapid innate immune response. These synthetic non-infectious molecules have proved to have a broad-range antiviral activity and to enhance the immunogenicity of an FMD inactivated vaccine in mice. Here, we have studied the involvement of pattern-recognition receptors (PRRs) in the ncRNA-induced innate response and analyzed the antiviral and cytokine profiles elicited in swine cultured cells, as well as peripheral blood mononuclear cells (PBMCs).

  12. Fluorescent dye labeled influenza virus mainly infects innate immune cells and activated lymphocytes and can be used in cell-mediated immune response assay

    OpenAIRE

    Xie, Dongxu

    2009-01-01

    Early results have recognized that influenza virus infects the innate and adaptive immune cells. The data presented in this paper demonstrated that influenza virus labeled with fluorescent dye not only retained the ability to infect and replicate in host cells, but also stimulated a similar human immune response as did unlabeled virus. Influenza virus largely infected the innate and activated adaptive immune cells. Influenza B type virus was different from that of A type virus. B type virus w...

  13. Immune evasion of porcine enteric coronaviruses and viral modulation of antiviral innate signaling.

    Science.gov (United States)

    Zhang, Qingzhan; Yoo, Dongwan

    2016-12-02

    Porcine epidemic diarrhea virus (PEDV) and porcine deltacoronavirus (PDCoV) are emerged and reemerging viruses in pigs, and together with transmissible gastroenteritis virus (TGEV), pose significant economic concerns to the swine industry. These viruses infect epithelial cells of the small intestine and cause watery diarrhea, dehydration, and a high mortality in neonatal piglets. Type I interferons (IFN-α/β) are major antiviral cytokines forming host innate immunity, and in turn, these enteric coronaviruses have evolved to modulate the host innate immune signaling during infection. Accumulating evidence however suggests that IFN induction and signaling in the intestinal epithelial cells differ from other epithelial cells, largely due to distinct features of the gut epithelial mucosal surface and commensal microflora, and it appears that type III interferon (IFN-λ) plays a key role to maintain the antiviral state in the gut. This review describes the recent understanding on the immune evasion strategies of porcine enteric coronaviruses and the role of different types of IFNs for intestinal antiviral innate immunity. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. HIF-mediated innate immune responses: cell signaling and therapeutic implications

    Directory of Open Access Journals (Sweden)

    Harris AJ

    2014-05-01

    Full Text Available Alison J Harris, AA Roger Thompson, Moira KB Whyte, Sarah R Walmsley Academic Unit of Respiratory Medicine, Department of Infection and Immunity, University of Sheffield, Sheffield, UK Abstract: Leukocytes recruited to infected, damaged, or inflamed tissues during an immune response must adapt to oxygen levels much lower than those in the circulation. Hypoxia inducible factors (HIFs are key mediators of cellular responses to hypoxia and, as in other cell types, HIFs are critical for the upregulation of glycolysis, which enables innate immune cells to produce adenosine triphosphate anaerobically. An increasing body of evidence demonstrates that hypoxia also regulates many other innate immunological functions, including cell migration, apoptosis, phagocytosis of pathogens, antigen presentation and production of cytokines, chemokines, and angiogenic and antimicrobial factors. Many of these functions are mediated by HIFs, which are not only stabilized posttranslationally by hypoxia, but also transcriptionally upregulated by inflammatory signals. Here, we review the role of HIFs in the responses of innate immune cells to hypoxia, both in vitro and in vivo, with a particular focus on myeloid cells, on which the majority of studies have so far been carried out. Keywords: hypoxia, neutrophils, monocytes, macrophages

  15. Virus-Heat Shock Protein Interaction and a Novel Axis for Innate Antiviral Immunity

    Directory of Open Access Journals (Sweden)

    Michael Oglesbee

    2012-09-01

    Full Text Available Virus infections induce heat shock proteins that in turn enhance virus gene expression, a phenomenon that is particularly well characterized for the major inducible 70 kDa heat shock protein (hsp70. However, hsp70 is also readily induced by fever, a phylogenetically conserved response to microbial infections, and when released from cells, hsp70 can stimulate innate immune responses through toll like receptors 2 and 4 (TLR2 and 4. This review examines how the virus-hsp70 relationship can lead to host protective innate antiviral immunity, and the importance of hsp70 dependent stimulation of virus gene expression in this host response. Beginning with the well-characterized measles virus-hsp70 relationship and the mouse model of neuronal infection in brain, we examine data indicating that the innate immune response is not driven by intracellular sensors of pathogen associated molecular patterns, but rather by extracellular ligands signaling through TLR2 and 4. Specifically, we address the relationship between virus gene expression, extracellular release of hsp70 (as a damage associated molecular pattern, and hsp70-mediated induction of antigen presentation and type 1 interferons in uninfected macrophages as a novel axis of antiviral immunity. New data are discussed that examines the more broad relevance of this protective mechanism using vesicular stomatitis virus, and a review of the literature is presented that supports the probable relevance to both RNA and DNA viruses and for infections both within and outside of the central nervous system.

  16. The Roles of RNase-L in Antimicrobial Immunity and the Cytoskeleton-Associated Innate Response.

    Science.gov (United States)

    Ezelle, Heather J; Malathi, Krishnamurthy; Hassel, Bret A

    2016-01-08

    The interferon (IFN)-regulated endoribonuclease RNase-L is involved in multiple aspects of the antimicrobial innate immune response. It is the terminal component of an RNA cleavage pathway in which dsRNA induces the production of RNase-L-activating 2-5A by the 2'-5'-oligoadenylate synthetase. The active nuclease then cleaves ssRNAs, both cellular and viral, leading to downregulation of their expression and the generation of small RNAs capable of activating retinoic acid-inducible gene-I (RIG-I)-like receptors or the nucleotide-binding oligomerization domain-like receptor 3 (NLRP3) inflammasome. This leads to IFNβ expression and IL-1β activation respectively, in addition to broader effects on immune cell function. RNase-L is also one of a growing number of innate immune components that interact with the cell cytoskeleton. It can bind to several cytoskeletal proteins, including filamin A, an actin-binding protein that collaborates with RNase-L to maintain the cellular barrier to viral entry. This antiviral activity is independent of catalytic function, a unique mechanism for RNase-L. We also describe here the interaction of RNase-L with the E3 ubiquitin ligase and scaffolding protein, ligand of nump protein X (LNX), a regulator of tight junction proteins. In order to better understand the significance and context of these novel binding partners in the antimicrobial response, other innate immune protein interactions with the cytoskeleton are also discussed.

  17. Natural selection on immune defense: A field experiment.

    Science.gov (United States)

    Langeloh, Laura; Behrmann-Godel, Jasminca; Seppälä, Otto

    2017-02-01

    Predicting the evolution of phenotypic traits requires an understanding of natural selection on them. Despite its indispensability in the fight against parasites, selection on host immune defense has remained understudied. Theory predicts immune traits to be under stabilizing selection due to associated trade-offs with other fitness-related traits. Empirical studies, however, report mainly positive directional selection. This discrepancy could be caused by low phenotypic variation in the examined individuals and/or variation in host resource level that confounds trade-offs in empirical studies. In a field experiment where we maintained Lymnaea stagnalis snails individually in cages in a lake, we investigated phenotypic selection on two immune defense traits, phenoloxidase (PO)-like activity and antibacterial activity, in hemolymph. We used a diverse laboratory population and manipulated snail resource level by limiting their food supply. For six weeks, we followed immune activity, growth, and two fitness components, survival and fecundity of snails. We found that PO-like activity and growth were under stabilizing selection, while antibacterial activity was under positive directional selection. Selection on immune traits was mainly driven by variation in survival. The form of selection on immune defense apparently depends on the particular trait, possibly due to its importance for countering the present parasite community. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

  18. Immunopathophysiology of inflammatory bowel disease: how genetics link barrier dysfunction and innate immunity to inflammation.

    Science.gov (United States)

    Mehta, Minesh; Ahmed, Shifat; Dryden, Gerald

    2017-08-01

    Inflammatory bowel diseases (IBD) comprise a distinct set of clinical symptoms resulting from chronic or relapsing immune activation and corresponding inflammation within the gastrointestinal (GI) tract. Diverse genetic mutations, encoding important aspects of innate immunity and mucosal homeostasis, combine with environmental triggers to create inappropriate, sustained inflammatory responses. Recently, significant advances have been made in understanding the interplay of the intestinal epithelium, mucosal immune system, and commensal bacteria as a foundation of the pathogenesis of inflammatory bowel disease. Complex interactions between specialized intestinal epithelial cells and mucosal immune cells determine different outcomes based on the environmental input: the development of tolerance in the presence of commensal bacterial or the promotion of inflammation upon recognition of pathogenic organisms. This article reviews key genetic abnormalities involved in inflammatory and homeostatic pathways that enhance susceptibility to immune dysregulation and combine with environmental triggers to trigger the development of chronic intestinal inflammation and IBD.

  19. Innate immune system still works at diapause, a physiological state of dormancy in insects

    International Nuclear Information System (INIS)

    Nakamura, Akihiro; Miyado, Kenji; Takezawa, Youki; Ohnami, Naoko; Sato, Masahiro; Ono, Chihiro; Harada, Yuichirou; Yoshida, Keiichi; Kawano, Natsuko; Kanai, Seiya; Miyado, Mami; Umezawa, Akihiro

    2011-01-01

    Highlights: → Two major types of cells are present in the body fluid isolated from the thoracic region of a diapausing pupa. → Phagocytosis and encapsulation by these cells were observed when latex beads as foreign targets were microinjected into a pupa. → Such behavior by these cells was still observed even when pupae were continuously chilled at 4 o C. → Innate cellular reactions can work in diapausing insects in a dormant state. -- Abstract: Diapause is most often observed in insects and is a physiologically dormant state different from other types of dormancy, such as hibernation. It allows insects to survive in harsh environments or extend longevity. In general, larval, pupal, or adult non-diapausing insects possess an innate immune system preventing the invasion of microorganisms into their bodies; however, it is unclear whether this system works under the dormant condition of diapause. We here report the occurrence of innate cellular reactions during diapause using pupae of a giant silkmoth, Samia cynthia pryeri. Scanning electron microscopic analysis demonstrated the presence of two major types of cells in the body fluid isolated from the thoracic region of a pupa. Phagocytosis and encapsulation, characteristics of innate cellular reactions, by these cells were observed when latex beads as foreign targets were microinjected into the internal portion of a pupa. Such behavior by these cells was still observed even when pupae were continuously chilled at 4 o C. Our results indicate that innate cellular reactions can work in diapausing insects in a dormant state.

  20. Innate immune system still works at diapause, a physiological state of dormancy in insects

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Akihiro [Department of Reproductive Biology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535 (Japan); Miyado, Kenji, E-mail: kmiyado@nch.go.jp [Department of Reproductive Biology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535 (Japan); Takezawa, Youki; Ohnami, Naoko [Department of Reproductive Biology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535 (Japan); Sato, Masahiro [Section of Gene Expression Regulation, Frontier Science Research Center, Kagoshima University, 1-21-20 Korimoto, Kagoshima 890-0065 (Japan); Ono, Chihiro; Harada, Yuichirou; Yoshida, Keiichi; Kawano, Natsuko; Kanai, Seiya; Miyado, Mami; Umezawa, Akihiro [Department of Reproductive Biology, National Center for Child Health and Development, 2-10-1 Okura, Setagaya, Tokyo 157-8535 (Japan)

    2011-07-01

    Highlights: {yields} Two major types of cells are present in the body fluid isolated from the thoracic region of a diapausing pupa. {yields} Phagocytosis and encapsulation by these cells were observed when latex beads as foreign targets were microinjected into a pupa. {yields} Such behavior by these cells was still observed even when pupae were continuously chilled at 4 {sup o}C. {yields} Innate cellular reactions can work in diapausing insects in a dormant state. -- Abstract: Diapause is most often observed in insects and is a physiologically dormant state different from other types of dormancy, such as hibernation. It allows insects to survive in harsh environments or extend longevity. In general, larval, pupal, or adult non-diapausing insects possess an innate immune system preventing the invasion of microorganisms into their bodies; however, it is unclear whether this system works under the dormant condition of diapause. We here report the occurrence of innate cellular reactions during diapause using pupae of a giant silkmoth, Samia cynthia pryeri. Scanning electron microscopic analysis demonstrated the presence of two major types of cells in the body fluid isolated from the thoracic region of a pupa. Phagocytosis and encapsulation, characteristics of innate cellular reactions, by these cells were observed when latex beads as foreign targets were microinjected into the internal portion of a pupa. Such behavior by these cells was still observed even when pupae were continuously chilled at 4 {sup o}C. Our results indicate that innate cellular reactions can work in diapausing insects in a dormant state.

  1. Murine and bovine γδ T cells enhance innate immunity against Brucella abortus infections.

    Directory of Open Access Journals (Sweden)

    Jerod A Skyberg

    Full Text Available γδ T cells have been postulated to act as a first line of defense against infectious agents, particularly intracellular pathogens, representing an important link between the innate and adaptive immune responses. Human γδ T cells expand in the blood of brucellosis patients and are active against Brucella in vitro. However, the role of γδ T cells in vivo during experimental brucellosis has not been studied. Here we report TCRδ(-/- mice are more susceptible to B. abortus infection than C57BL/6 mice at one week post-infection as measured by splenic colonization and splenomegaly. An increase in TCRγδ cells was observed in the spleens of B. abortus-infected C57BL/6 mice, which peaked at two weeks post-infection and occurred concomitantly with diminished brucellae. γδ T cells were the major source of IL-17 following infection and also produced IFN-γ. Depletion of γδ T cells from C57BL/6, IL-17Rα(-/-, and GMCSF(-/- mice enhanced susceptibility to B. abortus infection although this susceptibility was unaltered in the mutant mice; however, when γδ T cells were depleted from IFN-γ(-/- mice, enhanced susceptibility was observed. Neutralization of γδ T cells in the absence of TNF-α did not further impair immunity. In the absence of TNF-α or γδ T cells, B. abortus-infected mice showed enhanced IFN-γ, suggesting that they augmented production to compensate for the loss of γδ T cells and/or TNF-α. While the protective role of γδ T cells was TNF-α-dependent, γδ T cells were not the major source of TNF-α and activation of γδ T cells following B. abortus infection was TNF-α-independent. Additionally, bovine TCRγδ cells were found to respond rapidly to B. abortus infection upon co-culture with autologous macrophages and could impair the intramacrophage replication of B. abortus via IFN-γ. Collectively, these results demonstrate γδ T cells are important for early protection to B. abortus infections.

  2. Interferon-Mediated Innate Immune Responses against Malaria Parasite Liver Stages

    Directory of Open Access Journals (Sweden)

    Jessica L. Miller

    2014-04-01

    Full Text Available Mosquito-transmitted malaria parasites infect hepatocytes and asymptomatically replicate as liver stages. Using RNA sequencing, we show that a rodent malaria liver-stage infection stimulates a robust innate immune response including type I interferon (IFN and IFNγ pathways. Liver-stage infection is suppressed by these infection-engendered innate responses. This suppression was abrogated in mice deficient in IFNγ, the type I IFN α/β receptor (IFNAR, and interferon regulatory factor 3. Natural killer and CD49b+CD3+ natural killer T (NKT cells increased in the liver after a primary infection, and CD1d-restricted NKT cells, which secrete IFNγ, were critical in reducing liver-stage burden of a secondary infection. Lack of IFNAR signaling abrogated the increase in NKT cell numbers in the liver, showing a link between type I IFN signaling, cell recruitment, and subsequent parasite elimination. Our findings demonstrate innate immune sensing of malaria parasite liver-stage infection and that the ensuing innate responses can eliminate the parasite.

  3. Contribution to Tumor Angiogenesis From Innate Immune Cells Within the Tumor Microenvironment: Implications for Immunotherapy

    Directory of Open Access Journals (Sweden)

    Adriana Albini

    2018-04-01

    Full Text Available The critical role of angiogenesis in promoting tumor growth and metastasis is strongly established. However, tumors show considerable variation in angiogenic characteristics and in their sensitivity to antiangiogenic therapy. Tumor angiogenesis involves not only cancer cells but also various tumor-associated leukocytes (TALs and stromal cells. TALs produce chemokines, cytokines, proteases, structural proteins, and microvescicles. Vascular endothelial growth factor (VEGF and inflammatory chemokines are not only major proangiogenic factors but are also immune modulators, which increase angiogenesis and lead to immune suppression. In our review, we discuss the regulation of angiogenesis by innate immune cells in the tumor microenvironment, specific features, and roles of major players: macrophages, neutrophils, myeloid-derived suppressor and dendritic cells, mast cells, γδT cells, innate lymphoid cells, and natural killer cells. Anti-VEGF or anti-inflammatory drugs could balance an immunosuppressive microenvironment to an immune permissive one. Anti-VEGF as well as anti-inflammatory drugs could therefore represent partners for combinations with immune checkpoint inhibitors, enhancing the effects of immune therapy.

  4. The role of dehydroepiandrosterone on functional innate immune responses to acute stress.

    Science.gov (United States)

    Prall, Sean P; Larson, Emilee E; Muehlenbein, Michael P

    2017-12-01

    The androgen dehydroepiandrosterone (DHEA) responds to stress activation, exhibits anti-glucocorticoid properties, and modulates immunity in diverse ways, yet little is known of its role in acute stress responses. In this study, the effects of DHEA and its sulfate ester DHEA-S on human male immune function during exposure to an acute stressor is explored. Variation in DHEA, DHEA-S, testosterone, and cortisol, along with bacterial killing assays, was measured in response to a modified Trier Social Stress test in 27 young adult males. Cortisol was positively related to salivary innate immunity but only for participants who also exhibited high DHEA responses. Additionally, DHEA positively and DHEA-S negatively predicted salivary immunity, but the opposite was observed for serum-based innate immunity. The DHEA response to acute stress appears to be an important factor in stress-mediated immunological responses, with differential effects on immunity dependent upon the presence of other hormones, primarily cortisol and DHEA-S. These results suggest that DHEA plays an important role, alongside other hormones, in modulating immunological shifts during acute stress. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Ultrastructural and functional characterization of circulating hemocytes from Galleria mellonella larva: Cell types and their role in the innate immunity.

    Science.gov (United States)

    Wu, Gongqing; Liu, Yi; Ding, Ying; Yi, Yunhong

    2016-08-01

    Galleria mellonella larvae have been widely used as a model to study the virulence of various human pathogens. Hemocytes play important roles in the innate immune response of G. mellonella. In this study, the hemocytes of G. mellonella larvae were analyzed by transmission electron microscope, light microscope, and cytochemistry. The cytological and morphological analyses revealed four types of hemocytes; Plasmatocytes, granular cells, spherule cells and oenocytoids. Differential hemocyte counts showed that under our conditions plasmatocytes and granular cells were the most abundant circulating cell types in the hemolymph. We also investigated the role of different types of hemocytes in the cellular and humoral immune defenses. The in-vivo experiment showed that plasmatocytes, granular cells and oenocytoids phagocytized FITC-labelled Escherichia coli bacteria in larvae of G. mellonella, whereas the granular cells exhibited the strongest phagocytic ability against these microbial cells. After incubation with L-DOPA, plasmatocytes, granular cells and oenocytoids are stained brown, indicating the presence of phenoloxidase activity. These results shed new light on our understanding of the immune function of G. mellonella hemocytes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Balanced nuclear and cytoplasmic activities of EDS1 are required for a complete plant innate immune response.

    Directory of Open Access Journals (Sweden)

    Ana V García

    2010-07-01

    Full Text Available An important layer of plant innate immunity to host-adapted pathogens is conferred by intracellular nucleotide-binding/oligomerization domain-leucine rich repeat (NB-LRR receptors recognizing specific microbial effectors. Signaling from activated receptors of the TIR (Toll/Interleukin-1 Receptor-NB-LRR class converges on the nucleo-cytoplasmic immune regulator EDS1 (Enhanced Disease Susceptibility1. In this report we show that a receptor-stimulated increase in accumulation of nuclear EDS1 precedes or coincides with the EDS1-dependent induction and repression of defense-related genes. EDS1 is capable of nuclear transport receptor-mediated shuttling between the cytoplasm and nucleus. By enhancing EDS1 export from inside nuclei (through attachment of an additional nuclear export sequence (NES or conditionally releasing EDS1 to the nucleus (by fusion to a glucocorticoid receptor (GR in transgenic Arabidopsis we establish that the EDS1 nuclear pool is essential for resistance to biotrophic and hemi-biotrophic pathogens and for transcriptional reprogramming. Evidence points to post-transcriptional processes regulating receptor-triggered accumulation of EDS1 in nuclei. Changes in nuclear EDS1 levels become equilibrated with the cytoplasmic EDS1 pool and cytoplasmic EDS1 is needed for complete resistance and restriction of host cell death at infection sites. We propose that coordinated nuclear and cytoplasmic activities of EDS1 enable the plant to mount an appropriately balanced immune response to pathogen attack.

  7. 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

  8. Modulatory Effects of Antibody Replacement Therapy to Innate and Adaptive Immune Cells

    Directory of Open Access Journals (Sweden)

    Isabella Quinti

    2017-06-01

    Full Text Available Intravenous immunoglobulin administered at replacement dosages modulates innate and adaptive immune cells in primary antibody deficiencies (PAD in a different manner to what observed when high dosages are used or when their effect is analyzed by in vitro experimental conditions. The effects seem to be beneficial on innate cells in that dendritic cells maturate, pro-inflammatory monocytes decrease, and neutrophil function is preserved. The effects are less clear on adaptive immune cells. IVIg induced a transient increase of Treg and a long-term increase of CD4 cells. More complex and less understood is the interplay of IVIg with defective B cells of PAD patients. The paucity of data underlies the need of more studies on patients with PAD before drawing conclusions on the in vivo mechanisms of action of IVIg based on in vitro investigations.

  9. Biomarkers of Necrotising Soft Tissue Infections Aspects of the Innate Immune Response

    DEFF Research Database (Denmark)

    Hansen, Marco Bo

    2017-01-01

    -existent in this group of patients. Instead data regarding biomarkers are extrapolated from the wide and heterogenic group of patients with sepsis, even though the immunological responses are likely to differ because of the large amount of necrotic tissue seen in patients with NSTI. We performed the largest prospective......Necrotising soft tissue infection (NSTI) is a life-threatening and rapidly progressing bacterial infection involving one or more layers of the soft tissue compartments causing necrosis. The amputation and mortality rates remain high despite increased focus on the patients. Timely treatment...... of the innate immune response, which included the investigation of acute-phase proteins, pattern recognition molecules of the lectin complement pathway, and inflammatory cytokines. The objective was to investigate aspects of the innate immune response in patients with NSTI, focusing on biomarkers as prognostic...

  10. Porcine models for the study of local and systemic regulation of innate immune factors in obesity

    DEFF Research Database (Denmark)

    Højbøge, Tina Rødgaard

    state of low-grade inflammation in the adipose tissues, which involves several factors of the innate immune response having a range of systemic effects and which has been implicated in the development of the metabolic syndrome. To investigate the impact of obesity and obesity-related diseases good...... translational animal models are needed, and as such pigs have been proposed as relevant models for human obesity-induced inflammation as pigs share many genetic, anatomical and physiological features with humans. In this project the up- and downregulation of genes and proteins involved in the innate immune...... the number of animals to be used in a trial to obtain statistical power. For the gene regulation analysis, two platforms for quantitative real-time PCR (qPCR) were employed: The Rotor-Gene Q instrument and the microfluidics-based high-throughput Bio-Mark. For the serum protein concentrations analysis several...

  11. 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.

  12. 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...

  13. Regulation of Aeroallergen Immunity by the Innate Immune System: Laboratory Evidence for a New Paradigm

    OpenAIRE

    Horner, Anthony A.

    2009-01-01

    Over the last decade, it has become increasingly clear that innate responses to microbes are mediated largely by toll-like receptors (TLRs), which recognize a diverse family of molecules produced by viruses, bacteria and fungi. This article will present evidence that TLRs also play a dominant role in innate responses to non-infectious immunostimulatory materials present in house dust extracts (HDEs) and the living environments they represent. However, our investigations challenge the commonly...

  14. Three Pairs of Protease-Serpin Complexes Cooperatively Regulate the Insect Innate Immune Responses*

    OpenAIRE

    Jiang, Rui; Kim, Eun-Hye; Gong, Ji-Hee; Kwon, Hyun-Mi; Kim, Chan-Hee; Ryu, Kyoung-Hwa; Park, Ji-Won; Kurokawa, Kenji; Zhang, Jinghai; Gubb, David; Lee, Bok-Luel

    2009-01-01

    Serpins are known to be necessary for the regulation of several serine protease cascades. However, the mechanisms of how serpins regulate the innate immune responses of invertebrates are not well understood due to the uncertainty of the identity of the serine proteases targeted by the serpins. We recently reported the molecular activation mechanisms of three serine protease-mediated Toll and melanin synthesis cascades in a large beetle, Tenebrio molitor. Here, we purified three novel serpins ...

  15. Cyclic GMP-AMP Synthase is an Innate Immune Sensor of HIV and Other Retroviruses

    OpenAIRE

    Gao, Daxing; Wu, Jiaxi; Wu, You-Tong; Du, Fenghe; Aroh, Chukwuemika; Yan, Nan; Sun, Lijun; Chen, Zhijian J.

    2013-01-01

    Retroviruses, including HIV, can activate innate immune responses, but the host sensors for retroviruses are largely unknown. Here we show that HIV infection activates cyclic-GMP-AMP (cGAMP) synthase (cGAS) to produce cGAMP, which binds to and activates the adaptor protein STING to induce type-I interferons and other cytokines. Inhibitors of HIV reverse transcriptase, but not integrase, abrogated interferon-β induction by the virus, suggesting that the reverse transcribed HIV DNA triggers the...

  16. 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...

  17. Abiotic elicitors mediated elicitation of innate immunity in tomato: an ex vivo comparison

    OpenAIRE

    Chakraborty, Nilanjan; Ghosh, Sudeepa; Chandra, Swarnendu; Sengupta, Sarban; Acharya, Krishnendu

    2016-01-01

    Improvement of the host resistance by using hazard free chemical elicitors is emerging as an alternative approach in the field of plant disease management. In our present work, we have screened the efficacy and possible mechanism of abiogenic elicitors like Dipotassium hydrogen orthophosphate (K2HPO4), Oxalic acid?(OA), Isonicotinic acid (INA), Salicylic acid?(SA), Acetylsalicylate?(AS), Arachidonic acid (AA)?and Calcium chloride (CaCl2) to stimulate innate immune responses in Lycopersicum es...

  18. The innate immune response of equine bronchial epithelial cells is altered by training.

    Science.gov (United States)

    Frellstedt, Linda; Gosset, Philippe; Kervoaze, Gwenola; Hans, Aymeric; Desmet, Christophe; Pirottin, Dimitri; Bureau, Fabrice; Lekeux, Pierre; Art, Tatiana

    2015-01-17

    Respiratory diseases, including inflammatory airway disease (IAD), viral and bacterial infections, are common problems in exercising horses. The airway epithelium constitutes a major physical barrier against airborne infections and plays an essential role in the lung innate immune response mainly through toll-like receptor (TLR) activation. The aim of this study was to develop a model for the culture of equine bronchial epithelial cells (EBEC) in vitro and to explore EBEC innate immune responses in trained horses. Bronchial epithelial biopsies were taken from 6 adult horses during lower airway endoscopy. EBEC were grown in vitro by an explant method. The innate immune response of EBEC was evaluated in vitro by treatment with TLR ligands. TLR3 is the most strongly expressed TLR at the mRNA level in EBEC and stimulation of EBEC with Poly(I:C), an analog of viral dsRNA, triggers a strong secretion of IFN-β, TNF-α, IL-6 and CXCL8. We further evaluated the EBEC innate immune response in horses that underwent a 4-month-training program. While training had no effect on TLR mRNA expression in EBEC as well as in bronchial biopsies, it increased the production of IFN-β after stimulation with a TLR3 ligand and decreased the secretion of TNF-α and IL-6 after stimulation with a TLR2 and TLR3 ligand. These findings may be implicated in the increased risk for viral and bacterial infections observed in sport horses. Altogether, we report a successful model for the culture of EBEC that can be applied to the investigation of pathophysiologic conditions in longitudinal studies.

  19. Activation of innate immune genes in caprine blood leukocytes after systemic endotoxin challenge

    DEFF Research Database (Denmark)

    Salvesen, Øyvind; Reiten, Malin R; Heegaard, Peter M. H.

    2016-01-01

    observed peaking at 2 h, corroborating the increasing evidence that ISGs respond immediately to bacterial endotoxins. A slower response was manifested by four extrahepatic acute phase proteins (APP) (SAA3, HP, LF and LCN2) reaching maximum levels at 5 h. We report an immediate induction of ISGs...... insights into the dynamic regulation of innate immune genes, as well as raising new questions regarding the importance of ISGs and extrahepatic APPs in leukocytes after systemic endotoxin challenge....

  20. Induction of innate immune gene expression following methyl methanesulfonate-induced DNA damage in sea urchins

    OpenAIRE

    Reinardy, H. C.; Chapman, J.; Bodnar, A. G.

    2016-01-01

    Sea urchins are noted for the absence of neoplastic disease and represent a novel model to investigate cellular and systemic cancer protection mechanisms. Following intracoelomic injection of the DNA alkylating agent methyl methanesulfonate, DNA damage was detected in sea urchin cells and tissues (coelomocytes, muscle, oesophagus, ampullae and gonad) by the alkaline unwinding, fast micromethod. Gene expression analyses of the coelomocytes indicated upregulation of innate immune markers, inclu...

  1. Induction of Innate Immune Genes in Brain Create the Neurobiology of Addiction

    OpenAIRE

    Crews, FT; Zou, Jian; Qin, Liya

    2011-01-01

    Addiction occurs through repeated abuse of drugs that progressively reduce behavioral control and cognitive flexibility while increasing limbic negative emotion. Recent discoveries indicate neuroimmune signaling underlies addiction and co-morbid depression. Low threshold microglia undergo progressive stages of innate immune activation involving astrocytes and neurons with repeated drug abuse, stress, and/or cell damage signals. Increased brain NF-κB transcription of proinflammatory chemokines...

  2. The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

    Directory of Open Access Journals (Sweden)

    Stefan Landgraeber

    2014-01-01

    Full Text Available All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older people (>75 yrs of total joint replacement revision surgery. In some people implant debris (particles and ions from metals can influence the adaptive immune system as well, giving rise to the concept of metal sensitivity. However, a consensus of studies agrees that the dominant form of this response is due to innate reactivity by macrophages to implant debris where both danger (DAMP and pathogen (PAMP signalling elicit cytokine-based inflammatory responses. This paper discusses implant debris induced release of the cytokines and chemokines due to activation of the innate (and the adaptive immune system and the subsequent formation of osteolysis. Different mechanisms of implant-debris reactivity related to the innate immune system are detailed, for example, danger signalling (e.g., IL-1β, IL-18, IL-33, etc., toll-like receptor activation (e.g., IL-6, TNF-α, etc., apoptosis (e.g., caspases 3–9, bone catabolism (e.g., TRAP5b, and hypoxia responses (Hif1-α. Cytokine-based clinical and basic science studies are in progress to provide diagnosis and therapeutic intervention strategies.

  3. The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

    OpenAIRE

    Landgraeber, Stefan; Jäger, Marcus; Jacobs, Joshua J.; Hallab, Nadim James

    2014-01-01

    All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older peop...

  4. The Pathology of Orthopedic Implant Failure Is Mediated by Innate Immune System Cytokines

    Science.gov (United States)

    Landgraeber, Stefan; Jäger, Marcus; Jacobs, Joshua J.; Hallab, Nadim James

    2014-01-01

    All of the over 1 million total joint replacements implanted in the US each year are expected to eventually fail after 15–25 years of use, due to slow progressive subtle inflammation at the bone implant interface. This inflammatory disease state is caused by implant debris acting, primarily, on innate immune cells, that is, macrophages. This slow progressive pathological bone loss or “aseptic loosening” is a potentially life-threatening condition due to the serious complications in older people (>75 yrs) of total joint replacement revision surgery. In some people implant debris (particles and ions from metals) can influence the adaptive immune system as well, giving rise to the concept of metal sensitivity. However, a consensus of studies agrees that the dominant form of this response is due to innate reactivity by macrophages to implant debris where both danger (DAMP) and pathogen (PAMP) signalling elicit cytokine-based inflammatory responses. This paper discusses implant debris induced release of the cytokines and chemokines due to activation of the innate (and the adaptive) immune system and the subsequent formation of osteolysis. Different mechanisms of implant-debris reactivity related to the innate immune system are detailed, for example, danger signalling (e.g., IL-1β, IL-18, IL-33, etc.), toll-like receptor activation (e.g., IL-6, TNF-α, etc.), apoptosis (e.g., caspases 3–9), bone catabolism (e.g., TRAP5b), and hypoxia responses (Hif1-α). Cytokine-based clinical and basic science studies are in progress to provide diagnosis and therapeutic intervention strategies. PMID:24891761

  5. Central Nervous System and Innate Immune Mechanisms for Inflammation- and Cancer-induced Anorexia

    OpenAIRE

    Ruud, Johan

    2012-01-01

    Anyone who has experienced influenza or a bacterial infection knows what it means to be ill. Apart from feeling feverish, experiencing aching joints and muscles, you lose the desire to eat. Anorexia, defined as loss of appetite or persistent satiety leading to reduced energy intake, is a hallmark of acute inflammatory disease. The anorexia is part of the acute phase response, triggered as the result of activation of the innate immune system with concomitant release of inflammatory mediators, ...

  6. Voluntary activation of the sympathetic nervous system and attenuation of the innate immune response in humans.

    Science.gov (United States)

    Kox, Matthijs; van Eijk, Lucas T; Zwaag, Jelle; van den Wildenberg, Joanne; Sweep, Fred C G J; van der Hoeven, Johannes G; Pickkers, Peter

    2014-05-20

    Excessive or persistent proinflammatory cytokine production plays a central role in autoimmune diseases. Acute activation of the sympathetic nervous system attenuates the innate immune response. However, both the autonomic nervous system and innate immune system are regarded as systems that cannot be voluntarily influenced. Herein, we evaluated the effects of a training program on the autonomic nervous system and innate immune response. Healthy volunteers were randomized to either the intervention (n = 12) or control group (n = 12). Subjects in the intervention group were trained for 10 d in meditation (third eye meditation), breathing techniques (i.a., cyclic hyperventilation followed by breath retention), and exposure to cold (i.a., immersions in ice cold water). The control group was not trained. Subsequently, all subjects underwent experimental endotoxemia (i.v. administration of 2 ng/kg Escherichia coli endotoxin). In the intervention group, practicing the learned techniques resulted in intermittent respiratory alkalosis and hypoxia resulting in profoundly increased plasma epinephrine levels. In the intervention group, plasma levels of the anti-inflammatory cytokine IL-10 increased more rapidly after endotoxin administration, correlated strongly with preceding epinephrine levels, and were higher. Levels of proinflammatory mediators TNF-α, IL-6, and IL-8 were lower in the intervention group and correlated negatively with IL-10 levels. Finally, flu-like symptoms were lower in the intervention group. In conclusion, we demonstrate that voluntary activation of the sympathetic nervous system results in epinephrine release and subsequent suppression of the innate immune response in humans in vivo. These results could have important implications for the treatment of conditions associated with excessive or persistent inflammation, such as autoimmune diseases.

  7. Nongenetically modified Lactococcus lactis-adjuvanted vaccination enhanced innate immunity against Helicobacter pylori.

    Science.gov (United States)

    Liu, Wei; Tan, Zhoulin; Liu, Hai; Zeng, Zhiqin; Luo, Shuanghui; Yang, Huimin; Zheng, Lufeng; Xi, Tao; Xing, Yingying

    2017-10-01

    Gram-positive enhancer matrix particles (GEM) produced by Lactococcus lactis can enhance vaccine-induced immune response. However, the mechanism under which this adjuvant mounts the efficacy of orally administered vaccines remains unexplored. We used a prophylactic mice model to investigate the mechanism of GEM-adjuvanted vaccination. Helicobacter pylori urease-specific antibody response was monitored and detected in murine serum by ELISA. Urease-specific splenic cytokine profile was examined. Gastric inflammatory responses were measured on day 43 or 71 by quantitative real-time PCR, flow cytometry and histology. We found that GEM enhanced the efficiency of oral H. pylori vaccine by promoting innate immunity. The vaccine CUE-GEM composed of GEM particles and recombinant antigen CTB-UE provided protection of immunized mice against H. pylori insult. The protective response was associated with induction of postimmunization gastritis and local Th1/Th17 cell-medicated immune response. We showed that innate inflammatory responses including neutrophil chemokines CXCL1-2, neutrophils, and antimicrobial proteins S100A8 and MUC1 were significantly elevated. Within all infected mice, S100A8 and MUC1 levels were negatively correlated with H. pylori burden. Strikingly, mice receiving GEM also show reduction of colonization, possibly through natural host response pathways to recruit CD4 + T cells and promote S100A8 expression. These findings suggest that GEM-based vaccine may impact Th1/Th17 immunity to orchestrate innate immune response against H. pylori infection. © 2017 John Wiley & Sons Ltd.

  8. 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.

  9. A zebrafish larval model reveals early tissue-specific innate immune responses to Mucor circinelloides.

    Science.gov (United States)

    Voelz, Kerstin; Gratacap, Remi L; Wheeler, Robert T

    2015-11-01

    Mucormycosis is an emerging fungal infection that is clinically difficult to manage, with increasing incidence and extremely high mortality rates. Individuals with diabetes, suppressed immunity or traumatic injury are at increased risk of developing disease. These individuals often present with defects in phagocytic effector cell function. Research using mammalian models and phagocytic effector cell lines has attempted to decipher the importance of the innate immune system in host defence against mucormycosis. However, these model systems have not been satisfactory for direct analysis of the interaction between innate immune effector cells and infectious sporangiospores in vivo. Here, we report the first real-time in vivo analysis of the early innate immune response to mucormycete infection using a whole-animal zebrafish larval model system. We identified differential host susceptibility, dependent on the site of infection (hindbrain ventricle and swim bladder), as well as differential functions of the two major phagocyte effector cell types in response to viable and non-viable spores. Larval susceptibility to mucormycete spore infection was increased upon immunosuppressant treatment. We showed for the first time that macrophages and neutrophils were readily recruited in vivo to the site of infection in an intact host and that spore phagocytosis can be observed in real-time in vivo. While exploring innate immune effector recruitment dynamics, we discovered the formation of phagocyte clusters in response to fungal spores that potentially play a role in fungal spore dissemination. Spores failed to activate pro-inflammatory gene expression by 6 h post-infection in both infection models. After 24 h, induction of a pro-inflammatory response was observed only in hindbrain ventricle infections. Only a weak pro-inflammatory response was initiated after spore injection into the swim bladder during the same time frame. In the future, the zebrafish larva as a live whole

  10. Attenuated Innate Immunity in Embryonic Stem Cells and Its Implications in Developmental Biology and Regenerative Medicine.

    Science.gov (United States)

    Guo, Yan-Lin; Carmichael, Gordon G; Wang, Ruoxing; Hong, Xiaoxiao; Acharya, Dhiraj; Huang, Faqing; Bai, Fengwei

    2015-11-01

    Embryonic stem cells (ESCs) represent a promising cell source for regenerative medicine. Intensive research over the past 2 decades has led to the feasibility of using ESC-differentiated cells (ESC-DCs) in regenerative medicine. However, increasing evidence indicates that ESC-DCs generated by current differentiation methods may not have equivalent cellular functions to their in vivo counterparts. Recent studies have revealed that both human and mouse ESCs as well as some types of ESC-DCs lack or have attenuated innate immune responses to a wide range of infectious agents. These findings raise important concerns for their therapeutic applications since ESC-DCs, when implanted to a wound site of a patient, where they would likely be exposed to pathogens and inflammatory cytokines. Understanding whether an attenuated immune response is beneficial or harmful to the interaction between host and grafted cells becomes an important issue for ESC-based therapy. A substantial amount of recent evidence has demonstrated that the lack of innate antiviral responses is a common feature to ESCs and other types of pluripotent cells. This has led to the hypothesis that mammals may have adapted different antiviral mechanisms at different stages of organismal development. The underdeveloped innate immunity represents a unique and uncharacterized property of ESCs that may have important implications in developmental biology, immunology, and in regenerative medicine. © 2015 AlphaMed Press.

  11. Aspergillus-Associated Airway Disease, Inflammation, and the Innate Immune Response

    Science.gov (United States)

    Chotirmall, Sanjay H.; Al-Alawi, Mazen; Logan, P. Mark; Greene, Catherine M.; McElvaney, Noel G.

    2013-01-01

    Aspergillus moulds exist ubiquitously as spores that are inhaled in large numbers daily. Whilst most are removed by anatomical barriers, disease may occur in certain circumstances. Depending on the underlying state of the human immune system, clinical consequences can ensue ranging from an excessive immune response during allergic bronchopulmonary aspergillosis to the formation of an aspergilloma in the immunocompetent state. The severest infections occur in those who are immunocompromised where invasive pulmonary aspergillosis results in high mortality rates. The diagnosis of Aspergillus-associated pulmonary disease is based on clinical, radiological, and immunological testing. An understanding of the innate and inflammatory consequences of exposure to Aspergillus species is critical in accounting for disease manifestations and preventing sequelae. The major components of the innate immune system involved in recognition and removal of the fungus include phagocytosis, antimicrobial peptide production, and recognition by pattern recognition receptors. The cytokine response is also critical facilitating cell-to-cell communication and promoting the initiation, maintenance, and resolution of the host response. In the following review, we discuss the above areas with a focus on the innate and inflammatory response to airway Aspergillus exposure and how these responses may be modulated for therapeutic benefit. PMID:23971044

  12. Apolipoprotein E-specific innate immune response in astrocytes from targeted replacement mice

    Directory of Open Access Journals (Sweden)

    Montine Thomas J

    2006-04-01

    Full Text Available Abstract Background Inheritance of the three different alleles of the human apolipoprotein (apo E gene (APOE are associated with varying risk or clinical outcome from a variety of neurologic diseases. ApoE isoform-specific modulation of several pathogenic processes, in addition to amyloid β metabolism in Alzheimer's disease, have been proposed: one of these is innate immune response by glia. Previously we have shown that primary microglia cultures from targeted replacement (TR APOE mice have apoE isoform-dependent innate immune activation and paracrine damage to neurons that is greatest with TR by the ε4 allele (TR APOE4 and that derives from p38 mitogen-activated protein kinase (p38MAPK activity. Methods Primary cultures of TR APOE2, TR APOE3 and TR APOE4 astrocytes were stimulated with lipopolysaccharide (LPS. ApoE secretion, cytokine production, and nuclear factor-kappa B (NF-κB subunit activity were measured and compared. Results Here we showed that activation of primary astrocytes from TR APOE mice with LPS led to TR APOE-dependent differences in cytokine secretion that were greatest in TR APOE2 and that were associated with differences in NF-κB subunit activity. Conclusion Our results suggest that LPS activation of innate immune response in TR APOE glia results in opposing outcomes from microglia and astrocytes as a result of TR APOE-dependent activation of p38MAPK or NF-κB signaling in these two cell types.

  13. Transit through the flea vector induces a pretransmission innate immunity resistance phenotype in Yersinia pestis.

    Directory of Open Access Journals (Sweden)

    Viveka Vadyvaloo

    2010-02-01

    Full Text Available Yersinia pestis, the agent of plague, is transmitted to mammals by infected fleas. Y. pestis exhibits a distinct life stage in the flea, where it grows in the form of a cohesive biofilm that promotes transmission. After transmission, the temperature shift to 37 degrees C induces many known virulence factors of Y. pestis that confer resistance to innate immunity. These factors are not produced in the low-temperature environment of the flea, however, suggesting that Y. pestis is vulnerable to the initial encounter with innate immune cells at the flea bite site. In this study, we used whole-genome microarrays to compare the Y. pestis in vivo transcriptome in infective fleas to in vitro transcriptomes in temperature-matched biofilm and planktonic cultures, and to the previously characterized in vivo gene expression profile in the rat bubo. In addition to genes involved in metabolic adaptation to the flea gut and biofilm formation, several genes with known or predicted roles in resistance to innate immunity and pathogenicity in the mammal were upregulated in the flea. Y. pestis from infected fleas were more resistant to phagocytosis by macrophages than in vitro-grown bacteria, in part attributable to a cluster of insecticidal-like toxin genes that were highly expressed only in the flea. Our results suggest that transit through the flea vector induces a phenotype that enhances survival and dissemination of Y. pestis after transmission to the mammalian host.

  14. Aspergillus-Associated Airway Disease, Inflammation, and the Innate Immune Response

    Directory of Open Access Journals (Sweden)

    Sanjay H. Chotirmall

    2013-01-01

    Full Text Available Aspergillus moulds exist ubiquitously as spores that are inhaled in large numbers daily. Whilst most are removed by anatomical barriers, disease may occur in certain circumstances. Depending on the underlying state of the human immune system, clinical consequences can ensue ranging from an excessive immune response during allergic bronchopulmonary aspergillosis to the formation of an aspergilloma in the immunocompetent state. The severest infections occur in those who are immunocompromised where invasive pulmonary aspergillosis results in high mortality rates. The diagnosis of Aspergillus-associated pulmonary disease is based on clinical, radiological, and immunological testing. An understanding of the innate and inflammatory consequences of exposure to Aspergillus species is critical in accounting for disease manifestations and preventing sequelae. The major components of the innate immune system involved in recognition and removal of the fungus include phagocytosis, antimicrobial peptide production, and recognition by pattern recognition receptors. The cytokine response is also critical facilitating cell-to-cell communication and promoting the initiation, maintenance, and resolution of the host response. In the following review, we discuss the above areas with a focus on the innate and inflammatory response to airway Aspergillus exposure and how these responses may be modulated for therapeutic benefit.

  15. Involvement of Innate Immunity in the Development of Inflammatory and Autoimmune Diseases

    Czech Academy of Sciences Publication Activity Database

    Tlaskalová, Helena; Tučková, Ludmila; Štěpánková, Renata; Hudcovic, Tomáš; Palová-Jelínková, Lenka; Kozáková, Hana; Rossmann, Pavel; Sánchez, Daniel; Cinová, Jana; Hrnčíř, Tomáš; Kverka, Miloslav; Frolová, Lenka; Uhlig, H.; Powrie, F.; Bland, P.

    2005-01-01

    Roč. 1051, - (2005), s. 787-798 ISSN 0077-8923 R&D Projects: GA AV ČR IAA5020205; GA AV ČR KJB5020407; GA ČR GA310/05/2245; GA ČR GD310/03/H147; GA ČR GP310/04/P242; GA AV ČR IBS5020203; GA MZd NR8356 Institutional research plan: CEZ:AV0Z50200510 Keywords : innate immunity * mucosal immunity * mucosal barrier Subject RIV: EE - Microbiology, Virology Impact factor: 1.971, year: 2005

  16. Platelets and the innate immune system: Mechanisms of bacterial-induced platelet activation.

    OpenAIRE

    Cox, Dermot; Kerrigan, Steven W; Watson, Steve

    2011-01-01

    It has become clear that platelets are not simply cell fragments that can plug the leak in a damaged blood vessel, they are in fact key components in the innate immune system which is supported by the presence of Toll-like receptors (TLRs) on platelets. As the first responding cell to a site of injury they are well placed to direct the immune response to deal with any resulting exposure to pathogens. The response is triggered by bacteria binding to platelets which usually triggers platelet ac...

  17. Function of endoplasmic reticulum calcium ATPase in innate immunity-mediated programmed cell death

    Science.gov (United States)

    Zhu, Xiaohong; Caplan, Jeffrey; Mamillapalli, Padmavathi; Czymmek, Kirk; Dinesh-Kumar, Savithramma P

    2010-01-01

    Programmed cell death (PCD) initiated at the pathogen-infected sites during the plant innate immune response is thought to prevent the development of disease. Here, we describe the identification and characterization of an ER-localized type IIB Ca2+-ATPase (NbCA1) that function as a regulator of PCD. Silencing of NbCA1 accelerates viral immune receptor N- and fungal-immune receptor Cf9-mediated PCD, as well as non-host pathogen Pseudomonas syringae pv. tomato DC3000 and the general elicitor cryptogein-induced cell death. The accelerated PCD rescues loss-of-resistance phenotype of Rar1, HSP90-silenced plants, but not SGT1-silenced plants. Using a genetically encoded calcium sensor, we show that downregulation of NbCA1 results in the modulation of intracellular calcium signalling in response to cryptogein elicitor. We further show that NbCAM1 and NbrbohB function as downstream calcium decoders in N-immune receptor-mediated PCD. Our results indicate that ER-Ca2+-ATPase is a component of the calcium efflux pathway that controls PCD during an innate immune response. PMID:20075858

  18. Cationic amino acid transporter 2 enhances innate immunity during Helicobacter pylori infection.

    Directory of Open Access Journals (Sweden)

    Daniel P Barry

    Full Text Available Once acquired, Helicobacter pylori infection is lifelong due to an inadequate innate and adaptive immune response. Our previous studies indicate that interactions among the various pathways of arginine metabolism in the host are critical determinants of outcomes following infection. Cationic amino acid transporter 2 (CAT2 is essential for transport of L-arginine (L-Arg into monocytic immune cells during H. pylori infection. Once within the cell, this amino acid is utilized by opposing pathways that lead to elaboration of either bactericidal nitric oxide (NO produced from inducible NO synthase (iNOS, or hydrogen peroxide, which causes macrophage apoptosis, via arginase and the polyamine pathway. Because of its central role in controlling L-Arg availability in macrophages, we investigated the importance of CAT2 in vivo during H. pylori infection. CAT2(-/- mice infected for 4 months exhibited decreased gastritis and increased levels of colonization compared to wild type mice. We observed suppression of gastric macrophage levels, macrophage expression of iNOS, dendritic cell activation, and expression of granulocyte-colony stimulating factor in CAT2(-/- mice suggesting that CAT2 is involved in enhancing the innate immune response. In addition, cytokine expression in CAT2(-/- mice was altered from an antimicrobial Th1 response to a Th2 response, indicating that the transporter has downstream effects on adaptive immunity as well. These findings demonstrate that CAT2 is an important regulator of the immune response during H. pylori infection.

  19. Factors of Innate and Adaptive Local Immunity in Children with Primary Deficiencies of Antibody Formation

    Directory of Open Access Journals (Sweden)

    L.I. Chernyshova

    2013-10-01

    Full Text Available In 40 children with various types of primary immunodeficiencies (PID of antibody formation we examined factors of local immunity in saliva. It is found that in the saliva of children with PID of antibody formation in comparison with immunocompetent children the concentration of factors of adaptive immunity is significantly reduced. Lack of adaptive immunity in the PID of antibody formation to some extent is compensated by increased concentrations of innate immune factors on the mucous membranes — the free Sc, as well as lactoferrin in selective immunodeficiency of IgA. At PID of antibody formation we observed increased TNF-α level in the saliva, which may indicate the persistence of local inflammation on the membranes of the respiratory tract.

  20. Investigating the Role of the Arabidopsis Homologue of the Human G3BP in RNA Metabolism, Cellular Stress Responses and Innate Immunity

    KAUST Repository

    Abulfaraj, Aala A.

    2018-04-01

    Mitogen-activated protein kinases (MAPKs) belong to the most conserved signaling pathways and are found in all eukaryotes, including humans where they play important roles in various diseases and cancer. Stimulation of this signal transduction pathway by microbe-associated molecular patterns (MAMP) results in a multitude of events to regulate innate immune responses in Arabidopsis thaliana stimulating large-scale changes in gene expression. Starting from a phosphoproteomic screen in Arabidopsis thaliana wild type and mpk3, mpk4 and mpk6 mutants following microbe-associated molecular pattern (MAMP) treatment, several novel chromatin-associated proteins were identified that are differentially phosphorylated by stress-induced protein kinases. Arabidopsis Ras GTPase-activating protein SH3-domain-binding protein (AtG3BP-1) is a downstream putative substrate of the MAMP-stimulated MAPK pathway that is phosphorylated by MPK3, 4 and 6 in in vitro kinase assays. AtG3BP1 belongs to a highly conserved family of RNA-binding proteins in eukaryotes that link kinase receptormediated signaling to RNA metabolism. Here, we report the characterization of the Arabidopsis homolog of human G3BP1 in plant innate immunity. AtG3BP1 negatively regulates plant immunity and defense immune responses. Atg3bp1 mutant lines show constitutive stomata closure, expression of a number of key defense marker genes, and accumulate salicylic acid but not jasmonic acid. Furthermore, Atg3bp1 plants exhibit enhanced resistance to the biotrophic pathogen Pseudomonas syringae pv. tomato. Pathogen resistance was mediated by stomatal and apoplastic immunity in Atg3bp1. More generally, our data reinforce that AtG3BP1 is a key mediator of plant defense responses and transient expression of AtG3BP1 delivered striking disease resistance in the absence of yield penalty, highlighting a potential application of this gene in crop protection.

  1. The effect of hydration state and energy balance on innate immunity of a desert reptile.

    Science.gov (United States)

    Moeller, Karla T; Butler, Michael W; Denardo, Dale F

    2013-05-04

    Immune function is a vital physiological process that is often suppressed during times of resource scarcity due to investments in other physiological systems. While energy is the typical currency that has been examined in such trade-offs, limitations of other resources may similarly lead to trade-offs that affect immune function. Specifically, water is a critical resource with profound implications for organismal ecology, yet its availability can fluctuate at local, regional, and even global levels. Despite this, the effect of osmotic state on immune function has received little attention. Using agglutination and lysis assays as measures of an organism's plasma concentration of natural antibodies and capacity for foreign cell destruction, respectively, we tested the independent effects of osmotic state, digestive state, and energy balance on innate immune function in free-ranging and laboratory populations of the Gila monster, Heloderma suspectum. This desert-dwelling lizard experiences dehydration and energy resource fluctuations on a seasonal basis. Dehydration was expected to decrease innate immune function, yet we found that dehydration increased lysis and agglutination abilities in both lab and field studies, a relationship that was not simply an effect of an increased concentration of immune molecules. Laboratory-based differences in digestive state were not associated with lysis or agglutination metrics, although in our field population, a loss of fat stores was correlated with an increase in lysis. Depending on the life history of an organism, osmotic state may have a greater influence on immune function than energy availability. Thus, consideration of osmotic state as a factor influencing immune function will likely improve our understanding of ecoimmunology and the disease dynamics of a wide range of species.

  2. Interleukin-4 Receptor Alpha: From Innate to Adaptive Immunity in Murine Models of Cutaneous Leishmaniasis

    Directory of Open Access Journals (Sweden)

    Ramona Hurdayal

    2017-11-01

    Full Text Available The interleukin (IL-4 receptor alpha (IL-4Rα, ubiquitously expressed on both innate and adaptive immune cells, controls the signaling of archetypal type 2 immune regulators; IL-4 and IL-13, which elicit their signaling action by the type 1 IL-4Rα/gamma common and/or the type 2 IL-4Rα/IL-13Rα complexes. Global gene-deficient mouse models targeting IL-4, IL-13, or the IL-4Rα chain, followed by the development of conditional mice and generation of important cell-type-specific IL-4Rα-deficient mouse models, were indeed critical to gaining in-depth understanding of detrimental T helper (Th 2 mechanisms in type 1-controlled diseases. A primary example being cutaneous leishmaniasis, which is caused by the protozoan parasite Leishmania major, among others. The disease is characterized by localized self-healing cutaneous lesions and necrosis for which, currently, not a single vaccine has made it to a stage that can be considered effective. The spectrum of human leishmaniasis belongs to the top 10 infectious diseases according to the World Health Organization. As such, 350 million humans are at risk of infection and disease, with an incidence of 1.5–2 million new cases being reported annually. A major aim of our research is to identify correlates of host protection and evasion, which may aid in vaccine design and therapeutic interventions. In this review, we focus on the immune-regulatory role of the IL-4Rα chain from innate immune responses to the development of beneficial type 1 and detrimental type 2 adaptive immune responses during cutaneous Leishmania infection. We discuss the cell-specific requirements of the IL-4Rα chain on crucial innate immune cells during L. major infection, including, IL-4Rα-responsive skin keratinocytes, macrophages, and neutrophils, as well as dendritic cells (DCs. The latter, contributing to one of the paradigm shifts with respect to the role of IL-4 instructing DCs in vivo, to promote Th1 responses against L

  3. Dual antibody therapy to harness the innate anti-tumor immune response to enhance antibody targeting of tumors.

    Science.gov (United States)

    Chester, Cariad; Marabelle, Aurelien; Houot, Roch; Kohrt, Holbrook E

    2015-04-01

    Cancer immunotherapy is a rapidly evolving field that offers a novel paradigm for cancer treatment: therapies focus on enhancing the immune system's innate and adaptive anti-tumor response. Early immunotherapeutics have achieved impressive clinical outcomes and monoclonal antibodies are now integral to therapeutic strategies in a variety of cancers. However, only recently have antibodies targeting innate immune cells entered clinical development. Innate immune effector cells play important roles in generating and maintaining antitumor immunity. Antibody-dependent cell-mediated cytotoxicity (ADCC) and antibody-dependent cellular phagocytosis (ADCP) are important innate immune mechanisms for tumor eradication. These cytolytic processes are initiated by the detection of a tumor-targeting antibody and can be augmented by activating co-stimulatory pathways or blocking inhibitory signals on innate immune cells. The combination of FDA-approved monoclonal antibodies with innate effector-targeting antibodies has demonstrated potent preclinical therapeutic synergy and early-phase combinatorial clinical trials are ongoing. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Contribution of murine innate serum inhibitors toward interference within influenza virus immune assays.

    Science.gov (United States)

    Cwach, Kevin T; Sandbulte, Heather R; Klonoski, Joshua M; Huber, Victor C

    2012-03-01

    Prior to detection of an antibody response toward influenza viruses using the hemagglutination inhibition assay (HAI), sera are routinely treated to inactivate innate inhibitors using both heat inactivation (56°C) and recombinant neuraminidase [receptor-destroying enzyme (RDE)]. We revisited the contributions of innate serum inhibitors toward interference with influenza viruses in immune assays, using murine sera, with emphasis on the interactions with influenza A viruses of the H3N2 subtype. We used individual serum treatments: 56°C alone, RDE alone, or RDE + 56°C, to treat sera prior to evaluation within HAI, microneutralization, and macrophage uptake assays. Our data demonstrate that inhibitors present within untreated murine sera interfere with the HAI assay in a manner that is different from that seen for the microneutralization assay. Specifically, the γ class inhibitor α(2) -Macroglobulin (A2-M) can inhibit H3N2 viruses within the HAI assay, but not in the microneutralization assay. Based on these findings, we used a macrophage uptake assay to demonstrate that these inhibitors can increase uptake by macrophages when the influenza viruses express an HA from a 1968 H3N2 virus isolate, but not a 1997 H3N2 isolate. The practice of treating sera to inactivate innate inhibitors of influenza viruses prior to evaluation within immune assays has allowed us to effectively detect influenza virus-specific antibodies for decades. However, this practice has yielded an under-appreciation for the contribution of innate serum inhibitors toward host immune responses against these viruses, including contributions toward neutralization and macrophage uptake. © 2011 Blackwell Publishing Ltd.

  5. VPS9a activates the Rab5 GTPase ARA7 to confer distinct pre- and postinvasive plant innate immunity

    DEFF Research Database (Denmark)

    Nielsen, Mads Eggert; Jürgens, Gerd; Thordal-Christensen, Hans

    2017-01-01

    Plant innate immunity can effectively prevent the proliferation of filamentous pathogens. Papilla formation at the site of attack is essential for preinvasive immunity; in postinvasive immunity, the encasement of pathogen structures inside host cells can hamper disease. Whereas papillae are highly...... (Blumeria graminis f. sp hordei) in Arabidopsis thaliana. Surprisingly, VPS9a acts in addition to two previously well-described innate immunity components and thus represents an additional step in the regulation of how plants resist pathogens. We found VPS9a to be important for delivering membrane material...

  6. Tumor necrosis factor (TNF) receptor shedding controls thresholds of innate immune activation that balance opposing TNF functions in infectious and inflammatory diseases

    DEFF Research Database (Denmark)

    Xanthoulea, Sofia; Pasparakis, Manolis; Kousteni, Stavroula

    2004-01-01

    Tumor necrosis factor (TNF) is a potent cytokine exerting critical functions in the activation and regulation of immune and inflammatory responses. Due to its pleiotropic activities, the amplitude and duration of TNF function must be tightly regulated. One of the mechanisms that may have evolved...... to modulate TNF function is the proteolytic cleavage of its cell surface receptors. In humans, mutations affecting shedding of the p55TNF receptor (R) have been linked with the development of the TNFR-associated periodic syndromes, disorders characterized by recurrent fever attacks and localized inflammation....... Here we show that knock-in mice expressing a mutated nonsheddable p55TNFR develop Toll-like receptor-dependent innate immune hyperreactivity, which renders their immune system more efficient at controlling intracellular bacterial infections. Notably, gain of function for antibacterial host defenses...

  7. Age-Related Relationships between Innate Immunity and Plasma Carotenoids in an Obligate Avian Scavenger.

    Science.gov (United States)

    López-Rull, Isabel; Hornero-Méndez, Dámaso; Frías, Óscar; Blanco, Guillermo

    2015-01-01

    Variation in immunity is influenced by allocation trade-offs that are expected to change between age-classes as a result of the different environmental and physiological conditions that individuals encounter over their lifetime. One such trade-off occurs with carotenoids, which must be acquired with food and are involved in a variety of physiological functions. Nonetheless, relationships between immunity and carotenoids in species where these micronutrients are scarce due to diet are poorly studied. Among birds, vultures show the lowest concentrations of plasma carotenoids due to a diet based on carrion. Here, we investigated variations in the relationships between innate immunity (hemagglutination by natural antibodies and hemolysis by complement proteins), pathogen infection and plasma carotenoids in nestling and adult griffon vultures (Gyps fulvus) in the wild. Nestlings showed lower hemolysis, higher total carotenoid concentration and higher pathogen infection than adults. Hemolysis was negatively related to carotenoid concentration only in nestlings. A differential carotenoid allocation to immunity due to the incomplete development of the immune system of nestlings compared with adults is suggested linked to, or regardless of, potential differences in parasite infection, which requires experimental testing. We also found that individuals with more severe pathogen infections showed lower hemagglutination than those with a lower intensity infection irrespective of their age and carotenoid level. These results are consistent with the idea that intraspecific relationships between innate immunity and carotenoids may change across ontogeny, even in species lacking carotenoid-based coloration. Thus, even low concentrations of plasma carotenoids due to a scavenger diet can be essential to the development and activation of the immune system in growing birds.

  8. Drosophila as a Model for Human Diseases-Focus on Innate Immunity in Barrier Epithelia.

    Science.gov (United States)

    Bergman, P; Seyedoleslami Esfahani, S; Engström, Y

    2017-01-01

    Epithelial immunity protects the host from harmful microbial invaders but also controls the beneficial microbiota on epithelial surfaces. When this delicate balance between pathogen and symbiont is disturbed, clinical disease often occurs, such as in inflammatory bowel disease, cystic fibrosis, or atopic dermatitis, which all can be in part linked to impairment of barrier epithelia. Many innate immune receptors, signaling pathways, and effector molecules are evolutionarily conserved between human and Drosophila. This review describes the current knowledge on Drosophila as a model for human diseases, with a special focus on innate immune-related disorders of the gut, lung, and skin. The discovery of antimicrobial peptides, the crucial role of Toll and Toll-like receptors, and the evolutionary conservation of signaling to the immune systems of both human and Drosophila are described in a historical perspective. Similarities and differences between human and Drosophila are discussed; current knowledge on receptors, signaling pathways, and effectors are reviewed, including antimicrobial peptides, reactive oxygen species, as well as autophagy. We also give examples of human diseases for which Drosophila appears to be a useful model. In addition, the limitations of the Drosophila model are mentioned. Finally, we propose areas for future research, which include using the Drosophila model for drug screening, as a validation tool for novel genetic mutations in humans and for exploratory research of microbiota-host interactions, with relevance for infection, wound healing, and cancer. © 2017 Elsevier Inc. All rights reserved.

  9. The Emerging Role of TLR and Innate Immunity in Cardiovascular Disease

    Directory of Open Access Journals (Sweden)

    Rolf Spirig

    2012-01-01

    Full Text Available Cardiovascular disease is a complex disorder involving multiple pathophysiological processes, several of which involve activation of toll-like receptors (TLRs of the innate immune system. As sentinels of innate immunity TLRs are nonclonally germline-encoded molecular pattern recognition receptors that recognize exogenous as well as tissue-derived molecular dangers signals promoting inflammation. In addition to their expression in immune cells, TLRs are found in other tissues and cell types including cardiomyocytes, endothelial and vascular smooth muscle cells. TLRs are differentially regulated in various cell types by several cardiovascular risk factors such as hypercholesterolemia, hyperlipidemia, and hyperglycemia and may represent a key mechanism linking chronic inflammation, cardiovascular disease progression, and activation of the immune system. Modulation of TLR signaling by specific TLR agonists or antagonists, alone or in combination, may be a useful therapeutic approach to treat various cardiovascular inflammatory conditions such as atherosclerosis, peripheral arterial disease, secondary microvascular complications of diabetes, autoimmune disease, and ischemia reperfusion injury. In this paper we discuss recent developments and current evidence for the role of TLR in cardiovascular disease as well as the therapeutic potential of various compounds on inhibition of TLR-mediated inflammatory responses.

  10. Effect of the dietary inclusion of soybean components on the innate immune system in zebrafish.

    Science.gov (United States)

    Fuentes-Appelgren, Pamela; Opazo, Rafael; Barros, Luis; Feijoó, Carmen G; Urzúa, Victoria; Romero, Jaime

    2014-02-01

    Some components of plant-based meals, such as saponins and vegetal proteins, have been proposed as inducers of intestinal inflammation in some fish. However, the molecular and cellular bases for this phenomenon have not been reported. In this work, zebrafish were used as a model to evaluate the effects of individual soybean meal components, such as saponins and soy proteins. Zebrafish larvae fed a fish meal feed containing soy components were assessed according to low and high inclusion levels. The granulocytes associated with the digestive tract and the induction of genes related to the immune system were quantitated as markers of the effects of the dietary components. A significant increase in the number of granulocytes was observed after feeding fish diets containing high saponin or soy protein contents. These dietary components also induced the expression of genes related to the innate immune system, including myeloid-specific peroxidase, as well as the complement protein and cytokines. These results reveal the influence of dietary components on the stimulation of the immune system. These observations could be significant to understanding the contributions of saponin and soy protein to the onset of enteritis in aqua-cultured fish, and this knowledge may aid in defining the role of the innate immune system in other inflammatory diseases involving dietary components in mammals.

  11. Innate immunity and cellular senescence: The good and the bad in the developmental and aged brain.

    Science.gov (United States)

    Santoro, Antonietta; Spinelli, Chiara Carmela; Martucciello, Stefania; Nori, Stefania Lucia; Capunzo, Mario; Puca, Annibale Alessandro; Ciaglia, Elena

    2018-03-01

    Ongoing studies evidence cellular senescence in undifferentiated and specialized cells from tissues of all ages. Although it is believed that senescence plays a wider role in several stress responses in the mature age, its participation in certain physiological and pathological processes throughout life is coming to light. The "senescence machinery" has been observed in all brain cell populations, including components of innate immunity (e.g., microglia and astrocytes). As the beneficial versus detrimental implications of senescence is an open question, we aimed to analyze the contribution of immune responses in regulatory mechanisms governing its distinct functions in healthy (development, organogenesis, danger patrolling events) and diseased brain (glioma, neuroinflammation, neurodeneration), and the putative connection between cellular and molecular events governing the 2 states. Particularly this review offers new insights into the complex roles of senescence both as a chronological event as age advances, and as a molecular mechanism of brain homeostasis through the important contribution of innate immune responses and their crosstalk with neighboring cells in brain parenchyma. We also highlight the impact of the recently described glymphatic system and brain lymphatic vasculature in the interplay between peripheral and central immune surveillance and its potential implication during aging. This will open new ways to understand brain development, its deterioration during aging, and the occurrence of several oncological and neurodegenerative diseases. ©2018 Society for Leukocyte Biology.

  12. The bovine spleen: Interactions among splenic cell populations in the innate immunologic control of hemoparasitic infections

    Science.gov (United States)

    Over the past several years, innate immunity has been recognized as having an important role as a front-line defense mechanism and as an integral part of the adaptive immune response. Innate immunity in cattle exposed to hemoparasites is spleen-dependent and age-related. In this review, we discuss g...

  13. Complementary roles for lipid and protein allergens in triggering innate and adaptive immune systems.

    Science.gov (United States)

    Russano, A M; Agea, E; Casciari, C; de Benedictis, F M; Spinozzi, F

    2008-11-01

    Recent advances in allergy research mostly focussed on two major headings: improving protein allergen purification, which is aimed towards a better characterization of IgE- and T-cell reactive epitopes, and the potential new role for unconventional innate and regulatory T cells in controlling airway inflammation. These advancements could appear to be in conflict each other, as innate T cells have a poorly-defined antigen specificity that is often directed toward nonprotein substances, such as lipids. To reconcile these contrasting findings, the model of cypress pollinosis as paradigmatic for studying allergic diseases in adults is suggested. The biochemical characterization of major native protein allergens from undenatured pollen grain demonstrated that the most relevant substance with IgE-binding activity is a glycohydrolase enzyme, which easily denaturizes in stored grains. Moreover, lipids from the pollen membrane are implicated in early pollen grain capture and recognition by CD1(+) dendritic cells (DC) and CD1-restricted T lymphocytes. These T cells display Th0/Th2 functional activity and are also able to produce regulatory cytokines, such as IL-10 and TGF-beta. CD1(+) immature DCs expand in the respiratory mucosa of allergic subjects and are able to process both proteins and lipids. A final scenario may suggest that expansion and functional activation of CD1(+) DCs is a key step for mounting a Th0/Th2-deviated immune response, and that such innate response does not confer long-lasting protective immunity.

  14. Activation of Plant Innate Immunity by Extracellular High Mobility Group Box 3 and Its Inhibition by Salicylic Acid.

    Directory of Open Access Journals (Sweden)

    Hyong Woo Choi

    2016-03-01

    Full Text Available Damage-associated molecular pattern molecules (DAMPs signal the presence of tissue damage to induce immune responses in plants and animals. Here, we report that High Mobility Group Box 3 (HMGB3 is a novel plant DAMP. Extracellular HMGB3, through receptor-like kinases BAK1 and BKK1, induced hallmark innate immune responses, including i MAPK activation, ii defense-related gene expression, iii callose deposition, and iv enhanced resistance to Botrytis cinerea. Infection by necrotrophic B. cinerea released HMGB3 into the extracellular space (apoplast. Silencing HMGBs enhanced susceptibility to B. cinerea, while HMGB3 injection into apoplast restored resistance. Like its human counterpart, HMGB3 binds salicylic acid (SA, which results in inhibition of its DAMP activity. An SA-binding site mutant of HMGB3 retained its DAMP activity, which was no longer inhibited by SA, consistent with its reduced SA-binding activity. These results provide cross-kingdom evidence that HMGB proteins function as DAMPs and that SA is their conserved inhibitor.

  15. Adaptation of innate lymphoid cells to nutrient deprivation promotes type 2 barrier immunity

    Science.gov (United States)

    Survival of the host relies on the establishment of site-specific barrier defense tailored to constrain pressures imposed by commensal and parasitic exposures. The host is confronted with the additional challenge of maintaining barrier immunity in fluctuating states of dietary availability, yet how ...

  16. The role of lipopolysaccharide and peptidoglycan, two glycosylated bacterial microbe-associated molecular patterns (MAMPs), in plant innate immunity

    DEFF Research Database (Denmark)

    Erbs, Gitte; Newman, Mari-Anne

    2012-01-01

    innate immune system through the action of pattern recognition receptors (PRRs). A greater insight into the mechanisms of MAMP recognition and the description of PRRs for different microbial glycoconjugates will have considerable impact on the improvement of plant health and disease resistance. Here...... to as ‘innate immunity’. Innate immunity is the first line of defence against invading microorganisms in vertebrates and the only line of defence in invertebrates and plants. Bacterial glycoconjugates, such as lipopolysaccharides (LPSs) from the outer membrane of Gram-negative bacteria and peptidoglycan (PGN......) from the cell walls of both Gram-positive and Gram-negative bacteria, have been found to act as elicitors of plant innate immunity. These conserved, indispensable, microbe-specific molecules are also referred to as ‘microbe-associated molecular patterns’ (MAMPs). MAMPs are recognized by the plant...

  17. Codevelopment of Microbiota and Innate Immunity and the Risk for Group B Streptococcal Disease

    Directory of Open Access Journals (Sweden)

    Julia Kolter

    2017-11-01

    Full Text Available The pathogenesis of neonatal late-onset sepsis (LOD, which manifests between the third day and the third month of life, remains poorly understood. Group B Streptococcus (GBS is the most important cause of LOD in infants without underlying diseases or prematurity and the third most frequent cause of meningitis in the Western world. On the other hand, GBS is a common intestinal colonizer in infants. Accordingly, despite its adaption to the human lower gastrointestinal tract, GBS has retained its potential virulence and its transition from a commensal to a dangerous pathogen is unpredictable in the individual. Several cellular innate immune mechanisms, in particular Toll-like receptors, the inflammasome and the cGAS pathway, are engaged by GBS effectors like nucleic acids. These are likely to impact on the GBS-specific host resistance. Given the long evolution of streptococci as a normal constituent of the human microbiota, the emergence of GBS as the dominant neonatal sepsis cause just about 50 years ago is remarkable. It appears that intensive usage of tetracycline starting in the 1940s has been a selection advantage for the currently dominant GBS clones with superior adhesive and invasive properties. The historical replacement of Group A by Group B streptococci as a leading neonatal pathogen and the higher frequency of other β-hemolytic streptococci in areas with low GBS prevalence suggests the existence of a confined streptococcal niche, where locally competing streptococcal species are subject to environmental and immunological selection pressure. Thus, it seems pivotal to resolve neonatal innate immunity at mucous surfaces and its impact on microbiome composition and quality, i.e., genetic heterogeneity and metabolism, at the microanatomical level. Then, designer pro- and prebiotics, such as attenuated strains of GBS, and oligonucleotide priming of mucosal immunity may unfold their potential and facilitate adaptation of potentially

  18. Codevelopment of Microbiota and Innate Immunity and the Risk for Group B Streptococcal Disease.

    Science.gov (United States)

    Kolter, Julia; Henneke, Philipp

    2017-01-01

    The pathogenesis of neonatal late-onset sepsis (LOD), which manifests between the third day and the third month of life, remains poorly understood. Group B Streptococcus (GBS) is the most important cause of LOD in infants without underlying diseases or prematurity and the third most frequent cause of meningitis in the Western world. On the other hand, GBS is a common intestinal colonizer in infants. Accordingly, despite its adaption to the human lower gastrointestinal tract, GBS has retained its potential virulence and its transition from a commensal to a dangerous pathogen is unpredictable in the individual. Several cellular innate immune mechanisms, in particular Toll-like receptors, the inflammasome and the cGAS pathway, are engaged by GBS effectors like nucleic acids. These are likely to impact on the GBS-specific host resistance. Given the long evolution of streptococci as a normal constituent of the human microbiota, the emergence of GBS as the dominant neonatal sepsis cause just about 50 years ago is remarkable. It appears that intensive usage of tetracycline starting in the 1940s has been a selection advantage for the currently dominant GBS clones with superior adhesive and invasive properties. The historical replacement of Group A by Group B streptococci as a leading neonatal pathogen and the higher frequency of other β-hemolytic streptococci in areas with low GBS prevalence suggests the existence of a confined streptococcal niche, where locally competing streptococcal species are subject to environmental and immunological selection pressure. Thus, it seems pivotal to resolve neonatal innate immunity at mucous surfaces and its impact on microbiome composition and quality, i.e., genetic heterogeneity and metabolism, at the microanatomical level. Then, designer pro- and prebiotics, such as attenuated strains of GBS, and oligonucleotide priming of mucosal immunity may unfold their potential and facilitate adaptation of potentially hazardous streptococci as

  19. Identification and utility of innate immune system evasion mechanisms of ASFV.

    Science.gov (United States)

    Correia, Sílvia; Ventura, Sónia; Parkhouse, Robert Michael

    2013-04-01

    The interferon (IFN) system is an early innate anti-virus host defense mechanism that takes place shortly after entry of the pathogen and long before the onset of adaptive immunity. Thus, African swine fever virus (ASFV), as an acute and persistent virus in pigs, is predicted to have evolved multiple genes for the manipulation and evasion of interferon. Although, ASFV is known to interfere with signaling pathways controlling the transcription of cytokines, surprisingly no individual virus gene manipulating the induction or impact of IFN has been described. Since an initial bioinformatics search of the ASFV genome failed to identify potential antagonists of the IFN response, our strategy was to functionally screen early expressed, "unassigned" ASFV genes without existing homologies, particularly from MGFs 360 and 530, in luciferase reporter assays for their inhibition of the induction and impact of IFN. Specifically, we used reporter plasmids containing the luciferase gene under the control of: (1) the IFN-β promoter, to screen for inhibition of induction of type I IFN stimulated by the addition of Poly(I:C); (2) the ISRE DNA elements, to screen for the inhibition of the impact of type I IFN; and (3) the GAS DNA elements to screen for the inhibition of the impact of type II IFN. Our initial experiments revealed six ASFV genes inhibiting one or more of the three luciferase assays. From these, we have selected a total of 3 genes for presentation. The ASFV A276R gene from MGF360 inhibited the induction of IFN-β via both the TLR3 and the cytosolic pathways, targeting IRF3, but not IRF7 or NF-κB. The ASFV A528R inhibited the induction of both NF-κB and IRF3 branches of the type I IFN induction signaling pathway and the impact of IFN response via both IFN type I and type II stimulation. The ASFV I329L gene is a functional viral TLR3 homologue inhibiting the induction of IFN at the level of TRIF. Thus, these genes reduce the IFN response by targeting different

  20. The role of innate signaling in the homeostasis of tolerance and immunity in the intestine.

    Science.gov (United States)

    Wells, Jerry M; Loonen, Linda M P; Karczewski, Jurgen M

    2010-01-01

    In the intestine innate recognition of microbes is achieved through pattern recognition receptor (PRR) families expressed in immune cells and different cell lineages of the intestinal epithelium. Toll-like receptor (TLR) and nucleotide-binding and oligomerization domain-like receptor (NLR) families are emerging as key mediators of immunity through their role as maturation factors of immune cells and triggers for the production of cytokines and chemokines and antimicrobial factors. At the mucosal surface chronic activation of the immune system is avoided through the epithelial production of a glycocalyx, steady-state production of antimicrobial factors as well as the selective expression and localization of PRRs. Additionally, the polarization of epithelial TLR signaling and suppression of NF-kappaB activation by luminal commensals appears to contribute to the homeostasis of tolerance and immunity. Several studies have demonstrated that TLR signaling in epithelial cells contributes to a range of homeostatic mechanisms including proliferation, wound healing, epithelial integrity, and regulation of mucosal immune functions. The intestinal epithelium appears to have uniquely evolved to maintain mucosal tolerance and immunity, and future efforts to further understand the molecular mechanisms of intestinal homeostasis may have a major impact on human health. Copyright 2009 Elsevier GmbH. All rights reserved.

  1. Transcriptome Analysis of the Innate Immunity-Related Complement System in Spleen Tissue of Ctenopharyngodon idella Infected with Aeromonas hydrophila.

    Directory of Open Access Journals (Sweden)

    Yunfei Dang

    Full Text Available The grass carp (Ctenopharyngodon idella is an important commercial farmed herbivorous fish species in China, but is susceptible to Aeromonas hydrophila infections. In the present study, we performed de novo RNA-Seq sequencing of spleen tissue from specimens of a disease-resistant family, which were given intra-peritoneal injections containing PBS with or without a dose of A. hydrophila. The fish were sampled from the control group at 0 h, and from the experimental group at 4, 8, 12, 24, 48 and 72 h. 122.18 million clean reads were obtained from the normalized cDNA libraries; these were assembled into 425,260 contigs and then 191,795 transcripts. Of those, 52,668 transcripts were annotated with the NCBI Nr database, and 41,347 of the annotated transcripts were assigned into 90 functional groups. 20,569 unigenes were classified into six main categories, including 38 secondary KEGG pathways. 2,992 unigenes were used in the analysis of differentially expressed genes (DEGs. 89 of the putative DEGs were related to the immune system and 41 of them were involved in the complement and coagulation cascades pathway. This study provides insights into the complement and complement-related pathways involved in innate immunity, through expression profile analysis of the genomic resources in C. idella. We conclude that complement and complement-related genes play important roles during defense against A. hydrophila infection. The immune response is activated at 4 h after the bacterial injections, indicating that the complement pathways are activated at the early stage of bacterial infection. The study has improved our understanding of the immune response mechanisms in C. idella to bacterial pathogens.

  2. Widespread Shortening of 3' Untranslated Regions and Increased Exon Inclusion Are Evolutionarily Conserved Features of Innate Immune Responses to Infection.

    Directory of Open Access Journals (Sweden)

    Athma A Pai

    2016-09-01

    Full Text Available The contribution of pre-mRNA processing mechanisms to the regulation of immune responses remains poorly studied despite emerging examples of their role as regulators of immune defenses. We sought to investigate the role of mRNA processing in the cellular responses of human macrophages to live bacterial infections. Here, we used mRNA sequencing to quantify gene expression and isoform abundances in primary macrophages from 60 individuals, before and after infection with Listeria monocytogenes and Salmonella typhimurium. In response to both bacteria we identified thousands of genes that significantly change isoform usage in response to infection, characterized by an overall increase in isoform diversity after infection. In response to both bacteria, we found global shifts towards (i the inclusion of cassette exons and (ii shorter 3' UTRs, with near-universal shifts towards usage of more upstream polyadenylation sites. Using complementary data collected in non-human primates, we show that these features are evolutionarily conserved among primates. Following infection, we identify candidate RNA processing factors whose expression is associated with individual-specific variation in isoform abundance. Finally, by profiling microRNA levels, we show that 3' UTRs with reduced abundance after infection are significantly enriched for target sites for particular miRNAs. These results suggest that the pervasive usage of shorter 3' UTRs is a mechanism for particular genes to evade repression by immune-activated miRNAs. Collectively, our results suggest that dynamic changes in RNA processing may play key roles in the regulation of innate immune responses.

  3. 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...... the very essence of immune system physiology, a key to a rapid, efficient and optimally regulated immune response is the ability of the involved cells to rapidly shift between a stationary and a mobile state, combined with stringent regulation of cell migration during the mobile state. Through the co......-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...

  4. Innate Immunity and Inflammation Post-Stroke: An α7-Nicotinic Agonist Perspective

    Directory of Open Access Journals (Sweden)

    Silke Neumann

    2015-12-01

    Full Text Available Stroke is one of the leading causes of death and long-term disability, with limited treatment options available. Inflammation contributes to damage tissue in the central nervous system across a broad range of neuropathologies, including Alzheimer’s disease, pain, Schizophrenia, and stroke. While the immune system plays an important role in contributing to brain damage produced by ischemia, the damaged brain, in turn, can exert a powerful immune-suppressive effect that promotes infections and threatens the survival of stroke patients. Recently the cholinergic anti-inflammatory pathway, in particular its modulation using α7-nicotinic acetylcholine receptor (α7-nAChR ligands, has shown potential as a strategy to dampen the inflammatory response and facilitate functional recovery in stroke patients. Here we discuss the current literature on stroke-induced inflammation and the effects of α7-nAChR modulators on innate immune cells.

  5. Innate immune activity conditions the effect of regulatory variants upon monocyte gene expression.

    Science.gov (United States)

    Fairfax, Benjamin P; Humburg, Peter; Makino, Seiko; Naranbhai, Vivek; Wong, Daniel; Lau, Evelyn; Jostins, Luke; Plant, Katharine; Andrews, Robert; McGee, Chris; Knight, Julian C

    2014-03-07

    To systematically investigate the impact of immune stimulation upon regulatory variant activity, we exposed primary monocytes from 432 healthy Europeans to interferon-γ (IFN-γ) or differing durations of lipopolysaccharide and mapped expression quantitative trait loci (eQTLs). More than half of cis-eQTLs identified, involving hundreds of genes and associated pathways, are detected specifically in stimulated monocytes. Induced innate immune activity reveals multiple master regulatory trans-eQTLs including the major histocompatibility complex (MHC), coding variants altering enzyme and receptor function, an IFN-β cytokine network showing temporal specificity, and an interferon regulatory factor 2 (IRF2) transcription factor-modulated network. Induced eQTL are significantly enriched for genome-wide association study loci, identifying context-specific associations to putative causal genes including CARD9, ATM, and IRF8. Thus, applying pathophysiologically relevant immune stimuli assists resolution of functional genetic variants.

  6. [Aspects of the innate immune response to intramammary Staphylococcus aureus infections in cattle].

    Science.gov (United States)

    Pereyra, Elizabet A L; Dallard, Bibiana E; Calvinho, Luis F

    2014-01-01

    Staphylococcus aureus is the pathogen most frequently isolated from bovine mastitis worldwide, causing chronic intramammary infections that limit profitable dairying. The objective of this article is to characterize the mechanisms involved in S. aureus mammary gland infections considering two different aspects of the infectious process; on the one hand, the aspects involved in the host innate immune response and on the other hand, the capacity of this organism to evade the immune system and interact with different cell types. The exploration of S. aureus interactions with the immune response of bovine mammary gland will help identify targets to outline new preventive or curative alternatives for intramammary infections caused by this organism. Copyright © 2014 Asociación Argentina de Microbiología. Publicado por Elsevier España. All rights reserved.

  7. Innate immune response against an oomycete pathogen Aphanomyces invadans in common carp (Cyprinus carpio), a fish resistant to epizootic ulcerative syndrome.

    Science.gov (United States)

    Yadav, Manoj K; Pradhan, Pravata K; Sood, Neeraj; Chaudhary, Dharmendra K; Verma, Dev K; Chauhan, U K; Punia, Peyush; Jena, Joy K

    2016-03-01

    Infection with Aphanomyces invadans, also known as epizootic ulcerative syndrome, is a destructive disease of freshwater and brackishwater fishes. Although more than 130 species of fish have been confirmed to be susceptible to this disease, some of the commercially important fish species like common carp, milk fish and tilapia are reported to be resistant. Species that are naturally resistant to a particular disease, provide a potential model to study the mechanisms of resistance against that disease. In the present study, following experimental infection with A. invadans in common carp Cyprinus carpio, sequential changes in various innate immune parameters and histopathological alterations were monitored. Some of the studied innate immunity parameters viz. respiratory burst, alternative complement and total antiproteases activities of the infected common carp were higher compared to control fish, particularly at early stages of infection. On the other hand, some parameters such as myeloperoxidase, lysozyme and alpha-2 macroglobulin activities were not altered. Histopathological examination of the muscle at the site of injection revealed well developed granulomas at 12 days post infection, with subsequent regeneration of muscle fibers. From the results, it could be inferred that innate defense mechanisms of common carp are able to neutralize the virulence factors secreted by A. invadans, thereby, preventing its invasive spread and containing the infection. The results obtained here will help to better understand the mechanisms underlying resistance against A. invadans infection. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Mucosal innate immune cells regulate both gut homeostasis and intestinal inflammation.

    Science.gov (United States)

    Kurashima, Yosuke; Goto, Yoshiyuki; Kiyono, Hiroshi

    2013-12-01

    Continuous exposure of intestinal mucosal surfaces to diverse microorganisms and their metabolites reflects the biological necessity for a multifaceted, integrated epithelial and immune cell-mediated regulatory system. The development and function of the host cells responsible for the barrier function of the intestinal surface (e.g., M cells, Paneth cells, goblet cells, and columnar epithelial cells) are strictly regulated through both positive and negative stimulation by the luminal microbiota. Stimulation by damage-associated molecular patterns and commensal bacteria-derived microbe-associated molecular patterns provokes the assembly of inflammasomes, which are involved in maintaining the integrity of the intestinal epithelium. Mucosal immune cells located beneath the epithelium play critical roles in regulating both the mucosal barrier and the relative composition of the luminal microbiota. Innate lymphoid cells and mast cells, in particular, orchestrate the mucosal regulatory system to create a mutually beneficial environment for both the host and the microbiota. Disruption of mucosal homeostasis causes intestinal inflammation such as that seen in inflammatory bowel disease. Here, we review the recent research on the biological interplay among the luminal microbiota, epithelial cells, and mucosal innate immune cells in both healthy and pathological conditions. © 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Poliovirus intrahost evolution is required to overcome tissue-specific innate immune responses.

    Science.gov (United States)

    Xiao, Yinghong; Dolan, Patrick Timothy; Goldstein, Elizabeth Faul; Li, Min; Farkov, Mikhail; Brodsky, Leonid; Andino, Raul

    2017-08-29

    RNA viruses, such as poliovirus, have a great evolutionary capacity, allowing them to quickly adapt and overcome challenges encountered during infection. Here we show that poliovirus infection in immune-competent mice requires adaptation to tissue-specific innate immune microenvironments. The ability of the virus to establish robust infection and virulence correlates with its evolutionary capacity. We further identify a region in the multi-functional poliovirus protein 2B as a hotspot for the accumulation of minor alleles that facilitate a more effective suppression of the interferon response. We propose that population genetic dynamics enables poliovirus spread between tissues through optimization of the genetic composition of low frequency variants, which together cooperate to circumvent tissue-specific challenges. Thus, intrahost virus evolution determines pathogenesis, allowing a dynamic regulation of viral functions required to overcome barriers to infection.RNA viruses, such as polioviruses, have a great evolutionary capacity and can adapt quickly during infection. Here, the authors show that poliovirus infection in mice requires adaptation to innate immune microenvironments encountered in different tissues.

  10. Role of the peripheral innate immune system in the development of Alzheimer's disease.

    Science.gov (United States)

    Le Page, Aurélie; Dupuis, Gilles; Frost, Eric H; Larbi, Anis; Pawelec, Graham; Witkowski, Jacek M; Fulop, Tamas

    2017-12-21

    Alzheimer's disease is one of the most devastating neurodegenerative diseases. The exact cause of the disease is still not known although many scientists believe in the beta amyloid hypothesis which states that the accumulation of the amyloid peptide beta (Aβ) in brain is the initial cause which consequently leads to pathological neuroinflammation. However, it was recently shown that Aβ may have an important role in defending the brain against infections. Thus, the balance between positive and negative impact of Aβ may determine disease progression. Microglia in the brain are innate immune cells, and brain-initiated inflammatory responses reflected in the periphery suggests that Alzheimer's disease is to some extent also a systemic inflammatory disease. Greater permeability of the blood brain barrier facilitates the transport of peripheral immune cells to the brain and vice versa so that a vicious circle originating on the periphery may contribute to the development of overt clinical AD. Persistent inflammatory challenges by pathogens in the periphery, increasing with age, may also contribute to the central propagation of the pathological changes seen clinically. Therefore, the activation status of peripheral innate immune cells may represent an early biomarker of the upcoming impact on the brain. The modulation of these cells may thus become a useful mechanism for modifying disease progression. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. A novel mode of induction of the humoral innate immune response in Drosophila larvae

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    Hiroyuki Kenmoku

    2017-03-01

    Full Text Available Drosophila adults have been utilized as a genetically tractable model organism to decipher the molecular mechanisms of humoral innate immune responses. In an effort to promote the utility of Drosophila larvae as an additional model system, in this study, we describe a novel aspect of an induction mechanism for innate immunity in these larvae. By using a fine tungsten needle created for manipulating semi-conductor devices, larvae were subjected to septic injury. However, although Toll pathway mutants were susceptible to infection with Gram-positive bacteria as had been shown for Drosophila adults, microbe clearance was not affected in the mutants. In addition, Drosophila larvae were found to be sensitive to mechanical stimuli with respect to the activation of a sterile humoral response. In particular, pinching with forceps to a degree that might cause minor damage to larval tissues could induce the expression of the antifungal peptide gene Drosomycin; notably, this induction was partially independent of the Toll and immune deficiency pathways. We therefore propose that Drosophila larvae might serve as a useful model to analyze the infectious and non-infectious inflammation that underlies various inflammatory diseases such as ischemia, atherosclerosis and cancer.

  12. Cathepsin O is involved in the innate immune response and metamorphosis of Antheraea pernyi.

    Science.gov (United States)

    Sun, Yu-Xuan; Zhu, Bao-Jian; Tang, Lin; Sun, Yu; Chen, Chen; Nadeem Abbas, Muhammad; Wang, Lei; Qian, Cen; Wei, Guo-Qing; Liu, Chao-Liang

    2017-11-01

    Cathepsins are key members of mammalian papain-like cysteine proteases that play an important role in the immune response. In this study, a fragment of cDNA encoding cathepsin O proteinase (ApCathepsin O) was cloned from Antheraea pernyi. It contains an open reading frame of 1170bp and encodes a protein with 390 amino acid residues, including a conserved I29 inhibitor domain and a peptidase C1A (clan CA of cysteine proteases, papain family C1 subfamily) domain. Comparison with other previously reported cathepsin O proteins showed identity ranging from 45% to 79%. Quantitative real-time PCR (qRT-PCR) and Western blot analysis revealed that ApCathepsin O was highly expressed in the fat body; furthermore, the high expression during the pupal stage indicated that it might be involved during metamorphosis. After exposure to four different heat-killed pathogens (Escherichia coli, Beauveria bassiana, Micrococcus luteus, and A. pernyi nucleopolyhedrovirus), the expression levels of ApCathepsin O mRNA significantly increased and showed variable expression patterns. This indicates that ApCathepsin O is potentially involved in the innate immune system of A. pernyi. Interestingly, ApCathepsin O expression was upregulated after 20-hydroxyecdysone (20E) injection, which suggested that it might be regulated by 20E. In conclusion, ApCathepsin O is a protease that may play an important role in the innate immune response and metamorphosis of A. pernyi. Copyright © 2017. Published by Elsevier Inc.

  13. Mechanisms Underlying the Regulation of Innate and Adaptive Immunity by Vitamin D.

    Science.gov (United States)

    Wei, Ran; Christakos, Sylvia

    2015-09-24

    Non-classical actions of vitamin D were first suggested over 30 years ago when receptors for the active form of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), were detected in various tissues and cells that are not associated with the regulation of calcium homeostasis, including activated human inflammatory cells. The question that remained was the biological significance of the presence of vitamin D receptors in the different tissues and cells and, with regard to the immune system, whether or not vitamin D plays a role in the normal immune response and in modifying immune mediated diseases. In this article findings indicating that vitamin D is a key factor regulating both innate and adaptive immunity are reviewed with a focus on the molecular mechanisms involved. In addition, the physiological significance of vitamin D action, as suggested by in vivo studies in mouse models is discussed. Together, the findings indicate the importance of 1,25(OH)2D3 as a regulator of key components of the immune system. An understanding of the mechanisms involved will lead to potential therapeutic applications for the treatment of immune mediated diseases.

  14. The sweet side of a long pentraxin: how glycosylation affects PTX3 functions in innate immunity and inflammation

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    Antonio eInforzato

    2013-01-01

    Full Text Available Innate immunity represents the first line of defence against pathogens and plays key roles in activation and orientation of the adaptive immune response. The innate immune system comprises both a cellular and a humoral arm. Components of the humoral arm include soluble pattern recognition molecules (PRMs that recognise pathogen associated molecular patterns (PAMPs and initiate the immune response in coordination with the cellular arm, therefore acting as functional ancestors of antibodies. The long pentraxin PTX3 is a prototypic soluble PRM that is produced at sites of infection and inflammation by both somatic and immune cells. Gene targeting of this evolutionarily conserved protein has revealed a non-redundant role in resistance to selected pathogens. Moreover, PTX3 exerts important functions at the crossroad between innate immunity, inflammation and female fertility. The human PTX3 protein contains a single N-glycosylation site that is fully occupied by complex type oligosaccharides, mainly fucosylated and sialylated biantennary glycans. Glycosylation has been implicated in a number of PTX3 activities, including neutralization of influenza viruses, modulation of the complement system, and attenuation of leukocyte recruitment. Therefore, this post translational modification might act as a fine tuner of PTX3 functions in native immunity and inflammation.Here we review the studies on PTX3, with emphasis on the glycan-dependent mechanisms underlying pathogen recognition and crosstalk with other components of the innate immune system.

  15. Molecular mechanism of mast cell–mediated innate defense against endothelin and snake venom sarafotoxin

    Science.gov (United States)

    Schneider, Lars A.; Schlenner, Susan M.; Feyerabend, Thorsten B.; Wunderlin, Markus; Rodewald, Hans-Reimer

    2007-01-01

    Mast cells are protective against snake venom sarafotoxins that belong to the endothelin (ET) peptide family. The molecular mechanism underlying this recently recognized innate defense pathway is unknown, but secretory granule proteases have been invoked. To specifically disrupt a single protease function without affecting expression of other proteases, we have generated a mouse mutant selectively lacking mast cell carboxypeptidase A (Mc-cpa) activity. Using this mutant, we have now identified Mc-cpa as the essential protective mast cell enzyme. Mass spectrometry of peptide substrates after cleavage by normal or mutant mast cells showed that removal of a single amino acid, the C-terminal tryptophan, from ET and sarafotoxin by Mc-cpa is the principle molecular mechanism underlying this very rapid mast cell response. Mast cell proteases can also cleave ET and sarafotoxin internally, but such “nicking” is not protective because intramolecular disulfide bridges maintain peptide function. We conclude that mast cells attack ET and sarafotoxin exactly at the structure required for toxicity, and hence sarafotoxins could not “evade” Mc-cpa's substrate specificity without loss of toxicity. PMID:17923505

  16. Estradiol and Progesterone Strongly Inhibit the Innate Immune Response of Mononuclear Cells in Newborns ▿

    Science.gov (United States)

    Giannoni, Eric; Guignard, Laurence; Knaup Reymond, Marlies; Perreau, Matthieu; Roth-Kleiner, Matthias; Calandra, Thierry; Roger, Thierry

    2011-01-01

    Newborns are particularly susceptible to bacterial infections due to qualitative and quantitative deficiencies of the neonatal innate immune system. However, the mechanisms underlying these deficiencies are poorly understood. Given that fetuses are exposed to high concentrations of estradiol and progesterone during gestation and at time of delivery, we analyzed the effects of these hormones on the response of neonatal innate immune cells to endotoxin, bacterial lipopeptide, and Escherichia coli and group B Streptococcus, the two most common causes of early-onset neonatal sepsis. Here we show that at concentrations present in umbilical cord blood, estradiol and progesterone are as powerful as hydrocortisone for inhibition of cytokine production by cord blood mononuclear cells (CBMCs) and newborn monocytes. Interestingly, CBMCs and newborn monocytes are more sensitive to the effects of estradiol and progesterone than adult peripheral blood mononuclear cells and monocytes. This increased sensitivity is associated with higher expression levels of estrogen and membrane progesterone receptors but is independent of a downregulation of Toll-like receptor 2 (TLR2), TLR4, and myeloid differentiation primary response gene 88 in newborn cells. Estradiol and progesterone mediate their anti-inflammatory activity through inhibition of the NF-κB pathway but not the mitogen-activated protein kinase pathway in CBMCs. Altogether, these results suggest that elevated umbilical cord blood concentrations of estradiol and progesterone acting on mononuclear cells expressing high levels of steroid receptors contribute to impair innate immune responses in newborns. Therefore, intrauterine exposure to estradiol and progesterone may participate in increasing susceptibility to infection during the neonatal period. PMID:21518785

  17. Unfolded protein response (UPR) signaling regulates arsenic trioxide-mediated macrophage innate immune function disruption

    International Nuclear Information System (INIS)

    Srivastava, Ritesh K.; Li, Changzhao; Chaudhary, Sandeep C.; Ballestas, Mary E.; Elmets, Craig A.; Robbins, David J.; Matalon, Sadis; Deshane, Jessy S.; Afaq, Farrukh; Bickers, David R.; Athar, Mohammad

    2013-01-01

    Arsenic exposure is known to disrupt innate immune functions in humans and in experimental animals. In this study, we provide a mechanism by which arsenic trioxide (ATO) disrupts macrophage functions. ATO treatment of murine macrophage cells diminished internalization of FITC-labeled latex beads, impaired clearance of phagocytosed fluorescent bacteria and reduced secretion of pro-inflammatory cytokines. These impairments in macrophage functions are associated with ATO-induced unfolded protein response (UPR) signaling pathway characterized by the enhancement in proteins such as GRP78, p-PERK, p-eIF2α, ATF4 and CHOP. The expression of these proteins is altered both at transcriptional and translational levels. Pretreatment with chemical chaperon, 4-phenylbutyric acid (PBA) attenuated the ATO-induced activation in UPR signaling and afforded protection against ATO-induced disruption of macrophage functions. This treatment also reduced ATO-mediated reactive oxygen species (ROS) generation. Interestingly, treatment with antioxidant N-acetylcysteine (NAC) prior to ATO exposure, not only reduced ROS production and UPR signaling but also improved macrophage functions. These data demonstrate that UPR signaling and ROS generation are interdependent and are involved in the arsenic-induced pathobiology of macrophage. These data also provide a novel strategy to block the ATO-dependent impairment in innate immune responses. - Highlights: • Inorganic arsenic to humans and experimental animals disrupt innate immune responses. • The mechanism underlying arsenic impaired macrophage functions involves UPR signaling. • Chemical chaperon attenuates arsenic-mediated macrophage function impairment. • Antioxidant, NAC blocks impairment in arsenic-treated macrophage functions

  18. Role of Natural Killer Cells in the Innate Immune System After Intraportal Islet Transplantation in Mice.

    Science.gov (United States)

    Saeki, Y; Ishiyama, K; Ishida, N; Tanaka, Y; Ohdan, H

    Both liver natural killer (NK) and NK T cells of the innate immune system play a crucial role in islet graft loss after intraportal islet transplantation, although a relationship between NK and NK T cells in islet loss has not been proven. In this study, we investigated the role of NK cells in the innate immune system in islet graft loss after intraportal islet transplantation. To investigate the involvement of liver NK cells in islet destruction, we assessed the differences in graft survival after intraportal islet transplantation between CD1d -/- diabetic mice and NK cell-depleted CD1d -/- diabetic mice. The transplantation of 400 islets into the liver was sufficient to reverse hyperglycemia in wild-type diabetic mice (100%, 4/4). However, normoglycemia could not be achieved when 200 islets were transplanted (0%, 0/4). In contrast, intraportal transplantation of 200 islets in NK cell-depleted CD1d -/- diabetic mice ameliorated hyperglycemia in 71% of cases (5/7), whereas transplantation of the same number of islets in CD1d -/- diabetic mice did not (0%, 0/4). Histologic findings also confirmed that intact islets were observed in NK cell-depleted CD1d -/- diabetic mice, but were difficult to observe in CD1d -/- diabetic mice. The involvement of liver NK cells in the innate immune system related to islet graft loss after intraportal islet transplantation is revealed by improved graft survival and function in NK cell-depleted CD1d -/- diabetic mice. Our data reveal that regulation of NK cell activity is particularly important when insufficient islet numbers are used for transplantation. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Unfolded protein response (UPR) signaling regulates arsenic trioxide-mediated macrophage innate immune function disruption

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, Ritesh K.; Li, Changzhao; Chaudhary, Sandeep C. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States); Ballestas, Mary E. [Department of Pediatrics Infectious Disease, Children' s of Alabama, School of Medicine, University of Alabama at Birmingham, AL (United States); Elmets, Craig A. [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States); Robbins, David J. [Department of Surgery, Molecular Oncology Program, Miller School of Medicine, University of Miami, Miami (United States); Matalon, Sadis [Department of Anesthesiology, University of Alabama at Birmingham, Birmingham, AL (United States); Deshane, Jessy S. [Department of Medicine, Division of Pulmonary, Allergy and Critical Care Medicine, University of Alabama at Birmingham, Birmingham, AL (United States); Afaq, Farrukh [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States); Bickers, David R. [Department of Dermatology, Columbia University Medical Center, New York (United States); Athar, Mohammad, E-mail: mathar@uab.edu [Department of Dermatology and Skin Diseases Research Center, University of Alabama at Birmingham, Birmingham, AL (United States)

    2013-11-01

    Arsenic exposure is known to disrupt innate immune functions in humans and in experimental animals. In this study, we provide a mechanism by which arsenic trioxide (ATO) disrupts macrophage functions. ATO treatment of murine macrophage cells diminished internalization of FITC-labeled latex beads, impaired clearance of phagocytosed fluorescent bacteria and reduced secretion of pro-inflammatory cytokines. These impairments in macrophage functions are associated with ATO-induced unfolded protein response (UPR) signaling pathway characterized by the enhancement in proteins such as GRP78, p-PERK, p-eIF2α, ATF4 and CHOP. The expression of these proteins is altered both at transcriptional and translational levels. Pretreatment with chemical chaperon, 4-phenylbutyric acid (PBA) attenuated the ATO-induced activation in UPR signaling and afforded protection against ATO-induced disruption of macrophage functions. This treatment also reduced ATO-mediated reactive oxygen species (ROS) generation. Interestingly, treatment with antioxidant N-acetylcysteine (NAC) prior to ATO exposure, not only reduced ROS production and UPR signaling but also improved macrophage functions. These data demonstrate that UPR signaling and ROS generation are interdependent and are involved in the arsenic-induced pathobiology of macrophage. These data also provide a novel strategy to block the ATO-dependent impairment in innate immune responses. - Highlights: • Inorganic arsenic to humans and experimental animals disrupt innate immune responses. • The mechanism underlying arsenic impaired macrophage functions involves UPR signaling. • Chemical chaperon attenuates arsenic-mediated macrophage function impairment. • Antioxidant, NAC blocks impairment in arsenic-treated macrophage functions.

  20. Innate immunity drives the initiation of a murine model of primary biliary cirrhosis.

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    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.

  1. Transcriptional profiles of pulmonary innate immune responses to isogenic antibiotic-susceptible and multidrug-resistant Pseudomonas aeruginosa.

    Science.gov (United States)

    Tam, Vincent H; Pérez, Cynthia; Ledesma, Kimberly R; Lewis, Russell E

    2018-04-01

    The virulence of an isogenic pair of Pseudomonas aeruginosa strains was studied under similar experimental conditions in two animal infection models. The time to death was significantly longer for the multidrug resistant (MDR) than the wild-type strain. The transcriptional profiles of 84 innate immune response genes in the lungs of immune competent Balb/C mice were further compared. Significantly weaker expression of genes involved in production of soluble pattern recognition receptor and complement were observed in animals infected with the MDR strain. Altered patterns of innate immune system activation may explain the attenuated virulence in MDR bacteria. © 2018 The Societies and John Wiley & Sons Australia, Ltd.

  2. Leukocytes respiratory burst activity as indicator of innate immunity of pacu Piaractus mesopotamicus

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    JD Biller-Takahashi

    Full Text Available The present study evaluated the assay to quantify the respiratory burst activity of blood leukocytes of pacu as an indicator of the innate immune system, using the reduction of nitroblue tetrazolium (NBT to formazan as a measure of the production of reactive oxygen species (ROS. In order to assess the accuracy of the assay, fish were challenged by Aeromonas hydrophila and sampled one week after challenge. The A. hydrophila infection increased the leukocyte respiratory burst activity. The protocol showed a reliable and easy assay, appropriate to determine the respiratory burst activity of blood leukocytes of pacu, a neotropical fish, in the present experimental conditions.

  3. Genotype-Specific Regulation of Oral Innate Immunity by T2R38 Taste Receptor

    Science.gov (United States)

    Gil, Sucheol; Coldwell, Susan; Drury, Jeanie L.; Arroyo, Fabiola; Phi, Tran; Saadat, Sanaz; Kwong, Danny; Chung, Whasun Oh

    2015-01-01

    The bitter taste receptor T2R38 has been shown to regulate mucosal innate immune responses in the upper airway epithelium. Furthermore, SNPs in T2R38 influence the sensitivity to 6-n-propylthiouracil (PROP) and are associated with caries risk/protection. However, no study has been reported on the role of T2R38 in the innate immune responses to oral bacteria. We hypothesize that T2R38 regulates oral innate immunity and that this regulation is genotype-specific. Primary gingival epithelial cells carrying three common genotypes, PAV/PAV (PROP super-taster), AVI/PAV (intermediate) and AVI/AVI (non-taster) were stimulated with cariogenic bacteria Streptococcus mutans, periodontal pathogen Porphyromonas gingivalis or non-pathogen Fusobacterium nucleatum. QRT-PCR analyzed T2R38 mRNA, and T2R38-specific siRNA and ELISA were utilized to evaluate induction of hBD-2 (antimicrobial peptide), IL-1α and IL-8 in various donor-lines. Experiments were set up in duplicate and repeated three times. T2R38 mRNA induction in response to S. mutans was highest in PAV/PAV (4.3-fold above the unstimulated controls; p<0.05), while lowest in AVI/AVI (1.2-fold). In PAV/PAV, hBD-2 secretion in response to S. mutans was decreased by 77% when T2R38 was silenced. IL-1α secretion was higher in PAV/PAV compared to AVI/PAV or AVI/AVI with S. mutans stimulation, but it was reduced by half when T2R38 was silenced (p<0.05). In response to P. gingivalis, AVI/AVI showed 4.4-fold increase (p<0.05) in T2R38 expression, whereas the levels in PAV/PAV and AVI/PAV remained close to that of the controls. Secretion levels of IL-1α and IL-8 decreased in AVI/AVI in response to P. gingivalis when T2R38 was silenced (p<0.05), while the changes were not significant in PAV/PAV. Our data suggest that the regulation of gingival innate immunity by T2R38 is genotype-dependent and that the ability to induce a high level of hBD-2 by PAV/PAV carriers may be a reason for protection against caries in this group. PMID

  4. Intestinal innate antiviral immunity and immunobiotics: beneficial effects against rotavirus infection

    Directory of Open Access Journals (Sweden)

    Julio Villena

    2016-12-01

    Full Text Available The mucosal tissues of the gastrointestinal tract are the main portal entry of pathogens such as rotavirus (RVs, which is a leading cause of death due to diarrhea among young children across the globe and a major cause of severe acute intestinal infection in livestock animals. The interactions between intestinal epithelial cells (IECs and immune cells with RVs have been studied for several years, and now it is known that the innate immune responses triggered by this virus can have both beneficial and detrimental effects for the host. It was demonstrated that natural RVs infection in infants and experimental challenges in mice result in the intestinal activation of pattern recognition receptors (PRRs like Toll-like receptor 3 (TLR3 and striking secretion of pro-inflammatory mediators that can lead to increased local tissue damage and immunopathology. Therefore, modulating desregulated intestinal immune responses triggered by PRRs activation are a significant promise for reducing the burden of RVs diseases. The ability of immunoregulatory probiotic microorganisms (immunobiotics to protect against intestinal infections such as those caused by RVs, are among the oldest effects studied for these important group of beneficial microbes. In this review, we provide an update of the current status on the modulation of intestinal antiviral innate immunity by immunobiotics, and their beneficial impact on RVs infection. In addition, we describe the research of our group that demonstrated the capacity of immunobiotic strains to beneficially modulated TLR3-triggered immune response in IECs, reduce the disruption of intestinal homeostasis caused by intraepithelial lymphocytes, and improve the resistance to RVs infections.

  5. Candidate innate immune system gene expression in the ecological model Daphnia.

    Science.gov (United States)

    Decaestecker, Ellen; Labbé, Pierrick; Ellegaard, Kirsten; Allen, Judith E; Little, Tom J

    2011-10-01

    The last ten years have witnessed increasing interest in host-pathogen interactions involving invertebrate hosts. The invertebrate innate immune system is now relatively well characterised, but in a limited range of genetic model organisms and under a limited number of conditions. Immune systems have been little studied under real-world scenarios of environmental variation and parasitism. Thus, we have investigated expression of candidate innate immune system genes in the water flea Daphnia, a model organism for ecological genetics, and whose capacity for clonal reproduction facilitates an exceptionally rigorous control of exposure dose or the study of responses at many time points. A unique characteristic of the particular Daphnia clones and pathogen strain combinations used presently is that they have been shown to be involved in specific host-pathogen coevolutionary interactions in the wild. We choose five genes, which are strong candidates to be involved in Daphnia-pathogen interactions, given that they have been shown to code for immune effectors in related organisms. Differential expression of these genes was quantified by qRT-PCR following exposure to the bacterial pathogen Pasteuria ramosa. Constitutive expression levels differed between host genotypes, and some genes appeared to show correlated expression. However, none of the genes appeared to show a major modification of expression level in response to Pasteuria exposure. By applying knowledge from related genetic model organisms (e.g. Drosophila) to models for the study of evolutionary ecology and coevolution (i.e. Daphnia), the candidate gene approach is temptingly efficient. However, our results show that detection of only weak patterns is likely if one chooses target genes for study based on previously identified genome sequences by comparison to homologues from other related organisms. Future work on the Daphnia-Pasteuria system will need to balance a candidate gene approach with more comprehensive

  6. A virtual infection model quantifies innate effector mechanisms and Candida albicans immune escape in human blood.

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    Kerstin Hünniger

    2014-02-01

    Full Text Available Candida albicans bloodstream infection is increasingly frequent and can result in disseminated candidiasis associated with high mortality rates. To analyze the innate immune response against C. albicans, fungal cells were added to human whole-blood samples. After inoculation, C. albicans started to filament and predominantly associate with neutrophils, whereas only a minority of fungal cells became attached to monocytes. While many parameters of host-pathogen interaction were accessible to direct experimental quantification in the whole-blood infection assay, others were not. To overcome these limitations, we generated a virtual infection model that allowed detailed and quantitative predictions on the dynamics of host-pathogen interaction. Experimental time-resolved data were simulated using a state-based modeling approach combined with the Monte Carlo method of simulated annealing to obtain quantitative predictions on a priori unknown transition rates and to identify the main axis of antifungal immunity. Results clearly demonstrated a predominant role of neutrophils, mediated by phagocytosis and intracellular killing as well as the release of antifungal effector molecules upon activation, resulting in extracellular fungicidal activity. Both mechanisms together account for almost [Formula: see text] of C. albicans killing, clearly proving that beside being present in larger numbers than other leuk