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Sample records for antiviral innate immune

  1. Antiviral defense in shrimp: from innate immunity to viral infection.

    Science.gov (United States)

    Wang, Pei-Hui; Huang, Tianzhi; Zhang, Xiaobo; He, Jian-Guo

    2014-08-01

    The culture of penaeid shrimp is rapidly developing as a major business endeavor worldwide. However, viral diseases have caused huge economic loss in penaeid shrimp culture industries. Knowledge of shrimp innate immunity and antiviral responses has made important progress in recent years, allowing the design of better strategies for the prevention and control of shrimp diseases. In this study, we have updated information on shrimp antiviral immunity and interactions between shrimp hosts and viral pathogens. Current knowledge and recent progress in immune signaling pathways (e.g., Toll/IMD-NF-κB and JAK-STAT signaling pathways), RNAi, phagocytosis, and apoptosis in shrimp antiviral immunity are discussed. The mechanism of viral infection in shrimp hosts and the interactions between viruses and shrimp innate immune systems are also analyzed.

  2. Regulation of antiviral innate immunity by deubiquitinase CYLD

    Institute of Scientific and Technical Information of China (English)

    Minying Zhang; Andrew J Lee; Xuefeng Wu; Shao-Cong Sun

    2011-01-01

    An antiviral innate immune response involves induction of type Ⅰ interferons (IFNs) and their subsequent autocrine and paracrine actions,but the underlying regulatory mechanisms are incompletely understood.Here we report that CYLD,a deubiquitinase that specifically digests lysine 63-1inked ubiquitin chains,is required for antiviral host defense.Loss of CYLD renders mice considerably more susceptible to infection by vesicular stomatitis virus (VSV).Consistently,CYLD-deficient dendritic cells are more sensitive to VSV infection.This functional defect was not due to lack of type I IFN production but rather because of attenuated IFN receptor signaling.In the absence of CYLD,IFN-β is ineffective in the induction of antiviral genes and protection of cells from viral infection.These findings establish CYLD as a novel regulator of antiviral innate immunity and suggest a role for CYLD in regulating IFN receptor signaling.

  3. Danger, diversity and priming in innate antiviral immunity.

    Science.gov (United States)

    Collins, Susan E; Mossman, Karen L

    2014-10-01

    The prototypic response to viral infection involves the recognition of pathogen-associated molecular patterns (PAMPs) by pattern recognition receptors (PRRs), leading to the activation of transcription factors such as IRF3 and NFkB and production of type 1 IFN. While this response can lead to the induction of hundreds of IFN-stimulated genes (ISGs) and recruitment and activation of immune cells, such a comprehensive response is likely inappropriate for routine low level virus exposure. Moreover, viruses have evolved a plethora of immune evasion strategies to subvert antiviral signalling. There is emerging evidence that cells have developed very sensitive methods of detecting not only specific viral PAMPS, but also more general danger or stress signals associated with viral entry and replication. Such stress-induced cellular responses likely serve to prime cells to respond to further PAMP stimulation or allow for a rapid and localized intracellular response independent of IFN production and its potential immune sequelae. This review discusses diversity in innate antiviral players and pathways, the role of "danger" sensing, and how alternative pathways, such as the IFN-independent pathway, may serve to prime cells for further pathogen attack.

  4. Antiviral antibodies target adenovirus to phagolysosomes and amplify the innate immune response.

    Science.gov (United States)

    Zaiss, Anne K; Vilaysane, Akosua; Cotter, Matthew J; Clark, Sharon A; Meijndert, H Christopher; Colarusso, Pina; Yates, Robin M; Petrilli, Virginie; Tschopp, Jurg; Muruve, Daniel A

    2009-06-01

    Adenovirus is a nonenveloped dsDNA virus that activates intracellular innate immune pathways. In vivo, adenovirus-immunized mice displayed an enhanced innate immune response and diminished virus-mediated gene delivery following challenge with the adenovirus vector AdLacZ suggesting that antiviral Abs modulate viral interactions with innate immune cells. Under naive serum conditions in vitro, adenovirus binding and internalization in macrophages and the subsequent activation of innate immune mechanisms were inefficient. In contrast to the neutralizing effect observed in nonhematopoietic cells, adenovirus infection in the presence of antiviral Abs significantly increased FcR-dependent viral internalization in macrophages. In direct correlation with the increased viral internalization, antiviral Abs amplified the innate immune response to adenovirus as determined by the expression of NF-kappaB-dependent genes, type I IFNs, and caspase-dependent IL-1beta maturation. Immune serum amplified TLR9-independent type I IFN expression and enhanced NLRP3-dependent IL-1beta maturation in response to adenovirus, confirming that antiviral Abs specifically amplify intracellular innate pathways. In the presence of Abs, confocal microscopy demonstrated increased targeting of adenovirus to LAMP1-positive phagolysosomes in macrophages but not epithelial cells. These data show that antiviral Abs subvert natural viral tropism and target the adenovirus to phagolysosomes and the intracellular innate immune system in macrophages. Furthermore, these results illustrate a cross-talk where the adaptive immune system positively regulates the innate immune system and the antiviral state.

  5. 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 acidsensor...007 Mar 29. (.png) (.svg) (.html) (.csml) Show Innate immunity minireview series: making biochemical sense of nucleic acidsensor...itle Innate immunity minireview series: making biochemical sense of nucleic acidsensors that trigger antivir

  6. Innate antiviral immune signaling, viral evasion and modulation by HIV-1.

    Science.gov (United States)

    Rustagi, Arjun; Gale, Michael

    2014-03-20

    The intracellular innate antiviral response in human cells is an essential component of immunity against virus infection. As obligate intracellular parasites, all viruses must evade the actions of the host cell's innate immune response in order to replicate and persist. Innate immunity is induced when pathogen recognition receptors of the host cell sense viral products including nucleic acid as "non-self". This process induces downstream signaling through adaptor proteins to activate latent transcription factors that drive the expression of genes encoding antiviral and immune modulatory effector proteins that restrict virus replication and regulate adaptive immunity. The interferon regulatory factors (IRFs) are transcription factors that play major roles in innate immunity. In particular, IRF3 is activated in response to infection by a range of viruses including RNA viruses, DNA viruses and retroviruses. Among these viruses, human immunodeficiency virus type 1 (HIV-1) remains a major global health problem mediating chronic infection in millions of people wherein recent studies show that viral persistence is linked with the ability of the virus to dysregulate and evade the innate immune response. In this review, we discuss viral pathogen sensing, innate immune signaling pathways and effectors that respond to viral infection, the role of IRF3 in these processes and how it is regulated by pathogenic viruses. We present a contemporary overview of the interplay between HIV-1 and innate immunity, with a focus on understanding how innate immune control impacts infection outcome and disease.

  7. Evasion of host antiviral innate immunity by HSV-1, an update

    OpenAIRE

    Su, Chenhe; Zhan, Guoqing; Zheng, Chunfu

    2016-01-01

    Herpes simplex virus type 1 (HSV-1) infection triggers a rapid induction of host innate immune responses. The type I interferon (IFN) signal pathway is a central aspect of host defense which induces a wide range of antiviral proteins to control infection of incoming pathogens. In some cases, viral invasion also induces DNA damage response, autophagy, endoplasmic reticulum stress, cytoplasmic stress granules and other innate immune responses, which in turn affect viral infection. However, HSV-...

  8. Chitosan-induced antiviral activity and innate immunity in plants.

    Science.gov (United States)

    Iriti, Marcello; Varoni, Elena Maria

    2015-02-01

    Immunity represents a trait common to all living organisms, and animals and plants share some similarities. Therefore, in susceptible host plants, complex defence machinery may be stimulated by elicitors. Among these, chitosan deserves particular attention because of its proved efficacy. This survey deals with the antiviral activity of chitosan, focusing on its perception by the plant cell and mechanism of action. Emphasis has been paid to benefits and limitations of this strategy in crop protection, as well as to the potential of chitosan as a promising agent in virus disease control.

  9. Development of Antiviral Innate Immunity During In Vitro Differentiation of Mouse Embryonic Stem Cells.

    Science.gov (United States)

    D'Angelo, William; Acharya, Dhiraj; Wang, Ruoxing; Wang, Jundi; Gurung, Chandan; Chen, Bohan; Bai, Fengwei; Guo, Yan-Lin

    2016-04-15

    The innate immunity of embryonic stem cells (ESCs) has recently emerged as an important issue in ESC biology and in ESC-based regenerative medicine. We have recently reported that mouse ESCs (mESCs) do not have a functional type I interferon (IFN)-based antiviral innate immunity. They are deficient in expressing IFN in response to viral infection and have limited ability to respond to IFN. Using fibroblasts (FBs) as a cell model, the current study investigated the development of antiviral mechanisms during in vitro differentiation of mESCs. We demonstrate that mESC-differentiated FBs (mESC-FBs) share extensive similarities with naturally differentiated FBs in morphology, marker expression, and growth pattern, but their development of antiviral mechanisms lags behind. Nonetheless, the antiviral mechanisms are inducible during mESC differentiation as demonstrated by the transition of nuclear factor kappa B (NFκB), a key transcription factor for IFN expression, from its inactive state in mESCs to its active state in mESC-FBs and by increased responses of mESC-FBs to viral stimuli and IFN during their continued in vitro propagation. Together with our previously published study, the current data provide important insights into molecular basis for the deficiency of IFN expression in mESCs and the development of antiviral innate immunity during mESC differentiation.

  10. DDX3 functions in antiviral innate immunity through translational control of PACT.

    Science.gov (United States)

    Lai, Ming-Chih; Sun, H Sunny; Wang, Shainn-Wei; Tarn, Woan-Yuh

    2016-01-01

    It has emerged that DDX3 plays a role in antiviral innate immunity. However, the exact mechanism by which DDX3 functions in antiviral innate immunity remains to be determined. We found that the expression of the protein activator of the interferon-induced protein kinase (PACT) was regulated by DDX3 in human cells. PACT acts as a cellular activator of retinoic acid-inducible gene-I-like receptors in the sensing of viral RNAs. DDX3 facilitated the translation of PACT mRNA that may contain a structured 5' UTR. Knockdown of DDX3 decreased the viral RNA detection sensitivity of the cells. PACT partially rescued defects of interferon-β1 and chemokine (C-C motif) ligand 5/RANTES (regulated on activation normal T cell expressed and secreted) induction in DDX3-knockdown HEK293 cells. Therefore, DDX3 may participate in antiviral innate immunity, at least in part, by translational control of PACT. Moreover, we show that overexpression of the hepatitis C virus (HCV) core protein inhibited the translation of a reporter mRNA harboring the PACT 5' UTR. The HCV core protein was associated and colocalized with DDX3 in cytoplasmic stress granules, suggesting that the HCV core may abrogate the function of DDX3 by sequestering DDX3 in stress granules. The perturbation of DDX3 by viral proteins delineates a critical role for DDX3 in antiviral host defense.

  11. Emerging complexity and new roles for the RIG-I-like receptors in innate antiviral immunity

    Institute of Scientific and Technical Information of China (English)

    John; S.Errett; Michael; Gale; Jr.

    2015-01-01

    Innate immunity is critical for the control of virus infection and operates to restrict viral susceptibility and direct antiviral immunity for protection from acute or chronic viral-associated diseases including cancer. RIG-I like receptors(RLRs) are cytosolic RNA helicases that function as pathogen recognition receptors to detect RNA pathogen associated molecular patterns(PAMPs) of virus infection. The RLRs include RIG-I, MDA5, and LGP2. They function to recognize and bind to PAMP motifs within viral RNA in a process that directs the RLR to trigger downstream signaling cascades that induce innate immunity that controls viral replication and spread. Products of RLR signaling also serve to modulate the adaptive immune response to infection. Recent studies have additionally connected RLRs to signaling cascades that impart inflammatory and apoptotic responses to virus infection. Viral evasion of RLR signaling supports viral outgrowth and pathogenesis, including the onset of viral-associated cancer.

  12. The role of alternative polyadenylation in the antiviral innate immune response

    Science.gov (United States)

    Jia, Xin; Yuan, Shaochun; Wang, Yao; Fu, Yonggui; Ge, Yong; Ge, Yutong; Lan, Xihong; Feng, Yuchao; Qiu, Feifei; Li, Peiyi; Chen, Shangwu; Xu, Anlong

    2017-01-01

    Alternative polyadenylation (APA) is an important regulatory mechanism of gene functions in many biological processes. However, the extent of 3′ UTR variation and the function of APA during the innate antiviral immune response are unclear. Here, we show genome-wide poly(A) sites switch and average 3′ UTR length shortens gradually in response to vesicular stomatitis virus (VSV) infection in macrophages. Genes with APA and mRNA abundance change are enriched in immune-related categories such as the Toll-like receptor, RIG-I-like receptor, JAK-STAT and apoptosis-related signalling pathways. The expression of 3′ processing factors is down-regulated upon VSV infection. When the core 3′ processing factors are knocked down, viral replication is affected. Thus, our study reports the annotation of genes with APA in antiviral immunity and highlights the roles of 3′ processing factors on 3′ UTR variation upon viral infection. PMID:28233779

  13. 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.

  14. DMPD: The role of viral nucleic acid recognition in dendritic cells for innate andadaptive antiviral immunity. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18086372 The role of viral nucleic acid recognition in dendritic cells for innate andadaptive anti...ritic cells for innate andadaptive antiviral immunity. PubmedID 18086372 Title Th...e role of viral nucleic acid recognition in dendritic cells for innate andadaptive antiviral immunity. Autho

  15. Systems-Biology Approaches to Discover Anti-Viral Effectors of the Human Innate Immune Response

    Directory of Open Access Journals (Sweden)

    Andreas F.R. Sommer

    2011-07-01

    Full Text Available Virus infections elicit an immediate innate response involving antiviral factors. The activities of some of these factors are, in turn, blocked by viral countermeasures. The ensuing battle between the host and the viruses is crucial for determining whether the virus establishes a foothold and/or induces adaptive immune responses. A comprehensive systems-level understanding of the repertoire of anti-viral effectors in the context of these immediate virus-host responses would provide significant advantages in devising novel strategies to interfere with the initial establishment of infections. Recent efforts to identify cellular factors in a comprehensive and unbiased manner, using genome-wide siRNA screens and other systems biology “omics” methodologies, have revealed several potential anti-viral effectors for viruses like Human immunodeficiency virus type 1 (HIV-1, Hepatitis C virus (HCV, West Nile virus (WNV, and influenza virus. This review describes the discovery of novel viral restriction factors and discusses how the integration of different methods in systems biology can be used to more comprehensively identify the intimate interactions of viruses and the cellular innate resistance.

  16. Budesonide and formoterol reduce early innate anti-viral immune responses in vitro.

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    Janet M Davies

    Full Text Available Asthma is a chronic inflammatory airways disease in which respiratory viral infections frequently trigger exacerbations. Current treatment of asthma with combinations of inhaled corticosteroids and long acting beta2 agonists improves asthma control and reduces exacerbations but what impact this might have on innate anti-viral immunity is unclear. We investigated the in vitro effects of asthma drugs on innate anti-viral immunity. Peripheral blood mononuclear cells (PBMC from healthy and asthmatic donors were cultured for 24 hours with the Toll-like receptor 7 agonist, imiquimod, or rhinovirus 16 (RV16 in the presence of budesonide and/or formoterol. Production of proinflammatory cytokines and expression of anti-viral intracellular signalling molecules were measured by ELISA and RT-PCR respectively. In PBMC from healthy donors, budesonide alone inhibited IP-10 and IL-6 production induced by imiquimod in a concentration-dependent manner and the degree of inhibition was amplified when budesonide and formoterol were used in combination. Formoterol alone had little effect on these parameters, except at high concentrations (10⁻⁶ M when IL-6 production increased. In RV16 stimulated PBMC, the combination of budesonide and formoterol inhibited IFNα and IP-10 production in asthmatic as well as healthy donors. Combination of budesonide and formoterol also inhibited RV16-stimulated expression of the type I IFN induced genes myxovirus protein A and 2', 5' oligoadenylate synthetise. Notably, RV16 stimulated lower levels of type Myxovirus A and oligoadenylate synthase in PBMC of asthmatics than control donors. These in vitro studies demonstrate that combinations of drugs commonly used in asthma therapy inhibit both early pro-inflammatory cytokines and key aspects of the type I IFN pathway. These findings suggest that budesonide and formoterol curtail excessive inflammation induced by rhinovirus infections in patients with asthma, but whether this inhibits

  17. Intestinal innate antiviral immunity and immunobiotics: beneficial effects against rotavirus infection

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    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.

  18. Negative regulation of the innate antiviral immune response by TRIM62 from orange spotted grouper.

    Science.gov (United States)

    Yang, Ying; Huang, Youhua; Yu, Yepin; Zhou, Sheng; Wang, Shaowen; Yang, Min; Qin, Qiwei; Huang, Xiaohong

    2016-10-01

    Increased reports uncovered that mammalian tripartite motif-containing 62 (TRIM62) exerts crucial roles in cancer and innate immune response. However, the roles of fish TRIM62 in antiviral immune response remained uncertain. In this study, a TRIM62 gene was cloned from orange spotted grouper (EcTRIM62) and its roles in grouper RNA virus infection was elucidated in vitro. EcTRIM62 shared 99% and 83% identity to bicolor damselfish (Stegastes partitus) and human (Homo sapiens), respectively. Sequence alignment indicated that EcTRIM62 contained three domains, including a RING-finger domain, a B-box domain and a SPRY domain. In healthy grouper, the transcript of EcTRIM62 was predominantly detected in brain and liver, followed by heart, skin, spleen, fin, gill, intestine, and stomach. Subcellular localization analysis indicated that bright fluorescence spots were observed in the cytoplasm of EcTRIM62-transfected grouper spleen (GS) cells. During red-spotted grouper nervous necrosis (RGNNV) infection, overexpression of EcTRIM62 significantly enhanced the severity of CPE and increased viral gene transcriptions. Furthermore, the ectopic expression of EcTRIM62 significantly decreased the transcription level of interferon signaling molecules, including interferon regulatory factor 3 (IRF3), IRF7, interferon-stimulated gene 15 (ISG15), melanoma differentiation-associated protein 5 (MDA5), myxovirus resistance gene MXI, and MXII, suggesting that the negative regulation of interferon immune response by EcTRIM62 might directly contributed to its enhancing effect on RGNNV replication. Furthermore, our results also demonstrated that overexpression of EcTRIM62 was able to differently regulate the expression levels of pro-inflammation cytokines. In addition, we found the ectopic expression of EcTIRM62 negatively regulated MDA5-, but not mediator of IRF3 activation (MITA)-induced interferon immune response. Further studies showed that the deletion of RING domain and SPRY domain

  19. Evasion of antiviral innate immunity by Theiler's virus L* protein through direct inhibition of RNase L.

    Directory of Open Access Journals (Sweden)

    Frédéric Sorgeloos

    Full Text Available Theiler's virus is a neurotropic picornavirus responsible for chronic infections of the central nervous system. The establishment of a persistent infection and the subsequent demyelinating disease triggered by the virus depend on the expression of L*, a viral accessory protein encoded by an alternative open reading frame of the virus. We discovered that L* potently inhibits the interferon-inducible OAS/RNase L pathway. The antagonism of RNase L by L* was particularly prominent in macrophages where baseline oligoadenylate synthetase (OAS and RNase L expression levels are elevated, but was detectable in fibroblasts after IFN pretreatment. L* mutations significantly affected Theiler's virus replication in primary macrophages derived from wild-type but not from RNase L-deficient mice. L* counteracted the OAS/RNase L pathway through direct interaction with the ankyrin domain of RNase L, resulting in the inhibition of this enzyme. Interestingly, RNase L inhibition was species-specific as Theiler's virus L* protein blocked murine RNase L but not human RNase L or RNase L of other mammals or birds. Direct RNase L inhibition by L* and species specificity were confirmed in an in vitro assay performed with purified proteins. These results demonstrate a novel viral mechanism to elude the antiviral OAS/RNase L pathway. By targeting the effector enzyme of this antiviral pathway, L* potently inhibits RNase L, underscoring the importance of this enzyme in innate immunity against Theiler's virus.

  20. TRAF5 is a downstream target of MAVS in antiviral innate immune signaling.

    Directory of Open Access Journals (Sweden)

    Eric D Tang

    Full Text Available The recognition of nucleic acids by the innate immune system during viral infection results in the production of type I interferons and the activation of antiviral immune responses. The RNA helicases RIG-I and MDA-5 recognize distinct types of cytosolic RNA species and signal through the mitochondrial protein MAVS to stimulate the phosphorylation and activation of the transcription factors IRF3 and IRF7, thereby inducing type I interferon expression. Alternatively, the activation of NF-kappaB leads to proinflammatory cytokine production. The function of MAVS is dependent on both its C-terminal transmembrane (TM domain and N-terminal caspase recruitment domain (CARD. The TM domain mediates MAVS dimerization in response to viral RNA, allowing the CARD to bind to and activate the downstream effector TRAF3. Notably, dimerization of the MAVS CARD alone is sufficient to activate IRF3, IRF7, and NF-kappaB. However, TRAF3-deficient cells display only a partial reduction in interferon production in response to RNA virus infection and are not defective in NF-kappaB activation. Here we find that the related ubiquitin ligase TRAF5 is a downstream target of MAVS that mediates both IRF3 and NF-kappaB activation. The TM domain of MAVS allows it to dimerize and thereby associate with TRAF5 and induce its ubiquitination in a CARD-dependent manner. Also, NEMO is recruited to the dimerized MAVS CARD domain in a TRAF3 and TRAF5-dependent manner. Thus, our findings reveal a possible function for TRAF5 in mediating the activation of IRF3 and NF-kappaB downstream of MAVS through the recruitment of NEMO. TRAF5 may be a key molecule in the innate response against viral infection.

  1. Muscovy duck reovirus infection rapidly activates host innate immune signaling and induces an effective antiviral immune response involving critical interferons.

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    Chen, Zhilong; Luo, Guifeng; Wang, Quanxi; Wang, Song; Chi, Xiaojuan; Huang, Yifan; Wei, Haitao; Wu, Baocheng; Huang, Shile; Chen, Ji-Long

    2015-02-25

    Muscovy duck reovirus (MDRV) is a highly pathogenic virus in waterfowl and causes significant economic loss in the poultry industry worldwide. Because the host innate immunity plays a key role in defending against virus invasion, more and more attentions have been paid to the immune response triggered by viral infection. Here we found that the genomic RNA of MDRV was able to rapidly induce the production of interferons (IFNs) in host. Mechanistically, MDRV infection induced robust expression of IFNs in host mainly through RIG-I, MDA5 and TLR3-dependent signaling pathways. In addition, we observed that silencing VISA expression in 293T cells could significantly inhibit the secretion of IFNs. Remarkably, the production of IFNs was reduced by inhibiting the activation of NF-κB or knocking down the expression of IRF-7. Furthermore, our study showed that treatment of 293T cells and Muscovy duck embryo fibroblasts with IFNs markedly impaired MDRV replication, suggesting that these IFNs play an important role in antiviral response during the MDRV infection. Importantly, we also detected the induced expression of RIG-I, MDA5, TLR3 and type I IFN in Muscovy ducks infected with MDRV at different time points post infection. The results from in vivo studies were consistent with those in 293T cells infected with MDRV. Taken together, our findings reveal that the host can resist MDRV invasion by activating innate immune response involving RIG-I, MDA5 and TLR3-dependent signaling pathways that govern IFN production.

  2. STING agonists induce an innate antiviral immune response against hepatitis B virus.

    Science.gov (United States)

    Guo, Fang; Han, Yanxing; Zhao, Xuesen; Wang, Jianghua; Liu, Fei; Xu, Chunxiao; Wei, Lai; Jiang, Jian-Dong; Block, Timothy M; Guo, Ju-Tao; Chang, Jinhong

    2015-02-01

    Chronicity of hepatitis B virus (HBV) infection is due to the failure of a host to mount a sufficient immune response to clear the virus. The aim of this study was to identify small-molecular agonists of the pattern recognition receptor (PRR)-mediated innate immune response to control HBV infection. To achieve this goal, a coupled mouse macrophage and hepatocyte culture system mimicking the intrahepatic environment was established and used to screen small-molecular compounds that activate macrophages to produce cytokines, which in turn suppress HBV replication in a hepatocyte-derived stable cell line supporting HBV replication in a tetracycline-inducible manner. An agonist of the mouse stimulator of interferon (IFN) genes (STING), 5,6-dimethylxanthenone-4-acetic acid (DMXAA), was found to induce a robust cytokine response in macrophages that efficiently suppressed HBV replication in mouse hepatocytes by reducing the amount of cytoplasmic viral nucleocapsids. Profiling of cytokines induced by DMXAA and agonists of representative Toll-like receptors (TLRs) in mouse macrophages revealed that, unlike TLR agonists that induced a predominant inflammatory cytokine/chemokine response, the STING agonist induced a cytokine response dominated by type I IFNs. Moreover, as demonstrated in an HBV hydrodynamic mouse model, intraperitoneal administration of DMXAA significantly induced the expression of IFN-stimulated genes and reduced HBV DNA replication intermediates in the livers of mice. This study thus proves the concept that activation of the STING pathway induces an antiviral cytokine response against HBV and that the development of small-molecular human STING agonists as immunotherapeutic agents for treatment of chronic hepatitis B is warranted.

  3. Activation and Evasion of Innate Antiviral Immunity by Herpes Simplex Virus

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    Søren R. Paludan

    2009-11-01

    Full Text Available Herpes simplex virus (HSV, a human pathogenic virus, has evolved several strategies to evade the production and function of interferons (IFNs and cytokines generated by the innate immune system to restrict the virus. Equilibrium exists between the virus and the immune response, and a shift in this delicate balance either restricts the virus or enhances virus spread and tissue damage. Therefore, understanding of the cytokine response generated after HSV infection and the underlying virus-cell interactions is essential to improve our understanding of viral pathogenesis. This review summarizes the current knowledge on induction and evasion of the innate immune response by HSV.

  4. Accessory Factors of Cytoplasmic Viral RNA Sensors Required for Antiviral Innate Immune Response.

    Science.gov (United States)

    Oshiumi, Hiroyuki; Kouwaki, Takahisa; Seya, Tsukasa

    2016-01-01

    Type I interferon (IFN) induces many antiviral factors in host cells. RIG-I-like receptors (RLRs) are cytoplasmic viral RNA sensors that trigger the signal to induce the innate immune response that includes type I IFN production. RIG-I and MDA5 are RLRs that form nucleoprotein filaments along viral double-stranded RNA, resulting in the activation of MAVS adaptor molecule. The MAVS protein forms a prion-like aggregation structure, leading to type I IFN production. RIG-I and MDA5 undergo post-translational modification. TRIM25 and Riplet ubiquitin ligases deliver a K63-linked polyubiquitin moiety to the RIG-I N-terminal caspase activation and recruitment domains (CARDs) and C-terminal region; the polyubiquitin chain then stabilizes the two-CARD tetramer structure required for MAVS assembly. MDA5 activation is regulated by phosphorylation. RIOK3 is a protein kinase that phosphorylates the MDA5 protein in a steady state, and PP1α/γ dephosphorylate this protein, resulting in its activation. RIG-I and MDA5 require cytoplasmic RNA helicases for their efficient activation. LGP2, another RLR, is an RNA helicase involved in RLR signaling. This protein does not possess N-terminal CARDs and, thus, cannot trigger downstream signaling by itself. Recent studies have revealed that this protein modulates MDA5 filament formation, resulting in enhanced type I IFN production. Several other cytoplasmic RNA helicases are involved in RLR signaling. DDX3, DHX29, DHX36, and DDX60 RNA helicases have been reported to be involved in RLR-mediated type I IFN production after viral infection. However, the underlying mechanism is largely unknown. Future studies are required to reveal the role of RNA helicases in the RLR signaling pathway.

  5. Accessory factors of cytoplasmic viral RNA sensors required for antiviral innate immune response

    Directory of Open Access Journals (Sweden)

    Hiroyuki eOshiumi

    2016-05-01

    Full Text Available Type I interferon (IFN induces many antiviral factors in host cells. RIG-I-like receptors (RLRs are cytoplasmic viral RNA sensors that trigger the signal to induce the innate immune response that includes type I IFN production. RIG-I and MDA5 are RLRs that form nucleoprotein filaments along viral double-stranded RNA, resulting in the activation of MAVS adaptor molecule. The MAVS protein forms a prion-like aggregation structure, leading to type I IFN production. RIG-I and MDA5 undergo post-translational modification. TRIM25 and Riplet ubiquitin ligases deliver a K63-linked polyubiquitin moiety to the RIG-I N-terminal caspase activation and recruitment domains (CARDs and C-terminal region; the polyubiquitin chain then stabilizes the two-CARD tetramer structure required for MAVS assembly. MDA5 activation is regulated by phosphorylation. RIOK3 is a protein kinase that phosphorylates the MDA5 protein in a steady state, and PP1α/γ dephosphorylate this protein, resulting in its activation. RIG-I and MDA5 require cytoplasmic RNA helicases for their efficient activation. LGP2, another RLR, is an RNA helicase involved in RLR signaling. This protein does not possess N-terminal CARDs and thus cannot trigger downstream signaling by itself. Recent studies have revealed that this protein modulates MDA5 filament formation, resulting in enhanced type I IFN production. Several other cytoplasmic RNA helicases are involved in RLR signaling. DDX3, DHX29, DHX36, and DDX60 RNA helicases have been reported to be involved in RLR-mediated type I IFN production after viral infection. However, the underlying mechanism is largely unknown. Future studies are required to reveal the role of RNA helicases in the RLR signaling pathway.

  6. Accessory Factors of Cytoplasmic Viral RNA Sensors Required for Antiviral Innate Immune Response

    Science.gov (United States)

    Oshiumi, Hiroyuki; Kouwaki, Takahisa; Seya, Tsukasa

    2016-01-01

    Type I interferon (IFN) induces many antiviral factors in host cells. RIG-I-like receptors (RLRs) are cytoplasmic viral RNA sensors that trigger the signal to induce the innate immune response that includes type I IFN production. RIG-I and MDA5 are RLRs that form nucleoprotein filaments along viral double-stranded RNA, resulting in the activation of MAVS adaptor molecule. The MAVS protein forms a prion-like aggregation structure, leading to type I IFN production. RIG-I and MDA5 undergo post-translational modification. TRIM25 and Riplet ubiquitin ligases deliver a K63-linked polyubiquitin moiety to the RIG-I N-terminal caspase activation and recruitment domains (CARDs) and C-terminal region; the polyubiquitin chain then stabilizes the two-CARD tetramer structure required for MAVS assembly. MDA5 activation is regulated by phosphorylation. RIOK3 is a protein kinase that phosphorylates the MDA5 protein in a steady state, and PP1α/γ dephosphorylate this protein, resulting in its activation. RIG-I and MDA5 require cytoplasmic RNA helicases for their efficient activation. LGP2, another RLR, is an RNA helicase involved in RLR signaling. This protein does not possess N-terminal CARDs and, thus, cannot trigger downstream signaling by itself. Recent studies have revealed that this protein modulates MDA5 filament formation, resulting in enhanced type I IFN production. Several other cytoplasmic RNA helicases are involved in RLR signaling. DDX3, DHX29, DHX36, and DDX60 RNA helicases have been reported to be involved in RLR-mediated type I IFN production after viral infection. However, the underlying mechanism is largely unknown. Future studies are required to reveal the role of RNA helicases in the RLR signaling pathway. PMID:27252702

  7. Autoubiquitination of TRIM26 links TBK1 to NEMO in RLR-mediated innate antiviral immune response.

    Science.gov (United States)

    Ran, Yong; Zhang, Jing; Liu, Li-Li; Pan, Zhao-Yi; Nie, Ying; Zhang, Hong-Yan; Wang, Yan-Yi

    2016-02-01

    The transcription factors IRF3 and NF-κB are required for the expression of many genes involved in antiviral innate immune response, including type I interferons (IFNs) and proinflammatory cytokines. It is well established that TBK1 is an essential kinase engaged downstream of multiple pattern-recognition receptors (PRRs) to mediate IRF3 phosphorylation and activation, whereas the precise mechanisms of TBK1 activation have not been fully elucidated yet. Here, we identified tripartite motif 26 (TRIM26) as an important regulator for RNA virus-triggered innate immune response. Knockdown of TRIM26 impaired virus-triggered IRF3, NF-κB activation, IFN-β induction, and cellular antiviral response. TRIM26 was physically associated with TBK1 independent of viral infection. As an E3 ligase, TRIM26 underwent autoubiquitination upon viral infection. Ubiquitinated TRIM26 subsequently associated with NEMO, thus bridging TBK1-NEMO interaction, which is critical for the recruitment of TBK1 to the VISA signalsome and activation of TBK1. Our findings suggest that TRIM26 is an important regulator of innate immune responses against RNA viruses, which functions by bridging TBK1 to NEMO and mediating the activation of TBK1.

  8. Deficiency in Either 4E-BP1 or 4E-BP2 Augments Innate Antiviral Immune Responses

    Science.gov (United States)

    Nehdi, Atef; Sean, Polen; Linares, Izzar; Colina, Rodney; Jaramillo, Maritza; Alain, Tommy

    2014-01-01

    Genetic deletion of both 4E-BP1 and 4E-BP2 was found to protect cells against viral infections. Here we demonstrate that the individual loss of either 4E-BP1 or 4E-BP2 in mouse embryonic fibroblasts (MEFs) is sufficient to confer viral resistance. shRNA-mediated silencing of 4E-BP1 or 4E-BP2 renders MEFs resistant to viruses, and compared to wild type cells, MEFs knockout for either 4E-BP1 or 4E-BP2 exhibit enhanced translation of Irf-7 and consequently increased innate immune response to viruses. Accordingly, the replication of vesicular stomatitis virus, encephalomyocarditis virus, influenza virus and Sindbis virus is markedly suppressed in these cells. Importantly, expression of either 4E-BP1 or 4E-BP2 in double knockout or respective single knockout cells diminishes their resistance to viral infection. Our data show that loss of 4E-BP1 or 4E-BP2 potentiates innate antiviral immunity. These results provide further evidence for translational control of innate immunity and support targeting translational effectors as an antiviral strategy. PMID:25531441

  9. Transcriptomic Analysis of the Innate Antiviral Immune Response in Porcine Intestinal Epithelial Cells: Influence of Immunobiotic Lactobacilli

    Science.gov (United States)

    Albarracin, Leonardo; Kobayashi, Hisakazu; Iida, Hikaru; Sato, Nana; Nochi, Tomonori; Aso, Hisashi; Salva, Susana; Alvarez, Susana; Kitazawa, Haruki; Villena, Julio

    2017-01-01

    Lactobacillus rhamnosus CRL1505 and Lactobacillus plantarum CRL1506 are immunobiotic strains able to increase protection against viral intestinal infections as demonstrated in animal models and humans. To gain insight into the host–immunobiotic interaction, the transcriptomic response of porcine intestinal epithelial (PIE) cells to the challenge with viral molecular associated pattern poly(I:C) and the changes in the transcriptomic profile induced by the immunobiotics strains CRL1505 and CRL1506 were investigated in this work. By using microarray technology and reverse transcription PCR, we obtained a global overview of the immune genes involved in the innate antiviral immune response in PIE cells. Stimulation of PIE cells with poly(I:C) significantly increased the expression of IFN-α and IFN-β, several interferon-stimulated genes, cytokines, chemokines, adhesion molecules, and genes involved in prostaglandin biosynthesis. It was also determined that lactobacilli differently modulated immune gene expression in poly(I:C)-challenged PIE cells. Most notable changes were found in antiviral factors (IFN-α, IFN-β, NPLR3, OAS1, OASL, MX2, and RNASEL) and cytokines/chemokines (IL-1β, IL-6, CCL4, CCL5, and CXCL10) that were significantly increased in lactobacilli-treated PIE cells. Immunobiotics reduced the expression of IL-15 and RAE1 genes that mediate poly(I:C) inflammatory damage. In addition, lactobacilli treatments increased the expression PLA2G4A, PTGES, and PTGS2 that are involved in prostaglandin E2 biosynthesis. L. rhamnosus CRL1505 and L. plantarum CRL1506 showed quantitative and qualitative differences in their capacities to modulate the innate antiviral immune response in PIE cells, which would explain the higher capacity of the CRL1505 strain when compared to CRL1506 to protect against viral infection and inflammatory damage in vivo. These results provided valuable information for the deeper understanding of the host–immunobiotic interaction and their

  10. The innate antiviral immune system of the cat: molecular tools for the measurement of its state of activation.

    Science.gov (United States)

    Robert-Tissot, Céline; Rüegger, Vera L; Cattori, Valentino; Meli, Marina L; Riond, Barbara; Gomes-Keller, Maria Alice; Vögtlin, Andrea; Wittig, Burghardt; Juhls, Christiane; Hofmann-Lehmann, Regina; Lutz, Hans

    2011-10-15

    The innate immune system plays a central role in host defence against viruses. While many studies portray mechanisms in early antiviral immune responses of humans and mice, much remains to be discovered about these mechanisms in the cat. With the objective of shedding light on early host-virus interactions in felids, we have developed 12 real-time TaqMan(®) qPCR systems for feline genes relevant to innate responses to viral infection, including those encoding for various IFNα and IFNω subtypes, IFNβ, intracellular antiviral factor Mx, NK cell stimulator IL-15 and effectors perforin and granzyme B, as well as Toll-like receptors (TLRs) 3 and 8. Using these newly developed assays and others previously described, we measured the relative expression of selected markers at early time points after viral infection in vitro and in vivo. Feline embryonic fibroblasts (FEA) inoculated with feline leukemia virus (FeLV) indicated peak levels of IFNα, IFNβ and Mx expression already 6h after infection. In contrast, Crandell-Rees feline kidney (CrFK) cells inoculated with feline herpes virus (FHV) responded to infection with high levels of IFNα and IFNβ only after 24h, and no induction of Mx could be detected. In feline PBMCs challenged in vitro with feline immunodeficiency virus (FIV), maximal expression levels of IFNα, β and ω subtype genes as well as IL-15 and TLRs 3, 7 and 8 were measured between 12 and 24h after infection, whereas expression levels of proinflammatory cytokine gene IL-6 were consistently downregulated until 48h post inoculation. A marginal upregulation of granzyme B was also observed within 3h after infection. In an in vivo experiment, cats challenged with FIV exhibited a 2.4-fold increase in IFNα expression in blood 1 week post infection. We furthermore demonstrate the possibility of stimulating feline immune cells in vitro with various immune response modifiers (IRMs) already known for their immunostimulatory properties in mice and humans, namely

  11. Plasmacytoid Dendritic Cells Act as the Most Competent Cell Type in Linking Antiviral Innate and Adaptive Immune Responses

    Institute of Scientific and Technical Information of China (English)

    Zheng Zhang; Fu-Sheng Wang

    2005-01-01

    Appropriate in vivo control of plasmacytoid dendritic cell (pDC) recruitment and activation is a fundamental requirement for defense against viral infection. During this process, a pivotal event that influences the outcome of viral infection is the production of high levels of type I interferon by pDCs. In particular, recent research findings showed that pDCs not only shape the nature of innate resistance, but are also responsible for the successful transition from innate to adaptive immunity for viral resistance. In addition, pDCs can differentiate into antigen presenting cells that may regulate tolerance to a given pathogen. Importantly, in a series of recent clinical studies,pDCs appeared to be defective in number and function in conditions of chronic viral diseases such as infected with HIV-1, HBV or HCV. pDC-associated clinical antiviral therapy is also emerging. This review describes research findings exanining the functional and antiviral properties of in vivo pDC plasticity.

  12. Coronavirus papain-like proteases negatively regulate antiviral innate immune response through disruption of STING-mediated signaling.

    Directory of Open Access Journals (Sweden)

    Li Sun

    Full Text Available Viruses have evolved elaborate mechanisms to evade or inactivate the complex system of sensors and signaling molecules that make up the host innate immune response. Here we show that human coronavirus (HCoV NL63 and severe acute respiratory syndrome (SARS CoV papain-like proteases (PLP antagonize innate immune signaling mediated by STING (stimulator of interferon genes, also known as MITA/ERIS/MYPS. STING resides in the endoplasmic reticulum and upon activation, forms dimers which assemble with MAVS, TBK-1 and IKKε, leading to IRF-3 activation and subsequent induction of interferon (IFN. We found that expression of the membrane anchored PLP domain from human HCoV-NL63 (PLP2-TM or SARS-CoV (PLpro-TM inhibits STING-mediated activation of IRF-3 nuclear translocation and induction of IRF-3 dependent promoters. Both catalytically active and inactive forms of CoV PLPs co-immunoprecipitated with STING, and viral replicase proteins co-localize with STING in HCoV-NL63-infected cells. Ectopic expression of catalytically active PLP2-TM blocks STING dimer formation and negatively regulates assembly of STING-MAVS-TBK1/IKKε complexes required for activation of IRF-3. STING dimerization was also substantially reduced in cells infected with SARS-CoV. Furthermore, the level of ubiquitinated forms of STING, RIG-I, TBK1 and IRF-3 are reduced in cells expressing wild type or catalytic mutants of PLP2-TM, likely contributing to disruption of signaling required for IFN induction. These results describe a new mechanism used by CoVs in which CoV PLPs negatively regulate antiviral defenses by disrupting the STING-mediated IFN induction.

  13. MicroRNA-223 Promotes Type I Interferon Production in Antiviral Innate Immunity by Targeting Forkhead Box Protein O3 (FOXO3).

    Science.gov (United States)

    Chen, Luoquan; Song, Yinjing; He, Li; Wan, Xiaopeng; Lai, Lihua; Dai, Feng; Liu, Yang; Wang, Qingqing

    2016-07-08

    Effective recognition of viral infection and subsequent triggering of antiviral innate immune responses are essential for the host antiviral defense, which is tightly regulated by multiple regulators, including microRNAs. Previous reports have shown that some microRNAs are induced during virus infection and participate in the regulation of the innate antiviral response. However, whether the type I IFN response is regulated by miR-223 is still unknown. Here, we reported that vesicular stomatitis virus (VSV) infection induced significant up-regulation of miR-223 in murine macrophages. We observed that miR-223 overexpression up-regulated type I IFN expression levels in VSV-infected macrophages. We also demonstrated that miR-223 directly targets FOXO3 to regulate the type I IFN production. Furthermore, type I IFN, which is triggered by VSV infection, is responsible for the up-regulation of miR-223, thus forming a positive regulatory loop for type I IFN production. Our results uncovered a novel mechanism of miR-223-mediated regulation of type I IFN production in the antiviral innate immunity for the first time.

  14. Coronavirus membrane-associated papain-like proteases induce autophagy through interacting with Beclin1 to negatively regulate antiviral innate immunity.

    Science.gov (United States)

    Chen, Xiaojuan; Wang, Kai; Xing, Yaling; Tu, Jian; Yang, Xingxing; Zhao, Qian; Li, Kui; Chen, Zhongbin

    2014-12-01

    Autophagy plays important roles in modulating viral replication and antiviral immune response. Coronavirus infection is associated with the autophagic process, however, little is known about the mechanisms of autophagy induction and its contribution to coronavirus regulation of host innate responses. Here, we show that the membrane-associated papain-like protease PLP2 (PLP2-TM) of coronaviruses acts as a novel autophagy-inducing protein. Intriguingly, PLP2-TM induces incomplete autophagy process by increasing the accumulation of autophagosomes but blocking the fusion of autophagosomes with lysosomes. Furthermore, PLP2-TM interacts with the key autophagy regulators, LC3 and Beclin1, and promotes Beclin1 interaction with STING, the key regulator for antiviral IFN signaling. Finally, knockdown of Beclin1 partially reverses PLP2-TM's inhibitory effect on innate immunity which resulting in decreased coronavirus replication. These results suggested that coronavirus papain-like protease induces incomplete autophagy by interacting with Beclin1, which in turn modulates coronavirus replication and antiviral innate immunity.

  15. Induction and suppression of the innate antiviral responses by picornaviruses

    NARCIS (Netherlands)

    Feng, Q.

    2014-01-01

    On the front line of innate antiviral immune reactions is the type I interferon (IFN-α/β) system. IFN-α/β are small signaling molecules that can be produced by virtually all nucleated cells in our body upon virus infections, and induce a so-called “antiviral state” in neighboring cells by activating

  16. 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

  17. Antiviral Efficacy and Host Innate Immunity Associated with SB 9200 Treatment in the Woodchuck Model of Chronic Hepatitis B

    Science.gov (United States)

    Korolowicz, Kyle E.; Iyer, Radhakrishnan P.; Czerwinski, Stefanie; Suresh, Manasa; Yang, Junming; Padmanabhan, Seetharamaiyer; Sheri, Anjaneyulu; Pandey, Rajendra K.; Skell, Jeffrey; Marquis, Judith K.; Kallakury, Bhaskar V.; Tucker, Robin D.; Menne, Stephan

    2016-01-01

    SB 9200, an oral prodrug of the dinucleotide SB 9000, is being developed for the treatment of chronic hepatitis B virus (HBV) infection and represents a novel class of antivirals. SB 9200 is thought to activate the viral sensor proteins, retinoic acid-inducible gene 1 (RIG-I) and nucleotide-binding oligomerization domain-containing protein 2 (NOD2) resulting in interferon (IFN) mediated antiviral immune responses in virus-infected cells. Additionally, the binding of SB 9200 to these sensor proteins could also sterically block the ability of the viral polymerase to access pre-genomic RNA for nucleic acid synthesis. The immune stimulating and direct antiviral properties of SB 9200 were evaluated in woodchucks chronically infected with woodchuck hepatitis virus (WHV) by daily, oral dosing at 15 and 30 mg/kg for 12 weeks. Prolonged treatment resulted in 2.2 and 3.7 log10 reductions in serum WHV DNA and in 0.5 and 1.6 log10 declines in serum WHV surface antigen from pretreatment level with the lower or higher dose of SB 9200, respectively. SB 9200 treatment also resulted in lower hepatic levels of WHV nucleic acids and antigen and reduced liver inflammation. Following treatment cessation, recrudescence of viral replication was observed but with dose-dependent delays in viral relapse. The antiviral effects were associated with dose-dependent and long-lasting induction of IFN-α, IFN-β and IFN-stimulated genes in blood and liver, which correlated with the prolonged activation of the RIG-I/NOD2 pathway and hepatic presence of elevated RIG-I protein levels. These results suggest that in addition to a direct antiviral activity, SB 9200 induces antiviral immunity during chronic hepadnaviral infection via activation of the viral sensor pathway. PMID:27552102

  18. An innate antiviral pathway acting before interferons at epithelial surfaces

    DEFF Research Database (Denmark)

    Iversen, Marie B; Reinert, Line S; Thomsen, Martin K;

    2016-01-01

    Mucosal surfaces are exposed to environmental substances and represent a major portal of entry for microorganisms. The innate immune system is responsible for early defense against infections and it is believed that the interferons (IFNs) constitute the first line of defense against viruses. Here...... we identify an innate antiviral pathway that works at epithelial surfaces before the IFNs. The pathway is activated independently of known innate sensors of viral infections through a mechanism dependent on viral O-linked glycans, which induce CXCR3 chemokines and stimulate antiviral activity...

  19. Host-specific response to HCV infection in the chimeric SCID-beige/Alb-uPA mouse model: role of the innate antiviral immune response.

    Directory of Open Access Journals (Sweden)

    Kathie-Anne Walters

    2006-06-01

    Full Text Available The severe combined immunodeficiency disorder (SCID-beige/albumin (Alb-urokinase plasminogen activator (uPA mouse containing a human-mouse chimeric liver is currently the only small animal model capable of supporting hepatitis C virus (HCV infection. This model was utilized to characterize the host transcriptional response to HCV infection. The purpose of these studies was to investigate the genetic component of the host response to HCV infection and also to distinguish virus-induced gene expression changes from adaptive HCV-specific immune-mediated effects. Gene expression profiles from HCV-infected mice were also compared to those from HCV-infected patients. Analyses of the gene expression data demonstrate that host factors regulate the response to HCV infection, including the nature of the innate antiviral immune response. They also indicate that HCV mediates gene expression changes, including regulation of lipid metabolism genes, which have the potential to be directly cytopathic, indicating that liver pathology may not be exclusively mediated by HCV-specific adaptive immune responses. This effect appears to be inversely related to the activation of the innate antiviral immune response. In summary, the nature of the initial interferon response to HCV infection may determine the extent of viral-mediated effects on host gene expression.

  20. Moraxella catarrhalis decreases antiviral innate immune responses by down-regulation of TLR3 via inhibition of p53 in human bronchial epithelial cells.

    Science.gov (United States)

    Heinrich, Annina; Haarmann, Helge; Zahradnik, Sabrina; Frenzel, Katrin; Schreiber, Frauke; Klassert, Tilman E; Heyl, Kerstin A; Endres, Anne-Sophie; Schmidtke, Michaela; Hofmann, Jörg; Slevogt, Hortense

    2016-06-01

    Chronic obstructive pulmonary disease (COPD) is complicated by infectious exacerbations with acute worsening of respiratory symptoms. Coinfections of bacterial and viral pathogens are associated with more severe exacerbations. Moraxella catarrhalis is one of the most frequent lower respiratory tract pathogens detected in COPD. We therefore studied the impact of M. catarrhalis on the antiviral innate immune response that is mediated via TLR3 and p53. Molecular interactions between M. catarrhalis and normal human bronchial epithelial (NHBE) cells as well as Beas-2B cells were studied using flow cytometry, quantitative PCR analysis, chromatin immunoprecipitation, RNA interference, and ELISA. M. catarrhalis induces a significant down-regulation of TLR3 in human bronchial epithelial cells. In M. catarrhalis-infected cells, expression of p53 was decreased. We detected a reduced binding of p53 to the tlr3 promoter, resulting in reduced TLR3 gene transcription. M. catarrhalis diminished the TLR3-dependent secretion of IFN-β, IFN-λ, and chemokine (C-X-C motif) ligand 8. In addition in M. catarrhalis infected cells, expression of rhinovirus type 1A RNA was increased compared with uninfected cells. M. catarrhalis reduces antiviral defense functions of bronchial epithelial cells, which may increase susceptibility to viral infections.-Heinrich, A., Haarmann, H., Zahradnik, S., Frenzel, K., Schreiber, F., Klassert, T. E., Heyl, K. A., Endres, A.-S., Schmidtke, M., Hofmann, J., Slevogt, H. Moraxella catarrhalis decreases antiviral innate immune responses by down-regulation of TLR3 via inhibition of p53 in human bronchial epithelial cells.

  1. Innate Immunity and Neuroinflammation

    Directory of Open Access Journals (Sweden)

    Abhishek Shastri

    2013-01-01

    Full Text Available Inflammation of central nervous system (CNS is usually associated with trauma and infection. Neuroinflammation occurs in close relation to trauma, infection, and neurodegenerative diseases. Low-level neuroinflammation is considered to have beneficial effects whereas chronic neuroinflammation can be harmful. Innate immune system consisting of pattern-recognition receptors, macrophages, and complement system plays a key role in CNS homeostasis following injury and infection. Here, we discuss how innate immune components can also contribute to neuroinflammation and neurodegeneration.

  2. Innate immunity and neuroinflammation.

    Science.gov (United States)

    Shastri, Abhishek; Bonifati, Domenico Marco; Kishore, Uday

    2013-01-01

    Inflammation of central nervous system (CNS) is usually associated with trauma and infection. Neuroinflammation occurs in close relation to trauma, infection, and neurodegenerative diseases. Low-level neuroinflammation is considered to have beneficial effects whereas chronic neuroinflammation can be harmful. Innate immune system consisting of pattern-recognition receptors, macrophages, and complement system plays a key role in CNS homeostasis following injury and infection. Here, we discuss how innate immune components can also contribute to neuroinflammation and neurodegeneration.

  3. Porcine Epidemic Diarrhea Virus (PEDV) and Host Antiviral Innate Immunity%猪流行性腹泻病毒(PEDV)与抗病毒天然免疫

    Institute of Scientific and Technical Information of China (English)

    张百灵; 陈建飞; 邢雅玲; 冯力; 陈忠斌

    2011-01-01

    Porcine epidemic diarrhea virus (PEDV) is an animal coronavirus that causes pig intestinal diseases-porcine epidemic diarrhea ( PED). To date, it is not clear that how PEDV interacts with the host antiviral innate system and what is the molecular mechanisms that regulate the host innate antiviral immune responses. Based on the author's recent studies on human coronaviruses, this review will focus on recent advances in our understanding of the genome replication and viral protein functions of PEDV,especially the potential mechanisms of PEDV interaction with the host innate antiviral immune response.Similar to human coronaviruses, PEDV papain-like protease (PLP) is a multifunctional protein with protease activity, deubiquitinase (DUB) activity and interferon antagonism activity. PLP2 domain is a novel PEDV-encoded DUB and interferon antagonist from animal coronavirus. These studies will help to illustrate the mechanisms of PEDV regulation of the host innate antiviral immune responses and disease pathogenesis, and will also provide the fundamental theoretical clues for the development of novel immune control measures for animal coronavirus infection.%猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)是引起猪流行性腹泻病等肠道疾病的一种动物冠状病毒.PEDV与宿主系统相互作用,特别是其对宿主抗病毒天然免疫调节作用和机制是目前动物冠状病毒研究的基础科学问题之一.基于作者近几年来对人类重要冠状病毒对宿主抗病毒天然免疫系统调节作用的研究,本文对PEDV基因组与编码蛋白主要功能以及PEDV调节宿主抗病毒天然免疫反应及其可能机制的进展和现状进行了分析.与人类冠状病毒相似,PEDV编码的木瓜样蛋白酶(papain-like protease,PLP)是一个多功能蛋白酶,除了蛋白酶活性外,还具有去泛素化酶(DUB)活性和宿主干扰素拮抗活性,是PEDV编码的一种新型病毒来源DUB和宿主干扰素拮抗蛋白.这

  4. A distinct role of Riplet-mediated K63-Linked polyubiquitination of the RIG-I repressor domain in human antiviral innate immune responses.

    Directory of Open Access Journals (Sweden)

    Hiroyuki Oshiumi

    Full Text Available The innate immune system is essential for controlling viral infections, but several viruses have evolved strategies to escape innate immunity. RIG-I is a cytoplasmic viral RNA sensor that triggers the signal to induce type I interferon production in response to viral infection. RIG-I activation is regulated by the K63-linked polyubiquitin chain mediated by Riplet and TRIM25 ubiquitin ligases. TRIM25 is required for RIG-I oligomerization and interaction with the IPS-1 adaptor molecule. A knockout study revealed that Riplet was essential for RIG-I activation. However the molecular mechanism underlying RIG-I activation by Riplet remains unclear, and the functional differences between Riplet and TRIM25 are also unknown. A genetic study and a pull-down assay indicated that Riplet was dispensable for RIG-I RNA binding activity but required for TRIM25 to activate RIG-I. Mutational analysis demonstrated that Lys-788 within the RIG-I repressor domain was critical for Riplet-mediated K63-linked polyubiquitination and that Riplet was required for the release of RIG-I autorepression of its N-terminal CARDs, which leads to the association of RIG-I with TRIM25 ubiquitin ligase and TBK1 protein kinase. Our data indicate that Riplet is a prerequisite for TRIM25 to activate RIG-I signaling. We investigated the biological importance of this mechanism in human cells and found that hepatitis C virus (HCV abrogated this mechanism. Interestingly, HCV NS3-4A proteases targeted the Riplet protein and abrogated endogenous RIG-I polyubiquitination and association with TRIM25 and TBK1, emphasizing the biological importance of this mechanism in human antiviral innate immunity. In conclusion, our results establish that Riplet-mediated K63-linked polyubiquitination released RIG-I RD autorepression, which allowed the access of positive factors to the RIG-I protein.

  5. Experimenting with Innate Immunity

    CERN Document Server

    Twycross, Jamie

    2010-01-01

    In a previous paper the authors argued the case for incorporating ideas from innate immunity into artificial immune systems (AISs) and presented an outline for a conceptual framework for such systems. A number of key general properties observed in the biological innate and adaptive immune systems were highlighted, and how such properties might be instantiated in artificial systems was discussed in detail. The next logical step is to take these ideas and build a software system with which AISs with these properties can be implemented and experimentally evaluated. This paper reports on the results of that step - the libtissue system.

  6. libtissue - implementing innate immunity

    CERN Document Server

    Twycross, Jamie

    2010-01-01

    In a previous paper the authors argued the case for incorporating ideas from innate immunity into articficial immune systems (AISs) and presented an outline for a conceptual framework for such systems. A number of key general properties observed in the biological innate and adaptive immune systems were hughlighted, and how such properties might be instantiated in artificial systems was discussed in detail. The next logical step is to take these ideas and build a software system with which AISs with these properties can be implemented and experimentally evaluated. This paper reports on the results of that step - the libtissue system.

  7. Antiviral immunity in amphibians.

    Science.gov (United States)

    Chen, Guangchun; Robert, Jacques

    2011-11-01

    Although a variety of virus species can infect amphibians, diseases caused by ranaviruses ([RVs]; Iridoviridae) have become prominent, and are a major concern for biodiversity, agriculture and international trade. The relatively recent and rapid increase in prevalence of RV infections, the wide range of host species infected by RVs, the variability in host resistance among population of the same species and among different developmental stages, all suggest an important involvement of the amphibian immune system. Nevertheless, the roles of the immune system in the etiology of viral diseases in amphibians are still poorly investigated. We review here the current knowledge of antiviral immunity in amphibians, focusing on model species such as the frog Xenopus and the salamander (Ambystoma tigrinum), and on recent progress in generating tools to better understand how host immune defenses control RV infections, pathogenicity, and transmission.

  8. Involvement of zebrafish RIG-I in NF-κB and IFN signaling pathways: insights into functional conservation of RIG-I in antiviral innate immunity.

    Science.gov (United States)

    Nie, Li; Zhang, Ying-sheng; Dong, Wei-ren; Xiang, Li-xin; Shao, Jian-zhong

    2015-01-01

    The retinoic acid-inducible gene I (RIG-I) is a critical sensor for host recognition of RNA virus infection and initiation of antiviral signaling pathways in mammals. However, data on the occurrence and functions of this molecule in lower vertebrates are limited. In this study, we characterized an RIG-I homolog (DrRIG-I) from zebrafish. Structurally, this DrRIG-I shares a number of conserved functional domains/motifs with its mammalian counterparts, namely, caspase activation and recruitment domain, DExD/H box, a helicase domain, and a C-terminal domain. Functionally, stimulation with DrRIG-I CARD in zebrafish embryos significantly activated the NF-κB and IFN signaling pathways, leading to the expression of TNF-α, IL-8 and IFN-induced Mx, ISG15, and viperin. However, knockdown of TRIM25 (a pivotal activator for RIG-I receptors) significantly suppressed the induced activation of IFN signaling. Results suggested the functional conservation of RIG-I receptors in the NF-κB and IFN signaling pathways between teleosts and mammals, providing a perspective into the evolutionary history of RIG-I-mediated antiviral innate immunity.

  9. Innate immunity in Drosophila: Pathogens and pathways

    OpenAIRE

    Govind, Shubha

    2008-01-01

    Following in the footsteps of traditional developmental genetics, research over the last 15 years has shown that innate immunity against bacteria and fungi is governed largely by two NF-κB signal transduction pathways, Toll and IMD. Antiviral immunity appears to stem from RNA interference, whereas resistance against parasitoids is conferred by Toll signaling. The identification of these post-transcriptional regulatory mechanisms and the annotation of most Drosophila immunity genes have derive...

  10. Critical role of an antiviral stress granule containing RIG-I and PKR in viral detection and innate immunity.

    Directory of Open Access Journals (Sweden)

    Koji Onomoto

    Full Text Available Retinoic acid inducible gene I (RIG-I-like receptors (RLRs function as cytoplasmic sensors for viral RNA to initiate antiviral responses including type I interferon (IFN production. It has been unclear how RIG-I encounters and senses viral RNA. To address this issue, we examined intracellular localization of RIG-I in response to viral infection using newly generated anti-RIG-I antibody. Immunohistochemical analysis revealed that RLRs localized in virus-induced granules containing stress granule (SG markers together with viral RNA and antiviral proteins. Because of similarity in morphology and components, we termed these aggregates antiviral stress granules (avSGs. Influenza A virus (IAV deficient in non-structural protein 1 (NS1 efficiently generated avSGs as well as IFN, however IAV encoding NS1 produced little. Inhibition of avSGs formation by removal of either the SG component or double-stranded RNA (dsRNA-dependent protein kinase (PKR resulted in diminished IFN production and concomitant enhancement of viral replication. Furthermore, we observed that transfection of dsRNA resulted in IFN production in an avSGs-dependent manner. These results strongly suggest that the avSG is the locus for non-self RNA sensing and the orchestration of multiple proteins is critical in the triggering of antiviral responses.

  11. Latest advances in innate antiviral defence

    OpenAIRE

    Irving, Aaron; Williams, Bryan RG

    2009-01-01

    Recent identification of key components in the pattern recognition receptor pathway of retinoic acid-inducible gene-1-like receptors, coupled with the characterisation of a new cytoplasmic DNA-sensing molecule, has led to a greater understanding of the role that viral nucleic acids play in activating innate immunity. This activation of type-I interferon is essential for both limiting viral infection and stimulating activation of the adaptive immune response.

  12. Innate immune exploitation by a model herpesvirus

    Institute of Scientific and Technical Information of China (English)

    Pinghui FENG; Xiaonan DONG

    2010-01-01

    @@ Host innate immunity represents the first line of defense against invading pathogens and shapes the course and outcome of pathogen infection. Mammals have evolved an array of highly conserved pattern recognition receptors (PRRs) that monitor the presence of "non-self components or danger signals (Akira et al., 2006; Medzhitov, 2007). The innate immune signal transduction and viral regulation have been extensively reviewed elsewhere (Zhang et al., 2010), we therefore briefly summarize the signaling cascades that upregulate the transcription of antiviral inflammatory cytokines in response to viral infection.

  13. 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.

  14. Fine-Tuning of the RIG-I-Like Receptor/Interferon Regulatory Factor 3-Dependent Antiviral Innate Immune Response by the Glycogen Synthase Kinase 3/β-Catenin Pathway.

    Science.gov (United States)

    Khan, Kashif Aziz; Dô, Florence; Marineau, Alexandre; Doyon, Priscilla; Clément, Jean-François; Woodgett, James R; Doble, Bradley W; Servant, Marc J

    2015-09-01

    Induction of an antiviral innate immune response relies on pattern recognition receptors, including retinoic acid-inducible gene 1-like receptors (RLR), to detect invading pathogens, resulting in the activation of multiple latent transcription factors, including interferon regulatory factor 3 (IRF3). Upon sensing of viral RNA and DNA, IRF3 is phosphorylated and recruits coactivators to induce type I interferons (IFNs) and selected sets of IRF3-regulated IFN-stimulated genes (ISGs) such as those for ISG54 (Ifit2), ISG56 (Ifit1), and viperin (Rsad2). Here, we used wild-type, glycogen synthase kinase 3α knockout (GSK-3α(-/-)), GSK-3β(-/-), and GSK-3α/β double-knockout (DKO) embryonic stem (ES) cells, as well as GSK-3β(-/-) mouse embryonic fibroblast cells in which GSK-3α was knocked down to demonstrate that both isoforms of GSK-3, GSK-3α and GSK-3β, are required for this antiviral immune response. Moreover, the use of two selective small-molecule GSK-3 inhibitors (CHIR99021 and BIO-acetoxime) or ES cells reconstituted with the catalytically inactive versions of GSK-3 isoforms showed that GSK-3 activity is required for optimal induction of antiviral innate immunity. Mechanistically, GSK-3 isoform activation following Sendai virus infection results in phosphorylation of β-catenin at S33/S37/T41, promoting IRF3 DNA binding and activation of IRF3-regulated ISGs. This study identifies the role of a GSK-3/β-catenin axis in antiviral innate immunity.

  15. The innate immune playbook for restricting West Nile virus infection.

    Science.gov (United States)

    Quicke, Kendra M; Suthar, Mehul S

    2013-10-30

    West Nile virus (WNV) is an emerging mosquito-borne flavivirus that causes annual epidemics of encephalitic disease throughout the world. Despite the ongoing risk to public health, no approved vaccines or therapies exist for use in humans to prevent or combat WNV infection. The innate immune response is critical for controlling WNV replication, limiting virus-induced pathology, and programming protective humoral and cell-mediated immunity to WNV infection. The RIG-I like receptors, Toll-like receptors, and Nod-like receptors detect and respond to WNV by inducing a potent antiviral defense program, characterized by production of type I IFN, IL-1β and expression of antiviral effector genes. Recent research efforts have focused on uncovering the mechanisms of innate immune sensing, antiviral effector genes that inhibit WNV, and countermeasures employed by WNV to antagonize innate immune cellular defenses. In this review, we highlight the major research findings pertaining to innate immune regulation of WNV infection.

  16. Innate immune targets of hepatitis B virus infection.

    Science.gov (United States)

    Zou, Zhi-Qiang; Wang, Li; Wang, Kai; Yu, Ji-Guang

    2016-06-18

    Approximately 400 million people are chronically infected with hepatitis B virus (HBV) globally despite the widespread immunization of HBV vaccine and the development of antiviral therapies. The immunopathogenesis of HBV infection is initiated and driven by complexed interactions between the host immune system and the virus. Host immune responses to viral particles and proteins are regarded as the main determinants of viral clearance or persistent infection and hepatocyte injury. Innate immune system is the first defending line of host preventing from virus invasion. It is acknowledged that HBV has developed active tactics to escape innate immune recognition or actively interfere with innate immune signaling pathways and induce immunosuppression, which favor their replication. HBV reduces the expression of pattern-recognition receptors in the innate immune cells in humans. Also, HBV may interrupt different parts of antiviral signaling pathways, leading to the reduced production of antiviral cytokines such as interferons that contribute to HBV immunopathogenesis. A full comprehension of the mechanisms as to how HBV inactivates various elements of the innate immune response to initiate and maintain a persistent infection can be helpful in designing new immunotherapeutic methods for preventing and eradicating the virus. In this review, we aimed to summarize different branches the innate immune targeted by HBV infection. The review paper provides evidence that multiple components of immune responses should be activated in combination with antiviral therapy to disrupt the tolerance to HBV for eliminating HBV infection.

  17. Innate immune targets of hepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    Zhi-Qiang; Zou; Li; Wang; Kai; Wang; Ji-Guang; Yu

    2016-01-01

    Approximately 400 million people are chronically infected with hepatitis B virus(HBV) globally despitethe widespread immunization of HBV vaccine and the development of antiviral therapies. The immunopathogenesis of HBV infection is initiated and driven by complexed interactions between the host immune system and the virus. Host immune responses to viral particles and proteins are regarded as the main determinants of viral clearance or persistent infection and hepatocyte injury. Innate immune system is the first defending line of host preventing from virus invasion. It is acknowledged that HBV has developed active tactics to escape innate immune recognition or actively interfere with innate immune signaling pathways and induce immunosuppression, which favor their replication. HBV reduces the expression of pattern-recognition receptors in the innate immune cells in humans. Also, HBV may interrupt different parts of antiviral signaling pathways, leading to the reduced production of antiviral cytokines such as interferons that contribute to HBV immunopathogenesis. A full comprehension of the mechanisms as to how HBV inactivates various elements of the innate immune response to initiate and maintain a persistent infection can be helpful in designing new immunotherapeutic methods for preventing and eradicating the virus. In this review, we aimed to summarize different branches the innate immune targeted by HBV infection. The review paper provides evidence that multiple components of immune responses should be activated in combination with antiviral therapy to disrupt the tolerance to HBV for eliminating HBV infection.

  18. The complexity of Drosophila innate immunity

    Directory of Open Access Journals (Sweden)

    A Reumer

    2010-01-01

    Full Text Available Metazoans rely on efficient mechanisms to oppose infections caused by pathogens. The immediate and first-line defense mechanism(s in metazoans, referred to as the innate immune system, is initiated upon recognition of microbial intruders by germline encoded receptors and is executed by a set of rapid effector mechanisms. Adaptive immunity is restricted to vertebrate species and it is controlled and assisted by the innate immune system.Interestingly, most of the basic signaling cascades that regulate the primeval innate defense mechanism(s have been well conserved during evolution, for instance between humans and the fruit fly, Drosophila melanogaster. Being devoid of adaptive signaling and effector systems, Drosophila has become an established model system for studying pristine innate immune cascades and reactions. In general, an immune response is evoked when microorganisms pass the fruit fly’s physical barriers (e.g., cuticle, epithelial lining of gut and trachea, and it is mainly executed in the hemolymph, the equivalent of the mammalian blood. Innate immunity in the fruit fly consists of a phenoloxidase (PO response, a cellular response (hemocytes, an antiviral response, and the NF-κB dependent production of antimicrobial peptides referred to as the humoral response. The JAK/STAT and Jun kinase signaling cascades are also implicated in the defence against pathogens.

  19. Innate immune memory in plants.

    Science.gov (United States)

    Reimer-Michalski, Eva-Maria; Conrath, Uwe

    2016-08-01

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

  20. 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.

  1. IFN-λ: a novel cytokine in innate antiviral immunity%Ⅲ型干扰素——新型抗病毒细胞因子

    Institute of Scientific and Technical Information of China (English)

    杨祎; 侯炜

    2011-01-01

    干扰素(IFN)是抗病毒感染的第一道防线,Ⅰ型和Ⅱ型干扰素不仅可抑制病毒,而且还能参与天然免疫反应和获得性免疫反应.最近干扰素家族增添一位新成员:Ⅲ型干扰素,即IFN-λ,因其具有类似干扰素的抗病毒活性且能诱导干扰素相关基因的表达而命名.IFN-λ受体与Ⅰ型干扰素的受体不同,但具有与Ⅰ型干扰素类似的诱导表达方式和信号转导通路,并能激活一系列相似的干扰素刺激基因.就IFN-λ家族及其受体、基因表达和信号转导机制、抗病毒作用等进行综述.%The first line of defense against viral infections is mediated by interferons (IFNs), which are produced rapidly by the infected host. Type Ⅰ IFNs (IFN-α/β) and type Ⅱ IFNs (IFN-γ) are known to combat viruses both directly by inhibiting viral replication in the cells and indirectly by stimulating the innate and adaptive immune responses. Recently, a novel class of cytokines was discovered and named IFN-λ"alternatively type Ⅲ IFN or interleukin-28/29 (IL-28/29)", based on IFN-like antiviral activity and induction of typical IFN-inducible genes. Although IFN-λ and IFN-α/β bind distinct receptors, IFN-λ has the similar type I interferon induced expression and signal transduction pathways, and can activate a series of similar interferon stimulated genes (ISGs). Here, we review the literature on IFN-λ and discuss the current knowledge of the functions and mechanisms of action of IFN-λ.

  2. Antiviral Innate Immune Response Interferes with the Formation of Replication-Associated Membrane Structures Induced by a Positive-Strand RNA Virus

    Directory of Open Access Journals (Sweden)

    Diede Oudshoorn

    2016-12-01

    Full Text Available Infection with nidoviruses like corona- and arteriviruses induces a reticulovesicular network of interconnected endoplasmic reticulum (ER-derived double-membrane vesicles (DMVs and other membrane structures. This network is thought to accommodate the viral replication machinery and protect it from innate immune detection. We hypothesized that the innate immune response has tools to counteract the formation of these virus-induced replication organelles in order to inhibit virus replication. Here we have investigated the effect of type I interferon (IFN treatment on the formation of arterivirus-induced membrane structures. Our approach involved ectopic expression of arterivirus nonstructural proteins nsp2 and nsp3, which induce DMV formation in the absence of other viral triggers of the interferon response, such as replicating viral RNA. Thus, this setup can be used to identify immune effectors that specifically target the (formation of virus-induced membrane structures. Using large-scale electron microscopy mosaic maps, we found that IFN-β treatment significantly reduced the formation of the membrane structures. Strikingly, we also observed abundant stretches of double-membrane sheets (a proposed intermediate of DMV formation in IFN-β-treated samples, suggesting the disruption of DMV biogenesis. Three interferon-stimulated gene products, two of which have been reported to target the hepatitis C virus replication structures, were tested for their possible involvement, but none of them affected membrane structure formation. Our study reveals the existence of a previously unknown innate immune mechanism that antagonizes the viral hijacking of host membranes. It also provides a solid basis for further research into the poorly understood interactions between the innate immune system and virus-induced replication structures.

  3. Towards a Conceptual Framework for Innate Immunity

    CERN Document Server

    Twycross, Jamie

    2010-01-01

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

  4. Plant innate immunity multicomponent model

    Directory of Open Access Journals (Sweden)

    Giuseppe eAndolfo

    2015-11-01

    Full Text Available Our understanding of plant–pathogen interactions is making rapid advances in order to address issues of global importance such as improving agricultural productivity and sustainable food security. Innate immunity has evolved in plants, resulting in a wide diversity of defence mechanisms adapted to specific threats. The postulated PTI/ETI model describes two perception layers of plant innate immune system, which belong to a first immunity component of defence response activation. To better describe the sophisticated defence system of plants, we propose a new model of plant immunity. This model considers the plant’s ability to distinguish the feeding behaviour of their many foes, such as a second component that modulates innate immunity. This hypothesis provides a new viewpoint highlighting the relevance of hormone crosstalk and primary metabolism in regulating plant defence against the different behaviours of pathogens with the intention to stimulate further interest in this research area.

  5. Polyphasic innate immune responses to acute and chronic LCMV infection: Innate immunity to acute & chronic viral infection

    OpenAIRE

    Norris, Brian A; Uebelhoer, Luke S.; Nakaya, Helder I.; Price, Aryn A; Grakoui, Arash; Pulendran, Bali

    2013-01-01

    Resolution of acute and chronic viral infections requires activation of innate cells to initiate and maintain adaptive immune responses. Here we report that infection with acute Armstrong (ARM) or chronic Clone 13 (C13) strains of lymphocytic choriomeningitis virus (LCMV) led to two distinct phases of innate immune response. During the first 72hr of infection, dendritic cells upregulated activation markers, and stimulated anti-viral CD8+ T cells, independent of viral strain. Seven days after ...

  6. TLR-9 contributes to the antiviral innate immune sensing of rodent parvoviruses MVMp and H-1PV by normal human immune cells.

    Directory of Open Access Journals (Sweden)

    Zahari Raykov

    Full Text Available The oncotropism of Minute Virus of Mice (MVMp is partially related to the stimulation of an antiviral response mediated by type-I interferons (IFNs in normal but not in transformed mouse cells. The present work was undertaken to assess whether the oncotropism displayed against human cells by MVMp and its rat homolog H-1PV also depends on antiviral mechanisms and to identify the pattern recognition receptor (PRR involved. Despite their low proliferation rate which represents a drawback for parvovirus multiplication, we used human peripheral blood mononuclear cells (hPBMCs as normal model specifically because all known PRRs are functional in this mixed cell population and moreover because some of its subsets are among the main IFN producers upon infections in mammals. Human transformed models consisted in lines and tumor cells more or less permissive to both parvoviruses. Our results show that irrespective of their permissiveness, transformed cells do not produce IFNs nor develop an antiviral response upon parvovirus infection. However, MVMp- or H-1PV-infected hPBMCs trigger such defense mechanisms despite an absence of parvovirus replication and protein expression, pointing to the viral genome as the activating element. Substantial reduction of an inhibitory oligodeoxynucleotide (iODN of the latter IFN production identified TLR-9 as a potential PRR for parvoviruses in hPBMCs. However, neither the iODN treatment nor an antibody-induced neutralization of the IFN-triggered effects restored parvovirus multiplication in these cells as expected by their weak proliferation in culture. Finally, given that a TLR-9 activation could also not be observed in parvovirus-infected human lines reported to be endowed with a functional TLR-9 pathway (Namalwa, Raji, and HEK293-TLR9(+/+, our data suggest that transformed human cells do not sense MVMp or H-1PV either because of an absence of PRR expression or an intrinsic, or virus-driven defect in the endosomal

  7. GPCRs in invertebrate innate immunity.

    Science.gov (United States)

    Reboul, Jerome; Ewbank, Jonathan J

    2016-08-15

    G-protein coupled receptors (GPCRs) represent a privileged point of contact between cells and their surrounding environment. They have been widely adopted in vertebrates as mediators of signals involved in both innate and adaptive immunity. Invertebrates rely on innate immune defences to resist infection. We review here evidence from a number of different species, principally the genetically tractable Caenorhabditis elegans and Drosophila melanogaster that points to an important role for GPCRs in modulating innate immunity in invertebrates too. In addition to examples of GPCRs involved in regulating the expression of defence genes, we discuss studies in C. elegans addressing the role of GPCR signalling in pathogen aversive behaviour. Despite the many lacunae in our current knowledge, it is clear that GPCR signalling contributes to host defence across the animal kingdom.

  8. Innate immunity in Drosophila: Pathogens and pathways

    Institute of Scientific and Technical Information of China (English)

    Shubha Govind

    2008-01-01

    Following in the footsteps of traditional developmental genetics, research over the last 15 years has shown that innate immunity against bacteria and fungi is governed largely by two NF-κB signal transduction pathways, Toll and IMD. Antiviral immunity appears to stem from RNA interference, whereas resistance against parasitoids is conferred by Toll signaling. The identification of these post-transcriptional regulatory mechanisms and the annotation of most Drosophila immunity genes have derived from functional genomic studies using "model" pathogens, intact animals and cell lines. The D. melanogaster host has thus provided the core information that can be used to study responses to natural microbial and metazoan pathogens as they become identified, as well as to test ideas of selection and evolutionary change. These analyses are of general importance to understanding mechanisms of other insect host-pathogen interactions and determinants of variation in host resistance.

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

    Lifescience Database Archive (English)

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

  10. The Innate Immune Playbook for Restricting West Nile Virus Infection

    Directory of Open Access Journals (Sweden)

    Kendra M. Quicke

    2013-10-01

    Full Text Available West Nile virus (WNV is an emerging mosquito-borne flavivirus that causes annual epidemics of encephalitic disease throughout the world. Despite the ongoing risk to public health, no approved vaccines or therapies exist for use in humans to prevent or combat WNV infection. The innate immune response is critical for controlling WNV replication, limiting virus-induced pathology, and programming protective humoral and cell-mediated immunity to WNV infection. The RIG-I like receptors, Toll-like receptors, and Nod-like receptors detect and respond to WNV by inducing a potent antiviral defense program, characterized by production of type I IFN, IL-1β and expression of antiviral effector genes. Recent research efforts have focused on uncovering the mechanisms of innate immune sensing, antiviral effector genes that inhibit WNV, and countermeasures employed by WNV to antagonize innate immune cellular defenses. In this review, we highlight the major research findings pertaining to innate immune regulation of WNV infection.

  11. Innate immune interferon responses to human immunodeficiency virus-1 infection.

    Science.gov (United States)

    Hughes, Rose; Towers, Greg; Noursadeghi, Mahdad

    2012-07-01

    Type I interferon (IFN) responses represent the canonical host innate immune response to viruses, which serves to upregulate expression of antiviral restriction factors and augment adaptive immune defences. There is clear evidence for type I IFN activity in both acute and chronic HIV-1 infection in vivo, and plasmacytoid dendritic cells have been identified as one important source for these responses, through innate immune detection of viral RNA by Toll-like receptor 7. In addition, new insights into the molecular mechanisms that trigger induction of type I IFNs suggest innate immune receptors for viral DNA may also mediate these responses. It is widely recognised that HIV-1 restriction factors share the characteristic of IFN-inducible expression, and that the virus has evolved to counteract these antiviral mechanisms. However, in some target cells, such as macrophages, IFN can still effectively restrict virus. In this context, HIV-1 shows the ability to evade innate immune recognition and thereby avoid induction of type I IFN in order to successfully establish productive infection. The relative importance of evasion of innate immune detection and evasion of IFN-inducible restriction in the natural history of HIV-1 infection is not known, and the data suggest that type I IFN responses may play a role in both viral control and in the immunopathogenesis of progressive disease. Further study of the relationship between HIV-1 infection and type I IFN responses is required to unravel these issues and inform the development of novel therapeutics or vaccine strategies.

  12. DMPD: Triggering the innate antiviral response through IRF-3 activation. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17395583 Triggering the innate antiviral response through IRF-3 activation. Hiscott...g the innate antiviral response through IRF-3 activation. PubmedID 17395583 Title Triggering the innate anti...viral response through IRF-3 activation. Authors Hiscott J. Publication J Biol Ch

  13. Tuning innate immunity by translation.

    Science.gov (United States)

    Rauscher, Robert; Ignatova, Zoya

    2015-12-01

    In multicellular organisms, the epithelia is a contact surface with the surrounding environment and is exposed to a variety of adverse biotic (pathogenic) and abiotic (chemical) factors. Multi-layered pathways that operate on different time scales have evolved to preserve cellular integrity and elicit stress-specific response. Several stress-response programs are activated until a complete elimination of the stress is achieved. The innate immune response, which is triggered by pathogenic invasion, is rather harmful when active over a prolonged time, thus the response follows characteristic oscillatory trajectories. Here, we review different translation programs that function to precisely fine-tune the time at which various components of the innate immune response dwell between active and inactive. We discuss how different pro-inflammatory pathways are co-ordinated to temporally offset single reactions and to achieve an optimal balance between fighting pathogens and being less harmful for healthy cells.

  14. 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.

  15. 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.

  16. Rotavirus Antagonism of the Innate Immune Response

    Directory of Open Access Journals (Sweden)

    Michelle M. Arnold

    2009-11-01

    Full Text Available Rotavirus is a primary cause of severe dehydrating gastroenteritis in infants and young children. The virus is sensitive to the antiviral effects triggered by the interferon (IFN-signaling pathway, an important component of the host cell innate immune response. To counteract these effects, rotavirus encodes a nonstructural protein (NSP1 that induces the degradation of proteins involved in regulating IFN expression, such as members of the IFN regulatory factor (IRF family. In some instances, NSP1 also subverts IFN expression by causing the degradation of a component of the E3 ubiquitin ligase complex responsible for activating NF-κB. By antagonizing multiple components of the IFN-induction pathway, NSP1 aids viral spread and contributes to rotavirus pathogenesis.

  17. Innate immune response to viral infection of the lungs.

    Science.gov (United States)

    See, Hayley; Wark, Peter

    2008-12-01

    Viral respiratory tract infections are the most common infectious illnesses, though they are usually self-limiting and confined to the respiratory tract. The rapid identification of viruses and their effective elimination with minimal local and systemic inflammation is a testament to the efficiency of the innate immune response within the airways and lungs. A failure of this response appears to occur in those with asthma and chronic obstructive pulmonary disease, where viral infection is an important trigger for acute exacerbations. The innate immune response to viruses requires their early detection through pathogen recognition receptors and the recruitment of the efficient antiviral response that is centred around the release of type 1 interferons. The airway epithelium provides both a barrier and an early detector for viruses, and interacts closely with cells of the innate immune response, especially macrophages and dendritic cells, to eliminate infection and trigger a specific adaptive immune response.

  18. Self-consuming innate immunity in Arabidopsis

    DEFF Research Database (Denmark)

    Hofius, Daniel; Mundy, John; Petersen, Morten

    2009-01-01

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

  19. INNATE, ADAPTIVE AND INTRINSIC IMMUNITY IN HUMAN IMMUNODEFICIENCY VIRUS INFECTION

    Directory of Open Access Journals (Sweden)

    Suneth S. Perera

    2012-01-01

    Full Text Available The first line of defence of the innate immune system functions by recognizing highly conserved sets of molecular structures specific to the microbes, termed pathogen-associated molecular patterns, or PAMPs via the germ line-encoded receptors Pattern-Recognition Receptors (PRRs. In addition to the innate immune system, the vertebrates have also evolved a second line of defence termed adaptive immune system, which uses a diverse set of somatically rearranged receptors T-Cell Receptors (TCRs and B Cell Receptors (BCRs, which have the inherent ability to effectively recognise diverse antigens. The innate and adaptive immune systems are functionally tied in with the intrinsic immunity, which comprises of endogenous antiviral factors. Thus, this effective response to diverse microbial infections, including HIV, requires a coordinated interaction at several functional levels between innate, adaptive and intrinsic immune systems. This review provides a snapshot of roles played by the innate, adaptive and the intrinsic immune systems during HIV-infection, along with discussing recent developments highlighting the genomic basis of these responses and their regulation by micro-RNA (miRNAs.

  20. Innate immune response to viral infection.

    Science.gov (United States)

    Koyama, Shohei; Ishii, Ken J; Coban, Cevayir; Akira, Shizuo

    2008-09-01

    In viral infections the host innate immune system is meant to act as a first line defense to prevent viral invasion or replication before more specific protection by the adaptive immune system is generated. In the innate immune response, pattern recognition receptors (PRRs) are engaged to detect specific viral components such as viral RNA or DNA or viral intermediate products and to induce type I interferons (IFNs) and other pro-inflammatory cytokines in the infected cells and other immune cells. Recently these innate immune receptors and their unique downstream pathways have been identified. Here, we summarize their roles in the innate immune response to virus infection, discrimination between self and viral nucleic acids and inhibition by virulent factors and provide some recent advances in the coordination between innate and adaptive immune activation.

  1. DMPD: An arms race: innate antiviral responses and counteracting viral strategies. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18031256 An arms race: innate antiviral responses and counteracting viral strategie...s. Schroder M, Bowie AG. Biochem Soc Trans. 2007 Dec;35(Pt 6):1512-4. (.png) (.svg) (.html) (.csml) Show An arms race: innate anti...viral responses and counteracting viral strategies. PubmedID 18031256 Title An arms race: innate anti

  2. 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 ...

  3. 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.

  4. Paramyxovirus activation and inhibition of innate immune responses.

    Science.gov (United States)

    Parks, Griffith D; Alexander-Miller, Martha A

    2013-12-13

    Paramyxoviruses represent a remarkably diverse family of enveloped nonsegmented negative-strand RNA viruses, some of which are the most ubiquitous disease-causing viruses of humans and animals. This review focuses on paramyxovirus activation of innate immune pathways, the mechanisms by which these RNA viruses counteract these pathways, and the innate response to paramyxovirus infection of dendritic cells (DC). Paramyxoviruses are potent activators of extracellular complement pathways, a first line of defense that viruses must face during natural infections. We discuss mechanisms by which these viruses activate and combat complement to delay neutralization. Once cells are infected, virus replication drives type I interferon (IFN) synthesis that has the potential to induce a large number of antiviral genes. Here we describe four approaches by which paramyxoviruses limit IFN induction: by limiting synthesis of IFN-inducing aberrant viral RNAs, through targeted inhibition of RNA sensors, by providing viral decoy substrates for cellular kinase complexes, and through direct blocking of the IFN promoter. In addition, paramyxoviruses have evolved diverse mechanisms to disrupt IFN signaling pathways. We describe three general mechanisms, including targeted proteolysis of signaling factors, sequestering cellular factors, and upregulation of cellular inhibitors. DC are exceptional cells with the capacity to generate adaptive immunity through the coupling of innate immune signals and T cell activation. We discuss the importance of innate responses in DC following paramyxovirus infection and their consequences for the ability to mount and maintain antiviral T cells.

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

    Science.gov (United States)

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

    2013-11-01

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

  6. Drosophila as a model for antiviral immunity

    Institute of Scientific and Technical Information of China (English)

    Susanna; Valanne; Mika; Rmet

    2010-01-01

    The fruit fly Drosophila melanogaster has been successfully used to study numerous biological processes including immune response.Flies are naturally infected with more than twenty RNA viruses making it a valid model organism to study host-pathogen interactions during viral infections.The Drosophila antiviral immunity includes RNA interference,activation of the JAK/STAT and other signaling cascades and other mechanisms such as autophagy and interactions with other microorganisms.Here we review Drosophila as an immunological research model as well as recent advances in the field ofDrosophila antiviral immunity.

  7. Innate immune recognition of hepatitis B virus

    Institute of Scientific and Technical Information of China (English)

    Hong-Yan; Liu; Xiao-Yong; Zhang

    2015-01-01

    Hepatitis B virus(HBV) is a hepatotropic DNA virus and its infection results in acute or chronic hepatitis. It is reported that the host innate immune system contributes to viral control and liver pathology, while whether and how HBV can trigger the components of innate immunity remains controversial. In recent years, the data accumulated from HBV-infected patients, cellular and animal models have challenged the concept of a stealth virus for HBV infection. This editorial focuses on the current findings about the innate immune recognition to HBV. Such evaluation could help us to understand HBV immunopathogenesis and develop novel immune therapeutic strategies to combat HBV infection.

  8. Integrative Genomics-Based Discovery of Novel Regulators of the Innate Antiviral Response.

    Science.gov (United States)

    van der Lee, Robin; Feng, Qian; Langereis, Martijn A; Ter Horst, Rob; Szklarczyk, Radek; Netea, Mihai G; Andeweg, Arno C; van Kuppeveld, Frank J M; Huynen, Martijn A

    2015-10-01

    The RIG-I-like receptor (RLR) pathway is essential for detecting cytosolic viral RNA to trigger the production of type I interferons (IFNα/β) that initiate an innate antiviral response. Through systematic assessment of a wide variety of genomics data, we discovered 10 molecular signatures of known RLR pathway components that collectively predict novel members. We demonstrate that RLR pathway genes, among others, tend to evolve rapidly, interact with viral proteins, contain a limited set of protein domains, are regulated by specific transcription factors, and form a tightly connected interaction network. Using a Bayesian approach to integrate these signatures, we propose likely novel RLR regulators. RNAi knockdown experiments revealed a high prediction accuracy, identifying 94 genes among 187 candidates tested (~50%) that affected viral RNA-induced production of IFNβ. The discovered antiviral regulators may participate in a wide range of processes that highlight the complexity of antiviral defense (e.g. MAP3K11, CDK11B, PSMA3, TRIM14, HSPA9B, CDC37, NUP98, G3BP1), and include uncharacterized factors (DDX17, C6orf58, C16orf57, PKN2, SNW1). Our validated RLR pathway list (http://rlr.cmbi.umcn.nl/), obtained using a combination of integrative genomics and experiments, is a new resource for innate antiviral immunity research.

  9. Integrative Genomics-Based Discovery of Novel Regulators of the Innate Antiviral Response.

    Directory of Open Access Journals (Sweden)

    Robin van der Lee

    2015-10-01

    Full Text Available The RIG-I-like receptor (RLR pathway is essential for detecting cytosolic viral RNA to trigger the production of type I interferons (IFNα/β that initiate an innate antiviral response. Through systematic assessment of a wide variety of genomics data, we discovered 10 molecular signatures of known RLR pathway components that collectively predict novel members. We demonstrate that RLR pathway genes, among others, tend to evolve rapidly, interact with viral proteins, contain a limited set of protein domains, are regulated by specific transcription factors, and form a tightly connected interaction network. Using a Bayesian approach to integrate these signatures, we propose likely novel RLR regulators. RNAi knockdown experiments revealed a high prediction accuracy, identifying 94 genes among 187 candidates tested (~50% that affected viral RNA-induced production of IFNβ. The discovered antiviral regulators may participate in a wide range of processes that highlight the complexity of antiviral defense (e.g. MAP3K11, CDK11B, PSMA3, TRIM14, HSPA9B, CDC37, NUP98, G3BP1, and include uncharacterized factors (DDX17, C6orf58, C16orf57, PKN2, SNW1. Our validated RLR pathway list (http://rlr.cmbi.umcn.nl/, obtained using a combination of integrative genomics and experiments, is a new resource for innate antiviral immunity research.

  10. Mitochondrial DNA in the regulation of innate immune responses

    Directory of Open Access Journals (Sweden)

    Chunju Fang

    2015-10-01

    Full Text Available Abstract Mitochondrion is known as the energy factory of the cell, which is also a unique mammalian organelle and considered to be evolved from aerobic prokaryotes more than a billion years ago. Mitochondrial DNA, similar to that of its bacterial ancestor’s, consists of a circular loop and contains significant number of unmethylated DNA as CpG islands. The innate immune system plays an important role in the mammalian immune response. Recent research has demonstrated that mitochondrial DNA (mtDNA activates several innate immune pathways involving TLR9, NLRP3 and STING signaling, which contributes to the signaling platforms and results in effector responses. In addition to facilitating antibacterial immunity and regulating antiviral signaling, mounting evidence suggests that mtDNA contributes to inflammatory diseases following cellular damage and stress. Therefore, in addition to its well-appreciated roles in cellular metabolism and energy production, mtDNA appears to function as a key member in the innate immune system. Here, we highlight the emerging roles of mtDNA in innate immunity.

  11. 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.

  12. Innate immune responses in hepatitis C virus infection.

    Science.gov (United States)

    Li, Kui; Lemon, Stanley M

    2013-01-01

    Hepatitis C virus (HCV) is a major causative agent of chronic hepatitis and hepatocellular carcinoma worldwide and thus poses a significant public health threat. A hallmark of HCV infection is the extraordinary ability of the virus to persist in a majority of infected people. Innate immune responses represent the front line of defense of the human body against HCV immediately after infection. They also play a crucial role in orchestrating subsequent HCV-specific adaptive immunity that is pivotal for viral clearance. Accumulating evidence suggests that the host has evolved multifaceted innate immune mechanisms to sense HCV infection and elicit defense responses, while HCV has developed elaborate strategies to circumvent many of these. Defining the interplay of HCV with host innate immunity reveals mechanistic insights into hepatitis C pathogenesis and informs approaches to therapy. In this review, we summarize recent advances in understanding innate immune responses to HCV infection, focusing on induction and effector mechanisms of the interferon antiviral response as well as the evasion strategies of HCV.

  13. Evolutionary genetics of insect innate immunity

    OpenAIRE

    Viljakainen, Lumi

    2015-01-01

    Patterns of evolution in immune defense genes help to understand the evolutionary dynamics between hosts and pathogens. Multiple insect genomes have been sequenced, with many of them having annotated immune genes, which paves the way for a comparative genomic analysis of insect immunity. In this review, I summarize the current state of comparative and evolutionary genomics of insect innate immune defense. The focus is on the conserved and divergent components of immunity with an emphasis on g...

  14. Cholangiopathy with Respect to Biliary Innate Immunity

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    Kenichi Harada

    2012-01-01

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

  15. Innate Immune Effectors in Mycobacterial Infection

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    Hiroyuki Saiga

    2011-01-01

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

  16. 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.

  17. Viral infection: an evolving insight into the signal transduction pathways responsible for the innate immune response.

    Science.gov (United States)

    Kotwal, Girish J; Hatch, Steven; Marshall, William L

    2012-01-01

    The innate immune response is initiated by the interaction of stereotypical pathogen components with genetically conserved receptors for extracytosolic pathogen-associated molecular patterns (PAMPs) or intracytosolic nucleic acids. In multicellular organisms, this interaction typically clusters signal transduction molecules and leads to their activations, thereby initiating signals that activate innate immune effector mechanisms to protect the host. In some cases programmed cell death-a fundamental form of innate immunity-is initiated in response to genotoxic or biochemical stress that is associated with viral infection. In this paper we will summarize innate immune mechanisms that are relevant to viral pathogenesis and outline the continuing evolution of viral mechanisms that suppress the innate immunity in mammalian hosts. These mechanisms of viral innate immune evasion provide significant insight into the pathways of the antiviral innate immune response of many organisms. Examples of relevant mammalian innate immune defenses host defenses include signaling to interferon and cytokine response pathways as well as signaling to the inflammasome. Understanding which viral innate immune evasion mechanisms are linked to pathogenesis may translate into therapies and vaccines that are truly effective in eliminating the morbidity and mortality associated with viral infections in individuals.

  18. Innate Immune Activity in Glomerular Podocytes

    Science.gov (United States)

    Xia, Hong; Bao, Wenduona; Shi, Shaolin

    2017-01-01

    Glomerular podocytes are specialized in structure and play an essential role in glomerular filtration. In addition, podocyte stress can initiate glomerular damage by inducing the injury of other glomerular cell types. Studies have shown that podocytes possess the property of immune cells and may be involved in adaptive immunity. Emerging studies have also shown that podocytes possess signaling pathways of innate immune responses and that innate immune responses often result in podocyte injury. More recently, mitochondrial-derived damage-associated molecular patterns (mtDAMPs) have been shown to play a critical role in a variety of pathological processes in cells. In the present mini-review, we summarize the recent advances in the studies of innate immunity and its pathogenic role in podocytes, particularly, from the perspective of mtDAMPs. PMID:28228761

  19. Innate immune sensing and response to influenza.

    Science.gov (United States)

    Pulendran, Bali; Maddur, Mohan S

    2015-01-01

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

  20. Asthma is associated with multiple alterations in anti-viral innate signalling pathways.

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    Antonia L Pritchard

    Full Text Available BACKGROUND: Human rhinovirus (HRV infection is a major trigger for asthma exacerbations. Anti-viral immunity appears to be abnormal in asthma, with immune dysfunction reported in both airway structural cells and migratory, bone marrow derived cells. Though decreased capacity to produce anti-viral interferons (IFNs has been reported in asthma, a detailed analysis of the molecular events involved has not been undertaken. OBJECTIVE: To compare the molecular pathway controlling type I IFN synthesis in HRV-stimulated peripheral blood mononuclear cells (PBMC from asthmatic and healthy subjects. METHODS: PBMC from 22 allergic asthmatics and 20 healthy donors were cultured with HRV for 24 hours. Multiple components of the Toll-like receptor (TLR, IFN regulatory and NFκβ pathways were compared at the mRNA and protein level. RESULTS: Multiple deficiencies in the innate immune response to HRV were identified in asthma, with significantly lower expression of IFNα, IFNβ and interferon stimulated genes than in healthy subjects. This was accompanied by reduced expression of intra-cellular signalling molecules including interferon regulatory factors (IRF1, IRF7, NF-κB family members (p50, p52, p65 and IκKα and STAT1, and by reduced responsiveness to TLR7/TLR8 activation. These observations could not be attributed to alterations in the numbers of dendritic cell (DC subsets in asthma or baseline expression of the viral RNA sensing receptors TLR7/TLR8. In healthy subjects, blocking the activity of type-I IFN or depleting plasmacytoid DC recapitulated many of the abnormalities observed in asthma. CONCLUSIONS: Multiple abnormalities in innate anti-viral signalling pathways were identified in asthma, with deficiencies in both IFN-dependent and IFN-independent molecules identified.

  1. Inflammatory bowel disease related innate immunity and adaptive immunity

    Science.gov (United States)

    Huang, Yuan; Chen, Zhonge

    2016-01-01

    Inflammatory bowel disease (IBD) is a chronic nonspecific intestinal inflammatory disease, including ulcerative colitis (UC) and Crohn’s disease (CD). Its pathogenesis remains not yet clear. Current researchers believe that after environmental factors act on individuals with genetic susceptibility, an abnormal intestinal immune response is launched under stimulation of intestinal flora. However, previous studies only focused on adaptive immunity in the pathogenesis of IBD. Currently, roles of innate immune response in the pathogenesis of intestinal inflammation have also drawn much attention. In this study, IBD related innate immunity and adaptive immunity were explained, especially the immune mechanisms in the pathogenesis of IBD. PMID:27398134

  2. 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. PMID:19756242

  3. Innate and adaptive immune responses in HCV infections.

    Science.gov (United States)

    Heim, Markus H; Thimme, Robert

    2014-11-01

    Hepatitis C virus has been identified a quarter of a decade ago as a leading cause of chronic viral hepatitis that can lead to cirrhosis and hepatocellular carcinoma. Only a minority of patients can clear the virus spontaneously during acute infection. Elimination of HCV during acute infection correlates with a rapid induction of innate, especially interferon (IFN) induced genes, and a delayed induction of adaptive immune responses. However, the majority of patients is unable to clear the virus and develops viral persistence in face of an ongoing innate and adaptive immune response. The virus has developed several strategies to escape these immune responses. For example, to escape innate immunity, the HCV NS3/4A protease can efficiently cleave and inactivate two important signalling molecules in the sensory pathways that react to HCV pathogen-associated molecular patterns (PAMPs) to induce IFNs, i.e., the mitochondrial anti-viral signalling protein (MAVS) and the Toll-IL-1 receptor-domain-containing adaptor-inducing IFN-β (TRIF). Despite these escape mechanisms, IFN-stimulated genes (ISGs) are induced in a large proportion of patients with chronic infection. Of note, chronically HCV infected patients with constitutive IFN-stimulated gene (ISG) expression have a poor response to treatment with pegylated IFN-α (PegIFN-α) and ribavirin. The mechanisms that protect HCV from IFN-mediated innate immune reactions are not entirely understood, but might involve blockade of ISG protein translation at the ribosome, localization of viral replication to cell compartments that are not accessible to anti-viral IFN-stimulated effector systems, or direct antagonism of effector systems by viral proteins. Escape from adaptive immune responses can be achieved by emergence of viral escape mutations that avoid recognition by antibodies and T cells. In addition, chronic infection is characterized by the presence of functionally and phenotypically altered NK and T cell responses that

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

    Science.gov (United States)

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

    2012-10-01

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

  5. Characterization of Aedes aegypti innate-immune pathways that limit Chikungunya virus replication.

    Directory of Open Access Journals (Sweden)

    Melanie McFarlane

    2014-07-01

    Full Text Available Replication of arboviruses in their arthropod vectors is controlled by innate immune responses. The RNA sequence-specific break down mechanism, RNA interference (RNAi, has been shown to be an important innate antiviral response in mosquitoes. In addition, immune signaling pathways have been reported to mediate arbovirus infections in mosquitoes; namely the JAK/STAT, immune deficiency (IMD and Toll pathways. Very little is known about these pathways in response to chikungunya virus (CHIKV infection, a mosquito-borne alphavirus (Togaviridae transmitted by aedine species to humans resulting in a febrile and arthralgic disease. In this study, the contribution of several innate immune responses to control CHIKV replication was investigated. In vitro experiments identified the RNAi pathway as a key antiviral pathway. CHIKV was shown to repress the activity of the Toll signaling pathway in vitro but neither JAK/STAT, IMD nor Toll pathways were found to mediate antiviral activities. In vivo data further confirmed our in vitro identification of the vital role of RNAi in antiviral defence. Taken together these results indicate a complex interaction between CHIKV replication and mosquito innate immune responses and demonstrate similarities as well as differences in the control of alphaviruses and other arboviruses by mosquito immune pathways.

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

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    Xiaobo Lei

    2016-01-01

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

  7. Antimicrobial peptides in innate immune responses.

    Science.gov (United States)

    Sørensen, Ole E; Borregaard, Niels; Cole, Alexander 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 diseases like Crohn's disease and atopic dermatitis. AMPs are attractive candidates for development of novel antibiotics due to their in vivo activity profile and some peptides may serve as templates for further drug development.

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

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    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.

  9. Fungal glycans and the innate immune recognition

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    Rodrigo Tinoco Figueiredo

    2014-10-01

    Full Text Available Polysaccharides such as α- and β-glucans, chitin and glycoproteins extensively modified with both N- and O-linked carbohydrates are the major components of fungal surfaces. The fungal cell wall is an excellent target for the action of antifungal agents, since most of its components are absent from mammalian cells. Recognition of these carbohydrate-containing molecules by the innate immune system triggers inflammatory responses and activation of microbicidal mechanisms by leukocytes. This review will discuss the structure of surface fungal glycoconjugates and polysaccharides and their recognition by innate immune receptors.

  10. KEY PLAYERS IN INNATE IMMUNE RECOGNITION OF VIRUS INFECTION IN MAMMALS AND FISH

    OpenAIRE

    I Jakovlić; Zhang, Y.B.; WU, Q.J.; Jian-Fang Gui

    2006-01-01

    Viral infection of mammalian cells activates an innate antiviral immune response characterized by production of interferon and subsequent enhanced transcription of interferon–stimulated genes important for antiviral defense. Cells recognize viral infection through various pathogen–associated molecular patterns, of which dsRNA seems to be the most important. In mammals, several gene products are important in recognition of dsRNA: RIG–I, TLR3, PKR and mda–5. Recent research proved that fish pos...

  11. Genetics of innate immunity and UTI susceptibility.

    Science.gov (United States)

    Ragnarsdóttir, Bryndís; Lutay, Nataliya; Grönberg-Hernandez, Jenny; Köves, Bela; Svanborg, Catharina

    2011-07-12

    A functional and well-balanced immune response is required to resist most infections. Slight dysfunctions in innate immunity can turn the 'friendly' host defense into an unpleasant foe and give rise to disease. Beneficial and destructive forces of innate immunity have been discovered in the urinary tract and mechanisms by which they influence the severity of urinary tract infections (UTIs) have been elucidated. By modifying specific aspects of the innate immune response to UTI, genetic variation either exaggerates the severity of acute pyelonephritis to include urosepsis and renal scarring or protects against symptomatic disease by suppressing innate immune signaling, as in asymptomatic bacteriuria (ABU). Different genes are polymorphic in patients prone to acute pyelonephritis or ABU, respectively, and yet discussions of UTI susceptibility in clinical practice still focus mainly on social and behavioral factors or dysfunctional voiding. Is it not time for UTIs to enter the era of molecular medicine? Defining why certain individuals are protected from UTI while others have severe, recurrent infections has long been difficult, but progress is now being made, encouraging new approaches to risk assessment and therapy in this large and important patient group, as well as revealing promising facets of 'good' versus 'bad' inflammation.

  12. Antimicrobial Peptides in Innate Immunity against Mycobacteria.

    Science.gov (United States)

    Shin, Dong-Min; Jo, Eun-Kyeong

    2011-10-01

    Antimicrobial peptides/proteins are ancient and naturallyoccurring antibiotics in innate immune responses in a variety of organisms. Additionally, these peptides have been recognized as important signaling molecules in regulation of both innate and adaptive immunity. During mycobacterial infection, antimicrobial peptides including cathelicidin, defensin, and hepcidin have antimicrobial activities against mycobacteria, making them promising candidates for future drug development. Additionally, antimicrobial peptides act as immunomodulators in infectious and inflammatory conditions. Multiple crucial functions of cathelicidins in antimycobacterial immune defense have been characterized not only in terms of direct killing of mycobacteria but also as innate immune regulators, i.e., in secretion of cytokines and chemokines, and mediating autophagy activation. Defensin families are also important during mycobacterial infection and contribute to antimycobacterial defense and inhibition of mycobacterial growth both in vitro and in vivo. Hepcidin, although its role in mycobacterial infection has not yet been characterized, exerts antimycobacterial effects in activated macrophages. The present review focuses on recent efforts to elucidate the roles of host defense peptides in innate immunity to mycobacteria.

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    respond to a series of proinflammatory stimuli and are able to sense different types of danger through expression of functional pattern recognition receptors, contributing to the onset of innate immune responses. In this context, PC not only secrete a variety of chemokines, but they also overexpress...... adhesion molecules such as ICAM-1 and VCAM-1 involved in the control of immune cell trafficking across vessel walls. In addition to their role in innate immunity, pericytes are involved in adaptive immunity. It has been reported that interaction with PC anergizes T cells, attributed, at least in part...

  14. Alphacoronavirus protein 7 modulates host innate immune response.

    Science.gov (United States)

    Cruz, Jazmina L G; Becares, Martina; Sola, Isabel; Oliveros, Juan Carlos; Enjuanes, Luis; Zúñiga, Sonia

    2013-09-01

    Innate immune response is the first line of antiviral defense resulting, in most cases, in pathogen clearance with minimal clinical consequences. Viruses have developed diverse strategies to subvert host defense mechanisms and increase their survival. In the transmissible gastroenteritis virus (TGEV) as a model, we previously reported that accessory gene 7 counteracts the host antiviral response by associating with the catalytic subunit of protein phosphatase 1 (PP1c). In the present work, the effect of the absence of gene 7 on the host cell, during infection, was further analyzed by transcriptomic analysis. The pattern of gene expression of cells infected with a recombinant mutant TGEV, lacking gene 7 expression (rTGEV-Δ7), was compared to that of cells infected with the parental virus (rTGEV-wt). Genes involved in the immune response, the interferon response, and inflammation were upregulated during TGEV infection in the absence of gene 7. An exacerbated innate immune response during infection with rTGEV-Δ7 virus was observed both in vitro and in vivo. An increase in macrophage recruitment and activation in lung tissues infected with rTGEV-Δ7 virus was observed compared to cells infected with the parental virus. In summary, the absence of protein 7 both in vitro and in vivo led to increased proinflammatory responses and acute tissue damage after infection. In a porcine animal model, which is immunologically similar to humans, we present a novel example of how viral proteins counteract host antiviral pathways to determine the infection outcome and pathogenesis.

  15. Role of innate immunity in neonatal infection.

    Science.gov (United States)

    Cuenca, Alex G; Wynn, James L; Moldawer, Lyle L; Levy, Ofer

    2013-02-01

    Newborns are at increased risk of infection due to genetic, epigenetic, and environmental factors. Herein we examine the roles of the neonatal innate immune system in host defense against bacterial and viral infections. Full-term newborns express a distinct innate immune system biased toward T(H)2-/T(H)17-polarizing and anti-inflammatory cytokine production with relative impairment in T(H)1-polarizing cytokine production that leaves them particularly vulnerable to infection with intracellular pathogens. In addition to these distinct features, preterm newborns also have fragile skin, impaired T(H)17-polarizing cytokine production, and deficient expression of complement and of antimicrobial proteins and peptides (APPs) that likely contribute to susceptibility to pyogenic bacteria. Ongoing research is identifying APPs, including bacterial/permeability-increasing protein and lactoferrin, as well as pattern recognition receptor agonists that may serve to enhance protective newborn and infant immune responses as stand-alone immune response modifiers or vaccine adjuvants.

  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 o

  17. History of Innate Immunity in Neurodegenerative Disorders

    Directory of Open Access Journals (Sweden)

    Patrick eMcGeer

    2011-12-01

    Full Text Available The foundations of innate immunity in neurodegenerative disorders were first laid by Hortega in 1919. He identified and named microglia, recognizing them as cells of mesodermal origin. Van Furth in 1969 elaborated the monocyte phagocytic system with microglia as the brain representatives. Validation of these concepts did not occur until 1987 when HLA-DR was identified on activated microglia in a spectrum of neurological disorders. HLA-DR had already been established as a definitive marker of immunocompetent cells of mesodermal origin. It was soon determined that the observed inflammatory reaction was an innate immune response. A rapid expansion of the field took place as other markers of an innate immune response were found that were made by neurons, astrocytes, oligodendroglia and endothelial cells. The molecules included complement proteins and their regulators, inflammatory cytokines, chemokines, acute phase reactants, prostaglandins, proteases, protease inhibitors, coagulation factors, fibrinolytic factors, anaphylotoxins, integrins, free radical generators, and other unidentified neurotoxins. The Nimmerjahn movies demonstrated that resting microglia were constantly active, sampling the surround and responding rapidly to brain damage. Ways of reducing the neurotoxic innate immune response and stimulating a healing response continue to be sought as a means for ameliorating the pathology in a spectrum of chronic degenerative disorders.

  18. Innate immune functions in kidney transplantation

    NARCIS (Netherlands)

    Berger, Stefan Philip

    2009-01-01

    The innate immune system plays an important role in solid organ transplantation. This thesis focuses on the role of the lectin pathway of complement activation in kidney and simultaneous pancreas-kidney transplantation (SPKT) and describes the role of properdin in tubular complement activation and c

  19. Chitin modulates innate immune responses of keratinocytes.

    Directory of Open Access Journals (Sweden)

    Barbara Koller

    Full Text Available BACKGROUND: Chitin, after cellulose the second most abundant polysaccharide in nature, is an essential component of exoskeletons of crabs, shrimps and insects and protects these organisms from harsh conditions in their environment. Unexpectedly, chitin has been found to activate innate immune cells and to elicit murine airway inflammation. The skin represents the outer barrier of the human host defense and is in frequent contact with chitin-bearing organisms, such as house-dust mites or flies. The effects of chitin on keratinocytes, however, are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We hypothesized that chitin stimulates keratinocytes and thereby modulates the innate immune response of the skin. Here we show that chitin is bioactive on primary and immortalized keratinocytes by triggering production of pro-inflammatory cytokines and chemokines. Chitin stimulation further induced the expression of the Toll-like receptor (TLR TLR4 on keratinocytes at mRNA and protein level. Chitin-induced effects were mainly abrogated when TLR2 was blocked, suggesting that TLR2 senses chitin on keratinocytes. CONCLUSIONS/SIGNIFICANCE: We speculate that chitin-bearing organisms modulate the innate immune response towards pathogens by upregulating secretion of cytokines and chemokines and expression of MyD88-associated TLRs, two major components of innate immunity. The clinical relevance of this mechanism remains to be defined.

  20. 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.

  1. Nuclear Trafficking During Plant Innate Immunity

    Institute of Scientific and Technical Information of China (English)

    Jun Liu; Gitta Coaker

    2008-01-01

    Land plants possess innate immune systems that can control resistance against pathogen infection. Conceptually, there are two branches of the plant innate immune system. One branch recognizes conserved features of microbial pathogens, while a second branch specifically detects the presence of pathogen effector proteins by plant resistance (R) genes. Innate immunity controlled by plant R genes is called effector-triggered immunity. Although R genes can recognize all classes of plant pathogens, the majority can be grouped into one large family, encoding proteins with a nucleotide binding site and C-terminal leucine rich repeat domains. Despite the importance and number of R genes present in plants, we are just beginning to decipher the signaling events required to initiate defense responses. Recent exciting discoveries have implicated dynamic nuclear trafficking of plant R proteins to achieve effector-triggered immunity. Furthermore, there are several additional lines of evidence implicating nucleo-cyctoplasmic trafficking in plant disease resistance, as mutations in nucleoporins and importins can compromise resistance signaling. Taken together, these data illustrate the importance of nuclear trafficking in the manifestation of disease resistance mediated by R genes.

  2. Innate immunity in inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The human intestinal tract is home to an enormous bacterial flora. The host defense against microorganisms can be divided into innate and adaptive immunity. The former is the most immediate line of response to immunologic challenges presented by bacteria, viruses, and fungi. The mucosal immune system has evolved to balance the need to respond to pathogens while co-existing with commensal bacteria and food antigens. In inflammatory bowel disease (IBD), this hyporesponsiveness or tolerance breaks-down and inflammation supervenes driven by the intestinal microbial flora. Bacteria contain compounds and are recognized by a variety of receptors, including Toll-like receptors (TLRs) and NODs (a family of intracellular bacterial sensors) and are potent stimuli of innate immune responses. Several mutations in these receptors have been associated with development of IBD.

  3. Heat Shock Protein and Innate Immunity

    Institute of Scientific and Technical Information of China (English)

    Min-FuTsan; BaochongGao

    2004-01-01

    In addition to serving as molecular chaperones, heat shock proteins (HSPs) have been implicated in autoimmune diseases, antigen presentation and tumor immunity. Extensive work in the last 10 years has also suggested that HSPs such as Hsp60, Hsp70, Hsp90 and gp96, may be potent activators of the innate immune system capable of inducing the production of pro-inflammatory cytokines by the monocyte-macrophage system, and the activation and maturation of dendritic cells via the Toll-like receptor 2 and 4 signal transduction pathways. However, recent evidence suggests that the reported cytokine effects of HSPs may be a result of the contaminating bacterial cell-wall products. This concise review summarizes the current controversy over the role of HSPs in innate immunity. Cellular & Molecular Immunology.

  4. Heat Shock Protein and Innate Immunity

    Institute of Scientific and Technical Information of China (English)

    Min-Fu Tsan; Baochong Gao

    2004-01-01

    In addition to serving as molecular chaperones, heat shock proteins (HSPs) have been implicated in autoimmune diseases, antigen presentation and tumor immunity. Extensive work in the last 10 years has also suggested that HSPs such as Hsp60, Hsp70, Hsp90 and gp96, may be potent activators of the innate immune system capable of inducing the production of pro-inflammatory cytokines by the monocyte-macrophage system, and the activation and maturation of dendritic cells via the Toll-like receptor 2 and 4 signal transduction pathways. However, recent evidence suggests that the reported cytokine effects of HSPs may be a result of the contaminating bacterial cell-wall products. This concise review summarizes the current controversy over the role of HSPs in innate immunity.

  5. Two separate mechanisms of enforced viral replication balance innate and adaptive immune activation.

    Science.gov (United States)

    Shaabani, Namir; Khairnar, Vishal; Duhan, Vikas; Zhou, Fan; Tur, Rita Ferrer; Häussinger, Dieter; Recher, Mike; Tumanov, Alexei V; Hardt, Cornelia; Pinschewer, Daniel; Christen, Urs; Lang, Philipp A; Honke, Nadine; Lang, Karl S

    2016-02-01

    The induction of innate and adaptive immunity is essential for controlling viral infections. Limited or overwhelming innate immunity can negatively impair the adaptive immune response. Therefore, balancing innate immunity separately from activating the adaptive immune response would result in a better antiviral immune response. Recently, we demonstrated that Usp18-dependent replication of virus in secondary lymphatic organs contributes to activation of the innate and adaptive immune responses. Whether specific mechanisms can balance innate and adaptive immunity separately remains unknown. In this study, using lymphocytic choriomeningitis virus (LCMV) and replication-deficient single-cycle LCMV vectors, we found that viral replication of the initial inoculum is essential for activating virus-specific CD8(+) T cells. In contrast, extracellular distribution of virus along the splenic conduits is necessary for inducing systemic levels of type I interferon (IFN-I). Although enforced virus replication is driven primarily by Usp18, B cell-derived lymphotoxin beta contributes to the extracellular distribution of virus along the splenic conduits. Therefore, lymphotoxin beta regulates IFN-I induction independently of CD8(+) T-cell activity. We found that two separate mechanisms act together in the spleen to guarantee amplification of virus during infection, thereby balancing the activation of the innate and adaptive immune system.

  6. Natural innate and adaptive immunity to cancer.

    Science.gov (United States)

    Vesely, Matthew D; Kershaw, Michael H; Schreiber, Robert D; Smyth, Mark J

    2011-01-01

    The immune system can identify and destroy nascent tumor cells in a process termed cancer immunosurveillance, which functions as an important defense against cancer. Recently, data obtained from numerous investigations in mouse models of cancer and in humans with cancer offer compelling evidence that particular innate and adaptive immune cell types, effector molecules, and pathways can sometimes collectively function as extrinsic tumor-suppressor mechanisms. However, the immune system can also promote tumor progression. Together, the dual host-protective and tumor-promoting actions of immunity are referred to as cancer immunoediting. In this review, we discuss the current experimental and human clinical data supporting a cancer immunoediting process that provide the fundamental basis for further study of immunity to cancer and for the rational design of immunotherapies against cancer.

  7. Inhibition of pyrimidine biosynthesis pathway suppresses viral growth through innate immunity.

    Directory of Open Access Journals (Sweden)

    Marianne Lucas-Hourani

    Full Text Available Searching for stimulators of the innate antiviral response is an appealing approach to develop novel therapeutics against viral infections. Here, we established a cell-based reporter assay to identify compounds stimulating expression of interferon-inducible antiviral genes. DD264 was selected out of 41,353 compounds for both its immuno-stimulatory and antiviral properties. While searching for its mode of action, we identified DD264 as an inhibitor of pyrimidine biosynthesis pathway. This metabolic pathway was recently identified as a prime target of broad-spectrum antiviral molecules, but our data unraveled a yet unsuspected link with innate immunity. Indeed, we showed that DD264 or brequinar, a well-known inhibitor of pyrimidine biosynthesis pathway, both enhanced the expression of antiviral genes in human cells. Furthermore, antiviral activity of DD264 or brequinar was found strictly dependent on cellular gene transcription, nuclear export machinery, and required IRF1 transcription factor. In conclusion, the antiviral property of pyrimidine biosynthesis inhibitors is not a direct consequence of pyrimidine deprivation on the virus machinery, but rather involves the induction of cellular immune response.

  8. The Imd pathway is involved in antiviral immune responses in Drosophila.

    Directory of Open Access Journals (Sweden)

    Alexandre Costa

    Full Text Available Cricket Paralysis virus (CrPV is a member of the Dicistroviridae family of RNA viruses, which infect a broad range of insect hosts, including the fruit fly Drosophila melanogaster. Drosophila has emerged as an effective system for studying innate immunity because of its powerful genetic techniques and the high degree of gene and pathway conservation. Intra-abdominal injection of CrPV into adult flies causes a lethal infection that provides a robust assay for the identification of mutants with altered sensitivity to viral infection. To gain insight into the interactions between viruses and the innate immune system, we injected wild type flies with CrPV and observed that antimicrobial peptides (AMPs were not induced and hemocytes were depleted in the course of infection. To investigate the contribution of conserved immune signaling pathways to antiviral innate immune responses, CrPV was injected into isogenic mutants of the Immune Deficiency (Imd pathway, which resembles the mammalian Tumor Necrosis Factor Receptor (TNFR pathway. Loss-of-function mutations in several Imd pathway genes displayed increased sensitivity to CrPV infection and higher CrPV loads. Our data show that antiviral innate immune responses in flies infected with CrPV depend upon hemocytes and signaling through the Imd pathway.

  9. Comparative proteomic analysis of growth hormone secretagogue A233 treatment of murine macrophage cells J774A.2 indicates it has a role in antiviral innate response

    Directory of Open Access Journals (Sweden)

    Rebeca Martínez

    2016-03-01

    General Significance: The increase of IFN-γ level and the differential modulation of antiviral proteins by the A233 peptide suggest that the molecule could activate an innate immune response with a possible further impact in the treatment of acute and chronic diseases.

  10. Innate immune responses of salmonid fish to viral infections.

    Science.gov (United States)

    Collet, Bertrand

    2014-04-01

    Viruses are the most serious pathogenic threat to the production of the main aquacultured salmonid species the rainbow trout Oncorhynchus mykiss and the Atlantic salmon Salmo salar. The viral diseases Infectious Pancreatic Necrosis (IPN), Pancreatic Disease (PD), Infectious Haemorrhagic Necrosis (IHN), Viral Haemorrhagic Septicaemia (VHS), and Infectious Salmon Anaemia (ISA) cause massive economic losses to the global salmonid aquaculture industry every year. To date, no solution exists to treat livestock affected by a viral disease and only a small number of efficient vaccines are available to prevent infection. As a consequence, understanding the host immune response against viruses in these fish species is critical to develop prophylactic and preventive control measures. The innate immune response represents an important part of the host defence mechanism preventing viral replication after infection. It is a fast acting response designed to inhibit virus propagation immediately within the host, allowing for the adaptive specific immunity to develop. It has cellular and humoral components which act in synergy. This review will cover inflammation responses, the cell types involved, apoptosis, antimicrobial peptides. Particular attention will be given to the type I interferon system as the major player in the innate antiviral defence mechanism of salmonids. Viral evasion strategies will also be discussed.

  11. Innate immune evasion by hepatitis C virus and West Nile virus

    Science.gov (United States)

    Keller, Brian C; Johnson, Cynthia L.; Erickson, Andrea Kaup; Gale, Michael

    2009-01-01

    Antiviral immunity in mammals involves several levels of surveillance and effector actions by host factors to detect viral pathogens, trigger α/β interferon production, and to mediate innate defenses within infected cells. Our studies have focused on understanding how these processes are regulated during infection by hepatitis C virus (HCV) and West Nile virus (WNV). Both viruses are members of the Flaviviridae and are human pathogens but they each mediate a very different disease and course of infection. Our results demonstrate common and unique innate immune interactions of each virus that govern antiviral immunity, and demonstrate the central role of α/β interferon immune defenses in controlling the outcome of infection. PMID:17702639

  12. Heme on innate immunity and inflammation

    Directory of Open Access Journals (Sweden)

    Fabianno Ferreira Dutra

    2014-05-01

    Full Text Available Heme is an essential molecule expressed ubiquitously all through our tissues. Heme plays major functions in cellular physiology and metabolism as the prostetic group of diverse proteins. Once released from cells and from hemeproteins free heme causes oxidative damage and inflammation, thus acting as a prototypic damage-associated molecular pattern. In this context, free heme is a critical component of the pathological process of sterile and infectious hemolytic conditions including malaria, hemolytic anemias, ischemia-reperfusion and hemorrhage. The plasma scavanger proteins hemopexin and albumin reduce heme toxicity and are responsible for transporting free heme to intracellular compartments where it is catabolized by heme-oxygenase enzymes. Upon hemolysis or severe cellular damage the serum capacity to scavange heme may saturate and increase free heme to sufficient amounts to cause tissue damage in various organs. The mechanism by which heme causes reactive oxygen generation, activation of cells of the innate immune system and cell death are not fully understood. Although heme can directly promote lipid peroxidation by its iron atom, heme can also induce ROS generation and production of inflammatory mediators through the activation of selective signaling pathways. Heme activates innate immune cells such as macrophages and neutrophils through activation of innate immune receptors. The importance of these events has been demonstrated in infectious and non-infectious diseases models. In this review we will discuss the mechanisms behind heme-induced citotoxicity and inflammation and the consequences of these events on different tissues and diseases.

  13. The E3-ligase TRIM family of proteins regulates signaling pathways triggered by innate immune pattern-recognition receptors.

    Science.gov (United States)

    Versteeg, Gijs A; Rajsbaum, Ricardo; Sánchez-Aparicio, Maria Teresa; Maestre, Ana M; Valdiviezo, Julio; Shi, Mude; Inn, Kyung-Soo; Fernandez-Sesma, Ana; Jung, Jae; García-Sastre, Adolfo

    2013-02-21

    Innate immunity conferred by the type I interferon is critical for antiviral defense. To date only a limited number of tripartite motif (TRIM) proteins have been implicated in modulation of innate immunity and anti-microbial activity. Here we report the complementary DNA cloning and systematic analysis of all known 75 human TRIMs. We demonstrate that roughly half of the 75 TRIM-family members enhanced the innate immune response and that they do this at multiple levels in signaling pathways. Moreover, messenger RNA levels and localization of most of these TRIMs were found to be altered during viral infection, suggesting that their regulatory activities are highly controlled at both pre- and posttranscriptional levels. Taken together, our data demonstrate a very considerable dedication of this large protein family to the positive regulation of the antiviral response, which supports the notion that this family of proteins evolved as a component of innate immunity.

  14. Mitochondria-derived reactive oxygen species negatively regulates immune innate signaling pathways triggered by a DNA virus, but not by an RNA virus

    NARCIS (Netherlands)

    Gonzalez-Dosal, R.; Horan, K.A.; Paludan, S.R.

    2012-01-01

    Reactive oxygen species (ROS) are crucial secondary messengers of signaling pathways. Redox-dependent signaling events have been previously described in the innate immune response. However, the mechanism by which ROS modulates anti-viral innate immune signaling is not fully clarified. Here, we repor

  15. Innate immunity and primary biliary cirrhosis.

    Science.gov (United States)

    Selmi, Carlo; Lleo, Ana; Pasini, Simone; Zuin, Massimo; Gershwin, M Eric

    2009-02-01

    There has been a rapid growth in our understanding of the molecular bases of primary biliary cirrhosis (PBC). These efforts were initiated when the immunodominant mitochondrial autoantigen was cloned and sequenced. Using the recombinant cloned antigen as a tool, research has focused on the effector mechanisms of disease and the uniqueness of the primary target tissue, the intrahepatic bile ducts. Most recently, there have been experimental data suggesting that innate immunity changes may be critical to the initiation and perpetuation of the autoimmune injury, as in the case of the enhanced response of monocytes and memory B cells to infectious stimulation and environmental mimics. These observations are important as they help fill in the many gaps which remain on the most difficult subject of autoimmunity, etiology. Indeed, based on the available data, several experimental models of PBC have been developed. These models illustrate and suggest that PBC can be initiated by several mechanisms, all of which lead to loss of tolerance to the mitochondrial antigens. However, once this adaptive response develops, it appears that much of the subsequent pathology is exacerbated by innate responses. We suggest that future therapeutic efforts in PBC will depend heavily on understanding the nature of this innate immune responses and methodology to blunt their cytotoxicity.

  16. 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.

  17. Interactions between Innate Immunity, Microbiota, and Probiotics

    Directory of Open Access Journals (Sweden)

    GianMarco Giorgetti

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  19. MAP Kinase Cascades in Plant Innate Immunity

    Directory of Open Access Journals (Sweden)

    Magnus Wohlfahrt Rasmussen

    2012-07-01

    Full Text Available 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 (PRRs which trigger MAPK-dependent innate immune responses. In the model Arabidopsis, molecular genetic evidence implicates a number of MAPK cascade components in PAMP signaling, and in responses to immunity-related phytohormones such as ethylene, jasmonate and salicylate. In a few cases, cascade components have been directly linked to the transcription of target genes or to the regulation of phytohormone synthesis. Thus MAPKs are obvious targets for bacterial effector proteins and are likely guardees of resistance (R proteins, which mediate defense signaling in response to the action of effectors, or effector-triggered immunity (ETI. This mini-review discusses recent progress in this field with a focus on the Arabidopsis MAPKs MPK3, 4, 6 and 11 in their apparent pathways.

  20. Innate immune cells in the pathogenesis of primary systemic vasculitis.

    Science.gov (United States)

    Misra, Durga Prasanna; Agarwal, Vikas

    2016-02-01

    Innate immune system forms the first line of defense against foreign substances. Neutrophils, eosinophils, erythrocytes, platelets, monocytes, macrophages, dendritic cells, γδ T cells, natural killer and natural killer T cells comprise the innate immune system. Genetic polymorphisms influencing the activation of innate immune cells predispose to development of vasculitis and influence its severity. Abnormally activated innate immune cells cross-talk with other cells of the innate immune system, present antigens more efficiently and activate T and B lymphocytes and cause tissue destruction via cell-mediated cytotoxicity and release of pro-inflammatory cytokines. These secreted cytokines further recruit other cells to the sites of vascular injury. They are involved in both the initiation as well as the perpetuation of vasculitis. Evidences suggest reversal of aberrant activation of immune cells in response to therapy. Understanding the role of innate immune cells in vasculitis helps understand the potential of therapeutic modulation of their activation to treat vasculitis.

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

    Science.gov (United States)

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

    2016-12-01

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

  2. 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

  3. Innate immunity evasion by Dengue virus.

    Science.gov (United States)

    Morrison, Juliet; Aguirre, Sebastian; Fernandez-Sesma, Ana

    2012-03-01

    For viruses to productively infect their hosts, they must evade or inhibit important elements of the innate immune system, namely the type I interferon (IFN) response, which negatively influences the subsequent development of antigen-specific adaptive immunity against those viruses. Dengue virus (DENV) can inhibit both type I IFN production and signaling in susceptible human cells, including dendritic cells (DCs). The NS2B3 protease complex of DENV functions as an antagonist of type I IFN production, and its proteolytic activity is necessary for this function. DENV also encodes proteins that antagonize type I IFN signaling, including NS2A, NS4A, NS4B and NS5 by targeting different components of this signaling pathway, such as STATs. Importantly, the ability of the NS5 protein to bind and degrade STAT2 contributes to the limited host tropism of DENV to humans and non-human primates. In this review, we will evaluate the contribution of innate immunity evasion by DENV to the pathogenesis and host tropism of this virus.

  4. Implication of PMLIV in both intrinsic and innate immunity.

    Directory of Open Access Journals (Sweden)

    Faten El Asmi

    2014-02-01

    Full Text Available PML/TRIM19, the organizer of nuclear bodies (NBs, has been implicated in the antiviral response to diverse RNA and DNA viruses. Several PML isoforms generated from a single PML gene by alternative splicing, share the same N-terminal region containing the RBCC/tripartite motif but differ in their C-terminal sequences. Recent studies of all the PML isoforms reveal the specific functions of each. The knockout of PML renders mice more sensitive to vesicular stomatitis virus (VSV. Here we report that among PML isoforms (PMLI to PMLVIIb, only PMLIII and PMLIV confer resistance to VSV. Unlike PMLIII, whose anti-VSV activity is IFN-independent, PMLIV can act at two stages: it confers viral resistance directly in an IFN-independent manner and also specifically enhances IFN-β production via a higher activation of IRF3, thus protecting yet uninfected cells from oncoming infection. PMLIV SUMOylation is required for both activities. This demonstrates for the first time that PMLIV is implicated in innate immune response through enhanced IFN-β synthesis. Depletion of IRF3 further demonstrates the dual activity of PMLIV, since it abrogated PMLIV-induced IFN synthesis but not PMLIV-induced inhibition of viral proteins. Mechanistically, PMLIV enhances IFN-β synthesis by regulating the cellular distribution of Pin1 (peptidyl-prolyl cis/trans isomerase, inducing its recruitment to PML NBs where both proteins colocalize. The interaction of SUMOylated PMLIV with endogenous Pin1 and its recruitment within PML NBs prevents the degradation of activated IRF3, and thus potentiates IRF3-dependent production of IFN-β. Whereas the intrinsic antiviral activity of PMLIV is specific to VSV, its effect on IFN-β synthesis is much broader, since it affects a key actor of innate immune pathways. Our results show that, in addition to its intrinsic anti-VSV activity, PMLIV positively regulates IFN-β synthesis in response to different inducers, thus adding PML/TRIM19 to the

  5. Innate immunity in resistance to HIV infection.

    Science.gov (United States)

    Biasin, Mara; Clerici, Mario; Piacentini, Luca

    2010-11-01

    Resistance to human immunodeficiency virus (HIV) infection in subjects who do not seroconvert despite multiple exposures to the virus and to the progression to AIDS in HIV‐infected individuals depends on multiple factors involving both the innate and the adaptive immune system. The contribution of natural immunity in preventing HIV infection has so far received little attention, but many recently published articles suggest a key role for Toll‐like receptors, natural killer cells, interleukin‐22, acute‐phase amyloid A protein, and APOBEC3G in conferring resistance to HIV infection. The study of these factors will shed light on HIV pathogenesis and contribute to the development of new therapeutic approaches to this elusive disease.

  6. Ocular Surface as Barrier of Innate Immunity

    Science.gov (United States)

    Bolaños-Jiménez, Rodrigo; Navas, Alejandro; López-Lizárraga, Erika Paulina; de Ribot, Francesc March; Peña, Alexandra; Graue-Hernández, Enrique O; Garfias, Yonathan

    2015-01-01

    Sight is one of the most important senses that human beings possess. The ocular system is a complex structure equipped with mechanisms that prevent or limit damage caused by physical, chemical, infectious and environmental factors. These mechanisms include a series of anatomical, cellular and humoral factors that have been a matter of study. The cornea is not only the most powerful and important lens of the optical system, but also, it has been involved in many other physiological and pathological processes apart from its refractive nature; the morphological and histological properties of the cornea have been thoroughly studied for the last fifty years; drawing attention in its molecular characteristics of immune response. This paper will review the anatomical and physiological aspects of the cornea, conjunctiva and lacrimal apparatus, as well as the innate immunity at the ocular surface. PMID:26161163

  7. Impaired innate, humoral, and cellular immunity despite a take in smallpox vaccine recipients.

    Science.gov (United States)

    Kennedy, Richard B; Poland, Gregory A; Ovsyannikova, Inna G; Oberg, Ann L; Asmann, Yan W; Grill, Diane E; Vierkant, Robert A; Jacobson, Robert M

    2016-06-14

    Smallpox vaccine is highly effective, inducing protective immunity to smallpox and diseases caused by related orthopoxviruses. Smallpox vaccine efficacy was historically defined by the appearance of a lesion or "take" at the vaccine site, which leaves behind a characteristic scar. Both the take and scar are readily recognizable and were used during the eradication effort to indicate successful vaccination and to categorize individuals as "protected." However, the development of a typical vaccine take may not equate to the successful development of a robust, protective immune response. In this report, we examined two large (>1000) cohorts of recipients of either Dryvax(®) or ACAM2000 using a testing and replication study design and identified subgroups of individuals who had documented vaccine takes, but who failed to develop robust neutralizing antibody titers. Examination of these individuals revealed that they had suboptimal cellular immune responses as well. Further testing indicated these low responders had a diminished innate antiviral gene expression pattern (IFNA1, CXCL10, CXCL11, OASL) upon in vitro stimulation with vaccinia virus, perhaps indicative of a dysregulated innate response. Our results suggest that poor activation of innate antiviral pathways may result in suboptimal immune responses to the smallpox vaccine. These genes and pathways may serve as suitable targets for adjuvants in new attenuated smallpox vaccines and/or effective antiviral therapy targets against poxvirus infections.

  8. [Mechanisms underlying interferon-mediated host innate immunity during influenza A virus infection].

    Science.gov (United States)

    Chen, Chao; Chi, Xiaojuan; Bai, Qingling; Chen, Jilong

    2015-12-01

    Influenza A virus can create acute respiratory infection in humans and animals throughout the world, and it is still one of the major causes of morbidity and mortality in humans worldwide. Numerous studies have shown that influenza A virus infection induces rapidly host innate immune response. Influenza A virus triggers the activation of signaling pathways that are dependent on host pattern recognition receptors (PRRs) including toll like receptors (TLRs) and RIG-I like receptors (RLRs). Using a variety of regulatory mechanisms, these signaling pathways activate downstream transcript factors that control expression of various interferons and cytokines, such as type I and type III interferons. Thus, these interferons stimulate the transcript of relevant interferon-stimulated genes (ISGs) and expression of the antiviral proteins, which are critical components of host innate immunity. In this review, we will highlight the mechanisms by which influenza A virus infection induces the interferon-mediated host innate immunity.

  9. Integrative Genomics-Based Discovery of Novel Regulators of the Innate Antiviral Response

    NARCIS (Netherlands)

    Lee, R. van der; Feng, Q.; Langereis, M.A.; Horst, R. ter; Szklarczyk, R.J.; Netea, M.G.; Andeweg, A.C.; Kuppeveld, F.J.M. van; Huynen, M.A.

    2015-01-01

    The RIG-I-like receptor (RLR) pathway is essential for detecting cytosolic viral RNA to trigger the production of type I interferons (IFNalpha/beta) that initiate an innate antiviral response. Through systematic assessment of a wide variety of genomics data, we discovered 10 molecular signatures of

  10. Integrative Genomics-Based Discovery of Novel Regulators of the Innate Antiviral Response

    NARCIS (Netherlands)

    van der Lee, Robin; Feng, Qian; Langereis, Martijn A; Ter Horst, Rob; Szklarczyk, Radek; Netea, Mihai G; Andeweg, Arno C; van Kuppeveld, Frank J M; Huynen, Martijn A

    2015-01-01

    The RIG-I-like receptor (RLR) pathway is essential for detecting cytosolic viral RNA to trigger the production of type I interferons (IFNα/β) that initiate an innate antiviral response. Through systematic assessment of a wide variety of genomics data, we discovered 10 molecular signatures of known R

  11. Integrative Genomics-Based Discovery of Novel Regulators of the Innate Antiviral Response

    NARCIS (Netherlands)

    R. van der Lee (Robin); Q. Feng (Qian); M.A. Langereis (Martijn A.); R. ter Horst (Rob); R. Szklarczyk (Radek); M.G. Netea (Mihai); A.C. Andeweg (Arno); F.J.M. van Kuppeveld (Frank ); M. Huynen (Martijn)

    2015-01-01

    textabstractThe RIG-I-like receptor (RLR) pathway is essential for detecting cytosolic viral RNA to trigger the production of type I interferons (IFNα/β) that initiate an innate antiviral response. Through systematic assessment of a wide variety of genomics data, we discovered 10 molecular signature

  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. Mitochondrial reactive oxygen species modulate innate immune response to influenza A virus in human nasal epithelium.

    Science.gov (United States)

    Kim, Sujin; Kim, Min-Ji; Park, Do Yang; Chung, Hyo Jin; Kim, Chang-Hoon; Yoon, Joo-Heon; Kim, Hyun Jik

    2015-07-01

    The innate immune system of the nasal epithelium serves as a first line of defense against invading respiratory viruses including influenza A virus (IAV). Recently, it was verified that interferon (IFN)-related immune responses play a critical role in local antiviral innate immunity. Reactive oxygen species (ROS) generation by exogenous pathogens has also been demonstrated in respiratory epithelial cells and modulation of ROS has been reported to be important for respiratory virus-induced innate immune mechanisms. Passage-2 normal human nasal epithelial (NHNE) cells were inoculated with IAV (WS/33, H1N1) to assess the sources of IAV-induced ROS and the relationship between ROS and IFN-related innate immune responses. Both STAT1 and STAT2 phosphorylation and the mRNA levels of IFN-stimulated genes, including Mx1, 2,5-OAS1, IFIT1, and CXCL10, were induced after IAV infection up to three days post infection. Similarly, we observed that mitochondrial ROS generation increased maximally at 2 days after IAV infection. After suppression of mitochondrial ROS generation, IAV-induced phosphorylation of STAT and mRNA levels of IFN-stimulated genes were attenuated and actually, viral titers of IAV were significantly higher in cases with scavenging ROS. Our findings suggest that mitochondrial ROS might be responsible for controlling IAV infection and may be potential sources of ROS generation, which is required to initiate an innate immune response in NHNE cells.

  14. Innate Immune Activation in Primary HIV-1 Infection

    OpenAIRE

    Chang, J. Judy; Altfeld, Marcus

    2010-01-01

    There is growing evidence highlighting the role of the immune response during acute HIV-1 infection on the control or development of disease. The adaptive immune responses do not appear until after the HIV-1 infection is already well established and as such the role of the earlier and faster responding innate immunity needs to be more closely scrutinized. In particular, two aspects of the innate immunity with growing developments will be examined in this review; type I IFNs and NK cells. Both...

  15. Defensins: natural component of human innate immunity.

    Science.gov (United States)

    Jarczak, Justyna; Kościuczuk, Ewa M; Lisowski, Paweł; Strzałkowska, Nina; Jóźwik, Artur; Horbańczuk, Jarosław; Krzyżewski, Józef; Zwierzchowski, Lech; Bagnicka, Emilia

    2013-09-01

    The widespread use of antibiotics has contributed to a huge increase in the number of resistant bacteria. New classes of drugs are therefore being developed of which defensins are a potential source. Defensins are a group of antimicrobial peptides found in different living organisms, involved in the first line of defense in their innate immune response against pathogens. This review summarizes the results of studies of this family of human antimicrobial peptides (AMPs). There is a special emphasis on describing the entire group and individual peptides, history of their discovery, their functions and expression sites. The results of the recent studies on the use of the biologically active peptides in human medicine are also presented. The pharmaceutical potential of human defensins cannot be ignored, especially considering their strong antimicrobial activity and properties such as low molecular weight, reduced immunogenicity, broad activity spectrum and resistance to proteolysis, but there are still many challenges and questions regarding the possibilities of their practical application.

  16. Modulation of Antiviral Immunity by Heme Oxygenase-1.

    Science.gov (United States)

    Espinoza, Janyra A; González, Pablo A; Kalergis, Alexis M

    2017-03-01

    Heme oxygenase-1 (HO-1) is a stress-inducible, anti-inflammatory, and cytoprotective enzyme expressed in most cell types in the organism. Under several stress stimuli, HO-1 expression and activity is up-regulated to catalyze the rate-limiting enzymatic step of heme degradation into carbon monoxide, free iron, and biliverdin. Besides its effects on cell metabolism, HO-1 is also capable of modulating host innate and adaptive immune responses in response to sepsis, transplantation, and autoimmunity, and preventing oxidative damage associated with inflammation. In addition, recent studies have reported that HO-1 can exert a significant antiviral activity against a wide variety of viruses, including HIV, hepatitis C virus, hepatitis B virus, enterovirus 71, influenza virus, respiratory syncytial virus, dengue virus, and Ebola virus, among others. Herein, we address the current understanding of the functional significance of HO-1 against a variety of viruses and its potential as a therapeutic strategy to prevent and control viral infections. Furthermore, we review the most important features of the immunoregulatory functions for this enzyme.

  17. 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...... elicitors have, in recent years, been identified. Here, the current knowledge regarding bacterial elicitors of innate immunity in plants is presented...

  18. Innate immune pattern recognition: a cell biological perspective.

    Science.gov (United States)

    Brubaker, Sky W; Bonham, Kevin S; Zanoni, Ivan; Kagan, Jonathan C

    2015-01-01

    Receptors of the innate immune system detect conserved determinants of microbial and viral origin. Activation of these receptors initiates signaling events that culminate in an effective immune response. Recently, the view that innate immune signaling events rely on and operate within a complex cellular infrastructure has become an important framework for understanding the regulation of innate immunity. Compartmentalization within this infrastructure provides the cell with the ability to assign spatial information to microbial detection and regulate immune responses. Several cell biological processes play a role in the regulation of innate signaling responses; at the same time, innate signaling can engage cellular processes as a form of defense or to promote immunological memory. In this review, we highlight these aspects of cell biology in pattern-recognition receptor signaling by focusing on signals that originate from the cell surface, from endosomal compartments, and from within the cytosol.

  19. Attack, parry and riposte: molecular fencing between the innate immune system and human herpesviruses.

    Science.gov (United States)

    Le-Trilling, V T K; Trilling, M

    2015-07-01

    Once individuals acquire one of the eight human-pathogenic herpesviruses, the upcoming relationship is predefined to last lifelong. Despite the fact that acute phases of herpesviral replication are usually confined and controlled by a concerted action of all branches of the healthy immune system, sterile immunity is never reached. To accomplish this, herpesviruses evolved the unique ability to outlast episodes of efficient immunity in a dormant state called latency and a remarkable array of immune antagonists which counteract most (if not all) relevant aspects of intrinsic, innate and adaptive immune responses. Certain psychological and physiological conditions (such as stress, immuno-suppression or pregnancy) predispose for viral reactivation which can lead to recurrent disease and virus spread. One important pillar of immunity is the innate immune system. The leading cytokines of the innate immune response are interferons (IFN). IFNs reinforce intrinsic immunity, induce a cell-intrinsic antiviral state and recruit and orchestrate adaptive immunity. Consistently, individuals lacking a functional IFN system suffer from otherwise harmless opportunists and live-attenuated vaccines. The selective pressure elicited by IFNs drove herpesviruses to evolve numerous IFN antagonistic gene products. A molecular in-depth understanding of (herpes-) viral IFN antagonists might allow the design of novel antiviral drugs which reconstitute IFN responses by blocking the antagonistic function and thereby help the host to help himself. Additionally, virus mutants lacking immune evasins constitute promising candidates for vaccine viruses. Here we summarize the current knowledge on IFN antagonistic strategies of the eight human herpesviruses and try to decipher common strategies.

  20. Enhancing Cancer Immunotherapy Via Activation of Innate Immunity.

    Science.gov (United States)

    Goldberg, Jacob L; Sondel, Paul M

    2015-08-01

    Given recent technological advances and advances in our understanding of cancer, immunotherapy of cancer is being used with clear clinical benefit. The immunosuppression accompanying cancer itself, as well as with current cancer treatment with radiation or chemotherapy, impairs adaptive immune effectors to a greater extent than innate effector cells. In addition to being less suppressed, innate immune cells are capable of being enhanced via immune-stimulatory regimens. Most strategies being investigated to promote innate immune responses against cancer do not require complex, patient-specific, ex vivo cellular or molecular creation of therapeutic agents; thus they can, generally, be used as "off the shelf" therapeutics that could be administered by most cancer clinics. Successful applications of innate immunotherapy in the clinic have effectively targeted components of the innate immune response. Preclinical data demonstrate how initiation of innate immune responses can lead to subsequent adaptive long-term cancer immunity. We hypothesize that integration of innate immune activation strategies into combination therapies for cancer treatment will lead to more effective and long-term clinical benefit.

  1. Modulation of Innate Immune Signalling by Lipid-Mediated MAVS Transmembrane Domain Oligomerization.

    Directory of Open Access Journals (Sweden)

    Luis Nobre

    Full Text Available RIG-I-like receptors detect viral RNA in infected cells and promote oligomerization of the outer mitochondrial membrane protein MAVS to induce innate immunity to viral infection through type I interferon production. Mitochondrial reactive oxygen species (mROS have been shown to enhance anti-viral MAVS signalling, but the mechanisms have remained obscure. Using a biochemical oligomerization-reporter fused to the transmembrane domain of MAVS, we found that mROS inducers promoted lipid-dependent MAVS transmembrane domain oligomerization in the plane of the outer mitochondrial membrane. These events were mirrored by Sendai virus infection, which similarly induced lipid peroxidation and promoted lipid-dependent MAVS transmembrane domain oligomerization. Our observations point to a role for mROS-induced changes in lipid bilayer properties in modulating antiviral innate signalling by favouring the oligomerization of MAVS transmembrane domain in the outer-mitochondrial membrane.

  2. Crosstalk between innate and adaptive immunity inhepatitis B virus infection

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Hepatitis B virus (HBV) infection is a major public health problem worldwide. HBV is not directly cytotoxic toinfected hepatocytes; the clinical outcome of infectionresults from complicated interactions between the virusand the host immune system. In acute HBV infection,initiation of a broad, vigorous immune response is responsiblefor viral clearance and self-limited inflammatoryliver disease. Effective and coordinated innate andadaptive immune responses are critical for viral clearanceand the development of long-lasting immunity. Chronichepatitis B patients fail to mount efficient innate andadaptive immune responses to the virus. In particular,HBV-specific cytotoxic T cells, which are crucial for HBVclearance, are hyporesponsiveness to HBV infection.Accumulating experimental evidence obtained fromthe development of animal and cell line models hashighlighted the importance of innate immunity in theearly control of HBV spread. The virus has evolvedimmune escape strategies, with higher HBV loads andHBV protein concentrations associated with increasingimpairment of immune function. Therefore, treatmentof HBV infection requires inhibition of HBV replicationand protein expression to restore the suppressedhost immunity. Complicated interactions exist notonly between innate and adaptive responses, but alsoamong innate immune cells and different components ofadaptive responses. Improved insight into these complexinteractions are important in designing new therapeuticstrategies for the treatment HBV infection. In thisreview, we summarize the current knowledge regardingthe cross-talk between the innate and adaptive immuneresponses and among different immunocytes in HBVinfection.

  3. 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.

  4. The innate immune response to HIV-1: to sense or not to sense.

    Science.gov (United States)

    Landau, Nathaniel R

    2014-05-01

    The immune responses to viruses provide a means to quickly alert the host to the presence of an invader, activating a range of intrinsic and adaptive antiviral mechanisms. Several research groups have made advances in understanding the innate immune response to HIV-1, although their findings differ. Some investigators find that the virus slips under the radar of the pattern recognition receptors that sense viruses by co-opting host factors that restrict accessibility of the viral nucleic acids, while others find that the virus is sensed and activates a type-I interferon response. This article reviews the recent findings and discusses the similarities and differences.

  5. Neonatal plasmacytoid dendritic cells (pDCs display subset variation but can elicit potent anti-viral innate responses.

    Directory of Open Access Journals (Sweden)

    Xiaoming Zhang

    Full Text Available Neonates are highly susceptible to infectious diseases and defective antiviral pDC immune responses have been proposed to contribute to this phenomenon. Isolated cord blood pDCs innately responded to a variety of TLR7 and TLR9 dependent viruses, including influenza A virus (IAV, human immunodeficiency virus (HIV or herpes-simplex virus (HSV by efficiently producing IFN-α, TNF-α as well as chemokines. Interestingly, following activation by CpGA, but not viruses, cord pDCs tend to survive less efficiently. We found that a hallmark of pDCs in neonates is an extended CD2+pDCs compartment compared to adult pDCs without affecting the antiviral IFN-α response. Within CD2+pDCs, we identified a subpopulation expressing CD5 and responsible for IL-12p40 production, however this population is significantly decreased in cord blood compared to adult blood. Therefore, neonatal pDCs clearly display variation in phenotype and subset composition, but without major consequences for their antiviral responses.

  6. Estrogen receptors regulate innate immune cells and signaling pathways.

    Science.gov (United States)

    Kovats, Susan

    2015-04-01

    Humans show strong sex differences in immunity to infection and autoimmunity, suggesting sex hormones modulate immune responses. Indeed, receptors for estrogens (ERs) regulate cells and pathways in the innate and adaptive immune system, as well as immune cell development. ERs are ligand-dependent transcription factors that mediate long-range chromatin interactions and form complexes at gene regulatory elements, thus promoting epigenetic changes and transcription. ERs also participate in membrane-initiated steroid signaling to generate rapid responses. Estradiol and ER activity show profound dose- and context-dependent effects on innate immune signaling pathways and myeloid cell development. While estradiol most often promotes the production of type I interferon, innate pathways leading to pro-inflammatory cytokine production may be enhanced or dampened by ER activity. Regulation of innate immune cells and signaling by ERs may contribute to the reported sex differences in innate immune pathways. Here we review the recent literature and highlight several molecular mechanisms by which ERs regulate the development or functional responses of innate immune cells.

  7. Innate immunity in an in vitro murine blastocyst model using embryonic and trophoblast stem cells.

    Science.gov (United States)

    Aikawa, Hiroaki; Tamai, Miho; Mitamura, Keisuke; Itmainati, Fakhria; Barber, Glen N; Tagawa, Yoh-ichi

    2014-03-01

    The immune system has two broad components-innate and adaptive immunity. Adaptive immunity becomes established only after the onset of hematopoiesis, whereas the innate immune system may be actively protecting organisms from microbial invasion much earlier in development. Here, we address the question of whether the innate immune system functions in the early-stage embryo, i.e., the blastocyst. The innate immune system was studied by using in vitro blastocyst models, e.g., embryonic stem (ES) and trophoblast stem (TS) cell cultures. The expression of Toll-like receptors (TLR)-2, -3, and -5 could be detected in both ES and TS cells. The expression of interferon (IFN)-β was induced by the addition of polyinosinic:polycytidylic acid [poly(I:C)] in TS cells, but not ES cells, although TLR-3 was expressed at the same level in both cell types. In turn, ES cells responded to IFN-β exposure by expressing IFN-induced anti-viral genes, e.g., RNA-dependent protein kinase and 2', 5'-oligoadenylate synthetase (OAS). Neither a reduction in ES cell proliferation nor cell death in these cultures was observed after IFN-β stimulation. Furthermore, OAS1a expression was induced in ES/TS co-cultures after poly(I:C) stimulation, but was not induced when either cell type was cultured alone. In conclusion, TS cells react to poly(I:C) stimulation by producing IFN-β, which induces IFN-inducible genes in ES cells. This observation suggests that the trophectoderm, the outer layer of the blastocyst, may respond to viral infection, and then induce anti-viral gene expression via IFN-β signaling to the blastocyst inner cell mass.

  8. A tetrapod-like repertoire of innate immune receptors and effectors for coelacanths.

    Science.gov (United States)

    Boudinot, Pierre; Zou, Jun; Ota, Tatsuya; Buonocore, Francesco; Scapigliati, Giuseppe; Canapa, Adriana; Cannon, John; Litman, Gary; Hansen, John D

    2014-09-01

    The recent availability of both robust transcriptome and genome resources for coelacanth (Latimeria chalumnae) has led to unique discoveries for coelacanth immunity such as the lack of IgM, a central component of adaptive immunity. This study was designed to more precisely address the origins and evolution of gene families involved in the initial recognition and response to microbial pathogens, which effect innate immunity. Several multigene families involved in innate immunity are addressed, including: Toll-like receptors (TLRs), retinoic acid inducible gene 1 (RIG1)-like receptors (RLRs), the nucleotide-binding domain and leucine-rich repeat containing proteins (NLRs), diverse immunoglobulin domain-containing proteins (DICP) and modular domain immune-type receptors (MDIRs). Our analyses also include the tripartite motif-containing proteins (TRIM), which are involved in pathogen recognition as well as the positive regulation of antiviral immunity. Finally, this study addressed some of the downstream effectors of the antimicrobial response including IL-1 family members, type I and II interferons (IFN) and IFN-stimulated effectors (ISGs). Collectively, the genes and gene families in coelacanth that effect innate immune functions share characteristics both in content, structure and arrangement with those found in tetrapods but not in teleosts. The findings support the sister group relationship of coelacanth fish with tetrapods.

  9. A tetrapod-like repertoire of innate immune receptors and effectors for coelacanths

    Science.gov (United States)

    Boudinot, Pierre; Zou, Jun; Ota, Tatsuya; Buonocore, Francesco; Scapigliati, Giuseppe; Canapa, Adriana; Cannon, John; Litman, Gary; Hansen, John D.

    2014-01-01

    The recent availability of both robust transcriptome and genome resources for coelacanth (Latimeria chalumnae) has led to unique discoveries for coelacanth immunity such as the lack of IgM, a central component of adaptive immunity. This study was designed to more precisely address the origins and evolution of gene families involved in the initial recognition and response to microbial pathogens, which effect innate immunity. Several multigene families involved in innate immunity are addressed, including: Toll-like receptors (TLRs), retinoic acid inducible gene 1 (RIG1)-like receptors (RLRs), the nucleotide-binding domain and leucine-rich repeat containing proteins (NLRs), diverse immunoglobulin domain-containing proteins (DICP) and modular domain immune-type receptors (MDIRs). Our analyses also include the tripartite motif-containing proteins (TRIM), which are involved in pathogen recognition as well as the positive regulation of antiviral immunity. Finally, this study addressed some of the downstream effectors of the antimicrobial response including IL-1 family members, type I and II interferons (IFN) and IFN-stimulated effectors (ISGs). Collectively, the genes and gene families in coelacanth that effect innate immune functions share characteristics both in content, structure and arrangement with those found in tetrapods but not in teleosts. The findings support the sister group relationship of coelacanth fish with tetrapods.

  10. Innate immune activation in primary HIV-1 infection.

    Science.gov (United States)

    Chang, J Judy; Altfeld, Marcus

    2010-10-15

    There is growing evidence that highlights the role of the immune response during acute human immunodeficiency virus type 1 (HIV-1) infection in the control or development of disease. The adaptive immune responses do not appear until after HIV-1 infection is already well established, so the role of earlier and faster-responding innate immunity needs to be more closely scrutinized. In particular, 2 aspects of innate immunity for which there are growing research developments will be examined in this review: the actions of type I interferons and natural killer cells. These two components of the innate immune response contribute to viral control both by killing infected cells and by modulating other immune cells that develop. However, the role of interferon α in immune activation is a double-edged sword, causing recruitment of adaptive immune cells that can assist in viral control but concurrently contributing to immune activation-dependent disease progression. Understanding the complexity of how innate responses affect the outcome of HIV-1 infection will help in the development of vaccines that can use innate immunity to enhance viral control with minimal pathogenesis.

  11. Triggering receptor expressed on myeloid cells-1: New player in antiviral immunity?

    Directory of Open Access Journals (Sweden)

    Kelsey eRoe

    2014-11-01

    Full Text Available The triggering receptor expressed on myeloid cells (TREM family of protein receptors is quickly emerging as a critical regulator of a diverse array of cellular functions including amplification of inflammation. Although the ligand(s for TREMs have not yet been fully identified, circumstantial evidence indicates that danger- and pathogen-associated molecular patterns (DAMPs and PAMPs can induce cytokine production via TREM-1 activation. The discovery of novel functions of TREMs such as regulation of T cell proliferation and activation of antigen presenting cells suggests a larger role of TREM proteins in modulation of host immune responses to microbial pathogens such as bacteria and fungi. However, the significance of TREM signaling in innate immunity to virus infections and underlying mechanisms remains largely unclear. The nature and intensity of innate immune responses, specifically production of type I Interferon and inflammatory cytokines is a crucial event in dictating recovery versus adverse outcome of virus infections. In this review, we highlight the emerging roles of TREM-1, including synergy with classical pathogen recognition receptors. Based on the literature using viral PAMPs and other infectious disease models, we further discuss how TREM-1 may influence host-virus interactions and viral pathogenesis. A deeper conceptual understanding of the mechanisms associated with pathogenic and/or protective functions of TREM-1 in antiviral immunity is essential to develop novel therapeutic strategies for the control of virus infection by modulating innate immune signaling.

  12. Type I Interferon at the Interface of Antiviral Immunity and Immune Regulation: The Curious Case of HIV-1

    Directory of Open Access Journals (Sweden)

    Adriano Boasso

    2013-01-01

    Full Text Available Type I interferon (IFN-I play a critical role in the innate immune response against viral infections. They actively participate in antiviral immunity by inducing molecular mechanisms of viral restriction and by limiting the spread of the infection, but they also orchestrate the initial phases of the adaptive immune response and influence the quality of T cell immunity. During infection with the human immunodeficiency virus type 1 (HIV-1, the production of and response to IFN-I may be severely altered by the lymphotropic nature of the virus. In this review I consider the different aspects of virus sensing, IFN-I production, signalling, and effects on target cells, with a particular focus on the alterations observed following HIV-1 infection.

  13. 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.

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

    Directory of Open Access Journals (Sweden)

    Grimm Elizabeth

    2006-03-01

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

  15. Herpes simplex virus type 2 virion host shutoff protein suppresses innate dsRNA antiviral pathways in human vaginal epithelial cells.

    Science.gov (United States)

    Yao, Xiao-Dan; Rosenthal, Kenneth Lee

    2011-09-01

    Viruses that establish persistent infections have evolved numerous strategies to evade host innate antiviral responses. We functionally assessed the role of herpes simplex virus type 2 (HSV-2) virion host shutoff (vhs) protein on innate immune sensing pathways in human vaginal epithelial cells (VK2 ECs). Infection of cells with wild-type (WT) HSV-2 significantly decreased expression of innate immune sensors of viral infection, Toll-like receptor (TLR)2, TLR3, retinoic acid inducible gene I (RIG-I) and melanoma differentiation-associated gene 5 (Mda-5), relative to cells infected with a mutant that lacks vhs (vhsB) or mock-infected cells. Transfection with HSV-2 vhs similarly decreased expression of TLR2, TLR3, RIG-I and Mda-5, which was also confirmed in human embryonic kidney (HEK) 293 cells. vhsB infection of VK2 cells caused robust increases in the active form of interferon regulatory factor (IRF)3 and its translocation to the nucleus compared with the WT. Additionally, IRF3 activation by Sendai virus and polyinosinic : polycytidylic acid-induced stimulation of beta interferon (IFN-β) was significantly inhibited in vhs-transfected cells. Overall, our findings provide the first evidence that HSV-2 vhs plays roles in selectively inhibiting TLR3 and RIG-I/Mda-5, as well as TLR2-mediated antiviral pathways for sensing dsRNA and effectively suppresses IFN-β antiviral responses in human vaginal ECs.

  16. Neural regulation of innate and adaptive immunity in the gut

    NARCIS (Netherlands)

    Dhawan, S.

    2017-01-01

    This thesis investigates the role of neurotransmitters acetylcholine (ACh) and norepinephrine (NE), in modulating the innate and adaptive immune function in the intestine, during physiological and pathophysiological conditions. Furthermore, this thesis attempts to advance our current understanding o

  17. The Innate Immune-Related Genes in Catfish

    Directory of Open Access Journals (Sweden)

    Weidong Liu

    2012-11-01

    Full Text Available Catfish is one of the most important aquaculture species in America (as well as in Asia and Africa. In recent years, the production of catfish has suffered massive financial losses due to pathogen spread and breakouts. Innate immunity plays a crucial role in increasing resistance to pathogenic organisms and has generated increasing interest in the past few years. This review summarizes the current understanding of innate immune-related genes in catfish, including pattern recognition receptors, antimicrobial peptides, complements, lectins, cytokines, transferrin and gene expression profiling using microarrays and next generation sequencing technologies. This review will benefit the understanding of innate immune system in catfish and further efforts in studying the innate immune-related genes in fish.

  18. 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.

  19. Estrogen mediates innate and adaptive immune alterations to influenza infection in pregnant mice.

    Directory of Open Access Journals (Sweden)

    Michael A Pazos

    Full Text Available Pregnancy is a leading risk factor for severe complications during an influenza virus infection. Women infected during their second and third trimesters are at increased risk for severe cardiopulmonary complications, premature delivery, and death. Here, we establish a murine model of aerosolized influenza infection during pregnancy. We find significantly altered innate antiviral responses in pregnant mice, including decreased levels of IFN-β, IL-1α, and IFN-γ at early time points of infection. We also find reduced cytotoxic T cell activity and delayed viral clearance. We further demonstrate that pregnancy levels of the estrogen 17-β-estradiol are able to induce key anti-inflammatory phenotypes in immune responses to the virus independently of other hormones or pregnancy-related stressors. We conclude that elevated estrogen levels result in an attenuated anti-viral immune response, and that pregnancy-associated morbidities occur in the context of this anti-inflammatory phenotype.

  20. The nitric oxide pathway provides innate antiviral protection in conjunction with the type I interferon pathway in fibroblasts.

    Directory of Open Access Journals (Sweden)

    Devangi R Mehta

    Full Text Available The innate host response to virus infection is largely dominated by the production of type I interferon and interferon stimulated genes. In particular, fibroblasts respond robustly to viral infection and to recognition of viral signatures such as dsRNA with the rapid production of type I interferon; subsequently, fibroblasts are a key cell type in antiviral protection. We recently found, however, that primary fibroblasts deficient for the production of interferon, interferon stimulated genes, and other cytokines and chemokines mount a robust antiviral response against both DNA and RNA viruses following stimulation with dsRNA. Nitric oxide is a chemical compound with pleiotropic functions; its production by phagocytes in response to interferon-γ is associated with antimicrobial activity. Here we show that in response to dsRNA, nitric oxide is rapidly produced in primary fibroblasts. In the presence of an intact interferon system, nitric oxide plays a minor but significant role in antiviral protection. However, in the absence of an interferon system, nitric oxide is critical for the protection against DNA viruses. In primary fibroblasts, NF-κB and interferon regulatory factor 1 participate in the induction of inducible nitric oxide synthase expression, which subsequently produces nitric oxide. As large DNA viruses encode multiple and diverse immune modulators to disable the interferon system, it appears that the nitric oxide pathway serves as a secondary strategy to protect the host against viral infection in key cell types, such as fibroblasts, that largely rely on the type I interferon system for antiviral protection.

  1. Beyond empiricism: informing vaccine development through innate immunity research.

    Science.gov (United States)

    Levitz, Stuart M; Golenbock, Douglas T

    2012-03-16

    Although a great public heath success, vaccines provide suboptimal protection in some patient populations and are not available to protect against many infectious diseases. Insights from innate immunity research have led to a better understanding of how existing vaccines work and have informed vaccine development. New adjuvants and delivery systems are being designed based upon their capacity to stimulate innate immune sensors and target antigens to dendritic cells, the cells responsible for initiating adaptive immune responses. Incorporating these adjuvants and delivery systems in vaccines can beneficially alter the quantitative and qualitative nature of the adaptive immune response, resulting in enhanced protection.

  2. 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

    2017-01-01

    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. PMID:28333126

  3. MAP kinase cascades in Arabidopsis innate immunity

    DEFF Research Database (Denmark)

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

    2012-01-01

    Plant mitogen-activated protein kinase (MAPK) cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs) by host transmembrane pattern recognition receptors which trigger MAPK-dependent innate ...

  4. DMPD: TLR3 in antiviral immunity: key player or bystander? [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 16027039 TLR3 in antiviral immunity: key player or bystander? Schroder M, Bowie AG.... Trends Immunol. 2005 Sep;26(9):462-8. (.png) (.svg) (.html) (.csml) Show TLR3 in antiviral immunity: key pl...ayer or bystander? PubmedID 16027039 Title TLR3 in antiviral immunity: key player or bystander? Authors Schr

  5. Exploiting Mucosal Immunity for Antiviral Vaccines.

    Science.gov (United States)

    Iwasaki, Akiko

    2016-05-20

    Mucosal surfaces provide a remarkably effective barrier against potentially dangerous pathogens. Therefore, enhancing mucosal immunity through vaccines-strengthening that first line of defense-holds significant promise for reducing the burden of viral diseases. The large and varied class of viral pathogens, however, continues to present thorny challenges to vaccine development. Two primary difficulties exist: Viruses exhibit a stunning diversity of strategies for evading the host immune response, and even when we understand the nature of effective immune protection against a given virus, eliciting that protection is technically challenging. Only a few mucosal vaccines have surmounted these obstacles thus far. Recent developments, however, could greatly improve vaccine design. In this review, we first sketch out our understanding of mucosal immunity and then compare the herpes simplex virus, human immunodeficiency virus, and influenza virus to illustrate the distinct challenges of developing successful vaccines and to outline potential solutions.

  6. The Role of Cytokine PF4 in the Antiviral Immune Response of Shrimp

    Science.gov (United States)

    Chen, Yulei; Cao, Jiao; Zhang, Xiaobo

    2016-01-01

    During viral infection in vertebrates, cytokines play important roles in the host defense against the virus. However, the function of cytokines in invertebrates has not been well characterized. In this study, shrimp cytokines involved in viral infection were screened using a cytokine antibody microarray. The results showed that three cytokines, the Fas receptor (Fas), platelet factor 4 (PF4) and interleukin-22 (IL-22), were significantly upregulated in the white spot syndrome virus (WSSV)-challenged shrimp, suggesting that these cytokines played positive regulatory roles in the immune response of shrimp against the virus. Further experiments revealed that PF4 had positive effects on the antiviral immunity of shrimp by enhancing the shrimp phagocytic activity and inhibiting the apoptotic activity of virus-infected hemocytes. Therefore, our study presented a novel mechanism of cytokines in the innate immunity of invertebrates. PMID:27631372

  7. LSm14A Plays a Critical Role in Antiviral Immune Responses by Regulating MITA Level in a Cell-Specific Manner.

    Science.gov (United States)

    Liu, Tian-Tian; Yang, Qing; Li, Mi; Zhong, Bo; Ran, Yong; Liu, Li-Li; Yang, Yan; Wang, Yan-Yi; Shu, Hong-Bing

    2016-06-15

    Viral infection triggers induction of antiviral cytokines and effectors, which are critical mediators of innate antiviral immune response. It has been shown that the processing body-associated protein LSm14A is involved in the induction of antiviral cytokines in cell lines but in vivo evidence is lacking. By generating LSm14A-deficient mice, in this study, we show that LSm14A plays a critical and specific role in the induction of antiviral cytokines in dendritic cells (DCs) but not in macrophages and fibroblasts. Induction of antiviral cytokines triggered by the DNA viruses HSV-1 and murid herpesvirus 68 and the RNA virus vesicular stomatitis virus but not Sendai virus was impaired in Lsm14a(-/-) DCs, which is correlated to the functions of the adaptor protein MITA/STING in the antiviral signaling pathways. LSm14A deficiency specifically downregulated MITA/STING level in DCs by impairing its nuclear mRNA precursor processing and subsequently impaired antiviral innate and adaptive immune responses. Our findings reveal a nuclear mRNA precursor processing and cell-specific regulatory mechanism of antiviral immune responses.

  8. Innate Immune Signaling by, and Genetic Adjuvants for DNA Vaccination.

    Science.gov (United States)

    Kobiyama, Kouji; Jounai, Nao; Aoshi, Taiki; Tozuka, Miyuki; Takeshita, Fumihiko; Coban, Cevayir; Ishii, Ken J

    2013-01-01

    DNA vaccines can induce both humoral and cellular immune responses. Although some DNA vaccines are already licensed for infectious diseases in animals, they are not licensed for human use because the risk and benefit of DNA vaccines is still controversial. Indeed, in humans, the immunogenicity of DNA vaccines is lower than that of other traditional vaccines. To develop the use of DNA vaccines in the clinic, various approaches are in progress to enhance or improve the immunogenicity of DNA vaccines. Recent studies have shown that immunogenicity of DNA vaccines are regulated by innate immune responses via plasmid DNA recognition through the STING-TBK1 signaling cascade. Similarly, molecules that act as dsDNA sensors that activate innate immune responses through STING-TBK1 have been identified and used as genetic adjuvants to enhance DNA vaccine immunogenicity in mouse models. However, the mechanisms that induce innate immune responses by DNA vaccines are still unclear. In this review, we will discuss innate immune signaling upon DNA vaccination and genetic adjuvants of innate immune signaling molecules.

  9. Innate Immune Signaling by, Genetic Adjuvants for, DNA Vaccination

    Directory of Open Access Journals (Sweden)

    Kouji Kobiyama

    2013-07-01

    Full Text Available DNA vaccines can induce both humoral and cellular immune responses. Although some DNA vaccines are already licensed for infectious diseases in animals, they are not licensed for human use because the risk and benefit of DNA vaccines is still controversial. Indeed, in humans, the immunogenicity of DNA vaccines is lower than that of other traditional vaccines. To develop the use of DNA vaccines in the clinic, various approaches are in progress to enhance or improve the immunogenicity of DNA vaccines. Recent studies have shown that immunogenicity of DNA vaccines are regulated by innate immune responses via plasmid DNA recognition through the STING-TBK1 signaling cascade. Similarly, molecules that act as dsDNA sensors that activate innate immune responses through STING-TBK1 have been identified and used as genetic adjuvants to enhance DNA vaccine immunogenicity in mouse models. However, the mechanisms that induce innate immune responses by DNA vaccines are still unclear. In this review, we will discuss innate immune signaling upon DNA vaccination and genetic adjuvants of innate immune signaling molecules.

  10. Trained immunity: a memory for innate host defense

    NARCIS (Netherlands)

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

    2011-01-01

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

  11. 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 compone

  12. Neural regulation of innate and adaptive immunity in the gut

    OpenAIRE

    Dhawan, S.

    2017-01-01

    This thesis investigates the role of neurotransmitters acetylcholine (ACh) and norepinephrine (NE), in modulating the innate and adaptive immune function in the intestine, during physiological and pathophysiological conditions. Furthermore, this thesis attempts to advance our current understanding of the gut-brain immune axis, also known as the cholinergic anti-inflammatory pathway, coined largely due to the cholinergic nature of the vagus nerve.

  13. Relationships between innate immunity in bivalve molluscs and environmental pollution

    Directory of Open Access Journals (Sweden)

    MI Girón-Pérez

    2010-06-01

    Full Text Available The immune system of invertebrates, such as molluscs consists of innate mechanisms very effective against antigens commonly present in the environment. However, these defense strategies could be altered by pollutants. This review is focused mainly on the effect of metals, PCB, pesticides, PAHs, and others environmental pollutant on immune response of molluscs.

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

    Science.gov (United States)

    Suresh, Rahul; Mosser, David M.

    2013-01-01

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

  15. Innate immune responses to Helicobacter pylori infection: an overview.

    Science.gov (United States)

    Patel, Milan K; Trombly, Melanie I; Kurt-Jones, Evelyn A

    2012-01-01

    Innate immune receptors detect Helicobacter pylori infection and trigger downstream signaling events that result in the production of cytokines and interferon-β. This chapter gives an overview of the receptors and their roles in responding to H. pylori infection and details the downstream signaling events. The tools that have been developed to study the innate immune response to H. pylori are also discussed. Understanding the immune response to H. pylori is critical to develop better treatments for H. pylori-induced disease states including gastric malignancies and cancer.

  16. The innate immunity in the cnidarian Hydra vulgaris

    Directory of Open Access Journals (Sweden)

    B Altincicek

    2009-08-01

    Full Text Available Hydra vulgaris is currently receiving increased attention as a genetically tractable invertebrate model system for studying important processes of life such as the innate immune defense. Similar to complex animals, H. vulgaris polyps respond to injury by abrupt muscle contraction, by limited escape behavior, and by healing the damaged tissue. Simultaneously, cellular processes such as phagocytosis and programmed cell death as well as the massive production of antimicrobial peptides are induced. Recent studies identified several molecular pathways controlling these responses; however, the interdependence of innate immunity and, for example, regeneration and tissue remodeling is not well elucidated yet. H. vulgaris belongs to the Cnidaria representing the phylogenic sister group of bilaterian animals; hence, a better understanding of evolutionarily conserved as well as Hydra/Cnidaria-specific immune responses will provide deep insight into both origin and evolution of the animal innate immune system

  17. Innate immunity and chronic immune activation in HCV/HIV-1 co-infection.

    Science.gov (United States)

    Gonzalez, Veronica D; Landay, Alan L; Sandberg, Johan K

    2010-04-01

    Innate immune responses are critical in the defense against viral infections. NK cells, myeloid and plasmacytoid dendritic cells, and invariant CD1d-restricted NKT cells mediate both effector and regulatory functions in this early immune response. In chronic uncontrolled viral infections such as HCV and HIV-1, these essential immune functions are compromised and can become a double edged sword contributing to the immunopathogenesis of viral disease. In particular, recent findings indicate that innate immune responses play a central role in the chronic immune activation which is a primary driver of HIV-1 disease progression. HCV/HIV-1 co-infection is affecting millions of people and is associated with faster viral disease progression. Here, we review the role of innate immunity and chronic immune activation in HCV and HIV-1 infection, and discuss how mechanisms of innate immunity may influence protection as well as immunopathogenesis in the HCV/HIV-1 co-infected human host.

  18. Viral degradasome hijacks mitochondria to suppress innate immunity

    Institute of Scientific and Technical Information of China (English)

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

    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 importantfor the innate immune activation of the host,are also important for viral suppression of the innate immunity.

  19. Innate and adaptive immunity in inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Britta Siegmund; Martin Zeitz

    2011-01-01

    Inflammatory bowel diseases are the consequence of a dysregulated mucosal immune system. The mucosal immune system consists of two arms, innate and adaptive immunity, that have been studied separately for a long time. Functional studies from in vivo models of intestinal inflammation as well as results from genome-wide association studies strongly suggest a cross-regulation of both arms. The present review will illustrate this interaction by selecting examples from innate immunity and adaptive immunity, and their direct impact on each other. Broadening our view by focusing on the cross-regulated areas of the mucosal immune system will not only facilitate our understanding of disease, but furthermore will allow identification of future therapeutic targets.

  20. Innate and adaptive immunity in inflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    BrittaSiegmund; MartinZeitz

    2011-01-01

    Inflammatory bowel diseases are the consequence of a dysregulated mucosal immune system. The mucosal immune system consists of two arms, innate and adaptive immunity, that have been studied separately for a long time. Functional studies from in vivo models of intestinal inflammation as well as results from genome-wide association studies strongly suggest a crossregulation of both arms. The present review will illustrate this interaction by selecting examples from innate immunity and adaptive immunity, and their direct impact on each other. Broadening our view by focusing on the cross-regulated areas of the mucosal immune system will not only facilitate our understanding of disease, but furthermore will allow identification of future therapeutic targets.

  1. Heat Shock Proteins: Stimulators of Innate and Acquired Immunity

    Directory of Open Access Journals (Sweden)

    Camilo A. Colaco

    2013-01-01

    Full Text Available Adjuvants were reintroduced into modern immunology as the dirty little secret of immunologists by Janeway and thus began the molecular definition of innate immunity. It is now clear that the binding of pathogen-associated molecular patterns (PAMPs by pattern recognition receptors (PRRs on antigen presenting cells (APCs activates the innate immune response and provides the host with a rapid mechanism for detecting infection by pathogens and initiates adaptive immunity. Ironically, in addition to advancing the basic science of immunology, Janeway’s revelation on induction of the adaptive system has also spurred an era of rational vaccine design that exploits PRRs. Thus, defined PAMPs that bind to known PRRs are being specifically coupled to antigens to improve their immunogenicity. However, while PAMPs efficiently activate the innate immune response, they do not mediate the capture of antigen that is required to elicit the specific responses of the acquired immune system. Heat shock proteins (HSPs are molecular chaperones that are found complexed to client polypeptides and have been studied as potential cancer vaccines. In addition to binding PRRs and activating the innate immune response, HSPs have been shown to both induce the maturation of APCs and provide chaperoned polypeptides for specific triggering of the acquired immune response.

  2. Evolution of innate and adaptive immune systems in jawless vertebrates.

    Science.gov (United States)

    Kasamatsu, Jun

    2013-01-01

    Because jawless vertebrates are the most primitive vertebrates, they have been studied to gain understanding of the evolutionary processes that gave rise to the innate and adaptive immune systems in vertebrates. Jawless vertebrates have developed lymphocyte-like cells that morphologically resemble the T and B cells of jawed vertebrates, but they express variable lymphocyte receptors (VLRs) instead of the T and B cell receptors that specifically recognize antigens in jawed vertebrates. These VLRs act as antigen receptors, diversity being generated in their antigen-binding sites by assembly of highly diverse leucine-rich repeat modules. Therefore, jawless vertebrates have developed adaptive immune systems based on the VLRs. Although pattern recognition receptors, including Toll-like receptors (TLRs) and Rig-like receptors (RLRs), and their adaptor genes are conserved in jawless vertebrates, some transcription factor and inflammatory cytokine genes in the TLR and RLR pathways are not present. However, like jawed vertebrates, the initiation of adaptive immune responses in jawless vertebrates appears to require prior activation of the innate immune system. These observations imply that the innate immune systems of jawless vertebrates have a unique molecular basis that is distinct from that of jawed vertebrates. Altogether, although the molecular details of the innate and adaptive immune systems differ between jawless and jawed vertebrates, jawless vertebrates have developed versions of these immune systems that are similar to those of jawed vertebrates.

  3. Pattern recognition receptors and the innate immune response to viral infection.

    Science.gov (United States)

    Thompson, Mikayla R; Kaminski, John J; Kurt-Jones, Evelyn A; Fitzgerald, Katherine A

    2011-06-01

    The innate immune response to viral pathogens is critical in order to mobilize protective immunity. Cells of the innate immune system detect viral infection largely through germline-encoded pattern recognition receptors (PRRs) present either on the cell surface or within distinct intracellular compartments. These include the Toll-like receptors (TLRs), the retinoic acid-inducble gene I-like receptors (RLRs), the nucleotide oligomerization domain-like receptors (NLRs, also called NACHT, LRR and PYD domain proteins) and cytosolic DNA sensors. While in certain cases viral proteins are the trigger of these receptors, the predominant viral activators are nucleic acids. The presence of viral sensing PRRs in multiple cellular compartments allows innate cells to recognize and quickly respond to a broad range of viruses, which replicate in different cellular compartments. Here, we review the role of PRRs and associated signaling pathways in detecting viral pathogens in order to evoke production of interferons and cytokines. By highlighting recent progress in these areas, we hope to convey a greater understanding of how viruses activate PRR signaling and how this interaction shapes the anti-viral immune response.

  4. Pattern Recognition Receptors and the Innate Immune Response to Viral Infection

    Directory of Open Access Journals (Sweden)

    Katherine A. Fitzgerald

    2011-06-01

    Full Text Available The innate immune response to viral pathogens is critical in order to mobilize protective immunity. Cells of the innate immune system detect viral infection largely through germline-encoded pattern recognition receptors (PRRs present either on the cell surface or within distinct intracellular compartments. These include the Toll-like receptors (TLRs, the retinoic acid-inducble gene I-like receptors (RLRs, the nucleotide oligomerization domain-like receptors (NLRs, also called NACHT, LRR and PYD domain proteins and cytosolic DNA sensors. While in certain cases viral proteins are the trigger of these receptors, the predominant viral activators are nucleic acids. The presence of viral sensing PRRs in multiple cellular compartments allows innate cells to recognize and quickly respond to a broad range of viruses, which replicate in different cellular compartments. Here, we review the role of PRRs and associated signaling pathways in detecting viral pathogens in order to evoke production of interferons and cytokines. By highlighting recent progress in these areas, we hope to convey a greater understanding of how viruses activate PRR signaling and how this interaction shapes the anti-viral immune response.

  5. Hepatitis C Virus Evasion from RIG-I-Dependent Hepatic Innate Immunity

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    Helene Minyi Liu

    2010-01-01

    Full Text Available Exposure to hepatitis C virus (HCV usually results in persistent infection that often develops into chronic liver disease. Interferon-alpha (IFN treatment comprises the foundation of current approved therapy for chronic HCV infection but is limited in overall efficacy. IFN is a major effector of innate antiviral immunity and is naturally produced in response to viral infection when viral pathogen-associated molecular patterns (PAMPs are recognized as nonself and are bound by cellular pathogen recognition receptors (PRRs, including Toll-like receptors (TLRs and the RIG-I-like receptors (RLRs. Within hepatocytes, RIG-I is a major PRR of HCV infection wherein PAMP interactions serve to trigger intracellular signaling cascades in the infected hepatocyte to drive IFN production and the expression of interferon-stimulated genes (ISGs. ISGs function to limit virus replication, modulate the immune system, and to suppress virus spread. However, studies of HCV-host interactions have revealed several mechanisms of innate immune regulation and evasion that feature virus control of PRR signaling and regulation of hepatic innate immune programs that may provide a molecular basis for viral persistence.

  6. Innate immune responses to environmental allergens

    NARCIS (Netherlands)

    Kauffman, HF

    2006-01-01

    Aero-allergens, including plant pollens, house dust mite particles, fungal spores, and mycelium fragments, are continuously inhaled and deposited on the airway mucosa. These particles and their soluble components actively interact with innate recognition systems present in the mucosal layer (e.g., s

  7. 抗病毒天然免疫通路中IRF-3调控新机制%Regulation of Interferon Regulatory Factor-3 in Antiviral Innate Immune Response

    Institute of Scientific and Technical Information of China (English)

    刘殿波; 钱远宇; 张七斤; 陈忠斌

    2009-01-01

    干扰素调节因子-3(interferon regulatory factor-3,IRF-3)是IRF家族中重要转录因子之一,在调控干扰素(interferon,IFN)基因表达和抗病毒天然免疫反应中具有重要作用.最新发现的MITA(mediator of IRF-3 activation,又称STING/ERIS)蛋白是宿主抗病毒天然免疫反应中的一种重要调节分子.病毒侵染时,MITA与IRF-3相互作用,特异性激活IRF-3,并募集TANK结合激酶1(TANK binding kinase 1,TBK1)与IFN通路中的线粒体抗病毒信号蛋白MAVS(mitochondrial anti-viral signaling protein)形成复合物,且MITA可被TBK1磷酸化,诱导Ⅰ型IFN及IFN刺激基因(interferon stimulate genes,ISG)的表达,诱发抗病毒天然免疫反应.同时还发现,泛素连接酶RNF5(ring finger protein 5)可对MITA发生泛素化修饰从而抑制其对IRF-3活化,实现对宿主抗病毒天然免疫反应负调节作用.本室研究发现,严重性急性呼吸系统综合症冠状病毒(severe acute respiratory syndrome coronavirus,SARS-CoV)和人类新型冠状病毒(human coronavirus NL63,HCoV-NL63)的木瓜样蛋白酶(papain-like protease,PLP)利用其特有的去泛素化酶(deubiquitinase,DUB)活性,通过宿主细胞泛素-蛋白酶体信号系统对IRF-3的泛素化等翻译后修饰进行调节,从而成为该种病毒逃逸机体抗病毒防御系统主要手段之一.

  8. 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

  9. AID and APOBECs span the gap between innate and adaptive immunity

    Directory of Open Access Journals (Sweden)

    Arnaud eMoris

    2014-10-01

    Full Text Available The AID/APOBEC cytidine deaminases participate in a diversity of biological processes from the regulation of protein expression to embryonic development and host defenses. In its classical role, AID mutates germline-encoded sequences of B cell receptors, a key aspect of adaptive immunity, and APOBEC1, mutates apoprotein B pre-mRNA, yielding two isoforms important for cellular function and plasma lipid metabolism. Investigations over the last ten years have uncovered a role of the APOBEC superfamily in intrinsic immunity against viruses and innate immunity against viral infection by deamination and mutation of viral genomes. Further, discovery in the area of HIV infection revealed that the HIV viral infectivity factor (Vif protein interacted with APOBEC3G, targeting it for proteosomal degradation, overriding its antiviral function. More recently, our and others’ work have uncovered that the AID and APOBEC cytidine deaminase family members have an even more direct link between activity against viral infection and induction and shaping of adaptive immunity than previous thought, including that of antigen processing for cytotoxic T lymphocyte (CTL activity and natural killer (NK cell activation. Newly ascribed functions of these cytodine deaminases will be discussed, including their newly identified roles in adaptive immunity, epigenetic regulation, and cell differentiation. Herein this review we discuss AID and APOBEC cytodine deaminases as a link between innate and adaptive immunity uncovered by recent studies.

  10. Hepatic stellate cells and innate immunity in alcoholic liver disease

    Institute of Scientific and Technical Information of China (English)

    Yang-Gun Suh; Won-Il Jeong

    2011-01-01

    Constant alcohol consumption is a major cause of chronic liver disease, and there has been a growing concern regarding the increased mortality rates worldwide. Alcoholic liver diseases (ALDs) range from mild to more severe conditions, such as steatosis, steatohepatitis, fibrosis, cirrhosis, and hepatocellular carcinoma. The liver is enriched with innate immune cells (e.g. natural killer cells and Kupffer cells) and hepatic stellate cells (HSCs), and interestingly, emerging evidence suggests that innate immunity contributes to the development of ALDs (e.g. steatohepatitis and liver fibrosis). Indeed, HSCs play a crucial role in alcoholic steatosis via production of endocannabinoid and retinol metabolites. This review describes the roles of the innate immunity and HSCs in the pathogenesis of ALDs, and suggests therapeutic targets and strategies to assist in the reduction of ALD.

  11. Probiotics promote gut health through stimulation of epithelial innate immunity.

    Science.gov (United States)

    Pagnini, Cristiano; Saeed, Rubina; Bamias, Giorgos; Arseneau, Kristen O; Pizarro, Theresa T; Cominelli, Fabio

    2010-01-05

    Probiotic formulations are widely available and have a variety of proposed beneficial effects, including promotion of gut health. The mechanisms of action of probiotic bacteria in the intestine are still unclear but are generally attributed to an antiinflammatory effect. Here, we demonstrate that the multiple probiotic formulation VSL#3 prevents the onset of intestinal inflammation by local stimulation of epithelial innate immune responses (i.e., increased production of epithelial-derived TNF-alpha and restoration of epithelial barrier function in vivo). We also demonstrate that probiotic bacteria stimulate epithelial production of TNF-alpha and activate NF-kappaB in vitro. Our results support the hypothesis that probiotics promote gut health through stimulation, rather than suppression, of the innate immune system. Furthermore, our findings provide the perspective that defects in innate immunity may play a critical role in the pathogenesis and progression of intestinal disorders, such as inflammatory bowel disease.

  12. Is inflammaging an auto[innate]immunity subclinical syndrome?

    Directory of Open Access Journals (Sweden)

    Giunta Sergio

    2006-12-01

    Full Text Available Abstract The low-grade, chronic, systemic inflammatory state that characterizes the aging process (inflammaging results from late evolutive-based expression of the innate immune system. Inflammaging is characterized by the complex set of five conditions which can be described as 1. low-grade, 2. controlled, 3. asymptomatic, 4. chronic, 5. systemic, inflammatory state, and fits with the antagonistic pleiotropy theory on the evolution of aging postulating that senescence is the late deleterious effect of genes (pro-inflammatory versus anti-inflammatorythat are beneficial in early life. Evolutionary programming of the innate immune system may act via selection on these genetic traits. Here I propose that the already acquired knowledge in this field may pave the way to a new chapter in the pathophysiology of autoimmunity: the auto-innate-immunity syndromes. Indeed, differently from the well known chapter of conventional autoimmune diseases and syndromes where the main actor is the adaptive immunity, inflammaging may constitute the subclinical paradigm of a new chapter of autoimmunity, namely that arising from an autoimmune inflammatory response of the innate-immune-system, an old actor of immunity and yet a new actor of autoimmunity, also acting as a major determinant of elderly frailty and age-associated diseases.

  13. Innate immune responses in hepatitis B virus (HBV) infection.

    Science.gov (United States)

    Busca, Aurelia; Kumar, Ashok

    2014-02-07

    Hepatitis B virus (HBV) infection has a low rate of chronicity compared to HCV infection, but chronic liver inflammation can evolve to life threatening complications. Experimental data from HBV infected chimpanzees and HBV transgenic mice have indicated that cytotoxic T cells are the main cell type responsible for inhibition of viral replication, but also for hepatocyte lysis during chronic HBV infection. Their lower activation and impaired function in later stages of infection was suggested as a possible mechanism that allowed for low levels of viral replication. The lack of an interferon response in these models also indicated the importance of adaptive immunity in clearing the infection. Increased knowledge of the signalling pathways and pathogen associated molecular patterns that govern activation of innate immunity in the early stages of viral infections in general has led to a re-evaluation of the innate immune system in HBV infection. Numerous studies have shown that HBV employs active strategies to evade innate immune responses and induce immunosuppression. Some of the immune components targeted by HBV include dendritic cells, natural killer cells, T regulatory cells and signalling pathways of the interferon response. This review will present the current understanding of innate immunity in HBV infection and of the challenges associated with clearing of the HBV infection.

  14. 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.

  15. 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.

  16. The role of the innate immune system in granulomatous disorders

    Directory of Open Access Journals (Sweden)

    Helen Josephine Petersen

    2013-05-01

    Full Text Available The dynamic structure of the granuloma serves to protect the body from microbiological challenge. This organised aggregate of immune cells seeks to contain this challenge and protect against dissemination, giving host immune cells a chance to eradicate the threat. A number of systemic diseases are characterised by this specialised inflammatory process and granulomas have been shown to develop at multiple body sites and in various tissues. Central to this process is the macrophage and the arms of the innate immune response. This review seeks to explore how the innate immune response drives this inflammatory process in a contrast of diseases, particularly those with a component of immunodeficiency. By understanding the genes and inflammatory mechanisms behind this specialised immune response, will guide research in in the development of novel therapeutics to combat granulomatous diseases.

  17. Loss of CARD9-mediated innate activation attenuates severe influenza pneumonia without compromising host viral immunity.

    Science.gov (United States)

    Uematsu, Takayuki; Iizasa, Ei'ichi; Kobayashi, Noritada; Yoshida, Hiroki; Hara, Hiromitsu

    2015-12-02

    Influenza virus (IFV) infection is a common cause of severe viral pneumonia associated with acute respiratory distress syndrome (ARDS), which is difficult to control with general immunosuppressive therapy including corticosteroids due to the unfavorable effect on viral replication. Studies have suggested that the excessive activation of the innate immunity by IFV is responsible for severe pathologies. In this study, we focused on CARD9, a signaling adaptor known to regulate innate immune activation through multiple innate sensor proteins, and investigated its role in anti-IFV defense and lung pathogenesis in a mouse model recapitulating severe influenza pneumonia with ARDS. We found that influenza pneumonia was dramatically attenuated in Card9-deficient mice, which showed improved mortality with reduced inflammatory cytokines and chemokines in the infected lungs. However, viral clearance, type-I interferon production, and the development of anti-viral B and T cell immunity were not compromised by CARD9 deficiency. Syk or CARD9-deficient DCs but not macrophages showed impaired cytokine but not type-I interferon production in response to IFV in vitro, indicating a possible role for the Syk-CARD9 pathway in DCs in excessive inflammation of IFV-infected lungs. Therefore, inhibition of this pathway is an ideal therapeutic target for severe influenza pneumonia without affecting viral clearance.

  18. Association of the innate immunity and inflammation pathway with advanced prostate cancer risk.

    Directory of Open Access Journals (Sweden)

    Rémi Kazma

    Full Text Available Prostate cancer is the most frequent and second most lethal cancer in men in the United States. Innate immunity and inflammation may increase the risk of prostate cancer. To determine the role of innate immunity and inflammation in advanced prostate cancer, we investigated the association of 320 single nucleotide polymorphisms, located in 46 genes involved in this pathway, with disease risk using 494 cases with advanced disease and 536 controls from Cleveland, Ohio. Taken together, the whole pathway was associated with advanced prostate cancer risk (P = 0.02. Two sub-pathways (intracellular antiviral molecules and extracellular pattern recognition and four genes in these sub-pathways (TLR1, TLR6, OAS1, and OAS2 were nominally associated with advanced prostate cancer risk and harbor several SNPs nominally associated with advanced prostate cancer risk. Our results suggest that the innate immunity and inflammation pathway may play a modest role in the etiology of advanced prostate cancer through multiple small effects.

  19. Association of the innate immunity and inflammation pathway with advanced prostate cancer risk.

    Science.gov (United States)

    Kazma, Rémi; Mefford, Joel A; Cheng, Iona; Plummer, Sarah J; Levin, Albert M; Rybicki, Benjamin A; Casey, Graham; Witte, John S

    2012-01-01

    Prostate cancer is the most frequent and second most lethal cancer in men in the United States. Innate immunity and inflammation may increase the risk of prostate cancer. To determine the role of innate immunity and inflammation in advanced prostate cancer, we investigated the association of 320 single nucleotide polymorphisms, located in 46 genes involved in this pathway, with disease risk using 494 cases with advanced disease and 536 controls from Cleveland, Ohio. Taken together, the whole pathway was associated with advanced prostate cancer risk (P = 0.02). Two sub-pathways (intracellular antiviral molecules and extracellular pattern recognition) and four genes in these sub-pathways (TLR1, TLR6, OAS1, and OAS2) were nominally associated with advanced prostate cancer risk and harbor several SNPs nominally associated with advanced prostate cancer risk. Our results suggest that the innate immunity and inflammation pathway may play a modest role in the etiology of advanced prostate cancer through multiple small effects.

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

    Directory of Open Access Journals (Sweden)

    Oana Marcu

    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.

  1. Alemtuzumab treatment alters circulating innate immune cells in multiple sclerosis

    Science.gov (United States)

    Ahmetspahic, Diana; Ruck, Tobias; Schulte-Mecklenbeck, Andreas; Schwarte, Kathrin; Jörgens, Silke; Scheu, Stefanie; Windhagen, Susanne; Graefe, Bettina; Melzer, Nico; Klotz, Luisa; Arolt, Volker; Wiendl, Heinz; Meuth, Sven G.

    2016-01-01

    Objective: To characterize changes in myeloid and lymphoid innate immune cells in patients with relapsing-remitting multiple sclerosis (MS) during a 6-month follow-up after alemtuzumab treatment. Methods: Circulating innate immune cells including myeloid cells and innate lymphoid cells (ILCs) were analyzed before and 6 and 12 months after onset of alemtuzumab treatment. Furthermore, a potential effect on granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin (IL)–23 production by myeloid cells and natural killer (NK) cell cytolytic activity was determined. Results: In comparison to CD4+ T lymphocytes, myeloid and lymphoid innate cell subsets of patients with MS expressed significantly lower amounts of CD52 on their cell surface. Six months after CD52 depletion, numbers of circulating plasmacytoid dendritic cells (DCs) and conventional DCs were reduced compared to baseline. GM-CSF and IL-23 production in DCs remained unchanged. Within the ILC compartment, the subset of CD56bright NK cells specifically expanded under alemtuzumab treatment, but their cytolytic activity did not change. Conclusions: Our findings demonstrate that 6 months after alemtuzumab treatment, specific DC subsets are reduced, while CD56bright NK cells expanded in patients with MS. Thus, alemtuzumab specifically restricts the DC compartment and expands the CD56bright NK cell subset with potential immunoregulatory properties in MS. We suggest that remodeling of the innate immune compartment may promote long-term efficacy of alemtuzumab and preserve immunocompetence in patients with MS. PMID:27766281

  2. Manipulation of Innate Immunity for Cancer Therapy in Dogs

    Directory of Open Access Journals (Sweden)

    Daniel Regan

    2015-12-01

    Full Text Available Over the last one to two decades, the field of cancer immunotherapy has rapidly progressed from early preclinical studies to a successful clinical reality and fourth major pillar of human cancer therapy. While current excitement in the field of immunotherapy is being driven by several major breakthroughs including immune checkpoint inhibitors and adoptive cell therapies, these advances stem from a foundation of pivotal studies demonstrating the immune systems role in tumor control and eradication. The following will be a succinct review on veterinary cancer immunotherapy as it pertains to manipulation of the innate immune system to control tumor growth and metastasis. In addition, we will provide an update on recent progress in our understanding of the innate immune system in veterinary tumor immunology, and how these gains may lead to novel therapies for the treatment of cancer in companion animals.

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

    Science.gov (United States)

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

    2014-12-01

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

  4. Activation of innate immunity during systemic Candida infections

    NARCIS (Netherlands)

    Ifrim, D.C.

    2015-01-01

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

  5. Activation of the innate immune system in atherosclerotic disease

    NARCIS (Netherlands)

    Oude Nijhuis, M.M.; Keulen, J.K. van; Pasterkamp, G.; Quax, P.H.; Kleijn, D.P.V. de

    2007-01-01

    Innate immunity is the first line of defence against invading micro-organisms. The family of Toll-like receptors (TLRs) recognizes pathogen-associated molecular patterns (PAMPs) that are carried by the invading micro-organisms. Infectious pathogens have been implicated to play an important role in a

  6. Fungal strategies for overcoming host innate immune response.

    NARCIS (Netherlands)

    Chai, L.; Netea, M.G.; Vonk, A.G.; Kullberg, B.J.

    2009-01-01

    A successful pathogen is one that is able to effectively survive and evade detection by the host innate immune defense. Fungal pathogens have adopted strategies which evade host defense and eventually cause disease in at-risk patients. Shielding of stimulatory surface recognition molecules, shedding

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

    Directory of Open Access Journals (Sweden)

    Rahul Mittal

    2014-12-01

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

  8. 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.

  9. Tactics used by HIV-1 to evade host innate, adaptive, and intrinsic immunities

    Institute of Scientific and Technical Information of China (English)

    LU Lu; YU Fei; DU Lan-ying; XU Wei; JIANG Shi-bo

    2013-01-01

    Objective To review the mechanisms by which HIV evades different components of the host immune system.Data sources This review is based on data obtained from published articles from 1991 to 2012.To perform the PubMed literature search,the following key words were input:HIV and immune evasion.Study selection Articles containing information related to HIV immune evasion were selected.Results Although HIV is able to induce vigorous antiviral immune responses,viral replication cannot be fully controlled,and neither pre-existing infected cells nor latent HIV infection can be completely eradicated.Like many other enveloped viruses,HIV can escape recognition by the innate and adaptive immune systems.Recent findings have demonstrated that HIV can also successfully evade host restriction factors,the components of intrinsic immune system,such as APOBEC3G (apolipoprotein B mRNA-editing enzyme,catalytic polypeptide-like 3G),TRIM5α (tripartite motif 5-α),tetherin,and SAMHD1 (SAM-domain HD-domain containing protein).Conclusions HIV immune evasion plays an important role in HIV pathcgenesis.Fully understanding the tactics deployed by HIV to evade various components of the host immune systems will allow for the development of novel strategies aimed toward the prevention and cure of HIV/AIDS.

  10. DMPD: Antiviral innate immunity pathways. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available (.csml) Open .csml file with CIOPlayer Open .csml file with CIOPlayer - ※CIO Playerのご利用上の注意 Open .csml file with CIO Open .csml file with CIO - ※CIOのご利用上の注意 ...

  11. lncRNAs regulate the innate immune response to viral infection.

    Science.gov (United States)

    Ouyang, Jing; Hu, Jiayue; Chen, Ji-Long

    2016-01-01

    Long noncoding RNAs (lncRNAs) are extensively expressed in mammalian cells and play a crucial role as RNA regulators in various cellular processes. Increasing data reveal that they function in innate antiviral immunity through complex mechanisms. Thousands of lncRNAs are regulated by RNA virus or DNA virus infection. The significant differential expression of lncRNAs is induced by virus or host antiviral signaling mediated by interferons (IFNs) and tumor necrosis factor-α. In turn, these lncRNAs modulate the host immune response including the pathogen recognition receptor (PRR)-related signaling, the translocation and activation of transcription factors, the production of IFNs and cytokines, the IFN-activated JAK-STAT signaling and the transcription of antiviral IFN-stimulated genes (ISGs). Using gain- or loss-of-function analysis, the effect of lncRNAs on viral replication has been investigated to elucidate the essential role of lncRNA in the host-virus interaction. lncRNAs have shown specifically elevated or decreased levels in patients with viral diseases, suggesting the possibility of clinical application as biomarkers. Here we review the current advances of viral infection-associated host lncRNAs, their functional significance in different aspects of antiviral immune response, the specific mechanisms and unsolved issues. We also summarize the regulation of lncRNAs by viruses, PRR agonists and cytokines. In addition, virus-encoded lncRNAs and their functional involvement in host-virus interaction are addressed. WIREs RNA 2016, 7:129-143. doi: 10.1002/wrna.1321 For further resources related to this article, please visit the WIREs website.

  12. Functional genomics studies on the innate immunity of disease vectors

    Institute of Scientific and Technical Information of China (English)

    Luke A. Baton; Lindsey Garver; Zhiyong Xi; George Dimopoulos

    2008-01-01

    The increasing availability of genome sequences and the development of high-throughput techniques for gene expression profiling and functional characterization are transforming the study of innate immunity and other areas of insect biology. Already,functional genomic approaches have enabled a quantum advance in the characterization of mosquito immune responses to malaria parasite infection, and similar high-throughput functional genomic studies of other vector-pathogen interactions can be expected in the near future. The application of microarray-based and other expression analyses provide genomewide transcriptional profiles that can be used to identify insect immune system components that are differentially regulated upon exposure to various classes of pathogens, including many important etiologic agents of human and animal diseases. The role of infection-responsive or other candidate immune genes identified through comparative genomic approaches can then be functionally characterized, either in vivo, for instance in adult mosquitoes, or in vitro using cell lines. In most insect vectors of human pathogens, germ-line transgenesis is still technically difficult and maintenance of multiple transgenic lines logistically demanding.Consequently, transient RNA interference (RNAi)-mediated gene-silencing has rapidly become the method of choice for functional characterization of candidate innate immune genes. The powerful combination of transcriptional profiling in conjunction with assays using RNAi to determine gene function, and identify regulatory pathways, together with downstream cell biological approaches to determine protein localization and interactions,will continue to provide novel insights into the role of insect innate immunity in a variety of vector-pathogen interactions. Here we review advances in functional genomics studies of innate immunity in the insect disease vectors, over the past decade, with a particular focus on the Anopheles mosquito and its

  13. α-Defensins in human innate immunity.

    Science.gov (United States)

    Lehrer, Robert I; Lu, Wuyuan

    2012-01-01

    Defensins are small, multifunctional cationic peptides. They typically contain six conserved cysteines whose three intramolecular disulfides stabilize a largely β-sheet structure. This review of human α-defensins begins by describing their evolution, including their likely relationship to the Big Defensins of invertebrates, and their kinship to the β-defensin peptides of many if not all vertebrates, and the θ-defensins found in certain non-human primates. We provide a short history of the search for leukocyte-derived microbicidal molecules, emphasizing the roles played by luck (good), preconceived notions (mostly bad), and proper timing (essential). The antimicrobial, antiviral, antitoxic, and binding properties of human α-defensins are summarized. The structural features of α-defensins are described extensively and their functional contributions are assessed. The properties of HD6, an enigmatic Paneth cell α-defensin, are contrasted with those of the four myeloid α-defensins (HNP1-4) and of HD5, the other α-defensin of human Paneth cells. The review ends with a decalogue that may assist researchers or students interested in α-defensins and related aspects of neutrophil function.

  14. Innate immune signaling in cardiac ischemia

    NARCIS (Netherlands)

    Arslan, F.; de Kleijn, D.P.V.; Pasterkamp, G.

    2011-01-01

    Despite advances in treatment of patients who suffer from ischemic heart disease, morbidity related to myocardial infarction is increasing in Western societies. Acute and chronic immune responses elicited by myocardial ischemia have an important role in the functional deterioration of the heart. Res

  15. 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

  16. Pyruvate Carboxylase Activates the RIG-I-like Receptor-Mediated Antiviral Immune Response by Targeting the MAVS signalosome

    Science.gov (United States)

    Cao, Zhongying; Zhou, Yaqin; Zhu, Shengli; Feng, Jian; Chen, Xueyuan; Liu, Shi; Peng, Nanfang; Yang, Xiaodan; Xu, Gang; Zhu, Ying

    2016-01-01

    When retinoic acid-inducible gene 1 protein (RIG-I)-like receptors sense viral dsRNA in the cytosol, RIG-I and melanoma differentiation-associated gene 5 (MDA5) are recruited to the mitochondria to interact with mitochondrial antiviral signaling protein (MAVS) and initiate antiviral immune responses. In this study, we demonstrate that the biotin-containing enzyme pyruvate carboxylase (PC) plays an essential role in the virus-triggered activation of nuclear factor kappa B (NF-κB) signaling mediated by MAVS. PC contributes to the enhanced production of type I interferons (IFNs) and pro-inflammatory cytokines, and PC knockdown inhibits the virus-triggered innate immune response. In addition, PC shows extensive antiviral activity against RNA viruses, including influenza A virus (IAV), human enterovirus 71 (EV71), and vesicular stomatitis virus (VSV). Furthermore, PC mediates antiviral action by targeting the MAVS signalosome and induces IFNs and pro-inflammatory cytokines by promoting phosphorylation of NF-κB inhibitor-α (IκBα) and the IκB kinase (IKK) complex, as well as NF-κB nuclear translocation, which leads to activation of interferon-stimulated genes (ISGs), including double-stranded RNA-dependent protein kinase (PKR) and myxovirus resistance protein 1 (Mx1). Our findings suggest that PC is an important player in host antiviral signaling. PMID:26906558

  17. Airway Epithelial Orchestration of Innate Immune Function in Response to Virus Infection. A Focus on Asthma.

    Science.gov (United States)

    Ritchie, Andrew I; Jackson, David J; Edwards, Michael R; Johnston, Sebastian L

    2016-03-01

    Asthma is a very common respiratory condition with a worldwide prevalence predicted to increase. There are significant differences in airway epithelial responses in asthma that are of particular interest during exacerbations. Preventing exacerbations is a primary aim when treating asthma because they often necessitate unscheduled healthcare visits and hospitalizations and are a significant cause of morbidity and mortality. The most common cause of asthma exacerbations is a respiratory virus infection, of which the most likely type is rhinovirus infection. This article focuses on the role played by the epithelium in orchestrating the innate immune responses to respiratory virus infection. Recent studies show impaired bronchial epithelial cell innate antiviral immune responses, as well as augmentation of a pro-Th2 response characterized by the epithelial-derived cytokines IL-25 and IL-33, crucial in maintaining the Th2 cytokine response to virus infection in asthma. A better understanding of the mechanisms of these abnormal immune responses has the potential to lead to the development of novel therapeutic targets for virus-induced exacerbations. The aim of this article is to highlight current knowledge regarding the role of viruses and immune modulation in the asthmatic epithelium and to discuss exciting areas for future research and novel treatments.

  18. Toward understanding of rice innate immunity against Magnaporthe oryzae.

    Science.gov (United States)

    Azizi, P; Rafii, M Y; Abdullah, S N A; Nejat, N; Maziah, M; Hanafi, M M; Latif, M A; Sahebi, M

    2016-01-01

    The blast fungus, Magnaporthe oryzae, causes serious disease on a wide variety of grasses including rice, wheat and barley. The recognition of pathogens is an amazing ability of plants including strategies for displacing virulence effectors through the adaption of both conserved and variable pathogen elicitors. The pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) and effector-triggered immunity (ETI) were reported as two main innate immune responses in plants, where PTI gives basal resistance and ETI confers durable resistance. The PTI consists of extracellular surface receptors that are able to recognize PAMPs. PAMPs detect microbial features such as fungal chitin that complete a vital function during the organism's life. In contrast, ETI is mediated by intracellular receptor molecules containing nucleotide-binding (NB) and leucine rich repeat (LRR) domains that specifically recognize effector proteins produced by the pathogen. To enhance crop resistance, understanding the host resistance mechanisms against pathogen infection strategies and having a deeper knowledge of innate immunity system are essential. This review summarizes the recent advances on the molecular mechanism of innate immunity systems of rice against M. oryzae. The discussion will be centered on the latest success reported in plant-pathogen interactions and integrated defense responses in rice.

  19. 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.

  20. Antibody complementarity-determining regions (CDRs: a bridge between adaptive and innate immunity.

    Directory of Open Access Journals (Sweden)

    Elena Gabrielli

    Full Text Available BACKGROUND: It has been documented that, independently from the specificity of the native antibody (Ab for a given antigen (Ag, complementarity determining regions (CDR-related peptides may display differential antimicrobial, antiviral and antitumor activities. METHODOLOGY/PRINCIPAL FINDINGS: In this study we demonstrate that a synthetic peptide with sequence identical to V(HCDR3 of a mouse monoclonal Ab (mAb specific for difucosyl human blood group A is easily taken up by macrophages with subsequent stimulation of: i proinflammatory cytokine production; ii PI3K-Akt pathway and iii TLR-4 expression. Significantly, V(HCDR3 exerts therapeutic effect against systemic candidiasis without possessing direct candidacidal properties. CONCLUSIONS/SIGNIFICANCE: These results open a new scenario about the possibility that, beyond the half life of immunoglobulins, Ab fragments may effectively influence the antiinfective cellular immune response in a way reminiscent of regulatory peptides of innate immunity.

  1. [Regulation of innate immunity during xenogenic changes in blood circulation].

    Science.gov (United States)

    Shevchenko, V S

    2001-01-01

    Calcium-dependent innate immune response with participation of the superfamily of immunoglobulins to several intra- and extracorporal xenobiotics were studied at 216 recipients during synthetic cardiac valves implantation or veins transplantation in coronary arteries. It was shown that immediate immune response to xenobiotics was manifested by generation of the antitissue anodical autoprecipitin with specificity to the surface cell membrane component. This reaction initiated and regulated the subsequent dynamics of the two different fibrinogen autoimmune complexes formation, resulting in development of the immunogenic damages of blood circulation. Correction of these rapid innate immune responses is important for prevention and normalisation of the xenogenic damages of blood circulation during trans- and implantation on the heart impaired with endocarditis or aterosclerosis.

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

    Science.gov (United States)

    Günther, Claudia; Josenhans, Christine; Wehkamp, Jan

    2016-08-01

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

  3. 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.

  4. Interleukin-17 and innate immunity in infections and chronic inflammation.

    Science.gov (United States)

    Isailovic, Natasa; Daigo, Kenji; Mantovani, Alberto; Selmi, Carlo

    2015-06-01

    Interleukin 17 (IL-17) includes several cytokines among which IL-17A is considered as one of the major pro-inflammatory cytokine being central to the innate and adaptive immune responses. IL-17 is produced by unconventional T cells, members of innate lymphoid cells (ILCs), mast cells, as well as typical innate immune cells, such as neutrophils and macrophages located in the epithelial barriers and characterised by a rapid response to infectious agents by recruiting neutrophils as first line of defence and inducing the production of antimicrobial peptides. Th17 responses appear pivotal in chronic and acute infections by bacteria, parasites, and fungi, as well as in autoimmune and chronic inflammatory diseases, including rheumatoid arthritis, psoriasis, and psoriatic arthritis. The data discussed in this review cumulatively indicate that innate-derived IL-17 constitutes a major element in the altered immune response against self antigens or the perpetuation of inflammation, particularly at mucosal sites. New drugs targeting the IL17 pathway include brodalumab, ixekizumab, and secukinumab and their use in psoriatic disease is expected to dramatically impact our approach to this systemic condition.

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

    Science.gov (United States)

    Phongsisay, Vongsavanh

    2016-04-01

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

  6. A role for PML in innate immunity

    OpenAIRE

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

    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 ...

  7. MAP Kinase 4 Substrates and Plant Innate Immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt

    recognition, which also induce its localization to cytoplasmic processing bodies. All three proteins; PAT1, AOC3 and eIF4E also interacts with MPK4 in vivo although the functional outcome of these interactions are still elusive. The thesis comprise a general introduction to plant innate immunity followed...... by two review articles “MAP kinase cascades in Arabidopsis innate immunity” published in Frontiers in Plant Science and “mRNA decay in plant immunity” under revision for Cellular and Molecular Life Science. Together these sections gives a comprehensive overview of Arabidopsis defense signaling...

  8. Arginine Metabolism in Myeloid Cells Shapes Innate and Adaptive Immunity

    Science.gov (United States)

    Rodriguez, Paulo C.; Ochoa, Augusto C.; Al-Khami, Amir A.

    2017-01-01

    Arginine metabolism has been a key catabolic and anabolic process throughout the evolution of the immune response. Accruing evidence indicates that arginine-catabolizing enzymes, mainly nitric oxide synthases and arginases, are closely integrated with the control of immune response under physiological and pathological conditions. Myeloid cells are major players that exploit the regulators of arginine metabolism to mediate diverse, although often opposing, immunological and functional consequences. In this article, we focus on the importance of arginine catabolism by myeloid cells in regulating innate and adaptive immunity. Revisiting this matter could result in novel therapeutic approaches by which the immunoregulatory nodes instructed by arginine metabolism can be targeted.

  9. New insights into innate immune control of systemic candidiasis.

    Science.gov (United States)

    Lionakis, Michail S

    2014-08-01

    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.

  10. 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...) (.csml) Show Peptidoglycan signaling in innate immunity and inflammatory disease. PubmedID 15802263 Title ...Peptidoglycan signaling in innate immunity and inflammatory disease. Authors McDo

  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. Interactions between Innate Immunity, Microbiota, and Probiotics

    OpenAIRE

    2015-01-01

    The term “microbiota” means genetic inheritance associated with microbiota, which is about 100 times larger than the guest. The tolerance of the resident bacterial flora is an important key element of immune cell function. A key role in the interaction between the host and the microbiota is played by Paneth cell, which is able to synthesize and secrete proteins and antimicrobial peptides, such as α/β defensins, cathelicidin, 14 β-glycosidases, C-type lectins, and ribonuclease, in response to ...

  13. Plasmacytoid dendritic cells in antiviral immunity and autoimmunity

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Plasmacytoid dendritic cells (pDCs) represent a unique and crucial immune cell population capable of producing large amounts of type I interferons (IFNs) in response to viral infection.The function of pDCs as the professional type I IFN-producing cells is linked to their selective expression of Toll-like receptor 7 (TLR7) and TLR9,which sense viral nucleic acids within the endosomal compartments.Type I IFNs produced by pDCs not only directly inhibit viral replication but also play an essential role in linking the innate and adaptive immune system.The aberrant activation of pDCs by self nucleic acids through TLR signaling and the ongoing production of type I IFNs do occur in some autoimmune diseases.Therefore,pDC may serve as an attractive target for therapeutic manipulations of the immune system to treat viral infectious diseases and autoimmune diseases.

  14. Innate immunity against malaria parasites in Anopheles gambiae

    Institute of Scientific and Technical Information of China (English)

    Yang Chenand; Zhi-Hui Weng; Liangbiao Zheng

    2008-01-01

    Malaria continues to exert a huge toll in the world today, causing approximately 400 million cases and killing between 1-2 million people annually. Most of the malaria burden is borne by countries in Africa. For this reason, the major vector for malaria in this continent, Anopheles gambiae, is under intense study. With the completion of the draft sequence of this important vector, efforts are underway to develop novel control strategies.One promising area is to harness the power of the innate immunity of this mosquito species to block the transmission of the malaria parasites. Recent studies have demonstrated that Toll and Imd signaling pathways and other immunity-related genes (encoding proteins possibly function in recognition or as effector molecules) play significant roles in two different arms of innate immunity: level of infection intensity and melanization of Plasmodium oocysts.The challenges in the future are to understand how the functions of these different genes are coordinated in defense against malaria parasites, and if different arms of innate immunity are cross-regulated or coordinated.

  15. Toll-like receptors in invertebrate innate immunity

    Directory of Open Access Journals (Sweden)

    L Zheng

    2005-08-01

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

  16. Activation of invariant NKT cells enhances the innate immune response and improves the disease course in influenza A virus infection.

    Science.gov (United States)

    Ho, Ling-Pei; Denney, Laura; Luhn, Kerstin; Teoh, Denise; Clelland, Colin; McMichael, Andrew J

    2008-07-01

    Invariant NKT (iNKT) cells have an indubitable role in antiviral immunity, although the mechanisms by which these cells exert their functions are not fully elucidated. With the emerging importance of high-pathogenicity influenza A virus infections in humans, we questioned whether iNKT cells contribute to immune defence against influenza A virus and whether activation of these cells influences outcome. We show that activation of iNKT cells with alpha-galactosylceramide (alpha-GC) during influenza virus infection transiently enhanced early innate immune response without affecting T cell immunity, and reduced early viral titres in lungs of C57BL/6 mice. This is accompanied by a better disease course with improved weight loss profile. Temporal changes in iNKT cells in the liver, blood and lungs suggest activation and migration of iNKT cells from the liver to the lungs in mice that were administered alpha-GC. Improvement in viral titres appears dependent on activation of iNKT cells via the intraperitoneal route since intranasal administration of alpha-GC did not have the same effect. We conclude that activation of iNKT cells enhances early innate immune response in the lungs and contribute to antiviral immunity and improved disease course in influenza A virus infection.

  17. RNA helicase DDX3: at the crossroad of viral replication and antiviral immunity.

    Science.gov (United States)

    Valiente-Echeverría, Fernando; Hermoso, Marcela A; Soto-Rifo, Ricardo

    2015-09-01

    Asp-Glu-Ala-Asp (DEAD)-box polypeptide 3, or DDX3, belongs to the DEAD-box family of ATP-dependent RNA helicases and is known to play different roles in RNA metabolism ranging from transcription to nuclear export, translation, and assembly of stress granules. In addition, there is growing evidence that DDX3 is a component of the innate immune response against viral infections. As such, DDX3 has been shown to play roles both upstream and downstream of I-kappa beta kinase ε (IKKε)/TANK-binding kinase 1, leading to IFN-β production. Interestingly, several RNA viruses, including human threats such as HIV-1 and hepatitis C virus, hijack DDX3 to accomplish various steps of their replication cycles. Thus, it seems that viruses have evolved to exploit DDX3's functions while threatening the innate immune response. Understanding this interesting dichotomy in DDX3 function will help us not only to improve our knowledge of virus-host interactions but also to develop novel antiviral drugs targeting the multifaceted roles of DDX3 in viral replication.

  18. Innate Immune Sensors and Gastrointestinal Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Georgina L. Hold

    2011-01-01

    Full Text Available The gastrointestinal microbiota is a major source of immune stimulation. The interaction between host pattern-recognition receptors and conserved microbial ligands profoundly influences infection dynamics. Identifying and understanding the nature of these interactions is a key step towards obtaining a clearer picture of microbial pathogenesis. These interactions underpin a complex interplay between microbe and host that has far reaching consequences for both. Here, we review the role of pattern recognition receptors in three prototype diseases affecting the stomach, the small intestine, and large intestine, respectively (Helicobacter pylori infection, Salmonella infection, and inflammatory bowel disease. Specifically, we review the nature and impact of pathogen:receptor interactions, their impact upon pathogenesis, and address the relevance of pattern recognition receptors in the development of therapies for gastrointestinal diseases.

  19. Human Metapneumovirus Antagonism of Innate Immune Responses

    Directory of Open Access Journals (Sweden)

    Xiaoyong Bao

    2012-12-01

    Full Text Available  Human metapneumovirus (hMPV is a recently identified RNA virus belonging to the Paramyxoviridae family, which includes several major human and animal pathogens. Epidemiological studies indicate that hMPV is a significant human respiratory pathogen with worldwide distribution. It is associated with respiratory illnesses in children, adults, and immunocompromised patients, ranging from upper respiratory tract infections to severe bronchiolitis and pneumonia. Interferon (IFN represents a major line of defense against virus infection, and in response, viruses have evolved countermeasures to inhibit IFN production as well as IFN signaling. Although the strategies of IFN evasion are similar, the specific mechanisms by which paramyxoviruses inhibit IFN responses are quite diverse. In this review, we will present an overview of the strategies that hMPV uses to subvert cellular signaling in airway epithelial cells, the major target of infection, as well as in primary immune cells.

  20. Innate immunity at the forefront of psychoneuroimmunology.

    Science.gov (United States)

    Dantzer, Robert

    2004-01-01

    The last 15 years of research in psychoneuroimmunology have been marked by a renewed interest in the mechanisms of inflammation and participation of the brain in these mechanisms. Peripheral proinflammatory cytokines produced by activated accessory immune cells act in the brain to trigger sickness, in the form of fever, pituitary-adrenal axis activation, and sickness behavior. Communication between the periphery and brain takes place via both neural and humoral pathways. Recognition of the role of local production of cytokines and their downstream messengers in the central nervous system opens important new vistas for understanding and treating non-specific neurovegetative and psychiatric symptoms of diseases. In this presidential address, I present the main methodological and conceptual developments that have allowed such progress.

  1. Antimicrobial peptides important in innate immunity.

    Science.gov (United States)

    Cederlund, Andreas; Gudmundsson, Gudmundur H; Agerberth, Birgitta

    2011-10-01

    Antimicrobial peptides are present in all walks of life, from plants to animals, and they are considered to be endogenous antibiotics. In general, antimicrobial peptides are determinants of the composition of the microbiota and they function to fend off microbes and prevent infections. Antimicrobial peptides eliminate micro-organisms through disruption of their cell membranes. Their importance in human immunity, and in health as well as disease, has only recently been appreciated. The present review provides an introduction to the field of antimicrobial peptides in general and discusses two of the major classes of mammalian antimicrobial peptides: the defensins and the cathelicidins. The review focuses on their structures, their main modes of action and their regulation.

  2. Trappin-2/elafin modulate innate immune responses of human endometrial epithelial cells to PolyI:C.

    Directory of Open Access Journals (Sweden)

    Anna G Drannik

    Full Text Available BACKGROUND: Upon viral recognition, innate and adaptive antiviral immune responses are initiated by genital epithelial cells (ECs to eradicate or contain viral infection. Such responses, however, are often accompanied by inflammation that contributes to acquisition and progression of sexually transmitted infections (STIs. Hence, interventions/factors enhancing antiviral protection while reducing inflammation may prove beneficial in controlling the spread of STIs. Serine antiprotease trappin-2 (Tr and its cleaved form, elafin (E, are alarm antimicrobials secreted by multiple cells, including genital epithelia. METHODOLOGY AND PRINCIPAL FINDINGS: We investigated whether and how each Tr and E (Tr/E contribute to antiviral defenses against a synthetic mimic of viral dsRNA, polyinosine-polycytidylic acid (polyI:C and vesicular stomatitis virus. We show that delivery of a replication-deficient adenovector expressing Tr gene (Ad/Tr to human endometrial epithelial cells, HEC-1A, resulted in secretion of functional Tr, whereas both Tr/E were detected in response to polyI:C. Moreover, Tr/E were found to significantly reduce viral replication by either acting directly on virus or through enhancing polyI:C-driven antiviral protection. The latter was associated with reduced levels of pro-inflammatory factors IL-8, IL-6, TNFα, lowered expression of RIG-I, MDA5 and attenuated NF-κB activation. Interestingly, enhanced polyI:C-driven antiviral protection of HEC-Ad/Tr cells was partially mediated through IRF3 activation, but not associated with higher induction of IFNβ, suggesting multiple antiviral mechanisms of Tr/E and the involvement of alternative factors or pathways. CONCLUSIONS AND SIGNIFICANCE: This is the first evidence of both Tr/E altering viral binding/entry, innate recognition and mounting of antiviral and inflammatory responses in genital ECs that could have significant implications for homeostasis of the female genital tract.

  3. Innate immunity against moulds: lessons learned from invertebrate models.

    Science.gov (United States)

    Ben-Ami, Ronen

    2011-01-01

    The emergence over the past two decades of invasive mycoses as a significant problem in immunocompromised patients underscores the importance of deciphering innate immunity against filamentous fungi. However, the complexity and cost of traditionally used mammalian model hosts presents a bottleneck that has limited the rate of advances in this field. In contrast, invertebrate model hosts have several important advantages, including simple immune systems, genetic tractability, and amenity to high-throughput experiments. The application of these models to studies of host-pathogen interactions is contingent on two tenets: (1) host innate defenses are preserved across widely disparate taxa, and (2) similar fungal virulence factors are operative in insects and in mammals. Validation of these principles paved the way for the use of invertebrates as facile models for studying invasive mould infections. These studies have helped shape our understanding of human pattern recognition receptors, phagocytic cell function and antimicrobial proteins, and their roles in host defense against filamentous fungi.

  4. 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...... review the current knowledge about the bacterial MAMPs LPS and PGN, the fungal MAMPs ß-glucan, chitin and chitosan oligosaccharides and the bacterial suppressors EPS and cyclic glucan, with particular reference to the chemical structures of these molecules, the PRRs involved in their recognition (where...

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

    DEFF Research Database (Denmark)

    Madsen, Jens; Mollenhauer, Jan; Holmskov, Uffe

    2010-01-01

    Deleted in Malignant Brain Tumour 1 (DMBT1) is a gene that encodes alternatively spliced proteins involved in mucosal innate immunity. It also encodes a glycoprotein with a molecular mass of 340 kDa, and is referred to as gp-340 (DMBT1(gp340)) and salivary agglutinin (DMBT1(SAG)). DMBT1(gp340...... proteins, including serum and secretory IgA, C1q, lactoferrin, MUC5B and trefoil factor 2 (TFF2), all molecules with involvement in innate immunity and/or wound-healing processes. Recent generation of Dmbt1-deficient mice has provided the research field of DMBT1 with a model that allows research...... to progress from in vitro studies to in vivo functional studies of the multifunctional proteins encoded by the DMBT1 gene....

  6. Sublethal Heavy Metal Stress Stimulates Innate Immunity in Tomato

    Directory of Open Access Journals (Sweden)

    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.

  7. Innate immune programming by endotoxin and its pathological consequences

    Directory of Open Access Journals (Sweden)

    Matt eMorris

    2015-01-01

    Full Text Available Monocytes and macrophages play pivotal roles in inflammation and homeostasis. Recent studies suggest dynamic programming of macrophages and monocytes may give rise to distinct memory states. Lipopolysaccharide (LPS, a classical pattern recognition molecule, dynamically programs innate immune responses. Emerging studies have revealed complex dynamics of cellular responses to LPS, with high doses causing acute, resolving inflammation, while lower doses are associated with low-grade and chronic non-resolving inflammation. These phenomena hints at dynamic complexities of intra-cellular signaling circuits downstream of the Toll-like-receptor 4 (TLR4. In this review, we examine pathological effects of varying LPS doses with respect to the dynamics of innate immune responses and key molecular regulatory circuits responsible for these effects.

  8. Sublethal heavy metal stress stimulates innate immunity in tomato.

    Science.gov (United States)

    Chakraborty, Nilanjan; Chandra, Swarnendu; Acharya, Krishnendu

    2015-01-01

    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.

  9. Regulation of hepatic innate immunity by hepatitis C virus

    OpenAIRE

    Stacy M Horner; Gale, Michael

    2013-01-01

    Hepatitis C virus (HCV) is a global public health problem involving chronic infection of the liver in over 170 million people. Chronic HCV causes liver disease and is linked with liver cancer. Viral innate immune evasion strategies and human genetic determinants underlie the transition of acute HCV infection to viral persistence and the support of chronic infection. Host genetic factors, such as sequence polymorphisms in IFNL3, a gene in the host interferon system, can influence both the outc...

  10. Plasmodium activates the innate immune response of Anopheles gambiae mosquitoes.

    OpenAIRE

    Richman, A M; Dimopoulos, G; Seeley, D; Kafatos, F C

    1997-01-01

    Innate immune-related gene expression in the major disease vector mosquito Anopheles gambiae has been analyzed following infection by the malaria parasite, Plasmodium berghei. Substantially increased levels of mRNAs encoding the antibacterial peptide defensin and a putative Gram-negative bacteria-binding protein (GNBP) are observed 20-30 h after ingestion of an infected blood-meal, at a time which indicates that this induction is a response to parasite invasion of the midgut epithelium. The i...

  11. Protein synthesis regulation, a pillar of strength for innate immunity?

    Science.gov (United States)

    Argüello, Rafael J; Rodriguez Rodrigues, Christian; Gatti, Evelina; Pierre, Philippe

    2015-02-01

    Recognition of pathogen derived molecules by Pattern Recognition Receptors (PRR) induces the production of cytokines (i.e. type I interferons) that stimulate the surrounding cells to transcribe and translate hundreds of genes, in order to prevent further infection and organize the immune response. Here, we report on the rising matter that metabolism sensing and gene expression control at the level of mRNA translation, allow swift responses that mobilize host defenses and coordinate innate responses to infection.

  12. Modulating the innate immune response to influenza A virus: potential therapeutic use of anti-inflammatory drugs

    Directory of Open Access Journals (Sweden)

    Irene eRamos

    2015-07-01

    Full Text Available Infection by influenza A viruses (IAV is frequently characterized by robust inflammation that is usually more pronounced in the case of avian influenza. It is becoming clearer that the morbidity and pathogenesis caused by IAV is a consequence of this inflammatory response, with several components of the innate immune system acting as the main players. It has been postulated that using a therapeutic approach to limit the innate immune response in combination with antiviral drugs has the potential to diminish symptoms and tissue damage caused by IAV infection. Indeed, some anti-inflammatory agents have been shown to be effective in animal models at reducing IAV pathology as a proof of principle. The main challenge in developing such therapies is to selectively modulate signaling pathways that contribute to lung injury while maintaining the ability of the host cells to mount an antiviral response to control virus replication. However, the dissection of those pathways is very complex given the numerous components regulated by the same factors (i.e. NF kappa B transcription factors and the large number of players involved in this regulation, some of which may be undescribed or unknown. This article provides a comprehensive review of the current knowledge regarding the innate immune responses associated with tissue damage by IAV infection, the understanding of which is essential for the development of effective immunomodulatory drugs. Furthermore, we summarize the recent advances on the development and evaluation of such drugs as well as the lessons learned from those studies.

  13. Prognostic value of innate and adaptive immunity in colorectal cancer.

    Science.gov (United States)

    Grizzi, Fabio; Bianchi, Paolo; Malesci, Alberto; Laghi, Luigi

    2013-01-14

    Colorectal cancer (CRC) remains one of the major public health problems throughout the world. Originally depicted as a multi-step dynamical disease, CRC develops slowly over several years and progresses through cytologically distinct benign and malignant states, from single crypt lesions through adenoma, to malignant carcinoma with the potential for invasion and metastasis. Moving from histological observations since a long time, it has been recognized that inflammation and immunity actively participate in the pathogenesis, surveillance and progression of CRC. The advent of immunohistochemical techniques and of animal models has improved our understanding of the immune dynamical system in CRC. It is well known that immune cells have variable behavior controlled by complex interactions in the tumor microenvironment. Advances in immunology and molecular biology have shown that CRC is immunogenic and that host immune responses influence survival. Several lines of evidence support the concept that tumor stromal cells, are not merely a scaffold, but rather they influence growth, survival, and invasiveness of cancer cells, dynamically contributing to the tumor microenvironment, together with immune cells. Different types of immune cells infiltrate CRC, comprising cells of both the innate and adaptive immune system. A relevant issue is to unravel the discrepancy between the inhibitory effects on cancer growth exerted by the local immune response and the promoting effects on cancer proliferation, invasion, and dissemination induced by some types of inflammatory cells. Here, we sought to discuss the role played by innate and adaptive immune system in the local progression and metastasis of CRC, and the prognostic information that we can currently understand and exploit.

  14. Antimicrobial Peptides as Mediators of Innate Immunity in Teleosts

    Directory of Open Access Journals (Sweden)

    Barbara A. Katzenback

    2015-09-01

    Full Text Available Antimicrobial peptides (AMPs have been identified throughout the metazoa suggesting their evolutionarily conserved nature and their presence in teleosts is no exception. AMPs are short (18–46 amino acids, usually cationic, amphipathic peptides. While AMPs are diverse in amino acid sequence, with no two AMPs being identical, they collectively appear to have conserved functions in the innate immunity of animals towards the pathogens they encounter in their environment. Fish AMPs are upregulated in response to pathogens and appear to have direct broad-spectrum antimicrobial activity towards both human and fish pathogens. However, an emerging role for AMPs as immunomodulatory molecules has become apparent—the ability of AMPs to activate the innate immune system sheds light onto the multifaceted capacity of these small peptides to combat pathogens through direct and indirect means. Herein, this review focuses on the role of teleost AMPs as modulators of the innate immune system and their regulation in response to pathogens or other exogenous molecules. The capacity to regulate AMP expression by exogenous factors may prove useful in modulating AMP expression in fish to prevent disease, particularly in aquaculture settings where crowded conditions and environmental stress pre-dispose these fish to infection.

  15. Lipoglycans contribute to innate immune detection of mycobacteria.

    Directory of Open Access Journals (Sweden)

    Shyam Krishna

    Full Text Available Innate immune recognition is based on the detection, by pattern recognition receptors (PRRs, of molecular structures that are unique to microorganisms. Lipoglycans are macromolecules specific to the cell envelope of mycobacteria and related genera. They have been described to be ligands, as purified molecules, of several PRRs, including the C-type lectins Mannose Receptor and DC-SIGN, as well as TLR2. However, whether they are really sensed by these receptors in the context of a bacterium infection remains unclear. To address this question, we used the model organism Mycobacterium smegmatis to generate mutants altered for the production of lipoglycans. Since their biosynthesis cannot be fully abrogated, we manipulated the biosynthesis pathway of GDP-Mannose to obtain some strains with either augmented (∼1.7 fold or reduced (∼2 fold production of lipoglycans. Interestingly, infection experiments demonstrated a direct correlation between the amount of lipoglycans in the bacterial cell envelope on one hand and the magnitude of innate immune signaling in TLR2 reporter cells, monocyte/macrophage THP-1 cell line and human dendritic cells, as revealed by NF-κB activation and IL-8 production, on the other hand. These data establish that lipoglycans are bona fide Microbe-Associated Molecular Patterns contributing to innate immune detection of mycobacteria, via TLR2 among other PRRs.

  16. Antimicrobial Peptides as Mediators of Innate Immunity in Teleosts.

    Science.gov (United States)

    Katzenback, Barbara A

    2015-09-25

    Antimicrobial peptides (AMPs) have been identified throughout the metazoa suggesting their evolutionarily conserved nature and their presence in teleosts is no exception. AMPs are short (18-46 amino acids), usually cationic, amphipathic peptides. While AMPs are diverse in amino acid sequence, with no two AMPs being identical, they collectively appear to have conserved functions in the innate immunity of animals towards the pathogens they encounter in their environment. Fish AMPs are upregulated in response to pathogens and appear to have direct broad-spectrum antimicrobial activity towards both human and fish pathogens. However, an emerging role for AMPs as immunomodulatory molecules has become apparent-the ability of AMPs to activate the innate immune system sheds light onto the multifaceted capacity of these small peptides to combat pathogens through direct and indirect means. Herein, this review focuses on the role of teleost AMPs as modulators of the innate immune system and their regulation in response to pathogens or other exogenous molecules. The capacity to regulate AMP expression by exogenous factors may prove useful in modulating AMP expression in fish to prevent disease, particularly in aquaculture settings where crowded conditions and environmental stress pre-dispose these fish to infection.

  17. Club cells surviving influenza A virus infection induce temporary nonspecific antiviral immunity.

    Science.gov (United States)

    Hamilton, Jennifer R; Sachs, David; Lim, Jean K; Langlois, Ryan A; Palese, Peter; Heaton, Nicholas S

    2016-04-01

    A brief window of antigen-nonspecific protection has been observed after influenza A virus (IAV) infection. Although this temporary immunity has been assumed to be the result of residual nonspecific inflammation, this period of induced immunity has not been fully studied. Because IAV has long been characterized as a cytopathic virus (based on its ability to rapidly lyse most cell types in culture), it has been a forgone conclusion that directly infected cells could not be contributing to this effect. Using a Cre recombinase-expressing IAV, we have previously shown that club cells can survive direct viral infection. We show here not only that these cells can eliminate all traces of the virus and survive but also that they acquire a heightened antiviral response phenotype after surviving. Moreover, we experimentally demonstrate temporary nonspecific viral immunity after IAV infection and show that surviving cells are required for this phenotype. This work characterizes a virally induced modulation of the innate immune response that may represent a new mechanism to prevent viral diseases.

  18. Chikungunya virus induces IPS-1-dependent innate immune activation and protein kinase R-independent translational shutoff.

    Science.gov (United States)

    White, Laura K; Sali, Tina; Alvarado, David; Gatti, Evelina; Pierre, Philippe; Streblow, Daniel; Defilippis, Victor R

    2011-01-01

    Chikungunya virus (CHIKV) is an arthritogenic mosquito-transmitted alphavirus that is undergoing reemergence in areas around the Indian Ocean. Despite the current and potential danger posed by this virus, we know surprisingly little about the induction and evasion of CHIKV-associated antiviral immune responses. With this in mind we investigated innate immune reactions to CHIKV in human fibroblasts, a demonstrable in vivo target of virus replication and spread. We show that CHIKV infection leads to activation of the transcription factor interferon regulatory factor 3 (IRF3) and subsequent transcription of IRF3-dependent antiviral genes, including beta interferon (IFN-β). IRF3 activation occurs by way of a virus-induced innate immune signaling pathway that includes the adaptor molecule interferon promoter stimulator 1 (IPS-1). Despite strong transcriptional upregulation of these genes, however, translation of the corresponding proteins is not observed. We further demonstrate that translation of cellular (but not viral) genes is blocked during infection and that although CHIKV is found to trigger inactivation of the translational molecule eukaryotic initiation factor subunit 2α by way of the double-stranded RNA sensor protein kinase R, this response is not required for the block to protein synthesis. Furthermore, overall diminution of cellular RNA synthesis is also observed in the presence of CHIKV and transcription of IRF3-dependent antiviral genes appears specifically blocked late in infection. We hypothesize that the observed absence of IFN-β and antiviral proteins during infection results from an evasion mechanism exhibited by CHIKV that is dependent on widespread shutoff of cellular protein synthesis and a targeted block to late synthesis of antiviral mRNA transcripts.

  19. Self/not self, innate immunity, danger, cancer potential

    Science.gov (United States)

    Cooper, Edwin L.

    2010-03-01

    Self/not self is an important hypothesis that has guided research in immunology. It is closely connected to adaptive immunity (restricted to vertebrates) and innate immunity (found in vertebrates and invertebrates). Self/not self is now being challenged and investigators are turning to the danger hypothesis to guide and open new areas of research. Emerging information suggests that genes involved in development of cancer are present in Drosophila and C. elegans. Short life span may not preclude the presence of genes that are related to the development of cancer.

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

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

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

  1. 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).

  2. 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

    Directory of Open Access Journals (Sweden)

    Belén Borrego

    2015-07-01

    Full Text Available 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.

  3. 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

    2015-01-01

    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). PMID:26193305

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

    Directory of Open Access Journals (Sweden)

    N Parrinello

    2009-03-01

    Full Text Available 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 recognized genic elements indicating the essential features of the Ig superfamily and ancestor proto-MHC genes, suggesting a primitive pre-duplication and pre-recombination status. C. intestinalis genes for individuality in the absence of MHC could encode diverse molecular markers, including a wide panel of complement factors that could be responsible for self-nonself discrimination. Genome analysis reveals a number of innate immunity vertebrate-like genes which encode Toll-like and virus receptors, complement pathways components and receptors, CD94/NK-receptor-like, lectins, TNF, IL1-R, collagens. However, pure homology seeking for vertebrate-specific immunorelevant molecules is of limited value, and functional screening methods may be a more promising approach for tracing the immune system evolution. C. intestinalis, which displays acute and chronic inflammatory reactions, is a model organism for studying innate immunity genes expression and functions.

  5. 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.

  6. The role of innate immunity in spontaneous regression of cancer

    Directory of Open Access Journals (Sweden)

    J A Thomas

    2011-01-01

    Full Text Available Nature has provided us with infections - acute and chronic - and these infections have both harmful and beneficial effects on the human system. Worldwide, a number of chronic infections are associated with a risk of cancer, but it is also known that cancer regresses when associated with acute infections such as bacterial, viral, fungal, protozoal, etc. Acute infections are known to cure chronic diseases since the time of Hippocrates. The benefits of these fever producing acute infections has been applied in cancer vaccinology such as the Coley′s toxins. Immune cells like the natural killer cells, macrophages and dendritic cells have taken greater precedence in cancer immunity than ever before. This review provides an insight into the benefits of fever and its role in prevention of cancer, the significance of common infections in cancer regression, the dual nature of our immune system and the role of the often overlooked primary innate immunity in tumor immunology and spontaneous regression of cancer.

  7. Cancer immunoediting by the innate immune system in the absence of adaptive immunity.

    Science.gov (United States)

    O'Sullivan, Timothy; Saddawi-Konefka, Robert; Vermi, William; Koebel, Catherine M; Arthur, Cora; White, J Michael; Uppaluri, Ravi; Andrews, Daniel M; Ngiow, Shin Foong; Teng, Michele W L; Smyth, Mark J; Schreiber, Robert D; Bui, Jack D

    2012-09-24

    Cancer immunoediting is the process whereby immune cells protect against cancer formation by sculpting the immunogenicity of developing tumors. Although the full process depends on innate and adaptive immunity, it remains unclear whether innate immunity alone is capable of immunoediting. To determine whether the innate immune system can edit tumor cells in the absence of adaptive immunity, we compared the incidence and immunogenicity of 3'methylcholanthrene-induced sarcomas in syngeneic wild-type, RAG2(-/-), and RAG2(-/-)x γc(-/-) mice. We found that innate immune cells could manifest cancer immunoediting activity in the absence of adaptive immunity. This activity required natural killer (NK) cells and interferon γ (IFN-γ), which mediated the induction of M1 macrophages. M1 macrophages could be elicited by administration of CD40 agonists, thereby restoring editing activity in RAG2(-/-)x γc(-/-) mice. Our results suggest that in the absence of adaptive immunity, NK cell production of IFN-γ induces M1 macrophages, which act as important effectors during cancer immunoediting.

  8. The innate and adaptive immune response to avian influenza virus infections and vaccines

    Science.gov (United States)

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

  9. The RNA-Editing Enzyme ADAR1 Controls Innate Immune Responses to RNA

    Directory of Open Access Journals (Sweden)

    Niamh M. Mannion

    2014-11-01

    Full Text Available The ADAR RNA-editing enzymes deaminate adenosine bases to inosines in cellular RNAs. Aberrant interferon expression occurs in patients in whom ADAR1 mutations cause Aicardi-Goutières syndrome (AGS or dystonia arising from striatal neurodegeneration. Adar1 mutant mouse embryos show aberrant interferon induction and die by embryonic day E12.5. We demonstrate that Adar1 embryonic lethality is rescued to live birth in Adar1; Mavs double mutants in which the antiviral interferon induction response to cytoplasmic double-stranded RNA (dsRNA is prevented. Aberrant immune responses in Adar1 mutant mouse embryo fibroblasts are dramatically reduced by restoring the expression of editing-active cytoplasmic ADARs. We propose that inosine in cellular RNA inhibits antiviral inflammatory and interferon responses by altering RLR interactions. Transfecting dsRNA oligonucleotides containing inosine-uracil base pairs into Adar1 mutant mouse embryo fibroblasts reduces the aberrant innate immune response. ADAR1 mutations causing AGS affect the activity of the interferon-inducible cytoplasmic isoform more severely than the nuclear isoform.

  10. Innate immunity probed by lipopolysaccharides affinity strategy and proteomics.

    Science.gov (United States)

    Giangrande, Chiara; Colarusso, Lucia; Lanzetta, Rosa; Molinaro, Antonio; Pucci, Piero; Amoresano, Angela

    2013-01-01

    Lipopolysaccharides (LPSs) are ubiquitous and vital components of the cell surface of Gram-negative bacteria that have been shown to play a relevant role in the induction of the immune-system response. In animal and plant cells, innate immune defenses toward microorganisms are triggered by the perception of pathogen associated molecular patterns. These are conserved and generally indispensable microbial structures such as LPSs that are fundamental in the Gram-negative immunity recognition. This paper reports the development of an integrated strategy based on lipopolysaccharide affinity methodology that represents a new starting point to elucidate the molecular mechanisms elicited by bacterial LPS and involved in the different steps of innate immunity response. Biotin-tagged LPS was immobilized on streptavidin column and used as a bait in an affinity capture procedure to identify protein partners from human serum specifically interacting with this effector. The complex proteins/lipopolysaccharide was isolated and the protein partners were fractionated by gel electrophoresis and identified by mass spectrometry. This procedure proved to be very effective in specifically binding proteins functionally correlated with the biological role of LPS. Proteins specifically bound to LPS essentially gathered within two functional groups, regulation of the complement system (factor H, C4b, C4BP, and alpha 2 macroglobulin) and inhibition of LPS-induced inflammation (HRG and Apolipoproteins). The reported strategy might have important applications in the elucidation of biological mechanisms involved in the LPSs-mediated molecular recognition and anti-infection responses.

  11. Interferon-lambda contributes to innate immunity of mice against influenza A virus but not against hepatotropic viruses

    DEFF Research Database (Denmark)

    Mordstein, M; Kochs, G; Dumoutier, L;

    2008-01-01

    we performed influenza A virus infections of mice which carry functional alleles of the influenza virus resistance gene Mx1 and which, therefore, develop a more complete innate immune response to influenza viruses than standard laboratory mice. We demonstrate that intranasal administration of IFN...... a distinct receptor complex for signaling that is not present on all cell types. Since type I IFN receptor-deficient mice (IFNAR1(0/0)) exhibit greatly increased susceptibility to various viral diseases, it remained unclear to which degree IFN-lambda might contribute to innate immunity. To address this issue......Virus-infected cells secrete a broad range of interferon (IFN) subtypes which in turn trigger the synthesis of antiviral factors that confer host resistance. IFN-alpha, IFN-beta and other type I IFNs signal through a common universally expressed cell surface receptor, whereas IFN-lambda uses...

  12. UBXN1 Interferes with Rig-I-like Receptor-Mediated Antiviral Immune Response by Targeting MAVS

    Directory of Open Access Journals (Sweden)

    Penghua Wang

    2013-04-01

    Full Text Available RNA viruses are sensed by RIG-I-like receptors (RLRs, which signal through a mitochondria-associated adaptor molecule, MAVS, resulting in systemic antiviral immune responses. Although RLR signaling is essential for limiting RNA virus replication, it must be stringently controlled to prevent damage from inflammation. We demonstrate here that among all tested UBX-domain-containing protein family members, UBXN1 exhibits the strongest inhibitory effect on RNA-virus-induced type I interferon response. UBXN1 potently inhibits RLR- and MAVS-induced, but not TLR3-, TLR4-, or DNA-virus-induced innate immune responses. Depletion of UBXN1 enhances virus-induced innate immune responses, including those resulting from RNA viruses such as vesicular stomatitis, Sendai, West Nile, and dengue virus infection, repressing viral replication. Following viral infection, UBXN1 is induced, binds to MAVS, interferes with intracellular MAVS oligomerization, and disrupts the MAVS/TRAF3/TRAF6 signalosome. These findings underscore a critical role of UBXN1 in the modulation of a major antiviral signaling pathway.

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

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    Chia-Yi Yu

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

  14. Activation of unfolded protein response and autophagy during HCV infection modulates innate immune response.

    Science.gov (United States)

    Estrabaud, Emilie; De Muynck, Simon; Asselah, Tarik

    2011-11-01

    Autophagy, a process for catabolizing cytoplasmic components, has been implicated in the modulation of interactions between RNA viruses and their host. However, the mechanism underlying the functional role of autophagy in the viral life cycle still remains unclear. Hepatitis C virus (HCV) is a single-stranded, positive-sense, membrane-enveloped RNA virus that can cause chronic liver disease. Here we report that HCV induces the unfolded protein response (UPR), which in turn activates the autophagic pathway to promote HCV RNA replication in human hepatoma cells. Further analysis revealed that the entire autophagic process through to complete autolysosome maturation was required to promote HCV RNA replication and that it did so by suppressing innate antiviral immunity. Gene silencing or activation of the UPR-autophagy pathway activated or repressed, respectively, IFN-β activation mediated by an HCV-derived pathogen-associated molecular pattern (PAMP). Similar results were achieved with a PAMP derived from Dengue virus (DEV), indicating that HCV and DEV may both exploit the UPR-autophagy pathway to escape the innate immune response. Taken together, these results not only define the physiological significance of HCV-induced autophagy, but also shed light on the knowledge of host cellular responses upon HCV infection as well as on exploration of therapeutic targets for controlling HCV infection.

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

    Science.gov (United States)

    Yu, Chia-Yi; Chang, Tsung-Hsien; Liang, Jian-Jong; Chiang, Ruei-Lin; Lee, Yi-Ling; Liao, Ching-Len; Lin, Yi-Ling

    2012-01-01

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

  16. Hemagglutinin from the H5N1 virus activates Janus kinase 3 to dysregulate innate immunity.

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    Wei Xu

    Full Text Available Highly pathogenic avian influenza viruses (HPAIVs cause severe disease in humans. There are no effective vaccines or antiviral therapies currently available to control fatal outbreaks due in part to the lack of understanding of virus-mediated immunopathology. In our study, we used hemagglutinin (HA of H5N1 virus to investigate the related signaling pathways and their relationship to dysregulated innate immune reaction. We found the HA of H5N1 avian influenza triggered an abnormal innate immune signalling in the pulmonary epithelial cells, through an unusual process involving activation of Janus kinase 3 (JAK3 that is exclusively associated with γc chain and is essential for signaling via all γc cytokine receptors. By using a selective JAK3 inhibitor and JAK3 knockout mice, we have, for the first time, demonstrated the ability to target active JAK3 to counteract injury to the lungs and protect immunocytes from acute hypercytokinemia -induced destruction following the challenge of H5N1 HA in vitro and in vivo. On the basis of the present data, it appears that the efficacy of selective JAK3 inhibition is likely based on its ability to block multiple cytokines and protect against a superinflammatory response to pathogen-associated molecular patterns (PAMPs attack. Our findings highlight the potential value of selective JAK3 inhibitor in treating the fatal immunopathology caused by H5N1 challenge.

  17. Marginal zone B-cells, a gatekeeper of innate immunity.

    Science.gov (United States)

    Zouali, Moncef; Richard, Yolande

    2011-01-01

    To maintain the integrity of an organism constantly challenged by pathogens, the immune system is endowed with a variety of cell types. B lymphocytes were initially thought to only play a role in the adaptive branch of immunity. However, a number of converging observations revealed that two B-cell subsets, marginal zone (MZ) and B1 cells, exhibit unique developmental and functional characteristics, and can contribute to innate immune responses. In addition to their capacity to mount a local antibody response against type-2 T-cell-independent (TI-2) antigens, MZ B-cells can participate to T-cell-dependent (TD) immune responses through the capture and import of blood-borne antigens to follicular areas of the spleen. Here, we discuss the multiple roles of MZ B-cells in humans, non-human primates, and rodents. We also summarize studies - performed in transgenic mice expressing fully human antibodies on their B-cells and in macaques whose infection with Simian immunodeficiency virus (SIV) represents a suitable model for HIV-1 infection in humans - showing that infectious agents have developed strategies to subvert MZ B-cell functions. In these two experimental models, we observed that two microbial superantigens for B-cells (protein A from Staphylococcus aureus and protein L from Peptostreptococcus magnus) as well as inactivated AT-2 virions of HIV-1 and infectious SIV preferentially deplete innate-like B-cells - MZ B-cells and/or B1 B-cells - with different consequences on TI and TD antibody responses. These data revealed that viruses and bacteria have developed strategies to deplete innate-like B-cells during the acute phase of infection and to impair the antibody response. Unraveling the intimate mechanisms responsible for targeting MZ B-cells in humans will be important for understanding disease pathogenesis and for designing novel vaccine strategies.

  18. Marginal zone B-cells, a gatekeeper of innate immunity

    Directory of Open Access Journals (Sweden)

    Moncef eZOUALI

    2011-12-01

    Full Text Available To maintain the integrity of an organism constantly challenged by pathogens, the immune system is endowed with a variety of cell types. B-lymphocytes were initially thought to only play a role in the adaptative branch of immunity. However, a number of converging observations revealed that two B-cell subsets, marginal zone (MZ and B1 cells, exhibit unique developmental and functional characteristics, and can contribute to innate immune responses. In addition to their capacity to mount local antibody response against type 2 T-independent (TI-2 antigens, MZ B-cells can participate to T-dependent (TD immune response through the capture and import of blood-borne antigens to follicular areas of the spleen. Here, we discuss the multiple roles of MZ B-cells in rodents and primates. We also summarize studies —performed in transgenic mice expressing fully human antibodies on their B-cells and macaques whose infection with Simian Immunodeficiency Virus (SIV represents a suitable model for HIV-1 infection in humans— showing that infectious agents have developed strategies to subvert MZ B-cell functions. In these two experimental models, we observed that two microbial superantigens for B-cells (protein A from Staphylococcus aureus and protein L from Peptostreptococcus magnus as well as inactivated AT-2 virions of HIV-1 and infectious SIV preferentially deplete innate-like B-cells —MZ B-cells and/or B1 B-cells— with different consequences on TI and TD antibody responses. These data revealed that viruses and bacteria have developed strategies to deplete innate-like B-cells during the acute phase of infection and to impair the antibody response. Unraveling the intimate mechanisms responsible for targeting MZ B-cells in humans will be important for understanding disease pathogenesis and for designing novel vaccine strategies.

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

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    Wy Ching Ng

    2012-01-01

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

  20. Bridging Innate and Adaptive Antitumor Immunity Targeting Glycans

    Science.gov (United States)

    Pashov, Anastas; Monzavi-Karbassi, Bejatolah; Raghava, Gajendra P. S.; Kieber-Emmons, Thomas

    2010-01-01

    Effective immunotherapy for cancer depends on cellular responses to tumor antigens. The role of major histocompatibility complex (MHC) in T-cell recognition and T-cell receptor repertoire selection has become a central tenet in immunology. Structurally, this does not contradict earlier findings that T-cells can differentiate between small hapten structures like simple glycans. Understanding T-cell recognition of antigens as defined genetically by MHC and combinatorially by T cell receptors led to the “altered self” hypothesis. This notion reflects a more fundamental principle underlying immune surveillance and integrating evolutionarily and mechanistically diverse elements of the immune system. Danger associated molecular patterns, including those generated by glycan remodeling, represent an instance of altered self. A prominent example is the modification of the tumor-associated antigen MUC1. Similar examples emphasize glycan reactivity patterns of antigen receptors as a phenomenon bridging innate and adaptive but also humoral and cellular immunity and providing templates for immunotherapies. PMID:20617150

  1. 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...

  2. Innate immune responses to rotavirus infection in macrophages depend on MAVS but involve neither the NLRP3 inflammasome nor JNK and p38 signaling pathways.

    Science.gov (United States)

    Di Fiore, Izabel J M; Holloway, Gavan; Coulson, Barbara S

    2015-10-02

    Rotavirus infection is a major cause of life-threatening infantile gastroenteritis. The innate immune system provides an immediate mechanism of suppressing viral replication and is necessary for an effective adaptive immune response. Innate immunity involves host recognition of viral infection and establishment of a powerful antiviral state through the expression of pro-inflammatory cytokines such as type-1 interferon (IFN). Macrophages, the front-line cells of innate immunity, produce IFN and other cytokines in response to viral infection. However, the role of macrophages during rotavirus infection is not well defined. We demonstrate here that RRV rotavirus triggers the production of proinflammatory cytokines from mouse bone marrow-derived macrophages. IFN and antiviral cytokine production was abolished in rotavirus-infected MAVS (-/-) macrophages. This indicates that rotavirus triggers innate immunity in macrophages through RIG-I and/or MDA5 viral recognition, and MAVS signaling is essential for cytokine responses in macrophages. Rotavirus induced IFN expression in both wild type and MDA5 (-/-) macrophages, showing that MDA5 is not essential for IFN secretion following infection, and RIG-I and MDA5 may act redundantly in promoting rotavirus recognition. Interestingly, rotavirus neither stimulated mitogen-activated protein kinases p38 and JNK nor activated the NLRP3 inflammasome, demonstrating that these components might not be involved in innate responses to rotavirus infection in macrophages. Our results indicate that rotavirus elicits intracellular signaling in macrophages, resulting in the induction of IFN and antiviral cytokines, and advance our understanding of the involvement of these cells in innate responses against rotavirus.

  3. Polymorphisms in key innate immune genes and their effects on measles vaccine responses and vaccine failure in children from Mozambique.

    Science.gov (United States)

    Clifford, Holly D; Hayden, Catherine M; Khoo, Siew-Kim; Naniche, Denise; Mandomando, Inacio M; Zhang, Guicheng; Richmond, Peter; Le Souëf, Peter N

    2012-09-21

    Despite an effective vaccine, measles remains a major health problem globally, particularly in developing countries. More than 30% of children show primary vaccine failure and therefore remain vulnerable to measles. Genetic variation in key innate pathogen recognition receptors, such as the measles cell entry receptors CD46 and SLAM, measles attachment receptor DC-SIGN, the antiviral toll-like receptors (TLR)3, TLR7 and TLR8, and the cytosolic antiviral receptor RIG-I, may significantly affect measles IgG antibody responses. Measles is still highly prevalent in developing countries such as those in Africa however there is no previous data on the effect of these innate immune genes in a resident African population. Polymorphisms (n=29) in the candidate genes were genotyped in a cohort of vaccinated children (n=238) aged 6 months-14 years from Mozambique, Africa who either had vaccine failure and contracted measles (cases; n=66) or controls (n=172). Contrasting previous associations with measles responses in Caucasians and/or strong evidence for candidacy, we found little indication that these key innate immune genes affect measles IgG responses in our cohort of Mozambican children. We did however identify that CD46 and TLR8 variants may be involved in the occurrence of measles vaccine failure. This study highlights the importance of genetic studies in resident, non-Caucasian populations, from areas where determining the factors that may affect measles control is of a high priority.

  4. 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.

  5. Plasmodium activates the innate immune response of Anopheles gambiae mosquitoes.

    Science.gov (United States)

    Richman, A M; Dimopoulos, G; Seeley, D; Kafatos, F C

    1997-01-01

    Innate immune-related gene expression in the major disease vector mosquito Anopheles gambiae has been analyzed following infection by the malaria parasite, Plasmodium berghei. Substantially increased levels of mRNAs encoding the antibacterial peptide defensin and a putative Gram-negative bacteria-binding protein (GNBP) are observed 20-30 h after ingestion of an infected blood-meal, at a time which indicates that this induction is a response to parasite invasion of the midgut epithelium. The induction is dependent upon the ingestion of infective, sexual-stage parasites, and is not due to opportunistic co-penetration of resident gut micro-organisms into the hemocoel. The response is activated following infection both locally (in the midgut) and systemically (in remaining tissues, presumably fat body and/or hemocytes). The observation that Plasmodium can trigger a molecularly defined immune response in the vector constitutes an important advance in our understanding of parasite-vector interactions that are potentially involved in malaria transmission, and extends knowledge of the innate immune system of insects to encompass responses to protozoan parasites. PMID:9321391

  6. Feliform carnivores have a distinguished constitutive innate immune response.

    Science.gov (United States)

    Heinrich, Sonja K; Wachter, Bettina; Aschenborn, Ortwin H K; Thalwitzer, Susanne; Melzheimer, Jörg; Hofer, Heribert; Czirják, Gábor Á

    2016-05-15

    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.

  7. Feliform carnivores have a distinguished constitutive innate immune response

    Directory of Open Access Journals (Sweden)

    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.

  8. 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.

  9. RNA sensors of the innate immune system and their detection of pathogens.

    Science.gov (United States)

    Chen, Nanhua; Xia, Pengpeng; Li, Shuangjie; Zhang, Tangjie; Wang, Tony T; Zhu, Jianzhong

    2017-04-04

    The innate immune system plays a critical role in pathogen recognition and initiation of protective immune response through the recognition of pathogen associated molecular patterns (PAMPs) by its pattern recognition receptors (PRRs). Nucleic acids including RNA and DNA have been recognized as very important PAMPs of pathogens especially for viruses. RNA are the major PAMPs of RNA viruses, to which most severe disease causing viruses belong thus posing a tougher challenge to human and animal health. Therefore, the understanding of the immune biology of RNA PRRs is critical for control of pathogen infections especially for RNA virus infections. RNA PRRs are comprised of TLR3, TLR7, TLR8, RIG-I, MDA5, NLRP3, NOD2, and some other minorities. This review introduces these RNA PRRs by describing the cellular localizations, ligand recognitions, activation mechanisms, cell signaling pathways, and recognition of pathogens; the cross-talks between various RNA PRRs are also reviewed. The deep insights of these RNA PRRs can be utilized to improve anti-viral immune response. © 2017 IUBMB Life, 2017.

  10. The Role of Innate Immunity and Aeroallergens in Chronic Rhinosinusitis.

    Science.gov (United States)

    London, Nyall R; Tharakan, Anuj; Ramanathan, Murugappan

    2016-01-01

    Allergy has been inferred to contribute to the pathophysiology of chronic rhinosinusitis (CRS) although this role is controversial and the mechanism is debated. Furthermore, the role of aeroallergens in CRS is poorly defined and has been postulated to contribute to CRS through direct penetration in the sinuses or downstream systemic consequences. Common aeroallergens implicated in chronic rhinosinusitis include air pollution/second hand smoke, dust mite and pollen [1,2,3]. One emerging potential mechanism whereby aeroallergens contribute to CRS is through sinonasal epithelial barrier disruption (fig. 1). Characterization of cytokine disruption of sinonasal epithelial cell barrier has been described including interleukin (IL)-4 and IL-13, as well as aeroallergens such as house dust mite and cigarette smoke. Recent results have demonstrated severe barrier disruption in response to direct application of either particulate matter (PM) or house dust mite (HDM) to sinonasal epithelial cells. Sinonasal epithelial barrier disruption may contribute to CRS by enabling the perpetual and chronic exposure of inflammatory allergens and stimuli. The sinonasal epithelial barrier plays a significant role in innate immune host defense. Mechanisms of innate immune defense include pattern recognition receptors (PRRs), secreted endogenous antimicrobials and inflammatory cytokines that aid in repair mechanisms including IL-33. Here we discuss recent evidence implicating aeroallergens and dysregulated host innate immune responses in the development of CRS. 1Fig. 1. Aeroallergens and inflammatory stimuli disrupt sinonasal epithelial barrier function. These agents act to destabilize the barrier through stimulating endocytosis and destruction of cell junction proteins via oxidative stress and MyD88-dependent mechanisms. Furthermore, aeroallergens and inflammatory stimuli induce secretion of IL-25, IL-33, and TSLP from sinonasal epithelial cells.F01.

  11. Yersinia type Ⅲ effectors perturb host innate immune responses

    Institute of Scientific and Technical Information of China (English)

    Khavong Pha; Lorena Navarro

    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 Gramnegative bacteria that share in common a 70 kb virulence plasmid which encodes the T3 SS. 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 effector

  12. Pigeon RIG-I Function in Innate Immunity against H9N2 IAV and IBDV

    Directory of Open Access Journals (Sweden)

    Wenping Xu

    2015-07-01

    Full Text Available Retinoic acid-inducible gene I (RIG-I, a cytosolic pattern recognition receptor (PRR, can sense various RNA viruses, including the avian influenza virus (AIV and infectious bursal disease virus (IBDV, and trigger the innate immune response. Previous studies have shown that mammalian RIG-I (human and mice and waterfowl RIG-I (ducks and geese are essential for type I interferon (IFN synthesis during AIV infection. Like ducks, pigeons are also susceptible to infection but are ineffective propagators and disseminators of AIVs, i.e., “dead end” hosts for AIVs and even highly pathogenic avian influenza (HPAI. Consequently, we sought to identify pigeon RIG-I and investigate its roles in the detection of A/Chicken/Shandong/ZB/2007 (H9N2 (ZB07, Gansu/Tianshui (IBDV TS and Beijing/CJ/1980 (IBDV CJ-801 strains in chicken DF-1 fibroblasts or human 293T cells. Pigeon mRNA encoding the putative pigeon RIG-I analogs was identified. The exogenous expression of enhanced green fluorescence protein (EGFP-tagged pigeon RIG-I and caspase activation and recruitment domains (CARDs, strongly induced antiviral gene (IFN-β, Mx, and PKR mRNA synthesis, decreased viral gene (M gene and VP2 mRNA expression, and reduced the viral titers of ZB07 and IBDV TS/CJ-801 virus strains in chicken DF-1 cells, but not in 293T cells. We also compared the antiviral abilities of RIG-I proteins from waterfowl (duck and goose and pigeon. Our data indicated that waterfowl RIG-I are more effective in the induction of antiviral genes and the repression of ZB07 and IBDV TS/CJ-801 strain replication than pigeon RIG-I. Furthermore, chicken melanoma differentiation associated gene 5(MDA5/ mitochondrial antiviral signaling (MAVS silencing combined with RIG-I transfection suggested that pigeon RIG-I can restore the antiviral response in MDA5-silenced DF-1 cells but not in MAVS-silenced DF-1 cells. In conclusion, these results demonstrated that pigeon RIG-I and CARDs have a strong antiviral

  13. Innate immune responses in ALV-J infected chicks and chickens with hemangioma in vivo

    Directory of Open Access Journals (Sweden)

    Min eFeng

    2016-05-01

    Full Text Available Avian leukosis virus subgroup J (ALV-J infection can cause tumors and immunosuppression. Since the precise mechanism of the innate immune response induced by ALV-J is unknown, we investigated the antiviral innate immune responses induced by ALV-J in chicks and chickens that had developed tumors. Spleen levels of interleukin-6 (IL-6, IL-10, IL-1β and interferon-β (IFN-β were not significantly different between the infected chick groups and the control groups from 1 day post hatch to 7 days post hatch. However, IL-6, IL-1β and IFN-β protein levels in the three clinical samples with hemangiomas were dramatically increased compared to the healthy samples. In addition, the anti-inflammatory cytokine IL-10 increased sharply in two of three clinical samples. We also found a more than 20-fold up-regulation of ISG12-1 mRNA at 1 day post infection (d.p.i. and a 2-fold up-regulation of ZC3HAV1 mRNA at 4 d.p.i. However, there were no statistical differences in ISG12-1 and ZC3HAV1 mRNA expression levels in the tumorigenesis phase. ALV-J infection induced a significant increase of Toll-like receptor 7 (TLR-7 at 1 d.p.i. and dramatically increased the mRNA levels of melanoma differentiation-associated gene 5 (MDA5 in the tumorigenesis phase. Moreover, the protein levels of interferon regulatory factor 1 (IRF-1 and signal transducer and activator of transcription 1 (STAT1 were decreased in chickens with tumors. These results suggest that ALV-J was primarily recognized by chicken TLR7 and MDA5 at early and late in vivo infection stages, respectively. ALV-J strain SCAU-HN06 did not induce any significant antiviral innate immune response in one week old chicks. However, interferon-stimulated genes were not induced normally during the late phase of ALV-J infection due to a reduction of IRF1 and STAT1 expression.

  14. Innate Immune Responses in ALV-J Infected Chicks and Chickens with Hemangioma In Vivo.

    Science.gov (United States)

    Feng, Min; Dai, Manman; Xie, Tingting; Li, Zhenhui; Shi, Meiqing; Zhang, Xiquan

    2016-01-01

    Avian leukosis virus subgroup J (ALV-J) infection can cause tumors and immunosuppression. Since the precise mechanism of the innate immune response induced by ALV-J is unknown, we investigated the antiviral innate immune responses induced by ALV-J in chicks and chickens that had developed tumors. Spleen levels of interleukin-6 (IL-6), IL-10, IL-1β, and interferon-β (IFN-β) were not significantly different between the infected chick groups and the control groups from 1 day post hatch to 7 days post hatch. However, IL-6, IL-1β, and IFN-β protein levels in the three clinical samples with hemangiomas were dramatically increased compared to the healthy samples. In addition, the anti-inflammatory cytokine IL-10 increased sharply in two of three clinical samples. We also found a more than 20-fold up-regulation of ISG12-1 mRNA at 1 day post infection (d.p.i.) and a twofold up-regulation of ZC3HAV1 mRNA at 4 d.p.i. However, there were no statistical differences in ISG12-1 and ZC3HAV1 mRNA expression levels in the tumorigenesis phase. ALV-J infection induced a significant increase of Toll-like receptor 7 (TLR-7) at 1 d.p.i. and dramatically increased the mRNA levels of melanoma differentiation-associated gene 5 (MDA5) in the tumorigenesis phase. Moreover, the protein levels of interferon regulatory factor 1 (IRF-1) and signal transducer and activator of transcription 1 (STAT1) were decreased in chickens with tumors. These results suggest that ALV-J was primarily recognized by chicken TLR7 and MDA5 at early and late in vivo infection stages, respectively. ALV-J strain SCAU-HN06 did not induce any significant antiviral innate immune response in 1 week old chicks. However, interferon-stimulated genes were not induced normally during the late phase of ALV-J infection due to a reduction of IRF1 and STAT1 expression.

  15. Human breast milk and the gastrointestinal innate immune system.

    Science.gov (United States)

    Jakaitis, Brett M; Denning, Patricia W

    2014-06-01

    The gastrointestinal (GI) tract is a large potential portal for multiple infectious agents to enter the human body. The GI system performs multiple functions as part of the neonate's innate immune system, providing critical defense during a vulnerable period. Multiple mechanisms and actions are enhanced by the presence of human breast milk. Bioactive factors found in human milk work together to create and maintain an optimal and healthy environment, allowing the intestines to deliver ideal nutrition to the host and afford protection by a variety of mechanisms.

  16. Involvement of Fenneropenaeus chinensis Cathepsin C in antiviral immunity.

    Science.gov (United States)

    Wang, Shuai; Shi, Li-Jie; Liu, Ning; Chen, An-Jing; Zhao, Xiao-Fan; Wang, Jin-Xing

    2012-10-01

    Cathepsin C (Cath C) is a lysosomal cysteine protease that belongs to the papain superfamily. Cath C is capable of activating many chymotrypsin-like serine proteases and is reported to be a central coordinator for the activation of many serine proteinases in immune and inflammatory cells. In this study, Cath C cDNA was cloned from Fenneropenaeus chinensis (Fc). The complete cDNA of Fc-Cath C in Chinese white shrimp was found to be 1445-base pairs (bp) long. It contained an open reading frame (ORF) 1356-bp long and encoded a 451-amino acid residue protein, including a 17-amino acid residue signal peptide. Real-time PCR analysis results indicated that Fc-Cath C was present in all the tissues detected and exhibited high level of transcription in the hepatopancreas. In hemocytes, hepatopancreas, gills and intestine, Fc-Cath C was upregulated after stimulation by the Vibrio anguillarum and the white spot syndrome viruses (WSSVs). Replication of the WSSV increased after the injection of Fc-Cath C antiserum or knockdown Cath C by RNA interference. These results implied that Cath C might play a crucial role in the antiviral immune response of shrimp.

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

    NARCIS (Netherlands)

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

    2014-01-01

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

  18. Innate Immune Memory: Activation of Macrophage Killing Ability by Developmental Duties.

    Science.gov (United States)

    Schneider, David; Tate, Ann Thomas

    2016-06-20

    Innate immune systems in many taxa exhibit hallmarks of memory in response to previous microbial exposure. A new study demonstrates that innate immune memory in Drosophila embryonic macrophages can also be induced by the successful engulfment of apoptotic cells, highlighting the importance of early exposure events for developing responsive immune systems.

  19. Innate immune function in placenta and cord blood of hepatitis C--seropositive mother-infant dyads.

    Directory of Open Access Journals (Sweden)

    Christine Waasdorp Hurtado

    Full Text Available Vertical transmission accounts for the majority of pediatric cases of hepatitis C viral (HCV infection. In contrast to the adult population who develop persistent viremia in approximately 80% of cases following exposure, the rate of mother-to-child transmission (2-6% is strikingly low. Protection from vertical transmission likely requires the coordination of multiple components of the immune system. Placenta and decidua provide a direct connection between mother and infant. We hypothesized that innate immune responses would differ across the three compartments (decidua, placenta and cord blood and that hepatitis C exposure would modify innate immunity in these tissues. The study was comprised of HCV-infected and healthy control mother and infant pairs from whom cord blood, placenta and decidua were collected with isolation of mononuclear cells. Multiparameter flow cytometry was performed to assess the phenotype, intracellular cytokine production and cytotoxicity of the cells. In keeping with a model where the maternal-fetal interface provides antiviral protection, we found a gradient in proportional frequencies of NKT and gammadelta-T cells being higher in placenta than cord blood. Cytotoxicity of NK and NKT cells was enhanced in placenta and placental NKT cytotoxicity was further increased by HCV infection. HCV exposure had multiple effects on innate cells including a decrease in activation markers (CD69, TRAIL and NKp44 on NK cells and a decrease in plasmacytoid dendritic cells in both placenta and cord blood of exposed infants. In summary, the placenta represents an active innate immunological organ that provides antiviral protection against HCV transmission in the majority of cases; the increased incidence in preterm labor previously described in HCV-seropositive mothers may be related to enhanced cytotoxicity of NKT cells.

  20. Innate immune function in placenta and cord blood of hepatitis C--seropositive mother-infant dyads.

    Science.gov (United States)

    Hurtado, Christine Waasdorp; Golden-Mason, Lucy; Brocato, Megan; Krull, Mona; Narkewicz, Michael R; Rosen, Hugo R

    2010-08-30

    Vertical transmission accounts for the majority of pediatric cases of hepatitis C viral (HCV) infection. In contrast to the adult population who develop persistent viremia in approximately 80% of cases following exposure, the rate of mother-to-child transmission (2-6%) is strikingly low. Protection from vertical transmission likely requires the coordination of multiple components of the immune system. Placenta and decidua provide a direct connection between mother and infant. We hypothesized that innate immune responses would differ across the three compartments (decidua, placenta and cord blood) and that hepatitis C exposure would modify innate immunity in these tissues. The study was comprised of HCV-infected and healthy control mother and infant pairs from whom cord blood, placenta and decidua were collected with isolation of mononuclear cells. Multiparameter flow cytometry was performed to assess the phenotype, intracellular cytokine production and cytotoxicity of the cells. In keeping with a model where the maternal-fetal interface provides antiviral protection, we found a gradient in proportional frequencies of NKT and gammadelta-T cells being higher in placenta than cord blood. Cytotoxicity of NK and NKT cells was enhanced in placenta and placental NKT cytotoxicity was further increased by HCV infection. HCV exposure had multiple effects on innate cells including a decrease in activation markers (CD69, TRAIL and NKp44) on NK cells and a decrease in plasmacytoid dendritic cells in both placenta and cord blood of exposed infants. In summary, the placenta represents an active innate immunological organ that provides antiviral protection against HCV transmission in the majority of cases; the increased incidence in preterm labor previously described in HCV-seropositive mothers may be related to enhanced cytotoxicity of NKT cells.

  1. Emerging roles of interferon-stimulated genes in the innate immune response to hepatitis C virus infection.

    Science.gov (United States)

    Wong, Mun-Teng; Chen, Steve S-L

    2016-01-01

    Infection with hepatitis C virus (HCV), a major viral cause of chronic liver disease, frequently progresses to steatosis and cirrhosis, which can lead to hepatocellular carcinoma. HCV infection strongly induces host responses, such as the activation of the unfolded protein response, autophagy and the innate immune response. Upon HCV infection, the host induces the interferon (IFN)-mediated frontline defense to limit virus replication. Conversely, HCV employs diverse strategies to escape host innate immune surveillance. Type I IFN elicits its antiviral actions by inducing a wide array of IFN-stimulated genes (ISGs). Nevertheless, the mechanisms by which these ISGs participate in IFN-mediated anti-HCV actions remain largely unknown. In this review, we first outline the signaling pathways known to be involved in the production of type I IFN and ISGs and the tactics that HCV uses to subvert innate immunity. Then, we summarize the effector mechanisms of scaffold ISGs known to modulate IFN function in HCV replication. We also highlight the potential functions of emerging ISGs, which were identified from genome-wide siRNA screens, in HCV replication. Finally, we discuss the functions of several cellular determinants critical for regulating host immunity in HCV replication. This review will provide a basis for understanding the complexity and functionality of the pleiotropic IFN system in HCV infection. Elucidation of the specificity and the mode of action of these emerging ISGs will also help to identify novel cellular targets against which effective HCV therapeutics can be developed.

  2. [ROLE OF INNATE IMMUNITY FACTORS IN PERIODONTITIS PATHOGENESIS].

    Science.gov (United States)

    Gankovskaya, L V; Khelminskaya, N M; Molchanova, E A; Svitich, O A

    2016-01-01

    Chronic generalized periodontitis (CGP) is a disease of periodontium tissues supporting tooth induced by bacteria, that is characterized by the presence of processes of inflammation with destruction of bone tissue. The knowledge of molecular mechanisms of CGP pathogenesis facilitates creation of the most effective methods of therapy of this disease. Bacterial infection is a primary factor in periodontitis etiology, however is not sufficient for its start and subsequent development. It is known, that bacterial factors induce alocal inflammationreaction and.activate the system of innate immunity through activation of Toll-like receptors (TLR), located on the surface of resident cells and leukocytes. Activation of these cells results in production of pro-inflammatory cytokines and recruitment of phagocytes and lymphocytes into the inflammation zone. In review we examined the known data regarding factors of immune protection of periodontium including cell populations and cytokines, as well as mechanisms of tissue destruction, that support the tooth. Perspectives of therapy are also discussed

  3. Innate immune responses of young bulls to a novel environment.

    Science.gov (United States)

    Razzuoli, Elisabetta; Olzi, Emilio; Calà, Pietro; Cafazzo, Simona; Magnani, Diego; Vitali, Andrea; Lacetera, Nicola; Archetti, Laura; Lazzara, Fabrizio; Ferrari, Angelo; Nanni Costa, Leonardo; Amadori, Massimo

    2016-04-01

    Animal welfare during transportation has been investigated in several studies, as opposed to post-transportation phases. In this study, we evaluated the effect of a novel environment after transportation on 26 Friesian bulls, 242 ± 42 day-old, from ten different dairy farms. Animals were shipped to a breeding center in different seasons, and selected parameters of innate immunity (serum bactericidal activity, hemolytic complement, serum albumin, α, β, and γ-globulins, interleukin-6, TNF-α) were monitored before and after the arrival at days--4/0/4/15/30. Our results showed significant differences of IL-6 and TNF-α protein levels at destination in December (94 ± 1.3 pg/ml) and June (+788 pg/ml), respectively. Moreover, the serum levels of these cytokines increased between days 0 and 15 after the arrival, the modulation of IL-6 being in agreement with established models of physical and/or psychological stress. Concerning the modulation of albumin, alpha and beta-globulins, the highest levels were detected in April, whereas a significant decrease was observed between day 15 and 30 after arrival; on the contrary, γ-globulin levels significantly increased after day 15. The results of this study highlight the occurrence of innate immune responses of young bulls to the combined effects of climate (season) and novel farming conditions.

  4. Antimicrobial peptides: key components of the innate immune system.

    Science.gov (United States)

    Pasupuleti, Mukesh; Schmidtchen, Artur; Malmsten, Martin

    2012-06-01

    Life-threatening infectious diseases are on their way to cause a worldwide crisis, as treating them effectively is becoming increasingly difficult due to the emergence of antibiotic resistant strains. Antimicrobial peptides (AMPs) form an ancient type of innate immunity found universally in all living organisms, providing a principal first-line of defense against the invading pathogens. The unique diverse function and architecture of AMPs has attracted considerable attention by scientists, both in terms of understanding the basic biology of the innate immune system, and as a tool in the design of molecular templates for new anti-infective drugs. AMPs are gene-encoded short (antimicrobial activity. AMPs have been the subject of natural evolution, as have the microbes, for hundreds of millions of years. Despite this long history of co-evolution, AMPs have not lost their ability to kill or inhibit the microbes totally, nor have the microbes learnt to avoid the lethal punch of AMPs. AMPs therefore have potential to provide an important breakthrough and form the basis for a new class of antibiotics. In this review, we would like to give an overview of cationic antimicrobial peptides, origin, structure, functions, and mode of action of AMPs, which are highly expressed and found in humans, as well as a brief discussion about widely abundant, well characterized AMPs in mammals, in addition to pharmaceutical aspects and the additional functions of AMPs.

  5. Potential of Helper-Dependent Adenoviral Vectors in Modulating Airway Innate Immunity

    Institute of Scientific and Technical Information of China (English)

    Rahul Kushwah; Huibi Cao; Jim Hu

    2007-01-01

    Innate immune responses form the first line of defense against foreign insults and recently significant advances have been made in our understanding of the initiation of innate immune response along with its ability to modulate inflammation. In airway diseases such as asthma, COPD and cystic fibrosis, over reacting of the airway innate immune responses leads to cytokine imbalance and airway remodeling or damage. Helper-dependent adenoviral vectors have the potential to deliver genes to modulate airway innate immune responses and have many advantages over its predecessors. However, there still are a few limitations that need to be addressed prior to their use in clinical applications.

  6. 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

    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....

  7. Innate and adaptive immune responses to in utero infection with bovine viral diarrhea virus.

    Science.gov (United States)

    Hansen, Thomas R; Smirnova, Natalia P; Webb, Brett T; Bielefeldt-Ohmann, Helle; Sacco, Randy E; Van Campen, Hana

    2015-06-01

    Infection of pregnant cows with noncytopathic (ncp) bovine viral diarrhea virus (BVDV) induces rapid innate and adaptive immune responses, resulting in clearance of the virus in less than 3 weeks. Seven to 14 days after inoculation of the cow, ncpBVDV crosses the placenta and induces a fetal viremia. Establishment of persistent infection with ncpBVDV in the fetus has been attributed to the inability to mount an immune response before 90-150 days of gestational age. The result is 'immune tolerance', persistent viral replication and shedding of ncpBVDV. In contrast, we describe the chronic upregulation of fetal Type I interferon (IFN) pathway genes and the induction of IFN-γ pathways in fetuses of cows infected on day 75 of gestation. Persistently infected (PI) fetal IFN-γ concentrations also increased at day 97 at the peak of fetal viremia and IFN-γ mRNA was significantly elevated in fetal thymus, liver and spleen 14-22 days post maternal inoculation. PI fetuses respond to ncpBVDV infection through induction of Type I IFN and IFN-γ activated genes leading to a reduction in ncpBVDV titer. We hypothesize that fetal infection with BVDV persists because of impaired induction of IFN-γ in the face of activated Type I IFN responses. Clarification of the mechanisms involved in the IFN-associated pathways during BVDV fetal infection may lead to better detection methods, antiviral compounds and selection of genetically resistant breeding animals.

  8. Long-term activation of the innate immune system in atherosclerosis.

    Science.gov (United States)

    Christ, Anette; Bekkering, Siroon; Latz, Eicke; Riksen, Niels P

    2016-08-01

    Efforts to reverse the pathologic consequences of vulnerable plaques are often stymied by the complex treatment resistant pro-inflammatory environment within the plaque. This suggests that pro-atherogenic stimuli, such as LDL cholesterol and high fat diets may impart longer lived signals on (innate) immune cells that persist even after reversing the pro-atherogenic stimuli. Recently, a series of studies challenged the traditional immunological paradigm that innate immune cells cannot display memory characteristics. Epigenetic reprogramming in these myeloid cell subsets, after exposure to certain stimuli, has been shown to alter the expression of genes upon re-exposure. This phenomenon has been termed trained innate immunity or innate immune memory. The changed responses of 'trained' innate immune cells can confer nonspecific protection against secondary infections, suggesting that innate immune memory has likely evolved as an ancient mechanism to protect against pathogens. However, dysregulated processes of immunological imprinting mediated by trained innate immunity may also be detrimental under certain conditions as the resulting exaggerated immune responses could contribute to autoimmune and inflammatory diseases, such as atherosclerosis. Pro-atherogenic stimuli most likely cause epigenetic modifications that persist for prolonged time periods even after the initial stimulus has been removed. In this review we discuss the concept of trained innate immunity in the context of a hyperlipidemic environment and atherosclerosis. According to this idea the epigenome of myeloid (progenitor) cells is presumably modified for prolonged periods of time, which, in turn, could evoke a condition of continuous immune cell over-activation.

  9. Interferon-inducible GTPases in cell autonomous and innate immunity.

    Science.gov (United States)

    Meunier, Etienne; Broz, Petr

    2016-02-01

    Detection and clearance of invading pathogens requires a coordinated response of the adaptive and innate immune system. Host cell, however, also features different mechanisms that restrict pathogen replication in a cell-intrinsic manner, collectively referred to as cell-autonomous immunity. In immune cells, the ability to unleash those mechanisms strongly depends on the activation state of the cell, which is controlled by cytokines or the detection of pathogen-associated molecular patterns by pattern-recognition receptors. The interferon (IFN) class of cytokines is one of the strongest inducers of antimicrobial effector mechanisms and acts against viral, bacterial and parasitic intracellular pathogens. This has been linked to the upregulation of several hundreds of IFN-stimulated genes, among them the so-called IFN-inducible GTPases. Two subfamilies of IFN-inducible GTPases, the immunity-related GTPases (IRGs) and the guanylate-binding proteins (GBPs), have gained attention due to their exceptional ability to specifically target intracellular vacuolar pathogens and restrict their replication by destroying their vacuolar compartment. Their repertoire has recently been expanded to the regulation of inflammasome complexes, which are cytosolic multi-protein complexes that control an inflammatory cell death called pyroptosis and the release of cytokines like interleukin-1β and interleukin-18. Here we discuss recent advances in understanding the function, the targeting and regulation of IRG and GBP proteins during microbial infections.

  10. Polysaccharides isolated from Acai fruit induce innate immune responses.

    Directory of Open Access Journals (Sweden)

    Jeff Holderness

    Full Text Available The Açaí (Acai fruit is a popular nutritional supplement that purportedly enhances immune system function. These anecdotal claims are supported by limited studies describing immune responses to the Acai polyphenol fraction. Previously, we characterized γδ T cell responses to both polyphenol and polysaccharide fractions from several plant-derived nutritional supplements. Similar polyphenol and polysaccharide fractions are found in Acai fruit. Thus, we hypothesized that one or both of these fractions could activate γδ T cells. Contrary to previous reports, we did not identify agonist activity in the polyphenol fraction; however, the Acai polysaccharide fraction induced robust γδ T cell stimulatory activity in human, mouse, and bovine PBMC cultures. To characterize the immune response to Acai polysaccharides, we fractionated the crude polysaccharide preparation and tested these fractions for activity in human PBMC cultures. The largest Acai polysaccharides were the most active in vitro as indicated by activation of myeloid and γδ T cells. When delivered in vivo, Acai polysaccharide induced myeloid cell recruitment and IL-12 production. These results define innate immune responses induced by the polysaccharide component of Acai and have implications for the treatment of asthma and infectious disease.

  11. Innate immunity to RNA virus is regulated by temporal and reversible sumoylation of RIG-I and MDA5.

    Science.gov (United States)

    Hu, Ming-Ming; Liao, Chen-Yang; Yang, Qing; Xie, Xue-Qin; Shu, Hong-Bing

    2017-04-03

    Sensing of viral RNA by the cytosolic receptors RIG-I and melanoma differentiation-associated gene 5 (MDA5) leads to innate antiviral response. How RIG-I and MDA5 are dynamically regulated in innate antiviral response is not well understood. Here, we show that TRIM38 positively regulates MDA5- and RIG-I-mediated induction of downstream genes and acts as a SUMO E3 ligase for their dynamic sumoylation at K43/K865 and K96/K888, respectively, before and after viral infection. The sumoylation of MDA5 and RIG-I suppresses their K48-linked polyubiquitination and degradation in uninfected or early-infected cells. Sumoylation of the caspase recruitment domains of MDA5 and RIG-I is also required for their dephosphorylation by PP1 and activation upon viral infection. At the late phase of viral infection, both MDA5 and RIG-I are desumoylated by SENP2, resulting in their K48-linked polyubiquitination and degradation. These findings suggest that dynamic sumoylation and desumoylation of MDA5 and RIG-I modulate efficient innate immunity to RNA virus and its timely termination.

  12. Influenza A(H1N1pdm09 virus suppresses RIG-I initiated innate antiviral responses in the human lung.

    Directory of Open Access Journals (Sweden)

    Wenxin Wu

    Full Text Available Influenza infection is a major cause of morbidity and mortality. Retinoic acid-inducible gene I (RIG-I is believed to play an important role in the recognition of, and response to, influenza virus and other RNA viruses. Our study focuses on the hypothesis that pandemic H1N1/09 influenza virus alters the influenza-induced proinflammatory response and suppresses host antiviral activity. We first compared the innate response to a clinical isolate of influenza A(H1N1pdm09 virus, OK/09, a clinical isolate of seasonal H3N2 virus, OK/06, and to a laboratory adapted seasonal H1N1 virus, PR8, using a unique human lung organ culture model. Exposure of human lung tissue to either pandemic or seasonal influenza virus resulted in infection and replication in alveolar epithelial cells. Pandemic virus induces a diminished RIG-I mRNA and antiviral cytokine response than seasonal virus in human lung. The suppression of antiviral response and RIG-I mRNA expression was confirmed at the protein level by ELISA and western blot. We performed a time course of RIG-I and interferon-β (IFN-β mRNA induction by the two viruses. RIG-I and IFN-β induction by OK/09 was of lower amplitude and shorter duration than that caused by PR8. In contrast, the pandemic virus OK/09 caused similar induction of proinflammatory cytokines, IL-8 and IL-6, at both the transcriptional and translational level as PR8 in human lung. Differential antiviral responses did not appear to be due to a difference in cellular infectivity as immunohistochemistry showed that both viruses infected alveolar macrophages and epithelial cells. These findings show that influenza A(H1N1pdm09 virus suppresses anti-viral immune responses in infected human lung through inhibition of viral-mediated induction of the pattern recognition receptor, RIG-I, though proinflammatory cytokine induction was unaltered. This immunosuppression of the host antiviral response by pandemic virus may have contributed to the more

  13. Innate and adaptive immune responses in allergic contact dermatitis and autoimmune skin diseases.

    Science.gov (United States)

    Edele, Fanny; Esser, Philipp R; Lass, Christian; Laszczyk, Melanie N; Oswald, Eva; Strüh, Christian M; Rensing-Ehl, Anne; Martin, Stefan F

    2007-12-01

    Allergic contact dermatitis is induced by chemicals or metal ions. A hallmark of this T cell mediated skin disease is the activation of the innate immune system by contact allergens. This immune response results in inflammation and is a prerequisite for the activation of the adaptive immune system with tissue-specific migration of effector and regulatory T cells. Recent studies have begun to address in detail the innate immune cells as well as the innate receptors on these cells and the associated signaling pathways which lead to skin inflammation. We review here recent findings regarding innate and adaptive immune responses and immune regulation of contact dermatitis and other skin diseases as well as recent developments towards an in vitro assessment of the allergenic potential of chemicals. The elucidation of the innate inflammatory pathways, cellular components and mediators will help to identify new drug targets for more efficient treatment of allergic contact dermatitis and hopefully also for its prevention.

  14. Promising Targets for Cancer Immunotherapy: TLRs, RLRs, and STING-Mediated Innate Immune Pathways

    Science.gov (United States)

    Li, Kai; Qu, Shuai; Chen, Xi; Wu, Qiong; Shi, Ming

    2017-01-01

    Malignant cancers employ diverse and intricate immune evasion strategies, which lead to inadequately effective responses of many clinical cancer therapies. However, emerging data suggest that activation of the tolerant innate immune system in cancer patients is able, at least partially, to counteract tumor-induced immunosuppression, which indicates triggering of the innate immune response as a novel immunotherapeutic strategy may result in improved therapeutic outcomes for cancer patients. The promising innate immune targets include Toll-like Receptors (TLRs), RIG-I-like Receptors (RLRs), and Stimulator of Interferon Genes (STING). This review discusses the antitumor properties of TLRs, RLRs, and STING-mediated innate immune pathways, as well as the promising innate immune targets for potential application in cancer immunotherapy. PMID:28216575

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    Wei Fan

    2016-05-01

    Full Text Available 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

  17. 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

    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

  18. The Conserved Coronavirus Macrodomain Promotes Virulence and Suppresses the Innate Immune Response during Severe Acute Respiratory Syndrome Coronavirus Infection

    Directory of Open Access Journals (Sweden)

    Anthony R. Fehr

    2016-12-01

    Full Text Available ADP-ribosylation is a common posttranslational modification that may have antiviral properties and impact innate immunity. To regulate this activity, macrodomain proteins enzymatically remove covalently attached ADP-ribose from protein targets. All members of the Coronavirinae, a subfamily of positive-sense RNA viruses, contain a highly conserved macrodomain within nonstructural protein 3 (nsp3. However, its function or targets during infection remain unknown. We identified several macrodomain mutations that greatly reduced nsp3’s de-ADP-ribosylation activity in vitro. Next, we created recombinant severe acute respiratory syndrome coronavirus (SARS-CoV strains with these mutations. These mutations led to virus attenuation and a modest reduction of viral loads in infected mice, despite normal replication in cell culture. Further, macrodomain mutant virus elicited an early, enhanced interferon (IFN, interferon-stimulated gene (ISG, and proinflammatory cytokine response in mice and in a human bronchial epithelial cell line. Using a coinfection assay, we found that inclusion of mutant virus in the inoculum protected mice from an otherwise lethal SARS-CoV infection without reducing virus loads, indicating that the changes in innate immune response were physiologically significant. In conclusion, we have established a novel function for the SARS-CoV macrodomain that implicates ADP-ribose in the regulation of the innate immune response and helps to demonstrate why this domain is conserved in CoVs.

  19. Bridging Innate and Adaptive Antitumor Immunity Targeting Glycans

    Directory of Open Access Journals (Sweden)

    Anastas Pashov

    2010-01-01

    Full Text Available Effective immunotherapy for cancer depends on cellular responses to tumor antigens. The role of major histocompatibility complex (MHC in T-cell recognition and T-cell receptor repertoire selection has become a central tenet in immunology. Structurally, this does not contradict earlier findings that T-cells can differentiate between small hapten structures like simple glycans. Understanding T-cell recognition of antigens as defined genetically by MHC and combinatorially by T cell receptors led to the “altered self” hypothesis. This notion reflects a more fundamental principle underlying immune surveillance and integrating evolutionarily and mechanistically diverse elements of the immune system. Danger associated molecular patterns, including those generated by glycan remodeling, represent an instance of altered self. A prominent example is the modification of the tumor-associated antigen MUC1. Similar examples emphasize glycan reactivity patterns of antigen receptors as a phenomenon bridging innate and adaptive but also humoral and cellular immunity and providing templates for immunotherapies.

  20. Defense and counterdefense in the RNAi-based antiviral immune system in insects.

    Science.gov (United States)

    van Mierlo, Joël T; van Cleef, Koen W R; van Rij, Ronald P

    2011-01-01

    RNA interference (RNAi) is an important pathway to combat virus infections in insects and plants. Hallmarks of antiviral RNAi in these organisms are: (1) an increase in virus replication after inactivation of major actors in the RNAi pathway, (2) production of virus-derived small interfering RNAs (v-siRNAs), and (3) suppression of RNAi by dedicated viral proteins. In this chapter, we will review the mechanism of RNAi in insects, its function as an antiviral immune system, viral small RNA profiles, and viral counterdefense strategies. We will also consider alternative, inducible antiviral immune responses.

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

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    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. 

  2. Exploring the Innate Immune System: Using Complement-Medicated Cell Lysis in the Classroom

    Science.gov (United States)

    Fuller, Kevin G.

    2008-01-01

    The protein complement pathway comprises an important part of the innate immunity. The use of serum to demonstrate complement-mediated destruction across a series of bacterial dilutions allows an instructor to introduce a number of important biological concepts such as bacterial growth, activation cascades, and adaptive versus innate immunity.

  3. 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 ...NL, Fung-Leung WP. Cell Signal. 2008 Feb;20(2):269-76. Epub 2007 Aug 23. (.png) (.svg) (.html) (.csml) Show IRAK1: a critica...l signaling mediator of innate immunity. PubmedID 17890055 Title IRAK1: a critical signaling

  4. 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 Cytosolic DNA reco...gnition for triggering innate immune responses. PubmedID 18280611 Title Cytosolic DNA reco

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

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    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.

  6. Adiponectin promotes coxsackievirus B3 myocarditis by suppression of acute anti-viral immune responses.

    Science.gov (United States)

    Jenke, A; Holzhauser, L; Löbel, M; Savvatis, K; Wilk, S; Weithäuser, A; Pinkert, S; Tschöpe, C; Klingel, K; Poller, W; Scheibenbogen, C; Schultheiss, H P; Skurk, C

    2014-05-01

    Adiponectin (APN) is an immunomodulatory adipocytokine that improves outcome in patients with virus-negative inflammatory cardiomyopathy and mice with autoimmune myocarditis. Here, we investigated whether APN modulates cardiac inflammation and injury in coxsackievirus B3 (CVB3) myocarditis. Myocarditis was induced by CVB3 infection of APN-KO and WT mice. APN reconstitution was performed by adenoviral gene transfer. Expression analyses were performed by qRT-PCR and immunoblot. Cardiac histology was analyzed by H&E-stain and immunohistochemistry. APN-KO mice exhibited diminished subacute myocarditis with reduced viral load, attenuated inflammatory infiltrates determined by NKp46, F4/80 and CD3/CD4/CD8 expression and reduced IFNβ, IFNγ, TNFα, IL-1β and IL-12 levels. Moreover, myocardial injury assessed by necrotic lesions and troponin I release was attenuated resulting in preserved left ventricular function. Those changes were reversed by APN reconstitution. APN had no influence on adhesion, uptake or replication of CVB3 in cardiac myocytes. In acute CVB3 myocarditis, cardiac viral load did not differ between APN-KO and WT mice. However, APN-KO mice displayed an enhanced acute immune response, i.e. increased expression of myocardial CD14, IFNβ, IFNγ, IL-12, and TNFα resulting in increased cardiac infiltration with pro-inflammatory M1 macrophages and activated NK cells. Up-regulation of cardiac CD14 expression, type I and II IFNs and inflammatory cell accumulation in APN-KO mice was inhibited by APN reconstitution. Our observations indicate that APN promotes CVB3 myocarditis by suppression of toll-like receptor-dependent innate immune responses, polarization of anti-inflammatory M2 macrophages and reduction of number and activation of NK cells resulting in attenuated acute anti-viral immune responses.

  7. Effect of ethanol on innate antiviral pathways and HCV replication in human liver cells

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    Fausto Nelson

    2005-12-01

    alcohol have extremely low response rates to IFN therapy 9, but the mechanisms involved have not been clarified. MAPKs play essential roles in regulation of differentiation, cell growth, and responses to cytokines, chemokines and stress. The core element in MAPK signaling consists of a module of 3 kinases, named MKKK, MKK, and MAPK, which sequentially phosphorylate each other 10. Currently, four MAPK modules have been characterized in mammalian cells: Extracellular Regulated Kinases (ERK1 and 2, Stress activated/c-Jun N terminal kinase (SAPK/JNK, p38 MAP kinases, and ERK5 11. Interestingly, ethanol modulates MAPKs 12. However, information on how ethanol affects MAPKs in the context of innate antiviral pathways such as the Jak-Stat pathway in human cells is extremely limited. When IFN-α binds its receptor, two receptor associated tyrosine kinases, Tyk2 and Jak1 become activated by phosphorylation, and phosphorylate Stat1 and Stat2 on conserved tyrosine residues 13. Stat1 and Stat2 combine with the IRF-9 protein to form the transcription factor interferon stimulated gene factor 3 (ISGF-3, which binds to the interferon stimulated response element (ISRE, and induces transcription of IFN-α-induced genes (ISG. The ISGs mediate the antiviral effects of IFN. The transcriptional activities of Stats 1, 3, 4, 5a, and 5b are also regulated by serine phosphorylation 14. Phosphorylation of Stat1 on a conserved serine amino acid at position 727 (S727, results in maximal transcriptional activity of the ISGF-3 transcription factor complex 15. Although cross-talk between p38 MAPK and the Jak-Stat pathway is essential for IFN-induced ISRE transcription, p38 does not participate in IFN induction of Stat1 serine phosphorylation 1416171819. However, cellular stress responses induced by stimuli such as ultraviolet light do induce p38 MAPK mediated Stat1 S727 phosphorylation 18. In the current report, we postulated that alcohol and HCV proteins modulate MAPK and Jak-Stat pathways in human

  8. The adaptor protein FHL2 enhances the cellular innate immune response to influenza A virus infection.

    Science.gov (United States)

    Nordhoff, Carolin; Hillesheim, Andrea; Walter, Beate M; Haasbach, Emanuel; Planz, Oliver; Ehrhardt, Christina; Ludwig, Stephan; Wixler, Viktor

    2012-07-01

    The innate immune response of influenza A virus-infected cells is predominantly mediated by type I interferon-induced proteins. Expression of the interferon β (IFNβ) itself is initiated by accumulating viral RNA and is transmitted by different signalling cascades that feed into activation of the three transcriptional elements located in the IFNβ promoter, AP-1, IRF-3 and NF-κB. FHL2 (four-and-a-half LIM domain protein 2) is an adaptor molecule that shuttles between membrane and nucleus regulating signalling cascades and gene transcription. Here we describe FHL2 as a novel regulator of influenza A virus propagation. Using mouse FHL2 wild-type, knockout and rescued cells and human epithelial cells with different expression levels of FHL2 we showed that FHL2 decreases influenza A virus propagation by regulating the intrinsic cellular antiviral immune response. On virus infection FHL2 translocates into the nucleus, potentiating the IRF-3-dependent transcription of the IFNβ gene.

  9. Rotavirus nonstructural protein 1 antagonizes innate immune response by interacting with retinoic acid inducible gene I

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    Qin Lan

    2011-12-01

    Full Text Available Abstract Background The nonstructural protein 1 (NSP1 of rotavirus has been reported to block interferon (IFN signaling by mediating proteasome-dependent degradation of IFN-regulatory factors (IRFs and (or the β-transducin repeat containing protein (β-TrCP. However, in addition to these targets, NSP1 may subvert innate immune responses via other mechanisms. Results The NSP1 of rotavirus OSU strain as well as the IRF3 binding domain truncated NSP1 of rotavirus SA11 strain are unable to degrade IRFs, but can still inhibit host IFN response, indicating that NSP1 may target alternative host factor(s other than IRFs. Overexpression of NSP1 can block IFN-β promoter activation induced by the retinoic acid inducible gene I (RIG-I, but does not inhibit IFN-β activation induced by the mitochondrial antiviral-signaling protein (MAVS, indicating that NSP1 may target RIG-I. Immunoprecipitation experiments show that NSP1 interacts with RIG-I independent of IRF3 binding domain. In addition, NSP1 induces down-regulation of RIG-I in a proteasome-independent way. Conclusions Our findings demonstrate that inhibition of RIG-I mediated type I IFN responses by NSP1 may contribute to the immune evasion of rotavirus.

  10. Epithelial NEMO links innate immunity to chronic intestinal inflammation.

    Science.gov (United States)

    Nenci, Arianna; Becker, Christoph; Wullaert, Andy; Gareus, Ralph; van Loo, Geert; Danese, Silvio; Huth, Marion; Nikolaev, Alexei; Neufert, Clemens; Madison, Blair; Gumucio, Deborah; Neurath, Markus F; Pasparakis, Manolis

    2007-03-29

    Deregulation of intestinal immune responses seems to have a principal function in the pathogenesis of inflammatory bowel disease. The gut epithelium is critically involved in the maintenance of intestinal immune homeostasis-acting as a physical barrier separating luminal bacteria and immune cells, and also expressing antimicrobial peptides. However, the molecular mechanisms that control this function of gut epithelial cells are poorly understood. Here we show that the transcription factor NF-kappaB, a master regulator of pro-inflammatory responses, functions in gut epithelial cells to control epithelial integrity and the interaction between the mucosal immune system and gut microflora. Intestinal epithelial-cell-specific inhibition of NF-kappaB through conditional ablation of NEMO (also called IkappaB kinase-gamma (IKKgamma)) or both IKK1 (IKKalpha) and IKK2 (IKKbeta)-IKK subunits essential for NF-kappaB activation-spontaneously caused severe chronic intestinal inflammation in mice. NF-kappaB deficiency led to apoptosis of colonic epithelial cells, impaired expression of antimicrobial peptides and translocation of bacteria into the mucosa. Concurrently, this epithelial defect triggered a chronic inflammatory response in the colon, initially dominated by innate immune cells but later also involving T lymphocytes. Deficiency of the gene encoding the adaptor protein MyD88 prevented the development of intestinal inflammation, demonstrating that Toll-like receptor activation by intestinal bacteria is essential for disease pathogenesis in this mouse model. Furthermore, NEMO deficiency sensitized epithelial cells to tumour-necrosis factor (TNF)-induced apoptosis, whereas TNF receptor-1 inactivation inhibited intestinal inflammation, demonstrating that TNF receptor-1 signalling is crucial for disease induction. These findings demonstrate that a primary NF-kappaB signalling defect in intestinal epithelial cells disrupts immune homeostasis in the gastrointestinal tract

  11. Tim-3: An activation marker and activation limiter of innate immune cells

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    Gencheng eHan

    2013-12-01

    Full Text Available Tim-3 was initially identified on activated Th1, Th17, and Tc1 cells and induces T cell death or exhaustion after binding to its ligand, Gal-9. The observed relationship between dysregulated Tim-3 expression on T cells and the progression of many clinical diseases has identified this molecule as an important target for intervention in adaptive immunity. Recent data have shown that it also plays critical roles in regulating the activities of macrophages, monocytes, dendritic cells, mast cells, natural killer cells, and endothelial cells. Although the underlying mechanisms remain unclear, dysregulation of Tim-3 expression on these innate immune cells leads to an excessive or inhibited inflammatory response and subsequent autoimmune damage or viral or tumor evasion. In this review, we focus on the expression and function of Tim-3 on innate immune cells and discuss 1 how Tim-3 is expressed and regulated on different innate immune cells; 2 how it affects the activity of different innate immune cells; and 3 how dysregulated Tim-3 expression on innate immune cells affects adaptive immunity and disease progression. Tim-3 is involved in the optimal activation of innate immune cells through its varied expression. A better understanding of the physiopathological role of the Tim-3 pathway in innate immunity will shed new light on the pathogenesis of clinical diseases, such as autoimmune diseases, chronic viral infections, and cancer, and suggest new approaches to intervention.

  12. Identification and validation of Ifit1 as an important innate immune bottleneck.

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    Jason E McDermott

    Full Text Available The innate immune system plays important roles in a number of disparate processes. Foremost, innate immunity is a first responder to invasion by pathogens and triggers early defensive responses and recruits the adaptive immune system. The innate immune system also responds to endogenous damage signals that arise from tissue injury. Recently it has been found that innate immunity plays an important role in neuroprotection against ischemic stroke through the activation of the primary innate immune receptors, Toll-like receptors (TLRs. Using several large-scale transcriptomic data sets from mouse and mouse macrophage studies we identified targets predicted to be important in controlling innate immune processes initiated by TLR activation. Targets were identified as genes with high betweenness centrality, so-called bottlenecks, in networks inferred from statistical associations between gene expression patterns. A small set of putative bottlenecks were identified in each of the data sets investigated including interferon-stimulated genes (Ifit1, Ifi47, Tgtp and Oasl2 as well as genes uncharacterized in immune responses (Axud1 and Ppp1r15a. We further validated one of these targets, Ifit1, in mouse macrophages by showing that silencing it suppresses induction of predicted downstream genes by lipopolysaccharide (LPS-mediated TLR4 activation through an unknown direct or indirect mechanism. Our study demonstrates the utility of network analysis for identification of interesting targets related to innate immune function, and highlights that Ifit1 can exert a positive regulatory effect on downstream genes.

  13. Characterization of rotavirus RNAs that activate innate immune signaling through the RIG-I-like receptors.

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    Dina Uzri

    Full Text Available In mammalian cells, the first line of defense against viral pathogens is the innate immune response, which is characterized by induction of type I interferons (IFN and other pro-inflammatory cytokines that establish an antiviral milieu both in infected cells and in neighboring uninfected cells. Rotavirus, a double-stranded RNA virus of the Reoviridae family, is the primary etiological agent of severe diarrhea in young children worldwide. Previous studies demonstrated that rotavirus replication induces a MAVS-dependent type I IFN response that involves both RIG-I and MDA5, two cytoplasmic viral RNA sensors. This study reports the isolation and characterization of rotavirus RNAs that activate IFN signaling. Using an in vitro approach with purified rotavirus double-layer particles, nascent single-stranded RNA (ssRNA transcripts (termed in vitro ssRNA were found to be potent IFN inducers. In addition, large RNAs isolated from rotavirus-infected cells six hours post-infection (termed in vivo 6 hr large RNAs, also activated IFN signaling, whereas a comparable large RNA fraction isolated from cells infected for only one hour lacked this stimulatory activity. Experiments using knockout murine embryonic fibroblasts showed that RIG-I is required for and MDA5 partly contributes to innate immune signaling by both in vitro ssRNA and in vivo 6 hr large RNAs. Enzymatic studies demonstrated that in vitro ssRNA and in vivo 6 hr large RNA samples contain uncapped RNAs with exposed 5' phosphate groups. RNAs lacking 2'-O-methylated 5' cap structures were also detected in the in vivo 6 hr large RNA sample. Taken together, our data provide strong evidence that the rotavirus VP3 enzyme, which encodes both guanylyltransferase and methyltransferase activities, is not completely efficient at either 5' capping or 2'-O-methylation of the 5' cap structures of viral transcripts, and in this way produces RNA patterns that activate innate immune signaling through the RIG

  14. Arterivirus and nairovirus ovarian tumor domain-containing deubiquitinases target activated RIG-I to control innate immune signaling

    NARCIS (Netherlands)

    P.B. van Kasteren (Puck ); C. Beugeling (Corrine); D.K. Ninaber (Dennis); N. Frias-Staheli (Natalia); S. van Boheemen (Sander); A. García-Sastre (Adolfo); E.J. Snijder (Eric); M.A. Kikkert (Myrna)

    2012-01-01

    textabstractThe innate immune response constitutes the first line of defense against viral infection and is extensively regulated through ubiquitination. The removal of ubiquitin from innate immunity signaling factors by deubiquitinating enzymes (DUBs) therefore provides a potential opportunity for

  15. Pathogenesis of innate immunity and adaptive immunity in the mouse model of experimental autoimmune uveitis.

    Science.gov (United States)

    Bi, Hong-Sheng; Liu, Zheng-Feng; Cui, Yan

    2015-05-01

    Experimental autoimmune uveitis, a well-established model for human uveitis, is similar to human uveitis in many pathological features. Studies concerning the mechanisms of experimental autoimmune uveitis would cast a light on the pathogenesis of human uveitis as well as the search for more effective therapeutic agents. The cellular components of innate immunity include natural killer cells, gamma delta T lymphocytes, antigen-presenting dendritic cells, phagocytic macrophages, and granulocytes. It is believed that T cells are central in the generation of human uveitis. It has already become clear that CD4(+) effecter cells that predominantly produce interleukin-17 (the so-called Th17 cells) may play an important role in uveitis. In addition, the occurrence and recurrence of uveitis depends on a complex interplay between the elements of innate and adaptive immunity.

  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. Transgenesis and reverse genetics of mosquito innate immunity.

    Science.gov (United States)

    Shin, Sang Woon; Kokoza, Vladimir A; Raikhel, Alexander S

    2003-11-01

    In recent years, mosquito molecular biology has been a scene of astounding achievements, namely the development of genetic transformation, characterization of inducible tissue-specific promoters, and acquirement of mosquito genome sequences. However, the lack of a complete genetic tool box for mosquitoes remains a serious obstacle in our ability to study essential mosquito-specific mechanisms. Unlike Drosophila, very few null mutations for mosquito genes exist. The development of reverse-genetic analyses based on RNAi and transgenic techniques will help to compensate for these deficiencies and aid in identification of critical genes in important regulatory pathways. The study of mosquito innate immunity is one example and described here. In this study, we combine mosquito transgenesis with reverse genetics. The advantage of transgenesis is the ability to establish genetically stable, dominant-negative and overexpression phenotypes. Using the blood-meal-activated vitellogenin gene (Vg) promoter, we have generated transgenic mosquitoes with blood-meal-activated, overexpressed antimicrobial peptides, Defensin A and Cecropin A. Moreover, we have recently generated a transgenic dominant-negative Relish mosquito strain, which after taking a blood meal, becomes immune-deficient to infection by Gram-negative bacteria. The latter accomplishment has opened the door to a reverse-genetic approach in mosquitoes based on transgenesis.

  18. Innate Immunity and the Inter-exposure Interval Determine the Dynamics of Secondary Influenza Virus Infection and Explain Observed Viral Hierarchies.

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    Pengxing Cao

    2015-08-01

    Full Text Available Influenza is an infectious disease that primarily attacks the respiratory system. Innate immunity provides both a very early defense to influenza virus invasion and an effective control of viral growth. Previous modelling studies of virus-innate immune response interactions have focused on infection with a single virus and, while improving our understanding of viral and immune dynamics, have been unable to effectively evaluate the relative feasibility of different hypothesised mechanisms of antiviral immunity. In recent experiments, we have applied consecutive exposures to different virus strains in a ferret model, and demonstrated that viruses differed in their ability to induce a state of temporary immunity or viral interference capable of modifying the infection kinetics of the subsequent exposure. These results imply that virus-induced early immune responses may be responsible for the observed viral hierarchy. Here we introduce and analyse a family of within-host models of re-infection viral kinetics which allow for different viruses to stimulate the innate immune response to different degrees. The proposed models differ in their hypothesised mechanisms of action of the non-specific innate immune response. We compare these alternative models in terms of their abilities to reproduce the re-exposure data. Our results show that 1 a model with viral control mediated solely by a virus-resistant state, as commonly considered in the literature, is not able to reproduce the observed viral hierarchy; 2 the synchronised and desynchronised behaviour of consecutive virus infections is highly dependent upon the interval between primary virus and challenge virus exposures and is consistent with virus-dependent stimulation of the innate immune response. Our study provides the first mechanistic explanation for the recently observed influenza viral hierarchies and demonstrates the importance of understanding the host response to multi-strain viral infections

  19. Multigenic control of measles vaccine immunity mediated by polymorphisms in measles receptor, innate pathway, and cytokine genes.

    Science.gov (United States)

    Kennedy, Richard B; Ovsyannikova, Inna G; Haralambieva, Iana H; O'Byrne, Megan M; Jacobson, Robert M; Pankratz, V Shane; Poland, Gregory A

    2012-03-09

    Measles infection and vaccine response are complex biological processes that involve both viral and host genetic factors. We have previously investigated the influence of genetic polymorphisms on vaccine immune response, including measles vaccines, and have shown that polymorphisms in HLA, cytokine, cytokine receptor, and innate immune response genes are associated with variation in vaccine response but do not account for all of the inter-individual variance seen in vaccinated populations. In the current study we report the findings of a multigenic analysis of measles vaccine immunity, indicating a role for the measles virus receptor CD46, innate pattern-recognition receptors (DDX58, TLR2, 4, 5, 7 and 8) and intracellular signaling intermediates (MAP3K7, NFKBIA), and key antiviral molecules (VISA, OAS2, MX1, PKR) as well as cytokines (IFNA1, IL4, IL6, IL8, IL12B) and cytokine receptor genes (IL2RB, IL6R, IL8RA) in the genetic control of both humoral and cellular immune responses. This multivariate approach provided additional insights into the genetic control of measles vaccine responses over and above the information gained by our previous univariate SNP association analyses.

  20. 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

  1. Negative regulation of MDA5- but not RIG-I-mediated innate antiviral signaling by the dihydroxyacetone kinase.

    Science.gov (United States)

    Diao, Feici; Li, Shu; Tian, Yang; Zhang, Min; Xu, Liang-Guo; Zhang, Yan; Wang, Rui-Peng; Chen, Danying; Zhai, Zhonghe; Zhong, Bo; Tien, Po; Shu, Hong-Bing

    2007-07-10

    Viral infection leads to activation of the transcription factors interferon regulatory factor-3 and NF-kappaB, which collaborate to induce type I IFNs. The RNA helicase proteins RIG-I and MDA5 were recently identified as two cytoplasmic viral RNA sensors that recognize different species of viral RNAs produced during viral replication. In this study, we identified DAK, a functionally unknown dihydroacetone kinase, as a specific MDA5-interacting protein. DAK was associated with MDA5, but not RIG-I, under physiological conditions. Overexpression of DAK inhibited MDA5- but not RIG-I- or TLR3-mediated IFN-beta induction. Overexpression of DAK also inhibited cytoplasmic dsRNA and SeV-induced activation of the IFN-beta promoter, whereas knockdown of endogenous DAK by RNAi activated the IFN-beta promoter, and increased cytoplasmic dsRNA- or SeV-triggered activation of the IFN-beta promoter. In addition, overexpression of DAK inhibited MDA5- but not RIG-I-mediated antiviral activity, whereas DAK RNAi increased cytoplasmic dsRNA-triggered antiviral activity. These findings suggest that DAK is a physiological suppressor of MDA5 and specifically inhibits MDA5- but not RIG-I-mediated innate antiviral signaling.

  2. Innate and procured immunity inside the digestive tract of the medicinal leech

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    AC Silver

    2011-09-01

    Full Text Available Especially when combined with unique biological adaptations, invertebrate animals provide important insights into innate immunity because the immune response is not complicated by adaptive immunity that vertebrates evolved. One such example is the digestive tract of the medicinal leech, Hirudo verbana, which is unusual in two aspects, it contains a simple microbial community and it stores large amounts of vertebrate blood for a several months. In this review we will discuss aspects of the innate immunity of the leech and from the ingested blood that we term procured immunity to differentiate it from the immunity encoded by the leech genome.

  3. Vpu-Deficient HIV Strains Stimulate Innate Immune Signaling Responses in Target Cells

    OpenAIRE

    Doehle, Brian P.; Chang, Kristina; Fleming, Lamar; McNevin, John; Hladik, Florian; McElrath, M. Juliana; Gale, Michael

    2012-01-01

    Acute virus infection induces a cell-intrinsic innate immune response comprising our first line of immunity to limit virus replication and spread, but viruses have developed strategies to overcome these defenses. HIV-1 is a major public health problem; however, the virus-host interactions that regulate innate immune defenses against HIV-1 are not fully defined. We have recently identified the viral protein Vpu to be a key determinant responsible for HIV-1 targeting and degradation of interfer...

  4. 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 i...n innate immunity and human inflammatory disorders. Authors Le Bourhis L, Benko S

  5. 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

  6. Activation of the innate immune response against DENV in normal non-transformed human fibroblasts.

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    José Bustos-Arriaga

    2011-12-01

    Full Text Available BACKGROUND: When mosquitoes infected with DENV are feeding, the proboscis must traverse the epidermis several times ("probing" before reaching a blood vessel in the dermis. During this process, the salivary glands release the virus, which is likely to interact first with cells of the various epidermal and dermal layers, cells which could be physiologically relevant to DENV infection and replication in humans. However, important questions are whether more abundant non-hematopoietic cells such as fibroblasts become infected, and whether they play any role in antiviral innate immunity in the very early stages of infection, or even if they might be used by DENV as primary replication cells. METHODOLOGY/PRINCIPAL FINDINGS: Fibroblasts freshly released from healthy skin and infected 12 hours after their isolation show a positive signal for DENV. In addition, when primary skin fibroblast cultures were established and subsequently infected, we showed DENV-2 antigen-positive intracellular signal at 24 hours and 48 hours post-infection. Moreover, the fibroblasts showed productive infection in a conventional plaque assay. The skin fibroblasts infected with DENV-2 underwent potent signaling through both TLR3 and RIG- 1, but not Mda5, triggering up-regulation of IFNβ, TNFα, defensin 5 (HB5 and β defensin 2 (HβD2. In addition, DENV infected fibroblasts showed increased nuclear translocation of interferon (IFN regulatory factor 3 (IRF3, but not interferon regulatory factor 7 (IRF7, when compared with mock-infected fibroblasts. CONCLUSIONS/SIGNIFICANCE: In this work, we demonstrated the high susceptibility to DENV infection by primary fibroblasts from normal human skin, both in situ and in vitro. Our results suggest that these cells may contribute to the pro-inflammatory and anti-viral microenvironment in the early stages of interaction with DENV-2. Furthermore, the data suggest that fibroblast may also be used as a primary site of DENV replication and

  7. UNC93B1 mediates innate inflammation and antiviral defense in the liver during acute murine cytomegalovirus infection.

    Directory of Open Access Journals (Sweden)

    Meredith J Crane

    Full Text Available Antiviral defense in the liver during acute infection with the hepatotropic virus murine cytomegalovirus (MCMV involves complex cytokine and cellular interactions. However, the mechanism of viral sensing in the liver that promotes these cytokine and cellular responses has remained unclear. Studies here were undertaken to investigate the role of nucleic acid-sensing Toll-like receptors (TLRs in initiating antiviral immunity in the liver during infection with MCMV. We examined the host response of UNC93B1 mutant mice, which do not signal properly through TLR3, TLR7 and TLR9, to acute MCMV infection to determine whether liver antiviral defense depends on signaling through these molecules. Infection of UNC93B1 mutant mice revealed reduced production of systemic and liver proinflammatory cytokines including IFN-α, IFN-γ, IL-12 and TNF-α when compared to wild-type. UNC93B1 deficiency also contributed to a transient hepatitis later in acute infection, evidenced by augmented liver pathology and elevated systemic alanine aminotransferase levels. Moreover, viral clearance was impaired in UNC93B1 mutant mice, despite intact virus-specific CD8+ T cell responses in the liver. Altogether, these results suggest a combined role for nucleic acid-sensing TLRs in promoting early liver antiviral defense during MCMV infection.

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

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    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.

  9. Human papillomavirus immunization is associated with increased expression of different innate immune regulatory receptors.

    Science.gov (United States)

    Colmenares, V; Noyola, D E; Monsiváis-Urenda, A; Salgado-Bustamante, M; Estrada-Capetillo, L; González-Amaro, R; Baranda, L

    2012-07-01

    Human papillomavirus (HPV) is able to inhibit the secretion of gamma interferon (IFN-γ) and the expression of some immune innate cell receptors. Immunoglobulin-like transcript 2 (ILT2) is a regulatory receptor that seems to participate in the pathogenesis of viral infections. We have studied the expression and function of ILT2 and the expression of other NK cell receptors in 23 healthy women before and after immunization with the quadrivalent HPV (type 6/11/16/18) vaccine (Gardasil). Receptor expression was analyzed by flow cytometry in freshly isolated peripheral blood mononuclear cells as well as after in vitro stimulation with the quadrivalent HPV (type 6/11/16/18) vaccine. In addition, the regulatory function of ILT2 on cell proliferation and IFN-γ production was analyzed. We found a significant increase in the expression of ILT2 by NK and CD3(+) CD56(+) lymphocytes and monocytes after quadrivalent HPV (type 6/11/16/18) vaccine immunization. In addition, the in vitro stimulation with the quadrivalent HPV (type 6/11/16/18) vaccine also increased the proportion of CD3(-) CD56(+) ILT2(+) NK cells. Although the inhibitory function of ILT2 on cell proliferation was enhanced after HPV immunization, the in vitro engagement of this receptor did not affect the synthesis of IFN-γ induced by HPV. Finally, a significant increase in the expression of NKG2D, NKp30, and NKp46 by NK and CD3(+) CD56(+) lymphocytes was detected after quadrivalent HPV (type 6/11/16/18) vaccine immunization. Our data indicate that HPV immunization is associated with significant changes in the expression and function of different innate immune receptors, including ILT2, which may participate in the protective effect of HPV vaccines.

  10. A Role for Innate Immunity in the Development of Hypertension

    Science.gov (United States)

    Gomolak, Jessica R.; Didion, Sean P.

    2014-01-01

    Clinically, Angiotensin II (Ang II) has been implicated in some forms of hypertension and linked to vascular injury. Experimentally, chronic Ang II infusion leads to an increase in blood pressure, resulting in impaired endothelial function and vascular hypertrophy. Ang II also upregulates the activity and expression of a number of inflammatory molecules, including nuclear factor kappa B (NFκB) and pro-inflammatory cytokines, such as interleukin-6 (IL-6). More recently, it has been reported that Ang II is associated with upregulation of toll-like receptor TLR expression, specifically TLR4. Classical TLR4 signaling is mediated in large part by the effector protein myeloid differentiation factor 88 (MyD88), with resultant activation of NFκB, a transcription factor that promotes expression of a number of inflammatory gene products, including IL-6. A role for IL-6 has been previously implicated in the vascular dysfunction associated with Ang II-dependent hypertension. It is not known whether the MyD88 signaling pathway represents a cellular mechanism by which Ang II promotes endothelial dysfunction via NFκB activation and increases in IL-6. Taken together, we propose to mechanistically elucidate the role of innate immune signaling in Ang II-dependent hypertension. We hypothesize MyD88-deficiency will prevent the activation and transcription of NFκB-related gene products, including IL-6, thereby limiting Ang II-dependent hypertension and vascular complications. PMID:25441337

  11. Neuropathogenesis of Chikungunya infection: astrogliosis and innate immune activation.

    Science.gov (United States)

    Inglis, Fiona M; Lee, Kim M; Chiu, Kevin B; Purcell, Olivia M; Didier, Peter J; Russell-Lodrigue, Kasi; Weaver, Scott C; Roy, Chad J; MacLean, Andrew G

    2016-04-01

    Chikungunya, "that which bends up" in the Makonde dialect, is an emerging global health threat, with increasing incidence of neurological complications. Until 2013, Chikungunya infection had been largely restricted to East Africa and the Indian Ocean, with cases within the USA reported to be from foreign travel. However, in 2014, over 1 million suspected cases were reported in the Americas, and a recently infected human could serve as an unwitting reservoir for the virus resulting in an epidemic in the continental USA. Chikungunya infection is increasingly being associated with neurological sequelae. In this study, we sought to understand the role of astrocytes in the neuropathogenesis of Chikungunya infection. Even after virus has been cleared form the circulation, astrocytes were activated with regard to TLR2 expression. In addition, white matter astrocytes were hypertrophic, with increased arbor volume in gray matter astrocytes. Combined, these would alter the number and distribution of synapses that each astrocyte would be capable of forming. These results provide the first evidence that Chikungunya infection induces morphometric and innate immune activation of astrocytes in vivo. Perturbed glia-neuron signaling could be a major driving factor in the development of Chikungunya-associated neuropathology.

  12. Initial Immunopathogenesis of Multiple Sclerosis: Innate Immune Response

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    Norma Y. Hernández-Pedro

    2013-01-01

    Full Text Available Multiple sclerosis (MS is an inflammatory, demyelinating, and neurodegenerative disease of the central nervous system. The hallmark to MS is the demyelinated plaque, which consists of a well-demarcated hypocellular area characterized by the loss of myelin, the formation of astrocytic scars, and the mononuclear cell infiltrates concentrated in perivascular spaces composed of T cells, B lymphocytes, plasma cells, and macrophages. Activation of resident cells initiates an inflammatory cascade, leading to tissue destruction, demyelination, and neurological deficit. The immunological phenomena that lead to the activation of autoreactive T cells to myelin sheath components are the result of multiple and complex interactions between environment and genetic background conferring individual susceptibility. Within the CNS, an increase of TLR expression during MS is observed, even in the absence of any apparent microbial involvement. In the present review, we focus on the role of the innate immune system, the first line of defense of the organism, as promoter and mediator of cross reactions that generate molecular mimicry triggering the inflammatory response through an adaptive cytotoxic response in MS.

  13. Initial immunopathogenesis of multiple sclerosis: innate immune response.

    Science.gov (United States)

    Hernández-Pedro, Norma Y; Espinosa-Ramirez, Guillermo; de la Cruz, Verónica Pérez; Pineda, Benjamín; Sotelo, Julio

    2013-01-01

    Multiple sclerosis (MS) is an inflammatory, demyelinating, and neurodegenerative disease of the central nervous system. The hallmark to MS is the demyelinated plaque, which consists of a well-demarcated hypocellular area characterized by the loss of myelin, the formation of astrocytic scars, and the mononuclear cell infiltrates concentrated in perivascular spaces composed of T cells, B lymphocytes, plasma cells, and macrophages. Activation of resident cells initiates an inflammatory cascade, leading to tissue destruction, demyelination, and neurological deficit. The immunological phenomena that lead to the activation of autoreactive T cells to myelin sheath components are the result of multiple and complex interactions between environment and genetic background conferring individual susceptibility. Within the CNS, an increase of TLR expression during MS is observed, even in the absence of any apparent microbial involvement. In the present review, we focus on the role of the innate immune system, the first line of defense of the organism, as promoter and mediator of cross reactions that generate molecular mimicry triggering the inflammatory response through an adaptive cytotoxic response in MS.

  14. Infectious Disease: Connecting Innate Immunity to Biocidal Polymers.

    Science.gov (United States)

    Gabriel, Gregory J; Som, Abhigyan; Madkour, Ahmad E; Eren, Tarik; Tew, Gregory N

    2007-08-01

    Infectious disease is a critically important global healthcare issue. In the U.S. alone there are 2 million new cases of hospital-acquired infections annually leading to 90,000 deaths and 5 billion dollars of added healthcare costs. Couple these numbers with the appearance of new antibiotic resistant bacterial strains and the increasing occurrences of community-type outbreaks, and clearly this is an important problem. Our review attempts to bridge the research areas of natural host defense peptides (HDPs), a component of the innate immune system, and biocidal cationic polymers. Recently discovered peptidomimetics and other synthetic mimics of HDPs, that can be short oligomers as well as polymeric macromolecules, provide a unique link between these two areas. An emerging class of these mimics are the facially amphiphilic polymers that aim to emulate the physicochemical properties of HDPs but take advantage of the synthetic ease of polymers. These mimics have been designed with antimicrobial activity and, importantly, selectivity that rivals natural HDPs. In addition to providing some perspective on HDPs, selective mimics, and biocidal polymers, focus is given to the arsenal of biophysical techniques available to study their mode of action and interactions with phospholipid membranes. The issue of lipid type is highlighted and the important role of negative curvature lipids is illustrated. Finally, materials applications (for instance, in the development of permanently antibacterial surfaces) are discussed as this is an important part of controlling the spread of infectious disease.

  15. Chromogranin A-derived peptides are involved in innate immunity.

    Science.gov (United States)

    Aslam, R; Atindehou, M; Lavaux, T; Haïkel, Y; Schneider, F; Metz-Boutigue, M-H

    2012-01-01

    New endogenous antimicrobial peptides (AMPs) derived from chromogranin A (CgA) are secreted by nervous, endocrine and immune cells during stress. They display antimicrobial activities by lytic effects at micromolar range using a pore-forming mechanism against Gram-positive bacteria, filamentous fungi and yeasts. These AMPs can also penetrate quickly into neutrophils (without lytic effects), where, similarly to "cell penetrating peptides", they interact with cytoplasmic calmodulin, and induce calcium influx via Store Operated Channels therefore triggering neutrophils activation. Staphylococcus aureus and Salmonella enteritis are bacteria responsible for severe infections. We investigated here the effects of S. aureus and S. enteritis bacterial proteases on CgA-derived peptides and evaluated their antimicrobial activities. We showed that the Glu-C protease produced by S. aureus V8 induces the loss of the AMPs antibacterial activities and produces new antifungal peptides. In addition, four antimicrobial CGA-derived peptides (chromofungin, procatestatin, human/bovine catestatin) are degraded when treated with bacterial supernatants from S. aureus and S. enteritis, whereas, cateslytin, the short active form of catestatin, resists to this degradation. Finally, we demonstrate that several antimicrobial CgA-derived peptides are able to act synergistically with antibiotics against bacteria and fungi indicating their roles in innate defense.

  16. Does baseline innate immunity change with age? A multi-year study in great tits.

    Science.gov (United States)

    Vermeulen, Anke; Eens, Marcel; Van Dongen, Stefan; Müller, Wendt

    2017-03-16

    Throughout their life animals progressively accumulate mostly detrimental changes in cells, tissues and their functions, causing a decrease in individual performance and ultimately an increased risk of death. The latter may be amplified if it also leads to a deterioration of the immune system which forms the most important protection against the permanent threat of pathogens and infectious diseases. Here, we investigated how four baseline innate immune parameters (natural antibodies, complement activity, concentrations of haptoglobin and concentrations of nitric oxide) changed with age in free-living great tits (Parus major). We applied both cross-sectional and longitudinal approaches as birds were sampled for up to three years of their lives. Three out of the four selected innate immune parameters were affected by age. However, the shape of the response curves differed strongly among the innate immune parameters. Natural antibody levels increased during early life until mid-age to decrease thereafter when birds aged. Complement activity was highest in young birds, while levels slightly decreased with increasing age. Haptoglobin levels on the other hand, showed a linear, but highly variable increase with age, while nitric oxide concentrations were unaffected by age. The observed differences among the four studied innate immune traits not only indicate the importance of considering several immune traits at the same time, but also highlight the complexity of innate immunity. Unraveling the functional significance of the observed changes in innate immunity is thus a challenging next step.

  17. RNAi and antiviral defense in Drosophila: setting up a systemic immune response.

    Science.gov (United States)

    Karlikow, Margot; Goic, Bertsy; Saleh, Maria-Carla

    2014-01-01

    RNA interference (RNAi) controls gene expression in eukaryotic cells and thus, cellular homeostasis. In addition, in plants, nematodes and arthropods it is a central antiviral effector mechanism. Antiviral RNAi has been well described as a cell autonomous response, which is triggered by double-stranded RNA (dsRNA) molecules. This dsRNA is the precursor for the silencing of viral RNA in a sequence-specific manner. In plants, systemic antiviral immunity has been demonstrated, however much less is known in animals. Recently, some evidence for a systemic antiviral response in arthropods has come to light. Cell autonomous RNAi may not be sufficient to reach an efficient antiviral response, and the organism might rely on the spread and uptake of an RNAi signal of unknown origin. In this review, we offer a perspective on how RNAi-mediated antiviral immunity could confer systemic protection in insects and we propose directions for future research to understand the mechanism of RNAi-immune signal sorting, spreading and amplification.

  18. Evasion of antiviral immunity through sequestering of TBK1/IKKε/IRF3 into viral inclusion bodies.

    Science.gov (United States)

    Wu, Xiaodong; Qi, Xian; Qu, Bingqian; Zhang, Zerui; Liang, Mifang; Li, Chuan; Cardona, Carol J; Li, Dexin; Xing, Zheng

    2014-03-01

    Cells are equipped with pattern recognition receptors (PRRs) such as the Toll-like and RIG-I-like receptors that mount innate defenses against viruses. However, viruses have evolved multiple strategies to evade or thwart host antiviral responses. Viral inclusion bodies (IBs), which are accumulated aggregates of viral proteins, are commonly formed during the replication of some viruses in infected cells, but their role in viral immune evasion has rarely been explored. Severe fever with thrombocytopenia syndrome (SFTS) is an emerging febrile illness caused by a novel phlebovirus in the Bunyaviridae. The SFTS viral nonstructural protein NSs can suppress host beta interferon (IFN-β) responses. NSs can form IBs in infected and transfected cells. Through interaction with tank-binding kinase 1 (TBK1), viral NSs was able to sequester the IKK complex, including IKKε and IRF3, into IBs, although NSs did not interact with IKKε or IRF3 directly. When cells were infected with influenza A virus, IRF3 was phosphorylated and active phosphorylated IRF3 (p-IRF3) was translocated into the nucleus. In the presence of NSs, IRF3 could still be phosphorylated, but p-IRF3 was trapped in cytoplasmic IBs, resulting in reduced IFN-β induction and enhanced viral replication. Sequestration of the IKK complex and active IRF3 into viral IBs through the interaction of NSs and TBK1 is a novel mechanism for viral evasion of innate immunity.

  19. Transgenerational epigenetic effects on innate immunity in broilers: an underestimated field to be explored?

    Science.gov (United States)

    Berghof, T V L; Parmentier, H K; Lammers, A

    2013-11-01

    Transgenerational epigenetics is becoming more and more important for understanding the variation of physiological responses of individuals to the environment and the inheritance of these responses based on all mechanisms other than the actual DNA nucleotide sequence. Transgenerational epigenetics is the phenomenon that the information of the environment of (usually) a female animal is translated into memory-like responses preparing the offspring. As a consequence, individuals of the next generation may show different phenotypic traits depending whether their mothers were kept under different environmental conditions. This may result in either positive or negative effects on the next-generation individuals, which is different from individuals from mothers that have been kept in a different environment. Transgenerational epigenetic effects have been proposed and indicated for specific immune (T cell and antibody) responses (especially in mammals, but also in birds) and innate immunity (nonvertebrates), but surprisingly very little is known of transgenerational effects on innate immunity in chickens. Given the short lifespan of the chicken and therefore the likely dependence of chicken on innate immune mechanisms, more attention should be given to this arm of immunity and mechanisms of inheritance including transgenerational effects that can be initiated in the breeder generation. In addition, it is becoming evident that innate immunity also underlies metabolic disorders in broilers. In the current paper, we will argue that although very little is known of transgenerational effects of innate immunity in poultry, more attention should be given to this type of study. We will illustrate examples of transgenerational epigenetics, and finally propose strategies that should reveal the presence of transgenerational epigenetic effects on innate immunity in chickens and strategies to modulate breeder birds such that these effects positively affect innate immunity of broilers

  20. Axl Mediates ZIKA Virus Entry in Human Glial Cells and Modulates Innate Immune Responses

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    Laurent Meertens

    2017-01-01

    Full Text Available ZIKA virus (ZIKV is an emerging pathogen responsible for neurological disorders and congenital microcephaly. However, the molecular basis for ZIKV neurotropism remains poorly understood. Here, we show that Axl is expressed in human microglia and astrocytes in the developing brain and that it mediates ZIKV infection of glial cells. Axl-mediated ZIKV entry requires the Axl ligand Gas6, which bridges ZIKV particles to glial cells. Following binding, ZIKV is internalized through clathrin-mediated endocytosis and traffics to Rab5+ endosomes to establish productive infection. During entry, the ZIKV/Gas6 complex activates Axl kinase activity, which downmodulates interferon signaling and facilitates infection. ZIKV infection of human glial cells is inhibited by MYD1, an engineered Axl decoy receptor, and by the Axl kinase inhibitor R428. Our results highlight the dual role of Axl during ZIKV infection of glial cells: promoting viral entry and modulating innate immune responses. Therefore, inhibiting Axl function may represent a potential target for future antiviral therapies.

  1. Modulation of innate immune responses by influenza-specific ovine polyclonal antibodies used for prophylaxis.

    Directory of Open Access Journals (Sweden)

    Catherine Rinaldi

    Full Text Available In the event of a novel influenza A virus pandemic, prophylaxis mediated by antibodies provides an adjunct control option to vaccines and antivirals. This strategy is particularly pertinent to unvaccinated populations at risk during the lag time to produce and distribute an effective vaccine. Therefore, development of effective prophylactic therapies is of high importance. Although previous approaches have used systemic delivery of monoclonal antibodies or convalescent sera, available supply is a serious limitation. Here, we have investigated intranasal delivery of influenza-specific ovine polyclonal IgG antibodies for their efficacy against homologous influenza virus challenge in a mouse model. Both influenza-specific IgG and F(ab'2 reduced clinical scores, body weight loss and lung viral loads in mice treated 1 hour before virus exposure. Full protection from disease was also observed when antibody was delivered up to 3 days prior to virus infection. Furthermore, effective prophylaxis was independent of a strong innate immune response. This strategy presents a further option for prophylactic intervention against influenza A virus using ruminants to generate a bulk supply that could potentially be used in a pandemic setting, to slow virus transmission and reduce morbidity associated with a high cytokine phenotype.

  2. Age- and disease-related innate immunity of human leukocytes ex vivo.

    Science.gov (United States)

    Jatczak, Bogna; Leszek, Jerzy; Siemieniec, Iwona; Sochocka, Marta; Wiśniewska, Agnieszka; Tarkowski, Radosław; Bębenek, Marek; Błach-Olszewska, Zofia

    2012-01-01

    Two mechanisms of innate immunity, i.e. resistance to viral infection and the production of cytokines by leukocytes, were compared in blood isolated from four groups of donors: healthy young (19-35 years old), healthy elderly (over 60), elderly Alzheimer's disease (AD) patients, and elderly patients with alimentary tract cancer (CA). Peripheral blood leukocytes (PBLs) were isolated by gradient centrifugation in Gradisol G. The degree of resistance was calculated from the kinetics of vesicular stomatitis virus (VSV) replication in the PBLs. Cytokine (TNFα, IFNα, IFNγ, IL-12, and IL-10) levels were determined by ELISA. The antiviral resistance of the PBLs varied, but a difference was observed only between the young and elderly groups and not between the healthy elderly controls and those with AD or cancer. Differences observed in all the groups concerned the ability and intensity of cytokine production. The most impressive results were obtained for spontaneous TNF and IFNα release. While TNF was released spontaneously by the PBLs of the elderly CA patients and the young healthy group, it was usually undetected in the AD and only sometimes in the healthy elderly group. Leukocytes isolated from the elderly groups responded to VSV infection with more intense IFNα and IFNγ production than the younger group.

  3. c-di-GMP enhances protective innate immunity in a murine model of pertussis.

    Directory of Open Access Journals (Sweden)

    Shokrollah Elahi

    Full Text Available Innate immunity represents the first line of defense against invading pathogens in the respiratory tract. Innate immune cells such as monocytes, macrophages, dendritic cells, NK cells, and granulocytes contain specific pathogen-recognition molecules which induce the production of cytokines and subsequently activate the adaptive immune response. c-di-GMP is a ubiquitous second messenger that stimulates innate immunity and regulates biofilm formation, motility and virulence in a diverse range of bacterial species with potent immunomodulatory properties. In the present study, c-di-GMP was used to enhance the innate immune response against pertussis, a respiratory infection mainly caused by Bordetella pertussis. Intranasal treatment with c-di-GMP resulted in the induction of robust innate immune responses to infection with B. pertussis characterized by enhanced recruitment of neutrophils, macrophages, natural killer cells and dendritic cells. The immune responses were associated with an earlier and more vigorous expression of Th1-type cytokines, as well as an increase in the induction of nitric oxide in the lungs of treated animals, resulting in significant reduction of bacterial numbers in the lungs of infected mice. These results demonstrate that c-di-GMP is a potent innate immune stimulatory molecule that can be used to enhance protection against bacterial respiratory infections. In addition, our data suggest that priming of the innate immune system by c-di-GMP could further skew the immune response towards a Th1 type phenotype during subsequent infection. Thus, our data suggest that c-di-GMP might be useful as an adjuvant for the next generation of acellular pertussis vaccine to mount a more protective Th1 phenotype immune response, and also in other systems where a Th1 type immune response is required.

  4. Virus-cell fusion as a trigger of innate immunity dependent on the adaptor STING

    NARCIS (Netherlands)

    Holm, C.K.; Jensen, S.B.; Jakobsen, M.R.; Cheshenko, N.; Horan, K.A.; Moeller, H.B.; Gonzalez-Dosal, R.; Rasmussen, S.B.; Christensen, M.H.; Yarovinsky, T.O.; Rixon, F.J.; Herold, B.C.; Fitzgerald, K.A.; Paludan, S.R.

    2012-01-01

    The innate immune system senses infection by detecting either evolutionarily conserved molecules essential for the survival of microbes or the abnormal location of molecules. Here we demonstrate the existence of a previously unknown innate detection mechanism induced by fusion between viral envelope

  5. Another armament in gut immunity: lymphotoxin-mediated crosstalk between innate lymphoid and dendritic cells.

    Science.gov (United States)

    Spits, H

    2011-07-21

    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.

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

    NARCIS (Netherlands)

    H. Spits

    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

  7. [Innate immune mechanisms against recombinant adeno-associated virus vectors--a review].

    Science.gov (United States)

    Diao, Yong; Xu, Ruian

    2012-05-04

    Recombinant adeno-associated virus (rAAV) is one of the most commonly used vectors for gene therapy. Despite the promising safety profile demonstrated in preclinical trials, the clinic efficacy of using rAAV was hampered by undesired response from the immune system. It is important to understand the mechanisms that lead to the induction of immune response against rAAV. Although a crucial role for innate immunity is shaping adaptive immune responses, the innate immune to rAAV was ignored in the past. Till now, at least three human cell types (dendritic cells, macrophages and endothelial cells) were discovered to be involved in sensing rAAV infection. The engagement of TLR9 by rAAV vector genomes triggers the activation of NF-kappaB signaling cascades, leading to the induction of pro-inflammatory cytokine genes. The viral capsid components are detected by TLR2, and this leads to the production of type I interferon mediated by interferon regulatory factors (IRFs) pathway. Self-complementary rAAV vectors induced higher TLR9 dependent innate immune response than single stranded rAAV. This review highlights the recent findings regarding the innate immune responses to rAAV vectors, the signaling pathways involved, and the impacts of innate immunity on the adaptive immune response to rAAV and its transgene expression.

  8. Mx1 reveals innate pathways to antiviral resistance and lethal influenza disease.

    Science.gov (United States)

    Pillai, Padmini S; Molony, Ryan D; Martinod, Kimberly; Dong, Huiping; Pang, Iris K; Tal, Michal C; Solis, Angel G; Bielecki, Piotr; Mohanty, Subhasis; Trentalange, Mark; Homer, Robert J; Flavell, Richard A; Wagner, Denisa D; Montgomery, Ruth R; Shaw, Albert C; Staeheli, Peter; Iwasaki, Akiko

    2016-04-22

    Influenza A virus (IAV) causes up to half a million deaths worldwide annually, 90% of which occur in older adults. We show that IAV-infected monocytes from older humans have impaired antiviral interferon production but retain intact inflammasome responses. To understand the in vivo consequence, we used mice expressing a functional Mx gene encoding a major interferon-induced effector against IAV in humans. In Mx1-intact mice with weakened resistance due to deficiencies in Mavs and Tlr7, we found an elevated respiratory bacterial burden. Notably, mortality in the absence of Mavs and Tlr7 was independent of viral load or MyD88-dependent signaling but dependent on bacterial burden, caspase-1/11, and neutrophil-dependent tissue damage. Therefore, in the context of weakened antiviral resistance, vulnerability to IAV disease is a function of caspase-dependent pathology.

  9. Ambivalent Role of the Innate Immune Response in Rabies Virus Pathogenesis▿†

    OpenAIRE

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

    2011-01-01

    The neurotropic rabies virus (RABV) has developed several evasive strategies, including immunoevasion, to successfully infect the nervous system (NS) and trigger a fatal encephalomyelitis. Here we show that expression of LGP2, a protein known as either a positive or negative regulator of the RIG-I-mediated innate immune response, is restricted in the NS. We used a new transgenic mouse model (LGP2 TG) overexpressing LGP2 to impair the innate immune response to RABV and thus revealed the role o...

  10. Viral Infection: An Evolving Insight into the Signal Transduction Pathways Responsible for the Innate Immune Response

    OpenAIRE

    Kotwal, Girish J.; Steven Hatch; Marshall, William L.

    2012-01-01

    The innate immune response is initiated by the interaction of stereotypical pathogen components with genetically conserved receptors for extracytosolic pathogen-associated molecular patterns (PAMPs) or intracytosolic nucleic acids. In multicellular organisms, this interaction typically clusters signal transduction molecules and leads to their activations, thereby initiating signals that activate innate immune effector mechanisms to protect the host. In some cases programmed cell death—a funda...

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Innate immune response to pulmonary contusion: Identification of cell-type specific inflammatory responses

    OpenAIRE

    Hoth, J. Jason; Wells, Jonathan D.; Yoza, Barbara K.; McCall, Charles E.

    2012-01-01

    Lung injury from pulmonary contusion is a common traumatic injury, predominantly seen after blunt chest trauma such as in vehicular accidents. The local and systemic inflammatory response to injury includes activation of innate immune receptors, elaboration of a variety inflammatory mediators, and recruitment of inflammatory cells to the injured lung. Using a mouse model of pulmonary contusion, we had previously shown that innate immune Toll like receptors 2 and 4 (TLR2 and TLR4) mediate the ...

  13. Md1 and Rp105 regulate innate immunity and viral resistance in zebrafish.

    Science.gov (United States)

    Candel, Sergio; Sepulcre, María P; Espín-Palazón, Raquel; Tyrkalska, Sylwia D; de Oliveira, Sofía; Meseguer, José; Mulero, Victoriano

    2015-06-01

    TLR4 was the first TLR family member identified in mammals and is responsible for the activation of the immune response by bacterial LPS. Later, MD1 and RP105 were shown to form complexes that directly interact with the MD2-TLR4 complex, acting as physiological negative regulators of LPS signaling. Despite the general conservation of various TLR families from fish to mammals, several differences can be appreciated, such as the high tolerance of fish to LPS, the absence of the crucial accessory molecules Md2 and Cd14 for Tlr4 signaling in fish, the absence of Tlr4 in some fish species, and the confirmation that LPS does not signal through Tlr4 in zebrafish. The present study has identified the Rp105 and Md1 homologs in zebrafish, confirming (i) Rp105 and Tlr4 evolved from a common ancestor before the divergence between fish and tetrapods and (ii) the presence of Md1 in teleost fish and the lack of Md2, suggesting that the divergence of these accessory molecules occurred in the tetrapod lineage. Biochemical and functional studies indicate that Md1 binds both Rp105 and Tlr4 in zebrafish. Genetic inhibition of zebrafish Md1 and Rp105 reveals that Md1 or Rp105 deficiency impairs the expression of genes encoding pro-inflammatory and antiviral molecules, leading to increased susceptibility to viral infection. These results shed light on the evolutionary history of Md1 and Rp105 and uncover a previously unappreciated function of these molecules in the regulation of innate immunity.

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

    Science.gov (United States)

    Farrag, Mohamed A; Almajhdi, Fahad N

    2016-01-01

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

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

    DEFF Research Database (Denmark)

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

    2004-01-01

    with the temporal activation of the alpha/beta interferon-regulated Mx gene in white blood cells (WBC) and skin as well as the upregulation of the acute-phase serum proteins haptoglobin (Hp) and serum amyloid A (SAA). The viral strain used did provoke transient health impairment, namely, fever and leukopenia...... that were associated with viremia, viral shedding with nasal secretions, and antiviral seroconversion. Complete recovery was observed within 3 weeks. Elevated levels of SAA and Hp were apparent from days 4 to 13 and 8 to 11, respectively. In WBC, the levels of Mx mRNA and Mx protein were elevated from days......In this study, six immunocompetent calves were experimentally infected with a noncytopathic strain of bovine viral diarrhea virus (BVDV), and the effects of the viral infection on parameters of the innate immune response of the host were analyzed. Clinical and virological data were compared...

  16. Deubiquitinase function of arterivirus papain-like protease 2 suppresses the innate immune response in infected host cells.

    Science.gov (United States)

    van Kasteren, Puck B; Bailey-Elkin, Ben A; James, Terrence W; Ninaber, Dennis K; Beugeling, Corrine; Khajehpour, Mazdak; Snijder, Eric J; Mark, Brian L; Kikkert, Marjolein

    2013-02-26

    Protein ubiquitination regulates important innate immune responses. The discovery of viruses encoding deubiquitinating enzymes (DUBs) suggests they remove ubiquitin to evade ubiquitin-dependent antiviral responses; however, this has never been conclusively demonstrated in virus-infected cells. Arteriviruses are economically important positive-stranded RNA viruses that encode an ovarian tumor (OTU) domain DUB known as papain-like protease 2 (PLP2). This enzyme is essential for arterivirus replication by cleaving a site within the viral replicase polyproteins and also removes ubiquitin from cellular proteins. To dissect this dual specificity, which relies on a single catalytic site, we determined the crystal structure of equine arteritis virus PLP2 in complex with ubiquitin (1.45 Å). PLP2 binds ubiquitin using a zinc finger that is uniquely integrated into an exceptionally compact OTU-domain fold that represents a new subclass of zinc-dependent OTU DUBs. Notably, the ubiquitin-binding surface is distant from the catalytic site, which allowed us to mutate this surface to significantly reduce DUB activity without affecting polyprotein cleavage. Viruses harboring such mutations exhibited WT replication kinetics, confirming that PLP2-mediated polyprotein cleavage was intact, but the loss of DUB activity strikingly enhanced innate immune signaling. Compared with WT virus infection, IFN-β mRNA levels in equine cells infected with PLP2 mutants were increased by nearly an order of magnitude. Our findings not only establish PLP2 DUB activity as a critical factor in arteriviral innate immune evasion, but the selective inactivation of DUB activity also opens unique possibilities for developing improved live attenuated vaccines against arteriviruses and other viruses encoding similar dual-specificity proteases.

  17. Expression of microRNAs and innate immune factor genes in lung tissue of pigs infected with influenza virus (H1N2)

    DEFF Research Database (Denmark)

    Skovgaard, Kerstin; Cirera, S.; Vasby, D.

    , this response must be tightly regulated. Recently, microRNA (miRNA) has been proposed to play an important role in modulating and fine tuning the innate immune response in order to avoid such harmful overreactions. Little is known about the significance of miRNA regulation in the lung during acute influenza...... A infection. The present work aimed of providing a better understanding of the involvement of innate immune factors including miRNA in the host response to establishment and progression of influenza virus infection. Twenty pigs were challenged by aerosol containing H1N2 (A/swine/Denmark/12687/03) influenza...... virus. Expression of mRNA coding for cytokines, chemokines, pattern recognition receptors and other antiviral effector molecules were quantified in lung tissue at different time points after challenge (24h PI, 72h PI, and 14days PI). Likewise, microRNA in the lung tissue was quantified at the same time...

  18. The Role of the Innate Immune System of the Liver in the Control of HBV and HCV

    Institute of Scientific and Technical Information of China (English)

    Jun Wu; Ruth Br(o)ring; J(o)rg F. Schlaak

    2008-01-01

    Hepatitis B virus (HBV) and Hepatitis C virus (HCV) infection are among the most frequent causes of chronic liver disease worldwide. As recent studies suggested that Toll like receptor (TLR)-based therapies may represent a promising approach in the treatment of HBV infection, we have studied the role of the local innate immune system of the liver as possible mediator of this effect. Murine non-parenchymal liver cells (NPC; Kupffer cells, KC; sinusoidal endothelial cells, LSEC) were isolated from C57/BL6 and stimulated by TLR 1-9 agonists. Supernatants were harvested and assayed for their antiviral activity against HBV in HBV-Met cells and HCV in the murine HCV replicon cell line MH1. Only supernatants from TLR 3 and -4 stimulated KC and TLR 3 stimulated LSEC were able to potently suppress HBV and HCV replication. By using neutralizing antibodies we could demonstrate that the TLR 3- but not the TLR 4 mediated effect is exclusively mediated through IFN-β. Our data indicate that TLR 3 and -4 mediated stimulation of NPC leads to production of IFN-β which can potently suppress HBV and HCV replication. This is of relevance for the local control of viral hepatitis infection by the innate immune system of the liver, the development of novel TLR-based therapeutic approaches and sheds new light on the viral crosstalk between HCV (TLR 3 stimulator) and HBV.

  19. Structural basis of RNA recognition and activation by innate immune receptor RIG-I

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Fuguo; Ramanathan, Anand; Miller, Matthew T.; Tang, Guo-Qing; Gale, Jr., Michael; Patel, Smita S.; Marcotrigiano, Joseph (Rutgers); (RWJ-Med); (UW-MED)

    2012-05-29

    Retinoic-acid-inducible gene-I (RIG-I; also known as DDX58) is a cytoplasmic pathogen recognition receptor that recognizes pathogen-associated molecular pattern (PAMP) motifs to differentiate between viral and cellular RNAs. RIG-I is activated by blunt-ended double-stranded (ds)RNA with or without a 5'-triphosphate (ppp), by single-stranded RNA marked by a 5'-ppp and by polyuridine sequences. Upon binding to such PAMP motifs, RIG-I initiates a signalling cascade that induces innate immune defences and inflammatory cytokines to establish an antiviral state. The RIG-I pathway is highly regulated and aberrant signalling leads to apoptosis, altered cell differentiation, inflammation, autoimmune diseases and cancer. The helicase and repressor domains (RD) of RIG-I recognize dsRNA and 5'-ppp RNA to activate the two amino-terminal caspase recruitment domains (CARDs) for signalling. Here, to understand the synergy between the helicase and the RD for RNA binding, and the contribution of ATP hydrolysis to RIG-I activation, we determined the structure of human RIG-I helicase-RD in complex with dsRNA and an ATP analogue. The helicase-RD organizes into a ring around dsRNA, capping one end, while contacting both strands using previously uncharacterized motifs to recognize dsRNA. Small-angle X-ray scattering, limited proteolysis and differential scanning fluorimetry indicate that RIG-I is in an extended and flexible conformation that compacts upon binding RNA. These results provide a detailed view of the role of helicase in dsRNA recognition, the synergy between the RD and the helicase for RNA binding and the organization of full-length RIG-I bound to dsRNA, and provide evidence of a conformational change upon RNA binding. The RIG-I helicase-RD structure is consistent with dsRNA translocation without unwinding and cooperative binding to RNA. The structure yields unprecedented insight into innate immunity and has a broader impact on other areas of biology, including

  20. Interferon-lambda contributes to innate immunity of mice against influenza A virus but not against hepatotropic viruses.

    Directory of Open Access Journals (Sweden)

    Markus Mordstein

    Full Text Available Virus-infected cells secrete a broad range of interferon (IFN subtypes which in turn trigger the synthesis of antiviral factors that confer host resistance. IFN-alpha, IFN-beta and other type I IFNs signal through a common universally expressed cell surface receptor, whereas IFN-lambda uses a distinct receptor complex for signaling that is not present on all cell types. Since type I IFN receptor-deficient mice (IFNAR1(0/0 exhibit greatly increased susceptibility to various viral diseases, it remained unclear to which degree IFN-lambda might contribute to innate immunity. To address this issue we performed influenza A virus infections of mice which carry functional alleles of the influenza virus resistance gene Mx1 and which, therefore, develop a more complete innate immune response to influenza viruses than standard laboratory mice. We demonstrate that intranasal administration of IFN-lambda readily induced the antiviral factor Mx1 in mouse lungs and efficiently protected IFNAR1(0/0 mice from lethal influenza virus infection. By contrast, intraperitoneal application of IFN-lambda failed to induce Mx1 in the liver of IFNAR1(0/0 mice and did not protect against hepatotropic virus infections. Mice lacking functional IFN-lambda receptors were only slightly more susceptible to influenza virus than wild-type mice. However, mice lacking functional receptors for both IFN-alpha/beta and IFN-lambda were hypersensitive and even failed to restrict usually non-pathogenic influenza virus mutants lacking the IFN-antagonistic factor NS1. Interestingly, the double-knockout mice were not more susceptible against hepatotropic viruses than IFNAR1(0/0 mice. From these results we conclude that IFN-lambda contributes to inborn resistance against viral pathogens infecting the lung but not the liver.

  1. Targeting KIT on innate immune cells to enhance the antitumor activity of checkpoint inhibitors.

    Science.gov (United States)

    Stahl, Maximilian; Gedrich, Richard; Peck, Ronald; LaVallee, Theresa; Eder, Joseph Paul

    2016-06-01

    Innate immune cells such as mast cells and myeloid-derived suppressor cells are key components of the tumor microenvironment. Recent evidence indicates that levels of myeloid-derived suppressor cells in melanoma patients are associated with poor survival to checkpoint inhibitors. This suggests that targeting both the innate and adaptive suppressive components of the immune system will maximize clinical benefit and elicit more durable responses in cancer patients. Preclinical data suggest that targeting signaling by the receptor tyrosine kinase KIT, particularly on mast cells, may modulate innate immune cell numbers and activity in tumors. Here, we review data highlighting the importance of the KIT signaling in regulating antitumor immune responses and the potential benefit of combining selective KIT inhibitors with immune checkpoint inhibitors.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2016-01-01

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

  4. A single social defeat transiently suppresses the anti-viral immune response in mice

    NARCIS (Netherlands)

    de Groot, Johanna; Milligen, Florine J. van; Moonen-Leusen, Bernie W.M.; Thomas, Gethin; Koolhaas, Jaap M.

    1999-01-01

    Most of the studies dealing with effects of stress on anti-viral immunity have been carried out with stressors that are of long duration and that bear little relationship to the nature of the species. In this paper, we investigated the effect of a stressor mimicking real-life situations more closely

  5. Social stress in male mice impairs long-term antiviral immunity selectively in wounded subjects

    NARCIS (Netherlands)

    de Groot, Johanna; Boersma, Wim J.A.; Scholten, Jan Willem; Koolhaas, Jaap M.

    2002-01-01

    An important property of the antiviral immune response is its time-dependent character. Beginning with a few antigen-specific cells upon infection, it evolves to a stage where there is an abundance of antigen-specific cells and antibodies that are needed to clear the pathogen, and ends with circulat

  6. Innate Immune Responses to Engineered Nanomaterials During Allergic Airway Inflammation

    Science.gov (United States)

    Shipkowski, Kelly Anne

    disease would modulate the innate immune response to MWCNTs. We hypothesized that Th2 cytokines and the allergic asthmatic microenvironment would alter MWCNT-induced inflammasome activation and IL- 1beta secretion both in vitro and in vivo. In vitro, THP-1 cells, a human monocytic cell line, were differentiated into macrophages and exposed to MWCNTs and or recombinant Th2 cytokines, specifically IL-4 and/or IL-13. Exposure of THP-1 cells to MWCNTs alone caused dose-dependent secretion of IL-1beta, while co-exposure to IL-4 and/or IL-13 suppressed MWCNT-induced IL-1beta. Further analysis determined that IL-4 and IL-13 were phosphorylating the protein signal transducer and activator of transcription 6 (STAT6) and subsequently inhibiting inflammasome activation and function through suppression of caspase-1, a cysteine protease responsible for cleavage of pro-IL-1beta into an active, secretable form. In vivo, wild-type C57BL6 mice were sensitized intranasally with HDM allergen and exposed to MWCNTs via oropharyngeal aspiration. Treatment with MWCNTs alone induced secretion of IL-1beta in the bronchoalveolar lavage fluid (BALF) one day post-exposure, while sensitization with HDM prior to MWCNT exposure suppressed MWCNT-induced IL-1beta. Immunohistochemical (IHC) analysis of lung sections from exposed animals showed that HDM sensitization inhibited MWCNT-induced pro-casapse-1 protein expression, responsible for inflammasome activation, in the airway epithelium and macrophages. MWCNT exposure combined with HDM sensitization increased inflammatory cell infiltration and subsequent acute lung inflammation and chronic fibrosis. Analysis of the systemic effects of MWCNT exposure during allergic airway sensitization showed that MWCNTs and/or HDM allergen upregulated STAT3 mRNA expression in the lungs, liver, and spleen of exposed animals, and at the same induced mixed T helper (Th) responses in the different tissues. Collectively, these data suggest that the allergic microenvironment

  7. RNA Interference-Induced Innate Immunity, Off-Target Effect, or Immune Adjuvant?

    Science.gov (United States)

    Meng, Zhongji; Lu, Mengji

    2017-01-01

    RNA interference (RNAi) is a natural cellular mechanism that inhibits gene expression in a sequence-specific manner. In the last decade, RNAi has become a cornerstone in basic biological systems research and drug development efforts. The RNAi-based manipulation of mammalian cells facilitates target identification and validation; assists in identifying human disease etiologies; and expedites the development of treatments for infectious diseases, cancer, and other conditions. Several RNAi-based approaches are currently undergoing assessment in phase I and II clinical trials. However, RNAi-associated immune stimulation might act as a hurdle to safe and effective RNAi, particularly in clinical applications. The induction of innate immunity may originate from small interfering RNA (siRNA) sequence-dependent delivery vehicles and even the RNAi process itself. However, in the case of antagonistic cancers and viral infection, immune activation is beneficial; thus, immunostimulatory small interfering RNAs were designed to create bifunctional small molecules with RNAi and immunostimulatory activities. This review summarizes the research studies of RNAi-associated immune stimulation and the approaches for manipulating immunostimulatory activities.

  8. Innate immune system and tissue regeneration in planarians: an area ripe for exploration.

    Science.gov (United States)

    Peiris, T Harshani; Hoyer, Katrina K; Oviedo, Néstor J

    2014-08-01

    The immune system has been implicated as an important modulator of tissue regeneration. However, the mechanisms driving injury-induced immune response and tissue repair remain poorly understood. For over 200 years, planarians have been a classical model for studies on tissue regeneration, but the planarian immune system and its potential role in repair is largely unknown. We found through comparative genomic analysis and data mining that planarians contain many potential homologs of the innate immune system that are activated during injury and repair of adult tissues. These findings support the notion that the relationship between adult tissue repair and the immune system is an ancient feature of basal Bilateria. Further analysis of the planarian immune system during regeneration could potentially add to our understanding of how the innate immune system and inflammatory responses interplay with regenerative signals to induce scar-less tissue repair in the context of the adult organism.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

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

    2011-07-01

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

  11. 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

  12. 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, interferon-α,

  13. Basal inflammation and innate immune response in chronic multisite musculoskeletal pain

    NARCIS (Netherlands)

    Generaal, E.; Vogelzangs, N.; MacFarlane, G.J.; Geenen, R.; Smit, J.H.; Dekker, J.; Penninx, B.W.J.H.

    2014-01-01

    Dysregulation of the immune system may play a role in chronic pain, although study findings are inconsistent. This cross-sectional study examined whether basal inflammatory markers and the innate immune response are associated with the presence and severity of chronic multisite musculoskeletal pain.

  14. Inflammasome-mediated activation of microglia : Tissue-specific features of innate immunity

    NARCIS (Netherlands)

    Burm, S.M.

    2016-01-01

    Multiple sclerosis (MS) is a chronic neurodegenerative disease where lesions are found within the brain. Although the exact cause of MS is unknown, these lesions are characterized by activation of immune cells, including microglia and macrophages. Microglia are the resident innate immune cells of th

  15. The effects of age and social interactions on innate immunity in a leaf-cutting ant

    DEFF Research Database (Denmark)

    Armitage, S.A.O.; Boomsma, J.J.

    2010-01-01

    Both developmental and environmental factors shape investment in costly immune defences. Social insect workers have different selection pressures on their innate immune system compared to non-social insects because workers do not reproduce and their longevity affects the fitness of relatives. Fur...

  16. 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.

  17. Deregulation of innate and adaptive immune responses in human papillomavirus infection and cancer

    NARCIS (Netherlands)

    Karim, Rezaul

    2015-01-01

    HPVs need to avoid immune responses of the host in order to establish persistent infection. HPVs achieve this by dampening innate immunity of keratinocytes, the major cell type targeted by HPV. As there is reduced production of danger signals including antimicrobial molecules, proinflammatory cytoki

  18. Host defense peptides as effector molecules of the innate immune response: a sledgehammer for drug resistance?

    Science.gov (United States)

    Steinstraesser, Lars; Kraneburg, Ursula M; Hirsch, Tobias; Kesting, Marco; Steinau, Hans-Ulrich; Jacobsen, Frank; Al-Benna, Sammy

    2009-09-09

    Host defense peptides can modulate the innate immune response and boost infection-resolving immunity, while dampening potentially harmful pro-inflammatory (septic) responses. Both antimicrobial and/or immunomodulatory activities are an integral part of the process of innate immunity, which itself has many of the hallmarks of successful anti-infective therapies, namely rapid action and broad-spectrum antimicrobial activities. This gives these peptides the potential to become an entirely new therapeutic approach against bacterial infections. This review details the role and activities of these peptides, and examines their applicability as development candidates for use against bacterial infections.

  19. The Roles of Innate Immune Cells in Liver Injury and Regeneration

    Institute of Scientific and Technical Information of China (English)

    Zhongjun Dong; Haiming Wei; Rui Sun; Zhigang Tian

    2007-01-01

    For predominant abundance with liver-specific Kupffer cells, natural killer (NK) cells, and natural killer T (NKT)cells and their rapid responses to several stimuli, the liver is considered as an organ with innate immune features.In contrast to their roles in the defense of many infectious agents like hepatitis viruses and parasites, hepatic innate immune cells are also involved in the immunopathogenesis of human clinical liver diseases and several murine hepatitis models such as concanavalin A (Con A), lipopolysaccharide (LPS), or polyinosinic-polycytidylic acid (Poly I:C)-induced liver injury. In this review, the destructive roles of NK cells, NKT cells and Kupffer cells in the processes of immune-mediated liver injury and regeneration will be discussed, and some putative mechanisms involving the impairment of liver regeneration caused by activated hepatic innate immune cells are also proposed.

  20. Lactobacilli and bifidobacteria promote immune homeostasis by modulating innate immune responses to human rotavirus in neonatal gnotobiotic pigs.

    Directory of Open Access Journals (Sweden)

    Anastasia N Vlasova

    Full Text Available The effects of co-colonization with Lactobacillus rhamnosus GG (LGG and Bifidobacterium lactis Bb12 (Bb12 on 3-dose vaccination with attenuated HRV and challenge with virulent human rotavirus (VirHRV were assessed in 4 groups of gnotobiotic (Gn pigs: Pro+Vac (probiotic-colonized/vaccinated, Vac (vaccinated, Pro (probiotic-colonized, non-vaccinated and Control (non-colonized, non-vaccinated. Subsets of pigs were euthanized pre- [post-challenge day (PCD 0] and post (PCD7-VirHRV challenge to assess diarrhea, fecal HRV shedding and dendritic cell/innate immune responses. Post-challenge, Pro+Vac and Vac groups were completely protected from diarrhea; protection rates against HRV shedding were 100% and 83%, respectively. Diarrhea and HRV shedding were reduced in Pro compared to Control pigs following VirHRV challenge. Diarrhea scores and virus shedding were significantly higher in Controls, compared to all other groups, coincident with significantly higher serum interferon-alpha levels post-challenge. LGG+Bb12 colonization ±vaccine promoted immunomaturation as reflected by increased frequencies of CD4, SWC3a, CD11R1, MHCII expressing mononuclear cells (MNCs and conventional dendritic cells in intestinal tissues and blood post-challenge. Colonization decreased frequencies of toll-like receptors (TLR 2 and TLR4 expressing MNCs from vaccinated pigs (Pro+Vac pre-challenge and increased frequencies of TLR3 expressing MNCs from Pro pigs post-challenge, suggesting that probiotics likely exert anti-inflammatory (TLR2 and 4 down-regulation and antiviral (TLR3 up-regulation by HRV dsRNA actions via TLR signaling. Probiotic colonization alone (Pro increased frequencies of intestinal and systemic apoptotic MNCs pre-challenge, thereby regulating immune hyperreactivity and tolerance. However, these frequencies were decreased in intestinal and systemic tissues post-challenge, moderating HRV-induced apoptosis. Additionally, post-challenge, Pro+Vac and Pro groups had

  1. Cloning Changes the Response to Obesity of Innate Immune Factors in Blood, Liver, and Adipose Tissues in Domestic Pigs

    DEFF Research Database (Denmark)

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

    2013-01-01

    The objective of this study was to evaluate the usefulness of cloned pigs as porcine obesity models reflecting obesity-associated changes in innate immune factor gene expression profiles. Liver and adipose tissue expression of 43 innate immune genes as well as serum concentrations of six immune...

  2. 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

  3. 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...

  4. Innate immune recognition and regulation in liver injury: A brief report from a series of studies

    Institute of Scientific and Technical Information of China (English)

    TIAN ZhiGang

    2009-01-01

    The discovery of innate immune receptors and the emergence of liver Immunology (high content of NK and NKT cells in liver) led to the second research summit in innate immunity since the finding of NK cells in the middle 1970s. Liver disease is one of the most dangerous threats to humans, and the pro-gress in innate immunology and liver immunology made it possible to re-explain the cellular end too-lecular immune mechanisms of liver disease. In the past ten years, we have found that innate recogni-tion of hepatic NK and NKT subsets were involved in murine liver injury. We established a novel NK cell-dependent acute murine hepatitis model by activating Toll-like receptor-3 (TLR-3) with an injection of poly I:C, which may mimic mild viral hepatitis (such as Chronic Hepatitis B). We observed that a network of innate immune cells including NK, NKT and Kupffer cells is involved in liver immune injury in our established NK cell-dependent murine model. We noted that TLR-3 on Kupffer ceils activated by pretreatment with poly I:C might protect against bacterial toxin (LPS)-induced fuIminant hepatitis by down-regulating TLR-4 function, while TLR-3 pre-activation of NK cells might reduce Con A-induced NKT cell-mediated fulminant hepatitis by blocking NKT cell recruitment to the liver. We also found that the oversensitivity to injury by immune stimulation in HBV (hepatitis B virus) transgenic mice (full HBV gene-tg or HBs-tg) correlated to the over-expression of Real, an NKG2D (natural killer cell group 2D) ligand of NK cells or CDld, a ligand of TCR-V14 of NKT cells, on HBV+ hepatocytes, which leads to an innate immune response against hepatocytes and is critical in liver immune injury and regeneration.

  5. Coordinate actions of innate immune responses oppose those of the adaptive immune system during Salmonella infection of mice.

    Science.gov (United States)

    Hotson, Andrew N; Gopinath, Smita; Nicolau, Monica; Khasanova, Anna; Finck, Rachel; Monack, Denise; Nolan, Garry P

    2016-01-12

    The immune system enacts a coordinated response when faced with complex environmental and pathogenic perturbations. We used the heterogeneous responses of mice to persistent Salmonella infection to model system-wide coordination of the immune response to bacterial burden. We hypothesized that the variability in outcomes of bacterial growth and immune response across genetically identical mice could be used to identify immune elements that serve as integrators enabling co-regulation and interconnectedness of the innate and adaptive immune systems. Correlation analysis of immune response variation to Salmonella infection linked bacterial load with at least four discrete, interacting functional immune response "cassettes." One of these, the innate cassette, in the chronically infected mice included features of the innate immune system, systemic neutrophilia, and high serum concentrations of the proinflammatory cytokine interleukin-6. Compared with mice with a moderate bacterial load, mice with the highest bacterial burden exhibited high activity of this innate cassette, which was associated with a dampened activity of the adaptive T cell cassette-with fewer plasma cells and CD4(+) T helper 1 cells and increased numbers of regulatory T cells-and with a dampened activity of the cytokine signaling cassette. System-wide manipulation of neutrophil numbers revealed that neutrophils regulated signal transducer and activator of transcription (STAT) signaling in B cells during infection. Thus, a network-level approach demonstrated unappreciated interconnections that balanced innate and adaptive immune responses during the dynamic course of disease and identified signals associated with pathogen transmission status, as well as a regulatory role for neutrophils in cytokine signaling.

  6. The importance of becoming double-stranded: Innate immunity and the kinetic model of HIV-1 central plus strand synthesis

    Energy Technology Data Exchange (ETDEWEB)

    Poeschla, Eric, E-mail: poeschla.eric@mayo.edu

    2013-06-20

    Central initiation of plus strand synthesis is a conserved feature of lentiviruses and certain other retroelements. This complication of the standard reverse transcription mechanism produces a transient “central DNA flap” in the viral cDNA, which has been proposed to mediate its subsequent nuclear import. This model has assumed that the important feature is the flapped DNA structure itself rather than the process that produces it. Recently, an alternative kinetic model was proposed. It posits that central plus strand synthesis functions to accelerate conversion to the double-stranded state, thereby helping HIV-1 to evade single-strand DNA-targeting antiviral restrictions such as APOBEC3 proteins, and perhaps to avoid innate immune sensor mechanisms. The model is consistent with evidence that lentiviruses must often synthesize their cDNAs when dNTP concentrations are limiting and with data linking reverse transcription and uncoating. There may be additional kinetic advantages for the artificial genomes of lentiviral gene therapy vectors. - Highlights: • Two main functional models for HIV central plus strand synthesis have been proposed. • In one, a transient central DNA flap in the viral cDNA mediates HIV-1 nuclear import. • In the other, multiple kinetic consequences are emphasized. • One is defense against APOBEC3G, which deaminates single-stranded DNA. • Future questions pertain to antiviral restriction, uncoating and nuclear import.

  7. 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...

  8. Noncoding RNA danger motifs bridge innate and adaptive immunity and are potent adjuvants for vaccination

    OpenAIRE

    Wang, Lilin; Smith, Dan; Bot, Simona; Dellamary, Luis; Bloom, Amy; Bot, Adrian

    2002-01-01

    The adaptive immune response is triggered by recognition of T and B cell epitopes and is influenced by “danger” motifs that act via innate immune receptors. This study shows that motifs associated with noncoding RNA are essential features in the immune response reminiscent of viral infection, mediating rapid induction of proinflammatory chemokine expression, recruitment and activation of antigen-presenting cells, modulation of regulatory cytokines, subsequent differentiation of Th1 cells, iso...

  9. SNP discovery and molecular evolution in Anopheles gambiae, with special emphasis on innate immune system

    OpenAIRE

    Koutsos Anastasios; Morlais Isabelle; Simard Frédéric; Krishnakumar Sujatha; Cohuet Anna; Fontenille Didier; Mindrinos Michael; Kafatos Fotis C

    2008-01-01

    Abstract Background Anopheles innate immunity affects Plasmodium development and is a potential target of innovative malaria control strategies. The extent and distribution of nucleotide diversity in immunity genes might provide insights into the evolutionary forces that condition pathogen-vector interactions. The discovery of polymorphisms is an essential step towards association studies of susceptibility to infection. Results We sequenced coding fragments of 72 immune related genes in natur...

  10. Insect anti-viral immunity: roles of prostaglandins and other eicosanoids

    Science.gov (United States)

    Insect/microbe relationships are very complex, with an array of signaling systems acting in surveillance, detection and responses to the presence of microbes. We report that prostaglandins (PGs) are responsible for essential signaling in activating and coordinating insect innate immune reactions to ...

  11. 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.

  12. 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.

  13. Identification and isolation of stimulator of interferon genes (STING): an innate immune sensory and adaptor gene from camelids.

    Science.gov (United States)

    Premraj, A; Aleyas, A G; Nautiyal, B; Rasool, T J

    2013-10-01

    The mechanism by which type I interferon-mediated antiviral response is mounted by hosts against invading pathogen is an intriguing one. Of late, an endoplasmic reticulum transmembrane protein encoded by a gene called stimulator of interferon genes (STING) is implicated in the innate signalling pathways and has been identified and cloned in few mammalian species including human, mouse and pig. In this article, we report the identification of STING from three different species of a highly conserved family of mammals - the camelids. cDNAs encoding the STING of Old World camels - dromedary camel (Camelus dromedarius) and bactrian camel (Camelus bactrianus) and a New World camel - llama (Llama glama) were amplified using conserved primers and RACE. The complete STING cDNA of dromedary camel is 2171 bp long with a 706-bp 5' untranslated regions (UTR), an 1137-bp open reading frame (ORF) and a 328-bp 3' UTR. Sequence and phylogenetic analysis of the ORF of STING from these three camelids indicate high level of similarity among camelids and conservation of critical amino acid residues across different species. Quantitative real-time PCR analysis revealed high levels of STING mRNA expression in blood, spleen, lymph node and lung. The identification of camelid STING will help in better understanding of the role of this molecule in the innate immunity of the camelids and other mammals.

  14. The innate immune system and diabetes mellitus: the relevance of periodontitis? A hypothesis.

    Science.gov (United States)

    Lazenby, Martin G; Crook, Martin A

    2010-08-05

    About a decade ago, a hypothesis was proposed suggesting that the innate immune system, including acute-phase reactants, contribute to the development of T2DM [Type 2 DM (diabetes mellitus)] and the metabolic syndrome. In this model, it was hypothesized that the innate immune system modulates the effects of many factors, including genes, fetal programming, nutrition and aging, upon the later development of metabolic problems associated with insulin resistance. In this present article, we expand this hypothesis by looking at the involvement of periodontitis in DM and its complications. Periodontitis is a common inflammatory process involving the innate immune system and is associated with DM. We will also illustrate how dental disease is important in patients with DM and could be implicated in various diabetic complications.

  15. Innate immune gene expression differentiates the early avian intestinal response between Salmonella and Campylobacter.

    Science.gov (United States)

    Shaughnessy, Ronan G; Meade, Kieran G; Cahalane, Sarah; Allan, Brenda; Reiman, Carla; Callanan, John J; O'Farrelly, Cliona

    2009-12-15

    Salmonella enterica serovar Typhimurium and Campylobacter jejuni are major human pathogens, yet colonise chickens without causing pathology. The aim of this study was to compare intestinal innate immune responses to both bacterial species, in a 4-week-old broiler chicken model. Challenged and control birds were sacrificed and tissue samples taken for histopathology and RNA extraction. No significant clinical or pathological changes were observed in response to infection with either bacterial species. Expression of selected genes involved in pathogen detection and the innate immune response were profiled in caecal tissues by quantitative real-time PCR. TLR4 and TLR21 gene expression was transiently increased in response to both bacterial species (Pimmune genes in both infection models shed light on the tailored responses of the host immune system to specific microbes. It is further evidence that innate regulation of these responses is an important prerequisite to preventing development of disease.

  16. Innate immune response to arenaviral infection: a focus on the highly pathogenic New World hemorrhagic arenaviruses.

    Science.gov (United States)

    Koma, Takaaki; Huang, Cheng; Kolokoltsova, Olga A; Brasier, Allan R; Paessler, Slobodan

    2013-12-13

    Arenaviruses are enveloped, negative-stranded RNA viruses that belong to the family Arenaviridae. This diverse family can be further classified into OW (Old World) and NW (New World) arenaviruses based on their antigenicity, phylogeny, and geographical distribution. Many of the NW arenaviruses are highly pathogenic viruses that cause systemic human infections characterized by hemorrhagic fever and/or neurological manifestations, constituting public health problems in their endemic regions. NW arenavirus infection induces a variety of host innate immune responses, which could contribute to the viral pathogenesis and/or influence the final outcome of virus infection in vitro and in vivo. On the other hand, NW arenaviruses have also developed several strategies to counteract the host innate immune response. We will review current knowledge regarding the interplay between the host innate immune response and NW arenavirus infection in vitro and in vivo, with emphasis on viral-encoded proteins and their effect on the type I interferon response.

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

    Science.gov (United States)

    Ieni, Antonio; Barresi, Valeria; Rigoli, Luciana; Fedele, Francesco; Tuccari, Giovanni; Caruso, Rosario Alberto

    2016-01-15

    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.

  18. Are the innate and adaptive immune systems setting hypertension on fire?

    Science.gov (United States)

    Bomfim, Gisele F; Rodrigues, Fernanda Luciano; Carneiro, Fernando S

    2017-03-01

    Hypertension is the most common chronic cardiovascular disease and is associated with several pathological states, being an important cause of morbidity and mortality around the world. Low-grade inflammation plays a key role in hypertension and the innate and adaptive immune systems seem to contribute to hypertension development and maintenance. Hypertension is associated with vascular inflammation, increased vascular cytokines levels and infiltration of immune cells in the vasculature, kidneys and heart. However, the mechanisms that trigger inflammation and immune system activation in hypertension are completely unknown. Cells from the innate immune system express pattern recognition receptors (PRR), which detect conserved pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) that induce innate effector mechanisms to produce endogenous signals, such as inflammatory cytokines and chemokines, to alert the host about danger. Additionally, antigen-presenting cells (APC) act as sentinels that are activated by PAMPs and DAMPs to sense the presence of the antigen/neoantigen, which ensues the adaptive immune system activation. In this context, different lymphocyte types are activated and contribute to inflammation and end-organ damage in hypertension. This review will focus on experimental and clinical evidence demonstrating the contribution of the innate and adaptive immune systems to the development of hypertension.

  19. 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.

  20. Original Antigenic Sin Response to RNA Viruses and Antiviral Immunity

    Science.gov (United States)

    Park, Mee Sook; Kim, Jin Il; Park, Sehee; Lee, Ilseob

    2016-01-01

    The human immune system has evolved to fight against foreign pathogens. It plays a central role in the body's defense mechanism. However, the immune memory geared to fight off a previously recognized pathogen, tends to remember an original form of the pathogen when a variant form subsequently invades. This has been termed 'original antigenic sin'. This adverse immunological effect can alter vaccine effectiveness and sometimes cause enhanced pathogenicity or additional inflammatory responses, according to the type of pathogen and the circumstances of infection. Here we aim to give a simplified conceptual understanding of virus infection and original antigenic sin by comparing and contrasting the two examples of recurring infections such as influenza and dengue viruses in humans. PMID:27799871

  1. Toll-like receptor 11-initiated innate immune response in male mouse germ cells.

    Science.gov (United States)

    Chen, Qiaoyuan; Zhu, Weiwei; Liu, Zhenghui; Yan, Keqin; Zhao, Shutao; Han, Daishu

    2014-02-01

    Toxoplasma gondii and uropathogenic Escherichia coli (UPEC) may infect the testis and impair testicular function. Mechanisms underlying testicular innate immune response to these two pathogens remain to be clarified. The present study examined the function of TLR11, which can be recognized by T. gondii-derived profilin and UPEC, in initiating innate immune response in male mouse germ cells. TLR11 is predominantly expressed in spermatids. Profilin and UPEC induced the expressions of different inflammatory cytokine profiles in the germ cells. In particular, profilin induced the expressions of macrophage chemotactic protein 1 (MCP1), interleukin 12 (IL12), and interferon gamma (IFNG) through nuclear factor KB (NFKB) activation. UPEC induced the expressions of MCP1, IL12, and IFNG, as well as tumor necrosis factor alpha (TNFA), IL6, and IFNB, through the activation of NFKB, IFN regulatory factor 3, and mitogen-activated protein kinases. Evidence showed that profilin induced the innate response in male germ cells through TLR11 signaling, and UPEC triggered the response through TLR11 and other TLR-signaling pathways. We also provided evidence that local injection of profilin or UPEC induces the innate immune response in the germ cells. Data describe TLR11-mediated innate immune function of male germ cells in response to T. gondii profilin and UPEC stimulations. This system may play a role in testicular defense against T. gondii and UPEC infections in mice.

  2. Dysregulated innate immune function in the aetiopathogenesis of idiopathic inflammatory myopathies.

    Science.gov (United States)

    Day, Jessica; Otto, Sophia; Proudman, Susanna; Hayball, John D; Limaye, Vidya

    2017-01-01

    The idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of systemic muscle conditions that are believed to be autoimmune in nature. They have distinct pathological features, but the aetiopathogenesis of each subtype remains largely unknown. Recently, there has been increased interest in the complex role the innate immune system plays in initiating and perpetuating these conditions, and how this may differ between subtypes. This article summarises the traditional paradigms of IIM pathogenesis and reviews the accumulating evidence for disturbances in innate immune processes in these rare, but debilitating chronic conditions.

  3. The Role of Innate Immunity in Conditioning Mosquito Susceptibility to West Nile Virus

    Directory of Open Access Journals (Sweden)

    Abhishek N. Prasad

    2013-12-01

    Full Text Available Arthropod-borne viruses (arboviruses represent an emerging threat to human and livestock health globally. In particular, those transmitted by mosquitoes present the greatest challenges to disease control efforts. An understanding of the molecular basis for mosquito innate immunity to arbovirus infection is therefore critical to investigations regarding arbovirus evolution, virus-vector ecology, and mosquito vector competence. In this review, we discuss the current state of understanding regarding mosquito innate immunity to West Nile virus. We draw from the literature with respect to other virus-vector pairings to attempt to draw inferences to gaps in our knowledge about West Nile virus and relevant vectors.

  4. Steroid hormone signaling is essential to regulate innate immune cells and fight bacterial infection in Drosophila.

    Directory of Open Access Journals (Sweden)

    Jennifer C Regan

    2013-10-01

    Full Text Available Coupling immunity and development is essential to ensure survival despite changing internal conditions in the organism. Drosophila metamorphosis represents a striking example of drastic and systemic physiological changes that need to be integrated with the innate immune system. However, nothing is known about the mechanisms that coordinate development and immune cell activity in the transition from larva to adult. Here, we reveal that regulation of macrophage-like cells (hemocytes by the steroid hormone ecdysone is essential for an effective innate immune response over metamorphosis. Although it is generally accepted that steroid hormones impact immunity in mammals, their action on monocytes (e.g. macrophages and neutrophils is still not well understood. Here in a simpler model system, we used an approach that allows in vivo, cell autonomous analysis of hormonal regulation of innate immune cells, by combining genetic manipulation with flow cytometry, high-resolution time-lapse imaging and tissue-specific transcriptomic analysis. We show that in response to ecdysone, hemocytes rapidly upregulate actin dynamics, motility and phagocytosis of apoptotic corpses, and acquire the ability to chemotax to damaged epithelia. Most importantly, individuals lacking ecdysone-activated hemocytes are defective in bacterial phagocytosis and are fatally susceptible to infection by bacteria ingested at larval stages, despite the normal systemic and local production of antimicrobial peptides. This decrease in survival is comparable to the one observed in pupae lacking immune cells altogether, indicating that ecdysone-regulation is essential for hemocyte immune functions and survival after infection. Microarray analysis of hemocytes revealed a large set of genes regulated at metamorphosis by EcR signaling, among which many are known to function in cell motility, cell shape or phagocytosis. This study demonstrates an important role for steroid hormone regulation of

  5. The role of CC chemokine receptor 5 in antiviral immunity

    DEFF Research Database (Denmark)

    Nansen, Anneline; Christensen, Jan Pravsgaard; Andreasen, Susanne Ørding;

    2002-01-01

    that the virus-induced clonal expansion of antigen-specific T cells was augmented in CCR5(-/-) mice especially with regard to the CD4(+) subset. Despite absence of CCR5, intracerebral infection invariably resulted in lethal T cell-mediated meningitis, and quantitative and qualitative analysis of the inflammatory...... influence of CCR5 was found, not even when viral peptide was used as local trigger instead of live virus. Finally, long-term CD8(+) T cell-mediated immune surveillance was efficiently sustained in CCR5(-/-) mice. Taken together, these results indicate that expression of CCR5 is not critical for T cell...

  6. Innate immune receptors in carp: recognition of protozoan parasites

    NARCIS (Netherlands)

    Ribeiro, C.M.S.

    2010-01-01

    This PhD thesis reports on pattern recognition receptors involved in the immune responses of common carp (Cyprinus carpio) to two protozoan parasites Trypanoplasma borreli and Trypanosoma carassii. The immune responses of carp are fundamentally different when comparing these two extracellular blood

  7. Plant innate immunity: An updated insight into defense mechanism

    Indian Academy of Sciences (India)

    Mehanathan Muthamilarasan; Manoj Prasad

    2013-06-01

    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 effector-triggered immunity (ETI). MTI confers basal resistance, while ETI confers durable resistance, often resulting in hypersensitive response. Plants also possess systemic acquired resistance (SAR), which provides long-term defense against a broad-spectrum of pathogens. Salicylic-acid-mediated systemic acquired immunity provokes the defense response throughout the plant system during pathogen infection at a particular site. Trans-generational immune priming allows the plant to heritably shield their progeny towards pathogens previously encountered. Plants circumvent the viral infection through RNA interference phenomena by utilizing small RNAs. This review summarizes the molecular mechanisms of plant immune system, and the latest breakthroughs reported in plant defense. We discuss the plant–pathogen interactions and integrated defense responses in the context of presenting an integral understanding in plant molecular immunity.

  8. Gene expression analysis during recovery process indicates the mechanism for innate immune injury and repair from Coxsackievirus B3-induced myocarditis.

    Science.gov (United States)

    Yao, Hai-Lan; Song, Juan; Sun, Peng; Song, Qin-Qin; Sheng, Lin-Jun; Chi, Miao-Miao; Han, Jun

    2016-02-02

    To investigate the innate immune injury and repair mechanism during recovery from Coxsackievirus B3 (CVB3) induced myocarditis, we established an acute viral myocarditis recovery model by infecting BALB/c mice with CVB3. Histopathological examination of cardiac tissues after infection showed a gradual increase of myocardial injury to the maximum degree at 8 dpi (days post infection), followed by a recovery process with reduced viral replication. We also measured expression changes of innate immune genes in heart after 4, 8 and 12 days of infection using innate immune real-time PCR array. The results showed expression alterations in many Pattern Recognition Receptors (PRRs) genes upon CVB3 infection, which activated multiple important signaling pathways during recovery process. The expression of TLRs, RLRs, PKR and cytokines were strongly induced and reached the peak at 4 dpi in early myocarditis stage, followed by a gradual reduction in recovery stage, during which the levels were even lower than normal at 12 dpi. The strong correlation between cardiac histopathology score and chemokine expression level suggested that the chemokines might play a role in pathological changes during early myocarditis stage. In addition, we also found that both cell survival signaling pathways (AKT1, p38MAPK) and antiviral signaling pathways (IKKα/β/ε) were activated and promoted the recovery during late myocarditis stage. Altogether, our observations improved the understanding of formation and progression of the pathological lesions, as well as the repair mechanism for acute viral myocarditis.

  9. 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.

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

    Directory of Open Access Journals (Sweden)

    Michael Nevels

    2009-11-01

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

  11. Rhodiola inhibits dengue virus multiplication by inducing innate immune response genes RIG-I, MDA5 and ISG in human monocytes.

    Science.gov (United States)

    Diwaker, Drishya; Mishra, K P; Ganju, Lilly; Singh, S B

    2014-08-01

    Recognition of virus infection by retinoic acid-inducible gene (RIG) I and melanoma differentiation-associated protein (MDA) 5, which are RNA helicases, and interferon-stimulated gene (ISG) 15 activates cascades of signal transduction pathways leading to production of type I interferons and proinflammatory cytokines that orchestrate the elimination of the viruses. However, it has been demonstrated that RNA-helicase-mediated innate immunity plays an essential role in defending the host from infection. In our efforts to identify plant-derived antivirals that selectively enhance ISG- and RNA-helicase-mediated antiviral immune responses, we identified a plant, rhodiola, that significantly promoted ISG, RIG-I and MDA 5 gene expression and an antiviral immune response against dengue virus (DENV) infection. Rhodiola induced interferon (IFN) β and other cytokines, including IL-1β, TNF-α, IL-6 and IL-8, in infected cells. It was also found that rhodiola upregulated phosphorylated eIF-2α, PKR and NF-kB in infected cells. In addition, the number of NK cells was also increased by rhodiola treatment in dengue-virus-infected human PBMCs. Treatment with a crude extract of rhodiola (RAE) resulted in effects in the 20 % range, which is similar to the magnitude of the same effects observed in DENV infections. Taken together, our results imply that rhodiola induces pharmacological modulation of RIG-I, MDA 5 and ISG signal transduction pathways in favor of the induction of a beneficial antiviral immune response against dengue virus, which can be a novel therapeutic strategy for management of infection.

  12. Innate immune detection of flagellin positively and negatively regulates salmonella infection.

    Directory of Open Access Journals (Sweden)

    Marvin A Lai

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

  13. Innate immune detection of flagellin positively and negatively regulates salmonella infection.

    Science.gov (United States)

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

    2013-01-01

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

  14. Innate immunity and protective neuroinflammation: new emphasis on the role of neuroimmune regulatory proteins.

    Science.gov (United States)

    Griffiths, M; Neal, J W; Gasque, P

    2007-01-01

    Brain inflammation due to infection, hemorrhage, and aging is associated with activation of the local innate immune system as expressed by infiltrating cells, resident glial cells, and neurons. The innate immune response relies on the detection of "nonself" and "danger-self" ligands behaving as "eat me signals" by a plethora of pattern recognition receptors (PRRs) expressed by professional and amateur phagocytes to promote the clearance of pathogens, toxic cell debris (amyloid fibrils, aggregated synucleins, prions), and apoptotic cells accumulating within the brain parenchyma and the cerebrospinal fluid (CSF). These PRRs (e.g., complement, TLR, CD14, scavenger receptors) are highly conserved between vertebrates and invertebrates and may represent the most ancestral innate scavenging system involved in tissue homeostasis. However, in some diseases, these protective mechanisms lead to neurodegeneration on the ground that several innate immune molecules have neurocytotoxic activities. The response is a "double-edged sword" representing a fine balance between protective and detrimental effects. Several key regulatory mechanisms have now been evidenced in the control of CNS innate immunity, and these could be harnessed to explore novel therapeutic avenues. We will herein provide new emphasis on the role of neuroimmune regulatory proteins (NIRegs), such as CD95L, TNF, CD200, CD47, sialic acids, CD55, CD46, fH, C3a, HMGB1, which are involved in silencing innate immunity at the cellular and molecular levels and suppression of inflammation. For instance, NIRegs may play an important role in controlling lymphocyte/macrophage/microglia hyperinflammatory responses, while sparing host defense and repair mechanisms. Moreover, NIRegs have direct beneficial effects on neurogenesis and contributing to brain tissue remodeling.

  15. Zebra Fish Lacking Adaptive Immunity Acquire an Antiviral Alert State Characterized by Upregulated Gene Expression of Apoptosis, Multigene Families, and Interferon-Related Genes.

    Science.gov (United States)

    García-Valtanen, Pablo; Martínez-López, Alicia; López-Muñoz, Azucena; Bello-Perez, Melissa; Medina-Gali, Regla M; Ortega-Villaizán, María Del Mar; Varela, Monica; Figueras, Antonio; Mulero, Víctoriano; Novoa, Beatriz; Estepa, Amparo; Coll, Julio

    2017-01-01

    To investigate fish innate immunity, we have conducted organ and cell immune-related transcriptomic as well as immunohistologic analysis in mutant zebra fish (Danio rerio) lacking adaptive immunity (rag1(-/-)) at different developmental stages (egg, larvae, and adult), before and after infection with spring viremia carp virus (SVCV). The results revealed that, compared to immunocompetent zebra fish (rag1(+/+) ), rag1(-/-) acquired increased resistance to SVCV with age, correlating with elevated transcript levels of immune genes in skin/fins and lymphoid organs (head kidney and spleen). Gene sets corresponding to apoptotic functions, immune-related multigene families, and interferon-related genes were constitutively upregulated in uninfected adult rag1(-/-) zebra fish. Overexpression of activated CASPASE-3 in different tissues before and after infection with SVCV further confirmed increased apoptotic function in rag1(-/-) zebra fish. Concurrently, staining of different tissue samples with a pan-leukocyte antibody marker showed abundant leukocyte infiltrations in SVCV-infected rag1(-/-) fish, coinciding with increased transcript expression of genes related to NK-cells and macrophages, suggesting that these genes played a key role in the enhanced immune response of rag1(-/-) zebra fish to SVCV lethal infection. Overall, we present evidence that indicates that rag1(-/-) zebra fish acquire an antiviral alert state while they reach adulthood in the absence of adaptive immunity. This antiviral state was characterized by (i) a more rapid response to viral infection, which resulted in increased survival, (ii) the involvement of NK-cell- and macrophage-mediated transcript responses rather than B- and/or T-cell dependent cells, and (iii) enhanced apoptosis, described here for the first time, as well as the similar modulation of multigene family/interferon-related genes previously associated to fish that survived lethal viral infections. From this and other studies, it might

  16. 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.

  17. Characterization of human antiviral adaptive immune responses during hepatotropic virus infection in HLA-transgenic human immune system mice.

    Science.gov (United States)

    Billerbeck, Eva; Horwitz, Joshua A; Labitt, Rachael N; Donovan, Bridget M; Vega, Kevin; Budell, William C; Koo, Gloria C; Rice, Charles M; Ploss, Alexander

    2013-08-15

    Humanized mice have emerged as a promising model to study human immunity in vivo. Although they are susceptible to many pathogens exhibiting an almost exclusive human tropism, human immune responses to infection remain functionally impaired. It has recently been demonstrated that the expression of HLA molecules improves human immunity to lymphotropic virus infections in humanized mice. However, little is known about the extent of functional human immune responses in nonlymphoid tissues, such as in the liver, and the role of HLA expression in this context. Therefore, we analyzed human antiviral immunity in humanized mice during a hepatotropic adenovirus infection. We compared immune responses of conventional humanized NOD SCID IL-2Rγ-deficient (NSG) mice to those of a novel NOD SCID IL-2Rγ-deficient strain transgenic for both HLA-A*0201 and a chimeric HLA-DR*0101 molecule. Using a firefly luciferase-expressing adenovirus and in vivo bioluminescence imaging, we demonstrate a human T cell-dependent partial clearance of adenovirus-infected cells from the liver of HLA-transgenic humanized mice. This correlated with liver infiltration and activation of T cells, as well as the detection of Ag-specific humoral and cellular immune responses. When infected with a hepatitis C virus NS3-expressing adenovirus, HLA-transgenic humanized mice mounted an HLA-A*0201-restricted hepatitis C virus NS3-specific CD8(+) T cell response. In conclusion, our study provides evidence for the generation of partial functional antiviral immune responses against a hepatotropic pathogen in humanized HLA-transgenic mice. The adenovirus reporter system used in our study may serve as simple in vivo method to evaluate future strategies for improving human intrahepatic immune responses in humanized mice.

  18. Virus-associated activation of innate immunity induces rapid disruption of Peyer's patches in mice.

    Science.gov (United States)

    Heidegger, Simon; Anz, David; Stephan, Nicolas; Bohn, Bernadette; Herbst, Tina; Fendler, Wolfgang Peter; Suhartha, Nina; Sandholzer, Nadja; Kobold, Sebastian; Hotz, Christian; Eisenächer, Katharina; Radtke-Schuller, Susanne; Endres, Stefan; Bourquin, Carole

    2013-10-10

    Early in the course of infection, detection of pathogen-associated molecular patterns by innate immune receptors can shape the subsequent adaptive immune response. Here we investigate the influence of virus-associated innate immune activation on lymphocyte distribution in secondary lymphoid organs. We show for the first time that virus infection of mice induces rapid disruption of the Peyer's patches but not of other secondary lymphoid organs. The observed effect was not dependent on an active infectious process, but due to innate immune activation and could be mimicked by virus-associated molecular patterns such as the synthetic double-stranded RNA poly(I:C). Profound histomorphologic changes in Peyer's patches were associated with depletion of organ cellularity, most prominent among the B-cell subset. We demonstrate that the disruption is entirely dependent on type I interferon (IFN). At the cellular level, we show that virus-associated immune activation by IFN-α blocks B-cell trafficking to the Peyer's patches by downregulating expression of the homing molecule α4β7-integrin. In summary, our data identify a mechanism that results in type I IFN-dependent rapid but reversible disruption of intestinal lymphoid organs during systemic viral immune activation. We propose that such rerouted lymphocyte trafficking may impact the development of B-cell immunity to systemic viral pathogens.

  19. Microbial Degradation of Cellular Kinases Impairs Innate Immune Signaling and Paracrine TNFα Responses.

    Science.gov (United States)

    Barth, Kenneth; Genco, Caroline Attardo

    2016-10-04

    The NFκB and MAPK signaling pathways are critical components of innate immunity that orchestrate appropriate immune responses to control and eradicate pathogens. Their activation results in the induction of proinflammatory mediators, such as TNFα a potent bioactive molecule commonly secreted by recruited inflammatory cells, allowing for paracrine signaling at the site of an infection. In this study we identified a novel mechanism by which the opportunistic pathogen Porphyromonas gingivalis dampens innate immune responses by disruption of kinase signaling and degradation of inflammatory mediators. The intracellular immune kinases RIPK1, TAK1, and AKT were selectively degraded by the P. gingivalis lysine-specific gingipain (Kgp) in human endothelial cells, which correlated with dysregulated innate immune signaling. Kgp was also observed to attenuate endothelial responsiveness to TNFα, resulting in a reduction in signal flux through AKT, ERK and NFκB pathways, as well as a decrease in downstream proinflammatory mRNA induction of cytokines, chemokines and adhesion molecules. A deficiency in Kgp activity negated decreases to host cell kinase protein levels and responsiveness to TNFα. Given the essential role of kinase signaling in immune responses, these findings highlight a unique mechanism of pathogen-induced immune dysregulation through inhibition of cell activation, paracrine signaling, and dampened cellular proinflammatory responses.

  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-likereceptor signaling networ...he toll-likereceptor signaling network. PubmedID 17576036 Title Glucocorticoids a...nd the innate immune system: crosstalk with the toll-likereceptor signaling network. Authors Chinenov Y, Rog

  1. Weaned pigs experimentally infected with Salmonella display sexually dimorphic innate immune responses without affecting pathogen colonization patterns

    Science.gov (United States)

    Sexually dimorphic innate immune responses have been observed in several species, but have not been studied in response to a live pathogen challenge in pigs. This study aimed to elucidate sexually dimorphic innate immune responses along with Salmonella translocation patterns in newly weaned pigs ora...

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

    Lifescience Database Archive (English)

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

  3. Genomic HIV RNA induces innate immune responses through RIG-I-dependent sensing of secondary-structured RNA

    NARCIS (Netherlands)

    Berg, R.K.; Melchjorsen, J.; Rintahaka, J.; Diget, E.; Søby, S.; Horan, K.A.; Gorelick, R.J.; Matikainen, S.; Larsen, C.S.; Ostergaard, L.; Paludan, S.R.; Mogensen, T.H.

    2012-01-01

    BACKGROUND: Innate immune responses have recently been appreciated to play an important role in the pathogenesis of HIV infection. Whereas inadequate innate immune sensing of HIV during acute infection may contribute to failure to control and eradicate infection, persistent inflammatory responses la

  4. SUMO-Enriched Proteome for Drosophila Innate Immune Response

    Science.gov (United States)

    Handu, Mithila; Kaduskar, Bhagyashree; Ravindranathan, Ramya; Soory, Amarendranath; Giri, Ritika; Elango, Vijay Barathi; Gowda, Harsha; Ratnaparkhi, Girish S.

    2015-01-01

    Small ubiquitin-like modifier (SUMO) modification modulates the expression of defense genes in Drosophila, activated by the Toll/nuclear factor-κB and immune-deficient/nuclear factor-κB signaling networks. We have, however, limited understanding of the SUMO-modulated regulation of the immune response and lack information on SUMO targets in the immune system. In this study, we measured the changes to the SUMO proteome in S2 cells in response to a lipopolysaccharide challenge and identified 1619 unique proteins in SUMO-enriched lysates. A confident set of 710 proteins represents the immune-induced SUMO proteome and analysis suggests that specific protein domains, cellular pathways, and protein complexes respond to immune stress. A small subset of the confident set was validated by in-bacto SUMOylation and shown to be bona-fide SUMO targets. These include components of immune signaling pathways such as Caspar, Jra, Kay, cdc42, p38b, 14-3-3ε, as well as cellular proteins with diverse functions, many being components of protein complexes, such as prosß4, Rps10b, SmD3, Tango7, and Aats-arg. Caspar, a human FAF1 ortholog that negatively regulates immune-deficient signaling, is SUMOylated at K551 and responds to treatment with lipopolysaccharide in cultured cells. Our study is one of the first to describe SUMO proteome for the Drosophila immune response. Our data and analysis provide a global framework for the understanding of SUMO modification in the host response to pathogens. PMID:26290570

  5. Evasion of the human innate immune system by dengue virus

    OpenAIRE

    Pagni, Sarah; Fernandez-Sesma, Ana

    2012-01-01

    Dengue virus is a worldwide health problem, with billions of people at risk annually. Dengue virus causes a spectrum of diseases, namely dengue fever, dengue hemorrhagic fever and dengue shock syndrome with the latter two being linked to death. Understanding how dengue is able to evade the immune system and cause enhanced severity of disease is the main topics of interest in the Fernandez-Sesma laboratory at Mount Sinai School of Medicine. Using primary human immune cells, our group investiga...

  6. Host stress physiology and Trypanosoma haemoparasite infection influence innate immunity in the woylie (Bettongia penicillata).

    Science.gov (United States)

    Hing, Stephanie; Currie, Andrew; Broomfield, Steven; Keatley, Sarah; Jones, Krista; Thompson, R C Andrew; Narayan, Edward; Godfrey, Stephanie S

    2016-06-01

    Understanding immune function is critical to conserving wildlife in view of infectious disease threats, particularly in threatened species vulnerable to stress, immunocompromise and infection. However, few studies examine stress, immune function and infection in wildlife. We used a flow cytometry protocol developed for human infants to assess phagocytosis, a key component of innate immunity, in a critically endangered marsupial, the woylie (Bettongia penicillata). The effects of stress physiology and Trypanosoma infection on phagocytosis were investigated. Blood and faecal samples were collected from woylies in a captive facility over three months. Trypanosoma status was determined using PCR. Faecal cortisol metabolites (FCM) were quantified by enzyme-immunoassay. Mean phagocytosis measured was >90%. An interaction between sex and FCM influenced the percentage of phagocytosing leukocytes, possibly reflecting the influence of sex hormones and glucocorticoids. An interaction between Trypanosoma status and FCM influenced phagocytosis index, suggesting that stress physiology and infection status influence innate immunity.

  7. CpG oligodeoxynucleotide-specific goose TLR21 initiates an anti-viral immune response against NGVEV but not AIV strain H9N2 infection.

    Science.gov (United States)

    Qi, Yulin; Yan, Bing; Chen, Shun; Chen, Hongjun; Wang, Mingshu; Jia, Renyong; Zhu, Dekang; Liu, Mafeng; Liu, Fei; Yang, Qiao; Sun, Kunfeng; Wu, Ying; Chen, Xiaoyue; Jing, Bo; Cheng, Anchun

    2016-03-01

    Toll-like receptors (TLRs) recognize components of pathogens and mediate the host innate immune response. TLR21 is a TLR that specifically recognizes exogenous double-stranded DNA and rapidly signals to downstream innate immune factors. This study reports the cDNA of goose TLR21 and identifies its immune characteristics. The goose TLR21 is 3161 base pairs and encodes a 975 amino acid protein. As predicted, the goose transmembrane protein TLR21 has a signal peptide, leucine-rich repeat regions, a transmembrane domain, and a Toll/interleukin-1 receptor domain. Multiple sequence alignments and phylogenetic analyses showed that goose TLR21 has homology to chicken TLR21. The tissue distribution of TLR21 suggested that it has high transcript levels in immune-associated tissues, especially in the bursa of Fabricius, the Hadrian gland, and the thymus. After challenge with agonist ODN2006 and new type gosling viral enteritis virus (NGVEV), significant induction of TLR21 production, pro-inflammatory cytokines IL-1β and IL-6, and interferons were observed in peripheral blood mononuclear cells. Both synthetic DNA (ODN2006) and viral DNA (NGVEV) can be recognized by goose TLR21, which leads to a rapid up-regulation of pro-inflammatory cytokines and anti-viral molecules. In vivo, avian influenza A virus H9N2 and NGVEV were used to infect goslings, which was followed by a significant up-regulation of TLR21 mRNA transcripts in multiple tissues of NGVEV-infected geese. In general, goose TLR21 plays an important role in binding invading pathogenic DNA viruses, which subsequently triggers an innate immune response; furthermore, it acts as a functional homologue of mammalian TLR9, as TLR21 recognizes a mammalian TLR9 agonist.

  8. Biochemical and Functional Insights into the Integrated Regulation of Innate Immune Cell Responses by Teleost Leukocyte Immune-Type Receptors

    Directory of Open Access Journals (Sweden)

    Chenjie Fei

    2016-03-01

    Full Text Available Across vertebrates, innate immunity consists of a complex assortment of highly specialized cells capable of unleashing potent effector responses designed to destroy or mitigate foreign pathogens. The execution of various innate cellular behaviors such as phagocytosis, degranulation, or cell-mediated cytotoxicity are functionally indistinguishable when being performed by immune cells isolated from humans or teleost fishes; vertebrates that diverged from one another more than 450 million years ago. This suggests that vital components of the vertebrate innate defense machinery are conserved and investigating such processes in a range of model systems provides an important opportunity to identify fundamental features of vertebrate immunity. One characteristic that is highly conserved across vertebrate systems is that cellular immune responses are dependent on specialized immunoregulatory receptors that sense environmental stimuli and initiate intracellular cascades that can elicit appropriate effector responses. A wide variety of immunoregulatory receptor families have been extensively studied in mammals, and many have been identified as cell- and function-specific regulators of a range of innate responses. Although much less is known in fish, the growing database of genomic information has recently allowed for the identification of several immunoregulatory receptor gene families in teleosts. Many of these putative immunoregulatory receptors have yet to be assigned any specific role(s, and much of what is known has been based solely on structural and/or phylogenetic relationships with mammalian receptor families. As an attempt to address some of these shortcomings, this review will focus on our growing understanding of the functional roles played by specific members of the channel catfish (Ictalurus punctatus leukocyte immune-type receptors (IpLITRs, which appear to be important regulators of several innate cellular responses via classical as well

  9. TheQ1 Influence of Innate and Pre-Existing Immunity on Adenovirus Therapy

    OpenAIRE

    Zaiss, Anne K.; Machado, Hidevaldo B.; Herschman, Harvey R.

    2009-01-01

    Recombinant adenovirus serotype 5 (Ad5) vectors have been studied extensively in preclinical gene therapy models and in a range of clinical trials. However, innate immune responses to adenovirus vectors limit effectiveness of Ad5 based therapies. Moreover, extensive pre-existing Ad5 immunity in human populations will likely limit the clinical utility of adenovirus vectors, unless methods to circumvent neutralizing antibodies that bind virus and block target cell transduction can be developed;...

  10. Differential Innate Immune Stimulation Elicited by Adenovirus and Poxvirus Vaccine Vectors

    OpenAIRE

    Teigler, Jeffrey Edward

    2014-01-01

    Vaccines are one of the most effective advances in medical science and continue to be developed for applications against infectious diseases, cancers, and autoimmunity. A common strategy for vaccine construction is the use of viral vectors derived from various virus families, with Adenoviruses (Ad) and Poxviruses (Pox) being extensively used. Studies utilizing viral vectors have shown a broad variety of vaccine-elicited immune response phenotypes. However, innate immune stimulation elicited b...

  11. Human respiratory syncytial virus nucleoprotein and inclusion bodies antagonize the innate immune response mediated by MDA5 and MAVS.

    Science.gov (United States)

    Lifland, Aaron W; Jung, Jeenah; Alonas, Eric; Zurla, Chiara; Crowe, James E; Santangelo, Philip J

    2012-08-01

    Currently, the spatial distribution of human respiratory syncytial virus (hRSV) proteins and RNAs in infected cells is still under investigation, with many unanswered questions regarding the interaction of virus-induced structures and the innate immune system. Very few studies of hRSV have used subcellular imaging as a means to explore the changes in localization of retinoic-acid-inducible gene-I (RIG-I)-like receptors or the mitochondrial antiviral signaling (MAVS) protein, in response to the infection and formation of viral structures. In this investigation, we found that both RIG-I and melanoma differentiation-associated gene 5 (MDA5) colocalized with viral genomic RNA and the nucleoprotein (N) as early as 6 h postinfection (hpi). By 12 hpi, MDA5 and MAVS were observed within large viral inclusion bodies (IB). We used a proximity ligation assay (PLA) and determined that the N protein was in close proximity to MDA5 and MAVS in IBs throughout the course of the infection. Similar results were found with the transient coexpression of N and the phosphoprotein (P). Additionally, we demonstrated that the localization of MDA5 and MAVS in IBs inhibited the expression of interferon β mRNA 27-fold following Newcastle disease virus infection. From these data, we concluded that the N likely interacts with MDA5, is in close proximity to MAVS, and localizes these molecules within IBs in order to attenuate the interferon response. To our knowledge, this is the first report of a specific function for hRSV IBs and of the hRSV N protein as a modulator of the innate immune response.

  12. Lactobacillus gasseri SBT2055 stimulates immunoglobulin production and innate immunity after influenza vaccination in healthy adult volunteers

    Directory of Open Access Journals (Sweden)

    Jun Nishihira

    2016-09-01

    Full Text Available Background: Lactobacillus gasseri strain SBT2055 (LG2055 is a human intestine-originating probiotic bacterium and potent probiotic known to exert various health promotion effects, including prevention of abdominal adiposity in rats and humans. A recent finding in mice has suggested that oral administration of LG2055 induces a protective effect against influenza A virus infection. In this context, evidence for the efficacy of LG2055 using a human clinical trial was imminently required. Methods: To confirm this in humans, a randomized, double-blind, placebo-controlled, parallel- group study in healthy adult volunteers was conducted to examine the effect of drinkable yogurt (DY containing LG2055 on influenza, with vaccine-specific antibody responses as the primary objective and innate immune responses as the secondary objective. Subjects were asked to consume 100 g/day of DY with LG2055 (LG2055 group; n = 94 or without LG2055 (placebo group; n = 94 for 16 weeks. After 4 weeks, all subjects received a trivalent influenza vaccine. Results: We found that the intake of LG2055 DY increased hemagglutination inhibition titers against influenza viruses A/H1N1 and B and the rate of seroprotection against influenza B after vaccination as compared with the intake of placebo DY by healthy volunteers. In support of this result, we confirmed that total IgG and IgA levels in plasma and sIgA production in saliva were also higher in the LG2055 group than in the placebo group. Furthermore, the intake of LG2055 DY enhanced natural killer cell activity and myxovirus resistance A gene expression, which is one of the antiviral genes stimulated by type I or type III Interferons in peripheral blood mononuclear cells. Conclusions: These results strongly indicate that LG2055 activates both the innate and adaptive human immune responses, suggesting the potential to prevent influenza virus infections by providing specific probiotics as complementary foods.

  13. 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.

  14. Innate and adaptive immune responses to in utero infection with bovine viral diarrhea virus

    Science.gov (United States)

    Infection of pregnant cows with noncytopathic (ncp) BVDV induces rapid innate and adaptive immune responses resulting in clearance of the virus in less than 3 weeks. Seven to 14 days after inoculation of the cow, ncpBVDV crosses the placenta and induces a fetal viremia. Establishment of persistent ...

  15. The influence of probiotics on zebrafish Danio rerio innate immunity and hepatic stress.

    Science.gov (United States)

    Gioacchini, Giorgia; Giorgini, Elisabetta; Olivotto, Ike; Maradonna, Francesca; Merrifield, Daniel L; Carnevali, Oliana

    2014-04-01

    In this study, the effects of probiotic administration on zebrafish Danio rerio intestinal innate immunity and hepatic stress were evaluated. Zebrafish adults were treated for 10 days with the probiotic Lactobacillus rhamnosus IMC 501(®). To assess the effects at the molecular level, the mRNA levels of genes involved in the innate immune system, stress response, oxidative stress, and apoptosis were quantified by real-time polymerase chain reaction. An increase of biomarkers related to innate immune responses was observed in intestinal tissue from the probiotic-treated fish compared with the control fish. In addition, a decrease in the abundance of stress and apoptotic-related genes was observed in the liver of the probiotic-fed fish. Finally, imaging Fourier transform infrared analysis was conducted on liver sections and the data obtained confirmed that probiotic administration decreased oxidative stress levels, decreased DNA damage, and increased lipid saturation levels. Overall, the results show that probiotic administration may enhance zebrafish welfare by modulating the innate immune response and improving hepatic stress tolerance.

  16. Innate immune responses to Chlamydia pneumoniae infection: role of TLRs, NLRs, and the inflammasome.

    Science.gov (United States)

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

    2012-11-01

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

  17. Ontogeny of the common carp (Cyprinus carpio L.) innate immune system

    NARCIS (Netherlands)

    Huttenhuis, B.T.; Taverne-Thiele, J.J.; Grou, C.P.O.; Bergsma, J.; Saeij, J.P.J.; Nakayasu, C.; Rombout, J.H.W.M.

    2006-01-01

    The ontogeny of the teleost innate immune system was studied in carp using cellular, histological and quantitative molecular techniques. Carp myeloid cells first appeared ventro-lateral of the aorta at 2 days post fertilization (the start of hatching), and subsequently around the sinuses of the vena

  18. 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 music ev

  19. M-ficolin, an innate immune defence molecule, binds patterns of acetyl groups and activates complement

    DEFF Research Database (Denmark)

    Frederiksen, Pernille Dorthea; Thiel, Steffen; Larsen, Claus Bindslev;

    2005-01-01

    Ficolins play a role in the innate immune defence as pathogen-associated molecular pattern recognition molecules. Three ficolins are found in humans: H-ficolin, L-ficolin and M-ficolin. L-ficolin and H-ficolin circulate in blood in complexes with mannan-binding lectin-associated serine proteases...

  20. OTULIN Restricts Met1-Linked Ubiquitination to Control Innate Immune Signaling

    DEFF Research Database (Denmark)

    Fiil, Berthe Katrine; Damgaard, Rune Busk; Wagner, Sebastian Alexander;

    2013-01-01

    Conjugation of Met1-linked polyubiquitin (Met1-Ub) by the linear ubiquitin chain assembly complex (LUBAC) is an important regulatory modification in innate immune signaling. So far, only few Met1-Ub substrates have been described, and the regulatory mechanisms have remained elusive. We recently i...

  1. On the trail of innate immune responses: Plasmacytoid dendritic cells and beyond

    NARCIS (Netherlands)

    Balzarolo, M.

    2013-01-01

    Our study sheds new light on pDCs development and function, and might provide new clues for optimizing infection and cancer therapy by harnessing pDC cytotoxicity through TRAIL. Furthermore, this study provides interesting clues to understand the innate immune responses towards bacterial nucleic aci

  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;

    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. Selection for brain size impairs innate, but not adaptive immune responses.

    Science.gov (United States)

    Kotrschal, Alexander; Kolm, Niclas; Penn, Dustin J

    2016-03-16

    Both the brain and the immune system are energetically demanding organs, and when natural selection favours increased investment into one, then the size or performance of the other should be reduced. While comparative analyses have attempted to test this potential evolutionary trade-off, the results remain inconclusive. To test this hypothesis, we compared the tissue graft rejection (an assay for measuring innate and acquired immune responses) in guppies (Poecilia reticulata) artificially selected for large and small relative brain size. Individual scales were transplanted between pairs of fish, creating reciprocal allografts, and the rejection reaction was scored over 8 days (before acquired immunity develops). Acquired immune responses were tested two weeks later, when the same pairs of fish received a second set of allografts and were scored again. Compared with large-brained animals, small-brained animals of both sexes mounted a significantly stronger rejection response to the first allograft. The rejection response to the second set of allografts did not differ between large- and small-brained fish. Our results show that selection for large brain size reduced innate immune responses to an allograft, which supports the hypothesis that there is a selective trade-off between investing into brain size and innate immunity.

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

    Directory of Open Access Journals (Sweden)

    Yingru eLiu

    2011-03-01

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

  5. Receptor-Like Kinases in Plant Innate Immunity

    Institute of Scientific and Technical Information of China (English)

    Ying Wu; Jian-Min Zhou

    2013-01-01

    Plants employ a highly effective surveillance system to detect potential pathogens, which is critical for the success of land plants in an environment surrounded by numerous microbes. Recent efforts have led to the identification of a number of immune receptors and components of immune receptor complexes. It is now clear that receptor-like kinases (RLKs) and receptor-like proteins (RLPs) are key pattern-recognition receptors (PRRs) for microbe- and plant-derived molecular patterns that are associated with pathogen invasion. RLKs and RLPs involved in immune signaling belong to large gene families in plants and have undergone lineage specific expansion. Molecular evolution and population studies on phytopathogenic molecular signatures and their receptors have provided crucial insight into the co-evolution between plants and pathogens.

  6. Norovirus P particle efficiently elicits innate, humoral and cellular immunity.

    Directory of Open Access Journals (Sweden)

    Hao Fang

    Full Text Available Norovirus (NoV P domain complexes, the 24 mer P particles and the P dimers, induced effective humoral immunity, but their role in the cellular immune responses remained unclear. We reported here a study on cellular immune responses of the two P domain complexes in comparison with the virus-like particle (VLP of a GII.4 NoV (VA387 in mice. The P domain complexes induced significant central memory CD4(+ T cell phenotypes (CD4(+ CD44(+ CD62L(+ CCR7(+ and activated polyclonal CD4(+ T cells as shown by production of Interleukin (IL-2, Interferon (IFN-γ, and Tumor Necrosis Factor (TNF-α. Most importantly, VA387-specific CD4(+ T cell epitope induced a production of IFN-γ, indicating an antigen-specific CD4(+ T cell response in P domain complex-immunized mice. Furthermore, P domain complexes efficiently induced bone marrow-derived dendritic cell (BMDC maturation, evidenced by up-regulation of co-stimulatory and MHC class II molecules, as well as production of IL-12 and IL-1β. Finally, P domain complex-induced mature dendritic cells (DCs elicited proliferation of specific CD4(+ T cells targeting VA387 P domain. Overall, we conclude that the NoV P domain complexes are efficiently presented by DCs to elicit not only humoral but also cellular immune responses against NoVs. Since the P particle is highly effective for both humoral and cellular immune responses and easily produced in Escherichia coli (E. coli, it is a good choice of vaccine against NoVs and a vaccine platform against other diseases.

  7. Receptor-like kinase complexes in plant innate immunity

    DEFF Research Database (Denmark)

    Greeff, Michael Christiaan; Roux, Milena Edna; Mundy, John;

    2012-01-01

    , the aforementioned RLKs activate generic immune responses termed pattern-triggered immunity (PTI). RLKs can form complexes with other family members and engage a variety of intracellular signaling components and regulatory pathways upon stimulation. This review focuses on interesting new data about how......Receptor-like kinases (RLKs) are surface localized, transmembrane receptors comprising a large family of well-studied kinases. RLKs signal through their transmembrane and juxtamembrane domains with the aid of various interacting partners and downstream components. The N-terminal extracellular...

  8. Immunological Signatures after Bordetella pertussis Infection Demonstrate Importance of Pulmonary Innate Immune Cells

    Science.gov (United States)

    Brummelman, Jolanda; van der Maas, Larissa; Tilstra, Wichard; Pennings, Jeroen L. A.; Han, Wanda G. H.; van Els, Cécile A. C. M.; van Riet, Elly; Kersten, Gideon F. A.; Metz, Bernard

    2016-01-01

    Effective immunity against Bordetella pertussis is currently under discussion following the stacking evidence of pertussis resurgence in the vaccinated population. Natural immunity is more effective than vaccine-induced immunity indicating that knowledge on infection-induced responses may contribute to improve vaccination strategies. We applied a systems biology approach comprising microarray, flow cytometry and multiplex immunoassays to unravel the molecular and cellular signatures in unprotected mice and protected mice with infection-induced immunity, around a B. pertussis challenge. Pre-existing systemic memory Th1/Th17 cells, memory B-cells, and mucosal IgA specific for Ptx, Vag8, Fim2/3 were detected in the protected mice 56 days after an experimental infection. In addition, pre-existing high activity and reactivation of pulmonary innate cells such as alveolar macrophages, M-cells and goblet cells was detected. The pro-inflammatory responses in the lungs and serum, and neutrophil recruitment in the spleen upon an infectious challenge of unprotected mice were absent in protected mice. Instead, fast pulmonary immune responses in protected mice led to efficient bacterial clearance and harbored potential new gene markers that contribute to immunity against B. pertussis. These responses comprised of innate makers, such as Clca3, Retlna, Glycam1, Gp2, and Umod, next to adaptive markers, such as CCR6+ B-cells, CCR6+ Th17 cells and CXCR6+ T-cells as demonstrated by transcriptome analysis. In conclusion, besides effective Th1/Th17 and mucosal IgA responses, the primary infection-induced immunity benefits from activation of pulmonary resident innate immune cells, achieved by local pathogen-recognition. These molecular signatures of primary infection-induced immunity provided potential markers to improve vaccine-induced immunity against B. pertussis. PMID:27711188

  9. Functional and phenotypic profiling of innate immunity during Salmonella infection

    DEFF Research Database (Denmark)

    Sørensen, Rikke Brandt; Pedersen, Susanne Brix

    Salmonellae are food borne pathogens, typically acquired by the oral ingestion of contaminated food or water, causing disease in both healthy and immunocompromised individuals. To gain insight into early immune regulation events caused by Salmonella as well as inflammatory signatures induced by S...

  10. Integrating innate and adaptive immune cells: Mast cells as crossroads between regulatory and effector B and T cells.

    Science.gov (United States)

    Mekori, Yoseph A; Hershko, Alon Y; Frossi, Barbara; Mion, Francesca; Pucillo, Carlo E

    2016-05-05

    A diversity of immune mechanisms have evolved to protect normal tissues from infection, but from immune damage too. Innate cells, as well as adaptive cells, are critical contributors to the correct development of the immune response and of tissue homeostasis. There is a dynamic "cross-talk" between the innate and adaptive immunomodulatory mechanisms for an integrated control of immune damage as well as the development of the immune response. Mast cells have shown a great plasticity, modifying their behavior at different stages of immune response through interaction with effector and regulatory populations of adaptive immunity. Understanding the interplays among T effectors, regulatory T cells, B cells and regulatory B cells with mast cells will be critical in the future to assist in the development of therapeutic strategies to enhance and synergize physiological immune-modulator and -suppressor elements in the innate and adaptive immune system.

  11. Interferon and IL-27 antagonize the function of group 2 innate lymphoid cells and type 2 innate immune responses.

    Science.gov (United States)

    Moro, Kazuyo; Kabata, Hiroki; Tanabe, Masanobu; Koga, Satoshi; Takeno, Natsuki; Mochizuki, Miho; Fukunaga, Koichi; Asano, Koichiro; Betsuyaku, Tomoko; Koyasu, Shigeo

    2016-01-01

    Group 2 innate lymphoid cells (ILC2 cells) are type 2 cytokine-producing cells of the innate immune system with important roles in helminth infection and allergic inflammation. Here we found that tissue-resident ILC2 cells proliferated in situ without migrating during inflammatory responses. Both type I and type II interferons and interleukin 27 (IL-27) suppressed ILC2 function in a manner dependent on the transcription factor STAT1. ILC2-mediated lung inflammation was enhanced in the absence of the interferon-γ (IFN-γ) receptor on ILC2 cells in vivo. IFN-γ effectively suppressed the function of tissue-resident ILC2 cells but not that of inflammatory ILC2 cells, and IL-27 suppressed tissue-resident ILC2 cells but not tissue-resident TH2 cells during lung inflammation induced by Alternaria alternata. Our results demonstrate that suppression mediated by interferon and IL-27 is a negative feedback mechanism for ILC2 function in vivo.

  12. Genetic polymorphisms in host antiviral genes: associations with humoral and cellular immunity to measles vaccine.

    Science.gov (United States)

    Haralambieva, Iana H; Ovsyannikova, Inna G; Umlauf, Benjamin J; Vierkant, Robert A; Shane Pankratz, V; Jacobson, Robert M; Poland, Gregory A

    2011-11-08

    Host antiviral genes are important regulators of antiviral immunity and plausible genetic determinants of immune response heterogeneity after vaccination. We genotyped and analyzed 307 common candidate tagSNPs from 12 antiviral genes in a cohort of 745 schoolchildren immunized with two doses of measles-mumps-rubella (MMR) vaccine. Associations between SNPs/haplotypes and measles virus-specific immune outcomes were assessed using linear regression methodologies in Caucasians and African-Americans. Genetic variants within the DDX58/RIG-I gene, including a coding polymorphism (rs3205166/Val800Val), were associated as single-SNPs (p≤0.017; although these SNPs did not remain significant after correction for false discovery rate/FDR) and in haplotype-level analysis, with measles-specific antibody variations in Caucasians (haplotype allele p-value=0.021; haplotype global p-value=0.076). Four DDX58 polymorphisms, in high LD, demonstrated also associations (after correction for FDR) with variations in both measles-specific IFN-γ and IL-2 secretion in Caucasians (p≤0.001, q=0.193). Two intronic OAS1 polymorphisms, including the functional OAS1 SNP rs10774671 (p=0.003), demonstrated evidence of association with a significant allele-dose-related increase in neutralizing antibody levels in African-Americans. Genotype and haplotype-level associations demonstrated the role of ADAR genetic variants, including a non-synonymous SNP (rs2229857/Arg384Lys; p=0.01), in regulating measles virus-specific IFN-γ Elispot responses in Caucasians (haplotype global p-value=0.017). After correction for FDR, 15 single-SNP associations (11 SNPs in Caucasians and 4 SNPs in African-Americans) still remained significant at the q-valuemeasles vaccine in Caucasians and African-Americans.

  13. The innate and adaptive infiltrating immune systems as targets for breast cancer immunotherapy.

    Science.gov (United States)

    Law, Andrew M K; Lim, Elgene; Ormandy, Christopher J; Gallego-Ortega, David

    2017-04-01

    A cancer cell-centric view has long dominated the field of cancer biology. Research efforts have focussed on aberrant cancer cell signalling pathways and on changes to cancer cell DNA. Mounting evidence demonstrates that many cancer-associated cell types within the tumour stroma co-evolve and support tumour growth and development, greatly modifying cancer cell behaviour, facilitating invasion and metastasis and controlling dormancy and sensitivity to drug therapy. Thus, these stromal cells represent potential targets for cancer therapy. Among these cell types, immune cells have emerged as a promising target for therapy. The adaptive and the innate immune system play an important role in normal mammary development and breast cancer. The number of infiltrating adaptive immune system cells with tumour-rejecting capacity, primarily, T lymphocytes, is lower in breast cancer compared with other cancer types, but infiltration occurs in a large proportion of cases. There is strong evidence demonstrating the importance of the immunosuppressive role of the innate immune system during breast cancer progression. A consideration of components of both the innate and the adaptive immune system is essential for the design and development of immunotherapies in breast cancer. In this review, we focus on the importance of immunosuppressive myeloid-derived suppressor cells (MDSCs) as potential targets for breast cancer therapy.

  14. Innate immune receptors in heart failure: Side effect or potential therapeutic target?

    Institute of Scientific and Technical Information of China (English)

    Katharina; B; Wagner; Stephan; B; Felix; Alexander; Riad

    2014-01-01

    Heart failure(HF) is a leading cause of mortality and morbidity in western countries and occasions major expenses for public health systems. Although optimal medical treatment is widely available according to current guidelines, the prognosis of patients with HF is still poor. Despite the etiology of the disease, increased systemic or cardiac activation of the innate immune system is well documented in several types of HF. In some cases there is evidence of an association between innate immune activation and clinical outcome of patients with this disease. However, the few large trials conducted with the use of anti-inflammatory medication in HF have not revealed its benefits. Thus, greater understanding of the relationship between alteration in the immune system and development and progression of HF is urgently necessary: prior to designing therapeutic interventions that target pathological inflammatory processes in preventing harmful cardiac effects of immune modulatory therapy. In this regard, relatively recently discovered receptors of the innate immune system, i.e., namely toll-like receptors(TLRs) and nodlike receptors(NLRs)-are the focus of intense cardiovascular research. These receptors are main up-stream regulators of cytokine activation. This review will focus on current knowledge of the role of TLRs and NLRs, as well as on downstream cytokine activation, and will discuss potential therapeutic implications.

  15. 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.

  16. 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

  17. 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.

  18. Integrating Innate and Adaptive Immunity for Intrusion Detection

    CERN Document Server

    Tedesco, Gianni; Aickelin, Uwe

    2010-01-01

    Network Intrusion Detection Systems (NDIS) monitor a network with the aim of discerning malicious from benign activity on that network. While a wide range of approaches have met varying levels of success, most IDS's rely on having access to a database of known attack signatures which are written by security experts. Nowadays, in order to solve problems with false positive alters, correlation algorithms are used to add additional structure to sequences of IDS alerts. However, such techniques are of no help in discovering novel attacks or variations of known attacks, something the human immune system (HIS) is capable of doing in its own specialised domain. This paper presents a novel immune algorithm for application to an intrusion detection problem. The goal is to discover packets containing novel variations of attacks covered by an existing signature base.

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

    Science.gov (United States)

    Lauvau, Grégoire; Goriely, Stanislas

    2016-09-01

    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.

  20. Antiviral immunity in fish – functional analysis using DNA vaccination as a tool

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Lorenzen, Ellen; Einer-Jensen, Katja;

    2013-01-01

    In fish, DNA vaccines encoding the glycoproteins (G proteins) of the salmonid rhabdoviruses VHSV and IHNV have proved very efficient under experimental conditions. Nano-gram amounts of plasmid DNA can induce long-lasting protective immunity when delivered by intramuscular injection in rainbow trout...... fingerlings. Vaccination of fish at an early stage appears advantageous, since larger fish require higher doses of vaccine to be protected. Even in fish with an average size of 0.5 g at the time of vaccination, good protection can be obtained. Interestingly, immunity is established already a few days after...... CpG motifs in the plasmid backbone sequence might play a role, the viral G protein appears to have an inherent ability to stimulate innate immune mechanisms by receptors and pathways that still remain to be characterized in detail. Immunity to VHS in rainbow trout can be induced by DNA vaccination...