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Sample records for targeting host factors

  1. Targeting Host Factors to Treat West Nile and Dengue Viral Infections

    Directory of Open Access Journals (Sweden)

    Manoj N. Krishnan

    2014-02-01

    Full Text Available West Nile (WNV and Dengue (DENV viruses are major arboviral human pathogens belonging to the genus Flavivirus. At the current time, there are no approved prophylactics (e.g., vaccines or specific therapeutics available to prevent or treat human infections by these pathogens. Due to their minimal genome, these viruses require many host molecules for their replication and this offers a therapeutic avenue wherein host factors can be exploited as treatment targets. Since several host factors appear to be shared by many flaviviruses the strategy may result in pan-flaviviral inhibitors and may also attenuate the rapid emergence of drug resistant mutant viruses. The scope of this strategy is greatly enhanced by the recent en masse identification of host factors impacting on WNV and DENV infection. Excellent proof-of-principle experimental demonstrations for host-targeted control of infection and infection-induced pathogenesis have been reported for both WNV and DENV. These include exploiting not only those host factors supporting infection, but also targeting host processes contributing to pathogenesis and innate immune responses. While these early studies validated the host-targeting approach, extensive future investigations spanning a range of aspects are needed for a successful deployment in humans.

  2. Targeting host factors to treat West Nile and dengue viral infections.

    Science.gov (United States)

    Krishnan, Manoj N; Garcia-Blanco, Mariano A

    2014-02-10

    West Nile (WNV) and Dengue (DENV) viruses are major arboviral human pathogens belonging to the genus Flavivirus. At the current time, there are no approved prophylactics (e.g., vaccines) or specific therapeutics available to prevent or treat human infections by these pathogens. Due to their minimal genome, these viruses require many host molecules for their replication and this offers a therapeutic avenue wherein host factors can be exploited as treatment targets. Since several host factors appear to be shared by many flaviviruses the strategy may result in pan-flaviviral inhibitors and may also attenuate the rapid emergence of drug resistant mutant viruses. The scope of this strategy is greatly enhanced by the recent en masse identification of host factors impacting on WNV and DENV infection. Excellent proof-of-principle experimental demonstrations for host-targeted control of infection and infection-induced pathogenesis have been reported for both WNV and DENV. These include exploiting not only those host factors supporting infection, but also targeting host processes contributing to pathogenesis and innate immune responses. While these early studies validated the host-targeting approach, extensive future investigations spanning a range of aspects are needed for a successful deployment in humans.

  3. A Novel, Broad-Spectrum Inhibitor of Enterovirus Replication That Targets Host Cell Factor Phosphatidylinositol 4-Kinase IIIβ

    Science.gov (United States)

    van der Schaar, Hilde M.; Leyssen, Pieter; Thibaut, Hendrik J.; de Palma, Armando; van der Linden, Lonneke; Lanke, Kjerstin H. W.; Lacroix, Céline; Verbeken, Erik; Conrath, Katja; MacLeod, Angus M.; Mitchell, Dale R.; Palmer, Nicholas J.; van de Poël, Hervé; Andrews, Martin

    2013-01-01

    Despite their high clinical and socioeconomic impacts, there is currently no approved antiviral therapy for the prophylaxis or treatment of enterovirus infections. Here we report on a novel inhibitor of enterovirus replication, compound 1, 2-fluoro-4-(2-methyl-8-(3-(methylsulfonyl)benzylamino)imidazo[1,2-a]pyrazin-3-yl)phenol. This compound exhibited a broad spectrum of antiviral activity, as it inhibited all tested species of enteroviruses and rhinoviruses, with 50% effective concentrations ranging between 4 and 71 nM. After a lengthy resistance selection process, coxsackievirus mutants resistant to compound 1 were isolated that carried substitutions in their 3A protein. Remarkably, the same substitutions were recently shown to provide resistance to inhibitors of phosphatidylinositol 4-kinase IIIβ (PI4KIIIβ), a lipid kinase that is essential for enterovirus replication, suggesting that compound 1 may also target this host factor. Accordingly, compound 1 directly inhibited PI4KIIIβ in an in vitro kinase activity assay. Furthermore, the compound strongly reduced the PI 4-phosphate levels of the Golgi complex in cells. Rescue of coxsackievirus replication in the presence of compound 1 by a mutant PI4KIIIβ carrying a substitution in its ATP-binding pocket revealed that the compound directly binds the kinase at this site. Finally, we determined that an analogue of compound 1, 3-(3-fluoro-4-methoxyphenyl)-2-methyl-N-(pyridin-4-ylmethyl)imidazo[1,2-a]pyrazin-8-amine, is well tolerated in mice and has a dose-dependent protective activity in a coxsackievirus serotype B4-induced pancreatitis model. PMID:23896472

  4. IRG and GBP host resistance factors target aberrant, "non-self" vacuoles characterized by the missing of "self" IRGM proteins.

    Science.gov (United States)

    Haldar, Arun K; Saka, Hector A; Piro, Anthony S; Dunn, Joe Dan; Henry, Stanley C; Taylor, Gregory A; Frickel, Eva M; Valdivia, Raphael H; Coers, Jörn

    2013-01-01

    Interferon-inducible GTPases of the Immunity Related GTPase (IRG) and Guanylate Binding Protein (GBP) families provide resistance to intracellular pathogenic microbes. IRGs and GBPs stably associate with pathogen-containing vacuoles (PVs) and elicit immune pathways directed at the targeted vacuoles. Targeting of Interferon-inducible GTPases to PVs requires the formation of higher-order protein oligomers, a process negatively regulated by a subclass of IRG proteins called IRGMs. We found that the paralogous IRGM proteins Irgm1 and Irgm3 fail to robustly associate with "non-self" PVs containing either the bacterial pathogen Chlamydia trachomatis or the protozoan pathogen Toxoplasma gondii. Instead, Irgm1 and Irgm3 reside on "self" organelles including lipid droplets (LDs). Whereas IRGM-positive LDs are guarded against the stable association with other IRGs and GBPs, we demonstrate that IRGM-stripped LDs become high affinity binding substrates for IRG and GBP proteins. These data reveal that intracellular immune recognition of organelle-like structures by IRG and GBP proteins is partly dictated by the missing of "self" IRGM proteins from these structures.

  5. siRNA Screening Identifies the Host Hexokinase 2 (HK2) Gene as an Important Hypoxia-Inducible Transcription Factor 1 (HIF-1) Target Gene in Toxoplasma gondii-Infected Cells.

    Science.gov (United States)

    Menendez, Matthew T; Teygong, Crystal; Wade, Kristin; Florimond, Celia; Blader, Ira J

    2015-06-23

    Although it is established that oxygen availability regulates cellular metabolism and growth, little is known regarding how intracellular pathogens use host factors to grow at physiological oxygen levels. Therefore, large-scale human small interfering RNA screening was performed to identify host genes important for growth of the intracellular protozoan parasite Toxoplasma gondii at tissue oxygen tensions. Among the genes identified by this screen, we focused on the hexokinase 2 (HK2) gene because its expression is regulated by hypoxia-inducible transcription factor 1 (HIF-1), which is important for Toxoplasma growth. Toxoplasma increases host HK2 transcript and protein levels in a HIF-1-dependent manner. In addition, parasite growth at 3% oxygen is restored in HIF-1-deficient cells transfected with HK2 expression plasmids. Both HIF-1 activation and HK2 expression were accompanied by increases in host glycolytic flux, suggesting that enhanced HK2 expression in parasite-infected cells is functionally significant. Parasite dependence on host HK2 and HIF-1 expression is not restricted to transformed cell lines, as both are required for parasite growth in nontransformed C2C12 myoblasts and HK2 is upregulated in vivo following infection. While HK2 is normally associated with the cytoplasmic face of the outer mitochondrial membrane at physiological O2 levels, HK2 relocalizes to the host cytoplasm following infection, a process that is required for parasite growth at 3% oxygen. Taken together, our findings show that HIF-1-dependent expression and relocalization of HK2 represent a novel mechanism by which Toxoplasma establishes its replicative niche at tissue oxygen tensions. Little is known regarding how the host cell contributes to the survival of the intracellular parasite Toxoplasma gondii at oxygen levels that mimic those found in tissues. Our previous work showed that Toxoplasma activates the expression of an oxygen-regulated transcription factor that is required for

  6. Urinary tract infection pathogenesis: host factors.

    Science.gov (United States)

    Stapleton, Ann E

    2014-03-01

    Clinically, host factors in the pathogenesis of urinary tract infection (UTI) may be considered as modifiable (eg, behaviors associated with increased risk of UTI, anatomic and functional problems of the urinary tract) and thus potentially amenable to a change in patient behavior or treatment approach, or as intrinsic and nonmodifiable host factors that neither the patient nor the clinician can influence (eg, gender and genetic influences associated with UTI). Although considering nonmodifiable host factors may be discouraging to patients and clinicians at present, some genetic associations have the potential for future predictive value and may interface with future treatments. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Host factors involved in chikungunya virus replication

    NARCIS (Netherlands)

    Scholte, Florine Elisabeth Maria

    2015-01-01

    In this thesis the interplay of CHIKV with cellular (host) factors involved in its replication is addressed. An in-depth understanding of the interactions between the viral proteins and those of their host is required for the elucidation of molecular mechanisms underlying viral replication. A

  8. Plant pathology: monitoring a pathogen-targeted host protein.

    Science.gov (United States)

    Ellis, Jeff; Dodds, Peter

    2003-05-13

    A plant protein RIN4 is targeted and modified by bacterial pathogens as part of the disease process. At least two host resistance proteins monitor this pathogen interference and trigger the plant's defence responses.

  9. Late effects of radiation: host factors

    International Nuclear Information System (INIS)

    Fry, R.J.M.; Storer, J.B.

    1983-01-01

    The paper discusses the influence of host factors on radiation late effects and in particular cancer. Radiation induces cellular changes that result in initiated cells with a potential to become cancers. The expression of the initiated cells as tumors is influenced, if not determined, by both tissue and systemic factors that are sex-, age-, and species-dependent

  10. Structural basis for antagonizing a host restriction factor by C7 family of poxvirus host-range proteins

    OpenAIRE

    Meng, Xiangzhi; Krumm, Brian; Li, Yongchao; Deng, Junpeng; Xiang, Yan

    2015-01-01

    Productive viral replication requires overcoming many barriers posed by the host innate immune system. Human sterile alpha motif domain-containing 9 (SAMD9) is a newly identified antiviral factor that is specifically targeted by poxvirus proteins belonging to the C7 family of host-range factors. Here we provide the first, to our knowledge, atomic view of two functionally divergent proteins from the C7 family and determine the molecular basis that dictates whether they can target SAMD9 effecti...

  11. Host Cell Targeting by Enteropathogenic Bacteria T3SS Effectors.

    Science.gov (United States)

    Pinaud, Laurie; Sansonetti, Philippe J; Phalipon, Armelle

    2018-04-01

    Microbial pathogens possess a diversity of weapons that disrupt host homeostasis and immune defenses, thus resulting in the establishment of infection. The best-characterized system mediating bacterial protein delivery into target eukaryotic cells is the type III secretion system (T3SS) expressed by Gram-negative bacteria, including the human enteric pathogens Shigella, Salmonella, Yersinia, and enteropathogenic/enterohemorragic Escherichia coli (EPEC/EHEC). The emerging global view is that these T3SS-bearing pathogens share similarities in their ability to target key cellular pathways such as the cell cytoskeleton, trafficking, cell death/survival, and the NF-κB and MAPK signaling pathways. In particular, multiple host proteins are targeted in a given pathway, and different T3SS effectors from various pathogens share functional similarities. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. Host target-based approaches against arboviral diseases.

    Science.gov (United States)

    Rocha, Rebeca Froes; Del Sarto, Juliana Lemos; Marques, Rafael Elias; Costa, Vivian Vasconcelos; Teixeira, Mauro Martins

    2018-02-23

    In the 20th century, socioeconomic and environmental changes facilitated the reintroduction of mosquitoes in developing cities, resulting in the reinsertion of mosquito-borne viral diseases and the dispersal of their causative agents on a worldwide scale. Recurrent outbreaks of arboviral diseases are being reported, even in regions without a previous history of arboviral disease transmission. Of note, arboviral infections represented approximately 30% of all emerging vector-borne diseases in the last decade. Therapeutic strategies against infectious viral diseases include the use of different classes of molecules that act directly on the pathogen and/or act by optimizing the host immune response. Drugs targeting the virus usually provide amelioration of symptoms by suppressing and controlling the infection. However, it is limited by the short-window of effectiveness, ineffectiveness against latent viruses, development of drug-resistant mutants and toxic side effects. Disease may also be a consequence of an excessive, uncontrolled or misplaced inflammatory response, treatments that interfere in host immune response are interesting options and can be used isolated or in combination with virus-targeted therapies. The use of host-targeted therapies requires specific knowledge regarding host immune patterns that may trigger dengue virus (DENV), chikungunya virus (CHIKV) or Zika virus (ZIKV) disease.

  13. Host factors in HIV-1 replication: The good, the bad and the ugly

    NARCIS (Netherlands)

    Booiman, T.

    2015-01-01

    The ability of HIV-1 to replicate in its target cells is influenced by numerous host factors that act on different steps of the viral replication cycle. The effects of these host factors on the replication cycle can be cell type specific and they can either support or restrict viral replication.

  14. Emerging functions as host cell factors - an encyclopedia of annexin-pathogen interactions.

    Science.gov (United States)

    Kuehnl, Alexander; Musiol, Agnes; Raabe, Carsten A; Rescher, Ursula

    2016-10-01

    Emerging infectious diseases and drug-resistant infectious agents call for the development of innovative antimicrobial strategies. With pathogenicity now considered to arise from the complex and bi-directional interplay between a microbe and the host, host cell factor targeting has emerged as a promising approach that might overcome the limitations of classical antimicrobial drug development and could open up novel and efficient therapeutic strategies. Interaction with and modulation of host cell membranes is a recurrent theme in the host-microbe relationship. In this review, we provide an overview of what is currently known about the role of the Ca2+ dependent, membrane-binding annexin protein family in pathogen-host interactions, and discuss their emerging functions as host cell derived auxiliary proteins in microbe-host interactions and host cell targets.

  15. The Poxvirus C7L Host Range Factor Superfamily

    OpenAIRE

    Liu, Jia; Rothenburg, Stefan; McFadden, Grant

    2012-01-01

    Host range factors, expressed by the poxvirus family, determine the host tropism of species, tissue, and cell specificity. C7L family members exist in the genomes of most sequenced mammalian poxviruses, suggesting an evolutionarily conserved effort adapting to the hosts. In general, C7L orthologs influence the host tropism in mammalian cell culture, and for some poxviruses it is essential for the complete viral life cycle in vitro and in vivo. The C7L family members lack obvious sequence homo...

  16. Targeting host lipid synthesis and metabolism to inhibit dengue and hepatitis C viruses.

    Science.gov (United States)

    Villareal, Valerie A; Rodgers, Mary A; Costello, Deirdre A; Yang, Priscilla L

    2015-12-01

    Lipids are necessary for every step in the replication cycle of hepatitis C virus (HCV) and dengue virus (DENV), members of the family Flaviviridae. Recent studies have demonstrated that discrete steps in the replication cycles of these viruses can be inhibited by pharmacological agents that target host factors mediating lipid synthesis, metabolism, trafficking, and signal transduction. Despite this, targeting host lipid metabolism and trafficking as an antiviral strategy by blockade of entire pathways may be limited due to host toxicity. Knowledge of the molecular details of lipid structure and function in replication and the mechanisms whereby specific lipids are generated and trafficked to the relevant sites may enable more targeted antiviral strategies without global effects on the host cell. In this review, we discuss lipids demonstrated to be critical to the replication cycles of HCV and DENV and highlight potential areas for anti-viral development. This review article forms part of a symposium on flavivirus drug discovery in Antiviral Research. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Positive selection of HIV host factors and the evolution of lentivirus genes

    Directory of Open Access Journals (Sweden)

    Lengauer Thomas

    2010-06-01

    Full Text Available Abstract Background Positive selection of host proteins that interact with pathogens can indicate factors relevant for infection and potentially be a measure of pathogen driven evolution. Results Our analysis of 1439 primate genes and 175 lentivirus genomes points to specific host factors of high genetic variability that could account for differences in susceptibility to disease and indicate specific mechanisms of host defense and pathogen adaptation. We find that the largest amount of genetic change occurs in genes coding for cellular membrane proteins of the host as well as in the viral envelope genes suggesting cell entry and immune evasion as the primary evolutionary interface between host and pathogen. We additionally detect the innate immune response as a gene functional group harboring large differences among primates that could potentially account for the different levels of immune activation in the HIV/SIV primate infection. We find a significant correlation between the evolutionary rates of interacting host and viral proteins pointing to processes of the host-pathogen biology that are relatively conserved among species and to those undergoing accelerated genetic evolution. Conclusions These results indicate specific host factors and their functional groups experiencing pathogen driven evolutionary selection pressures. Individual host factors pointed to by our analysis might merit further study as potential targets of antiretroviral therapies.

  18. Enterotoxigenic Escherichia coli prevents host NF-κB activation by targeting IκBα polyubiquitination.

    Science.gov (United States)

    Wang, Xiaogang; Hardwidge, Philip R

    2012-12-01

    The NF-κB pathway regulates innate immune responses to infection. NF-κB is activated after pathogen-associated molecular patterns are detected, leading to the induction of proinflammatory host responses. As a countermeasure, bacterial pathogens have evolved mechanisms to subvert NF-κB signaling. Enterotoxigenic Escherichia coli (ETEC) causes diarrheal disease and significant morbidity and mortality for humans in developing nations. The extent to which this important pathogen subverts innate immune responses by directly targeting the NF-κB pathway is an understudied topic. Here we report that ETEC secretes a heat-stable, proteinaceous factor that blocks NF-κB signaling normally induced by tumor necrosis factor (TNF), interleukin-1β, and flagellin. Pretreating intestinal epithelial cells with ETEC supernatant significantly blocked the degradation of the NF-κB inhibitor IκBα without affecting IκBα phosphorylation. Data from immunoprecipitation experiments suggest that the ETEC factor functions by preventing IκBα polyubiquitination. Inhibiting clathrin function blocked the activity of the secreted ETEC factor, suggesting that this yet-uncharacterized activity may utilize clathrin-dependent endocytosis to enter host cells. These data suggest that ETEC evades the host innate immune response by directly modulating NF-κB signaling.

  19. Host genetic factors in susceptibility to HIV-1 infection and ...

    Indian Academy of Sciences (India)

    A lot of investigations have been targeted towards the ex- ploration of the viral genetics of HIV-1, associated with the progression to AIDS in HIV-1 infected individuals. How- ever, very little is known about the host genetic aspects in the pathogenesis of the infection (Michael 1999; Carrington et al. 2001; Kumar et al. 2006 ...

  20. Foreign Direct Investment, Host Country Factors and Economic Growth

    OpenAIRE

    Edna Maeyen Solomon

    2011-01-01

    This paper analyses how the levels of economic development, human capital, financial development and the qualities of the economic and political environments in host countries simultaneously affects the impact of aggregate inflows of Foreign Direct Investment (FDI) on economic growth. Multiple interaction terms are employed between inward FDI and each of the host country factors mentioned above. The System GMM estimator is applied to a panel of 111 countries from 1981 to 2005. The results sho...

  1. Structural basis for antagonizing a host restriction factor by C7 family of poxvirus host-range proteins.

    Science.gov (United States)

    Meng, Xiangzhi; Krumm, Brian; Li, Yongchao; Deng, Junpeng; Xiang, Yan

    2015-12-01

    Human sterile alpha motif domain-containing 9 (SAMD9) protein is a host restriction factor for poxviruses, but it can be overcome by some poxvirus host-range proteins that share homology with vaccinia virus C7 protein. To understand the mechanism of action for this important family of host-range factors, we determined the crystal structures of C7 and myxoma virus M64, a C7 family member that is unable to antagonize SAMD9. Despite their different functions and only 23% sequence identity, the two proteins have very similar overall structures, displaying a previously unidentified fold comprised of a compact 12-stranded antiparallel β-sandwich wrapped in two short α helices. Extensive structure-guided mutagenesis of C7 identified three loops clustered on one edge of the β sandwich as critical for viral replication and binding with SAMD9. The loops are characterized with functionally important negatively charged, positively charged, and hydrophobic residues, respectively, together forming a unique "three-fingered molecular claw." The key residues of the claw are not conserved in two C7 family members that do not antagonize SAMD9 but are conserved in distantly related C7 family members from four poxvirus genera that infect diverse mammalian species. Indeed, we found that all in the latter group of proteins bind SAMD9. Taken together, our data indicate that diverse mammalian poxviruses use a conserved molecular claw in a C7-like protein to target SAMD9 and overcome host restriction.

  2. Analyses of Brucella pathogenesis, host immunity, and vaccine targets using systems biology and bioinformatics

    Directory of Open Access Journals (Sweden)

    Yongqun eHe

    2012-02-01

    Full Text Available Brucella is a Gram-negative, facultative intracellular bacterium that causes zoonotic brucellosis in humans and various animals. Out of ten classified Brucella species, B. melitensis, B. abortus, B. suis, and B. canis are pathogenic to humans. In the past decade, the mechanisms of Brucella pathogenesis and host immunity have been extensively investigated using the cutting edge systems biology and bioinformatics approaches. This article provides a comprehensive review of the applications of Omics (including genomics, transcriptomics, and proteomics and bioinformatics technologies for the analysis of Brucella pathogenesis, host immune responses, and vaccine targets. Based on more than 30 sequenced Brucella genomes, comparative genomics is able to identify gene variations among Brucella strains that help to explain host specificity and virulence differences among Brucella species. Diverse transcriptomics and proteomics gene expression studies have been conducted to analyze gene expression profiles of wild type Brucella strains and mutants under different laboratory conditions. High throughput Omics analyses of host responses to infections with virulent or attenuated Brucella strains have been focused on responses by mouse and cattle macrophages, bovine trophoblastic cells, mouse and boar splenocytes, and ram buffy coat. Differential serum responses in humans and rams to Brucella infections have been analyzed using high throughput serum antibody screening technology. The Vaxign reverse vaccinology has been used to predict many Brucella vaccine targets. More than 180 Brucella virulence factors and their gene interaction networks have been identified using advanced literature mining methods. The recent development of community-based Vaccine Ontology and Brucellosis Ontology provides an efficient way for Brucella data integration, exchange, and computer-assisted automated reasoning.

  3. Analyses of Brucella Pathogenesis, Host Immunity, and Vaccine Targets using Systems Biology and Bioinformatics

    Science.gov (United States)

    He, Yongqun

    2011-01-01

    Brucella is a Gram-negative, facultative intracellular bacterium that causes zoonotic brucellosis in humans and various animals. Out of 10 classified Brucella species, B. melitensis, B. abortus, B. suis, and B. canis are pathogenic to humans. In the past decade, the mechanisms of Brucella pathogenesis and host immunity have been extensively investigated using the cutting edge systems biology and bioinformatics approaches. This article provides a comprehensive review of the applications of Omics (including genomics, transcriptomics, and proteomics) and bioinformatics technologies for the analysis of Brucella pathogenesis, host immune responses, and vaccine targets. Based on more than 30 sequenced Brucella genomes, comparative genomics is able to identify gene variations among Brucella strains that help to explain host specificity and virulence differences among Brucella species. Diverse transcriptomics and proteomics gene expression studies have been conducted to analyze gene expression profiles of wild type Brucella strains and mutants under different laboratory conditions. High throughput Omics analyses of host responses to infections with virulent or attenuated Brucella strains have been focused on responses by mouse and cattle macrophages, bovine trophoblastic cells, mouse and boar splenocytes, and ram buffy coat. Differential serum responses in humans and rams to Brucella infections have been analyzed using high throughput serum antibody screening technology. The Vaxign reverse vaccinology has been used to predict many Brucella vaccine targets. More than 180 Brucella virulence factors and their gene interaction networks have been identified using advanced literature mining methods. The recent development of community-based Vaccine Ontology and Brucellosis Ontology provides an efficient way for Brucella data integration, exchange, and computer-assisted automated reasoning. PMID:22919594

  4. HDG1 transcription factor targets

    NARCIS (Netherlands)

    Horstman, A.; Boutilier, K.A.; Sanchez Perez, Gabino

    2015-01-01

    The AIL transcription factor BABY BOOM (BBM) is required together with the related PLETHORA proteins for embryo and root meristem development and its expression is sufficient to confer pluripotency and totipotency to somatic tissues. We show that BBM and other AIL proteins interact with multiple

  5. Autophagy is highly targeted among host comparative proteomes during infection with different virulent RABV strains.

    Science.gov (United States)

    Li, Ling; Jin, Hongli; Wang, Hualei; Cao, Zengguo; Feng, Na; Wang, Jianzhong; Zhao, Yongkun; Zheng, Xuexing; Hou, Pengfei; Li, Nan; Chi, Hang; Huang, Pei; Jiao, Cuicui; Li, Qian; Wang, Lina; Wang, Tiecheng; Sun, Weiyang; Gao, Yuwei; Tu, Changchun; Hu, Guixue; Yang, Songtao; Xia, Xianzhu

    2017-03-28

    Rabies virus (RABV) is a neurotropic virus that causes serious disease in humans and animals worldwide. It has been reported that different RABV strains can result in divergent prognoses in animal model. To identify host factors that affect different infection processes, a kinetic analysis of host proteome alterations in mouse brains infected with different virulent RABV strains was performed using isobaric tags for a relative and absolute quantification (iTRAQ)-liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomics approach, and this analysis identified 147 differentially expressed proteins (DEPs) between the pathogenic challenge virus standard (CVS)-11 strain and the attenuated SRV9 strain. Bioinformatics analyses of these DEPs revealed that autophagy and several pathways associated with autophagy, such as mammalian target of rapamycin (mTOR) signaling, p70S6K signaling, nuclear factor erythroid 2-related factor 2 (NRF2)-mediated oxidative stress and superoxide radical degradation, were dysregulated. Validation of the proteomic data showed that attenuated SRV9 induced more autophagosome accumulation than CVS-11 in an in vitro model. Our findings provide new insights into the pathogenesis of RABV and encourage further studies on this topic.

  6. Identification of host-dependent survival factors for intracellular Mycobacterium tuberculosis through an siRNA screen.

    Directory of Open Access Journals (Sweden)

    Shilpi Jayaswal

    2010-04-01

    Full Text Available The stable infection of host macrophages by Mycobacterium tuberculosis (Mtb involves, and depends on, the attenuation of the diverse microbicidal responses mounted by the host cell. This is primarily achieved through targeted perturbations of the host cellular signaling machinery. Therefore, in view of the dependency of the pathogen on host molecules for its intracellular survival, we wanted to test whether targeting such factors could provide an alternate route for the therapeutic management of tuberculosis. To first identify components of the host signaling machinery that regulate intracellular survival of Mtb, we performed an siRNA screen against all known kinases and phosphatases in murine macrophages infected with the virulent strain, H37Rv. Several validated targets could be identified by this method where silencing led either to a significant decrease, or enhancement in the intracellular mycobacterial load. To further resolve the functional relevance of these targets, we also screened against these identified targets in cells infected with different strains of multiple drug-resistant mycobacteria which differed in terms of their intracellular growth properties. The results obtained subsequently allowed us to filter the core set of host regulatory molecules that functioned independently of the phenotypic variations exhibited by the pathogen. Then, using a combination of both in vitro and in vivo experimentation, we could demonstrate that at least some of these host factors provide attractive targets for anti-TB drug development. These results provide a "proof-of-concept" demonstration that targeting host factors subverted by intracellular Mtb provides an attractive and feasible strategy for the development of anti-tuberculosis drugs. Importantly, our findings also emphasize the advantage of such an approach by establishing its equal applicability to infections with Mtb strains exhibiting a range of phenotypic diversifications, including

  7. Host and Environmental Factors Affecting the Intestinal Microbiota in Chickens

    Science.gov (United States)

    Kers, Jannigje G.; Velkers, Francisca C.; Fischer, Egil A. J.; Hermes, Gerben D. A.; Stegeman, J. A.; Smidt, Hauke

    2018-01-01

    The initial development of intestinal microbiota in poultry plays an important role in production performance, overall health and resistance against microbial infections. Multiplexed sequencing of 16S ribosomal RNA gene amplicons is often used in studies, such as feed intervention or antimicrobial drug trials, to determine corresponding effects on the composition of intestinal microbiota. However, considerable variation of intestinal microbiota composition has been observed both within and across studies. Such variation may in part be attributed to technical factors, such as sampling procedures, sample storage, DNA extraction, the choice of PCR primers and corresponding region to be sequenced, and the sequencing platforms used. Furthermore, part of this variation in microbiota composition may also be explained by different host characteristics and environmental factors. To facilitate the improvement of design, reproducibility and interpretation of poultry microbiota studies, we have reviewed the literature on confounding factors influencing the observed intestinal microbiota in chickens. First, it has been identified that host-related factors, such as age, sex, and breed, have a large effect on intestinal microbiota. The diversity of chicken intestinal microbiota tends to increase most during the first weeks of life, and corresponding colonization patterns seem to differ between layer- and meat-type chickens. Second, it has been found that environmental factors, such as biosecurity level, housing, litter, feed access and climate also have an effect on the composition of the intestinal microbiota. As microbiota studies have to deal with many of these unknown or hidden host and environmental variables, the choice of study designs can have a great impact on study outcomes and interpretation of the data. Providing details on a broad range of host and environmental factors in articles and sequence data repositories is highly recommended. This creates opportunities to

  8. Host pharmacokinetics and drug accumulation of anthelmintics within target helminth parasites of ruminants.

    Science.gov (United States)

    Lifschitz, A; Lanusse, C; Alvarez, L

    2017-07-01

    Anthelmintic drugs require effective concentrations to be attained at the site of parasite location for a certain period to assure their efficacy. The processes of absorption, distribution, metabolism and excretion (pharmacokinetic phase) directly influence drug concentrations attained at the site of action and the resultant pharmacological effect. The aim of the current review article was to provide an overview of the relationship between the pharmacokinetic features of different anthelmintic drugs, their availability in host tissues, accumulation within target helminths and resulting therapeutic efficacy. It focuses on the anthelmintics used in cattle and sheep for which published information on the overall topic is available; benzimidazoles, macrocyclic lactones and monepantel. Physicochemical properties, such as water solubility and dissolution rate, determine the ability of anthelmintic compounds to accumulate in the target parasites and consequently final clinical efficacy. The transcuticular absorption process is the main route of penetration for different drugs in nematodes and cestodes. However, oral ingestion is a main route of drug entry into adult liver flukes. Among other factors, the route of administration may substantially affect the pharmacokinetic behaviour of anthelmintic molecules and modify their efficacy. Oral administration improves drug efficacy against nematodes located in the gastroinestinal tract especially if parasites have a reduced susceptibility. Partitioning of the drug between gastrointestinal contents, mucosal tissue and the target parasite is important to enhance the drug exposure of the nematodes located in the lumen of the abomasum and/or small intestine. On the other hand, large inter-animal variability in drug exposure and subsequent high variability in efficacy is observed after topical administration of anthelmintic compounds. As it has been extensively demonstrated under experimental and field conditions, understanding

  9. Vibrio elicits targeted transcriptional responses from copepod hosts.

    Science.gov (United States)

    Almada, Amalia A; Tarrant, Ann M

    2016-06-01

    Copepods are abundant crustaceans that harbor diverse bacterial communities, yet the nature of their interactions with microbiota are poorly understood. Here, we report that Vibrio elicits targeted transcriptional responses in the estuarine copepod Eurytemora affinis We pre-treated E. affinis with an antibiotic cocktail and exposed them to either a zooplankton specialist (Vibrio sp. F10 9ZB36) or a free-living species (Vibrio ordalii 12B09) for 24 h. We then identified via RNA-Seq a total of 78 genes that were differentially expressed following Vibrio exposure, including homologs of C-type lectins, chitin-binding proteins and saposins. The response differed between the two Vibrio treatments, with the greatest changes elicited upon inoculation with V. sp. F10 We suggest that these differentially regulated genes play important roles in cuticle integrity, the innate immune response, and general stress response, and that their expression may enable E. affinis to recognize and regulate symbiotic vibrios. We further report that V. sp. F10 culturability is specifically altered upon colonization of E. affinis These findings suggest that rather than acting as passive environmental vectors, copepods discriminately interact with vibrios, which may ultimately impact the abundance and activity of copepod-associated bacteria. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. A Trematode Parasite Derived Growth Factor Binds and Exerts Influences on Host Immune Functions via Host Cytokine Receptor Complexes.

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    Azad A Sulaiman

    2016-11-01

    Full Text Available The trematode Fasciola hepatica is responsible for chronic zoonotic infection globally. Despite causing a potent T-helper 2 response, it is believed that potent immunomodulation is responsible for rendering this host reactive non-protective host response thereby allowing the parasite to remain long-lived. We have previously identified a growth factor, FhTLM, belonging to the TGF superfamily can have developmental effects on the parasite. Herein we demonstrate that FhTLM can exert influence over host immune functions in a host receptor specific fashion. FhTLM can bind to receptor members of the Transforming Growth Factor (TGF superfamily, with a greater affinity for TGF-β RII. Upon ligation FhTLM initiates the Smad2/3 pathway resulting in phenotypic changes in both fibroblasts and macrophages. The formation of fibroblast CFUs is reduced when cells are cultured with FhTLM, as a result of TGF-β RI kinase activity. In parallel the wound closure response of fibroblasts is also delayed in the presence of FhTLM. When stimulated with FhTLM blood monocyte derived macrophages adopt an alternative or regulatory phenotype. They express high levels interleukin (IL-10 and arginase-1 while displaying low levels of IL-12 and nitric oxide. Moreover they also undergo significant upregulation of the inhibitory receptor PD-L1 and the mannose receptor. Use of RNAi demonstrates that this effect is dependent on TGF-β RII and mRNA knock-down leads to a loss of IL-10 and PD-L1. Finally, we demonstrate that FhTLM aids newly excysted juveniles (NEJs in their evasion of antibody-dependent cell cytotoxicity (ADCC by reducing the NO response of macrophages-again dependent on TGF-β RI kinase. FhTLM displays restricted expression to the F. hepatica gut resident NEJ stages. The altered fibroblast responses would suggest a role for dampened tissue repair responses in facilitating parasite migration. Furthermore, the adoption of a regulatory macrophage phenotype would allow

  11. 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↓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. PMID:22761576

  12. 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.

  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. Microbial Hub Taxa Link Host and Abiotic Factors to Plant Microbiome Variation.

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    Matthew T Agler

    2016-01-01

    Full Text Available Plant-associated microorganisms have been shown to critically affect host physiology and performance, suggesting that evolution and ecology of plants and animals can only be understood in a holobiont (host and its associated organisms context. Host-associated microbial community structures are affected by abiotic and host factors, and increased attention is given to the role of the microbiome in interactions such as pathogen inhibition. However, little is known about how these factors act on the microbial community, and especially what role microbe-microbe interaction dynamics play. We have begun to address this knowledge gap for phyllosphere microbiomes of plants by simultaneously studying three major groups of Arabidopsis thaliana symbionts (bacteria, fungi and oomycetes using a systems biology approach. We evaluated multiple potential factors of microbial community control: we sampled various wild A. thaliana populations at different times, performed field plantings with different host genotypes, and implemented successive host colonization experiments under lab conditions where abiotic factors, host genotype, and pathogen colonization was manipulated. Our results indicate that both abiotic factors and host genotype interact to affect plant colonization by all three groups of microbes. Considering microbe-microbe interactions, however, uncovered a network of interkingdom interactions with significant contributions to community structure. As in other scale-free networks, a small number of taxa, which we call microbial "hubs," are strongly interconnected and have a severe effect on communities. By documenting these microbe-microbe interactions, we uncover an important mechanism explaining how abiotic factors and host genotypic signatures control microbial communities. In short, they act directly on "hub" microbes, which, via microbe-microbe interactions, transmit the effects to the microbial community. We analyzed two "hub" microbes (the

  15. Microbial Hub Taxa Link Host and Abiotic Factors to Plant Microbiome Variation.

    Science.gov (United States)

    Agler, Matthew T; Ruhe, Jonas; Kroll, Samuel; Morhenn, Constanze; Kim, Sang-Tae; Weigel, Detlef; Kemen, Eric M

    2016-01-01

    Plant-associated microorganisms have been shown to critically affect host physiology and performance, suggesting that evolution and ecology of plants and animals can only be understood in a holobiont (host and its associated organisms) context. Host-associated microbial community structures are affected by abiotic and host factors, and increased attention is given to the role of the microbiome in interactions such as pathogen inhibition. However, little is known about how these factors act on the microbial community, and especially what role microbe-microbe interaction dynamics play. We have begun to address this knowledge gap for phyllosphere microbiomes of plants by simultaneously studying three major groups of Arabidopsis thaliana symbionts (bacteria, fungi and oomycetes) using a systems biology approach. We evaluated multiple potential factors of microbial community control: we sampled various wild A. thaliana populations at different times, performed field plantings with different host genotypes, and implemented successive host colonization experiments under lab conditions where abiotic factors, host genotype, and pathogen colonization was manipulated. Our results indicate that both abiotic factors and host genotype interact to affect plant colonization by all three groups of microbes. Considering microbe-microbe interactions, however, uncovered a network of interkingdom interactions with significant contributions to community structure. As in other scale-free networks, a small number of taxa, which we call microbial "hubs," are strongly interconnected and have a severe effect on communities. By documenting these microbe-microbe interactions, we uncover an important mechanism explaining how abiotic factors and host genotypic signatures control microbial communities. In short, they act directly on "hub" microbes, which, via microbe-microbe interactions, transmit the effects to the microbial community. We analyzed two "hub" microbes (the obligate biotrophic

  16. Complement factor H in host defense and immune evasion.

    Science.gov (United States)

    Parente, Raffaella; Clark, Simon J; Inforzato, Antonio; Day, Anthony J

    2017-05-01

    Complement is the major humoral component of the innate immune system. It recognizes pathogen- and damage-associated molecular patterns, and initiates the immune response in coordination with innate and adaptive immunity. When activated, the complement system unleashes powerful cytotoxic and inflammatory mechanisms, and thus its tight control is crucial to prevent damage to host tissues and allow restoration of immune homeostasis. Factor H is the major soluble inhibitor of complement, where its binding to self markers (i.e., particular glycan structures) prevents complement activation and amplification on host surfaces. Not surprisingly, mutations and polymorphisms that affect recognition of self by factor H are associated with diseases of complement dysregulation, such as age-related macular degeneration and atypical haemolytic uremic syndrome. In addition, pathogens (i.e., non-self) and cancer cells (i.e., altered-self) can hijack factor H to evade the immune response. Here we review recent (and not so recent) literature on the structure and function of factor H, including the emerging roles of this protein in the pathophysiology of infectious diseases and cancer.

  17. Scabies Mite Peritrophins Are Potential Targets of Human Host Innate Immunity

    Science.gov (United States)

    Holt, Deborah C.; Kemp, Dave J.; Fischer, Katja

    2011-01-01

    Background Pruritic scabies lesions caused by Sarcoptes scabiei burrowing in the stratum corneum of human skin facilitate opportunistic bacterial infections. Emerging resistance to current therapeutics emphasizes the need to identify novel targets for protective intervention. We have characterized several protein families located in the mite gut as crucial factors for host-parasite interactions. Among these multiple proteins inhibit human complement, presumably to avoid complement-mediated damage of gut epithelial cells. Peritrophins are major components of the peritrophic matrix often found in the gut of arthropods. We hypothesized that a peritrophin, if abundant in the scabies mite gut, could be an activator of complement. Methodology/Principal Findings A novel full length scabies mite peritrophin (SsPTP1) was identified in a cDNA library from scabies mites. The amino acid sequence revealed four putative chitin binding domains (CBD). Recombinant expression of one CBD of the highly repetitive SsPTP1 sequence as TSP-hexaHis-fusion protein resulted in soluble protein, which demonstrated chitin binding activity in affinity chromatography assays. Antibodies against a recombinant SsPTP1 fragment were used to immunohistochemically localize native SsPTP1 in the mite gut and in fecal pellets within the upper epidermis, co-localizing with serum components such as host IgG and complement. Enzymatic deglycosylation confirmed strong N- and O-glycosylation of the native peritrophin. Serum incubation followed by immunoblotting with a monoclonal antibody against mannan binding lectin (MBL), the recognition molecule of the lectin pathway of human complement activation, indicated that MBL may specifically bind to glycosylated SsPTP1. Conclusions/Significance This study adds a new aspect to the accumulating evidence that complement plays a major role in scabies mite biology. It identifies a novel peritrophin localized in the mite gut as a potential target of the lectin pathway of

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

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    Angela Mika

    2011-09-01

    Full Text Available BACKGROUND: Pruritic scabies lesions caused by Sarcoptes scabiei burrowing in the stratum corneum of human skin facilitate opportunistic bacterial infections. Emerging resistance to current therapeutics emphasizes the need to identify novel targets for protective intervention. We have characterized several protein families located in the mite gut as crucial factors for host-parasite interactions. Among these multiple proteins inhibit human complement, presumably to avoid complement-mediated damage of gut epithelial cells. Peritrophins are major components of the peritrophic matrix often found in the gut of arthropods. We hypothesized that a peritrophin, if abundant in the scabies mite gut, could be an activator of complement. METHODOLOGY/PRINCIPAL FINDINGS: A novel full length scabies mite peritrophin (SsPTP1 was identified in a cDNA library from scabies mites. The amino acid sequence revealed four putative chitin binding domains (CBD. Recombinant expression of one CBD of the highly repetitive SsPTP1 sequence as TSP-hexaHis-fusion protein resulted in soluble protein, which demonstrated chitin binding activity in affinity chromatography assays. Antibodies against a recombinant SsPTP1 fragment were used to immunohistochemically localize native SsPTP1 in the mite gut and in fecal pellets within the upper epidermis, co-localizing with serum components such as host IgG and complement. Enzymatic deglycosylation confirmed strong N- and O-glycosylation of the native peritrophin. Serum incubation followed by immunoblotting with a monoclonal antibody against mannan binding lectin (MBL, the recognition molecule of the lectin pathway of human complement activation, indicated that MBL may specifically bind to glycosylated SsPTP1. CONCLUSIONS/SIGNIFICANCE: This study adds a new aspect to the accumulating evidence that complement plays a major role in scabies mite biology. It identifies a novel peritrophin localized in the mite gut as a potential target of the

  19. Diffusion of information throughout the host interactome reveals gene expression variations in network proximity to target proteins of hepatitis C virus.

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    Ettore Mosca

    Full Text Available Hepatitis C virus infection is one of the most common and chronic in the world, and hepatitis associated with HCV infection is a major risk factor for the development of cirrhosis and hepatocellular carcinoma (HCC. The rapidly growing number of viral-host and host protein-protein interactions is enabling more and more reliable network-based analyses of viral infection supported by omics data. The study of molecular interaction networks helps to elucidate the mechanistic pathways linking HCV molecular activities and the host response that modulates the stepwise hepatocarcinogenic process from preneoplastic lesions (cirrhosis and dysplasia to HCC. Simulating the impact of HCV-host molecular interactions throughout the host protein-protein interaction (PPI network, we ranked the host proteins in relation to their network proximity to viral targets. We observed that the set of proteins in the neighborhood of HCV targets in the host interactome is enriched in key players of the host response to HCV infection. In opposition to HCV targets, subnetworks of proteins in network proximity to HCV targets are significantly enriched in proteins reported as differentially expressed in preneoplastic and neoplastic liver samples by two independent studies. Using multi-objective optimization, we extracted subnetworks that are simultaneously "guilt-by-association" with HCV proteins and enriched in proteins differentially expressed. These subnetworks contain established, recently proposed and novel candidate proteins for the regulation of the mechanisms of liver cells response to chronic HCV infection.

  20. Target identification in Fusobacterium nucleatum by subtractive genomics approach and enrichment analysis of host-pathogen protein-protein interactions.

    Science.gov (United States)

    Kumar, Amit; Thotakura, Pragna Lakshmi; Tiwary, Basant Kumar; Krishna, Ramadas

    2016-05-12

    Fusobacterium nucleatum, a well studied bacterium in periodontal diseases, appendicitis, gingivitis, osteomyelitis and pregnancy complications has recently gained attention due to its association with colorectal cancer (CRC) progression. Treatment with berberine was shown to reverse F. nucleatum-induced CRC progression in mice by balancing the growth of opportunistic pathogens in tumor microenvironment. Intestinal microbiota imbalance and the infections caused by F. nucleatum might be regulated by therapeutic intervention. Hence, we aimed to predict drug target proteins in F. nucleatum, through subtractive genomics approach and host-pathogen protein-protein interactions (HP-PPIs). We also carried out enrichment analysis of host interacting partners to hypothesize the possible mechanisms involved in CRC progression due to F. nucleatum. In subtractive genomics approach, the essential, virulence and resistance related proteins were retrieved from RefSeq proteome of F. nucleatum by searching against Database of Essential Genes (DEG), Virulence Factor Database (VFDB) and Antibiotic Resistance Gene-ANNOTation (ARG-ANNOT) tool respectively. A subsequent hierarchical screening to identify non-human homologous, metabolic pathway-independent/pathway-specific and druggable proteins resulted in eight pathway-independent and 27 pathway-specific druggable targets. Co-aggregation of F. nucleatum with host induces proinflammatory gene expression thereby potentiates tumorigenesis. Hence, proteins from IBDsite, a database for inflammatory bowel disease (IBD) research and those involved in colorectal adenocarcinoma as interpreted from The Cancer Genome Atlas (TCGA) were retrieved to predict drug targets based on HP-PPIs with F. nucleatum proteome. Prediction of HP-PPIs exhibited 186 interactions contributed by 103 host and 76 bacterial proteins. Bacterial interacting partners were accounted as putative targets. And enrichment analysis of host interacting partners showed statistically

  1. Visual genome-wide RNAi screening to identify human host factors required for Trypanosoma cruzi infection.

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    Auguste Genovesio

    Full Text Available The protozoan parasite Trypanosoma cruzi is the etiologic agent of Chagas disease, a neglected tropical infection that affects millions of people in the Americas. Current chemotherapy relies on only two drugs that have limited efficacy and considerable side effects. Therefore, the development of new and more effective drugs is of paramount importance. Although some host cellular factors that play a role in T. cruzi infection have been uncovered, the molecular requirements for intracellular parasite growth and persistence are still not well understood. To further study these host-parasite interactions and identify human host factors required for T. cruzi infection, we performed a genome-wide RNAi screen using cellular microarrays of a printed siRNA library that spanned the whole human genome. The screening was reproduced 6 times and a customized algorithm was used to select as hits those genes whose silencing visually impaired parasite infection. The 162 strongest hits were subjected to a secondary screening and subsequently validated in two different cell lines. Among the fourteen hits confirmed, we recognized some cellular membrane proteins that might function as cell receptors for parasite entry and others that may be related to calcium release triggered by parasites during cell invasion. In addition, two of the hits are related to the TGF-beta signaling pathway, whose inhibition is already known to diminish levels of T. cruzi infection. This study represents a significant step toward unveiling the key molecular requirements for host cell invasion and revealing new potential targets for antiparasitic therapy.

  2. Host-targeting agents in the treatment of hepatitis C: a beginning and an end?

    Science.gov (United States)

    Baugh, James M; Garcia-Rivera, Jose A; Gallay, Philippe A

    2013-11-01

    The development of two distinct classes of hepatitis C antiviral agents, direct-acting antivirals (DAAs) and host-targeting antivirals (HTAs), have distinctly impacted the hepatitis C virus (HCV) field by generating higher sustained virological response (SVR) rates within infected patients, via reductions in both adverse side effects and duration of treatment when compared to the old standard of care. Today DAAs are actively incorporated into the standard of care and continue to receive the most advanced clinical trial analysis. With a multitude of innovative and potent second-generation DAA compounds currently being tested in clinical trials, it is clear that the future of DAAs looks very bright. In comparison to the other class of compounds, HTAs have been slightly less impactful, despite the fact that primary treatment regimens for HCV began with the use of an HTA - interferon alpha (IFNα). The compound was advantageous in that it provided a broad-reaching antiviral response; however deleterious side effects and viral/patient resistance has since made the compound outdated. HTA research has since moved onward to target a number of cellular host factors that are required for HCV viral entry and replication such as scavenger receptor-BI (SR-BI), 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMGCoA reductase), cyclophilin A (CypA), fatty acid synthase (FASN) and miRNA-122. The rationale behind pursuing these HTAs is based upon the extremely low mutational rate that occurs within eukaryotic cells, thereby creating a high genetic barrier to drug resistance for anti-HCV compounds, as well as pan-genotypic coverage to all HCV genotypes and serotypes. As the end appears near for HCV, it becomes important to ask if the development of novel HTAs should also be analyzed in combination with other DAAs, in order to address potential hard-to-treat HCV patient populations. Since the treatment regimens for HCV began with the use of a global HTA, could one end the field as well

  3. Wolbachia as an infectious extrinsic factor manipulating host signalling pathways

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    Ilaria eNegri

    2012-01-01

    Full Text Available Wolbachia pipientis is a widespread endosymbiont of filarial nematodes and arthropods. While in worms the symbiosis is obligate, in arthropods Wolbachia induces several reproductive manipulations (i.e. cytoplasmic incompatibility, parthenogenesis, feminization of genetic males and male-killing in order to increase the number of infected females. These various phenotypic effects may be linked to differences in host physiology, and in particular to endocrine-related processes governing growth, development and reproduction. Indeed, a number of evidences links Wolbachia symbiosis to insulin and ecdysteroid signalling, two multilayered pathways known to work antagonistically, jointly or even independently for the regulation of different molecular networks. At present it is not clear whether Wolbachia manipulates one pathway, thus affecting other related metabolic networks, or if it targets both pathways, even interacting at several points in each of them. Interestingly, in view of the interplay between hormone signalling and epigenetic machinery, a direct influence of the infection on hormonal signalling involving ecdysteroids might be achievable through the manipulation of the host’s epigenetic pathways.

  4. Growth factors and chemotactic factors from parasitic helminths: molecular evidence for roles in host-parasite interactions versus parasite development.

    Science.gov (United States)

    Freitas, Tori C; Pearce, Edward J

    2010-06-01

    For decades molecular helminthologists have been interested in identifying proteins expressed by the parasite that have roles in modulating the host immune response. In some cases, the aim was targeting parasite-derived orthologues of mammalian cytokines and growth factors known to have functions in immune modulation. In others, novel proteins without homology to mammalian cytokines were isolated by investigating effects of purified worm extracts on various immunological processes. Often, the role parasite-derived growth factors play in worm development was ignored. Here, we review growth factors and chemotactic factors expressed by parasitic helminths and discuss their recognised and potential roles in immunomodulation and/or parasite development. (c) 2010 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

  5. Host genetic factors predisposing to HIV-associated neurocognitive disorder.

    Science.gov (United States)

    Kallianpur, Asha R; Levine, Andrew J

    2014-09-01

    The success of combination antiretroviral therapy (cART) in transforming the lives of HIV-infected individuals with access to these drugs is tempered by the increasing threat of HIV-associated neurocognitive disorders (HAND) to their overall health and quality of life. Intensive investigations over the past two decades have underscored the role of host immune responses, inflammation, and monocyte-derived macrophages in HAND, but the precise pathogenic mechanisms underlying HAND remain only partially delineated. Complicating research efforts and therapeutic drug development are the sheer complexity of HAND phenotypes, diagnostic imprecision, and the growing intersection of chronic immune activation with aging-related comorbidities. Yet, genetic studies still offer a powerful means of advancing individualized care for HIV-infected individuals at risk. There is an urgent need for 1) longitudinal studies using consistent phenotypic definitions of HAND in HIV-infected subpopulations at very high risk of being adversely impacted, such as children, 2) tissue studies that correlate neuropathological changes in multiple brain regions with genomic markers in affected individuals and with changes at the RNA, epigenomic, and/or protein levels, and 3) genetic association studies using more sensitive subphenotypes of HAND. The NIH Brain Initiative and Human Connectome Project, coupled with rapidly evolving systems biology and machine learning approaches for analyzing high-throughput genetic, transcriptomic and epigenetic data, hold promise for identifying actionable biological processes and gene networks that underlie HAND. This review summarizes the current state of understanding of host genetic factors predisposing to HAND in light of past challenges and suggests some priorities for future research to advance the understanding and clinical management of HAND in the cART era.

  6. In silico target network analysis of de novo-discovered, tick saliva-specific microRNAs reveals important combinatorial effects in their interference with vertebrate host physiology

    Czech Academy of Sciences Publication Activity Database

    Hackenberg, M.; Langenberger, D.; Schwarz, Alexandra; Erhart, Jan; Kotsyfakis, Michalis

    2017-01-01

    Roč. 23, č. 8 (2017), s. 1259-1269 ISSN 1355-8382 Institutional support: RVO:60077344 Keywords : tick-vertebrate host interaction * deep- sequencing * microRNA * gene target prediction * interactomes/systems biology * disease biology Subject RIV: EB - Gene tics ; Molecular Biology OBOR OECD: Biochemistry and molecular biology Impact factor: 4.605, year: 2016

  7. Sequence- and interactome-based prediction of viral protein hotspots targeting host proteins: a case study for HIV Nef.

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    Mahdi Sarmady

    Full Text Available Virus proteins alter protein pathways of the host toward the synthesis of viral particles by breaking and making edges via binding to host proteins. In this study, we developed a computational approach to predict viral sequence hotspots for binding to host proteins based on sequences of viral and host proteins and literature-curated virus-host protein interactome data. We use a motif discovery algorithm repeatedly on collections of sequences of viral proteins and immediate binding partners of their host targets and choose only those motifs that are conserved on viral sequences and highly statistically enriched among binding partners of virus protein targeted host proteins. Our results match experimental data on binding sites of Nef to host proteins such as MAPK1, VAV1, LCK, HCK, HLA-A, CD4, FYN, and GNB2L1 with high statistical significance but is a poor predictor of Nef binding sites on highly flexible, hoop-like regions. Predicted hotspots recapture CD8 cell epitopes of HIV Nef highlighting their importance in modulating virus-host interactions. Host proteins potentially targeted or outcompeted by Nef appear crowding the T cell receptor, natural killer cell mediated cytotoxicity, and neurotrophin signaling pathways. Scanning of HIV Nef motifs on multiple alignments of hepatitis C protein NS5A produces results consistent with literature, indicating the potential value of the hotspot discovery in advancing our understanding of virus-host crosstalk.

  8. The malarial host-targeting signal is conserved in the Irish potato famine pathogen.

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    2006-05-01

    Full Text Available Animal and plant eukaryotic pathogens, such as the human malaria parasite Plasmodium falciparum and the potato late blight agent Phytophthora infestans, are widely divergent eukaryotic microbes. Yet they both produce secretory virulence and pathogenic proteins that alter host cell functions. In P. falciparum, export of parasite proteins to the host erythrocyte is mediated by leader sequences shown to contain a host-targeting (HT motif centered on an RxLx (E, D, or Q core: this motif appears to signify a major pathogenic export pathway with hundreds of putative effectors. Here we show that a secretory protein of P. infestans, which is perceived by plant disease resistance proteins and induces hypersensitive plant cell death, contains a leader sequence that is equivalent to the Plasmodium HT-leader in its ability to export fusion of green fluorescent protein (GFP from the P. falciparum parasite to the host erythrocyte. This export is dependent on an RxLR sequence conserved in P. infestans leaders, as well as in leaders of all ten secretory oomycete proteins shown to function inside plant cells. The RxLR motif is also detected in hundreds of secretory proteins of P. infestans, Phytophthora sojae, and Phytophthora ramorum and has high value in predicting host-targeted leaders. A consensus motif further reveals E/D residues enriched within approximately 25 amino acids downstream of the RxLR, which are also needed for export. Together the data suggest that in these plant pathogenic oomycetes, a consensus HT motif may reside in an extended sequence of approximately 25-30 amino acids, rather than in a short linear sequence. Evidence is presented that although the consensus is much shorter in P. falciparum, information sufficient for vacuolar export is contained in a region of approximately 30 amino acids, which includes sequences flanking the HT core. Finally, positional conservation between Phytophthora RxLR and P. falciparum RxLx (E, D, Q is

  9. The gills of reef fish support a distinct microbiome influenced by host-specific factors.

    Science.gov (United States)

    Pratte, Zoe A; Besson, Marc; Hollman, Rebecca D; Stewart, Frank J

    2018-02-16

    diversity. Focusing on ecologically distinct types of coral reef fish, we provide a comprehensive analysis of the fish gill microbiome. By comparison to microbiomes of the gut and the surrounding environment, we identify microbes unique to the gill niche. These microbes may be targets for further studies to determine the contribution of the microbiome to waste exchange or host immunity. We also show that, despite exhibiting a unique taxonomic signature, the gill microbiome is influenced by factors that also influence the gut microbiome. These factors include the specific identity of the host individual. These results suggest basic principles describing how association with fishes structures the composition of microbial communities. Copyright © 2018 American Society for Microbiology.

  10. A heparan-dependent herpesvirus targets the olfactory neuroepithelium for host entry.

    Science.gov (United States)

    Milho, Ricardo; Frederico, Bruno; Efstathiou, Stacey; Stevenson, Philip G

    2012-01-01

    Herpesviruses are ubiquitous pathogens that cause much disease. The difficulty of clearing their established infections makes host entry an important target for control. However, while herpesviruses have been studied extensively in vitro, how they cross differentiated mucus-covered epithelia in vivo is unclear. To establish general principles we tracked host entry by Murid Herpesvirus-4 (MuHV-4), a lymphotropic rhadinovirus related to the Kaposi's Sarcoma-associated Herpesvirus. Spontaneously acquired virions targeted the olfactory neuroepithelium. Like many herpesviruses, MuHV-4 binds to heparan sulfate (HS), and virions unable to bind HS showed poor host entry. While the respiratory epithelium expressed only basolateral HS and was bound poorly by incoming virions, the neuroepithelium also displayed HS on its apical neuronal cilia and was bound strongly. Incoming virions tracked down the neuronal cilia, and either infected neurons or reached the underlying microvilli of the adjacent glial (sustentacular) cells and infected them. Thus the olfactory neuroepithelium provides an important and complex site of HS-dependent herpesvirus uptake.

  11. Early host cell targets of Yersinia pestis during primary pneumonic plague.

    Directory of Open Access Journals (Sweden)

    Roger D Pechous

    Full Text Available Inhalation of Yersinia pestis causes primary pneumonic plague, a highly lethal syndrome with mortality rates approaching 100%. Pneumonic plague progression is biphasic, with an initial pre-inflammatory phase facilitating bacterial growth in the absence of host inflammation, followed by a pro-inflammatory phase marked by extensive neutrophil influx, an inflammatory cytokine storm, and severe tissue destruction. Using a FRET-based probe to quantitate injection of effector proteins by the Y. pestis type III secretion system, we show that these bacteria target alveolar macrophages early during infection of mice, followed by a switch in host cell preference to neutrophils. We also demonstrate that neutrophil influx is unable to limit bacterial growth in the lung and is ultimately responsible for the severe inflammation during the lethal pro-inflammatory phase.

  12. CD151, a novel host factor of nuclear export signaling in influenza virus infection.

    Science.gov (United States)

    Qiao, Yongkang; Yan, Yan; Tan, Kai Sen; Tan, Sheryl S L; Seet, Ju Ee; Arumugam, Thiruma Valavan; Chow, Vincent T K; Wang, De Yun; Tran, Thai

    2017-12-21

    Despite advances in our understanding of the mechanisms of influenza A virus (IAV) infection, the crucial virus-host interactions during the viral replication cycle still remain incomplete. Tetraspanin CD151 is highly expressed in the human respiratory tract, but its pathological role in IAV infection is unknown. We sought to characterize the functional role and mechanisms of action of CD151 in IAV infection of the upper and lower respiratory tracts with H1N1 and H3N2 strains. We used CD151-null mice in an in vivo model of IAV infection and clinical donor samples of in vitro-differentiated human nasal epithelial cells cultured at air-liquid interface. As compared with wild-type infected mice, CD151-null infected mice exhibited a significant reduction in virus titer and improvement in survival that is associated with pronounced host antiviral response and inflammasome activation together with accelerated lung repair. Interestingly, we show that CD151 complexes newly synthesized viral proteins with host nuclear export proteins and stabilizes microtubule complexes, which are key processes necessary for the polarized trafficking of viral progeny to the host plasma membrane for assembly. Our results provide new mechanistic insights into our understanding of IAV infection. We show that CD151 is a critical novel host factor of nuclear export signaling whereby the IAV nuclear export uses it to complement its own nuclear export proteins (a site not targeted by current therapy), making this regulation unique, and holds promise for the development of novel alternative/complementary strategies to reduce IAV severity. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  13. The Endosymbiotic Bacterium Wolbachia Selectively Kills Male Hosts by Targeting the Masculinizing Gene.

    Directory of Open Access Journals (Sweden)

    Takahiro Fukui

    2015-07-01

    Full Text Available Pathogens are known to manipulate the reproduction and development of their hosts for their own benefit. Wolbachia is an endosymbiotic bacterium that infects a wide range of insect species. Wolbachia is known as an example of a parasite that manipulates the sex of its host's progeny. Infection of Ostrinia moths by Wolbachia causes the production of all-female progeny, however, the mechanism of how Wolbachia accomplishes this male-specific killing is unknown. Here we show for the first time that Wolbachia targets the host masculinizing gene of Ostrinia to accomplish male-killing. We found that Wolbachia-infected O. furnacalis embryos do not express the male-specific splice variant of doublesex, a gene which acts at the downstream end of the sex differentiation cascade, throughout embryonic development. Transcriptome analysis revealed that Wolbachia infection markedly reduces the mRNA level of Masc, a gene that encodes a protein required for both masculinization and dosage compensation in the silkworm Bombyx mori. Detailed bioinformatic analysis also elucidated that dosage compensation of Z-linked genes fails in Wolbachia-infected O. furnacalis embryos, a phenomenon that is extremely similar to that observed in Masc mRNA-depleted male embryos of B. mori. Finally, injection of in vitro transcribed Masc cRNA into Wolbachia-infected embryos rescued male progeny. Our results show that Wolbachia-induced male-killing is caused by a failure of dosage compensation via repression of the host masculinizing gene. Our study also shows a novel strategy by which a pathogen hijacks the host sex determination cascade.

  14. Host heterogeneous ribonucleoprotein K (hnRNP K as a potential target to suppress hepatitis B virus replication.

    Directory of Open Access Journals (Sweden)

    2005-07-01

    Full Text Available BACKGROUND: Hepatitis B virus (HBV infection results in complications such as cirrhosis and hepatocellular carcinoma. Suppressing viral replication in chronic HBV carriers is an effective approach to controlling disease progression. Although antiviral compounds are available, we aimed to identify host factors that have a significant effect on viral replication efficiency. METHODS AND FINDINGS: We studied a group of hepatitis B carriers by associating serum viral load with their respective HBV genomes, and observed a significant association between high patient serum viral load with a natural sequence variant within the HBV enhancer II (Enh II regulatory region at position 1752. Using a viral fragment as an affinity binding probe, we isolated a host DNA-binding protein belonging to the class of heterogeneous nuclear ribonucleoproteins--hnRNP K--that binds to and modulates the replicative efficiency of HBV. In cell transfection studies, overexpression of hnRNP K augmented HBV replication, while gene silencing of endogenous hnRNP K carried out by small interfering RNAs resulted in a significant reduction of HBV viral load. CONCLUSION: The evidence presented in this study describes a wider role for hnRNP K beyond maintenance of host cellular functions and may represent a novel target for pharmacologic intervention of HBV replication.

  15. Comparative Methods for Molecular Determination of Host-Specificity Factors in Plant-Pathogenic Fungi

    Directory of Open Access Journals (Sweden)

    Nilam Borah

    2018-03-01

    Full Text Available Many plant-pathogenic fungi are highly host-specific. In most cases, host-specific interactions evolved at the time of speciation of the respective host plants. However, host jumps have occurred quite frequently, and still today the greatest threat for the emergence of new fungal diseases is the acquisition of infection capability of a new host by an existing plant pathogen. Understanding the mechanisms underlying host-switching events requires knowledge of the factors determining host-specificity. In this review, we highlight molecular methods that use a comparative approach for the identification of host-specificity factors. These cover a wide range of experimental set-ups, such as characterization of the pathosystem, genotyping of host-specific strains, comparative genomics, transcriptomics and proteomics, as well as gene prediction and functional gene validation. The methods are described and evaluated in view of their success in the identification of host-specificity factors and the understanding of their functional mechanisms. In addition, potential methods for the future identification of host-specificity factors are discussed.

  16. A novel method for producing target cells and assessing cytotoxic T lymphocyte activity in outbred hosts

    Directory of Open Access Journals (Sweden)

    Bendinelli Mauro

    2009-03-01

    Full Text Available Abstract Background Cytotoxic T lymphocytes play a crucial role in the immunological control of microbial infections and in the design of vaccines and immunotherapies. Measurement of cytotoxic T lymphocyte activity requires that the test antigen is presented by target cells having the same or compatible class I major hystocompatibility complex antigens as the effector cells. Conventional assays use target cells labeled with 51chromium and infer cytotoxic T lymphocyte activity by measuring the isotope released by the target cells lysed following incubation with antigen-specific cytotoxic T lymphocytes. This assay is sensitive but needs manipulation and disposal of hazardous radioactive reagents and provides a bulk estimate of the reporter released, which may be influenced by spontaneous release of the label and other poorly controllable variables. Here we describe a novel method for producing target in outbred hosts and assessing cytotoxic T lymphocyte activity by flow cytometry. Results The method consists of culturing skin fibroblasts, immortalizing them with a replication defective clone of simian virus 40, and finally transducing them with a bicistronic vector encoding the target antigen and the reporter green fluorescent protein. When used in a flow cytometry-based assay, the target cells obtained with this method proved valuable for assessing the viral envelope protein specific cytotoxic T lymphocyte activity in domestic cats acutely or chronically infected with feline immunodeficiency virus, a lentivirus similar to human immunodeficiency virus and used as animal model for AIDS studies. Conclusion Given the versatility of the bicistronic vector used, its ability to deliver multiple and large transgenes in target cells, and its extremely wide cell specificity when pseudotyped with the vesicular stomatitis virus envelope protein, the method is potentially exploitable in many animal species.

  17. Ubiquitin systems mark pathogen-containing vacuoles as targets for host defense by guanylate binding proteins.

    Science.gov (United States)

    Haldar, Arun K; Foltz, Clémence; Finethy, Ryan; Piro, Anthony S; Feeley, Eric M; Pilla-Moffett, Danielle M; Komatsu, Masaki; Frickel, Eva-Maria; Coers, Jörn

    2015-10-13

    Many microbes create and maintain pathogen-containing vacuoles (PVs) as an intracellular niche permissive for microbial growth and survival. The destruction of PVs by IFNγ-inducible guanylate binding protein (GBP) and immunity-related GTPase (IRG) host proteins is central to a successful immune response directed against numerous PV-resident pathogens. However, the mechanism by which IRGs and GBPs cooperatively detect and destroy PVs is unclear. We find that host cell priming with IFNγ prompts IRG-dependent association of Toxoplasma- and Chlamydia-containing vacuoles with ubiquitin through regulated translocation of the E3 ubiquitin ligase tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6). This initial ubiquitin labeling elicits p62-mediated escort and deposition of GBPs to PVs, thereby conferring cell-autonomous immunity. Hypervirulent strains of Toxoplasma gondii evade this process via specific rhoptry protein kinases that inhibit IRG function, resulting in blockage of downstream PV ubiquitination and GBP delivery. Our results define a ubiquitin-centered mechanism by which host cells deliver GBPs to PVs and explain how hypervirulent parasites evade GBP-mediated immunity.

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

    Lifescience Database Archive (English)

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

  19. Analysis of protein targets in pathogen-host interaction in infectious diseases: a case study on Plasmodium falciparum and Homo sapiens interaction network.

    Science.gov (United States)

    Saha, Sovan; Sengupta, Kaustav; Chatterjee, Piyali; Basu, Subhadip; Nasipuri, Mita

    2017-09-23

    Infection and disease progression is the outcome of protein interactions between pathogen and host. Pathogen, the role player of Infection, is becoming a severe threat to life as because of its adaptability toward drugs and evolutionary dynamism in nature. Identifying protein targets by analyzing protein interactions between host and pathogen is the key point. Proteins with higher degree and possessing some topologically significant graph theoretical measures are found to be drug targets. On the other hand, exceptional nodes may be involved in infection mechanism because of some pathway process and biologically unknown factors. In this article, we attempt to investigate characteristics of host-pathogen protein interactions by presenting a comprehensive review of computational approaches applied on different infectious diseases. As an illustration, we have analyzed a case study on infectious disease malaria, with its causative agent Plasmodium falciparum acting as 'Bait' and host, Homo sapiens/human acting as 'Prey'. In this pathogen-host interaction network based on some interconnectivity and centrality properties, proteins are viewed as central, peripheral, hub and non-hub nodes and their significance on infection process. Besides, it is observed that because of sparseness of the pathogen and host interaction network, there may be some topologically unimportant but biologically significant proteins, which can also act as Bait/Prey. So, functional similarity or gene ontology mapping can help us in this case to identify these proteins. © The Author 2017. Published by Oxford University Press. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. Coxsackievirus mutants that can bypass host factor PI4KIIIbeta and the need for high levels of PI4P lipids for replication

    NARCIS (Netherlands)

    van der Schaar, H.M.; van der Linden, L.; Lanke, K.H.W.; Strating, J.R.P.M.; Purstinger, G.; Vries, E. De; de Haan, C.A.; Neyts, J.; Kuppeveld, F.J.M. van

    2012-01-01

    RNA viruses can rapidly mutate and acquire resistance to drugs that directly target viral enzymes, which poses serious problems in a clinical context. Therefore, there is a growing interest in the development of antiviral drugs that target host factors critical for viral replication, since they are

  1. Toxoplasma gondii GRA7-Targeted ASC and PLD1 Promote Antibacterial Host Defense via PKCα.

    Directory of Open Access Journals (Sweden)

    Hyun-Jung Koh

    2017-01-01

    Full Text Available Tuberculosis is a global health problem and at least one-third of the world's population is infected with Mycobacterium tuberculosis (MTB. MTB is a successful pathogen that enhances its own intracellular survival by inhibiting inflammation and arresting phago-lysosomal fusion. We previously demonstrated that Toxoplasma gondii (T. gondii dense granule antigen (GRA 7 interacts with TNF receptor-associated factor 6 via Myeloid differentiation primary response gene 88, enabling innate immune responses in macrophages. To extend these studies, we found that GRA7 interacts with host proteins involved in antimicrobial host defense mechanisms as a therapeutic strategy for tuberculosis. Here, we show that protein kinase C (PKCα-mediated phosphorylation of T. gondii GRA7-I (Ser52 regulates the interaction of GRA7 with PYD domain of apoptosis-associated speck-like protein containing a carboxy-terminal CARD, which is capable of oligomerization and inflammasome activation can lead to antimicrobial defense against MTB. Furthermore, GRA7-III interacted with the PX domain of phospholipase D1, facilitating its enzyme activity, phago-lysosomal maturation, and subsequent antimicrobial activity in a GRA7-III (Ser135 phosphorylation-dependent manner via PKCα. Taken together, these results underscore a previously unrecognized role of GRA7 in modulating antimicrobial host defense mechanism during mycobacterial infection.

  2. Identification and Structural Basis of Binding to Host Lung Glycogen by Streptococcal Virulence Factors

    Energy Technology Data Exchange (ETDEWEB)

    Lammerts van Bueren,A.; Higgins, M.; Wang, D.; Burke, R.; Boraston, A.

    2007-01-01

    The ability of pathogenic bacteria to recognize host glycans is often essential to their virulence. Here we report structure-function studies of previously uncharacterized glycogen-binding modules in the surface-anchored pullulanases from Streptococcus pneumoniae (SpuA) and Streptococcus pyogenes (PulA). Multivalent binding to glycogen leads to a strong interaction with alveolar type II cells in mouse lung tissue. X-ray crystal structures of the binding modules reveal a novel fusion of tandem modules into single, bivalent functional domains. In addition to indicating a structural basis for multivalent attachment, the structure of the SpuA modules in complex with carbohydrate provides insight into the molecular basis for glycogen specificity. This report provides the first evidence that intracellular lung glycogen may be a novel target of pathogenic streptococci and thus provides a rationale for the identification of the streptococcal {alpha}-glucan-metabolizing machinery as virulence factors.

  3. Human Adenovirus Core Protein V Is Targeted by the Host SUMOylation Machinery To Limit Essential Viral Functions.

    Science.gov (United States)

    Freudenberger, Nora; Meyer, Tina; Groitl, Peter; Dobner, Thomas; Schreiner, Sabrina

    2018-02-15

    Human adenoviruses (HAdV) are nonenveloped viruses containing a linear, double-stranded DNA genome surrounded by an icosahedral capsid. To allow proper viral replication, the genome is imported through the nuclear pore complex associated with viral core proteins. Until now, the role of these incoming virion proteins during the early phase of infection was poorly understood. The core protein V is speculated to bridge the core and the surrounding capsid. It binds the genome in a sequence-independent manner and localizes in the nucleus of infected cells, accumulating at nucleoli. Here, we show that protein V contains conserved SUMO conjugation motifs (SCMs). Mutation of these consensus motifs resulted in reduced SUMOylation of the protein; thus, protein V represents a novel target of the host SUMOylation machinery. To understand the role of protein V SUMO posttranslational modification during productive HAdV infection, we generated a replication-competent HAdV with SCM mutations within the protein V coding sequence. Phenotypic analyses revealed that these SCM mutations are beneficial for adenoviral replication. Blocking protein V SUMOylation at specific sites shifts the onset of viral DNA replication to earlier time points during infection and promotes viral gene expression. Simultaneously, the altered kinetics within the viral life cycle are accompanied by more efficient proteasomal degradation of host determinants and increased virus progeny production than that observed during wild-type infection. Taken together, our studies show that protein V SUMOylation reduces virus growth; hence, protein V SUMOylation represents an important novel aspect of the host antiviral strategy to limit virus replication and thereby points to potential intervention strategies. IMPORTANCE Many decades of research have revealed that HAdV structural proteins promote viral entry and mainly physical stability of the viral genome in the capsid. Our work over the last years showed that this

  4. Dual miRNA Targeting Restricts Host Range and Attenuates Neurovirulence of Flaviviruses

    Science.gov (United States)

    Tsetsarkin, Konstantin A.; Liu, Guangping; Kenney, Heather; Bustos-Arriaga, Jose; Hanson, Christopher T.; Whitehead, Stephen S.; Pletnev, Alexander G.

    2015-01-01

    Mosquito-borne flaviviruses are among the most significant arboviral pathogens worldwide. Vaccinations and mosquito population control programs remain the most reliable means for flavivirus disease prevention, and live attenuated viruses remain one of the most attractive flavivirus vaccine platforms. Some live attenuated viruses are capable of infecting principle mosquito vectors, as demonstrated in the laboratory, which in combination with their intrinsic genetic instability could potentially lead to a vaccine virus reversion back to wild-type in nature, followed by introduction and dissemination of potentially dangerous viral strains into new geographic locations. To mitigate this risk we developed a microRNA-targeting approach that selectively restricts replication of flavivirus in the mosquito host. Introduction of sequences complementary to a mosquito-specific mir-184 and mir-275 miRNAs individually or in combination into the 3’NCR and/or ORF region resulted in selective restriction of dengue type 4 virus (DEN4) replication in mosquito cell lines and adult Aedes mosquitos. Moreover a combined targeting of DEN4 genome with mosquito-specific and vertebrate CNS-specific mir-124 miRNA can silence viral replication in two evolutionally distant biological systems: mosquitoes and mouse brains. Thus, this approach can reinforce the safety of newly developed or existing vaccines for use in humans and could provide an additional level of biosafety for laboratories using viruses with altered pathogenic or transmissibility characteristics. PMID:25906260

  5. Dual miRNA targeting restricts host range and attenuates neurovirulence of flaviviruses.

    Directory of Open Access Journals (Sweden)

    Konstantin A Tsetsarkin

    2015-04-01

    Full Text Available Mosquito-borne flaviviruses are among the most significant arboviral pathogens worldwide. Vaccinations and mosquito population control programs remain the most reliable means for flavivirus disease prevention, and live attenuated viruses remain one of the most attractive flavivirus vaccine platforms. Some live attenuated viruses are capable of infecting principle mosquito vectors, as demonstrated in the laboratory, which in combination with their intrinsic genetic instability could potentially lead to a vaccine virus reversion back to wild-type in nature, followed by introduction and dissemination of potentially dangerous viral strains into new geographic locations. To mitigate this risk we developed a microRNA-targeting approach that selectively restricts replication of flavivirus in the mosquito host. Introduction of sequences complementary to a mosquito-specific mir-184 and mir-275 miRNAs individually or in combination into the 3'NCR and/or ORF region resulted in selective restriction of dengue type 4 virus (DEN4 replication in mosquito cell lines and adult Aedes mosquitos. Moreover a combined targeting of DEN4 genome with mosquito-specific and vertebrate CNS-specific mir-124 miRNA can silence viral replication in two evolutionally distant biological systems: mosquitoes and mouse brains. Thus, this approach can reinforce the safety of newly developed or existing vaccines for use in humans and could provide an additional level of biosafety for laboratories using viruses with altered pathogenic or transmissibility characteristics.

  6. Epidermal growth factor receptor: Target for delivery and silencing

    NARCIS (Netherlands)

    Santos Oliveira, S.|info:eu-repo/dai/nl/304841455

    2008-01-01

    Epidermal growth factor receptor in cancer therapy Recently, cancer research has been able to identify molecular targets that are specific for (or highly expressed by) cancer cells. These molecular targets serve as models for the development of rationally designed anticancer drugs that target

  7. The SARS-coronavirus-host interactome: identification of cyclophilins as target for pan-coronavirus inhibitors.

    Directory of Open Access Journals (Sweden)

    Susanne Pfefferle

    2011-10-01

    Full Text Available Coronaviruses (CoVs are important human and animal pathogens that induce fatal respiratory, gastrointestinal and neurological disease. The outbreak of the severe acute respiratory syndrome (SARS in 2002/2003 has demonstrated human vulnerability to (Coronavirus CoV epidemics. Neither vaccines nor therapeutics are available against human and animal CoVs. Knowledge of host cell proteins that take part in pivotal virus-host interactions could define broad-spectrum antiviral targets. In this study, we used a systems biology approach employing a genome-wide yeast-two hybrid interaction screen to identify immunopilins (PPIA, PPIB, PPIH, PPIG, FKBP1A, FKBP1B as interaction partners of the CoV non-structural protein 1 (Nsp1. These molecules modulate the Calcineurin/NFAT pathway that plays an important role in immune cell activation. Overexpression of NSP1 and infection with live SARS-CoV strongly increased signalling through the Calcineurin/NFAT pathway and enhanced the induction of interleukin 2, compatible with late-stage immunopathogenicity and long-term cytokine dysregulation as observed in severe SARS cases. Conversely, inhibition of cyclophilins by cyclosporine A (CspA blocked the replication of CoVs of all genera, including SARS-CoV, human CoV-229E and -NL-63, feline CoV, as well as avian infectious bronchitis virus. Non-immunosuppressive derivatives of CspA might serve as broad-range CoV inhibitors applicable against emerging CoVs as well as ubiquitous pathogens of humans and livestock.

  8. Host factors that modify Plasmodium falciparum adhesion to endothelial receptors.

    Science.gov (United States)

    Mahamar, Almahamoudou; Attaher, Oumar; Swihart, Bruce; Barry, Amadou; Diarra, Bacary S; Kanoute, Moussa B; Cisse, Kadidia B; Dembele, Adama B; Keita, Sekouba; Gamain, Benoît; Gaoussou, Santara; Issiaka, Djibrilla; Dicko, Alassane; Duffy, Patrick E; Fried, Michal

    2017-10-24

    P. falciparum virulence is related to adhesion and sequestration of infected erythrocytes (IE) in deep vascular beds, but the endothelial receptors involved in severe malaria remain unclear. In the largest ever study of clinical isolates, we surveyed adhesion of freshly collected IE from children under 5 years of age in Mali to identify novel vascular receptors, and examined the effects of host age, hemoglobin type, blood group and severe malaria on levels of IE adhesion to a panel of endothelial receptors. Several novel molecules, including integrin α3β1, VE-cadherin, ICAM-2, junctional adhesion molecule-B (JAM-B), laminin, and cellular fibronectin, supported binding of IE from children. Severe malaria was not significantly associated with levels of IE adhesion to any of the 19 receptors. Hemoglobin AC, which reduces severe malaria risk, reduced IE binding to the receptors CD36 and integrin α5β1, while hemoglobin AS did not modify IE adhesion to any receptors. Blood groups A, AB and B significantly reduced IE binding to ICAM-1. Severe malaria risk varies with age, but age significantly impacted the level of IE binding to only a few receptors: IE binding to JAM-B decreased with age, while binding to CD36 and integrin α5β1 significantly increased with age.

  9. Differential compartmentalization of Streptococcus pyogenes virulence factors and host protein binding properties as a mechanism for host adaptation.

    Science.gov (United States)

    Kilsgård, Ola; Karlsson, Christofer; Malmström, Erik; Malmström, Johan

    2016-11-01

    Streptococcus pyogenes is an important human pathogen responsible for substantial morbidity and mortality worldwide. Although S. pyogenes is a strictly human pathogen with no other known animal reservoir, several murine infection models exist to explore different aspects of the bacterial pathogenesis. Inoculating mice with wild-type S. pyogenes strains can result in the generation of new bacterial phenotypes that are hypervirulent compared to the original inoculum. In this study, we used a serial mass spectrometry based proteomics strategy to investigate if these hypervirulent strains have an altered distribution of virulence proteins across the intracellular, surface associated and secreted bacterial compartments and if any change in compartmentalization can alter the protein-protein interaction network between bacteria and host proteins. Quantitative analysis of the S. pyogenes surface and secreted proteomes revealed that animal passaged strains are associated with significantly higher amount of virulence factors on the bacterial surface and in the media. This altered virulence factor compartmentalization results in increased binding of several mouse plasma proteins to the bacterial surface, a trend that was consistent for mouse plasma from several different mouse strains. In general, both the wild-type strain and animal passaged strain were capable of binding high amounts of human plasma proteins. However, compared to the non-passaged strains, the animal passaged strains displayed an increased ability to bind mouse plasma proteins, in particular for M protein binders, indicating that the increased affinity for mouse blood plasma proteins is a consequence of host adaptation of this pathogen to a new host. In conclusion, plotting the total amount of virulence factors against the total amount of plasma proteins associated to the bacterial surface could clearly separate out animal passaged strains from wild type strains indicating a virulence model that could

  10. Host-derived, pore-forming toxin-like protein and trefoil factor complex protects the host against microbial infection.

    Science.gov (United States)

    Xiang, Yang; Yan, Chao; Guo, Xiaolong; Zhou, Kaifeng; Li, Sheng'an; Gao, Qian; Wang, Xuan; Zhao, Feng; Liu, Jie; Lee, Wen-Hui; Zhang, Yun

    2014-05-06

    Aerolysins are virulence factors belonging to the bacterial β-pore-forming toxin superfamily. Surprisingly, numerous aerolysin-like proteins exist in vertebrates, but their biological functions are unknown. βγ-CAT, a complex of an aerolysin-like protein subunit (two βγ-crystallin domains followed by an aerolysin pore-forming domain) and two trefoil factor subunits, has been identified in frogs (Bombina maxima) skin secretions. Here, we report the rich expression of this protein, in the frog blood and immune-related tissues, and the induction of its presence in peritoneal lavage by bacterial challenge. This phenomena raises the possibility of its involvement in antimicrobial infection. When βγ-CAT was administrated in a peritoneal infection model, it greatly accelerated bacterial clearance and increased the survival rate of both frogs and mice. Meanwhile, accelerated Interleukin-1β release and enhanced local leukocyte recruitments were determined, which may partially explain the robust and effective antimicrobial responses observed. The release of interleukin-1β was potently triggered by βγ-CAT from the frog peritoneal cells and murine macrophages in vitro. βγ-CAT was rapidly endocytosed and translocated to lysosomes, where it formed high molecular mass SDS-stable oligomers (>170 kDa). Lysosomal destabilization and cathepsin B release were detected, which may explain the activation of caspase-1 inflammasome and subsequent interleukin-1β maturation and release. To our knowledge, these results provide the first functional evidence of the ability of a host-derived aerolysin-like protein to counter microbial infection by eliciting rapid and effective host innate immune responses. The findings will also largely help to elucidate the possible involvement and action mechanisms of aerolysin-like proteins and/or trefoil factors widely existing in vertebrates in the host defense against pathogens.

  11. Requirement for Vibrio cholerae Integration Host Factor in Conjugative DNA Transfer

    OpenAIRE

    McLeod, Sarah M.; Burrus, Vincent; Waldor, Matthew K.

    2006-01-01

    The requirement for host factors in the transmission of integrative and conjugative elements (ICEs) has not been extensively explored. Here we tested whether integration host factor (IHF) or Fis, two host-encoded nucleoid proteins, are required for transfer of SXT, a Vibrio cholerae-derived ICE that can be transmitted to many gram-negative species. Fis did not influence the transfer of SXT to or from V. cholerae. In contrast, IHF proved to be required for V. cholerae to act as an SXT donor. I...

  12. A loss of function analysis of host factors influencing Vaccinia virus replication by RNA interference.

    Directory of Open Access Journals (Sweden)

    Philippa M Beard

    Full Text Available Vaccinia virus (VACV is a large, cytoplasmic, double-stranded DNA virus that requires complex interactions with host proteins in order to replicate. To explore these interactions a functional high throughput small interfering RNA (siRNA screen targeting 6719 druggable cellular genes was undertaken to identify host factors (HF influencing the replication and spread of an eGFP-tagged VACV. The experimental design incorporated a low multiplicity of infection, thereby enhancing detection of cellular proteins involved in cell-to-cell spread of VACV. The screen revealed 153 pro- and 149 anti-viral HFs that strongly influenced VACV replication. These HFs were investigated further by comparisons with transcriptional profiling data sets and HFs identified in RNAi screens of other viruses. In addition, functional and pathway analysis of the entire screen was carried out to highlight cellular mechanisms involved in VACV replication. This revealed, as anticipated, that many pro-viral HFs are involved in translation of mRNA and, unexpectedly, suggested that a range of proteins involved in cellular transcriptional processes and several DNA repair pathways possess anti-viral activity. Multiple components of the AMPK complex were found to act as pro-viral HFs, while several septins, a group of highly conserved GTP binding proteins with a role in sequestering intracellular bacteria, were identified as strong anti-viral VACV HFs. This screen has identified novel and previously unexplored roles for cellular factors in poxvirus replication. This advancement in our understanding of the VACV life cycle provides a reliable knowledge base for the improvement of poxvirus-based vaccine vectors and development of anti-viral theraputics.

  13. DMPD: The interferon regulatory factor family in host defense: mechanism of action. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 17502370 The interferon regulatory factor family in host defense: mechanism of acti....html) (.csml) Show The interferon regulatory factor family in host defense: mechanism of action. PubmedID 1...7502370 Title The interferon regulatory factor family in host defense: mechanism

  14. Herpes simplex virus 1 targets the murine olfactory neuroepithelium for host entry.

    Science.gov (United States)

    Shivkumar, Maitreyi; Milho, Ricardo; May, Janet S; Nicoll, Michael P; Efstathiou, Stacey; Stevenson, Philip G

    2013-10-01

    Herpes simplex virus 1 (HSV-1) is a ubiquitous and important human pathogen. It is known to persist in trigeminal ganglia (TG), but how it reaches this site has been difficult to determine, as viral transmission is sporadic, pathogenesis is complicated, and early infection is largely asymptomatic. We used mice to compare the most likely natural HSV-1 host entry routes: oral and nasal. Intranasal infection was 100-fold more efficient than oral and targeted predominantly the olfactory neuroepithelium. Live imaging of HSV-1-expressed luciferase showed infection progressing from the nose to the TG and then reemerging in the facial skin. The brain remained largely luciferase negative throughout. Infected cell tagging by viral Cre recombinase expression in floxed reporter gene mice showed nasal virus routinely reaching the TG and only rarely reaching the olfactory bulbs. Thus, HSV-1 spread from the olfactory neuroepithelium to the TG and reemerged peripherally without causing significant neurological disease. This recapitulation of typical clinical infection suggests that HSV-1 might sometimes also enter humans via the respiratory tract.

  15. Induction of virulence factors in Giardia duodenalis independent of host attachment

    Science.gov (United States)

    Emery, Samantha J.; Mirzaei, Mehdi; Vuong, Daniel; Pascovici, Dana; Chick, Joel M.; Lacey, Ernest; Haynes, Paul A.

    2016-01-01

    Giardia duodenalis is responsible for the majority of parasitic gastroenteritis in humans worldwide. Host-parasite interaction models in vitro provide insights into disease and virulence and help us to understand pathogenesis. Using HT-29 intestinal epithelial cells (IEC) as a model we have demonstrated that initial sensitisation by host secretions reduces proclivity for trophozoite attachment, while inducing virulence factors. Host soluble factors triggered up-regulation of membrane and secreted proteins, including Tenascins, Cathepsin-B precursor, cystatin, and numerous Variant-specific Surface Proteins (VSPs). By comparison, host-cell attached trophozoites up-regulated intracellular pathways for ubiquitination, reactive oxygen species (ROS) detoxification and production of pyridoxal phosphate (PLP). We reason that these results demonstrate early pathogenesis in Giardia involves two independent host-parasite interactions. Motile trophozoites respond to soluble secreted signals, which deter attachment and induce expression of virulence factors. Trophozoites attached to host cells, in contrast, respond by up-regulating intracellular pathways involved in clearance of ROS, thus anticipating the host defence response. PMID:26867958

  16. TAL effectors: highly adaptable phytobacterial virulence factors and readily engineered DNA targeting proteins

    Science.gov (United States)

    Doyle, Erin L.; Stoddard, Barry L.; Voytas, Daniel F.; Bogdanove, Adam J.

    2013-01-01

    Transcription activator-like (TAL) effectors are transcription factors injected into plant cells by pathogenic bacteria in the genus Xanthomonas. They function as virulence factors by activating host genes important for disease, or as avirulence factors by turning on genes that provide resistance. DNA binding specificity is encoded by polymorphic repeats in each protein that correspond one-to-one with different nucleotides. This code has facilitated target identification and opened new avenues for engineering disease resistance. It has also enabled TAL effector customization for targeted gene control, genome editing, and other applications. This article reviews the structural basis for TAL effector-DNA specificity, the impact of the TAL effector-DNA code on plant pathology and engineered resistance, and recent accomplishments and future challenges in TAL effector-based DNA targeting. PMID:23707478

  17. Identification of common biological pathways and drug targets across multiple respiratory viruses based on human host gene expression analysis.

    Directory of Open Access Journals (Sweden)

    Steven B Smith

    Full Text Available Pandemic and seasonal respiratory viruses are a major global health concern. Given the genetic diversity of respiratory viruses and the emergence of drug resistant strains, the targeted disruption of human host-virus interactions is a potential therapeutic strategy for treating multi-viral infections. The availability of large-scale genomic datasets focused on host-pathogen interactions can be used to discover novel drug targets as well as potential opportunities for drug repositioning.In this study, we performed a large-scale analysis of microarray datasets involving host response to infections by influenza A virus, respiratory syncytial virus, rhinovirus, SARS-coronavirus, metapneumonia virus, coxsackievirus and cytomegalovirus. Common genes and pathways were found through a rigorous, iterative analysis pipeline where relevant host mRNA expression datasets were identified, analyzed for quality and gene differential expression, then mapped to pathways for enrichment analysis. Possible repurposed drugs targets were found through database and literature searches. A total of 67 common biological pathways were identified among the seven different respiratory viruses analyzed, representing fifteen laboratories, nine different cell types, and seven different array platforms. A large overlap in the general immune response was observed among the top twenty of these 67 pathways, adding validation to our analysis strategy. Of the top five pathways, we found 53 differentially expressed genes affected by at least five of the seven viruses. We suggest five new therapeutic indications for existing small molecules or biological agents targeting proteins encoded by the genes F3, IL1B, TNF, CASP1 and MMP9. Pathway enrichment analysis also identified a potential novel host response, the Parkin-Ubiquitin Proteasomal System (Parkin-UPS pathway, which is known to be involved in the progression of neurodegenerative Parkinson's disease.Our study suggests that

  18. Making Bunyaviruses Talk: Interrogation Tactics to Identify Host Factors Required for Infection

    Directory of Open Access Journals (Sweden)

    Amber M. Riblett

    2016-05-01

    Full Text Available The identification of host cellular genes that act as either proviral or antiviral factors has been aided by the development of an increasingly large number of high-throughput screening approaches. Here, we review recent advances in which these new technologies have been used to interrogate host genes for the ability to impact bunyavirus infection, both in terms of technical advances as well as a summary of biological insights gained from these studies.

  19. Systems engineering meets quantitative systems pharmacology: from low-level targets to engaging the host defenses.

    Science.gov (United States)

    Androulakis, Ioannis P

    2015-01-01

    Quantitative systems pharmacology aims at systematizing, in a model-based manner, the integration of systems biology and pharmacology in an effort to rationalize the process of assessing the ability of a drug to enhance well-being by off-setting the effects of a disease. Systems engineering, on the other hand, has enabled us to develop principles and methodologies for designing and operating engineered networks of structures exploring the integration of the underlying governing (design) laws. Although the computational tools which have resulted in major advances in the design, analysis, and operation of complex engineered structures have had tremendous success in the analysis of systems pharmacology models, it is argued in this opinion paper, that exploring the underlying conceptual foundation of complex systems engineering will enable us to move toward integrated models at the host level to explore, and possibly, induce synergies between low-level drug targets and higher level, systemic, defense mechanisms. This is an approach which would require refocusing of the key activities; however, it is likely the more promising approach as we enter the new era of personalized and precision medicine. We finally argue for the development of an allostatic approach to quantitative systems pharmacology and the development of an integrated framework for considering drugs in their broader context, beyond their local site of action. WIREs Syst Biol Med 2015, 7:101-112. doi: 10.1002/wsbm.1294 For further resources related to this article, please visit the WIREs website. The author has declared no conflicts of interest for this article. © 2015 Wiley Periodicals, Inc.

  20. Genome-wide transcriptional profiling of Botrytis cinerea genes targeting plant cell walls during infections of different hosts

    Directory of Open Access Journals (Sweden)

    Barbara eBlanco-Ulate

    2014-09-01

    Full Text Available Cell walls are barriers that impair colonization of host tissues, but also are important reservoirs of energy-rich sugars. Growing hyphae of necrotrophic fungal pathogens, such as Botrytis cinerea (Botrytis, henceforth, secrete enzymes that disassemble cell wall polysaccharides. In this work we describe the annotation of 275 putative secreted Carbohydrate-Active enZymes (CAZymes identified in the Botrytis B05.10 genome. Using RNAseq we determined which Botrytis CAZymes were expressed during infections of lettuce leaves, ripe tomato fruit, and grape berries. On the three hosts, Botrytis expressed a common group of 229 potentially secreted CAZymes, including 28 pectin backbone-modifying enzymes, 21 hemicellulose-modifying proteins, 18 enzymes that might target pectin and hemicellulose side-branches, and 16 enzymes predicted to degrade cellulose. The diversity of the Botrytis CAZymes may be partly responsible for its wide host range. Thirty-six candidate CAZymes with secretion signals were found exclusively when Botrytis interacted with ripe tomato fruit and grape berries. Pectin polysaccharides are notably abundant in grape and tomato cell walls, but lettuce leaf walls have less pectin and are richer in hemicelluloses and cellulose. The results of this study not only suggest that Botrytis targets similar wall polysaccharide networks on fruit and leaves, but also that it may selectively attack host wall polysaccharide substrates depending on the host tissue.

  1. Genome-wide transcriptional profiling of Botrytis cinerea genes targeting plant cell walls during infections of different hosts

    Science.gov (United States)

    Blanco-Ulate, Barbara; Morales-Cruz, Abraham; Amrine, Katherine C. H.; Labavitch, John M.; Powell, Ann L. T.; Cantu, Dario

    2014-01-01

    Cell walls are barriers that impair colonization of host tissues, but also are important reservoirs of energy-rich sugars. Growing hyphae of necrotrophic fungal pathogens, such as Botrytis cinerea (Botrytis, henceforth), secrete enzymes that disassemble cell wall polysaccharides. In this work we describe the annotation of 275 putative secreted Carbohydrate-Active enZymes (CAZymes) identified in the Botrytis B05.10 genome. Using RNAseq we determined which Botrytis CAZymes were expressed during infections of lettuce leaves, ripe tomato fruit, and grape berries. On the three hosts, Botrytis expressed a common group of 229 potentially secreted CAZymes, including 28 pectin backbone-modifying enzymes, 21 hemicellulose-modifying proteins, 18 enzymes that might target pectin and hemicellulose side-branches, and 16 enzymes predicted to degrade cellulose. The diversity of the Botrytis CAZymes may be partly responsible for its wide host range. Thirty-six candidate CAZymes with secretion signals were found exclusively when Botrytis interacted with ripe tomato fruit and grape berries. Pectin polysaccharides are notably abundant in grape and tomato cell walls, but lettuce leaf walls have less pectin and are richer in hemicelluloses and cellulose. The results of this study not only suggest that Botrytis targets similar wall polysaccharide networks on fruit and leaves, but also that it may selectively attack host wall polysaccharide substrates depending on the host tissue. PMID:25232357

  2. Host gene targets for novel influenza therapies elucidated by high-throughput RNA interference screens

    CSIR Research Space (South Africa)

    Meliopoulos, VA

    2012-01-01

    Full Text Available Influenza virus encodes only 11 viral proteins but replicates in a broad range of avian and mammalian species by exploiting host cell functions. Genome-wide RNA interference (RNAi) has proven to be a powerful tool for identifying the host molecules...

  3. A Bacterial Pathogen Targets a Host Rab-Family GTPase Defense Pathway with a GAP.

    Science.gov (United States)

    Spanò, Stefania; Gao, Xiang; Hannemann, Sebastian; Lara-Tejero, María; Galán, Jorge E

    2016-02-10

    Cell-autonomous defense mechanisms are potent strategies that protect individual cells against intracellular pathogens. The Rab-family GTPase Rab32 was previously shown to restrict the intracellular human pathogen Salmonella Typhi, but its potential broader role in antimicrobial defense remains unknown. We show that Rab32 represents a general cell-autonomous, antimicrobial defense that is counteracted by two Salmonella effectors. Mice lacking Rab-32 or its nucleotide exchange factor BLOC-3 are permissive to S. Typhi infection and exhibit increased susceptibility to S. Typhimurium. S. Typhimurium counters this defense pathway by delivering two type III secretion effectors, SopD2, a Rab32 GAP, and GtgE, a specific Rab32 protease. An S. Typhimurium mutant strain lacking these two effectors exhibits markedly reduced virulence, which is fully restored in BLOC-3-deficient mice. These results demonstrate that a cell-autonomous, Rab32-dependent host defense pathway plays a central role in the defense against vacuolar pathogens and describe a mechanism evolved by a bacterial pathogen to counter it. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Genome-Wide Chromosomal Targets of Oncogenic Transcription Factors

    National Research Council Canada - National Science Library

    Lyer, Vishwanath R

    2006-01-01

    .... Our work over the past year has successfully identified targets of c-Myc, E2F4 and Stat1, all factors important in breast cancer, and our data supports the idea that it is possible to comprehensively...

  5. Endogenous tissue factor pathway inhibitor has a limited effect on host defence in murine pneumococcal pneumonia

    NARCIS (Netherlands)

    van den Boogaard, Florry E.; van 't Veer, Cornelis; Roelofs, Joris J. T. H.; Meijers, Joost C. M.; Schultz, Marcus J.; Broze, George J.; van der Poll, Tom

    2015-01-01

    Streptococcus (S.) pneumoniae is the most common causative pathogen in community-acquired pneumonia. Coagulation and inflammation interact in the host response to infection. Tissue factor pathway inhibitor (TFPI) is a natural anticoagulant protein that inhibits tissue factor (TF), the main activator

  6. A Computational Drug Repositioning Approach for Targeting Oncogenic Transcription Factors

    OpenAIRE

    Gayvert, Kaitlyn; Dardenne, Etienne; Cheung, Cynthia; Boland, Mary Regina; Lorberbaum, Tal; Wanjala, Jackline; Chen, Yu; Rubin, Mark; Tatonetti, Nicholas P.; Rickman, David; Elemento, Olivier

    2016-01-01

    Mutations in transcription factors (TFs) genes are frequently observed in tumors, often leading to aberrant transcriptional activity. Unfortunately, TFs are often considered undruggable due to the absence of targetable enzymatic activity. To address this problem, we developed CRAFTT, a Computational drug-Repositioning Approach For Targeting Transcription factor activity. CRAFTT combines ChIP-seq with drug-induced expression profiling to identify small molecules that can specifically perturb T...

  7. Dual RNA-Sequencing of Eucalyptus nitens during Phytophthora cinnamomi Challenge Reveals Pathogen and Host Factors Influencing Compatibility.

    Science.gov (United States)

    Meyer, Febé E; Shuey, Louise S; Naidoo, Sitha; Mamni, Thandekile; Berger, Dave K; Myburg, Alexander A; van den Berg, Noëlani; Naidoo, Sanushka

    2016-01-01

    Damage caused by Phytophthora cinnamomi Rands remains an important concern on forest tree species. The pathogen causes root and collar rot, stem cankers, and dieback of various economically important Eucalyptus spp. In South Africa, susceptible cold tolerant Eucalyptus plantations have been affected by various Phytophthora spp. with P. cinnamomi considered one of the most virulent. The molecular basis of this compatible interaction is poorly understood. In this study, susceptible Eucalyptus nitens plants were stem inoculated with P. cinnamomi and tissue was harvested five days post inoculation. Dual RNA-sequencing, a technique which allows the concurrent detection of both pathogen and host transcripts during infection, was performed. Approximately 1% of the reads mapped to the draft genome of P. cinnamomi while 78% of the reads mapped to the Eucalyptus grandis genome. The highest expressed P. cinnamomi gene in planta was a putative crinkler effector (CRN1). Phylogenetic analysis indicated the high similarity of this P. cinnamomi CRN1 to that of Phytophthora infestans. Some CRN effectors are known to target host nuclei to suppress defense. In the host, over 1400 genes were significantly differentially expressed in comparison to mock inoculated trees, including suites of pathogenesis related (PR) genes. In particular, a PR-9 peroxidase gene with a high similarity to a Carica papaya PR-9 ortholog previously shown to be suppressed upon infection by Phytophthora palmivora was down-regulated two-fold. This PR-9 gene may represent a cross-species effector target during P. cinnamomi infection. This study identified pathogenicity factors, potential manipulation targets, and attempted host defense mechanisms activated by E. nitens that contributed to the susceptible outcome of the interaction.

  8. Dual RNA-sequencing of Eucalyptus nitens during Phytophthora cinnamomi challenge reveals pathogen and host factors influencing compatibility

    Directory of Open Access Journals (Sweden)

    Febe Elizabeth Meyer

    2016-03-01

    Full Text Available Damage caused by Phytophthora cinnamomi Rands remains an important concern on forest tree species. The pathogen causes root and collar rot, stem cankers and dieback of various economically important Eucalyptus spp. In South Africa, susceptible cold tolerant Eucalyptus plantations have been affected by various Phytophthora spp. with P. cinnamomi considered one of the most virulent. The molecular basis of this compatible interaction is poorly understood. In this study, susceptible Eucalyptus nitens plants were stem inoculated with P. cinnamomi and tissue was harvested five days post inoculation. Dual RNA-sequencing, a technique which allows the concurrent detection of both pathogen and host transcripts during infection, was performed. Approximately 1% of the reads mapped to the draft genome of P. cinnamomi while 78% of the reads mapped to the Eucalyptus grandis genome. The highest expressed P. cinnamomi gene in planta was a putative crinkler effector (CRN1. Phylogenetic analysis indicated the high similarity of this P. cinnamomi CRN1 to that of Phytophthora infestans. Some CRN effectors are known to target host nuclei to suppress defense. In the host, over 1400 genes were significantly differentially expressed in comparison to mock inoculated trees, including suites of pathogenesis related (PR genes. In particular, a PR-9 peroxidase gene with a high similarity to a Carica papaya PR-9 ortholog previously shown to be suppressed upon infection by Phytophthora palmivora was down-regulated two-fold. This PR-9 gene may represent a cross-species effector target during P. cinnamomi infection. This study identified pathogenicity factors, potential manipulation targets and attempted host defense mechanisms activated by E. nitens that contributed to the susceptible outcome of the interaction.

  9. Citizen science data reveal ecological, historical and evolutionary factors shaping interactions between woody hosts and wood-inhabiting fungi.

    Science.gov (United States)

    Heilmann-Clausen, Jacob; Maruyama, Pietro K; Bruun, Hans Henrik; Dimitrov, Dimitar; Laessøe, Thomas; Frøslev, Tobias Guldberg; Dalsgaard, Bo

    2016-12-01

    Woody plants host diverse communities of associated organisms, including wood-inhabiting fungi. In this group, host effects on species richness and interaction network structure are not well understood, especially not at large geographical scales. We investigated ecological, historical and evolutionary determinants of fungal species richness and network modularity, that is, subcommunity structure, across woody hosts in Denmark, using a citizen science data set comprising > 80 000 records of > 1000 fungal species on 91 genera of woody plants. Fungal species richness was positively related to host size, wood pH, and the number of species in the host genus, with limited influence of host frequency and host history, that is, time since host establishment in the area. Modularity patterns were unaffected by host history, but largely reflected host phylogeny. Notably, fungal communities differed substantially between angiosperm and gymnosperm hosts. Host traits and evolutionary history appear to be more important than host frequency and recent history in structuring interactions between hosts and wood-inhabiting fungi. High wood acidity appears to act as a stress factor reducing fungal species richness, while large host size, providing increased niche diversity, enhances it. In some fungal groups that are known to interact with live host cells in the establishment phase, host selectivity is common, causing a modular community structure. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  10. Design and Construction of a Smart Targeting Drug Delivery System Based on Phototriggered Competition of Host-Guest Interaction.

    Science.gov (United States)

    Zhao, Dan; Yi, Xiaoqing; Yuan, Gongdao; Zhuo, Renxi; Li, Feng

    2017-09-01

    A smart targeting drug delivery nanocarrier is successfully constructed based on phototriggered competition of host-guest interaction. The targeting motif, i.e., biotin is first concealed by β-cyclodextrin (β-CD) via host-guest interaction. When the nanoparticles are exposed to UV light, the cleavage of photosensitive groups results in the exposure of adamantane (Ad) groups initially located in the interior of nanoassemblies, and β-CDs capped on biotin ligands can be replaced by Ad because of the higher binding constant between Ad and β-CD than that between biotin and β-CD. The competition of host-guest interaction leads to the recovery of targeting capacity of biotin ligands on the nanocarriers. By virtue of photoregulation, the nanocarriers exhibit controllable ligand-receptor recognition, which is proved by flow cytometry, laser confocal microscopy, and cytotoxicity assay. This strategy has a potential to improve the selectivity and safety of targeting drug delivery systems. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Yersinia pestis Targets the Host Endosome Recycling Pathway during the Biogenesis of the Yersinia-Containing Vacuole To Avoid Killing by Macrophages

    Science.gov (United States)

    Connor, Michael G.; Pulsifer, Amanda R.; Ceresa, Brian K.

    2018-01-01

    ABSTRACT Yersinia pestis has evolved many strategies to evade the innate immune system. One of these strategies is the ability to survive within macrophages. Upon phagocytosis, Y. pestis prevents phagolysosome maturation and establishes a modified compartment termed the Yersinia-containing vacuole (YCV). Y. pestis actively inhibits the acidification of this compartment, and eventually, the YCV transitions from a tight-fitting vacuole into a spacious replicative vacuole. The mechanisms to generate the YCV have not been defined. However, we hypothesized that YCV biogenesis requires Y. pestis interactions with specific host factors to subvert normal vesicular trafficking. In order to identify these factors, we performed a genome-wide RNA interference (RNAi) screen to identify host factors required for Y. pestis survival in macrophages. This screen revealed that 71 host proteins are required for intracellular survival of Y. pestis. Of particular interest was the enrichment for genes involved in endosome recycling. Moreover, we demonstrated that Y. pestis actively recruits Rab4a and Rab11b to the YCV in a type three secretion system-independent manner, indicating remodeling of the YCV by Y. pestis to resemble a recycling endosome. While recruitment of Rab4a was necessary to inhibit YCV acidification and lysosomal fusion early during infection, Rab11b appeared to contribute to later stages of YCV biogenesis. We also discovered that Y. pestis disrupts global host endocytic recycling in macrophages, possibly through sequestration of Rab11b, and this process is required for bacterial replication. These data provide the first evidence that Y. pestis targets the host endocytic recycling pathway to avoid phagolysosomal maturation and generate the YCV. PMID:29463656

  12. TF Target Mapper: A BLAST search tool for the identification of Transcription Factor target genes

    Directory of Open Access Journals (Sweden)

    van der Spek Peter

    2006-03-01

    Full Text Available Abstract Background In the current era of high throughput genomics a major challenge is the genome-wide identification of target genes for specific transcription factors. Chromatin immunoprecipitation (ChIP allows the isolation of in vivo binding sites of transcription factors and provides a powerful tool for examining gene regulation. Crosslinked chromatin is immunoprecipitated with antibodies against specific transcription factors, thus enriching for sequences bound in vivo by these factors in the immunoprecipitated DNA. Cloning and sequencing the immunoprecipitated sequences allows identification of transcription factor target genes. Routinely, thousands of such sequenced clones are used in BLAST searches to map their exact location in the genome and the genes located in the vicinity. These genes represent potential targets of the transcription factor of interest. Such bioinformatics analysis is very laborious if performed manually and for this reason there is a need for developing bioinformatic tools to automate and facilitate it. Results In order to facilitate this analysis we generated TF Target Mapper (Transcription Factor Target Mapper. TF Target Mapper is a BLAST search tool allowing rapid extraction of annotated information on genes around each hit. It combines sequence cleaning/filtering, pattern searching and BLAST searches with extraction of information on genes located around each BLAST hit and comparisons of the output list of genes or gene ontology IDs with user-implemented lists. We successfully applied and tested TF Target Mapper to analyse sequences bound in vivo by the transcription factor GATA-1. We show that TF Target Mapper efficiently extracted information on genes around ChIPed sequences, thus identifying known (e.g. α-globin and ζ-globin and potentially novel GATA-1 gene targets. Conclusion TF Target Mapper is a very efficient BLAST search tool that allows the rapid extraction of annotated information on the genes

  13. TF Target Mapper: a BLAST search tool for the identification of Transcription Factor target genes.

    NARCIS (Netherlands)

    S. Horsman (Sebastiaan); M.J. Moorhouse (Michael); V. de Jager (Victor); P.J. van der Spek (Peter); F.G. Grosveld (Frank); J. Strouboulis (John); E. Katsantoni (Eleni)

    2006-01-01

    textabstractBACKGROUND: In the current era of high throughput genomics a major challenge is the genome-wide identification of target genes for specific transcription factors. Chromatin immunoprecipitation (ChIP) allows the isolation of in vivo binding sites of transcription factors and provides a

  14. Systems integration of biodefense omics data for analysis of pathogen-host interactions and identification of potential targets.

    Directory of Open Access Journals (Sweden)

    Peter B McGarvey

    2009-09-01

    Full Text Available The NIAID (National Institute for Allergy and Infectious Diseases Biodefense Proteomics program aims to identify targets for potential vaccines, therapeutics, and diagnostics for agents of concern in bioterrorism, including bacterial, parasitic, and viral pathogens. The program includes seven Proteomics Research Centers, generating diverse types of pathogen-host data, including mass spectrometry, microarray transcriptional profiles, protein interactions, protein structures and biological reagents. The Biodefense Resource Center (www.proteomicsresource.org has developed a bioinformatics framework, employing a protein-centric approach to integrate and support mining and analysis of the large and heterogeneous data. Underlying this approach is a data warehouse with comprehensive protein + gene identifier and name mappings and annotations extracted from over 100 molecular databases. Value-added annotations are provided for key proteins from experimental findings using controlled vocabulary. The availability of pathogen and host omics data in an integrated framework allows global analysis of the data and comparisons across different experiments and organisms, as illustrated in several case studies presented here. (1 The identification of a hypothetical protein with differential gene and protein expressions in two host systems (mouse macrophage and human HeLa cells infected by different bacterial (Bacillus anthracis and Salmonella typhimurium and viral (orthopox pathogens suggesting that this protein can be prioritized for additional analysis and functional characterization. (2 The analysis of a vaccinia-human protein interaction network supplemented with protein accumulation levels led to the identification of human Keratin, type II cytoskeletal 4 protein as a potential therapeutic target. (3 Comparison of complete genomes from pathogenic variants coupled with experimental information on complete proteomes allowed the identification and

  15. A Family of Salmonella Type III Secretion Effector Proteins Selectively Targets the NF-κB Signaling Pathway to Preserve Host Homeostasis.

    Science.gov (United States)

    Sun, Hui; Kamanova, Jana; Lara-Tejero, Maria; Galán, Jorge E

    2016-03-01

    Microbial infections usually lead to host innate immune responses and inflammation. These responses most often limit pathogen replication although they can also result in host-tissue damage. The enteropathogenic bacteria Salmonella Typhimurium utilizes a type III secretion system to induce intestinal inflammation by delivering specific effector proteins that stimulate signal transduction pathways resulting in the production of pro-inflammatory cytokines. We show here that a family of related Salmonella Typhimurium effector proteins PipA, GogA and GtgA redundantly target components of the NF-κB signaling pathway to inhibit transcriptional responses leading to inflammation. We show that these effector proteins are proteases that cleave both the RelA (p65) and RelB transcription factors but do not target p100 (NF-κB2) or p105 (NF-κB1). A Salmonella Typhimurium strain lacking these effectors showed increased ability to stimulate NF-κB and increased virulence in an animal model of infection. These results indicate that bacterial pathogens can evolve determinants to preserve host homeostasis and that those determinants can reduce the pathogen's virulence.

  16. Interaction of a Blumeria graminis f. sp. hordei effector candidate with a barley ARF-GAP suggests that host vesicle trafficking is a fungal pathogenicity target.

    Science.gov (United States)

    Schmidt, Sarah M; Kuhn, Hannah; Micali, Cristina; Liller, Corinna; Kwaaitaal, Mark; Panstruga, Ralph

    2014-08-01

    Filamentous phytopathogens, such as fungi and oomycetes, secrete effector proteins to establish successful interactions with their plant hosts. In contrast with oomycetes, little is known about effector functions in true fungi. We used a bioinformatics pipeline to identify Blumeria effector candidates (BECs) from the obligate biotrophic barley powdery mildew pathogen, Blumeria graminis f. sp. hordei (Bgh). BEC1-BEC5 are expressed at different time points during barley infection. BEC1, BEC2 and BEC4 have orthologues in the Arabidopsis thaliana-infecting powdery mildew fungus Golovinomyces orontii. Arabidopsis lines stably expressing the G. orontii BEC2 orthologue, GoEC2, are more susceptible to infection with the non-adapted fungus Erysiphe pisi, suggesting that GoEC2 contributes to powdery mildew virulence. For BEC3 and BEC4, we identified thiopurine methyltransferase, a ubiquitin-conjugating enzyme, and an ADP ribosylation factor-GTPase-activating protein (ARF-GAP) as potential host targets. Arabidopsis knockout lines of the respective HvARF-GAP orthologue (AtAGD5) allowed higher entry levels of E. pisi, but exhibited elevated resistance to the oomycete Hyaloperonospora arabidopsidis. We hypothesize that ARF-GAP proteins are conserved targets of powdery and downy mildew effectors, and we speculate that BEC4 might interfere with defence-associated host vesicle trafficking. © 2013 BSPP AND JOHN WILEY & SONS LTD.

  17. Host MicroRNA miR-197 Plays a Negative Regulatory Role in the Enterovirus 71 Infectious Cycle by Targeting the RAN Protein.

    Science.gov (United States)

    Tang, Wen-Fang; Huang, Ru-Ting; Chien, Kun-Yi; Huang, Jo-Yun; Lau, Kean-Seng; Jheng, Jia-Rong; Chiu, Cheng-Hsun; Wu, Tzong-Yuan; Chen, Chung-Yung; Horng, Jim-Tong

    2016-02-01

    Enterovirus 71 (EV71), a member of Picornaviridae, is associated with severe central nervous system complications. In this study, we identified a cellular microRNA (miRNA), miR-197, whose expression was downregulated by viral infection in a time-dependent manner. In miR-197 mimic-transfected cells, EV71 replication was inhibited, whereas the internal ribosome entry site (IRES) activity was decreased in EV71 strains with or without predicted miR-197 target sites, indicating that miR-197 targets host proteins to modulate viral replication. We thus used a quantitative proteomics approach, aided by the TargetScan algorithm, to identify putative target genes of miR-197. Among them, RAN was selected and validated as a genuine target in a 3' untranslated region (UTR) reporter assay. Reduced production of RAN by RNA interference markedly reduced the synthesis of EV71-encoded viral proteins and virus titers. Furthermore, reintroduction of nondegradable RAN into these knockdown cells rescued viral protein synthesis. miR-197 levels were modulated by EV71 to maintain RAN mRNA translatability at late times postinfection since we demonstrated that cap-independent translation exerted by its intrinsic IRES activity was occurring at times when translation attenuation was induced by EV71. EV71-induced downregulation of miR-197 expression increased the expression of RAN, which supported the nuclear transport of the essential viral proteins 3D/3CD and host protein hnRNP K for viral replication. Our data suggest that downregulation of cellular miRNAs may constitute a newly identified mechanism that sustains the expression of host proteins to facilitate viral replication. Enterovirus 71 (EV71) is a picornavirus with a positive-sense single-stranded RNA that globally inhibits the cellular translational system, mainly by cleaving cellular eukaryotic translation initiation factor 4G (eIF4G) and poly(A)-binding protein (PABP), which inhibits the association of the ribosome with the host

  18. Molecular Mechanisms of Foot-and-Mouth Disease Virus Targeting the Host Antiviral Response

    Directory of Open Access Journals (Sweden)

    Miguel Rodríguez Pulido

    2017-06-01

    Full Text Available Foot-and-mouth disease virus (FMDV is the causative agent of an acute vesicular disease affecting pigs, cattle and other domestic, and wild animals worldwide. The aim of the host interferon (IFN response is to limit viral replication and spread. Detection of the viral genome and products by specialized cellular sensors initiates a signaling cascade that leads to a rapid antiviral response involving the secretion of type I- and type III-IFNs and other antiviral cytokines with antiproliferative and immunomodulatory functions. During co-evolution with their hosts, viruses have acquired strategies to actively counteract host antiviral responses and the balance between innate response and viral antagonism may determine the outcome of disease and pathogenesis. FMDV proteases Lpro and 3C have been found to antagonize the host IFN response by a repertoire of mechanisms. Moreover, the putative role of other viral proteins in IFN antagonism is being recently unveiled, uncovering sophisticated immune evasion strategies different to those reported to date for other members of the Picornaviridae family. Here, we review the interplay between antiviral responses induced by FMDV infection and viral countermeasures to block them. Research on strategies used by viruses to modulate immunity will provide insights into the function of host pathways involved in defense against pathogens and will also lead to development of new therapeutic strategies to fight virus infections.

  19. Respiratory virus modulation of host nucleocytoplasmic transport; target for therapeutic intervention?

    Directory of Open Access Journals (Sweden)

    Leon eCaly

    2015-08-01

    Full Text Available The respiratory diseases caused by Rhinovirus, Respiratory Syncytial Virus and Influenza virus represent a large social and financial burden on healthcare worldwide. Although all three viruses have distinctly unique properties in terms of infection and replication, they share the ability to exploit/manipulate the host-cell nucleocytoplasmic transport system in order to replicate effectively and efficiently. This review outlines the various ways in which infection by these viruses impacts on the host nucleocytoplasmic transport system, and examples where inhibition thereof in turn decreases viral replication. The highly conserved nature of the nucleocytoplasmic transport system and the viral proteins that interact with it make this virus-host interface a prime candidate for the development of specific antiviral therapeutics in the future.

  20. Host-related factors explaining interindividual variability of carotenoid bioavailability and tissue concentrations in humans

    NARCIS (Netherlands)

    Bohn, Torsten; Desmarchelier, Charles; Dragsted, Lars O.; Nielsen, Charlotte S.; Stahl, Wilhelm; Rühl, Ralph; Keijer, Jaap; Borel, Patrick

    2017-01-01

    Carotenoid dietary intake and their endogenous levels have been associated with a decreased risk of several chronic diseases. There are indications that carotenoid bioavailability depends, in addition to the food matrix, on host factors. These include diseases (e.g. colitis), life-style habits (e.g.

  1. The host factor RAD51 is involved in mungbean yellow mosaic India virus (MYMIV) DNA replication.

    Science.gov (United States)

    Suyal, Geetika; Mukherjee, Sunil K; Choudhury, Nirupam R

    2013-09-01

    Geminiviruses replicate their single-stranded genomes with the help of only a few viral factors and various host cellular proteins primarily by rolling-circle replication (RCR) and/or recombination-dependent replication. AtRAD51 has been identified, using the phage display technique, as a host factor that potentially interacts with the Rep protein of mungbean yellow mosaic India virus (MYMIV), a member of the genus Begomovirus. In this study, we demonstrate the interaction between MYMIV Rep and a host factor, AtRAD51, using yeast two-hybrid and β-galactosidase assays, and this interaction was confirmed using a co-immunoprecipitation assay. The AtRAD51 protein complemented the rad51∆ mutation of Saccharomyces cerevisiae in an ex vivo yeast-based geminivirus DNA replication restoration assay. The semiquantitative RT-PCR and northern hybridization data revealed a higher level of expression of the Rad51 transcript in MYMIV-infected mungbean than in uninfected, healthy plants. Our findings provide evidence for a possible cross-talk between RAD51 and MYMIV Rep, which essentially controls viral DNA replication in plants, presumably in conjunction with other host factors. The present study demonstrates for the first time the involvement of a eukaryotic RAD51 protein in MYMIV replication, and this is expected to shed light on the machinery involved in begomovirus DNA replication.

  2. GRP78 Is an Important Host Factor for Japanese Encephalitis Virus Entry and Replication in Mammalian Cells.

    Science.gov (United States)

    Nain, Minu; Mukherjee, Sriparna; Karmakar, Sonali Porey; Paton, Adrienne W; Paton, James C; Abdin, M Z; Basu, Anirban; Kalia, Manjula; Vrati, Sudhanshu

    2017-03-15

    Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is the leading cause of viral encephalitis in Southeast Asia with potential to become a global pathogen. Here, we identify glucose-regulated protein 78 (GRP78) as an important host protein for virus entry and replication. Using the plasma membrane fractions from mouse neuronal (Neuro2a) cells, mass spectroscopy analysis identified GRP78 as a protein interacting with recombinant JEV envelope protein domain III. GRP78 was found to be expressed on the plasma membranes of Neuro2a cells, mouse primary neurons, and human epithelial Huh-7 cells. Antibodies against GRP78 significantly inhibited JEV entry in all three cell types, suggesting an important role of the protein in virus entry. Depletion of GRP78 by small interfering RNA (siRNA) significantly blocked JEV entry into Neuro2a cells, further supporting its role in virus uptake. Immunofluorescence studies showed extensive colocalization of GRP78 with JEV envelope protein in virus-infected cells. This interaction was also confirmed by immunoprecipitation studies. Additionally, GRP78 was shown to have an important role in JEV replication, as treatment of cells post-virus entry with subtilase cytotoxin that specifically cleaved GRP78 led to a substantial reduction in viral RNA replication and protein synthesis, resulting in significantly reduced extracellular virus titers. Our results indicate that GRP78, an endoplasmic reticulum chaperon of the HSP70 family, is a novel host factor involved at multiple steps of the JEV life cycle and could be a potential therapeutic target. IMPORTANCE Recent years have seen a rapid spread of mosquito-borne diseases caused by flaviviruses. The flavivirus family includes West Nile, dengue, Japanese encephalitis, and Zika viruses, which are major threats to public health with potential to become global pathogens. JEV is the major cause of viral encephalitis in several parts of Southeast Asia, affecting a predominantly pediatric

  3. Identification and Initial Characterization of the Effectors of an Anther Smut Fungus and Potential Host Target Proteins

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    Venkata S. Kuppireddy

    2017-11-01

    Full Text Available (1 Background: Plant pathogenic fungi often display high levels of host specificity and biotrophic fungi; in particular, they must manipulate their hosts to avoid detection and to complete their obligate pathogenic lifecycles. One important strategy of such fungi is the secretion of small proteins that serve as effectors in this process. Microbotryum violaceum is a species complex whose members infect members of the Caryophyllaceae; M. lychnidis-dioicae, a parasite on Silene latifolia, is one of the best studied interactions. We are interested in identifying and characterizing effectors of the fungus and possible corresponding host targets; (2 Methods: In silico analysis of the M. lychnidis-dioicae genome and transcriptomes allowed us to predict a pool of small secreted proteins (SSPs with the hallmarks of effectors, including a lack of conserved protein family (PFAM domains and also localized regions of disorder. Putative SSPs were tested for secretion using a yeast secretion trap method. We then used yeast two-hybrid analyses for candidate-secreted effectors to probe a cDNA library from a range of growth conditions of the fungus, including infected plants; (3 Results: Roughly 50 SSPs were identified by in silico analysis. Of these, 4 were studied further and shown to be secreted, as well as examined for potential host interactors. One of the putative effectors, MVLG_01732, was found to interact with Arabidopsis thaliana calcium-dependent lipid binding protein (AtCLB and with cellulose synthase interactive protein 1 orthologues; and (4 Conclusions: The identification of a pool of putative effectors provides a resource for functional characterization of fungal proteins that mediate the delicate interaction between pathogen and host. The candidate targets of effectors, e.g., AtCLB, involved in pollen germination suggest tantalizing insights that could drive future studies.

  4. Pneumococcal penumonia presenting with septic shock: host-ant pathogen-related factors and outcomes

    OpenAIRE

    García Vidal, Carolina; Ardanuy Tisaire, María Carmen; Tubau, Fe; Viasus, Diego; Dorca i Sargatal, Jordi; Liñares Louzao, Josefina; Gudiol i Munté, Francesc; Carratalà, Jordi

    2009-01-01

    BACKGROUND: Host- and pathogen-related factors associated with septic shock in pneumococcal pneumonia are not well defined. The aim of this study was to identify risk factors for septic shock and to ascertain patient outcomes. Serotypes, genotypes and antibiotic resistance of isolated strains were also analysed. METHODS: Observational analysis of a prospective cohort of non-severely immunosuppressed hospitalised adults with pneumococcal pneumonia. Septic shock was defined as a systolic blood ...

  5. Requirement for Vibrio cholerae integration host factor in conjugative DNA transfer.

    Science.gov (United States)

    McLeod, Sarah M; Burrus, Vincent; Waldor, Matthew K

    2006-08-01

    The requirement for host factors in the transmission of integrative and conjugative elements (ICEs) has not been extensively explored. Here we tested whether integration host factor (IHF) or Fis, two host-encoded nucleoid proteins, are required for transfer of SXT, a Vibrio cholerae-derived ICE that can be transmitted to many gram-negative species. Fis did not influence the transfer of SXT to or from V. cholerae. In contrast, IHF proved to be required for V. cholerae to act as an SXT donor. In the absence of IHF, V. cholerae displayed a modest defect for serving as an SXT recipient. Surprisingly, SXT integration into or excision from the V. cholerae chromosome, which requires an SXT-encoded integrase related to lambda integrase, did not require IHF. Therefore, the defect in SXT transmission in the V. cholerae IHF mutant is probably not related to IHF's ability to promote DNA recombination. The V. cholerae IHF mutant was also highly impaired as a donor of RP4, a broad-host-range conjugative plasmid. Thus, the V. cholerae IHF mutant appears to have a general defect in conjugation. Escherichia coli IHF mutants were not impaired as donors or recipients of SXT or RP4, indicating that IHF is a V. cholerae-specific conjugation factor.

  6. The interactomes of influenza virus NS1 and NS2 proteins identify new host factors and provide insights for ADAR1 playing a supportive role in virus replication.

    Science.gov (United States)

    de Chassey, Benoît; Aublin-Gex, Anne; Ruggieri, Alessia; Meyniel-Schicklin, Laurène; Pradezynski, Fabrine; Davoust, Nathalie; Chantier, Thibault; Tafforeau, Lionel; Mangeot, Philippe-Emmanuel; Ciancia, Claire; Perrin-Cocon, Laure; Bartenschlager, Ralf; André, Patrice; Lotteau, Vincent

    2013-01-01

    Influenza A NS1 and NS2 proteins are encoded by the RNA segment 8 of the viral genome. NS1 is a multifunctional protein and a virulence factor while NS2 is involved in nuclear export of viral ribonucleoprotein complexes. A yeast two-hybrid screening strategy was used to identify host factors supporting NS1 and NS2 functions. More than 560 interactions between 79 cellular proteins and NS1 and NS2 proteins from 9 different influenza virus strains have been identified. These interacting proteins are potentially involved in each step of the infectious process and their contribution to viral replication was tested by RNA interference. Validation of the relevance of these host cell proteins for the viral replication cycle revealed that 7 of the 79 NS1 and/or NS2-interacting proteins positively or negatively controlled virus replication. One of the main factors targeted by NS1 of all virus strains was double-stranded RNA binding domain protein family. In particular, adenosine deaminase acting on RNA 1 (ADAR1) appeared as a pro-viral host factor whose expression is necessary for optimal viral protein synthesis and replication. Surprisingly, ADAR1 also appeared as a pro-viral host factor for dengue virus replication and directly interacted with the viral NS3 protein. ADAR1 editing activity was enhanced by both viruses through dengue virus NS3 and influenza virus NS1 proteins, suggesting a similar virus-host co-evolution.

  7. The interactomes of influenza virus NS1 and NS2 proteins identify new host factors and provide insights for ADAR1 playing a supportive role in virus replication.

    Directory of Open Access Journals (Sweden)

    Benoît de Chassey

    Full Text Available Influenza A NS1 and NS2 proteins are encoded by the RNA segment 8 of the viral genome. NS1 is a multifunctional protein and a virulence factor while NS2 is involved in nuclear export of viral ribonucleoprotein complexes. A yeast two-hybrid screening strategy was used to identify host factors supporting NS1 and NS2 functions. More than 560 interactions between 79 cellular proteins and NS1 and NS2 proteins from 9 different influenza virus strains have been identified. These interacting proteins are potentially involved in each step of the infectious process and their contribution to viral replication was tested by RNA interference. Validation of the relevance of these host cell proteins for the viral replication cycle revealed that 7 of the 79 NS1 and/or NS2-interacting proteins positively or negatively controlled virus replication. One of the main factors targeted by NS1 of all virus strains was double-stranded RNA binding domain protein family. In particular, adenosine deaminase acting on RNA 1 (ADAR1 appeared as a pro-viral host factor whose expression is necessary for optimal viral protein synthesis and replication. Surprisingly, ADAR1 also appeared as a pro-viral host factor for dengue virus replication and directly interacted with the viral NS3 protein. ADAR1 editing activity was enhanced by both viruses through dengue virus NS3 and influenza virus NS1 proteins, suggesting a similar virus-host co-evolution.

  8. Borrelia host adaptation Regulator (BadR) regulates rpoS to modulate host adaptation and virulence factors in Borrelia burgdorferi

    OpenAIRE

    Miller, Christine L.; Rajasekhar Karna, S. L.; Seshu, J.

    2013-01-01

    The RpoS transcription factor of Borrelia burgdorferi is a “gatekeeper” because it activates genes required for spirochetes to transition from tick to vertebrate hosts. However, it remains unknown how RpoS becomes repressed to allow the spirochetes to transition back from the vertebrate host to the tick vector. Here we show that a putative carbohydrate-responsive regulatory protein, designated BadR (Borrelia host adaptation Regulator), is a transcriptional repressor of rpoS. BadR levels are e...

  9. Seneca Valley Virus Suppresses Host Type I Interferon Production by Targeting Adaptor Proteins MAVS, TRIF, and TANK for Cleavage.

    Science.gov (United States)

    Qian, Suhong; Fan, Wenchun; Liu, Tingting; Wu, Mengge; Zhang, Huawei; Cui, Xiaofang; Zhou, Yun; Hu, Junjie; Wei, Shaozhong; Chen, Huanchun; Li, Xiangmin; Qian, Ping

    2017-08-15

    Seneca Valley virus (SVV) is an oncolytic RNA virus belonging to the Picornaviridae family. Its nucleotide sequence is highly similar to those of members of the Cardiovirus genus. SVV is also a neuroendocrine cancer-selective oncolytic picornavirus that can be used for anticancer therapy. However, the interaction between SVV and its host is yet to be fully characterized. In this study, SVV inhibited antiviral type I interferon (IFN) responses by targeting different host adaptors, including mitochondrial antiviral signaling (MAVS), Toll/interleukin 1 (IL-1) receptor domain-containing adaptor inducing IFN-β (TRIF), and TRAF family member-associated NF-κB activator (TANK), via viral 3C protease (3C pro ). SVV 3C pro mediated the cleavage of MAVS, TRIF, and TANK at specific sites, which required its protease activity. The cleaved MAVS, TRIF, and TANK lost the ability to regulate pattern recognition receptor (PRR)-mediated IFN production. The cleavage of TANK also facilitated TRAF6-induced NF-κB activation. SVV was also found to be sensitive to IFN-β. Therefore, SVV suppressed antiviral IFN production to escape host antiviral innate immune responses by cleaving host adaptor molecules. IMPORTANCE Host cells have developed various defenses against microbial pathogen infection. The production of IFN is the first line of defense against microbial infection. However, viruses have evolved many strategies to disrupt this host defense. SVV, a member of the Picornavirus genus, is an oncolytic virus that shows potential functions in anticancer therapy. It has been demonstrated that IFN can be used in anticancer therapy for certain tumors. However, the relationship between oncolytic virus and innate immune response in anticancer therapy is still not well known. In this study, we showed that SVV has evolved as an effective mechanism to inhibit host type I IFN production by using its 3C pro to cleave the molecules MAVS, TRIF, and TANK directly. These molecules are crucial for

  10. Effects of Host Plant Factors on the Bacterial Communities Associated with Two Whitefly Sibling Species.

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    Ming-Ming Su

    Full Text Available Although discrepancy in the specific traits and ecological characteristics of Bemisia tabaci between species are partially attributed to the B. tabaci-associated bacteria, the factors that affect the diversity of B. tabaci-associated bacteria are not well-understood. We used the metagenomic approach to characterize the B. tabaci-associated bacterial community because the approach is an effective tool to identify the bacteria.To investigate the effects of the host plant and a virus, tomato yellow leaf curl virus (TYLCV, on the bacterial communities of B. tabaci sibling species B and Q, we analyzed the bacterial communities associated with whitefly B and Q collected from healthy cotton, healthy tomato, and TYLCV-infected tomato. The analysis used miseq-based sequencing of a variable region of the bacterial 16S rDNA gene. For the bacteria associated with B. tabaci, we found that the influence of the host plant species was greater than that of the whitefly cryptic species. With further analysis of host plants infected with the TYLCV, the virus had no significant effects on the B. tabaci-associated bacterial community.The effects of different plant hosts and TYLCV-infection on the diversity of B. tabaci-associated bacterial communities were successfully analyzed in this study. To explain why B. tabaci sibling species with different host ranges differ in performance, the analysis of the bacterial community may be essential to the explanation.

  11. Effects of Host Plant Factors on the Bacterial Communities Associated with Two Whitefly Sibling Species.

    Science.gov (United States)

    Su, Ming-Ming; Guo, Lei; Tao, Yun-Li; Zhang, You-Jun; Wan, Fang-Hao; Chu, Dong

    2016-01-01

    Although discrepancy in the specific traits and ecological characteristics of Bemisia tabaci between species are partially attributed to the B. tabaci-associated bacteria, the factors that affect the diversity of B. tabaci-associated bacteria are not well-understood. We used the metagenomic approach to characterize the B. tabaci-associated bacterial community because the approach is an effective tool to identify the bacteria. To investigate the effects of the host plant and a virus, tomato yellow leaf curl virus (TYLCV), on the bacterial communities of B. tabaci sibling species B and Q, we analyzed the bacterial communities associated with whitefly B and Q collected from healthy cotton, healthy tomato, and TYLCV-infected tomato. The analysis used miseq-based sequencing of a variable region of the bacterial 16S rDNA gene. For the bacteria associated with B. tabaci, we found that the influence of the host plant species was greater than that of the whitefly cryptic species. With further analysis of host plants infected with the TYLCV, the virus had no significant effects on the B. tabaci-associated bacterial community. The effects of different plant hosts and TYLCV-infection on the diversity of B. tabaci-associated bacterial communities were successfully analyzed in this study. To explain why B. tabaci sibling species with different host ranges differ in performance, the analysis of the bacterial community may be essential to the explanation.

  12. Host factors that promote retrotransposon integration are similar in distantly related eukaryotes.

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    Sudhir Kumar Rai

    2017-12-01

    Full Text Available Retroviruses and Long Terminal Repeat (LTR-retrotransposons have distinct patterns of integration sites. The oncogenic potential of retrovirus-based vectors used in gene therapy is dependent on the selection of integration sites associated with promoters. The LTR-retrotransposon Tf1 of Schizosaccharomyces pombe is studied as a model for oncogenic retroviruses because it integrates into the promoters of stress response genes. Although integrases (INs encoded by retroviruses and LTR-retrotransposons are responsible for catalyzing the insertion of cDNA into the host genome, it is thought that distinct host factors are required for the efficiency and specificity of integration. We tested this hypothesis with a genome-wide screen of host factors that promote Tf1 integration. By combining an assay for transposition with a genetic assay that measures cDNA recombination we could identify factors that contribute differentially to integration. We utilized this assay to test a collection of 3,004 S. pombe strains with single gene deletions. Using these screens and immunoblot measures of Tf1 proteins, we identified a total of 61 genes that promote integration. The candidate integration factors participate in a range of processes including nuclear transport, transcription, mRNA processing, vesicle transport, chromatin structure and DNA repair. Two candidates, Rhp18 and the NineTeen complex were tested in two-hybrid assays and were found to interact with Tf1 IN. Surprisingly, a number of pathways we identified were found previously to promote integration of the LTR-retrotransposons Ty1 and Ty3 in Saccharomyces cerevisiae, indicating the contribution of host factors to integration are common in distantly related organisms. The DNA repair factors are of particular interest because they may identify the pathways that repair the single stranded gaps flanking the sites of strand transfer following integration of LTR retroelements.

  13. Host transcription factors in the immediate pro-inflammatory response to the parasitic mite Psoroptes ovis.

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    Stewart T G Burgess

    Full Text Available BACKGROUND: Sheep scab, caused by infestation with the ectoparasitic mite Psoroptes ovis, results in the rapid development of cutaneous inflammation and leads to the crusted skin lesions characteristic of the disease. We described previously the global host transcriptional response to infestation with P. ovis, elucidating elements of the inflammatory processes which lead to the development of a rapid and profound immune response. However, the mechanisms by which this response is instigated remain unclear. To identify novel methods of intervention a better understanding of the early events involved in triggering the immune response is essential. The objective of this study was to gain a clearer understanding of the mechanisms and signaling pathways involved in the instigation of the immediate pro-inflammatory response. RESULTS: Through a combination of transcription factor binding site enrichment and pathway analysis we identified key roles for a number of transcription factors in the instigation of cutaneous inflammation. In particular, defined roles were elucidated for the transcription factors NF-kB and AP-1 in the orchestration of the early pro-inflammatory response, with these factors being implicated in the activation of a suite of inflammatory mediators. CONCLUSIONS: Interrogation of the host temporal response to P. ovis infestation has enabled the further identification of the mechanisms underlying the development of the immediate host pro-inflammatory response. This response involves key regulatory roles for the transcription factors NF-kB and AP-1. Pathway analysis demonstrated that the activation of these transcription factors may be triggered following a host LPS-type response, potentially involving TLR4-signalling and also lead to the intriguing possibility that this could be triggered by a P. ovis allergen.

  14. Host factors that promote retrotransposon integration are similar in distantly related eukaryotes.

    Science.gov (United States)

    Rai, Sudhir Kumar; Sangesland, Maya; Lee, Michael; Esnault, Caroline; Cui, Yujin; Chatterjee, Atreyi Ghatak; Levin, Henry L

    2017-12-01

    Retroviruses and Long Terminal Repeat (LTR)-retrotransposons have distinct patterns of integration sites. The oncogenic potential of retrovirus-based vectors used in gene therapy is dependent on the selection of integration sites associated with promoters. The LTR-retrotransposon Tf1 of Schizosaccharomyces pombe is studied as a model for oncogenic retroviruses because it integrates into the promoters of stress response genes. Although integrases (INs) encoded by retroviruses and LTR-retrotransposons are responsible for catalyzing the insertion of cDNA into the host genome, it is thought that distinct host factors are required for the efficiency and specificity of integration. We tested this hypothesis with a genome-wide screen of host factors that promote Tf1 integration. By combining an assay for transposition with a genetic assay that measures cDNA recombination we could identify factors that contribute differentially to integration. We utilized this assay to test a collection of 3,004 S. pombe strains with single gene deletions. Using these screens and immunoblot measures of Tf1 proteins, we identified a total of 61 genes that promote integration. The candidate integration factors participate in a range of processes including nuclear transport, transcription, mRNA processing, vesicle transport, chromatin structure and DNA repair. Two candidates, Rhp18 and the NineTeen complex were tested in two-hybrid assays and were found to interact with Tf1 IN. Surprisingly, a number of pathways we identified were found previously to promote integration of the LTR-retrotransposons Ty1 and Ty3 in Saccharomyces cerevisiae, indicating the contribution of host factors to integration are common in distantly related organisms. The DNA repair factors are of particular interest because they may identify the pathways that repair the single stranded gaps flanking the sites of strand transfer following integration of LTR retroelements.

  15. Phylogenetic diversity and host specialization of Corynespora cassiicola responsible for emerging target spot disease of cotton and other crops in the southeastern United States.

    Science.gov (United States)

    Sumabat, Leilani; Kemerait, Robert C; Brewer, Marin Talbot

    2018-02-13

    Corynespora cassiicola is a ubiquitous fungus causing emerging plant diseases worldwide, including target spot of cotton, soybean, and tomato, which have rapidly increased in incidence and severity throughout the southeastern United States. The objectives of this study were to understand the causes for the emerging target spot epidemics in the U.S. by comparing phylogenetic relationships of isolates from cotton, tomato, soybean, and other crop plants and ornamental hosts, and through the determination of the host range of isolates from emerging populations. Fifty-three isolates were sampled from plants in the southeastern U.S. and 1,380 nucleotides from four nuclear loci were sequenced. Additionally, sequences of the same loci from twenty-three isolates representing each of the distinct lineages of C. cassiicola described from previous studies were included. Isolates clustered based on host of origin, irrespective of the geographic location of sampling. There was no genetic diversity detected among isolates from cotton, which were genetically distinct from isolates from other host species. Furthermore, pathogenicity and virulence assays of 40 isolates from various hosts onto cotton, soybean, tomato, and cucumber showed that isolates from cotton were more aggressive to cotton than those from other hosts. Soybean and tomato were most susceptible to isolates that originated from the same host, providing evidence of host specialization. These results suggest that emerging target spot epidemics in the U.S. are caused by either the introduction of host-specific isolates or the evolution of more aggressive lineages on each host.

  16. Alzheimer’s disease: Risk factors and therapeutic targets

    Directory of Open Access Journals (Sweden)

    Laxman Pokhrel

    2015-09-01

    Full Text Available Alzheimer’s disease (AD, a neurodegenerative disorder, has been determined as an outcome of genetic as well as behavioral conditions. The complete understanding of its generation and progress is yet to be understood. However, there has been a significant progress in the diagnosis and identification of the associated risk factors of AD. Several of the risk factors were found connected with cholesterol. Scientists are mainly focusing on the reduction of amyloid β and stabilization of tau protein towards the development of its drugs. To modulate amyloid β, the key components of cholesterol metabolism have been attractive targets and the enzymes involved in the phosphorylation of tau have been tried to stabilize tau protein. This review article briefly highlights the symptoms, risk factors, and drug targets of AD.

  17. Targeting chitinase gene of Helicoverpa armigera by host-induced RNA interference confers insect resistance in tobacco and tomato.

    Science.gov (United States)

    Mamta; Reddy, K R K; Rajam, M V

    2016-02-01

    Helicoverpa armigera Hübner (Lepidoptera: Noctuidae) is a devastating agricultural insect pest with broad spectrum of host range, causing million dollars crop loss annually. Limitations in the present conventional and transgenic approaches have made it crucial to develop sustainable and environmental friendly methods for crop improvement. In the present study, host-induced RNA interference (HI-RNAi) approach was used to develop H. armigera resistant tobacco and tomato plants. Chitinase (HaCHI) gene, critically required for insect molting and metamorphosis was selected as a potential target. Hair-pin RNAi construct was prepared from the conserved off-target free partial HaCHI gene sequence and was used to generate several HaCHI-RNAi tobacco and tomato plants. Northern hybridization confirmed the production of HaCHI gene-specific siRNAs in HaCHI-RNAi tobacco and tomato lines. Continuous feeding on leaves of RNAi lines drastically reduced the target gene transcripts and consequently, affected the overall growth and survival of H. armigera. Various developmental deformities were also manifested in H. armigera larvae after feeding on the leaves of RNAi lines. These results demonstrated the role of chitinase in insect development and potential of HI-RNAi for effective management of H. armigera.

  18. Human subtilase SKI-1/S1P is a master regulator of the HCV Lifecycle and a potential host cell target for developing indirect-acting antiviral agents.

    Science.gov (United States)

    Olmstead, Andrea D; Knecht, Wolfgang; Lazarov, Ina; Dixit, Surjit B; Jean, François

    2012-01-01

    HCV infection is a major risk factor for liver cancer and liver transplantation worldwide. Overstimulation of host lipid metabolism in the liver by HCV-encoded proteins during viral infection creates a favorable environment for virus propagation and pathogenesis. In this study, we hypothesize that targeting cellular enzymes acting as master regulators of lipid homeostasis could represent a powerful approach to developing a novel class of broad-spectrum antivirals against infection associated with human Flaviviridae viruses such as hepatitis C virus (HCV), whose assembly and pathogenesis depend on interaction with lipid droplets (LDs). One such master regulator of cholesterol metabolic pathways is the host subtilisin/kexin-isozyme-1 (SKI-1)--or site-1 protease (S1P). SKI-1/S1P plays a critical role in the proteolytic activation of sterol regulatory element binding proteins (SREBPs), which control expression of the key enzymes of cholesterol and fatty-acid biosynthesis. Here we report the development of a SKI-1/S1P-specific protein-based inhibitor and its application to blocking the SREBP signaling cascade. We demonstrate that SKI-1/S1P inhibition effectively blocks HCV from establishing infection in hepatoma cells. The inhibitory mechanism is associated with a dramatic reduction in the abundance of neutral lipids, LDs, and the LD marker: adipose differentiation-related protein (ADRP)/perilipin 2. Reduction of LD formation inhibits virus assembly from infected cells. Importantly, we confirm that SKI-1/S1P is a key host factor for HCV infection by using a specific active, site-directed, small-molecule inhibitor of SKI-1/S1P: PF-429242. Our studies identify SKI-1/S1P as both a novel regulator of the HCV lifecycle and as a potential host-directed therapeutic target against HCV infection and liver steatosis. With identification of an increasing number of human viruses that use host LDs for infection, our results suggest that SKI-1/S1P inhibitors may allow development of

  19. Human subtilase SKI-1/S1P is a master regulator of the HCV Lifecycle and a potential host cell target for developing indirect-acting antiviral agents.

    Directory of Open Access Journals (Sweden)

    Andrea D Olmstead

    2012-01-01

    Full Text Available HCV infection is a major risk factor for liver cancer and liver transplantation worldwide. Overstimulation of host lipid metabolism in the liver by HCV-encoded proteins during viral infection creates a favorable environment for virus propagation and pathogenesis. In this study, we hypothesize that targeting cellular enzymes acting as master regulators of lipid homeostasis could represent a powerful approach to developing a novel class of broad-spectrum antivirals against infection associated with human Flaviviridae viruses such as hepatitis C virus (HCV, whose assembly and pathogenesis depend on interaction with lipid droplets (LDs. One such master regulator of cholesterol metabolic pathways is the host subtilisin/kexin-isozyme-1 (SKI-1--or site-1 protease (S1P. SKI-1/S1P plays a critical role in the proteolytic activation of sterol regulatory element binding proteins (SREBPs, which control expression of the key enzymes of cholesterol and fatty-acid biosynthesis. Here we report the development of a SKI-1/S1P-specific protein-based inhibitor and its application to blocking the SREBP signaling cascade. We demonstrate that SKI-1/S1P inhibition effectively blocks HCV from establishing infection in hepatoma cells. The inhibitory mechanism is associated with a dramatic reduction in the abundance of neutral lipids, LDs, and the LD marker: adipose differentiation-related protein (ADRP/perilipin 2. Reduction of LD formation inhibits virus assembly from infected cells. Importantly, we confirm that SKI-1/S1P is a key host factor for HCV infection by using a specific active, site-directed, small-molecule inhibitor of SKI-1/S1P: PF-429242. Our studies identify SKI-1/S1P as both a novel regulator of the HCV lifecycle and as a potential host-directed therapeutic target against HCV infection and liver steatosis. With identification of an increasing number of human viruses that use host LDs for infection, our results suggest that SKI-1/S1P inhibitors may allow

  20. Drug-Target Interaction Prediction with Graph Regularized Matrix Factorization.

    Science.gov (United States)

    Ezzat, Ali; Zhao, Peilin; Wu, Min; Li, Xiao-Li; Kwoh, Chee-Keong

    2017-01-01

    Experimental determination of drug-target interactions is expensive and time-consuming. Therefore, there is a continuous demand for more accurate predictions of interactions using computational techniques. Algorithms have been devised to infer novel interactions on a global scale where the input to these algorithms is a drug-target network (i.e., a bipartite graph where edges connect pairs of drugs and targets that are known to interact). However, these algorithms had difficulty predicting interactions involving new drugs or targets for which there are no known interactions (i.e., "orphan" nodes in the network). Since data usually lie on or near to low-dimensional non-linear manifolds, we propose two matrix factorization methods that use graph regularization in order to learn such manifolds. In addition, considering that many of the non-occurring edges in the network are actually unknown or missing cases, we developed a preprocessing step to enhance predictions in the "new drug" and "new target" cases by adding edges with intermediate interaction likelihood scores. In our cross validation experiments, our methods achieved better results than three other state-of-the-art methods in most cases. Finally, we simulated some "new drug" and "new target" cases and found that GRMF predicted the left-out interactions reasonably well.

  1. Use of model plant hosts to identify Pseudomonas aeruginosa virulence factors

    Science.gov (United States)

    Rahme, Laurence G.; Tan, Man-Wah; Le, Long; Wong, Sandy M.; Tompkins, Ronald G.; Calderwood, Stephen B.; Ausubel, Frederick M.

    1997-01-01

    We used plants as an in vivo pathogenesis model for the identification of virulence factors of the human opportunistic pathogen Pseudomonas aeruginosa. Nine of nine TnphoA mutant derivatives of P. aeruginosa strain UCBPP-PA14 that were identified in a plant leaf assay for less pathogenic mutants also exhibited significantly reduced pathogenicity in a burned mouse pathogenicity model, suggesting that P. aeruginosa utilizes common strategies to infect both hosts. Seven of these nine mutants contain TnphoA insertions in previously unknown genes. These results demonstrate that an alternative nonvertebrate host of a human bacterial pathogen can be used in an in vivo high throughput screen to identify novel bacterial virulence factors involved in mammalian pathogenesis. PMID:9371831

  2. DAF as a therapeutic target for steroid hormones: implications for host-pathogen interactions.

    Science.gov (United States)

    Nowicki, Bogdan; Nowicki, Stella

    2013-01-01

    In this chapter, we present a concise historic prospective and a summary of accumulated knowledge on steroid hormones, DAF expression, and therapeutic implication of steroid hormone treatment on multiple pathologies, including infection and the host-pathogen interactions. DAF/CD55 plays multiple physiologic functions including tissue protection from the cytotoxic complement injury, an anti-inflammatory function due to its anti-adherence properties which enhance transmigration of monocytes and macrophages and reduce tissue injury. DAF physiologic functions are essential in many organ systems including pregnancy for protection of the semiallogeneic fetus or for preventing uncontrolled infiltration by white cells in their pro- and/or anti-inflammatory functions. DAF expression appears to have multiple regulatory tissue-specific and/or menstrual cycle-specific mechanisms, which involve complex signaling mechanisms. Regulation of DAF expression may involve a direct or an indirect effect of at least the estrogen, progesterone, and corticosteroid regulatory pathways. DAF is exploited in multiple pathologic conditions by pathogens and viruses in chronic tissue infection processes. The binding of Escherichia coli bearing Dr adhesins to the DAF/CD55 receptor is DAF density dependent and triggers internalization of E. coli via an endocytic pathway involving CD55, lipid rafts, and microtubules. Dr+ E. coli or Dr antigen may persist in vivo in the interstitium for several months. Further understanding of such processes should be instrumental in designing therapeutic strategies for multiple conditions involving DAF's protective or pathologic functions and tailoring host expression of DAF.

  3. Genome-wide CRISPR screen reveals novel host factors required for Staphylococcus aureus α-hemolysin-mediated toxicity.

    Science.gov (United States)

    Virreira Winter, Sebastian; Zychlinsky, Arturo; Bardoel, Bart W

    2016-04-12

    Staphylococcus aureus causes a wide variety of infections and antibiotic resistant strains are a major problem in hospitals. One of the best studied virulence factors of S. aureus is the pore-forming toxin alpha hemolysin (αHL) whose mechanism of action is incompletely understood. We performed a genome-wide loss-of-function screen using CRISPR/Cas9 technology to identify host targets required for αHL susceptibility in human myeloid cells. We found gRNAs for ten genes enriched after intoxication with αHL and focused on the top five hits. Besides a disintegrin and metalloproteinase domain-containing protein 10 (ADAM10), the host receptor for αHL, we identified three proteins, Sys1 golgi trafficking protein (SYS1), ADP-ribosylation factor 1 (ARFRP1), and tetraspanin-14 (TSPAN14) which regulate the presentation of ADAM10 on the plasma membrane post-translationally. Interestingly, we also showed that cells lacking sphingomyelin synthase 1 (SGMS1) resist αHL intoxication, but have only a slightly reduced ADAM10 surface expression. SGMS1 regulates lipid raft formation, suggesting that αHL requires these membrane microdomains for attachment and cytotoxicity.

  4. MAMs are attractive targets for bacterial repurposing of the host cell: MAM-functions might be key for undermining an infected cell.

    Science.gov (United States)

    Escoll, Pedro; Rolando, Monica; Buchrieser, Carmen

    2017-02-01

    Pathogenic bacteria frequently target the endoplasmic reticulum (ER) and mitochondria in order to exploit host functions. ER-mitochondria inter-organelle communication is topologically sub-compartmentalized at mitochondria-associated ER membranes (MAMs). MAMs are specific membranous microdomains with unique regulatory functions such as lipid synthesis and trafficking, calcium homeostasis, mitochondrial morphology, inflammasome activation, autophagosome formation, and apoptosis. These important cellular processes are all modulated by pathogens to subvert host functions and promote infection, thus it is tempting to assume that pathogenic bacteria target MAMs to subvert these different pathways in their hosts. First lines of evidence that support this hypothesis come from Legionella pneumophila. This intracellular bacterium secretes an effector that exhibits sphingosine-1 phosphate lyase activity (LpSpl) that seems to target MAMs to modulate the autophagy response to infection. Here we thus propose the concept that MAMs could be targeted by pathogenic bacteria to undermine key host cellular processes. © 2016 WILEY Periodicals, Inc.

  5. Gut Microbiome and Infant Health: Brain-Gut-Microbiota Axis and Host Genetic Factors.

    Science.gov (United States)

    Cong, Xiaomei; Xu, Wanli; Romisher, Rachael; Poveda, Samantha; Forte, Shaina; Starkweather, Angela; Henderson, Wendy A

    2016-09-01

    The development of the neonatal gut microbiome is influenced by multiple factors, such as delivery mode, feeding, medication use, hospital environment, early life stress, and genetics. The dysbiosis of gut microbiota persists during infancy, especially in high-risk preterm infants who experience lengthy stays in the Neonatal intensive care unit (NICU). Infant microbiome evolutionary trajectory is essentially parallel with the host (infant) neurodevelopmental process and growth. The role of the gut microbiome, the brain-gut signaling system, and its interaction with the host genetics have been shown to be related to both short and long term infant health and bio-behavioral development. The investigation of potential dysbiosis patterns in early childhood is still lacking and few studies have addressed this host-microbiome co-developmental process. Further research spanning a variety of fields of study is needed to focus on the mechanisms of brain-gut-microbiota signaling system and the dynamic host-microbial interaction in the regulation of health, stress and development in human newborns.

  6. Host Factors and Biomarkers Associated with Poor Outcomes in Adults with Invasive Pneumococcal Disease.

    Directory of Open Access Journals (Sweden)

    Shigeo Hanada

    Full Text Available Invasive pneumococcal disease (IPD causes considerable morbidity and mortality. We aimed to identify host factors and biomarkers associated with poor outcomes in adult patients with IPD in Japan, which has a rapidly-aging population.In a large-scale surveillance study of 506 Japanese adults with IPD, we investigated the role of host factors, disease severity, biomarkers based on clinical laboratory data, treatment regimens, and bacterial factors on 28-day mortality.Overall mortality was 24.1%, and the mortality rate increased from 10.0% in patients aged ˂50 years to 33.1% in patients aged ≥80 years. Disease severity also increased 28-day mortality, from 12.5% among patients with bacteraemia without sepsis to 35.0% in patients with severe sepsis and 56.9% with septic shock. The death rate within 48 hours after admission was high at 54.9%. Risk factors for mortality identified by multivariate analysis were as follows: white blood cell (WBC count <4000 cells/μL (odds ratio [OR], 6.9; 95% confidence interval [CI], 3.7-12.8, p < .001; age ≥80 years (OR, 6.5; 95% CI, 2.0-21.6, p = .002; serum creatinine ≥2.0 mg/dL (OR, 4.5; 95% CI, 2.5-8.1, p < .001; underlying liver disease (OR, 3.5; 95% CI, 1.6-7.8, p = .002; mechanical ventilation (OR, 3.0; 95% CI, 1.7-5.6, p < .001; and lactate dehydrogenase ≥300 IU/L (OR, 2.4; 95% CI, 1.4-4.0, p = .001. Pneumococcal serotype and drug resistance were not associated with poor outcomes.Host factors, disease severity, and biomarkers, especially WBC counts and serum creatinine, were more important determinants of mortality than bacterial factors.

  7. The Rewiring of Ubiquitination Targets in a Pathogenic Yeast Promotes Metabolic Flexibility, Host Colonization and Virulence.

    Directory of Open Access Journals (Sweden)

    Delma S Childers

    2016-04-01

    Full Text Available Efficient carbon assimilation is critical for microbial growth and pathogenesis. The environmental yeast Saccharomyces cerevisiae is "Crabtree positive", displaying a rapid metabolic switch from the assimilation of alternative carbon sources to sugars. Following exposure to sugars, this switch is mediated by the transcriptional repression of genes (carbon catabolite repression and the turnover (catabolite inactivation of enzymes involved in the assimilation of alternative carbon sources. The pathogenic yeast Candida albicans is Crabtree negative. It has retained carbon catabolite repression mechanisms, but has undergone posttranscriptional rewiring such that gluconeogenic and glyoxylate cycle enzymes are not subject to ubiquitin-mediated catabolite inactivation. Consequently, when glucose becomes available, C. albicans can continue to assimilate alternative carbon sources alongside the glucose. We show that this metabolic flexibility promotes host colonization and virulence. The glyoxylate cycle enzyme isocitrate lyase (CaIcl1 was rendered sensitive to ubiquitin-mediated catabolite inactivation in C. albicans by addition of a ubiquitination site. This mutation, which inhibits lactate assimilation in the presence of glucose, reduces the ability of C. albicans cells to withstand macrophage killing, colonize the gastrointestinal tract and cause systemic infections in mice. Interestingly, most S. cerevisiae clinical isolates we examined (67% have acquired the ability to assimilate lactate in the presence of glucose (i.e. they have become Crabtree negative. These S. cerevisiae strains are more resistant to macrophage killing than Crabtree positive clinical isolates. Moreover, Crabtree negative S. cerevisiae mutants that lack Gid8, a key component of the Glucose-Induced Degradation complex, are more resistant to macrophage killing and display increased virulence in immunocompromised mice. Thus, while Crabtree positivity might impart a fitness

  8. Factors influencing the policy responses of host governments to mass refugee influxes.

    Science.gov (United States)

    Jacobsen, K

    1996-01-01

    "The policy responses of asylum governments to mass influxes of refugees have varied considerably. Focusing on less developed countries, this article explores why some host governments respond in relatively generous ways, while other governments act more restrictively. The policy alternatives available to receiving governments are classified, and a set of factors influencing refugee policy formation is explored. These factors include: the costs and benefits of accepting international assistance, relations with the sending country, political calculations about the local community's absorption capacity, and national security considerations." excerpt

  9. Energy transfer between a nanosystem and its host fluid: A multiscale factorization approach

    International Nuclear Information System (INIS)

    Sereda, Yuriy V.; Espinosa-Duran, John M.; Ortoleva, Peter J.

    2014-01-01

    Energy transfer between a macromolecule or supramolecular assembly and a host medium is considered from the perspective of Newton's equations and Lie-Trotter factorization. The development starts by demonstrating that the energy of the molecule evolves slowly relative to the time scale of atomic collisions-vibrations. The energy is envisioned to be a coarse-grained variable that coevolves with the rapidly fluctuating atomistic degrees of freedom. Lie-Trotter factorization is shown to be a natural framework for expressing this coevolution. A mathematical formalism and workflow for efficient multiscale simulation of energy transfer is presented. Lactoferrin and human papilloma virus capsid-like structure are used for validation

  10. In silico design of fragment-based drug targeting host processing α-glucosidase i for dengue fever

    Science.gov (United States)

    Toepak, E. P.; Tambunan, U. S. F.

    2017-02-01

    Dengue is a major health problem in the tropical and sub-tropical regions. The development of antiviral that targeting dengue’s host enzyme can be more effective and efficient treatment than the viral enzyme. Host enzyme processing α-glucosidase I has an important role in the maturation process of dengue virus envelope glycoprotein. The inhibition of processing α-glucosidase I can become a promising target for dengue fever treatment. The antiviral approach using in silico fragment-based drug design can generate drug candidates with high binding affinity. In this research, 198.621 compounds were obtained from ZINC15 Biogenic Database. These compounds were screened to find the favorable fragments according to Rules of Three and pharmacological properties. The screening fragments were docked into the active site of processing α-glucosidase I. The potential fragment candidates from the molecular docking simulation were linked with castanospermine (CAST) to generate ligands with a better binding affinity. The Analysis of ligand - enzyme interaction showed ligands with code LRS 22, 28, and 47 have the better binding free energy than the standard ligand. Ligand LRS 28 (N-2-4-methyl-5-((1S,3S,6S,7R,8R,8aR)-1,6,7,8-tetrahydroxyoctahydroindolizin-3-yl) pentyl) indolin-1-yl) propionamide) itself among the other ligands has the lowest binding free energy. Pharmacological properties prediction also showed the ligands LRS 22, 28, and 47 can be promising as the dengue fever drug candidates.

  11. Transgenic Bt rice does not challenge host preference of the target pest of rice leaffolder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae.

    Directory of Open Access Journals (Sweden)

    Xiao Sun

    Full Text Available BACKGROUND: Transgenic Bt rice line T2A-1 expresses a synthesized cry2A gene that shows high resistance to Lepidoptera pests, including Cnaphalocrocis medinalis (Guenée (Lepidoptera: Pyralidae. Plant volatile orientation cues and the physical characteristics of the leaf surface play key roles in host location or host-plant acceptance of phytophagous insects. These volatile compounds and physical traits may become altered in Bt rice and it is not known whether this influences the behavior of C. medinalis when searching for oviposition sites. RESULTS: The results of electronic nose analysis showed that the Radar map of Bt rice cultivars was analogous to the non- Bt rice cultivars at each growing stage. PCA analysis was able to partly discriminate between some of the Bt vs. non-Bt rice sensors, but could not to separate Bt cultivars from non-Bt cultivars. The total ion chromatogram between Bt and non-Bt rice cultivars at the seedling, booting and tillering stages were similar and 25 main compounds were identified by GC-MS. For most compounds, there was no significant difference in compound quantities between Bt and non-Bt rice cultivars at equivalent growth stages. The densities of the tubercle papicles and the trichomes on the upper and lower surfaces were statistically equal in Bt and non-Bt rice. The target pest, C. medinalis, was attracted to host rice plants, but it could not distinguish between the transgenic and the isogenic rice lines. CONCLUSIONS: There were no significant differences between the Bt rice line, T2A-1 and the non-Bt rice for volatiles produced or in its physical characteristics and there were no negative impacts on C. medinalis oviposition behavior. These results add to the mounting evidence that Bt rice has no negative impact on the target insect oviposition behavior.

  12. Transgenic Bt Rice Does Not Challenge Host Preference of the Target Pest of Rice Leaffolder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae)

    Science.gov (United States)

    Sun, Xiao; Zhou, Wen; Liu, Hao; Zhang, Aijun; Ai, Chao-Ren; Zhou, Shuang-Shuang; Zhou, Chang-Xiang; Wang, Man-Qun

    2013-01-01

    Background Transgenic Bt rice line T2A-1 expresses a synthesized cry2A gene that shows high resistance to Lepidoptera pests, including Cnaphalocrocis medinalis (Guenée) (Lepidoptera: Pyralidae). Plant volatile orientation cues and the physical characteristics of the leaf surface play key roles in host location or host-plant acceptance of phytophagous insects. These volatile compounds and physical traits may become altered in Bt rice and it is not known whether this influences the behavior of C. medinalis when searching for oviposition sites. Results The results of electronic nose analysis showed that the Radar map of Bt rice cultivars was analogous to the non- Bt rice cultivars at each growing stage. PCA analysis was able to partly discriminate between some of the Bt vs. non-Bt rice sensors, but could not to separate Bt cultivars from non-Bt cultivars. The total ion chromatogram between Bt and non-Bt rice cultivars at the seedling, booting and tillering stages were similar and 25 main compounds were identified by GC-MS. For most compounds, there was no significant difference in compound quantities between Bt and non-Bt rice cultivars at equivalent growth stages. The densities of the tubercle papicles and the trichomes on the upper and lower surfaces were statistically equal in Bt and non-Bt rice. The target pest, C. medinalis, was attracted to host rice plants, but it could not distinguish between the transgenic and the isogenic rice lines. Conclusions There were no significant differences between the Bt rice line, T2A-1 and the non-Bt rice for volatiles produced or in its physical characteristics and there were no negative impacts on C. medinalis oviposition behavior. These results add to the mounting evidence that Bt rice has no negative impact on the target insect oviposition behavior. PMID:24244410

  13. Time resolved bovine host reponse to virulence factors mapped in milk by selected reaction monitoring

    DEFF Research Database (Denmark)

    Bislev, Stine Lønnerup; Kusebauch, Ulrike; Codrea, Marius Cosmin

    in milk samples from cows challenged with peptidoglycan (PGN) from the gram-positive bacteria Staphylococcus aureus and lipopolysaccharide (LPS) from the gram-negative bacteria Escherichia coli for 54 hours. This method allowed for the first time a thorough proteome analysis of the time-resolved response...... to gram-positive and gram-negative cell wall components. The results demonstrated that the extent of protein regulation is much larger after challenge with LPS than with PGN underpinning the growing evidence that gram-negative bacteria cause a far more acute host response than gram-positive bacteria......TIME RESOLVED BOVINE HOST RESPONSE TO VIRULENCE FACTORS, MAPPED IN MILK BY SELECTED REACTION MONITORING S.L. Bislev1, U. Kusebauch2, M.C. Codrea1, R. Moritz2, C.M. Røntved1, E. Bendixen1 1 Department of Animal Science, Faculty of Science and Technology, Aarhus University, Tjele, Denmark; 2...

  14. Host-Country Related Risk Factors in International Construction: Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Güzin AYDOGAN

    2014-09-01

    Full Text Available Internationalization has been on the agenda of construction firms as a strategic option in global competition. Due to globalization every sector including the construction industry has faced with high levels of competitiveness, uncertainty, and risk. International construction involves common risks to domestic construction, as well as risks that are related to the host country. These risks have serious effects on the performance of international projects. Since the sustainable competitiveness of international contractors depends largely on the effective management of these risks, their assessment becomes vital for the success of international contractors. The main aim of this study is to analyse the risks for international construction projects that are related to the host country. Meta-analysis technique is used in order to determine these risks. This paper, therefore, reviews the literature that has been published in four most respected construction and management journals, these being; Journal of Construction Engineering and Management, Journal of Management in Engineering, Construction Management and Economics, and International Journal of Project Management for the period of 2000-2010. International construction risk assessment models are also reviewed within the context of this study, since host country related risk factors were found to have serious effects on the profitability of international contractors due to literature review. As a result; political stability, law and regulations, exchange rate risk, cultural differences, inflation, expropriation, tax discrimination, language barrier, bribery and corruption, force majeure, and societal conflicts in the host country are found to be the most important risk factors in international construction. Findings of this study can be used in risk assessment models for international construction projects.

  15. Factors affecting patterns of Amblyomma triste (Acari: Ixodidae) parasitism in a rodent host.

    Science.gov (United States)

    Colombo, Valeria C; Nava, Santiago; Antoniazzi, Leandro R; Monje, Lucas D; Racca, Andrea L; Guglielmone, Alberto A; Beldomenico, Pablo M

    2015-07-30

    Here we offer a multivariable analysis that explores associations of different factors (i.e., environmental, host parameters, presence of other ectoparasites) with the interaction of Amblyomma triste immature stages and one of its main hosts in Argentina, the rodent Akodon azarae. Monthly and for two years, we captured and sampled rodents at 16 points located at 4 different sites in the Parana River Delta region. The analyses were conducted with Generalized Linear Mixed Models with a negative binomial response (counts of larvae or nymphs). The independent variables assessed were: (a) environmental: trapping year, season, presence of cattle; type of vegetation (natural grassland or implanted forest); rodent abundance; (b) host parameters: body length; sex; body condition; blood cell counts; natural antibody titres; and (c) co-infestation with other ectoparasites: other stage of A. triste; Ixodes loricatus; lice; mites; and fleas. Two-way interaction terms deemed a priori as relevant were also included in the analysis. Larvae were affected by all environmental variables assessed and by the presence of other ectoparasites (lice, fleas and other tick species). Host factors significantly associated with larval count were sex and levels of natural antibodies. Nymphs were associated with season, presence of cattle, body condition, body length and with burdens of I. loricatus. In most cases, the direction and magnitude of the associations were context-dependent (many interaction terms were significant). The findings of greater significance and implications of our study are two. Firstly, as burdens of A. triste larvae and nymphs were greater where cattle were present, and larval tick burdens were higher in implanted forests, silvopastoral practices developing in the region may affect the population dynamics of A. triste, and consequently the eco-epidemiology of Rickettsia parkeri. Secondly, strong associations and numerous interactions with other ectoparasites suggest that

  16. Classifying transcription factor targets and discovering relevant biological features

    Directory of Open Access Journals (Sweden)

    DeLisi Charles

    2008-05-01

    Full Text Available Abstract Background An important goal in post-genomic research is discovering the network of interactions between transcription factors (TFs and the genes they regulate. We have previously reported the development of a supervised-learning approach to TF target identification, and used it to predict targets of 104 transcription factors in yeast. We now include a new sequence conservation measure, expand our predictions to include 59 new TFs, introduce a web-server, and implement an improved ranking method to reveal the biological features contributing to regulation. The classifiers combine 8 genomic datasets covering a broad range of measurements including sequence conservation, sequence overrepresentation, gene expression, and DNA structural properties. Principal Findings (1 Application of the method yields an amplification of information about yeast regulators. The ratio of total targets to previously known targets is greater than 2 for 11 TFs, with several having larger gains: Ash1(4, Ino2(2.6, Yaf1(2.4, and Yap6(2.4. (2 Many predicted targets for TFs match well with the known biology of their regulators. As a case study we discuss the regulator Swi6, presenting evidence that it may be important in the DNA damage response, and that the previously uncharacterized gene YMR279C plays a role in DNA damage response and perhaps in cell-cycle progression. (3 A procedure based on recursive-feature-elimination is able to uncover from the large initial data sets those features that best distinguish targets for any TF, providing clues relevant to its biology. An analysis of Swi6 suggests a possible role in lipid metabolism, and more specifically in metabolism of ceramide, a bioactive lipid currently being investigated for anti-cancer properties. (4 An analysis of global network properties highlights the transcriptional network hubs; the factors which control the most genes and the genes which are bound by the largest set of regulators. Cell-cycle and

  17. Structure-Based Modification of a Clostridium difficile-Targeting Endolysin Affects Activity and Host Range▿

    Science.gov (United States)

    Mayer, Melinda J.; Garefalaki, Vasiliki; Spoerl, Rebecca; Narbad, Arjan; Meijers, Rob

    2011-01-01

    Endolysin CD27L causes cell lysis of the pathogen Clostridium difficile, a major cause of nosocomial infection. We report a structural and functional analysis of the catalytic activity of CD27L against C. difficile and other bacterial strains. We show that truncation of the endolysin to the N-terminal domain, CD27L1–179, gave an increased lytic activity against cells of C. difficile, while the C-terminal region, CD27L180–270, failed to produce lysis. CD27L1–179 also has increased activity against other bacterial species that are targeted by the full-length protein and in addition was able to lyse some CD27L-insensitive strains. However, CD27L1–179 retained a measure of specificity, failing to lyse a wide range of bacteria. The use of green fluorescent protein (GFP)-labeled proteins demonstrated that both CD27L and CD27L1–179 bound to C. difficile cell walls. The crystal structure of CD27L1–179 confirms that the enzyme is a zinc-dependent N-acetylmuramoyl-l-alanine amidase. A structure-based sequence analysis allowed us to identify four catalytic residues, a proton relay cascade, and a substrate binding pocket. A BLAST search shows that the closest-related amidases almost exclusively target Clostridia. This implied that the catalytic domain alone contained features that target a specific bacterial species. To test this hypothesis, we modified Leu 98 to a Trp residue which is found in an endolysin from a bacteriophage of Listeria monocytogenes (PlyPSA). This mutation in CD27L resulted in an increased activity against selected serotypes of L. monocytogenes, demonstrating the potential to tune the species specificity of the catalytic domain of an endolysin. PMID:21803993

  18. Structure-based modification of a Clostridium difficile-targeting endolysin affects activity and host range.

    Science.gov (United States)

    Mayer, Melinda J; Garefalaki, Vasiliki; Spoerl, Rebecca; Narbad, Arjan; Meijers, Rob

    2011-10-01

    Endolysin CD27L causes cell lysis of the pathogen Clostridium difficile, a major cause of nosocomial infection. We report a structural and functional analysis of the catalytic activity of CD27L against C. difficile and other bacterial strains. We show that truncation of the endolysin to the N-terminal domain, CD27L1-179, gave an increased lytic activity against cells of C. difficile, while the C-terminal region, CD27L180-270, failed to produce lysis. CD27L1-179 also has increased activity against other bacterial species that are targeted by the full-length protein and in addition was able to lyse some CD27L-insensitive strains. However, CD27L1-179 retained a measure of specificity, failing to lyse a wide range of bacteria. The use of green fluorescent protein (GFP)-labeled proteins demonstrated that both CD27L and CD27L1-179 bound to C. difficile cell walls. The crystal structure of CD27L1-179 confirms that the enzyme is a zinc-dependent N-acetylmuramoyl-l-alanine amidase. A structure-based sequence analysis allowed us to identify four catalytic residues, a proton relay cascade, and a substrate binding pocket. A BLAST search shows that the closest-related amidases almost exclusively target Clostridia. This implied that the catalytic domain alone contained features that target a specific bacterial species. To test this hypothesis, we modified Leu 98 to a Trp residue which is found in an endolysin from a bacteriophage of Listeria monocytogenes (PlyPSA). This mutation in CD27L resulted in an increased activity against selected serotypes of L. monocytogenes, demonstrating the potential to tune the species specificity of the catalytic domain of an endolysin.

  19. Viral small interfering RNAs target host genes to mediate disease symptoms in plants.

    Directory of Open Access Journals (Sweden)

    Neil A Smith

    2011-05-01

    Full Text Available The Cucumber mosaic virus (CMV Y-satellite RNA (Y-Sat has a small non-protein-coding RNA genome that induces yellowing symptoms in infected Nicotiana tabacum (tobacco. How this RNA pathogen induces such symptoms has been a longstanding question. We show that the yellowing symptoms are a result of small interfering RNA (siRNA-directed RNA silencing of the chlorophyll biosynthetic gene, CHLI. The CHLI mRNA contains a 22-nucleotide (nt complementary sequence to the Y-Sat genome, and in Y-Sat-infected plants, CHLI expression is dramatically down-regulated. Small RNA sequencing and 5' RACE analyses confirmed that this 22-nt sequence was targeted for mRNA cleavage by Y-Sat-derived siRNAs. Transformation of tobacco with a RNA interference (RNAi vector targeting CHLI induced Y-Sat-like symptoms. In addition, the symptoms of Y-Sat infection can be completely prevented by transforming tobacco with a silencing-resistant variant of the CHLI gene. These results suggest that siRNA-directed silencing of CHLI is solely responsible for the Y-Sat-induced symptoms. Furthermore, we demonstrate that two Nicotiana species, which do not develop yellowing symptoms upon Y-Sat infection, contain a single nucleotide polymorphism within the siRNA-targeted CHLI sequence. This suggests that the previously observed species specificity of Y-Sat-induced symptoms is due to natural sequence variation in the CHLI gene, preventing CHLI silencing in species with a mismatch to the Y-Sat siRNA. Taken together, these findings provide the first demonstration of small RNA-mediated viral disease symptom production and offer an explanation of the species specificity of the viral disease.

  20. Expression profile of host restriction factors in HIV-1 elite controllers.

    Science.gov (United States)

    Abdel-Mohsen, Mohamed; Raposo, Rui André Saraiva; Deng, Xutao; Li, Manqing; Liegler, Teri; Sinclair, Elizabeth; Salama, Mohamed S; Ghanem, Hussam El-Din A; Hoh, Rebecca; Wong, Joseph K; David, Michael; Nixon, Douglas F; Deeks, Steven G; Pillai, Satish K

    2013-10-16

    Several host-encoded antiviral factors suppress HIV-1 replication in a cell-autonomous fashion in vitro. The relevance of these defenses to the control of HIV-1 in vivo remains to be elucidated. We hypothesized that cellular restriction of HIV-1 replication plays a significant role in the observed suppression of HIV-1 in "elite controllers", individuals who maintain undetectable levels of viremia in the absence of antiretroviral therapy (ART). We comprehensively compared the expression levels of 34 host restriction factors and cellular activation levels in CD4+ T cells and sorted T cell subsets between elite controllers, HIV-1-infected (untreated) non-controllers, ART-suppressed, and uninfected individuals. Expression of schlafen 11, a codon usage-based inhibitor of HIV-1 protein synthesis, was significantly elevated in CD4+ T cells from elite controllers as compared to both non-controllers (p = 0.048) and ART-suppressed individuals (p = 0.024), with this effect most apparent in central memory CD4+ T cells. Schlafen 11 expression levels were comparable between controllers and uninfected individuals. Cumulative restriction factor expression was positively correlated with CD4+ T cell activation (r² = 0.597, p < 0.0001), viral load (r² = 0.34, p = 0.015), and expression of ISG15 (r² = 0.73, p < 0.0001), a marker of interferon exposure. APOBEC3C, APOBEC3D, CTR9, TRIM26, and TRIM32 were elevated in elite controllers with respect to ART-suppressed individuals, while levels were comparable to uninfected individuals and non-controllers. Host restriction factor expression typically scales with cellular activation levels. However, the elevated mRNA and protein expression of schlafen 11, despite low activation and viral load, violates the global pattern and may be a signature characteristic of HIV-1 elite control.

  1. Targeted Cancer Therapy with Tumor Necrosis Factor-Alpha

    Directory of Open Access Journals (Sweden)

    Weibo Cai Ph.D.

    2008-01-01

    Full Text Available Tumor necrosis factor-alpha (TNF-α, a member of the TNF superfamily, was the first cytokine to be evaluated for cancer biotherapy. However, the clinical use of TNF-α is severely limited by its toxicity. Currently, TNF-α is administered only through locoregional drug delivery systems such as isolated limb perfusion and isolated hepatic perfusion. To reduce the systemic toxicity of TNF-α, various strategies have been explored over the last several decades. This review summarizes current state-of-the-art targeted cancer therapy using TNF-α. Passive targeting, cell-based therapy, gene therapy with inducible or tissue-specific promoters, targeted polymer-DNA complexes, tumor pre-targeting, antibody-TNF-α conjugate, scFv/TNF-α fusion proteins, and peptide/TNF-α fusion proteins have all been investigated to combat cancer. Many of these agents are already in advanced clinical trials. Molecular imaging, which can significantly speed up the drug development process, and nanomedicine, which can integrate both imaging and therapeutic components, has the potential to revolutionize future cancer patient management. Cooperative efforts from scientists within multiple disciplines, as well as close partnerships among many organizations/entities, are needed to quickly translate novel TNF-α-based therapeutics into clinical investigation.

  2. The Respiratory Pathogen Moraxella catarrhalis Targets Collagen for Maximal Adherence to Host Tissues

    Directory of Open Access Journals (Sweden)

    Birendra Singh

    2016-03-01

    Full Text Available Moraxella catarrhalis is a human respiratory pathogen that causes acute otitis media in children and is associated with exacerbations in patients suffering from chronic obstructive pulmonary disease (COPD. The first step in M. catarrhalis colonization is adherence to the mucosa, epithelial cells, and extracellular matrix (ECM. The objective of this study was to evaluate the role of M. catarrhalis interactions with collagens from various angles. Clinical isolates (n = 43 were tested for collagen binding, followed by a detailed analysis of protein-protein interactions using recombinantly expressed proteins. M. catarrhalis-dependent interactions with collagen produced by human lung fibroblasts and tracheal tissues were studied by utilizing confocal immunohistochemistry and high-resolution scanning electron microscopy. A mouse smoke-induced chronic obstructive pulmonary disease (COPD model was used to estimate the adherence of M. catarrhalis in vivo. We found that all M. catarrhalis clinical isolates tested adhered to fibrillar collagen types I, II, and III and network-forming collagens IV and VI. The trimeric autotransporter adhesins ubiquitous surface protein A2 (UspA2 and UspA2H were identified as major collagen-binding receptors. M. catarrhalis wild type adhered to human tracheal tissue and collagen-producing lung fibroblasts, whereas UspA2 and UspA2H deletion mutants did not. Moreover, in the COPD mouse model, bacteria devoid of UspA2 and UspA2H had a reduced level of adherence to the respiratory tract compared to the adherence of wild-type bacteria. Our data therefore suggest that the M. catarrhalis UspA2 and UspA2H-dependent interaction with collagens is highly critical for adherence in the host and, furthermore, may play an important role in the establishment of disease.

  3. A Computational Drug Repositioning Approach for Targeting Oncogenic Transcription Factors

    Directory of Open Access Journals (Sweden)

    Kaitlyn M. Gayvert

    2016-06-01

    Full Text Available Mutations in transcription factor (TF genes are frequently observed in tumors, often leading to aberrant transcriptional activity. Unfortunately, TFs are often considered undruggable due to the absence of targetable enzymatic activity. To address this problem, we developed CRAFTT, a computational drug-repositioning approach for targeting TF activity. CRAFTT combines ChIP-seq with drug-induced expression profiling to identify small molecules that can specifically perturb TF activity. Application to ENCODE ChIP-seq datasets revealed known drug-TF interactions, and a global drug-protein network analysis supported these predictions. Application of CRAFTT to ERG, a pro-invasive, frequently overexpressed oncogenic TF, predicted that dexamethasone would inhibit ERG activity. Dexamethasone significantly decreased cell invasion and migration in an ERG-dependent manner. Furthermore, analysis of electronic medical record data indicates a protective role for dexamethasone against prostate cancer. Altogether, our method provides a broadly applicable strategy for identifying drugs that specifically modulate TF activity.

  4. Targeting the epidermal growth factor receptor in solid tumor malignancies

    DEFF Research Database (Denmark)

    Nedergaard, Mette K; Hedegaard, Chris J; Poulsen, Hans S

    2012-01-01

    to the extracellular part of EGFR, blocking the binding sites for the EGFR ligands, and intracellular tyrosine kinase inhibitors (TKIs) that block the ATP binding site of the tyrosine kinase domain. Besides an EGFRvIII-targeted vaccine, conjugated anti-EGFR mAbs have been used in different settings to deliver lethal......The epidermal growth factor receptor (EGFR) is over-expressed, as well as mutated, in many types of cancers. In particular, the EGFR variant type III mutant (EGFRvIII) has attracted much attention as it is frequently and exclusively found on many tumor cells, and hence both EGFR and EGFRvIII have...... been proposed as valid targets in many cancer therapy settings. Different strategies have been developed in order to either inhibit EGFR/EGFRvIII activity or to ablate EGFR/EGFRvIII-positive tumor cells. Drugs that inhibit these receptors include monoclonal antibodies (mAbs) that bind...

  5. An Interferon Regulated MicroRNA Provides Broad Cell-Intrinsic Antiviral Immunity through Multihit Host-Directed Targeting of the Sterol Pathway.

    Directory of Open Access Journals (Sweden)

    Kevin A Robertson

    2016-03-01

    Full Text Available In invertebrates, small interfering RNAs are at the vanguard of cell-autonomous antiviral immunity. In contrast, antiviral mechanisms initiated by interferon (IFN signaling predominate in mammals. Whilst mammalian IFN-induced miRNA are known to inhibit specific viruses, it is not known whether host-directed microRNAs, downstream of IFN-signaling, have a role in mediating broad antiviral resistance. By performing an integrative, systematic, global analysis of RNA turnover utilizing 4-thiouridine labeling of newly transcribed RNA and pri/pre-miRNA in IFN-activated macrophages, we identify a new post-transcriptional viral defense mechanism mediated by miR-342-5p. On the basis of ChIP and site-directed promoter mutagenesis experiments, we find the synthesis of miR-342-5p is coupled to the antiviral IFN response via the IFN-induced transcription factor, IRF1. Strikingly, we find miR-342-5p targets mevalonate-sterol biosynthesis using a multihit mechanism suppressing the pathway at different functional levels: transcriptionally via SREBF2, post-transcriptionally via miR-33, and enzymatically via IDI1 and SC4MOL. Mass spectrometry-based lipidomics and enzymatic assays demonstrate the targeting mechanisms reduce intermediate sterol pathway metabolites and total cholesterol in macrophages. These results reveal a previously unrecognized mechanism by which IFN regulates the sterol pathway. The sterol pathway is known to be an integral part of the macrophage IFN antiviral response, and we show that miR-342-5p exerts broad antiviral effects against multiple, unrelated pathogenic viruses such Cytomegalovirus and Influenza A (H1N1. Metabolic rescue experiments confirm the specificity of these effects and demonstrate that unrelated viruses have differential mevalonate and sterol pathway requirements for their replication. This study, therefore, advances the general concept of broad antiviral defense through multihit targeting of a single host pathway.

  6. A T4SS Effector Targets Host Cell Alpha-Enolase Contributing to Brucella abortus Intracellular Lifestyle.

    Science.gov (United States)

    Marchesini, María I; Morrone Seijo, Susana M; Guaimas, Francisco F; Comerci, Diego J

    2016-01-01

    Brucella abortus , the causative agent of bovine brucellosis, invades and replicates within cells inside a membrane-bound compartment known as the Brucella containing vacuole (BCV). After trafficking along the endocytic and secretory pathways, BCVs mature into endoplasmic reticulum-derived compartments permissive for bacterial replication. Brucella Type IV Secretion System (VirB) is a major virulence factor essential for the biogenesis of the replicative organelle. Upon infection, Brucella uses the VirB system to translocate effector proteins from the BCV into the host cell cytoplasm. Although the functions of many translocated proteins remain unknown, some of them have been demonstrated to modulate host cell signaling pathways to favor intracellular survival and replication. BPE123 (BAB2_0123) is a B. abortus VirB-translocated effector protein recently identified by our group whose function is yet unknown. In an attempt to identify host cell proteins interacting with BPE123, a pull-down assay was performed and human alpha-enolase (ENO-1) was identified by LC/MS-MS as a potential interaction partner of BPE123. These results were confirmed by immunoprecipitation assays. In bone-marrow derived macrophages infected with B. abortus , ENO-1 associates to BCVs in a BPE123-dependent manner, indicating that interaction with translocated BPE123 is also occurring during the intracellular phase of the bacterium. Furthermore, ENO-1 depletion by siRNA impaired B. abortus intracellular replication in HeLa cells, confirming a role for α-enolase during the infection process. Indeed, ENO-1 activity levels were enhanced upon B. abortus infection of THP-1 macrophagic cells, and this activation is highly dependent on BPE123. Taken together, these results suggest that interaction between BPE123 and host cell ENO-1 contributes to the intracellular lifestyle of B. abortus .

  7. Human host defense peptide LL-37 stimulates virulence factor production and adaptive resistance in Pseudomonas aeruginosa.

    Directory of Open Access Journals (Sweden)

    Nikola Strempel

    Full Text Available A multitude of different virulence factors as well as the ability to rapidly adapt to adverse environmental conditions are important features for the high pathogenicity of Pseudomonas aeruginosa. Both virulence and adaptive resistance are tightly controlled by a complex regulatory network and respond to external stimuli, such as host signals or antibiotic stress, in a highly specific manner. Here, we demonstrate that physiological concentrations of the human host defense peptide LL-37 promote virulence factor production as well as an adaptive resistance against fluoroquinolone and aminoglycoside antibiotics in P. aeruginosa PAO1. Microarray analyses of P. aeruginosa cells exposed to LL-37 revealed an upregulation of gene clusters involved in the production of quorum sensing molecules and secreted virulence factors (PQS, phenazine, hydrogen cyanide (HCN, elastase and rhamnolipids and in lipopolysaccharide (LPS modification as well as an induction of genes encoding multidrug efflux pumps MexCD-OprJ and MexGHI-OpmD. Accordingly, we detected significantly elevated levels of toxic metabolites and proteases in bacterial supernatants after LL-37 treatment. Pre-incubation of bacteria with LL-37 for 2 h led to a decreased susceptibility towards gentamicin and ciprofloxacin. Quantitative Realtime PCR results using a PAO1-pqsE mutant strain present evidence that the quinolone response protein and virulence regulator PqsE may be implicated in the regulation of the observed phenotype in response to LL-37. Further experiments with synthetic cationic antimicrobial peptides IDR-1018, 1037 and HHC-36 showed no induction of pqsE expression, suggesting a new role of PqsE as highly specific host stress sensor.

  8. [A new calibration transfer method based on target factor analysis].

    Science.gov (United States)

    Wang, Yan-bin; Yuan, Hong-fu; Lu, Wan-zhen

    2005-03-01

    A new calibration transfer method based on target factor analysis is proposed.The performance of the new method compared with the piecewise direct standardization method. This method was applied to two data sets, of which one is a simulation data set, and the other is an NIR data set composed of benzene, toluene, xylene and isooctane. The results obtained with this new method are at least as well as those obtained by PDS with the biggest improvement occurring when the spectra have some non-linear responses.

  9. Atick salivary protein targets cathepsin G and chymase and inhibits host inflammation and platelet aggregation

    Czech Academy of Sciences Publication Activity Database

    Chmelař, Jindřich; Oliveira, C. J.; Řezáčová, Pavlína; Francischetti, I.M.B.; Kovářová, Zuzana; Pejler, G.; Kopáček, Petr; Ribeiro, J.M.C.; Mareš, Michael; Kopecký, Jan; Kotsyfakis, Michalis

    2011-01-01

    Roč. 117, č. 2 (2011), s. 736-744 ISSN 0006-4971 R&D Projects: GA AV ČR IAA600960811; GA MŠk(CZ) LC06009; GA ČR(CZ) GAP207/10/2183 Institutional research plan: CEZ:AV0Z60220518; CEZ:AV0Z40550506 Keywords : parasite serpin * IRS-2 * tick * Ixodes ricinus * platelet aggregation * inflammation * cathepsin G * chymase Subject RIV: EC - Immunology Impact factor: 9.898, year: 2011

  10. The Role of the Tumor Vasculature in the Host Immune Response: Implications for Therapeutic Strategies Targeting the Tumor Microenvironment.

    Science.gov (United States)

    Hendry, Shona A; Farnsworth, Rae H; Solomon, Benjamin; Achen, Marc G; Stacker, Steven A; Fox, Stephen B

    2016-01-01

    Recently developed cancer immunotherapy approaches including immune checkpoint inhibitors and chimeric antigen receptor T cell transfer are showing promising results both in trials and in clinical practice. These approaches reflect increasing recognition of the crucial role of the tumor microenvironment in cancer development and progression. Cancer cells do not act alone, but develop a complex relationship with the environment in which they reside. The host immune response to tumors is critical to the success of immunotherapy; however, the determinants of this response are incompletely understood. The immune cell infiltrate in tumors varies widely in density, composition, and clinical significance. The tumor vasculature is a key component of the microenvironment that can influence tumor behavior and treatment response and can be targeted through the use of antiangiogenic drugs. Blood vascular and lymphatic endothelial cells have important roles in the trafficking of immune cells, controlling the microenvironment, and modulating the immune response. Improving access to the tumor through vascular alteration with antiangiogenic drugs may prove an effective combinatorial strategy with immunotherapy approaches and might be applicable to many tumor types. In this review, we briefly discuss the host's immune response to cancer and the treatment strategies utilizing this response, before focusing on the pathological features of tumor blood and lymphatic vessels and the contribution these might make to tumor immune evasion.

  11. Antisense Oligonucleotides Targeting Parasite Inositol 1,4,5-Trisphosphate Receptor Inhibits Mammalian Host Cell Invasion by Trypanosoma cruzi

    Science.gov (United States)

    Hashimoto, Muneaki; Nara, Takeshi; Hirawake, Hiroko; Morales, Jorge; Enomoto, Masahiro; Mikoshiba, Katsuhiko

    2014-02-01

    Chagas disease is caused by an intracellular parasitic protist, Trypanosoma cruzi. As there are no highly effective drugs against this agent that also demonstrate low toxicity, there is an urgent need for development of new drugs to treat Chagas disease. We have previously demonstrated that the parasite inositol 1,4,5-trisphosphate receptor (TcIP3R) is crucial for invasion of the mammalian host cell by T. cruzi. Here, we report that TcIP3R is a short-lived protein and that its expression is significantly suppressed in trypomastigotes. Treatment of trypomastigotes, an infective stage of T. cruzi, with antisense oligonucleotides specific to TcIP3R deceased TcIP3R protein levels and impaired trypomastigote invasion of host cells. Due to the resulting instability and very low expression level of TcIP3R in trypomastigotes indicates that TcIP3R is a promising target for antisense therapy in Chagas disease.

  12. Yersinia virulence factors - a sophisticated arsenal for combating host defences [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Steve Atkinson

    2016-06-01

    Full Text Available The human pathogens Yersinia pseudotuberculosis and Yersinia enterocolitica cause enterocolitis, while Yersinia pestis is responsible for pneumonic, bubonic, and septicaemic plague. All three share an infection strategy that relies on a virulence factor arsenal to enable them to enter, adhere to, and colonise the host while evading host defences to avoid untimely clearance. Their arsenal includes a number of adhesins that allow the invading pathogens to establish a foothold in the host and to adhere to specific tissues later during infection. When the host innate immune system has been activated, all three pathogens produce a structure analogous to a hypodermic needle. In conjunction with the translocon, which forms a pore in the host membrane, the channel that is formed enables the transfer of six ‘effector’ proteins into the host cell cytoplasm. These proteins mimic host cell proteins but are more efficient than their native counterparts at modifying the host cell cytoskeleton, triggering the host cell suicide response. Such a sophisticated arsenal ensures that yersiniae maintain the upper hand despite the best efforts of the host to counteract the infecting pathogen.

  13. Prevotella intermedia ATCC 25611 targets host cell lamellipodia in epithelial cell adhesion and invasion.

    Science.gov (United States)

    Gursoy, U K; Könönen, E; Uitto, V-J

    2009-08-01

    The Prevotella intermedia group bacteria, namely P. intermedia, Prevotella nigrescens, and Prevotella pallens, are phylogenetically closely related and potentially connected with oral and gastrointestinal tract disease pathogenesis. The aim of the present study was to examine whether these species differ in their capabilities of adhesion to and invasion of epithelial cells. Adhesion and invasion were assayed by standard antibiotic/culture assays and fluorescent microscopy techniques. The effect of Prevotella strains on epithelial cell viability was measured using a commercial cell proliferation assay. The strains P. intermedia ATCC 25611 and P. nigrescens ATCC 33263 adhered to epithelial cells, the adhesion numbers of P. intermedia being twice as high as those of P. nigrescens. These strains invaded epithelial cells but invasion was weak. The adhesion of P. intermedia was specifically targeted to epithelial cell lamellipodia. The number of adhered P. intermedia cells increased or decreased when the formation of lamellipodia was stimulated or inhibited, respectively. None of the tested strains showed toxic effects on epithelial cells; a clinical P. intermedia strain even increased the number of viable cells by about 20%. The results suggest that among the P. intermedia group bacteria, P. intermedia and P. nigrescens type strains can adhere to and invade epithelial cells, the capability of P. intermedia ATCC 25611(T) being highest in this context. This strain proved to have a special affinity in binding to epithelial cell lamellipodia.

  14. Shift of graft-versus-host-disease target organ tropism by dietary vitamin A.

    Directory of Open Access Journals (Sweden)

    Christian Koenecke

    Full Text Available Gut-homing of donor T cells is causative for the development of intestinal GvHD in recipients of allogeneic hematopoietic stem cell transplantation (HSCT. Expression of the gut-specific homing receptors integrin-α4β7 and chemokine receptor CCR9 on T cells is imprinted in gut-associated lymphoid tissues (GALT under the influence of the vitamin A metabolite retinoic acid. Here we addressed the role of vitamin A deficiency in HSCT-recipients for donor T cell migration in the course of experimental GvHD. Vitamin A-deficient (VAD mice were prepared by feeding them a vitamin A-depleted diet. Experiments were performed in a C57BL/6 into BALB/c model of acute GvHD. We found that expression of integrin-α4β7 and CCR9 in GALT was reduced in VAD recipients after HSCT. Competitive in vivo homing assays showed that allogeneic T cells primed in VAD mice did not home as efficiently to the intestine as T cells primed in mice fed with standard diet (STD. The course of GvHD was ameliorated in VAD HSCT-recipients and, consequently, their survival was prolonged compared to recipients receiving STD. However, VAD-recipients were not protected and died of clinical GvHD. We found reduced numbers of donor T cells in the intestine but increased cell counts and tissue damage in other organs of VAD-recipients. Furthermore, we observed high IFN-γ(+CD4(+ and low FoxP3(+CD4(+ frequencies of total donor CD4(+ T cells in VAD as compared to STD recipients. Taken together, these results indicate that dietary vitamin A deficiency in HSCT-recipients changed target organ tropism in GvHD but also resulted in fatal inflammation after HSCT.

  15. Energy transfer between a nanosystem and its host fluid: A multiscale factorization approach

    Energy Technology Data Exchange (ETDEWEB)

    Sereda, Yuriy V.; Espinosa-Duran, John M.; Ortoleva, Peter J., E-mail: ortoleva@indiana.edu [Center for Cell and Virus Theory, Department of Chemistry, Indiana University, 800 E. Kirkwood Ave, Bloomington, Indiana 47405 (United States)

    2014-02-21

    Energy transfer between a macromolecule or supramolecular assembly and a host medium is considered from the perspective of Newton's equations and Lie-Trotter factorization. The development starts by demonstrating that the energy of the molecule evolves slowly relative to the time scale of atomic collisions-vibrations. The energy is envisioned to be a coarse-grained variable that coevolves with the rapidly fluctuating atomistic degrees of freedom. Lie-Trotter factorization is shown to be a natural framework for expressing this coevolution. A mathematical formalism and workflow for efficient multiscale simulation of energy transfer is presented. Lactoferrin and human papilloma virus capsid-like structure are used for validation.

  16. Monkeypox Virus Host Factor Screen Using Haploid Cells Identifies Essential Role of GARP Complex in Extracellular Virus Formation.

    Science.gov (United States)

    Realegeno, Susan; Puschnik, Andreas S; Kumar, Amrita; Goldsmith, Cynthia; Burgado, Jillybeth; Sambhara, Suryaprakash; Olson, Victoria A; Carroll, Darin; Damon, Inger; Hirata, Tetsuya; Kinoshita, Taroh; Carette, Jan E; Satheshkumar, Panayampalli Subbian

    2017-06-01

    Monkeypox virus (MPXV) is a human pathogen that is a member of the Orthopoxvirus genus, which includes Vaccinia virus and Variola virus (the causative agent of smallpox). Human monkeypox is considered an emerging zoonotic infectious disease. To identify host factors required for MPXV infection, we performed a genome-wide insertional mutagenesis screen in human haploid cells. The screen revealed several candidate genes, including those involved in Golgi trafficking, glycosaminoglycan biosynthesis, and glycosylphosphatidylinositol (GPI)-anchor biosynthesis. We validated the role of a set of vacuolar protein sorting (VPS) genes during infection, VPS51 to VPS54 (VPS51-54), which comprise the Golgi-associated retrograde protein (GARP) complex. The GARP complex is a tethering complex involved in retrograde transport of endosomes to the trans -Golgi apparatus. Our data demonstrate that VPS52 and VPS54 were dispensable for mature virion (MV) production but were required for extracellular virus (EV) formation. For comparison, a known antiviral compound, ST-246, was used in our experiments, demonstrating that EV titers in VPS52 and VPS54 knockout (KO) cells were comparable to levels exhibited by ST-246-treated wild-type cells. Confocal microscopy was used to examine actin tail formation, one of the viral egress mechanisms for cell-to-cell dissemination, and revealed an absence of actin tails in VPS52KO- or VPS54KO-infected cells. Further evaluation of these cells by electron microscopy demonstrated a decrease in levels of wrapped viruses (WVs) compared to those seen with the wild-type control. Collectively, our data demonstrate the role of GARP complex genes in double-membrane wrapping of MVs necessary for EV formation, implicating the host endosomal trafficking pathway in orthopoxvirus infection. IMPORTANCE Human monkeypox is an emerging zoonotic infectious disease caused by Monkeypox virus (MPXV). Of the two MPXV clades, the Congo Basin strain is associated with severe

  17. Graft-versus-host disease after orthotopic liver transplantation: multivariate analysis of risk factors.

    Science.gov (United States)

    Elfeki, Mohamed A; Pungpapong, Surakit; Genco, Petrina V; Nakhleh, Raouf E; Nguyen, Justin H; Harnois, Denise M

    2015-12-01

    Graft-versus-host disease (GVHD) is a rare, fatal complication following orthotopic liver transplantation (OLT). To date, several risk factors have been proposed, but reports on these factors have been inconclusive. This is a retrospective, case-control study of prospectively collected data from 2775 OLTs performed at our institution. Eight cases of GVHD after OLT were diagnosed on the basis of the patient's clinical characteristics, and the findings were confirmed with skin and colonic biopsies. Each case was matched to three controls based on the diagnosis of liver disease, recipient's age, and blood group. Univariate and multivariate analyses were performed to identify risk factors associated with the development of GVHD after OLT. The univariate and multivariate analyses identified two main risk factors associated with development of GVHD in OLT recipients, a difference between recipient and donor age of >20 yr, and any human leukocyte antigen class I matches. Taking these two risk factors into consideration while matching prospective donors and recipients may reduce further incidence of GVHD in OLT patients. However, further studies are recommended to validate these findings. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Posthodiplostomum cuticola (Digenea: Diplostomatidae) in intermediate fish hosts: factors contributing to the parasite infection and prey selection by the definitive bird host

    Czech Academy of Sciences Publication Activity Database

    Ondračková, Markéta; Šimková, A.; Gelnar, M.; Jurajda, Pavel

    2004-01-01

    Roč. 129, č. 6 (2004), s. 761-770 ISSN 0031-1820 R&D Projects: GA ČR GA524/02/0924; GA ČR GP524/03/P108 Institutional research plan: CEZ:AV0Z6093917 Keywords : fish assemblages * intermediate host * complex life-cycle Subject RIV: EG - Zoology Impact factor: 1.685, year: 2004

  19. The correlated factors of the uneven performances of the CDM host countries

    Science.gov (United States)

    Zhu, Jinshan

    2012-03-01

    The Kyoto Protocol’s Clean Development Mechanism (CDM) has experienced a rapid growth. Up to 2010, 2763 projects have been registered, standing for about 433 million ton CO2 equivalent (CO2-eq.) of annual carbon credits. However, the performances of CDM host countries are remarkably unbalanced. Previous literature suggested that economic and investment conditions, energy intensity, energy structure, the share of annual carbon credits from high global warming potential (GWP) green house gas (GHG), capacity and institutional buildings of domestic CDM governance can play important roles in promoting CDM. This quantitative analysis shows that domestic economic and investment conditions are the most decisive factors determining the performance of the CDM host countries. Additionally, the influence of carbon intensity of energy consumption is relatively modest, and energy intensity of GDP as well as the share of annual carbon credits from high GWP GHG is less significant. Moreover, several leading CDM countries are not as successful as they seem to be, when the influences of their vast territories, distinguished economic and investment conditions are excluded. Therefore, to simply transplant the CDM governances of these countries can hardly guarantee that other countries will boost their carbon credit outputs.

  20. Influence of host factors and parasite biomass on the severity of imported Plasmodium falciparum malaria.

    Directory of Open Access Journals (Sweden)

    Nicolas Argy

    Full Text Available Imported malaria in France is characterized by various clinical manifestations observed in a heterogeneous population of patients such as travelers/expatriates and African migrants. In this population, host factors and parasite biomass associated with severe imported malaria are poorly known.From data collected by the Centre National de Référence du Paludisme, we identified epidemiological, demographic and biological features including parasite biomass and anti-plasmodial antibody levels (negative, positive and strongly positive serology associated with different disease severity groups (very severe, moderately severe, and uncomplicated malaria in 3 epidemiological groups (travelers/expatriates, first- and second-generation migrants.Age, ethnicity, absence of prior infection with P. falciparum, antibody levels, plasma PfHRP2 levels, total and circulating parasite biomass were related to severe malaria onset. Sequestered parasite biomass tended to be increased in very severe malaria, and was strongly correlated to the antibody level of the host.Prior exposure to P. falciparum is associated with high anti-plasmodial antibody levels which influence clinical presentation of imported malaria and its correlated circulating and sequestered parasite burden.

  1. Experimental infections with Mycoplasma agalactiae identify key factors involved in host-colonization.

    Directory of Open Access Journals (Sweden)

    Eric Baranowski

    Full Text Available Mechanisms underlying pathogenic processes in mycoplasma infections are poorly understood, mainly because of limited sequence similarities with classical, bacterial virulence factors. Recently, large-scale transposon mutagenesis in the ruminant pathogen Mycoplasma agalactiae identified the NIF locus, including nifS and nifU, as essential for mycoplasma growth in cell culture, while dispensable in axenic media. To evaluate the importance of this locus in vivo, the infectivity of two knock-out mutants was tested upon experimental infection in the natural host. In this model, the parental PG2 strain was able to establish a systemic infection in lactating ewes, colonizing various body sites such as lymph nodes and the mammary gland, even when inoculated at low doses. In these PG2-infected ewes, we observed over the course of infection (i the development of a specific antibody response and (ii dynamic changes in expression of M. agalactiae surface variable proteins (Vpma, with multiple Vpma profiles co-existing in the same animal. In contrast and despite a sensitive model, none of the knock-out mutants were able to survive and colonize the host. The extreme avirulent phenotype of the two mutants was further supported by the absence of an IgG response in inoculated animals. The exact role of the NIF locus remains to be elucidated but these data demonstrate that it plays a key role in the infectious process of M. agalactiae and most likely of other pathogenic mycoplasma species as many carry closely related homologs.

  2. Pneumococcal pneumonia presenting with septic shock: host- and pathogen-related factors and outcomes.

    Science.gov (United States)

    Garcia-Vidal, C; Ardanuy, C; Tubau, F; Viasus, D; Dorca, J; Liñares, J; Gudiol, F; Carratalà, J

    2010-01-01

    Host- and pathogen-related factors associated with septic shock in pneumococcal pneumonia are not well defined. The aim of this study was to identify risk factors for septic shock and to ascertain patient outcomes. Serotypes, genotypes and antibiotic resistance of isolated strains were also analysed. Observational analysis of a prospective cohort of non-severely immunosuppressed hospitalised adults with pneumococcal pneumonia. Septic shock was defined as a systolic blood pressure of 4 h after fluid replacement. 1041 patients with pneumococcal pneumonia diagnosed by Gram stain and culture of appropriate samples and/or urine antigen test were documented, of whom 114 (10.9%) had septic shock at admission. After adjustment, independent risk factors for shock were current tobacco smoking (OR, 2.11; 95% CI, 1.02 to 4.34; p = 0.044), chronic corticosteroid treatment (OR, 4.45; 95% CI, 1.75 to 11.32; p = 0.002) and serotype 3 (OR, 2.24; 95% CI, 1.12 to 4.475; p = 0.022). No significant differences were found in genotypes and rates of antibiotic resistance. Compared with the remaining patients, patients with septic shock required mechanical ventilation more frequently (37% vs 4%; pshock. Septic shock is a frequent complication of pneumococcal pneumonia and causes high morbidity and mortality. Current tobacco smoking, chronic corticosteroid treatment and infection caused by serotype 3 are independent risk factors for this complication.

  3. No Major Host Genetic Risk Factor Contributed to A(H1N12009 Influenza Severity.

    Directory of Open Access Journals (Sweden)

    Koldo Garcia-Etxebarria

    Full Text Available While most patients affected by the influenza A(H1N1 pandemic experienced mild symptoms, a small fraction required hospitalization, often without concomitant factors that could explain such a severe course. We hypothesize that host genetic factors could contribute to aggravate the disease. To test this hypothesis, we compared the allele frequencies of 547,296 genome-wide single nucleotide polymorphisms (SNPs between 49 severe and 107 mild confirmed influenza A cases, as well as against a general population sample of 549 individuals. When comparing severe vs. mild influenza A cases, only one SNP was close to the conventional p = 5×10-8. This SNP, rs28454025, sits in an intron of the GSK233 gene, which is involved in a neural development, but seems not to have any connections with immunological or inflammatory functions. Indirectly, a previous association reported with CD55 was replicated. Although sample sizes are low, we show that the statistical power in our design was sufficient to detect highly-penetrant, quasi-Mendelian genetic factors. Hence, and assuming that rs28454025 is likely to be a false positive, no major genetic factor was detected that could explain poor influenza A course.

  4. Improving Aspergillus niger as a production host through manipulation of pH responding transcription factors

    DEFF Research Database (Denmark)

    Poulsen, Lars; Bruno, K.S.; Thykær, Jette

    ). In the present study the effect of modulation of transcription factors in Aspergillus niger, which is an industrially important micro-organism used in various processes including organic acid and enzyme production, was investigated. The strategy described in this work focuses on regulation connected to pH....... It was chosen as an important process parameter, due to its significant influences on both organic acid and enzyme production. A previous transcription analysis identified several putative transcription factors with pH responding behavior (Andersen et al., 2009). A number of these genes were selected as targets...

  5. Evaluation of host and viral factors associated with severe dengue based on the 2009 WHO classification.

    Science.gov (United States)

    Pozo-Aguilar, Jorge O; Monroy-Martínez, Verónica; Díaz, Daniel; Barrios-Palacios, Jacqueline; Ramos, Celso; Ulloa-García, Armando; García-Pillado, Janet; Ruiz-Ordaz, Blanca H

    2014-12-11

    Dengue fever (DF) is the most prevalent arthropod-borne viral disease affecting humans. The World Health Organization (WHO) proposed a revised classification in 2009 to enable the more effective identification of cases of severe dengue (SD). This was designed primarily as a clinical tool, but it also enables cases of SD to be differentiated into three specific subcategories (severe vascular leakage, severe bleeding, and severe organ dysfunction). However, no study has addressed whether this classification has advantage in estimating factors associated with the progression of disease severity or dengue pathogenesis. We evaluate in a dengue outbreak associated risk factors that could contribute to the development of SD according to the 2009 WHO classification. A prospective cross-sectional study was performed during an epidemic of dengue in 2009 in Chiapas, Mexico. Data were analyzed for host and viral factors associated with dengue cases, using the 1997 and 2009 WHO classifications. The cost-benefit ratio (CBR) was also estimated. The sensitivity in the 1997 WHO classification for determining SD was 75%, and the specificity was 97.7%. For the 2009 scheme, these were 100% and 81.1%, respectively. The 2009 classification showed a higher benefit (537%) with a lower cost (10.2%) than the 1997 WHO scheme. A secondary antibody response was strongly associated with SD. Early viral load was higher in cases of SD than in those with DF. Logistic regression analysis identified predictive SD factors (secondary infection, disease phase, viral load) within the 2009 classification. However, within the 1997 scheme it was not possible to differentiate risk factors between DF and dengue hemorrhagic fever or dengue shock syndrome. The critical clinical stage for determining SD progression was the transition from fever to defervescence in which plasma leakage can occur. The clinical phenotype of SD is influenced by the host (secondary response) and viral factors (viral load). The 2009

  6. Immune Checkpoint Blockade in Cancer Treatment: A Double-Edged Sword Cross-Targeting the Host as an “Innocent Bystander”

    Directory of Open Access Journals (Sweden)

    Lucia Gelao

    2014-03-01

    Full Text Available Targeted immune checkpoint blockade augments anti-tumor immunity and induces durable responses in patients with melanoma and other solid tumors. It also induces specific “immune-related adverse events” (irAEs. IrAEs mainly include gastrointestinal, dermatological, hepatic and endocrinological toxicities. Off-target effects that arise appear to account for much of the toxicity of the immune checkpoint blockade. These unique “innocent bystander” effects are likely a direct result of breaking immune tolerance upon immune check point blockade and require specific treatment guidelines that include symptomatic therapies or systemic corticosteroids. What do we need going forward to limit immune checkpoint blockade-induced toxicity? Most importantly, we need a better understanding of the roles played by these agents in normal tissues, so that we can begin to predict potentially problematic side effects on the basis of their selectivity profile. Second, we need to focus on the predictive factors of the response and toxicity of the host rather than serially focusing on individual agents. Third, rigorous biomarker-driven clinical trials are needed to further elucidate the mechanisms of both the benefit and toxicity. We will summarize the double-edged sword effect of immunotherapeutics in cancer treatment.

  7. HCV-induced miR-21 contributes to evasion of host immune system by targeting MyD88 and IRAK1.

    Science.gov (United States)

    Chen, Yanni; Chen, Junbo; Wang, Hui; Shi, Jingjing; Wu, Kailang; Liu, Shi; Liu, Yingle; Wu, Jianguo

    2013-01-01

    Upon recognition of viral components by pattern recognition receptors, such as the toll-like receptors (TLRs) and retinoic acid-inducible gene I (RIG-I)-like helicases, cells are activated to produce type I interferon (IFN) and proinflammatory cytokines. These pathways are tightly regulated by the host to prevent an inappropriate cellular response, but viruses can modulate these pathways to proliferate and spread. In this study, we revealed a novel mechanism in which hepatitis C virus (HCV) evades the immune surveillance system to proliferate by activating microRNA-21 (miR-21). We demonstrated that HCV infection upregulates miR-21, which in turn suppresses HCV-triggered type I IFN production, thus promoting HCV replication. Furthermore, we demonstrated that miR-21 targets two important factors in the TLR signaling pathway, myeloid differentiation factor 88 (MyD88) and interleukin-1 receptor-associated kinase 1 (IRAK1), which are involved in HCV-induced type I IFN production. HCV-mediated activation of miR-21 expression requires viral proteins and several signaling components. Moreover, we identified a transcription factor, activating protein-1 (AP-1), which is partly responsible for miR-21 induction in response to HCV infection through PKCε/JNK/c-Jun and PKCα/ERK/c-Fos cascades. Taken together, our results indicate that miR-21 is upregulated during HCV infection and negatively regulates IFN-α signaling through MyD88 and IRAK1 and may be a potential therapeutic target for antiviral intervention.

  8. The gut microbiota composition in dichorionic triplet sets suggests a role for host genetic factors.

    Science.gov (United States)

    Murphy, Kiera; O' Shea, Carol Anne; Ryan, C Anthony; Dempsey, Eugene M; O' Toole, Paul W; Stanton, Catherine; Ross, R Paul

    2015-01-01

    Monozygotic and dizygotic twin studies investigating the relative roles of host genetics and environmental factors in shaping gut microbiota composition have produced conflicting results. In this study, we investigated the gut microbiota composition of a healthy dichorionic triplet set. The dichorionic triplet set contained a pair of monozygotic twins and a fraternal sibling, with similar pre- and post-natal environmental conditions including feeding regime. V4 16S rRNA and rpoB amplicon pyrosequencing was employed to investigate microbiota composition, and the species and strain diversity of the culturable bifidobacterial population was also examined. At month 1, the monozygotic pair shared a similar microbiota distinct to the fraternal sibling. By month 12 however, the profile was more uniform between the three infants. Principal coordinate analysis (PCoA) of the microbiota composition revealed strong clustering of the monozygotic pair at month 1 and a separation of the fraternal infant. At months 2 and 3 the phylogenetic distance between the monozygotic pair and the fraternal sibling has greatly reduced and by month 12 the monozygotic pair no longer clustered separately from the fraternal infant. Pulse field gel electrophoresis (PFGE) analysis of the bifidobacterial population revealed a lack of strain diversity, with identical strains identified in all three infants at month 1 and 12. The microbiota of two antibiotic-treated dichorionic triplet sets was also investigated. Not surprisingly, in both triplet sets early life antibiotic administration appeared to be a major determinant of microbiota composition at month 1, irrespective of zygosity. By month 12, early antibiotic administration appeared to no longer exert such a strong influence on gut microbiota composition. We hypothesize that initially host genetics play a significant role in the composition of an individual's gut microbiota, unless an antibiotic intervention is given, but by month 12 environmental

  9. The gut microbiota composition in dichorionic triplet sets suggests a role for host genetic factors.

    Directory of Open Access Journals (Sweden)

    Kiera Murphy

    Full Text Available Monozygotic and dizygotic twin studies investigating the relative roles of host genetics and environmental factors in shaping gut microbiota composition have produced conflicting results. In this study, we investigated the gut microbiota composition of a healthy dichorionic triplet set. The dichorionic triplet set contained a pair of monozygotic twins and a fraternal sibling, with similar pre- and post-natal environmental conditions including feeding regime. V4 16S rRNA and rpoB amplicon pyrosequencing was employed to investigate microbiota composition, and the species and strain diversity of the culturable bifidobacterial population was also examined. At month 1, the monozygotic pair shared a similar microbiota distinct to the fraternal sibling. By month 12 however, the profile was more uniform between the three infants. Principal coordinate analysis (PCoA of the microbiota composition revealed strong clustering of the monozygotic pair at month 1 and a separation of the fraternal infant. At months 2 and 3 the phylogenetic distance between the monozygotic pair and the fraternal sibling has greatly reduced and by month 12 the monozygotic pair no longer clustered separately from the fraternal infant. Pulse field gel electrophoresis (PFGE analysis of the bifidobacterial population revealed a lack of strain diversity, with identical strains identified in all three infants at month 1 and 12. The microbiota of two antibiotic-treated dichorionic triplet sets was also investigated. Not surprisingly, in both triplet sets early life antibiotic administration appeared to be a major determinant of microbiota composition at month 1, irrespective of zygosity. By month 12, early antibiotic administration appeared to no longer exert such a strong influence on gut microbiota composition. We hypothesize that initially host genetics play a significant role in the composition of an individual's gut microbiota, unless an antibiotic intervention is given, but by

  10. Interactions of HIV and drugs of abuse: the importance of glia, neural progenitors, and host genetic factors.

    Science.gov (United States)

    Hauser, Kurt F; Knapp, Pamela E

    2014-01-01

    Considerable insight has been gained into the comorbid, interactive effects of HIV and drug abuse in the brain using experimental models. This review, which considers opiates, methamphetamine, and cocaine, emphasizes the importance of host genetics and glial plasticity in driving the pathogenic neuron remodeling underlying neuro-acquired immunodeficiency syndrome and drug abuse comorbidity. Clinical findings are less concordant than experimental work, and the response of individuals to HIV and to drug abuse can vary tremendously. Host-genetic variability is important in determining viral tropism, neuropathogenesis, drug responses, and addictive behavior. However, genetic differences alone cannot account for individual variability in the brain "connectome." Environment and experience are critical determinants in the evolution of synaptic circuitry throughout life. Neurons and glia both exercise control over determinants of synaptic plasticity that are disrupted by HIV and drug abuse. Perivascular macrophages, microglia, and to a lesser extent astroglia can harbor the infection. Uninfected bystanders, especially astroglia, propagate and amplify inflammatory signals. Drug abuse by itself derails neuronal and glial function, and the outcome of chronic exposure is maladaptive plasticity. The negative consequences of coexposure to HIV and drug abuse are determined by numerous factors including genetics, sex, age, and multidrug exposure. Glia and some neurons are generated throughout life, and their progenitors appear to be targets of HIV and opiates/psychostimulants. The chronic nature of HIV and drug abuse appears to result in sustained alterations in the maturation and fate of neural progenitors, which may affect the balance of glial populations within multiple brain regions. © 2014 Elsevier Inc. All rights reserved.

  11. The Perfect Match: Factors That Characterize the AACSB International Initial Accreditation Host School and Mentor Relationship

    Science.gov (United States)

    Solomon, Norman A.; Scherer, Robert F.; Oliveti, Joseph J.; Mochel, Lucienne; Bryant, Michael

    2017-01-01

    Initial Association to Advance Collegiate Schools of Business International accreditation involves a process of pairing mentor and host schools to provide guidance and feedback on the congruence of the host school with the accreditation standards. The mentor serves as the primary resource for assisting the host school in identifying gaps with the…

  12. Differential expression and interaction of host factors augment HIV-1 gene expression in neonatal mononuclear cells

    International Nuclear Information System (INIS)

    Sundaravaradan, Vasudha; Mehta, Roshni; Harris, David T.; Zack, Jerome A.; Ahmad, Nafees

    2010-01-01

    We have previously shown a higher level of HIV-1 replication and gene expression in neonatal (cord) blood mononuclear cells (CBMC) compared with adult blood cells (PBMC), which could be due to differential expression of host factors. We performed the gene expression profile of CBMC and PBMC and found that 8013 genes were expressed at higher levels in CBMC than PBMC and 8028 genes in PBMC than CBMC, including 1181 and 1414 genes upregulated after HIV-1 infection in CBMC and PBMC, respectively. Several transcription factors (NF-κB, E2F, HAT-1, TFIIE, Cdk9, Cyclin T1), signal transducers (STAT3, STAT5A) and cytokines (IL-1β, IL-6, IL-10) were upregulated in CBMC than PBMC, which are known to influence HIV-1 replication. In addition, a repressor of HIV-1 transcription, YY1, was down regulated in CBMC than PBMC and several matrix metalloproteinase (MMP-7, -12, -14) were significantly upregulated in HIV-1 infected CBMC than PBMC. Furthermore, we show that CBMC nuclear extracts interacted with a higher extent to HIV-1 LTR cis-acting sequences, including NF-κB, NFAT, AP1 and NF-IL6 compared with PBMC nuclear extracts and retroviral based short hairpin RNA (shRNA) for STAT3 and IL-6 down regulated their own and HIV-1 gene expression, signifying that these factors influenced differential HIV-1 gene expression in CBMC than PBMC.

  13. Genome-Wide Search for Host Association Factors during Ovine Progressive Pneumonia Virus Infection.

    Directory of Open Access Journals (Sweden)

    Jesse Thompson

    Full Text Available Ovine progressive pneumonia virus (OPPV is an important virus that causes serious diseases in sheep and goats with a prevalence of 36% in the USA. Although OPPV was discovered more than half of a century ago, little is known about the infection and pathogenesis of this virus. In this report, we used RNA-seq technology to conduct a genome-wide probe for cellular factors that are associated with OPPV infection. A total of approximately 22,000 goat host genes were detected of which 657 were found to have been significantly up-regulated and 889 down-regulated at 12 hours post-infection. In addition to previously known restriction factors from other viral infections, a number of factors which may be specific for OPPV infection were uncovered. The data from this RNA-seq study will be helpful in our understanding of OPPV infection, and also for further study in the prevention and intervention of this viral disease.

  14. KAP1 Is a Host Restriction Factor That Promotes Human Adenovirus E1B-55K SUMO Modification

    DEFF Research Database (Denmark)

    Bürck, Carolin; Mund, Andreas; Berscheminski, Julia

    2016-01-01

    and chromatin compaction. In response to DNA damage, KAP1 is phosphorylated and functionally inactive, resulting in chromatin relaxation. We discovered that KAP1 posttranslational modification is dramatically altered during HAdV infection to limit the antiviral capacity of this host restriction factor, which...... epigenetic gene silencing and to promote SUMO modification of E1B-55K by a so far unknown mechanism. IMPORTANCE: Here we describe a novel cellular restriction factor for Human Adenovirus (HAdV) that sheds light on very early modulation processes in viral infection. We reported that chromatin formation...... characterized, but represent a decisive moment in establishing a productive infection. Here, we identify a novel host viral restriction factor, KAP1. This heterochromatin associated transcription factor regulates the dynamic organization of host chromatin structure via its ability to influence epigenetic marks...

  15. SAMD9 is an innate antiviral host factor with stress response properties that can be antagonized by poxviruses.

    Science.gov (United States)

    Liu, Jia; McFadden, Grant

    2015-02-01

    We show that SAMD9 is an innate host antiviral stress response element that participates in the formation of antiviral granules. Poxviruses, myxoma virus and vaccinia virus specifically, utilize a virus-encoded host range factor(s), such as a member of the C7L superfamily, to antagonize SAMD9 to prevent granule formation in a eukaryotic initiation factor 2α (eIF2α)-independent manner. When SAMD9 is stimulated due to failure of the viral antagonism during infection, the resulting antiviral granules exhibit properties different from those of the canonical stress granules. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  16. Coxsackievirus mutants that can bypass host factor PI4KIIIβ and the need for high levels of PI4P lipids for replication.

    Science.gov (United States)

    van der Schaar, Hilde M; van der Linden, Lonneke; Lanke, Kjerstin H W; Strating, Jeroen R P M; Pürstinger, Gerhard; de Vries, Erik; de Haan, Cornelis A M; Neyts, Johan; van Kuppeveld, Frank J M

    2012-11-01

    RNA viruses can rapidly mutate and acquire resistance to drugs that directly target viral enzymes, which poses serious problems in a clinical context. Therefore, there is a growing interest in the development of antiviral drugs that target host factors critical for viral replication, since they are unlikely to mutate in response to therapy. We recently demonstrated that phosphatidylinositol-4-kinase IIIβ (PI4KIIIβ) and its product phosphatidylinositol-4-phosphate (PI4P) are essential for replication of enteroviruses, a group of medically important RNA viruses including poliovirus (PV), coxsackievirus, rhinovirus, and enterovirus 71. Here, we show that enviroxime and GW5074 decreased PI4P levels at the Golgi complex by directly inhibiting PI4KIIIβ. Coxsackievirus mutants resistant to these inhibitors harbor single point mutations in the non-structural protein 3A. These 3A mutations did not confer compound-resistance by restoring the activity of PI4KIIIβ in the presence of the compounds. Instead, replication of the mutant viruses no longer depended on PI4KIIIβ, since their replication was insensitive to siRNA-mediated depletion of PI4KIIIβ. The mutant viruses also did not rely on other isoforms of PI4K. Consistently, no high level of PI4P could be detected at the replication sites induced by the mutant viruses in the presence of the compounds. Collectively, these findings indicate that through specific single point mutations in 3A, CVB3 can bypass an essential host factor and lipid for its propagation, which is a new example of RNA viruses acquiring resistance against antiviral compounds, even when they directly target host factors.

  17. Host-specific interactions with environmental factors shape the distribution of symbiodinium across the Great Barrier Reef.

    Directory of Open Access Journals (Sweden)

    Linda Tonk

    Full Text Available The endosymbiotic dinoflagellates (genus Symbiodinium within coral reef invertebrates are critical to the survival of the holobiont. The genetic variability of Symbiodinium may contribute to the tolerance of the symbiotic association to elevated sea surface temperatures (SST. To assess the importance of factors such as the local environment, host identity and biogeography in driving Symbiodinium distributions on reef-wide scales, data from studies on reef invertebrate-Symbiodinium associations from the Great Barrier Reef (GBR were compiled.The resulting database consisted of 3717 entries from 26 studies. It was used to explore ecological patterns such as host-specificity and environmental drivers structuring community complexity using a multi-scalar approach. The data was analyzed in several ways: (i frequently sampled host species were analyzed independently to investigate the influence of the environment on symbiont distributions, thereby excluding the influence of host specificity, (ii host species distributions across sites were added as an environmental variable to determine the contribution of host identity on symbiont distribution, and (iii data were pooled based on clade (broad genetic groups dividing the genus Symbiodinium to investigate factors driving Symbiodinium distributions using lower taxonomic resolution. The results indicated that host species identity plays a dominant role in determining the distribution of Symbiodinium and environmental variables shape distributions on a host species-specific level. SST derived variables (especially SSTstdev most often contributed to the selection of the best model. Clade level comparisons decreased the power of the predictive model indicating that it fails to incorporate the main drivers behind Symbiodinium distributions.Including the influence of different host species on Symbiodinium distributional patterns improves our understanding of the drivers behind the complexity of Symbiodinium

  18. Host-specific interactions with environmental factors shape the distribution of symbiodinium across the Great Barrier Reef.

    Science.gov (United States)

    Tonk, Linda; Sampayo, Eugenia M; Weeks, Scarla; Magno-Canto, Marites; Hoegh-Guldberg, Ove

    2013-01-01

    The endosymbiotic dinoflagellates (genus Symbiodinium) within coral reef invertebrates are critical to the survival of the holobiont. The genetic variability of Symbiodinium may contribute to the tolerance of the symbiotic association to elevated sea surface temperatures (SST). To assess the importance of factors such as the local environment, host identity and biogeography in driving Symbiodinium distributions on reef-wide scales, data from studies on reef invertebrate-Symbiodinium associations from the Great Barrier Reef (GBR) were compiled. The resulting database consisted of 3717 entries from 26 studies. It was used to explore ecological patterns such as host-specificity and environmental drivers structuring community complexity using a multi-scalar approach. The data was analyzed in several ways: (i) frequently sampled host species were analyzed independently to investigate the influence of the environment on symbiont distributions, thereby excluding the influence of host specificity, (ii) host species distributions across sites were added as an environmental variable to determine the contribution of host identity on symbiont distribution, and (iii) data were pooled based on clade (broad genetic groups dividing the genus Symbiodinium) to investigate factors driving Symbiodinium distributions using lower taxonomic resolution. The results indicated that host species identity plays a dominant role in determining the distribution of Symbiodinium and environmental variables shape distributions on a host species-specific level. SST derived variables (especially SSTstdev) most often contributed to the selection of the best model. Clade level comparisons decreased the power of the predictive model indicating that it fails to incorporate the main drivers behind Symbiodinium distributions. Including the influence of different host species on Symbiodinium distributional patterns improves our understanding of the drivers behind the complexity of Symbiodinium

  19. Host Factors Influencing the Retrohoming Pathway of Group II Intron RmInt1, Which Has an Intron-Encoded Protein Naturally Devoid of Endonuclease Activity.

    Directory of Open Access Journals (Sweden)

    Rafael Nisa-Martínez

    Full Text Available Bacterial group II introns are self-splicing catalytic RNAs and mobile retroelements that have an open reading frame encoding an intron-encoded protein (IEP with reverse transcriptase (RT and RNA splicing or maturase activity. Some IEPs carry a DNA endonuclease (En domain, which is required to cleave the bottom strand downstream from the intron-insertion site for target DNA-primed reverse transcription (TPRT of the inserted intron RNA. Host factors complete the insertion of the intron. By contrast, the major retrohoming pathway of introns with IEPs naturally lacking endonuclease activity, like the Sinorhizobium meliloti intron RmInt1, is thought to involve insertion of the intron RNA into the template for lagging strand DNA synthesis ahead of the replication fork, with possible use of the nascent strand to prime reverse transcription of the intron RNA. The host factors influencing the retrohoming pathway of such introns have not yet been described. Here, we identify key candidates likely to be involved in early and late steps of RmInt1 retrohoming. Some of these host factors are common to En+ group II intron retrohoming, but some have different functions. Our results also suggest that the retrohoming process of RmInt1 may be less dependent on the intracellular free Mg2+ concentration than those of other group II introns.

  20. Multidisciplinary approach to the treatment of invasive fungal infections in adult patients. Prophylaxis, empirical, preemptive or targeted therapy, which is the best in the different hosts?

    Directory of Open Access Journals (Sweden)

    Rafael Zaragoza

    2008-11-01

    Full Text Available Rafael Zaragoza1, Javier Pemán2, Miguel Salavert3, Ángel Viudes2, Amparo Solé4, Isidro Jarque5, Emilio Monte6, Eva Romá6, Emilia Cantón71Servicio de Medicina Intensiva, Hospital Universitario Dr Peset, Valencia, Spain; 2Servicio de Microbiología; 3Unidad de Enfermedades Infecciosas; 4Unidad de Trasplante Pulmonar; 5Servicio de Hematología; 6Servicio de Farmacia; 7Unidad de Microbiología Experimental, Centro de Investigación, Hospital Universitario La Fe Valencia, SpainAbstract: The high morbidity, mortality, and health care costs associated with invasive fungal infections, especially in the critical care setting and immunocompromised host, have made it an excellent target for prophylactic, empiric, and preemptive therapy interventions principally based on early identification of risk factors. Early diagnosis and treatment are associated with a better prognosis. In the last years there have been important developments in antifungal pharmacotherapy. An approach to the new diagnosis tools in the clinical mycology laboratory and an analysis of the use new antifungal agents and its application in different clinical situations has been made. Furthermore, an attempt of developing a state of the art in each clinical scenario (critically ill, hematological, and solid organ transplant patients has been performed, trying to choose the best strategy for each clinical situation (prophylaxis, pre-emptive, empirical, or targeted therapy. The high mortality rates in these settings make mandatory the application of early de-escalation therapy in critically ill patients with fungal infection. In addition, the possibility of antifungal combination therapy might be considered in solid organ transplant and hematological patients.Keywords: invasive fungal infections, prophylaxis, empirical therapy, preemptive treatment, targeted therapy

  1. Targeting TBP-associated factors in ovarian cancer

    Directory of Open Access Journals (Sweden)

    Jennifer R Ribeiro

    2014-03-01

    Full Text Available As ovarian tumors progress, they undergo a process of dedifferentiation, allowing adaptive changes in growth and morphology that promote metastasis and chemoresistance. Herein, we outline a hypothesis that TATA-box binding protein (TBP associated factors (TAFs, which compose the RNA Polymerase II initiation factor, TFIID, contribute to regulation of dedifferentiation states in ovarian cancer. Numerous studies demonstrate that TAFs regulate differentiation and proliferation states; their expression is typically high in pluripotent cells and reduced upon differentiation. Strikingly, TAF2 exhibits copy number increases or mRNA overexpression in 73% of high grade serous ovarian cancers (HGSC. At the biochemical level, TAF2 directs TFIID to TATA-less promoters by contact with an Initiator element, which may lead to the deregulation of the transcriptional output of these tumor cells. TAF4, which is altered in 66% of HGSC, is crucial for the stability of the TFIID complex and helps drive dedifferentiation of mouse embryonic fibroblasts to induced pluripotent stem cells. Its ovary-enriched paralog, TAF4B, is altered in 26% of HGSC. Here, we show that Taf4b mRNA correlates with Cyclin D2 mRNA expression in human granulosa cell tumors. TAF4B may also contribute to regulation of tumor microenvironment due to its estrogen-responsiveness and ability to act as a cofactor for NFκB. Conversely, TAF9, a cofactor for p53 in regulating apoptosis, may act as a tumor suppressor in ovarian cancer, since it is downregulated or deleted in 98% of HGSC. We conclude that a greater understanding of mechanisms of transcriptional regulation that execute signals from oncogenic signaling cascades is needed in order to expand our understanding of the etiology and progression of ovarian cancer, and most importantly to identify novel targets for therapeutic intervention.

  2. Elongation factor-P at the crossroads of the host-endosymbiont interface.

    Science.gov (United States)

    Rajkovic, Andrei; Witzky, Anne; Navarre, William; Darwin, Andrew J; Ibba, Michael

    2015-09-23

    Elongation factor P (EF-P) is an ancient bacterial translational factor that aids the ribosome in polymerizing oligo-prolines. EF-P structurally resembles tRNA and binds in-between the exit and peptidyl sites of the ribosome to accelerate the intrinsically slow reaction of peptidyl-prolyl bond formation. Recent studies have identified in separate organisms, two evolutionarily convergent EF-P post-translational modification systems (EPMS), split predominantly between gammaproteobacteria, and betaproteobacteria. In both cases EF-P receives a post-translational modification, critical for its function, on a highly conserved residue that protrudes into the peptidyl-transfer center of the ribosome. EPMSs are comprised of a gene(s) that synthesizes the precursor molecule used in modifying EF-P, and a gene(s) encoding an enzyme that reacts with the precursor molecule to catalyze covalent attachment to EF-P. However, not all organisms genetically encode a complete EPMS. For instance, some symbiotic bacteria harbor efp and the corresponding gene that enzymatically attaches the modification, but lack the ability to synthesize the substrate used in the modification reaction. Here we highlight the recent discoveries made regarding EPMSs, with a focus on how these incomplete modification pathways shape or have been shaped by the endosymbiont-host relationship.

  3. Contribution of host factors and workplace exposure to the outcome of occupational asthma

    Directory of Open Access Journals (Sweden)

    P. Maestrelli

    2012-06-01

    Full Text Available The outcome of occupational asthma after diagnosis is often poor. The identification of factors associated with a worse outcome may help in the management of the disease, determining its prognosis and assessing the permanent impairment attributable to occupational exposure. The aim of this systematic review was to provide the available evidence from the medical literature to answer the question: “What is the contribution of host factors and workplace exposure to the risk of a bad outcome of occupational asthma?” A systematic literature search was conducted in March 2010. We retrieved 177 abstracts. Of these, 67 were assessed as potentially relevant. After full text evaluation, 35 articles that were actually relevant for the question were included in the analysis. The information obtained was sufficient to establish that older age, high-molecular-weight agents, impaired lung function and longer duration of exposure to the offending agent at the time of diagnosis had a negative role on the outcome of occupational asthma. Atopy and smoking at diagnosis did not seem to influence the outcome of occupational asthma. A limited number of studies considered sex and the pattern of asthmatic reaction on specific inhalation challenge and their findings were contradictory.

  4. Host genetic factors in American cutaneous leishmaniasis: a critical appraisal of studies conducted in an endemic area of Brazil

    Directory of Open Access Journals (Sweden)

    Léa Cristina Castellucci

    2014-06-01

    Full Text Available American cutaneous leishmaniasis (ACL is a vector-transmitted infectious disease with an estimated 1.5 million new cases per year. In Brazil, ACL represents a significant public health problem, with approximately 30,000 new reported cases annually, representing an incidence of 18.5 cases per 100,000 inhabitants. Corte de Pedra is in a region endemic for ACL in the state of Bahia (BA, northeastern Brazil, with 500-1,300 patients treated annually. Over the last decade, population and family-based candidate gene studies were conducted in Corte de Pedra, founded on previous knowledge from studies on mice and humans. Notwithstanding limitations related to sample size and power, these studies contribute important genetic biomarkers that identify novel pathways of disease pathogenesis and possible new therapeutic targets. The present paper is a narrative review about ACL immunogenetics in BA, highlighting in particular the interacting roles of the wound healing gene FLI1 with interleukin-6 and genes SMAD2 and SMAD3 of the transforming growth factor beta signalling pathway. This research highlights the need for well-powered genetic and functional studies on Leishmania braziliensis infection as essential to define and validate the role of host genes in determining resistance/susceptibility regarding this disease.

  5. The secreted Candida albicans protein Pra1 disrupts host defense by broadly targeting and blocking complement C3 and C3 activation fragments.

    Science.gov (United States)

    Luo, Shanshan; Dasari, Prasad; Reiher, Nadine; Hartmann, Andrea; Jacksch, Susanne; Wende, Elisabeth; Barz, Dagmar; Niemiec, Maria Joanna; Jacobsen, Ilse; Beyersdorf, Niklas; Hünig, Thomas; Klos, Andreas; Skerka, Christine; Zipfel, Peter F

    2018-01-01

    Candida albicans the most frequently isolated clinical fungal pathogen can cause local as well as systemic and life-threatening infections particularly in immune-compromised individuals. A better and more detailed understanding how C. albicans evades human immune attack is therefore needed for identifying fungal immune-evasive proteins and develop new therapies. Here, we identified Pra1, the pH-regulated C. albicans antigen as a hierarchical complement inhibitor that targets C3, the central human complement component. Pra1 cleaved C3 at a unique site and further inhibited effector function of the activation fragments. The newly formed C3a-like peptide lacked the C-terminal arginine residue needed for C3a-receptor binding and activation. Moreover, Pra1 also blocked C3a-like antifungal activity as shown in survival assays, and the C3b-like molecule formed by Pra1 was degraded by the host protease Factor I. Pra1 also bound to C3a and C3b generated by human convertases and blocked their effector functions, like C3a antifungal activity shown by fungal survival, blocked C3a binding to human C3a receptor-expressing HEK cells, activation of Fura2-AM loaded cells, intracellular Ca 2+ signaling, IL-8 release, C3b deposition, as well as opsonophagocytosis and killing by human neutrophils. Thus, upon infection C. albicans uses Pra1 to destroy C3 and to disrupt host complement attack. In conclusion, candida Pra1 represents the first fungal C3-cleaving protease identified and functions as a fungal master regulator of innate immunity and as a central fungal immune-escape protein. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Going the Distance: Mapping Host Galaxies of LIGO and VIRGO Sources in Three Dimensions using Local Cosmography and Targeted Follow-Up

    Science.gov (United States)

    Singer, Leo P.; Chen, Hsin-Yu; Holz, Daniel E.; Farr, Will M.; Price, Larry R.; Raymond, Vivien; Cenko, S. Bradley; Gehrels, Neil; Cannizzo, John K.; Kasliwal, Mansi M.; hide

    2016-01-01

    The Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) discovered gravitational waves (GWs) from a binary black hole merger in 2015 September and may soon observe signals from neutron star mergers. There is considerable interest in searching for their faint and rapidly fading electromagnetic (EM) counterparts, though GW position uncertainties are as coarse as hundreds of square degrees. Because LIGO's sensitivity to binary neutron stars is limited to the local universe, the area on the sky that must be searched could be reduced by weighting positions by mass, luminosity, or star formation in nearby galaxies. Since GW observations provide information about luminosity distance, combining the reconstructed volume with positions and redshifts of galaxies could reduce the area even more dramatically. A key missing ingredient has been a rapid GW parameter estimation algorithm that reconstructs the full distribution of sky location and distance. We demonstrate the first such algorithm, which takes under a minute, fast enough to enable immediate EM follow-up. By combining the three-dimensional posterior with a galaxy catalog, we can reduce the number of galaxies that could conceivably host the event by a factor of 1.4, the total exposure time for the Swift X-ray Telescope by a factor of 2, the total exposure time for a synoptic optical survey by a factor of 2, and the total exposure time for a narrow-field optical telescope by a factor of 3. This encourages us to suggest a new role for small field of view optical instruments in performing targeted searches of the most massive galaxies within the reconstructed volumes.

  7. GOING THE DISTANCE: MAPPING HOST GALAXIES OF LIGO AND VIRGO SOURCES IN THREE DIMENSIONS USING LOCAL COSMOGRAPHY AND TARGETED FOLLOW-UP

    International Nuclear Information System (INIS)

    Singer, Leo P.; Cenko, S. Bradley; Gehrels, Neil; Cannizzo, John; Chen, Hsin-Yu; Holz, Daniel E.; Farr, Ben; Farr, Will M.; Veitch, John; Berry, Christopher P. L.; Mandel, Ilya; Price, Larry R.; Raymond, Vivien; Kasliwal, Mansi M.; Nissanke, Samaya; Coughlin, Michael; Urban, Alex L.; Vitale, Salvatore; Mohapatra, Satya; Graff, Philip

    2016-01-01

    The Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) discovered gravitational waves (GWs) from a binary black hole merger in 2015 September and may soon observe signals from neutron star mergers. There is considerable interest in searching for their faint and rapidly fading electromagnetic (EM) counterparts, though GW position uncertainties are as coarse as hundreds of square degrees. Because LIGO’s sensitivity to binary neutron stars is limited to the local universe, the area on the sky that must be searched could be reduced by weighting positions by mass, luminosity, or star formation in nearby galaxies. Since GW observations provide information about luminosity distance, combining the reconstructed volume with positions and redshifts of galaxies could reduce the area even more dramatically. A key missing ingredient has been a rapid GW parameter estimation algorithm that reconstructs the full distribution of sky location and distance. We demonstrate the first such algorithm, which takes under a minute, fast enough to enable immediate EM follow-up. By combining the three-dimensional posterior with a galaxy catalog, we can reduce the number of galaxies that could conceivably host the event by a factor of 1.4, the total exposure time for the Swift X-ray Telescope by a factor of 2, the total exposure time for a synoptic optical survey by a factor of 2, and the total exposure time for a narrow-field optical telescope by a factor of 3. This encourages us to suggest a new role for small field of view optical instruments in performing targeted searches of the most massive galaxies within the reconstructed volumes.

  8. GOING THE DISTANCE: MAPPING HOST GALAXIES OF LIGO AND VIRGO SOURCES IN THREE DIMENSIONS USING LOCAL COSMOGRAPHY AND TARGETED FOLLOW-UP

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Leo P.; Cenko, S. Bradley; Gehrels, Neil; Cannizzo, John [Astroparticle Physics Laboratory, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States); Chen, Hsin-Yu; Holz, Daniel E.; Farr, Ben [Department of Physics, Enrico Fermi Institute, and Kavli Institute for Cosmological Physics, University of Chicago, Chicago, IL 60637 (United States); Farr, Will M.; Veitch, John; Berry, Christopher P. L.; Mandel, Ilya [School of Physics and Astronomy, University of Birmingham, Birmingham, B15 2TT (United Kingdom); Price, Larry R.; Raymond, Vivien [LIGO Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Kasliwal, Mansi M. [Cahill Center for Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Nissanke, Samaya [Institute of Mathematics, Astrophysics and Particle Physics, Radboud University, Heyendaalseweg 135, 6525 AJ Nijmegen (Netherlands); Coughlin, Michael [Department of Physics and Astronomy, Harvard University, Cambridge, MA 02138 (United States); Urban, Alex L. [Leonard E. Parker Center for Gravitation, Cosmology, and Astrophysics, University of Wisconsin–Milwaukee, Milwaukee, WI 53201 (United States); Vitale, Salvatore; Mohapatra, Satya [LIGO Laboratory, Massachusetts Institute of Technology, 185 Albany Street, Cambridge, MA 02139 (United States); Graff, Philip [Department of Physics, University of Maryland, College Park, MD 20742 (United States)

    2016-09-20

    The Advanced Laser Interferometer Gravitational-wave Observatory (LIGO) discovered gravitational waves (GWs) from a binary black hole merger in 2015 September and may soon observe signals from neutron star mergers. There is considerable interest in searching for their faint and rapidly fading electromagnetic (EM) counterparts, though GW position uncertainties are as coarse as hundreds of square degrees. Because LIGO’s sensitivity to binary neutron stars is limited to the local universe, the area on the sky that must be searched could be reduced by weighting positions by mass, luminosity, or star formation in nearby galaxies. Since GW observations provide information about luminosity distance, combining the reconstructed volume with positions and redshifts of galaxies could reduce the area even more dramatically. A key missing ingredient has been a rapid GW parameter estimation algorithm that reconstructs the full distribution of sky location and distance. We demonstrate the first such algorithm, which takes under a minute, fast enough to enable immediate EM follow-up. By combining the three-dimensional posterior with a galaxy catalog, we can reduce the number of galaxies that could conceivably host the event by a factor of 1.4, the total exposure time for the Swift X-ray Telescope by a factor of 2, the total exposure time for a synoptic optical survey by a factor of 2, and the total exposure time for a narrow-field optical telescope by a factor of 3. This encourages us to suggest a new role for small field of view optical instruments in performing targeted searches of the most massive galaxies within the reconstructed volumes.

  9. Modeling the prevention of colorectal cancer from the combined impact of host and behavioral risk factors.

    Science.gov (United States)

    Frampton, Matthew; Houlston, Richard S

    2017-03-01

    This study investigated the utility of modeling modifiable lifestyle risk factors in addition to genetic variation in colorectal cancer (CRC) screening/prevention. We derived a polygenic risk score for CRC susceptibility variants in combination with the established nongenetic risk factors of inflammatory bowel disease (IBD), adiposity, alcohol, red meat, fruit, vegetables, smoking, physical activity, and aspirin. We used the 37 known risk variants and 50 and 100% of all risk variants as calculated from a heritability estimate. We derived absolute risk from UK population age structure, incidence, and mortality rate data. Taking into account all risk factors (known variants), 42.2% of 55- to 59-year-old men with CRC have a risk at least as high as that of an average 60-year-old, the minimum eligible age for the UK NHS National Bowel Cancer Screening Program. If the male population is stratified by known variants and IBD status, then risk-difference estimates imply that for 10,000 50-year-old men in the 99th percentile, 760 cases could be prevented over a 25-year period through the modifiable risk factors, but in the lowest percentile, only 90 could be prevented. CRC screening and prevention centered on modifiable risk factors could be optimized if targeted at individuals at higher polygenic risk.Genet Med 19 3, 314-321.

  10. Helminth burden and ecological factors associated with alterations in wild host gastrointestinal microbiota

    DEFF Research Database (Denmark)

    Newbold, Lindsay K.; Burthe, Sarah J.; Oliver, Anna E.

    2017-01-01

    Infection by gastrointestinal helminths of humans, livestock and wild animals is common, but the impact of such endoparasites on wild hosts and their gut microbiota represents an important overlooked component of population dynamics. Wild host gut microbiota and endoparasites occupy the same phys...... in the proventriculus, diverting host immune responses away from themselves. This study, within live wild animals, provides a vital foundation to better understand the mechanisms that underpin the three-way relationship between helminths, microbiota and hosts....... physical niche spaces with both affecting host nutrition and health. However, associations between the two are poorly understood. Here we used the commonly parasitized European shag (Phalacrocorax aristotelis) as a model wild host. Forty live adults from the same colony were sampled. Endoscopy was employed...

  11. HSV usurps eukaryotic initiation factor 3 subunit M for viral protein translation: novel prevention target.

    Directory of Open Access Journals (Sweden)

    Natalia Cheshenko

    2010-07-01

    Full Text Available Prevention of genital herpes is a global health priority. B5, a recently identified ubiquitous human protein, was proposed as a candidate HSV entry receptor. The current studies explored its role in HSV infection. Viral plaque formation was reduced by approximately 90% in human cells transfected with small interfering RNA targeting B5 or nectin-1, an established entry receptor. However, the mechanisms were distinct. Silencing of nectin-1 prevented intracellular delivery of viral capsids, nuclear transport of a viral tegument protein, and release of calcium stores required for entry. In contrast, B5 silencing had no effect on these markers of entry, but inhibited viral protein translation. Specifically, viral immediate early genes, ICP0 and ICP4, were transcribed, polyadenylated and transported from the nucleus to the cytoplasm, but the viral transcripts did not associate with ribosomes or polysomes in B5-silenced cells. In contrast, immediate early gene viral transcripts were detected in polysome fractions isolated from control cells. These findings are consistent with sequencing studies demonstrating that B5 is eukaryotic initiation factor 3 subunit m (eIF3m. Although B5 silencing altered the polysome profile of cells, silencing had little effect on cellular RNA or protein expression and was not cytotoxic, suggesting that this subunit is not essential for host cellular protein synthesis. Together these results demonstrate that B5 plays a major role in the initiation of HSV protein translation and could provide a novel target for strategies to prevent primary and recurrent herpetic disease.

  12. Downregulation of transcription factor aflR in Aspergillus flavus confers reduction to aflatoxin accumulation in transgenic maize with alteration of host plant architecture.

    Science.gov (United States)

    Masanga, Joel Okoyo; Matheka, Jonathan Mutie; Omer, Rasha Adam; Ommeh, Sheila Cecily; Monda, Ethel Oranga; Alakonya, Amos Emitati

    2015-08-01

    We report success of host-induced gene silencing in downregulation of aflatoxin biosynthesis in Aspergillus flavus infecting maize transformed with a hairpin construct targeting transcription factor aflR. Infestation of crops by aflatoxin-producing fungi results in economic losses as well as negative human and animal health effects. Currently, the control strategies against aflatoxin accumulation are not effective to the small holder farming systems in Africa and this has led to widespread aflatoxin exposure especially in rural populations of sub-Saharan Africa that rely on maize as a staple food crop. A recent strategy called host-induced gene silencing holds great potential for developing aflatoxin-resistant plant germplasm for the African context where farmers are unable to make further investments other than access to the germplasm. We transformed maize with a hairpin construct targeting the aflatoxin biosynthesis transcription factor aflR. The developed transgenic maize were challenged with an aflatoxigenic Aspergillus flavus strain from Eastern Kenya, a region endemic to aflatoxin outbreaks. Our results indicated that aflR was downregulated in A. flavus colonizing transgenic maize. Further, maize kernels from transgenic plants accumulated significantly lower levels of aflatoxins (14-fold) than those from wild type plants. Interestingly, we observed that our silencing cassette caused stunting and reduced kernel placement in the transgenic maize. This could have been due to "off-target" silencing of unintended genes in transformed plants by aflR siRNAs. Overall, this work indicates that host-induced gene silencing has potential in developing aflatoxin-resistant germplasm.

  13. Parasitic plants in agriculture: Chemical ecology of germination and host-plant location as targets for sustainable control: A review

    Science.gov (United States)

    Justin B. Runyon; John F. Tooker; Mark C. Mescher; Consuelo M. De Moraes

    2009-01-01

    Parasitic plants are among the most problematic pests of agricultural crops worldwide. Effective means of control are generally lacking, in part because of the close physiological connection between the established parasite and host plant hindering efficient control using traditional methods. Seed germination and host location are critical early-growth stages that...

  14. Helminth burden and ecological factors associated with alterations in wild host gastrointestinal microbiota

    DEFF Research Database (Denmark)

    Newbold, Lindsay K; Burthe, Sarah J; Oliver, Anna E

    2017-01-01

    physical niche spaces with both affecting host nutrition and health. However, associations between the two are poorly understood. Here we used the commonly parasitized European shag (Phalacrocorax aristotelis) as a model wild host. Forty live adults from the same colony were sampled. Endoscopy was employed...

  15. Host Factors Invovled in the Entry of Coronaviruses into Mammalian Cells

    NARCIS (Netherlands)

    Burkard, C.

    2015-01-01

    Enveloped viruses need to fuse with a host cell membrane in order to deliver their genome into the host cell. While some viruses fuse with the plasma membrane, many viruses are endocytosed prior to fusion. Specific cues in the endosomal microenvironment induce conformational changes in the viral

  16. A chromosomally encoded virulence factor protects the Lyme disease pathogen against host-adaptive immunity.

    Directory of Open Access Journals (Sweden)

    Xiuli Yang

    2009-03-01

    Full Text Available Borrelia burgdorferi, the bacterial pathogen of Lyme borreliosis, differentially expresses select genes in vivo, likely contributing to microbial persistence and disease. Expression analysis of spirochete genes encoding potential membrane proteins showed that surface-located membrane protein 1 (lmp1 transcripts were expressed at high levels in the infected murine heart, especially during early stages of infection. Mice and humans with diagnosed Lyme borreliosis also developed antibodies against Lmp1. Deletion of lmp1 severely impaired the pathogen's ability to persist in diverse murine tissues including the heart, and to induce disease, which was restored upon chromosomal complementation of the mutant with the lmp1 gene. Lmp1 performs an immune-related rather than a metabolic function, as its deletion did not affect microbial persistence in immunodeficient mice, but significantly decreased spirochete resistance to the borreliacidal effects of anti-B. burgdorferi sera in a complement-independent manner. These data demonstrate the existence of a virulence factor that helps the pathogen evade host-acquired immune defense and establish persistent infection in mammals.

  17. The innate immune response to RSV: Advances in our understanding of critical viral and host factors.

    Science.gov (United States)

    Sun, Yan; López, Carolina B

    2017-01-11

    Respiratory syncytial virus (RSV) causes mild to severe respiratory illness in humans and is a major cause of hospitalizations of infants and the elderly. Both the innate and the adaptive immune responses contribute to the control of RSV infection, but despite successful viral clearance, protective immunity against RSV re-infection is usually suboptimal and infections recur. Poor understanding of the mechanisms limiting the induction of long-lasting immunity has delayed the development of an effective vaccine. The innate immune response plays a critical role in driving the development of adaptive immunity and is thus a crucial determinant of the infection outcome. Advances in recent years have improved our understanding of cellular and viral factors that influence the onset and quality of the innate immune response to RSV. These advances include the identification of a complex system of cellular sensors that mediate RSV detection and stimulate transcriptome changes that lead to virus control and the discovery that cell stress and apoptosis participate in the control of RSV infection. In addition, it was recently demonstrated that defective viral genomes (DVGs) generated during RSV replication are the primary inducers of the innate immune response. Newly discovered host pathways involved in the innate response to RSV, together with the potential generation of DVG-derived oligonucleotides, present various novel opportunities for the design of vaccine adjuvants able to induce a protective response against RSV and similar viruses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. miR-370 suppresses HBV gene expression and replication by targeting nuclear factor IA.

    Science.gov (United States)

    Fan, Hongxia; Lv, Ping; Lv, Jing; Zhao, Xiaopei; Liu, Min; Zhang, Guangling; Tang, Hua

    2017-05-01

    Hepatitis B virus (HBV) infection is a major health problem worldwide. The roles of microRNAs in the regulation of HBV expression are being increasingly recognized. In this study, we found that overexpression of miR-370 suppressed HBV gene expression and replication in Huh7 cells, whereas antisense knockdown of endogenous miR-370 enhanced HBV gene expression and replication in Huh7 cells and HepG2.2.15 cells. Further, we identified the transcription factor nuclear factor IA (NFIA) as a new host target of miR-370. Overexpression and knockdown studies showed that NFIA stimulated HBV gene expression and replication. Importantly, overexpression of NFIA counteracted the effect of miR-370 on HBV gene expression and replication. Further mechanistic studies showed that miR-370 suppressed HBV replication and gene expression by repressing HBV Enhancer I activity, and one of the NFIA binding site in the Enhancer I element was responsible for the repressive effect of miR-370 on HBV Enhancer I activity. Altogether, our results demonstrated that miR-370 suppressed HBV gene expression and replication through repressing NFIA expression, which stimulates HBV replication via direct regulation on HBV Enhancer I activities. Our findings may provide a new antiviral strategy for HBV infection. J. Med. Virol. 89:834-844, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  19. Genetic Factors in Rhizobium Affecting the Symbiotic Carbon Costs of N2 Fixation and Host Plant Biomass Production

    DEFF Research Database (Denmark)

    Skøt, L.; Hirsch, P. R.; Witty, J. F.

    1986-01-01

    The effect of genetic factors in Rhizobium on host plant biomass production and on the carbon costs of N2 fixation in pea root nodules was studied. Nine strains of Rhizobium leguminosarum were constructed, each containing one of three symbiotic plasmids in combination with one of three different...

  20. Genome-wide association study identifies vitamin B5 biosynthesis as a host specificity factor in Campylobacter.

    Science.gov (United States)

    Sheppard, Samuel K; Didelot, Xavier; Meric, Guillaume; Torralbo, Alicia; Jolley, Keith A; Kelly, David J; Bentley, Stephen D; Maiden, Martin C J; Parkhill, Julian; Falush, Daniel

    2013-07-16

    Genome-wide association studies have the potential to identify causal genetic factors underlying important phenotypes but have rarely been performed in bacteria. We present an association mapping method that takes into account the clonal population structure of bacteria and is applicable to both core and accessory genome variation. Campylobacter is a common cause of human gastroenteritis as a consequence of its proliferation in multiple farm animal species and its transmission via contaminated meat and poultry. We applied our association mapping method to identify the factors responsible for adaptation to cattle and chickens among 192 Campylobacter isolates from these and other host sources. Phylogenetic analysis implied frequent host switching but also showed that some lineages were strongly associated with particular hosts. A seven-gene region with a host association signal was found. Genes in this region were almost universally present in cattle but were frequently absent in isolates from chickens and wild birds. Three of the seven genes encoded vitamin B5 biosynthesis. We found that isolates from cattle were better able to grow in vitamin B5-depleted media and propose that this difference may be an adaptation to host diet.

  1. Biotic mortality factors affecting emerald ash borer (Agrilus planipennis) are highly dependent on life stage and host tree crown condition.

    Science.gov (United States)

    Jennings, D E; Duan, J J; Shrewsbury, P M

    2015-10-01

    Emerald ash borer (EAB), Agrilus planipennis, is a serious invasive forest pest in North America responsible for killing tens to hundreds of millions of ash trees since it was accidentally introduced in the 1990 s. Although host-plant resistance and natural enemies are known to be important sources of mortality for EAB in Asia, less is known about the importance of different sources of mortality at recently colonized sites in the invaded range of EAB, and how these relate to host tree crown condition. To further our understanding of EAB population dynamics, we used a large-scale field experiment and life-table analyses to quantify the fates of EAB larvae and the relative importance of different biotic mortality factors at 12 recently colonized sites in Maryland. We found that the fates of larvae were highly dependent on EAB life stage and host tree crown condition. In relatively healthy trees (i.e., with a low EAB infestation) and for early instars, host tree resistance was the most important mortality factor. Conversely, in more unhealthy trees (i.e., with a moderate to high EAB infestation) and for later instars, parasitism and predation were the major sources of mortality. Life-table analyses also indicated how the lack of sufficient levels of host tree resistance and natural enemies contribute to rapid population growth of EAB at recently colonized sites. Our findings provide further evidence of the mechanisms by which EAB has been able to successfully establish and spread in North America.

  2. Development and evaluation of a host-targeted antiviral that abrogates herpes simplex virus replication through modulation of arginine-associated metabolic pathways.

    Science.gov (United States)

    Sanchez, Maria Dulfary; Ochoa, Augusto C; Foster, Timothy P

    2016-08-01

    Since their inception five decades ago, most antivirals have been engineered to disrupt a single viral protein or process that is essential for viral replication. This approach has limited the overall therapeutic effectiveness and applicability of current antivirals due to restricted viral specificity, a propensity for development of drug resistance, and an inability to control deleterious host-mediated inflammation. As obligate intracellular parasites, viruses are reliant on host metabolism and macromolecular synthesis pathways. Of these biosynthetic processes, many viruses, including Herpes simplex viruses (HSV), are absolutely dependent on the bioavailability of arginine, a non-essential amino acid that is critical for many physiological and pathophysiological processes associated with either facilitating viral replication or progression of disease. To assess if targeting host arginine-associated metabolic pathways would inhibit HSV replication, a pegylated recombinant human Arginase I (peg-ArgI) was generated and its in vitro anti-herpetic activity was evaluated. Cells continuously treated with peg-ArgI for over 48 h exhibited no signs of cytotoxicity or loss of cell viability. The antiviral activity of peg-ArgI displayed a classical dose-response curve with IC50's in the sub-nanomolar range. peg-ArgI potently inhibited HSV-1 and HSV-2 viral replication, infectious virus production, cell-to-cell spread/transmission and virus-mediated cytopathic effects. Not unexpectedly given its host-targeted mechanism of action, peg-ArgI showed similar effectiveness at controlling replication of single and multidrug resistant HSV-1 mutants. These findings illustrate that targeting host arginine-associated metabolic pathways is an effective means of controlling viral replicative processes. Further exploration into the breadth of viruses inhibited by peg-ArgI, as well as the ability of peg-ArgI to suppress arginine-associated virus-mediated pathophysiological disease

  3. Host transcription factor Speckled 110 kDa (Sp110), a nuclear body protein, is hijacked by hepatitis B virus protein X for viral persistence.

    Science.gov (United States)

    Sengupta, Isha; Das, Dipanwita; Singh, Shivaram Prasad; Chakravarty, Runu; Das, Chandrima

    2017-12-15

    Promyelocytic leukemia nuclear bodies (PML-NB) are sub-nuclear organelles that are the hub of numerous proteins. DNA/RNA viruses often hijack the cellular factors resident in PML-NBs to promote their proliferation in host cells. Hepatitis B virus (HBV), belonging to Hepadnaviridae family, remains undetected in early infection as it does not induce the innate immune response and is known to be the cause of several hepatic diseases leading to cirrhosis and hepatocellular carcinoma. The association of PML-NB proteins and HBV is being addressed in a number of recent studies. Here, we report that the PML-NB protein Speckled 110 kDa (Sp110) is SUMO1-modified and undergoes a deSUMOylation-driven release from the PML-NB in the presence of HBV. Intriguingly, Sp110 knockdown significantly reduced viral DNA load in the culture supernatant by activation of the type I interferon-response pathway. Furthermore, we found that Sp110 differentially regulates several direct target genes of hepatitis B virus protein X (HBx), a viral co-factor. Subsequently, we identified Sp110 as a novel interactor of HBx and found this association to be essential for the exit of Sp110 from the PML-NB during HBV infection and HBx recruitment on the promoter of these genes. HBx, in turn, modulates the recruitment of its associated transcription cofactors p300/HDAC1 to these co-regulated genes, thereby altering the host gene expression program in favor of viral persistence. Thus, we report a mechanism by which HBV can evade host immune response by hijacking the PML-NB protein Sp110, and therefore, we propose it to be a novel target for antiviral therapy. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Factors leading to inflation targeting - the impact of adoption

    NARCIS (Netherlands)

    Samarina, Anna; Sturm, Jan-Egbert

    2013-01-01

    This paper examines how the analysis of inflation targeting (IT) adoption is affected by the choice of the analyzed period. We test whether country characteristics influence the decision to apply IT differently before and after its adoption, using panel probit models for 60 countries over the period

  5. Factors leading to inflation targeting : The impact of adoption

    NARCIS (Netherlands)

    Samarina, Anna; Sturm, Jan-Egbert

    2013-01-01

    This paper examines how the analysis of inflation targeting (IT) adoption is affected by allowing for a structural change after adoption, using panel probit models for 60 countries over the period 1985-2008. Our findings suggest that there is a structural change after IT adoption. Including the

  6. Brucella TIR-like protein TcpB/Btp1 specifically targets the host adaptor protein MAL/TIRAP to promote infection.

    Science.gov (United States)

    Li, Wenna; Ke, Yuehua; Wang, Yufei; Yang, Mingjuan; Gao, Junguang; Zhan, Shaoxia; Xinying, Du; Huang, Liuyu; Li, Wenfeng; Chen, Zeliang; Li, Juan

    2016-08-26

    Brucella spp. are known to avoid host immune recognition and weaken the immune response to infection. Brucella like accomplish this by employing two clever strategies, called the stealth strategy and hijacking strategy. The TIR domain-containing protein (TcpB/Btp1) of Brucella melitensis is thought to be involved in inhibiting host NF-κB activation by binding to adaptors downstream of Toll-like receptors. However, of the five TIR domain-containing adaptors conserved in mammals, whether MyD88 or MAL, even other three adaptors, are specifically targeted by TcpB has not been identified. Here, we confirmed the effect of TcpB on B.melitensis virulence in mice and found that TcpB selectively targets MAL. By using siRNA against MAL, we found that TcpB from B.melitensis is involved in intracellular survival and that MAL affects intracellular replication of B.melitensis. Our results confirm that TcpB specifically targets MAL/TIRAP to disrupt downstream signaling pathways and promote intra-host survival of Brucella spp. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Microscopy-based Assays for High-throughput Screening of Host Factors Involved in Brucella Infection of Hela Cells.

    Science.gov (United States)

    Casanova, Alain; Low, Shyan H; Emmenlauer, Mario; Conde-Alvarez, Raquel; Salcedo, Suzana P; Gorvel, Jean-Pierre; Dehio, Christoph

    2016-08-05

    Brucella species are facultative intracellular pathogens that infect animals as their natural hosts. Transmission to humans is most commonly caused by direct contact with infected animals or by ingestion of contaminated food and can lead to severe chronic infections. Brucella can invade professional and non-professional phagocytic cells and replicates within endoplasmic reticulum (ER)-derived vacuoles. The host factors required for Brucella entry into host cells, avoidance of lysosomal degradation, and replication in the ER-like compartment remain largely unknown. Here we describe two assays to identify host factors involved in Brucella entry and replication in HeLa cells. The protocols describe the use of RNA interference, while alternative screening methods could be applied. The assays are based on the detection of fluorescently labeled bacteria in fluorescently labeled host cells using automated wide-field microscopy. The fluorescent images are analyzed using a standardized image analysis pipeline in CellProfiler which allows single cell-based infection scoring. In the endpoint assay, intracellular replication is measured two days after infection. This allows bacteria to traffic to their replicative niche where proliferation is initiated around 12 hr after bacterial entry. Brucella which have successfully established an intracellular niche will thus have strongly proliferated inside host cells. Since intracellular bacteria will greatly outnumber individual extracellular or intracellular non-replicative bacteria, a strain constitutively expressing GFP can be used. The strong GFP signal is then used to identify infected cells. In contrast, for the entry assay it is essential to differentiate between intracellular and extracellular bacteria. Here, a strain encoding for a tetracycline-inducible GFP is used. Induction of GFP with simultaneous inactivation of extracellular bacteria by gentamicin enables the differentiation between intracellular and extracellular

  8. Interaction of CSFV E2 protein with swine host factors as detected by yeast two-hybrid system.

    Directory of Open Access Journals (Sweden)

    Douglas P Gladue

    Full Text Available E2 is one of the envelope glycoproteins of pestiviruses, including classical swine fever virus (CSFV and bovine viral diarrhea virus (BVDV. E2 is involved in several critical functions, including virus entry into target cells, induction of a protective immune response and virulence in swine. However, there is no information regarding any host binding partners for the E2 proteins. Here, we utilized the yeast two-hybrid system and identified fifty-seven host proteins as positive binding partners which bound E2 from both CSFV and BVDV with the exception of two proteins that were found to be positive for binding only to CSFV E2. Alanine scanning of CSFV E2 demonstrated that the binding sites for these cellular proteins on E2 are likely non-linear binding sites. The possible roles of the identified host proteins are discussed as the results presented here will be important for future studies to elucidate mechanisms of host protein-virus interactions during pestivirus infection. However, due to the limitations of the yeast two hybrid system, the proteins identified is not exhaustive and each interaction identified needs to be confirmed by independent experimental approaches in the context of virus-infected cells before any definitive conclusion can be drawn on relevance for the virus life cycle.

  9. Identification of RNA Binding Proteins Associated with Dengue Virus RNA in Infected Cells Reveals Temporally Distinct Host Factor Requirements.

    Directory of Open Access Journals (Sweden)

    Olga V Viktorovskaya

    2016-08-01

    Full Text Available There are currently no vaccines or antivirals available for dengue virus infection, which can cause dengue hemorrhagic fever and death. A better understanding of the host pathogen interaction is required to develop effective therapies to treat DENV. In particular, very little is known about how cellular RNA binding proteins interact with viral RNAs. RNAs within cells are not naked; rather they are coated with proteins that affect localization, stability, translation and (for viruses replication.Seventy-nine novel RNA binding proteins for dengue virus (DENV were identified by cross-linking proteins to dengue viral RNA during a live infection in human cells. These cellular proteins were specific and distinct from those previously identified for poliovirus, suggesting a specialized role for these factors in DENV amplification. Knockdown of these proteins demonstrated their function as viral host factors, with evidence for some factors acting early, while others late in infection. Their requirement by DENV for efficient amplification is likely specific, since protein knockdown did not impair the cell fitness for viral amplification of an unrelated virus. The protein abundances of these host factors were not significantly altered during DENV infection, suggesting their interaction with DENV RNA was due to specific recruitment mechanisms. However, at the global proteome level, DENV altered the abundances of proteins in particular classes, including transporter proteins, which were down regulated, and proteins in the ubiquitin proteasome pathway, which were up regulated.The method for identification of host factors described here is robust and broadly applicable to all RNA viruses, providing an avenue to determine the conserved or distinct mechanisms through which diverse viruses manage the viral RNA within cells. This study significantly increases the number of cellular factors known to interact with DENV and reveals how DENV modulates and usurps

  10. Right on target: Exploring the factors leading to inflation targeting adoption

    NARCIS (Netherlands)

    Samarina, A..; de Haan, J.

    2014-01-01

    This paper examines which economic, fiscal, external, financial, and institutional characteristics of countries affect the likelihood that they adopt inflation targeting (IT) as their monetary policy strategy. We estimate a panel binary response model for 60 countries and two subsamples consisting

  11. Yeast screens for host factors in positive-strand RNA virus replication based on a library of temperature-sensitive mutants.

    Science.gov (United States)

    Nawaz-ul-Rehman, Muhammad Shah; Reddisiva Prasanth, K; Baker, Jannine; Nagy, Peter D

    2013-02-01

    RNA viruses exploit host cells by altering cellular pathways, recruiting host factors, remodeling intracellular membranes and escaping host antiviral responses. Model hosts, such as Saccharomyces cerevisiae (yeast), are valuable to identify host factors involved in viral RNA replication. The many advantages of using yeast include the availability of various yeast mutant libraries, such as (i) single gene-deletion library; (ii) the essential gene library (yTHC); and (iii) the yeast ORF over-expression library. Here, we have used a novel temperature-sensitive (ts) mutant library of essential yeast genes to identify 118 host proteins affecting replication of Tomato bushy stunt virus, in yeast model host. Testing 787 ts mutants led to the identification of host factors, of which 72 proteins facilitated TBSV replication in yeast and 46 proteins were inhibitory. Altogether, ~85% of the identified proteins are novel host factors affecting tombusvirus replication. The ts mutant library screen also led to the identification of 17 essential genes, which have been documented before, thus confirming the importance of these genomic screens. Overall, we show the power of ts mutant library in identification of host factors for RNA virus replication. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. Identification of host cytosolic sensors and bacterial factors regulating the type I interferon response to Legionella pneumophila.

    Directory of Open Access Journals (Sweden)

    Kathryn M Monroe

    2009-11-01

    Full Text Available Legionella pneumophila is a gram-negative bacterial pathogen that replicates in host macrophages and causes a severe pneumonia called Legionnaires' Disease. The innate immune response to L. pneumophila remains poorly understood. Here we focused on identifying host and bacterial factors involved in the production of type I interferons (IFN in response to L. pneumophila. It was previously suggested that the delivery of L. pneumophila DNA to the host cell cytosol is the primary signal that induces the type I IFN response. However, our data are not easily reconciled with this model. We provide genetic evidence that two RNA-sensing proteins, RIG-I and MDA5, participate in the IFN response to L. pneumophila. Importantly, these sensors do not seem to be required for the IFN response to L. pneumophila DNA, whereas we found that RIG-I was required for the response to L. pneumophila RNA. Thus, we hypothesize that bacterial RNA, or perhaps an induced host RNA, is the primary stimulus inducing the IFN response to L. pneumophila. Our study also identified a secreted effector protein, SdhA, as a key suppressor of the IFN response to L. pneumophila. Although viral suppressors of cytosolic RNA-sensing pathways have been previously identified, analogous bacterial factors have not been described. Thus, our results provide new insights into the molecular mechanisms by which an intracellular bacterial pathogen activates and also represses innate immune responses.

  13. Identification and functional characterization of Rca1, a transcription factor involved in both antifungal susceptibility and host response in Candida albicans.

    Science.gov (United States)

    Vandeputte, Patrick; Pradervand, Sylvain; Ischer, Françoise; Coste, Alix T; Ferrari, Sélène; Harshman, Keith; Sanglard, Dominique

    2012-07-01

    The identification of novel transcription factors associated with antifungal response may allow the discovery of fungus-specific targets for new therapeutic strategies. A collection of 241 Candida albicans transcriptional regulator mutants was screened for altered susceptibility to fluconazole, caspofungin, amphotericin B, and 5-fluorocytosine. Thirteen of these mutants not yet identified in terms of their role in antifungal response were further investigated, and the function of one of them, a mutant of orf19.6102 (RCA1), was characterized by transcriptome analysis. Strand-specific RNA sequencing and phenotypic tests assigned Rca1 as the regulator of hyphal formation through the cyclic AMP/protein kinase A (cAMP/PKA) signaling pathway and the transcription factor Efg1, but also probably through its interaction with a transcriptional repressor, most likely Tup1. The mechanisms responsible for the high level of resistance to caspofungin and fluconazole observed resulting from RCA1 deletion were investigated. From our observations, we propose that caspofungin resistance was the consequence of the deregulation of cell wall gene expression and that fluconazole resistance was linked to the modulation of the cAMP/PKA signaling pathway activity. In conclusion, our large-scale screening of a C. albicans transcription factor mutant collection allowed the identification of new effectors of the response to antifungals. The functional characterization of Rca1 assigned this transcription factor and its downstream targets as promising candidates for the development of new therapeutic strategies, as Rca1 influences host sensing, hyphal development, and antifungal response.

  14. Adaptation to toxic hosts as a factor in the evolution of insecticide resistance.

    Science.gov (United States)

    Alyokhin, Andrei; Chen, Yolanda H

    2017-06-01

    Insecticide resistance is a serious economic problem that jeopardizes sustainability of chemical control of herbivorous insects and related arthropods. It can be viewed as a specific case of adaptation to toxic chemicals, which has been driven in large part, but not exclusively, by the necessity for insect pests to tolerate defensive compounds produced by their host plants. Synthetic insecticides may simply change expression of specific sets of detoxification genes that have evolved due to ancestral associations with host plants. Feeding on host plants with more abundant or novel secondary metabolites has even been shown to prime insect herbivores to tolerate pesticides. Clear understanding of basic evolutionary processes is important for achieving lasting success in managing herbivorous arthropods. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Influence of temperature on symptom expression, detection of host factors in virus infected Piper nigrum L.

    Science.gov (United States)

    Umadevi, P; Bhat, A I; Krishnamurthy, K S; Anandaraj, M

    2016-05-01

    Expression of symptoms in black pepper plants (Piper nigrum) infected with Piper yellow mottle virus (PYMoV) vary depending on the season, being high during summer months. Here, we explored the influence of temperature on symptom expression in PYMoV infected P. nigrum. Our controlled environment study revealed increase in virus titer, total proteins, IAA and reducing sugars when exposed to temperature stress. There was change in the 2-D separated protein before and after exposure. The 2-D proteomics LC-MS identified host and viral proteins suggesting virus-host interaction during symptom expression. The analysis as well as detection of host biochemical compounds may help in understanding the detailed mechanisms underlying the viral replication and damage to the crop, and thereby plan management strategies.

  16. Vascular Risk Factors as Treatment Target to Prevent Cognitive Decline

    NARCIS (Netherlands)

    Richard, Edo; Moll van Charante, Eric P.; van Gool, Willem A.

    2012-01-01

    Epidemiological studies have consistently shown that vascular risk factors including hypertension, diabetes, obesity, hypercholesterolemia, smoking, and lack of physical exercise are associated with an increased risk of cognitive decline and dementia. Neuroradiological and neuropathological studies

  17. Control of stochastic gene expression by host factors at the HIV promoter.

    Directory of Open Access Journals (Sweden)

    John C Burnett

    2009-01-01

    Full Text Available The HIV promoter within the viral long terminal repeat (LTR orchestrates many aspects of the viral life cycle, from the dynamics of viral gene expression and replication to the establishment of a latent state. In particular, after viral integration into the host genome, stochastic fluctuations in viral gene expression amplified by the Tat positive feedback loop can contribute to the formation of either a productive, transactivated state or an inactive state. In a significant fraction of cells harboring an integrated copy of the HIV-1 model provirus (LTR-GFP-IRES-Tat, this bimodal gene expression profile is dynamic, as cells spontaneously and continuously flip between active (Bright and inactive (Off expression modes. Furthermore, these switching dynamics may contribute to the establishment and maintenance of proviral latency, because after viral integration long delays in gene expression can occur before viral transactivation. The HIV-1 promoter contains cis-acting Sp1 and NF-kappaB elements that regulate gene expression via the recruitment of both activating and repressing complexes. We hypothesized that interplay in the recruitment of such positive and negative factors could modulate the stability of the Bright and Off modes and thereby alter the sensitivity of viral gene expression to stochastic fluctuations in the Tat feedback loop. Using model lentivirus variants with mutations introduced in the Sp1 and NF-kappaB elements, we employed flow cytometry, mRNA quantification, pharmacological perturbations, and chromatin immunoprecipitation to reveal significant functional differences in contributions of each site to viral gene regulation. Specifically, the Sp1 sites apparently stabilize both the Bright and the Off states, such that their mutation promotes noisy gene expression and reduction in the regulation of histone acetylation and deacetylation. Furthermore, the NF-kappaB sites exhibit distinct properties, with kappaB site I serving a

  18. Quantotypic Properties of QconCAT Peptides Targeting Bovine Host Response to Streptococcus uberis

    DEFF Research Database (Denmark)

    Bislev, Stine Lønnerup; Kusebauch, Ulrike; Codrea, Marius Cosmin

    2012-01-01

    Mammalian host response to pathogens is associated with fluctuations in high abundant proteins in body fluids as well as in regulation of proteins expressed in relatively low copy numbers like cytokines secreted from immune cells and endothelium. Hence, efficient monitoring of proteins associated...

  19. Identification of host-microbe interaction factors in the genomes of soft rot-associated pathogens Dickeya dadantii 3937 and Pectobacterium carotovorum WPP14 with supervised machine learning.

    Science.gov (United States)

    Ma, Bing; Charkowski, Amy O; Glasner, Jeremy D; Perna, Nicole T

    2014-06-21

    A wealth of genome sequences has provided thousands of genes of unknown function, but identification of functions for the large numbers of hypothetical genes in phytopathogens remains a challenge that impacts all research on plant-microbe interactions. Decades of research on the molecular basis of pathogenesis focused on a limited number of factors associated with long-known host-microbe interaction systems, providing limited direction into this challenge. Computational approaches to identify virulence genes often rely on two strategies: searching for sequence similarity to known host-microbe interaction factors from other organisms, and identifying islands of genes that discriminate between pathogens of one type and closely related non-pathogens or pathogens of a different type. The former is limited to known genes, excluding vast collections of genes of unknown function found in every genome. The latter lacks specificity, since many genes in genomic islands have little to do with host-interaction. In this study, we developed a supervised machine learning approach that was designed to recognize patterns from large and disparate data types, in order to identify candidate host-microbe interaction factors. The soft rot Enterobacteriaceae strains Dickeya dadantii 3937 and Pectobacterium carotovorum WPP14 were used for development of this tool, because these pathogens are important on multiple high value crops in agriculture worldwide and more genomic and functional data is available for the Enterobacteriaceae than any other microbial family. Our approach achieved greater than 90% precision and a recall rate over 80% in 10-fold cross validation tests. Application of the learning scheme to the complete genome of these two organisms generated a list of roughly 200 candidates, many of which were previously not implicated in plant-microbe interaction and many of which are of completely unknown function. These lists provide new targets for experimental validation and

  20. siRNA Screen Identifies Trafficking Host Factors that Modulate Alphavirus Infection.

    Directory of Open Access Journals (Sweden)

    Sheli R Radoshitzky

    2016-03-01

    Full Text Available Little is known about the repertoire of cellular factors involved in the replication of pathogenic alphaviruses. To uncover molecular regulators of alphavirus infection, and to identify candidate drug targets, we performed a high-content imaging-based siRNA screen. We revealed an actin-remodeling pathway involving Rac1, PIP5K1- α, and Arp3, as essential for infection by pathogenic alphaviruses. Infection causes cellular actin rearrangements into large bundles of actin filaments termed actin foci. Actin foci are generated late in infection concomitantly with alphavirus envelope (E2 expression and are dependent on the activities of Rac1 and Arp3. E2 associates with actin in alphavirus-infected cells and co-localizes with Rac1-PIP5K1-α along actin filaments in the context of actin foci. Finally, Rac1, Arp3, and actin polymerization inhibitors interfere with E2 trafficking from the trans-Golgi network to the cell surface, suggesting a plausible model in which transport of E2 to the cell surface is mediated via Rac1- and Arp3-dependent actin remodeling.

  1. Cell Penetrating Bispecific Antibodies for Targeting Oncogenic Transcription Factors in Advanced Prostate Cancer

    Science.gov (United States)

    2016-12-01

    Bispecific Antibodies for Targeting Oncogenic Transcription Factors in Advanced Prostate Cancer Michael Lilly, MD Richard Weisbart, MD Medical...0534, entitled Cell- penetrating bispecific antibodies for targeting oncogenic transcription factors in advanced prostate cancer . The research is a... Prostate cancer , antibody, bispecific, androgen receptor, castration-resistant 3

  2. Factors affecting virus dynamics and microbial host-virus interactions in marine environments

    NARCIS (Netherlands)

    Mojica, K.D.A.; Brussaard, C.P.D.

    2014-01-01

    Marine microorganisms constitute the largest percentage of living biomass and serve as the major driving force behind nutrient and energy cycles. While viruses only comprise a small percentage of this biomass (i.e., 5%), they dominate in numerical abundance and genetic diversity. Through host

  3. Identification of a Transcription Factor That Regulates Host Cell Exit and Virulence of Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Lalitha Srinivasan

    2016-05-01

    Full Text Available The interaction of Mycobacterium tuberculosis (Mtb with host cell death signaling pathways is characterized by an initial anti-apoptotic phase followed by a pro-necrotic phase to allow for host cell exit of the bacteria. The bacterial modulators regulating necrosis induction are poorly understood. Here we describe the identification of a transcriptional repressor, Rv3167c responsible for regulating the escape of Mtb from the phagosome. Increased cytosolic localization of MtbΔRv3167c was accompanied by elevated levels of mitochondrial reactive oxygen species and reduced activation of the protein kinase Akt, and these events were critical for the induction of host cell necrosis and macroautophagy. The increase in necrosis led to an increase in bacterial virulence as reflected in higher bacterial burden and reduced survival of mice infected with MtbΔRv3167c. The regulon of Rv3167c thus contains the bacterial mediators involved in escape from the phagosome and host cell necrosis induction, both of which are crucial steps in the intracellular lifecycle and virulence of Mtb.

  4. Variations on the larval incubation of Anodontites trapesialis (Unionoida, Mycetopodidae): Synergetic effect of the environmental factors and host availability

    OpenAIRE

    Callil,CT.; Krinski,D.; Silva,FA.

    2012-01-01

    The unionid Anodontites trapesilais (Lamarck, 1819) like most freshwater mussels is a parasite of fish. So it is trivial to assume that the availability of hosts is an important factor for the maintenance of unionoid populations. What seems obvious is not always so easy to demonstrate. This study proposes to investigate the effects of abiotic and biotic variables related to the incubation of larvae in A. trapesialis. For this, we estimate different biological indexes and try to capture the di...

  5. Listeriolysin S Is a Streptolysin S-Like Virulence Factor That Targets Exclusively Prokaryotic CellsIn Vivo.

    Science.gov (United States)

    Quereda, Juan J; Nahori, Marie A; Meza-Torres, Jazmín; Sachse, Martin; Titos-Jiménez, Patricia; Gomez-Laguna, Jaime; Dussurget, Olivier; Cossart, Pascale; Pizarro-Cerdá, Javier

    2017-04-04

    Streptolysin S (SLS)-like virulence factors from clinically relevant Gram-positive pathogens have been proposed to behave as potent cytotoxins, playing key roles in tissue infection. Listeriolysin S (LLS) is an SLS-like hemolysin/bacteriocin present among Listeria monocytogenes strains responsible for human listeriosis outbreaks. As LLS cytotoxic activity has been associated with virulence, we investigated the LLS-specific contribution to host tissue infection. Surprisingly, we first show that LLS causes only weak red blood cell (RBC) hemolysis in vitro and neither confers resistance to phagocytic killing nor favors survival of L. monocytogenes within the blood cells or in the extracellular space (in the plasma). We reveal that LLS does not elicit specific immune responses, is not cytotoxic for eukaryotic cells, and does not impact cell infection by L. monocytogenes Using in vitro cell infection systems and a murine intravenous infection model, we actually demonstrate that LLS expression is undetectable during infection of cells and murine inner organs. Importantly, upon intravenous animal inoculation, L. monocytogenes is found in the gastrointestinal system, and only in this environment LLS expression is detected in vivo Finally, we confirm that LLS production is associated with destruction of target bacteria. Our results demonstrate therefore that LLS does not contribute to L. monocytogenes tissue injury and virulence in inner host organs as previously reported. Moreover, we describe that LlsB, a putative posttranslational modification enzyme encoded in the LLS operon, is necessary for murine inner organ colonization. Overall, we demonstrate that LLS is the first SLS-like virulence factor targeting exclusively prokaryotic cells during in vivo infections. IMPORTANCE The most severe human listeriosis outbreaks are caused by L. monocytogenes strains harboring listeriolysin S (LLS), previously described as a cytotoxin that plays a critical role in host inner

  6. Human nonsense-mediated RNA decay initiates widely by endonucleolysis and targets snoRNA host genes

    DEFF Research Database (Denmark)

    Lykke-Andersen, Søren; Chen, Yun; Ardal, Britt

    2014-01-01

    . We also show that a large proportion of genes hosting snoRNAs in their introns produce considerable amounts of NMD-sensitive splice variants, indicating that these RNAs are merely by-products of a primary snoRNA production process. Additionally, transcripts from genes encoding multiple snoRNAs often...... yield alternative transcript isoforms that allow for differential expression of individual coencoded snoRNAs. Based on our findings, we hypothesize that snoRNA host genes need to be highly transcribed to accommodate high levels of snoRNA production and that the expression of individual snoRNAs...... and their cognate spliced RNA can be uncoupled via alternative splicing and NMD....

  7. Disruption and formation of surface salt bridges are coupled to DNA binding by integration host factor: a computational analysis

    OpenAIRE

    Ma, L.; Sundlass, N. K.; Raines, R. T.; Cui, Q.

    2010-01-01

    Revealing the thermodynamic driving force of protein/DNA interactions is crucial to the understanding of factors that dictate the properties and function of protein-DNA complexes. For the binding of DNA to DNA-wrapping proteins, such as the integration host factor (IHF), Record and co-workers have proposed that the disruption of a large number of pre-existing salt-bridges is coupled with the binding process (J. Mol. Biol., 310, 2001, 379). To test this proposal, we have carried out explicit s...

  8. siRNA Screen Identifies Trafficking Host Factors that Modulate Alphavirus Infection

    Science.gov (United States)

    2016-05-20

    of host modulators of virus infection Scott C Weaver, M.S., Ph.D. Professor, Institute for Human Infections and Immunity , The University of Texas...Koyuncu OO, Enquist LW (2011) Subversion of the actin cytoskeleton during 885 viral infection. Nat Rev Microbiol 9: 427-439. 886 40. Sanchez EG...Imelli N, Boucke K, et al. (2008) Subversion of CtBP1-891 controlled macropinocytosis by human adenovirus serotype 3. EMBO J 27: 956-969. 892 43

  9. Optimal control issues in plant disease with host demographic factor and botanical fungicides

    Science.gov (United States)

    Anggriani, N.; Mardiyah, M.; Istifadah, N.; Supriatna, A. K.

    2018-03-01

    In this paper, we discuss a mathematical model of plant disease with the effect of fungicide. We assume that the fungicide is given as a preventive treatment to infectious plants. The model is constructed based on the development of the disease in which the monomolecular is monocyclic. We show the value of the Basic Reproduction Number (BRN) ℛ0 of the plant disease transmission. The BRN is computed from the largest eigenvalue of the next generation matrix of the model. The result shows that in the region where ℛ0 greater than one there is a single stable endemic equilibrium. However, in the region where ℛ0 less than one this endemic equilibrium becomes unstable. The dynamics of the model is highly sensitive to changes in contact rate and infectious period. We also discuss the optimal control of the infected plant host by considering a preventive treatment aimed at reducing the infected host plant. The obtaining optimal control shows that it can reduce the number of infected hosts compared to that without control. Some numerical simulations are also given to illustrate our analytical results.

  10. Factors affecting the anthelmintic efficacy of papaya latex in vivo: host sex and intensity of infection.

    Science.gov (United States)

    Luoga, Wenceslaus; Mansur, Fadlul; Lowe, Ann; Duce, Ian R; Buttle, David J; Behnke, Jerzy M

    2015-07-01

    The development of plant-derived cysteine proteinases, such as those in papaya latex, as novel anthelmintics requires that the variables affecting efficacy be fully evaluated. Here, we conducted two experiments, the first to test for any effect of host sex and the second to determine whether the intensity of the worm burden carried by mice would influence efficacy. In both experiments, we used the standard C3H mouse reference strain in which papaya latex supernatant (PLS) consistently shows >80 % reduction in Heligmosomoides bakeri worm burdens, but to broaden the perspective, we also included for comparison mice of other strains that are known to respond more poorly to treatment with papaya latex. Our results confirmed that there is a strong genetic influence affecting efficacy of PLS in removing adult worm burdens. However, there was no effect of host sex on efficacy (C3H and NIH) and no effect of infection intensity (C3H and BALB/c). These results offer optimism that plant-derived cysteine proteinases (CPs), such as these from papaya latex, can function as effective anthelmintics, with neither host sex nor infection intensity presenting further hurdles to impede their development for future medicinal and veterinary usage.

  11. Host and geographical factors influence the thermal niche of enteric bacteria isolated from native Australian mammals.

    Science.gov (United States)

    Okada, S; Gordon, D M

    2001-10-01

    The thermal profiles of 118 bacterial strains, representing six species of the family Enterobacteriaceae, isolated from a variety of native Australian mammals were determined under in vitro conditions. Each of the bacterial species had a unique thermal profile and differed in their minimum or maximum temperature for growth and in their response to changing temperatures. The taxonomic classification of the host from which the bacterial strains were isolated explained a significant amount of the variation in thermal profile among strains of a species. Host effects were detected at all taxonomic levels: order, family, genus, and species. The locality (State or Territory) or climate zone from which the strain was collected explained a significant amount of the variation in the thermal profile of Citrobacter freundii, Enterobacter cloacae and Klebsiella pneumoniae strains. Genetically similar strains, as determined by allozyme profiles, had similar thermal profiles for the bacterial species Hafnia alvei and Escherichia coli. The results of this study indicate that there are potentially many aspects of host biology that may determine the thermal profile of these bacteria.

  12. Validation-based insertional mutagenesis for identification of Nup214 as a host factor for EV71 replication in RD cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bei; Zhang, XiaoYu; Zhao, Zhendong, E-mail: timjszzd@163.com

    2013-08-02

    Highlights: •We introduced a new mutagenesis strategy named VBIM to the viral research. •This method can identify either host factors or host restriction factors. •Using VBIM system, we identified Nup214 as a host factor for EV71 replication in RD cells. -- Abstract: Lentiviral validation-based insertional mutagenesis (VBIM) is a sophisticated, forward genetic approach that is used for the investigation of signal transduction in mammalian cells. Using VBIM, we conducted function-based genetic screening for host genes that affect enterovirus 71 (EV71) viral replication. This included host factors that are required for the life cycle of EV71 and host restriction factors that inhibit EV71 replication. Several cell clones, resistant to EV71, were produced using EV71 infection as a selection pressure and the nuclear pore protein 214 (Nup214) was identified as a host factor required for EV71 replication. In SD2-2, the corresponding VBIM lentivirus transformed clone, the expression of endogenous Nup214 was significantly down-regulated by the reverse inserted VBIM promoter. After Cre recombinase-mediated excision of the VBIM promoter, the expression of Nup214 recovered and the clone regained sensitivity to the EV71 infection. Furthermore, over-expression of Nup214 in the cells suggested that Nup214 was promoting EV71 replication. Results of this study indicate that a successful mutagenesis strategy has been established for screening host genes related to viral replication.

  13. Validation-based insertional mutagenesis for identification of Nup214 as a host factor for EV71 replication in RD cells

    International Nuclear Information System (INIS)

    Wang, Bei; Zhang, XiaoYu; Zhao, Zhendong

    2013-01-01

    Highlights: •We introduced a new mutagenesis strategy named VBIM to the viral research. •This method can identify either host factors or host restriction factors. •Using VBIM system, we identified Nup214 as a host factor for EV71 replication in RD cells. -- Abstract: Lentiviral validation-based insertional mutagenesis (VBIM) is a sophisticated, forward genetic approach that is used for the investigation of signal transduction in mammalian cells. Using VBIM, we conducted function-based genetic screening for host genes that affect enterovirus 71 (EV71) viral replication. This included host factors that are required for the life cycle of EV71 and host restriction factors that inhibit EV71 replication. Several cell clones, resistant to EV71, were produced using EV71 infection as a selection pressure and the nuclear pore protein 214 (Nup214) was identified as a host factor required for EV71 replication. In SD2-2, the corresponding VBIM lentivirus transformed clone, the expression of endogenous Nup214 was significantly down-regulated by the reverse inserted VBIM promoter. After Cre recombinase-mediated excision of the VBIM promoter, the expression of Nup214 recovered and the clone regained sensitivity to the EV71 infection. Furthermore, over-expression of Nup214 in the cells suggested that Nup214 was promoting EV71 replication. Results of this study indicate that a successful mutagenesis strategy has been established for screening host genes related to viral replication

  14. Co-factors necessary for PPAR mediated transactivation of endogenous target genes

    DEFF Research Database (Denmark)

    Grøntved, Lars; Nielsen, Ronni; Stunnenberg, Henk

    of endogenous target gene in different cell types are elusive. To mutually compare the ability of the PPAR subtypes to activate endogenous target genes in a given cell, PPARa, PPARb/d and PPARg2 were HA tagged and rapidly, equally and synchronously expressed using adenoviral delivery. Within a few hours after...... subtype specific activation of target genes. Accumulating evidence suggests that transcriptional co-factors can function as master regulators for nuclear receptors and impose promoter selectivity. To study co-factor necessity for PPAR mediated transactivation of endogenous target genes, specific co...

  15. Streptococcus pyogenes Sortase Mutants Are Highly Susceptible to Killing by Host Factors Due to Aberrant Envelope Physiology

    Science.gov (United States)

    Raz, Assaf; Tanasescu, Ana-Maria; Zhao, Anna M.; Serrano, Anna; Alston, Tricia; Sol, Asaf; Bachrach, Gilad; Fischetti, Vincent A.

    2015-01-01

    Cell wall anchored virulence factors are critical for infection and colonization of the host by Gram-positive bacteria. Such proteins have an N-terminal leader sequence and a C-terminal sorting signal, composed of an LPXTG motif, a hydrophobic stretch, and a few positively charged amino acids. The sorting signal halts translocation across the membrane, allowing sortase to cleave the LPXTG motif, leading to surface anchoring. Deletion of sortase prevents the anchoring of virulence factors to the wall; the effects on bacterial physiology however, have not been thoroughly characterized. Here we show that deletion of Streptococcus pyogenes sortase A leads to accumulation of sorting intermediates, particularly at the septum, altering cellular morphology and physiology, and compromising membrane integrity. Such cells are highly sensitive to cathelicidin, and are rapidly killed in blood and plasma. These phenomena are not a loss-of-function effect caused by the absence of anchored surface proteins, but specifically result from the accumulation of sorting intermediates. Reduction in the level of sorting intermediates leads to a return of the sortase mutant to normal morphology, while expression of M protein with an altered LPXTG motif in wild type cells leads to toxicity in the host environment, similar to that observed in the sortase mutant. These unanticipated effects suggest that inhibition of sortase by small-molecule inhibitors could similarly lead to the rapid elimination of pathogens from an infected host, making such inhibitors much better anti-bacterial agents than previously believed. PMID:26484774

  16. THE BIOTIC FACTOR OF TREMATOD OPISTHORHIS FELINEUS INVASION INFLUENCE ON HOST IMMUNE STATUS AND SOMATIC CELLS PROLIFERATIVE ACTIVITY

    Directory of Open Access Journals (Sweden)

    A. G. Rybka

    2016-01-01

    Full Text Available The paper confirms long-time opisthorhis invasion role as a risk factor of host immune system reconstitution as well as an important factor in holangiocarcinomas development. It was shown that opisthorhosis invasion primal stage induce host immune system reconstitution. Host immune B-cells system is activated by metacercaria antigens, while the same antigens inhibits T-cells activity. Opisthorhis metabolites stimulate proliferative mithogen-induced T-cells acti vity. Chronic opisthorchis invasion leads to immune system disbalance. It means: decrease of specific and non-speci fic natural killers activity, number of high proliferative activity T-lymphocytes and the shift of regulatory T-cells subset to suppressors prevalence. At the same time specific as well as non-specific T-suppressors functional ability is very low. It was shown T-cells helper-amplifier activation. Despite of circulating B-cells decrease the antibody produced cells number is spleen increases significantly at the same time with circulating immune complexes accumulation. Even 3–6 month after dehelmintisation the immune system disbalance decreases but lefts. In addition, chronic opisthorhis invasion leads to the proliferative processes activation in ductal epithelium, liver, lymph nodes and in other organs which leads to cancer proliferation. According to the results obtained the opisthorhis infected patients needs to be immunocorrected before as well as after dehelmintisation for holangiocancerogenesis profylaxis.

  17. KAP1 Is a Host Restriction Factor That Promotes Human Adenovirus E1B-55K SUMO Modification.

    Science.gov (United States)

    Bürck, Carolin; Mund, Andreas; Berscheminski, Julia; Kieweg, Lisa; Müncheberg, Sarah; Dobner, Thomas; Schreiner, Sabrina

    2016-01-15

    Once transported to the replication sites, human adenoviruses (HAdVs) need to ensure decondensation and transcriptional activation of their viral genomes to synthesize viral proteins and initiate steps to reprogram the host cell for viral replication. These early stages during adenoviral infection are poorly characterized but represent a decisive moment in the establishment of a productive infection. Here, we identify a novel host viral restriction factor, KAP1. This heterochromatin-associated transcription factor regulates the dynamic organization of the host chromatin structure via its ability to influence epigenetic marks and chromatin compaction. In response to DNA damage, KAP1 is phosphorylated and functionally inactive, resulting in chromatin relaxation. We discovered that KAP1 posttranslational modification is dramatically altered during HAdV infection to limit the antiviral capacity of this host restriction factor, which represents an essential step required for efficient viral replication. Conversely, we also observed during infection an HAdV-mediated decrease of KAP1 SUMO moieties, known to promote chromatin decondensation events. Based on our findings, we provide evidence that HAdV induces KAP1 deSUMOylation to minimize epigenetic gene silencing and to promote SUMO modification of E1B-55K by a so far unknown mechanism. Here we describe a novel cellular restriction factor for human adenovirus (HAdV) that sheds light on very early modulation processes in viral infection. We reported that chromatin formation and cellular SWI/SNF chromatin remodeling play key roles in HAdV transcriptional regulation. We observed that the cellular chromatin-associated factor and epigenetic reader SPOC1 represses HAdV infection and gene expression. Here, we illustrate the role of the SPOC1-interacting factor KAP1 during productive HAdV growth. KAP1 binds to the viral E1B-55K protein, promoting its SUMO modification, therefore illustrating a crucial step for efficient viral

  18. Identification of Burkholderia cenocepacia strain H111 virulence factors using nonmammalian infection hosts

    DEFF Research Database (Denmark)

    Schwager, Stephan; Agnoli, Kirsty; Köthe, Manuela

    2013-01-01

    or siderophores. Instead, the mutants contained insertions in metabolic and regulatory genes. Mutants attenuated in virulence in the C. elegans infection model were also tested in the Drosophila melanogaster pricking model, and those also attenuated in this model were further tested in Galleria mellonella. Six...... of the 22 mutants were attenuated in D. melanogaster, and five of these were less pathogenic in the G. mellonella model. We show that genes encoding enzymes of the purine, pyrimidine, and shikimate biosynthesis pathways are critical for virulence in multiple host models of infection....

  19. Induction of NKG2D ligands by gamma radiation and tumor necrosis factor-alpha may participate in the tissue damage during acute graft-versus-host disease.

    Science.gov (United States)

    Gannagé, Monique; Buzyn, Agnès; Bogiatzi, Sofia I; Lambert, Marion; Soumelis, Vassili; Dal Cortivo, Liliane; Cavazzana-Calvo, Marina; Brousse, Nicole; Caillat-Zucman, Sophie

    2008-03-27

    Immunopathology of acute graft-versus-host disease (aGVHD) involves secretion of proinflammatory cytokines with subsequent expression of danger signals by injured host tissues. This explanation, however, does not explain the cluster of aGVHD target organs (skin, gut, and liver). NKG2D ligands (MICA/B and ULBP1-3 proteins) are stress-induced molecules that act as danger signals to alert NK and alphabeta or gammadelta CD8 T cells through engagement of the activating NKG2D receptor. We observed a strong and reversible induction of MICA/B expression in skin and liver sections during aGVHD. Tumor necrosis factor-alpha and gamma-radiation up-regulated expression of MICA/B and ULBP proteins in vitro on skin and intestine epithelial cell lines and ex vivo in normal skin explants. This NKG2D-ligand induction was regulated by a complex interplay between NFkB and JNK activation pathways. Our data suggest that NKG2D ligand induction might participate in the amplification loop that leads to tissue damage during aGVHD.

  20. A Plasmodium falciparum host-targeting motif functions in export during blood stage infection of the rodent malarial parasite Plasmodium berghei.

    Directory of Open Access Journals (Sweden)

    Julia J MacKenzie

    2008-06-01

    Full Text Available Plasmodium falciparum (P. falciparum secretes hundreds of proteins--including major virulence proteins--into the host erythrocyte. In order to reach the host cytoplasm, most P. falciparum proteins contain an N terminal host-targeting (HT motif composed of 11 amino acids. In silico analyses have suggested that the HT motif is conserved throughout the Plasmodium species but experimental evidence only exists for P. falciparum. Here, we show that in the rodent malaria parasite Plasmodium berghei (P. berghei a reporter-like green fluorescent protein expressed by the parasite can be exported to the erythrocyte cytoplasm in a HT-specific manner. This provides the first experimental proof that the HT motif can function as a signal for protein delivery to the erythrocyte across Plasmodium species. Further, it suggests that P. berghei may serve as a model for validation of P. falciparum secretome proteins. We also show that tubovesicular membranes extend from the vacuolar parasite into the erythrocyte cytoplasm and speculate that these structures may facilitate protein export to the erythrocyte.

  1. Blood cell-derived tissue factor influences host response during murine endotoxemia

    NARCIS (Netherlands)

    Schoenmakers, Saskia H. H. F.; Groot, Angelique P.; Florquin, Sandrine; Reitsma, Pieter H.; Spek, C. Arnold

    2004-01-01

    During endotoxemia, blood coagulation becomes activated due to tissue factor (TF) expression on leukocytes and/or endothelial cells. We investigated the influence of blood cell-derived tissue factor on murine endotoxemia. Therefore, we generated mice that lack tissue factor on their blood cells by

  2. Tissue factor is an angiogenic-specific receptor for factor VII-targeted immunotherapy and photodynamic therapy.

    Science.gov (United States)

    Hu, Zhiwei; Cheng, Jijun; Xu, Jie; Ruf, Wolfram; Lockwood, Charles J

    2017-02-01

    Identification of target molecules specific for angiogenic vascular endothelial cells (VEC), the inner layer of pathological neovasculature, is critical for discovery and development of neovascular-targeting therapy for angiogenesis-dependent human diseases, notably cancer, macular degeneration and endometriosis, in which vascular endothelial growth factor (VEGF) plays a central pathophysiological role. Using VEGF-stimulated vascular endothelial cells (VECs) isolated from microvessels, venous and arterial blood vessels as in vitro angiogenic models and unstimulated VECs as a quiescent VEC model, we examined the expression of tissue factor (TF), a membrane-bound receptor on the angiogenic VEC models compared with quiescent VEC controls. We found that TF is specifically expressed on angiogenic VECs in a time-dependent manner in microvessels, venous and arterial vessels. TF-targeted therapeutic agents, including factor VII (fVII)-IgG1 Fc and fVII-conjugated photosensitizer, can selectively bind angiogenic VECs, but not the quiescent VECs. Moreover, fVII-targeted photodynamic therapy can selectively and completely eradicate angiogenic VECs. We conclude that TF is an angiogenic-specific receptor and the target molecule for fVII-targeted therapeutics. This study supports clinical trials of TF-targeted therapeutics for the treatment of angiogenesis-dependent diseases such as cancer, macular degeneration and endometriosis.

  3. ESCMID Study Group for Infections in Compromised Hosts (ESGICH) Consensus Document on the safety of targeted and biological therapies: an infectious diseases perspective (Introduction).

    Science.gov (United States)

    Fernández-Ruiz, M; Meije, Y; Manuel, O; Akan, H; Carratalà, J; Aguado, J M; Delaloye, J

    2018-02-07

    The field of new biological agents is increasing exponentially over the past years, thus making prevention and management of associated infectious complications a challenge for nonspecialized clinicians. The present consensus document is an initiative of the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) Study Group for Infections in Compromised Hosts (ESGICH) aimed at analysing, from an infectious diseases perspective, the safety of targeted and biological therapies. Computer-based Medline searches with MeSH terms pertaining to each agent or therapeutic family. The document is structured in sections according to the targeted site of action of each drug class: proinflammatory cytokines; interleukins, immunoglobulins and other soluble immune mediators; cell surface receptors and associated signaling pathways; intracellular signaling pathways; lymphoma and leukaemia cells surface antigens; and other targeted therapies. A common outline is followed for each agent: summary of mechanism of action, approved indications and common off-label uses; expected impact on the host's susceptibility to infection; available clinical evidence (i.e. pivotal clinical trials, postmarketing studies, case series and case reports); and suggested prevention and risk minimization strategies. The methodologic and practical difficulties of assessing the specific risk posed by a given agent are also discussed. This ESGICH consensus document constitutes not only a comprehensive overview of the molecular rationale and clinical experience on the risk of infection associated with approved targeted therapies but also an attempt to propose a series of recommendations with the purpose of guiding physicians from different disciplines into this emerging framework. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  4. Proteomic Analysis of the Action of the Mycobacterium ulcerans Toxin Mycolactone: Targeting Host Cells Cytoskeleton and Collagen

    Science.gov (United States)

    Gama, José B.; Ohlmeier, Steffen; Martins, Teresa G.; Fraga, Alexandra G.; Sampaio-Marques, Belém; Carvalho, Maria A.; Proença, Fernanda; Silva, Manuel T.; Pedrosa, Jorge; Ludovico, Paula

    2014-01-01

    Buruli ulcer (BU) is a neglected tropical disease caused by Mycobacterium ulcerans. The tissue damage characteristic of BU lesions is known to be driven by the secretion of the potent lipidic exotoxin mycolactone. However, the molecular action of mycolactone on host cell biology mediating cytopathogenesis is not fully understood. Here we applied two-dimensional electrophoresis (2-DE) to identify the mechanisms of mycolactone's cellular action in the L929 mouse fibroblast proteome. This revealed 20 changed spots corresponding to 18 proteins which were clustered mainly into cytoskeleton-related proteins (Dync1i2, Cfl1, Crmp2, Actg1, Stmn1) and collagen biosynthesis enzymes (Plod1, Plod3, P4ha1). In line with cytoskeleton conformational disarrangements that are observed by immunofluorescence, we found several regulators and constituents of both actin- and tubulin-cytoskeleton affected upon exposure to the toxin, providing a novel molecular basis for the effect of mycolactone. Consistent with these cytoskeleton-related alterations, accumulation of autophagosomes as well as an increased protein ubiquitination were observed in mycolactone-treated cells. In vivo analyses in a BU mouse model revealed mycolactone-dependent structural changes in collagen upon infection with M. ulcerans, associated with the reduction of dermal collagen content, which is in line with our proteomic finding of mycolactone-induced down-regulation of several collagen biosynthesis enzymes. Our results unveil the mechanisms of mycolactone-induced molecular cytopathogenesis on exposed host cells, with the toxin compromising cell structure and homeostasis by inducing cytoskeleton alterations, as well as disrupting tissue structure, by impairing the extracellular matrix biosynthesis. PMID:25101965

  5. Proteomic analysis of the action of the Mycobacterium ulcerans toxin mycolactone: targeting host cells cytoskeleton and collagen.

    Science.gov (United States)

    Gama, José B; Ohlmeier, Steffen; Martins, Teresa G; Fraga, Alexandra G; Sampaio-Marques, Belém; Carvalho, Maria A; Proença, Fernanda; Silva, Manuel T; Pedrosa, Jorge; Ludovico, Paula

    2014-08-01

    Buruli ulcer (BU) is a neglected tropical disease caused by Mycobacterium ulcerans. The tissue damage characteristic of BU lesions is known to be driven by the secretion of the potent lipidic exotoxin mycolactone. However, the molecular action of mycolactone on host cell biology mediating cytopathogenesis is not fully understood. Here we applied two-dimensional electrophoresis (2-DE) to identify the mechanisms of mycolactone's cellular action in the L929 mouse fibroblast proteome. This revealed 20 changed spots corresponding to 18 proteins which were clustered mainly into cytoskeleton-related proteins (Dync1i2, Cfl1, Crmp2, Actg1, Stmn1) and collagen biosynthesis enzymes (Plod1, Plod3, P4ha1). In line with cytoskeleton conformational disarrangements that are observed by immunofluorescence, we found several regulators and constituents of both actin- and tubulin-cytoskeleton affected upon exposure to the toxin, providing a novel molecular basis for the effect of mycolactone. Consistent with these cytoskeleton-related alterations, accumulation of autophagosomes as well as an increased protein ubiquitination were observed in mycolactone-treated cells. In vivo analyses in a BU mouse model revealed mycolactone-dependent structural changes in collagen upon infection with M. ulcerans, associated with the reduction of dermal collagen content, which is in line with our proteomic finding of mycolactone-induced down-regulation of several collagen biosynthesis enzymes. Our results unveil the mechanisms of mycolactone-induced molecular cytopathogenesis on exposed host cells, with the toxin compromising cell structure and homeostasis by inducing cytoskeleton alterations, as well as disrupting tissue structure, by impairing the extracellular matrix biosynthesis.

  6. The host plant metabolite glucose is the precursor of diffusible signal factor (DSF) family signals in Xanthomonas campestris.

    Science.gov (United States)

    Deng, Yinyue; Liu, Xiaoling; Wu, Ji'en; Lee, Jasmine; Chen, Shaohua; Cheng, Yingying; Zhang, Chunyan; Zhang, Lian-Hui

    2015-04-01

    Plant pathogen Xanthomonas campestris pv. campestris produces cis-11-methyl-2-dodecenoic acid (diffusible signal factor [DSF]) as a cell-cell communication signal to regulate biofilm dispersal and virulence factor production. Previous studies have demonstrated that DSF biosynthesis is dependent on the presence of RpfF, an enoyl-coenzyme A (CoA) hydratase, but the DSF synthetic mechanism and the influence of the host plant on DSF biosynthesis are still not clear. We show here that exogenous addition of host plant juice or ethanol extract to the growth medium of X. campestris pv. campestris could significantly boost DSF family signal production. It was subsequently revealed that X. campestris pv. campestris produces not only DSF but also BDSF (cis-2-dodecenoic acid) and another novel DSF family signal, which was designated DSF-II. BDSF was originally identified in Burkholderia cenocepacia to be involved in regulation of motility, biofilm formation, and virulence in B. cenocepacia. Functional analysis suggested that DSF-II plays a role equal to that of DSF in regulation of biofilm dispersion and virulence factor production in X. campestris pv. campestris. Furthermore, chromatographic separation led to identification of glucose as a specific molecule stimulating DSF family signal biosynthesis in X. campestris pv. campestris. (13)C-labeling experiments demonstrated that glucose acts as a substrate to provide a carbon element for DSF biosynthesis. The results of this study indicate that X. campestris pv. campestris could utilize a common metabolite of the host plant to enhance DSF family signal synthesis and therefore promote virulence. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

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

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    Gisela Canedo-Marroquín

    2017-08-01

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

  8. Variations on the larval incubation of Anodontites trapesialis (Unionoida, Mycetopodidae: Synergetic effect of the environmental factors and host availability

    Directory of Open Access Journals (Sweden)

    CT. Callil

    Full Text Available The unionid Anodontites trapesilais (Lamarck, 1819 like most freshwater mussels is a parasite of fish. So it is trivial to assume that the availability of hosts is an important factor for the maintenance of unionoid populations. What seems obvious is not always so easy to demonstrate. This study proposes to investigate the effects of abiotic and biotic variables related to the incubation of larvae in A. trapesialis. For this, we estimate different biological indexes and try to capture the dimensionality of the fish, along with the temporal variation of environmental variables. From the application of a CCA, it was demonstrated that there was a synchronicity among the factors and variables proposed here, and we infer that the flood pulse acts as a synergistic factor in this process.

  9. Variations on the larval incubation of Anodontites trapesialis (Unionoida, Mycetopodidae): Synergetic effect of the environmental factors and host availability.

    Science.gov (United States)

    Callil, C T; Krinski, D; Silva, F A

    2012-08-01

    The unionid Anodontites trapesilais (Lamarck, 1819) like most freshwater mussels is a parasite of fish. So it is trivial to assume that the availability of hosts is an important factor for the maintenance of unionoid populations. What seems obvious is not always so easy to demonstrate. This study proposes to investigate the effects of abiotic and biotic variables related to the incubation of larvae in A. trapesialis. For this, we estimate different biological indexes and try to capture the dimensionality of the fish, along with the temporal variation of environmental variables. From the application of a CCA, it was demonstrated that there was a synchronicity among the factors and variables proposed here, and we infer that the flood pulse acts as a synergistic factor in this process.

  10. Enhanced Host-Parasite Resistance Based on Down-Regulation of Phelipanche aegyptiaca Target Genes Is Likely by Mobile Small RNA

    Directory of Open Access Journals (Sweden)

    Neeraj K. Dubey

    2017-09-01

    Full Text Available RNA silencing refers to diverse mechanisms that control gene expression at transcriptional and post-transcriptional levels which can also be used in parasitic pathogens of plants that Broomrapes (Orobanche/Phelipanche spp. are holoparasitic plants that subsist on the roots of a variety of agricultural crops and cause severe negative effects on the yield and yield quality of those crops. Effective methods for controlling parasitic weeds are scarce, with only a few known cases of genetic resistance. In the current study, we suggest an improved strategy for the control of parasitic weeds based on trans-specific gene-silencing of three parasite genes at once. We used two strategies to express dsRNA containing selected sequences of three Phelipanche aegyptiaca genes PaACS, PaM6PR, and PaPrx1 (pma: transient expression using Tobacco rattle virus (TRV:pma as a virus-induced gene-silencing vector and stable expression in transgenic tomato Solanum lycopersicum (Mill. plants harboring a hairpin construct (pBINPLUS35:pma. siRNA-mediated transgene-silencing (20–24 nt was detected in the host plants. Our results demonstrate that the quantities of PaACS and PaM6PR transcripts from P. aegyptiaca tubercles grown on transgenic tomato or on TRV-infected Nicotiana benthamiana plants were significantly reduced. However, only partial reductions in the quantity of PaPrx1 transcripts were observed in the parasite tubercles grown on tomato and on N. benthamiana plants. Concomitant with the suppression of the target genes, there were significant decreases in the number and weight of the parasite tubercles that grew on the host plants, in both the transient and the stable experimental systems. The results of the work carried out using both strategies point to the movement of mobile exogenous siRNA from the host to the parasite, leading to the impaired expression of essential parasite target genes.

  11. A population-based study to investigate host genetic factors associated with hepatitis B infection and pathogenesis in the Chinese population

    Directory of Open Access Journals (Sweden)

    O'Brien Stephen J

    2008-01-01

    genes involved in the pathway leading to chronic viral infection, liver cirrhosis and, ultimately, hepatocellular carcinoma would provide insights to those factors leading to HBV replication, liver inflammation, fibrosis, and the carcinogenic process. An understanding of the contribution of host genetic factors and their interactions may inform public health policy, improve diagnostics and clinical management, and provide targets for drug development.

  12. Listeriolysin S Is a Streptolysin S-Like Virulence Factor That Targets Exclusively Prokaryotic Cells In Vivo

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    Juan J. Quereda

    2017-04-01

    Full Text Available Streptolysin S (SLS-like virulence factors from clinically relevant Gram-positive pathogens have been proposed to behave as potent cytotoxins, playing key roles in tissue infection. Listeriolysin S (LLS is an SLS-like hemolysin/bacteriocin present among Listeria monocytogenes strains responsible for human listeriosis outbreaks. As LLS cytotoxic activity has been associated with virulence, we investigated the LLS-specific contribution to host tissue infection. Surprisingly, we first show that LLS causes only weak red blood cell (RBC hemolysis in vitro and neither confers resistance to phagocytic killing nor favors survival of L. monocytogenes within the blood cells or in the extracellular space (in the plasma. We reveal that LLS does not elicit specific immune responses, is not cytotoxic for eukaryotic cells, and does not impact cell infection by L. monocytogenes. Using in vitro cell infection systems and a murine intravenous infection model, we actually demonstrate that LLS expression is undetectable during infection of cells and murine inner organs. Importantly, upon intravenous animal inoculation, L. monocytogenes is found in the gastrointestinal system, and only in this environment LLS expression is detected in vivo. Finally, we confirm that LLS production is associated with destruction of target bacteria. Our results demonstrate therefore that LLS does not contribute to L. monocytogenes tissue injury and virulence in inner host organs as previously reported. Moreover, we describe that LlsB, a putative posttranslational modification enzyme encoded in the LLS operon, is necessary for murine inner organ colonization. Overall, we demonstrate that LLS is the first SLS-like virulence factor targeting exclusively prokaryotic cells during in vivo infections.

  13. Nuclear Localization of the C1 Factor (Host Cell Factor) in Sensory Neurons Correlates with Reactivation of Herpes Simplex Virus from Latency

    Science.gov (United States)

    Kristie, Thomas M.; Vogel, Jodi L.; Sears, Amy E.

    1999-02-01

    After a primary infection, herpes simplex virus is maintained in a latent state in neurons of sensory ganglia until complex stimuli reactivate viral lytic replication. Although the mechanisms governing reactivation from the latent state remain unknown, the regulated expression of the viral immediate early genes represents a critical point in this process. These genes are controlled by transcription enhancer complexes whose assembly requires and is coordinated by the cellular C1 factor (host cell factor). In contrast to other tissues, the C1 factor is not detected in the nuclei of sensory neurons. Experimental conditions that induce the reactivation of herpes simplex virus in mouse model systems result in rapid nuclear localization of the protein, indicating that the C1 factor is sequestered in these cells until reactivation signals induce a redistribution of the protein. The regulated localization suggests that C1 is a critical switch determinant of the viral lytic-latent cycle.

  14. CARMA3 Is a Host Factor Regulating the Balance of Inflammatory and Antiviral Responses against Viral Infection

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    Changying Jiang

    2016-03-01

    Full Text Available Host response to RNA virus infection is sensed by RNA sensors such as RIG-I, which induces MAVS-mediated NF-κB and IRF3 activation to promote inflammatory and antiviral responses, respectively. Here, we have found that CARMA3, a scaffold protein previously shown to mediate NF-κB activation induced by GPCR and EGFR, positively regulates MAVS-induced NF-κB activation. However, our data suggest that CARMA3 sequesters MAVS from forming high-molecular-weight aggregates, thereby suppressing TBK1/IRF3 activation. Interestingly, following NF-κB activation upon virus infection, CARMA3 is targeted for proteasome-dependent degradation, which releases MAVS to activate IRF3. When challenged with vesicular stomatitis virus or influenza A virus, CARMA3-deficient mice showed reduced disease symptoms compared to those of wild-type mice as a result of less inflammation and a stronger ability to clear infected virus. Altogether, our results reveal the role of CARMA3 in regulating the balance of host antiviral and pro-inflammatory responses against RNA virus infection.

  15. Neighborhood Regularized Logistic Matrix Factorization for Drug-Target Interaction Prediction.

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    Yong Liu

    2016-02-01

    Full Text Available In pharmaceutical sciences, a crucial step of the drug discovery process is the identification of drug-target interactions. However, only a small portion of the drug-target interactions have been experimentally validated, as the experimental validation is laborious and costly. To improve the drug discovery efficiency, there is a great need for the development of accurate computational approaches that can predict potential drug-target interactions to direct the experimental verification. In this paper, we propose a novel drug-target interaction prediction algorithm, namely neighborhood regularized logistic matrix factorization (NRLMF. Specifically, the proposed NRLMF method focuses on modeling the probability that a drug would interact with a target by logistic matrix factorization, where the properties of drugs and targets are represented by drug-specific and target-specific latent vectors, respectively. Moreover, NRLMF assigns higher importance levels to positive observations (i.e., the observed interacting drug-target pairs than negative observations (i.e., the unknown pairs. Because the positive observations are already experimentally verified, they are usually more trustworthy. Furthermore, the local structure of the drug-target interaction data has also been exploited via neighborhood regularization to achieve better prediction accuracy. We conducted extensive experiments over four benchmark datasets, and NRLMF demonstrated its effectiveness compared with five state-of-the-art approaches.

  16. Neighborhood Regularized Logistic Matrix Factorization for Drug-Target Interaction Prediction.

    Science.gov (United States)

    Liu, Yong; Wu, Min; Miao, Chunyan; Zhao, Peilin; Li, Xiao-Li

    2016-02-01

    In pharmaceutical sciences, a crucial step of the drug discovery process is the identification of drug-target interactions. However, only a small portion of the drug-target interactions have been experimentally validated, as the experimental validation is laborious and costly. To improve the drug discovery efficiency, there is a great need for the development of accurate computational approaches that can predict potential drug-target interactions to direct the experimental verification. In this paper, we propose a novel drug-target interaction prediction algorithm, namely neighborhood regularized logistic matrix factorization (NRLMF). Specifically, the proposed NRLMF method focuses on modeling the probability that a drug would interact with a target by logistic matrix factorization, where the properties of drugs and targets are represented by drug-specific and target-specific latent vectors, respectively. Moreover, NRLMF assigns higher importance levels to positive observations (i.e., the observed interacting drug-target pairs) than negative observations (i.e., the unknown pairs). Because the positive observations are already experimentally verified, they are usually more trustworthy. Furthermore, the local structure of the drug-target interaction data has also been exploited via neighborhood regularization to achieve better prediction accuracy. We conducted extensive experiments over four benchmark datasets, and NRLMF demonstrated its effectiveness compared with five state-of-the-art approaches.

  17. The stress-response factor SigH modulates the interaction between Mycobacterium tuberculosis and host phagocytes.

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    Noton K Dutta

    Full Text Available The Mycobacterium tuberculosis stress response factor SigH plays a crucial role in modulating the pathogen's response to heat, oxidative-stress, envelope damage and hypoxia. We hypothesized that the lack of this key stress response factor would alter the interaction between the pathogen and its host cells. We compared the interaction of Mtb, Mtb:Δ-sigH and a strain where the mutation had been genetically complemented (Mtb: Δ-sigH:CO with primary rhesus macaque bone marrow derived macrophages (Rh-BMDMs. The expression of numerous inducible and homeostatic (CCL β-chemokines and several apoptotic markers was induced to higher levels in the cells infected with Mtb:Δ-sigH, relative to Mtb or the complemented strain. The differential expression of these genes manifested into functional differences in chemotaxis and apoptosis in cells infected with these two strains. The mutant strain also exhibited reduced late-stage survival in Rh-BMDMs. We hypothesize that the product of one or more SigH-dependent genes may modulate the innate interaction of Mtb with host cells, effectively reducing the chemokine-mediated recruitment of immune effector cells, apoptosis of infected monocytes and enhancing the long-term survival and replication of the pathogen in this milieu The significantly higher induction of Prostaglandin Synthetase 2 (PTGS2 or COX2 in Rh-BMDMs infected with Mtb relative to Mtb: Δ-sigH may explain reduced apoptosis in Mtb-infected cells, as PTGS2 is known to inhibit p53-dependent apoptosis.The SigH-regulon modulates the innate interaction of Mtb with host phagocytes, perhaps as part of a strategy to limit its clearance and prolong its survival. The SigH regulon appears to be required to modulate innate immune responses directed against Mtb.

  18. Baculovirus DNA Replication-Specific Expression Factors Trigger Apoptosis and Shutoff of Host Protein Synthesis during Infection▿

    Science.gov (United States)

    Schultz, Kimberly L. W.; Friesen, Paul D.

    2009-01-01

    Apoptosis is an important antivirus defense. To define the poorly understood pathways by which invertebrates respond to viruses by inducing apoptosis, we have identified replication events that trigger apoptosis in baculovirus-infected cells. We used RNA silencing to ablate factors required for multiplication of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Transfection with double-stranded RNA (dsRNA) complementary to the AcMNPV late expression factors (lefs) that are designated as replicative lefs (lef-1, lef-2, lef-3, lef-11, p143, dnapol, and ie-1/ie-0) blocked virus DNA synthesis and late gene expression in permissive Spodoptera frugiperda cells. dsRNAs specific to designated nonreplicative lefs (lef-8, lef-9, p47, and pp31) blocked late gene expression without affecting virus DNA replication. Thus, both classes of lefs functioned during infection as defined. Silencing the replicative lefs prevented AcMNPV-induced apoptosis of Spodoptera cells, whereas silencing the nonreplicative lefs did not. Thus, the activity of replicative lefs or virus DNA replication is sufficient to trigger apoptosis. Confirming this conclusion, AcMNPV-induced apoptosis was suppressed by silencing the replicative lefs in cells from a divergent species, Drosophila melanogaster. Silencing replicative but not nonreplicative lefs also abrogated AcMNPV-induced shutdown of host protein synthesis, suggesting that virus DNA replication triggers inhibition of host biosynthetic processes and that apoptosis and translational arrest are linked. Our findings suggest that baculovirus DNA replication triggers a host cell response similar to the DNA damage response in vertebrates, which causes translational arrest and apoptosis. Pathways for detecting virus invasion and triggering apoptosis may therefore be conserved between insects and mammals. PMID:19706708

  19. Baculovirus DNA replication-specific expression factors trigger apoptosis and shutoff of host protein synthesis during infection.

    Science.gov (United States)

    Schultz, Kimberly L W; Friesen, Paul D

    2009-11-01

    Apoptosis is an important antivirus defense. To define the poorly understood pathways by which invertebrates respond to viruses by inducing apoptosis, we have identified replication events that trigger apoptosis in baculovirus-infected cells. We used RNA silencing to ablate factors required for multiplication of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Transfection with double-stranded RNA (dsRNA) complementary to the AcMNPV late expression factors (lefs) that are designated as replicative lefs (lef-1, lef-2, lef-3, lef-11, p143, dnapol, and ie-1/ie-0) blocked virus DNA synthesis and late gene expression in permissive Spodoptera frugiperda cells. dsRNAs specific to designated nonreplicative lefs (lef-8, lef-9, p47, and pp31) blocked late gene expression without affecting virus DNA replication. Thus, both classes of lefs functioned during infection as defined. Silencing the replicative lefs prevented AcMNPV-induced apoptosis of Spodoptera cells, whereas silencing the nonreplicative lefs did not. Thus, the activity of replicative lefs or virus DNA replication is sufficient to trigger apoptosis. Confirming this conclusion, AcMNPV-induced apoptosis was suppressed by silencing the replicative lefs in cells from a divergent species, Drosophila melanogaster. Silencing replicative but not nonreplicative lefs also abrogated AcMNPV-induced shutdown of host protein synthesis, suggesting that virus DNA replication triggers inhibition of host biosynthetic processes and that apoptosis and translational arrest are linked. Our findings suggest that baculovirus DNA replication triggers a host cell response similar to the DNA damage response in vertebrates, which causes translational arrest and apoptosis. Pathways for detecting virus invasion and triggering apoptosis may therefore be conserved between insects and mammals.

  20. Factor Analysis of Therapist-Identified Treatment Targets in Community-Based Children's Mental Health.

    Science.gov (United States)

    Love, Allison R; Okado, Izumi; Orimoto, Trina E; Mueller, Charles W

    2018-01-01

    The present study used exploratory and confirmatory factor analyses to identify underlying latent factors affecting variation in community therapists' endorsement of treatment targets. As part of a statewide practice management program, therapist completed monthly reports of treatment targets (up to 10 per month) for a sample of youth (n = 790) receiving intensive in-home therapy. Nearly 75 % of youth were diagnosed with multiple co-occurring disorders. Five factors emerged: Disinhibition, Societal Rules Evasion, Social Engagement Deficits, Emotional Distress, and Management of Biodevelopmental Outcomes. Using logistic regression, primary diagnosis predicted therapist selection of Disinhibition and Emotional Distress targets. Client age predicted endorsement of Societal Rules Evasion targets. Practice-to-research implications are discussed.

  1. Virulence factors of Actinobacillus pleuropneumoniae involved in colonization, persistence and induction of lesions in its porcine host.

    Science.gov (United States)

    Chiers, Koen; De Waele, Tine; Pasmans, Frank; Ducatelle, Richard; Haesebrouck, Freddy

    2010-01-01

    Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. The virulence factors of this microorganism involved in colonization and the induction of lung lesions have been thoroughly studied and some have been well characterized. A. pleuropneumoniae binds preferentially to cells of the lower respiratory tract in a process involving different adhesins and probably biofilm formation. Apx toxins and lipopolysaccharides exert pathogenic effects on several host cells, resulting in typical lung lesions. Lysis of host cells is essential for the bacterium to obtain nutrients from the environment and A. pleuropneumoniae has developed several uptake mechanisms for these nutrients. In addition to persistence in lung lesions, colonization of the upper respiratory tract--and of the tonsils in particular--may also be important for long-term persistent asymptomatic infection. Information on virulence factors involved in tonsillar and nasal cavity colonization and persistence is scarce, but it can be speculated that similar features as demonstrated for the lung may play a role. © The authors, published by INRA/EDP Sciences, 2010.

  2. Innate immunity in HIV-1 infection: epithelial and non-specific host factors of mucosal immunity- a workshop report.

    Science.gov (United States)

    Nittayananta, W; Weinberg, A; Malamud, D; Moyes, D; Webster-Cyriaque, J; Ghosh, S

    2016-04-01

    The interplay between HIV-1 and epithelial cells represents a critical aspect in mucosal HIV-1 transmission. Epithelial cells lining the oral cavity cover subepithelial tissues, which contain virus-susceptible host cells including CD4(+) T lymphocytes, monocytes/macrophages, and dendritic cells. Oral epithelia are among the sites of first exposure to both cell-free and cell-associated virus HIV-1 through breast-feeding and oral-genital contact. However, oral mucosa is considered to be naturally resistant to HIV-1 transmission. Oral epithelial cells have been shown to play a crucial role in innate host defense. Nevertheless, it is not clear to what degree these local innate immune factors contribute to HIV-1 resistance of the oral mucosa. This review paper addressed the following issues that were discussed at the 7th World Workshop on Oral Health and Disease in AIDS held in Hyderabad, India, during November 6-9, 2014: (i) What is the fate of HIV-1 after interactions with oral epithelial cells?; (ii) What are the keratinocyte and other anti-HIV effector oral factors, and how do they contribute to mucosal protection?; (iii) How can HIV-1 interactions with oral epithelium affect activation and populations of local immune cells?; (iv) How can HIV-1 interactions alter functions of oral epithelial cells? © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. Oral Microbiota: Microbial Biomarkers of Metabolic Syndrome Independent of Host Genetic Factors

    Directory of Open Access Journals (Sweden)

    Jiyeon Si

    2017-12-01

    Full Text Available The oral microbiota plays a critical role in both local and systemic inflammation. Metabolic syndrome (MetS is characterized by low-grade inflammation, and many studies have been conducted on the gut microbiota from stool specimens. However, the etiological role of the oral microbiota in the development of MetS is unclear. In this study, we analyzed the oral and gut microbiome from 228 subgingival plaque and fecal samples from a Korean twin-family cohort with and without MetS. Significant differences in microbial diversity and composition were observed in both anatomical niches. However, a host genetic effect on the oral microbiota was not observed. A co-occurrence network analysis showed distinct microbiota clusters that were dependent on the MetS status. A comprehensive analysis of the oral microbiome identified Granulicatella and Neisseria as bacteria enriched in subjects with MetS and Peptococcus as bacteria abundant in healthy controls. Validation of the identified oral bacteria by quantitative PCR (qPCR showed that healthy controls possessed significantly lower levels of G. adiacens (p = 0.023 and a higher ratio of Peptococcus to Granulicatella (p < 0.05 than MetS subjects. Our results support that local oral microbiota can be associated with systemic disorders. The microbial biomarkers identified in this study would aid in determination of which individuals develop chronic diseases from their MetS and contribute to strategic disease management.

  4. Host DNA damage response factors localize to merkel cell polyomavirus DNA replication sites to support efficient viral DNA replication.

    Science.gov (United States)

    Tsang, Sabrina H; Wang, Xin; Li, Jing; Buck, Christopher B; You, Jianxin

    2014-03-01

    Accumulating evidence indicates a role for Merkel cell polyomavirus (MCPyV) in the development of Merkel cell carcinoma (MCC), making MCPyV the first polyomavirus to be clearly associated with human cancer. With the high prevalence of MCPyV infection and the increasing amount of MCC diagnosis, there is a need to better understand the virus and its oncogenic potential. In this study, we examined the relationship between the host DNA damage response (DDR) and MCPyV replication. We found that components of the ATM- and ATR-mediated DDR pathways accumulate in MCPyV large T antigen (LT)-positive nuclear foci in cells infected with native MCPyV virions. To further study MCPyV replication, we employed our previously established system, in which recombinant MCPyV episomal DNA is autonomously replicated in cultured cells. Similar to native MCPyV infection, where both MCPyV origin and LT are present, the host DDR machinery colocalized with LT in distinct nuclear foci. Immunofluorescence in situ hybridization and bromodeoxyuridine (BrdU) incorporation analysis showed that these DDR proteins and MCPyV LT in fact colocalized at the actively replicating MCPyV replication complexes, which were absent when a replication-defective LT mutant or an MCPyV-origin mutant was introduced in place of wild-type LT or wild-type viral origin. Inhibition of DDR kinases using chemical inhibitors and ATR/ATM small interfering RNA (siRNA) knockdown reduced MCPyV DNA replication without significantly affecting LT expression or the host cell cycle. This study demonstrates that these host DDR factors are important for MCPyV DNA replication, providing new insight into the host machinery involved in the MCPyV life cycle. MCPyV is the first polyomavirus to be clearly associated with human cancer. However, the MCPyV life cycle and its oncogenic mechanism remain poorly understood. In this report, we show that, in cells infected with native MCPyV virions, components of the ATM- and ATR-mediated DDR

  5. Simultaneous Determination of Aspirin, Salicylamide, and Caffeine in Pain Relievers by Target Factor Analysis

    Science.gov (United States)

    Msimanga, Huggins Z.; Charles, Melissa J.; Martin, Nea W.

    1997-09-01

    A factor analysis-based experiment for the undergraduate instrumental analysis labs is reported. Target factor analysis (TFA) is investigated as an option to the use of high-performance liquid chromatography (HPLC) in the analysis of a pain reliever sample containing aspirin, caffeine, and salicylamide.

  6. Serratia marcescens suppresses host cellular immunity via the production of an adhesion-inhibitory factor against immunosurveillance cells.

    Science.gov (United States)

    Ishii, Kenichi; Adachi, Tatsuo; Hamamoto, Hiroshi; Sekimizu, Kazuhisa

    2014-02-28

    Injection of a culture supernatant of Serratia marcescens into the bloodstream of the silkworm Bombyx mori increased the number of freely circulating immunosurveillance cells (hemocytes). Using a bioassay with live silkworms, serralysin metalloprotease was purified from the culture supernatant and identified as the factor responsible for this activity. Serralysin inhibited the in vitro attachment of both silkworm hemocytes and murine peritoneal macrophages. Incubation of silkworm hemocytes or murine macrophages with serralysin resulted in degradation of the cellular immune factor BmSPH-1 or calreticulin, respectively. Furthermore, serralysin suppressed in vitro phagocytosis of bacteria by hemocytes and in vivo bacterial clearance in silkworms. Disruption of the ser gene in S. marcescens attenuated its host killing ability in silkworms and mice. These findings suggest that serralysin metalloprotease secreted by S. marcescens suppresses cellular immunity by decreasing the adhesive properties of immunosurveillance cells, thereby contributing to bacterial pathogenesis.

  7. Serratia marcescens Suppresses Host Cellular Immunity via the Production of an Adhesion-inhibitory Factor against Immunosurveillance Cells*

    Science.gov (United States)

    Ishii, Kenichi; Adachi, Tatsuo; Hamamoto, Hiroshi; Sekimizu, Kazuhisa

    2014-01-01

    Injection of a culture supernatant of Serratia marcescens into the bloodstream of the silkworm Bombyx mori increased the number of freely circulating immunosurveillance cells (hemocytes). Using a bioassay with live silkworms, serralysin metalloprotease was purified from the culture supernatant and identified as the factor responsible for this activity. Serralysin inhibited the in vitro attachment of both silkworm hemocytes and murine peritoneal macrophages. Incubation of silkworm hemocytes or murine macrophages with serralysin resulted in degradation of the cellular immune factor BmSPH-1 or calreticulin, respectively. Furthermore, serralysin suppressed in vitro phagocytosis of bacteria by hemocytes and in vivo bacterial clearance in silkworms. Disruption of the ser gene in S. marcescens attenuated its host killing ability in silkworms and mice. These findings suggest that serralysin metalloprotease secreted by S. marcescens suppresses cellular immunity by decreasing the adhesive properties of immunosurveillance cells, thereby contributing to bacterial pathogenesis. PMID:24398686

  8. A mechanistic overview of herbal medicine and botanical compounds to target transcriptional factors in Breast cancer.

    Science.gov (United States)

    Zhao, Yingke; Liu, Yue

    2018-04-01

    The abnormalities of transcription factors, such as NF-κB, STAT, estrogen receptor, play a critical role in the initiation and progression of breast cancer. Due to the limitation of current treatment, transcription factors could be promising therapeutic targets, which have received close attention. In this review, we introduced herbal medicines, as well as botanical compounds that had been verified with anti-tumor properties via regulating transcription factors. Herbs, compounds, as well as formulae reported with various transcriptional targets, were summarized thoroughly, to provide implication for the future research on basic experiment and clinical application. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Endogenous growth factor stimulation of hemocyte proliferation induces resistance to Schistosoma mansoni challenge in the snail host.

    Science.gov (United States)

    Pila, Emmanuel A; Gordy, Michelle A; Phillips, Valerie K; Kabore, Alethe L; Rudko, Sydney P; Hanington, Patrick C

    2016-05-10

    Digenean trematodes are a large, complex group of parasitic flatworms that infect an incredible diversity of organisms, including humans. Larval development of most digeneans takes place within a snail (Gastropoda). Compatibility between snails and digeneans is often very specific, such that suitable snail hosts define the geographical ranges of diseases caused by these worms. The immune cells (hemocytes) of a snail are sentinels that act as a crucial barrier to infection by larval digeneans. Hemocytes coordinate a robust and specific immunological response, participating directly in parasite killing by encapsulating and clearing the infection. Hemocyte proliferation and differentiation are influenced by unknown digenean-specific exogenous factors. However, we know nothing about the endogenous control of hemocyte development in any gastropod model. Here, we identify and functionally characterize a progranulin [Biomphalaria glabrata granulin (BgGRN)] from the snail B. glabrata, a natural host for the human blood fluke Schistosoma mansoni Granulins are growth factors that drive proliferation of immune cells in organisms, spanning the animal kingdom. We demonstrate that BgGRN induces proliferation of B. glabrata hemocytes, and specifically drives the production of an adherent hemocyte subset that participates centrally in the anti-digenean defense response. Additionally, we demonstrate that susceptible B. glabrata snails can be made resistant to infection with S. mansoni by first inducing hemocyte proliferation with BgGRN. This marks the functional characterization of an endogenous growth factor of a gastropod mollusc, and provides direct evidence of gain of resistance in a snail-digenean infection model using a defined factor to induce snail resistance to infection.

  10. Critical determinants of the interactions of capsule-expressing Neisseria meningitidis with host cells: the role of receptor density in increased cellular targeting via the outer membrane Opa proteins.

    Science.gov (United States)

    Bradley, Christopher J; Griffiths, Natalie J; Rowe, Helen A; Heyderman, Robert S; Virji, Mumtaz

    2005-10-01

    Neisseria meningitidis capsule is an important virulence determinant required for survival in the blood but is reportedly involved in inhibiting cellular interactions mediated by meningococcal outer membrane adhesins. However, evidence from our previous studies suggested that target receptor density on host cells may determine whether or not capsulate bacteria can adhere via outer membrane proteins such as Opa. To confirm this and evaluate the impact of capsulation on bacterial interactions, we used Opa(+) and Opa(-) derivatives of capsulate and acapsulate meningococcal isolates and transfected cell lines expressing CEACAM1, a receptor targeted by Opa proteins. To assess the extent and rate of cell association, subpopulations of stably transfected Chinese hamster ovary cells with different receptor levels were derived. A quantitative correlation of CEACAM1 levels and Opa-dependent binding of both capsulate and acapsulate bacteria was demonstrated, which was accelerated at high receptor densities. However, it appears that invasion by Opa(+) capsulate bacteria only occurs when a threshold level of CEACAM density has been reached. Target cells expressing high levels of CEACAM1 (MFI c. 400) bound threefold more, but internalized 20-fold more Opa(+) capsulate bacteria than those with intermediate expression (MFI c. 100). No overall selection of acapsulate phenotype was observed in the internalized population. These observations confirm that capsule may not be an adequate barrier for cellular interactions and demonstrate the role of a host factor that may determine capsulate bacterial invasion potential. Upregulation of CEACAMs, which can occur in response to inflammatory cytokines, could lead to translocation of a small number of fully capsulate bacteria across mucosal epithelium into the bloodstream sufficient to cause a rapid onset of disseminated disease. Thus the data also suggest a novel rationale for the epidemiological observations that individuals with prior

  11. Supervised non-negative tensor factorization for automatic hyperspectral feature extraction and target discrimination

    Science.gov (United States)

    Anderson, Dylan; Bapst, Aleksander; Coon, Joshua; Pung, Aaron; Kudenov, Michael

    2017-05-01

    Hyperspectral imaging provides a highly discriminative and powerful signature for target detection and discrimination. Recent literature has shown that considering additional target characteristics, such as spatial or temporal profiles, simultaneously with spectral content can greatly increase classifier performance. Considering these additional characteristics in a traditional discriminative algorithm requires a feature extraction step be performed first. An example of such a pipeline is computing a filter bank response to extract spatial features followed by a support vector machine (SVM) to discriminate between targets. This decoupling between feature extraction and target discrimination yields features that are suboptimal for discrimination, reducing performance. This performance reduction is especially pronounced when the number of features or available data is limited. In this paper, we propose the use of Supervised Nonnegative Tensor Factorization (SNTF) to jointly perform feature extraction and target discrimination over hyperspectral data products. SNTF learns a tensor factorization and a classification boundary from labeled training data simultaneously. This ensures that the features learned via tensor factorization are optimal for both summarizing the input data and separating the targets of interest. Practical considerations for applying SNTF to hyperspectral data are presented, and results from this framework are compared to decoupled feature extraction/target discrimination pipelines.

  12. Passive immunization against tumor necrosis factor-alpha impairs host defense during pneumococcal pneumonia in mice

    NARCIS (Netherlands)

    van der Poll, T.; Keogh, C. V.; Buurman, W. A.; Lowry, S. F.

    1997-01-01

    Streptococcus pneumoniae is the most frequent cause of community-acquired pneumonia. We sought to determine the role of tumor necrosis factor-alpha (TNF) in the pathogenesis of pneumococcal pneumonia. Induction of pneumonia in C57B1/6 mice by intranasal inoculation with 10(6) colony-forming units

  13. Pediatric acute respiratory distress syndrome: Host factors in Down syndrome and the general population

    NARCIS (Netherlands)

    Bruijn, M.

    2013-01-01

    We find that Down syndrome is an important risk factor for developing acute respiratory distress syndrome (ARDS) in children, but the reason why remains to be elucidated. In addition, we find several differences between adult and pediatric ARDS. The association between C-reactive protein (CRP)

  14. Larvae of the ectoparasitic wasp, Eulophus pennicornis, release factors which adversely affect haemocytes of their host, Lacanobia oleracea.

    Science.gov (United States)

    Richards, E H.; Edwards, J P.

    2002-09-01

    When larvae of the ectoparasitic wasp Eulophus pennicornis were incubated for 4 h on balls of cotton wool soaked in tissue culture medium (TC-100), they released a variety of factors. Subsequent incubation of these larval wasp secretions with monolayers of haemocytes from their host, Lacanobia oleracea, demonstrated that they adversely affect haemocyte morphology, behaviour and viability. For instance, when monolayers of haemocytes were incubated for 18 h in TC-100, approximately 73% of the cells present, attached firmly to and spread over the tissue culture surface by extending pseudopods. By contrast, when incubated in TC-100 containing larval wasp secretions, only about 27% of the haemocytes present remained attached to the tissue culture surface after washing. The majority of these had a rounded configuration and neither spread nor extended pseudopods. Furthermore, viability assays indicated that approximately 36% of the attached haemocytes were dead, as opposed to 11-12% in the controls. The E. pennicornis secretions also significantly reduced the ability of L. oleracea haemocytes to move across the surface of the slide and form clumps (pfactor(s) that can kill and/or alter the behaviour of host haemocytes. As a result, the ability of the haemocytes to execute important immune responses is compromised. Preliminary data suggest that the active molecules are proteins, and that their mechanism of action may involve inhibition of polymerization and/or disorganization of the haemocyte cytoskeleton.

  15. CD4+ T cells targeting dominant and cryptic epitopes from Bacillus anthracis Lethal Factor

    Directory of Open Access Journals (Sweden)

    Stephanie eAscough

    2016-01-01

    Full Text Available Anthrax is an endemic infection in many countries, particularly in the developing world. The causative agent, Bacillus anthracis, mediates disease through the secretion of binary exotoxins. Until recently, research into adaptive immunity targeting this bacterial pathogen has largely focused on the humoral response to these toxins. There is, however, growing recognition that cellular immune responses involving IFNγ producing CD4+ T cells also contribute significantly to a protective memory response. An established concept in adaptive immunity to infection is that during infection of host cells, new microbial epitopes may be revealed, leading to immune recognition of so called ‘cryptic’ or ‘subdominant’ epitopes. We analysed the response to both cryptic and immunodominant T cell epitopes derived from the toxin component lethal factor and presented by a range of HLA-DR alleles. Using IFNγ-ELISPOT assays we characterised epitopes that elicited a response following immunisation with synthetic peptide and the whole protein and tested their capacities to bind purified HLA-DR molecules in vitro. We found that DR1 transgenics demonstrated T cell responses to a greater number of domain III cryptic epitopes than other HLA-DR transgenics, and that this pattern was repeated with the immunodominant epitopes, a greater proportion of these epitopes induced a T cell response when presented within the context of the whole protein. Immunodominant epitopes LF457-476 and LF467-487 were found to induce a T cell response to the peptide, as well as to the whole native LF protein in DR1 and DR15, but not in DR4 trangenics. The analysis of Domain I revealed the presence of several unique cryptic epitopes all of which showed a strong to moderate relative binding affinity to HLA-DR4 molecules. However, none of the cryptic epitopes from either domain III or I displayed notably high binding affinities across all HLA-DR alleles assayed. These responses were

  16. Targeted Construction of Light-Harvesting Metal-Organic Frameworks Featuring Efficient Host-Guest Energy Transfer.

    Science.gov (United States)

    Zhao, Xiaoyu; Song, Xiaoyu; Li, Yang; Chang, Ze; Chen, Long

    2018-02-14

    Metal-organic frameworks (MOFs) have emerged as promising light-harvesting platforms for energy-transfer materials. However, the targeted construction of MOFs with desirable photophysical properties and pore structures is still a challenge. Herein, 1,1,2,2-tetrakis(4-(pyridin-4-yl)phenyl)ethene (tppe) is selected as the ligand for the construction of light-harvesting MOFs due to its highly emissive and rigid backbone, which could benefit the light-harvesting performance of the MOFs. Three MOFs (MOFs 1-3) were obtained on the basis of different metal centers (Zn 2+ and Cd 2+ ) and carboxylate building blocks. The complete structure characterization of the MOFs helps the illustration of the principles for structure tuning of this system. All three MOFs exhibit strong tppe-originated photoluminescence emission, with quantum yields as high as 47.6%. The fluorescence quantum yield and time-resolved fluorescence studies reveal that a remarkable energy-transfer efficiency (up to 96%) was achieved in this system. These results clearly indicate tppe-MOFs could be promising light-harvesting materials.

  17. The relationship between host factors of allergic nature and respiratory symptoms.

    Science.gov (United States)

    Gepts, L; Minette, A

    1977-01-01

    Respiratory symptoms and personal history of allergy were examined in 1659 children, including the entire elementary school population of four villages of the Belgian Ardennes. Levels of atmospheric pollution were monitored during the survey and proved to be very low. It is suggested that socio-economic factors produce a small increase in respiratory symptoms, particularly in cough symptoms. A personal history of eczema and of hay fever was highly associated with dyspnea and wheezing.

  18. Glycosylphosphatidylinositol-anchored proteases of Candida albicans target proteins necessary for both cellular processes and host-pathogen interactions

    Czech Academy of Sciences Publication Activity Database

    Albrecht, A.; Felk, A.; Pichová, Iva; Naglik, J. R.; Schaller, M.; Groot de, P.; MacCallum, D.; Odds, F. C.; Schäfer, W.; Klis, F.; Monod, M.; Hube, B.

    2006-01-01

    Roč. 281, č. 2 (2006), s. 688-694 ISSN 0021-9258 R&D Projects: GA ČR(CZ) GA303/04/0432 Grant - others:DFG(DE) Hu528/8; DFG(DE) Scha897/1; GFC(XE) QLK2-2000-00795; GFC(XE) MRTN-CT-2003-504148 Institutional research plan: CEZ:AV0Z40550506 Keywords : GPL * SAP * GFP * BEC Subject RIV: CE - Biochemistry Impact factor: 5.808, year: 2006

  19. Association of oral yeast carriage with specific host factors and altered mouth sensation.

    Science.gov (United States)

    Shimizu, Chika; Kuriyama, Tomoari; Williams, David W; Karasawa, Tadahiro; Inoue, Katsumi; Nakagawa, Kiyomasa; Yamamoto, Etsuhide

    2008-04-01

    The aim of this study was to determine if there was a significant association between the presence of altered mouth and taste sensations with oral carriage of yeasts and to assess the factors that influence the yeast carriage. The oral and dental status including unstimulated (USFR) and stimulated (SSFR) whole salivary flow rates of a total of 509 subjects was recorded. Saliva specimens were collected for microbiologic examination. Multiple logistic regression analysis was performed to identify any factors that were significantly associated with the prevalence of oral yeasts. Old age, clinical signs of oral dryness, denture wearing, and a reduction in USFR increased the prevalence of yeasts, whereas patient gender, levels of dentition, the sensation of dry or burning mouth, taste disorders, and SSFR were not associated with increased prevalence of oral yeasts. An increased prevalence of oral yeasts was not found to relate to changes in mouth sensation alone. Other factors, most notably patient age, the wearing of dentures, clinical signs of oral dryness, and salivary flow rate under rest conditions, were, however, found to be closely associated with oral yeast carriage.

  20. From endosymbionts to host communities: factors determining the reproductive success of arthropod vectors.

    Science.gov (United States)

    Messika, Irit; Garrido, Mario; Kedem, Hadar; China, Victor; Gavish, Yoni; Dong, Qunfeng; Fuqua, Clay; Clay, Keith; Hawlena, Hadas

    2017-08-01

    Elucidating the factors determining reproductive success has challenged scientists since Darwin, but the exact pathways that shape the evolution of life history traits by connecting extrinsic (e.g., landscape structure) and intrinsic (e.g., female's age and endosymbionts) factors and reproductive success have rarely been studied. Here we collected female fleas from wild rodents in plots differing in their densities and proportions of the most dominant rodent species. We then combined path analysis and model selection approaches to explore the network of effects, ranging from micro to macroscales, determining the reproductive success of these fleas. Our results suggest that female reproductive success is directly and positively associated with their infection by Mycoplasma bacteria and their own body mass, and with the rodent species size and total density. In addition, we found evidence for indirect effects of rodent sex and rodent community diversity on female reproductive success. These results highlight the importance of exploring interrelated factors across organization scales while studying the reproductive success of wild organisms, and they have implications for the control of vector-borne diseases.

  1. Nerve growth factor in bladder dysfunction: contributing factor, biomarker, and therapeutic target

    NARCIS (Netherlands)

    Ochodnický, Peter; Cruz, Célia D.; Yoshimura, Naoki; Michel, Martin C.

    2011-01-01

    In the last two decades, nerve growth factor (NGF), initially described as a prototypical trophic factor in the development of sensory and sympathetic innervation, has emerged as a complex regulator of neural plasticity along the micturition pathways. This review aims to summarize the current

  2. Tritium inventory of a target factor in an ICF power plant

    International Nuclear Information System (INIS)

    Sherohman, J.W.

    1981-01-01

    A preliminary parametric study has been performed to estimate the tritium inventory of a conjectured Target Factory. The inventory of a proposed tritiated fuel processing system was determined as a function of production efficiency, storage factor, and time interval for the slowest processing step. Results indicated that a study of this type will be beneficial in evaluating possible processing schemes for the production of tritiated laser fusion targets

  3. Global Assessment of Schistosomiasis Control Over the Past Century Shows Targeting the Snail Intermediate Host Works Best.

    Directory of Open Access Journals (Sweden)

    Susanne H Sokolow

    2016-07-01

    Full Text Available Despite control efforts, human schistosomiasis remains prevalent throughout Africa, Asia, and South America. The global schistosomiasis burden has changed little since the new anthelmintic drug, praziquantel, promised widespread control.We evaluated large-scale schistosomiasis control attempts over the past century and across the globe by identifying factors that predict control program success: snail control (e.g., molluscicides or biological control, mass drug administrations (MDA with praziquantel, or a combined strategy using both. For data, we compiled historical information on control tactics and their quantitative outcomes for all 83 countries and territories in which: (i schistosomiasis was allegedly endemic during the 20th century, and (ii schistosomiasis remains endemic, or (iii schistosomiasis has been "eliminated," or is "no longer endemic," or transmission has been interrupted.Widespread snail control reduced prevalence by 92 ± 5% (N = 19 vs. 37 ± 7% (N = 29 for programs using little or no snail control. In addition, ecological, economic, and political factors contributed to schistosomiasis elimination. For instance, snail control was most common and widespread in wealthier countries and when control began earlier in the 20th century.Snail control has been the most effective way to reduce schistosomiasis prevalence. Despite evidence that snail control leads to long-term disease reduction and elimination, most current schistosomiasis control efforts emphasize MDA using praziquantel over snail control. Combining drug-based control programs with affordable snail control seems the best strategy for eliminating schistosomiasis.

  4. The role of host and microbial factors in the pathogenesis of pneumococcal bacteraemia arising from a single bacterial cell bottleneck.

    Science.gov (United States)

    Gerlini, Alice; Colomba, Leonarda; Furi, Leonardo; Braccini, Tiziana; Manso, Ana Sousa; Pammolli, Andrea; Wang, Bo; Vivi, Antonio; Tassini, Maria; van Rooijen, Nico; Pozzi, Gianni; Ricci, Susanna; Andrew, Peter W; Koedel, Uwe; Moxon, E Richard; Oggioni, Marco R

    2014-03-01

    The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic variants was investigated. Sequential analyses of blood samples indicated that most episodes of bacteraemia were monoclonal events providing compelling evidence for a single bacterial cell bottleneck at the origin of invasive disease. With respect to host determinants, results identified novel properties of splenic macrophages and a role for neutrophils in early clearance of pneumococci. Concerning microbial factors, whole genome sequencing provided genetic evidence for the clonal origin of the bacteraemia and identified SNPs in distinct sub-units of F0/F1 ATPase in the majority of the ex vivo isolates. When compared to parental organisms of the inoculum, ex-vivo pneumococci with mutant alleles of the F0/F1 ATPase had acquired the capacity to grow at low pH at the cost of the capacity to grow at high pH. Although founded by a single cell, the genotypes of pneumococci in septicaemic mice indicate strong selective pressure for fitness, emphasising the within-host complexity of the pathogenesis of invasive disease.

  5. The role of host and microbial factors in the pathogenesis of pneumococcal bacteraemia arising from a single bacterial cell bottleneck.

    Directory of Open Access Journals (Sweden)

    Alice Gerlini

    2014-03-01

    Full Text Available The pathogenesis of bacteraemia after challenge with one million pneumococci of three isogenic variants was investigated. Sequential analyses of blood samples indicated that most episodes of bacteraemia were monoclonal events providing compelling evidence for a single bacterial cell bottleneck at the origin of invasive disease. With respect to host determinants, results identified novel properties of splenic macrophages and a role for neutrophils in early clearance of pneumococci. Concerning microbial factors, whole genome sequencing provided genetic evidence for the clonal origin of the bacteraemia and identified SNPs in distinct sub-units of F0/F1 ATPase in the majority of the ex vivo isolates. When compared to parental organisms of the inoculum, ex-vivo pneumococci with mutant alleles of the F0/F1 ATPase had acquired the capacity to grow at low pH at the cost of the capacity to grow at high pH. Although founded by a single cell, the genotypes of pneumococci in septicaemic mice indicate strong selective pressure for fitness, emphasising the within-host complexity of the pathogenesis of invasive disease.

  6. Identification of direct targets of plant transcription factors using the GR fusion technique.

    Science.gov (United States)

    Yamaguchi, Nobutoshi; Winter, Cara M; Wellmer, Frank; Wagner, Doris

    2015-01-01

    The glucocorticoid receptor-dependent activation of plant transcription factors has proven to be a powerful tool for the identification of their direct target genes. In the absence of the synthetic steroid hormone dexamethasone (dex), transcription factors fused to the hormone-binding domain of the glucocorticoid receptor (TF-GR) are held in an inactive state, due to their cytoplasmic localization. This requires physical interaction with the heat shock protein 90 (HSP90) complex. Hormone binding leads to disruption of the interaction between GR and HSP90 and allows TF-GR fusion proteins to enter the nucleus. Once inside the nucleus, they bind to specific DNA sequences and immediately activate or repress expression of their targets. This system is well suited for the identification of direct target genes of transcription factors in plants, as (A) there is little basal protein activity in the absence of dex, (B) steroid application leads to rapid transcription factor activation, (C) no side effects of dex treatment are observed on the physiology of the plant, and (D) secondary effects of transcription factor activity can be eliminated by simultaneous application of an inhibitor of protein biosynthesis, cycloheximide (cyc). In this chapter, we describe detailed protocols for the preparation of plant material, for dex and cyc treatment, for RNA extraction, and for the PCR-based or genome-wide identification of direct targets of transcription factors fused to GR.

  7. No Major Host Genetic Risk Factor Contributed to A(H1N1)2009 Influenza Severity

    Science.gov (United States)

    Garcia-Etxebarria, Koldo; Bracho, María Alma; Galán, Juan Carlos; Pumarola, Tomàs; Castilla, Jesús; Ortiz de Lejarazu, Raúl; Rodríguez-Dominguez, Mario; Quintela, Inés; Bonet, Núria; Garcia-Garcerà, Marc; Domínguez, Angela; González-Candelas, Fernando; Calafell, Francesc

    2015-01-01

    While most patients affected by the influenza A(H1N1) pandemic experienced mild symptoms, a small fraction required hospitalization, often without concomitant factors that could explain such a severe course. We hypothesize that host genetic factors could contribute to aggravate the disease. To test this hypothesis, we compared the allele frequencies of 547,296 genome-wide single nucleotide polymorphisms (SNPs) between 49 severe and 107 mild confirmed influenza A cases, as well as against a general population sample of 549 individuals. When comparing severe vs. mild influenza A cases, only one SNP was close to the conventional p = 5×10−8. This SNP, rs28454025, sits in an intron of the GSK233 gene, which is involved in a neural development, but seems not to have any connections with immunological or inflammatory functions. Indirectly, a previous association reported with CD55 was replicated. Although sample sizes are low, we show that the statistical power in our design was sufficient to detect highly-penetrant, quasi-Mendelian genetic factors. Hence, and assuming that rs28454025 is likely to be a false positive, no major genetic factor was detected that could explain poor influenza A course. PMID:26379185

  8. Effect of host-related factors on the intensity of liver fibrosis in patients with chronic hepatitis C virus infection

    Directory of Open Access Journals (Sweden)

    Costa Luciano Bello

    2002-01-01

    Full Text Available There is increasing interest in the identification of factors associated with liver disease progression in patients infected with hepatitis C virus (HCV. We assessed host-related factors associated with a histologically advanced stage of this disease and determined the rate of liver fibrosis progression in HCV-infected patients. We included patients submitted to liver biopsy, who were anti-HCV and HCV RNA positive, who showed a parenteral risk factor (blood transfusion or intravenous drug use, and who gave information about alcohol consumption.Patients were divided into two groups for analysis: group 1 - grades 0 to 2; group 2 - grades 3 to 4. The groups were compared in terms of sex, age at the time of infection, estimated duration of infection and alcoholism. The rate of fibrosis progression (index of fibrosis was determined based on the relationship between disease stage and duration of infection (years. Logistic regression analysis revealed that age at the time of infection (P or = 40 years (median = 0.47. The main factors associated with a more rapid fibrosis progression were age at the time of infection and the estimated duration of infection. Patients who acquired HCV after 40 years of age showed a higher rate of fibrosis progression.

  9. No Major Host Genetic Risk Factor Contributed to A(H1N1)2009 Influenza Severity.

    Science.gov (United States)

    Garcia-Etxebarria, Koldo; Bracho, María Alma; Galán, Juan Carlos; Pumarola, Tomàs; Castilla, Jesús; Ortiz de Lejarazu, Raúl; Rodríguez-Dominguez, Mario; Quintela, Inés; Bonet, Núria; Garcia-Garcerà, Marc; Domínguez, Angela; González-Candelas, Fernando; Calafell, Francesc

    2015-01-01

    While most patients affected by the influenza A(H1N1) pandemic experienced mild symptoms, a small fraction required hospitalization, often without concomitant factors that could explain such a severe course. We hypothesize that host genetic factors could contribute to aggravate the disease. To test this hypothesis, we compared the allele frequencies of 547,296 genome-wide single nucleotide polymorphisms (SNPs) between 49 severe and 107 mild confirmed influenza A cases, as well as against a general population sample of 549 individuals. When comparing severe vs. mild influenza A cases, only one SNP was close to the conventional p = 5×10-8. This SNP, rs28454025, sits in an intron of the GSK233 gene, which is involved in a neural development, but seems not to have any connections with immunological or inflammatory functions. Indirectly, a previous association reported with CD55 was replicated. Although sample sizes are low, we show that the statistical power in our design was sufficient to detect highly-penetrant, quasi-Mendelian genetic factors. Hence, and assuming that rs28454025 is likely to be a false positive, no major genetic factor was detected that could explain poor influenza A course.

  10. Targeted overexpression of cyclic AMP-dependent protein kinase subunit in Toxoplasma gondii promotes replication and virulence in host cells.

    Science.gov (United States)

    Sun, Hongchao; Wang, Suhua; Zhao, Xianfeng; Yao, Chaoqun; Zhuang, Haohan; Huang, Yechuan; Chen, Xueqiu; Yang, Yi; Du, Aifang

    2017-08-30

    Toxoplasma gondii (T. gondii) is one of the most common parasite that can infect almost any warm-blooded animals including humans. The cyclic nucleotide-dependent protein kinase (PKA) regulates a spectrum of intracellular signal pathways in many organisms. Protein kinase catalytic subunit (PKAC) is the core of the whole protein, and plays an important role in the life cycle of T.gondii. Here, T.gondii PKAC (TgPKAC) overexpression strain (TgPKAC-OE) was constructed. The growth of the TgPKAC-OE, RH△Ku80, and TgPKAC inhibition strains (TgPKAC-H89) were analysed by SYBR-green real-time PCR, and the ultrastructure was observed by transmission electron microscopy. The survival rate in mice was also recorded to analyse the virulence of the parasites. We also investigated the subcellular localization of TgPKAC in Vero cells by laser scanning microscope. We found that TgPKAC-OE strain exhibited obviously increased growth rate in Vero cells in vitro, and infected mice survived for a shorter time compared to wild type strain. Ultrastructural analysis found more autophagosomes-like structures in TgPKAC-H89 parasite compared to RH△Ku80 strain, and the relative expression level of Toxoplasma gondii autophagy-related protein (ATG8) in TgPKAC-H89 parasite was higher than wild type parasite. Laser confocal results showed that TgPKAC was mainly expressed in the cytoplasm of Vero cells. In conclusion, we hypothesized that inhibition of TgPKAC could cause autophagy of Toxoplasma gondii and then influence the replication of the parasite. TgPKAC plays an important role in parasite virulence in vivo, and the subcellular localization was successfully detected in Vero cells. Our data will provide a basis for further study of TgPKAC function and help screen drug targets of T. gondii. Copyright © 2017. Published by Elsevier B.V.

  11. The likelihood of achieving quantified road safety targets: a binary logistic regression model for possible factors.

    Science.gov (United States)

    Sze, N N; Wong, S C; Lee, C Y

    2014-12-01

    In past several decades, many countries have set quantified road safety targets to motivate transport authorities to develop systematic road safety strategies and measures and facilitate the achievement of continuous road safety improvement. Studies have been conducted to evaluate the association between the setting of quantified road safety targets and road fatality reduction, in both the short and long run, by comparing road fatalities before and after the implementation of a quantified road safety target. However, not much work has been done to evaluate whether the quantified road safety targets are actually achieved. In this study, we used a binary logistic regression model to examine the factors - including vehicle ownership, fatality rate, and national income, in addition to level of ambition and duration of target - that contribute to a target's success. We analyzed 55 quantified road safety targets set by 29 countries from 1981 to 2009, and the results indicate that targets that are in progress and with lower level of ambitions had a higher likelihood of eventually being achieved. Moreover, possible interaction effects on the association between level of ambition and the likelihood of success are also revealed. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. The natural history of parallel transjugular intrahepatic portosystemic stent shunts using uncovered stent: the role of host-related factors.

    Science.gov (United States)

    Helmy, Ahmed; Redhead, Doris N; Stanley, Adrian J; Hayes, Peter C

    2006-06-01

    Parallel shunts (PS) are used in the management of transjugular intrahepatic portosystemic stent-shunt (TIPS) insufficiency, a major limitation of the technique. This study describes the natural history of PS, and uses them as a model to assess the role of host factors in the development of primary shunt insufficiency. Out of 338 patients with TIPS, 40 (11.8%) patients required insertion of a PS. Baseline and follow-up data of these patients were collected. Regular shunt surveillance involved biannual clinic visits and transjugular portography. The non-PS group (group 1; n = 298) and the PS group (group 2; n = 40) had similar baseline demographic and disease characteristics. Index shunts of both groups and the PS produced a significant portal pressure gradient drop (P < 0.001), which was less in the index shunts of Group 2 (P < 0.02 for both). PS had similar cumulative shunt patency rates to those of the index shunts of Group 1, and both were greater than those of index shunts in Group 2 (P < 0.001 for both). The intervention rate (number of interventions/number of check portograms x 100) was similar for PS and the index shunts of Group 1 (38.7% and 43% respectively), but was significantly higher in the index shunts of Group 2 (85.6%; P < 0.01 for both). In Group 1 and Group 2, 144 patients (48.3%) and 21 patients (52.5%) died during follow-up after a median period of 23.4 and 8.9 months respectively. These findings do not support the hypothesis that shunt insufficiency is related to host factors.

  13. Novel Data Fusion Method and Exploration of Multiple Information Sources for Transcription Factor Target Gene Prediction

    Science.gov (United States)

    Dai, Xiaofeng; Yli-Harja, Olli; Lähdesmäki, Harri

    2010-12-01

    Background. Revealing protein-DNA interactions is a key problem in understanding transcriptional regulation at mechanistic level. Computational methods have an important role in predicting transcription factor target gene genomewide. Multiple data fusion provides a natural way to improve transcription factor target gene predictions because sequence specificities alone are not sufficient to accurately predict transcription factor binding sites. Methods. Here we develop a new data fusion method to combine multiple genome-level data sources and study the extent to which DNA duplex stability and nucleosome positioning information, either alone or in combination with other data sources, can improve the prediction of transcription factor target gene. Results. Results on a carefully constructed test set of verified binding sites in mouse genome demonstrate that our new multiple data fusion method can reduce false positive rates, and that DNA duplex stability and nucleosome occupation data can improve the accuracy of transcription factor target gene predictions, especially when combined with other genome-level data sources. Cross-validation and other randomization tests confirm the predictive performance of our method. Our results also show that nonredundant data sources provide the most efficient data fusion.

  14. Characterisation of mouse mammary tumour virus and host related regulatory factors

    International Nuclear Information System (INIS)

    Müllner, M.

    2012-01-01

    , respectively. Thus, a region located at the 5’ end of the env coding region was demonstrated to be involved in the Rem/RmRE-independent RNA export. Deletion of this region led to a complete loss of single-spliced env mRNA export. Cloning of this 5’ transport element (5’TE) into the heterologous HIV-1 gag RNA reporter construct revealed that the 5’TE-mediated nuclear export is independent of a virally encoded accessory protein. Additional results have shown that the MMTV env mRNA nucleo-cytoplasmic transport is dependent on the cellular factor Tap. Together, the results presented in this work clearly demonstrate that MMTV exploits different strategies to export various viral RNA messages from the nucleus. On the one hand, transport of full length genomic RNA is mediated by the Rem/RmRE interaction which then allows binding of the nuclear export factor CRM1. On the other hand, single-spliced env mRNA makes use of a cis-acting transport element located at the 5’ end of the subgenomic RNA. Export via this structure is dependent on the cellular Tap nuclear export factor. However, molecular details about the MMTV export strategies still have to be determined.(author) [de

  15. Insights into the functional characteristics of geminivirus rolling-circle replication initiator protein and its interaction with host factors affecting viral DNA replication.

    Science.gov (United States)

    Rizvi, Irum; Choudhury, Nirupam Roy; Tuteja, Narendra

    2015-02-01

    Geminiviruses are DNA viruses that infect several economically important crops, resulting in a reduction in their overall yield. These plant viruses have circular, single-stranded DNA genomes that replicate mainly by a rolling-circle mechanism. Geminivirus infection results in crosstalk between viral and cellular factors to complete the viral life cycle or counteract the infection as part of defense mechanisms of host plants. The geminiviral replication initiator protein Rep is the only essential viral factor required for replication. It is multifunctional and is known to interact with a number of host factors to modulate the cellular environment or to function as a part of the replication machinery. This review provides a holistic view of the research related to the viral Rep protein and various host factors involved in geminiviral DNA replication. Studies on the promiscuous nature of geminiviral satellite DNAs are also reviewed.

  16. The Xanthomonas Type III Effector XopD Targets the Arabidopsis Transcription Factor MYB30 to Suppress Plant Defense[W

    Science.gov (United States)

    Canonne, Joanne; Marino, Daniel; Jauneau, Alain; Pouzet, Cécile; Brière, Christian; Roby, Dominique; Rivas, Susana

    2011-01-01

    Plant and animal pathogens inject type III effectors (T3Es) into host cells to suppress host immunity and promote successful infection. XopD, a T3E from Xanthomonas campestris pv vesicatoria, has been proposed to promote bacterial growth by targeting plant transcription factors and/or regulators. Here, we show that XopD from the B100 strain of X. campestris pv campestris is able to target MYB30, a transcription factor that positively regulates Arabidopsis thaliana defense and associated cell death responses to bacteria through transcriptional activation of genes related to very-long-chain fatty acid (VLCFA) metabolism. XopD specifically interacts with MYB30, resulting in inhibition of the transcriptional activation of MYB30 VLCFA-related target genes and suppression of Arabidopsis defense. The helix-loop-helix domain of XopD is necessary and sufficient to mediate these effects. These results illustrate an original strategy developed by Xanthomonas to subvert plant defense and promote development of disease. PMID:21917550

  17. Multi-faceted proteomic characterization of host protein complement of Rift Valley fever virus virions and identification of specific heat shock proteins, including HSP90, as important viral host factors.

    Science.gov (United States)

    Nuss, Jonathan E; Kehn-Hall, Kylene; Benedict, Ashwini; Costantino, Julie; Ward, Michael; Peyser, Brian D; Retterer, Cary J; Tressler, Lyal E; Wanner, Laura M; McGovern, Hugh F; Zaidi, Anum; Anthony, Scott M; Kota, Krishna P; Bavari, Sina; Hakami, Ramin M

    2014-01-01

    Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV). Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry) with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90), as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF.

  18. Multi-faceted proteomic characterization of host protein complement of Rift Valley fever virus virions and identification of specific heat shock proteins, including HSP90, as important viral host factors.

    Directory of Open Access Journals (Sweden)

    Jonathan E Nuss

    Full Text Available Rift Valley fever is a potentially fatal disease of humans and domestic animals caused by Rift Valley fever virus (RVFV. Infection with RVFV in ruminants can cause near 100% abortion rates and recent outbreaks in naïve human populations have suggested case fatality rates of greater than thirty percent. To elucidate the roles that host proteins play during RVFV infection, proteomic analysis of RVFV virions was conducted using complementary analytical approaches, followed by functional validation studies of select identified host factors. Coupling the more traditional Gel LC/MS/MS approach (SDS PAGE followed by liquid chromatography tandem mass spectrometry with an alternative technique that preserves protein complexes allowed the protein complement of these viral particles to be thoroughly examined. In addition to viral proteins present within the virions and virion-associated host proteins, multiple macromolecular complexes were identified. Bioinformatic analysis showed that host chaperones were among over-represented protein families associated with virions, and functional experiments using siRNA gene silencing and small molecule inhibitors identified several of these heat shock proteins, including heat shock protein 90 (HSP90, as important viral host factors. Further analysis indicated that HSP inhibition effects occur during the replication/transcription phase of the virus life cycle, leading to significant lowering of viral titers without compromising the functional capacity of released virions. Overall, these studies provide much needed further insight into interactions between RVFV and host cells, increasing our understanding of the infection process and suggesting novel strategies for anti-viral development. In particular, considering that several HSP90 inhibitors have been advancing through clinical trials for cancer treatment, these results also highlight the exciting potential of repurposing HSP90 inhibitors to treat RVF.

  19. Late acute graft-versus-host disease: a prospective analysis of clinical outcomes and circulating angiogenic factors.

    Science.gov (United States)

    Holtan, Shernan G; Khera, Nandita; Levine, John E; Chai, Xiaoyu; Storer, Barry; Liu, Hien D; Inamoto, Yoshihiro; Chen, George L; Mayer, Sebastian; Arora, Mukta; Palmer, Jeanne; Flowers, Mary E D; Cutler, Corey S; Lukez, Alexander; Arai, Sally; Lazaryan, Aleksandr; Newell, Laura F; Krupski, Christa; Jagasia, Madan H; Pusic, Iskra; Wood, William; Renteria, Anne S; Yanik, Gregory; Hogan, William J; Hexner, Elizabeth; Ayuk, Francis; Holler, Ernst; Watanaboonyongcharoen, Phandee; Efebera, Yvonne A; Ferrara, James L M; Panoskaltsis-Mortari, Angela; Weisdorf, Daniel; Lee, Stephanie J; Pidala, Joseph

    2016-11-10

    Late acute (LA) graft-versus-host disease (GVHD) is persistent, recurrent, or new-onset acute GVHD symptoms occurring >100 days after allogeneic hematopoietic cell transplantation (HCT). The aim of this analysis is to describe the onset, course, morbidity, and mortality of and examine angiogenic factors associated with LA GVHD. A prospective cohort of patients (n = 909) was enrolled as part of an observational study within the Chronic GVHD Consortium. Eighty-three patients (11%) developed LA GVHD at a median of 160 (interquartile range, 128-204) days after HCT. Although 51 out of 83 (61%) achieved complete or partial response to initial therapy by 28 days, median failure-free survival was only 7.1 months (95% confidence interval, 3.4-19.1 months), and estimated overall survival (OS) at 2 years was 56%. Given recently described alterations of circulating angiogenic factors in classic acute GVHD, we examined whether alterations in such factors could be identified in LA GVHD. We first tested cases (n = 55) and controls (n = 50) from the Chronic GVHD Consortium and then validated the findings in 37 cases from Mount Sinai Acute GVHD International Consortium. Plasma amphiregulin (AREG; an epidermal growth factor [EGF] receptor ligand) was elevated, and an AREG/EGF ratio at or above the median was associated with inferior OS and increased nonrelapse mortality in both cohorts. Elevation of AREG was detected in classic acute GVHD, but not chronic GVHD. These prospective data characterize the clinical course of LA GVHD and demonstrate alterations in angiogenic factors that make LA GVHD biologically distinct from chronic GVHD. © 2016 by The American Society of Hematology.

  20. The host factor polyhedrin promoter binding protein (PPBP) is involved in transcription from the baculovirus polyhedrin gene promoter.

    Science.gov (United States)

    Ghosh, S; Jain, A; Mukherjee, B; Habib, S; Hasnain, S E

    1998-09-01

    Hypertranscription and temporal expression from the Autographa californica nuclear polyhedrosis (AcNPV) baculovirus polyhedrin promoter involves an alpha-amanitin-resistant RNA polymerase and requires a trans-acting viral factor(s). We previously reported that a 30-kDa host factor, polyhedrin promoter binding protein (PPBP), binds with unusual affinity, specificity, and stability to the transcriptionally important motif AATAAATAAGTATT within the polyhedrin (polh) initiator promoter and also displays coding strand-specific single-stranded DNA (ssDNA)-binding activity (S. Burma, B. Mukherjee, A. Jain, S. Habib, and S. E. Hasnain, J. Biol. Chem. 269:2750-2757, 1994; B. Mukherjee, S. Burma, and S. E. Hasnain, J. Biol. Chem. 270:4405-4411, 1995). We now present evidence which indicates that an additional factor(s) is involved in stabilizing PPBP-duplex promoter and PPBP-ssDNA interactions. TBP (TATA box binding protein) present in Spodoptera frugiperda (Sf9) cells is characteristically distinct from PPBP and does not interact directly with the polh promoter. Replacement of PPBP cognate sequences within the polh promoter with random nucleotides abolished PPBP binding in vitro and also failed to express the luciferase reporter gene in vivo. Phosphocellulose fractions of total nuclear extract from virus-infected cells which support in vitro transcription from the polh promoter contain PPBP activity. When PPBP was sequestered by the presence of oligonucleotides containing PPBP cognate sequence motifs, in vitro transcription of a C-free reporter cassette was affected but was restored by the exogenous addition of nuclear extract containing PPBP. When PPBP was mopped out in vivo by a plasmid carrying PPBP cognate sequence present in trans, polh promoter-driven expression of the luciferase reporter was abolished, demonstrating that binding of PPBP to the polh promoter is essential for transcription.

  1. Tumor necrosis factor alpha converting enzyme: an encouraging target for various inflammatory disorders.

    Science.gov (United States)

    Bahia, Malkeet S; Silakari, Om

    2010-05-01

    Tumor necrosis factor alpha is one of the most common pro-inflammatory cytokines responsible for various inflammatory disorders. It plays an important role in the origin and progression of rheumatoid arthritis and also in other autoimmune disease conditions. Some anti-tumor necrosis factor alpha antibodies like Enbrel, Humira and Remicade have been successfully used in these disease conditions as antagonists of tumor necrosis factor alpha. Inhibition of generation of active form of tumor necrosis factor alpha is a promising therapy for various inflammatory disorders. Therefore, the inhibition of an enzyme (tumor necrosis factor alpha converting enzyme), which is responsible for processing inactive form of tumor necrosis factor alpha into its active soluble form, is an encouraging target. Many tumor necrosis factor alpha converting enzyme inhibitors have been the candidates of clinical trials but none of them have reached in to the market because of their broad spectrum inhibitory activity for other matrix metalloproteases. Selectivity of tumor necrosis factor alpha converting enzyme inhibition over matrix metalloproteases is of utmost importance. If selectivity is achieved successfully, side-effects can be over-ruled and this approach may become a novel therapy for treatment of rheumatoid arthritis and other inflammatory disorders. This cytokine not only plays a pivotal role in inflammatory conditions but also in some cancerous conditions. Thus, successful targeting of tumor necrosis factor alpha converting enzyme may result in multifunctional therapy.

  2. Targeting the insulin-like growth factor network in cancer therapy.

    Science.gov (United States)

    Heidegger, Isabel; Pircher, Andreas; Klocker, Helmut; Massoner, Petra

    2011-04-15

    During the last decades, changes in the insulin-like growth factor (IGF) signaling have been related to the pathogenesis of cancer. Therefore, IGFs became highly attractive therapeutic cancer targets. Several drugs including monoclonal antibodies (mAB), small molecule tyrosine kinase inhibitors (RTKIs), anti-sense oligonucleotids (ASOs) and IGF-binding proteins (IGFBPs) targeting the IGF axis were developed. With over 60 ongoing clinical trials, the IGF1 receptor (IGF1R) is currently one of the most studied molecular targets in the field of oncology. In this review, we provide an overview on the IGF axis, its signaling pathways and its significance in neoplasia. We critically review the preclinical and clinical studies investigating the role of IGF1R as a cancer target and discuss preliminary results and possible limitations.

  3. An infrared small target detection method based on nonnegative matrix factorization and compressed sensing

    Science.gov (United States)

    Chen, Qiwei; Wang, Yiming

    2017-07-01

    According to the low rank property of the background and the sparse features of the target in infrared image, a novel infrared small target detection method based on the nonnegative matrix factorization (NMF) and compressed sensing technology was presented in this paper. This method trained background model through NMF, and then sampled the infrared image sequences directly using the block compressed sensing technology. Through the alternating direction method of multipliers (ADMM), the infrared small target was extracted and the background was recovered from the image. At the same time, the background was updated by the update algorithm, to adapt to the changes in the background. The simulation results show that the proposed method can detect the infrared target precisely and efficiently.

  4. Imaging Diagnostic and Therapeutic Targets : Human Epidermal Growth Factor Receptor 2

    NARCIS (Netherlands)

    Gebhart, Geraldine; Flamen, Patrick; Vries, de Elisabeth G. E.; Jhaveri, Komal; Wimana, Zena

    2016-01-01

    Since the approval of trastuzumab, a humanized monoclonal antibody against the extracellular domain of human epidermal growth factor receptor 2 (HER2), 3 other HER2-targeting agents have gained regulatory approval: lapatinib, pertuzumab, and trastuzumab-emtansine. These agents have revolutionized

  5. Targeting Family Risk Factors in the Context of Treating Youth Depression: A Survey of Psychologists

    Science.gov (United States)

    Parra, Gilbert R.; Buckholdt, Kelly E.; Olsen, James P.; Jobe-Shields, Lisa; Davis, Genevieve L.; Gamble, Heather L.

    2011-01-01

    This study investigated the practices and perceptions of psychologists related to targeting family risk factors when treating youth depression. Participants were practicing psychologists recruited through the National Register of Health Service Providers in Psychology (N = 279). Psychologists completed a brief anonymous survey about addressing…

  6. A single gene target of an ETS-family transcription factor determines neuronal CO2-chemosensitivity

    DEFF Research Database (Denmark)

    Brandt, Julia P; Aziz-Zaman, Sonya; Juozaityte, Vaida

    2012-01-01

    . We report here a mechanism that endows C. elegans neurons with the ability to detect CO(2). The ETS-5 transcription factor is necessary for the specification of CO(2)-sensing BAG neurons. Expression of a single ETS-5 target gene, gcy-9, which encodes a receptor-type guanylate cyclase, is sufficient...

  7. Tumor infarction in mice by antibody-directed targeting of tissue factor to tumor vasculature

    NARCIS (Netherlands)

    Huang, XM; Molema, G; King, S; Watkins, L; Edgington, TS; Thorpe, PE

    1997-01-01

    Selective occlusion of tumor vasculature was tested as a therapy for solid tumors in a mouse model. The formation of blood clots (thrombosis) within the tumor Vessels was initiated by targeting the cell surface domain of human tissue factor, by means of a bispecific antibody, to an experimentally

  8. Recurrent invasive pneumococcal disease in children--host factors and vaccination response.

    Science.gov (United States)

    Ingels, Helene Andrea Sinclair

    2015-07-01

    Streptococcus pneumoniae is still a leading cause of septicaemia, pneumonia and meningitis in young children world-wide with over half a million children dying annually from pneumococcal disease.  Some children are prone to repeated episodes of invasive pneumococcal disease (IPD) because of an underlying predisposing disease. Recurrent IPD (rIPD) is a rarity and published reports on rIPD are limited by having few children included, selected groups of patients or short follow-up periods. Deficiencies in the innate or adaptive immune system have been described in children with rIPD, but the frequency of immunodeficiency among such patients is unknown. The aim of this PhD thesis was to examine paediatric cases of laboratory-confirmed rIPD, over a 33-year period in Denmark, to determine risk factors and study aspects of the immunological background for this problem in children. In October 2007, a seven-valent pneumococcal conjugate vaccine (PCV7) was implemented in the Danish infant immunization programme. An additional aim of the thesis was to examine the impact of vaccination on a population level, following the first three years of general PCV7 vaccination in Denmark. The thesis consists of three papers, which are all directly or indirectly based on data retrieved from the National Streptococcus Pneumoniae Registry. This registry is nationwide and dates back to 1938. The registry contains data from all laboratory-confirmed cases of IPD in Denmark and is continually updated for national surveillance. In Paper 1, we conducted a 33-year retrospective nationwide study of paediatric rIPD. By using data from the National Streptococcus Pneumoniae Registry combined with clinical data from hospital records, we could describe one of the largest known cohorts of children (n:59) with rIPD . We covered epidemiological, microbiological, and clinical features of this clinical entity. Of all children experiencing rIPD, 47% had a known predisposing underlying disease at the time of

  9. Targeting of insect epicuticular lipids by the entomopathogenic fungus Beauveria bassiana: hydrocarbon oxidation within the context of a host-pathogen interaction

    Science.gov (United States)

    Pedrini, Nicolás; Ortiz-Urquiza, Almudena; Huarte-Bonnet, Carla; Zhang, Shizhu; Keyhani, Nemat O.

    2013-01-01

    Broad host range entomopathogenic fungi such as Beauveria bassiana attack insect hosts via attachment to cuticular substrata and the production of enzymes for the degradation and penetration of insect cuticle. The outermost epicuticular layer consists of a complex mixture of non-polar lipids including hydrocarbons, fatty acids, and wax esters. Long chain hydrocarbons are major components of the outer waxy layer of diverse insect species, where they serve to protect against desiccation and microbial parasites, and as recognition molecules or as a platform for semiochemicals. Insect pathogenic fungi have evolved mechanisms for overcoming this barrier, likely with sets of lipid degrading enzymes with overlapping substrate specificities. Alkanes and fatty acids are substrates for a specific subset of fungal cytochrome P450 monooxygenases involved in insect hydrocarbon degradation. These enzymes activate alkanes by terminal oxidation to alcohols, which are further oxidized by alcohol and aldehyde dehydrogenases, whose products can enter β-oxidation pathways. B. bassiana contains at least 83 genes coding for cytochrome P450s (CYP), a subset of which are involved in hydrocarbon oxidation, and several of which represent new CYP subfamilies/families. Expression data indicated differential induction by alkanes and insect lipids and four CYP proteins have been partially characterized after heterologous expression in yeast. Gene knockouts revealed a phenotype for only one (cyp52X1) out of six genes examined to date. CYP52X1 oxidizes long chain fatty acids and participates in the degradation of specific epicuticular lipid components needed for breaching the insect waxy layer. Examining the hydrocarbon oxidizing CYP repertoire of pathogens involved in insect epicuticle degradation can lead to the characterization of enzymes with novel substrate specificities. Pathogen targeting may also represent an important co-evolutionary process regarding insect cuticular hydrocarbon

  10. Radiation-induced mouse chimeras: a cellular analysis of the major lymphoid compartments, factors affecting lethal graft versus host disease and host-tumor interactions

    International Nuclear Information System (INIS)

    Almaraz, R.

    1981-01-01

    The major lymphoid compartments of allogeneic bone marrow chimeras were evaluated for the extent of cell chimerism and distribution of Thy 1 and la bearing cells. These chimeras contained lymphoid cell primarily of donor origin. The bone marrow compartment was a mixture of host and donor origin cells. The distribution of Thy 1 and la bearing cells was similar as in normal mice. The effect of adult thymectomy alone or followed by whole-body irradiation and bone marrow reconstitution on the distribution of the Thy 1 positive cells was also investigated. Thymectomy with or without WBI and bone marrow reconstitution significantly lowered the number of Thy 1 bearing cells in the blood and spleen. The number of la bearing cells did not appear to be affected by thymectomy. The role of circulating lymphoid cells in the incidence of lethal graft versus host disease (GVHD) in radiation induced fully allogeneic mouse chimeras was studied. Mice reconstituted with allogeneic bone marrow from bled donors had a statistically lower incidence of GVHD than those reconstituted with bone marrow from unbled donors. Addition of mature peripheral lymphocytes from blood to the reconstituting bone marrow cells from bled donors reduplicated the high incidence of lethal GVHD. It was demonstrated that the bone marrow of mice not exsanguinated prior to harvesting of bone marrow contained significant numbers of peripheral contaminating cells in the harvested bone marrow. The role of suppressor cell elimination in resisting tumor growth was investigated using radiation induced mouse chimeras. Local effects of irradiation alone at the site of tumor inoculation could account for this lack of growth

  11. National Climate Policies: Aiming at the Factor 4 Target by 2050?

    International Nuclear Information System (INIS)

    Godard, Olivier

    2016-01-01

    The paper considers how the governments of midsize developed countries could define national strategies to control greenhouse gas emissions, assuming that such strategies are the product of cognitive and ethical choices relating to global climate scenarios and the rule for allocating shares of expected global climate damage to individual States. After evaluating the carbon value linked to each cognitive-ethical configuration, I identify the configurations that justify the target of dividing national emissions by 4 between 1990 and 2050 - a goal known as 'Factor 4'. Lastly, I examine the resulting constraints on the shape of the control trajectory leading to that target

  12. Construction of a mouse model of factor VIII deficiency by gene targeting

    Energy Technology Data Exchange (ETDEWEB)

    Bi, L.; Lawler, A.; Gearhart, J. [Univ. of Pennsylvania School of Medicine, Philadelphia, PA (United States)] [and others

    1994-09-01

    To develop a small animal model of hemophilia A for gene therapy experiments, we set out to construct a mouse model for factor VIII deficiency by gene targeting. First, we screened a mouse liver cDNA library using a human FVIII cDNA probe. We cloned a 2.6 Kb partial mouse factor VIII cDNA which extends from 800 base pairs of the 3{prime} end of exon 14 to the 5{prime} end of exon 26. A mouse genomic library made from strain 129 was then screened to obtain genomic fragments covering the exons desired for homologous recombination. Two genomic clones were obtained, and one covering exon 15 through 22 was used for gene targeting. To make gene targeting constructs, a 5.8 Kb genomic DNA fragment covering exons 15 to 19 of the mouse FVIII gene was subcloned, and the neo expression cassette was inserted into exons 16 and 17 separately by different strategies. These two constructs were named MFVIIIC-16 and MFVIIIC-17. The constructs were linearized and transfected into strain 129 mouse ES cells by electroporation. Factor VIII gene-knockout ES cell lines were selected by G-418 and screened by genomic Southern blots. Eight exon 16 targeted cell lines and five exon 17 targeted cell lines were obtained. Three cell lines from each construct were injected into blastocysts and surgically transferred into foster mothers. Multiple chimeric mice with 70-90% hair color derived from the ES-cell genotype were seen with both constructs. Germ line transmission of the ES-cell genotype has been obtained for the MFVIIIC-16 construct, and multiple hemophilia A carrier females have been identified. Factor VIII-deficient males will be conceived soon.

  13. Identification of the key weather factors affecting overwintering success of Apolygus lucorum eggs in dead host tree branches.

    Science.gov (United States)

    Pan, Hongsheng; Liu, Bing; Lu, Yanhui; Desneux, Nicolas

    2014-01-01

    Understanding the effects of weather on insect population dynamics is crucial to simulate and forecast pest outbreaks, which is becoming increasingly important with the effects of climate change. The mirid bug Apolygus lucorum is an important pest on cotton, fruit trees and other crops in China, and primarily lays its eggs on dead parts of tree branches in the fall for subsequent overwintering. As such, the eggs that hatch the following spring are most strongly affected by ambient weather factors, rather than by host plant biology. In this study, we investigated the effects of three major weather factors: temperature, relative humidity and rainfall, on the hatching rate of A. lucorum eggs overwintering on dead branches of Chinese date tree (Ziziphus jujuba). Under laboratory conditions, rainfall (simulated via soaking) was necessary for the hatching of overwintering A. lucorum eggs. In the absence of rainfall (unsoaked branches), very few nymphs successfully emerged under any of the tested combinations of temperature and relative humidity. In contrast, following simulated rainfall, the hatching rate of the overwintering eggs increased dramatically. Hatching rate and developmental rate were positively correlated with relative humidity and temperature, respectively. Under field conditions, the abundance of nymphs derived from overwintering eggs was positively correlated with rainfall amount during the spring seasons of 2009-2013, while the same was not true for temperature and relative humidity. Overall, our findings indicate that rainfall is the most important factor affecting the hatching rate of overwintering A. lucorum eggs on dead plant parts and nymph population levels during the spring season. It provides the basic information for precisely forecasting the emergence of A. lucorum and subsequently timely managing its population in spring, which will make it possible to regional control of this insect pest widely occurring in multiple crops in summer.

  14. Identification of the key weather factors affecting overwintering success of Apolygus lucorum eggs in dead host tree branches.

    Directory of Open Access Journals (Sweden)

    Hongsheng Pan

    Full Text Available Understanding the effects of weather on insect population dynamics is crucial to simulate and forecast pest outbreaks, which is becoming increasingly important with the effects of climate change. The mirid bug Apolygus lucorum is an important pest on cotton, fruit trees and other crops in China, and primarily lays its eggs on dead parts of tree branches in the fall for subsequent overwintering. As such, the eggs that hatch the following spring are most strongly affected by ambient weather factors, rather than by host plant biology. In this study, we investigated the effects of three major weather factors: temperature, relative humidity and rainfall, on the hatching rate of A. lucorum eggs overwintering on dead branches of Chinese date tree (Ziziphus jujuba. Under laboratory conditions, rainfall (simulated via soaking was necessary for the hatching of overwintering A. lucorum eggs. In the absence of rainfall (unsoaked branches, very few nymphs successfully emerged under any of the tested combinations of temperature and relative humidity. In contrast, following simulated rainfall, the hatching rate of the overwintering eggs increased dramatically. Hatching rate and developmental rate were positively correlated with relative humidity and temperature, respectively. Under field conditions, the abundance of nymphs derived from overwintering eggs was positively correlated with rainfall amount during the spring seasons of 2009-2013, while the same was not true for temperature and relative humidity. Overall, our findings indicate that rainfall is the most important factor affecting the hatching rate of overwintering A. lucorum eggs on dead plant parts and nymph population levels during the spring season. It provides the basic information for precisely forecasting the emergence of A. lucorum and subsequently timely managing its population in spring, which will make it possible to regional control of this insect pest widely occurring in multiple crops in

  15. Targeting both viral and host determinants of human immunodeficiency virus entry, using a new lentiviral vector coexpressing the T20 fusion inhibitor and a selective CCL5 intrakine.

    Science.gov (United States)

    Petit, Nicolas; Dorgham, Karim; Levacher, Béatrice; Burlion, Aude; Gorochov, Guy; Marodon, Gilles

    2014-08-01

    Numerous strategies targeting early and late steps of the HIV life cycle have been proposed for gene therapy. However, targeting viral and host determinants of HIV entry is the only strategy that would prevent viral DNA-mediated CD4(+) cell death while diminishing the possibility for the virus to escape. To this end, we devised a bicistronic lentiviral vector expressing the membrane-bound form of the T20 fusion inhibitor, referred to as the C46 peptide, and a CCR5 superagonist, modified to sequester CCR5 away from the cell surface, referred to as the P2-CCL5 intrakine. We tested the effects of the vector on HIV infection and replication, using the human CEMR5 cell line expressing CD4 and CCR5, and primary human T cells. Transduced cells expressed the C46 peptide, detected with the 2F5 monoclonal antibody by flow cytometry. Expression of the P2-CCL5 intrakine correlates with lower levels of cell surface CCR5. Complete protection against HIV infection could be observed in cells expressing the protective transgenes. Importantly, we show that the combination of the transgenes was more potent than either transgene alone, showing the interest of expressing two entry inhibitors to inhibit HIV infection. Last, genetically modified cells possessed a selective advantage over nonmodified cells on HIV challenge in vitro, showing that modified cells were protected from HIV-induced cell death. Our results demonstrate that lentiviral vectors coexpressing the T20 fusion inhibitor and the P2-CCL5 intrakine represent promising tools for HIV gene therapy.

  16. Transcription profile of Escherichia coli: genomic SELEX search for regulatory targets of transcription factors

    Science.gov (United States)

    Ishihama, Akira; Shimada, Tomohiro; Yamazaki, Yukiko

    2016-01-01

    Bacterial genomes are transcribed by DNA-dependent RNA polymerase (RNAP), which achieves gene selectivity through interaction with sigma factors that recognize promoters, and transcription factors (TFs) that control the activity and specificity of RNAP holoenzyme. To understand the molecular mechanisms of transcriptional regulation, the identification of regulatory targets is needed for all these factors. We then performed genomic SELEX screenings of targets under the control of each sigma factor and each TF. Here we describe the assembly of 156 SELEX patterns of a total of 116 TFs performed in the presence and absence of effector ligands. The results reveal several novel concepts: (i) each TF regulates more targets than hitherto recognized; (ii) each promoter is regulated by more TFs than hitherto recognized; and (iii) the binding sites of some TFs are located within operons and even inside open reading frames. The binding sites of a set of global regulators, including cAMP receptor protein, LeuO and Lrp, overlap with those of the silencer H-NS, suggesting that certain global regulators play an anti-silencing role. To facilitate sharing of these accumulated SELEX datasets with the research community, we compiled a database, ‘Transcription Profile of Escherichia coli’ (www.shigen.nig.ac.jp/ecoli/tec/). PMID:26843427

  17. Leveraging growth factor induced macropinocytosis for targeted treatment of lung cancer.

    Science.gov (United States)

    Iglesias, Raul; Koria, Piyush

    2015-12-01

    Targeted therapy focused on highly expressed growth factor receptors is increasingly becoming popular for the treatment of lung cancer. Cancer cells exhibit higher levels of macropinocytosis than the normally quiescent non-cancerous cells, which can further be enhanced by growth factors. Here, we show the targeted enhancement of macropinocytosis in lung cancer cells for the delivery of the mitochondriotoxic peptide (KLAKLAK)2 using keratinocyte growth factor (KGF). We report the formation of a nanoparticle (NP) comprising of two chimeric fusion proteins, both fused to elastin-like polypeptide (ELP), (KLAKLAK)2-ELP and KGF-ELP. We show that (KLAKLAK)2-ELP nanoparticles are internalized via macropinocytosis and its internalization is facilitated by the interaction of the ELP domain with cell surface heparin sulfate proteoglycans. This internalization leads to mitochondrial depolarization and subsequent cell death. Also, we demonstrate that KGF-ELP selectively enhances macropinocytosis in cancer cells expressing high levels of the keratinocyte growth factor receptor (KGFR). Finally, the heterogeneous NPs consisting of (KLAKLAK)2-ELP and KGF-ELP selectively kill KGFR-expressing lung cancer cells. Hence, this multipronged approach of targeting highly active processes and receptors in cancer cells will be tremendously selective in the treatment of both early-stage and advanced-stage lung cancers, thereby improving patient's prognosis and survival rate.

  18. Transcription profile of Escherichia coli: genomic SELEX search for regulatory targets of transcription factors.

    Science.gov (United States)

    Ishihama, Akira; Shimada, Tomohiro; Yamazaki, Yukiko

    2016-03-18

    Bacterial genomes are transcribed by DNA-dependent RNA polymerase (RNAP), which achieves gene selectivity through interaction with sigma factors that recognize promoters, and transcription factors (TFs) that control the activity and specificity of RNAP holoenzyme. To understand the molecular mechanisms of transcriptional regulation, the identification of regulatory targets is needed for all these factors. We then performed genomic SELEX screenings of targets under the control of each sigma factor and each TF. Here we describe the assembly of 156 SELEX patterns of a total of 116 TFs performed in the presence and absence of effector ligands. The results reveal several novel concepts: (i) each TF regulates more targets than hitherto recognized; (ii) each promoter is regulated by more TFs than hitherto recognized; and (iii) the binding sites of some TFs are located within operons and even inside open reading frames. The binding sites of a set of global regulators, including cAMP receptor protein, LeuO and Lrp, overlap with those of the silencer H-NS, suggesting that certain global regulators play an anti-silencing role. To facilitate sharing of these accumulated SELEX datasets with the research community, we compiled a database, 'Transcription Profile of Escherichia coli' (www.shigen.nig.ac.jp/ecoli/tec/). © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  19. Comparative analysis of FoxP3(+) regulatory T cells in the target tissues and blood in chronic graft versus host disease.

    Science.gov (United States)

    Imanguli, M M; Cowen, E W; Rose, J; Dhamala, S; Swaim, W; Lafond, S; Yagi, B; Gress, R E; Pavletic, S Z; Hakim, F T

    2014-10-01

    Activation and migration of regulatory T cells (Treg) into tissue is critical in control of inflammation, but has not been examined extensively in chronic graft versus host disease (cGVHD). In parallel studies of tissues and blood, we determined that FoxP3(+) T cells increased in proportion to T effectors (Teff) in tissue infiltrates in oral and cutaneous lichenoid cGVHD. These FoxP3(+) cells expressed distinguishing phenotypic and functional markers of Treg (CD3(+), CD4(+), CD27(+), ICOS(+) and CD39(+)), not found on FoxP3(-) Teff. Both Teff and FoxP3(+) Treg expressed T-bet and the chemokine receptor CXCR3, however, consistent with a common mechanism of chemokine-mediated migration into tissue. Furthermore, functional markers (ICOS and CD39) and chemokine receptors (CXCR3) were both present in a higher proportion of FoxP3(+) cells in tissues than in peripheral blood, consistent with recruitment and activation of Treg in cGVHD target tissues. Finally, the 'activated' CD45RA(-)FoxP3(hi) subset of Treg cells, which highly express functional markers, were found in comparable frequencies in cGVHD patients and normal controls, despite a significant deficit in naive 'resting' Treg. These findings are consistent with Treg capacity to upregulate functional markers and traffick into tissue in cGVHD.

  20. Cardio-oncology Related to Heart Failure: Epidermal Growth Factor Receptor Target-Based Therapy.

    Science.gov (United States)

    Kenigsberg, Benjamin; Jain, Varun; Barac, Ana

    2017-04-01

    Cancer therapy targeting the epidermal growth factor receptor (EGFR)/erythroblastic leukemia viral oncogene B (ErbB)/human EGFR receptor (HER) family of tyrosine kinases has been successfully used in treatment of several malignancies. The ErbB pathways play a role in the maintenance of cardiac homeostasis. This article summarizes current knowledge about EGFR/ErbB/HER receptor-targeted cancer therapeutics focusing on their cardiotoxicity profiles, molecular mechanisms, and implications in clinical cardio-oncology. The article discusses challenges in predicting, monitoring, and treating cardiac dysfunction and heart failure associated with ErbB-targeted cancer therapeutics and highlights opportunities for researchers and clinical investigators. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. An Adenovirus DNA Replication Factor, but Not Incoming Genome Complexes, Targets PML Nuclear Bodies.

    Science.gov (United States)

    Komatsu, Tetsuro; Nagata, Kyosuke; Wodrich, Harald

    2016-02-01

    Promyelocytic leukemia protein nuclear bodies (PML-NBs) are subnuclear domains implicated in cellular antiviral responses. Despite the antiviral activity, several nuclear replicating DNA viruses use the domains as deposition sites for the incoming viral genomes and/or as sites for viral DNA replication, suggesting that PML-NBs are functionally relevant during early viral infection to establish productive replication. Although PML-NBs and their components have also been implicated in the adenoviral life cycle, it remains unclear whether incoming adenoviral genome complexes target PML-NBs. Here we show using immunofluorescence and live-cell imaging analyses that incoming adenovirus genome complexes neither localize at nor recruit components of PML-NBs during early phases of infection. We further show that the viral DNA binding protein (DBP), an early expressed viral gene and essential DNA replication factor, independently targets PML-NBs. We show that DBP oligomerization is required to selectively recruit the PML-NB components Sp100 and USP7. Depletion experiments suggest that the absence of one PML-NB component might not affect the recruitment of other components toward DBP oligomers. Thus, our findings suggest a model in which an adenoviral DNA replication factor, but not incoming viral genome complexes, targets and modulates PML-NBs to support a conducive state for viral DNA replication and argue against a generalized concept that PML-NBs target incoming viral genomes. The immediate fate upon nuclear delivery of genomes of incoming DNA viruses is largely unclear. Early reports suggested that incoming genomes of herpesviruses are targeted and repressed by PML-NBs immediately upon nuclear import. Genome localization and/or viral DNA replication has also been observed at PML-NBs for other DNA viruses. Thus, it was suggested that PML-NBs may immediately sense and target nuclear viral genomes and hence serve as sites for deposition of incoming viral genomes and

  2. Host-defense and trefoil factor family peptides in skin secretions of the Mawa clawed frog Xenopus boumbaensis (Pipidae).

    Science.gov (United States)

    Conlon, J Michael; Mechkarska, Milena; Kolodziejek, Jolanta; Leprince, Jérôme; Coquet, Laurent; Jouenne, Thierry; Vaudry, Hubert; Nowotny, Norbert; King, Jay D

    2015-10-01

    Peptidomic analysis of norepinephrine-stimulated skin secretions from the octoploid Mawa clawed frog Xenopus boumbaensis Loumont, 1983 led to the identification and characterization of 15 host-defense peptides belonging to the magainin (two peptides), peptide glycine-leucine-amide (PGLa; three peptides), xenopsin precursor fragment (XPF; three peptides), caerulein precursor fragment (CPF; two peptides), and caerulein precursor fragment-related peptide (CPF-RP; five peptides) families. In addition, caerulein and three peptides with structural similarity to the trefoil factor family (TFF) peptides, xP2 and xP4 from Xenopus laevis were also present in the secretions. Consistent with data from comparisons of the nucleotides sequence of mitochondrial and nuclear genes, the primary structures of the peptides suggest a close phylogenetic relationship between X. boumbaensis and the octoploid frogs Xenopus amieti and Xenopus andrei. As the three species occupy disjunct ranges within Cameroon, it is suggested that they diverged from a common ancestor by allopatric speciation. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Population dynamics of intermediate snail hosts of Fasciola hepatica and some environmental factors in San Juan y Martinez municipality, Cuba

    Directory of Open Access Journals (Sweden)

    Roberto Cañete

    2004-05-01

    Full Text Available The variation of abundances of intermediate snail hosts of Fasciola hepatica in Cuba (Fossaria cubensis and Pseudosuccinea columella was studied during one year under natural conditions at five sampling sites in San Juan y Martinez municipality, Pinar del Rio province, Cuba. The effect of some environmental variables on the lymnaeid abundances was also studied. A canonical correspondence analysis showed that both species do not generally occur together in the same habitat and that most factors affect them in an opposite fashion, although both of them correlate positively through time to the diversity of the habitats. F. cubensis prefers the sites that are in or closer to the city whereas P. columella is more abundant in rural sites. Lymnaeid abundances are mainly affected by nitrite and nitrate concentrations as well as by the abundance of the thiarid Tarebia granifera. F. cubensis is more abundant in polluted habitats with low densities (or absence of T. granifera whereas P. columella prefers cleaner habitats and can coexist with the thiarid, even at its higher densities. The implications of divergent preferences of the two lymnaeids for the control of fasciolosis are discussed.

  4. Interaction of the human cytomegalovirus particle with the host cell induces hypoxia-inducible factor 1 alpha

    International Nuclear Information System (INIS)

    McFarlane, Steven; Nicholl, Mary Jane; Sutherland, Jane S.; Preston, Chris M.

    2011-01-01

    The cellular protein hypoxia-inducible factor 1 alpha (HIF-1α) was induced after infection of human fibroblasts with human cytomegalovirus (HCMV). HCMV irradiated with ultraviolet light (uv-HCMV) also elicited the effect, demonstrating that the response was provoked by interaction of the infecting virion with the cell and that viral gene expression was not required. Although induction of HIF-1α was initiated by an early event, accumulation of the protein was not detected until 9 hours post infection, with levels increasing thereafter. Infection with uv-HCMV resulted in increased abundance of HIF-1α-specific RNA, indicating stimulation of transcription. In addition, greater phosphorylation of the protein kinase Akt was observed, and the activity of this enzyme was required for induction of HIF-1α to occur. HIF-1α controls the expression of many cellular gene products; therefore the findings reveal new ways in which interaction of the HCMV particle with the host cell may cause significant alterations to cellular physiology.

  5. O-GlcNAc Transferase/Host Cell Factor C1 Complex Regulates Gluconeogenesis by Modulating PGC-1α Stability

    Science.gov (United States)

    Ruan, Hai-Bin; Han, Xuemei; Li, Min-Dian; Singh, Jay Prakash; Qian, Kevin; Azarhoush, Sascha; Zhao, Lin; Bennett, Anton M.; Samuel, Varman T.; Wu, Jing; Yates, John R.; Yang, Xiaoyong

    2012-01-01

    SUMMARY A major cause of hyperglycemia in diabetic patients is inappropriate hepatic gluconeogenesis. PGC-1α is a master regulator of gluconeogenesis, and its activity is controlled by various post-translational modifications. A small portion of glucose metabolizes through the hexosamine biosynthetic pathway, which leads to O-linked β-N-acetylglucosamine (O-GlcNAc) modification of cytoplasmic and nuclear proteins. Using a proteomic approach, we identified a broad variety of proteins associated with O-GlcNAc transferase (OGT), among which host cell factor C1 (HCF-1) is highly abundant. HCF-1 recruits OGT to O-GlcNAcylate PGC-1α and O-GlcNAcylation facilitates the binding of the deubiquitinase BAP1, thus protecting PGC-1α from degradation and promoting gluconeogenesis. Glucose availability modulates gluconeogenesis through the regulation of PGC-1α O-GlcNAcylation and stability by the OGT/HCF1 complex. Hepatic knockdown of OGT and HCF-1 improves glucose homeostasis in diabetic mice. These findings define the OGT/HCF-1 complex as a glucose sensor and key regulator of gluconeogenesis, shedding light on new strategies for treating diabetes. PMID:22883232

  6. Functional transcription factor target discovery via compendia of binding and expression profiles.

    Science.gov (United States)

    Banks, Christopher J; Joshi, Anagha; Michoel, Tom

    2016-02-09

    Genome-wide experiments to map the DNA-binding locations of transcription-associated factors (TFs) have shown that the number of genes bound by a TF far exceeds the number of possible direct target genes. Distinguishing functional from non-functional binding is therefore a major challenge in the study of transcriptional regulation. We hypothesized that functional targets can be discovered by correlating binding and expression profiles across multiple experimental conditions. To test this hypothesis, we obtained ChIP-seq and RNA-seq data from matching cell types from the human ENCODE resource, considered promoter-proximal and distal cumulative regulatory models to map binding sites to genes, and used a combination of linear and non-linear measures to correlate binding and expression data. We found that a high degree of correlation between a gene's TF-binding and expression profiles was significantly more predictive of the gene being differentially expressed upon knockdown of that TF, compared to using binding sites in the cell type of interest only. Remarkably, TF targets predicted from correlation across a compendium of cell types were also predictive of functional targets in other cell types. Finally, correlation across a time course of ChIP-seq and RNA-seq experiments was also predictive of functional TF targets in that tissue.

  7. Identification of target genes of transcription factor activator protein 2 gamma in breast cancer cells

    International Nuclear Information System (INIS)

    Ailan, He; Shuanglin, Xiang; Xiangwen, Xiao; Daolong, Ren; Lu, Gan; Xiaofeng, Ding; Xi, Qiao; Xingwang, Hu; Rushi, Liu; Jian, Zhang

    2009-01-01

    Activator protein 2 gamma (AP-2γ) is a member of the transcription factor activator protein-2 (AP-2) family, which is developmentally regulated and plays a role in human neoplasia. AP-2γ has been found to be overexpressed in most breast cancers, and have a dual role to inhibit tumor initiation and promote tumor progression afterwards during mammary tumorigensis. To identify the gene targets that mediate its effects, we performed chromatin immunoprecipitation (ChIP) to isolate AP-2γ binding sites on genomic DNA from human breast cancer cell line MDA-MB-453. 20 novel DNA fragments proximal to potential AP-2γ targets were obtained. They are categorized into functional groups of carcinogenesis, metabolism and others. A combination of sequence analysis, reporter gene assays, quantitative real-time PCR, electrophoretic gel mobility shift assays and immunoblot analysis further confirmed the four AP-2γ target genes in carcinogenesis group: ErbB2, CDH2, HPSE and IGSF11. Our results were consistent with the previous reports that ErbB2 was the target gene of AP-2γ. Decreased expression and overexpression of AP-2γ in human breast cancer cells significantly altered the expression of these four genes, indicating that AP-2γ directly regulates them. This suggested that AP-2γ can coordinate the expression of a network of genes, involving in carcinogenesis, especially in breast cancer. They could serve as therapeutic targets against breast cancers in the future

  8. Influence of Cellular and Molecular Factors on Membrane Target Sensitivity to Insecticides.

    Science.gov (United States)

    Raymond, Valérie; Goven, Delphine; Benzidane, Yassine; List, Olivier; Lapied, Bruno

    2017-01-01

    The effective control of insect pests is based on the use of insecticides. Most of these compounds act on molecular targets in the insect nervous system. However, the largescale deployment of insecticide treatment has led to the development of resistance, which decreases insecticide efficacy. Although the resistance mechanisms are largely studied today, this review aims to point out new insights on the less-known cellular and molecular factors involved in the modulation of the sensitivity of the targets to insecticides. This review will focus on the phosphorylation/dephosphorylation process, the post-transcriptional events such as editing and alternative splicing and the influence of the association with auxiliary proteins of the receptors and/or ion channels targeted by insecticides. In addition, the involvement of calcium-dependent signaling pathways in the modulation of the sensitivity of the target to insecticides will also be considered and discussed. Finally, this review will insist on different strategies proposed to optimize the efficacy of insecticide treatment while reducing doses to decrease side effects on environment and on non-target organisms by combining two different chemical insecticides or a given active ingredient associated with biological and/or chemical synergistic agents. This review is part of the special issue "Insecticide Mode of Action: From Insect to Mammalian Toxicity". Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Let-7 microRNAs Regenerate Peripheral Nerve Regeneration by Targeting Nerve Growth Factor

    OpenAIRE

    Li, Shiying; Wang, Xinghui; Gu, Yun; Chen, Chu; Wang, Yaxian; Liu, Jie; Hu, Wen; Yu, Bin; Wang, Yongjun; Ding, Fei; Liu, Yan; Gu, Xiaosong

    2015-01-01

    Peripheral nerve injury is a common clinical problem. Nerve growth factor (NGF) promotes peripheral nerve regeneration, but its clinical applications are limited by several constraints. In this study, we found that the time-dependent expression profiles of eight let-7 family members in the injured nerve after sciatic nerve injury were roughly similar to each other. Let-7 microRNAs (miRNAs) significantly reduced cell proliferation and migration of primary Schwann cells (SCs) by directly target...

  10. Hydrodynamic and symmetry safety factors of HiPER's targets

    Energy Technology Data Exchange (ETDEWEB)

    Hallo, L; Olazabal-Loume, M; Ribeyre, X; Drean, V; Schurtz, G; Feugeas, J-L; Breil, J; Nicolai, Ph; Maire, P-H [CELIA, Universite Bordeaux 1, 351 cours de La Liberation, 33405 Talence (France)], E-mail: hallo@celia.u-bordeaux1.fr

    2009-01-15

    Hydrodynamics and robustness of three high yield targets within the HiPER project are presented. Using realistic illumination nonuniformity configuration, hydrodynamic perturbations sensitivity analysis is carried out. A rather simple hydrodynamic perturbation modeling sequence is validated thanks to 2D simulations. 1D simulations post-processed with such a modeling sequence provide a good estimation of the thermonuclear burn. First estimates of hydrodynamic safety factor are given.

  11. Assessing unintended effects of a mammary-specific transgene at the whole animal level in host and non-target animals.

    Science.gov (United States)

    Clark, Merritt; Murray, James D; Maga, Elizabeth A

    2014-04-01

    Risk assessment in transgenic plants is intrinsically different than that for transgenic animals; however both require the verification of proper transgene function and in conjunction, an estimate of any unintended effects caused by expression of the transgene. This work was designed to gather data regarding methodologies to detect pleiotropic effects at the whole animal level using a line of transgenic goats that produce the antimicrobial protein human lysozyme (hLZ) in their milk with the goal of using the milk to treat childhood diarrhea. Metabolomics was used to determine the serum metabolite profile of both the host (lactating does) and non-target organism (kid goats raised on control or hLZ milk) prior to weaning (60 days), at weaning (90 days) and 1 month post-weaning (120 days). In addition, intestinal histology of the kid goats was also carried out. Histological analysis of intestinal segments of the pre-weaning group revealed significantly wider duodenal villi (p = 0.014) and significantly longer villi (p = 0.028) and deeper crypts (p = 0.030) in the ileum of kid goats consuming hLZ milk. Serum metabolomics was capable of detecting differences over time but revealed no significant differences in metabolites between control and hLZ fed kids after correction for false discovery rate. Serum metabolomics of control or hLZ lactating does showed only one significant difference in an unknown metabolite (q = 0.0422). The results as a whole indicate that consumption of hLZ milk results in positive or insignificant intestinal morphology and metabolic changes. This work contributes to the establishment of the safety and durability of the hLZ mammary-specific transgene.

  12. Nuclear Imprisonment: Viral Strategies to Arrest Host mRNA Nuclear Export

    Science.gov (United States)

    Kuss, Sharon K.; Mata, Miguel A.; Zhang, Liang; Fontoura, Beatriz M. A.

    2013-01-01

    Viruses possess many strategies to impair host cellular responses to infection. Nuclear export of host messenger RNAs (mRNA) that encode antiviral factors is critical for antiviral protein production and control of viral infections. Several viruses have evolved sophisticated strategies to inhibit nuclear export of host mRNAs, including targeting mRNA export factors and nucleoporins to compromise their roles in nucleo-cytoplasmic trafficking of cellular mRNA. Here, we present a review of research focused on suppression of host mRNA nuclear export by viruses, including influenza A virus and vesicular stomatitis virus, and the impact of this viral suppression on host antiviral responses. PMID:23872491

  13. A novel, broad-spectrum inhibitor of enterovirus replication that targets host cell factor phosphatidylinositol 4-kinase IIIβ

    NARCIS (Netherlands)

    van der Schaar, H.M.; Leyssen, Pieter; Thibaut, H.J.; de Palma, Armando; van der Linden, Lonneke; Lanke, Kjerstin H.W.; Lacroix, Céline; Verbeken, Erik; Conrath, Katja; Macleod, Angus M; Mitchell, Dale R; Palmer, Nicholas J; van de Poël, Hervé; Andrews, Martin; Neyts, Johan; van Kuppeveld, F.J.M.

    2013-01-01

    Despite their high clinical and socioeconomic impacts, there is currently no approved antiviral therapy for the prophylaxis or treatment of enterovirus infections. Here we report on a novel inhibitor of enterovirus replication, compound 1,

  14. Factors associated with high probability of target blood pressure non-achievement in hypertensive patients

    Directory of Open Access Journals (Sweden)

    S. P. Zhemanyuk

    2017-12-01

    Full Text Available One of the topic issue of modern cardiology is factors of target blood pressure level non-achievement clarifying due to a better understanding how we can reduce cardiovascular complications. The aim of the study is to determine the factors of poor blood pressure control using the ambulatory blood pressure monitoring parameters and adenosine 5'-diphosphate-induced platelet aggregation parameters in patients with arterial hypertension. Material and methods. The study involved 153 patients with essential hypertension (EH stage II, II degree. The ambulatory blood pressure monitoring (ABPM was performed in patients during at least two of first-line antihypertensive drugs in optimal daily doses usage by the ABPM bifunctional device (Incart, S.-P., R.F.. Platelet aggregation was carried out using light transmittance aggregation by optical analyzer (Solar, R.B. with adenosine 5'-diphosphate (Sigma-Aldrich at final concentration of 10.0 × 10-6 mol / L. The first group were inadequately controlled essential hypertensive individuals with high systolic or/and diastolic BP level according to the ABPM results, and the second one were patients with adequately controlled EH. Groups of patients were comparable in age (60.39 ± 10.74 years vs. 62.80 ± 9.63; p = 0.181, respectively. In the group of EH patients who reached the target level of blood pressure, women predominated (60% vs. 39.81%; p = 0.021, respectively. We used the binary logistic regression analysis to determine the predictors of target blood pressure level poor reaching using ABPM and platelet aggregation parameters. Results According to the univariate logistic regression analysis, the dependent factors influencing the target blood pressure level poor reaching are the average diurnal diastolic blood pressure (DBP (OR = 44.8; diurnal variability of systolic blood pressure (SBP (OR = 4.4; square index of hypertension for diurnal periods SBP (OR = 318.9; square index of hypertension for diurnal

  15. SARS-coronavirus replication/transcription complexes are membrane-protected and need a host factor for activity in vitro.

    Directory of Open Access Journals (Sweden)

    Martijn J van Hemert

    2008-05-01

    Full Text Available SARS-coronavirus (SARS-CoV replication and transcription are mediated by a replication/transcription complex (RTC of which virus-encoded, non-structural proteins (nsps are the primary constituents. The 16 SARS-CoV nsps are produced by autoprocessing of two large precursor polyproteins. The RTC is believed to be associated with characteristic virus-induced double-membrane structures in the cytoplasm of SARS-CoV-infected cells. To investigate the link between these structures and viral RNA synthesis, and to dissect RTC organization and function, we isolated active RTCs from infected cells and used them to develop the first robust assay for their in vitro activity. The synthesis of genomic RNA and all eight subgenomic mRNAs was faithfully reproduced by the RTC in this in vitro system. Mainly positive-strand RNAs were synthesized and protein synthesis was not required for RTC activity in vitro. All RTC activity, enzymatic and putative membrane-spanning nsps, and viral RNA cosedimented with heavy membrane structures. Furthermore, the pelleted RTC required the addition of a cytoplasmic host factor for reconstitution of its in vitro activity. Newly synthesized subgenomic RNA appeared to be released, while genomic RNA remained predominantly associated with the RTC-containing fraction. RTC activity was destroyed by detergent treatment, suggesting an important role for membranes. The RTC appeared to be protected by membranes, as newly synthesized viral RNA and several replicase/transcriptase subunits were protease- and nuclease-resistant and became susceptible to degradation only upon addition of a non-ionic detergent. Our data establish a vital functional dependence of SARS-CoV RNA synthesis on virus-induced membrane structures.

  16. Evaluation of factors influencing the development of late Marek's disease virus-induced immunosuppression: virus pathotype and host sex.

    Science.gov (United States)

    Faiz, Nik M; Cortes, Aneg L; Guy, James S; Fletcher, Oscar J; Cimino, Thomas; Gimeno, Isabel M

    2017-08-01

    Marek's disease virus (MDV) is a herpesvirus that induces lymphoma and immunosuppression in chickens. MDV-induced immunosuppression (MDV-IS) is complex and can be divided into two phases: early-MDV-IS associated with cytolytic infection in the lymphoid organs in chickens lacking maternal antibodies against MDV (MAbs) and late-MDV-IS that appears later in the pathogenesis and occurs even in chickens bearing MAbs. We have recently developed a model to reproduce late-MDV-IS under laboratory conditions. This model evaluates late-MDV-IS indirectly by assessing the effect of MDV infection on the efficacy of infectious laryngotracheitis (ILT) vaccines against challenge with ILT virus. In the present study, we have used this model to investigate the role of two factors (MDV pathotype and host sex) on the development of late-MDV-IS. Five MDV strains representing three different pathotypes: virulent (vMDV; 617A, GA), very virulent (vvMDV; Md5), and very virulent plus (vv+MDV; 648A, 686), were evaluated. Only vv+ strains were able to induce late-MDV-IS. An immunosuppression rank (IS-rank) was established based on the ability of MDV to reduce the efficacy of chicken embryo origin vaccine (values go from 0 to 100, with 100 being the highest immunosuppressive ability). The IS-rank of the evaluated MDV strains ranged from 5.97 (GA) to 20.8 (617A) in the vMDV strains, 5.97 to 16.24 in the vvMDV strain Md5, and 39.08 to 68.2 in the vv+ strains 648A and 686. In this study both male and female chickens were equally susceptible to MDV-IS by vv+MDV 686. Our findings suggest that late-MDV-IS is a unique feature of vv+ strains.

  17. Identification of elongation factor G as the conserved cellular target of argyrin B.

    Directory of Open Access Journals (Sweden)

    Beat Nyfeler

    Full Text Available Argyrins, produced by myxobacteria and actinomycetes, are cyclic octapeptides with antibacterial and antitumor activity. Here, we identify elongation factor G (EF-G as the cellular target of argyrin B in bacteria, via resistant mutant selection and whole genome sequencing, biophysical binding studies and crystallography. Argyrin B binds a novel allosteric pocket in EF-G, distinct from the known EF-G inhibitor antibiotic fusidic acid, revealing a new mode of protein synthesis inhibition. In eukaryotic cells, argyrin B was found to target mitochondrial elongation factor G1 (EF-G1, the closest homologue of bacterial EF-G. By blocking mitochondrial translation, argyrin B depletes electron transport components and inhibits the growth of yeast and tumor cells. Further supporting direct inhibition of EF-G1, expression of an argyrin B-binding deficient EF-G1 L693Q variant partially rescued argyrin B-sensitivity in tumor cells. In summary, we show that argyrin B is an antibacterial and cytotoxic agent that inhibits the evolutionarily conserved target EF-G, blocking protein synthesis in bacteria and mitochondrial translation in yeast and mammalian cells.

  18. Infection by Toxoplasma gondii Specifically Induces Host c-Myc and the Genes This Pivotal Transcription Factor Regulates

    Science.gov (United States)

    Franco, Magdalena; Shastri, Anjali J.

    2014-01-01

    Toxoplasma gondii infection has previously been described to cause dramatic changes in the host transcriptome by manipulating key regulators, including STATs, NF-κB, and microRNAs. Here, we report that Toxoplasma tachyzoites also mediate rapid and sustained induction of another pivotal regulator of host cell transcription, c-Myc. This induction is seen in cells infected with all three canonical types of Toxoplasma but not the closely related apicomplexan parasite Neospora caninum. Coinfection of cells with both Toxoplasma and Neospora still results in an increase in the level of host c-Myc, showing that c-Myc is actively upregulated by Toxoplasma infection (rather than repressed by Neospora). We further demonstrate that this upregulation may be mediated through c-Jun N-terminal protein kinase (JNK) and is unlikely to be a nonspecific host response, as heat-killed Toxoplasma parasites do not induce this increase and neither do nonviable parasites inside the host cell. Finally, we show that the induced c-Myc is active and that transcripts dependent on its function are upregulated, as predicted. Hence, c-Myc represents an additional way in which Toxoplasma tachyzoites have evolved to specifically alter host cell functions during intracellular growth. PMID:24532536

  19. miR-218 suppresses cardiac myxoma proliferation by targeting myocyte enhancer factor 2D.

    Science.gov (United States)

    Cao, Quanxing; Dong, Pingshuan; Wang, Yanyu; Zhang, Junwei; Shi, Xinge; Wang, Yongsheng

    2015-05-01

    Cardiac myxoma is the most common type of human heart tumor, yet the molecular mechanism is still poorly understood. In the present study, we found that the level of myocyte enhancer factor 2D (MEF2D), a key regulatory protein for cardiac development, was elevated in specimens of cardiac myxoma, and was positively associated with the proliferation of myxoma cells. MEF2D suppression reduced the proliferation of myxoma cells and its tumorigenicity. Cell cycle progression was also inhibited by MEF2D suppression. miR-218, which is downregulated in myxoma, suppressed MEF2D expression by targeting its mRNA 3'UTR. Altogether, we found that miR-218/MEF2D may be an effective target for myxoma treatment.

  20. Epidermal growth factor receptor is a preferred target for treating amyloid-β-induced memory loss.

    Science.gov (United States)

    Wang, Lei; Chiang, Hsueh-Cheng; Wu, Wenjuan; Liang, Bin; Xie, Zuolei; Yao, Xinsheng; Ma, Weiwei; Du, Shuwen; Zhong, Yi

    2012-10-09

    Current understanding of amyloid-β (Aβ) metabolism and toxicity provides an extensive list of potential targets for developing drugs for treating Alzheimer's disease. We took two independent approaches, including synaptic-plasticity-based analysis and behavioral screening of synthetic compounds, for identifying single compounds that are capable of rescuing the Aβ-induced memory loss in both transgenic fruit fly and transgenic mouse models. Two clinically available drugs and three synthetic compounds not only showed positive effects in behavioral tests but also antagonized the Aβ oligomers-induced activation of the epidermal growth factor receptor (EGFR). Such surprising converging outcomes from two parallel approaches lead us to conclude that EGFR is a preferred target for treating Aβ-induced memory loss.

  1. Prevalence and intensity of fleas parasitizing an isolated population of screaming hairy armadillo in Buenos Aires province, Argentina: host-related factors and temporal dynamics.

    Science.gov (United States)

    Ezquiaga, M Cecilia; Abba, Agustín M; Cassini, Guillermo H; Lareschi, Marcela

    2017-11-01

    Fleas (Siphonaptera) of an isolated population of Chaetophractus vellerosus (Mammalia: Xenarthra) from Magdalena (Buenos Aires province) were studied, and their presence was associated with host-related factors (age, sex, weight, size, and physical condition) and temporal dynamics (seasonality and year). Three species of fleas were identified: Polygenis (Polygenis) platensis (Rhopalopsyllidae), Tunga penetrans (Tungidae), and Pulex irritans (Pulicidae). Prevalences were significant for year, season, and physical condition. Intensities were significantly different for year, physical condition, and weight. The intensities of fleas were higher in 2009 than in other years, probably because of lower rainfall than the annual average leading to extremely dry climatic conditions in 2008. Intensities decreased in individuals with major body weight and increased in individuals with poor physical condition. In this study, the dynamics of the flea community associated with an armadillo population is analyzed for the first time taking into account host-related factors and temporal dynamics, and also how these factors influence the community.

  2. Non-Steroidal Anti-inflammatory Drugs As Host-Directed Therapy for Tuberculosis : A Systematic Review

    NARCIS (Netherlands)

    Kroesen, Vera M.; Gröschel, Matthias I.; Martinson, Neil; Zumla, Alimuddin; Maeurer, Markus; van der Werf, Tjip S.; Vilaplana, Cristina

    2017-01-01

    Lengthy, antimicrobial therapy targeting the pathogen is the mainstay of conventional tuberculosis treatment, complicated by emerging drug resistances. Host-directed therapies, including non-steroidal anti-inflammatory drugs (NSAIDs), in contrast, target host factors to mitigate disease severity. In

  3. Facility factors dominate the ability to achieve target haemoglobin levels in haemodialysis patients.

    Science.gov (United States)

    Chan, Kevin E; Lafayette, Richard A; Whittemore, Alice S; Hlatky, Mark A; Moran, John

    2008-09-01

    Our objective was to determine whether patient factors, processes of care and measures of erythropoietin (EPO) responsiveness were associated with successful anemia management at the individual patient level. We retrospectively reviewed laboratory and demographic data from 1499 patients receiving hemodialysis in 15 units operated by the same dialysis provider. We performed univariate and multivariate logistic regression analysis to determine predictors of an average 3-month hemoglobin level below or above the target interval of 11.0-12.5 g/dL. To explain the effect of facility on anemia performance, we calculated correlations between measures of EPO responsiveness and the probability of achieving the target interval by facility. Patients above the target hemoglobin range demonstrated an association with parathyroid hormone (PTH) (OR = 0.96 per 100 pg/mL increase), female gender (OR = 0.68), EPO protocol use (OR = 0.94 per 10% increase in use) and facility (range of OR = 0.26-2.59 for 15 participating sites). Patients below the target hemoglobin range demonstrated an association with CRP (OR = 1.10 per mg/L increase), PTH (OR = 1.07 per 100 pg/mL increase), iron deficiency (OR = 1.07 per 10% increase), EPO protocol use (OR = 0.89 per 10% increase in use), iron protocol use (OR = 0.93 per 10% increase in use) and facility (range of OR = 0.58-3.41 over 15 units). EPO index (r = 0.71), EPO dose (r = 0.73), hemoglobin (r = -0.60) and EPO per unit weight (r = 0.76) were significantly correlated with the probability of achieving the target hemoglobin by facility. The facility significantly influences the outcome of anemia management in patients with ESRD. In part, this is due to the patients' EPO responsiveness, which may be influenced by facility care patterns.

  4. Defining the factors that contribute to on-target specificity of antisense oligonucleotides.

    Directory of Open Access Journals (Sweden)

    Walt F Lima

    Full Text Available To better understand the factors that influence the activity and specificity of antisense oligonucleotides (ASOs, we designed a minigene encoding superoxide dismutase 1 (SOD-1 and cloned the minigene into vectors for T7 transcription of pre-mRNA and splicing in a nuclear extract or for stable integration in cells. We designed a series of ASOs that covered the entire mRNA and determined the binding affinities and activities of the ASOs in a cell-free system and in cells. The mRNA bound known RNA-binding proteins on predicted binding sites in the mRNA. The higher order structure of the mRNA had a significantly greater effect than the RNA-binding proteins on ASO binding affinities as the ASO activities in cells and in the cell-free systems were consistent. We identified several ASOs that exhibited off-target hybridization to the SOD-1 minigene mRNA in the cell-free system. Off-target hybridization occurred only at highly accessible unstructured sites in the mRNA and these interactions were inhibited by both the higher order structure of the mRNA and by RNA-binding proteins. The same off-target hybridization interactions were identified in cells that overexpress E. coli RNase H1. No off-target activity was observed for cells expressing only endogenous human RNase H1. Neither were these off-target heteroduplexes substrates for recombinant human RNase H1 under multiple-turnover kinetics suggesting that the endogenous enzyme functions under similar kinetic parameters in cells and in the cell-free system. These results provide a blueprint for design of more potent and more specific ASOs.

  5. Expression of growth factor receptors and targeting of EGFR in cholangiocarcinoma cell lines

    International Nuclear Information System (INIS)

    Xu, Ling; Hausmann, Martin; Dietmaier, Wolfgang; Kellermeier, Silvia; Pesch, Theresa; Stieber-Gunckel, Manuela; Lippert, Elisabeth; Klebl, Frank; Rogler, Gerhard

    2010-01-01

    Cholangiocarcinoma (CC) is a malignant neoplasm of the bile ducts or the gallbladder. Targeting of growth factor receptors showed therapeutic potential in palliative settings for many solid tumors. The aim of this study was to determine the expression of seven growth factor receptors in CC cell lines and to assess the effect of blocking the EGFR receptor in vitro. Expression of EGFR (epithelial growth factor receptor), HGFR (hepatocyte growth factor receptor) IGF1R (insulin-like growth factor 1 receptor), IGF2R (insulin-like growth factor 2 receptor) and VEGFR1-3 (vascular endothelial growth factor receptor 1-3) were examined in four human CC cell lines (EGI-1, HuH28, OZ and TFK-1). The effect of the anti-EGFR-antibody cetuximab on cell growth and apoptosis was studied and cell lines were examined for KRAS mutations. EGFR, HGFR and IGFR1 were present in all four cell lines tested. IGFR2 expression was confirmed in EGI-1 and TFK-1. No growth-inhibitory effect was found in EGI-1 cells after incubation with cetuximab. Cetuximab dose-dependently inhibited growth in TFK-1. Increased apoptosis was only seen in TFK-1 cells at the highest cetuximab dose tested (1 mg/ml), with no dose-response-relationship at lower concentrations. In EGI-1 a heterozygous KRAS mutation was found in codon 12 (c.35G>A; p.G12D). HuH28, OZ and TFK-1 lacked KRAS mutation. CC cell lines express a pattern of different growth receptors in vitro. Growth factor inhibitor treatment could be affected from the KRAS genotype in CC. The expression of EGFR itself does not allow prognoses on growth inhibition by cetuximab

  6. Structure of the parasite communities of a coral reef fish assemblage (Labridae): testing ecological and phylogenetic host factors.

    Science.gov (United States)

    Muñoz, Gabriela; Grutter, Alexandra S; Cribb, Tom H

    2007-02-01

    The role of ecological and phylogenetic processes is fundamental to understanding how parasite communities are structured. However, for coral reef fishes, such information is almost nonexistent. In this study, we analyzed the structure of the parasite communities based on composition, richness, abundance, and biovolume of ecto- and endoparasites of 14 wrasse species (Labridae) from Lizard Island, Great Barrier Reef, Australia. We determine whether the structure of the parasite communities from these fishes was related to ecological characteristics (body size, abundance, swimming ability, and diet) and/or the phylogenetic relatedness of the hosts. We examined 264 fishes from which almost 37,000 individual parasites and 98 parasite categories (types and species) were recorded. Gnathiid and cestode larvae were the most prevalent and abundant parasites in most fishes. Mean richness, abundance, and biovolume of ectoparasites per fish species were positively correlated with host body size only after controlling for the host phylogeny, whereas no such correlation was found for endoparasites with any host variable. Because most ectoparasites have direct transmission, one possible explanation for this pattern is that increased space (host body size) may increase the colonization and recruitment of ectoparasites. However, endoparasites generally have indirect transmission that can be affected by many other variables, such as number of prey infected and rate of parasite transmission.

  7. Trial Characteristics as Contextual Factors when Evaluating Targeted Therapies in Patients with Psoriatic Disease

    DEFF Research Database (Denmark)

    Ballegaard, Christine; Jørgensen, Tanja S; Skougaard, Marie

    2018-01-01

    characteristics in stratified and meta-regression analyses. Odds ratios (OR) were calculated and compared among the trial eligibility criteria via the Ratio of Odds Ratios (ROR). RESULTS: Forty-eight PsA and psoriasis trials (51 comparisons, 17,737 patients) were eligible. Overall retention was OR 2.16 (1.70 to 2.......75) with higher odds for PsA trials compared with psoriasis trials (ROR = 2.55 [1.64 to 3.97]). The eligibility criteria "targeted therapy history", "minimum required disease duration", "required negative rheumatoid factor", and "required CASPAR criteria" were of importance for achieving ACR20 in Ps...

  8. Targeting the Central Pocket in Human Transcription Factor TEAD as a Potential Cancer Therapeutic Strategy

    OpenAIRE

    Pobbati, Ajaybabu V.; Han, Xiao; Hung, Alvin W.; Weiguang, Seetoh; Huda, Nur; Chen, Guo-Ying; Kang, CongBao; Chia, Cheng San Brian; Luo, Xuelian; Hong, Wanjin; Poulsen, Anders

    2015-01-01

    The human TEAD family of transcription factors (TEAD1-4) is required for YAP-mediated transcription in the Hippo pathway. Hyperactivation of TEAD’s co-activator YAP contributes to tissue overgrowth and human cancers, suggesting that pharmacological interference of TEAD-YAP activity may be an effective strategy for anticancer therapy. Here we report the discovery of a central pocket in the YAP-binding domain (YBD) of TEAD that is targetable by small molecule inhibitors. Our X-ray crystallograp...

  9. Genome-wide identification of the regulatory targets of a transcription factor using biochemical characterization and computational genomic analysis

    Directory of Open Access Journals (Sweden)

    Jolly Emmitt R

    2005-11-01

    Full Text Available Abstract Background A major challenge in computational genomics is the development of methodologies that allow accurate genome-wide prediction of the regulatory targets of a transcription factor. We present a method for target identification that combines experimental characterization of binding requirements with computational genomic analysis. Results Our method identified potential target genes of the transcription factor Ndt80, a key transcriptional regulator involved in yeast sporulation, using the combined information of binding affinity, positional distribution, and conservation of the binding sites across multiple species. We have also developed a mathematical approach to compute the false positive rate and the total number of targets in the genome based on the multiple selection criteria. Conclusion We have shown that combining biochemical characterization and computational genomic analysis leads to accurate identification of the genome-wide targets of a transcription factor. The method can be extended to other transcription factors and can complement other genomic approaches to transcriptional regulation.

  10. Global genetic differentiation in a cosmopolitan pest of stored beans: effects of geography, host-plant usage and anthropogenic factors.

    Science.gov (United States)

    Tuda, Midori; Kagoshima, Kumiko; Toquenaga, Yukihiko; Arnqvist, Göran

    2014-01-01

    Genetic differentiation can be promoted allopatrically by geographic isolation of populations due to limited dispersal ability and diversification over time or sympatrically through, for example, host-race formation. In crop pests, the trading of crops across the world can lead to intermixing of genetically distinct pest populations. However, our understanding of the importance of allopatric and sympatric genetic differentiation in the face of anthropogenic genetic intermixing is limited. Here, we examined global sequence variation in two mitochondrial and one nuclear genes in the seed beetle Callosobruchus maculatus that uses different legumes as hosts. We analyzed 180 samples from 42 populations of this stored bean pest from tropical and subtropical continents and archipelagos: Africa, the Middle East, South and Southeast Asia, Oceania and South America. For the mitochondrial genes, there was weak but significant genetic differentiation across continents/archipelagos. Further, we found pronounced differentiation among subregions within continents/archipelagos both globally and within Africa but not within Asia. We suggest that multiple introductions into Asia and subsequent intermixing within Asia have generated this pattern. The isolation by distance hypothesis was supported globally (with or without continents controlled) but not when host species was restricted to cowpeas Vigna unguiculata, the ancestral host of C. maculatus. We also document significant among-host differentiation both globally and within Asia, but not within Africa. We failed to reject a scenario of a constant population size in the recent past combined with selective neutrality for the mitochondrial genes. We conclude that mitochondrial DNA differentiation is primarily due to geographic isolation within Africa and to multiple invasions by different alleles, followed by host shifts, within Asia. The weak inter-continental differentiation is most likely due to frequent inter-continental gene

  11. Local examination of skin diffusion using FTIR spectroscopic imaging and multivariate target factor analysis.

    Science.gov (United States)

    Tetteh, J; Mader, K T; Andanson, J-M; McAuley, W J; Lane, M E; Hadgraft, J; Kazarian, S G; Mitchell, J C

    2009-05-29

    In the context of trans-dermal drug delivery it is very important to have mechanistic insight into the barrier function of the skin's stratum corneum and the diffusion mechanisms of topically applied drugs. Currently spectroscopic imaging techniques are evolving which enable a spatial examination of various types of samples in a dynamic way. ATR-FTIR imaging opens up the possibility to monitor spatial diffusion profiles across the stratum corneum of a skin sample. Multivariate data analyses methods based on factor analysis are able to provide insight into the large amount of spectroscopically complex and highly overlapping signals generated. Multivariate target factor analysis was used for spectral resolution and local diffusion profiles with time through stratum corneum. A model drug, 4-cyanophenol in polyethylene glycol 600 and water was studied. Results indicate that the average diffusion profiles between spatially different locations show similar profiles despite the heterogeneous nature of the biological sample and the challenging experimental set-up.

  12. On the importance of macroeconomic factors for the foreign student’s decision to stay in the host country

    DEFF Research Database (Denmark)

    Vasiljeva, Kristine

    labour income difference between the home and the host countries significantly negatively affects the student’s probability of staying in the host country. The differences in the unemployment rates, welfare benefits, business cycles do not affect the probability of staying. The more hierarchical society...... in the home country is, the less likely male students are to stay. The employment outcome of student migrants has also been analysed and it is positively related to English language knowledge, but not to the abovementioned macroeconomic and culture related variables....

  13. The insulin-like growth factor (IGF) axis as an anticancer target in prostate cancer.

    Science.gov (United States)

    Heidegger, Isabel; Massoner, Petra; Sampson, Natalie; Klocker, Helmut

    2015-10-28

    Prostate cancer (PCa) is the most common cancer and the second leading cause of cancer death in males. In recent years, several new targeting agents have been introduced for the treatment of advanced stages of the disease. However, development of resistance limits the efficacy of new drugs and there is a further need to develop additional novel treatment approaches. One of the most investigated targets in cancer research is the insulin-like growth factor (IGF) axis, whose receptors are overexpressed in several cancer entities including PCa. In preclinical studies in PCa, targeting of the IGF axis receptors showed promising anti-tumor effects. Currently available data on clinical studies do not meet the expectations for this new treatment approach. In this review we provide a summary of preclinical and clinical studies on the IGF axis in PCa including treatment with monoclonal antibodies and tyrosine kinase inhibitors. Moreover, we summarize preliminary results from ongoing studies and discuss limitations and side effects of the substances used. We also address the role of the IGF axis in the biomarkers setting including IGF-binding proteins and genetic variants. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  14. Transcription Factor STAT3 as a Novel Molecular Target for Cancer Prevention

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Ailian; Yang, Zhengduo [Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 (United States); Shen, Yicheng [College of Natural Sciences, The University of Texas at Austin, Austin, TX 78712 (United States); Zhou, Jia [Chemical Biology Program, Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555 (United States); Shen, Qiang, E-mail: qshen@mdanderson.org [Department of Clinical Cancer Prevention, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 (United States)

    2014-04-16

    Signal Transducers and Activators of Transcription (STATs) are a family of transcription factors that regulate cell proliferation, differentiation, apoptosis, immune and inflammatory responses, and angiogenesis. Cumulative evidence has established that STAT3 has a critical role in the development of multiple cancer types. Because it is constitutively activated during disease progression and metastasis in a variety of cancers, STAT3 has promise as a drug target for cancer therapeutics. Recently, STAT3 was found to have an important role in maintaining cancer stem cells in vitro and in mouse tumor models, suggesting STAT3 is integrally involved in tumor initiation, progression and maintenance. STAT3 has been traditionally considered as nontargetable or undruggable, and the lag in developing effective STAT3 inhibitors contributes to the current lack of FDA-approved STAT3 inhibitors. Recent advances in cancer biology and drug discovery efforts have shed light on targeting STAT3 globally and/or specifically for cancer therapy. In this review, we summarize current literature and discuss the potential importance of STAT3 as a novel target for cancer prevention and of STAT3 inhibitors as effective chemopreventive agents.

  15. Hypoxia-Inducible Factors: Mediators of Cancer Progression; Prognostic and Therapeutic Targets in Soft Tissue Sarcomas

    International Nuclear Information System (INIS)

    Sadri, Navid; Zhang, Paul J.

    2013-01-01

    Soft-tissue sarcomas remain aggressive tumors that result in death in greater than a third of patients due to either loco-regional recurrence or distant metastasis. Surgical resection remains the main choice of treatment for soft tissue sarcomas with pre- and/or post-operational radiation and neoadjuvant chemotherapy employed in more advanced stage disease. However, in recent decades, there has been little progress in the average five-year survival for the majority of patients with high-grade soft tissue sarcomas, highlighting the need for improved targeted therapeutic agents. Clinical and preclinical studies demonstrate that tumor hypoxia and up-regulation of hypoxia-inducible factors (HIFs) is associated with decreased survival, increased metastasis, and resistance to therapy in soft tissue sarcomas. HIF-mediated gene expression regulates many critical aspects of tumor biology, including cell survival, metabolic programming, angiogenesis, metastasis, and therapy resistance. In this review, we discuss HIFs and HIF-mediated genes as potential prognostic markers and therapeutic targets in sarcomas. Many pharmacological agents targeting hypoxia-related pathways are in development that may hold therapeutic potential for treating both primary and metastatic sarcomas that demonstrate increased HIF expression

  16. Transcription Factor STAT3 as a Novel Molecular Target for Cancer Prevention

    International Nuclear Information System (INIS)

    Xiong, Ailian; Yang, Zhengduo; Shen, Yicheng; Zhou, Jia; Shen, Qiang

    2014-01-01

    Signal Transducers and Activators of Transcription (STATs) are a family of transcription factors that regulate cell proliferation, differentiation, apoptosis, immune and inflammatory responses, and angiogenesis. Cumulative evidence has established that STAT3 has a critical role in the development of multiple cancer types. Because it is constitutively activated during disease progression and metastasis in a variety of cancers, STAT3 has promise as a drug target for cancer therapeutics. Recently, STAT3 was found to have an important role in maintaining cancer stem cells in vitro and in mouse tumor models, suggesting STAT3 is integrally involved in tumor initiation, progression and maintenance. STAT3 has been traditionally considered as nontargetable or undruggable, and the lag in developing effective STAT3 inhibitors contributes to the current lack of FDA-approved STAT3 inhibitors. Recent advances in cancer biology and drug discovery efforts have shed light on targeting STAT3 globally and/or specifically for cancer therapy. In this review, we summarize current literature and discuss the potential importance of STAT3 as a novel target for cancer prevention and of STAT3 inhibitors as effective chemopreventive agents

  17. Incidence, risk factors, and outcome of cytomegalovirus viremia and gastroenteritis in patients with gastrointestinal graft-versus-host disease.

    Science.gov (United States)

    Bhutani, Divaya; Dyson, Gregory; Manasa, Richard; Deol, Abhinav; Ratanatharathorn, Voravit; Ayash, Lois; Abidi, Muneer; Lum, Lawrence G; Al-Kadhimi, Zaid; Uberti, Joseph P

    2015-01-01

    Gastrointestinal (GI) graft-versus-host disease (GVHD) is one of the most common causes of morbidity and mortality after allogeneic stem cell transplantation. In addition, cytomegalovirus (CMV) infection of the gastrointestinal tract can complicate the post-transplantation course of these patients and it can be difficult to differentiate the 2 diagnoses given that they can present with similar symptoms. We retrospectively analyzed 252 patients who were diagnosed with GI GVHD to evaluate the incidence, risk factors, and outcomes of CMV viremia and CMV gastroenteritis in these patients. The median age at the time of transplantation was 51 years, 35% were related donor transplantations, and 65% were unrelated donor transplantations. A total of 114 (45%) patients developed CMV viremia at a median of 34 days (range, 14 to 236 days) after transplantation. Only recipient CMV IgG serostatus was significantly associated with development of CMV viremia (P gastroenteritis; 2 patients had evidence of CMV gastroenteritis and GVHD on the first biopsy and 29 on the second biopsy. Median time to development of CMV gastroenteritis was 52 days (range, 19 to 236 days) after transplantation. Using death as a competing risk, the cumulative incidence of CMV gastroenteritis at 1 year was 16.4%. The incidence of CMV gastroenteritis in relation to the donor/recipient serostatus was as follows: D+/R+, 22%; D-/R+, 31%; D+/R-, 12%; and D-/R-, 0. Median follow-up time for the 252 patients was 35.4 (95% CI 23.8 to 44.8) months. The estimated overall survival rate at 1 and 2 years was .45 (95% confidence interval [CI], .39 to .52) and .39 (95% CI, .33 to .46), respectively. Of the examined variables, those related to the overall survival were maximal clinical GVHD grade (P gastroenteritis (P = .008). Development of CMV viremia was not associated with increased mortality. In conclusion, CMV gastroenteritis is common complication in patients with GI GVHD and can adversely affect the prognosis

  18. Global analysis of ion dependence unveils hidden steps in DNA binding and bending by integration host factor

    Science.gov (United States)

    Vivas, Paula; Velmurugu, Yogambigai; Kuznetsov, Serguei V.; Rice, Phoebe A.; Ansari, Anjum

    2013-09-01

    Proteins that recognize and bind to specific sites on DNA often distort the DNA at these sites. The rates at which these DNA distortions occur are considered to be important in the ability of these proteins to discriminate between specific and nonspecific sites. These rates have proven difficult to measure for most protein-DNA complexes in part because of the difficulty in separating the kinetics of unimolecular conformational rearrangements (DNA bending and kinking) from the kinetics of bimolecular complex association and dissociation. A notable exception is the Integration Host Factor (IHF), a eubacterial architectural protein involved in chromosomal compaction and DNA recombination, which binds with subnanomolar affinity to specific DNA sites and bends them into sharp U-turns. The unimolecular DNA bending kinetics has been resolved using both stopped-flow and laser temperature-jump perturbation. Here we expand our investigation by presenting a global analysis of the ionic strength dependence of specific binding affinity and relaxation kinetics of an IHF-DNA complex. This analysis enables us to obtain each of the underlying elementary rates (DNA bending/unbending and protein-DNA association/dissociation), and their ionic strength dependence, even under conditions where the two processes are coupled. Our analysis indicates interesting differences in the ionic strength dependence of the bi- versus unimolecular steps. At moderate [KCl] (100-500 mM), nearly all the ionic strength dependence to the overall equilibrium binding affinity appears in the bimolecular association/dissociation of an initial, presumably weakly bent, encounter complex, with a slope SKbi ≈ 8 describing the loglog-dependence of the equilibrium constant to form this complex on [KCl]. In contrast, the unimolecular equilibrium constant to form the fully wrapped specific complex from the initial complex is nearly independent of [KCl], with SKuni protein-DNA contacts in the fully wrapped complex

  19. Host factors that interact with the pestivirus N-terminal protease, Npro, are components of the ribonucleoprotein complex.

    Science.gov (United States)

    Jefferson, Matthew; Donaszi-Ivanov, Andras; Pollen, Sean; Dalmay, Tamas; Saalbach, Gerhard; Powell, Penny P

    2014-09-01

    The viral N-terminal protease N(pro) of pestiviruses counteracts cellular antiviral defenses through inhibition of IRF3. Here we used mass spectrometry to identify a new role for N(pro) through its interaction with over 55 associated proteins, mainly ribosomal proteins and ribonucleoproteins, including RNA helicase A (DHX9), Y-box binding protein (YBX1), DDX3, DDX5, eIF3, IGF2BP1, multiple myeloma tumor protein 2, interleukin enhancer binding factor 3 (IEBP3), guanine nucleotide binding protein 3, and polyadenylate-binding protein 1 (PABP-1). These are components of the translation machinery, ribonucleoprotein particles (RNPs), and stress granules. Significantly, we found that stress granule formation was inhibited in MDBK cells infected with a noncytopathic bovine viral diarrhea virus (BVDV) strain, Kyle. However, ribonucleoproteins binding to N(pro) did not inhibit these proteins from aggregating into stress granules. N(pro) interacted with YBX1 though its TRASH domain, since the mutant C112R protein with an inactive TRASH domain no longer redistributed to stress granules. Interestingly, RNA helicase A and La autoantigen relocated from a nuclear location to form cytoplasmic granules with N(pro). To address a proviral role for N(pro) in RNP granules, we investigated whether N(pro) affected RNA interference (RNAi), since interacting proteins are involved in RISC function during RNA silencing. Using glyceraldehyde-3-phosphate dehydrogenase (GAPDH) silencing with small interfering RNAs (siRNAs) followed by Northern blotting of GAPDH, expression of N(pro) had no effect on RNAi silencing activity, contrasting with other viral suppressors of interferon. We propose that N(pro) is involved with virus RNA translation in the cytoplasm for virus particle production, and when translation is inhibited following stress, it redistributes to the replication complex. Although the pestivirus N-terminal protease, N(pro), has been shown to have an important role in degrading IRF3 to

  20. Reduced abundance of the CYP6CY3-targeting let-7 and miR-100 miRNAs accounts for host adaptation of Myzus persicae nicotianae.

    Science.gov (United States)

    Peng, Tianfei; Pan, Yiou; Gao, Xiwu; Xi, Jinghui; Zhang, Lei; Ma, Kangsheng; Wu, Yongqiang; Zhang, Juhong; Shang, Qingli

    2016-08-01

    Nicotine is one of the most abundant and toxic secondary plant metabolites in nature and is defined by high toxicity to plant-feeding insects. Studies suggest that increased expression of cytochrome P450 (CYP6CY3) and the homologous CYP6CY4 genes in Myzus persicae nicotianae is correlated with tolerance to nicotine. Indeed, through expression analyses of the CYP6CY3 and CYP6CY4 genes of different M. persicae subspecies, we determined that the mRNA levels of these two genes were much higher in M. persicae nicotianae than in M. persicae sensu stricto. We hypothesized that the expression of these two genes is subject to post-transcriptional regulation. To investigate the underlying mechanism, the miRNA profile of M. persicae nicotianae was sequenced, and twenty-two miRNAs were predicted to target CYP6CY3. Validation of these miRNAs identified two miRNAs, let-7 and miR-100, whose abundance was highly inversely correlated with the abundance of the CYP6CY3 gene. This result implies that the let-7 and miR-100 miRNAs play a major role in the post-transcriptional regulation of the CYP6CY3 gene. Modulation of the abundance of let-7 and miR-100 through the addition of inhibitors/mimics of let-7 or miR-100 to artificial diet significantly altered the tolerance of M. persicae nicotianae to nicotine, further confirming the regulatory role of these two miRNAs. Interestingly, after decreasing the transcript levels of CYP6CY3 by modulating regulatory miRNAs, the transcript levels of the homologous isozyme CYP6CY4 were significantly elevated, suggesting a compensatory mechanism between the CYP6CY3 gene and its homologous CYP6CY4 gene. Our findings provide insight into the molecular drivers of insect host shifts and reveal an important source of genetic variation for adaptive evolution in insect species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Identification of direct regulatory targets of the transcription factor Sox10 based on function and conservation

    Directory of Open Access Journals (Sweden)

    Lee Sanghyuk

    2008-09-01

    Full Text Available Abstract Background Sox10, a member of the Sry-related HMG-Box gene family, is a critical transcription factor for several important cell lineages, most notably the neural crest stem cells and the derivative peripheral glial cells and melanocytes. Thus far, only a handful of direct target genes are known for this transcription factor limiting our understanding of the biological network it governs. Results We describe identification of multiple direct regulatory target genes of Sox10 through a procedure based on function and conservation. By combining RNA interference technique and DNA microarray technology, we have identified a set of genes that show significant down-regulation upon introduction of Sox10 specific siRNA into Schwannoma cells. Subsequent comparative genomics analyses led to potential binding sites for Sox10 protein conserved across several mammalian species within the genomic region proximal to these genes. Multiple sites belonging to 4 different genes (proteolipid protein, Sox10, extracellular superoxide dismutase, and pleiotrophin were shown to directly interact with Sox10 by chromatin immunoprecipitation assay. We further confirmed the direct regulation through the identified cis-element for one of the genes, extracellular superoxide dismutase, using electrophoretic mobility shift assay and reporter assay. Conclusion In sum, the process of combining differential expression profiling and comparative genomics successfully led to further defining the role of Sox10, a critical transcription factor for the development of peripheral glia. Our strategy utilizing relatively accessible techniques and tools should be applicable to studying the function of other transcription factors.

  2. c-Met in esophageal squamous cell carcinoma: an independent prognostic factor and potential therapeutic target

    International Nuclear Information System (INIS)

    Ozawa, Yohei; Nakamura, Yasuhiro; Fujishima, Fumiyoshi; Felizola, Saulo JA; Takeda, Kenichiro; Okamoto, Hiroshi; Ito, Ken; Ishida, Hirotaka; Konno, Takuro; Kamei, Takashi; Miyata, Go; Ohuchi, Noriaki; Sasano, Hironobu

    2015-01-01

    c-Met is widely known as a poor prognostic factor in various human malignancies. Previous studies have suggested the involvement of c-Met and/or its ligand, hepatocyte growth factor (HGF), in esophageal squamous cell carcinoma (ESCC), but the correlation between c-Met status and clinical outcome remains unclear. Furthermore, the identification of a novel molecular therapeutic target might potentially help improve the clinical outcome of ESCC patients. The expression of c-Met and HGF was immunohistochemically assessed in 104 surgically obtained tissue specimens. The correlation between c-Met/HGF expression and patients’ clinicopathological features, including survival, was evaluated. We also investigated changes in cell functions and protein expression of c-Met and its downstream signaling pathway components under treatments with HGF and/or c-Met inhibitor in ESCC cell lines. Elevated expression of c-Met was significantly correlated with tumor depth and pathological stage. Patients with high c-Met expression had significantly worse survival. In addition, multivariate analysis identified the high expression of c-Met as an independent prognostic factor. Treatment with c-Met inhibitor under HGF stimulation significantly inhibited the invasive capacity of an ESCC cell line with elevated c-Met mRNA expression. Moreover, c-Met and its downstream signaling inactivation was also detected after treatment with c-Met inhibitor. The results of our study identified c-Met expression as an independent prognostic factor in ESCC patients and demonstrated that c-Met could be a potential molecular therapeutic target for the treatment of ESCC with elevated c-Met expression. The online version of this article (doi:10.1186/s12885-015-1450-3) contains supplementary material, which is available to authorized users

  3. Parental Factors Associated with Child Post-traumatic Stress Following Injury: A Consideration of Intervention Targets

    Directory of Open Access Journals (Sweden)

    Anna E. Wise

    2017-08-01

    Full Text Available Post-traumatic stress disorder (PTSD symptoms are relatively common following pediatric traumatic injury and are related to poor long-term child outcomes. However, due to concerns regarding the efficacy of early child preventive interventions, and difficulty intervening with injured and medicated children soon after the event, it is not feasible to provide early psychological interventions to children exposed to traumatic injury. Parental PTSD symptoms and reactions to the child’s traumatic injury impact child outcomes and provide potential targets for early intervention to reduce child symptom development without involving the child. The authors conducted a review of the literature using Psycinfo and Pubmed research databases (publication years = 1990–2017 and identified 65 published studies relevant to the topic of the review. The present review considers parent factors [parenting styles, parental post-traumatic pathology (PTS, adaptive and maladaptive coping strategies, and communication regarding the traumatic injury] and their impact on child PTS. We focus specifically on factors amenable to intervention. We further review moderators of these relationships (e.g., child age and gender, parent gender and conclude that it is unlikely that a one-size-fits-all approach to treatment will be successful. Rather, it is necessary to consider the age and gender of parent child dyads in designing and providing targeted interventions to families following the traumatic injury of a child.

  4. Targeting Hypoxia-Inducible Factors for the Treatment of Anemia in Chronic Kidney Disease Patients.

    Science.gov (United States)

    Locatelli, Francesco; Fishbane, Steven; Block, Geoffrey A; Macdougall, Iain C

    2017-01-01

    Anemia, a common complication of chronic kidney disease (CKD), has previously been attributed primarily to decreased production of erythropoietin. More recently, it has become apparent that the etiology of anemia involves several other factors, most notably dysfunctional iron metabolism, mediated via increased hepcidin activity and reduced clearance. Current management of anemia in patients with advanced CKD is based on erythropoiesis-stimulating agents and iron supplementation, along with red blood cell transfusions when necessary; however, safety considerations associated with these therapies highlight the need to pursue alternative treatment options targeting other mechanisms such as hypoxia-inducible factors (HIFs) that act as central regulators of erythropoiesis by coordinating a series of graded hypoxic responses. This review discusses the discovery of the HIF pathway and its regulation via HIF prolyl hydroxylase enzymes in the context of erythropoiesis and iron metabolism. The rationale for targeting this pathway and the clinical development of HIF prolyl hydroxylase inhibitors are reviewed, with a commentary on the potential implications of this class of agents in CKD anemia management. Key Messages: Pharmacologic activation of the HIF pathway results in a transient pseudo-hypoxic state that stimulates erythropoiesis in CKD patients with anemia. Results from clinical studies of a number of HIF prolyl hydroxylase inhibitors are increasingly available and provide support for the continued evaluation of the risk-benefit ratio of this novel therapeutic approach to the treatment of anemia in CKD. © 2017 S. Karger AG, Basel.

  5. Targeting the Central Pocket in Human Transcription Factor TEAD as a Potential Cancer Therapeutic Strategy.

    Science.gov (United States)

    Pobbati, Ajaybabu V; Han, Xiao; Hung, Alvin W; Weiguang, Seetoh; Huda, Nur; Chen, Guo-Ying; Kang, CongBao; Chia, Cheng San Brian; Luo, Xuelian; Hong, Wanjin; Poulsen, Anders

    2015-11-03

    The human TEAD family of transcription factors (TEAD1-4) is required for YAP-mediated transcription in the Hippo pathway. Hyperactivation of TEAD's co-activator YAP contributes to tissue overgrowth and human cancers, suggesting that pharmacological interference of TEAD-YAP activity may be an effective strategy for anticancer therapy. Here we report the discovery of a central pocket in the YAP-binding domain (YBD) of TEAD that is targetable by small-molecule inhibitors. Our X-ray crystallography studies reveal that flufenamic acid, a non-steroidal anti-inflammatory drug (NSAID), binds to the central pocket of TEAD2 YBD. Our biochemical and functional analyses further demonstrate that binding of NSAIDs to TEAD inhibits TEAD-YAP-dependent transcription, cell migration, and proliferation, indicating that the central pocket is important for TEAD function. Therefore, our studies discover a novel way of targeting TEAD transcription factors and set the stage for therapeutic development of specific TEAD-YAP inhibitors against human cancers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Transforming growth factor β activated kinase 1: a potential therapeutic target for rheumatic diseases.

    Science.gov (United States)

    Fechtner, Sabrina; Fox, David A; Ahmed, Salahuddin

    2017-07-01

    Pro-inflammatory cytokines such as IL-1β, IL-6 and TNF-α are central regulators of autoinflammatory diseases. While targeting these cytokines has proven to be a successful clinical strategy, the long-term challenges such as drug resistance, lack of efficacy and poor clinical outcomes in some patients are some of the limitations faced by these therapies. This has ignited strategies to reduce inflammation by potentially targeting a variety of molecules, including cell surface receptors, signalling proteins and/or transcription factors to minimize cytokine-induced inflammation and tissue injury. In this regard, transforming growth factor β activated kinase 1 (TAK1) is activated in the inflammatory signal transduction pathways in response to IL-1β, TNF-α or toll-like receptor stimulation. Because of its ideal position upstream of mitogen-activated protein kinases and the IκB kinase complex in signalling cascades, targeting TAK1 may be an attractive strategy for treating diseases characterized by chronic inflammation. Here, we discuss the emerging role of TAK1 in mediating the IL-1β, TNF-α and toll-like receptor mediated inflammatory responses in diseases such as RA, OA, gout and SS. We also review evidence suggesting that TAK1 inhibition may have potential therapeutic value. Finally, we focus on the current status of the development of TAK1 inhibitors and suggest further opportunities for testing TAK1 inhibitors in rheumatic diseases. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Pharmacological targeting of the transcription factor SOX18 delays breast cancer in mice

    Science.gov (United States)

    Overman, Jeroen; Fontaine, Frank; Moustaqil, Mehdi; Mittal, Deepak; Sierecki, Emma; Sacilotto, Natalia; Zuegg, Johannes; Robertson, Avril AB; Holmes, Kelly; Salim, Angela A; Mamidyala, Sreeman; Butler, Mark S; Robinson, Ashley S; Lesieur, Emmanuelle; Johnston, Wayne; Alexandrov, Kirill; Black, Brian L; Hogan, Benjamin M; De Val, Sarah; Capon, Robert J; Carroll, Jason S; Bailey, Timothy L; Koopman, Peter; Jauch, Ralf; Smyth, Mark J; Cooper, Matthew A; Gambin, Yann; Francois, Mathias

    2017-01-01

    Pharmacological targeting of transcription factors holds great promise for the development of new therapeutics, but strategies based on blockade of DNA binding, nuclear shuttling, or individual protein partner recruitment have yielded limited success to date. Transcription factors typically engage in complex interaction networks, likely masking the effects of specifically inhibiting single protein-protein interactions. Here, we used a combination of genomic, proteomic and biophysical methods to discover a suite of protein-protein interactions involving the SOX18 transcription factor, a known regulator of vascular development and disease. We describe a small-molecule that is able to disrupt a discrete subset of SOX18-dependent interactions. This compound selectively suppressed SOX18 transcriptional outputs in vitro and interfered with vascular development in zebrafish larvae. In a mouse pre-clinical model of breast cancer, treatment with this inhibitor significantly improved survival by reducing tumour vascular density and metastatic spread. Our studies validate an interactome-based molecular strategy to interfere with transcription factor activity, for the development of novel disease therapeutics. DOI: http://dx.doi.org/10.7554/eLife.21221.001 PMID:28137359

  8. Complexity of CNC transcription factors as revealed by gene targeting of the Nrf3 locus.

    Science.gov (United States)

    Derjuga, Anna; Gourley, Tania S; Holm, Teresa M; Heng, Henry H Q; Shivdasani, Ramesh A; Ahmed, Rafi; Andrews, Nancy C; Blank, Volker

    2004-04-01

    Cap'n'collar (CNC) family basic leucine zipper transcription factors play crucial roles in the regulation of mammalian gene expression and development. To determine the in vivo function of the CNC protein Nrf3 (NF-E2-related factor 3), we generated mice deficient in this transcription factor. We performed targeted disruption of two Nrf3 exons coding for CNC homology, basic DNA-binding, and leucine zipper dimerization domains. Nrf3 null mice developed normally and revealed no obvious phenotypic differences compared to wild-type animals. Nrf3(-/-) mice were fertile, and gross anatomy as well as behavior appeared normal. The mice showed normal age progression and did not show any apparent additional phenotype during their life span. We observed no differences in various blood parameters and chemistry values. We infected wild-type and Nrf3(-/-) mice with acute lymphocytic choriomeningitis virus and found no differences in these animals with respect to their number of virus-specific CD8 and CD4 T cells as well as their B-lymphocyte response. To determine whether the mild phenotype of Nrf3 null animals is due to functional redundancy, we generated mice deficient in multiple CNC factors. Contrary to our expectations, an absence of Nrf3 does not seem to cause additional lethality in compound Nrf3(-/-)/Nrf2(-/-) and Nrf3(-/-)/p45(-/-) mice. We hypothesize that the role of Nrf3 in vivo may become apparent only after appropriate challenge to the mice.

  9. Intraspecific variation in host susceptibility and climatic factors mediate epidemics of sudden oak death in western US forests

    Science.gov (United States)

    D. Huberli; K.J. Hayden; M. Calver; M. Garbelotto

    2011-01-01

    Umbellularia californica is one of the key infectious hosts of the exotic Phytophthora ramorum, which causes sudden oak death (SOD) in California and Oregon forests. This study provides a comprehensive analysis of the epidemiologically relevant parameters for SOD in California and southern Oregon, including potential differences between the two...

  10. Expression of hypoxia-inducible factor 1 alpha and its downstream targets in fibroepithelial tumors of the breast

    NARCIS (Netherlands)

    Kuijper, Arno; Groep, P. van der; Wall, E. van der; Diest, P.J. van

    2005-01-01

    INTRODUCTION Hypoxia-inducible factor 1 (HIF-1) alpha and its downstream targets carbonic anhydrase IX (CAIX) and vascular endothelial growth factor (VEGF) are key factors in the survival of proliferating tumor cells in a hypoxic microenvironment. We studied the expression and prognostic relevance

  11. Host factor I, Hfq, binds to Escherichia coli ompA mRNA in a growth rate-dependent fashion and regulates its stability

    DEFF Research Database (Denmark)

    Vytvytska, O; Jakobsen, J S; Balcunaite, G

    1998-01-01

    ompA was purified and identified as Hfq, a host factor initially recognized for its function in phage Qbeta replication. The ompA RNA-binding activity parallels the amount of Hfq, which is elevated in bacteria cultured at slow growth rate, a condition leading to facilitated degradation of the ompA m...... suggest a regulatory role for Hfq that specifically facilitates the ompA mRNA degradation in a growth rate-dependent manner....

  12. Tumor Necrosis Factor-Alpha Targeting Can Protect against Arthritis with Low Sensitization to Infection

    Directory of Open Access Journals (Sweden)

    Nadia Belmellat

    2017-11-01

    Full Text Available Tumor necrosis factor-alpha (TNF-α blockade is an effective treatment for rheumatoid arthritis (RA and other inflammatory diseases, but in patients, it is associated with reduced resistance to the infectious agents Mycobacterium tuberculosis and Listeria monocytogenes, among others. Our goal was to model infection and arthritis in mice and to compare etanercept, a currently used anti-TNF-α inhibitor, to an anti-TNF-α vaccine. We developed a murine surrogate of the TNF-α kinoid and produced an anti-murine TNF-α vaccine (TNFKi composed of keyhole limpet hemocyanin conjugated to TNF-α, which resulted in anti-TNF-α antibody production in mice. We also used etanercept (a soluble receptor of TNF commonly used to treat RA as a control of TNF neutralization. In a mouse model of collagen-induced arthritis, TNFKi protected against inflammation similar to etanercept. In a mouse model of acute L. monocytogenes infection, all TNFKi-treated mice showed cleared bacterial infection and survived, whereas etanercept-treated mice showed large liver granulomas and quickly died. Moreover, TNFKi mice infected with the virulent H37Rv M. tuberculosis showed resistance to infection, in contrast with etanercept-treated mice or controls. Depending on the TNF-α blockade strategy, treating arthritis with a TNF-α inhibitor could result in a different profile of infection suceptibility. Our TNFKi vaccine allowed for a better remaining host defense than did etanercept.

  13. Transcription factor HBP1 is a direct anti-cancer target of transcription factor FOXO1 in invasive oral cancer.

    Science.gov (United States)

    Chan, Chien-Yi; Huang, Shih-Yi; Sheu, Jim Jinn-Chyuan; Roth, Mendel M; Chou, I-Tai; Lien, Chia-Hsien; Lee, Ming-Fen; Huang, Chun-Yin

    2017-02-28

    Either FOXO1 or HBP1 transcription factor is a downstream effector of the PI3K/Akt pathway and associated with tumorigenesis. However, the relationship between FOXO1 and HBP1 in oral cancer remains unclear. Analysis of 30 oral tumor specimens revealed that mean mRNA levels of both FOXO1 and HBP1 in non-invasive and invasive oral tumors were found to be significantly lower than that of the control tissues, and the status of low FOXO1 and HBP1 (oral tumors. To investigate if HBP1 is a direct transcription target of FOXO1, we searched potential FOXO1 binding sites in the HBP1 promoter using the MAPPER Search Engine, and two putative FOXO1 binding sites located in the HBP1 promoter -132 to -125 bp and -343 to -336 bp were predicted. These binding sites were then confirmed by both reporter gene assays and the in cellulo ChIP assay. In addition, Akt activity manipulated by PI3K inhibitor LY294002 or Akt mutants was shown to negatively affect FOXO1-mediated HBP1 promoter activation and gene expression. Last, the biological significance of the FOXO1-HBP1 axis in oral cancer malignancy was evaluated in cell growth, colony formation, and invasiveness. The results indicated that HBP1 knockdown potently promoted malignant phenotypes of oral cancer and the suppressive effect of FOXO1 on cell growth, colony formation, and invasion was alleviated upon HBP1 knockdown in invasive oral cancer cells. Taken together, our data provide evidence for HBP1 as a direct downstream target of FOXO1 in oral cancer malignancy.

  14. Dissecting the signaling events that impact classical nuclear import and target nuclear transport factors.

    Directory of Open Access Journals (Sweden)

    Mohamed Kodiha

    2009-12-01

    Full Text Available Signaling through MEK-->ERK1/2 and PI3 kinases is implicated in many aspects of cell physiology, including the survival of oxidant exposure. Oxidants play a role in numerous physiological and pathophysiological processes, many of which rely on transport in and out of the nucleus. However, how oxidative stress impacts nuclear trafficking is not well defined.To better understand the effect of stress on nucleocytoplasmic trafficking, we exposed cells to the oxidant diethyl maleate. This treatment activated MEK-->ERK1/2 as well as PI3 kinase-->Akt cascades and triggered the inhibition of classical nuclear import. To define the molecular mechanisms that regulate nuclear transport, we examined whether MEK and PI3 kinase signaling affected the localization of key transport factors. Using recently developed tools for image acquisition and analysis, the subcellular distributions of importin-alpha, CAS, and nucleoporins Nup153 and Nup88 were quantified in different cellular compartments. These studies identified specific profiles for the localization of transport factors in the nucleus and cytoplasm, and at the nuclear envelope. Our results demonstrate that MEK and PI3 kinase signaling as well as oxidative stress control nuclear trafficking and the localization of transport components. Furthermore, stress not only induced changes in transport factor distribution, but also upregulated post-translational modification of transport factors. Our results are consistent with the idea that the phosphorylation of importin-alpha, CAS, Nup153, and Nup88, and the O-GlcNAc modification of Nup153 increase when cells are exposed to oxidant.Our studies defined the complex regulation of classical nuclear import and identified key transport factors that are targeted by stress, MEK, and PI3 kinase signaling.

  15. Molecular targets for the therapy of cancer associated with metabolic syndrome (transcription and growth factors).

    Science.gov (United States)

    Yunusova, Natalia V; Kondakova, Irina V; Kolomiets, Larisa A; Afanas'ev, Sergey G; Chernyshova, Alena L; Kudryavtsev, Igor V; Tsydenova, Anastasia A

    2017-11-08

    Metabolic syndrome (MS) is one of the leading risk factors for the development of cardiovascular diseases, type II diabetes mellitus and reproductive system diseases. Currently, not only cardiovascular disease and reproductive history risks related with MS are frequently discussed, but it has been also shown that MS is associated with increased risk of some common cancers (endometrial cancer, postmenopausal breast cancer, colorectal cancer, biliary tract cancers and liver cancer for men). Further studies are required to understand the mechanisms of the involvement of MS components in the pathogenesis of malignant neoplasms. Changes in the expression of transcription and growth factors in the peripheral tissues as well as in cancer tissues of patients with MS were revealed. Transcription factors (AMP-activated protein kinase-1, STAT3, sterol regulatory element-binding protein-1 and peroxisome proliferator-activated receptor-γ), leptin and adiponectin receptors seem to be the most promising molecular targets for the therapy of cancers associated with MS. © 2017 John Wiley & Sons Australia, Ltd.

  16. Community-acquired pneumonia and positive urinary antigen tests: Factors associated with targeted antibiotic therapy.

    Science.gov (United States)

    Mothes, A; Léotard, S; Nicolle, I; Smets, A; Chirio, D; Rotomondo, C; Tiger, F; Del Giudice, P; Perrin, C; Néri, D; Foucault, C; Della Guardia, M; Hyvernat, H; Roger, P-M

    2016-10-01

    The use of rapid microbiological tests is supported by antimicrobial stewardship policies. Targeted antibiotic therapy (TAT) for community-acquired pneumonia (CAP) with positive urinary antigen test (UAT) has been associated with a favorable impact on outcome. We aimed to determine the factors associated with TAT prescription. We conducted a retrospective multicenter study including all patients presenting with CAP and positive UAT for Streptococcus pneumoniae or Legionella pneumophila from January 2010 to December 2013. Patients presenting with aspiration pneumonia, coinfection, and neutropenia were excluded. CAP severity was assessed using the Pneumonia Severity Index (PSI). TAT was defined as the administration of amoxicillin for pneumococcal infection and either macrolides or fluoroquinolones (inactive against S. pneumoniae) for Legionella infection. A total of 861 patients were included, including 687 pneumococcal infections and 174 legionellosis from eight facilities and 37 medical departments. TAT was prescribed to 273 patients (32%). Four factors were found independently associated with a lower rate of TAT: a PSI score≥4 (OR 0.37), Hospital A (OR 0.41), hospitalization in the intensive care unit (OR 0.44), and cardiac comorbidities (OR 0.60). Four other factors were associated with a high rate of TAT: positive blood culture for S. pneumoniae (OR 2.32), Hospitals B (OR 2.34), E (OR 2.68), and H (OR 9.32). TAT in CAP with positive UAT was related to the hospitals as well as to patient characteristics. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  17. Anxiety sensitivity and working memory capacity: Risk factors and targets for health behavior promotion.

    Science.gov (United States)

    Otto, Michael W; Eastman, Abraham; Lo, Stephen; Hearon, Bridget A; Bickel, Warren K; Zvolensky, Michael; Smits, Jasper A J; Doan, Stacey N

    2016-11-01

    Understanding the nature and influence of specific risk profiles is increasingly important for health behavior promotion. The purpose of this article is to document the value of two factors-anxiety sensitivity (AS) and working memory capacity (WMC)-for enhancing risk for the initiation and/or maintenance of a range of negative health behaviors. AS is a distress-related risk factor that potentiates avoidance/coping motivations for negative health behaviors. Stress provides the conditions for negative somatic and affective states, and AS amplifies the aversiveness of these experiences and correspondingly hinders adaptive functioning. In contrast, low WMC is hypothesized to exert its effect by decreasing the capacity to filter out current temptations, attenuating a focus on longer-term goals and impairing the application of relevant coping skills at times of stress. In this review, we provide conceptual models for the separate roles of high AS and low WMC in negative health behaviors, review the influence of these factors on specific health behavior exemplars (eating behaviors/obesity, physical activity, smoking, alcohol use, and sleep promotion), provide preliminary evidence for their value as independent treatment targets for health-behavior promotion, and encourage specific research directions in relation to these variables. Copyright © 2016. Published by Elsevier Ltd.

  18. Transcription Factors Expressed in Lateral Organ Boundaries: Identification of Downstream Targets

    Energy Technology Data Exchange (ETDEWEB)

    Springer, Patricia S

    2010-07-12

    The processes of lateral organ initiation and patterning are central to the generation of mature plant form. Characterization of the molecular mechanisms underlying these processes is essential to our understanding of plant development. Communication between the shoot apical meristem and initiating organ primordia is important both for functioning of the meristem and for proper organ patterning, and very little is known about this process. In particular, the boundary between meristem and leaf is emerging as a critical region that is important for SAM maintenance and regulation of organogenesis. The goal of this project was to characterize three boundary-expressed genes that encode predicted transcription factors. Specifically, we have studied LATERAL ORGAN BOUNDARIES (LOB), LATERAL ORGAN FUSION1 (LOF1), and LATERAL ORGAN FUSION2 (LOF2). LOB encodes the founding member of the LOB-DOMAIN (LBD) plant-specific DNA binding transcription factor family and LOF1 and LOF2 encode paralogous MYB-domain transcription factors. We characterized the genetic relationship between these three genes and other boundary and meristem genes. We also used an ectopic inducible expression system to identify direct targets of LOB.

  19. Soluble tumour necrosis factor (TNF)-receptor levels in serum as markers of anti-viral host reactivity

    DEFF Research Database (Denmark)

    Bartholdy, C; Nansen, A; Marker, O

    1999-01-01

    -gamma. A simple correlation between release of sTNF-Rs in vivo and macrophage activation in vitro was not present. These findings indicate that sTNF-R75 is indeed a sensitive marker of both innate and specific cell-mediated host reactivity during viral infection, but it is not correlated to a single immunological......The role of soluble receptors for TNF-alpha (sTNF-Rs) as markers of virus-induced host responses was studied by the use of murine model infections. A marked elevation in serum levels of sTNF-R75, but not sTNF-R55, was found 1 day after infection with vesicular stomatitis virus (VSV). In mice...

  20. Interactions of HIV and drugs of abuse: the importance of glia, neural progenitors, and host genetic factors

    OpenAIRE

    Hauser, Kurt F.; Knapp, Pamela E.

    2014-01-01

    Considerable insight has been gained into the comorbid, interactive effects of HIV and drug abuse in the brain using experimental models. This review, which considers opiates, methamphetamine, and cocaine, emphasizes the importance of host genetics and glial plasticity in driving the pathogenic neuron remodeling underlying neuro-acquired immunodeficiency syndrome (neuroAIDS) and drug abuse comorbidity. Clinical findings are less concordant than experimental work, and the response of individua...

  1. Targeting insulin-like growth factor 1 leads to amelioration of inflammatory demyelinating disease.

    Directory of Open Access Journals (Sweden)

    Matthew F Cusick

    Full Text Available In patients with multiple sclerosis (MS and in mice with experimental autoimmune encephalomyelitis (EAE, proliferating autoreactive T cells play an important role in the pathogenesis of the disease. Due to the importance of these myelin-specific T cells, these cells have been therapeutic targets in a variety of treatments. Previously we found that Lenaldekar (LDK, a novel small molecule, could inhibit exacerbations in a preclinical model of MS when given at the start of an EAE exacerbation. In those studies, we found that LDK could inhibit human T cell recall responses and murine myelin responses in vitro. In these new studies, we found that LDK could inhibit myelin specific T cell responses through the insulin-like growth factor-1 receptor (IGF-1R pathway. Alteration of this pathway led to marked reduction in T cell proliferation and expansion. Blocking this pathway could account for the observed decreases in clinical signs and inflammatory demyelinating disease, which was accompanied by axonal preservation. Our data indicate that IGF-1R could be a potential target for new therapies for the treatment of autoimmune diseases where autoreactive T cell expansion is a requisite for disease.

  2. Comprehensive reanalysis of transcription factor knockout expression data in Saccharomyces cerevisiae reveals many new targets.

    Science.gov (United States)

    Reimand, Jüri; Vaquerizas, Juan M; Todd, Annabel E; Vilo, Jaak; Luscombe, Nicholas M

    2010-08-01

    Transcription factor (TF) perturbation experiments give valuable insights into gene regulation. Genome-scale evidence from microarray measurements may be used to identify regulatory interactions between TFs and targets. Recently, Hu and colleagues published a comprehensive study covering 269 TF knockout mutants for the yeast Saccharomyces cerevisiae. However, the information that can be extracted from this valuable dataset is limited by the method employed to process the microarray data. Here, we present a reanalysis of the original data using improved statistical techniques freely available from the BioConductor project. We identify over 100,000 differentially expressed genes-nine times the total reported by Hu et al. We validate the biological significance of these genes by assessing their functions, the occurrence of upstream TF-binding sites, and the prevalence of protein-protein interactions. The reanalysed dataset outperforms the original across all measures, indicating that we have uncovered a vastly expanded list of relevant targets. In summary, this work presents a high-quality reanalysis that maximizes the information contained in the Hu et al. compendium. The dataset is available from ArrayExpress (accession: E-MTAB-109) and it will be invaluable to any scientist interested in the yeast transcriptional regulatory system.

  3. A mammalian transcription factor-specific peptide repository for targeted proteomics.

    Science.gov (United States)

    Simicevic, Jovan; Moniatte, Marc; Hamelin, Romain; Ahrné, Erik; Deplancke, Bart

    2015-02-01

    Site-specific transcription factors (TFs) play an essential role in mammalian development and function as they are vital for the majority of cellular processes. Despite their biological importance, TF proteomic data is scarce in the literature, likely due to difficulties in detecting peptides as the abundance of TFs in cells tends to be low. In recent years, significant improvements in MS-based technologies in terms of sensitivity and specificity have increased the interest in developing quantitative methodologies specifically targeting relatively lowly abundant proteins such as TFs in mammalian models. Such efforts would be greatly aided by the availability of TF peptide-specific information as such data would not only enable improvements in speed and accuracy of protein identifications, but also ameliorate cross-comparisons of quantitative proteomics data and allow for a more efficient development of targeted proteomics assays. However, to date, no comprehensive TF proteotypic peptide database has been developed. To address this evident lack of TF peptide data in public repositories, we are generating a comprehensive, experimentally derived TF proteotypic peptide spectral library dataset based on in vitro protein expression. Our library currently contains peptide information for 89 TFs and this number is set to increase in the near future. All MS data have been deposited in the ProteomeXchange with identifier PXD001212 (http://proteomecentral.proteomexchange.org/dataset/PXD001212). © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. An Interbacterial NAD(P)+ Glycohydrolase Toxin Requires Elongation Factor Tu for Delivery to Target Cells

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, John C.; Quentin, Dennis; Sawai, Shin; LeRoux, Michele; Harding, Brittany N.; Ledvina, Hannah E.; Tran, Bao Q.; Robinson, Howard; Goo, Young Ah; Goodlett, David R.; Raunser, Stefan; Mougous, Joseph D.

    2015-10-08

    Type VI secretion (T6S) influences the composition of microbial communities by catalyzing the delivery of toxins between adjacent bacterial cells. Here, we demonstrate that a T6S integral membrane toxin from Pseudomonas aeruginosa, Tse6, acts on target cells by degrading the universally essential dinucleotides NAD+ and NADP+. Structural analyses of Tse6 show that it resembles mono-ADP-ribosyltransferase proteins, such as diphtheria toxin, with the exception of a unique loop that both excludes proteinaceous ADP-ribose acceptors and contributes to hydrolysis. We find that entry of Tse6 into target cells requires its binding to an essential housekeeping protein, translation elongation factor Tu (EF-Tu). These proteins participate in a larger assembly that additionally directs toxin export and provides chaperone activity. Visualization of this complex by electron microscopy defines the architecture of a toxin-loaded T6S apparatus and provides mechanistic insight into intercellular membrane protein delivery between bacteria.

  5. SUPERPIXEL BASED FACTOR ANALYSIS AND TARGET TRANSFORMATION METHOD FOR MARTIAN MINERALS DETECTION

    Directory of Open Access Journals (Sweden)

    X. Wu

    2018-04-01

    Full Text Available The Factor analysis and target transformation (FATT is an effective method to test for the presence of particular mineral on Martian surface. It has been used both in thermal infrared (Thermal Emission Spectrometer, TES and near-infrared (Compact Reconnaissance Imaging Spectrometer for Mars, CRISM hyperspectral data. FATT derived a set of orthogonal eigenvectors from a mixed system and typically selected first 10 eigenvectors to least square fit the library mineral spectra. However, minerals present only in a limited pixels will be ignored because its weak spectral features compared with full image signatures. Here, we proposed a superpixel based FATT method to detect the mineral distributions on Mars. The simple linear iterative clustering (SLIC algorithm was used to partition the CRISM image into multiple connected image regions with spectral homogeneous to enhance the weak signatures by increasing their proportion in a mixed system. A least square fitting was used in target transformation and performed to each region iteratively. Finally, the distribution of the specific minerals in image was obtained, where fitting residual less than a threshold represent presence and otherwise absence. We validate our method by identifying carbonates in a well analysed CRISM image in Nili Fossae on Mars. Our experimental results indicate that the proposed method work well both in simulated and real data sets.

  6. Targeting the Hippo Pathway and Cancer through the TEAD Family of Transcription Factors.

    Science.gov (United States)

    Holden, Jeffrey K; Cunningham, Christian N

    2018-03-20

    The Hippo pathway is a critical transcriptional signaling pathway that regulates cell growth, proliferation and organ development. The transcriptional enhanced associate domain (TEAD) protein family consists of four paralogous transcription factors that function to modulate gene expression in response to the Hippo signaling pathway. Transcriptional activation of these proteins occurs upon binding to the co-activator YAP/TAZ whose entry into the nucleus is regulated by Lats1/2 kinase. In recent years, it has become apparent that the dysregulation and/or overexpression of Hippo pathway effectors is implicated in a wide range of cancers, including prostate, gastric and liver cancer. A large body of work has been dedicated to understanding the therapeutic potential of modulating the phosphorylation and localization of YAP/TAZ. However, YAP/TAZ are considered to be natively unfolded and may be intractable as drug targets. Therefore, TEAD proteins present themselves as an excellent therapeutic target for intervention of the Hippo pathway. This review summarizes the functional role of TEAD proteins in cancer and assesses the therapeutic potential of antagonizing TEAD function in vivo.

  7. Targeting the Hippo Pathway and Cancer through the TEAD Family of Transcription Factors

    Directory of Open Access Journals (Sweden)

    Jeffrey K. Holden

    2018-03-01

    Full Text Available The Hippo pathway is a critical transcriptional signaling pathway that regulates cell growth, proliferation and organ development. The transcriptional enhanced associate domain (TEAD protein family consists of four paralogous transcription factors that function to modulate gene expression in response to the Hippo signaling pathway. Transcriptional activation of these proteins occurs upon binding to the co-activator YAP/TAZ whose entry into the nucleus is regulated by Lats1/2 kinase. In recent years, it has become apparent that the dysregulation and/or overexpression of Hippo pathway effectors is implicated in a wide range of cancers, including prostate, gastric and liver cancer. A large body of work has been dedicated to understanding the therapeutic potential of modulating the phosphorylation and localization of YAP/TAZ. However, YAP/TAZ are considered to be natively unfolded and may be intractable as drug targets. Therefore, TEAD proteins present themselves as an excellent therapeutic target for intervention of the Hippo pathway. This review summarizes the functional role of TEAD proteins in cancer and assesses the therapeutic potential of antagonizing TEAD function in vivo.

  8. Targeted release of transcription factors for cell reprogramming by a natural micro-syringe.

    Science.gov (United States)

    Berthoin, Lionel; Toussaint, Bertrand; Garban, Frédéric; Le Gouellec, Audrey; Caulier, Benjamin; Polack, Benoît; Laurin, David

    2016-11-20

    Ectopic expression of defined transcription factors (TFs) for cell fate handling has proven high potential interest in reprogramming differentiated cells, in particular for regenerative medicine, ontogenesis study and cell based modelling. Pluripotency or transdifferentiation induction as TF mediated differentiation is commonly produced by transfer of genetic information with safety concerns. The direct delivery of proteins could represent a safer alternative but still needs significant advances to be efficient. We have successfully developed the direct delivery of proteins by an attenuated bacterium with a type 3 secretion system that does not require challenging and laborious steps for production and purification of recombinant molecules. Here we show that this natural micro-syringe is able to inject TFs to primary human fibroblasts and cord blood CD34 + hematopoietic stem cells. The signal sequence for vectorization of the TF Oct4 has no effect on DNA binding to its nucleic target. As soon as one hour after injection, vectorized TFs are detectable in the nucleus. The injection process is not associated with toxicity and the bacteria can be completely removed from cell cultures. A three days targeted release of Oct4 or Sox2 embryonic TFs results in the induction of the core pluripotency genes expression in fibroblasts and CD34 + hematopoietic stem cells. This micro-syringe vectorization represents a new strategy for TF delivery and has potential applications for cell fate reprogramming. Copyright © 2016 Elsevier B.V. All rights reserved.

  9. A single gene target of an ETS-family transcription factor determines neuronal CO2-chemosensitivity.

    Directory of Open Access Journals (Sweden)

    Julia P Brandt

    Full Text Available Many animals possess neurons specialized for the detection of carbon dioxide (CO(2, which acts as a cue to elicit behavioral responses and is also an internally generated product of respiration that regulates animal physiology. In many organisms how such neurons detect CO(2 is poorly understood. We report here a mechanism that endows C. elegans neurons with the ability to detect CO(2. The ETS-5 transcription factor is necessary for the specification of CO(2-sensing BAG neurons. Expression of a single ETS-5 target gene, gcy-9, which encodes a receptor-type guanylate cyclase, is sufficient to bypass a requirement for ets-5 in CO(2-detection and transforms neurons into CO(2-sensing neurons. Because ETS-5 and GCY-9 are members of gene families that are conserved between nematodes and vertebrates, a similar mechanism might act in the specification of CO(2-sensing neurons in other phyla.

  10. Bookmarking target genes in mitosis: a shared epigenetic trait of phenotypic transcription factors and oncogenes?

    Science.gov (United States)

    Zaidi, Sayyed K; Grandy, Rodrigo A; Lopez-Camacho, Cesar; Montecino, Martin; van Wijnen, Andre J; Lian, Jane B; Stein, Janet L; Stein, Gary S

    2014-01-15

    The regulatory information for phenotype, proliferation, and growth of normal and tumor cells must be maintained through genome replication in the S phase and cell division during mitosis. Epigenetic mechanisms that include DNA methylation, posttranslational modifications of histones, selective utilization of histone variants, and inheritable RNA molecules play pivotal roles in maintaining cellular identity through mitotic divisions. Recent studies demonstrate that mitotic occupancy of genes, which are determinants of cell fate, growth, and proliferation, by lineage-restricted transcription factors is a key epigenetic mechanism for retention and transmission of cellular expression memory. Evidence is emerging for the presence of distinct transcriptional regulatory microenvironments in mitotic chromosomes in which the genes bookmarked for reactivation postmitotically reside. Importantly, some oncoproteins are present in mitotic microenvironments where they occupy target genes during mitosis and may contribute to perpetuating the transformed phenotype. We discuss emerging regulatory implications of epigenetically bookmarking genes during mitosis for physiologic control as well as for the onset and progression of cancer.

  11. Determination of mineral matter in coal by target transformation factor analysis

    International Nuclear Information System (INIS)

    Roscoe, B.A.; Hopke, P.K.

    1980-01-01

    There is an increasing need to determine the nature of mineral matter in coal. The mineral matter is composed of all inclusions in the coal whether or not they are distinct from the coal. The need for this information is based on the increased use of coal and the problems associated with its use such as boiler tube fouling, air pollution, and coal liquefaction. By utilizing target transformation factor analysis, it is possible to identify the number of mineral phases that may be present in the coal as well as the composition of these mineral phases including major, minor, and trace elements. It is thus possible to determine the mineral phases and reconstruct the mineralogy of the coal sampled such that general characteristics of the mineral phases can be determined. From this information, insight into the formation of the coal can be obtained and better methods of utilizing the coal can be devised

  12. Single base mismatches in the mRNA target site allow specific seed region-mediated off-target binding of siRNA targeting human coagulation factor 7.

    Science.gov (United States)

    Ravon, Morgane; Berrera, Marco; Ebeling, Martin; Certa, Ulrich

    2012-01-01

    We have analyzed the off-target activity of two siRNAs (F7-1, F7-2) that knock-down human blood coagulation factor 7 mRNA. F7-1 modulates a significant number of non-target transcripts while F7-2 shows high selectivity for the target transcript under various experimental conditions. The 3'-UTRs of all F7-1 off-target genes show statistically significant enrichment of the reverse complement of the F7-1 siRNA seed region located in the guide strand. Seed region enrichment was confirmed in off-target transcripts modulated by siRNA targeting the glucocorticoid receptor. To investigate how these sites contribute to off-target recognition of F7-1, we employed CXCL5 transcript as model system because it contains five F7-1 seed sequence motifs with single base mismatches. We show by transient transfection of reporter gene constructs into HEK293 cells that three out of five sites located in the 3'-UTR region are required for F7-1 off-target activity. For further mechanistic dissection, the sequences of these sites were synthesized and inserted either individually or joined in dimeric or trimeric constructs. Only the fusion constructs were silenced by F7-1 while the individual sites had no off-target activity. Based on F7-1 as a model, a single mismatch between the siRNA seed region and mRNA target sites is tolerated for target recognition and the CXCL5 data suggest a requirement for binding to multiple target sites in off-target transcripts.

  13. Cholesterol Sulfate and Cholesterol Sulfotransferase Inhibit Gluconeogenesis by Targeting Hepatocyte Nuclear Factor

    Science.gov (United States)

    Shi, Xiongjie; Cheng, Qiuqiong; Xu, Leyuan; Yan, Jiong; Jiang, Mengxi; He, Jinhan; Xu, Meishu; Stefanovic-Racic, Maja; Sipula, Ian; O'Doherty, Robert Martin; Ren, Shunlin

    2014-01-01

    Sulfotransferase (SULT)-mediated sulfation represents a critical mechanism in regulating the chemical and functional homeostasis of endogenous and exogenous molecules. The cholesterol sulfotransferase SULT2B1b catalyzes the sulfoconjugation of cholesterol to synthesize cholesterol sulfate (CS). In this study, we showed that the expression of SULT2B1b in the liver was induced in obese mice and during the transition from the fasted to the fed state, suggesting that the regulation of SULT2B1b is physiologically relevant. CS and SULT2B1b inhibited gluconeogenesis by targeting the gluconeogenic factor hepatocyte nuclear factor 4α (HNF4α) in both cell cultures and transgenic mice. Treatment of mice with CS or transgenic overexpression of the CS-generating enzyme SULT2B1b in the liver inhibited hepatic gluconeogenesis and alleviated metabolic abnormalities both in mice with diet-induced obesity (DIO) and in leptin-deficient (ob/ob) mice. Mechanistically, CS and SULT2B1b inhibited gluconeogenesis by suppressing the expression of acetyl coenzyme A (acetyl-CoA) synthetase (Acss), leading to decreased acetylation and nuclear exclusion of HNF4α. Our results also suggested that leptin is a potential effector of SULT2B1b in improving metabolic function. We conclude that SULT2B1b and its enzymatic by-product CS are important metabolic regulators that control glucose metabolism, suggesting CS as a potential therapeutic agent and SULT2B1b as a potential therapeutic target for metabolic disorders. PMID:24277929

  14. Distribution of intermediate host snails of schistosomiasis and fascioliasis in relation to environmental factors during the dry season in the Tchologo region, Côte d'Ivoire

    Science.gov (United States)

    Krauth, Stefanie J.; Wandel, Nathalie; Traoré, Seïdinan I.; Vounatsou, Penelope; Hattendorf, Jan; Achi, Louise Y.; McNeill, Kristopher; N'Goran, Eliézer K.; Utzinger, Jürg

    2017-10-01

    Snail-borne trematodiases, such as fascioliasis and schistosomiasis, belong to the neglected tropical diseases; yet, millions of people and livestock are affected. The spatial and temporal distribution of intermediate host snails plays an important role in the epidemiology and control of trematodiases. Snail distribution is influenced by numerous environmental and anthropomorphic factors. The aim of this study was to assess the distribution and constitution of the snail fauna during the dry season in constructed and natural water bodies in the Tchologo region, northern Côte d'Ivoire, and to relate these findings to environmental factors and human infections. Snails were collected using standard procedures and environmental parameters were assessed from a total of 50 water bodies in and around 30 randomly selected villages. A canonical correspondence analysis was performed to establish the relationship between snail occurrence and environmental factors. Furthermore, a total of 743 people from the same 30 villages and nearby settlements were invited for stool and urine examination for the diagnosis of Fasciola spp., Schistosoma haematobium and Schistosoma mansoni. Snails of medical importance of the genera Biomphalaria, Bulinus, Lymnaea and Physa were found. Differences in snail occurrence from sites sampled in December 2014 and snails sampled in February 2015, as well as between the northern and southern part of the study area, were revealed. Various environmental factors, such as temperature and human activities, were related to the occurrence of intermediate host snail species in the region. Only 2.3% of human participants tested positive for schistosomiasis, while no Fasciola eggs were found in stool samples. We conclude that intermediate host snails of Fasciola and Schistosoma co-occur in water bodies in the Tchologo region and that the distribution of these snails correlates not only with environmental factors, but also with the presence of humans and animals

  15. Evaluating Transcription Factor Activity Changes by Scoring Unexplained Target Genes in Expression Data.

    Directory of Open Access Journals (Sweden)

    Evi Berchtold

    Full Text Available Several methods predict activity changes of transcription factors (TFs from a given regulatory network and measured expression data. But available gene regulatory networks are incomplete and contain many condition-dependent regulations that are not relevant for the specific expression measurement. It is not known which combination of active TFs is needed to cause a change in the expression of a target gene. A method to systematically evaluate the inferred activity changes is missing. We present such an evaluation strategy that indicates for how many target genes the observed expression changes can be explained by a given set of active TFs. To overcome the problem that the exact combination of active TFs needed to activate a gene is typically not known, we assume a gene to be explained if there exists any combination for which the predicted active TFs can possibly explain the observed change of the gene. We introduce the i-score (inconsistency score, which quantifies how many genes could not be explained by the set of activity changes of TFs. We observe that, even for these minimal requirements, published methods yield many unexplained target genes, i.e. large i-scores. This holds for all methods and all expression datasets we evaluated. We provide new optimization methods to calculate the best possible (minimal i-score given the network and measured expression data. The evaluation of this optimized i-score on a large data compendium yields many unexplained target genes for almost every case. This indicates that currently available regulatory networks are still far from being complete. Both the presented Act-SAT and Act-A* methods produce optimal sets of TF activity changes, which can be used to investigate the difficult interplay of expression and network data. A web server and a command line tool to calculate our i-score and to find the active TFs associated with the minimal i-score is available from https://services.bio.ifi.lmu.de/i-score.

  16. Initial Gut Microbial Composition as a Key Factor Driving Host Response to Antibiotic Treatment, as Exemplified by the Presence or Absence of Commensal Escherichia coli.

    Science.gov (United States)

    Ju, Tingting; Shoblak, Yasmeen; Gao, Yanhua; Yang, Kaiyuan; Fouhse, Janelle; Finlay, B Brett; So, Yee Wing; Stothard, Paul; Willing, Benjamin P

    2017-09-01

    Antibiotics are important for treating bacterial infection; however, efficacies and side effects of antibiotics vary in medicine and experimental models. A few studies have correlated microbiota composition variations with health outcomes in response to antibiotics; however, no study has demonstrated causality. We had noted variation in colonic expression of C-type lectins, regenerating islet-derived protein 3β (Reg3β) and Reg3γ, after metronidazole treatment in a mouse model. To investigate the effects of specific variations in the preexisting microbiome on host response to antibiotics, mice harboring a normal microbiota were allocated to 4 treatments in a 2-by-2 factorial arrangement with or without commensal Escherichia coli and with or without metronidazole in drinking water. E. coli colonized readily without causing a notable shift in the microbiota or host response. Metronidazole administration reduced microbiota biodiversity, indicated by decreased Chao1 and Shannon index values, and altered microbiota composition. However, the presence of E. coli strongly affected metronidazole-induced microbiota shifts. Remarkably, this single commensal bacterium in the context of a complex population led to variations in host responses to metronidazole treatment, including increased expression of antimicrobial peptides Reg3β and Reg3γ and intestinal inflammation indicated by tumor necrosis factor alpha levels. Similar results were obtained from 2-week antibiotic exposure and with additional E. coli isolates. The results of this proof-of-concept study indicate that even minor variations in initial commensal microbiota can drive shifts in microbial composition and host response after antibiotic administration. As well as providing an explanation for variability in animal models using antibiotics, the findings encourage the development of personalized medication in antibiotic therapies. IMPORTANCE This work provides an understanding of variability in studies where

  17. Transcription factor Fos-related antigen 1 is an effective target for a breast cancer vaccine

    Science.gov (United States)

    Luo, Yunping; Zhou, He; Mizutani, Masato; Mizutani, Noriko; Reisfeld, Ralph A.; Xiang, Rong

    2003-07-01

    Protection against breast cancer was achieved with a DNA vaccine against murine transcription factor Fos-related antigen 1, which is overexpressed in aggressively proliferating D2F2 murine breast carcinoma. Growth of primary s.c. tumor and dissemination of pulmonary metastases was markedly suppressed by this oral DNA vaccine, carried by attenuated Salmonella typhimurium, encoding murine Fos-related antigen 1, fused with mutant polyubiquitin, and cotransformed with secretory murine IL-18. The life span of 60% of vaccinated mice was tripled in the absence of detectable tumor growth after lethal tumor cell challenge. Immunological mechanisms involved activation of T, natural killer, and dendritic cells, as indicated by up-regulation of their activation markers and costimulatory molecules. Markedly increased specific target cell lysis was mediated by both MHC class I-restricted CD8+ T cells and natural killer cells isolated from splenocytes of vaccinated mice, including a significant release of proinflammatory cytokines IFN- and IL-2. Importantly, fluorescence analysis of fibroblast growth factor 2 and tumor cell-induced vessel growth in Matrigel plugs demonstrated marked suppression of angiogenesis only in vaccinated animals. Taken together, this multifunctional DNA vaccine proved effective in protecting against growth and metastases of breast cancer by combining the action of immune effector cells with suppression of tumor angiogenesis. vaccine | tumor | metastases | antiangiogenesis

  18. Spatial and Temporal Epidemiology of Nephropathia Epidemica Incidence and Hantavirus Seroprevalence in Rodent Hosts: Identification of the Main Environmental Factors in Europe.

    Science.gov (United States)

    Monchatre-Leroy, E; Crespin, L; Boué, F; Marianneau, P; Calavas, D; Hénaux, V

    2017-08-01

    In Europe, the increasing number of nephropathia epidemica (NE) infections in humans, caused by Puumala virus carried by bank voles (Myodes glareolus), has triggered studies of environmental factors driving these infections. NE infections have been shown to occur in specific geographical areas characterized by environmental factors that influence the distribution and dynamics of host populations and virus persistence in the soil. Here, we review the influence of environmental conditions (including climate factors, food availability and habitat conditions) with respect to incidence in humans and seroprevalence in rodents, considering both direct and indirect transmission pathways. For each type of environmental factor, results and discrepancies between studies are presented and examined in the light of biological hypotheses. Overall, food availability and temperature appear to be the main drivers of host seroprevalence and NE incidence, but data quality and statistical approaches varied greatly among studies. We highlight the issues that now need to be addressed and suggest improvements for study design in regard to the current knowledge on hantavirus epidemiology. © 2016 Blackwell Verlag GmbH.

  19. Structures of mithramycin analogues bound to DNA and implications for targeting transcription factor FLI1.

    Science.gov (United States)

    Hou, Caixia; Weidenbach, Stevi; Cano, Kristin E; Wang, Zhonghua; Mitra, Prithiba; Ivanov, Dmitri N; Rohr, Jürgen; Tsodikov, Oleg V

    2016-10-14

    Transcription factors have been considered undruggable, but this paradigm has been recently challenged. DNA binding natural product mithramycin (MTM) is a potent antagonist of oncogenic transcription factor EWS-FLI1. Structural details of MTM recognition of DNA, including the FLI1 binding sequence GGA(A/T), are needed to understand how MTM interferes with EWS-FLI1. We report a crystal structure of an MTM analogue MTM SA-Trp bound to a DNA oligomer containing a site GGCC, and two structures of a novel analogue MTM SA-Phe in complex with DNA. MTM SA-Phe is bound to sites AGGG and GGGT on one DNA, and to AGGG and GGGA(T) (a FLI1 binding site) on the other, revealing how MTM recognizes different DNA sequences. Unexpectedly, at sub-micromolar concentrations MTMs stabilize FLI1-DNA complex on GGAA repeats, which are critical for the oncogenic function of EWS-FLI1. We also directly demonstrate by nuclear magnetic resonance formation of a ternary FLI1-DNA-MTM complex on a single GGAA FLI1/MTM binding site. These biochemical and structural data and a new FLI1-DNA structure suggest that MTM binds the minor groove and perturbs FLI1 bound nearby in the major groove. This ternary complex model may lead to development of novel MTM analogues that selectively target EWS-FLI1 or other oncogenic transcription factors, as anti-cancer therapeutics. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  20. An intracellular targeted antibody detects EGFR as an independent prognostic factor in ovarian carcinomas

    International Nuclear Information System (INIS)

    Noske, Aurelia; Denkert, Carsten; Schwabe, Michael; Weichert, Wilko; Darb-Esfahani, Silvia; Buckendahl, Ann-Christin; Sehouli, Jalid; Braicu, Elena I; Budczies, Jan; Dietel, Manfred

    2011-01-01

    In ovarian cancer, the reported rate of EGFR expression varies between 4-70% depending on assessment method and data on patient outcome are conflicting. Methods: In this study we investigated EGFR expression and its prognostic value in a cohort of 121 invasive ovarian carcinomas, using a novel antibody against the intracellular domain of the receptor. We further evaluated an association between EGFR, the nuclear transporter CRM1 as well as COX-2. Furthermore, we evaluated EGFR expression in ten ovarian cancer cell lines and incubated cancer cells with Leptomycin B, a CRM1 specific inhibitor. We observed a membranous and cytoplasmic EGFR expression in 36.4% and 64% of ovarian carcinomas, respectively. Membranous EGFR was an independent prognostic factor for poor overall survival in ovarian cancer patients (HR 2.7, CI 1.1-6.4, p = 0.02) which was also found in the serous subtype (HR 4.6, CI 1.6-13.4, p = 0.004). We further observed a significant association of EGFR with COX-2 and nuclear CRM1 expression (chi-square test for trends, p = 0.006 and p = 0.013, respectively). In addition, combined membranous EGFR/COX-2 expression was significantly related to unfavorable overall survival (HR 7.2, CI 2.3-22.1, p = 0.001). In cell culture, we observed a suppression of EGFR protein levels after exposure to Leptomycin B in OVCAR-3 and SKOV-3 cells. Our results suggest that the EGFR/COX-2/CRM1 interaction might be involved in progression of ovarian cancer and patient prognosis. Hence, it is an interesting anti-cancer target for a combination therapy. Further studies will also be needed to investigate whether EGFR is also predictive for benefit from EGFR targeted therapies

  1. The epidermal growth factor receptor as a target for gastrointestinal cancer therapy.

    Science.gov (United States)

    Tedesco, Karen L; Lockhart, A Craig; Berlin, Jordan D

    2004-10-01

    The epidermal growth factor receptor (EGFR) is a member of the family of transmembrane protein kinase receptors known as the erbB or HER receptor family. When activated, EGFR phosphorylates and activates other intracellular proteins that affect cell signaling pathways, cellular proliferation, control of apoptosis and angiogenesis. EGFR signaling is best thought of as a network of activating and inactivating proteins with EGFR as the entry point into the network. EGFR overexpression occurs in most GI malignancies and while data are not entirely consistent, EGFR overexpression often confers a poor prognosis in those GI malignancies that have been studied. It often correlates with poorly differentiated histology, more advanced stage and other known poor prognostic markers. The EGFR is a tempting target because of its presence and overexpression on so many tumor types. However, downstream of the EGFR are several proteins that may be activated without EGFR thus allowing blockade to be overcome. Therefore, while blocking the activity of the EGFR protein appears to be a promising anticancer strategy, a simplistic strategy of blocking only EGFR is likely to only impact a minority of patients. It is time for the laboratory and clinical researchers to work closely together to develop this treatment strategy, moving back and forth from clinical to laboratory to best understand how to block this network effectively enough to produce a broader antitumor effect. While multiple methods of targeting the EGFR pathway are under development, including the inhibition of downstream proteins, only two modalities have entered clinical trials in GI malignancies: small molecule inhibitors of the intracellular kinase domain of EGFR and antibodies designed to block the extracellular ligand-binding domain of EGFR. EGFR inhibitors are still experimental in every GI malignancy with the notable exception of cetuximab that is approved for second or third-line therapy of metastatic colorectal

  2. Small interference RNA targeting tissue factor inhibits human lung adenocarcinoma growth in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Wang Jianing

    2011-05-01

    Full Text Available Abstract Background The human coagulation trigger tissue factor (TF is overexpressed in several types of cancer and involved in tumor growth, vascularization, and metastasis. To explore the role of TF in biological processes of lung adenocarcinoma, we used RNA interference (RNAi technology to silence TF in a lung adenocarcinoma cell line A549 with high-level expression of TF and evaluate its antitumor effects in vitro and in vivo. Methods The specific small interfering RNA (siRNA designed for targeting human TF was transfected into A549 cells. The expression of TF was detected by reverse transcription-PCR and Western blot. Cell proliferation was measured by MTT and clonogenic assays. Cell apoptosis was assessed by flow cytometry. The metastatic potential of A549 cells was determined by wound healing, the mobility and Matrigel invasion assays. Expressions of PI3K/Akt, Erk1/2, VEGF and MMP-2/-9 in transfected cells were detected by Western blot. In vivo, the effect of TF-siRNA on the growth of A549 lung adenocarcinoma xenografts in nude mice was investigated. Results TF -siRNA significantly reduced the expression of TF in the mRNA and protein levels. The down-regulation of TF in A549 cells resulted in the suppression of cell proliferation, invasion and metastasis and induced cell apoptosis in dose-dependent manner. Erk MAPK, PI3K/Akt pathways as well as VEGF and MMP-2/-9 expressions were inhibited in TF-siRNA transfected cells. Moreover, intratumoral injection of siRNA targeting TF suppressed the tumor growth of A549 cells in vivo model of lung adenocarcinoma. Conclusions Down-regulation of TF using siRNA could provide a potential approach for gene therapy against lung adenocarcinoma, and the antitumor effects may be associated with inhibition of Erk MAPK, PI3K/Akt pathways.

  3. Microphthalmia-associated transcription factor as the molecular target of cadmium toxicity in human melanocytes

    Energy Technology Data Exchange (ETDEWEB)

    Chantarawong, Wipa [Department of Molecular Biology and Applied Physiology, Tohoku University School of Medicine, Sendai (Japan); Inter Departmental Multidisciplinary Graduate Program in Bioscience, Faculty of Science, Kasetsart University, Bangkok (Thailand); Takeda, Kazuhisa; Sangartit, Weerapon; Yoshizawa, Miki [Department of Molecular Biology and Applied Physiology, Tohoku University School of Medicine, Sendai (Japan); Pradermwong, Kantimanee [Department of Zoology, Faculty of Science, Kasetsart University, Bangkok (Thailand); Shibahara, Shigeki, E-mail: shibahar@med.tohoku.ac.jp [Department of Molecular Biology and Applied Physiology, Tohoku University School of Medicine, Sendai (Japan)

    2014-11-28

    Highlights: • In human melanocytes, cadmium decreases the expression of MITF-M and tyrosinase and their mRNAs. • In human melanoma cells, cadmium decreases the expression of MITF-M protein and tyrosinase mRNA. • Expression of MITF-H is less sensitive to cadmium toxicity in melanocyte-linage cells. • Cadmium does not decrease the expression of MITF-H in retinal pigment epithelial cells. • MITF-M is the molecular target of cadmium toxicity in melanocytes. - Abstract: Dietary intake of cadmium is inevitable, causing age-related increase in cadmium accumulation in many organs, including hair, choroid and retinal pigment epithelium (RPE). Cadmium has been implicated in the pathogenesis of hearing loss and macular degeneration. The functions of cochlea and retina are maintained by melanocytes and RPE, respectively, and the differentiation of these pigment cells is regulated by microphthalmia-associated transcription factor (MITF). In the present study, we explored the potential toxicity of cadmium in the cochlea and retina by using cultured human melanocytes and human RPE cell lines. MITF consists of multiple isoforms, including melanocyte-specific MITF-M and widely expressed MITF-H. Levels of MITF-M protein and its mRNA in human epidermal melanocytes and HMV-II melanoma cells were decreased significantly by cadmium. In parallel with the MITF reduction, mRNA levels of tyrosinase, the key enzyme of melanin biosynthesis that is regulated by MITF-M, were also decreased. In RPE cells, however, the levels of total MITF protein, constituting mainly MITF-H, were not decreased by cadmium. We thus identify MITF-M as the molecular target of cadmium toxicity in melanocytes, thereby accounting for the increased risk of disability from melanocyte malfunction, such as hearing and vision loss among people with elevated cadmium exposure.

  4. Microphthalmia-associated transcription factor as the molecular target of cadmium toxicity in human melanocytes

    International Nuclear Information System (INIS)

    Chantarawong, Wipa; Takeda, Kazuhisa; Sangartit, Weerapon; Yoshizawa, Miki; Pradermwong, Kantimanee; Shibahara, Shigeki

    2014-01-01

    Highlights: • In human melanocytes, cadmium decreases the expression of MITF-M and tyrosinase and their mRNAs. • In human melanoma cells, cadmium decreases the expression of MITF-M protein and tyrosinase mRNA. • Expression of MITF-H is less sensitive to cadmium toxicity in melanocyte-linage cells. • Cadmium does not decrease the expression of MITF-H in retinal pigment epithelial cells. • MITF-M is the molecular target of cadmium toxicity in melanocytes. - Abstract: Dietary intake of cadmium is inevitable, causing age-related increase in cadmium accumulation in many organs, including hair, choroid and retinal pigment epithelium (RPE). Cadmium has been implicated in the pathogenesis of hearing loss and macular degeneration. The functions of cochlea and retina are maintained by melanocytes and RPE, respectively, and the differentiation of these pigment cells is regulated by microphthalmia-associated transcription factor (MITF). In the present study, we explored the potential toxicity of cadmium in the cochlea and retina by using cultured human melanocytes and human RPE cell lines. MITF consists of multiple isoforms, including melanocyte-specific MITF-M and widely expressed MITF-H. Levels of MITF-M protein and its mRNA in human epidermal melanocytes and HMV-II melanoma cells were decreased significantly by cadmium. In parallel with the MITF reduction, mRNA levels of tyrosinase, the key enzyme of melanin biosynthesis that is regulated by MITF-M, were also decreased. In RPE cells, however, the levels of total MITF protein, constituting mainly MITF-H, were not decreased by cadmium. We thus identify MITF-M as the molecular target of cadmium toxicity in melanocytes, thereby accounting for the increased risk of disability from melanocyte malfunction, such as hearing and vision loss among people with elevated cadmium exposure

  5. MicroRNA-214 suppresses gluconeogenesis by targeting activating transcriptional factor 4.

    Science.gov (United States)

    Li, Kai; Zhang, Jin; Yu, Junjie; Liu, Bin; Guo, Yajie; Deng, Jiali; Chen, Shanghai; Wang, Chunxia; Guo, Feifan

    2015-03-27

    Although the gluconeogenesis pathway is already a target for the treatment of type 2 diabetes, the potential role of microRNAs (miRNAs) in gluconeogenesis remains unclear. Here, we investigated the physiological functions of miR-214 in gluconeogenesis. The expression of miR-214 was suppressed by glucagon via protein kinase A signaling in primary hepatocytes, and miR-214 was down-regulated in the livers of fasted, high fat diet-induced diabetic and leptin receptor-mutated (db/db) mice. The overexpression of miR-214 in primary hepatocytes suppressed glucose production, and silencing miR-214 reversed this effect. Gluconeogenesis was suppressed in the livers of mice injected with an adenovirus expressing miR-214 (Ad-miR-214). Additionally, Ad-miR-214 alleviated high fat diet-induced elevation of gluconeogenesis and hyperglycemia. Furthermore, we found that activating transcription factor 4 (ATF4), a reported target of miR-214, can reverse the suppressive effect of miR-214 on gluconeogenesis in primary hepatocytes, and this suppressive effect was blocked in liver-specific ATF4 knock-out mice. ATF4 regulated gluconeogenesis via affecting forkhead box protein O1 (FOXO1) transcriptional activity. Finally, liver-specific miR-214 transgenic mice exhibited suppressed gluconeogenesis and reduced expression of ATF4, phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase in liver. Taken together, our results suggest that the miR-214-ATF4 axis is a novel pathway for the regulation of hepatic gluconeogenesis. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  6. MicroRNA-214 Suppresses Gluconeogenesis by Targeting Activating Transcriptional Factor 4*

    Science.gov (United States)

    Li, Kai; Zhang, Jin; Yu, Junjie; Liu, Bin; Guo, Yajie; Deng, Jiali; Chen, Shanghai; Wang, Chunxia; Guo, Feifan

    2015-01-01

    Although the gluconeogenesis pathway is already a target for the treatment of type 2 diabetes, the potential role of microRNAs (miRNAs) in gluconeogenesis remains unclear. Here, we investigated the physiological functions of miR-214 in gluconeogenesis. The expression of miR-214 was suppressed by glucagon via protein kinase A signaling in primary hepatocytes, and miR-214 was down-regulated in the livers of fasted, high fat diet-induced diabetic and leptin receptor-mutated (db/db) mice. The overexpression of miR-214 in primary hepatocytes suppressed glucose production, and silencing miR-214 reversed this effect. Gluconeogenesis was suppressed in the livers of mice injected with an adenovirus expressing miR-214 (Ad-miR-214). Additionally, Ad-miR-214 alleviated high fat diet-induced elevation of gluconeogenesis and hyperglycemia. Furthermore, we found that activating transcription factor 4 (ATF4), a reported target of miR-214, can reverse the suppressive effect of miR-214 on gluconeogenesis in primary hepatocytes, and this suppressive effect was blocked in liver-specific ATF4 knock-out mice. ATF4 regulated gluconeogenesis via affecting forkhead box protein O1 (FOXO1) transcriptional activity. Finally, liver-specific miR-214 transgenic mice exhibited suppressed gluconeogenesis and reduced expression of ATF4, phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase in liver. Taken together, our results suggest that the miR-214-ATF4 axis is a novel pathway for the regulation of hepatic gluconeogenesis. PMID:25657009

  7. The Glycoproteins of All Filovirus Species Use the Same Host Factors for Entry into Bat and Human Cells but Entry Efficiency Is Species Dependent.

    Directory of Open Access Journals (Sweden)

    Markus Hoffmann

    Full Text Available Ebola and marburgviruses, members of the family Filoviridae, can cause severe hemorrhagic fever in humans. The ongoing Ebola virus (EBOV disease epidemic in Western Africa claimed more than 11,300 lives and was associated with secondary cases outside Africa, demonstrating that filoviruses pose a global health threat. Bats constitute an important natural reservoir of filoviruses, including viruses of the recently identified Cuevavirus genus within the Filoviridae family. However, the interactions of filoviruses with bat cells are incompletely understood. Here, we investigated whether filoviruses employ different strategies to enter human and bat cells. For this, we examined host cell entry driven by glycoproteins (GP from all filovirus species into cell lines of human and fruit bat origin. We show that all GPs were able to mediate entry into human and most fruit bat cell lines with roughly comparable efficiency. In contrast, the efficiency of entry into the cell line EidNi/41 derived from a straw-colored fruit bat varied markedly between the GPs of different filovirus species. Furthermore, inhibition studies demonstrated that filoviruses employ the same host cell factors for entry into human, non-human primate and fruit bat cell lines, including cysteine proteases, two pore channels and NPC1 (Niemann-Pick C1 molecule. Finally, processing of GP by furin and the presence of the mucin-like domain in GP were dispensable for entry into both human and bat cell lines. Collectively, these results show that filoviruses rely on the same host cell factors for entry into human and fruit bat cells, although the efficiency of the usage of these factors might differ between filovirus species.

  8. Phenological patterns of Spodoptera Guenée, 1852 (Lepidoptera: Noctuidae) is more affected by ENSO than seasonal factors and host plant availability in a Brazilian Savanna

    Science.gov (United States)

    Piovesan, Mônica; Specht, Alexandre; Carneiro, Eduardo; Paula-Moraes, Silvana Vieira; Casagrande, Mirna Martins

    2017-09-01

    The identification of factors responsible for the population dynamics is fundamental for pest management, since losses can reach 18% of annual production. Besides regular seasonal environmental factors and crop managements, additional supra-annual meteorological phenomena can also affect population dynamics, although its relevance has been rarely investigated. Among crop pests, Spodoptera stands out due to its worldwide distribution, high degree of polyphagy, thus causing damages in several crops in the world. Aiming to distinguish the relevance of different factors shaping population dynamics of Spodoptera in an ecosystem constituted of dry and rainy seasons, the current study used circular statistics to identify phenological patterns and test if its population fluctuation is driven by El Niño-Southern Oscillation (ENSO) effect, seasonal meteorological parameters, and/or host plant availability. Samplings were done in an intercropping system, in the Brazilian Savanna, during the new moon cycles between July/2013 and June/2016. Species were recorded all year round, but demonstrated differently non-uniform distribution, being concentrated in different seasons of the year. Population fluctuations were mostly affected by the ENSO intensity, despite the contrasting seasonal meteorological variation or host plant availability in a 400-m radius. Studies involving the observation of supra-annual phenomena, although rare, reach similar conclusions in relation to Neotropical insect fauna. Therefore, it is paramount to have long-term sampling studies to obtain a more precise response of the pest populations towards the agroecosystem conditions.

  9. Interaction of CSFV E2 protein with swine host factors as detected by yeast two-hybrid system

    Science.gov (United States)

    E2 is one of the envelope glycoproteins of pestiviruses, including classical swine fever virus (CSFV) and bovine viral diarrhea virus (BVDV). E2 is involved in several critical functions, including virus entry into target cells, induction of a protective immune response and virulence in swine. Howev...

  10. Factor analysis of geochemical data from ore and host rocks of the uranium mineralization at Mika, N. E. Nigeria

    International Nuclear Information System (INIS)

    Funtua, I. I.

    1997-01-01

    The Mika uranium occurrence is located in one of a series of NW-NE trending shear zones which host uraniferous Jurassic rhyolitic dykes located in Pan-African brecciated granites within peraluminous granite complex of NE Nigeria. The bodies of mineralization are about 100 metres long and up to 4 metres thick. The U mineralization associated with the rhyolite dykes contains predominantly meta-autunite and apatite, while that of the brecciated granites displays variable mineralogy with meta-autunite, one or two generations of coffinite and colloformic, pitch blend in open veins. The mineralization is thought to be related to bimodel magmatism of the Burashika group and the reactivation of regional structures. Multivariate statistical evaluation of geochemical data of 28 elements/oxides in 296 host rock and mineralized samples from the surface and drill cores display a coherent association of [(U, Pb, Zn, Cu, P 2 O 5 , Fe 2 O 3 ) + Mo], [(CaO, Zr, Sr) +(Y, Mo, V, As)] and [(MgO, K 2 O) + (TiO 2 , Rb)] in the mineralized rocks; reflecting the presence of hamatized phosphate bearing ores in association with sulphide minerals and apatite in the granite rhyolites. A link of the mineralizing fluids with the emplacement of the rhyolites is implied from the striking resemblance between the above element association in mineralized rocks to those of the unmineralized rhyolites. A source of ore fluids over saturated in uranium and silica emanating from crystallizing rhyolitic melts which were expelled into faults and/or shear zones in the surrounding country rock is inferred

  11. Evaluation in medical education: A topical review of target parameters, data collection tools and confounding factors

    Directory of Open Access Journals (Sweden)

    Schiekirka, Sarah

    2015-09-01

    Full Text Available Background and objective: Evaluation is an integral part of education in German medical schools. According to the quality standards set by the German Society for Evaluation, evaluation tools must provide an accurate and fair appraisal of teaching quality. Thus, data collection tools must be highly reliable and valid. This review summarises the current literature on evaluation of medical education with regard to the possible dimensions of teaching quality, the psychometric properties of survey instruments and potential confounding factors.Methods: We searched Pubmed, PsycINFO and PSYNDEX for literature on evaluation in medical education and included studies published up until June 30, 2011 as well as articles identified in the “grey literature”. Results are presented as a narrative review.Results: We identified four dimensions of teaching quality: structure, process, teacher characteristics, and outcome. Student ratings are predominantly used to address the first three dimensions, and a number of reliable tools are available for this purpose. However, potential confounders of student ratings pose a threat to the validity of these instruments. Outcome is usually operationalised in terms of student performance on examinations, but methodological problems may limit the usability of these data for evaluation purposes. In addition, not all examinations at German medical schools meet current quality standards.Conclusion: The choice of tools for evaluating medical education should be guided by the dimension that is targeted by the evaluation. Likewise, evaluation results can only be interpreted within the context of the construct addressed by the data collection tool that was used as well as its specific confounding factors.

  12. Cell physiology regulation by hypoxia inducible factor-1: Targeting oxygen-related nanomachineries of hypoxic cells.

    Science.gov (United States)

    Eskandani, Morteza; Vandghanooni, Somayeh; Barar, Jaleh; Nazemiyeh, Hossein; Omidi, Yadollah

    2017-06-01

    Any dysfunctionality in maintaining the oxygen homeostasis by mammalian cells may elicit hypoxia/anoxia, which results in inescapable oxidative stress and possible subsequent detrimental impacts on certain cells/tissues with high demands to oxygen molecules. The ischemic damage in turn can trigger initiation of a number of diseases including organs ischemia, metabolic disorders, inflammatory diseases, different types of malignancies, and alteration in wound healing process. Thus, full comprehension of molecular mechanism(s) and cellular physiology of the oxygen homeostasis is the cornerstone of the mammalian cells metabolism, energetic pathways and health and disease conditions. An imbalance in oxygen content within the cellular microenvironment activates a cascade of molecular events that are often compensated, otherwise pathologic condition occurs through a complexed network of biomolecules. Hypoxia inducible factor-1 (HIF-1) plays a key transcriptional role in the adaptation of cell physiology in relation with the oxygen content within a cell. In this current study, we provide a comprehensive review on the molecular mechanisms of oxygen sensing and homeostasis and the impacts of HIF-1 in hypoxic/anoxic conditions. Moreover, different molecular and biochemical responses of the cells to the surrounding environment are discussed in details. Finally, modern technological approaches for targeting the hypoxia related proteins are articulated. Copyright © 2017. Published by Elsevier B.V.

  13. Radiolabeled Probes Targeting Hypoxia-Inducible Factor-1-Active Tumor Microenvironments

    Directory of Open Access Journals (Sweden)

    Masashi Ueda

    2014-01-01

    Full Text Available Because tumor cells grow rapidly and randomly, hypoxic regions arise from the lack of oxygen supply in solid tumors. Hypoxic regions in tumors are known to be resistant to chemotherapy and radiotherapy. Hypoxia-inducible factor-1 (HIF-1 expressed in hypoxic regions regulates the expression of genes related to tumor growth, angiogenesis, metastasis, and therapy resistance. Thus, imaging of HIF-1-active regions in tumors is of great interest. HIF-1 activity is regulated by the expression and degradation of its α subunit (HIF-1α, which is degraded in the proteasome under normoxic conditions, but escapes degradation under hypoxic conditions, allowing it to activate transcription of HIF-1-target genes. Therefore, to image HIF-1-active regions, HIF-1-dependent reporter systems and injectable probes that are degraded in a manner similar to HIF-1α have been recently developed and used in preclinical studies. However, no probe currently used in clinical practice directly assesses HIF-1 activity. Whether the accumulation of 18F-FDG or 18F-FMISO can be utilized as an index of HIF-1 activity has been investigated in clinical studies. In this review, the current status of HIF-1 imaging in preclinical and clinical studies is discussed.

  14. Diacetoxyscirpenol as a new anticancer agent to target hypoxia-inducible factor 1

    Science.gov (United States)

    Choi, Yong-Joon; Shin, Hyun-Woo; Chun, Yang-Sook; Leutou, Alain Simplice; Son, Byeng Wha; Park, Jong-Wan

    2016-01-01

    Hypoxia activates hypoxia-inducible factor 1, which promotes the progression of malignancy by stimulating angiogenesis and by augmenting the ability of tumors to survive. Thus, HIF-1 is one of the most compelling targets for treating cancers. The aim of this study was to find a small molecule that inhibits HIF-1 under hypoxia in cancer cells. 7,280 compounds in a chemical library were tested in a cancer cell line expressing luciferase HIF-dependently. Through three rounds of screening, we finally picked up a compound that originates from a marine bacterium parasitizing red alga. The antibiotic potently inhibited HIF-1 expression and its transcriptional activity in cancer cells exposed to hypoxia. Through two-step fractionation, diacetoxyscirpenol was purified and identified as a HIF-inhibiting ingredient. Mechanistically, diacetoxyscirpenol inhibits the synthesis of HIF-1α protein and also interferes with the dimerization of HIF-1α and ARNT. It attenuates HIF-mediated gene expression in cancer cells exposed to hypoxia, and by doing so reduces tumorigenic and angiogenic potentials of cancer cells. More importantly, diacetoxyscirpenol retarded tumor growth in mice, and reduced HIF-1α expression and vascular formation in the tumors. Overall, diacetoxyscirpenol is considered a potential drug deregulating the HIF-1 signaling pathway, and it could be beneficially employed for treating malignant tumors with hypoxic microenvironment. PMID:27613833

  15. Platelet-activating factor (PAF) receptor as a promising target for cancer cell repopulation after radiotherapy

    Science.gov (United States)

    da Silva-Jr, I A; Chammas, R; Lepique, A P; Jancar, S

    2017-01-01

    A major drawback of radiotherapy is the accelerated growth of the surviving tumor cells. Radiotherapy generates a variety of lipids that bind to the receptor for platelet-activating factor, expressed by cells in the tumor microenvironment. In the present study, using the TC-1 tumor cell line, we found that irradiation induced a twofold increase in receptor expression and generated agonists of receptor. Irradiated cells induced a 20-fold increase in live TC-1 proliferation in vitro. Furthermore, subcutaneous co-injection of irradiated TC-1 cells with TC-1 expressing luciferase (TC-1 fluc+) markedly increased TC-1 fluc+ proliferation in a receptor-dependent way. Moreover we used a human carcinoma cell line not expressing the PAF receptor (KBM) and the same cell transfected with the receptor gene (KBP). Following co-injection of live KBP cells with irradiated KBM in RAG mice, the tumor growth was significantly increased compared with tumor formed following co-injection of live KBM with irradiated KBM. This tumor cell repopulation correlated with increased infiltration of tumor-promoting macrophages (CD206+). We propose that receptor represents a possible target for improving the efficacy of radiotherapy through inhibition of tumor repopulation. PMID:28134937

  16. Orexin-corticotropin-releasing factor receptor heteromers in the ventral tegmental area as targets for cocaine.

    Science.gov (United States)

    Navarro, Gemma; Quiroz, César; Moreno-Delgado, David; Sierakowiak, Adam; McDowell, Kimberly; Moreno, Estefanía; Rea, William; Cai, Ning-Sheng; Aguinaga, David; Howell, Lesley A; Hausch, Felix; Cortés, Antonio; Mallol, Josefa; Casadó, Vicent; Lluís, Carme; Canela, Enric I; Ferré, Sergi; McCormick, Peter J

    2015-04-29

    Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R-OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R-OX1R heteromer. Cocaine binding to the σ1R-CRF1R-OX1R complex promotes a long-term disruption of the orexin-A-CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking. Copyright © 2015 the authors 0270-6474/15/356639-15$15.00/0.

  17. Orexin–Corticotropin-Releasing Factor Receptor Heteromers in the Ventral Tegmental Area as Targets for Cocaine

    Science.gov (United States)

    Navarro, Gemma; Quiroz, César; Moreno-Delgado, David; Sierakowiak, Adam; McDowell, Kimberly; Moreno, Estefanía; Rea, William; Cai, Ning-Sheng; Aguinaga, David; Howell, Lesley A.; Hausch, Felix; Cortés, Antonio; Mallol, Josefa; Casadó, Vicent; Lluís, Carme; Canela, Enric I.

    2015-01-01

    Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R–OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R–OX1R heteromer. Cocaine binding to the σ1R–CRF1R–OX1R complex promotes a long-term disruption of the orexin-A–CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking. PMID:25926444

  18. Circumvention of nuclear factor kappaB-induced chemoresistance by cytoplasmic-targeted anthracyclines.

    Science.gov (United States)

    Bilyeu, Jennifer D; Panta, Ganesh R; Cavin, Lakita G; Barrett, Christina M; Turner, Eddie J; Sweatman, Trevor W; Israel, Mervyn; Lothstein, Leonard; Arsura, Marcello

    2004-04-01

    Nuclear factor kappaB (NF-kappaB) has been implicated in inducible chemoresistance against anthracyclines. In an effort to improve the cytotoxicity of anthracyclines while reducing their cardiotoxic effects, we have developed a novel class of extranuclear-localizing 14-O-acylanthracyclines that bind to the phorbol ester/diacylglycerol-binding C1b domain of conventional and novel protein kinase C (PKC) isoforms, thereby promoting an apoptotic response. Because PKCs have been shown to be involved in NF-kappaB activation, in this report, we determined the mechanism of NF-kappaB activation by N-benzyladriamycin-14-valerate (AD 198) and N-benzyladriamycin-14-pivalate (AD 445), two novel 14-O-acylanthracylines. We show that the induction of NF-kappaB activity in response to drug treatment relies on the activation of PKC-delta and NF-kappaB-activating kinase (NAK), independent of ataxia telengectasia mutated and p53 activities. In turn, NAK activates the IKK complex through phosphorylation of the IKK-2 subunit. We find that neither NF-kappaB activation nor ectopic expression of Bcl-X(L) confers protection from AD 198-induced cell killing. Overall, our data indicate that activation of novel PKC isoforms by cytoplasmic-targeted 14-O-acylanthracyclines promotes an apoptotic response independent of DNA damage, which is unimpeded by inducible activation of NF-kappaB.

  19. Effects of a Workplace Intervention Targeting Psychosocial Risk Factors on Safety and Health Outcomes.

    Science.gov (United States)

    Hammer, Leslie B; Truxillo, Donald M; Bodner, Todd; Rineer, Jennifer; Pytlovany, Amy C; Richman, Amy

    2015-01-01

    The goal of this study was to test the effectiveness of a workplace intervention targeting work-life stress and safety-related psychosocial risk factors on health and safety outcomes. Data were collected over time using a randomized control trial design with 264 construction workers employed in an urban municipal department. The intervention involved family- and safety-supportive supervisor behavior training (computer-based), followed by two weeks of behavior tracking and a four-hour, facilitated team effectiveness session including supervisors and employees. A significant positive intervention effect was found for an objective measure of blood pressure at the 12-month follow-up. However, no significant intervention results were found for self-reported general health, safety participation, or safety compliance. These findings suggest that an intervention focused on supervisor support training and a team effectiveness process for planning and problem solving should be further refined and utilized in order to improve employee health with additional research on the beneficial effects on worker safety.

  20. Inhibition of fibroblasts reduced head and neck cancer growth by targeting fibroblast growth factor receptor.

    Science.gov (United States)

    Sweeny, Larissa; Liu, Zhiyong; Lancaster, William; Hart, Justin; Hartman, Yolanda E; Rosenthal, Eben L

    2012-07-01

    Head and neck squamous cell carcinoma (HNSCC) is a complex disease process involving interactions with carcinoma-associated fibroblasts and endothelial cells. We further investigated these relationships by suppressing stromal cell growth through the inhibition of fibroblast growth factor receptor (FGFR). Preclinical investigation. HNSCC cell lines (FADU, OSC19, Cal27, SCC1, SCC5, SCC22A), fibroblast (HS27), and endothelial cells (human umbilical vascular endothelial cell) were cultured individually or in coculture. Proliferation was assessed following treatment with a range of physiologic concentrations of FGFR inhibitor PD173074. Mice bearing established HNSCC xenografts were treated with PD173074 (12 mg/kg), and tumor histology was analyzed for stromal composition, proliferation (Ki67 staining), and apoptosis (TUNEL [terminal deoxynucleotidyl transferase dUTP nick end labeling] staining). In vitro, inhibition of FGFR with PD173074 dramatically reduced proliferation of fibroblasts and endothelial cells compared to untreated controls. However, HNSCC cell proliferation was not affected by inhibition of FGFR. When cocultured with fibroblasts, HNSCC cells proliferation increased by 15% to 80% (P fibroblast-enhanced tumor cell growth was suppressed by FGFR inhibition. Additionally, treatment of mice bearing HNSCC xenografts with PD173074 resulted in significant growth inhibition (P < .001). Additionally, those tumors from mice treated with PD173074 had a smaller stromal component, decreased proliferation, and increased apoptosis. Targeting the FGFR pathway in head and neck cancer acts through the stromal components to decrease HNSCC growth in vivo and in vitro. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

  1. Identification of the Drosophila Mes4 gene as a novel target of the transcription factor DREF

    Energy Technology Data Exchange (ETDEWEB)

    Suyari, Osamu; Ida, Hiroyuki [Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Yoshioka, Yasuhide; Kato, Yasuko; Hashimoto, Reina [Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Venture Laboratory, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Yamaguchi, Masamitsu, E-mail: myamaguc@kit.ac.jp [Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Insect Biomedical Research Center, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan)

    2009-05-01

    The Mes4 gene has been identified as one of the maternal Dorsal target genes in Drosophila. In the present study, we found a DNA replication-related element (DRE, 5'-TATCGATA) in the Mes4 promoter recognized by the DRE-binding factor (DREF). Luciferase transient expression assays in S2 cells using Mes4 promoter-luciferase fusion plasmids revealed that the DRE sequence is essential for Mes4 promoter activity. Requirement of DRE for Mes4 promoter activity was further confirmed by anti-{beta}-galactosidase antibody-staining of various tissues from transgenic flies carrying Mes4 promoter-lacZ fusion genes. Furthermore, wild type Mes4 promoter activity was decreased by 40% in DREF-depleted S2 cells. These results indicate that DREF positively regulates Mes4 gene expression. Band mobility shift analyses using Kc cell nuclear extracts further indicated that the DRE sequence in the Mes4 promoter is especially important for binding to DREF. Moreover, specific binding of DREF to the involved genomic region could be demonstrated by chromatin immunoprecipitation assays using anti-DREF antibodies. These results, taken together, indicate that the DRE/DREF system activates transcription of the Mes4 gene. In addition, knockdown of the Mes4 gene in wing imaginal discs using the GAL4-UAS system caused an atrophied wing phenotype, suggesting that Mes4 is required for wing morphogenesis.

  2. Targeting the centriolar replication factor STIL synergizes with DNA damaging agents for treatment of ovarian cancer

    Science.gov (United States)

    Rabinowicz, Noa; Mangala, Lingegowda S.; Brown, Kevin R.; Checa-Rodriguez, Cintia; Castiel, Asher; Moskovich, Oren; Zarfati, Giulia; Trakhtenbrot, Luba; Levy-Barda, Adva; Jiang, Dahai; Rodriguez-Aguayo, Cristian; Pradeep, Sunila; van Praag, Yael; Lopez-Berestein, Gabriel; David, Ahuvit; Novikov, Ilya; Huertas, Pablo; Rottapel, Robert; Sood, Anil K.; Izraeli, Shai

    2017-01-01

    Advanced ovarian cancer is an incurable disease. Thus, novel therapies are required. We wished to identify new therapeutic targets for ovarian cancer. ShRNA screen performed in 42 ovarian cancer cell lines identified the centriolar replication factor STIL as an essential gene for ovarian cancer cells. This was verified in-vivo in orthotopic human ovarian cancer mouse models. STIL depletion by administration of siRNA in neutral liposomes resulted in robust anti-tumor effect that was further enhanced in combination with cisplatin. Consistent with this finding, STIL depletion enhanced the extent of DNA double strand breaks caused by DNA damaging agents. This was associated with centrosomal depletion, ongoing genomic instability and enhanced formation of micronuclei. Interestingly, the ongoing DNA damage was not associated with reduced DNA repair. Indeed, we observed that depletion of STIL enhanced canonical homologous recombination repair and increased BRCA1 and RAD51 foci in response to DNA double strand breaks. Thus, inhibition of STIL significantly enhances the efficacy of DNA damaging chemotherapeutic drugs in treatment of ovarian cancer. PMID:28423708

  3. Pediatric spinal epidural abscess in an immunocompetent host without risk factors: Case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Alessandra Vergori

    2015-01-01

    The rarity and the possible differential diagnosis can lead to underestimate SEA occurrence in children without risk factors. It seems therefore essential to maintain a high attention to pediatric SEAs. A prompt diagnosis and adequate therapy are essential prognostic factors for remission.

  4. C7L family of poxvirus host range genes inhibits antiviral activities induced by type I interferons and interferon regulatory factor 1.

    Science.gov (United States)

    Meng, Xiangzhi; Schoggins, John; Rose, Lloyd; Cao, Jingxin; Ploss, Alexander; Rice, Charles M; Xiang, Yan

    2012-04-01

    Vaccinia virus (VACV) K1L and C7L function equivalently in many mammalian cells to support VACV replication and antagonize antiviral activities induced by type I interferons (IFNs). While K1L is limited to orthopoxviruses, genes that are homologous to C7L are found in diverse mammalian poxviruses. In this study, we showed that the C7L homologues from sheeppox virus and swinepox virus could rescue the replication defect of a VACV mutant deleted of both K1L and C7L (vK1L(-)C7L(-)). Interestingly, the sheeppox virus C7L homologue could rescue the replication of vK1L(-)C7L(-) in human HeLa cells but not in murine 3T3 and LA-4 cells, in contrast to all other C7L homologues. Replacing amino acids 134 and 135 of the sheeppox virus C7L homologue, however, made it functional in the two murine cell lines, suggesting that these two residues are critical for antagonizing a putative host restriction factor which has some subtle sequence variation in human and murine cells. Furthermore, the C7L family of host range genes from diverse mammalian poxviruses were all capable of antagonizing type I IFN-induced antiviral activities against VACV. Screening of a library of more than 350 IFN-stimulated genes (ISGs) identified interferon-regulated factor 1 (IRF1) as an inhibitor of vK1L(-)C7L(-) but not wild-type VACV. Expression of either K1L or C7L, however, rendered vK1L(-)C7L(-) resistant to IRF1-induced antiviral activities. Altogether, our data show that K1L and C7L antagonize IRF1-induced antiviral activities and that the host modulation function of C7L is evolutionally conserved in all poxviruses that can readily replicate in tissue-cultured mammalian cells.

  5. MC1R variation and melanoma risk in relation to host/clinical and environmental factors in CDKN2A positive and negative melanoma patients.

    Science.gov (United States)

    Ghiorzo, Paola; Bonelli, Luigina; Pastorino, Lorenza; Bruno, William; Barile, Monica; Andreotti, Virginia; Nasti, Sabina; Battistuzzi, Linda; Grosso, Marco; Bianchi-Scarrà, Giovanna; Queirolo, Paola

    2012-09-01

    Host, environmental and genetic factors differently modulate cutaneous melanoma (CM) risk across populations. Currently, the main genetic risk determinants are germline mutations in the major known high-risk susceptibility genes, CDKN2A and CDK4, and variants of the low-risk gene MC1R, which is key in the pigmentation process. This case-control study aimed at investigating the influence of the main host and environmental risk factors and of MC1R variation on CM risk in 390 CDKN2A-negative and 49 CDKN2A-positive Italian individuals. Multivariate analysis showed that MC1R variation, number of nevi and childhood sunburns doubled CM risk in CDKN2A-negative individuals. In CDKN2A-positive individuals, family history of CM and presence of atypical nevi, rather than MC1R status, modified risk (20.75- and 2.83-fold, respectively). Occupational sun exposure increased CM risk (three to sixfold) in both CDKN2A-negative and CDKN2A-positive individuals, reflecting the occupational habits of the Ligurian population and the geographical position of Liguria. © 2012 John Wiley & Sons A/S.

  6. Baculovirus DNA Replication-Specific Expression Factors Trigger Apoptosis and Shutoff of Host Protein Synthesis during Infection▿

    OpenAIRE

    Schultz, Kimberly L. W.; Friesen, Paul D.

    2009-01-01

    Apoptosis is an important antivirus defense. To define the poorly understood pathways by which invertebrates respond to viruses by inducing apoptosis, we have identified replication events that trigger apoptosis in baculovirus-infected cells. We used RNA silencing to ablate factors required for multiplication of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). Transfection with double-stranded RNA (dsRNA) complementary to the AcMNPV late expression factors (lefs) that are des...

  7. Decision factors for cooperative multiple warhead UAV target classification and attack with control applications

    Science.gov (United States)

    Decker, Douglas Dwayne

    Autonomous wide area search, classification and attack using Unmanned Combat Air Vehicles (UCAVs) is considered. The wide area search and attack scenario is modelled, capturing the important problem parameters of target density in the battle space, the density of false targets, the seeker and Autonomous Target Recognition (ATR) modules' performance parameters, as well as munition parameters such as search rate, time, and warhead lethality. The analysis in this research is an important stepping stone towards establishing benefits of cooperative search and engagement in a multi-vehicle scenario. This research uses probabilistic analysis to formulate and analytically solve for the probability of success in search and engagement as well as probabilities of other events of interest. Two methods are used to compute these probabilities. The first method utilizes a detailed examination of the sub-events required for the event of interest to occur. The second method utilizes a Markov chain approach. In each method, general expressions are first obtained that are applicable to any assumed a priori distributions of targets and false targets. These expressions are subsequently applied to a multiple warhead munition/UCAV operating in a single target/multiple false target scenario and then several multiple target/multiple false target scenarios. This research shows how the analytically derived results can be applied to all facets of the balanced system design and operation of Wide Area Search Munitions (WASM) including the evaluation of cooperation schemes and rules of engagement. This dissertation also formulates the problem as a control problem and examines the possibility of utilizing this formulation in the real-time estimation of the target and false target distribution parameters.

  8. Limonene inhibits streptococcal biofilm formation by targeting surface-associated virulence factors.

    Science.gov (United States)

    Subramenium, Ganapathy Ashwinkumar; Vijayakumar, Karuppiah; Pandian, Shunmugiah Karutha

    2015-08-01

    The present study explores the efficacy of limonene, a cyclic terpene found in the rind of citrus fruits, for antibiofilm potential against species of the genus Streptococcus, which have been deeply studied worldwide owing to their multiple pathogenic efficacy. Limonene showed a concentration-dependent reduction in the biofilm formation of Streptococcus pyogenes (SF370), with minimal biofilm inhibitory concentration (MBIC) of 400 μg ml - 1. Limonene was found to possess about 75-95 % antibiofilm activity against all the pathogens tested, viz. Streptococcus pyogenes (SF370 and 5 clinical isolates), Streptococcus mutans (UA159) and Streptococcus mitis (ATCC 6249) at 400 μg ml - 1 concentration. Microscopic analysis of biofilm architecture revealed a quantitative breach in biofilm formation. Results of a surface-coating assay suggested that the possible mode of action of limonene could be by inhibiting bacterial adhesion to surfaces, thereby preventing the biofilm formation cascade. Susceptibility of limonene-treated Streptococcus pyogenes to healthy human blood goes in unison with gene expression studies in which the mga gene was found to be downregulated. Anti-cariogenic efficacy of limonene against Streptococcus mutans was confirmed, with inhibition of acid production and downregulation of the vicR gene. Downregulation of the covR, mga and vicR genes, which play a critical role in regulating surface-associated proteins in Streptococcus pyogenes and Streptococcus mutans, respectively, is yet further evidence to show that limonene targets surface-associated proteins. The results of physiological assays and gene expression studies clearly show that the surface-associated antagonistic mechanism of limonene also reduces surface-mediated virulence factors.

  9. Targeting the epidermal growth factor receptor in radiotherapy: radiobiological mechanisms, preclinical and clinical results

    International Nuclear Information System (INIS)

    Baumann, Michael; Krause, Mechthild

    2004-01-01

    Background and purpose: Inhibition of the epidermal growth factor receptor (EGFR) is a fastly developing field in preclinical and clinical cancer research. This review presents the current status of knowledge and discusses radiobiological mechanisms which may underly the efficacy of EGFR inhibitors combined with irradiation. Materials and methods: Preclinical and clinical results on combined targeting of the EGFR and irradiation from the literature and from this laboratory are reviewed. Focus is given to the radiobiological rationale of this approach and to endpoints of experimental radiotherapy. Results: Overexpression of the EGFR is associated with decreased local tumour control after radiotherapy, especially when the overall treatment time is long. Inhibition of the EGFR either alone or in combination with irradiation decreases the growth rate of tumours expressing this receptor. Preclinical data provide proof-of-principle that local tumour control may be improved by combining irradiation with C225 mAb. In a randomised phase III clinical trial, simultaneous irradiation and treatment with the EGFR antibody Cetuximab (Erbitux[reg]; C225) in head and neck cancer patients resulted in significantly improved locoregional tumour control and survival compared to curative irradiation alone. Acute skin reactions increased in the experimental arm. The underlying mechanisms of enhanced radiation effects of combined EGFR inhibition with irradiation and of the partly conflicting results in different studies are poorly understood. There is increasing evidence, that important intertumoral heterogeneity in the response to EGFR inhibition alone and combined with irradiation exists, which appears to be at least partly dependent on specific mutations of the receptor as well as of molecules that are involved in the intracellular signal transduction pathway. Conclusions and outlook: Further investigations at all levels of the translational research chain exploring the mechanisms of

  10. Characterization of the Wheat Stripe Rust (Puccinia striiformis f. sp. tritici) Fungal Effector Candidate PEC6 and Its Corresponding Host Targets

    DEFF Research Database (Denmark)

    Liu, Changhai

    Stripe rust caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most important fungal diseases on wheat worldwide and a serious threat to wheat production. Understanding the plant-microbe interaction mechanism is the basic step to assist future plant breeding aiming at increasing...... disease resistance. Based on the sequenced stripe rust fungus genome, several hundreds of small, secreted candidates for effector proteins are predicted. Effectors are believed to be pivotal for fungal pathogenicity with key roles in suppressing host defense. Thus, identifying key effectors...... and understanding their mechanisms of action is fundamentally important to guide future fights against the stripe rust disease. In this PhD project, I studied the potential function of six stripe rust fungal effector candidates which are highly expressed in haustoria, by employing the Pseudomonas fluorescens Et...

  11. Anti-tumor necrosis factor-a for the treatment of steroid-refractory acute graft-versus-host disease

    Directory of Open Access Journals (Sweden)

    M.C. Nogueira

    2007-12-01

    Full Text Available Allogeneic stem cell transplantation has been increasingly performed for a variety of hematologic diseases. Clinically significant acute graft-versus-host disease (GVHD occurs in 9 to 50% of patients who receive allogeneic grafts, resulting in high morbidity and mortality. There is no standard therapy for patients with acute GVHD who do not respond to steroids. Studies have shown a possible benefit of anti-TNF-a (infliximabfor the treatment of acute GVHD. We report here on the outcomes of 10 recipients of related or unrelated stem cell transplants who received 10 mg/kg infliximab, iv, once weekly for a median of 3.5 doses (range: 1-6 for the treatment of severe acute GVHD and who were not responsive to standard therapy. All patients had acute GVHD grades II to IV (II = 2, III = 3, IV = 5. Overall, 9 patients responded and 1 patient had progressive disease. Among the responders, 3 had complete responses and 6 partial responses. All patients with cutaneous or gastrointestinal involvement responded, while only 2 of 6 patients with liver disease showed any response. None of the 10 patients had any kind of immediate toxicity. Four patients died, all of them with sepsis. Six patients are still alive after a median follow-up time of 544 days (92-600 after transplantation. Considering the severity of the cases and the bad prognosis associated with advanced acute GVHD, we find our results encouraging. Anti-TNF-a seems to be a useful agent for the treatment of acute GVHD.

  12. Identification of a New Host Factor Required for Antiviral RNAi and Amplification of Viral siRNAs.

    Science.gov (United States)

    Guo, Zhongxin; Wang, Xian-Bing; Wang, Ying; Li, Wan-Xiang; Gal-On, Amit; Ding, Shou-Wei

    2018-02-01

    Small interfering RNAs (siRNAs) are processed from virus-specific dsRNA to direct antiviral RNA interference (RNAi) in diverse eukaryotic hosts. We have recently performed a sensitized genetic screen in Arabidopsis ( Arabidopsis thaliana ) and identified two related phospholipid flippases required for antiviral RNAi and the amplification of virus-derived siRNAs by plant RNA-dependent RNA polymerase1 (RDR1) and RDR6. Here we report the identification and cloning of ANTIVIRAL RNAI - DEFECTIVE2 ( AVI2 ) from the same genetic screen. AVI2 encodes a multispan transmembrane protein broadly conserved in plants and animals with two homologous human proteins known as magnesium transporters. We show that avi2 mutant plants display no developmental defects and develop severe disease symptoms after infection with a mutant Cucumber mosaic virus (CMV) defective in RNAi suppression. AVI2 is induced by CMV infection, particularly in veins, and is required for antiviral RNAi and RDR6-dependent biogenesis of viral siRNAs. AVI2 is also necessary for Dicer-like2-mediated amplification of 22-nucleotide viral siRNAs induced in dcl4 mutant plants by infection, but dispensable for RDR6-dependent biogenesis of endogenous transacting siRNAs. Further genetic studies illustrate that AVI2 plays a partially redundant role with AVI2H, the most closely related member in the AVI2 gene family, in RDR1-dependent biogenesis of viral siRNAs and the endogenous virus-activated siRNAs (vasi-RNAs). Interestingly, we discovered a specific genetic interaction of AVI2 with AVI1 flippase that is critical for plant development. We propose that AVI1 and AVI2 participate in the virus-induced formation of the RDR1/RDR6-specific, membrane-bound RNA synthesis compartment, essential for the biogenesis of highly abundant viral siRNAs and vasi-RNAs. © 2018 American Society of Plant Biologists. All Rights Reserved.

  13. HostPhinder: A Phage Host Prediction Tool

    Directory of Open Access Journals (Sweden)

    Julia Villarroel

    2016-05-01

    Full Text Available The current dramatic increase of antibiotic resistant bacteria has revitalised the interest in bacteriophages as alternative antibacterial treatment. Meanwhile, the development of bioinformatics methods for analysing genomic data places high-throughput approaches for phage characterization within reach. Here, we present HostPhinder, a tool aimed at predicting the bacterial host of phages by examining the phage genome sequence. Using a reference database of 2196 phages with known hosts, HostPhinder predicts the host species of a query phage as the host of the most genomically similar reference phages. As a measure of genomic similarity the number of co-occurring k-mers (DNA sequences of length k is used. Using an independent evaluation set, HostPhinder was able to correctly predict host genus and species for 81% and 74% of the phages respectively, giving predictions for more phages than BLAST and significantly outperforming BLAST on phages for which both had predictions. HostPhinder predictions on phage draft genomes from the INTESTI phage cocktail corresponded well with the advertised targets of the cocktail. Our study indicates that for most phages genomic similarity correlates well with related bacterial hosts. HostPhinder is available as an interactive web service [1] and as a stand alone download from the Docker registry [2].

  14. Comparing mechanisms of host manipulation across host and parasite taxa

    Science.gov (United States)

    Lafferty, Kevin D.; Shaw, Jenny C.

    2013-01-01

    Parasites affect host behavior in several ways. They can alter activity, microhabitats or both. For trophically transmitted parasites (the focus of our study), decreased activity might impair the ability of hosts to respond to final-host predators, and increased activity and altered microhabitat choice might increase contact rates between hosts and final-host predators. In an analysis of trophically transmitted parasites, more parasite groups altered activity than altered microhabitat choice. Parasites that infected vertebrates were more likely to impair the host’s reaction to predators, whereas parasites that infected invertebrates were more likely to increase the host’s contact with predators. The site of infection might affect how parasites manipulate their hosts. For instance, parasites in the central nervous system seem particularly suited to manipulating host behavior. Manipulative parasites commonly occupy the body cavity, muscles and central nervous systems of their hosts. Acanthocephalans in the data set differed from other taxa in that they occurred exclusively in the body cavity of invertebrates. In addition, they were more likely to alter microhabitat choice than activity. Parasites in the body cavity (across parasite types) were more likely to be associated with increased host contact with predators. Parasites can manipulate the host through energetic drain, but most parasites use more sophisticated means. For instance, parasites target four physiological systems that shape behavior in both invertebrates and vertebrates: neural, endocrine, neuromodulatory and immunomodulatory. The interconnections between these systems make it difficult to isolate specific mechanisms of host behavioral manipulation.

  15. Same host, same lagoon, different transmission pathways: effects of exogenous factors on larval emergence in two marine digenean parasites

    Czech Academy of Sciences Publication Activity Database

    Born-Torrijos, A.; Raga, J. A.; Holzer, Astrid S.; Kostadinova, Aneta

    2014-01-01

    Roč. 113, č. 2 (2014), s. 545-554 ISSN 0932-0113 R&D Projects: GA ČR GAP505/10/1562 Institutional support: RVO:60077344 Keywords : patterns * water * life-cycles Subject RIV: EH - Ecology, Behaviour Impact factor: 2.098, year: 2014

  16. The efficacy of targeted interventions for modifiable psychosocial risk factors of persistent nonspecific low back pain e A systematic review

    DEFF Research Database (Denmark)

    Kent, Peter; Kjær, Per

    2012-01-01

    were randomised controlled trials of targeted psychosocial interventions that used trial designs capable of providing robust information on the efficacy of targeted treatment (treatment effect modification) for the outcomes of pain, activity limitation and psychosocial factors (fear avoidance......, catastrophisation, anxiety and depression). Results and conclusion: Four studies met the inclusion criteria and collectively investigated nine hypotheses about targeted treatment on 28 subgroup/treatment outcomes. There were only two statistically significant results. Graded activity plus Treatment Based...... Classification targeted to people with high movement-related fear was more effective than Treatment Based Classification at reducing movement-related fear at 4 weeks. Active rehabilitation (physical exercise classes with cognitivebehavioural principles) was more effective than usual GP care at reducing activity...

  17. Whole-Genome Sequencing of Invasion-Resistant Cells Identifies Laminin α2 as a Host Factor for Bacterial Invasion

    DEFF Research Database (Denmark)

    van Wijk, Xander M.; Döhrmann, Simon; Hallstrom, Bjorn

    2017-01-01

    To understand the role of glycosaminoglycans in bacterial cellular invasion, xylosyltransferase-deficient mutants of Chinese hamster ovary (CHO) cells were created using clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated gene 9 (CRISPR-cas9) gene targeting. When...... these mutants were compared to the pgsA745 cell line, a CHO xylosyltransferase mutant generated previously using chemical mutagenesis, an unexpected result was obtained. Bacterial invasion of pgsA745 cells by group B Streptococcus (GBS), group A Streptococcus, and Staphylococcus aureus was markedly reduced...... compared to the invasion of wild-type cells, but newly generated CRISPR-cas9 mutants were only resistant to GBS. Invasion of pgsA745 cells was not restored by transfection with xylosyltransferase, suggesting that an additional mutation conferring panresistance to multiple bacteria was present in pgsA745...

  18. Inhibition of human immunodeficiency virus type 1 replication with artificial transcription factors targeting the highly conserved primer-binding site

    NARCIS (Netherlands)

    Eberhardy, Scott R.; Goncalves, Joao; Coelho, Sofia; Segal, David J.; Berkhout, Ben; Barbas, Carlos F.

    2006-01-01

    The human immunodeficiency virus type 1 (HIV-1) primer-binding site (PBS) is a highly conserved region in the HIV genome and represents an attractive target for the development of new anti-HIV therapies. In this study, we designed four artificial zinc finger transcription factors to bind at or

  19. Magnesium wasting associated with epidermal-growth-factor receptor-targeting antibodies in colorectal cancer: a prospective study.

    NARCIS (Netherlands)

    Tejpar, S.; Piessevaux, H.; Claes, K.; Piront, P.; Hoenderop, J.G.J.; Verslype, C.; Cutsem, E. van

    2007-01-01

    BACKGROUND: Preliminary evidence suggests that magnesium wasting occurs in patients who are treated with epidermal-growth-factor receptor (EGFR)-targeting antibodies for colorectal cancer. The mechanism of this side-effect is unknown, and if all or a subset of patients are affected is also unclear.

  20. Imported falciparum malaria in adults: host- and parasite-related factors associated with severity. The French prospective multicenter PALUREA cohort study.

    Science.gov (United States)

    Bruneel, Fabrice; Tubach, Florence; Mira, Jean-Paul; Houze, Sandrine; Gibot, Sebastien; Huisse, Marie-Genevieve; Megarbane, Bruno; Choquet, Christophe; Corne, Philippe; Peytel, Eric; Villers, Daniel; Camus, Christophe; Bouchaud, Olivier; Caumes, Eric; Girard, Pierre-Marie; Simon, Fabrice; Kalloumeh, Antoine; Roy, Carine; Durand, Remy; Le Bras, Jacques; Matheron, Sophie; Wolff, Michel

    2016-10-01

    Prospective data on potential factors associated with severity of imported Plasmodium falciparum malaria are lacking. We evaluated whether several host- and parasite-related biomarkers may improve early severity evaluation. Prospective multicenter observational study comparing uncomplicated and severe imported falciparum malaria in adults conducted in France in 52 units, from 2007 to 2010. Association of several host- and parasite-related biomarkers with severity of malaria was tested using univariate and multivariate analyses. Of 295 patients, 140 had uncomplicated malaria and 155 severe malaria (including very severe and less severe cases according to predefined criteria). Curative intravenous quinine treatment was used in 154/155 patients with severe malaria and atovaquone/proguanil in 74 % of patients with uncomplicated malaria. Hospital mortality was 5.2 % (8 patients), all in the severe malaria group. Among host-related biomarkers, CRP, procalcitonin, and sTREM-1 were significantly higher and albumin was significantly lower in severe versus uncomplicated malaria; only the last three biomarkers also differed significantly between the very and less severe malaria groups. Among parasite-related biomarkers, only plasma PfHRP2 was significantly higher in severe versus uncomplicated malaria and in very severe versus less severe malaria; parasitemia did not differ between very and less severe malaria. By multivariate analysis, only lower plasma albumin and higher sTREM-1 were associated with greater severity, with intermediate accuracies. During imported malaria, the most useful biomarkers associated with severity seem to be plasma albumin and sTREM-1; and among parasite-related parameters, PfHRP2 was more strongly associated with severity than parasitemia was.

  1. Yip1A, a Novel Host Factor for the Activation of the IRE1 Pathway of the Unfolded Protein Response during Brucella Infection

    Science.gov (United States)

    Taguchi, Yuki; Imaoka, Koichi; Kataoka, Michiyo; Uda, Akihiko; Nakatsu, Daiki; Horii-Okazaki, Sakuya; Kunishige, Rina; Kano, Fumi; Murata, Masayuki

    2015-01-01

    Brucella species replicate within host cells in the form of endoplasmic reticulum (ER)-derived vacuoles. The mechanisms by which the bacteria are sequestered into such vacuoles and obtain a continuous membrane supply for their replication remain to be elucidated. In the present study, we provided several lines of evidence that demonstrate the mechanism by which B. abortus acquires the ER-derived membrane. First, during Brucella infection, the IRE1 pathway, but not the PERK and ATF6 pathways, of the unfolded protein response (UPR) was activated in a time-dependent manner, and the COPII vesicle components Sar1, Sec23, and Sec24D were upregulated. Second, a marked accretion of ER-derived vacuoles was observed around replicating bacteria using fluorescent microscopy and electron microscopy. Third, we identified a novel host factor, Yip1A, for the activation of the IRE1 pathway in response to both tunicamycin treatment and infection with B. abortus. We found that Yip1A is responsible for the phosphorylation of IRE1 through high-order assembly of Ire1 molecules at ER exit sites (ERES) under the UPR conditions. In Yip1A-knockdown cells, B. abortus failed to generate the ER-derived vacuoles, and remained in endosomal/lysosomal compartments. These results indicate that the activation of the IRE1 pathway and the subsequent formation of ER-derived vacuoles are critical for B. abortus to establish a safe replication niche, and that Yip1A is indispensable for these processes. Furthermore, we showed that the autophagy-related proteins Atg9 and WIPI1, but not DFCP1, were required for the biogenesis of the ER-derived membrane compartments.  On the basis of our findings, we propose a model for intracellular Brucella replication that exploits the host UPR and ER-derived vacuole formation machineries, both of which depend on Yip1A-mediated IRE1 activation. PMID:25742138

  2. Hypoxia-Independent Downregulation of Hypoxia-Inducible Factor 1 Targets by Androgen Deprivation Therapy in Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Ragnum, Harald Bull [Department of Radiation Biology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Røe, Kathrine [Department of Radiation Biology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Division of Medicine, Department of Oncology, Akershus University Hospital, Lørenskog (Norway); Holm, Ruth; Vlatkovic, Ljiljana [Department of Pathology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Nesland, Jahn Marthin [Department of Pathology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Medical Faculty, University of Oslo, Oslo (Norway); Aarnes, Eva-Katrine [Department of Radiation Biology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Ree, Anne Hansen [Division of Medicine, Department of Oncology, Akershus University Hospital, Lørenskog (Norway); Medical Faculty, University of Oslo, Oslo (Norway); Flatmark, Kjersti [Department of Tumor Biology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Department of Gastrointestinal Surgery, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Seierstad, Therese [Department of Radiology and Nuclear Medicine, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Faculty of Health Sciences, Buskerud University College, Drammen (Norway); Lilleby, Wolfgang [Department of Oncology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway); Lyng, Heidi, E-mail: heidi.lyng@rr-research.no [Department of Radiation Biology, The Norwegian Radium Hospital, Oslo University Hospital, Oslo (Norway)

    2013-11-15

    Purpose: We explored changes in hypoxia-inducible factor 1 (HIF1) signaling during androgen deprivation therapy (ADT) of androgen-sensitive prostate cancer xenografts under conditions in which no significant change in immunostaining of the hypoxia marker pimonidazole had occurred. Methods and Materials: Gene expression profiles of volume-matched androgen-exposed and androgen-deprived CWR22 xenografts, with similar pimonidazole-positive fractions, were compared. Direct targets of androgen receptor (AR) and HIF1 transcription factors were identified among the differentially expressed genes by using published lists. Biological processes affected by ADT were determined by gene ontology analysis. HIF1α protein expression in xenografts and biopsy samples from 35 patients receiving neoadjuvant ADT was assessed by immunohistochemistry. Results: A total of 1344 genes showed more than 2-fold change in expression by ADT, including 35 downregulated and 5 upregulated HIF1 targets. Six genes were shared HIF1 and AR targets, and their downregulation was confirmed with quantitative RT-PCR. Significant suppression of the biological processes proliferation, metabolism, and stress response in androgen-deprived xenografts was found, consistent with tumor regression. Nineteen downregulated HIF1 targets were involved in those significant biological processes, most of them in metabolism. Four of these were shared AR and HIF1 targets, including genes encoding the regulatory glycolytic proteins HK2, PFKFB3, and SLC2A1. Most of the downregulated HIF1 targets were induced by hypoxia in androgen-responsive prostate cancer cell lines, confirming their role as hypoxia-responsive HIF1 targets in prostate cancer. Downregulation of HIF1 targets was consistent with the absence of HIF1α protein in xenografts and downregulation in patients by ADT (P<.001). Conclusions: AR repression by ADT may lead to downregulation of HIF1 signaling independently of hypoxic fraction, and this may contribute to

  3. Hypoxia-Independent Downregulation of Hypoxia-Inducible Factor 1 Targets by Androgen Deprivation Therapy in Prostate Cancer

    International Nuclear Information System (INIS)

    Ragnum, Harald Bull; Røe, Kathrine; Holm, Ruth; Vlatkovic, Ljiljana; Nesland, Jahn Marthin; Aarnes, Eva-Katrine; Ree, Anne Hansen; Flatmark, Kjersti; Seierstad, Therese; Lilleby, Wolfgang; Lyng, Heidi

    2013-01-01

    Purpose: We explored changes in hypoxia-inducible factor 1 (HIF1) signaling during androgen deprivation therapy (ADT) of androgen-sensitive prostate cancer xenografts under conditions in which no significant change in immunostaining of the hypoxia marker pimonidazole had occurred. Methods and Materials: Gene expression profiles of volume-matched androgen-exposed and androgen-deprived CWR22 xenografts, with similar pimonidazole-positive fractions, were compared. Direct targets of androgen receptor (AR) and HIF1 transcription factors were identified among the differentially expressed genes by using published lists. Biological processes affected by ADT were determined by gene ontology analysis. HIF1α protein expression in xenografts and biopsy samples from 35 patients receiving neoadjuvant ADT was assessed by immunohistochemistry. Results: A total of 1344 genes showed more than 2-fold change in expression by ADT, including 35 downregulated and 5 upregulated HIF1 targets. Six genes were shared HIF1 and AR targets, and their downregulation was confirmed with quantitative RT-PCR. Significant suppression of the biological processes proliferation, metabolism, and stress response in androgen-deprived xenografts was found, consistent with tumor regression. Nineteen downregulated HIF1 targets were involved in those significant biological processes, most of them in metabolism. Four of these were shared AR and HIF1 targets, including genes encoding the regulatory glycolytic proteins HK2, PFKFB3, and SLC2A1. Most of the downregulated HIF1 targets were induced by hypoxia in androgen-responsive prostate cancer cell lines, confirming their role as hypoxia-responsive HIF1 targets in prostate cancer. Downregulation of HIF1 targets was consistent with the absence of HIF1α protein in xenografts and downregulation in patients by ADT (P<.001). Conclusions: AR repression by ADT may lead to downregulation of HIF1 signaling independently of hypoxic fraction, and this may contribute to

  4. Bevacizumab reduces tumor targeting of antiepidermal growth factor and anti-insulin-like growth factor 1 receptor antibodies

    NARCIS (Netherlands)

    Heskamp, Sandra; Boerman, Otto C.; Molkenboer-Kuenen, Janneke D. M.; Oyen, Wim J. G.; van der Graaf, Winette T. A.; van Laarhoven, Hanneke W. M.

    2013-01-01

    Bevacizumab (antivascular endothelial growth factor [anti-VEGF]) and cetuximab (antiepidermal growth factor receptor [anti-EGFR]) are approved antibodies for treatment of cancer. However, in advanced colorectal cancer, the combination fails to improve survival. As the reason for the lack of activity

  5. Environmental factors regulate Paneth cell phenotype and host susceptibility to intestinal inflammation in Irgm1-deficient mice

    Directory of Open Access Journals (Sweden)

    Allison R. Rogala

    2018-02-01

    Full Text Available Crohn's disease (CD represents a chronic inflammatory disorder of the intestinal tract. Several susceptibility genes have been linked to CD, though their precise role in the pathogenesis of this disorder remains unclear. Immunity-related GTPase M (IRGM is an established risk allele in CD. We have shown previously that conventionally raised (CV mice lacking the IRGM ortholog, Irgm1 exhibit abnormal Paneth cells (PCs and increased susceptibility to intestinal injury. In the present study, we sought to utilize this model system to determine if environmental conditions impact these phenotypes, as is thought to be the case in human CD. To accomplish this, wild-type and Irgm1−/− mice were rederived into specific pathogen-free (SPF and germ-free (GF conditions. We next assessed how these differential housing environments influenced intestinal injury patterns, and epithelial cell morphology and function in wild-type and Irgm1−/− mice. Remarkably, in contrast to CV mice, SPF Irgm1−/− mice showed only a slight increase in susceptibility to dextran sodium sulfate-induced inflammation. SPF Irgm1−/− mice also displayed minimal abnormalities in PC number and morphology, and in antimicrobial peptide expression. Goblet cell numbers and epithelial proliferation were also unaffected by Irgm1 in SPF conditions. No microbial differences were observed between wild-type and Irgm1−/− mice, but gut bacterial communities differed profoundly between CV and SPF mice. Specifically, Helicobacter sequences were significantly increased in CV mice; however, inoculating SPF Irgm1−/− mice with Helicobacter hepaticus was not sufficient to transmit a pro-inflammatory phenotype. In summary, our findings suggest the impact of Irgm1-deficiency on susceptibility to intestinal inflammation and epithelial function is critically dependent on environmental influences. This work establishes the importance of Irgm1−/− mice as a model to elucidate host

  6. The B-domain of factor VIII reduces cell membrane attachement to host cells in serum free conditions

    DEFF Research Database (Denmark)

    Kolind, Mille Petersen; Nørby, Peder Lisby; Flintegaard, Thomas Veje

    2010-01-01

    binding of rFVIII to the cell membrane could be a factor diminishing the production yield. We studied the contribution of the rFVIII B-domain to membrane attachment by transfecting several constructs containing increasing lengths of the B-domain into cells under serum free conditions. We found that 90......Factor VIII (FVIII) is an important protein in the blood coagulation cascade and dysfunction or deficiency of FVIII causes haemophilia A. Replacement therapy with exogenous recombinant FVIII (rFVIII) works as a substitute for the missing or non-functioning FVIII. The rFVIII protein has been...... engineered extensively throughout the years to increase the low production yields that initially were obtained from mammalian cell cultures. The scope of this work was to investigate the interaction of rFVIII with the cell membrane surface of the producing cells in serum free medium. We wondered whether...

  7. Genome-wide association study identifies vitamin B5 biosynthesis as a host specificity factor in Campylobacter

    OpenAIRE

    Sheppard, Samuel K.; Didelot, Xavier; Meric, Guillaume; Torralbo, Alicia; Jolley, Keith A.; Kelly, David J.; Bentley, Stephen D.; Maiden, Martin C. J.; Parkhill, Julian; Falush, Daniel

    2013-01-01

    Genome-wide association studies have the potential to identify causal genetic factors underlying important phenotypes but have rarely been performed in bacteria. We present an association mapping method that takes into account the clonal population structure of bacteria and is applicable to both core and accessory genome variation. Campylobacter is a common cause of human gastroenteritis as a consequence of its proliferation in multiple farm animal species and its transmission via contaminate...

  8. HER-2 as a Progression Factor and Therapeutic Target in Breast Cancer

    National Research Council Canada - National Science Library

    1999-01-01

    ...). We had observed previously that upon reduction of llER-2 in MCF-7 cells by ribozyme-targeting estradiol lost its ability to induce anchorage- independent colony formation in soft agar of the tumor cell...

  9. Interleukin 21 blockade modulates activated T- and B-cell homeostasis via B-cell activating factor pathway-mediated inhibition in a murine model of acute graft-versus-host disease.

    Science.gov (United States)

    Lim, Jung-Yeon; Park, Min-Jung; Im, Keon-Il; Kim, Nayoun; Park, Hyun-Sil; Lee, Sung-Hee; Kim, Eun-Kung; Nam, Young-Sun; Lee, Eun-Sol; Cho, Mi-La; Cho, Seok-Goo

    2015-01-01

    Interleukin (IL) 21 plays a key role in the development of acute graft-versus-host disease (GVHD) after allogeneic bone marrow transplantation. Therapeutic manipulation of IL-21 activity may improve acute GVHD during the early-posttransplant period. We investigated the mechanisms regulating T- and B-cells during IL-21 blockade in acute GVHD. Interleukin 21 blockade enhanced regulatory T and T helper (Th) 2 cell differentiation and inhibited Th1- and Th17-derived transcription factors and cytokines as a modulator of activated T-cells. Interleukin 21(-/-) cell recipients showed increased mature B- and marginal-zone B-cells, but decreased memory B-cells, germinal center formation, and plasma cells that did not lead to immunoglobulin production. B-cell activating factor (BAFF) and a proliferation-inducing ligand (APRIL) are involved in the induction and maintenance of T- and B-cell responses. We observed decreased levels of only BAFF during acute GVHD and confirmed that mammalian target of rapamycin complex 1 was reduced by the BAFF/BAFF-receptor pathway. Therefore, this study suggests that IL-21 blockade modulates activated T- and B-cell homeostasis via BAFF-pathway-mediated inhibition in acute GVHD following murine allogeneic bone marrow transplantation. Copyright © 2015 ISEH - International Society for Experimental Hematology. Published by Elsevier Inc. All rights reserved.

  10. Effectiveness of a selective alcohol prevention program targeting personality risk factors: Results of interaction analyses.

    Science.gov (United States)

    Lammers, Jeroen; Goossens, Ferry; Conrod, Patricia; Engels, Rutger; Wiers, Reinout W; Kleinjan, Marloes

    2017-08-01

    To explore whether specific groups of adolescents (i.e., scoring high on personality risk traits, having a lower education level, or being male) benefit more from the Preventure intervention with regard to curbing their drinking behaviour. A clustered randomized controlled trial, with participants randomly assigned to a 2-session coping skills intervention or a control no-intervention condition. Fifteen secondary schools throughout The Netherlands; 7 schools in the intervention and 8 schools in the control condition. 699 adolescents aged 13-15; 343 allocated to the intervention and 356 to the control condition; with drinking experience and elevated scores in either negative thinking, anxiety sensitivity, impulsivity or sensation seeking. Differential effectiveness of the Preventure program was examined for the personality traits group, education level and gender on past-month binge drinking (main outcome), binge frequency, alcohol use, alcohol frequency and problem drinking, at 12months post-intervention. Preventure is a selective school-based alcohol prevention programme targeting personality risk factors. The comparator was a no-intervention control. Intervention effects were moderated by the personality traits group and by education level. More specifically, significant intervention effects were found on reducing alcohol use within the anxiety sensitivity group (OR=2.14, CI=1.40, 3.29) and reducing binge drinking (OR=1.76, CI=1.38, 2.24) and binge drinking frequency (β=0.24, p=0.04) within the sensation seeking group at 12months post-intervention. Also, lower educated young adolescents reduced binge drinking (OR=1.47, CI=1.14, 1.88), binge drinking frequency (β=0.25, p=0.04), alcohol use (OR=1.32, CI=1.06, 1.65) and alcohol use frequency (β=0.47, p=0.01), but not those in the higher education group. Post hoc latent-growth analyses revealed significant effects on the development of binge drinking (β=-0.19, p=0.02) and binge drinking frequency (β=-0.10, p=0

  11. Simian Virus 40 depends on ER protein folding and quality control factors for entry into host cells

    DEFF Research Database (Denmark)

    Schelhaas, Mario; Malmström, Johan; Pelkmans, Lucas

    2007-01-01

    Cell entry of Simian Virus 40 (SV40) involves caveolar/lipid raft-mediated endocytosis, vesicular transport to the endoplasmic reticulum (ER), translocation into the cytosol, and import into the nucleus. We analyzed the effects of ER-associated processes and factors on infection and on isolated...... viruses and found that SV40 makes use of the thiol-disulfide oxidoreductases, ERp57 and PDI, as well as the retrotranslocation proteins Derlin-1 and Sel1L. ERp57 isomerizes specific interchain disulfides connecting the major capsid protein, VP1, to a crosslinked network of neighbors, thus uncoupling about...

  12. Therapeutic effect of photodynamic therapy combined with targeted delivery of silencing vascular endothelial growth factor (Conference Presentation)

    Science.gov (United States)

    Hsu, Yih-Chih

    2016-03-01

    Photodynamic therapy is a novel therapeutic modality to treat cancer by using a photosensitizer which is activated by a light source to produce reactive oxygen species and mediates tumours oxygen-independent hypoxic conditions. Vascular endothelial growth factor (VEGF) is one of the primary factors that affect tumor angiogenesis. Another emerging treatment to cure cancer is the use of interference RNA to silence a specific mRNA sequence. Such treatment requires a delivery system such as liposomes. The nanoparticle size measured was about 30 nm. Cellular uptake study was performed to verify that the nanoparticles have a sigma receptor mediated pathway. Non-targeted LCP NPs did not show significant difference with or without haloperidol but has a lower intensity as than targeted LCP NPs. These results confirm that LCP NPs have a receptor mediated pathway. Cell viability was found to decrease at 25 nM of transfected VEGF siRNA. Combined therapy of PDT and VEGF siRNA showed significant response as compared with PDT and gene therapy alone. In vivo toxicity assay with mice treated with targeted LCP NPs containing control siRNA or VEGF siRNA and non-targeted LCP NPs containing VEGF siRNA did not show any significant difference with the PBS injected group which suggests that there is no toxicity with the dose. It suggests that PDT combined with targeted gene therapy has a potential mean to achieve better therapeutic outcome.

  13. Host genetics affect microbial ecosystems via host immunity.

    Science.gov (United States)

    El Kafsi, Hela; Gorochov, Guy; Larsen, Martin

    2016-10-01

    Genetic evolution of multicellular organisms has occurred in response to environmental challenges, including competition for nutrients, climate change, physical and chemical stressors, and pathogens. However, fitness of an organism is dependent not only on defense efficacy, but also on the ability to take advantage of symbiotic organisms. Indeed, microbes not only encompass pathogenicity, but also enable efficient nutrient uptake from diets nondegradable by the host itself. Moreover, microbes play important roles in the development of host immunity. Here we review associations between specific host genes and variance in microbiota composition and compare with interactions between microbes and host immunity. Recent genome-wide association studies reveal that symbiosis between host and microbiota is the exquisite result of genetic coevolution. Moreover, a subset of microbes from human and mouse microbiota have been identified to interact with humoral and cellular immunity. Interestingly, microbes associated with both host genetics and host immunity are taxonomically related. Most involved are Bifidobacterium, Lactobacillus, and Akkermansia, which are dually associated with both host immunity and host genetics. We conclude that future therapeutics targeting microbiota in the context of chronic inflammatory diseases need to consider both immune and genetic host features associated with microbiota homeostasis.

  14. Supplementation of host response by targeting nitric oxide to the macrophage cytosol is efficacious in the hamster model of visceral leishmaniasis and adds to efficacy of amphotericin B

    Directory of Open Access Journals (Sweden)

    Sanketkumar Pandya

    2016-08-01

    Full Text Available We investigated efficacy of nitric oxide (NO against Leishmania donovani. NO is a mediator of host response to infection, with direct parasiticidal activity in addition to its role in signalling to evoke innate macrophage responses. However, it is short-lived and volatile, and is therefore difficult to introduce into infected cells and maintain inracellular concentrations for meaningful periods of time. We incorporated diethylenetriamine NO adduct (DETA/NO, a prodrug, into poly(lactide-co-glycolide particles of ∼200 nm, with or without amphotericin B (AMB. These particles sustained NO levels in mouse macrophage culture supernatants, generating an area under curve (AUC0.08-24h of 591.2 ± 95.1 mM × h. Free DETA/NO resulted in NO peaking at 3 h and declining rapidly to yield an AUC of 462.5 ± 193.4. Particles containing AMB and DETA/NO were able to kill ∼98% of promastigotes and ∼76% of amastigotes in 12 h when tested in vitro. Promastigotes and amastigotes were killed less efficiently by particles containing a single drug– either DETA/NO (∼42%, 35% or AMB (∼90%, 50% alone, or by equivalent concentrations of drugs in solution. In a pre-clinical efficacy study of power >0.95 in the hamster model, DETA/NO particles were non-inferior to Fungizone® but not Ambisome®, resulting in significant (∼73% reduction in spleen parasites in 7 days. Particles containing both DETA/NO and AMB were superior (∼93% reduction to Ambisome®. We conclude that NO delivered to the cytosol of macrophages infected with Leishmania possesses intrinsic activity and adds significantly to the efficacy of AMB.

  15. An Aromatic Diamidine That Targets Kinetoplast DNA, Impairs the Cell Cycle in Trypanosoma cruzi, and Diminishes Trypomastigote Release from Infected Mammalian Host Cells.

    Science.gov (United States)

    Girard, Richard M B M; Crispim, Marcell; Stolić, Ivana; Damasceno, Flávia Silva; Santos da Silva, Marcelo; Pral, Eizabeth Mieko Furusho; Elias, Maria Carolina; Bajić, Miroslav; Silber, Ariel Mariano

    2016-10-01

    Trypanosoma cruzi is the etiological agent of Chagas disease, affecting approximately 10 million people in the Americas and with some 40 million people at risk. The objective of this study was to evaluate the anti-T. cruzi activity of three new diamidines that have a 3,4-ethylenedioxy extension of the thiophene core, designated MB17, MB19, and MB38. All three diamidines exhibited dose-dependent inhibition of epimastigote replication. The mechanisms of action of these diamidines were investigated. Unlike MB17 and MB19, MB38 exhibited a significant increase in the number of annexin-propidium iodide double-labeled cells compared to levels in control parasites. As MB17 had shown a lower 50% inhibitory concentration (IC50) against epimastigote growth, the mechanism of action of this drug was studied in more detail. MB17 triggered a decrease in the intracellular ATP levels. As a consequence, MB17 affected the genomic DNA and kinetoplast DNA (kDNA) and impaired the parasite cell cycle. Moreover, MB17 caused DNA fragmentation, with a more severe effect on kDNA than on nuclear DNA, resulting in dyskinetoplastic cells. MB17 was tested for toxicity and effectiveness for the treatment of infected CHO-K1 cells, exhibiting a 50% cytotoxic concentration (CC50) of 13.47 ± 0.37 μM and an IC50 of 0.14 ± 0.12 μM against trypomastigote release. MB17 also diminished the infection index by 60% at 0.5 μM. In conclusion, despite belonging to the same family, these diamidines have different efficiencies. To summarize, MB17 was the most potent of these diamidines against epimastigotes, producing DNA damage preferentially in kDNA, impairing the parasite cell cycle, and decreasing the infection index and trypomastigote release from infected mammalian host cells, with a high selectivity index (SI) (cruzi. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  16. Targeting c-kit receptor in neuroblastomas and colorectal cancers using stem cell factor (SCF)-based recombinant bacterial toxins.

    Science.gov (United States)

    Choudhary, Swati; Pardo, Alessa; Rosinke, Reinhard; Batra, Janendra K; Barth, Stefan; Verma, Rama S

    2016-01-01

    Autocrine activation of c-kit (KIT receptor tyrosine kinase) has been postulated to be a potent oncogenic driver in small cell lung cancer, neuroblastoma (NB), and poorly differentiated colorectal carcinoma (CRC). Although targeted therapy involving tyrosine kinase inhibitors (TKIs) such as imatinib mesylate is highly effective for gastrointestinal stromal tumor carrying V560G c-kit mutation, it does not show much potential for targeting wild-type KIT (WT-KIT). Our study demonstrates the role of stem cell factor (SCF)-based toxin conjugates for targeting WT-KIT-overexpressing malignancies such as NBs and CRCs. We constructed SCF-based recombinant bacterial toxins by genetically fusing mutated form of natural ligand SCF to receptor binding deficient forms of Diphtheria toxin (DT) or Pseudomonas exotoxin A (ETA') and evaluated their efficacy in vitro. Efficient targeting was achieved in all receptor-positive neuroblastoma (IMR-32 and SHSY5Y) and colon cancer cell lines (COLO 320DM, HCT 116, and DLD-1) but not in receptor-negative breast carcinoma cell line (MCF-7) thereby proving specificity. While dose- and time-dependent cytotoxicity was observed in both neuroblastoma cell lines, COLO 320DM and HCT 116 cells, only an anti-proliferative effect was observed in DLD-1 cells. We prove that these novel targeting agents have promising potential as KIT receptor tyrosine kinase targeting system.

  17. Population differences in host immune factors may influence survival of Gunnison's prairie dogs (Cynomys Gunnisoni) during plague outbreaks

    Science.gov (United States)

    Busch, Joseph D.; Van Andel, Roger; Cordova, Jennifer; Colman, Rebecca E.; Keim, Paul; Rocke, Tonie E.; Leid, Jeff G.; Van Pelt, William E.; Wagner, David M.

    2011-01-01

    Over the past 40 yr, epizootics of plague (Yersinia pestis) in northern Arizona have reduced populations of the Gunnison’s prairie dog (Cynomys gunnisoni), with the exception of a large population found in the Aubrey Valley (AV). To examine potential mechanisms accounting for their survival, we collected prairie dog serum samples in 2005–2006 from AV and a neighboring population near Seligman (SE), Arizona. We quantified gene expression at 58 diverse immune proteins using a multiplexed enzyme-linked immunosorbent assay panel. We found a subset of proteins important in coagulation and inflammation (tissue factor [TF], calbindin [Cal], and thrombopoietin [TPO]) and T-cell responses (CD40L and CD40) that were present in AV at levels two to eight times greater than SE. These results suggest that AV and SE animals might differ in their ability to mount an immune response.

  18. Selective factors associated with the evolution of codon usage in natural populations of arboviruses and their practical application to infer possible hosts for emerging viruses

    Science.gov (United States)

    Arboviruses (arthropod borne viruses) have life cycles that include both vertebrate and invertebrate hosts with substantial differences in vector and host specificity between different viruses. Most arboviruses utilize RNA for their genetic material and are completely dependent on host tRNAs for the...

  19. Interactions between the R2R3-MYB transcription factor, AtMYB61, and target DNA binding sites.

    Directory of Open Access Journals (Sweden)

    Michael B Prouse

    Full Text Available Despite the prominent roles played by R2R3-MYB transcription factors in the regulation of plant gene expression, little is known about the details of how these proteins interact with their DNA targets. For example, while Arabidopsis thaliana R2R3-MYB protein AtMYB61 is known to alter transcript abundance of a specific set of target genes, little is known about the specific DNA sequences to which AtMYB61 binds. To address this gap in knowledge, DNA sequences bound by AtMYB61 were identified using cyclic amplification and selection of targets (CASTing. The DNA targets identified using this approach corresponded to AC elements, sequences enriched in adenosine and cytosine nucleotides. The preferred target sequence that bound with the greatest affinity to AtMYB61 recombinant protein was ACCTAC, the AC-I element. Mutational analyses based on the AC-I element showed that ACC nucleotides in the AC-I element served as the core recognition motif, critical for AtMYB61 binding. Molecular modelling predicted interactions between AtMYB61 amino acid residues and corresponding nucleotides in the DNA targets. The affinity between AtMYB61 and specific target DNA sequences did not correlate with AtMYB61-driven transcriptional activation with each of the target sequences. CASTing-selected motifs were found in the regulatory regions of genes previously shown to be regulated by AtMYB61. Taken together, these findings are consistent with the hypothesis that AtMYB61 regulates transcription from specific cis-acting AC elements in vivo. The results shed light on the specifics of DNA binding by an important family of plant-specific transcriptional regulators.

  20. Staphylococcus aureus hijacks a skin commensal to intensify its virulence: immunization targeting β-hemolysin and CAMP factor.

    Science.gov (United States)

    Lo, Chih-Wei; Lai, Yiu-Kay; Liu, Yu-Tsueng; Gallo, Richard L; Huang, Chun-Ming

    2011-02-01

    The need for a new anti-Staphylococcus aureus therapy that can effectively cripple bacterial infection, neutralize secretory virulence factors, and lower the risk of creating bacterial resistance is undisputed. Here, we propose what is, to our knowledge, a previously unreported infectious mechanism by which S. aureus may commandeer Propionibacterium acnes, a key member of the human skin microbiome, to spread its invasion and highlight two secretory virulence factors (S. aureus β-hemolysin and P. acnes CAMP (Christie, Atkins, Munch-Peterson) factor) as potential molecular targets for immunotherapy against S. aureus infection. Our data demonstrate that the hemolysis and cytolysis by S. aureus were noticeably augmented when S. aureus was grown with P. acnes. The augmentation was significantly abrogated when the P. acnes CAMP factor was neutralized or β-hemolysin of S. aureus was mutated. In addition, the hemolysis and cytolysis of recombinant β-hemolysin were markedly enhanced by recombinant CAMP factor. Furthermore, P. acnes exacerbated S. aureus-induced skin lesions in vivo. The combination of CAMP factor neutralization and β-hemolysin immunization cooperatively suppressed the skin lesions caused by coinfection of P. acnes and S. aureus. These observations suggest a previously unreported immunotherapy targeting the interaction of S. aureus with a skin commensal.

  1. Heterogeneity in host risk factors for incident melanoma and non-melanoma skin cancer in a cohort of US women.

    Science.gov (United States)

    Qureshi, Abrar A; Zhang, Mingfeng; Han, Jiali

    2011-01-01

    Melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) are 3 type