Code-assisted discovery of TAL effector targets in bacterial leaf streak of rice reveals contrast with bacterial blight and a novel susceptibility gene.

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Raul A Cernadas

2014-02-01

Full Text Available Bacterial leaf streak of rice, caused by Xanthomonas oryzae pv. oryzicola (Xoc is an increasingly important yield constraint in this staple crop. A mesophyll colonizer, Xoc differs from X. oryzae pv. oryzae (Xoo, which invades xylem to cause bacterial blight of rice. Both produce multiple distinct TAL effectors, type III-delivered proteins that transactivate effector-specific host genes. A TAL effector finds its target(s via a partially degenerate code whereby the modular effector amino acid sequence identifies nucleotide sequences to which the protein binds. Virulence contributions of some Xoo TAL effectors have been shown, and their relevant targets, susceptibility (S genes, identified, but the role of TAL effectors in leaf streak is uncharacterized. We used host transcript profiling to compare leaf streak to blight and to probe functions of Xoc TAL effectors. We found that Xoc and Xoo induce almost completely different host transcriptional changes. Roughly one in three genes upregulated by the pathogens is preceded by a candidate TAL effector binding element. Experimental analysis of the 44 such genes predicted to be Xoc TAL effector targets verified nearly half, and identified most others as false predictions. None of the Xoc targets is a known bacterial blight S gene. Mutational analysis revealed that Tal2g, which activates two genes, contributes to lesion expansion and bacterial exudation. Use of designer TAL effectors discriminated a sulfate transporter gene as the S gene. Across all targets, basal expression tended to be higher than genome-average, and induction moderate. Finally, machine learning applied to real vs. falsely predicted targets yielded a classifier that recalled 92% of the real targets with 88% precision, providing a tool for better target prediction in the future. Our study expands the number of known TAL effector targets, identifies a new class of S gene, and improves our ability to predict functional targeting.

BID-F1 and BID-F2 domains of Bartonella henselae effector protein BepF trigger together with BepC the formation of invasome structures.

Science.gov (United States)

Truttmann, Matthias C; Guye, Patrick; Dehio, Christoph

2011-01-01

The gram-negative, zoonotic pathogen Bartonella henselae (Bhe) translocates seven distinct Bartonella effector proteins (Beps) via the VirB/VirD4 type IV secretion system (T4SS) into human cells, thereby interfering with host cell signaling [1], [2]. In particular, the effector protein BepG alone or the combination of effector proteins BepC and BepF trigger massive F-actin rearrangements that lead to the establishment of invasome structures eventually resulting in the internalization of entire Bhe aggregates [2], [3]. In this report, we investigate the molecular function of the effector protein BepF in the eukaryotic host cell. We show that the N-terminal [E/T]PLYAT tyrosine phosphorylation motifs of BepF get phosphorylated upon translocation but do not contribute to invasome-mediated Bhe uptake. In contrast, we found that two of the three BID domains of BepF are capable to trigger invasome formation together with BepC, while a mutation of the WxxxE motif of the BID-F1 domain inhibited its ability to contribute to the formation of invasome structures. Next, we show that BepF function during invasome formation can be replaced by the over-expression of constitutive-active Rho GTPases Rac1 or Cdc42. Finally we demonstrate that BID-F1 and BID-F2 domains promote the formation of filopodia-like extensions in NIH 3T3 and HeLa cells as well as membrane protrusions in HeLa cells, suggesting a role for BepF in Rac1 and Cdc42 activation during the process of invasome formation.

Epigenetic control of effectors in plant pathogens

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Mark eGijzen

2014-11-01

Full Text Available Plant pathogens display impressive versatility in adapting to host immune systems. Pathogen effector proteins facilitate disease but can become avirulence (Avr factors when the host acquires discrete recognition capabilities that trigger immunity. The mechanisms that lead to changes to pathogen Avr factors that enable escape from host immunity are diverse, and include epigenetic switches that allow for reuse or recycling of effectors. This perspective outlines possibilities of how epigenetic control of Avr effector gene expression may have arisen and persisted in plant pathogens, and how it presents special problems for diagnosis and detection of specific pathogen strains or pathotypes.

BID-F1 and BID-F2 domains of Bartonella henselae effector protein BepF trigger together with BepC the formation of invasome structures.

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Matthias C Truttmann

Full Text Available The gram-negative, zoonotic pathogen Bartonella henselae (Bhe translocates seven distinct Bartonella effector proteins (Beps via the VirB/VirD4 type IV secretion system (T4SS into human cells, thereby interfering with host cell signaling [1], [2]. In particular, the effector protein BepG alone or the combination of effector proteins BepC and BepF trigger massive F-actin rearrangements that lead to the establishment of invasome structures eventually resulting in the internalization of entire Bhe aggregates [2], [3]. In this report, we investigate the molecular function of the effector protein BepF in the eukaryotic host cell. We show that the N-terminal [E/T]PLYAT tyrosine phosphorylation motifs of BepF get phosphorylated upon translocation but do not contribute to invasome-mediated Bhe uptake. In contrast, we found that two of the three BID domains of BepF are capable to trigger invasome formation together with BepC, while a mutation of the WxxxE motif of the BID-F1 domain inhibited its ability to contribute to the formation of invasome structures. Next, we show that BepF function during invasome formation can be replaced by the over-expression of constitutive-active Rho GTPases Rac1 or Cdc42. Finally we demonstrate that BID-F1 and BID-F2 domains promote the formation of filopodia-like extensions in NIH 3T3 and HeLa cells as well as membrane protrusions in HeLa cells, suggesting a role for BepF in Rac1 and Cdc42 activation during the process of invasome formation.

RNAi effector diversity in nematodes.

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Johnathan J Dalzell

2011-06-01

Full Text Available While RNA interference (RNAi has been deployed to facilitate gene function studies in diverse helminths, parasitic nematodes appear variably susceptible. To test if this is due to inter-species differences in RNAi effector complements, we performed a primary sequence similarity survey for orthologs of 77 Caenorhabditis elegans RNAi pathway proteins in 13 nematode species for which genomic or transcriptomic datasets were available, with all outputs subjected to domain-structure verification. Our dataset spanned transcriptomes of Ancylostoma caninum and Oesophagostomum dentatum, and genomes of Trichinella spiralis, Ascaris suum, Brugia malayi, Haemonchus contortus, Meloidogyne hapla, Meloidogyne incognita and Pristionchus pacificus, as well as the Caenorhabditis species C. brenneri, C. briggsae, C. japonica and C. remanei, and revealed that: (i Most of the C. elegans proteins responsible for uptake and spread of exogenously applied double stranded (dsRNA are absent from parasitic species, including RNAi-competent plant-nematodes; (ii The Argonautes (AGOs responsible for gene expression regulation in C. elegans are broadly conserved, unlike those recruited during the induction of RNAi by exogenous dsRNA; (iii Secondary Argonautes (SAGOs are poorly conserved, and the nuclear AGO NRDE-3 was not identified in any parasite; (iv All five Caenorhabditis spp. possess an expanded RNAi effector repertoire relative to the parasitic nematodes, consistent with the propensity for gene loss in nematode parasites; (v In spite of the quantitative differences in RNAi effector complements across nematode species, all displayed qualitatively similar coverage of functional protein groups. In summary, we could not identify RNAi effector deficiencies that associate with reduced susceptibility in parasitic nematodes. Indeed, similarities in the RNAi effector complements of RNAi refractory and competent nematode parasites support the broad applicability of this research

Tricking the guard: exploiting plant defense for disease susceptibility.

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Lorang, J; Kidarsa, T; Bradford, C S; Gilbert, B; Curtis, M; Tzeng, S-C; Maier, C S; Wolpert, T J

2012-11-02

Typically, pathogens deploy virulence effectors to disable defense. Plants defeat effectors with resistance proteins that guard effector targets. We found that a pathogen exploits a resistance protein by activating it to confer susceptibility in Arabidopsis. The guard mechanism of plant defense is recapitulated by interactions among victorin (an effector produced by the necrotrophic fungus Cochliobolus victoriae), TRX-h5 (a defense-associated thioredoxin), and LOV1 (an Arabidopsis susceptibility protein). In LOV1's absence, victorin inhibits TRX-h5, resulting in compromised defense but not disease by C. victoriae. In LOV1's presence, victorin binding to TRX-h5 activates LOV1 and elicits a resistance-like response that confers disease susceptibility. We propose that victorin is, or mimics, a conventional pathogen virulence effector that was defeated by LOV1 and confers virulence to C. victoriae solely because it incites defense.

An Immunity-Triggering Effector from the Barley Smut Fungus Ustilago hordei Resides in an Ustilaginaceae-Specific Cluster Bearing Signs of Transposable Element-Assisted Evolution

KAUST Repository

Ali, Shawkat

2014-07-03

The basidiomycete smut fungus Ustilago hordei was previously shown to comprise isolates that are avirulent on various barley host cultivars. Through genetic crosses we had revealed that a dominant avirulence locus UhAvr1 which triggers immunity in barley cultivar Hannchen harboring resistance gene Ruh1, resided within an 80-kb region. DNA sequence analysis of this genetically delimited region uncovered the presence of 7 candidate secreted effector proteins. Sequence comparison of their coding sequences among virulent and avirulent parental and field isolates could not distinguish UhAvr1 candidates. Systematic deletion and complementation analyses revealed that UhAvr1 is UHOR_10022 which codes for a small effector protein of 171 amino acids with a predicted 19 amino acid signal peptide. Virulence in the parental isolate is caused by the insertion of a fragment of 5.5 kb with similarity to a common U. hordei transposable element (TE), interrupting the promoter of UhAvr1 and thereby changing expression and hence recognition of UhAVR1p. This rearrangement is likely caused by activities of TEs and variation is seen among isolates. Using GFP-chimeric constructs we show that UhAvr1 is induced only in mated dikaryotic hyphae upon sensing and infecting barley coleoptile cells. When infecting Hannchen, UhAVR1p causes local callose deposition and the production of reactive oxygen species and necrosis indicative of the immune response. UhAvr1 does not contribute significantly to overall virulence. UhAvr1 is located in a cluster of ten effectors with several paralogs and over 50% of TEs. This cluster is syntenous with clusters in closely-related U. maydis and Sporisorium reilianum. In these corn-infecting species, these clusters harbor however more and further diversified homologous effector families but very few TEs. This increased variability may have resulted from past selection pressure by resistance genes since U. maydis is not known to trigger immunity in its corn host. �

An immunity-triggering effector from the Barley smut fungus Ustilago hordei resides in an Ustilaginaceae-specific cluster bearing signs of transposable element-assisted evolution.

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Shawkat Ali

2014-07-01

Full Text Available The basidiomycete smut fungus Ustilago hordei was previously shown to comprise isolates that are avirulent on various barley host cultivars. Through genetic crosses we had revealed that a dominant avirulence locus UhAvr1 which triggers immunity in barley cultivar Hannchen harboring resistance gene Ruh1, resided within an 80-kb region. DNA sequence analysis of this genetically delimited region uncovered the presence of 7 candidate secreted effector proteins. Sequence comparison of their coding sequences among virulent and avirulent parental and field isolates could not distinguish UhAvr1 candidates. Systematic deletion and complementation analyses revealed that UhAvr1 is UHOR_10022 which codes for a small effector protein of 171 amino acids with a predicted 19 amino acid signal peptide. Virulence in the parental isolate is caused by the insertion of a fragment of 5.5 kb with similarity to a common U. hordei transposable element (TE, interrupting the promoter of UhAvr1 and thereby changing expression and hence recognition of UhAVR1p. This rearrangement is likely caused by activities of TEs and variation is seen among isolates. Using GFP-chimeric constructs we show that UhAvr1 is induced only in mated dikaryotic hyphae upon sensing and infecting barley coleoptile cells. When infecting Hannchen, UhAVR1p causes local callose deposition and the production of reactive oxygen species and necrosis indicative of the immune response. UhAvr1 does not contribute significantly to overall virulence. UhAvr1 is located in a cluster of ten effectors with several paralogs and over 50% of TEs. This cluster is syntenous with clusters in closely-related U. maydis and Sporisorium reilianum. In these corn-infecting species, these clusters harbor however more and further diversified homologous effector families but very few TEs. This increased variability may have resulted from past selection pressure by resistance genes since U. maydis is not known to trigger immunity

An Immunity-Triggering Effector from the Barley Smut Fungus Ustilago hordei Resides in an Ustilaginaceae-Specific Cluster Bearing Signs of Transposable Element-Assisted Evolution

KAUST Repository

Ali, Shawkat; Laurie, John D.; Linning, Rob; Cervantes-Chá vez, José Antonio; Gaudet, Denis; Bakkeren, Guus

2014-01-01

The basidiomycete smut fungus Ustilago hordei was previously shown to comprise isolates that are avirulent on various barley host cultivars. Through genetic crosses we had revealed that a dominant avirulence locus UhAvr1 which triggers immunity in barley cultivar Hannchen harboring resistance gene Ruh1, resided within an 80-kb region. DNA sequence analysis of this genetically delimited region uncovered the presence of 7 candidate secreted effector proteins. Sequence comparison of their coding sequences among virulent and avirulent parental and field isolates could not distinguish UhAvr1 candidates. Systematic deletion and complementation analyses revealed that UhAvr1 is UHOR_10022 which codes for a small effector protein of 171 amino acids with a predicted 19 amino acid signal peptide. Virulence in the parental isolate is caused by the insertion of a fragment of 5.5 kb with similarity to a common U. hordei transposable element (TE), interrupting the promoter of UhAvr1 and thereby changing expression and hence recognition of UhAVR1p. This rearrangement is likely caused by activities of TEs and variation is seen among isolates. Using GFP-chimeric constructs we show that UhAvr1 is induced only in mated dikaryotic hyphae upon sensing and infecting barley coleoptile cells. When infecting Hannchen, UhAVR1p causes local callose deposition and the production of reactive oxygen species and necrosis indicative of the immune response. UhAvr1 does not contribute significantly to overall virulence. UhAvr1 is located in a cluster of ten effectors with several paralogs and over 50% of TEs. This cluster is syntenous with clusters in closely-related U. maydis and Sporisorium reilianum. In these corn-infecting species, these clusters harbor however more and further diversified homologous effector families but very few TEs. This increased variability may have resulted from past selection pressure by resistance genes since U. maydis is not known to trigger immunity in its corn host. �

Transcriptome analysis of the fungal pathogen Fusarium oxysporum f. sp. medicaginis during colonisation of resistant and susceptible Medicago truncatula hosts identifies differential pathogenicity profiles and novel candidate effectors.

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Thatcher, Louise F; Williams, Angela H; Garg, Gagan; Buck, Sally-Anne G; Singh, Karam B

2016-11-03

Pathogenic members of the Fusarium oxysporum species complex are responsible for vascular wilt disease on many important crops including legumes, where they can be one of the most destructive disease causing necrotrophic fungi. We previously developed a model legume-infecting pathosystem based on the reference legume Medicago truncatula and a pathogenic F. oxysporum forma specialis (f. sp.) medicaginis (Fom). To dissect the molecular pathogenicity arsenal used by this root-infecting pathogen, we sequenced its transcriptome during infection of a susceptible and resistant host accession. High coverage RNA-Seq of Fom infected root samples harvested from susceptible (DZA315) or resistant (A17) M. truncatula seedlings at early or later stages of infection (2 or 7 days post infection (dpi)) and from vegetative (in vitro) samples facilitated the identification of unique and overlapping sets of in planta differentially expressed genes. This included enrichment, particularly in DZA315 in planta up-regulated datasets, for proteins associated with sugar, protein and plant cell wall metabolism, membrane transport, nutrient uptake and oxidative processes. Genes encoding effector-like proteins were identified, including homologues of the F. oxysporum f. sp. lycopersici Secreted In Xylem (SIX) proteins, and several novel candidate effectors based on predicted secretion, small protein size and high in-planta induced expression. The majority of the effector candidates contain no known protein domains but do share high similarity to predicted proteins predominantly from other F. oxysporum ff. spp. as well as other Fusaria (F. solani, F. fujikori, F. verticilloides, F. graminearum and F. pseudograminearum), and from another wilt pathogen of the same class, a Verticillium species. Overall, this suggests these novel effector candidates may play important roles in Fusaria and wilt pathogen virulence. Combining high coverage in planta RNA-Seq with knowledge of fungal pathogenicity

A Phytophthora sojae effector PsCRN63 forms homo-/hetero-dimers to suppress plant immunity via an inverted association manner.

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Li, Qi; Zhang, Meixiang; Shen, Danyu; Liu, Tingli; Chen, Yanyu; Zhou, Jian-Min; Dou, Daolong

2016-05-31

Oomycete pathogens produce a large number of effectors to promote infection. Their mode of action are largely unknown. Here we show that a Phytophthora sojae effector, PsCRN63, suppresses flg22-induced expression of FRK1 gene, a molecular marker in pathogen-associated molecular patterns (PAMP)-triggered immunity (PTI). However, PsCRN63 does not suppress upstream signaling events including flg22-induced MAPK activation and BIK1 phosphorylation, indicating that it acts downstream of MAPK cascades. The PsCRN63-transgenic Arabidopsis plants showed increased susceptibility to bacterial pathogen Pseudomonas syringae pathovar tomato (Pst) DC3000 and oomycete pathogen Phytophthora capsici. The callose deposition were suppressed in PsCRN63-transgenic plants compared with the wild-type control plants. Genes involved in PTI were also down-regulated in PsCRN63-transgenic plants. Interestingly, we found that PsCRN63 forms an dimer that is mediated by inter-molecular interactions between N-terminal and C-terminal domains in an inverted association manner. Furthermore, the N-terminal and C-terminal domains required for the dimerization are widely conserved among CRN effectors, suggesting that homo-/hetero-dimerization of Phytophthora CRN effectors is required to exert biological functions. Indeed, the dimerization was required for PTI suppression and cell death-induction activities of PsCRN63.

Presence-only approach to assess landslide triggering-thickness susceptibility: a test for the Mili catchment (north-eastern Sicily, Italy)

KAUST Repository

Lombardo, Luigi

2016-06-29

This study evaluates the performances of the presence-only approach, Maximum Entropy, in assessing landslide triggering-thickness susceptibility within the Mili catchment (Sicily, Italy). This catchment underwent several meteorological stresses, resulting in hundreds of shallow rapid mass movements between 2007 and 2011. In particular, the area has become known for two disasters, which occurred in 2009 and 2010; the first weather system did not pass directly over the catchment; however, peak rainfall was registered over the basin during the second meteorological event. Field data were collected to associate the depth from the slope surface that material was mobilised at the triggering zone to each mass movement within the catchment. This information has been used to model the landslide susceptibility for two classes of processes, divided into shallow failures for maximum depths of 1 m and deep ones in case of values equal or greater than 1 m. Topographic attributes from a 2-m DEM were used as predictors, together with medium resolution vegetation indexes derived from ASTER scenes and geological, land use and tectonic maps. The presence-only approach discriminated between the two depth classes at the landslide trigger zone, producing excellent prediction skills associated with relatively low variances across a set of 50 randomly generated replicates. The role of each predictor was assessed to ascertain the significance to the final model output. This work uses simple field measurements to produce triggering-thickness susceptibility, which is a novel approach and may perform better as a proxy for landslide hazard assessments with respect to more common susceptibility practises. © 2016, Springer Science+Business Media Dordrecht.

Assessment of earthquake-triggered landslide susceptibility in El Salvador based on an Artificial Neural Network model

Science.gov (United States)

García-Rodríguez, M. J.; Malpica, J. A.

2010-06-01

This paper presents an approach for assessing earthquake-triggered landslide susceptibility using artificial neural networks (ANNs). The computational method used for the training process is a back-propagation learning algorithm. It is applied to El Salvador, one of the most seismically active regions in Central America, where the last severe destructive earthquakes occurred on 13 January 2001 (Mw 7.7) and 13 February 2001 (Mw 6.6). The first one triggered more than 600 landslides (including the most tragic, Las Colinas landslide) and killed at least 844 people. The ANN is designed and programmed to develop landslide susceptibility analysis techniques at a regional scale. This approach uses an inventory of landslides and different parameters of slope instability: slope gradient, elevation, aspect, mean annual precipitation, lithology, land use, and terrain roughness. The information obtained from ANN is then used by a Geographic Information System (GIS) to map the landslide susceptibility. In a previous work, a Logistic Regression (LR) was analysed with the same parameters considered in the ANN as independent variables and the occurrence or non-occurrence of landslides as dependent variables. As a result, the logistic approach determined the importance of terrain roughness and soil type as key factors within the model. The results of the landslide susceptibility analysis with ANN are checked using landslide location data. These results show a high concordance between the landslide inventory and the high susceptibility estimated zone. Finally, a comparative analysis of the ANN and LR models are made. The advantages and disadvantages of both approaches are discussed using Receiver Operating Characteristic (ROC) curves.

X-linked inhibitor of apoptosis regulates T cell effector function

DEFF Research Database (Denmark)

Zehntner, Simone P; Bourbonnière, Lyne; Moore, Craig S

2007-01-01

To understand how the balance between pro- and anti-apoptotic signals influences effector function in the immune system, we studied the X-linked inhibitor of apoptosis (XIAP), an endogenous regulator of cellular apoptosis. Real-time PCR showed increased XIAP expression in blood of mice with exper......To understand how the balance between pro- and anti-apoptotic signals influences effector function in the immune system, we studied the X-linked inhibitor of apoptosis (XIAP), an endogenous regulator of cellular apoptosis. Real-time PCR showed increased XIAP expression in blood of mice...... dramatically reduced within the CNS. Flow cytometry showed an 88-93% reduction in T cells. The proportion of TUNEL(+) apoptotic CD4(+) T cells in the CNS was increased from Neurons...... and oligodendrocytes were not affected; neither did apoptosis increase in liver, where XIAP knockdown also occurred. ASO-XIAP increased susceptibility of T cells to activation-induced apoptosis in vitro. Our results identify XIAP as a critical controller of apoptotic susceptibility of effector T cell function...

Modular Study of the Type III Effector Repertoire in Pseudomonas syringae pv. tomato DC3000 Reveals a Matrix of Effector Interplay in Pathogenesis

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Hai-Lei Wei

2018-05-01

Full Text Available Summary: The bacterial pathogen Pseudomonas syringae pv. tomato DC3000 suppresses the two-tiered innate immune system of Nicotiana benthamiana and other plants by injecting a complex repertoire of type III secretion effector (T3E proteins. Effectorless polymutant DC3000D36E was used with a modularized system for native delivery of the 29 DC3000 T3Es singly and in pairs. Assays of the performance of this T3E library in N. benthamiana leaves revealed a matrix of T3E interplay, with six T3Es eliciting death and eight others variously suppressing the death activity of the six. The T3E library was also interrogated for effects on DC3000D36E elicitation of a reactive oxygen species burst, for growth in planta, and for T3Es that reversed these effects. Pseudomonas fluorescens and Agrobacterium tumefaciens heterologous delivery systems yielded notably different sets of death-T3Es. The DC3000D36E T3E library system highlights the importance of 13 T3Es and their interplay in interactions with N. benthamiana. : Wei et al. used a Pseudomonas syringae strain lacking all known type III effectors with a modularized library expressing the 29 active effectors in the strain’s native repertoire, individually and in pairs, to comprehensively determine effector actions and interplay in inducing and suppressing responses associated with plant pathogenesis and immunity. Keywords: effector-triggered-immunity, pattern-triggered-immunity, Hop proteins, plant immunity, mini-Tn7

Isotretinoin as a Possible Environmental Trigger to Autoimmunity in Genetically Susceptible Patients

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Jocelyn Nugroho

2017-01-01

Full Text Available Introduction. Isotretinoin is commonly used to treat cystic acne. Definitive mechanisms of action for isotretinoin are not known though despite many side effects having been documented. Various case reports have noted autoimmune diseases succeeding isotretinoin treatment. Case Report. A 16-year-old female presents with symptoms of tremors, lack of focus, sleeplessness, emotional liability, bulging eyes, loose stools, heat intolerance, and missed menstrual periods. Symptoms manifested shortly after the patient finished a course of oral isotretinoin treatment for acne. Physical exam showed resting tremors, bilateral proptosis, hyperactivity, and rapid speech. A diagnosis of Graves’ Disease was made by correlating symptoms, physical exam findings, ultrasound, and positive family history of autoimmune thyroid disease. Conclusion. Emergence of autoimmune thyroid diseases depends upon genetic predisposition and environmental triggers. Mechanism of action for isotretinoin is not known but the drug may play a role in triggering autoimmunity in genetically susceptible individuals.

Assessment of earthquake-triggered landslide susceptibility in El Salvador based on an Artificial Neural Network model

Directory of Open Access Journals (Sweden)

M. J. García-Rodríguez

2010-06-01

Full Text Available This paper presents an approach for assessing earthquake-triggered landslide susceptibility using artificial neural networks (ANNs. The computational method used for the training process is a back-propagation learning algorithm. It is applied to El Salvador, one of the most seismically active regions in Central America, where the last severe destructive earthquakes occurred on 13 January 2001 (M_w 7.7 and 13 February 2001 (M_w 6.6. The first one triggered more than 600 landslides (including the most tragic, Las Colinas landslide and killed at least 844 people.

The ANN is designed and programmed to develop landslide susceptibility analysis techniques at a regional scale. This approach uses an inventory of landslides and different parameters of slope instability: slope gradient, elevation, aspect, mean annual precipitation, lithology, land use, and terrain roughness. The information obtained from ANN is then used by a Geographic Information System (GIS to map the landslide susceptibility. In a previous work, a Logistic Regression (LR was analysed with the same parameters considered in the ANN as independent variables and the occurrence or non-occurrence of landslides as dependent variables. As a result, the logistic approach determined the importance of terrain roughness and soil type as key factors within the model. The results of the landslide susceptibility analysis with ANN are checked using landslide location data. These results show a high concordance between the landslide inventory and the high susceptibility estimated zone. Finally, a comparative analysis of the ANN and LR models are made. The advantages and disadvantages of both approaches are discussed using Receiver Operating Characteristic (ROC curves.

In Planta Functional Analysis and Subcellular Localization of the Oomycete Pathogen Plasmopara viticola Candidate RXLR Effector Repertoire

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Yunxiao Liu

2018-04-01

Full Text Available Downy mildew is one of the most destructive diseases of grapevine, causing tremendous economic loss in the grape and wine industry. The disease agent Plasmopara viticola is an obligate biotrophic oomycete, from which over 100 candidate RXLR effectors have been identified. In this study, 83 candidate RXLR effector genes (PvRXLRs were cloned from the P. viticola isolate “JL-7-2” genome. The results of the yeast signal sequence trap assay indicated that most of the candidate effectors are secretory proteins. The biological activities and subcellular localizations of all the 83 effectors were analyzed via a heterologous Agrobacterium-mediated Nicotiana benthamiana expression system. Results showed that 52 effectors could completely suppress cell death triggered by elicitin, 10 effectors could partially suppress cell death, 11 effectors were unable to suppress cell death, and 10 effectors themselves triggered cell death. Live-cell imaging showed that the majority of the effectors (76 of 83 could be observed with informative fluorescence signals in plant cells, among which 34 effectors were found to be targeted to both the nucleus and cytosol, 29 effectors were specifically localized in the nucleus, and 9 effectors were targeted to plant membrane system. Interestingly, three effectors PvRXLR61, 86 and 161 were targeted to chloroplasts, and one effector PvRXLR54 was dually targeted to chloroplasts and mitochondria. However, western blot analysis suggested that only PvRXLR86 carried a cleavable N-terminal transit peptide and underwent processing in planta. Many effectors have previously been predicted to target organelles, however, to the best of our knowledge, this is the first study to provide experimental evidence of oomycete effectors targeted to chloroplasts and mitochondria.

Presence-only approach to assess landslide triggering-thickness susceptibility: a test for the Mili catchment (north-eastern Sicily, Italy)

KAUST Repository

Lombardo, Luigi; Fubelli, G.; Amato, G.; Bonasera, M.

2016-01-01

This study evaluates the performances of the presence-only approach, Maximum Entropy, in assessing landslide triggering-thickness susceptibility within the Mili catchment (Sicily, Italy). This catchment underwent several meteorological stresses

TAL effectors and the executor R genes.

Science.gov (United States)

Zhang, Junli; Yin, Zhongchao; White, Frank

2015-01-01

Transcription activator-like (TAL) effectors are bacterial type III secretion proteins that function as transcription factors in plants during Xanthomonas/plant interactions, conditioning either host susceptibility and/or host resistance. Three types of TAL effector associated resistance (R) genes have been characterized-recessive, dominant non-transcriptional, and dominant TAL effector-dependent transcriptional based resistance. Here, we discuss the last type of R genes, whose functions are dependent on direct TAL effector binding to discrete effector binding elements in the promoters. Only five of the so-called executor R genes have been cloned, and commonalities are not clear. We have placed the protein products in two groups for conceptual purposes. Group 1 consists solely of the protein from pepper, BS3, which is predicted to have catalytic function on the basis of homology to a large conserved protein family. Group 2 consists of BS4C-R, XA27, XA10, and XA23, all of which are relatively short proteins from pepper or rice with multiple potential transmembrane domains. Group 2 members have low sequence similarity to proteins of unknown function in closely related species. Firm predictions await further experimentation on these interesting new members to the R gene repertoire, which have potential broad application in new strategies for disease resistance.

TAL effectors and the executor R genes

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Junli eZhang

2015-08-01

Full Text Available Transcription activation-like (TAL effectors are bacterial type III secretion proteins that function as transcription factors in plants during Xanthomonas/plant interactions, conditioning either host susceptibility and/or host resistance. Three types of TAL effector associated resistance (R genes have been characterized - recessive, dominant non-transcriptional and dominant TAL effector-dependent transcriptional based resistance. Here, we discuss the last type of R genes, whose functions are dependent on direct TAL effector binding to discrete effector binding elements in the promoters. Only five of the so-called executor R genes have been cloned, and commonalities are not clear. We have placed the protein products in two groups for conceptual purposes. Group 1 consists solely of the protein from pepper, BS3, which is predicted to have catalytic function on the basis of homology to a large conserved protein family. Group 2 consists of BS4C-R, XA27, XA10, and XA23, all of which are relatively short proteins from pepper or rice with multiple potential transmembrane domains. Group 2 members have low sequence similarity to proteins of unknown function in closely related species. Firm predictions await further experimentation on these interesting new members to the R gene repertoire, which have potential broad application in new strategies for disease resistance.

Effector/memory CD8+ T cells synergize with co-stimulation competent macrophages to trigger autoimmune peripheral neuropathy.

Science.gov (United States)

Yang, Mu; Shi, Xiang Qun; Peyret, Corentin; Oladiran, Oladayo; Wu, Sonia; Chambon, Julien; Fournier, Sylvie; Zhang, Ji

2018-04-05

Autoimmune peripheral neuropathy (APN) such as Guillain Barre Syndrome (GBS) is a debilitating illness and sometimes life threatening. The molecular and cellular mechanisms remain elusive but exposure to environmental factors including viral/bacterial infection and injury is highly associated with disease incidence. We demonstrated previously that both male and female B7.2 (CD86) transgenic L31 and L31/CD4KO mice develop spontaneous APN. Here we further reveal that CD8 + T cells in these mice exhibit an effector/memory phenotype, which bears a resemblance to the CD8 + T cell response following persistent cytomegalovirus (CMV) infection in humans and mice, whilst CMV has been considered as one of the most relevant pathogens in APN development. These activated, peripheral myelin Ag specific CD8 + T cells are required for the disease initiation. While an injury to a peripheral nerve results in Wallerian degeneration in control littermates, the same injury accelerates the development of APN in other non-injured nerves of L31 mice which have a predisposed inflammatory background consisting of effector/memory CD8 + T (CD8 + T EM ) cells. However, CD8 + T EM cells alone are not sufficient. A certain threshold of B7.2 expression on nerve macrophages is an additional requisite. Our findings reveal that indeed, the synergism between CD8 + T EM cells and co-stimulation competent macrophages is crucial in inducing autoimmune-mediated peripheral neuropathy. The identification of decisive molecular/cellular players connecting environmental triggers and the occurrence of APN provides opportunities to prevent disease onset, reduce relapses and develop new therapeutic strategies. Crown Copyright © 2018. Published by Elsevier Inc. All rights reserved.

Salicylic Acid and Jasmonic Acid Pathways are Activated in Spatially Different Domains Around the Infection Site During Effector-Triggered Immunity in Arabidopsis thaliana.

Science.gov (United States)

Betsuyaku, Shigeyuki; Katou, Shinpei; Takebayashi, Yumiko; Sakakibara, Hitoshi; Nomura, Nobuhiko; Fukuda, Hiroo

2018-01-01

The innate immune response is, in the first place, elicited at the site of infection. Thus, the host response can be different among the infected cells and the cells surrounding them. Effector-triggered immunity (ETI), a form of innate immunity in plants, is triggered by specific recognition between pathogen effectors and their corresponding plant cytosolic immune receptors, resulting in rapid localized cell death known as hypersensitive response (HR). HR cell death is usually limited to a few cells at the infection site, and is surrounded by a few layers of cells massively expressing defense genes such as Pathogenesis-Related Gene 1 (PR1). This virtually concentric pattern of the cellular responses in ETI is proposed to be regulated by a concentration gradient of salicylic acid (SA), a phytohormone accumulated around the infection site. Recent studies demonstrated that jasmonic acid (JA), another phytohormone known to be mutually antagonistic to SA in many cases, is also accumulated in and required for ETI, suggesting that ETI is a unique case. However, the molecular basis for this uniqueness remained largely to be solved. Here, we found that, using intravital time-lapse imaging, the JA signaling pathway is activated in the cells surrounding the central SA-active cells around the infection sites in Arabidopsis thaliana. This distinct spatial organization explains how these two phythormone pathways in a mutually antagonistic relationship can be activated simultaneously during ETI. Our results re-emphasize that the spatial consideration is a key strategy to gain mechanistic insights into the apparently complex signaling cross-talk in immunity. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists.

Salicylic acid receptors activate jasmonic acid signalling through a non-canonical pathway to promote effector-triggered immunity.

Science.gov (United States)

Liu, Lijing; Sonbol, Fathi-Mohamed; Huot, Bethany; Gu, Yangnan; Withers, John; Mwimba, Musoki; Yao, Jian; He, Sheng Yang; Dong, Xinnian

2016-10-11

It is an apparent conundrum how plants evolved effector-triggered immunity (ETI), involving programmed cell death (PCD), as a major defence mechanism against biotrophic pathogens, because ETI-associated PCD could leave them vulnerable to necrotrophic pathogens that thrive on dead host cells. Interestingly, during ETI, the normally antagonistic defence hormones, salicylic acid (SA) and jasmonic acid (JA) associated with defence against biotrophs and necrotrophs respectively, both accumulate to high levels. In this study, we made the surprising finding that JA is a positive regulator of RPS2-mediated ETI. Early induction of JA-responsive genes and de novo JA synthesis following SA accumulation is activated through the SA receptors NPR3 and NPR4, instead of the JA receptor COI1. We provide evidence that NPR3 and NPR4 may mediate this effect by promoting degradation of the JA transcriptional repressor JAZs. This unique interplay between SA and JA offers a possible explanation of how plants can mount defence against a biotrophic pathogen without becoming vulnerable to necrotrophic pathogens.

Tomato Cf resistance proteins mediate recognition of cognate homologous effectors from fungi pathogenic on dicots and monocots.

Science.gov (United States)

Stergiopoulos, Ioannis; van den Burg, Harrold A; Okmen, Bilal; Beenen, Henriek G; van Liere, Sabine; Kema, Gert H J; de Wit, Pierre J G M

2010-04-20

Most fungal effectors characterized so far are species-specific and facilitate virulence on a particular host plant. During infection of its host tomato, Cladosporium fulvum secretes effectors that function as virulence factors in the absence of cognate Cf resistance proteins and induce effector-triggered immunity in their presence. Here we show that homologs of the C. fulvum Avr4 and Ecp2 effectors are present in other pathogenic fungi of the Dothideomycete class, including Mycosphaerella fijiensis, the causal agent of black Sigatoka disease of banana. We demonstrate that the Avr4 homolog of M. fijiensis is a functional ortholog of C. fulvum Avr4 that protects fungal cell walls against hydrolysis by plant chitinases through binding to chitin and, despite the low overall sequence homology, triggers a Cf-4-mediated hypersensitive response (HR) in tomato. Furthermore, three homologs of C. fulvum Ecp2 are found in M. fijiensis, one of which induces different levels of necrosis or HR in tomato lines that lack or contain a putative cognate Cf-Ecp2 protein, respectively. In contrast to Avr4, which acts as a defensive virulence factor, M. fijiensis Ecp2 likely promotes virulence by interacting with a putative host target causing host cell necrosis, whereas Cf-Ecp2 could possibly guard the virulence target of Ecp2 and trigger a Cf-Ecp2-mediated HR. Overall our data suggest that Avr4 and Ecp2 represent core effectors that are collectively recognized by single cognate Cf-proteins. Transfer of these Cf genes to plant species that are attacked by fungi containing these cognate core effectors provides unique ways for breeding disease-resistant crops.

Susceptibility assessment of earthquake-triggered landslides in El Salvador using logistic regression

Science.gov (United States)

García-Rodríguez, M. J.; Malpica, J. A.; Benito, B.; Díaz, M.

2008-03-01

This work has evaluated the probability of earthquake-triggered landslide occurrence in the whole of El Salvador, with a Geographic Information System (GIS) and a logistic regression model. Slope gradient, elevation, aspect, mean annual precipitation, lithology, land use, and terrain roughness are the predictor variables used to determine the dependent variable of occurrence or non-occurrence of landslides within an individual grid cell. The results illustrate the importance of terrain roughness and soil type as key factors within the model — using only these two variables the analysis returned a significance level of 89.4%. The results obtained from the model within the GIS were then used to produce a map of relative landslide susceptibility.

An Aphid Effector Targets Trafficking Protein VPS52 in a Host-Specific Manner to Promote Virulence.

Science.gov (United States)

Rodriguez, Patricia A; Escudero-Martinez, Carmen; Bos, Jorunn I B

2017-03-01

Plant- and animal-feeding insects secrete saliva inside their hosts, containing effectors, which may promote nutrient release and suppress immunity. Although for plant pathogenic microbes it is well established that effectors target host proteins to modulate host cell processes and promote disease, the host cell targets of herbivorous insects remain elusive. Here, we show that the existing plant pathogenic microbe effector paradigm can be extended to herbivorous insects in that effector-target interactions inside host cells modify critical host processes to promote plant susceptibility. We showed that the effector Mp1 from Myzus persicae associates with the host Vacuolar Protein Sorting Associated Protein52 (VPS52). Using natural variants, we provide a strong link between effector virulence activity and association with VPS52, and show that the association is highly specific to M persicae -host interactions. Also, coexpression of Mp1, but not Mp1-like variants, specifically with host VPS52s resulted in effector relocalization to vesicle-like structures that associate with prevacuolar compartments. We show that high VPS52 levels negatively impact virulence, and that aphids are able to reduce VPS52 levels during infestation, indicating that VPS52 is an important virulence target. Our work is an important step forward in understanding, at the molecular level, how a major agricultural pest promotes susceptibility during infestation of crop plants. We give evidence that an herbivorous insect employs effectors that interact with host proteins as part of an effective virulence strategy, and that these effectors likely function in a species-specific manner. © 2017 American Society of Plant Biologists. All Rights Reserved.

Presence-only approach to assess landslide triggering-thickness susceptibility. A test for the Mili catchment (North-Eastern Sicily, Italy)

Science.gov (United States)

Lombardo, Luigi; Fubelli, Giandomenico; Amato, Gabriele; Bonasera, Mauro; Hochschild, Volker; Rotigliano, Edoardo

2015-04-01

This study aims at comparing the performances of a presence only approach, namely Maximum Entropy, in assessing landslide triggering-thickness susceptibility within the Mili catchment, located in the north-eastern Sicily, Italy. This catchment has been recently exposed to three main meteorological extreme events, resulting in the activation of multiple fast landslides, which occurred on the 1st October 2009, 10th March 2010 and 1st March 2011. Differently from the 2009 event, which only marginally hit the catchment, the 2010 and 2011 storms fully involved the area of the Mili catchment. Detailed field data was collected to associate the thickness of mobilised materials at the triggering zone to each mass movement within the catchment. This information has been used to model the landslide susceptibility for two classes of processes clustered into shallow failures for maximum depths of 0.5m and deep ones in case of values equal or greater than 0.5m. As the authors believed that the peculiar geomorphometry of this narrow and steep catchment played a fundamental role in generating two distinct patterns of landslide thicknesses during the initiation phase, a HRDEM was used to extract topographic attributes to express near-triggering geomorphological conditions. On the other hand, medium resolution vegetation indexes derived from ASTER scenes were used as explanatory variables pertaining to a wider spatial neighbourhood, whilst a revised geological map, the land use from CORINE and a tectonic map were used to convey an even wider area connected to the slope instability. The choice of a presence-only approach allowed to effectively discriminate between the two types of landslide thicknesses at the triggering zone, producing outstanding prediction skills associated with relatively low variances across a set of 20 randomly generated replicates. The validation phase produced indeed average AUC values of 0.91 with a standard deviation of 0.03 for both the modelled landslide

Structure-function analysis of the Fusarium oxysporum Avr2 effector allows uncoupling of its immune-suppressing activity from recognition

NARCIS (Netherlands)

Di, X.; Cao, L.; Hughes, R.K.; Tintor, N.; Banfield, M.J.; Takken, F.L.W.

2017-01-01

Plant pathogens employ effector proteins to manipulate their hosts. Fusarium oxysporum f. sp. lycopersici (Fol), the causal agent of tomato wilt disease, produces effector protein Avr2. Besides being a virulence factor, Avr2 triggers immunity in I-2 carrying tomato (Solanum lycopersicum). Fol

Screening the budding yeast genome reveals unique factors affecting K2 toxin susceptibility.

Science.gov (United States)

Servienė, Elena; Lukša, Juliana; Orentaitė, Irma; Lafontaine, Denis L J; Urbonavičius, Jaunius

2012-01-01

Understanding how biotoxins kill cells is of prime importance in biomedicine and the food industry. The budding yeast (S. cerevisiae) killers serve as a convenient model to study the activity of biotoxins consistently supplying with significant insights into the basic mechanisms of virus-host cell interactions and toxin entry into eukaryotic target cells. K1 and K2 toxins are active at the cell wall, leading to the disruption of the plasma membrane and subsequent cell death by ion leakage. K28 toxin is active in the cell nucleus, blocking DNA synthesis and cell cycle progression, thereby triggering apoptosis. Genome-wide screens in the budding yeast S. cerevisiae identified several hundred effectors of K1 and K28 toxins. Surprisingly, no such screen had been performed for K2 toxin, the most frequent killer toxin among industrial budding yeasts. We conducted several concurrent genome-wide screens in S. cerevisiae and identified 332 novel K2 toxin effectors. The effectors involved in K2 resistance and hypersensitivity largely map in distinct cellular pathways, including cell wall and plasma membrane structure/biogenesis and mitochondrial function for K2 resistance, and cell wall stress signaling and ion/pH homeostasis for K2 hypersensitivity. 70% of K2 effectors are different from those involved in K1 or K28 susceptibility. Our work demonstrates that despite the fact that K1 and K2 toxins share some aspects of their killing strategies, they largely rely on different sets of effectors. Since the vast majority of the host factors identified here is exclusively active towards K2, we conclude that cells have acquired a specific K2 toxin effectors set. Our work thus indicates that K1 and K2 have elaborated different biological pathways and provides a first step towards the detailed characterization of K2 mode of action.

An Aphid Effector Targets Trafficking Protein VPS52 in a Host-Specific Manner to Promote Virulence1[OPEN

Science.gov (United States)

2017-01-01

Plant- and animal-feeding insects secrete saliva inside their hosts, containing effectors, which may promote nutrient release and suppress immunity. Although for plant pathogenic microbes it is well established that effectors target host proteins to modulate host cell processes and promote disease, the host cell targets of herbivorous insects remain elusive. Here, we show that the existing plant pathogenic microbe effector paradigm can be extended to herbivorous insects in that effector-target interactions inside host cells modify critical host processes to promote plant susceptibility. We showed that the effector Mp1 from Myzus persicae associates with the host Vacuolar Protein Sorting Associated Protein52 (VPS52). Using natural variants, we provide a strong link between effector virulence activity and association with VPS52, and show that the association is highly specific to M. persicae-host interactions. Also, coexpression of Mp1, but not Mp1-like variants, specifically with host VPS52s resulted in effector relocalization to vesicle-like structures that associate with prevacuolar compartments. We show that high VPS52 levels negatively impact virulence, and that aphids are able to reduce VPS52 levels during infestation, indicating that VPS52 is an important virulence target. Our work is an important step forward in understanding, at the molecular level, how a major agricultural pest promotes susceptibility during infestation of crop plants. We give evidence that an herbivorous insect employs effectors that interact with host proteins as part of an effective virulence strategy, and that these effectors likely function in a species-specific manner. PMID:28100451

Demonstration of NK cell-mediated lysis of varicella-zoster virus (VZV)-infected cells: characterization of the effector cells

Energy Technology Data Exchange (ETDEWEB)

Tilden, A.B.; Cauda, R.; Grossi, C.E.; Balch, C.M.; Lakeman, A.D.; Whitley, R.J.

1986-06-01

Infection with varicella-zoster virus (VZV) rendered RAJI cells more susceptible to lysis by non-adherent blood lymphocytes. At an effector to target ratio of 80:1 the mean percentage of /sup 51/Cr release of VZV-infected RAJI cells was 41 +/- 12%, whereas that of uninfected RAJI cells was 15 +/- 6%. The increased susceptibility to lysis was associated with increased effector to target conjugate formation in immunofluorescence binding assays. The effector cells cytotoxic for VZV-infected RAJI cells were predominantly Leu-11a/sup +/ Leu-4/sup -/ granular lymphocytes as demonstrated by fluorescence-activated cell sorting. The effector cell active against VZV-infected RAJI cells appeared similar to those active against herpes simplex virus (HSV)-infected cells, because in cold target competition experiments the lysis of /sup 51/Cr-labeled VZV-infected RAJI cells was efficiently inhibited by either unlabeled VZV-infected RAJI cells (mean 71% inhibition, 2:1 ratio unlabeled to labeled target) or HSV-infected RAJI cells (mean 69% inhibition) but not by uninfected RAJI cells (mean 10% inhibition). In contrast, competition experiments revealed donor heterogeneity in the overlap between effector cells for VZV- or HSV-infected RAJI vs K-562 cells.

A massive expansion of effector genes underlies gall-formation in the wheat pest Mayetiola destructor

DEFF Research Database (Denmark)

Zhao, Chaoyang; Escalante, Lucio Navarro; Chen, Hang

2015-01-01

Gall-forming arthropods are highly specialized herbivores that, in combination with their hosts, produce extended phenotypes with unique morphologies [1]. Many are economically important, and others have improved our understanding of ecology and adaptive radiation [2]. However, the mechanisms...... in plants and E3-ligase-mimicking effectors in plant pathogenic bacteria. SSGP-71 proteins and wheat Skp proteins interact in vivo. Mutations in different SSGP-71 genes avoid the effector-triggered immunity that is directed by the wheat resistance genes H6 and H9. Results point to effectors as the agents...

Manipulation of host membranes by bacterial effectors.

Science.gov (United States)

Ham, Hyeilin; Sreelatha, Anju; Orth, Kim

2011-07-18

Bacterial pathogens interact with host membranes to trigger a wide range of cellular processes during the course of infection. These processes include alterations to the dynamics between the plasma membrane and the actin cytoskeleton, and subversion of the membrane-associated pathways involved in vesicle trafficking. Such changes facilitate the entry and replication of the pathogen, and prevent its phagocytosis and degradation. In this Review, we describe the manipulation of host membranes by numerous bacterial effectors that target phosphoinositide metabolism, GTPase signalling and autophagy.

The Role of CD39 in Modulating Effector Immune Responses in Inflammatory Bowel Disease

OpenAIRE

Huang, Huang

2015-01-01

Inflammatory bowel disease is associated with excessive inflammation of the bowel and intestinal tissues in genetically susceptible individuals. IBD can manifest in two major forms, ulcerative colitis and Crohn’s disease. T helper type 17 cells (Th17) are effector lymphocytes that have been linked to intestinal inflammation in both mice and humans. Effector Th17 cells and regulatory T cells (Treg) – a subset pivotal to immune-tolerance maintenance – derive from the same CD4 progenitors. Our i...

The effector SPRYSEC-19 of Globodera rostochiensis suppresses CC-NB-LRR-mediated disease resistance in plants.

Science.gov (United States)

Postma, Wiebe J; Slootweg, Erik J; Rehman, Sajid; Finkers-Tomczak, Anna; Tytgat, Tom O G; van Gelderen, Kasper; Lozano-Torres, Jose L; Roosien, Jan; Pomp, Rikus; van Schaik, Casper; Bakker, Jaap; Goverse, Aska; Smant, Geert

2012-10-01

The potato cyst nematode Globodera rostochiensis invades roots of host plants where it transforms cells near the vascular cylinder into a permanent feeding site. The host cell modifications are most likely induced by a complex mixture of proteins in the stylet secretions of the nematodes. Resistance to nematodes conferred by nucleotide-binding-leucine-rich repeat (NB-LRR) proteins usually results in a programmed cell death in and around the feeding site, and is most likely triggered by the recognition of effectors in stylet secretions. However, the actual role of these secretions in the activation and suppression of effector-triggered immunity is largely unknown. Here we demonstrate that the effector SPRYSEC-19 of G. rostochiensis physically associates in planta with the LRR domain of a member of the SW5 resistance gene cluster in tomato (Lycopersicon esculentum). Unexpectedly, this interaction did not trigger defense-related programmed cell death and resistance to G. rostochiensis. By contrast, agroinfiltration assays showed that the coexpression of SPRYSEC-19 in leaves of Nicotiana benthamiana suppresses programmed cell death mediated by several coiled-coil (CC)-NB-LRR immune receptors. Furthermore, SPRYSEC-19 abrogated resistance to Potato virus X mediated by the CC-NB-LRR resistance protein Rx1, and resistance to Verticillium dahliae mediated by an unidentified resistance in potato (Solanum tuberosum). The suppression of cell death and disease resistance did not require a physical association of SPRYSEC-19 and the LRR domains of the CC-NB-LRR resistance proteins. Altogether, our data demonstrated that potato cyst nematodes secrete effectors that enable the suppression of programmed cell death and disease resistance mediated by several CC-NB-LRR proteins in plants.

Modulating Cytotoxic Effector Functions by Fc Engineering to Improve Cancer Therapy.

Science.gov (United States)

Kellner, Christian; Otte, Anna; Cappuzzello, Elisa; Klausz, Katja; Peipp, Matthias

2017-09-01

In the last two decades, monoclonal antibodies have revolutionized the therapy of cancer patients. Although antibody therapy has continuously been improved, still a significant number of patients do not benefit from antibody therapy. Therefore, rational optimization of the antibody molecule by Fc engineering represents a major area of translational research to further improve this potent therapeutic option. Monoclonal antibodies are able to trigger a variety of effector mechanisms. Especially Fc-mediated effector functions such as antibody-dependent cell-mediated cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP), and complement- dependent cytotoxicity (CDC) are considered important in antibody therapy of cancer. Novel mechanistic insights into the action of monoclonal antibodies allowed the development of various Fc engineering approaches to modulate antibodies' effector functions. Strategies in modifying the Fc glycosylation profile (Fc glyco-engineering) or approaches in engineering the protein backbone (Fc protein engineering) have been intensively evaluated. In the current review, Fc engineering strategies resulting in improved ADCC, ADCP and CDC activity are summarized and discussed.

Shigella IpaH Family Effectors as a Versatile Model for Studying Pathogenic Bacteria.

Science.gov (United States)

Ashida, Hiroshi; Sasakawa, Chihiro

2015-01-01

Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis). Via the type III secretion system (T3SS), Shigella deliver a subset of virulence proteins (effectors) that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC). Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections.

Shigella IpaH family effectors as a versatile model for studying pathogenic bacteria

Directory of Open Access Journals (Sweden)

Hiroshi eAshida

2016-01-01

Full Text Available Shigella spp. are highly adapted human pathogens that cause bacillary dysentery (shigellosis. Via the type III secretion system (T3SS, Shigella deliver a subset of virulence proteins (effectors that are responsible for pathogenesis, with functions including pyroptosis, invasion of the epithelial cells, intracellular survival, and evasion of host immune responses. Intriguingly, T3SS effector activity and strategies are not unique to Shigella, but are shared by many other bacterial pathogens, including Salmonella, Yersinia, and enteropathogenic Escherichia coli (EPEC. Therefore, studying Shigella T3SS effectors will not only improve our understanding of bacterial infection systems, but also provide a molecular basis for developing live bacterial vaccines and antibacterial drugs. One of Shigella T3SS effectors, IpaH family proteins, which have E3 ubiquitin ligase activity and are widely conserved among other bacterial pathogens, are very relevant because they promote bacterial survival by triggering cell death and modulating the host immune responses. Here, we describe selected examples of Shigella pathogenesis, with particular emphasis on the roles of IpaH family effectors, which shed new light on bacterial survival strategies and provide clues about how to overcome bacterial infections.

Signaling Mechanisms in Pattern-Triggered Immunity (PTI)

KAUST Repository

Bigeard, Jean; Colcombet, Jean; Hirt, Heribert

2015-01-01

In nature, plants constantly have to face pathogen attacks. However, plant disease rarely occurs due to efficient immune systems possessed by the host plants. Pathogens are perceived by two different recognition systems that initiate the so-called pattern-triggered immunity (PTI) and effector-triggered immunity (ETI), both of which are accompanied by a set of induced defenses that usually repel pathogen attacks. Here we discuss the complex network of signaling pathways occurring during PTI, focusing on the involvement of mitogen-activated protein kinases. © 2015 The Author.

The Pseudomonas syringae type III effector HopG1 targets mitochondria, alters plant development, and suppresses plant innate immunity

Science.gov (United States)

Block, Anna; Guo, Ming; Li, Guangyong; Elowsky, Christian; Clemente, Thomas E.; Alfano, James R.

2009-01-01

Summary The bacterial plant pathogen Pseudomonas syringae uses a type III protein secretion system to inject type III effectors into plant cells. Primary targets of these effectors appear to be effector-triggered immunity (ETI) and pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). The type III effector HopG1 is a suppressor of ETI that is broadly conserved in bacterial plant pathogens. Here we show that HopG1 from P. syringae pv. tomato DC3000 also suppresses PTI. Interestingly, HopG1 localizes to plant mitochondria, suggesting that its suppression of innate immunity may be linked to a perturbation of mitochondrial function. While HopG1 possesses no obvious mitochondrial signal peptide, its N-terminal two-thirds was sufficient for mitochondrial localization. A HopG1-GFP fusion lacking HopG1’s N-terminal 13 amino acids was not localized to the mitochondria reflecting the importance of the N-terminus for targeting. Constitutive expression of HopG1 in Arabidopsis thaliana, Nicotiana tabacum (tobacco) and Lycopersicon esculentum (tomato) dramatically alters plant development resulting in dwarfism, increased branching and infertility. Constitutive expression of HopG1 in planta leads to reduced respiration rates and an increased basal level of reactive oxygen species. These findings suggest that HopG1’s target is mitochondrial and that effector/target interaction promotes disease by disrupting mitochondrial functions. PMID:19863557

A combined triggering-propagation modeling approach for the assessment of rainfall induced debris flow susceptibility

Science.gov (United States)

Stancanelli, Laura Maria; Peres, David Johnny; Cancelliere, Antonino; Foti, Enrico

2017-07-01

Rainfall-induced shallow slides can evolve into debris flows that move rapidly downstream with devastating consequences. Mapping the susceptibility to debris flow is an important aid for risk mitigation. We propose a novel practical approach to derive debris flow inundation maps useful for susceptibility assessment, that is based on the integrated use of DEM-based spatially-distributed hydrological and slope stability models with debris flow propagation models. More specifically, the TRIGRS infiltration and infinite slope stability model and the FLO-2D model for the simulation of the related debris flow propagation and deposition are combined. An empirical instability-to-debris flow triggering threshold calibrated on the basis of observed events, is applied to link the two models and to accomplish the task of determining the amount of unstable mass that develops as a debris flow. Calibration of the proposed methodology is carried out based on real data of the debris flow event occurred on 1 October 2009, in the Peloritani mountains area (Italy). Model performance, assessed by receiver-operating-characteristics (ROC) indexes, evidences fairly good reproduction of the observed event. Comparison with the performance of the traditional debris flow modeling procedure, in which sediment and water hydrographs are inputed as lumped at selected points on top of the streams, is also performed, in order to assess quantitatively the limitations of such commonly applied approach. Results show that the proposed method, besides of being more process-consistent than the traditional hydrograph-based approach, can potentially provide a more accurate simulation of debris-flow phenomena, in terms of spatial patterns of erosion and deposition as well on the quantification of mobilized volumes and depths, avoiding overestimation of debris flow triggering volume and, thus, of maximum inundation flow depths.

Distinct regions of the Phytophthora essential effector Avh238 determine its function in cell death activation and plant immunity suppression.

Science.gov (United States)

Yang, Bo; Wang, Qunqing; Jing, Maofeng; Guo, Baodian; Wu, Jiawei; Wang, Haonan; Wang, Yang; Lin, Long; Wang, Yan; Ye, Wenwu; Dong, Suomeng; Wang, Yuanchao

2017-04-01

Phytophthora pathogens secrete effectors to manipulate host innate immunity, thus facilitating infection. Among the RXLR effectors highly induced during Phytophthora sojae infection, Avh238 not only contributes to pathogen virulence but also triggers plant cell death. However, the detailed molecular basis of Avh238 functions remains largely unknown. We mapped the regions responsible for Avh238 functions in pathogen virulence and plant cell death induction using a strategy that combines investigation of natural variation and large-scale mutagenesis assays. The correlation between cellular localization and Avh238 functions was also evaluated. We found that the 79 th residue (histidine or leucine) of Avh238 determined its cell death-inducing activity, and that the 53 amino acids in its C-terminal region are responsible for promoting Phytophthora infection. Transient expression of Avh238 in Nicotiana benthamiana revealed that nuclear localization is essential for triggering cell death, while Avh238-mediated suppression of INF1-triggered cell death requires cytoplasmic localization. Our results demonstrate that a representative example of an essential Phytophthora RXLR effector can evolve to escape recognition by the host by mutating one nucleotide site, and can also retain plant immunosuppressive activity to enhance pathogen virulence in planta. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

A translocated effector required for Bartonella dissemination from derma to blood safeguards migratory host cells from damage by co-translocated effectors.

Science.gov (United States)

Okujava, Rusudan; Guye, Patrick; Lu, Yun-Yueh; Mistl, Claudia; Polus, Florine; Vayssier-Taussat, Muriel; Halin, Cornelia; Rolink, Antonius G; Dehio, Christoph

2014-06-01

Numerous bacterial pathogens secrete multiple effectors to modulate host cellular functions. These effectors may interfere with each other to efficiently control the infection process. Bartonellae are Gram-negative, facultative intracellular bacteria using a VirB type IV secretion system to translocate a cocktail of Bartonella effector proteins (Beps) into host cells. Based on in vitro infection models we demonstrate here that BepE protects infected migratory cells from injurious effects triggered by BepC and is required for in vivo dissemination of bacteria from the dermal site of inoculation to blood. Human endothelial cells (HUVECs) infected with a ΔbepE mutant of B. henselae (Bhe) displayed a cell fragmentation phenotype resulting from Bep-dependent disturbance of rear edge detachment during migration. A ΔbepCE mutant did not show cell fragmentation, indicating that BepC is critical for triggering this deleterious phenotype. Complementation of ΔbepE with BepEBhe or its homologues from other Bartonella species abolished cell fragmentation. This cyto-protective activity is confined to the C-terminal Bartonella intracellular delivery (BID) domain of BepEBhe (BID2.EBhe). Ectopic expression of BID2.EBhe impeded the disruption of actin stress fibers by Rho Inhibitor 1, indicating that BepE restores normal cell migration via the RhoA signaling pathway, a major regulator of rear edge retraction. An intradermal (i.d.) model for B. tribocorum (Btr) infection in the rat reservoir host mimicking the natural route of infection by blood sucking arthropods allowed demonstrating a vital role for BepE in bacterial dissemination from derma to blood. While the Btr mutant ΔbepDE was abacteremic following i.d. inoculation, complementation with BepEBtr, BepEBhe or BIDs.EBhe restored bacteremia. Given that we observed a similar protective effect of BepEBhe on infected bone marrow-derived dendritic cells migrating through a monolayer of lymphatic endothelial cells we propose that

A translocated effector required for Bartonella dissemination from derma to blood safeguards migratory host cells from damage by co-translocated effectors.

Directory of Open Access Journals (Sweden)

Rusudan Okujava

2014-06-01

Full Text Available Numerous bacterial pathogens secrete multiple effectors to modulate host cellular functions. These effectors may interfere with each other to efficiently control the infection process. Bartonellae are Gram-negative, facultative intracellular bacteria using a VirB type IV secretion system to translocate a cocktail of Bartonella effector proteins (Beps into host cells. Based on in vitro infection models we demonstrate here that BepE protects infected migratory cells from injurious effects triggered by BepC and is required for in vivo dissemination of bacteria from the dermal site of inoculation to blood. Human endothelial cells (HUVECs infected with a ΔbepE mutant of B. henselae (Bhe displayed a cell fragmentation phenotype resulting from Bep-dependent disturbance of rear edge detachment during migration. A ΔbepCE mutant did not show cell fragmentation, indicating that BepC is critical for triggering this deleterious phenotype. Complementation of ΔbepE with BepEBhe or its homologues from other Bartonella species abolished cell fragmentation. This cyto-protective activity is confined to the C-terminal Bartonella intracellular delivery (BID domain of BepEBhe (BID2.EBhe. Ectopic expression of BID2.EBhe impeded the disruption of actin stress fibers by Rho Inhibitor 1, indicating that BepE restores normal cell migration via the RhoA signaling pathway, a major regulator of rear edge retraction. An intradermal (i.d. model for B. tribocorum (Btr infection in the rat reservoir host mimicking the natural route of infection by blood sucking arthropods allowed demonstrating a vital role for BepE in bacterial dissemination from derma to blood. While the Btr mutant ΔbepDE was abacteremic following i.d. inoculation, complementation with BepEBtr, BepEBhe or BIDs.EBhe restored bacteremia. Given that we observed a similar protective effect of BepEBhe on infected bone marrow-derived dendritic cells migrating through a monolayer of lymphatic endothelial cells we

Mesenchymal stromal cells engage complement and complement receptor bearing innate effector cells to modulate immune responses.

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Guido Moll

Full Text Available Infusion of human third-party mesenchymal stromal cells (MSCs appears to be a promising therapy for acute graft-versus-host disease (aGvHD. To date, little is known about how MSCs interact with the body's innate immune system after clinical infusion. This study shows, that exposure of MSCs to blood type ABO-matched human blood activates the complement system, which triggers complement-mediated lymphoid and myeloid effector cell activation in blood. We found deposition of complement component C3-derived fragments iC3b and C3dg on MSCs and fluid-phase generation of the chemotactic anaphylatoxins C3a and C5a. MSCs bound low amounts of immunoglobulins and lacked expression of complement regulatory proteins MCP (CD46 and DAF (CD55, but were protected from complement lysis via expression of protectin (CD59. Cell-surface-opsonization and anaphylatoxin-formation triggered complement receptor 3 (CD11b/CD18-mediated effector cell activation in blood. The complement-activating properties of individual MSCs were furthermore correlated with their potency to inhibit PBMC-proliferation in vitro, and both effector cell activation and the immunosuppressive effect could be blocked either by using complement inhibitor Compstatin or by depletion of CD14/CD11b-high myeloid effector cells from mixed lymphocyte reactions. Our study demonstrates for the first time a major role of the complement system in governing the immunomodulatory activity of MSCs and elucidates how complement activation mediates the interaction with other immune cells.

The Effector SPRYSEC-19 of Globodera rostochiensis Suppresses CC-NB-LRR-Mediated Disease Resistance in Plants1[C][W][OA

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Postma, Wiebe J.; Slootweg, Erik J.; Rehman, Sajid; Finkers-Tomczak, Anna; Tytgat, Tom O.G.; van Gelderen, Kasper; Lozano-Torres, Jose L.; Roosien, Jan; Pomp, Rikus; van Schaik, Casper; Bakker, Jaap; Goverse, Aska; Smant, Geert

2012-01-01

The potato cyst nematode Globodera rostochiensis invades roots of host plants where it transforms cells near the vascular cylinder into a permanent feeding site. The host cell modifications are most likely induced by a complex mixture of proteins in the stylet secretions of the nematodes. Resistance to nematodes conferred by nucleotide-binding-leucine-rich repeat (NB-LRR) proteins usually results in a programmed cell death in and around the feeding site, and is most likely triggered by the recognition of effectors in stylet secretions. However, the actual role of these secretions in the activation and suppression of effector-triggered immunity is largely unknown. Here we demonstrate that the effector SPRYSEC-19 of G. rostochiensis physically associates in planta with the LRR domain of a member of the SW5 resistance gene cluster in tomato (Lycopersicon esculentum). Unexpectedly, this interaction did not trigger defense-related programmed cell death and resistance to G. rostochiensis. By contrast, agroinfiltration assays showed that the coexpression of SPRYSEC-19 in leaves of Nicotiana benthamiana suppresses programmed cell death mediated by several coiled-coil (CC)-NB-LRR immune receptors. Furthermore, SPRYSEC-19 abrogated resistance to Potato virus X mediated by the CC-NB-LRR resistance protein Rx1, and resistance to Verticillium dahliae mediated by an unidentified resistance in potato (Solanum tuberosum). The suppression of cell death and disease resistance did not require a physical association of SPRYSEC-19 and the LRR domains of the CC-NB-LRR resistance proteins. Altogether, our data demonstrated that potato cyst nematodes secrete effectors that enable the suppression of programmed cell death and disease resistance mediated by several CC-NB-LRR proteins in plants. PMID:22904163

Using hierarchical clustering of secreted protein families to classify and rank candidate effectors of rust fungi.

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Diane G O Saunders

Full Text Available Rust fungi are obligate biotrophic pathogens that cause considerable damage on crop plants. Puccinia graminis f. sp. tritici, the causal agent of wheat stem rust, and Melampsora larici-populina, the poplar leaf rust pathogen, have strong deleterious impacts on wheat and poplar wood production, respectively. Filamentous pathogens such as rust fungi secrete molecules called disease effectors that act as modulators of host cell physiology and can suppress or trigger host immunity. Current knowledge on effectors from other filamentous plant pathogens can be exploited for the characterisation of effectors in the genome of recently sequenced rust fungi. We designed a comprehensive in silico analysis pipeline to identify the putative effector repertoire from the genome of two plant pathogenic rust fungi. The pipeline is based on the observation that known effector proteins from filamentous pathogens have at least one of the following properties: (i contain a secretion signal, (ii are encoded by in planta induced genes, (iii have similarity to haustorial proteins, (iv are small and cysteine rich, (v contain a known effector motif or a nuclear localization signal, (vi are encoded by genes with long intergenic regions, (vii contain internal repeats, and (viii do not contain PFAM domains, except those associated with pathogenicity. We used Markov clustering and hierarchical clustering to classify protein families of rust pathogens and rank them according to their likelihood of being effectors. Using this approach, we identified eight families of candidate effectors that we consider of high value for functional characterization. This study revealed a diverse set of candidate effectors, including families of haustorial expressed secreted proteins and small cysteine-rich proteins. This comprehensive classification of candidate effectors from these devastating rust pathogens is an initial step towards probing plant germplasm for novel resistance components.

The Bacterial Effector HopX1 Targets JAZ Transcriptional Repressors to Activate Jasmonate Signaling and Promote Infection in Arabidopsis

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Gimenez-Ibanez, Selena; Boter, Marta; Fernández-Barbero, Gemma; Chini, Andrea; Rathjen, John P.; Solano, Roberto

2014-01-01

Pathogenicity of Pseudomonas syringae is dependent on a type III secretion system, which secretes a suite of virulence effector proteins into the host cytoplasm, and the production of a number of toxins such as coronatine (COR), which is a mimic of the plant hormone jasmonate-isoleuce (JA-Ile). Inside the plant cell, effectors target host molecules to subvert the host cell physiology and disrupt defenses. However, despite the fact that elucidating effector action is essential to understanding bacterial pathogenesis, the molecular function and host targets of the vast majority of effectors remain largely unknown. Here, we found that effector HopX1 from Pseudomonas syringae pv. tabaci (Pta) 11528, a strain that does not produce COR, interacts with and promotes the degradation of JAZ proteins, a key family of JA-repressors. We show that hopX1 encodes a cysteine protease, activity that is required for degradation of JAZs by HopX1. HopX1 associates with JAZ proteins through its central ZIM domain and degradation occurs in a COI1-independent manner. Moreover, ectopic expression of HopX1 in Arabidopsis induces the expression of JA-dependent genes, represses salicylic acid (SA)-induced markers, and complements the growth of a COR-deficient P. syringae pv. tomato (Pto) DC3000 strain during natural bacterial infections. Furthermore, HopX1 promoted susceptibility when delivered by the natural type III secretion system, to a similar extent as the addition of COR, and this effect was dependent on its catalytic activity. Altogether, our results indicate that JAZ proteins are direct targets of bacterial effectors to promote activation of JA-induced defenses and susceptibility in Arabidopsis. HopX1 illustrates a paradigm of an alternative evolutionary solution to COR with similar physiological outcome. PMID:24558350

Enavatuzumab, a Humanized Anti-TWEAK Receptor Monoclonal Antibody, Exerts Antitumor Activity through Attracting and Activating Innate Immune Effector Cells

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Shiming Ye

2017-01-01

Full Text Available Enavatuzumab is a humanized IgG1 anti-TWEAK receptor monoclonal antibody that was evaluated in a phase I clinical study for the treatment of solid malignancies. The current study was to determine whether and how myeloid effector cells were involved in postulated mechanisms for its potent antitumor activity in xenograft models. The initial evidence for a role of effector cells was obtained in a subset of tumor xenograft mouse models whose response to enavatuzumab relied on the binding of Fc of the antibody to Fcγ receptor. The involvement of effector cells was further confirmed by immunohistochemistry, which revealed strong infiltration of CD45+ effector cells into tumor xenografts in responding models, but minimal infiltration in nonresponders. Consistent with the xenograft studies, human effector cells preferentially migrated toward in vivo-responsive tumor cells treated by enavatuzumab in vitro, with the majority of migratory cells being monocytes. Conditioned media from enavatuzumab-treated tumor cells contained elevated levels of chemokines, which might be responsible for enavatuzumab-triggered effector cell migration. These preclinical studies demonstrate that enavatuzumab can exert its potent antitumor activity by actively recruiting and activating myeloid effectors to kill tumor cells. Enavatuzumab-induced chemokines warrant further evaluation in clinical studies as potential biomarkers for such activity.

Phytophthora suppressor of RNA silencing 2 is a conserved RxLR effector that promotes infection in soybean and Arabidopsis thaliana.

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Xiong, Qin; Ye, Wenwu; Choi, Duseok; Wong, James; Qiao, Yongli; Tao, Kai; Wang, Yuanchao; Ma, Wenbo

2014-12-01

The genus Phytophthora consists of notorious and emerging pathogens of economically important crops. Each Phytophthora genome encodes several hundreds of cytoplasmic effectors, which are believed to manipulate plant immune response inside the host cells. However, the majority of Phytophthora effectors remain functionally uncharacterized. We recently discovered two effectors from the soybean stem and root rot pathogen Phytophthora sojae with the activity to suppress RNA silencing in plants. These effectors are designated Phytophthora suppressor of RNA silencing (PSRs). Here, we report that the P. sojae PSR2 (PsPSR2) belongs to a conserved and widespread effector family in Phytophthora. A PsPSR2-like effector produced by P. infestans (PiPSR2) can also suppress RNA silencing in plants and promote Phytophthora infection, suggesting that the PSR2 family effectors have conserved functions in plant hosts. Using Agrobacterium rhizogenes-mediated hairy roots induction, we demonstrated that the expression of PsPSR2 rendered hypersusceptibility of soybean to P. sojae. Enhanced susceptibility was also observed in PsPSR2-expressing Arabidopsis thaliana plants during Phytophthora but not bacterial infection. These experiments provide strong evidence that PSR2 is a conserved Phytophthora effector family that performs important virulence functions specifically during Phytophthora infection of various plant hosts.

Evidence for horizontal gene transfer and separation of effector recognition from effector function revealed by analysis of effector genes shared between cape-gooseberry- and tomato-infecting formae speciales of Fusarium oxysporum.

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Simbaqueba, Jaime; Catanzariti, Ann-Maree; González, Carolina; Jones, David A

2018-05-22

RNAseq reads from cape-gooseberry plants (Physalis peruviana) infected with Fusarium oxysporum f. sp. physali (Foph) were mapped against the lineage-specific transcriptome of Fusarium oxysporum f. sp. lycopersici (Fol) to look for putative effector genes. Homologues of Fol SIX1 (designated SIX1a and SIX1b), SIX7, SIX10, SIX12, SIX15 and Ave1 were identified. The near identity of the Foph and Fol SIX7, SIX10 and SIX12 genes and their intergenic regions suggest that this gene cluster may have undergone recent lateral transfer. Foph SIX1a and SIX1b were tested for their ability to complement a SIX1 knockout mutant of Fol. This mutant has reduced pathogenicity on susceptible tomato plants, but is able to infect otherwise resistant tomato plants carrying the I-3 gene for Fusarium wilt resistance (SIX1 corresponds to Avr3). Neither, SIX1a nor SIX1b could restore full pathogenicity on susceptible tomato plants, suggesting that any role they may play in pathogenicity is likely to be specific to cape gooseberry. SIX1b, but not SIX1a, was able to restore avirulence on tomato plants carrying I-3. These findings separate the recognition of SIX1 from its role as an effector and suggest direct recognition by I-3. A hypervariable region of SIX1 undergoing diversifying selection within the F. oxysporum species complex is likely to play an important role in SIX1 recognition. These findings also indicate that I-3 could potentially be deployed as a transgene in cape gooseberry to protect this emerging crop from Foph. Alternatively, cape gooseberry germplasm could be explored for I-3 homologues capable of providing resistance to Foph. This article is protected by copyright. All rights reserved. © 2018 BSPP and John Wiley & Sons Ltd.

Ambiguous Role of Interleukin-12 in Yersinia enterocolitica Infection in Susceptible and Resistant Mouse Strains

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Bohn, Erwin; Schmitt, Edgar; Bielfeldt, Claudia; Noll, Annette; Schulte, Ralf; Autenrieth, Ingo B.

1998-01-01

Endogenous interleukin-12 (IL-12) mediates protection against Yersinia enterocolitica in C57BL/6 mice by triggering gamma interferon (IFN-γ) production in NK and CD4+ T cells. Administration of exogenous IL-12 confers protection against yersiniae in Yersinia-susceptible BALB/c mice but exacerbates yersiniosis in resistant C57BL/6 mice. Therefore, we wanted to dissect the different mechanisms exerted by IL-12 during Yersinia infections by using different models of Yersinia-resistant and -susceptible mice, including resistant C57BL/6 mice, susceptible BALB/c mice, intermediate-susceptible wild-type 129/Sv mice, 129/Sv IFN-γ-receptor-deficient (IFN-γR−/−) mice and C57BL/6 tumor necrosis factor (TNF) receptor p55 chain-deficient (TNFR p55−/−) mice. IFN-γR−/− mice turned out to be highly susceptible to infection by Y. enterocolitica compared with IFN-γR+/+ mice. Administration of IL-12 was protective in IFN-γR+/+ mice but not in IFN-γR−/− mice, suggesting that IFN-γR-induced mechanisms are essential for IL-12-induced resistance against yersiniae. BALB/c mice could be rendered Yersinia resistant by administration of anti-CD4 antibodies or by administration of IL-12. In contrast, C57BL/6 mice could be rendered more resistant by administration of transforming growth factor β (TGF-β). Furthermore, IL-12-triggered toxic effects in C57BL/6 mice were abrogated by coadministration of TGF-β. While administration of IL-12 alone increased TNF-α levels, administration of TGF-β or TGF-β plus IL-12 decreased both TNF-α and IFN-γ levels in Yersinia-infected C57BL/6 mice. Moreover, IL-12 did not induce toxicity in Yersinia-infected TNFR p55−/− mice, suggesting that TNF-α accounts for IL-12-induced toxicity. Taken together, IL-12 may induce different effector mechanisms in BALB/c and C57BL/6 mice resulting either in protection or exacerbation. These results are important for understanding the critical balance of proinflammatory and regulatory

Defining essential processes in plant pathogenesis with Pseudomonas syringae pv. tomato DC3000 disarmed polymutants and a subset of key type III effectors.

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Wei, Hai-Lei; Collmer, Alan

2017-12-25

Pseudomonas syringae pv. tomato DC3000 and its derivatives cause disease in tomato, Arabidopsis and Nicotiana benthamiana. The primary virulence factors include a repertoire of 29 effector proteins injected into plant cells by the type III secretion system and the phytotoxin coronatine. The complete repertoire of effector genes and key coronatine biosynthesis genes have been progressively deleted and minimally reassembled to reconstitute basic pathogenic ability in N. benthamiana, and in Arabidopsis plants that have mutations in target genes that mimic effector actions. This approach and molecular studies of effector activities and plant immune system targets have highlighted a small subset of effectors that contribute to essential processes in pathogenesis. Most notably, HopM1 and AvrE1 redundantly promote an aqueous apoplastic environment, and AvrPtoB and AvrPto redundantly block early immune responses, two conditions that are sufficient for substantial bacterial growth in planta. In addition, disarmed DC3000 polymutants have been used to identify the individual effectors responsible for specific activities of the complete repertoire and to more effectively study effector domains, effector interplay and effector actions on host targets. Such work has revealed that AvrPtoB suppresses cell death elicitation in N. benthamiana that is triggered by another effector in the DC3000 repertoire, highlighting an important aspect of effector interplay in native repertoires. Disarmed DC3000 polymutants support the natural delivery of test effectors and infection readouts that more accurately reveal effector functions in key pathogenesis processes, and enable the identification of effectors with similar activities from a broad range of other pathogens that also defeat plants with cytoplasmic effectors. © 2017 BSPP AND JOHN WILEY & SONS LTD.

Oomycetes, effectors, and all that jazz.

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Bozkurt, Tolga O; Schornack, Sebastian; Banfield, Mark J; Kamoun, Sophien

2012-08-01

Plant pathogenic oomycetes secrete a diverse repertoire of effector proteins that modulate host innate immunity and enable parasitic infection. Understanding how effectors evolve, translocate and traffic inside host cells, and perturb host processes are major themes in the study of oomycete-plant interactions. The last year has seen important progress in the study of oomycete effectors with, notably, the elucidation of the 3D structures of five RXLR effectors, and novel insights into how cytoplasmic effectors subvert host cells. In this review, we discuss these and other recent advances and highlight the most important open questions in oomycete effector biology. Copyright © 2012 Elsevier Ltd. All rights reserved.

A generalized quantitative antibody homeostasis model: maintenance of global antibody equilibrium by effector functions.

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Prechl, József

2017-11-01

The homeostasis of antibodies can be characterized as a balanced production, target-binding and receptor-mediated elimination regulated by an interaction network, which controls B-cell development and selection. Recently, we proposed a quantitative model to describe how the concentration and affinity of interacting partners generates a network. Here we argue that this physical, quantitative approach can be extended for the interpretation of effector functions of antibodies. We define global antibody equilibrium as the zone of molar equivalence of free antibody, free antigen and immune complex concentrations and of dissociation constant of apparent affinity: [Ab]=[Ag]=[AbAg]= K D . This zone corresponds to the biologically relevant K D range of reversible interactions. We show that thermodynamic and kinetic properties of antibody-antigen interactions correlate with immunological functions. The formation of stable, long-lived immune complexes correspond to a decrease of entropy and is a prerequisite for the generation of higher-order complexes. As the energy of formation of complexes increases, we observe a gradual shift from silent clearance to inflammatory reactions. These rules can also be applied to complement activation-related immune effector processes, linking the physicochemical principles of innate and adaptive humoral responses. Affinity of the receptors mediating effector functions shows a wide range of affinities, allowing the continuous sampling of antibody-bound antigen over the complete range of concentrations. The generation of multivalent, multicomponent complexes triggers effector functions by crosslinking these receptors on effector cells with increasing enzymatic degradation potential. Thus, antibody homeostasis is a thermodynamic system with complex network properties, nested into the host organism by proper immunoregulatory and effector pathways. Maintenance of global antibody equilibrium is achieved by innate qualitative signals modulating a

Distinct activities of Bartonella henselae type IV secretion effector proteins modulate capillary-like sprout formation.

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Scheidegger, F; Ellner, Y; Guye, P; Rhomberg, T A; Weber, H; Augustin, H G; Dehio, C

2009-07-01

The zoonotic pathogen Bartonella henselae (Bh) can lead to vasoproliferative tumour lesions in the skin and inner organs known as bacillary angiomatosis and bacillary peliosis. The knowledge on the molecular and cellular mechanisms involved in this pathogen-triggered angiogenic process is confined by the lack of a suitable animal model and a physiologically relevant cell culture model of angiogenesis. Here we employed a three-dimensional in vitro angiogenesis assay of collagen gel-embedded endothelial cell (EC) spheroids to study the angiogenic properties of Bh. Spheroids generated from Bh-infected ECs displayed a high capacity to form sprouts, which represent capillary-like projections into the collagen gel. The VirB/VirD4 type IV secretion system and a subset of its translocated Bartonella effector proteins (Beps) were found to profoundly modulate this Bh-induced sprouting activity. BepA, known to protect ECs from apoptosis, strongly promoted sprout formation. In contrast, BepG, triggering cytoskeletal rearrangements, potently inhibited sprouting. Hence, the here established in vitro model of Bartonella- induced angiogenesis revealed distinct and opposing activities of type IV secretion system effector proteins, which together with a VirB/VirD4-independent effect may control the angiogenic activity of Bh during chronic infection of the vasculature.

Dynamic stresses, coulomb failure, and remote triggering: corrected

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Hill, David P.

2012-01-01

Dynamic stresses associated with crustal surface waves with 15–30 s periods and peak amplitudes Coulomb failure models based on a frictional strength threshold offer one explanation for instances of rapid‐onset triggered seismicity that develop during the surface‐wave peak dynamic stressing. Evaluation of the triggering potential of surface‐wave dynamic stresses acting on critically stressed faults using a Mohr’s circle representation together with the Coulomb failure criteria indicates that Love waves should have a higher triggering potential than Rayleigh waves for most fault orientations and wave incidence angles. That (1) the onset of triggered seismicity often appears to begin during the Rayleigh wave rather than the earlier arriving Love wave, and (2) Love‐wave amplitudes typically exceed those for Rayleigh waves suggests that the explanation for rapid‐onset dynamic triggering may not reside solely with a simple static‐threshold friction mode. The results also indicate that normal faults should be more susceptible to dynamic triggering by 20‐s Rayleigh‐wave stresses than thrust faults in the shallow seismogenic crust (<10  km) while the advantage tips in favor of reverse faults greater depths. This transition depth scales with wavelength and coincides roughly with the transition from retrograde‐to‐prograde particle motion. Locally elevated pore pressures may have a role in the observed prevalence of dynamic triggering in extensional regimes and geothermal/volcanic systems. The result is consistent with the apparent elevated susceptibility of extensional or transtensional tectonic regimes to remote triggering by Rayleigh‐wave dynamic stresses than compressional or transpressional regimes.

Effector-mediated discovery of a novel resistance gene against Bremia lactucae in a nonhost lettuce species.

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Giesbers, Anne K J; Pelgrom, Alexandra J E; Visser, Richard G F; Niks, Rients E; Van den Ackerveken, Guido; Jeuken, Marieke J W

2017-11-01

Candidate effectors from lettuce downy mildew (Bremia lactucae) enable high-throughput germplasm screening for the presence of resistance (R) genes. The nonhost species Lactuca saligna comprises a source of B. lactucae R genes that has hardly been exploited in lettuce breeding. Its cross-compatibility with the host species L. sativa enables the study of inheritance of nonhost resistance (NHR). We performed transient expression of candidate RXLR effector genes from B. lactucae in a diverse Lactuca germplasm set. Responses to two candidate effectors (BLR31 and BLN08) were genetically mapped and tested for co-segregation with disease resistance. BLN08 induced a hypersensitive response (HR) in 55% of the L. saligna accessions, but responsiveness did not co-segregate with resistance to Bl:24. BLR31 triggered an HR in 5% of the L. saligna accessions, and revealed a novel R gene providing complete B. lactucae race Bl:24 resistance. Resistant hybrid plants that were BLR31 nonresponsive indicated other unlinked R genes and/or nonhost QTLs. We have identified a candidate avirulence effector of B. lactucae (BLR31) and its cognate R gene in L. saligna. Concurrently, our results suggest that R genes are not required for NHR of L. saligna. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Allelic barley MLA immune receptors recognize sequence-unrelated avirulence effectors of the powdery mildew pathogen.

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Lu, Xunli; Kracher, Barbara; Saur, Isabel M L; Bauer, Saskia; Ellwood, Simon R; Wise, Roger; Yaeno, Takashi; Maekawa, Takaki; Schulze-Lefert, Paul

2016-10-18

Disease-resistance genes encoding intracellular nucleotide-binding domain and leucine-rich repeat proteins (NLRs) are key components of the plant innate immune system and typically detect the presence of isolate-specific avirulence (AVR) effectors from pathogens. NLR genes define the fastest-evolving gene family of flowering plants and are often arranged in gene clusters containing multiple paralogs, contributing to copy number and allele-specific NLR variation within a host species. Barley mildew resistance locus a (Mla) has been subject to extensive functional diversification, resulting in allelic resistance specificities each recognizing a cognate, but largely unidentified, AVR a gene of the powdery mildew fungus, Blumeria graminis f. sp. hordei (Bgh). We applied a transcriptome-wide association study among 17 Bgh isolates containing different AVR a genes and identified AVR a1 and AVR a13 , encoding candidate-secreted effectors recognized by Mla1 and Mla13 alleles, respectively. Transient expression of the effector genes in barley leaves or protoplasts was sufficient to trigger Mla1 or Mla13 allele-specific cell death, a hallmark of NLR receptor-mediated immunity. AVR a1 and AVR a13 are phylogenetically unrelated, demonstrating that certain allelic MLA receptors evolved to recognize sequence-unrelated effectors. They are ancient effectors because corresponding loci are present in wheat powdery mildew. AVR A1 recognition by barley MLA1 is retained in transgenic Arabidopsis, indicating that AVR A1 directly binds MLA1 or that its recognition involves an evolutionarily conserved host target of AVR A1 Furthermore, analysis of transcriptome-wide sequence variation among the Bgh isolates provides evidence for Bgh population structure that is partially linked to geographic isolation.

Modeling the effector - regulatory T cell cross-regulation reveals the intrinsic character of relapses in Multiple Sclerosis

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Torrealdea Javier

2011-07-01

Full Text Available Abstract Background The relapsing-remitting dynamics is a hallmark of autoimmune diseases such as Multiple Sclerosis (MS. Although current understanding of both cellular and molecular mechanisms involved in the pathogenesis of autoimmune diseases is significant, how their activity generates this prototypical dynamics is not understood yet. In order to gain insight about the mechanisms that drive these relapsing-remitting dynamics, we developed a computational model using such biological knowledge. We hypothesized that the relapsing dynamics in autoimmunity can arise through the failure in the mechanisms controlling cross-regulation between regulatory and effector T cells with the interplay of stochastic events (e.g. failure in central tolerance, activation by pathogens that are able to trigger the immune system. Results The model represents five concepts: central tolerance (T-cell generation by the thymus, T-cell activation, T-cell memory, cross-regulation (negative feedback between regulatory and effector T-cells and tissue damage. We enriched the model with reversible and irreversible tissue damage, which aims to provide a comprehensible link between autoimmune activity and clinical relapses and active lesions in the magnetic resonances studies in patients with Multiple Sclerosis. Our analysis shows that the weakness in this negative feedback between effector and regulatory T-cells, allows the immune system to generate the characteristic relapsing-remitting dynamics of autoimmune diseases, without the need of additional environmental triggers. The simulations show that the timing at which relapses appear is highly unpredictable. We also introduced targeted perturbations into the model that mimicked immunotherapies that modulate effector and regulatory populations. The effects of such therapies happened to be highly dependent on the timing and/or dose, and on the underlying dynamic of the immune system. Conclusion The relapsing dynamic in MS

Differential expression of candidate salivary effector proteins in field collections of Hessian fly, Mayetiola destructor

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Johnson, A J; Shukle, R H; Chen, M-S; Srivastava, S; Subramanyam, S; Schemerhorn, B J; Weintraub, P G; Abdel Moniem, H E M; Flanders, K L; Buntin, G D; Williams, C E

2015-01-01

Evidence is emerging that some proteins secreted by gall-forming parasites of plants act as effectors responsible for systemic changes in the host plant, such as galling and nutrient tissue formation. A large number of secreted salivary gland proteins (SSGPs) that are the putative effectors responsible for the physiological changes elicited in susceptible seedling wheat by Hessian fly, Mayetiola destructor (Say), larvae have been documented. However, how the genes encoding these candidate effectors might respond under field conditions is unknown. The goal of this study was to use microarray analysis to investigate variation in SSGP transcript abundance amongst field collections from different geographical regions (southeastern USA, central USA, and the Middle East). Results revealed significant variation in SSGP transcript abundance amongst the field collections studied. The field collections separated into three distinct groups that corresponded to the wheat classes grown in the different geographical regions as well as to recently described Hessian fly populations. These data support previous reports correlating Hessian fly population structure with micropopulation differences owing to agro-ecosystem parameters such as cultivation of regionally adapted wheat varieties, deployment of resistance genes and variation in climatic conditions. PMID:25528896

Cognate antigen stimulation generates potent CD8+ inflammatory effector T cells.

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Hsueh-Cheng eSung

2013-12-01

Full Text Available Inflammatory reactions are believed to be triggered by innate signals and have a major protective role by recruiting innate immunity cells, favoring lymphocyte activation and differentiation, and thus contributing to the sequestration and elimination of the injurious stimuli. Although certain lymphocyte types such as TH17 cells co-participate in inflammatory reactions, their generation from the naïve pool requires the pre-existence of an inflammatory milieu. In this context, inflammation is always regarded as beginning with an innate response that may be eventually perpetuated and amplified by certain lymphocyte types. In contrast, we here show that even in sterile immunizations or in MyD88 deficient mice, CD8 T cells produce a burst of pro-inflammatory cytokines and chemokines. These functions follow opposite rules to the classic CD8 effector functions since they are generated prior to cell expansion and decline before antigen elimination. As few as 56 CD8+ inflammatory effector cells in a lymph node can mobilize 107 cells in 24h, including lymphocytes, natural killer cells and several accessory cell types involved in inflammatory reactions. Thus, although inflammation modulates cognate responses, CD8 cognate responses also initiate local inflammatory reactions.

Heritability of Susceptibility to Ionizing Radiation-Induced Apoptosis of Human Lymphocyte Subpopulations

International Nuclear Information System (INIS)

Schmitz, Annette; Bayer, Jan; Dechamps, Nathalie; Goldin, Lynn; Thomas, Gilles

2007-01-01

Purpose: To evaluate the heritability of intrinsic radiosensitivity, the induction of apoptosis in lymphocyte subpopulations was determined on samples from related individuals belonging to large kindred families. Methods and Materials: Quiescent lymphocytes from 334 healthy individuals were gamma-irradiated in vitro. Apoptosis was determined 18 h after irradiation by eight-color flow cytometry. Radiosensitivity was quantified from dose-effect curves. Intrafamilial correlations and heritability were computed for 199 father-mother-offspring trios using the programs SOLAR (Sequential Oligogenic Linkage Analysis Routines) and SAGE (Statistical Analysis for Genetic Epidemiology). Segregation analyses were conducted using SAGE. Results: Marked differential susceptibility of naive and memory T lymphocytes was demonstrated. Also, although age and gender were significant covariates, their effects only accounted for a minor part of the inter-individual variation. Parent-offspring and sib-sib correlations were significant for the radiosensitivity of B cells, T4, and T8 and of effector memory T4 and T8 subpopulations. In the T4-effector memory subpopulation, the phenotype showed correlations most consistent with dominant or additive genetic effects, and the results of the segregation analysis were consistent with the contribution of a bi-allelic dominant locus. Conclusions: Heritability was demonstrated for the susceptibility to ionizing radiation-induced apoptosis of lymphocyte populations, and the segregation of the T4-effector memory radiosensitivity phenotype was consistent with a simple mendelian transmission model involving one major gene

Systematic Identification of Intracellular-Translocated Candidate Effectors in Edwardsiella piscicida

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Lingzhi Zhang

2018-02-01

Full Text Available Many bacterial pathogens inject effectors directly into host cells to target a variety of host cellular processes and promote bacterial dissemination and survival. Identifying the bacterial effectors and elucidating their functions are central to understanding the molecular pathogenesis of these pathogens. Edwardsiella piscicida is a pathogen with a wide host range, and very few of its effectors have been identified to date. Here, based on the genes significantly regulated by macrophage infection, we identified 25 intracellular translocation-positive candidate effectors, including all five previously reported effectors, namely EseG, EseJ, EseH, EseK, and EvpP. A subsequent secretion analysis revealed diverse secretion patterns for the 25 effector candidates, suggesting that multiple transport pathways were involved in the internalization of these candidate effectors. Further, we identified two novel type VI secretion system (T6SS putative effectors and three outer membrane vesicles (OMV-dependent putative effectors among the candidate effectors described above, and further analyzed their contribution to bacterial virulence in a zebrafish model. This work demonstrates an effective approach for screening bacterial effectors and expands the effectors repertoire in E. piscicida.

On the sensitivity of transtensional versus transpressional tectonic regimes to remote dynamic triggering by Coulomb failure

Science.gov (United States)

Hill, David P.

2015-01-01

 Accumulating evidence, although still strongly spatially aliased, indicates that although remote dynamic triggering of small-to-moderate (MwCoulomb failure supports this apparent difference for rapid-onset triggering susceptibility.

Inverse gene-for-gene interactions contribute additively to tan spot susceptibility in wheat.

Science.gov (United States)

Liu, Zhaohui; Zurn, Jason D; Kariyawasam, Gayan; Faris, Justin D; Shi, Gongjun; Hansen, Jana; Rasmussen, Jack B; Acevedo, Maricelis

2017-06-01

Tan spot susceptibility is conferred by multiple interactions of necrotrophic effector and host sensitivity genes. Tan spot of wheat, caused by Pyrenophora tritici-repentis, is an important disease in almost all wheat-growing areas of the world. The disease system is known to involve at least three fungal-produced necrotrophic effectors (NEs) that interact with the corresponding host sensitivity (S) genes in an inverse gene-for-gene manner to induce disease. However, it is unknown if the effects of these NE-S gene interactions contribute additively to the development of tan spot. In this work, we conducted disease evaluations using different races and quantitative trait loci (QTL) analysis in a wheat recombinant inbred line (RIL) population derived from a cross between two susceptible genotypes, LMPG-6 and PI 626573. The two parental lines each harbored a single known NE sensitivity gene with LMPG-6 having the Ptr ToxC sensitivity gene Tsc1 and PI 626573 having the Ptr ToxA sensitivity gene Tsn1. Transgressive segregation was observed in the population for all races. QTL mapping revealed that both loci (Tsn1 and Tsc1) were significantly associated with susceptibility to race 1 isolates, which produce both Ptr ToxA and Ptr ToxC, and the two genes contributed additively to tan spot susceptibility. For isolates of races 2 and 3, which produce only Ptr ToxA and Ptr ToxC, only Tsn1 and Tsc1 were associated with tan spot susceptibility, respectively. This work clearly demonstrates that tan spot susceptibility in this population is due primarily to two NE-S interactions. Breeders should remove both sensitivity genes from wheat lines to obtain high levels of tan spot resistance.

Allele-specific DNA methylation of disease susceptibility genes in Japanese patients with inflammatory bowel disease.

Science.gov (United States)

Chiba, Hirofumi; Kakuta, Yoichi; Kinouchi, Yoshitaka; Kawai, Yosuke; Watanabe, Kazuhiro; Nagao, Munenori; Naito, Takeo; Onodera, Motoyuki; Moroi, Rintaro; Kuroha, Masatake; Kanazawa, Yoshitake; Kimura, Tomoya; Shiga, Hisashi; Endo, Katsuya; Negoro, Kenichi; Nagasaki, Masao; Unno, Michiaki; Shimosegawa, Tooru

2018-01-01

Inflammatory bowel disease (IBD) has an unknown etiology; however, accumulating evidence suggests that IBD is a multifactorial disease influenced by a combination of genetic and environmental factors. The influence of genetic variants on DNA methylation in cis and cis effects on expression have been demonstrated. We hypothesized that IBD susceptibility single-nucleotide polymorphisms (SNPs) regulate susceptibility gene expressions in cis by regulating DNA methylation around SNPs. For this, we determined cis-regulated allele-specific DNA methylation (ASM) around IBD susceptibility genes in CD4+ effector/memory T cells (Tem) in lamina propria mononuclear cells (LPMCs) in patients with IBD and examined the association between the ASM SNP genotype and neighboring susceptibility gene expressions. CD4+ effector/memory T cells (Tem) were isolated from LPMCs in 15 Japanese IBD patients (ten Crohn's disease [CD] and five ulcerative colitis [UC] patients). ASM analysis was performed by methylation-sensitive SNP array analysis. We defined ASM as a changing average relative allele score ([Formula: see text]) >0.1 after digestion by methylation-sensitive restriction enzymes. Among SNPs showing [Formula: see text] >0.1, we extracted the probes located on tag-SNPs of 200 IBD susceptibility loci and around IBD susceptibility genes as candidate ASM SNPs. To validate ASM, bisulfite-pyrosequencing was performed. Transcriptome analysis was examined in 11 IBD patients (seven CD and four UC patients). The relation between rs36221701 genotype and neighboring gene expressions were analyzed. We extracted six candidate ASM SNPs around IBD susceptibility genes. The top of [Formula: see text] (0.23) was rs1130368 located on HLA-DQB1. ASM around rs36221701 ([Formula: see text] = 0.14) located near SMAD3 was validated using bisulfite pyrosequencing. The SMAD3 expression was significantly associated with the rs36221701 genotype (p = 0.016). We confirmed the existence of cis-regulated ASM around

Allele-specific DNA methylation of disease susceptibility genes in Japanese patients with inflammatory bowel disease

Science.gov (United States)

Chiba, Hirofumi; Kakuta, Yoichi; Kinouchi, Yoshitaka; Kawai, Yosuke; Watanabe, Kazuhiro; Nagao, Munenori; Naito, Takeo; Onodera, Motoyuki; Moroi, Rintaro; Kuroha, Masatake; Kanazawa, Yoshitake; Kimura, Tomoya; Shiga, Hisashi; Endo, Katsuya; Negoro, Kenichi; Nagasaki, Masao; Unno, Michiaki; Shimosegawa, Tooru

2018-01-01

Background Inflammatory bowel disease (IBD) has an unknown etiology; however, accumulating evidence suggests that IBD is a multifactorial disease influenced by a combination of genetic and environmental factors. The influence of genetic variants on DNA methylation in cis and cis effects on expression have been demonstrated. We hypothesized that IBD susceptibility single-nucleotide polymorphisms (SNPs) regulate susceptibility gene expressions in cis by regulating DNA methylation around SNPs. For this, we determined cis-regulated allele-specific DNA methylation (ASM) around IBD susceptibility genes in CD4+ effector/memory T cells (Tem) in lamina propria mononuclear cells (LPMCs) in patients with IBD and examined the association between the ASM SNP genotype and neighboring susceptibility gene expressions. Methods CD4+ effector/memory T cells (Tem) were isolated from LPMCs in 15 Japanese IBD patients (ten Crohn's disease [CD] and five ulcerative colitis [UC] patients). ASM analysis was performed by methylation-sensitive SNP array analysis. We defined ASM as a changing average relative allele score (ΔRAS¯) >0.1 after digestion by methylation-sensitive restriction enzymes. Among SNPs showing ΔRAS¯ >0.1, we extracted the probes located on tag-SNPs of 200 IBD susceptibility loci and around IBD susceptibility genes as candidate ASM SNPs. To validate ASM, bisulfite-pyrosequencing was performed. Transcriptome analysis was examined in 11 IBD patients (seven CD and four UC patients). The relation between rs36221701 genotype and neighboring gene expressions were analyzed. Results We extracted six candidate ASM SNPs around IBD susceptibility genes. The top of ΔRAS¯ (0.23) was rs1130368 located on HLA-DQB1. ASM around rs36221701 (ΔRAS¯ = 0.14) located near SMAD3 was validated using bisulfite pyrosequencing. The SMAD3 expression was significantly associated with the rs36221701 genotype (p = 0.016). Conclusions We confirmed the existence of cis-regulated ASM around IBD

RXLR and CRN effectors from the sunflower downy mildew pathogen Plasmopara halstedii induce hypersensitive-like responses in resistant sunflower lines

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Quentin Gascuel

2016-12-01

Full Text Available Plasmopara halstedii is an obligate biotrophic oomycete causing downy mildew disease on sunflower, Helianthus annuus, an economically important oil crop. Severe symptoms of the disease (e.g. plant dwarfism, leaf bleaching, sporulation and production of infertile flower strongly impair seed yield. Pl resistance genes conferring resistance to specific P. halstedii pathotypes were located on sunflower genetic map but yet not cloned. They are present in cultivated lines to protect them against downy mildew disease. Among the 16 different P. halstedii pathotypes recorded in France, pathotype 710 is frequently found, and therefore continuously controlled in sunflower by different Pl genes. High-throughput sequencing of cDNA from P. halstedii led us to identify potential effectors with the characteristic RXLR or CRN motifs described in other oomycetes. Expression of six P. halstedii putative effectors, five RXLR and one CRN, was analysed by qRT-PCR in pathogen spores and in the pathogen infecting sunflower leaves and these six effectors were selected for functional analyses. We developed a new method for transient expression in sunflower plant leaves and showed for the first time subcellular localization of P. halstedii effectors fused to a fluorescent protein in sunflower leaf cells. Overexpression of the CRN and of 3 RXLR effectors induced hypersensitive-like cell death reactions in some sunflower near-isogenic lines resistant to pathotype 710 and not in susceptible corresponding lines, suggesting they could be involved in Pl loci-mediated resistances.

SPRYSEC effector proteins in Globodera rostochiensis

NARCIS (Netherlands)

Rehman, S.

2008-01-01

Plant pathogens inject so-called effector molecules into the cells of a host plant to promote their growth and reproduction in these hosts. In plant parasitic nematodes, these effector molecules are produced in the salivary glands. The objective of this thesis was to identify and characterize

Uncovering the Legionella genus effector repertoire - strength in diversity and numbers

Science.gov (United States)

Burstein, David; Amaro, Francisco; Zusman, Tal; Lifshitz, Ziv; Cohen, Ofir; Gilbert, Jack A; Pupko, Tal; Shuman, Howard A; Segal, Gil

2016-01-01

Infection by the human pathogen Legionella pneumophila relies on the translocation of ~300 virulence proteins, termed effectors, which manipulate host-cell processes. However, almost no information exists regarding effectors in other Legionella pathogens. Here we sequenced, assembled and characterized the genomes of 38 Legionella species, and predicted their effector repertoire using a previously validated machine-learning approach. This analysis revealed a treasure trove of 5,885 predicted effectors. The effector repertoire of different Legionella species was found to be largely non-overlapping, and only seven core-effectors were shared among all species studied. Species-specific effectors had atypically low GC content, suggesting exogenous acquisition, possibly from their natural protozoan hosts. Furthermore, we detected numerous novel conserved effector domains, and discovered new domain combinations, which allowed inferring yet undescribed effector functions. The effector collection and network of domain architectures described here can serve as a roadmap for future studies of effector function and evolution. PMID:26752266

Effector proteins of rust fungi.

Science.gov (United States)

Petre, Benjamin; Joly, David L; Duplessis, Sébastien

2014-01-01

Rust fungi include many species that are devastating crop pathogens. To develop resistant plants, a better understanding of rust virulence factors, or effector proteins, is needed. Thus far, only six rust effector proteins have been described: AvrP123, AvrP4, AvrL567, AvrM, RTP1, and PGTAUSPE-10-1. Although some are well established model proteins used to investigate mechanisms of immune receptor activation (avirulence activities) or entry into plant cells, how they work inside host tissues to promote fungal growth remains unknown. The genome sequences of four rust fungi (two Melampsoraceae and two Pucciniaceae) have been analyzed so far. Genome-wide analyses of these species, as well as transcriptomics performed on a broader range of rust fungi, revealed hundreds of small secreted proteins considered as rust candidate secreted effector proteins (CSEPs). The rust community now needs high-throughput approaches (effectoromics) to accelerate effector discovery/characterization and to better understand how they function in planta. However, this task is challenging due to the non-amenability of rust pathosystems (obligate biotrophs infecting crop plants) to traditional molecular genetic approaches mainly due to difficulties in culturing these species in vitro. The use of heterologous approaches should be promoted in the future.

Tissue specific heterogeneity in effector immune cell response

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Saba eTufail

2013-08-01

Full Text Available Post pathogen invasion, migration of effector T-cell subsets to specific tissue locations is of prime importance for generation of robust immune response. Effector T cells are imprinted with distinct ‘homing codes’ (adhesion molecules and chemokine receptors during activation which regulate their targeted trafficking to specific tissues. Internal cues in the lymph node microenvironment along with external stimuli from food (vitamin A and sunlight (vitamin D3 prime dendritic cells, imprinting them to play centrestage in the induction of tissue tropism in effector T cells. B cells as well, in a manner similar to effector T cells, exhibit tissue tropic migration. In this review, we have focused on the factors regulating the generation and migration of effector T cells to various tissues alongwith giving an overview of tissue tropism in B cells.

Co-ordinate regulation of distinct host cell signalling pathways by multifunctional enteropathogenic Escherichia coli effector molecules.

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Kenny, Brendan; Ellis, Sarah; Leard, Alan D; Warawa, Jonathan; Mellor, Harry; Jepson, Mark A

2002-05-01

Enteropathogenic Escherichia coli (EPEC) is a major cause of paediatric diarrhoea and a model for the family of attaching and effacing (A/E) pathogens. A/E pathogens encode a type III secretion system to transfer effector proteins into host cells. The EPEC Tir effector protein acts as a receptor for the bacterial surface protein intimin and is involved in the formation of Cdc42-independent, actin-rich pedestal structures beneath the adhered bacteria. In this paper, we demonstrate that EPEC binding to HeLa cells also induces Tir-independent, cytoskeletal rearrangement evidenced by the early, transient formation of filopodia-like structures at sites of infection. Filopodia formation is dependent on expression of the EPEC Map effector molecule - a protein that targets mitochondria and induces their dysfunction. We show that Map-induced filopodia formation is independent of mitochondrial targeting and is abolished by cellular expression of the Cdc42 inhibitory WASP-CRIB domain, demonstrating that Map has at least two distinct functions in host cells. The transient nature of the filopodia is related to an ability of EPEC to downregulate Map-induced cell signalling that, like pedestal formation, was dependent on both Tir and intimin proteins. The ability of Tir to downregulate filopodia was impaired by disrupting a putative GTPase-activating protein (GAP) motif, suggesting that Tir may possess such a function, with its interaction with intimin triggering this activity. Furthermore, we also found that Map-induced cell signalling inhibits pedestal formation, revealing that the cellular effects of Tir and Map must be co-ordinately regulated during infection. Possible implications of the multifunctional nature of EPEC effector molecules in pathogenesis are discussed.

Special-purpose multifingered robotic end-effectors

International Nuclear Information System (INIS)

Crowder, R.M.

1990-01-01

A number of advanced multifingered robotic end-effectors have been developed recently in which the finger joints are powered from external actuators. Although this gives dexterous performance, there are considerable problems with power transmission, due to the use of flexible tendons between the external actuators and the individual finger joints. If a multifingered robotic end-effector is to be operated in a confined space, local actuation of the fingers needs to be fully considered, even if there is a reduction in hand dexterity over that of an externally mounted actuator system. The University of Southampton has developed a number of end-effectors that incorporate integral finger actuators and mechanisms, two examples of which are discussed in this paper

Comparative reactivity of human IgE to cynomolgus monkey and human effector cells and effects on IgE effector cell potency

Science.gov (United States)

Saul, Louise; Saul, Louise; Josephs, Debra H; Josephs, Debra H; Cutler, Keith; Cutler, Keith; Bradwell, Andrew; Bradwell, Andrew; Karagiannis, Panagiotis; Karagiannis, Panagiotis; Selkirk, Chris; Selkirk, Chris; Gould, Hannah J; Gould, Hannah J; Jones, Paul; Jones, Paul; Spicer, James F; Spicer, James F; Karagiannis, Sophia N; Karagiannis, Sophia N

2014-01-01

Background: Due to genetic similarities with humans, primates of the macaque genus such as the cynomolgus monkey are often chosen as models for toxicology studies of antibody therapies. IgE therapeutics in development depend upon engagement with the FcεRI and FcεRII receptors on immune effector cells for their function. Only limited knowledge of the primate IgE immune system is available to inform the choice of models for mechanistic and safety evaluations.   Methods: The recognition of human IgE by peripheral blood lymphocytes from cynomolgus monkey and man was compared. We used effector cells from each species in ex vivo affinity, dose-response, antibody-receptor dissociation and potency assays. Results: We report cross-reactivity of human IgE Fc with cynomolgus monkey cells, and comparable binding kinetics to peripheral blood lymphocytes from both species. In competition and dissociation assays, however, human IgE dissociated faster from cynomolgus monkey compared with human effector cells. Differences in association and dissociation kinetics were reflected in effector cell potency assays of IgE-mediated target cell killing, with higher concentrations of human IgE needed to elicit effector response in the cynomolgus monkey system. Additionally, human IgE binding on immune effector cells yielded significantly different cytokine release profiles in each species. Conclusion: These data suggest that human IgE binds with different characteristics to human and cynomolgus monkey IgE effector cells. This is likely to affect the potency of IgE effector functions in these two species, and so has relevance for the selection of biologically-relevant model systems when designing pre-clinical toxicology and functional studies. PMID:24492303

Ambient air pollution triggers wheezing symptoms in infants

DEFF Research Database (Denmark)

Andersen, Zorana Jovanovic; Loft, S; Ketzel, Matthias

2008-01-01

There is limited evidence for the role of air pollution in the development and triggering of wheezing symptoms in young children. A study was undertaken to examine the effect of exposure to air pollution on wheezing symptoms in children under the age of 3 years with genetic susceptibility to asthma....

Characterisation of cell death inducing Phytophthora capsici CRN effectors suggests diverse activities in the host nucleus

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Remco eStam

2013-10-01

Full Text Available Plant-Microbe interactions are complex associations that feature recognition of Pathogen Associated Molecular Patterns by the plant immune system and dampening of subsequent responses by pathogen encoded secreted effectors. With large effector repertoires now identified in a range of sequenced microbial genomes, much attention centres on understanding their roles in immunity or disease. These studies not only allow identification of pathogen virulence factors and strategies, they also provide an important molecular toolset suited for studying immunity in plants. The Phytophthora intracellular effector repertoire encodes a large class of proteins that translocate into host cells and exclusively target the host nucleus. Recent functional studies have implicated the CRN protein family as an important class of diverse effectors that target distinct subnuclear compartments and modify host cell signalling. Here, we characterised three necrosis inducing CRNs and show that there are differences in the levels of cell death. We show that only expression of CRN20_624 has an additive effect on PAMP induced cell death but not AVR3a induced ETI. Given their distinctive phenotypes, we assessed localisation of each CRN with a set of nuclear markers and found clear differences in CRN subnuclear distribution patterns. These assays also revealed that expression of CRN83_152 leads to a distinct change in nuclear chromatin organisation, suggesting a distinct series of events that leads to cell death upon over-expression. Taken together, our results suggest diverse functions carried by CRN C-termini, which can be exploited to identify novel processes that take place in the host nucleus and are required for immunity or susceptibility.

Susceptibility Genes in Thyroid Autoimmunity

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Yoshiyuki Ban

2005-01-01

Full Text Available The autoimmune thyroid diseases (AITD are complex diseases which are caused by an interaction between susceptibility genes and environmental triggers. Genetic susceptibility in combination with external factors (e.g. dietary iodine is believed to initiate the autoimmune response to thyroid antigens. Abundant epidemiological data, including family and twin studies, point to a strong genetic influence on the development of AITD. Various techniques have been employed to identify the genes contributing to the etiology of AITD, including candidate gene analysis and whole genome screening. These studies have enabled the identification of several loci (genetic regions that are linked with AITD, and in some of these loci, putative AITD susceptibility genes have been identified. Some of these genes/loci are unique to Graves' disease (GD and Hashimoto's thyroiditis (HT and some are common to both the diseases, indicating that there is a shared genetic susceptibility to GD and HT. The putative GD and HT susceptibility genes include both immune modifying genes (e.g. HLA, CTLA-4 and thyroid specific genes (e.g. TSHR, Tg. Most likely, these loci interact and their interactions may influence disease phenotype and severity.

Robotic end-effector for rewaterproofing shuttle tiles

Science.gov (United States)

Manouchehri, Davoud; Hansen, Joseph M.; Wu, Cheng M.; Yamamoto, Brian S.; Graham, Todd

1992-11-01

This paper summarizes work by Rockwell International's Space Systems Division's Robotics Group at Downey, California. The work is part of a NASA-led team effort to automate Space Shuttle rewaterproofing in the Orbiter Processing Facility at the Kennedy Space Center and the ferry facility at the Ames-Dryden Flight Research Facility. Rockwell's effort focuses on the rewaterproofing end-effector, whose function is to inject hazardous dimethylethyloxysilane into thousands of ceramic tiles on the underside of the orbiter after each flight. The paper has five sections. First, it presents background on the present manual process. Second, end-effector requirements are presented, including safety and interface control. Third, a design is presented for the five end-effector systems: positioning, delivery, containment, data management, and command and control. Fourth, end-effector testing and integrating to the total system are described. Lastly, future applications for this technology are discussed.

Mycobacterium tuberculosis effectors interfering host apoptosis signaling.

Science.gov (United States)

Liu, Minqiang; Li, Wu; Xiang, Xiaohong; Xie, Jianping

2015-07-01

Tuberculosis remains a serious human public health concern. The coevolution between its pathogen Mycobacterium tuberculosis and human host complicated the way to prevent and cure TB. Apoptosis plays subtle role in this interaction. The pathogen endeavors to manipulate the apoptosis via diverse effectors targeting key signaling nodes. In this paper, we summarized the effectors pathogen used to subvert the apoptosis, such as LpqH, ESAT-6/CFP-10, LAMs. The interplay between different forms of cell deaths, such as apoptosis, autophagy, necrosis, is also discussed with a focus on the modes of action of effectors, and implications for better TB control.

Genome-scale identification of Legionella pneumophila effectors using a machine learning approach.

Directory of Open Access Journals (Sweden)

David Burstein

2009-07-01

Full Text Available A large number of highly pathogenic bacteria utilize secretion systems to translocate effector proteins into host cells. Using these effectors, the bacteria subvert host cell processes during infection. Legionella pneumophila translocates effectors via the Icm/Dot type-IV secretion system and to date, approximately 100 effectors have been identified by various experimental and computational techniques. Effector identification is a critical first step towards the understanding of the pathogenesis system in L. pneumophila as well as in other bacterial pathogens. Here, we formulate the task of effector identification as a classification problem: each L. pneumophila open reading frame (ORF was classified as either effector or not. We computationally defined a set of features that best distinguish effectors from non-effectors. These features cover a wide range of characteristics including taxonomical dispersion, regulatory data, genomic organization, similarity to eukaryotic proteomes and more. Machine learning algorithms utilizing these features were then applied to classify all the ORFs within the L. pneumophila genome. Using this approach we were able to predict and experimentally validate 40 new effectors, reaching a success rate of above 90%. Increasing the number of validated effectors to around 140, we were able to gain novel insights into their characteristics. Effectors were found to have low G+C content, supporting the hypothesis that a large number of effectors originate via horizontal gene transfer, probably from their protozoan host. In addition, effectors were found to cluster in specific genomic regions. Finally, we were able to provide a novel description of the C-terminal translocation signal required for effector translocation by the Icm/Dot secretion system. To conclude, we have discovered 40 novel L. pneumophila effectors, predicted over a hundred additional highly probable effectors, and shown the applicability of machine

Testing for the 'predictability' of dynamically triggered earthquakes in The Geysers geothermal field

Science.gov (United States)

Aiken, Chastity; Meng, Xiaofeng; Hardebeck, Jeanne

2018-03-01

The Geysers geothermal field is well known for being susceptible to dynamic triggering of earthquakes by large distant earthquakes, owing to the introduction of fluids for energy production. Yet, it is unknown if dynamic triggering of earthquakes is 'predictable' or whether dynamic triggering could lead to a potential hazard for energy production. In this paper, our goal is to investigate the characteristics of triggering and the physical conditions that promote triggering to determine whether or not triggering is in anyway foreseeable. We find that, at present, triggering in The Geysers is not easily 'predictable' in terms of when and where based on observable physical conditions. However, triggered earthquake magnitude positively correlates with peak imparted dynamic stress, and larger dynamic stresses tend to trigger sequences similar to mainshock-aftershock sequences. Thus, we may be able to 'predict' what size earthquakes to expect at The Geysers following a large distant earthquake.

Seismic wave triggering of nonvolcanic tremor, episodic tremor and slip, and earthquakes on Vancouver Island

Science.gov (United States)

Rubinstein, Justin L.; Gomberg, Joan; Vidale, John E.; Wech, Aaron G.; Kao, Honn; Creager, Kenneth C.; Rogers, Garry

2009-02-01

We explore the physical conditions that enable triggering of nonvolcanic tremor and earthquakes by considering local seismic activity on Vancouver Island, British Columbia during and immediately after the arrival of large-amplitude seismic waves from 30 teleseismic and 17 regional or local earthquakes. We identify tremor triggered by four of the teleseismic earthquakes. The close temporal and spatial proximity of triggered tremor to ambient tremor and aseismic slip indicates that when a fault is close to or undergoing failure, it is particularly susceptible to triggering of further events. The amplitude of the triggering waves also influences the likelihood of triggering both tremor and earthquakes such that large amplitude waves triggered tremor in the absence of detectable aseismic slip or ambient tremor. Tremor and energy radiated from regional/local earthquakes share the same frequency passband so that tremor cannot be identified during these smaller, more frequent events. We confidently identify triggered local earthquakes following only one teleseism, that with the largest amplitude, and four regional or local events that generated vigorous aftershock sequences in their immediate vicinity. Earthquakes tend to be triggered in regions different from tremor and with high ambient seismicity rates. We also note an interesting possible correlation between large teleseismic events and episodic tremor and slip (ETS) episodes, whereby ETS events that are "late" and have built up more stress than normal are susceptible to triggering by the slight nudge of the shaking from a large, distant event, while ETS events that are "early" or "on time" are not.

Effectors from Wheat Rust Fungi Suppress Multiple Plant Defense Responses.

Science.gov (United States)

Ramachandran, Sowmya R; Yin, Chuntao; Kud, Joanna; Tanaka, Kiwamu; Mahoney, Aaron K; Xiao, Fangming; Hulbert, Scot H

2017-01-01

Fungi that cause cereal rust diseases (genus Puccinia) are important pathogens of wheat globally. Upon infection, the fungus secretes a number of effector proteins. Although a large repository of putative effectors has been predicted using bioinformatic pipelines, the lack of available high-throughput effector screening systems has limited functional studies on these proteins. In this study, we mined the available transcriptomes of Puccinia graminis and P. striiformis to look for potential effectors that suppress host hypersensitive response (HR). Twenty small (wheat, confirming its activity in a homologous system. Overall, this study provides the first evidence for the presence of effectors in Puccinia species suppressing multiple plant defense responses.

RXLR and CRN Effectors from the Sunflower Downy Mildew Pathogen Plasmopara halstedii Induce Hypersensitive-Like Responses in Resistant Sunflower Lines

Science.gov (United States)

Gascuel, Quentin; Buendia, Luis; Pecrix, Yann; Blanchet, Nicolas; Muños, Stéphane; Vear, Felicity; Godiard, Laurence

2016-01-01

Plasmopara halstedii is an obligate biotrophic oomycete causing downy mildew disease on sunflower, Helianthus annuus, an economically important oil crop. Severe symptoms of the disease (e.g., plant dwarfism, leaf bleaching, sporulation and production of infertile flower) strongly impair seed yield. Pl resistance genes conferring resistance to specific P. halstedii pathotypes were located on sunflower genetic map but yet not cloned. They are present in cultivated lines to protect them against downy mildew disease. Among the 16 different P. halstedii pathotypes recorded in France, pathotype 710 is frequently found, and therefore continuously controlled in sunflower by different Pl genes. High-throughput sequencing of cDNA from P. halstedii led us to identify potential effectors with the characteristic RXLR or CRN motifs described in other oomycetes. Expression of six P. halstedii putative effectors, five RXLR and one CRN, was analyzed by qRT-PCR in pathogen spores and in the pathogen infecting sunflower leaves and selected for functional analyses. We developed a new method for transient expression in sunflower plant leaves and showed for the first time subcellular localization of P. halstedii effectors fused to a fluorescent protein in sunflower leaf cells. Overexpression of the CRN and of 3 RXLR effectors induced hypersensitive-like cell death reactions in some sunflower near-isogenic lines resistant to pathotype 710 and not in susceptible corresponding lines, suggesting they could be involved in Pl loci-mediated resistances. PMID:28066456

Testing for the ‘predictability’ of dynamically triggered earthquakes in Geysers Geothermal Field

Science.gov (United States)

Aiken, Chastity; Meng, Xiaofeng; Hardebeck, Jeanne L.

2018-01-01

The Geysers geothermal field is well known for being susceptible to dynamic triggering of earthquakes by large distant earthquakes, owing to the introduction of fluids for energy production. Yet, it is unknown if dynamic triggering of earthquakes is ‘predictable’ or whether dynamic triggering could lead to a potential hazard for energy production. In this paper, our goal is to investigate the characteristics of triggering and the physical conditions that promote triggering to determine whether or not triggering is in anyway foreseeable. We find that, at present, triggering in The Geysers is not easily ‘predictable’ in terms of when and where based on observable physical conditions. However, triggered earthquake magnitude positively correlates with peak imparted dynamic stress, and larger dynamic stresses tend to trigger sequences similar to mainshock–aftershock sequences. Thus, we may be able to ‘predict’ what size earthquakes to expect at The Geysers following a large distant earthquake.

The phytopathogenic virulent effector protein RipI induces apoptosis in budding yeast Saccharomyces cerevisiae.

Science.gov (United States)

Deng, Meng-Ying; Sun, Yun-Hao; Li, Pai; Fu, Bei; Shen, Dong; Lu, Yong-Jun

2016-10-01

Virulent protein toxins secreted by the bacterial pathogens can cause cytotoxicity by various molecular mechanisms to combat host cell defense. On the other hand, these proteins can also be used as probes to investigate the defense pathway of host innate immunity. Ralstonia solanacearum, one of the most virulent bacterial phytopathogens, translocates more than 70 effector proteins via type III secretion system during infection. Here, we characterized the cytotoxicity of effector RipI in budding yeast Saccharomyce scerevisiae, an alternative host model. We found that over-expression of RipI resulted in severe growth defect and arginine (R) 117 within the predicted integrase motif was required for inhibition of yeast growth. The phenotype of death manifested the hallmarks of apoptosis. Our data also revealed that RipI-induced apoptosis was independent of Yca1 and mitochondria-mediated apoptotic pathways because Δyca1 and Δaif1 were both sensitive to RipI as compared with the wild type. We further demonstrated that RipI was localized in the yeast nucleus and the N-terminal 1-174aa was required for the localization. High-throughput RNA sequencing analysis showed that upon RipI over-expression, 101 unigenes of yeast ribosome presented lower expression level, and 42 GO classes related to the nucleus or recombination were enriched with differential expression levels. Taken together, our data showed that a nuclear-targeting effector RipI triggers yeast apoptosis, potentially dependent on its integrase function. Our results also provided an alternative strategy to dissect the signaling pathway of cytotoxicity induced by the protein toxins. Copyright © 2016 Elsevier Ltd. All rights reserved.

INFLUENCE OF MODIFIED BIOFLAVONOIDS UPON EFFECTOR LYMPHOCYTES IN MURINE MODEL OF CONTACT SENSITIVITY

Directory of Open Access Journals (Sweden)

D. Z. Albegova

2015-01-01

Full Text Available Contact sensitivity reaction (CSR to 2,4-dinitrofluorobenzene (DNFB in mice is a model of in vivo immune response, being an experimental analogue to contact dermatitis in humans. CSR sensitization phase begins after primary contact with antigen, lasting for 10-15 days in humans, and 5-7 days, in mice. Repeated skin exposure to the sensitizing substance leads to its recognition and triggering immune inflammatory mechanisms involving DNFB-specific effector T lymphocytes. The CSR reaches its maximum 18-48 hours after re-exposure to a hapten. There is only scarce information in the literature about effects of flavonoids on CSR, including both stimulatory and inhibitory effects. Flavonoids possessed, predominantly, suppressive effects against the CSR development. In our laboratory, a model of contact sensitivity was reproduced in CBA mice by means of cutaneous sensitization by 2,4-dinitrofluorobenzene. The aim of the study was to identify the mechanisms of immunomodulatory action of quercetin dihydrate and modified bioflavonoids, using the method of adoptive transfer contact sensitivity by splenocytes and T-lymphocytes. As shown in our studies, a 30-min pre-treatment of splenocytes and T-lymphocytes from sensitized mice with modified bioflavonoids before the cell transfer caused complete prevention of contact sensitivity reaction in syngeneic recipient mice. Meanwhile, this effect was not associated with cell death induction due to apoptosis or cytotoxicity. Quercetin dihydrate caused only partially suppression the activity of adaptively formed T-lymphocytes, the contact sensitivity effectors. It was shown that the modified bioflavonoid more stronger suppress adoptive transfer of contact sensitivity in comparison with quercetin dehydrate, without inducing apoptosis of effector cells. Thus, the modified bioflavonoid is a promising compound for further studies in a model of contact sensitivity, due to its higher ability to suppress transfer of CSR with

Sunlight triggers cutaneous lupus through a CSF-1-dependent mechanism in MRL-Fas(lpr) mice.

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Menke, Julia; Hsu, Mei-Yu; Byrne, Katelyn T; Lucas, Julie A; Rabacal, Whitney A; Croker, Byron P; Zong, Xiao-Hua; Stanley, E Richard; Kelley, Vicki R

2008-11-15

Sunlight (UVB) triggers cutaneous lupus erythematosus (CLE) and systemic lupus through an unknown mechanism. We tested the hypothesis that UVB triggers CLE through a CSF-1-dependent, macrophage (Mø)-mediated mechanism in MRL-Fas(lpr) mice. By constructing mutant MRL-Fas(lpr) strains expressing varying levels of CSF-1 (high, intermediate, none), and use of an ex vivo gene transfer to deliver CSF-1 intradermally, we determined that CSF-1 induces CLE in lupus-susceptible MRL-Fas(lpr) mice, but not in lupus-resistant BALB/c mice. UVB incites an increase in Møs, apoptosis in the skin, and CLE in MRL-Fas(lpr), but not in CSF-1-deficient MRL-Fas(lpr) mice. Furthermore, UVB did not induce CLE in BALB/c mice. Probing further, UVB stimulates CSF-1 expression by keratinocytes leading to recruitment and activation of Møs that, in turn, release mediators, which induce apoptosis in keratinocytes. Thus, sunlight triggers a CSF-1-dependent, Mø-mediated destructive inflammation in the skin leading to CLE in lupus-susceptible MRL-Fas(lpr) but not lupus-resistant BALB/c mice. Taken together, CSF-1 is envisioned as the match and lupus susceptibility as the tinder leading to CLE.

The influence of computer-generated path on the robot’s effector stability of motion

Science.gov (United States)

Foit, K.; Banaś, W.; Gwiazda, A.; Ćwikła, G.

2017-08-01

The off-line trajectory planning is often carried out due to economical and practical reasons: the robot is not excluded from the production process and the operator could benefit from testing programs in the virtual environment. On the other hand, the dedicated off-line programming and simulation software is often limited in features and is intended to roughly check the program. It should be expected that the arm of the real robot’s manipulator will realize the trajectory in different manner: the acceleration and deceleration phases may trigger the vibrations of the kinematic chain that could affect the precision of effector positioning and degrade the quality of process realized by the robot. The purpose of this work is the analysis of the selected cases, when the robot’s effector has been moved along the programmed path. The off-line generated, test trajectories have different arrangement of points: such approach has allowed evaluating the time needed to complete the each of the tasks, as well as measuring the level of the vibration of the robot’s wrist. All tests were performed without the load. The conclusions of the experiment may be useful during the trajectory planning in order to avoid the critical configuration of points.

GIS-based landslide susceptibility mapping for the 2005 Kashmir earthquake region

Science.gov (United States)

Kamp, Ulrich; Growley, Benjamin J.; Khattak, Ghazanfar A.; Owen, Lewis A.

2008-11-01

The Mw 7.6 October 8, 2005 Kashmir earthquake triggered several thousand landslides throughout the Himalaya of northern Pakistan and India. These were concentrated in six different geomorphic-geologic-anthropogenic settings. A spatial database, which included 2252 landslides, was developed and analyzed using ASTER satellite imagery and geographical information system (GIS) technology. A multi-criterion evaluation was applied to determine the significance of event-controlling parameters in triggering the landslides. The parameters included lithology, faults, slope gradient, slope aspect, elevation, land cover, rivers and roads. The results showed four classes of landslide susceptibility. Furthermore, they indicated that lithology had the strongest influence on landsliding, particularly when the rock is highly fractured, such as in shale, slate, clastic sediments, and limestone and dolomite. Moreover, the proximity of the landslides to faults, rivers, and roads was also an important factor in helping to initiate failures. In addition, landslides occurred particularly in moderate elevations on south facing slopes. Shrub land, grassland, and also agricultural land were highly susceptible to failures, while forested slopes had few landslides. One-third of the study area was highly or very highly susceptible to future landsliding and requires immediate mitigation action. The rest of the region had a low or moderate susceptibility to landsliding and remains relatively stable. This study supports the view that (1) earthquake-triggered landslides are concentrated in specific zones associated with event-controlling parameters; and (2) in the western Himalaya deforestation and road construction contributed significantly to landsliding during and shortly after earthquakes.

The cytoskeleton is disrupted by the bacterial effector HrpZ, but not by the bacterial PAMP flg22, in tobacco BY-2 cells.

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Guan, Xin; Buchholz, Günther; Nick, Peter

2013-04-01

Plant innate immunity is composed of two layers. Basal immunity is triggered by pathogen-associated molecular patterns (PAMPs) such as the flagellin-peptide flg22 and is termed PAMP-triggered immunity (PTI). In addition, effector-triggered immunity (ETI) linked with programmed cell death and cytoskeletal reorganization can be induced by pathogen-derived factors, such as the Harpin proteins originating from phytopathogenic bacteria. To get insight into the link between cytoskeleton and PTI or ETI, this study followed the responses of actin filaments and microtubules to flg22 and HrpZ in vivo by spinning-disc confocal microscopy in GFP-tagged marker lines of tobacco BY-2. At a concentration that clearly impairs mitosis, flg22 can induce only subtle cytoskeletal responses. In contrast, HrpZ causes a rapid and massive bundling of actin microfilaments (completed in ~20 min, i.e. almost simultaneously with extracellular alkalinization), which is followed by progressive disintegration of actin cables and cytoplasmic microtubules, a loss of cytoplasmic structure, and vacuolar disintegration. Cytoskeletal disruption is proposed as an early event that discriminates HrpZ-triggered ETI-like defence from flg22-triggered PTI.

Review: Potential biotechnological assets related to plant immunity modulation applicable in engineering disease-resistant crops.

Science.gov (United States)

Silva, Marilia Santos; Arraes, Fabrício Barbosa Monteiro; Campos, Magnólia de Araújo; Grossi-de-Sa, Maira; Fernandez, Diana; Cândido, Elizabete de Souza; Cardoso, Marlon Henrique; Franco, Octávio Luiz; Grossi-de-Sa, Maria Fátima

2018-05-01

This review emphasizes the biotechnological potential of molecules implicated in the different layers of plant immunity, including, pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI), effector-triggered susceptibility (ETS), and effector-triggered immunity (ETI) that can be applied in the development of disease-resistant genetically modified (GM) plants. These biomolecules are produced by pathogens (viruses, bacteria, fungi, oomycetes) or plants during their mutual interactions. Biomolecules involved in the first layers of plant immunity, PTI and ETS, include inhibitors of pathogen cell-wall-degrading enzymes (CWDEs), plant pattern recognition receptors (PRRs) and susceptibility (S) proteins, while the ETI-related biomolecules include plant resistance (R) proteins. The biomolecules involved in plant defense PTI/ETI responses described herein also include antimicrobial peptides (AMPs), pathogenesis-related (PR) proteins and ribosome-inhibiting proteins (RIPs), as well as enzymes involved in plant defensive secondary metabolite biosynthesis (phytoanticipins and phytoalexins). Moreover, the regulation of immunity by RNA interference (RNAi) in GM disease-resistant plants is also considered. Therefore, the present review does not cover all the classes of biomolecules involved in plant innate immunity that may be applied in the development of disease-resistant GM crops but instead highlights the most common strategies in the literature, as well as their advantages and disadvantages. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

The Genome Biology of Effector Gene Evolution in Filamentous Plant Pathogens.

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Sánchez-Vallet, Andrea; Fouché, Simone; Fudal, Isabelle; Hartmann, Fanny E; Soyer, Jessica L; Tellier, Aurélien; Croll, Daniel

2018-05-16

Filamentous pathogens, including fungi and oomycetes, pose major threats to global food security. Crop pathogens cause damage by secreting effectors that manipulate the host to the pathogen's advantage. Genes encoding such effectors are among the most rapidly evolving genes in pathogen genomes. Here, we review how the major characteristics of the emergence, function, and regulation of effector genes are tightly linked to the genomic compartments where these genes are located in pathogen genomes. The presence of repetitive elements in these compartments is associated with elevated rates of point mutations and sequence rearrangements with a major impact on effector diversification. The expression of many effectors converges on an epigenetic control mediated by the presence of repetitive elements. Population genomics analyses showed that rapidly evolving pathogens show high rates of turnover at effector loci and display a mosaic in effector presence-absence polymorphism among strains. We conclude that effective pathogen containment strategies require a thorough understanding of the effector genome biology and the pathogen's potential for rapid adaptation. Expected final online publication date for the Annual Review of Phytopathology Volume 56 is August 25, 2018. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Nematode effector proteins: an emerging paradigm of parasitism

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Phytonematodes use a stylet and secreted effectors to invade host tissues and extract nutrients to support their growth and development. The molecular function of nematode effectors is currently the subject of intense investigation. In this review, we summarize our current understanding of nematode ...

Functional heterogeneity of human effector CD8+ T cells.

Science.gov (United States)

Takata, Hiroshi; Naruto, Takuya; Takiguchi, Masafumi

2012-02-09

Effector CD8(+) T cells are believed to be terminally differentiated cells having cytotoxic activity and the ability to produce effector cytokines such as INF-γ and TNF-α. We investigated the difference between CXCR1(+) and CXCR1(-) subsets of human effector CD27(-)CD28(-)CD8(+) T cells. The subsets expressed cytolytic molecules similarly and exerted substantial cytolytic activity, whereas only the CXCR1(-) subset had IL-2 productivity and self-proliferative activity and was more resistant to cell death than the CXCR1(+) subset. These differences were explained by the specific up-regulation of CAMK4, SPRY2, and IL-7R in the CXCR1(-) subset and that of pro-apoptotic death-associated protein kinase 1 (DAPK1) in the CXCR1(+) subset. The IL-2 producers were more frequently found in the IL-7R(+) subset of the CXCR1(-) effector CD8(+) T cells than in the IL-7R(-) subset. IL-7/IL-7R signaling promoted cell survival only in the CXCR1(-) subset. The present study has highlighted a novel subset of effector CD8(+) T cells producing IL-2 and suggests the importance of this subset in the homeostasis of effector CD8(+) T cells.

Principles and applications of TAL effectors for plant physiology and metabolism.

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Bogdanove, Adam J

2014-06-01

Recent advances in DNA targeting allow unprecedented control over gene function and expression. Targeting based on TAL effectors is arguably the most promising for systems biology and metabolic engineering. Multiple, orthogonal TAL-effector reagents of different types can be used in the same cell. Furthermore, variation in base preferences of the individual structural repeats that make up the TAL effector DNA recognition domain makes targeting stringency tunable. Realized applications range from genome editing to epigenome modification to targeted gene regulation to chromatin labeling and capture. The principles that govern TAL effector DNA recognition make TAL effectors well suited for applications relevant to plant physiology and metabolism. TAL effector targeting has merits that are distinct from those of the RNA-based DNA targeting CRISPR/Cas9 system. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Salmonella Effector Protein SopA Modulates Innate Immune Responses by Targeting TRIM E3 Ligase Family Members.

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Jana Kamanova

2016-04-01

Full Text Available Salmonella Typhimurium stimulates inflammatory responses in the intestinal epithelium, which are essential for its ability to replicate within the intestinal tract. Stimulation of these responses is strictly dependent on the activity of a type III secretion system encoded within its pathogenicity island 1, which through the delivery of effector proteins, triggers signaling pathways leading to inflammation. One of these effectors is SopA, a HECT-type E3 ligase, which is required for the efficient stimulation of inflammation in an animal model of Salmonella Typhimurium infection. We show here that SopA contributes to the stimulation of innate immune responses by targeting two host E3 ubiquitin ligases, TRIM56 and TRIM65. We also found that TRIM65 interacts with the innate immune receptor MDA5 enhancing its ability to stimulate interferon-β signaling. Therefore, by targeting TRIM56 and TRIM65, SopA can stimulate signaling through two innate immune receptors, RIG-I and MDA5. These findings describe a Salmonella mechanism to modulate inflammatory responses by directly targeting innate immune signaling mechanisms.

Intraspecies Competition in Serratia marcescens Is Mediated by Type VI-Secreted Rhs Effectors and a Conserved Effector-Associated Accessory Protein.

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Alcoforado Diniz, Juliana; Coulthurst, Sarah J

2015-07-01

The type VI secretion system (T6SS) is widespread in Gram-negative bacteria and can deliver toxic effector proteins into eukaryotic cells or competitor bacteria. Antibacterial T6SSs are increasingly recognized as key mediators of interbacterial competition and may contribute to the outcome of many polymicrobial infections. Multiple antibacterial effectors can be delivered by these systems, with diverse activities against target cells and distinct modes of secretion. Polymorphic toxins containing Rhs repeat domains represent a recently identified and as-yet poorly characterized class of T6SS-dependent effectors. Previous work had revealed that the potent antibacterial T6SS of the opportunistic pathogen Serratia marcescens promotes intraspecies as well as interspecies competition (S. L. Murdoch, K. Trunk, G. English, M. J. Fritsch, E. Pourkarimi, and S. J. Coulthurst, J Bacteriol 193:6057-6069, 2011, http://dx.doi.org/10.1128/JB.05671-11). In this study, two new Rhs family antibacterial effectors delivered by this T6SS have been identified. One of these was shown to act as a DNase toxin, while the other contains a novel, cytoplasmic-acting toxin domain. Importantly, using S. marcescens, it has been demonstrated for the first time that Rhs proteins, rather than other T6SS-secreted effectors, can be the primary determinant of intraspecies competition. Furthermore, a new family of accessory proteins associated with T6SS effectors has been identified, exemplified by S. marcescens EagR1, which is specifically required for deployment of its associated Rhs effector. Together, these findings provide new insight into how bacteria can use the T6SS to deploy Rhs-family effectors and mediate different types of interbacterial interactions. Infectious diseases caused by bacterial pathogens represent a continuing threat to health and economic prosperity. To counter this threat, we must understand how such organisms survive and prosper. The type VI secretion system is a weapon that

Analysis of Two in Planta Expressed LysM Effector Homologs from the Fungus Mycosphaerella graminicola Reveals Novel Functional Properties and Varying Contributions to Virulence on Wheat1[W][OA

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Marshall, Rosalind; Kombrink, Anja; Motteram, Juliet; Loza-Reyes, Elisa; Lucas, John; Hammond-Kosack, Kim E.; Thomma, Bart P.H.J.; Rudd, Jason J.

2011-01-01

Secreted effector proteins enable plant pathogenic fungi to manipulate host defenses for successful infection. Mycosphaerella graminicola causes Septoria tritici blotch disease of wheat (Triticum aestivum) leaves. Leaf infection involves a long (approximately 7 d) period of symptomless intercellular colonization prior to the appearance of necrotic disease lesions. Therefore, M. graminicola is considered as a hemibiotrophic (or necrotrophic) pathogen. Here, we describe the molecular and functional characterization of M. graminicola homologs of Ecp6 (for extracellular protein 6), the Lysin (LysM) domain-containing effector from the biotrophic tomato (Solanum lycopersicum) leaf mold fungus Cladosporium fulvum, which interferes with chitin-triggered immunity in plants. Three LysM effector homologs are present in the M. graminicola genome, referred to as Mg3LysM, Mg1LysM, and MgxLysM. Mg3LysM and Mg1LysM genes were strongly transcriptionally up-regulated specifically during symptomless leaf infection. Both proteins bind chitin; however, only Mg3LysM blocked the elicitation of chitin-induced plant defenses. In contrast to C. fulvum Ecp6, both Mg1LysM and Mg3LysM also protected fungal hyphae against plant-derived hydrolytic enzymes, and both genes show significantly more nucleotide polymorphism giving rise to nonsynonymous amino acid changes. While Mg1LysM deletion mutant strains of M. graminicola were fully pathogenic toward wheat leaves, Mg3LysM mutant strains were severely impaired in leaf colonization, did not trigger lesion formation, and were unable to undergo asexual sporulation. This virulence defect correlated with more rapid and pronounced expression of wheat defense genes during the symptomless phase of leaf colonization. These data highlight different functions for MgLysM effector homologs during plant infection, including novel activities that distinguish these proteins from C. fulvum Ecp6. PMID:21467214

Genomic characterisation of the effector complement of the potato cyst nematode Globodera pallida.

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Thorpe, Peter; Mantelin, Sophie; Cock, Peter Ja; Blok, Vivian C; Coke, Mirela C; Eves-van den Akker, Sebastian; Guzeeva, Elena; Lilley, Catherine J; Smant, Geert; Reid, Adam J; Wright, Kathryn M; Urwin, Peter E; Jones, John T

2014-10-23

The potato cyst nematode Globodera pallida has biotrophic interactions with its host. The nematode induces a feeding structure - the syncytium - which it keeps alive for the duration of the life cycle and on which it depends for all nutrients required to develop to the adult stage. Interactions of G. pallida with the host are mediated by effectors, which are produced in two sets of gland cells. These effectors suppress host defences, facilitate migration and induce the formation of the syncytium. The recent completion of the G. pallida genome sequence has allowed us to identify the effector complement from this species. We identify 128 orthologues of effectors from other nematodes as well as 117 novel effector candidates. We have used in situ hybridisation to confirm gland cell expression of a subset of these effectors, demonstrating the validity of our effector identification approach. We have examined the expression profiles of all effector candidates using RNAseq; this analysis shows that the majority of effectors fall into one of three clusters of sequences showing conserved expression characteristics (invasive stage nematode only, parasitic stage only or invasive stage and adult male only). We demonstrate that further diversity in the effector pool is generated by alternative splicing. In addition, we show that effectors target a diverse range of structures in plant cells, including the peroxisome. This is the first identification of effectors from any plant pathogen that target this structure. This is the first genome scale search for effectors, combined to a life-cycle expression analysis, for any plant-parasitic nematode. We show that, like other phylogenetically unrelated plant pathogens, plant parasitic nematodes deploy hundreds of effectors in order to parasitise plants, with different effectors required for different phases of the infection process.

Fibre optic sensor on robot end effector for flexible assembly

International Nuclear Information System (INIS)

Yung, K.L.; Lau, W.S.; Choi, C.K.; Shan, Y.Y.

1995-01-01

A fibre optic sensor system was constructed for use on robot end effectors for flexible assembly. The sensor detected the deviations between robot end effector and the workpiece. The signal was fed back to robot controller to shift the end effector until the centre of end effector and the centre of workpiece were aligned at the correct orientation. Then workpiece can be grasped symmetrically. Sensor fusion concept was used to guard against sensor system failure. Fuzzy linguistic variable and control rule concept were introduced in the sensor integration. The experimental setup for the sensor integrated system was shown. The accuracy was also discussed

Nanorobotic end-effectors: Design, fabrication, and in situ characterization

Science.gov (United States)

Fan, Zheng

Nano-robotic end-effectors have promising applications for nano-fabrication, nano-manufacturing, nano-optics, nano-medical, and nano-sensing; however, low performances of the conventional end-effectors have prevented the widespread utilization of them in various fields. There are two major difficulties in developing the end-effectors: their nano-fabrication and their advanced characterization in the nanoscale. Here we introduce six types of end-effectors: the nanotube fountain pen (NFP), the super-fine nanoprobe, the metal-filled carbon nanotube (m CNT)-based sphere-on-pillar (SOP) nanoantennas, the tunneling nanosensor, and the nanowire-based memristor. The investigations on the NFP are focused on nano-fluidics and nano-fabrications. The NFP could direct write metallic "inks" and fabricating complex metal nanostructures from 0D to 3D with a position servo control, which is critically important to future large-scale, high-throughput nanodevice production. With the help of NFP, we could fabricate the end-effectors such as super-fine nanoprobe and m CNT-based SOP nanoantennas. Those end-effectors are able to detect local flaws or characterize the electrical/mechanical properties of the nanostructure. Moreover, using electron-energy-loss-spectroscopy (EELS) technique during the operation of the SOP optical antenna opens a new basis for the application of nano-robotic end-effectors. The technique allows advanced characterization of the physical changes, such as carrier diffusion, that are directly responsible for the device's properties. As the device was coupled with characterization techniques of scanning-trasmission-electron-microscopy (STEM), the development of tunneling nanosensor advances this field of science into quantum world. Furthermore, the combined STEM-EELS technique plays an important role in our understanding of the memristive switching performance in the nanowire-based memristor. The developments of those nano-robotic end-effectors expend the study

Investigation of a bio-inspired lift-enhancing effector on a 2D airfoil.

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Johnston, Joe; Gopalarathnam, Ashok

2012-09-01

A flap mounted on the upper surface of an airfoil, called a 'lift-enhancing effector', has been shown in wind tunnel tests to have a similar function to a bird's covert feathers, which rise off the wing's surface in response to separated flows. The effector, fabricated from a thin Mylar sheet, is allowed to rotate freely about its leading edge. The tests were performed in the NCSU subsonic wind tunnel at a chord Reynolds number of 4 × 10(5). The maximum lift coefficient with the effector was the same as that for the clean airfoil, but was maintained over an angle-of-attack range from 12° to almost 20°, resulting in a very gentle stall behavior. To better understand the aerodynamics and to estimate the deployment angle of the free-moving effector, fixed-angle effectors fabricated out of stiff wood were also tested. A progressive increase in the stall angle of attack with increasing effector angle was observed, with diminishing returns beyond the effector angle of 60°. Drag tests on both the free-moving and fixed effectors showed a marked improvement in drag at high angles of attack. Oil flow visualization on the airfoil with and without the fixed-angle effectors proved that the effector causes the separation point to move aft on the airfoil, as compared to the clean airfoil. This is thought to be the main mechanism by which an effector improves both lift and drag. A comparison of the fixed-effector results with those from the free-effector tests shows that the free effector's deployment angle is between 30° and 45°. When operating at and beyond the clean airfoil's stall angle, the free effector automatically deploys to progressively higher angles with increasing angles of attack. This slows down the rapid upstream movement of the separation point and avoids the severe reduction in the lift coefficient and an increase in the drag coefficient that are seen on the clean airfoil at the onset of stall. Thus, the effector postpones the stall by 4-8° and makes the

Design and force analysis of end-effector for plug seedling transplanter.

Science.gov (United States)

Jiang, Zhuohua; Hu, Yang; Jiang, Huanyu; Tong, Junhua

2017-01-01

Automatic transplanters have been very important in greenhouses since the popularization of seedling nurseries. End-effector development is a key technology for transplanting plug seedlings. Most existing end-effectors have problems with holding root plugs or releasing plugs. An efficient end-effector driven by a linear pneumatic cylinder was designed in this study, which could hold root plugs firmly and release plugs easily. This end-effector with four needles could clamp the plug simultaneously while the needles penetrate into the substrate. The depth and verticality of the needles could be adjusted conveniently for different seedling trays. The effectiveness of this end-effector was tested by a combinational trial examining three seedling nursery factors (the moisture content of the substrate, substrate bulk density and the volume proportion of substrate ingredients). Results showed that the total transplanting success rate for the end-effector was 100%, and the root plug harm rate was below 17%. A force measure system with tension and pressure transducers was installed on the designed end-effector. The adhesive force FL between the root plug and the cell of seedling trays and the extrusion force FK on the root plug were measured and analyzed. The results showed that all three variable factors and their interactions had significant effects on the extrusion force. Each factor had a significant effect on adhesive force. Additionally, it was found that the end-effector did not perform very well when the value of FK/FL was beyond the range of 5.99~8.67. This could provide a scientific basis for end-effector application in transplanting.

Chronic Alcohol Ingestion Delays T Cell Activation and Effector Function in Sepsis.

Science.gov (United States)

Margoles, Lindsay M; Mittal, Rohit; Klingensmith, Nathan J; Lyons, John D; Liang, Zhe; Serbanescu, Mara A; Wagener, Maylene E; Coopersmith, Craig M; Ford, Mandy L

2016-01-01

Sepsis is the leading cause of death in intensive care units in the US, and it is known that chronic alcohol use is associated with higher incidence of sepsis, longer ICU stays, and higher mortality from sepsis. Both sepsis and chronic alcohol use are associated with immune deficits such as decreased lymphocyte numbers, impaired innate immunity, delayed-type hypersensitivity reactions, and susceptibility to infections; however, understanding of specific pathways of interaction or synergy between these two states of immune dysregulation is lacking. This study therefore sought to elucidate mechanisms underlying the immune dysregulation observed during sepsis in the setting of chronic alcohol exposure. Using a murine model of chronic ethanol ingestion followed by sepsis induction via cecal ligation and puncture, we determined that while CD4+ and CD8+ T cells isolated from alcohol fed mice eventually expressed the same cellular activation markers (CD44, CD69, and CD43) and effector molecules (IFN-γ, TNF) as their water fed counterparts, there was an overall delay in the acquisition of these phenotypes. This early lag in T cell activation was associated with significantly reduced IL-2 production at a later timepoint in both the CD4+ and CD8+ T cell compartments in alcohol sepsis, as well as with a reduced accumulation of CD8dim activated effectors. Taken together, these data suggest that delayed T cell activation may result in qualitative differences in the immune response to sepsis in the setting of chronic alcohol ingestion.

Design and force analysis of end-effector for plug seedling transplanter.

Directory of Open Access Journals (Sweden)

Zhuohua Jiang

Full Text Available Automatic transplanters have been very important in greenhouses since the popularization of seedling nurseries. End-effector development is a key technology for transplanting plug seedlings. Most existing end-effectors have problems with holding root plugs or releasing plugs. An efficient end-effector driven by a linear pneumatic cylinder was designed in this study, which could hold root plugs firmly and release plugs easily. This end-effector with four needles could clamp the plug simultaneously while the needles penetrate into the substrate. The depth and verticality of the needles could be adjusted conveniently for different seedling trays. The effectiveness of this end-effector was tested by a combinational trial examining three seedling nursery factors (the moisture content of the substrate, substrate bulk density and the volume proportion of substrate ingredients. Results showed that the total transplanting success rate for the end-effector was 100%, and the root plug harm rate was below 17%. A force measure system with tension and pressure transducers was installed on the designed end-effector. The adhesive force FL between the root plug and the cell of seedling trays and the extrusion force FK on the root plug were measured and analyzed. The results showed that all three variable factors and their interactions had significant effects on the extrusion force. Each factor had a significant effect on adhesive force. Additionally, it was found that the end-effector did not perform very well when the value of FK/FL was beyond the range of 5.99~8.67. This could provide a scientific basis for end-effector application in transplanting.

Epstein–Barr Virus Susceptibility in Activated PI3Kδ Syndrome (APDS Immunodeficiency

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Jean-Marie Carpier

2018-01-01

Full Text Available Activated PI3Kδ Syndrome (APDS is an inherited immune disorder caused by heterozygous, gain-of-function mutations in the genes encoding the phosphoinositide 3-kinase delta (PI3Kδ subunits p110δ or p85δ. This recently described primary immunodeficiency disease (PID is characterized by recurrent sinopulmonary infections, lymphoproliferation, and susceptibility to herpesviruses, with Epstein–Barr virus (EBV infection being most notable. A broad range of PIDs having disparate, molecularly defined genetic etiology can cause susceptibility to EBV, lymphoproliferative disease, and lymphoma. Historically, PID patients with loss-of-function mutations causing defective cell-mediated cytotoxicity or antigen receptor signaling were found to be highly susceptible to pathological EBV infection. By contrast, the gain of function in PI3K signaling observed in APDS patients paradoxically renders these patients susceptible to EBV, though the underlying mechanisms are incompletely understood. At a cellular level, APDS patients exhibit deranged B lymphocyte development and defects in class switch recombination, which generally lead to defective immunoglobulin production. Moreover, APDS patients also demonstrate an abnormal skewing of T cells toward terminal effectors with short telomeres and senescence markers. Here, we review APDS with a particular focus on how the altered lymphocyte biology in these patients may confer EBV susceptibility.

Controlling transcription in human pluripotent stem cells using CRISPR-effectors.

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Genga, Ryan M; Kearns, Nicola A; Maehr, René

2016-05-15

The ability to manipulate transcription in human pluripotent stem cells (hPSCs) is fundamental for the discovery of key genes and mechanisms governing cellular state and differentiation. Recently developed CRISPR-effector systems provide a systematic approach to rapidly test gene function in mammalian cells, including hPSCs. In this review, we discuss recent advances in CRISPR-effector technologies that have been employed to control transcription through gene activation, gene repression, and epigenome engineering. We describe an application of CRISPR-effector mediated transcriptional regulation in hPSCs by targeting a synthetic promoter driving a GFP transgene, demonstrating the ease and effectiveness of CRISPR-effector mediated transcriptional regulation in hPSCs. Copyright © 2015 Elsevier Inc. All rights reserved.

Genome-Wide Analysis of Corynespora cassiicola Leaf Fall Disease Putative Effectors.

Science.gov (United States)

Lopez, David; Ribeiro, Sébastien; Label, Philippe; Fumanal, Boris; Venisse, Jean-Stéphane; Kohler, Annegret; de Oliveira, Ricardo R; Labutti, Kurt; Lipzen, Anna; Lail, Kathleen; Bauer, Diane; Ohm, Robin A; Barry, Kerrie W; Spatafora, Joseph; Grigoriev, Igor V; Martin, Francis M; Pujade-Renaud, Valérie

2018-01-01

Corynespora cassiicola is an Ascomycetes fungus with a broad host range and diverse life styles. Mostly known as a necrotrophic plant pathogen, it has also been associated with rare cases of human infection. In the rubber tree, this fungus causes the Corynespora leaf fall (CLF) disease, which increasingly affects natural rubber production in Asia and Africa. It has also been found as an endophyte in South American rubber plantations where no CLF outbreak has yet occurred. The C. cassiicola species is genetically highly diverse, but no clear relationship has been evidenced between phylogenetic lineage and pathogenicity. Cassiicolin, a small glycosylated secreted protein effector, is thought to be involved in the necrotrophic interaction with the rubber tree but some virulent C. cassiicola isolates do not have a cassiicolin gene. This study set out to identify other putative effectors involved in CLF. The genome of a highly virulent C. cassiicola isolate from the rubber tree (CCP) was sequenced and assembled. In silico prediction revealed 2870 putative effectors, comprising CAZymes, lipases, peptidases, secreted proteins and enzymes associated with secondary metabolism. Comparison with the genomes of 44 other fungal species, focusing on effector content, revealed a striking proximity with phylogenetically unrelated species ( Colletotrichum acutatum, Colletotrichum gloesporioides, Fusarium oxysporum, nectria hematococca , and Botrosphaeria dothidea ) sharing life style plasticity and broad host range. Candidate effectors involved in the compatible interaction with the rubber tree were identified by transcriptomic analysis. Differentially expressed genes included 92 putative effectors, among which cassiicolin and two other secreted singleton proteins. Finally, the genomes of 35 C. cassiicola isolates representing the genetic diversity of the species were sequenced and assembled, and putative effectors identified. At the intraspecific level, effector

Genome-Wide Analysis of Corynespora cassiicola Leaf Fall Disease Putative Effectors

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David Lopez

2018-03-01

Full Text Available Corynespora cassiicola is an Ascomycetes fungus with a broad host range and diverse life styles. Mostly known as a necrotrophic plant pathogen, it has also been associated with rare cases of human infection. In the rubber tree, this fungus causes the Corynespora leaf fall (CLF disease, which increasingly affects natural rubber production in Asia and Africa. It has also been found as an endophyte in South American rubber plantations where no CLF outbreak has yet occurred. The C. cassiicola species is genetically highly diverse, but no clear relationship has been evidenced between phylogenetic lineage and pathogenicity. Cassiicolin, a small glycosylated secreted protein effector, is thought to be involved in the necrotrophic interaction with the rubber tree but some virulent C. cassiicola isolates do not have a cassiicolin gene. This study set out to identify other putative effectors involved in CLF. The genome of a highly virulent C. cassiicola isolate from the rubber tree (CCP was sequenced and assembled. In silico prediction revealed 2870 putative effectors, comprising CAZymes, lipases, peptidases, secreted proteins and enzymes associated with secondary metabolism. Comparison with the genomes of 44 other fungal species, focusing on effector content, revealed a striking proximity with phylogenetically unrelated species (Colletotrichum acutatum, Colletotrichum gloesporioides, Fusarium oxysporum, nectria hematococca, and Botrosphaeria dothidea sharing life style plasticity and broad host range. Candidate effectors involved in the compatible interaction with the rubber tree were identified by transcriptomic analysis. Differentially expressed genes included 92 putative effectors, among which cassiicolin and two other secreted singleton proteins. Finally, the genomes of 35 C. cassiicola isolates representing the genetic diversity of the species were sequenced and assembled, and putative effectors identified. At the intraspecific level, effector

Space-based multifunctional end effector systems functional requirements and proposed designs

Science.gov (United States)

Mishkin, A. H.; Jau, B. M.

1988-01-01

The end effector is an essential element of teleoperator and telerobot systems to be employed in space in the next decade. The report defines functional requirements for end effector systems to perform operations that are currently only feasible through Extra-Vehicular Activity (EVA). Specific tasks and functions that the end effectors must be capable of performing are delineated. Required capabilities for forces and torques, clearances, compliance, and sensing are described, using current EVA requirements as guidelines where feasible. The implications of these functional requirements on the elements of potential end effector systems are discussed. The systems issues that must be considered in the design of space-based manipulator systems are identified; including impacts on subsystems tightly coupled to the end effector, i.e., control station, information processing, manipulator arm, tool and equipment stowage. Possible end effector designs are divided into three categories: single degree-of-freedom end effectors, multiple degree of freedom end effectors, and anthropomorphic hands. Specific design alternatives are suggested and analyzed within the individual categories. Two evaluations are performed: the first considers how well the individual end effectors could substitute for EVA; the second compares how manipulator systems composed of the top performers from the first evaluation would improve the space shuttle Remote Manipulator System (RMS) capabilities. The analysis concludes that the anthropomorphic hand is best-suited for EVA tasks. A left- and right-handed anthropomorphic manipulator arm configuration is suggested as appropriate to be affixed to the RMS, but could also be used as part of the Smart Front End for the Orbital Maneuvering Vehicle (OMV). The technical feasibility of the anthropomorphic hand and its control are demonstrated. An evolutionary development approach is proposed and approximate scheduling provided for implementing the suggested

Identification and Characterisation CRN Effectors in Phytophthora capsici Shows Modularity and Functional Diversity.

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Remco Stam

Full Text Available Phytophthora species secrete a large array of effectors during infection of their host plants. The Crinkler (CRN gene family encodes a ubiquitous but understudied class of effectors with possible but as of yet unknown roles in infection. To appreciate CRN effector function in Phytophthora, we devised a simple Crn gene identification and annotation pipeline to improve effector prediction rates. We predicted 84 full-length CRN coding genes and assessed CRN effector domain diversity in sequenced Oomycete genomes. These analyses revealed evidence of CRN domain innovation in Phytophthora and expansion in the Peronosporales. We performed gene expression analyses to validate and define two classes of CRN effectors, each possibly contributing to infection at different stages. CRN localisation studies revealed that P. capsici CRN effector domains target the nucleus and accumulate in specific sub-nuclear compartments. Phenotypic analyses showed that few CRN domains induce necrosis when expressed in planta and that one cell death inducing effector, enhances P. capsici virulence on Nicotiana benthamiana. These results suggest that the CRN protein family form an important class of intracellular effectors that target the host nucleus during infection. These results combined with domain expansion in hemi-biotrophic and necrotrophic pathogens, suggests specific contributions to pathogen lifestyles. This work will bolster CRN identification efforts in other sequenced oomycete species and set the stage for future functional studies towards understanding CRN effector functions.

T3SS-dependent differential modulations of the jasmonic acid pathway in susceptible and resistant genotypes of Malus spp. challenged with Erwinia amylovora.

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Dugé De Bernonville, Thomas; Gaucher, Matthieu; Flors, Victor; Gaillard, Sylvain; Paulin, Jean-Pierre; Dat, James F; Brisset, Marie-Noëlle

2012-06-01

Fire blight is a bacterial disease of Maloideae caused by Erwinia amylovora (Ea). This necrogenic enterobacterium uses a type III secretion system (T3SS) to inject type III effectors into the plant cells to cause disease on its susceptible hosts, including economically important crops like apple and pear. The expressions of marker genes of the salicylic acid (SA) and jasmonic acid (JA) defense regulation pathways were monitored by RT-qPCR in leaves of two apple genotypes, one susceptible and one resistant, challenged with a wild type strain, a T3SS-deficient strain or water. The transcriptional data taken together with hormone level measurements indicated that the SA pathway was similarly induced in both apple genotypes during infection by Ea. On the contrary, the data clearly showed a strong T3SS-dependent down-regulation of the JA pathway in leaves of the susceptible genotype but not in those of the resistant one. Accordingly, methyl-jasmonate treated susceptible plants displayed an increased resistance to Ea. Bacterial mutant analysis indicated that JA manipulation by Ea mainly relies on the type III effector DspA/E. Taken together, our data suggest that the T3SS-dependent down-regulation of the JA pathway is a critical step in the infection process of Malus spp. by Ea. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Evaluation of secretion prediction highlights differing approaches needed for oomycete and fungal effectors

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Jana eSperschneider

2015-12-01

Full Text Available The steadily increasing number of sequenced fungal and oomycete genomes has enabled detailed studies of how these eukaryotic microbes infect plants and cause devastating losses in food crops. During infection, fungal and oomycete pathogens secrete effector molecules which manipulate host plant cell processes to the pathogen’s advantage. Proteinaceous effectors are synthesised intracellularly and must be externalised to interact with host cells. Computational prediction of secreted proteins from genomic sequences is an important technique to narrow down the candidate effector repertoire for subsequent experimental validation. In this study, we benchmark secretion prediction tools on experimentally validated fungal and oomycete effectors. We observe that for a set of fungal SwissProt protein sequences, SignalP 4 and the neural network predictors of SignalP 3 (D-score and SignalP 2 perform best. For effector prediction in particular, the use of a sensitive method can be desirable to obtain the most complete candidate effector set. We show that the neural network predictors of SignalP 2 and 3, as well as TargetP were the most sensitive tools for fungal effector secretion prediction, whereas the hidden Markov model predictors of SignalP 2 and 3 were the most sensitive tools for oomycete effectors. Thus, previous versions of SignalP retain value for oomycete effector prediction, as the current version, SignalP 4, was unable to reliably predict the signal peptide of the oomycete Crinkler effectors in the test set. Our assessment of subcellular localisation predictors shows that cytoplasmic effectors are often predicted as not extracellular. This limits the reliability of secretion predictions that depend on these tools. We present our assessment with a view to informing future pathogenomics studies and suggest revised pipelines for secretion prediction to obtain optimal effector predictions in fungi and oomycetes.

Sunlight Triggers Cutaneous Lupus through a Colony Stimulating Factor-1 (CSF-1) Dependent Mechanism in MRL-Faslpr mice

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Menke, Julia; Hsu, Mei-Yu; Byrne, Katelyn T.; Lucas, Julie A.; Rabacal, Whitney A.; Croker, Byron P.; Zong, Xiao-Hua; Stanley, E. Richard; Kelley, Vicki R.

2008-01-01

Sunlight (UVB) triggers cutaneous (CLE) and systemic lupus through an unknown mechanism. We tested the hypothesis that UVB triggers CLE through a CSF-1-dependent, macrophage (Mø) -mediated mechanism in MRL-Faslpr mice. By constructing mutant MRL-Faslpr strains expressing varying levels of CSF-1 (high, intermediate, none), and use of an ex-vivo gene transfer to deliver CSF-1 intra-dermally, we determined that CSF-1 induces CLE in lupus-susceptible, MRL-Faslpr mice, but not in lupus-resistant, BALB/c mice. Notably, UVB incites an increase in Mø, apoptosis in the skin and CLE in MRL-Faslpr, but not in CSF-1-deficient MRL-Faslpr mice. Furthermore, UVB did not induce CLE in BALB/c mice. Probing further, UVB stimulates CSF-1 expression by keratinocytes leading to recruitment and activation of Mø that, in turn, release mediators, which induce apoptosis in keratinocytes. Thus, sunlight triggers a CSF-1-dependent, Mø-mediated destructive inflammation in the skin leading to CLE in lupus-susceptible MRL-Faslpr, but not lupus-resistant BALB/c mice. Taken together, we envision CSF-1 as the “match” and lupus-susceptibility as the “tinder” leading to CLE. PMID:18981160

Effector profiles distinguish formae speciales of Fusarium oxysporum.

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van Dam, Peter; Fokkens, Like; Schmidt, Sarah M; Linmans, Jasper H J; Kistler, H Corby; Ma, Li-Jun; Rep, Martijn

2016-11-01

Formae speciales (ff.spp.) of the fungus Fusarium oxysporum are often polyphyletic within the species complex, making it impossible to identify them on the basis of conserved genes. However, sequences that determine host-specific pathogenicity may be expected to be similar between strains within the same forma specialis. Whole genome sequencing was performed on strains from five different ff.spp. (cucumerinum, niveum, melonis, radicis-cucumerinum and lycopersici). In each genome, genes for putative effectors were identified based on small size, secretion signal, and vicinity to a "miniature impala" transposable element. The candidate effector genes of all genomes were collected and the presence/absence patterns in each individual genome were clustered. Members of the same forma specialis turned out to group together, with cucurbit-infecting strains forming a supercluster separate from other ff.spp. Moreover, strains from different clonal lineages within the same forma specialis harbour identical effector gene sequences, supporting horizontal transfer of genetic material. These data offer new insight into the genetic basis of host specificity in the F. oxysporum species complex and show that (putative) effectors can be used to predict host specificity in F. oxysporum. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

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Wesley Smith

Level-1 Trigger Hardware and Software The hardware of the trigger components has been mostly finished. The ECAL Endcap Trigger Concentrator Cards (TCC) are in production while Barrel TCC firmware has been upgraded, and the Trigger Primitives can now be stored by the Data Concentrator Card for readout by the DAQ. The Regional Calorimeter Trigger (RCT) system is complete, and the timing is being finalized. All 502 HCAL trigger links to RCT run without error. The HCAL muon trigger timing has been equalized with DT, RPC, CSC and ECAL. The hardware and firmware for the Global Calorimeter Trigger (GCT) jet triggers are being commissioned and data from these triggers is available for readout. The GCT energy sums from rings of trigger towers around the beam pipe beam have been changed to include two rings from both sides. The firmware for Drift Tube Track Finder, Barrel Sorter and Wedge Sorter has been upgraded, and the synchronization of the DT trigger is satisfactory. The CSC local trigger has operated flawlessly u...

The Activation of Phytophthora Effector Avr3b by Plant Cyclophilin is Required for the Nudix Hydrolase Activity of Avr3b.

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Kong, Guanghui; Zhao, Yao; Jing, Maofeng; Huang, Jie; Yang, Jin; Xia, Yeqiang; Kong, Liang; Ye, Wenwu; Xiong, Qin; Qiao, Yongli; Dong, Suomeng; Ma, Wenbo; Wang, Yuanchao

2015-08-01

Plant pathogens secrete an arsenal of effector proteins to impair host immunity. Some effectors possess enzymatic activities that can modify their host targets. Previously, we demonstrated that a Phytophthora sojae RXLR effector Avr3b acts as a Nudix hydrolase when expressed in planta; and this enzymatic activity is required for full virulence of P. sojae strain P6497 in soybean (Glycine max). Interestingly, recombinant Avr3b produced by E. coli does not have the hydrolase activity unless it was incubated with plant protein extracts. Here, we report the activation of Avr3b by a prolyl-peptidyl isomerase (PPIase), cyclophilin, in plant cells. Avr3b directly interacts with soybean cyclophilin GmCYP1, which activates the hydrolase activity of Avr3b in a PPIase activity-dependent manner. Avr3b contains a putative Glycine-Proline (GP) motif; which is known to confer cyclophilin-binding in other protein substrates. Substitution of the Proline (P132) in the putative GP motif impaired the interaction of Avr3b with GmCYP1; as a result, the mutant Avr3bP132A can no longer be activated by GmCYP1, and is also unable to promote Phytophthora infection. Avr3b elicits hypersensitive response (HR) in soybean cultivars producing the resistance protein Rps3b, but Avr3bP132A lost its ability to trigger HR. Furthermore, silencing of GmCYP1 rendered reduced cell death triggered by Avr3b, suggesting that GmCYP1-mediated Avr3b maturation is also required for Rps3b recognition. Finally, cyclophilins of Nicotiana benthamiana can also interact with Avr3b and activate its enzymatic activity. Overall, our results demonstrate that cyclophilin is a "helper" that activates the enzymatic activity of Avr3b after it is delivered into plant cells; as such, cyclophilin is required for the avirulence and virulence functions of Avr3b.

Magnetic resonance visualization of conductive structures by sequence-triggered direct currents and spin-echo phase imaging

Energy Technology Data Exchange (ETDEWEB)

Eibofner, Frank; Wojtczyk, Hanne; Graf, Hansjörg, E-mail: hansjoerg.graf@med.uni-tuebingen.de, E-mail: drGraf@t-online.de [Section on Experimental Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany); Clasen, Stephan [Department of Diagnostic and Interventional Radiology, University Hospital Tübingen, Tübingen D-72076 (Germany)

2014-06-15

Purpose: Instrument visualization in interventional magnetic resonance imaging (MRI) is commonly performed via susceptibility artifacts. Unfortunately, this approach suffers from limited conspicuity in inhomogeneous tissue and disturbed spatial encoding. Also, susceptibility artifacts are controllable only by sequence parameters. This work presents the basics of a new visualization method overcoming such problems by applying sequence-triggered direct current (DC) pulses in spin-echo (SE) imaging. SE phase images allow for background free current path localization. Methods: Application of a sequence-triggered DC pulse in SE imaging, e.g., during a time period between radiofrequency excitation and refocusing, results in transient field inhomogeneities. Dependent on the additional z-magnetic field from the DC, a phase offset results despite the refocusing pulse. False spatial encoding is avoided by DC application during periods when read-out or slice-encoding gradients are inactive. A water phantom containing a brass conductor (water equivalent susceptibility) and a titanium needle (serving as susceptibility source) was used to demonstrate the feasibility. Artifact dependence on current strength and orientation was examined. Results: Without DC, the brass conductor was only visible due to its water displacement. The titanium needle showed typical susceptibility artifacts. Applying triggered DC pulses, the phase offset of spins near the conductor appeared. Because SE phase images are homogenous also in regions of persistent field inhomogeneities, the position of the conductor could be determined with high reliability. Artifact characteristic could be easily controlled by amperage leaving sequence parameters unchanged. For an angle of 30° between current and static field visualization was still possible. Conclusions: SE phase images display the position of a conductor carrying pulsed DC free from artifacts caused by persistent field inhomogeneities. Magnitude and phase

Analysis of Trigger Factors in Episodic Migraineurs Using a Smartphone Headache Diary Applications

Science.gov (United States)

Park, Jeong-Wook; Chu, Min Kyung; Kim, Jae-Moon; Park, Sang-Gue; Cho, Soo-Jin

2016-01-01

Background Various stimuli can trigger migraines in susceptible individuals. We examined migraine trigger factors by using a smartphone headache diary application. Method Episodic migraineurs who agreed to participate in our study downloaded smartphone headache diary application, which was designed to capture the details regarding headache trigger factors and characteristics for 3 months. The participants were asked to access the smartphone headache diary application daily and to confirm the presence of a headache and input the types of trigger factors. Results Sixty-two participants kept diary entries until the end of the study. The diary data for 4,579 days were analyzed. In this data set, 1,099 headache days (336 migraines, 763 non-migraine headaches) were recorded; of these, 772 headache events had with trigger factors, and 327 events did not have trigger factors. The common trigger factors that were present on headache days included stress, fatigue, sleep deprivation, hormonal changes, and weather changes. The likelihood of a headache trigger was 57.7% for stress, 55.1% for sleep deprivation, 48.5% for fatigue, and 46.5% for any trigger. The headaches with trigger factors were associated with greater pain intensity (pSmartphone headache diary application is an effective tool to assess migraine trigger factors. The headaches with trigger factors had greater severity or migraine features. The type of triggers and the presence of preventive medication influenced the headache characteristics; hence, an investigation of trigger factors would be helpful in understanding migraine occurrences. PMID:26901341

Analysis of Trigger Factors in Episodic Migraineurs Using a Smartphone Headache Diary Applications.

Science.gov (United States)

Park, Jeong-Wook; Chu, Min Kyung; Kim, Jae-Moon; Park, Sang-Gue; Cho, Soo-Jin

2016-01-01

Various stimuli can trigger migraines in susceptible individuals. We examined migraine trigger factors by using a smartphone headache diary application. Episodic migraineurs who agreed to participate in our study downloaded smartphone headache diary application, which was designed to capture the details regarding headache trigger factors and characteristics for 3 months. The participants were asked to access the smartphone headache diary application daily and to confirm the presence of a headache and input the types of trigger factors. Sixty-two participants kept diary entries until the end of the study. The diary data for 4,579 days were analyzed. In this data set, 1,099 headache days (336 migraines, 763 non-migraine headaches) were recorded; of these, 772 headache events had with trigger factors, and 327 events did not have trigger factors. The common trigger factors that were present on headache days included stress, fatigue, sleep deprivation, hormonal changes, and weather changes. The likelihood of a headache trigger was 57.7% for stress, 55.1% for sleep deprivation, 48.5% for fatigue, and 46.5% for any trigger. The headaches with trigger factors were associated with greater pain intensity (pSmartphone headache diary application is an effective tool to assess migraine trigger factors. The headaches with trigger factors had greater severity or migraine features. The type of triggers and the presence of preventive medication influenced the headache characteristics; hence, an investigation of trigger factors would be helpful in understanding migraine occurrences.

Type VI secretion system MIX-effectors carry both antibacterial and anti-eukaryotic activities.

Science.gov (United States)

Ray, Ann; Schwartz, Nika; de Souza Santos, Marcela; Zhang, Junmei; Orth, Kim; Salomon, Dor

2017-11-01

Most type VI secretion systems (T6SSs) described to date are protein delivery apparatuses that mediate bactericidal activities. Several T6SSs were also reported to mediate virulence activities, although only few anti-eukaryotic effectors have been described. Here, we identify three T6SSs in the marine bacterium Vibrio proteolyticus and show that T6SS1 mediates bactericidal activities under warm marine-like conditions. Using comparative proteomics, we find nine potential T6SS1 effectors, five of which belong to the polymorphic MIX-effector class. Remarkably, in addition to six predicted bactericidal effectors, the T6SS1 secretome includes three putative anti-eukaryotic effectors. One of these is a MIX-effector containing a cytotoxic necrotizing factor 1 domain. We demonstrate that T6SS1 can use this MIX-effector to target phagocytic cells, resulting in morphological changes and actin cytoskeleton rearrangements. In conclusion, the V. proteolyticus T6SS1, a system homologous to one found in pathogenic vibrios, uses a suite of polymorphic effectors that target both bacteria and eukaryotic neighbors. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

The Fusarium oxysporum effector Six6 contributes to virulence and suppresses I-2-mediated cell death.

Science.gov (United States)

Gawehns, F; Houterman, P M; Ichou, F Ait; Michielse, C B; Hijdra, M; Cornelissen, B J C; Rep, M; Takken, F L W

2014-04-01

Plant pathogens secrete effectors to manipulate their host and facilitate colonization. Fusarium oxysporum f. sp. lycopersici is the causal agent of Fusarium wilt disease in tomato. Upon infection, F. oxysporum f. sp. lycopersici secretes numerous small proteins into the xylem sap (Six proteins). Most Six proteins are unique to F. oxysporum, but Six6 is an exception; a homolog is also present in two Colletotrichum spp. SIX6 expression was found to require living host cells and a knockout of SIX6 in F. oxysporum f. sp. lycopersici compromised virulence, classifying it as a genuine effector. Heterologous expression of SIX6 did not affect growth of Agrobacterium tumefaciens in Nicotiana benthamiana leaves or susceptibility of Arabidopsis thaliana toward Verticillium dahliae, Pseudomonas syringae, or F. oxysporum, suggesting a specific function for F. oxysporum f. sp. lycopersici Six6 in the F. oxysporum f. sp. lycopersici- tomato pathosystem. Remarkably, Six6 was found to specifically suppress I-2-mediated cell death (I2CD) upon transient expression in N. benthamiana, whereas it did not compromise the activity of other cell-death-inducing genes. Still, this I2CD suppressing activity of Six6 does not allow the fungus to overcome I-2 resistance in tomato, suggesting that I-2-mediated resistance is independent from cell death.

Chronic Alcohol Ingestion Delays T Cell Activation and Effector Function in Sepsis.

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Lindsay M Margoles

Full Text Available Sepsis is the leading cause of death in intensive care units in the US, and it is known that chronic alcohol use is associated with higher incidence of sepsis, longer ICU stays, and higher mortality from sepsis. Both sepsis and chronic alcohol use are associated with immune deficits such as decreased lymphocyte numbers, impaired innate immunity, delayed-type hypersensitivity reactions, and susceptibility to infections; however, understanding of specific pathways of interaction or synergy between these two states of immune dysregulation is lacking. This study therefore sought to elucidate mechanisms underlying the immune dysregulation observed during sepsis in the setting of chronic alcohol exposure. Using a murine model of chronic ethanol ingestion followed by sepsis induction via cecal ligation and puncture, we determined that while CD4+ and CD8+ T cells isolated from alcohol fed mice eventually expressed the same cellular activation markers (CD44, CD69, and CD43 and effector molecules (IFN-γ, TNF as their water fed counterparts, there was an overall delay in the acquisition of these phenotypes. This early lag in T cell activation was associated with significantly reduced IL-2 production at a later timepoint in both the CD4+ and CD8+ T cell compartments in alcohol sepsis, as well as with a reduced accumulation of CD8dim activated effectors. Taken together, these data suggest that delayed T cell activation may result in qualitative differences in the immune response to sepsis in the setting of chronic alcohol ingestion.

Characterization of the largest effector gene cluster of Ustilago maydis.

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Thomas Brefort

2014-07-01

Full Text Available In the genome of the biotrophic plant pathogen Ustilago maydis, many of the genes coding for secreted protein effectors modulating virulence are arranged in gene clusters. The vast majority of these genes encode novel proteins whose expression is coupled to plant colonization. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. Here we present the functional analysis of this genomic region. We show that a 19A deletion mutant behaves like an endophyte, i.e. is still able to colonize plants and complete the infection cycle. However, tumors, the most conspicuous symptoms of maize smut disease, are only rarely formed and fungal biomass in infected tissue is significantly reduced. The generation and analysis of strains carrying sub-deletions identified several genes significantly contributing to tumor formation after seedling infection. Another of the effectors could be linked specifically to anthocyanin induction in the infected tissue. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. We propose that the analysis of plant responses to effector mutant strains that lack a strong virulence phenotype may be a general way to visualize differences in effector function.

Effector candidates in the secretome of Piriformospora indica, a ubiquitous plant-associated fungus

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Maryam eRafiqi

2013-07-01

Full Text Available One of the emerging systems in plant-microbe interaction is the study of proteins, referred to as effectors, secreted by microbes in order to modulate host cells function and structure and to promote microbial growth on plant tissue. Current knowledge on fungal effectors derives mainly from biotrophic and hemibiotrophic plant fungal pathogens that have a limited host range. Here, we focus on effectors of Piriformospora indica, a soil borne endophyte forming intimate associations with roots of a wide range of plant species. Complete genome sequencing provides an opportunity to investigate the role of effectors during the interaction of this mutualistic fungus with plants. We describe in silico analyses to predict effectors of P. indica and we explore effector features considered here to mine a high priority protein list for functional analysis.

Hematopoietic Stem and Progenitor Cells as Effectors in Innate Immunity

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Jennifer L. Granick

2012-01-01

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

Resistant and susceptible responses in alfalfa (Medicago sativa to bacterial stem blight caused by Pseudomonas syringae pv. syringae.

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Lev G Nemchinov

Full Text Available Bacterial stem blight caused by Pseudomonas syringae pv. syringae is a common disease of alfalfa (Medicago sativa L. Little is known about host-pathogen interactions and host defense mechanisms. Here, individual resistant and susceptible plants were selected from cultivars Maverick and ZG9830 and used for transcript profiling at 24 and 72 hours after inoculation (hai with the isolate PssALF3. Bioinformatic analysis revealed a number of differentially expressed genes (DEGs in resistant and susceptible genotypes. Although resistant plants from each cultivar produced a hypersensitive response, transcriptome analyses indicated that they respond differently at the molecular level. The number of DEGs was higher in resistant plants of ZG9830 at 24 hai than in Maverick, suggesting that ZG9830 plants had a more rapid effector triggered immune response. Unique up-regulated genes in resistant ZG9830 plants included genes encoding putative nematode resistance HSPRO2-like proteins, orthologs for the rice Xa21 and soybean Rpg1-b resistance genes, and TIR-containing R genes lacking both NBS and LRR domains. The suite of R genes up-regulated in resistant Maverick plants had an over-representation of R genes in the CC-NBS-LRR family including two genes for atypical CCR domains and a putative ortholog of the Arabidopsis RPM1 gene. Resistance in both cultivars appears to be mediated primarily by WRKY family transcription factors and expression of genes involved in protein phosphorylation, regulation of transcription, defense response including synthesis of isoflavonoids, and oxidation-reduction processes. These results will further the identification of mechanisms involved in resistance to facilitate selection of parent populations and development of commercial varieties.

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Wesley Smith

Level-1 Trigger Hardware and Software The trigger synchronization procedures for running with cosmic muons and operating with the LHC were reviewed during the May electronics week. Firmware maintenance issues were also reviewed. Link tests between the new ECAL endcap trigger concentrator cards (TCC48) and the Regional Calorimeter Trigger have been performed. Firmware for the energy sum triggers and an upgraded tau trigger of the Global Calorimeter Triggers has been developed and is under test. The optical fiber receiver boards for the Track-Finder trigger theta links of the DT chambers are now all installed. The RPC trigger is being made more robust by additional chamber and cable shielding and also by firmware upgrades. For the CSC’s the front-end and trigger motherboard firmware have been updated. New RPC patterns and DT/CSC lookup tables taking into account phi asymmetries in the magnetic field configuration are under study. The motherboard for the new pipeline synchronizer of the Global Trigg...

Target selection biases from recent experience transfer across effectors.

Science.gov (United States)

Moher, Jeff; Song, Joo-Hyun

2016-02-01

Target selection is often biased by an observer's recent experiences. However, not much is known about whether these selection biases influence behavior across different effectors. For example, does looking at a red object make it easier to subsequently reach towards another red object? In the current study, we asked observers to find the uniquely colored target object on each trial. Randomly intermixed pre-trial cues indicated the mode of action: either an eye movement or a visually guided reach movement to the target. In Experiment 1, we found that priming of popout, reflected in faster responses following repetition of the target color on consecutive trials, occurred regardless of whether the effector was repeated from the previous trial or not. In Experiment 2, we examined whether an inhibitory selection bias away from a feature could transfer across effectors. While priming of popout reflects both enhancement of the repeated target features and suppression of the repeated distractor features, the distractor previewing effect isolates a purely inhibitory component of target selection in which a previewed color is presented in a homogenous display and subsequently inhibited. Much like priming of popout, intertrial suppression biases in the distractor previewing effect transferred across effectors. Together, these results suggest that biases for target selection driven by recent trial history transfer across effectors. This indicates that representations in memory that bias attention towards or away from specific features are largely independent from their associated actions.

Proliferation requirements of cytomegalovirus-specific, effector-type human CD8+ T cells

NARCIS (Netherlands)

van Leeuwen, Ester M.; Gamadia, Laila E.; Baars, Paul A.; Remmerswaal, Ester B.; ten Berge, Ineke J.; van Lier, René A.

2002-01-01

Two prototypic types of virus-specific CD8(+) T cells can be found in latently infected individuals: CD45R0(+)CD27(+)CCR7(-) effector-memory, and CD45RA(+)CD27(-)CCR7(-) effector-type cells. It has recently been implied that CD45RA(+)CD27(-)CCR7(-) T cells are terminally differentiated effector

TRIGGER

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W. Smith

2012-01-01

  Level-1 Trigger The Level-1 Trigger group is ready to deploy improvements to the L1 Trigger algorithms for 2012. These include new high-PT patterns for the RPC endcap, an improved CSC PT assignment, a new PT-matching algorithm for the Global Muon Trigger, and new calibrations for ECAL, HCAL, and the Regional Calorimeter Trigger. These should improve the efficiency, rate, and stability of the L1 Trigger. The L1 Trigger group also is migrating the online systems to SLC5. To make the data transfer from the Global Calorimeter Trigger to the Global Trigger more reliable and also to allow checking the data integrity online, a new optical link system has been developed by the GCT and GT groups and successfully tested at the CMS electronics integration facility in building 904. This new system is now undergoing further tests at Point 5 before being deployed for data-taking this year. New L1 trigger menus have recently been studied and proposed by Emmanuelle Perez and the L1 Detector Performance Group...

Rainfall-induced landslide susceptibility zonation of Puerto Rico

Science.gov (United States)

Chiara Lepore; Sameer A. Kamal; Peter Shanahan; Rafael L. Bras

2011-01-01

Landslides are a major geologic hazard with estimated tens of deaths and $1–2 billion in economic losses per year in the US alone. The island of Puerto Rico experiences one or two large events per year, often triggered in steeply sloped areas by prolonged and heavy rainfall. Identifying areas susceptible to landslides thus has great potential value for Puerto Rico and...

Identification of Anaplasma marginale type IV secretion system effector proteins.

Directory of Open Access Journals (Sweden)

Svetlana Lockwood

Full Text Available Anaplasma marginale, an obligate intracellular alphaproteobacterium in the order Rickettsiales, is a tick-borne pathogen and the leading cause of anaplasmosis in cattle worldwide. Complete genome sequencing of A. marginale revealed that it has a type IV secretion system (T4SS. The T4SS is one of seven known types of secretion systems utilized by bacteria, with the type III and IV secretion systems particularly prevalent among pathogenic Gram-negative bacteria. The T4SS is predicted to play an important role in the invasion and pathogenesis of A. marginale by translocating effector proteins across its membrane into eukaryotic target cells. However, T4SS effector proteins have not been identified and tested in the laboratory until now.By combining computational methods with phylogenetic analysis and sequence identity searches, we identified a subset of potential T4SS effectors in A. marginale strain St. Maries and chose six for laboratory testing. Four (AM185, AM470, AM705 [AnkA], and AM1141 of these six proteins were translocated in a T4SS-dependent manner using Legionella pneumophila as a reporter system.The algorithm employed to find T4SS effector proteins in A. marginale identified four such proteins that were verified by laboratory testing. L. pneumophila was shown to work as a model system for A. marginale and thus can be used as a screening tool for A. marginale effector proteins. The first T4SS effector proteins for A. marginale have been identified in this work.

TRIGGER

CERN Multimedia

Wesley Smith

Level-1 Trigger Hardware and Software The production of the trigger hardware is now basically finished, and in time for the turn-on of the LHC. The last boards produced are the Trigger Concentrator Cards for the ECAL Endcaps (TCC-EE). After the recent installation of the four EE Dees, the TCC-EE prototypes were used for their commissioning. Production boards are arriving and are being tested continuously, with the last ones expected in November. The Regional Calorimeter Trigger hardware is fully integrated after installation of the last EE cables. Pattern tests from the HCAL up to the GCT have been performed successfully. The HCAL triggers are fully operational, including the connection of the HCAL-outer and forward-HCAL (HO/HF) technical triggers to the Global Trigger. The HCAL Trigger and Readout (HTR) board firmware has been updated to permit recording of the tower “feature bit” in the data. The Global Calorimeter Trigger hardware is installed, but some firmware developments are still n...

System for exchanging tools and end effectors on a robot

International Nuclear Information System (INIS)

Burry, D.B.; Williams, P.M.

1991-01-01

A system and method for exchanging tools and end effectors on a robot permits exchange during a programmed task. The exchange mechanism is located off the robot, thus reducing the mass of the robot arm and permitting smaller robots to perform designated tasks. A simple spring/collet mechanism mounted on the robot is used which permits the engagement and disengagement of the tool or end effector without the need for a rotational orientation of the tool to the end effector/collet interface. As the tool changing system is not located on the robot arm no umbilical cords are located on robot. 12 figures

The genome sequence and effector complement of the flax rust pathogen Melampsora lini

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Adnane eNemri

2014-03-01

Full Text Available Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp. Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimise parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analysed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote

The genome sequence and effector complement of the flax rust pathogen Melampsora lini.

Science.gov (United States)

Nemri, Adnane; Saunders, Diane G O; Anderson, Claire; Upadhyaya, Narayana M; Win, Joe; Lawrence, Gregory J; Jones, David A; Kamoun, Sophien; Ellis, Jeffrey G; Dodds, Peter N

2014-01-01

Rust fungi cause serious yield reductions on crops, including wheat, barley, soybean, coffee, and represent real threats to global food security. Of these fungi, the flax rust pathogen Melampsora lini has been developed most extensively over the past 80 years as a model to understand the molecular mechanisms that underpin pathogenesis. During infection, M. lini secretes virulence effectors to promote disease. The number of these effectors, their function and their degree of conservation across rust fungal species is unknown. To assess this, we sequenced and assembled de novo the genome of M. lini isolate CH5 into 21,130 scaffolds spanning 189 Mbp (scaffold N50 of 31 kbp). Global analysis of the DNA sequence revealed that repetitive elements, primarily retrotransposons, make up at least 45% of the genome. Using ab initio predictions, transcriptome data and homology searches, we identified 16,271 putative protein-coding genes. An analysis pipeline was then implemented to predict the effector complement of M. lini and compare it to that of the poplar rust, wheat stem rust and wheat stripe rust pathogens to identify conserved and species-specific effector candidates. Previous knowledge of four cloned M. lini avirulence effector proteins and two basidiomycete effectors was used to optimize parameters of the effector prediction pipeline. Markov clustering based on sequence similarity was performed to group effector candidates from all four rust pathogens. Clusters containing at least one member from M. lini were further analyzed and prioritized based on features including expression in isolated haustoria and infected leaf tissue and conservation across rust species. Herein, we describe 200 of 940 clusters that ranked highest on our priority list, representing 725 flax rust candidate effectors. Our findings on this important model rust species provide insight into how effectors of rust fungi are conserved across species and how they may act to promote infection on their

Diverse Secreted Effectors Are Required for Salmonella Persistence in a Mouse Infection Model

Energy Technology Data Exchange (ETDEWEB)

Kidwai, Afshan S.; Mushamiri, Ivy T.; Niemann, George; Brown, Roslyn N.; Adkins, Joshua N.; Heffron, Fred

2013-08-12

Salmonella enterica serovar Typhimurium causes typhoid-like disease in mice and is a model of typhoid fever in humans. One of the hallmarks of typhoid is persistence, the ability of the bacteria to survive in the host weeks after infection. Virulence factors called effectors facilitate this process by direct transfer to the cytoplasm of infected cells thereby subverting cellular processes. Secretion of effectors to the cell cytoplasm takes place through multiple routes, including two separate type III secretion (T3SS) apparati as well as outer membrane vesicles. The two T3SS are encoded on separate pathogenicity islands, SPI-1 and -2, with SPI-1 more strongly associated with the intestinal phase of infection, and SPI-2 with the systemic phase. Both T3SS are required for persistence, but the effectors required have not been systematically evaluated. In this study, mutations in 48 described effectors were tested for persistence. We replaced each effector with a specific DNA barcode sequence by allelic exchange and co-infected with a wild-type reference to calculate the ratio of wild-type parent to mutant at different times after infection. The competitive index (CI) was determined by quantitative PCR in which primers that correspond to the barcode were used for amplification. Mutations in all but seven effectors reduced persistence demonstrating that most effectors were required. One exception was CigR, a recently discovered effector that is widely conserved throughout enteric bacteria. Deletion of cigR increased lethality, suggesting that it may be an anti-virulence factor. The fact that almost all Salmonella effectors are required for persistence argues against redundant functions. This is different from effector repertoires in other intracellular pathogens such as Legionella.

Diacylglycerol kinases in T cell tolerance and effector function

Directory of Open Access Journals (Sweden)

Shelley S Chen

2016-11-01

Full Text Available Diacylglycerol kinases (DGKs are a family of enzymes that regulate the relative levels of diacylglycerol (DAG and phosphatidic acid (PA in cells by phosphorylating DAG to produce PA. Both DAG and PA are important second messengers cascading T cell receptor (TCR signal by recruiting multiple effector molecules such as RasGRP1, PKC, and mTOR. Studies have revealed important physiological functions of DGKs in the regulation of receptor signaling and the development and activation of immune cells. In this review, we will focus on recent progresses in our understanding of two DGK isoforms,  and , in CD8 T effector and memory cell differentiation, regulatory T cell development and function, and invariant NKT cell development and effector lineage differentiation.

A novel Meloidogyne graminicola effector, MgGPP, is secreted into host cells and undergoes glycosylation in concert with proteolysis to suppress plant defenses and promote parasitism.

Directory of Open Access Journals (Sweden)

Jiansong Chen

2017-04-01

Full Text Available Plant pathogen effectors can recruit the host post-translational machinery to mediate their post-translational modification (PTM and regulate their activity to facilitate parasitism, but few studies have focused on this phenomenon in the field of plant-parasitic nematodes. In this study, we show that the plant-parasitic nematode Meloidogyne graminicola has evolved a novel effector, MgGPP, that is exclusively expressed within the nematode subventral esophageal gland cells and up-regulated in the early parasitic stage of M. graminicola. The effector MgGPP plays a role in nematode parasitism. Transgenic rice lines expressing MgGPP become significantly more susceptible to M. graminicola infection than wild-type control plants, and conversely, in planta, the silencing of MgGPP through RNAi technology substantially increases the resistance of rice to M. graminicola. Significantly, we show that MgGPP is secreted into host plants and targeted to the ER, where the N-glycosylation and C-terminal proteolysis of MgGPP occur. C-terminal proteolysis promotes MgGPP to leave the ER, after which it is transported to the nucleus. In addition, N-glycosylation of MgGPP is required for suppressing the host response. The research data provide an intriguing example of in planta glycosylation in concert with proteolysis of a pathogen effector, which depict a novel mechanism by which parasitic nematodes could subjugate plant immunity and promote parasitism and may present a promising target for developing new strategies against nematode infections.

TRIGGER

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by Wesley Smith

2010-01-01

Level-1 Trigger Hardware and Software The overall status of the L1 trigger has been excellent and the running efficiency has been high during physics fills. The timing is good to about 1%. The fine-tuning of the time synchronization of muon triggers is ongoing and will be completed after more than 10 nb-1 of data have been recorded. The CSC trigger primitive and RPC trigger timing have been refined. A new configuration for the CSC Track Finder featured modified beam halo cuts and improved ghost cancellation logic. More direct control was provided for the DT opto-receivers. New RPC Cosmic Trigger (RBC/TTU) trigger algorithms were enabled for collision runs. There is further work planned during the next technical stop to investigate a few of the links from the ECAL to the Regional Calorimeter Trigger (RCT). New firmware and a new configuration to handle trigger rate spikes in the ECAL barrel are also being tested. A board newly developed by the tracker group (ReTRI) has been installed and activated to block re...

Dynamic Earthquake Triggering on Seismogenic Faults in Oklahoma

Science.gov (United States)

Qin, Y.; Chen, X.; Peng, Z.; Aiken, C.

2016-12-01

Regions with high pore pressure are generally more susceptible to dynamic triggering from transient stress change caused by surface wave of distant earthquakes. The stress threshold from triggering studies can help understand the stress state of seismogenic faults. The recent dramatic seismicity increase in central US provides a rich database for assessing dynamic triggering phenomena. We begin our study by conducting a systematic analysis of dynamic triggering for the continental U.S using ANSS catalog (with magnitude of completeness Mc=3) from 49 global mainshocks (Ms>6.5, depth1kPa). We calculate β value for each 1° by 1° bins in 30 days before and 10 days after the mainshock. To identify regions that experience triggering from a distant mainshock, we generate a stacked map using β≥2 - which represents significant seismicity rate increase. As expected, the geothermal and volcanic fields in California show clear response to distant earthquakes. We also note areas in Oklahoma and north Texas show enhanced triggering, where wastewater-injection induced seismicity are occurring. Next we focus on Oklahoma and use a local catalog from Oklahoma Geological Survey with lower completeness threshold Mc to calculate the beta map in 0.2° by 0.2° bins for each selected mainshock to obtain finer spatial resolutions of the triggering behavior. For those grids with β larger than 2.0, we use waveforms from nearby stations to search for triggered events. The April 2015 M7.8 Nepal earthquake causes a statistically significant increase of local seismicity (β=3.5) in the Woodward area (west Oklahoma) during an on-going earthquake sequence. By visually examining the surface wave from the nearest station, we identify 3 larger local events, and 10 additional smaller events with weaker but discernable amplitude. Preliminary analysis shows that the triggering is related to Rayleigh wave, which would cause dilatational or shear stress changes along the strike direction of

The Shigella flexneri OspB effector: an early immunomodulator.

Science.gov (United States)

Ambrosi, Cecilia; Pompili, Monica; Scribano, Daniela; Limongi, Dolores; Petrucca, Andrea; Cannavacciuolo, Sonia; Schippa, Serena; Zagaglia, Carlo; Grossi, Milena; Nicoletti, Mauro

2015-01-01

Through the action of the type three secretion system (T3SS) Shigella flexneri delivers several effectors into host cells to promote cellular invasion, multiplication and to exploit host-cell signaling pathways to modulate the host innate immune response. Although much progress has been made in the understanding of many type III effectors, the molecular and cellular mechanism of the OspB effector is still poorly characterized. In this study we present new evidence that better elucidates the role of OspB as pro-inflammatory factor at very early stages of infection. Indeed, we demonstrate that, during the first hour of infection, OspB is required for full activation of ERK1/2 and p38 MAPKs and the cytosolic phospholipase A(2) (cPLA(2)). Activation of cPLA(2) ultimately leads to the production and secretion of PMN chemoattractant metabolite(s) uncoupled with release of IL-8. Moreover, we also present evidence that OspB is required for the development of the full and promptly inflammatory reaction characteristic of S. flexneri wild-type infection in vivo. Based on OspB and OspF similarity (both effectors share similar transcription regulation, temporal secretion into host cells and nuclear localization) we hypothesized that OspB and OspF effectors may form a pair aimed at modulating the host cell response throughout the infection process, with opposite effects. A model is presented to illustrate how OspB activity would promote S. flexneri invasion and bacterial dissemination at early critical phases of infection. Copyright © 2014 Elsevier GmbH. All rights reserved.

Yersinia type III effectors perturb host innate immune responses

Science.gov (United States)

Pha, Khavong; Navarro, Lorena

2016-01-01

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

TRIGGER

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Roberta Arcidiacono

2013-01-01

Trigger Studies Group (TSG) The Trigger Studies Group has just concluded its third 2013 workshop, where all POGs presented the improvements to the physics object reconstruction, and all PAGs have shown their plans for Trigger development aimed at the 2015 High Level Trigger (HLT) menu. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger menu development, path timing, Trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – this last task in collaboration with PdmV (Physics Data and Monte Carlo Validation group). In the last months the group has delivered several HLT rate estimates and comparisons, using the available data and Monte Carlo samples. The studies were presented at the Trigger workshops in September and December, and STEAM has contacted POGs and PAGs to understand the origin of the discrepancies observed between 8 TeV data and Monte Carlo simulations. The most recent results show what the...

The Absence of Remotely Triggered Seismicity in Japan from 1997 to 2002

Science.gov (United States)

Wakefield, R. H.; Brodsky, E. E.

2003-12-01

the dynamic triggering thresholds at the respective locations. This assumes the bound is frequency independent. In none of the cases were thresholds exceeded over a large enough region or by large enough amplitude to produce a statistically significant increase in the cataloged rate of seismicity during the period from 1997 to 2002. All previously documented examples of triggering have occurred following shallow earthquakes with Mw > 7. With the exception of Volcano Islands, all of the events of this study have Mw 7 are required to produce sufficient shaking to trigger seismicity, or Japan is less susceptible to triggering than the western US or Greece. We assume that the depth of the Volcano Islands earthquake prohibits any substantial surface shaking. We conclude that more data is required associated with shallow, crustal events with Mw > 7 in order to determine whether or not Japan is susceptible to regional triggering.

The Alpha-Melanocyte Stimulating Hormone Induces Conversion of Effector T Cells into Treg Cells

Directory of Open Access Journals (Sweden)

Andrew W. Taylor

2011-01-01

Full Text Available The neuropeptide alpha-melanocyte stimulating hormone (α-MSH has an important role in modulating immunity and homeostasis. The production of IFN-γ by effector T cells is suppressed by α-MSH, while TGF-β production is promoted in the same cells. Such α-MSH-treated T cells have immune regulatory activity and suppress hypersensitivity, autoimmune diseases, and graft rejection. Previous characterizations of the α-MSH-induced Treg cells showed that the cells are CD4+ T cells expressing the same levels of CD25 as effector T cells. Therefore, we further analyzed the α-MSH-induced Treg cells for expression of effector and regulatory T-cell markers. Also, we examined the potential for α-MSH-induced Treg cells to be from the effector T-cell population. We found that the α-MSH-induced Treg cells are CD25+  CD4+ T cells that share similar surface markers as effector T cells, except that they express on their surface LAP. Also, the α-MSH treatment augments FoxP3 message in the effector T cells, and α-MSH induction of regulatory activity was limited to the effector CD25+ T-cell population. Therefore, α-MSH converts effector T cells into Treg cells, which suppress immunity targeting specific antigens and tissues.

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

The novel GrCEP12 peptide from the plant-parasitic nematode Globodera rostochiensis suppresses flg22-mediated PTI.

Science.gov (United States)

Chen, Shiyan; Chronis, Demosthenis; Wang, Xiaohong

2013-09-01

The potato cyst nematode Globodera rostochiensis is a biotrophic pathogen that secretes effector proteins into host root cells to promote successful plant parasitism. In addition to the role in generating within root tissue the feeding cells essential for nematode development, (1) nematode secreted effectors are becoming recognized as suppressors of plant immunity. (2)(-) (4) Recently we reported that the effector ubiquitin carboxyl extension protein (GrUBCEP12) from G. rostochiensis is processed into free ubiquitin and a 12-amino acid GrCEP12 peptide in planta. Transgenic potato lines overexpressing the derived GrCEP12 peptide showed increased susceptibility to G. rostochiensis and to an unrelated bacterial pathogen Streptomyces scabies, suggesting that GrCEP12 has a role in suppressing host basal defense or possibly pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI) during the parasitic interaction. (3) To determine if GrCEP12 functions as a PTI suppressor we evaluated whether GrCEP12 suppresses flg22-induced PTI responses in Nicotiana benthamiana. Interestingly, we found that transient expression of GrCEP12 in N. benthamiana leaves suppressed reactive oxygen species (ROS) production and the induction of two PTI marker genes triggered by the bacterial PAMP flg22, providing direct evidence that GrCEP12 indeed has an activity in PTI suppression.

SPRYSEC effectors: a versatile protein-binding platform to disrupt plant innate immunity

Directory of Open Access Journals (Sweden)

Amalia Diaz-Granados

2016-10-01

Full Text Available Persistent infections by sedentary plant-parasitic nematodes are a major threat to important food crops all over the world. These round worms manipulate host plant cell morphology and physiology to establish sophisticated feeding structures. Key modifications to plant cells during their transition into feeding structures are largely attributed to the activity of effectors secreted by the nematodes. The SPRYSEC effectors were initially identified in the potato cyst nematodes Globodera rostochiensis and G. pallida, and are characterized by a single SPRY domain, a non-catalytic domain present in modular proteins with different functions. The SPRY domain is wide-spread among eukaryotes and thought to be involved in mediating protein-protein interactions. Thus far, the SPRY domain is only reported as a functional domain in effectors of plant-parasitic nematodes, but not of other plant pathogens. SPRYSEC effectors have been implicated in both suppression and activation of plant immunity, but other possible roles in nematode virulence remain undefined. Here, we review the latest reports on the structure, function, and sequence diversity of SPRYSEC effectors, which provide support for a model featuring these effectors as a versatile protein-binding platform for the nematodes to target a wide range of host proteins during parasitism.

TRIGGER

CERN Multimedia

W. Smith

2010-01-01

Level-1 Trigger Hardware and Software The Level-1 Trigger hardware has performed well during both the recent proton-proton and heavy ion running. Efforts were made to improve the visibility and handling of alarms and warnings. The tracker ReTRI boards that prevent fixed frequencies of Level-1 Triggers are now configured through the Trigger Supervisor. The Global Calorimeter Trigger (GCT) team has introduced a buffer cleanup procedure at stops and a reset of the QPLL during configuring to ensure recalibration in case of a switch from the LHC clock to the local clock. A device to test the cables between the Regional Calorimeter Trigger and the GCT has been manufactured. A wrong charge bit was fixed in the CSC Trigger. The ECAL group is improving crystal masking and spike suppression in the trigger primitives. New firmware for the Drift Tube Track Finder (DTTF) sorters was developed to improve fake track tagging and sorting. Zero suppression was implemented in the DT Sector Collector readout. The track finder b...

TRIGGER

CERN Multimedia

Wesley Smith

Trigger Hardware The status of the trigger components was presented during the September CMS Week and Annual Review and at the monthly trigger meetings in October and November. Procedures for cold and warm starts (e.g. refreshing of trigger parameters stored in registers) of the trigger subsystems have been studied. Reviews of parts of the Global Calorimeter Trigger (GCT) and the Global Trigger (GT) have taken place in October and November. The CERN group summarized the status of the Trigger Timing and Control (TTC) system. All TTC crates and boards are installed in the underground counting room, USC55. The central clock system will be upgraded in December (after the Global Run at the end of November GREN) to the new RF2TTC LHC machine interface timing module. Migration of subsystem's TTC PCs to SLC4/ XDAQ 3.12 is being prepared. Work is on going to unify the access to Local Timing Control (LTC) and TTC CMS interface module (TTCci) via SOAP (Simple Object Access Protocol, a lightweight XML-based messaging ...

Development and testing of the cooling coil cleaning end effector

International Nuclear Information System (INIS)

Johnson, K.I.; Mullen, O.D.; Powell, M.R.; Daly, D.S.; Engel, D.W.

1997-01-01

The Retrieval Process Development and Enhancement (KPD ampersand E) program has developed and tested an end effector to support the waste retrieval mission at the Idaho National Engineering and Environmental Laboratory (INEEL). The end effector was developed specifically to remove a sticky waste material from the cooling coils in the High Level Liquid Waste (HLLW) tank, and to vacuum up a sediment layer that has settled beneath the cooling coils. An extensive testing program was conducted in the hydraulic test bed (HTB) at the Pacific Northwest National Laboratory (PNNL) to evaluate the performance of the end effector under simulated in-tank conditions. A mock up of the cooling coils was installed in the test bed tank, and simulated waste materials were included to represent the sticky waste on the tubes and the particulate waste settled beneath them. The testing program focused on assessing long-duration mining strategies for cleaning the cooling coils and removing the particulate waste forms. The report describes the results of the end effector testing program at PNNL. Section 2 describes the physical characteristics of the HLLW tanks, including the layout of the cooling coils, and it also describes what is known of the waste forms in the tanks. Section 3 describes the cleaning and retrieval strategy that was used in developing the end effector design. Section 4 describes the cooling coil mockup in the hydraulic test bed. Section 5 discusses the rationale used in selecting the simulants for the tarry waste and particulate waste forms. Section 6 describes the tests that were performed to evaluate cleaning of the cooling coils and retrieval of the particulate simulant. Section 7 summarizes the cleaning and retrieval tests, assesses the relative importance of cleaning the cooling coils and retrieving the particulate waste, and suggests modifications that would simplify the end effector design

Identification and functional analysis of secreted effectors from phytoparasitic nematodes.

Science.gov (United States)

Rehman, Sajid; Gupta, Vijai K; Goyal, Aakash K

2016-03-21

Plant parasitic nematodes develop an intimate and long-term feeding relationship with their host plants. They induce a multi-nucleate feeding site close to the vascular bundle in the roots of their host plant and remain sessile for the rest of their life. Nematode secretions, produced in the oesophageal glands and secreted through a hollow stylet into the host plant cytoplasm, are believed to play key role in pathogenesis. To combat these persistent pathogens, the identity and functional analysis of secreted effectors can serve as a key to devise durable control measures. In this review, we will recapitulate the knowledge over the identification and functional characterization of secreted nematode effector repertoire from phytoparasitic nematodes. Despite considerable efforts, the identity of genes encoding nematode secreted proteins has long been severely hampered because of their microscopic size, long generation time and obligate biotrophic nature. The methodologies such as bioinformatics, protein structure modeling, in situ hybridization microscopy, and protein-protein interaction have been used to identify and to attribute functions to the effectors. In addition, RNA interference (RNAi) has been instrumental to decipher the role of the genes encoding secreted effectors necessary for parasitism and genes attributed to normal development. Recent comparative and functional genomic approaches have accelerated the identification of effectors from phytoparasitic nematodes and offers opportunities to control these pathogens. Plant parasitic nematodes pose a serious threat to global food security of various economically important crops. There is a wealth of genomic and transcriptomic information available on plant parasitic nematodes and comparative genomics has identified many effectors. Bioengineering crops with dsRNA of phytonematode genes can disrupt the life cycle of parasitic nematodes and therefore holds great promise to develop resistant crops against plant

Plum pox virus capsid protein suppresses plant pathogen-associated molecular pattern (PAMP)-triggered immunity.

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Nicaise, Valerie; Candresse, Thierry

2017-08-01

The perception of pathogen-associated molecular patterns (PAMPs) by immune receptors launches defence mechanisms referred to as PAMP-triggered immunity (PTI). Successful pathogens must suppress PTI pathways via the action of effectors to efficiently colonize their hosts. So far, plant PTI has been reported to be active against most classes of pathogens, except viruses, although this defence layer has been hypothesized recently as an active part of antiviral immunity which needs to be suppressed by viruses for infection success. Here, we report that Arabidopsis PTI genes are regulated upon infection by viruses and contribute to plant resistance to Plum pox virus (PPV). Our experiments further show that PPV suppresses two early PTI responses, the oxidative burst and marker gene expression, during Arabidopsis infection. In planta expression of PPV capsid protein (CP) was found to strongly impair these responses in Nicotiana benthamiana and Arabidopsis, revealing its PTI suppressor activity. In summary, we provide the first clear evidence that plant viruses acquired the ability to suppress PTI mechanisms via the action of effectors, highlighting a novel strategy employed by viruses to escape plant defences. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Structure and evolution of barley powdery mildew effector candidates

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Pedersen Carsten

2012-12-01

Full Text Available Abstract Background Protein effectors of pathogenicity are instrumental in modulating host immunity and disease resistance. The powdery mildew pathogen of grasses Blumeria graminis causes one of the most important diseases of cereal crops. B. graminis is an obligate biotrophic pathogen and as such has an absolute requirement to suppress or avoid host immunity if it is to survive and cause disease. Results Here we characterise a superfamily predicted to be the full complement of Candidates for Secreted Effector Proteins (CSEPs in the fungal barley powdery mildew parasite B. graminis f.sp. hordei. The 491 genes encoding these proteins constitute over 7% of this pathogen’s annotated genes and most were grouped into 72 families of up to 59 members. They were predominantly expressed in the intracellular feeding structures called haustoria, and proteins specifically associated with the haustoria were identified by large-scale mass spectrometry-based proteomics. There are two major types of effector families: one comprises shorter proteins (100–150 amino acids, with a high relative expression level in the haustoria and evidence of extensive diversifying selection between paralogs; the second type consists of longer proteins (300–400 amino acids, with lower levels of differential expression and evidence of purifying selection between paralogs. An analysis of the predicted protein structures underscores their overall similarity to known fungal effectors, but also highlights unexpected structural affinities to ribonucleases throughout the entire effector super-family. Candidate effector genes belonging to the same family are loosely clustered in the genome and are associated with repetitive DNA derived from retro-transposons. Conclusions We employed the full complement of genomic, transcriptomic and proteomic analyses as well as structural prediction methods to identify and characterize the members of the CSEPs superfamily in B. graminis f

Antimicrobial susceptibility patterns of Brazilian Haemophilus parasuis field isolates

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Michela Miani

Full Text Available ABSTRACT: Haemophilus parasuis is the etiological agent of Glässer’s disease (GD, an ubiquitous infection of swine characterized by systemic fibrinous polyserositis, polyarthritis and meningitis. Intensive use of antimicrobial agents in swine husbandries during the last years triggered the development of antibiotic resistances in bacterial pathogens. Thus, regular susceptibility testing is crucial to ensure efficacy of different antimicrobial agents to this porcine pathogen. In this study, 50 clinical isolates from South Brazilian pig herds were characterized and analyzed for their susceptibility to commonly used antibiotic. The identification and typing of clinical isolates was carried out by a modified indirect hemagglutination assay combined with a multiplex PCR. The susceptibility of each isolate was analyzed by broth microdilution method against a panel of 21 antimicrobial compounds. We found that field isolates are highly resistance to gentamycin, bacitracin, lincomycin and tiamulin, but sensitive to ampicillin, clindamycin, neomycin, penicillin, danofloxacin and enrofloxacin. Furthermore, an individual susceptibility analysis indicated that enrofloxacin is effective to treat clinical isolates with the exception of those classified as serovar 1. The results presented here firstly demonstrate the susceptibility of Brazilian clinical isolates of H. parasuis to antimicrobials widely used by swine veterinary practitioners and strengthen the need to perform susceptibility test prior to antibiotic therapy during GD outbreaks. In addition, because only six antimicrobial drugs (28.6% were found effective against field isolates, a continuous surveillance of the susceptibility profile should be of major concern to the swine industry.

T3SEdb: data warehousing of virulence effectors secreted by the bacterial Type III Secretion System.

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Tay, Daniel Ming Ming; Govindarajan, Kunde Ramamoorthy; Khan, Asif M; Ong, Terenze Yao Rui; Samad, Hanif M; Soh, Wei Wei; Tong, Minyan; Zhang, Fan; Tan, Tin Wee

2010-10-15

Effectors of Type III Secretion System (T3SS) play a pivotal role in establishing and maintaining pathogenicity in the host and therefore the identification of these effectors is important in understanding virulence. However, the effectors display high level of sequence diversity, therefore making the identification a difficult process. There is a need to collate and annotate existing effector sequences in public databases to enable systematic analyses of these sequences for development of models for screening and selection of putative novel effectors from bacterial genomes that can be validated by a smaller number of key experiments. Herein, we present T3SEdb http://effectors.bic.nus.edu.sg/T3SEdb, a specialized database of annotated T3SS effector (T3SE) sequences containing 1089 records from 46 bacterial species compiled from the literature and public protein databases. Procedures have been defined for i) comprehensive annotation of experimental status of effectors, ii) submission and curation review of records by users of the database, and iii) the regular update of T3SEdb existing and new records. Keyword fielded and sequence searches (BLAST, regular expression) are supported for both experimentally verified and hypothetical T3SEs. More than 171 clusters of T3SEs were detected based on sequence identity comparisons (intra-cluster difference up to ~60%). Owing to this high level of sequence diversity of T3SEs, the T3SEdb provides a large number of experimentally known effector sequences with wide species representation for creation of effector predictors. We created a reliable effector prediction tool, integrated into the database, to demonstrate the application of the database for such endeavours. T3SEdb is the first specialised database reported for T3SS effectors, enriched with manual annotations that facilitated systematic construction of a reliable prediction model for identification of novel effectors. The T3SEdb represents a platform for inclusion of

T3SEdb: data warehousing of virulence effectors secreted by the bacterial Type III Secretion System

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Tong Minyan

2010-10-01

Full Text Available Abstract Background Effectors of Type III Secretion System (T3SS play a pivotal role in establishing and maintaining pathogenicity in the host and therefore the identification of these effectors is important in understanding virulence. However, the effectors display high level of sequence diversity, therefore making the identification a difficult process. There is a need to collate and annotate existing effector sequences in public databases to enable systematic analyses of these sequences for development of models for screening and selection of putative novel effectors from bacterial genomes that can be validated by a smaller number of key experiments. Results Herein, we present T3SEdb http://effectors.bic.nus.edu.sg/T3SEdb, a specialized database of annotated T3SS effector (T3SE sequences containing 1089 records from 46 bacterial species compiled from the literature and public protein databases. Procedures have been defined for i comprehensive annotation of experimental status of effectors, ii submission and curation review of records by users of the database, and iii the regular update of T3SEdb existing and new records. Keyword fielded and sequence searches (BLAST, regular expression are supported for both experimentally verified and hypothetical T3SEs. More than 171 clusters of T3SEs were detected based on sequence identity comparisons (intra-cluster difference up to ~60%. Owing to this high level of sequence diversity of T3SEs, the T3SEdb provides a large number of experimentally known effector sequences with wide species representation for creation of effector predictors. We created a reliable effector prediction tool, integrated into the database, to demonstrate the application of the database for such endeavours. Conclusions T3SEdb is the first specialised database reported for T3SS effectors, enriched with manual annotations that facilitated systematic construction of a reliable prediction model for identification of novel effectors

Remotely triggered seismicity in north China following the 2008 M w 7.9 Wenchuan earthquake

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Peng, Zhigang; Wang, Weijun; Chen, Qi-Fu; Jiang, Tao

2010-11-01

We conduct a systematic survey of remote triggering of earthquakes in north China following the 2008 M w 7.9 Wenchuan earthquake. We identify triggered earthquakes as impulsive seismic energies with clear P and S arrivals on 5 Hz high-pass-filtered three-component velocity seismograms during and immediately after the passage of teleseismic waves. We find clearly triggered seismic activity near the Babaoshan and Huangzhuang-Gaoliying faults southwest of Beijing, and near the aftershock zone of the 1976 M W 7.6 Tangshan earthquake. While several earthquakes occur during and immediately after the teleseismic waves in the aftershock zone of the 1975 M w 7.0 Haicheng earthquake, the change of seismicity is not significant enough to establish the direct triggering relationship. Our results suggest that intraplate regions with active faults associated with major earthquakes during historic or recent times are susceptible to remote triggering. We note that this does not always guarantee the triggering to occur, indicating that other conditions are needed. Since none of these regions is associated with any active geothermal or volcanic activity, we infer that dynamic triggering could be ubiquitous and occur in a wide range of tectonic environments.

TRIGGER

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Wesley Smith

Level-1 Trigger Hardware and Software The final parts of the Level-1 trigger hardware are now being put in place. For the ECAL endcaps, more than half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are now available at CERN, such that one complete endcap can be covered. The Global Trigger now correctly handles ECAL calibration sequences, without being influenced by backpressure. The Regional Calorimeter Trigger (RCT) hardware is complete and working in USC55. Intra-crate tests of all 18 RCT crates and the Global Calorimeter Trigger (GCT) are regularly taking place. Pattern tests have successfully captured data from HCAL through RCT to the GCT Source Cards. HB/HE trigger data are being compared with emulator results to track down the very few remaining hardware problems. The treatment of hot and dead cells, including their recording in the database, has been defined. For the GCT, excellent agreement between the emulator and data has been achieved for jets and HF ET sums. There is still som...

TRIGGER

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W. Smith

Level-1 Trigger Hardware and Software The trigger system has been constantly in use in cosmic and commissioning data taking periods. During CRAFT running it delivered 300 million muon and calorimeter triggers to CMS. It has performed stably and reliably. During the abort gaps it has also provided laser and other calibration triggers. Timing issues, namely synchronization and latency issues, have been solved. About half of the Trigger Concentrator Cards for the ECAL Endcap (TCC-EE) are installed, and the firmware is being worked on. The production of the other half has started. The HCAL Trigger and Readout (HTR) card firmware has been updated, and new features such as fast parallel zero-suppression have been included. Repairs of drift tube (DT) trigger mini-crates, optical links and receivers of sector collectors are under way and have been completed on YB0. New firmware for the optical receivers of the theta links to the drift tube track finder is being installed. In parallel, tests with new eta track finde...

TRIGGER

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R. Carlin with contributions from D. Acosta

2012-01-01

Level-1 Trigger Data-taking continues at cruising speed, with high availability of all components of the Level-1 trigger. We have operated the trigger up to a luminosity of 7.6E33, where we approached 100 kHz using the 7E33 prescale column.  Recently, the pause without triggers in case of an automatic "RESYNC" signal (the "settle" and "recover" time) was reduced in order to minimise the overall dead-time. This may become very important when the LHC comes back with higher energy and luminosity after LS1. We are also preparing for data-taking in the proton-lead run in early 2013. The CASTOR detector will make its comeback into CMS and triggering capabilities are being prepared for this. Steps to be taken include improved cooperation with the TOTEM trigger system and using the LHC clock during the injection and ramp phases of LHC. Studies are being finalised that will have a bearing on the Trigger Technical Design Report (TDR), which is to be rea...

Hitting the Sweet Spot: Glycans as Targets of Fungal Defense Effector Proteins

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Markus Künzler

2015-05-01

Full Text Available Organisms which rely solely on innate defense systems must combat a large number of antagonists with a comparatively low number of defense effector molecules. As one solution of this problem, these organisms have evolved effector molecules targeting epitopes that are conserved between different antagonists of a specific taxon or, if possible, even of different taxa. In order to restrict the activity of the defense effector molecules to physiologically relevant taxa, these target epitopes should, on the other hand, be taxon-specific and easily accessible. Glycans fulfill all these requirements and are therefore a preferred target of defense effector molecules, in particular defense proteins. Here, we review this defense strategy using the example of the defense system of multicellular (filamentous fungi against microbial competitors and animal predators.

Multilayered Regulation of Ethylene Induction Plays a Positive Role in Arabidopsis Resistance against Pseudomonas syringae1[OPEN

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Guan, Rongxia; Su, Jianbin; Meng, Xiangzong; Li, Sen; Liu, Yidong; Xu, Juan; Zhang, Shuqun

2015-01-01

Ethylene, a key phytohormone involved in plant-pathogen interaction, plays a positive role in plant resistance against fungal pathogens. However, its function in plant bacterial resistance remains unclear. Here, we report a detailed analysis of ethylene induction in Arabidopsis (Arabidopsis thaliana) in response to Pseudomonas syringae pv tomato DC3000 (Pst). Ethylene biosynthesis is highly induced in both pathogen/microbe-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI), and the induction is potentiated by salicylic acid (SA) pretreatment. In addition, Pst actively suppresses PAMP-triggered ethylene induction in a type III secretion system-dependent manner. SA potentiation of ethylene induction is dependent mostly on MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) and MPK3 and their downstream ACS2 and ACS6, two type I isoforms of 1-aminocyclopropane-1-carboxylic acid synthases (ACSs). ACS7, a type III ACS whose expression is enhanced by SA pretreatment, is also involved. Pst expressing the avrRpt2 effector gene (Pst-avrRpt2), which is capable of triggering ETI, induces a higher level of ethylene production, and the elevated portion is dependent on SALICYLIC ACID INDUCTION DEFICIENT2 and NONEXPRESSER OF PATHOGENESIS-RELATED GENE1, two key players in SA biosynthesis and signaling. High-order ACS mutants with reduced ethylene induction are more susceptible to both Pst and Pst-avrRpt2, demonstrating a positive role of ethylene in plant bacterial resistance mediated by both PAMP-triggered immunity and ETI. PMID:26265775

Type IV Secretion System of Brucella spp. and its Effectors

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Yuehua eKe

2015-10-01

Full Text Available Brucella spp. cause brucellosis in domestic and wild animals. They are intracellular bacterial pathogens and used as model organisms to study intracellular bacterial infections. Brucella VirB T4SS is a key virulence factor that plays important roles in mediating intracellular survival and manipulating host immune response to infection. In this review, we will discuss roles of Brucella VirB T4SS and in more detail of all 15 identified effectors, which may be crucial for Brucella pathogenesis. VirB T4SS regulates the inflammation response and manipulates vesicle trafficking inside host cells, suggesting that it plays crucial roles in the inhibition of the host immune response and intracellular survival during infection. So, we listed some key molecular events in the intracellular life cycle of Brucella potentially targeted by the VirB T4SS effectors. Elucidating functions of the effectors secreted will be crucial to clarifying mechanism of T4SS during infection. Studying the effectors secreted by Brucella spp. might provide insights into the mechanisms by which the bacteria hijack the host signaling pathways, which help us to develop better vaccines and therapies against brucellosis.

Type IV secretion system of Brucella spp. and its effectors.

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Ke, Yuehua; Wang, Yufei; Li, Wengfeng; Chen, Zeliang

2015-01-01

Brucella spp. are intracellular bacterial pathogens that cause infection in domestic and wild animals. They are often used as model organisms to study intracellular bacterial infections. Brucella VirB T4SS is a key virulence factor that plays important roles in mediating intracellular survival and manipulating host immune response to infection. In this review, we discuss the roles of Brucella VirB T4SS and 15 effectors that are proposed to be crucial for Brucella pathogenesis. VirB T4SS regulates the inflammation response and manipulates vesicle trafficking inside host cells. VirB T4SS also plays crucial roles in the inhibition of the host immune response and intracellular survival during infection. Here, we list the key molecular events in the intracellular life cycle of Brucella that are potentially targeted by the VirB T4SS effectors. Elucidating the functions of these effectors will help clarify the molecular role of T4SS during infection. Furthermore, studying the effectors secreted by Brucella spp. might provide insights into the mechanisms used by the bacteria to hijack the host signaling pathways and aid in the development of better vaccines and therapies against brucellosis.

Susceptibility of Phelipanche and Orobanche species to AAL-toxin.

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de Zélicourt, Axel; Montiel, Grégory; Pouvreau, Jean-Bernard; Thoiron, Séverine; Delgrange, Sabine; Simier, Philippe; Delavault, Philippe

2009-10-01

Fusarium and Alternaria spp. are phytopathogenic fungi which are known to be virulent on broomrapes and to produce sphinganine-analog mycotoxins (SAMs). AAL-toxin is a SAM produced by Alternaria alternata which causes the inhibition of sphinganine N-acyltransferase, a key enzyme in sphingolipid biosynthesis, leading to accumulation of sphingoid bases. These long chain bases (LCBs) are determinant in the occurrence of programmed cell death (PCD) in susceptible plants. We showed that broomrapes are sensitive to AAL-toxin, which is not common plant behavior, and that AAL-toxin triggers cell death at the apex of the radicle as well as LCB accumulation and DNA laddering. We also demonstrated that three Lag1 homologs, encoding components of sphinganine N-acyltransferase in yeast, are present in the Orobanche cumana genome and two of them are mutated leading to an enhanced susceptibility to AAL-toxin. We therefore propose a model for the molecular mechanism governing broomrape susceptibility to the fungus Alternaria alternata.

Identification of Novel Host Interactors of Effectors Secreted by Salmonella and Citrobacter

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Sontag, Ryan L.; Nakayasu, Ernesto S.; Brown, Roslyn N.; Niemann, George S.; Sydor, Michael A.; Sanchez, Octavio; Ansong, Charles; Lu, Shao-Yeh; Choi, Hyungwon; Valleau, Dylan; Weitz, Karl K.; Savchenko, Alexei; Cambronne, Eric D.; Adkins, Joshua N.; McFall-Ngai, Margaret J.

2016-07-12

Many pathogenic bacteria of the familyEnterobacteriaceaeuse type III secretion systems to inject virulence proteins, termed “effectors,” into the host cell cytosol. Although host-cellular activities of several effectors have been demonstrated, the function and host-targeted pathways of most of the effectors identified to date are largely undetermined. To gain insight into host proteins targeted by bacterial effectors, we performed coaffinity purification of host proteins from cell lysates using recombinant effectors from theEnterobacteriaceaeintracellular pathogensSalmonella entericaserovar Typhimurium andCitrobacter rodentium. We identified 54 high-confidence host interactors for theSalmonellaeffectors GogA, GtgA, GtgE, SpvC, SrfH, SseL, SspH1, and SssB collectively and 21 interactors for theCitrobactereffectors EspT, NleA, NleG1, and NleK. We biochemically validated the interaction between the SrfHSalmonellaprotein and the extracellular signal-regulated kinase 2 (ERK2) host protein kinase, which revealed a role for this effector in regulating phosphorylation levels of this enzyme, which plays a central role in signal transduction.

IMPORTANCEDuring infection, pathogenic bacteria face an adverse environment of factors driven by both cellular and humoral defense mechanisms. To help evade the immune response and ultimately proliferate inside the host, many bacteria evolved specialized secretion systems to deliver effector proteins directly into host cells. Translocated effector proteins function to subvert host defense mechanisms. Numerous pathogenic bacteria use a specialized secretion system called type III secretion to deliver effectors into the host cell cytosol. Here, we identified 75 new host targets ofSalmonellaandCitrobactereffectors, which will help elucidate their mechanisms of

The RxLR effector Avh241 from Phytophthora sojae requires plasma membrane localization to induce plant cell death.

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Yu, Xiaoli; Tang, Junli; Wang, Qunqing; Ye, Wenwu; Tao, Kai; Duan, Shuyi; Lu, Chenchen; Yang, Xinyu; Dong, Suomeng; Zheng, Xiaobo; Wang, Yuanchao

2012-10-01

• The Phytophthora sojae genome encodes hundreds of RxLR effectors predicted to manipulate various plant defense responses, but the molecular mechanisms involved are largely unknown. Here we have characterized in detail the P. sojae RxLR effector Avh241. • To determine the function and localization of Avh241, we transiently expressed it on different plants. Silencing of Avh241 in P. sojae, we determined its virulence during infection. Through the assay of promoting infection by Phytophthora capsici to Nicotiana benthamiana, we further confirmed this virulence role. • Avh241 induced cell death in several different plants and localized to the plant plasma membrane. An N-terminal motif within Avh241 was important for membrane localization and cell death-inducing activity. Two mitogen-activated protein kinases, NbMEK2 and NbWIPK, were required for the cell death triggered by Avh241 in N. benthamiana. Avh241 was important for the pathogen's full virulence on soybean. Avh241 could also promote infection by P. capsici and the membrane localization motif was not required to promote infection. • This work suggests that Avh241 interacts with the plant immune system via at least two different mechanisms, one recognized by plants dependent on subcellular localization and one promoting infection independent on membrane localization. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

Effect of long-term voluntary exercise wheel running on susceptibility to bacterial pulmonary infections in a mouse model

DEFF Research Database (Denmark)

van de Weert-van Leeuwen, Pauline B; de Vrankrijker, Angélica M M; Fentz, Joachim

2013-01-01

moderate exercise has many health benefits, healthy mice showed increased bacterial (P. aeruginosa) load and symptoms, after regular voluntary exercise, with perseverance of the phagocytic capacity of monocytes and neutrophils. Whether patients, suffering from bacterial infectious diseases, should......Regular moderate exercise has been suggested to exert anti-inflammatory effects and improve immune effector functions, resulting in reduced disease incidence and viral infection susceptibility. Whether regular exercise also affects bacterial infection susceptibility is unknown. The aim...... of this study was to investigate whether regular voluntary exercise wheel running prior to a pulmonary infection with bacteria (P. aeruginosa) affects lung bacteriology, sickness severity and phagocyte immune function in mice. Balb/c mice were randomly placed in a cage with or without a running wheel. After 28...

Phytoplasma effector SAP54 induces indeterminate leaf-like flower development in Arabidopsis plants.

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MacLean, Allyson M; Sugio, Akiko; Makarova, Olga V; Findlay, Kim C; Grieve, Victoria M; Tóth, Réka; Nicolaisen, Mogens; Hogenhout, Saskia A

2011-10-01

Phytoplasmas are insect-transmitted bacterial plant pathogens that cause considerable damage to a diverse range of agricultural crops globally. Symptoms induced in infected plants suggest that these phytopathogens may modulate developmental processes within the plant host. We report herein that Aster Yellows phytoplasma strain Witches' Broom (AY-WB) readily infects the model plant Arabidopsis (Arabidopsis thaliana) ecotype Columbia, inducing symptoms that are characteristic of phytoplasma infection, such as the production of green leaf-like flowers (virescence and phyllody) and increased formation of stems and branches (witches' broom). We found that the majority of genes encoding secreted AY-WB proteins (SAPs), which are candidate effector proteins, are expressed in Arabidopsis and the AY-WB insect vector Macrosteles quadrilineatus (Hemiptera; Cicadellidae). To identify which of these effector proteins induce symptoms of phyllody and virescence, we individually expressed the effector genes in Arabidopsis. From this screen, we have identified a novel AY-WB effector protein, SAP54, that alters floral development, resulting in the production of leaf-like flowers that are similar to those produced by plants infected with this phytoplasma. This study offers novel insight into the effector profile of an insect-transmitted plant pathogen and reports to our knowledge the first example of a microbial pathogen effector protein that targets flower development in a host.

A novel Meloidogyne graminicola effector, MgMO237, interacts with multiple host defence-related proteins to manipulate plant basal immunity and promote parasitism.

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Chen, Jiansong; Hu, Lili; Sun, Longhua; Lin, Borong; Huang, Kun; Zhuo, Kan; Liao, Jinling

2018-02-27

Plant-parasitic nematodes can secrete effector proteins into the host tissue to facilitate their parasitism. In this study, we report a novel effector protein, MgMO237, from Meloidogyne graminicola, which is exclusively expressed within the dorsal oesophageal gland cell and markedly up-regulated in parasitic third-/fourth-stage juveniles of M. graminicola. Transient expression of MgMO237 in protoplasts from rice roots showed that MgMO237 was localized in the cytoplasm and nucleus of the host cells. Rice plants overexpressing MgMO237 showed an increased susceptibility to M. graminicola. In contrast, rice plants expressing RNA interference vectors targeting MgMO237 showed an increased resistance to M. graminicola. In addition, yeast two-hybrid and co-immunoprecipitation assays showed that MgMO237 interacted specifically with three rice endogenous proteins, i.e. 1,3-β-glucan synthase component (OsGSC), cysteine-rich repeat secretory protein 55 (OsCRRSP55) and pathogenesis-related BetvI family protein (OsBetvI), which are all related to host defences. Moreover, MgMO237 can suppress host defence responses, including the expression of host defence-related genes, cell wall callose deposition and the burst of reactive oxygen species. These results demonstrate that the effector MgMO237 probably promotes the parasitism of M. graminicola by interacting with multiple host defence-related proteins and suppressing plant basal immunity in the later parasitic stages of nematodes. © 2018 BSPP AND JOHN WILEY & SONS LTD.

Meta-analytic approach to the accurate prediction of secreted virulence effectors in gram-negative bacteria

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Sato Yoshiharu

2011-11-01

Full Text Available Abstract Background Many pathogens use a type III secretion system to translocate virulence proteins (called effectors in order to adapt to the host environment. To date, many prediction tools for effector identification have been developed. However, these tools are insufficiently accurate for producing a list of putative effectors that can be applied directly for labor-intensive experimental verification. This also suggests that important features of effectors have yet to be fully characterized. Results In this study, we have constructed an accurate approach to predicting secreted virulence effectors from Gram-negative bacteria. This consists of a support vector machine-based discriminant analysis followed by a simple criteria-based filtering. The accuracy was assessed by estimating the average number of true positives in the top-20 ranking in the genome-wide screening. In the validation, 10 sets of 20 training and 20 testing examples were randomly selected from 40 known effectors of Salmonella enterica serovar Typhimurium LT2. On average, the SVM portion of our system predicted 9.7 true positives from 20 testing examples in the top-20 of the prediction. Removal of the N-terminal instability, codon adaptation index and ProtParam indices decreased the score to 7.6, 8.9 and 7.9, respectively. These discrimination features suggested that the following characteristics of effectors had been uncovered: unstable N-terminus, non-optimal codon usage, hydrophilic, and less aliphathic. The secondary filtering process represented by coexpression analysis and domain distribution analysis further refined the average true positive counts to 12.3. We further confirmed that our system can correctly predict known effectors of P. syringae DC3000, strongly indicating its feasibility. Conclusions We have successfully developed an accurate prediction system for screening effectors on a genome-wide scale. We confirmed the accuracy of our system by external validation

TRIGGER

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W. Smith

At the March meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, the program of trigger pattern tests and vertical slice tests and planning for the Global Runs starting this summer. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and integration testing is in full swing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. After full checkout, trigger subsystems will be then operated in the CMS Global Runs. Continuous...

TRIGGER

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Wesley Smith

2011-01-01

Level-1 Trigger Hardware and Software New Forward Scintillating Counters (FSC) for rapidity gap measurements have been installed and integrated into the Trigger recently. For the Global Muon Trigger, tuning of quality criteria has led to improvements in muon trigger efficiencies. Several subsystems have started campaigns to increase spares by recovering boards or producing new ones. The barrel muon sector collector test system has been reactivated, new η track finder boards are in production, and φ track finder boards are under revision. In the CSC track finder, an η asymmetry problem has been corrected. New pT look-up tables have also improved efficiency. RPC patterns were changed from four out of six coincident layers to three out of six in the barrel, which led to a significant increase in efficiency. A new PAC firmware to trigger on heavy stable charged particles allows looking for chamber hit coincidences in two consecutive bunch-crossings. The redesign of the L1 Trigger Emulator...

TRIGGER

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W. Smith from contributions of C. Leonidopoulos, I. Mikulec, J. Varela and C. Wulz.

Level-1 Trigger Hardware and Software Over the past few months, the Level-1 trigger has successfully recorded data with cosmic rays over long continuous stretches as well as LHC splash events, beam halo, and collision events. The L1 trigger hardware, firmware, synchronization, performance and readiness for beam operation were reviewed in October. All L1 trigger hardware is now installed at Point 5, and most of it is completely commissioned. While the barrel ECAL Trigger Concentrator Cards are fully operational, the recently delivered endcap ECAL TCC system is still being commissioned. For most systems there is a sufficient number of spares available, but for a few systems additional reserve modules are needed. It was decided to increase the overall L1 latency by three bunch crossings to increase the safety margin for trigger timing adjustments. In order for CMS to continue data taking during LHC frequency ramps, the clock distribution tree needs to be reset. The procedures for this have been tested. A repl...

Flexible trigger menu implementation on the Global Trigger for the CMS Level-1 trigger upgrade

Science.gov (United States)

MATSUSHITA, Takashi; CMS Collaboration

2017-10-01

The CMS experiment at the Large Hadron Collider (LHC) has continued to explore physics at the high-energy frontier in 2016. The integrated luminosity delivered by the LHC in 2016 was 41 fb-1 with a peak luminosity of 1.5 × 1034 cm-2s-1 and peak mean pile-up of about 50, all exceeding the initial estimations for 2016. The CMS experiment has upgraded its hardware-based Level-1 trigger system to maintain its performance for new physics searches and precision measurements at high luminosities. The Global Trigger is the final step of the CMS Level-1 trigger and implements a trigger menu, a set of selection requirements applied to the final list of objects from calorimeter and muon triggers, for reducing the 40 MHz collision rate to 100 kHz. The Global Trigger has been upgraded with state-of-the-art FPGA processors on Advanced Mezzanine Cards with optical links running at 10 GHz in a MicroTCA crate. The powerful processing resources of the upgraded system enable implementation of more algorithms at a time than previously possible, allowing CMS to be more flexible in how it handles the available trigger bandwidth. Algorithms for a trigger menu, including topological requirements on multi-objects, can be realised in the Global Trigger using the newly developed trigger menu specification grammar. Analysis-like trigger algorithms can be represented in an intuitive manner and the algorithms are translated to corresponding VHDL code blocks to build a firmware. The grammar can be extended in future as the needs arise. The experience of implementing trigger menus on the upgraded Global Trigger system will be presented.

In Planta Processing and Glycosylation of a Nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-Like Effector and Its Interaction with a Host CLAVATA2-Like Receptor to Promote Parasitism1[OPEN

Science.gov (United States)

Chen, Shiyan; Lang, Ping; Chronis, Demosthenis; Zhang, Sheng; De Jong, Walter S.; Mitchum, Melissa G.

2015-01-01

Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants. PMID:25416475

In planta processing and glycosylation of a nematode CLAVATA3/ENDOSPERM SURROUNDING REGION-like effector and its interaction with a host CLAVATA2-like receptor to promote parasitism.

Science.gov (United States)

Chen, Shiyan; Lang, Ping; Chronis, Demosthenis; Zhang, Sheng; De Jong, Walter S; Mitchum, Melissa G; Wang, Xiaohong

2015-01-01

Like other biotrophic plant pathogens, plant-parasitic nematodes secrete effector proteins into host cells to facilitate infection. Effector proteins that mimic plant CLAVATA3/ENDOSPERM SURROUNDING REGION-related (CLE) proteins have been identified in several cyst nematodes, including the potato cyst nematode (PCN); however, the mechanistic details of this cross-kingdom mimicry are poorly understood. Plant CLEs are posttranslationally modified and proteolytically processed to function as bioactive ligands critical to various aspects of plant development. Using ectopic expression coupled with nanoliquid chromatography-tandem mass spectrometry analysis, we show that the in planta mature form of proGrCLE1, a multidomain CLE effector secreted by PCN during infection, is a 12-amino acid arabinosylated glycopeptide (named GrCLE1-1Hyp4,7g) with striking structural similarity to mature plant CLE peptides. This glycopeptide is more resistant to hydrolytic degradation and binds with higher affinity to a CLAVATA2-like receptor (StCLV2) from potato (Solanum tuberosum) than its nonglycosylated forms. We further show that StCLV2 is highly up-regulated at nematode infection sites and that transgenic potatoes with reduced StCLV2 expression are less susceptible to PCN infection, indicating that interference of the CLV2-mediated signaling pathway confers nematode resistance in crop plants. These results strongly suggest that phytonematodes have evolved to utilize host cellular posttranslational modification and processing machinery for the activation of CLE effectors following secretion into plant cells and highlight the significance of arabinosylation in regulating nematode CLE effector activity. Our finding also provides evidence that multidomain CLEs are modified and processed similarly to single-domain CLEs, adding new insight into CLE maturation in plants. © 2015 American Society of Plant Biologists. All Rights Reserved.

Assessments on landslide susceptibility in the Tseng-wen reservoir watershed, Taiwan

Science.gov (United States)

Chen, Yu-Chin; Chen, Yung-Chau; Chen, Wen-Fu

2014-05-01

Typhoon Morakot under the strong influence of southwestern monsoon wind struck Taiwan on 8 August 2009, and dumped record-breaking rains in southern Taiwan. It triggered enormous landslides in mountains and severe flooding in low-lying areas. In addition, it destroyed or damaged houses, agricultural fields, roads, bridges, and other infrastructure facilities, causing massive economic loss and, more tragically, human casualties. In order to evaluate landslide hazard and risk assessment, it is important to understand the potential sites of landslide and their spatial distribution. Multi-temporal satellite images and geo-spatial data are used to build landslide susceptibility map for the post-disaster in the Tseng-wen reservoir watershed in this research. Elevation, slope, aspect, NDVI (normalized differential vegetation index), relief, roughness, distance to river, and distance to road are the considered factors for estimating landslide susceptibility. Maximum hourly rainfall and total rainfall, accompanied with typhoon event, are selected as the trigger factors of landslide events. Logistic regression analysis is adopted as the statistical method to model landslide susceptibility. The assessed susceptibility is represented in 4 levels which are high, high-intermediate, intermediate, and low level, respectively. Landslide spatial distribution can be depicted as a landslide susceptibility map with respect to each considered influence factors for a specified susceptible level. The landslide areas are about 358 ha and 1,485 ha before and after typhoon Morakot. The new landslide area, induced by typhoon Morakot, is as almost 4 times as the landslide area before typhoon Morakot. In addition, there is about 44.56% landslide area elevation ranging from 500m to 1000m and about 57.22% average slope ranging from 30° to 45° of landslide area. Furthermore, the devastating landslides were happened at those sites close to rivers, exposed area, and area with big land cover change

NALP3 inflammasome functional polymorphisms and gout susceptibility.

Science.gov (United States)

Miao, Zhi-Min; Zhao, Shi-Hua; Yan, Sheng-Li; Li, Chang-Gui; Wang, Yan-Gang; Meng, Dong-Mei; Zhou, Li; Mi, Qing-Sheng

2009-01-01

Gout is the most common autoinflammatory arthritis characterized by elevated serum urate and recurrent attacks of intra-articular crystal deposition of monosodium urate (MSU). Although the pathogenesis of gout is still unclear, accumulated studies indicate that genetic factors trigger gout development, including some susceptibility genes that control the production and clearance of urate and lead to hyperuricemia. However, the epidemiological evidence suggests that only less than 10% of hyperuricemia patients develop gout, indicating that other genes unrelated to the urate metabolism may also contribute to the diseases susceptibility. Accumulated evidences have implied that MSU crystal-induced inflammation is a paradigm of innate immunity and that NALP3 inflammasome, an innate immune complex containing NALP3, ASC and CARD-8, is involved in gout development. Recent studies suggest that NALP3 and CARD-8 functional mutations contribute to the development of autoinflammatory diseases including hereditary periodic fever syndrome, arthritis as well as hypertension susceptibility. Taking into account these genetic findings, here we would like to propose a novel hypothesis that functional mutations in NALP3 inflammasome may make NALP3 inflammasome as attractive susceptibility candidates and genetic markers for gout. Further clinical genetic studies need to be performed to confirm the role of NALP3 inflammasome in the etiology of gout.

Subtle variation within conserved effector operon gene products contributes to T6SS-mediated killing and immunity.

Science.gov (United States)

Alteri, Christopher J; Himpsl, Stephanie D; Zhu, Kevin; Hershey, Haley L; Musili, Ninette; Miller, Jessa E; Mobley, Harry L T

2017-11-01

Type VI secretion systems (T6SS) function to deliver lethal payloads into target cells. Many studies have shown that protection against a single, lethal T6SS effector protein requires a cognate antidote immunity protein, both of which are often encoded together in a two-gene operon. The T6SS and an effector-immunity pair is sufficient for both killing and immunity. HereIn this paper we describe a T6SS effector operon that differs from conventional effector-immunity pairs in that eight genes are necessary for lethal effector function, yet can be countered by a single immunity protein. In this study, we investigated the role that the PefE T6SS immunity protein plays in recognition between two strains harboring nearly identical effector operons. Interestingly, despite containing seven of eight identical effector proteins, the less conserved immunity proteins only provided protection against their native effectors, suggesting that specificity and recognition could be dependent on variation within an immunity protein and one effector gene product. The variable effector gene product, PefD, is encoded upstream from pefE, and displays toxic activity that can be countered by PefE independent of T6SS-activity. Interestingly, while the entire pef operon was necessary to exert toxic activity via the T6SS in P. mirabilis, production of PefD and PefE alone was unable to exert this effector activity. Chimeric PefE proteins constructed from two P. mirabilis strains were used to localize immunity function to three amino acids. A promiscuous immunity protein was created using site-directed mutagenesis to change these residues from one variant to another. These findings support the notion that subtle differences between conserved effectors are sufficient for T6SS-mediated kin discrimination and that PefD requires additional factors to function as a T6SS-dependent effector.

TRIGGER

CERN Multimedia

W. Smith, from contributions of D. Acosta

2012-01-01

  The L1 Trigger group deployed several major improvements this year. Compared to 2011, the single-muon trigger rate has been reduced by a factor of 2 and the η coverage has been restored to 2.4, with high efficiency. During the current technical stop, a higher jet seed threshold will be applied in the Global Calorimeter Trigger in order to significantly reduce the strong pile-up dependence of the HT and multi-jet triggers. The currently deployed L1 menu, with the “6E33” prescales, has a total rate of less than 100 kHz and operates with detector readout dead time of less than 3% for luminosities up to 6.5 × 1033 cm–2s–1. Further prescale sets have been created for 7 and 8 × 1033 cm–2s–1 luminosities. The L1 DPG is evaluating the performance of the Trigger for upcoming conferences and publication. Progress on the Trigger upgrade was reviewed during the May Upgrade Week. We are investigating scenarios for stagin...

TRIGGER

CERN Multimedia

R. Arcidiacono

2013-01-01

  In 2013 the Trigger Studies Group (TSG) has been restructured in three sub-groups: STEAM, for the development of new HLT menus and monitoring their performance; STORM, for the development of HLT tools, code and actual configurations; and FOG, responsible for the online operations of the High Level Trigger. The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for Trigger Menu development, path timing, trigger performance studies coordination, HLT offline DQM as well as HLT release, menu and conditions validation – in collaboration and with the technical support of the PdmV group. Since the end of proton-proton data taking, the group has started preparing for 2015 data taking, with collisions at 13 TeV and 25 ns bunch spacing. The reliability of the extrapolation to higher energy is being evaluated comparing the trigger rates on 7 and 8 TeV Monte Carlo samples with the data taken in the past two years. The effect of 25 ns bunch spacing is being studied on the d...

TRIGGER

CERN Multimedia

W. Smith

Level-1 Trigger Hardware and Software The road map for the final commissioning of the level-1 trigger system has been set. The software for the trigger subsystems is being upgraded to run under CERN Scientific Linux 4 (SLC4). There is also a new release for the Trigger Supervisor (TS 1.4), which implies upgrade work by the subsystems. As reported by the CERN group, a campaign to tidy the Trigger Timing and Control (TTC) racks has begun. The machine interface was upgraded by installing the new RF2TTC module, which receives RF signals from LHC Point 4. Two Beam Synchronous Timing (BST) signals, one for each beam, can now be received in CMS. The machine group will define the exact format of the information content shortly. The margin on the locking range of the CMS QPLL is planned for study for different subsystems in the next Global Runs, using a function generator. The TTC software has been successfully tested on SLC4. Some TTC subsystems have already been upgraded to SLC4. The TTCci Trigger Supervisor ...

The barley powdery mildew effector candidates CSEP0081 and CSEP0254 promote fungal infection success

DEFF Research Database (Denmark)

Ahmed, Ali Abdurehim; Pedersen, Carsten; Thordal-Christensen, Hans

2016-01-01

Effectors play significant roles in the success of pathogens. Recent advances in genome sequencing have revealed arrays of effectors and effector candidates from a wide range of plant pathogens. Yet, the vast majority of them remain uncharacterized. Among the ~500 Candidate Secreted Effector...... independent silencing of the transcripts for these CSEPs significantly reduced the fungal penetration and haustoria formation rate. Both CSEPs are likely required during and after the formation of haustoria, in which their transcripts were found to be differentially expressed, rather than in epiphytic tissue...

Functions and requirements for the INEL light duty utility arm gripper end effector

International Nuclear Information System (INIS)

Pace, D.P.; Barnes, G.E.

1995-02-01

This gripper end effector system functions and requirements document defines the system functions that the end effector must perform as well as the requirements the design must meet. Safety, quality assurance, operations, environmental conditions, and regulatory requirements have been considered. The main purpose of this document is to provide a basis for the end effector engineering, design, and fabrication activities. The document shall be the living reference document to initiate the development activities and will be updated as system technologies are finalized

Functions and requirements for the INEL light duty utility arm sampler end effector

International Nuclear Information System (INIS)

Pace, D.P.; Barnes, G.E.

1995-02-01

This sampler end effector system functions and requirements document defines the system functions that the end effector must perform as well as the requirements the design must meet. Safety, quality assurance, operations, environmental conditions, and regulatory requirements have been considered. The main purpose of this document is to provide a basis for the end effector engineering, design, and fabrication activities. The document shall be the living reference document to initiate the development activities and will be updated as system technologies are finalized

Establishment of an inducing medium for type III effector secretion in Xanthomonas campestris pv. campestris

Directory of Open Access Journals (Sweden)

Guo-Feng Jiang

2013-09-01

Full Text Available It is well known that the type III secretion system (T3SS and type III (T3 effectors are essential for the pathogenicity of most bacterial phytopathogens and that the expression of T3SS and T3 effectors is suppressed in rich media but induced in minimal media and plants. To facilitate in-depth studies on T3SS and T3 effectors, it is crucial to establish a medium for T3 effector expression and secretion. Xanthomonas campestris pv. campestris (Xcc is a model bacterium for studying plant-pathogen interactions. To date no medium for Xcc T3 effector secretion has been defined. Here, we compared four minimal media (MME, MMX, XVM2, and XOM2 which are reported for T3 expression induction in Xanthomonas spp. and found that MME is most efficient for expression and secretion of Xcc T3 effectors. By optimization of carbon and nitrogen sources and pH value based on MME, we established XCM1 medium, which is about 3 times stronger than MME for Xcc T3 effectors secretion. We further optimized the concentration of phosphate, calcium, and magnesium in XCM1 and found that XCM1 with a lower concentration of magnesium (renamed as XCM2 is about 10 times as efficient as XCM1 (meanwhile, about 30 times stronger than MME. Thus, we established an inducing medium XCM2 which is preferred for T3 effector secretion in Xcc.

The Legionella pneumophila IcmSW complex interacts with multiple Dot/Icm effectors to facilitate type IV translocation.

Directory of Open Access Journals (Sweden)

Eric D Cambronne

2007-12-01

Full Text Available Many gram-negative pathogens use a type IV secretion system (T4SS to deliver effector proteins into eukaryotic host cells. The fidelity of protein translocation depends on the efficient recognition of effector proteins by the T4SS. Legionella pneumophila delivers a large number of effector proteins into eukaryotic cells using the Dot/Icm T4SS. How the Dot/Icm system is able to recognize and control the delivery of effectors is poorly understood. Recent studies suggest that the IcmS and IcmW proteins interact to form a stable complex that facilitates translocation of effector proteins by the Dot/Icm system by an unknown mechanism. Here we demonstrate that the IcmSW complex is necessary for the productive translocation of multiple Dot/Icm effector proteins. Effector proteins that were able to bind IcmSW in vitro required icmS and icmW for efficient translocation into eukaryotic cells during L. pneumophila infection. We identified regions in the effector protein SidG involved in icmSW-dependent translocation. Although the full-length SidG protein was translocated by an icmSW-dependent mechanism, deletion of amino terminal regions in the SidG protein resulted in icmSW-independent translocation, indicating that the IcmSW complex is not contributing directly to recognition of effector proteins by the Dot/Icm system. Biochemical and genetic studies showed that the IcmSW complex interacts with a central region of the SidG protein. The IcmSW interaction resulted in a conformational change in the SidG protein as determined by differences in protease sensitivity in vitro. These data suggest that IcmSW binding to effectors could enhance effector protein delivery by mediating a conformational change that facilitates T4SS recognition of a translocation domain located in the carboxyl region of the effector protein.

Identification and characterisation of a hyper-variable apoplastic effector gene family of the potato cyst nematodes.

Science.gov (United States)

Eves-van den Akker, Sebastian; Lilley, Catherine J; Jones, John T; Urwin, Peter E

2014-09-01

Sedentary endoparasitic nematodes are obligate biotrophs that modify host root tissues, using a suite of effector proteins to create and maintain a feeding site that is their sole source of nutrition. Using assumptions about the characteristics of genes involved in plant-nematode biotrophic interactions to inform the identification strategy, we provide a description and characterisation of a novel group of hyper-variable extracellular effectors termed HYP, from the potato cyst nematode Globodera pallida. HYP effectors comprise a large gene family, with a modular structure, and have unparalleled diversity between individuals of the same population: no two nematodes tested had the same genetic complement of HYP effectors. Individuals vary in the number, size, and type of effector subfamilies. HYP effectors are expressed throughout the biotrophic stages in large secretory cells associated with the amphids of parasitic stage nematodes as confirmed by in situ hybridisation. The encoded proteins are secreted into the host roots where they are detectable by immunochemistry in the apoplasm, between the anterior end of the nematode and the feeding site. We have identified HYP effectors in three genera of plant parasitic nematodes capable of infecting a broad range of mono- and dicotyledon crop species. In planta RNAi targeted to all members of the effector family causes a reduction in successful parasitism.

CBL-interacting protein kinase 6 negatively regulates immune response to Pseudomonas syringae in Arabidopsis.

Science.gov (United States)

Sardar, Atish; Nandi, Ashis Kumar; Chattopadhyay, Debasis

2017-06-15

Cytosolic calcium ion (Ca2+) is an essential mediator of the plant innate immune response. Here, we report that a calcium-regulated protein kinase Calcineurin B-like protein (CBL)-interacting protein kinase 6 (CIPK6) functions as a negative regulator of immunity against the bacterial pathogen Pseudomonas syringae in Arabidopsis thaliana. Arabidopsis lines with compromised expression of CIPK6 exhibited enhanced disease resistance to the bacterial pathogen and to P. syringae harboring certain but not all avirulent effectors, while restoration of CIPK6 expression resulted in abolition of resistance. Plants overexpressing CIPK6 were more susceptible to P. syringae. Enhanced resistance in the absence of CIPK6 was accompanied by increased accumulation of salicylic acid and elevated expression of defense marker genes. Salicylic acid accumulation was essential for improved immunity in the absence of CIPK6. CIPK6 negatively regulated the oxidative burst associated with perception of pathogen-associated microbial patterns (PAMPs) and bacterial effectors. Accelerated and enhanced activation of the mitogen-activated protein kinase cascade in response to bacterial and fungal elicitors was observed in the absence of CIPK6. The results of this study suggested that CIPK6 negatively regulates effector-triggered and PAMP-triggered immunity in Arabidopsis. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Quetiapine, an atypical antipsychotic, is protective against autoimmune-mediated demyelination by inhibiting effector T cell proliferation.

Directory of Open Access Journals (Sweden)

Feng Mei

Full Text Available Quetiapine (Que, a commonly used atypical antipsychotic drug (APD, can prevent myelin from breakdown without immune attack. Multiple sclerosis (MS, an autoimmune reactive inflammation demyelinating disease, is triggered by activated myelin-specific T lymphocytes (T cells. In this study, we investigated the potential efficacy of Que as an immune-modulating therapeutic agent for experimental autoimmune encephalomyelitis (EAE, a mouse model for MS. Que treatment was initiated on the onset of MOG(35-55 peptide induced EAE mice and the efficacy of Que on modulating the immune response was determined by Flow Cytometry through analyzing CD4(+/CD8(+ populations and the proliferation of effector T cells (CD4(+CD25(- in peripheral immune organs. Our results show that Que dramatically attenuates the severity of EAE symptoms. Que treatment decreases the extent of CD4(+/CD8(+ T cell infiltration into the spinal cord and suppresses local glial activation, thereby diminishing the loss of mature oligodendrocytes and myelin breakdown in the spinal cord of EAE mice. Our results further demonstrate that Que treatment decreases the CD4(+/CD8(+ T cell populations in lymph nodes and spleens of EAE mice and inhibits either MOG(35-55 or anti-CD3 induced proliferation as well as IL-2 production of effector T cells (CD4(+CD25(- isolated from EAE mice spleen. Together, these findings suggest that Que displays an immune-modulating role during the course of EAE, and thus may be a promising candidate for treatment of MS.

Effector-independent motor sequence representations exist in extrinsic and intrinsic reference frames.

Science.gov (United States)

Wiestler, Tobias; Waters-Metenier, Sheena; Diedrichsen, Jörn

2014-04-02

Many daily activities rely on the ability to produce meaningful sequences of movements. Motor sequences can be learned in an effector-specific fashion (such that benefits of training are restricted to the trained hand) or an effector-independent manner (meaning that learning also facilitates performance with the untrained hand). Effector-independent knowledge can be represented in extrinsic/world-centered or in intrinsic/body-centered coordinates. Here, we used functional magnetic resonance imaging (fMRI) and multivoxel pattern analysis to determine the distribution of intrinsic and extrinsic finger sequence representations across the human neocortex. Participants practiced four sequences with one hand for 4 d, and then performed these sequences during fMRI with both left and right hand. Between hands, these sequences were equivalent in extrinsic or intrinsic space, or were unrelated. In dorsal premotor cortex (PMd), we found that sequence-specific activity patterns correlated higher for extrinsic than for unrelated pairs, providing evidence for an extrinsic sequence representation. In contrast, primary sensory and motor cortices showed effector-independent representations in intrinsic space, with considerable overlap of the two reference frames in caudal PMd. These results suggest that effector-independent representations exist not only in world-centered, but also in body-centered coordinates, and that PMd may be involved in transforming sequential knowledge between the two. Moreover, although effector-independent sequence representations were found bilaterally, they were stronger in the hemisphere contralateral to the trained hand. This indicates that intermanual transfer relies on motor memories that are laid down during training in both hemispheres, but preferentially draws upon sequential knowledge represented in the trained hemisphere.

Identification of proteins similar to AvrE type III effector proteins from ...

African Journals Online (AJOL)

Type III effector proteins are injected into host cells through type III secretion systems. Some effectors are similar to host proteins to promote pathogenicity, while others lead to the activation of disease resistance. We used partial least squares alignment-free bioinformatics methods to identify proteins similar to AvrE proteins ...

End-Effector Development for the PIP Puck Handling Robot

International Nuclear Information System (INIS)

Fowley, M.D.

2001-01-01

It has been decided that excess, weapons-grade plutonium shall be immobilized to prevent nuclear proliferation. The method of immobilization is to encapsulate the plutonium in a ceramic puck, roughly the size of a hockey puck, using a sintering process. This method has been officially identified as the Plutonium Immobilization Process (PIP). A Can-in-Canister storage method will be used to further immobilize the plutonium. The Can-in-Canister method uses the existing design of a Defense Waste Processing Facility (DWPF) canister to house the plutonium pucks. the process begins with several pucks being stacked in a stainless steel can. Several of the stainless steel cans are stacked in a cage-like magazine. Several of the magazines are then placed in a DWPF canister. The DWPF canister is then filled with molten glass containing high-level, radioactive waste from the DWPF vitrification process. The Can-in-Canister method makes reclamation of plutonium from the pucks technically difficult and highly undesirable. The mechanical requirements of the Can-in-Canister process, in conjunction with the amount of time required to immobilize the vast quantities of weapons-grade plutonium, will expose personnel to unnecessarily high levels of radiation if the processes were completed manually, in glove boxes. Therefore, automated equipment is designed into the process to reduce or eliminate personnel exposure. Robots are used whenever the automated handling operations become complicated. There are two such operations in the initial stages of the Can-in-Canister process, which required a six-axis robot. The first operation is a press unloading process. The second operation is a tray transfer process. To successfully accomplish the operational tasks described in the two operations, the end-effector of the robot must be versatile, lightweight, and rugged. As a result of these demands, an extensive development process was undertaken to design the optimum end-effector for these puck

TRIGGER

CERN Multimedia

by Wesley Smith

2011-01-01

Level-1 Trigger Hardware and Software After the winter shutdown minor hardware problems in several subsystems appeared and were corrected. A reassessment of the overall latency has been made. In the TTC system shorter cables between TTCci and TTCex have been installed, which saved one bunch crossing, but which may have required an adjustment of the RPC timing. In order to tackle Pixel out-of-syncs without influencing other subsystems, a special hardware/firmware re-sync protocol has been introduced in the Global Trigger. The link between the Global Calorimeter Trigger and the Global Trigger with the new optical Global Trigger Interface and optical receiver daughterboards has been successfully tested in the Electronics Integration Centre in building 904. New firmware in the GCT now allows a setting to remove the HF towers from energy sums. The HF sleeves have been replaced, which should lead to reduced rates of anomalous signals, which may allow their inclusion after this is validated. For ECAL, improvements i...

TRIGGER

CERN Multimedia

W. Smith from contributions of C. Leonidopoulos

2010-01-01

Level-1 Trigger Hardware and Software Since nearly all of the Level-1 (L1) Trigger hardware at Point 5 has been commissioned, activities during the past months focused on the fine-tuning of synchronization, particularly for the ECAL and the CSC systems, on firmware upgrades and on improving trigger operation and monitoring. Periodic resynchronizations or hard resets and a shortened luminosity section interval of 23 seconds were implemented. For the DT sector collectors, an automatic power-off was installed in case of high temperatures, and the monitoring capabilities of the opto-receivers and the mini-crates were enhanced. The DTTF and the CSCTF now have improved memory lookup tables. The HCAL trigger primitive logic implemented a new algorithm providing better stability of the energy measurement in the presence of any phase misalignment. For the Global Calorimeter Trigger, additional Source Cards have been manufactured and tested. Testing of the new tau, missing ET and missing HT algorithms is underw...

Loss of the interferon-γ-inducible regulatory immunity-related GTPase (IRG), Irgm1, causes activation of effector IRG proteins on lysosomes, damaging lysosomal function and predicting the dramatic susceptibility of Irgm1-deficient mice to infection.

Science.gov (United States)

Maric-Biresev, Jelena; Hunn, Julia P; Krut, Oleg; Helms, J Bernd; Martens, Sascha; Howard, Jonathan C

2016-04-20

The interferon-γ (IFN-γ)-inducible immunity-related GTPase (IRG), Irgm1, plays an essential role in restraining activation of the IRG pathogen resistance system. However, the loss of Irgm1 in mice also causes a dramatic but unexplained susceptibility phenotype upon infection with a variety of pathogens, including many not normally controlled by the IRG system. This phenotype is associated with lymphopenia, hemopoietic collapse, and death of the mouse. We show that the three regulatory IRG proteins (GMS sub-family), including Irgm1, each of which localizes to distinct sets of endocellular membranes, play an important role during the cellular response to IFN-γ, each protecting specific membranes from off-target activation of effector IRG proteins (GKS sub-family). In the absence of Irgm1, which is localized mainly at lysosomal and Golgi membranes, activated GKS proteins load onto lysosomes, and are associated with reduced lysosomal acidity and failure to process autophagosomes. Another GMS protein, Irgm3, is localized to endoplasmic reticulum (ER) membranes; in the Irgm3-deficient mouse, activated GKS proteins are found at the ER. The Irgm3-deficient mouse does not show the drastic phenotype of the Irgm1 mouse. In the Irgm1/Irgm3 double knock-out mouse, activated GKS proteins associate with lipid droplets, but not with lysosomes, and the Irgm1/Irgm3(-/-) does not have the generalized immunodeficiency phenotype expected from its Irgm1 deficiency. The membrane targeting properties of the three GMS proteins to specific endocellular membranes prevent accumulation of activated GKS protein effectors on the corresponding membranes and thus enable GKS proteins to distinguish organellar cellular membranes from the membranes of pathogen vacuoles. Our data suggest that the generalized lymphomyeloid collapse that occurs in Irgm1(-/-) mice upon infection with a variety of pathogens may be due to lysosomal damage caused by off-target activation of GKS proteins on lysosomal

Identification and characterisation of a hyper-variable apoplastic effector gene family of the potato cyst nematodes.

Directory of Open Access Journals (Sweden)

Sebastian Eves-van den Akker

2014-09-01

Full Text Available Sedentary endoparasitic nematodes are obligate biotrophs that modify host root tissues, using a suite of effector proteins to create and maintain a feeding site that is their sole source of nutrition. Using assumptions about the characteristics of genes involved in plant-nematode biotrophic interactions to inform the identification strategy, we provide a description and characterisation of a novel group of hyper-variable extracellular effectors termed HYP, from the potato cyst nematode Globodera pallida. HYP effectors comprise a large gene family, with a modular structure, and have unparalleled diversity between individuals of the same population: no two nematodes tested had the same genetic complement of HYP effectors. Individuals vary in the number, size, and type of effector subfamilies. HYP effectors are expressed throughout the biotrophic stages in large secretory cells associated with the amphids of parasitic stage nematodes as confirmed by in situ hybridisation. The encoded proteins are secreted into the host roots where they are detectable by immunochemistry in the apoplasm, between the anterior end of the nematode and the feeding site. We have identified HYP effectors in three genera of plant parasitic nematodes capable of infecting a broad range of mono- and dicotyledon crop species. In planta RNAi targeted to all members of the effector family causes a reduction in successful parasitism.

Absence of remote earthquake triggering within the Coso and Salton Sea geothermal production fields

Science.gov (United States)

Zhang, Qiong; Lin, Guoqing; Zhan, Zhongwen; Chen, Xiaowei; Qin, Yan; Wdowinski, Shimon

2017-01-01

Geothermal areas are long recognized to be susceptible to remote earthquake triggering, probably due to the high seismicity rates and presence of geothermal fluids. However, anthropogenic injection and extraction activity may alter the stress state and fluid flow within the geothermal fields. Here we examine the remote triggering phenomena in the Coso geothermal field and its surrounding areas to assess possible anthropogenic effects. We find that triggered earthquakes are absent within the geothermal field but occur in the surrounding areas. Similar observation is also found in the Salton Sea geothermal field. We hypothesize that continuous geothermal operation has eliminated any significant differential pore pressure between fractures inside the geothermal field through flushing geothermal precipitations and sediments out of clogged fractures. To test this hypothesis, we analyze the pore-pressure-driven earthquake swarms, and they are found to occur outside or on the periphery of the geothermal production field. Therefore, our results suggest that the geothermal operation has changed the subsurface fracture network, and differential pore pressure is the primary controlling factor of remote triggering in geothermal fields.

Multilayered Regulation of Ethylene Induction Plays a Positive Role in Arabidopsis Resistance against Pseudomonas syringae.

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Guan, Rongxia; Su, Jianbin; Meng, Xiangzong; Li, Sen; Liu, Yidong; Xu, Juan; Zhang, Shuqun

2015-09-01

Ethylene, a key phytohormone involved in plant-pathogen interaction, plays a positive role in plant resistance against fungal pathogens. However, its function in plant bacterial resistance remains unclear. Here, we report a detailed analysis of ethylene induction in Arabidopsis (Arabidopsis thaliana) in response to Pseudomonas syringae pv tomato DC3000 (Pst). Ethylene biosynthesis is highly induced in both pathogen/microbe-associated molecular pattern (PAMP)-triggered immunity and effector-triggered immunity (ETI), and the induction is potentiated by salicylic acid (SA) pretreatment. In addition, Pst actively suppresses PAMP-triggered ethylene induction in a type III secretion system-dependent manner. SA potentiation of ethylene induction is dependent mostly on MITOGEN-ACTIVATED PROTEIN KINASE6 (MPK6) and MPK3 and their downstream ACS2 and ACS6, two type I isoforms of 1-aminocyclopropane-1-carboxylic acid synthases (ACSs). ACS7, a type III ACS whose expression is enhanced by SA pretreatment, is also involved. Pst expressing the avrRpt2 effector gene (Pst-avrRpt2), which is capable of triggering ETI, induces a higher level of ethylene production, and the elevated portion is dependent on SALICYLIC ACID INDUCTION DEFICIENT2 and NONEXPRESSER OF PATHOGENESIS-RELATED GENE1, two key players in SA biosynthesis and signaling. High-order ACS mutants with reduced ethylene induction are more susceptible to both Pst and Pst-avrRpt2, demonstrating a positive role of ethylene in plant bacterial resistance mediated by both PAMP-triggered immunity and ETI. © 2015 American Society of Plant Biologists. All Rights Reserved.

A Plant Immune Receptor Detects Pathogen Effectors that Target WRKY Transcription Factors.

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Sarris, Panagiotis F; Duxbury, Zane; Huh, Sung Un; Ma, Yan; Segonzac, Cécile; Sklenar, Jan; Derbyshire, Paul; Cevik, Volkan; Rallapalli, Ghanasyam; Saucet, Simon B; Wirthmueller, Lennart; Menke, Frank L H; Sohn, Kee Hoon; Jones, Jonathan D G

2015-05-21

Defense against pathogens in multicellular eukaryotes depends on intracellular immune receptors, yet surveillance by these receptors is poorly understood. Several plant nucleotide-binding, leucine-rich repeat (NB-LRR) immune receptors carry fusions with other protein domains. The Arabidopsis RRS1-R NB-LRR protein carries a C-terminal WRKY DNA binding domain and forms a receptor complex with RPS4, another NB-LRR protein. This complex detects the bacterial effectors AvrRps4 or PopP2 and then activates defense. Both bacterial proteins interact with the RRS1 WRKY domain, and PopP2 acetylates lysines to block DNA binding. PopP2 and AvrRps4 interact with other WRKY domain-containing proteins, suggesting these effectors interfere with WRKY transcription factor-dependent defense, and RPS4/RRS1 has integrated a "decoy" domain that enables detection of effectors that target WRKY proteins. We propose that NB-LRR receptor pairs, one member of which carries an additional protein domain, enable perception of pathogen effectors whose function is to target that domain. Copyright © 2015 Elsevier Inc. All rights reserved.

The inactivation of RNase G reduces the Stenotrophomonas maltophilia susceptibility to quinolones by triggering the heat shock response.

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Alejandra eBernardini

2015-10-01

Full Text Available Quinolone resistance is usually due to mutations in the genes encoding bacterial topoisomerases. However different reports have shown that neither clinical quinolone resistant isolates nor in vitro obtained S. maltophilia mutants present mutations in such genes. The mechanisms so far described consist on efflux pumps' overexpression. Our objective is to get information on novel mechanisms of S. maltophilia quinolone resistance. For this purpose, a transposon-insertion mutant library was obtained in S. maltophilia D457.. One mutant presenting reduced susceptibility to nalidixic acid was selected. Inverse PCR showed that the inactivated gene encodes RNase G. Complementation of the mutant with wild-type RNase G allele restored the susceptibility to quinolones. Transcriptomic and real-time RT-PCR analyses showed that several genes encoding heat-shock response proteins were expressed at higher levels in the RNase defective mutant than in the wild-type strain. In agreement with this situation, heat-shock reduces the S. maltophilia susceptibility to quinolone. We can then conclude that the inactivation of the RNase G reduces the susceptibility of S. maltophilia to quinolones, most likely by regulating the expression of heat-shock response genes. Heat-shock induces a transient phenotype of quinolone resistance in S. maltophilia.

Human memory CD8 T cell effector potential is epigenetically preserved during in vivo homeostasis.

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Abdelsamed, Hossam A; Moustaki, Ardiana; Fan, Yiping; Dogra, Pranay; Ghoneim, Hazem E; Zebley, Caitlin C; Triplett, Brandon M; Sekaly, Rafick-Pierre; Youngblood, Ben

2017-06-05

Antigen-independent homeostasis of memory CD8 T cells is vital for sustaining long-lived T cell-mediated immunity. In this study, we report that maintenance of human memory CD8 T cell effector potential during in vitro and in vivo homeostatic proliferation is coupled to preservation of acquired DNA methylation programs. Whole-genome bisulfite sequencing of primary human naive, short-lived effector memory (T EM ), and longer-lived central memory (T CM ) and stem cell memory (T SCM ) CD8 T cells identified effector molecules with demethylated promoters and poised for expression. Effector-loci demethylation was heritably preserved during IL-7- and IL-15-mediated in vitro cell proliferation. Conversely, cytokine-driven proliferation of T CM and T SCM memory cells resulted in phenotypic conversion into T EM cells and was coupled to increased methylation of the CCR7 and Tcf7 loci. Furthermore, haploidentical donor memory CD8 T cells undergoing in vivo proliferation in lymphodepleted recipients also maintained their effector-associated demethylated status but acquired T EM -associated programs. These data demonstrate that effector-associated epigenetic programs are preserved during cytokine-driven subset interconversion of human memory CD8 T cells. © 2017 Abdelsamed et al.

Analysis of Trigger Factors in Episodic Migraineurs Using a Smartphone Headache Diary Applications.

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Jeong-Wook Park

Full Text Available Various stimuli can trigger migraines in susceptible individuals. We examined migraine trigger factors by using a smartphone headache diary application.Episodic migraineurs who agreed to participate in our study downloaded smartphone headache diary application, which was designed to capture the details regarding headache trigger factors and characteristics for 3 months. The participants were asked to access the smartphone headache diary application daily and to confirm the presence of a headache and input the types of trigger factors.Sixty-two participants kept diary entries until the end of the study. The diary data for 4,579 days were analyzed. In this data set, 1,099 headache days (336 migraines, 763 non-migraine headaches were recorded; of these, 772 headache events had with trigger factors, and 327 events did not have trigger factors. The common trigger factors that were present on headache days included stress, fatigue, sleep deprivation, hormonal changes, and weather changes. The likelihood of a headache trigger was 57.7% for stress, 55.1% for sleep deprivation, 48.5% for fatigue, and 46.5% for any trigger. The headaches with trigger factors were associated with greater pain intensity (p<0.001, headache-related disability (p<0.001, abortive medication use (p = 0.02, and the proportion of migraine (p < 0.001, relative to those without trigger factors. Traveling (odd ratios [OR]: 6.4, hormonal changes (OR: 3.5, noise (OR: 2.8, alcohol (OR: 2.5, overeating (OR: 2.4, and stress (OR:1.8 were significantly associated with migraines compared to non-migraine headaches. The headaches that were associated with hormonal changes or noise were more often migraines, regardless of the preventive medication. The headaches due to stress, overeating, alcohol, and traveling were more often migraines without preventive medication, but it was not evident with preventive medication.Smartphone headache diary application is an effective tool to assess migraine

Identification, structure, and function of a novel type VI secretion peptidoglycan glycoside hydrolase effector-immunity pair.

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Whitney, John C; Chou, Seemay; Russell, Alistair B; Biboy, Jacob; Gardiner, Taylor E; Ferrin, Michael A; Brittnacher, Mitchell; Vollmer, Waldemar; Mougous, Joseph D

2013-09-13

Bacteria employ type VI secretion systems (T6SSs) to facilitate interactions with prokaryotic and eukaryotic cells. Despite the widespread identification of T6SSs among Gram-negative bacteria, the number of experimentally validated substrate effector proteins mediating these interactions remains small. Here, employing an informatics approach, we define novel families of T6S peptidoglycan glycoside hydrolase effectors. Consistent with the known intercellular self-intoxication exhibited by the T6S pathway, we observe that each effector gene is located adjacent to a hypothetical open reading frame encoding a putative periplasmically localized immunity determinant. To validate our sequence-based approach, we functionally investigate a representative family member from the soil-dwelling bacterium Pseudomonas protegens. We demonstrate that this protein is secreted in a T6SS-dependent manner and that it confers a fitness advantage in growth competition assays with Pseudomonas putida. In addition, we determined the 1.4 Å x-ray crystal structure of this effector in complex with its cognate immunity protein. The structure reveals the effector shares highest overall structural similarity to a glycoside hydrolase family associated with peptidoglycan N-acetylglucosaminidase activity, suggesting that T6S peptidoglycan glycoside hydrolase effector families may comprise significant enzymatic diversity. Our structural analyses also demonstrate that self-intoxication is prevented by the immunity protein through direct occlusion of the effector active site. This work significantly expands our current understanding of T6S effector diversity.

Identification, Structure, and Function of a Novel Type VI Secretion Peptidoglycan Glycoside Hydrolase Effector-Immunity Pair*

Science.gov (United States)

Whitney, John C.; Chou, Seemay; Russell, Alistair B.; Biboy, Jacob; Gardiner, Taylor E.; Ferrin, Michael A.; Brittnacher, Mitchell; Vollmer, Waldemar; Mougous, Joseph D.

2013-01-01

Bacteria employ type VI secretion systems (T6SSs) to facilitate interactions with prokaryotic and eukaryotic cells. Despite the widespread identification of T6SSs among Gram-negative bacteria, the number of experimentally validated substrate effector proteins mediating these interactions remains small. Here, employing an informatics approach, we define novel families of T6S peptidoglycan glycoside hydrolase effectors. Consistent with the known intercellular self-intoxication exhibited by the T6S pathway, we observe that each effector gene is located adjacent to a hypothetical open reading frame encoding a putative periplasmically localized immunity determinant. To validate our sequence-based approach, we functionally investigate a representative family member from the soil-dwelling bacterium Pseudomonas protegens. We demonstrate that this protein is secreted in a T6SS-dependent manner and that it confers a fitness advantage in growth competition assays with Pseudomonas putida. In addition, we determined the 1.4 Å x-ray crystal structure of this effector in complex with its cognate immunity protein. The structure reveals the effector shares highest overall structural similarity to a glycoside hydrolase family associated with peptidoglycan N-acetylglucosaminidase activity, suggesting that T6S peptidoglycan glycoside hydrolase effector families may comprise significant enzymatic diversity. Our structural analyses also demonstrate that self-intoxication is prevented by the immunity protein through direct occlusion of the effector active site. This work significantly expands our current understanding of T6S effector diversity. PMID:23878199

Air Pollution Exposure—A Trigger for Myocardial Infarction?

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Niklas Berglind

2010-03-01

Full Text Available The association between ambient air pollution exposure and hospitalization for cardiovascular events has been reported in several studies with conflicting results. A case-crossover design was used to investigate the effects of air pollution in 660 first-time myocardial infarction cases in Stockholm in 1993–1994, interviewed shortly after diagnosis using a standard protocol. Air pollution data came from central urban background monitors. No associations were observed between the risk for onset of myocardial infarction and two-hour or 24-hour air pollution exposure. No evidence of susceptible subgroups was found. This study provides no support that moderately elevated air pollution levels trigger first-time myocardial infarction.

TRIGGER

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W. Smith

2011-01-01

Level-1 Trigger Hardware and Software Overall the L1 trigger hardware has been running very smoothly during the last months of proton running. Modifications for the heavy-ion run have been made where necessary. The maximal design rate of 100 kHz can be sustained without problems. All L1 latencies have been rechecked. The recently installed Forward Scintillating Counters (FSC) are being used in the heavy ion run. The ZDC scintillators have been dismantled, but the calorimeter itself remains. We now send the L1 accept signal and other control signals to TOTEM. Trigger cables from TOTEM to CMS will be installed during the Christmas shutdown, so that the TOTEM data can be fully integrated within the CMS readout. New beam gas triggers have been developed, since the BSC-based trigger is no longer usable at high luminosities. In particular, a special BPTX signal is used after a quiet period with no collisions. There is an ongoing campaign to provide enough spare modules for the different subsystems. For example...

TRIGGER

CERN Multimedia

J. Alimena

2013-01-01

Trigger Strategy Group The Strategy for Trigger Evolution And Monitoring (STEAM) group is responsible for the development of future High-Level Trigger menus, as well as of its DQM and validation, in collaboration and with the technical support of the PdmV group. Taking into account the beam energy and luminosity expected in 2015, a rough estimate of the trigger rates indicates a factor four increase with respect to 2012 conditions. Assuming that a factor two can be tolerated thanks to the increase in offline storage and processing capabilities, a toy menu has been developed using the new OpenHLT workflow to estimate the transverse energy/momentum thresholds that would halve the current trigger rates. The CPU time needed to run the HLT has been compared between data taken with 25 ns and 50 ns bunch spacing, for equivalent pile-up: no significant difference was observed on the global time per event distribution at the only available data point, corresponding to a pile-up of about 10 interactions. Using th...

Preparation of the Drager Fabius CE and Drager Zeus anaesthetic machines for patients susceptible to malignant hyperthermia.

LENUS (Irish Health Repository)

Shanahan, Hiliary

2012-05-01

Malignant hyperthermia may follow exposure to trace quantities of inhalational anaesthetics. In susceptible patients, the complete avoidance of these triggers is advised when possible; however, failing this, it is essential to washout or purge the anaesthesia machine of residual inhalational anaesthetics.

Tissue stiffening coordinates morphogenesis by triggering collective cell migration in vivo.

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Barriga, Elias H; Franze, Kristian; Charras, Guillaume; Mayor, Roberto

2018-02-22

Collective cell migration is essential for morphogenesis, tissue remodelling and cancer invasion. In vivo, groups of cells move in an orchestrated way through tissues. This movement involves mechanical as well as molecular interactions between cells and their environment. While the role of molecular signals in collective cell migration is comparatively well understood, how tissue mechanics influence collective cell migration in vivo remains unknown. Here we investigated the importance of mechanical cues in the collective migration of the Xenopus laevis neural crest cells, an embryonic cell population whose migratory behaviour has been likened to cancer invasion. We found that, during morphogenesis, the head mesoderm underlying the cephalic neural crest stiffens. This stiffening initiates an epithelial-to-mesenchymal transition in neural crest cells and triggers their collective migration. To detect changes in their mechanical environment, neural crest cells use mechanosensation mediated by the integrin-vinculin-talin complex. By performing mechanical and molecular manipulations, we show that mesoderm stiffening is necessary and sufficient to trigger neural crest migration. Finally, we demonstrate that convergent extension of the mesoderm, which starts during gastrulation, leads to increased mesoderm stiffness by increasing the cell density underneath the neural crest. These results show that convergent extension of the mesoderm has a role as a mechanical coordinator of morphogenesis, and reveal a link between two apparently unconnected processes-gastrulation and neural crest migration-via changes in tissue mechanics. Overall, we demonstrate that changes in substrate stiffness can trigger collective cell migration by promoting epithelial-to-mesenchymal transition in vivo. More broadly, our results raise the idea that tissue mechanics combines with molecular effectors to coordinate morphogenesis.

A Poly-ADP-Ribose Trigger Releases the Auto-Inhibition of a Chromatin Remodeling Oncogene.

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Singh, Hari R; Nardozza, Aurelio P; Möller, Ingvar R; Knobloch, Gunnar; Kistemaker, Hans A V; Hassler, Markus; Harrer, Nadine; Blessing, Charlotte; Eustermann, Sebastian; Kotthoff, Christiane; Huet, Sébastien; Mueller-Planitz, Felix; Filippov, Dmitri V; Timinszky, Gyula; Rand, Kasper D; Ladurner, Andreas G

2017-12-07

DNA damage triggers chromatin remodeling by mechanisms that are poorly understood. The oncogene and chromatin remodeler ALC1/CHD1L massively decompacts chromatin in vivo yet is inactive prior to DNA-damage-mediated PARP1 induction. We show that the interaction of the ALC1 macrodomain with the ATPase module mediates auto-inhibition. PARP1 activation suppresses this inhibitory interaction. Crucially, release from auto-inhibition requires a poly-ADP-ribose (PAR) binding macrodomain. We identify tri-ADP-ribose as a potent PAR-mimic and synthetic allosteric effector that abrogates ATPase-macrodomain interactions, promotes an ungated conformation, and activates the remodeler's ATPase. ALC1 fragments lacking the regulatory macrodomain relax chromatin in vivo without requiring PARP1 activation. Further, the ATPase restricts the macrodomain's interaction with PARP1 under non-DNA damage conditions. Somatic cancer mutants disrupt ALC1's auto-inhibition and activate chromatin remodeling. Our data show that the NAD + -metabolite and nucleic acid PAR triggers ALC1 to drive chromatin relaxation. Modular allostery in this oncogene tightly controls its robust, DNA-damage-dependent activation. Copyright © 2017 Elsevier Inc. All rights reserved.

GTP- and GDP-Dependent Rab27a Effectors in Pancreatic Beta-Cells.

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Yamaoka, Mami; Ishizaki, Toshimasa; Kimura, Toshihide

2015-01-01

Small guanosine triphosphatases (GTPases) participate in a wide variety of cellular functions including proliferation, differentiation, adhesion, and intracellular transport. Conventionally, only the guanosine 5'-triphosphate (GTP)-bound small GTPase interacts with effector proteins, and the resulting downstream signals control specific cellular functions. Therefore, the GTP-bound form is regarded as active, and the focus has been on searching for proteins that bind the GTP form to look for their effectors. The Rab family small GTPase Rab27a is highly expressed in some secretory cells and is involved in the control of membrane traffic. The present study reviews recent progress in our understanding of the roles of Rab27a and its effectors in pancreatic beta-cells. In the basal state, GTP-bound Rab27a controls insulin secretion at pre-exocytic stages via its GTP-dependent effectors. We previously identified novel guanosine 5'-diphosphate (GDP)-bound Rab27-interacting proteins. Interestingly, GDP-bound Rab27a controls endocytosis of the secretory membrane via its interaction with these proteins. We also demonstrated that the insulin secretagogue glucose converts Rab27a from its GTP- to GDP-bound forms. Thus, GTP- and GDP-bound Rab27a regulate pre-exocytic and endocytic stages in membrane traffic, respectively. Since the physiological importance of GDP-bound GTPases has been largely overlooked, we consider that the investigation of GDP-dependent effectors for other GTPases is necessary for further understanding of cellular function.

Intrinsic disorder in pathogen effectors: protein flexibility as an evolutionary hallmark in a molecular arms race.

Science.gov (United States)

Marín, Macarena; Uversky, Vladimir N; Ott, Thomas

2013-09-01

Effector proteins represent a refined mechanism of bacterial pathogens to overcome plants' innate immune systems. These modular proteins often manipulate host physiology by directly interfering with immune signaling of plant cells. Even if host cells have developed efficient strategies to perceive the presence of pathogenic microbes and to recognize intracellular effector activity, it remains an open question why only few effectors are recognized directly by plant resistance proteins. Based on in-silico genome-wide surveys and a reevaluation of published structural data, we estimated that bacterial effectors of phytopathogens are highly enriched in long-disordered regions (>50 residues). These structurally flexible segments have no secondary structure under physiological conditions but can fold in a stimulus-dependent manner (e.g., during protein-protein interactions). The high abundance of intrinsic disorder in effectors strongly suggests positive evolutionary selection of this structural feature and highlights the dynamic nature of these proteins. We postulate that such structural flexibility may be essential for (1) effector translocation, (2) evasion of the innate immune system, and (3) host function mimicry. The study of these dynamical regions will greatly complement current structural approaches to understand the molecular mechanisms of these proteins and may help in the prediction of new effectors.

Effector Regulatory T Cell Differentiation and Immune Homeostasis Depend on the Transcription Factor Myb.

Science.gov (United States)

Dias, Sheila; D'Amico, Angela; Cretney, Erika; Liao, Yang; Tellier, Julie; Bruggeman, Christine; Almeida, Francisca F; Leahy, Jamie; Belz, Gabrielle T; Smyth, Gordon K; Shi, Wei; Nutt, Stephen L

2017-01-17

FoxP3-expressing regulatory T (Treg) cells are essential for maintaining immune homeostasis. Activated Treg cells undergo further differentiation into an effector state that highly expresses genes critical for Treg cell function, although how this process is coordinated on a transcriptional level is poorly understood. Here, we demonstrate that mice lacking the transcription factor Myb in Treg cells succumbed to a multi-organ inflammatory disease. Myb was specifically expressed in, and required for the differentiation of, thymus-derived effector Treg cells. The combination of transcriptome and genomic footprint analyses revealed that Myb directly regulated a large proportion of the gene expression specific to effector Treg cells, identifying Myb as a critical component of the gene regulatory network controlling effector Treg cell differentiation and function. Copyright © 2017 Elsevier Inc. All rights reserved.

Exact positioning of the robotic arm end effector

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Korepanov, Valery; Dudkin, Fedir

2016-07-01

Orbital service becomes a new challenge of space exploration. The necessity to introduce it is connected first of all with an attractive opportunity to prolong the exploitation terms of expensive commercial satellites by, e.g., refilling of fuel or changing batteries. Other application area is a fight with permanently increasing amount of space litter - defunct satellites, burnt-out rocket stages, discarded trash and other debris. Now more than few tens of thousands orbiting objects larger than 5-10 cm (or about 1 million junks larger than 1 cm) are a huge problem for crucial and costly satellites and manned vehicles. For example, in 2014 the International Space Station had to change three times its orbit to avoid collision with space debris. So the development of the concepts and actions related to removal of space debris or non-operational satellites with use of robotic arm of a servicing satellite is very actual. Such a technology is also applicable for unmanned exploratory missions in solar system, for example for collecting a variety of samples from a celestial body surface. Naturally, the robotic arm movements should be controlled with great accuracy at influence of its non-rigidity, thermal and other factors. In these circumstances often the position of the arm end effector has to be controlled with high accuracy. The possibility of coordinate determination for the robotic arm end effector with use of a low frequency active electromagnetic system has been considered in the presented report. The proposed design of such a system consists of a small magnetic dipole source, which is mounted inside of the arm end effector and two or three 3-component magnetic field sensors mounted on a servicing satellite body. The data from this set of 3-component magnetic field sensors, which are fixed relatively to the satellite body, allows use of the mathematical approach for determination of position and orientation of the magnetic dipole source. The theoretical

Chloroplastic protein NRIP1 mediates innate immune receptor recognition of a viral effector

Science.gov (United States)

Caplan, Jeffrey L.; Mamillapalli, Padmavathi; Burch-Smith, Tessa M.; Czymmek, Kirk; Dinesh-Kumar, S.P.

2008-01-01

Summary Plant innate immunity relies on the recognition of pathogen effector molecules by nucleotide-binding-leucine-rich repeat (NB-LRR) immune receptor families. Previously we have shown the N immune receptor, a member of TIR-NB-LRR family, indirectly recognizes the 50-kDa helicase (p50) domain of Tobacco mosaic virus (TMV) through its TIR domain. We have identified an N receptor-interacting protein, NRIP1, that directly interacts with both N's TIR domain and p50. NRIP1 is a functional rhodanese sulfurtransferase and is required for N to provide complete resistance to TMV. Interestingly, NRIP1 that normally localizes to the chloroplasts is recruited to the cytoplasm and nucleus by the p50 effector. As a consequence, NRIP1 interacts with N only in the presence of the p50 effector. Our findings show that a chloroplastic protein is intimately involved in pathogen recognition. We propose that N's activation requires a pre-recognition complex containing the p50 effector and NRIP1. PMID:18267075

Antibody-Mediated Targeting of Tau In Vivo Does Not Require Effector Function and Microglial Engagement

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Seung-Hye Lee

2016-08-01

Full Text Available The spread of tau pathology correlates with cognitive decline in Alzheimer’s disease. In vitro, tau antibodies can block cell-to-cell tau spreading. Although mechanisms of anti-tau function in vivo are unknown, effector function might promote microglia-mediated clearance. In this study, we investigated whether antibody effector function is required for targeting tau. We compared efficacy in vivo and in vitro of two versions of the same tau antibody, with and without effector function, measuring tau pathology, neuron health, and microglial function. Both antibodies reduced accumulation of tau pathology in Tau-P301L transgenic mice and protected cultured neurons against extracellular tau-induced toxicity. Only the full-effector antibody enhanced tau uptake in cultured microglia, which promoted release of proinflammatory cytokines. In neuron-microglia co-cultures, only effectorless anti-tau protected neurons, suggesting full-effector tau antibodies can induce indirect toxicity via microglia. We conclude that effector function is not required for efficacy, and effectorless tau antibodies may represent a safer approach to targeting tau.

The presence of lytic HSV-1 transcripts and clonally expanded T cells with a memory effector phenotype in human sensory ganglia.

Science.gov (United States)

Derfuss, Tobias; Arbusow, Viktor; Strupp, Michael; Brandt, Thomas; Theil, Diethilde

2009-05-01

Herpes simplex virus type 1 (HSV-1) latent persistence in human trigeminal ganglia (TG) is accompanied by a chronic CD8 T-cell infiltration. Thus far, during HSV-1 latency only a single transcript, namely the latency-associated transcript (LAT), has been identified to be synthesized but not translated into a protein. In contrast, the chronic CD8 T-cell infiltration suggests that an antigen trigger must be present. The focus of the current work was to look for HSV-1 transcription activity as a potential trigger of the immune response and to demonstrate whether the immune cells are clonally expanded and have a phenotype that suggests that they have been triggered by viral antigen. By combining in situ hybridization, laser cutting microscopy, and single-cell real time RT-PCR, we demonstrated expression of the HSV-1 immediate early (IE) genes ICP0 and ICP4 in human trigeminal neurons. Using CDR3 spectratyping, we showed that the infiltrating T cells are clonally expanded, indicating an antigen-driven immune response. Moreover, the persisting CD8(+) T cells had prominent features of the memory effector phenotype. Chemokines CCL5 and CXCL10 were expressed by a subpopulation of infiltrating cells and the corresponding chemokine receptors CCR5 and CXCR3 were co-expressed on virtually all T cells bearing the CD8 phenotype. Thus, HSV-1 IE genes are expressed in human TG, and the infiltrating T cells bear several characteristics that suggest viral antigenic stimulation.

Transcriptome profiling of resistant and susceptible Cavendish banana roots following inoculation with Fusarium oxysporum f. sp. cubense tropical race 4

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Li Chun-yu

2012-08-01

Full Text Available Abstract Background Fusarium wilt, caused by the fungal pathogen Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4, is considered the most lethal disease of Cavendish bananas in the world. The disease can be managed in the field by planting resistant Cavendish plants generated by somaclonal variation. However, little information is available on the genetic basis of plant resistance to Foc TR4. To a better understand the defense response of resistant banana plants to the Fusarium wilt pathogen, the transcriptome profiles in roots of resistant and susceptible Cavendish banana challenged with Foc TR4 were compared. Results RNA-seq analysis generated more than 103 million 90-bp clean pair end (PE reads, which were assembled into 88,161 unigenes (mean size = 554 bp. Based on sequence similarity searches, 61,706 (69.99% genes were identified, among which 21,273 and 50,410 unigenes were assigned to gene ontology (GO categories and clusters of orthologous groups (COG, respectively. Searches in the Kyoto Encyclopedia of Genes and Genomes Pathway database (KEGG mapped 33,243 (37.71% unigenes to 119 KEGG pathways. A total of 5,008 genes were assigned to plant-pathogen interactions, including disease defense and signal transduction. Digital gene expression (DGE analysis revealed large differences in the transcriptome profiles of the Foc TR4-resistant somaclonal variant and its susceptible wild-type. Expression patterns of genes involved in pathogen-associated molecular pattern (PAMP recognition, activation of effector-triggered immunity (ETI, ion influx, and biosynthesis of hormones as well as pathogenesis-related (PR genes, transcription factors, signaling/regulatory genes, cell wall modification genes and genes with other functions were analyzed and compared. The results indicated that basal defense mechanisms are involved in the recognition of PAMPs, and that high levels of defense-related transcripts may contribute to Foc TR4 resistance in

Major life events as potential triggers of sudden cardiac arrest.

Science.gov (United States)

Wicks, April F; Lumley, Thomas; Lemaitre, Rozenn N; Sotoodehnia, Nona; Rea, Thomas D; McKnight, Barbara; Strogatz, David S; Bovbjerg, Viktor E; Siscovick, David S

2012-05-01

We investigated the risk of sudden cardiac arrest in association with the recent loss of, or separation from, a family member or friend. Our case-crossover study included 490 apparently healthy married residents of King County, Washington, who suffered sudden cardiac arrest between 1988 and 2005. We compared exposure to spouse-reported family/friend events occurring ≤ 1 month before sudden cardiac arrest with events occurring in the previous 5 months. We evaluated potential effect modification by habitual vigorous physical activity. Recent family/friend events were associated with a higher risk of sudden cardiac arrest (odds ratio [OR] = 1.6; 95% confidence interval [CI] = 1.1-2.4). ORs for cases with and without habitual vigorous physical activity were 1.1 (0.6-2.2) and 2.0 (1.2-3.1), respectively (interaction P = 0.02). These results suggest family/friend events may trigger sudden cardiac arrest and raise the hypothesis that habitual vigorous physical activity may lower susceptibility to these potential triggers.

Effector gene birth in plant parasitic nematodes: Neofunctionalization of a housekeeping glutathione synthetase gene

Science.gov (United States)

Lilley, Catherine J.; Maqbool, Abbas; Wu, Duqing; Yusup, Hazijah B.; Jones, Laura M.; Birch, Paul R. J.; Urwin, Peter E.

2018-01-01

Plant pathogens and parasites are a major threat to global food security. Plant parasitism has arisen four times independently within the phylum Nematoda, resulting in at least one parasite of every major food crop in the world. Some species within the most economically important order (Tylenchida) secrete proteins termed effectors into their host during infection to re-programme host development and immunity. The precise detail of how nematodes evolve new effectors is not clear. Here we reconstruct the evolutionary history of a novel effector gene family. We show that during the evolution of plant parasitism in the Tylenchida, the housekeeping glutathione synthetase (GS) gene was extensively replicated. New GS paralogues acquired multiple dorsal gland promoter elements, altered spatial expression to the secretory dorsal gland, altered temporal expression to primarily parasitic stages, and gained a signal peptide for secretion. The gene products are delivered into the host plant cell during infection, giving rise to “GS-like effectors”. Remarkably, by solving the structure of GS-like effectors we show that during this process they have also diversified in biochemical activity, and likely represent the founding members of a novel class of GS-like enzyme. Our results demonstrate the re-purposing of an endogenous housekeeping gene to form a family of effectors with modified functions. We anticipate that our discovery will be a blueprint to understand the evolution of other plant-parasitic nematode effectors, and the foundation to uncover a novel enzymatic function. PMID:29641602

Subversion of the Endocytic and Secretory Pathways by Bacterial Effector Proteins

Directory of Open Access Journals (Sweden)

Mary M. Weber

2018-01-01

Full Text Available Intracellular bacteria have developed numerous strategies to hijack host vesicular trafficking pathways to form their unique replicative niches. To promote intracellular replication, the bacteria must interact with host organelles and modulate host signaling pathways to acquire nutrients and membrane for the growing parasitophorous vacuole all while suppressing activation of the immune response. To facilitate host cell subversion, bacterial pathogens use specialized secretion systems to deliver bacterial virulence factors, termed effectors, into the host cell that mimic, agonize, and/or antagonize the function of host proteins. In this review we will discuss how bacterial effector proteins from Coxiella burnetii, Brucella abortus, Salmonella enterica serovar Typhimurium, Legionella pneumophila, Chlamydia trachomatis, and Orientia tsutsugamushi manipulate the endocytic and secretory pathways. Understanding how bacterial effector proteins manipulate host processes not only gives us keen insight into bacterial pathogenesis, but also enhances our understanding of how eukaryotic membrane trafficking is regulated.

Structural basis for sequence-specific recognition of DNA by TAL effectors

KAUST Repository

Deng, Dong

2012-01-05

TAL (transcription activator-like) effectors, secreted by phytopathogenic bacteria, recognize host DNA sequences through a central domain of tandem repeats. Each repeat comprises 33 to 35 conserved amino acids and targets a specific base pair by using two hypervariable residues [known as repeat variable diresidues (RVDs)] at positions 12 and 13. Here, we report the crystal structures of an 11.5-repeat TAL effector in both DNA-free and DNA-bound states. Each TAL repeat comprises two helices connected by a short RVD-containing loop. The 11.5 repeats form a right-handed, superhelical structure that tracks along the sense strand of DNA duplex, with RVDs contacting the major groove. The 12th residue stabilizes the RVD loop, whereas the 13th residue makes a base-specific contact. Understanding DNA recognition by TAL effectors may facilitate rational design of DNA-binding proteins with biotechnological applications.

Brucella Modulates Secretory Trafficking via Multiple Type IV Secretion Effector Proteins

Science.gov (United States)

Myeni, Sebenzile; Child, Robert; Ng, Tony W.; Kupko, John J.; Wehrly, Tara D.; Porcella, Stephen F.; Knodler, Leigh A.; Celli, Jean

2013-01-01

The intracellular pathogenic bacterium Brucella generates a replicative vacuole (rBCV) derived from the endoplasmic reticulum via subversion of the host cell secretory pathway. rBCV biogenesis requires the expression of the Type IV secretion system (T4SS) VirB, which is thought to translocate effector proteins that modulate membrane trafficking along the endocytic and secretory pathways. To date, only a few T4SS substrates have been identified, whose molecular functions remain unknown. Here, we used an in silico screen to identify putative T4SS effector candidate proteins using criteria such as limited homology in other bacterial genera, the presence of features similar to known VirB T4SS effectors, GC content and presence of eukaryotic-like motifs. Using β-lactamase and CyaA adenylate cyclase reporter assays, we identified eleven proteins translocated into host cells by Brucella, five in a VirB T4SS-dependent manner, namely BAB1_0678 (BspA), BAB1_0712 (BspB), BAB1_0847 (BspC), BAB1_1671 (BspE) and BAB1_1948 (BspF). A subset of the translocated proteins targeted secretory pathway compartments when ectopically expressed in HeLa cells, and the VirB effectors BspA, BspB and BspF inhibited protein secretion. Brucella infection also impaired host protein secretion in a process requiring BspA, BspB and BspF. Single or combined deletions of bspA, bspB and bspF affected Brucella ability to replicate in macrophages and persist in the liver of infected mice. Taken together, these findings demonstrate that Brucella modulates secretory trafficking via multiple T4SS effector proteins that likely act coordinately to promote Brucella pathogenesis. PMID:23950720

Flexible trigger menu implementation on the Global Trigger for the CMS Level-1 trigger upgrade

CERN Document Server

Matsushita, Takashi

2017-01-01

The CMS experiment at the Large Hadron Collider (LHC) has continued to explore physics at the high-energy frontier in 2016. The integrated luminosity delivered by the LHC in 2016 was 41~fb$^{-1}$ with a peak luminosity of 1.5 $\\times$ 10$^{34}$ cm$^{-2}$s$^{-1}$ and peak mean pile-up of about 50, all exceeding the initial estimations for 2016. The CMS experiment has upgraded its hardware-based Level-1 trigger system to maintain its performance for new physics searches and precision measurements at high luminosities. The Global Trigger is the final step of the CMS \\mbox{Level-1} trigger and implements a trigger menu, a set of selection requirements applied to the final list of objects from calorimeter and muon triggers, for reducing the 40 MHz collision rate to 100 kHz. The Global Trigger has been upgraded with state-of-the-art FPGA processors on Advanced Mezzanine Cards with optical links running at 10 GHz in a MicroTCA crate. The powerful processing resources of the upgraded system enable implemen...

Autoreactive T effector memory differentiation mirrors β-cell function in type 1 diabetes.

Science.gov (United States)

Yeo, Lorraine; Woodwyk, Alyssa; Sood, Sanjana; Lorenc, Anna; Eichmann, Martin; Pujol-Autonell, Irma; Melchiotti, Rossella; Skowera, Ania; Fidanis, Efthymios; Dolton, Garry M; Tungatt, Katie; Sewell, Andrew K; Heck, Susanne; Saxena, Alka; Beam, Craig A; Peakman, Mark

2018-05-31

In type 1 diabetes, cytotoxic CD8 T cells with specificity for β-cell autoantigens are found in the pancreatic islets where they are implicated in the destruction of insulin-secreting β cells. In contrast, the disease relevance of β-cell-reactive CD8 T cells that are detectable in the circulation, and their relationship to β-cell function, are not known. Here, we tracked multiple, circulating β-cell-reactive CD8 T cell subsets and measured β-cell function longitudinally for two years, starting immediately after diagnosis of type 1 diabetes. We found that change in β-cell-specific effector memory CD8 T cells expressing CD57 was positively correlated with C-peptide change in subjects below 12 years of age. Autoreactive CD57+ effector memory CD8 T cells bore the signature of enhanced effector function (higher expression of granzyme B, killer specific protein 37 and CD16, and reduced expression of CD28) compared with their CD57-negative counterparts, and network association modelling indicated that the dynamics of β-cell-reactive CD57+ effector memory CD8 T cell subsets were strongly linked. Thus, coordinated changes in circulating β-cell-specific CD8 T cells within the CD57+ effector memory subset calibrate to functional insulin reserve in type 1 diabetes, providing a tool for immune monitoring and a mechanism-based target for immunotherapy.

Identification of antibody glycosylation structures that predict monoclonal antibody Fc-effector function.

Science.gov (United States)

Chung, Amy W; Crispin, Max; Pritchard, Laura; Robinson, Hannah; Gorny, Miroslaw K; Yu, Xiaojie; Bailey-Kellogg, Chris; Ackerman, Margaret E; Scanlan, Chris; Zolla-Pazner, Susan; Alter, Galit

2014-11-13

To determine monoclonal antibody (mAb) features that predict fragment crystalizable (Fc)-mediated effector functions against HIV. Monoclonal antibodies, derived from Chinese hamster ovary cells or Epstein-Barr virus-immortalized mouse heteromyelomas, with specificity to key regions of the HIV envelope including gp120-V2, gp120-V3 loop, gp120-CD4(+) binding site, and gp41-specific antibodies, were functionally profiled to determine the relative contribution of the variable and constant domain features of the antibodies in driving robust Fc-effector functions. Each mAb was assayed for antibody-binding affinity to gp140(SR162), antibody-dependent cellular cytotoxicity (ADCC), antibody-dependent cellular phagocytosis (ADCP) and for the ability to bind to FcγRIIa, FcγRIIb and FcγRIIIa receptors. Antibody glycan profiles were determined by HPLC. Neither the specificity nor the affinity of the mAbs determined the potency of Fc-effector function. FcγRIIIa binding strongly predicted ADCC and decreased galactose content inversely correlated with ADCP, whereas N-glycolylneuraminic acid-containing structures exhibited enhanced ADCP. Additionally, the bi-antenary glycan arm onto which galactose was added predicted enhanced binding to FcγRIIIa and ADCC activity, independent of the specificity of the mAb. Our studies point to the specific Fc-glycan structures that can selectively promote Fc-effector functions independently of the antibody specificity. Furthermore, we demonstrated antibody glycan structures associated with enhanced ADCP activity, an emerging Fc-effector function that may aid in the control and clearance of HIV infection.

High immunosuppressive burden in advanced hepatocellular carcinoma patients: Can effector functions be restored?

Science.gov (United States)

Lugade, Amit A; Kalathil, Suresh; Miller, Austin; Iyer, Renuka; Thanavala, Yasmin

2013-07-01

The accumulation of immunosuppressive cells and exhausted effector T cells highlight an important immune dysfunction in advanced stage hepatocellular carcinoma (HCC) patients. These cells significantly hamper the efficacy immunotherapies and facilitate HCC progression. We have recently demonstrated that the multipronged depletion of immunosuppressive cells potentially restores effector T-cell function in HCC.

WO3/Pt nanoparticles are NADPH oxidase biomimetics that mimic effector cells in vitro and in vivo

International Nuclear Information System (INIS)

Clark, Andrea J; Coury, Emma L; Meilhac, Alexandra M; Petty, Howard R

2016-01-01

To provide a means of delivering an artificial immune effector cell-like attack on tumor cells, we report the tumoricidal ability of inorganic WO 3 /Pt nanoparticles that mimic a leukocyte’s functional abilities. These nanoparticles route electrons from organic structures and electron carriers to form hydroxyl radicals within tumor cells. During visible light exposure, WO 3 /Pt nanoparticles manufacture hydroxyl radicals, degrade organic compounds, use NADPH, trigger lipid peroxidation, promote lysosomal membrane disruption, promote the loss of reduced glutathione, and activate apoptosis. In a model of advanced breast cancer metastasis to the eye’s anterior chamber, we show that WO 3 /Pt nanoparticles prolong the survival of 4T1 tumor-bearing Balb/c mice. This new generation of inorganic photosensitizers do not photobleach, and therefore should provide an important therapeutic advance in photodynamic therapy. As biomimetic nanoparticles destroy targeted cells, they may be useful in treating ocular and other forms of cancer. (paper)

WO3/Pt nanoparticles are NADPH oxidase biomimetics that mimic effector cells in vitro and in vivo

Science.gov (United States)

Clark, Andrea J.; Coury, Emma L.; Meilhac, Alexandra M.; Petty, Howard R.

2016-02-01

To provide a means of delivering an artificial immune effector cell-like attack on tumor cells, we report the tumoricidal ability of inorganic WO3/Pt nanoparticles that mimic a leukocyte’s functional abilities. These nanoparticles route electrons from organic structures and electron carriers to form hydroxyl radicals within tumor cells. During visible light exposure, WO3/Pt nanoparticles manufacture hydroxyl radicals, degrade organic compounds, use NADPH, trigger lipid peroxidation, promote lysosomal membrane disruption, promote the loss of reduced glutathione, and activate apoptosis. In a model of advanced breast cancer metastasis to the eye’s anterior chamber, we show that WO3/Pt nanoparticles prolong the survival of 4T1 tumor-bearing Balb/c mice. This new generation of inorganic photosensitizers do not photobleach, and therefore should provide an important therapeutic advance in photodynamic therapy. As biomimetic nanoparticles destroy targeted cells, they may be useful in treating ocular and other forms of cancer.

The pore-forming bacterial effector, VopQ, halts autophagic turnover.

Science.gov (United States)

Sreelatha, Anju; Orth, Kim; Starai, Vincent J

2013-12-01

Vibrio parahemolyticus Type III effector VopQ is both necessary and sufficient to induce autophagy within one hour of infection. We demonstrated that VopQ interacts with the Vo domain of the conserved vacuolar H(+)-ATPase. Membrane-associated VopQ subsequently forms pores in the membranes of acidic compartments, resulting in immediate release of protons without concomitant release of lumenal protein contents. These studies show how a bacterial pathogen can compromise host ion potentials using a gated pore-forming effector to equilibrate levels of small molecules found in endolysosomal compartments and disrupt cellular processes such as autophagy.

Role of Rab family GTPases and their effectors in melanosomal logistics.

Science.gov (United States)

Ohbayashi, Norihiko; Fukuda, Mitsunori

2012-04-01

Rab GTPases constitute a family of small GTPases that regulate a variety of membrane trafficking events in all eukaryotic cells by recruiting their specific effector molecules. Recent accumulating evidence indicates that members of the mammalian Rab small GTPase family are involved in certain physiological and pathological processes. In particular, functional impairments of specific Rab proteins, e.g. Rab38 and Rab27A, their regulators or their effectors cause pigmentation disorders in humans and coat colour variations in mice because such impairments cause defects in melanosomal logistics, i.e. defects in melanosome biogenesis and transport. Genetic and biochemical analyses of the gene products responsible for mammalian pigmentation disorders in the past decade have revealed that Rab-mediated endosomal transport systems and melanosome transport systems play crucial roles in the efficient darkening of mammalian hair and skin. In this article, we review current knowledge regarding melanosomal logistics, with particular focus on the roles of Rab small GTPases and their effectors.

The LHCb trigger

International Nuclear Information System (INIS)

Korolko, I.

1998-01-01

This paper describes progress in the development of the LHCb trigger system since the letter of intent. The trigger philosophy has significantly changed, resulting in an increase of trigger efficiency for signal B events. It is proposed to implement a level-1 vertex topology trigger in specialised hardware. (orig.)

TRIGGER

CERN Multimedia

W. Smith

At the December meeting, the CMS trigger group reported on progress in production, tests in the Electronics Integration Center (EIC) in Prevessin 904, progress on trigger installation in the underground counting room at point 5, USC55, and results from the Magnet Test and Cosmic Challenge (MTCC) phase II. The trigger group is engaged in the final stages of production testing, systems integration, and software and firmware development. Most systems are delivering final tested electronics to CERN. The installation in USC55 is underway and moving towards integration testing. A program of orderly connection and checkout with subsystems and central systems has been developed. This program includes a series of vertical subsystem slice tests providing validation of a portion of each subsystem from front-end electronics through the trigger and DAQ to data captured and stored. This is combined with operations and testing without beam that will continue until startup. The plans for start-up, pilot and early running tri...

Cell volume homeostatic mechanisms: effectors and signalling pathways

DEFF Research Database (Denmark)

Hoffmann, E K; Pedersen, Stine Helene Falsig

2011-01-01

. Later work addressed the mechanisms through which cellular signalling pathways regulate the volume regulatory effectors or flux pathways. These studies were facilitated by the molecular identification of most of the relevant channels and transporters, and more recently also by the increased...

The Salmonella effector protein SpvC, a phosphothreonine lyase is functional in plant cells

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Christina eNeumann

2014-10-01

Full Text Available Salmonella is one of the most prominent causes of food poisoning and growing evidence indicates that contaminated fruits and vegetables are an increasing concern for human health. Successful infection demands the suppression of the host immune system, which is often achieved via injection of bacterial effector proteins into host cells. In this report we present the function of Salmonella effector protein in plant cell, supporting the new concept of trans-kingdom competence of this bacterium. We screened a range of Salmonella Typhimurium effector proteins for interference with plant immunity. Among these, the phosphothreonine lyase SpvC attenuated the induction of immunity-related genes when present in plant cells. Using in vitro and in vivo systems we show that this effector protein interacts with and dephosphorylates activated Arabidopsis Mitogen-activated Protein Kinase 6 (MPK6, thereby inhibiting defense signaling. Moreover, the requirement of Salmonella SpvC was shown by the decreased proliferation of the ΔspvC mutant in Arabidopsis plants. These results suggest that some Salmonella effector proteins could have a conserved function during proliferation in different hosts. The fact that Salmonella and other Enterobacteriaceae use plants as hosts strongly suggests that plants represent a much larger reservoir for animal pathogens than so far estimated.

The Salmonella effector protein SpvC, a phosphothreonine lyase is functional in plant cells

KAUST Repository

Neumann, Christina

2014-10-17

Salmonella is one of the most prominent causes of food poisoning and growing evidence indicates that contaminated fruits and vegetables are an increasing concern for human health. Successful infection demands the suppression of the host immune system, which is often achieved via injection of bacterial effector proteins into host cells. In this report we present the function of Salmonella effector protein in plant cell, supporting the new concept of trans-kingdom competence of this bacterium. We screened a range of Salmonella Typhimurium effector proteins for interference with plant immunity. Among these, the phosphothreonine lyase SpvC attenuated the induction of immunity-related genes when present in plant cells. Using in vitro and in vivo systems we show that this effector protein interacts with and dephosphorylates activated Arabidopsis Mitogen-activated Protein Kinase 6 (MPK6), thereby inhibiting defense signaling. Moreover, the requirement of Salmonella SpvC was shown by the decreased proliferation of the ΔspvC mutant in Arabidopsis plants. These results suggest that some Salmonella effector proteins could have a conserved function during proliferation in different hosts. The fact that Salmonella and other Enterobacteriaceae use plants as hosts strongly suggests that plants represent a much larger reservoir for animal pathogens than so far estimated.

The Leukotriene B4/BLT1 Axis Is a Key Determinant in Susceptibility and Resistance to Histoplasmosis

Science.gov (United States)

Secatto, Adriana; Soares, Elyara Maria; Locachevic, Gisele Aparecida; Assis, Patricia Aparecida; Paula-Silva, Francisco Wanderlei Garcia; Serezani, Carlos Henrique; de Medeiros, Alexandra Ivo; Faccioli, Lúcia Helena

2014-01-01

The bioactive lipid mediator leukotriene B4 (LTB4) greatly enhances phagocyte antimicrobial functions against a myriad of pathogens. In murine histoplasmosis, inhibition of the LT-generating enzyme 5-lypoxigenase (5-LO) increases the susceptibility of the host to infection. In this study, we investigated whether murine resistance or susceptibility to Histoplasma capsulatum infection is associated with leukotriene production and an enhancement of in vivo and/or in vitro antimicrobial effector function. We show that susceptible C57BL/6 mice exhibit a higher fungal burden in the lung and spleen, increased mortality, lower expression levels of 5-LO and leukotriene B4 receptor 1 (BLT1) and decreased LTB4 production compared to the resistant 129/Sv mice. Moreover, we demonstrate that endogenous and exogenous LTs are required for the optimal phagocytosis of H. capsulatum by macrophages from both murine strains, although C57BL/6 macrophages are more sensitive to the effects of LTB4 than 129/Sv macrophages. Therefore, our results provide novel evidence that LTB4 production and BLT1 signaling are required for a histoplasmosis-resistant phenotype. PMID:24465479

Actin Cytoskeleton Manipulation by Effector Proteins Secreted by Diarrheagenic Escherichia coli Pathotypes

Directory of Open Access Journals (Sweden)

Fernando Navarro-Garcia

2013-01-01

Full Text Available The actin cytoskeleton is a dynamic structure necessary for cell and tissue organization, including the maintenance of epithelial barriers. Disruption of the epithelial barrier coincides with alterations of the actin cytoskeleton in several disease states. These disruptions primarily affect the paracellular space, which is normally regulated by tight junctions. Thereby, the actin cytoskeleton is a common and recurring target of bacterial virulence factors. In order to manipulate the actin cytoskeleton, bacteria secrete and inject toxins and effectors to hijack the host cell machinery, which interferes with host-cell pathways and with a number of actin binding proteins. An interesting model to study actin manipulation by bacterial effectors is Escherichia coli since due to its genome plasticity it has acquired diverse genetic mobile elements, which allow having different E. coli varieties in one bacterial species. These E. coli pathotypes, including intracellular and extracellular bacteria, interact with epithelial cells, and their interactions depend on a specific combination of virulence factors. In this paper we focus on E. coli effectors that mimic host cell proteins to manipulate the actin cytoskeleton. The study of bacterial effector-cytoskeleton interaction will contribute not only to the comprehension of the molecular causes of infectious diseases but also to increase our knowledge of cell biology.

Learning-based position control of a closed-kinematic chain robot end-effector

Science.gov (United States)

Nguyen, Charles C.; Zhou, Zhen-Lei

1990-01-01

A trajectory control scheme whose design is based on learning theory, for a six-degree-of-freedom (DOF) robot end-effector built to study robotic assembly of NASA hardwares in space is presented. The control scheme consists of two control systems: the feedback control system and the learning control system. The feedback control system is designed using the concept of linearization about a selected operating point, and the method of pole placement so that the closed-loop linearized system is stabilized. The learning control scheme consisting of PD-type learning controllers, provides additional inputs to improve the end-effector performance after each trial. Experimental studies performed on a 2 DOF end-effector built at CUA, for three tracking cases show that actual trajectories approach desired trajectories as the number of trials increases. The tracking errors are substantially reduced after only five trials.

Mechanism of IRSp53 inhibition and combinatorial activation by Cdc42 and downstream effectors.

Science.gov (United States)

Kast, David J; Yang, Changsong; Disanza, Andrea; Boczkowska, Malgorzata; Madasu, Yadaiah; Scita, Giorgio; Svitkina, Tatyana; Dominguez, Roberto

2014-04-01

The Rho family GTPase effector IRSp53 has essential roles in filopodia formation and neuronal development, but its regulatory mechanism is poorly understood. IRSp53 contains a membrane-binding BAR domain followed by an unconventional CRIB motif that overlaps with a proline-rich region (CRIB-PR) and an SH3 domain that recruits actin cytoskeleton effectors. Using a fluorescence reporter assay, we show that human IRSp53 adopts a closed inactive conformation that opens synergistically with the binding of human Cdc42 to the CRIB-PR and effector proteins, such as the tumor-promoting factor Eps8, to the SH3 domain. The crystal structure of Cdc42 bound to the CRIB-PR reveals a new mode of effector binding to Rho family GTPases. Structure-inspired mutations disrupt autoinhibition and Cdc42 binding in vitro and decouple Cdc42- and IRSp53-dependent filopodia formation in cells. The data support a combinatorial mechanism of IRSp53 activation.

Plant parasitic nematode effectors target host defence and nuclear functions to establish feeding cells

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Michaël eQuentin

2013-03-01

Full Text Available Plant parasitic nematodes are microscopic worms, the most damaging species of which have adopted a sedentary lifestyle within their hosts. These obligate endoparasites have a biotrophic relationship with plants, in which they induce the differentiation of root cells into hypertrophied, multinucleate feeding cells. Effectors synthesised in the oesophageal glands of the nematode are injected into the plant cells via the syringe-like stylet and play a key role in manipulating the host machinery. The establishment of specialized feeding cells requires these effectors to modulate many aspects of plant cell morphogenesis and physiology, including defence responses. This cell reprogramming requires changes to host nuclear processes. Some proteins encoded by parasitism genes target host nuclei. Several of these proteins were immunolocalised within feeding cell nuclei or shown to interact with host nuclear proteins. Comparative genomics and functional analyses are gradually revealing the roles of nematode effectors. We describe here these effectors and their hypothesised roles in the unique feeding behaviour of these pests.

Bacterial effector HopF2 interacts with AvrPto and suppresses Arabidopsis innate immunity at the plasma membrane

Science.gov (United States)

Plant pathogenic bacteria inject a cocktail of effector proteins into host plant cells to modulate the host immune response, thereby promoting pathogenicity. How or whether these effectors work cooperatively is largely unknown. The Pseudomonas syringae DC3000 effector HopF2 suppresses the host plan...

BAT Triggering Performance

Science.gov (United States)

McLean, Kassandra M.; Fenimore, E. E.; Palmer, D. M.; BAT Team

2006-09-01

The Burst Alert Telescope (BAT) onboard Swift has detected and located about 160 gamma-ray bursts (GRBs) in its first twenty months of operation. BAT employs two triggering systems to find GRBs: image triggering, which looks for a new point source in the field of view, and rate triggering, which looks for a significant increase in the observed counts. The image triggering system looks at 1 minute, 5 minute, and full pointing accumulations of counts in the detector plane in the energy range of 15-50 keV, with about 50 evaluations per pointing (about 40 minutes). The rate triggering system looks through 13 different time scales (from 4ms to 32s), 4 overlapping energy bins (covering 15-350 keV), 9 regions of the detector plane (from the full plane to individual quarters), and two background sampling models to search for GRBs. It evaluates 27000 trigger criteria in a second, for close to 1000 criteria. The image triggering system looks at 1, 5, and 40 minute accumulations of counts in the detector plane in the energy range of 15-50 keV. Both triggering systems are working very well with the settings from before launch and after we turned on BAT. However, we now have more than a year and a half of data to evaluate these triggering systems and tweak them for optimal performance, as well as lessons learned from these triggering systems.

Strain Specific Factors Control Effector Gene Silencing in Phytophthora sojae.

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Sirjana Devi Shrestha

Full Text Available The Phytophthora sojae avirulence gene Avr3a encodes an effector that is capable of triggering immunity on soybean plants carrying the resistance gene Rps3a. P. sojae strains that express Avr3a are avirulent to Rps3a plants, while strains that do not are virulent. To study the inheritance of Avr3a expression and virulence towards Rps3a, genetic crosses and self-fertilizations were performed. A cross between P. sojae strains ACR10 X P7076 causes transgenerational gene silencing of Avr3a allele, and this effect is meiotically stable up to the F5 generation. However, test-crosses of F1 progeny (ACR10 X P7076 with strain P6497 result in the release of silencing of Avr3a. Expression of Avr3a in the progeny is variable and correlates with the phenotypic penetrance of the avirulence trait. The F1 progeny from a direct cross of P6497 X ACR10 segregate for inheritance for Avr3a expression, a result that could not be explained by parental imprinting or heterozygosity. Analysis of small RNA arising from the Avr3a gene sequence in the parental strains and hybrid progeny suggests that the presence of small RNA is necessary but not sufficient for gene silencing. Overall, we conclude that inheritance of the Avr3a gene silenced phenotype relies on factors that are variable among P. sojae strains.

CXCR3 Directs Antigen-Specific Effector CD4+ T Cell Migration to the Lung During Parainfluenza Virus Infection

DEFF Research Database (Denmark)

Kohlmeier, Jacob E; Cookenham, Tres; Miller, Shannon C

2009-01-01

effector CD4(+) T cell migration to the lungs. To assess the role of CCR5 and CXCR3 in vivo, we directly compared the migration of Ag-specific wild-type and chemokine receptor-deficient effector T cells in mixed bone marrow chimeric mice during a parainfluenza virus infection. CXCR3-deficient effector CD4......(+) T cells were 5- to 10-fold less efficient at migrating to the lung compared with wild-type cells, whereas CCR5-deficient effector T cells were not impaired in their migration to the lung. In contrast to its role in trafficking, CXCR3 had no impact on effector CD4(+) T cell proliferation, phenotype......, or function in any of the tissues examined. These findings demonstrate that CXCR3 controls virus-specific effector CD4(+) T cell migration in vivo, and suggest that blocking CXCR3-mediated recruitment may limit T cell-induced immunopathology during respiratory virus infections....

Polymicrobial sepsis impairs bystander recruitment of effector cells to infected skin despite optimal sensing and alarming function of skin resident memory CD8 T cells.

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Derek B Danahy

2017-09-01

Full Text Available Sepsis is a systemic infection that enhances host vulnerability to secondary infections normally controlled by T cells. Using CLP sepsis model, we observed that sepsis induces apoptosis of circulating memory CD8 T-cells (TCIRCM and diminishes their effector functions, leading to impaired CD8 T-cell mediated protection to systemic pathogen re-infection. In the context of localized re-infections, tissue resident memory CD8 T-cells (TRM provide robust protection in a variety of infectious models. TRM rapidly 'sense' infection in non-lymphoid tissues and 'alarm' the host by enhancing immune cell recruitment to the site of the infection to accelerate pathogen clearance. Here, we show that compared to pathogen-specific TCIRCM, sepsis does not invoke significant numerical decline of Vaccinia virus induced skin-TRM keeping their effector functions (e.g., Ag-dependent IFN-γ production intact. IFN-γ-mediated recruitment of immune cells to the site of localized infection was, however, reduced in CLP hosts despite TRM maintaining their 'sensing and alarming' functions. The capacity of memory CD8 T-cells in the septic environment to respond to inflammatory cues and arrive to the site of secondary infection/antigen exposure remained normal suggesting T-cell-extrinsic factors contributed to the observed lesion. Mechanistically, we showed that IFN-γ produced rapidly during sepsis-induced cytokine storm leads to reduced IFN-γR1 expression on vascular endothelium. As a consequence, decreased expression of adhesion molecules and/or chemokines (VCAM1 and CXCL9 on skin endothelial cells in response to TRM-derived IFN-γ was observed, leading to sub-optimal bystander-recruitment of effector cells and increased susceptibility to pathogen re-encounter. Importantly, as visualized by intravital 2-photon microscopy, exogenous administration of CXCL9/10 was sufficient to correct sepsis-induced impairments in recruitment of effector cells at the localized site of TRM

Intramuscular injection of malignant hyperthermia trigger agents induces hypermetabolism in susceptible and nonsusceptible individuals.

Science.gov (United States)

Metterlein, Thomas; Schuster, Frank; Kranke, Peter; Roewer, Norbert; Anetseder, Martin

2010-01-01

A new minimally invasive metabolic test for the diagnosis of susceptibility for malignant hyperthermia measuring intramuscular p(CO(2)) and lactate following local application of caffeine and halothane in humans was recently proposed. The present study tested the hypothesis that a more simplified test protocol allows a differentiation between malignant hyperthermia susceptible (MHS) and malignant hyperthermia nonsusceptible (MHN) and control individuals. With approval of the local ethics committee and informed consent, microdialysis and p(CO(2)) probes with attached microtubing were placed into the lateral vastus muscle of six MHS, seven MHN and seven control individuals. Following equilibration, boluses of 500 microl caffeine 80 mmol l(-1) and halothane 10 vol% dissolved in soybean oil were injected locally. p(CO(2)) and lactate were measured spectrophotometrically. The maximal rate of p(CO(2)) increase was significantly higher in MHS than in MHN and control individuals following application of halothane and caffeine, respectively. Intramuscular caffeine injection leads to a significantly higher increase of local lactate levels in MHS than in MHN and control individuals, whereas halothane increased local lactate levels in all investigated groups. Haemodynamic and systemic metabolic parameters did not differ between the investigated groups. Local caffeine and halothane injection increased intramuscular metabolism in MHS individuals significantly more than in the two other groups. In contrast to previous investigations, direct injection of the concentrations of halothane described here increased lactate and p(CO(2)) even in MHN skeletal muscle.

IgG-Fc-mediated effector functions: molecular definition of interaction sites for effector ligands and the role of glycosylation.

Science.gov (United States)

Jefferis, R; Lund, J; Pound, J D

1998-06-01

The Fc region of human IgG expresses interaction sites for many effector ligands. In this review the topographical distributions of ten of these sites are discussed in relation to functional requirement. It is apparent that interaction sites localised to the inter-CH2-CH3 domain region of the Fc allow for functional divalency, whereas sites localised to the hinge proximal region of the CH2 domain are functionally monovalent, with expression of the latter sites being particularly dependent on glycosylation. All x-ray crystal structures for Fc and Fc-ligand complexes report that the protein structure of the hinge proximal region of the CH2 domain is "disordered", suggesting "internal mobility". We propose a model in which such "internal mobility" results in the generation of a dynamic equilibrium between multiple conformers, certain of which express interaction sites specific to individual ligands. The emerging understanding of the influence of oligosaccharide/protein interactions on protein conformation and biological function of IgG antibodies suggests a potential to generate novel glycoforms of antibody molecules having unique profiles of effector functions.

DMPD: MyDths and un-TOLLed truths: sensor, instructive and effector immunity totuberculosis. [Dynamic Macrophage Pathway CSML Database

Lifescience Database Archive (English)

Full Text Available 18191460 MyDths and un-TOLLed truths: sensor, instructive and effector immunity totuberculosis...g) (.svg) (.html) (.csml) Show MyDths and un-TOLLed truths: sensor, instructive and effector immunity totuberculosis...e and effector immunity totuberculosis. Authors Reiling N, Ehlers S, Holscher C. Publication Immunol Lett. 2

TRIGGER

CERN Multimedia

W. Smith

Level-1 Trigger Hardware The CERN group is working on the TTC system. Seven out of nine sub-detector TTC VME crates with all fibers cabled are installed in USC55. 17 Local Trigger Controller (LTC) boards have been received from production and are in the process of being tested. The RF2TTC module replacing the TTCmi machine interface has been delivered and will replace the TTCci module used to mimic the LHC clock. 11 out of 12 crates housing the barrel ECAL off-detector electronics have been installed in USC55 after commissioning at the Electronics Integration Centre in building 904. The cabling to the Regional Calorimeter Trigger (RCT) is terminated. The Lisbon group has completed the Synchronization and Link mezzanine board (SLB) production. The Palaiseau group has fully tested and installed 33 out of 40 Trigger Concentrator Cards (TCC). The seven remaining boards are being remade. The barrel TCC boards have been tested at the H4 test beam, and good agreement with emulator predictions were found. The cons...

Effector-Triggered Self-Replication in Coupled Subsystems

NARCIS (Netherlands)

Komáromy, Dávid; Tezcan, Meniz; Schaeffer, Gaël; Marić, Ivana; Otto, Sijbren

2017-01-01

In living systems processes like genome duplication and cell division are carefully synchronized through subsystem coupling. If we are to create life de novo, similar control over essential processes such as self-replication need to be developed. Here we report that coupling two dynamic

Predicting the biodistribution of radiolabeled cMORF effector in MORF-pretargeted mice

International Nuclear Information System (INIS)

Liu, Guozheng; Dou, Shuping; He, Jiang; Liu, Xinrong; Rusckowski, Mary; Hnatowich, Donald J.

2007-01-01

Pretargeting with phosphorodiamidate morpholino oligomers (MORFs) involves administration of a MORF-conjugated anti-tumor antibody such as MN14 as a pretargeting agent before that of the radiolabeled complementary MORF (cMORF) as the effector. The dosages of the pretargeting agent and effector, the pretargeting interval, and the detection time are the four pretargeting variables. The goal of this study was to develop a semiempirical description capable of predicting the biodistribution of the radiolabeled effector in pretargeted mice and then to compare predictions with experimental results from pretargeting studies in tumored animals in which the pretargeting interval and the detection time were both fixed but the dosages of both the effector and the pretargeting agent were separately varied. Pretargeting studies in LS174T tumored mice were performed using the anti-CEA antibody MN14 conjugated with MORF and the cMORF radiolabeled with 99m Tc. A description was developed based on our previous observations in the same mouse model of the blood and tumor levels of MORF-MN14, accessibility of MORF-MN14 to labeled cMORF, the tumor accumulation of labeled cMORF relative to MORF-MN14 levels therein, and the kidney accumulation of labeled cMORF. The predicted values were then compared with the experimental values. The predicted biodistribution of the radiolabeled effector and the experimental data were in gratifying agreement in normal organs, suggesting that the description of the pretargeting process was reliable. The tumor accumulations occasionally fell outside two standard deviations of that predicted, but after tumor size correction, good agreement between predicted and experimental values was observed here as well. A semiempirical description of the biodistribution of labeled cMORF was capable of predicting the biodistribution of the radiolabeled effector in the pretargeted tumored mouse model, demonstrating that the underlying pretargeting concepts are correct. We

Effector Gene Suites in Some Soil Isolates of Fusarium oxysporum Are Not Sufficient Predictors of Vascular Wilt in Tomato.

Science.gov (United States)

Jelinski, Nicolas A; Broz, Karen; Jonkers, Wilfried; Ma, Li-Jun; Kistler, H Corby

2017-07-01

Seventy-four Fusarium oxysporum soil isolates were assayed for known effector genes present in an F. oxysporum f. sp. lycopersici race 3 tomato wilt strain (FOL MN-25) obtained from the same fields in Manatee County, Florida. Based on the presence or absence of these genes, four haplotypes were defined, two of which represented 96% of the surveyed isolates. These two most common effector haplotypes contained either all or none of the assayed race 3 effector genes. We hypothesized that soil isolates with all surveyed effector genes, similar to FOL MN-25, would be pathogenic toward tomato, whereas isolates lacking all effectors would be nonpathogenic. However, inoculation experiments revealed that presence of the effector genes alone was not sufficient to ensure pathogenicity on tomato. Interestingly, a nonpathogenic isolate containing the full suite of unmutated effector genes (FOS 4-4) appears to have undergone a chromosomal rearrangement yet remains vegetatively compatible with FOL MN-25. These observations confirm the highly dynamic nature of the F. oxysporum genome and support the conclusion that pathogenesis among free-living populations of F. oxysporum is a complex process. Therefore, the presence of effector genes alone may not be an accurate predictor of pathogenicity among soil isolates of F. oxysporum.

CCR9 Is Not Required for the Homing of Pro-inflammatory Effector T cells, but Is Crucial for Recruitment and Expansion of FoxP3+ CD8+ Tregs in the Small Intestine

DEFF Research Database (Denmark)

Gomez-Casado, Cristina; Joeris, Thorsten; Holmkvist, Petra

Chemokine receptor 9 (CCR9) is required for the homeostatic recruitment of T cells to the mucosa of the small intestine. Accordingly, CCR9 has been suggested as a potential target to inhibit the recruitment of proinflammatory effector T cells (Teff) in inflammatory bowel disease (IBD). Since...... the contribution of CCR9 to the recruitment of Teff in inflammation is not entirely clear, we aimed to address this question using IFABPtOva mice. These mice express Ovalbumin (Ova) specifically in small intestinal epithelial cells, which allows triggering of acute inflammation following transfer of Ova......-specific CD8+ T cells (OT-I cells) and adjuvant treatment. Strikingly, intestinal inflammation in IFABP-tOva mice could also be triggered following transfer of CCR9-deficient OT-I cells, demonstrating that CCR9 is not required for homing of Teff cells. Interestingly, OTI cells transferred to IFABP-tOva mice...

Mechanism of host substrate acetylation by a YopJ family effector.

Science.gov (United States)

Zhang, Zhi-Min; Ma, Ka-Wai; Gao, Linfeng; Hu, Zhenquan; Schwizer, Simon; Ma, Wenbo; Song, Jikui

2017-07-24

The Yersinia outer protein J (YopJ) family of bacterial effectors depends on a novel acetyltransferase domain to acetylate signalling proteins from plant and animal hosts. However, the underlying mechanism is unclear. Here, we report the crystal structures of PopP2, a YopJ effector produced by the plant pathogen Ralstonia solanacearum, in complex with inositol hexaphosphate (InsP 6 ), acetyl-coenzyme A (AcCoA) and/or substrate Resistance to Ralstonia solanacearum 1 (RRS1-R) WRKY . PopP2 recognizes the WRKYGQK motif of RRS1-R WRKY to position a targeted lysine in the active site for acetylation. Importantly, the PopP2-RRS1-R WRKY association is allosterically regulated by InsP 6 binding, suggesting a previously unidentified role of the eukaryote-specific cofactor in substrate interaction. Furthermore, we provide evidence for the reaction intermediate of PopP2-mediated acetylation, an acetyl-cysteine covalent adduct, lending direct support to the 'ping-pong'-like catalytic mechanism proposed for YopJ effectors. Our study provides critical mechanistic insights into the virulence activity of YopJ class of acetyltransferases.

Bio-effectors from waste materials as growth promoters for tomato plants, an agronomic and metabolomic study

Science.gov (United States)

Abou Chehade, Lara; Chami, Ziad Al; De Pascali, Sandra; Cavoski, Ivana; Fanizzi, Francesco Paolo

2015-04-01

In organic farming, where nutrient management is constrained and sustainability is claimed, bio-effectors pave their way. Considering selected bio-effectors, this study integrates metabolomics to agronomy in depicting induced relevant phenomena. Extracts of three agro-industrial wastes (Lemon processing residues, Fennel processing residues and Brewer's spent grain) are being investigated as sources of bio-effectors for the third trial consequently. Corresponding individual and mixture aqueous extracts are assessed for their synergistic and/or single agronomic and qualitative performances on soil-grown tomato, compared to both a control and humic acid treatments. A metabolomic profiling of tomato fruits via the Proton Nuclear Magnetic Resonance (NMR) spectroscopy, as holistic indicator of fruit quality and extract-induced responses, complements crop productivity and organoleptic/nutritional qualitative analyses. Results are expected to show mainly an enhancement of the fruit qualitative traits, and to confirm partly the previous results of better crop productivity and metabolism enhancement. Waste-derived bio-effectors could be, accordingly, demonstrated as potential candidates of plant-enhancing substances. Keywords: bio-effectors, organic farming, agro-industrial wastes, nuclear magnetic resonance (NMR), tomato.

Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

International Nuclear Information System (INIS)

Mesquita Júnior, D.; Cruvinel, W.M.; Araujo, J.A.P.; Salmazi, K.C.; Kallas, E.G.; Andrade, L.E.C.

2014-01-01

Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25 +/high CD127 Ø/low FoxP3 + , and effector T cells were defined as CD25 + CD127 + FoxP3 Ø . The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4 + TREG and CD28 + TREG cells and an increased frequency of CD40L + TREG cells. There was a decrease in the TREG/effector-T ratio for GITR + , HLA-DR + , OX40 + , and CD45RO + cells, and an increased ratio of TREG/effector-T CD40L + cells in patients with SLE. In addition, CD40L + TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease

Imbalanced expression of functional surface molecules in regulatory and effector T cells in systemic lupus erythematosus

Energy Technology Data Exchange (ETDEWEB)

Mesquita Júnior, D. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Cruvinel, W.M. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Departamento de Biomedicina, Universidade Católica de Goiás, Goiânia, GO (Brazil); Araujo, J.A.P. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil); Salmazi, K.C.; Kallas, E.G. [Disciplina de Imunologia Clínica e Alergia, Departamento de Clínica Médica, Faculdade de Medicina, Universidade de São Paulo, São Paulo, SP (Brazil); Andrade, L.E.C. [Disciplina de Reumatologia, Departamento de Medicina, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP (Brazil)

2014-08-22

Regulatory T (TREG) cells play an important role in maintaining immune tolerance and avoiding autoimmunity. We analyzed the expression of membrane molecules in TREG and effector T cells in systemic lupus erythematosus (SLE). TREG and effector T cells were analyzed for the expression of CTLA-4, PD1, CD28, CD95, GITR, HLA-DR, OX40, CD40L, and CD45RO in 26 patients with active disease, 31 with inactive disease, and 26 healthy controls. TREG cells were defined as CD25{sup +/high}CD127{sup Ø/low}FoxP3{sup +}, and effector T cells were defined as CD25{sup +}CD127{sup +}FoxP3{sup Ø}. The ratio of TREG to effector T cells expressing GITR, PD1, HLA-DR, OX40, CD40L, and CD45RO was determined in the three groups. The frequency of TREG cells was similar in patients with SLE and controls. However, SLE patients had a decreased frequency of CTLA-4{sup +}TREG and CD28{sup +}TREG cells and an increased frequency of CD40L{sup +}TREG cells. There was a decrease in the TREG/effector-T ratio for GITR{sup +}, HLA-DR{sup +}, OX40{sup +}, and CD45RO{sup +} cells, and an increased ratio of TREG/effector-T CD40L{sup +} cells in patients with SLE. In addition, CD40L{sup +}TREG cell frequency correlated with the SLE disease activity index (P=0.0163). In conclusion, our findings showed several abnormalities in the expression of functionally critical surface molecules in TREG and effector T cells in SLE that may be relevant to the pathogenesis of this disease.

NOMAD Trigger Studies

International Nuclear Information System (INIS)

Varvell, K.

1995-01-01

The author reports on the status of an offline study of the NOMAD triggers, which has several motivations. Of primary importance is to demonstrate, using offline information recorded by the individual subdetectors comprising NOMAD, that the online trigger system is functioning as expected. Such an investigation serves to complement the extensive monitoring which is already carried out online. More specific to the needs of the offline software and analysis, the reconstruction of tracks and vertices in the detector requires some knowledge of the time at which the trigger has occurred, in order to locate relevant hits in the drift chambers and muon chambers in particular. The fact that the different triggers allowed by the MIOTRINO board take varying times to form complicates this task. An offline trigger algorithm may serve as a tool to shed light on situations where the online trigger status bits have not been recorded correctly, as happens in a small number of cases, or as an aid to studies with the aim of further refinement of the online triggers themselves

Fructose 1-phosphate is the preferred effector of the metabolic regulator Cra of Pseudomonas putida.

Science.gov (United States)

Chavarría, Max; Santiago, César; Platero, Raúl; Krell, Tino; Casasnovas, José M; de Lorenzo, Víctor

2011-03-18

The catabolite repressor/activator (Cra) protein is a global sensor and regulator of carbon fluxes through the central metabolic pathways of gram-negative bacteria. To examine the nature of the effector (or effectors) that signal such fluxes to the protein of Pseudomonas putida, the Cra factor of this soil microorganism has been purified and characterized and its three-dimensional structure determined. Analytical ultracentrifugation, gel filtration, and mobility shift assays showed that the effector-free Cra is a dimer that binds an operator DNA sequence in the promoter region of the fruBKA cluster. Furthermore, fructose 1-phosphate (F1P) was found to most efficiently dissociate the Cra-DNA complex. Thermodynamic parameters of the F1P-Cra-DNA interaction calculated by isothermal titration calorimetry revealed that the factor associates tightly to the DNA sequence 5'-TTAAACGTTTCA-3' (K(D) = 26.3 ± 3.1 nM) and that F1P binds the protein with an apparent stoichiometry of 1.06 ± 0.06 molecules per Cra monomer and a K(D) of 209 ± 20 nM. Other possible effectors, like fructose 1,6-bisphosphate, did not display a significant affinity for the regulator under the assay conditions. Moreover, the structure of Cra and its co-crystal with F1P at a 2-Å resolution revealed that F1P fits optimally the geometry of the effector pocket. Our results thus single out F1P as the preferred metabolic effector of the Cra protein of P. putida.

Fructose 1-Phosphate Is the Preferred Effector of the Metabolic Regulator Cra of Pseudomonas putida*

Science.gov (United States)

Chavarría, Max; Santiago, César; Platero, Raúl; Krell, Tino; Casasnovas, José M.; de Lorenzo, Víctor

2011-01-01

The catabolite repressor/activator (Cra) protein is a global sensor and regulator of carbon fluxes through the central metabolic pathways of Gram-negative bacteria. To examine the nature of the effector (or effectors) that signal such fluxes to the protein of Pseudomonas putida, the Cra factor of this soil microorganism has been purified and characterized and its three-dimensional structure determined. Analytical ultracentrifugation, gel filtration, and mobility shift assays showed that the effector-free Cra is a dimer that binds an operator DNA sequence in the promoter region of the fruBKA cluster. Furthermore, fructose 1-phosphate (F1P) was found to most efficiently dissociate the Cra-DNA complex. Thermodynamic parameters of the F1P-Cra-DNA interaction calculated by isothermal titration calorimetry revealed that the factor associates tightly to the DNA sequence 5′-TTAAACGTTTCA-3′ (KD = 26.3 ± 3.1 nm) and that F1P binds the protein with an apparent stoichiometry of 1.06 ± 0.06 molecules per Cra monomer and a KD of 209 ± 20 nm. Other possible effectors, like fructose 1,6-bisphosphate, did not display a significant affinity for the regulator under the assay conditions. Moreover, the structure of Cra and its co-crystal with F1P at a 2-Å resolution revealed that F1P fits optimally the geometry of the effector pocket. Our results thus single out F1P as the preferred metabolic effector of the Cra protein of P. putida. PMID:21239488

Design criteria for the light duty utility arm system end effectors

International Nuclear Information System (INIS)

Pardini, A.F.

1995-01-01

This document provides the criteria for the design of end effectors that will be used as part of the Light Duty Utility Arm (LDUA) System. The LDUA System consists of a deployment vehicle, a vertical positioning mast, a light duty multi-axis robotic arm, a tank riser interface and confinement, a tool interface plate, a control system, and an operations control trailer. The criteria specified in this document will apply to all end effector systems being developed for use on or with the LDUA system at the Hanford site. The requirement stipulated in this document are mandatory

The Coding and Effector Transfer of Movement Sequences

Science.gov (United States)

Kovacs, Attila J.; Muhlbauer, Thomas; Shea, Charles H.

2009-01-01

Three experiments utilizing a 14-element arm movement sequence were designed to determine if reinstating the visual-spatial coordinates, which require movements to the same spatial locations utilized during acquisition, results in better effector transfer than reinstating the motor coordinates, which require the same pattern of homologous muscle…

Global study of holistic morphological effectors in the budding yeast Saccharomyces cerevisiae.

Science.gov (United States)

Suzuki, Godai; Wang, Yang; Kubo, Karen; Hirata, Eri; Ohnuki, Shinsuke; Ohya, Yoshikazu

2018-02-20

The size of the phenotypic effect of a gene has been thoroughly investigated in terms of fitness and specific morphological traits in the budding yeast Saccharomyces cerevisiae, but little is known about gross morphological abnormalities. We identified 1126 holistic morphological effectors that cause severe gross morphological abnormality when deleted, and 2241 specific morphological effectors with weak holistic effects but distinctive effects on yeast morphology. Holistic effectors fell into many gene function categories and acted as network hubs, affecting a large number of morphological traits, interacting with a large number of genes, and facilitating high protein expression. Holistic morphological abnormality was useful for estimating the importance of a gene to morphology. The contribution of gene importance to fitness and morphology could be used to efficiently classify genes into functional groups. Holistic morphological abnormality can be used as a reproducible and reliable gene feature for high-dimensional morphological phenotyping. It can be used in many functional genomic applications.

Abstract and Effector-Selective Decision Signals Exhibit Qualitatively Distinct Dynamics before Delayed Perceptual Reports.

Science.gov (United States)

Twomey, Deirdre M; Kelly, Simon P; O'Connell, Redmond G

2016-07-13

Electrophysiological research has isolated neural signatures of decision formation in a variety of brain regions. Studies in rodents and monkeys have focused primarily on effector-selective signals that translate the emerging decision into a specific motor plan, but, more recently, research on the human brain has identified an abstract signature of evidence accumulation that does not appear to play any direct role in action preparation. The functional dissociations between these distinct signal types have only begun to be characterized, and their dynamics during decisions with deferred actions with or without foreknowledge of stimulus-effector mapping, a commonly studied task scenario in single-unit and functional imaging investigations, have not been established. Here we traced the dynamics of distinct abstract and effector-selective decision signals in the form of the broad-band centro-parietal positivity (CPP) and limb-selective β-band (8-16 and 18-30 Hz) EEG activity, respectively, during delayed-reported motion direction decisions with and without foreknowledge of direction-response mapping. With foreknowledge, the CPP and β-band signals exhibited a similar gradual build-up following evidence onset, but whereas choice-predictive β-band activity persisted up until the delayed response, the CPP dropped toward baseline after peaking. Without foreknowledge, the CPP exhibited identical dynamics, whereas choice-selective β-band activity was eliminated. These findings highlight qualitative functional distinctions between effector-selective and abstract decision signals and are of relevance to the assumptions founding functional neuroimaging investigations of decision-making. Neural signatures of evidence accumulation have been isolated in numerous brain regions. Although animal neurophysiology has largely concentrated on effector-selective decision signals that translate the emerging decision into a specific motor plan, recent research on the human brain has

CD4+CD25+ regulatory T cells control CD8+ T-cell effector differentiation by modulating IL-2 homeostasis

Science.gov (United States)

McNally, Alice; Hill, Geoffrey R.; Sparwasser, Tim; Thomas, Ranjeny; Steptoe, Raymond J.

2011-01-01

CD4+CD25+ regulatory T cells (Treg) play a crucial role in the regulation of immune responses. Although many mechanisms of Treg suppression in vitro have been described, the mechanisms by which Treg modulate CD8+ T cell differentiation and effector function in vivo are more poorly defined. It has been proposed, in many instances, that modulation of cytokine homeostasis could be an important mechanism by which Treg regulate adaptive immunity; however, direct experimental evidence is sparse. Here we demonstrate that CD4+CD25+ Treg, by critically regulating IL-2 homeostasis, modulate CD8+ T-cell effector differentiation. Expansion and effector differentiation of CD8+ T cells is promoted by autocrine IL-2 but, by competing for IL-2, Treg limit CD8+ effector differentiation. Furthermore, a regulatory loop exists between Treg and CD8+ effector T cells, where IL-2 produced during CD8+ T-cell effector differentiation promotes Treg expansion. PMID:21502514

The effector repertoire of Fusarium oxysporum determines the tomato xylem proteome composition following infection

Directory of Open Access Journals (Sweden)

Fleur eGawehns

2015-11-01

Full Text Available Plant pathogens secrete small proteins, of which some are effectors that promote infection. During colonization of the tomato xylem vessels the fungus Fusarium oxysporum f. sp. lycopersici (Fol secretes small proteins that are referred to as SIX (Secreted In Xylem proteins. Of these, Six1 (Avr3, Six3 (Avr2, Six5 and Six6 are required for full virulence, denoting them as effectors. To investigate their activities in the plant, the xylem sap proteome of plants inoculated with Fol wild-type or either AVR2, AVR3, SIX2, SIX5 or SIX6 knockout strains was analyzed with nano-Liquid Chromatography-Mass Spectrometry (nLC-MSMS. Compared to mock-inoculated sap 12 additional plant proteins appeared while 45 proteins were no longer detectable in the xylem sap of Fol-infected plants. Of the 285 proteins found in both uninfected and infected plants the abundance of 258 proteins changed significantly following infection. The xylem sap proteome of plants infected with four Fol effector knockout strains differed significantly from plants infected with wild-type Fol, while that of the SIX2-knockout inoculated plants remained unchanged. Besides an altered abundance of a core set of 24 differentially accumulated proteins (DAPs, each of the four effector knockout strains affected specifically the abundance of a subset of DAPs. Hence, Fol effectors have both unique and shared effects on the composition of the tomato xylem sap proteome.

Triggering at high luminosity: fake triggers from pile-up

International Nuclear Information System (INIS)

Johnson, R.

1983-01-01

Triggers based on a cut in transverse momentum (p/sub t/) have proved to be useful in high energy physics both because they indicte that a hard constituent scattering has occurred and because they can be made quickly enough to gate electronics. These triggers will continue to be useful at high luminosities if overlapping events do not cause an excessive number of fake triggers. In this paper, I determine if this is indeed a problem at high luminosity machines

Evidence of end-effector based gait machines in gait rehabilitation after CNS lesion.

Science.gov (United States)

Hesse, S; Schattat, N; Mehrholz, J; Werner, C

2013-01-01

A task-specific repetitive approach in gait rehabilitation after CNS lesion is well accepted nowadays. To ease the therapists' and patients' physical effort, the past two decades have seen the introduction of gait machines to intensify the amount of gait practice. Two principles have emerged, an exoskeleton- and an endeffector-based approach. Both systems share the harness and the body weight support. With the end-effector-based devices, the patients' feet are positioned on two foot plates, whose movements simulate stance and swing phase. This article provides an overview on the end-effector based machine's effectiveness regarding the restoration of gait. For the electromechanical gait trainer GT I, a meta analysis identified nine controlled trials (RCT) in stroke subjects (n = 568) and were analyzed to detect differences between end-effector-based locomotion + physiotherapy and physiotherapy alone. Patients practising with the machine effected in a superior gait ability (210 out of 319 patients, 65.8% vs. 96 out of 249 patients, 38.6%, respectively, Z = 2.29, p = 0.020), due to a larger training intensity. Only single RCTs have been reported for other devices and etiologies. The introduction of end-effector based gait machines has opened a new succesful chapter in gait rehabilitation after CNS lesion.

Trigger finger

Science.gov (United States)

... digit; Trigger finger release; Locked finger; Digital flexor tenosynovitis ... cut or hand Yellow or green drainage from the cut Hand pain or discomfort Fever If your trigger finger returns, call your surgeon. You may need another surgery.

Human reinforcement learning subdivides structured action spaces by learning effector-specific values.

Science.gov (United States)

Gershman, Samuel J; Pesaran, Bijan; Daw, Nathaniel D

2009-10-28

Humans and animals are endowed with a large number of effectors. Although this enables great behavioral flexibility, it presents an equally formidable reinforcement learning problem of discovering which actions are most valuable because of the high dimensionality of the action space. An unresolved question is how neural systems for reinforcement learning-such as prediction error signals for action valuation associated with dopamine and the striatum-can cope with this "curse of dimensionality." We propose a reinforcement learning framework that allows for learned action valuations to be decomposed into effector-specific components when appropriate to a task, and test it by studying to what extent human behavior and blood oxygen level-dependent (BOLD) activity can exploit such a decomposition in a multieffector choice task. Subjects made simultaneous decisions with their left and right hands and received separate reward feedback for each hand movement. We found that choice behavior was better described by a learning model that decomposed the values of bimanual movements into separate values for each effector, rather than a traditional model that treated the bimanual actions as unitary with a single value. A decomposition of value into effector-specific components was also observed in value-related BOLD signaling, in the form of lateralized biases in striatal correlates of prediction error and anticipatory value correlates in the intraparietal sulcus. These results suggest that the human brain can use decomposed value representations to "divide and conquer" reinforcement learning over high-dimensional action spaces.

Virus-specific regulatory T cells ameliorate encephalitis by repressing effector T cell functions from priming to effector stages.

Directory of Open Access Journals (Sweden)

Jingxian Zhao

2014-08-01

Full Text Available Several studies have demonstrated the presence of pathogen-specific Foxp3+ CD4 regulatory T cells (Treg in infected animals, but little is known about where and how these cells affect the effector T cell responses and whether they are more suppressive than bulk Treg populations. We recently showed the presence of both epitope M133-specific Tregs (M133 Treg and conventional CD4 T cells (M133 Tconv in the brains of mice with coronavirus-induced encephalitis. Here, we provide new insights into the interactions between pathogenic Tconv and Tregs responding to the same epitope. M133 Tregs inhibited the proliferation but not initial activation of M133 Tconv in draining lymph nodes (DLN. Further, M133 Tregs inhibited migration of M133 Tconv from the DLN. In addition, M133 Tregs diminished microglia activation and decreased the number and function of Tconv in the infected brain. Thus, virus-specific Tregs inhibited pathogenic CD4 T cell responses during priming and effector stages, particularly those recognizing cognate antigen, and decreased mortality and morbidity without affecting virus clearance. These cells are more suppressive than bulk Tregs and provide a targeted approach to ameliorating immunopathological disease in infectious settings.

A Legionella pneumophila effector protein encoded in a region of genomic plasticity binds to Dot/Icm-modified vacuoles.

Directory of Open Access Journals (Sweden)

Shira Ninio

2009-01-01

Full Text Available Legionella pneumophila is an opportunistic pathogen that can cause a severe pneumonia called Legionnaires' disease. In the environment, L. pneumophila is found in fresh water reservoirs in a large spectrum of environmental conditions, where the bacteria are able to replicate within a variety of protozoan hosts. To survive within eukaryotic cells, L. pneumophila require a type IV secretion system, designated Dot/Icm, that delivers bacterial effector proteins into the host cell cytoplasm. In recent years, a number of Dot/Icm substrate proteins have been identified; however, the function of most of these proteins remains unknown, and it is unclear why the bacterium maintains such a large repertoire of effectors to promote its survival. Here we investigate a region of the L. pneumophila chromosome that displays a high degree of plasticity among four sequenced L. pneumophila strains. Analysis of GC content suggests that several genes encoded in this region were acquired through horizontal gene transfer. Protein translocation studies establish that this region of genomic plasticity encodes for multiple Dot/Icm effectors. Ectopic expression studies in mammalian cells indicate that one of these substrates, a protein called PieA, has unique effector activities. PieA is an effector that can alter lysosome morphology and associates specifically with vacuoles that support L. pneumophila replication. It was determined that the association of PieA with vacuoles containing L. pneumophila requires modifications to the vacuole mediated by other Dot/Icm effectors. Thus, the localization properties of PieA reveal that the Dot/Icm system has the ability to spatially and temporally control the association of an effector with vacuoles containing L. pneumophila through activities mediated by other effector proteins.

Generation of knockout rabbits using transcription activator-like effector nucleases.

Science.gov (United States)

Wang, Yu; Fan, Nana; Song, Jun; Zhong, Juan; Guo, Xiaogang; Tian, Weihua; Zhang, Quanjun; Cui, Fenggong; Li, Li; Newsome, Philip N; Frampton, Jon; Esteban, Miguel A; Lai, Liangxue

2014-01-01

Zinc-finger nucleases and transcription activator-like effector nucleases are novel gene-editing platforms contributing to redefine the boundaries of modern biological research. They are composed of a non-specific cleavage domain and a tailor made DNA-binding module, which enables a broad range of genetic modifications by inducing efficient DNA double-strand breaks at desired loci. Among other remarkable uses, these nucleases have been employed to produce gene knockouts in mid-size and large animals, such as rabbits and pigs, respectively. This approach is cost effective, relatively quick, and can produce invaluable models for human disease studies, biotechnology or agricultural purposes. Here we describe a protocol for the efficient generation of knockout rabbits using transcription activator-like effector nucleases, and a perspective of the field.

The Potato Aphid Salivary Effector Me47 Is a Glutathione-S-Transferase Involved in Modifying Plant Responses to Aphid Infestation.

Science.gov (United States)

Kettles, Graeme J; Kaloshian, Isgouhi

2016-01-01

Polyphagous aphid pests cause considerable economic damage to crop plants, primarily through the depletion of photoassimilates and transfer of viruses. The potato aphid (Macrosiphum euphorbiae) is a notable pest of solanaceous crops, however, the molecular mechanisms that underpin the ability to colonize these hosts are unknown. It has recently been demonstrated that like other aphid species, M. euphorbiae injects a battery of salivary proteins into host plants during feeding. It is speculated that these proteins function in a manner analagous to secreted effectors from phytopathogenic bacteria, fungi and oomycetes. Here, we describe a novel aphid effector (Me47) which was identified from the potato aphid salivary secretome as a putative glutathione-S-transferase (GST). Expression of Me47 in Nicotiana benthamiana enhanced reproductive performance of green peach aphid (Myzus persicae). Similarly, delivery of Me47 into leaves of tomato (Solanum lycopersicum) by Pseudomonas spp. enhanced potato aphid fecundity. In contrast, delivery of Me47 into Arabidopsis thaliana reduced GPA reproductive performance, indicating that Me47 impacts the outcome of plant-aphid interactions differently depending on the host species. Delivery of Me47 by the non-pathogenic Pseudomonas fluorescens revealed that Me47 protein or activity triggers defense gene transcriptional upregulation in tomato but not Arabidopsis. Recombinant Me47 was purified and demonstrated to have GST activity against two specific isothiocyanates (ITCs), compounds implicated in herbivore defense. Whilst GSTs have previously been associated with development of aphid resistance to synthetic insecticides, the findings described here highlight a novel function as both an elicitor and suppressor of plant defense when delivered into host tissues.

Functional analysis of NopM, a novel E3 ubiquitin ligase (NEL domain effector of Rhizobium sp. strain NGR234.

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Da-Wei Xin

Full Text Available Type 3 effector proteins secreted via the bacterial type 3 secretion system (T3SS are not only virulence factors of pathogenic bacteria, but also influence symbiotic interactions between nitrogen-fixing nodule bacteria (rhizobia and leguminous host plants. In this study, we characterized NopM (nodulation outer protein M of Rhizobium sp. strain NGR234, which shows sequence similarities with novel E3 ubiquitin ligase (NEL domain effectors from the human pathogens Shigella flexneri and Salomonella enterica. NopM expressed in Escherichia coli, but not the non-functional mutant protein NopM-C338A, showed E3 ubiquitin ligase activity in vitro. In vivo, NopM, but not inactive NopM-C338A, promoted nodulation of the host plant Lablab purpureus by NGR234. When NopM was expressed in yeast, it inhibited mating pheromone signaling, a mitogen-activated protein (MAP kinase pathway. When expressed in the plant Nicotiana benthamiana, NopM inhibited one part of the plant's defense response, as shown by a reduced production of reactive oxygen species (ROS in response to the flagellin peptide flg22, whereas it stimulated another part, namely the induction of defense genes. In summary, our data indicate the potential for NopM as a functional NEL domain E3 ubiquitin ligase. Our findings that NopM dampened the flg22-induced ROS burst in N. benthamiana but promoted defense gene induction are consistent with the concept that pattern-triggered immunity is split in two separate signaling branches, one leading to ROS production and the other to defense gene induction.

Structure of the effector-binding domain of the arabinose repressor AraR from Bacillus subtilis

Energy Technology Data Exchange (ETDEWEB)

Procházková, Kateřina; Čermáková, Kateřina [Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6 (Czech Republic); Pachl, Petr; Sieglová, Irena [Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6 (Czech Republic); Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 (Czech Republic); Fábry, Milan [Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 (Czech Republic); Otwinowski, Zbyszek [UT Southwestern Medical Center, Dallas, Texas (United States); Řezáčová, Pavlína, E-mail: rezacova@uochb.cas.cz [Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6 (Czech Republic); Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4 (Czech Republic)

2012-02-01

The crystal structure of the effector-binding domain of the transcriptional repressor AraR from B. subtilis in complex with the effector molecule (l-arabinose) was determined at 2.2 Å resolution. A detailed analysis of the crystal identified a dimer organization that is distinctive from that of other members of the GalR/LacI family. In Bacillus subtilis, the arabinose repressor AraR negatively controls the expression of genes in the metabolic pathway of arabinose-containing polysaccharides. The protein is composed of two domains of different phylogenetic origin and function: an N-terminal DNA-binding domain belonging to the GntR family and a C-terminal effector-binding domain that shows similarity to members of the GalR/LacI family. The crystal structure of the C-terminal effector-binding domain of AraR in complex with the effector l-arabinose has been determined at 2.2 Å resolution. The l-arabinose binding affinity was characterized by isothermal titration calorimetry and differential scanning fluorimetry; the K{sub d} value was 8.4 ± 0.4 µM. The effect of l-arabinose on the protein oligomeric state was investigated in solution and detailed analysis of the crystal identified a dimer organization which is distinctive from that of other members of the GalR/LacI family.

Yeast as a Heterologous Model System to Uncover Type III Effector Function.

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Crina Popa

2016-02-01

Full Text Available Type III effectors (T3E are key virulence proteins that are injected by bacterial pathogens inside the cells of their host to subvert cellular processes and contribute to disease. The budding yeast Saccharomyces cerevisiae represents an important heterologous system for the functional characterisation of T3E proteins in a eukaryotic environment. Importantly, yeast contains eukaryotic processes with low redundancy and are devoid of immunity mechanisms that counteract T3Es and mask their function. Expression in yeast of effectors from both plant and animal pathogens that perturb conserved cellular processes often resulted in robust phenotypes that were exploited to elucidate effector functions, biochemical properties, and host targets. The genetic tractability of yeast and its amenability for high-throughput functional studies contributed to the success of this system that, in recent years, has been used to study over 100 effectors. Here, we provide a critical view on this body of work and describe advantages and limitations inherent to the use of yeast in T3E research. "Favourite" targets of T3Es in yeast are cytoskeleton components and small GTPases of the Rho family. We describe how mitogen-activated protein kinase (MAPK signalling, vesicle trafficking, membrane structures, and programmed cell death are also often altered by T3Es in yeast and how this reflects their function in the natural host. We describe how effector structure-function studies and analysis of candidate targeted processes or pathways can be carried out in yeast. We critically analyse technologies that have been used in yeast to assign biochemical functions to T3Es, including transcriptomics and proteomics, as well as suppressor, gain-of-function, or synthetic lethality screens. We also describe how yeast can be used to select for molecules that block T3E function in search of new antibacterial drugs with medical applications. Finally, we provide our opinion on the limitations

Phytoplasma Effector SAP54 Induces Indeterminate Leaf-Like Flower Development in Arabidopsis Plants1[C][W][OA

Science.gov (United States)

MacLean, Allyson M.; Sugio, Akiko; Makarova, Olga V.; Findlay, Kim C.; Grieve, Victoria M.; Tóth, Réka; Nicolaisen, Mogens; Hogenhout, Saskia A.

2011-01-01

Phytoplasmas are insect-transmitted bacterial plant pathogens that cause considerable damage to a diverse range of agricultural crops globally. Symptoms induced in infected plants suggest that these phytopathogens may modulate developmental processes within the plant host. We report herein that Aster Yellows phytoplasma strain Witches’ Broom (AY-WB) readily infects the model plant Arabidopsis (Arabidopsis thaliana) ecotype Columbia, inducing symptoms that are characteristic of phytoplasma infection, such as the production of green leaf-like flowers (virescence and phyllody) and increased formation of stems and branches (witches’ broom). We found that the majority of genes encoding secreted AY-WB proteins (SAPs), which are candidate effector proteins, are expressed in Arabidopsis and the AY-WB insect vector Macrosteles quadrilineatus (Hemiptera; Cicadellidae). To identify which of these effector proteins induce symptoms of phyllody and virescence, we individually expressed the effector genes in Arabidopsis. From this screen, we have identified a novel AY-WB effector protein, SAP54, that alters floral development, resulting in the production of leaf-like flowers that are similar to those produced by plants infected with this phytoplasma. This study offers novel insight into the effector profile of an insect-transmitted plant pathogen and reports to our knowledge the first example of a microbial pathogen effector protein that targets flower development in a host. PMID:21849514

Genetic analysis of environmental strains of the plant pathogen Phytophthora capsici reveals heterogeneous repertoire of effectors and possible effector evolution via genomic island.

Science.gov (United States)

Iribarren, María Josefina; Pascuan, Cecilia; Soto, Gabriela; Ayub, Nicolás Daniel

2015-11-01

Phytophthora capsici is a virulent oomycete pathogen of many vegetable crops. Recently, it has been demonstrated that the recognition of the RXLR effector AVR3a1 of P. capsici (PcAVR3a1) triggers a hypersensitive response and plays a critical role in mediating non-host resistance. Here, we analyzed the occurrence of PcAVR3a1 in 57 isolates of P. capsici derived from globe squash, eggplant, tomato and bell pepper cocultivated in a small geographical area. The occurrence of PcAVR3a1 in environmental strains of P. capsici was confirmed by PCR in only 21 of these pathogen isolates. To understand the presence-absence pattern of PcAVR3a1 in environmental strains, the flanking region of this gene was sequenced. PcAVR3a1 was found within a genetic element that we named PcAVR3a1-GI (PcAVR3a1 genomic island). PcAVR3a1-GI was flanked by a 22-bp direct repeat, which is related to its site-specific recombination site. In addition to the PcAVR3a1 gene, PcAVR3a1-GI also encoded a phage integrase probably associated with the excision and integration of this mobile element. Exposure to plant induced the presence of an episomal circular intermediate of PcAVR3a1-GI, indicating that this mobile element is functional. Collectively, these findings provide evidence of PcAVR3a1 evolution via mobile elements in environmental strains of Phytophthora. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Transcription Factor Networks Directing the Development, Function, and Evolution of Innate Lymphoid Effectors

Science.gov (United States)

Kang, Joonsoo; Malhotra, Nidhi

2015-01-01

Mammalian lymphoid immunity is mediated by fast and slow responders to pathogens. Fast innate lymphocytes are active within hours after infections in mucosal tissues. Slow adaptive lymphocytes are conventional T and B cells with clonal antigen receptors that function days after pathogen exposure. A transcription factor (TF) regulatory network guiding early T cell development is at the core of effector function diversification in all innate lymphocytes, and the kinetics of immune responses is set by developmental programming. Operational units within the innate lymphoid system are not classified by the types of pathogen-sensing machineries but rather by discrete effector functions programmed by regulatory TF networks. Based on the evolutionary history of TFs of the regulatory networks, fast effectors likely arose earlier in the evolution of animals to fortify body barriers, and in mammals they often develop in fetal ontogeny prior to the establishment of fully competent adaptive immunity. PMID:25650177

Topological Trigger Developments

CERN Multimedia

Likhomanenko, Tatiana

2015-01-01

The main b-physics trigger algorithm used by the LHCb experiment is the so-called topological trigger. The topological trigger selects vertices which are a) detached from the primary proton-proton collision and b) compatible with coming from the decay of a b-hadron. In the LHC Run 1, this trigger utilized a custom boosted decision tree algorithm, selected an almost 100% pure sample of b-hadrons with a typical efficiency of 60-70%, and its output was used in about 60% of LHCb papers. This talk presents studies carried out to optimize the topological trigger for LHC Run 2. In particular, we have carried out a detailed comparison of various machine learning classifier algorithms, e.g., AdaBoost, MatrixNet and uBoost. The topological trigger algorithm is designed to select all "interesting" decays of b-hadrons, but cannot be trained on every such decay. Studies have therefore been performed to determine how to optimize the performance of the classification algorithm on decays not used in the training. These inclu...

Depigmented-polymerised allergoids favour regulatory over effector T cells: enhancement by 1α, 25-dihydroxyvitamin D3.

Science.gov (United States)

Urry, Zoe L; Richards, David F; Black, Cheryl; Morales, Maria; Carnés, Jerónimo; Hawrylowicz, Catherine M; Robinson, Douglas S

2014-05-29

Allergen immunotherapy (SIT) is the only treatment for allergic disease capable of modifying disease long term. To reduce the risk of anaphylaxis from SIT, allergen-extracts have been modified by polymerisation with glutaraldehyde to reduce IgE binding. It is suggested that these allergoid extracts also have reduced T cell activity, which could compromise clinical efficacy. Effective SIT is thought to act through regulatory T cells (Tregs) rather than activation of effector T cells. There is no published data on the activity of modified extracts on Tregs. We compared the capacity of modified (depigmented-polymerised) versus unmodified (native) allergen extracts of grass pollen and house dust mite to stimulate proliferation/cytokine production and to modulate Treg/effector T cell frequency in cultures of peripheral blood mononuclear cells (PBMC), from volunteers sensitised to both allergens in vitro. Depigmented-polymerised allergen extracts stimulated less proliferation of PBMC, and reduced effector cell numbers after 7 days in culture than did native extracts. However, the frequency of Foxp3+ Tregs in cultures were similar to those seen with native extract so that ratios of regulatory to effector T cells were significantly increased in cultures stimulated with depigmented-polymerised extracts. Addition of 1α, 25-dihydroxyvitamin D3 further favoured Treg, and reduced effector cytokine production, but not interleukin-10. Depigmented-polymerised allergen extracts appear to favour Treg expansion over activation of effector T cells and this may relate to their demonstrated efficacy and safety in SIT. 1α, 25-dihydroxyvitamin D3 further reduces effector T cell activation by allergen extracts and may be a useful adjuvant for SIT.

A bacterial toxin-antitoxin module is the origin of inter-bacterial and inter-kingdom effectors of Bartonella.

Science.gov (United States)

Harms, Alexander; Liesch, Marius; Körner, Jonas; Québatte, Maxime; Engel, Philipp; Dehio, Christoph

2017-10-01

Host-targeting type IV secretion systems (T4SS) evolved from conjugative T4SS machineries that mediate interbacterial plasmid transfer. However, the origins of effectors secreted by these virulence devices have remained largely elusive. Previous work showed that some effectors exhibit homology to toxins of bacterial toxin-antitoxin modules, but the evolutionary trajectories underlying these ties had not been resolved. We previously reported that FicT toxins of FicTA toxin-antitoxin modules disrupt cellular DNA topology via their enzymatic FIC (filamentation induced by cAMP) domain. Intriguingly, the FIC domain of the FicT toxin VbhT of Bartonella schoenbuchensis is fused to a type IV secretion signal-the BID (Bep intracellular delivery) domain-similar to the Bartonella effector proteins (Beps) that are secreted into eukaryotic host cells via the host-targeting VirB T4SS. In this study, we show that the VbhT toxin is an interbacterial effector protein secreted via the conjugative Vbh T4SS that is closely related to the VirB T4SS and encoded by plasmid pVbh of B. schoenbuchensis. We therefore propose that the Vbh T4SS together with its effector VbhT represent an evolutionary missing link on a path that leads from a regular conjugation system and FicTA toxin-antitoxin modules to the VirB T4SS and the Beps. Intriguingly, phylogenetic analyses revealed that the fusion of FIC and BID domains has probably occurred independently in VbhT and the common ancestor of the Beps, suggesting parallel evolutionary paths. Moreover, several other examples of TA module toxins that are bona fide substrates of conjugative T4SS indicate that their recruitment as interbacterial effectors is prevalent and serves yet unknown biological functions in the context of bacterial conjugation. We propose that the adaptation for interbacterial transfer favors the exaptation of FicT and other TA module toxins as inter-kingdom effectors and may thus constitute an important stepping stone in the

A bacterial toxin-antitoxin module is the origin of inter-bacterial and inter-kingdom effectors of Bartonella.

Directory of Open Access Journals (Sweden)

Alexander Harms

2017-10-01

Full Text Available Host-targeting type IV secretion systems (T4SS evolved from conjugative T4SS machineries that mediate interbacterial plasmid transfer. However, the origins of effectors secreted by these virulence devices have remained largely elusive. Previous work showed that some effectors exhibit homology to toxins of bacterial toxin-antitoxin modules, but the evolutionary trajectories underlying these ties had not been resolved. We previously reported that FicT toxins of FicTA toxin-antitoxin modules disrupt cellular DNA topology via their enzymatic FIC (filamentation induced by cAMP domain. Intriguingly, the FIC domain of the FicT toxin VbhT of Bartonella schoenbuchensis is fused to a type IV secretion signal-the BID (Bep intracellular delivery domain-similar to the Bartonella effector proteins (Beps that are secreted into eukaryotic host cells via the host-targeting VirB T4SS. In this study, we show that the VbhT toxin is an interbacterial effector protein secreted via the conjugative Vbh T4SS that is closely related to the VirB T4SS and encoded by plasmid pVbh of B. schoenbuchensis. We therefore propose that the Vbh T4SS together with its effector VbhT represent an evolutionary missing link on a path that leads from a regular conjugation system and FicTA toxin-antitoxin modules to the VirB T4SS and the Beps. Intriguingly, phylogenetic analyses revealed that the fusion of FIC and BID domains has probably occurred independently in VbhT and the common ancestor of the Beps, suggesting parallel evolutionary paths. Moreover, several other examples of TA module toxins that are bona fide substrates of conjugative T4SS indicate that their recruitment as interbacterial effectors is prevalent and serves yet unknown biological functions in the context of bacterial conjugation. We propose that the adaptation for interbacterial transfer favors the exaptation of FicT and other TA module toxins as inter-kingdom effectors and may thus constitute an important stepping

Lessons from (triggered) tremor

Science.gov (United States)

Gomberg, Joan

2010-01-01

I test a “clock-advance” model that implies triggered tremor is ambient tremor that occurs at a sped-up rate as a result of loading from passing seismic waves. This proposed model predicts that triggering probability is proportional to the product of the ambient tremor rate and a function describing the efficacy of the triggering wave to initiate a tremor event. Using data mostly from Cascadia, I have compared qualitatively a suite of teleseismic waves that did and did not trigger tremor with ambient tremor rates. Many of the observations are consistent with the model if the efficacy of the triggering wave depends on wave amplitude. One triggered tremor observation clearly violates the clock-advance model. The model prediction that larger triggering waves result in larger triggered tremor signals also appears inconsistent with the measurements. I conclude that the tremor source process is a more complex system than that described by the clock-advance model predictions tested. Results of this and previous studies also demonstrate that (1) conditions suitable for tremor generation exist in many tectonic environments, but, within each, only occur at particular spots whose locations change with time; (2) any fluid flow must be restricted to less than a meter; (3) the degree to which delayed failure and secondary triggering occurs is likely insignificant; and 4) both shear and dilatational deformations may trigger tremor. Triggered and ambient tremor rates correlate more strongly with stress than stressing rate, suggesting tremor sources result from time-dependent weakening processes rather than simple Coulomb failure.

Repertoire Development and the Control of Cytotoxic/Effector Function in Human γδ T Cells

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Elizabeth M. Urban

2010-01-01

Full Text Available T cells develop into two major populations distinguished by their T cell receptor (TCR chains. Cells with the αβ TCR generally express CD4 or CD8 lineage markers and mostly fall into helper or cytotoxic/effector subsets. Cells expressing the alternate γδ TCR in humans generally do not express lineage markers, do not require MHC for antigen presentation, and recognize nonpeptidic antigens. We are interested in the dominant Vγ2Vδ2+ T cell subset in human peripheral blood and the control of effector function in this population. We review the literature on γδ T cell generation and repertoire selection, along with recent work on CD56 expression and defining a cytotoxic/effector lineage within the phosphoantigen-reactive Vγ2Vδ2 cells. A unique mechanism for MHC-independent repertoire selection is linked to the control of effector function that is vital to the role for γδ T cells in tumor surveillance. Better understanding of these mechanisms will improve our ability to exploit this population for tumor immunotherapy.

A translocator-specific export signal establishes the translocator-effector secretion hierarchy that is important for type III secretion system function

Science.gov (United States)

Tomalka, Amanda G.; Stopford, Charles M.; Lee, Pei-Chung; Rietsch, Arne

2012-01-01

Summary Type III secretion systems are used by many Gram-negative pathogens to directly deliver effector proteins into the cytoplasm of host cells. To accomplish this, bacteria secrete translocator proteins that form a pore in the host-cell membrane through which the effector proteins are then introduced into the host cell. Evidence from multiple systems indicates that the pore-forming translocator proteins are exported before effectors, but how this secretion hierarchy is established is unclear. Here we used the P. aeruginosa translocator protein PopD as a model to identify its export signals. The amino-terminal secretion signal and chaperone, PcrH, are required for export under all conditions. Two novel signals in PopD, one proximal to the chaperone-binding site and one at the very C-terminus of the protein, are required for export of PopD before effector proteins. These novel export signals establish the translocator-effector secretion hierarchy, which in turn, is critical for the delivery of effectors into host cells. PMID:23121689

Structure and evolution of barley powdery mildew effector candidates

DEFF Research Database (Denmark)

Pedersen, Carsten; Themaat, Emiel Ver Loren van; McGuffin, Liam J.

2012-01-01

Protein effectors of pathogenicity are instrumental in modulating host immunity and disease resistance. The powdery mildew pathogen of grasses Blumeria graminis causes one of the most important diseases of cereal crops. B. graminis is an obligate biotrophic pathogen and as such has an absolute...

The Central Trigger Processor (CTP)

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Franchini, Matteo

2016-01-01

The Central Trigger Processor (CTP) receives trigger information from the calorimeter and muon trigger processors, as well as from other sources of trigger. It makes the Level-1 decision (L1A) based on a trigger menu.

The Trigger Processor and Trigger Processor Algorithms for the ATLAS New Small Wheel Upgrade

CERN Document Server

Lazovich, Tomo; The ATLAS collaboration

2015-01-01

The ATLAS New Small Wheel (NSW) is an upgrade to the ATLAS muon endcap detectors that will be installed during the next long shutdown of the LHC. Comprising both MicroMegas (MMs) and small-strip Thin Gap Chambers (sTGCs), this system will drastically improve the performance of the muon system in a high cavern background environment. The NSW trigger, in particular, will significantly reduce the rate of fake triggers coming from track segments in the endcap not originating from the interaction point. We will present an overview of the trigger, the proposed sTGC and MM trigger algorithms, and the hardware implementation of the trigger. In particular, we will discuss both the heart of the trigger, an ATCA system with FPGA-based trigger processors (using the same hardware platform for both MM and sTGC triggers), as well as the full trigger electronics chain, including dedicated cards for transmission of data via GBT optical links. Finally, we will detail the challenges of ensuring that the trigger electronics can ...

Generation of knockout rabbits using transcription activator-like effector nucleases

Directory of Open Access Journals (Sweden)

Yu Wang

2014-01-01

Full Text Available Zinc-finger nucleases and transcription activator-like effector nucleases are novel gene-editing platforms contributing to redefine the boundaries of modern biological research. They are composed of a non-specific cleavage domain and a tailor made DNA-binding module, which enables a broad range of genetic modifications by inducing efficient DNA double-strand breaks at desired loci. Among other remarkable uses, these nucleases have been employed to produce gene knockouts in mid-size and large animals, such as rabbits and pigs, respectively. This approach is cost effective, relatively quick, and can produce invaluable models for human disease studies, biotechnology or agricultural purposes. Here we describe a protocol for the efficient generation of knockout rabbits using transcription activator-like effector nucleases, and a perspective of the field.

Test plan for the remote conveyance and innovative end effector demonstration

Energy Technology Data Exchange (ETDEWEB)

Rice, P.; Smith, A.M. [EG& G Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.; Peterson, R.

1994-08-01

This test plan describes the demonstration of innovative equipment and processes specifically designed to be superior to currently employed technology for buried waste retrieval. The dumping of dry soil into a funnel/dumpster arrangement has been found to be the primary mechanism for dust generation during the retrieval of buried transuranic waste. The primary goal of the innovative end effector is to reduce dust generation and the potential spread of airborne contaminants during the dumping operation. In addition, regardless of the excavation technique, exhumed waste will have to be conveyed away from the retrieval area to a packaging area or directly to a treatment facility. The remote conveyance system is aimed at developing a remotely controlled vehicle to convey retrieved waste that will operate on variable terrain and remove workers from the hazardous zone. To demonstrate the remote conveyance system and the innovative end effector, the Buried Waste Integrated Demonstration (BWID) Program has subcontracted with RAHCO International to provide equipment and services to perform a demonstration of the technologies. The demonstration will be performed in two phases. In Phase I, the subcontractor will perform a full scale demonstration to assess the ability of the innovative end effector to control dust generation and the potential spread of contamination during dumping operations. Phase II includes performing a retrieval/conveyance demonstration. This demonstration will excavate, dump, and convey simulated waste to demonstrate the functionality of the system (e.g., maneuverability, retrieval rates, and system integration). Phase II of the demonstration will include all elements of the remote conveyance and end effector system. This test plan will describe the demonstration objectives, data quality objectives, equipment operation, and methods for collecting data during the demonstration.

Test plan for the remote conveyance and innovative end effector demonstration

International Nuclear Information System (INIS)

Rice, P.; Smith, A.M.; Peterson, R.

1994-08-01

This test plan describes the demonstration of innovative equipment and processes specifically designed to be superior to currently employed technology for buried waste retrieval. The dumping of dry soil into a funnel/dumpster arrangement has been found to be the primary mechanism for dust generation during the retrieval of buried transuranic waste. The primary goal of the innovative end effector is to reduce dust generation and the potential spread of airborne contaminants during the dumping operation. In addition, regardless of the excavation technique, exhumed waste will have to be conveyed away from the retrieval area to a packaging area or directly to a treatment facility. The remote conveyance system is aimed at developing a remotely controlled vehicle to convey retrieved waste that will operate on variable terrain and remove workers from the hazardous zone. To demonstrate the remote conveyance system and the innovative end effector, the Buried Waste Integrated Demonstration (BWID) Program has subcontracted with RAHCO International to provide equipment and services to perform a demonstration of the technologies. The demonstration will be performed in two phases. In Phase I, the subcontractor will perform a full scale demonstration to assess the ability of the innovative end effector to control dust generation and the potential spread of contamination during dumping operations. Phase II includes performing a retrieval/conveyance demonstration. This demonstration will excavate, dump, and convey simulated waste to demonstrate the functionality of the system (e.g., maneuverability, retrieval rates, and system integration). Phase II of the demonstration will include all elements of the remote conveyance and end effector system. This test plan will describe the demonstration objectives, data quality objectives, equipment operation, and methods for collecting data during the demonstration

Interaction of barley powdery mildew effector candidate CSEP0055 with the defence protein PR17c

DEFF Research Database (Denmark)

Zhang, Wenjing; Pedersen, Carsten; Kwaaitaal, Mark Adrianus Cornelis J

2012-01-01

A large number of effector candidates have been identified recently in powdery mildew fungi. However, their roles and how they perform their functions remain unresolved. In this study, we made use of host-induced gene silencing and confirmed that the secreted barley powdery mildew effector candid...

Density-independent population projection trajectories of chromosome-substituted lines resistant and susceptible to organophosphate insecticides in Drosophila melanogaster

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Miyo Takahiro

2004-11-01

Full Text Available Abstract Background Seasonal fluctuations in susceptibility to organophosphate insecticides were observed in the Katsunuma population of Drosophila melanogaster for two consecutive years; susceptibility to three organophosphates tended to increase in the fall. To examine the hypothesis that variation in fitness among resistant and susceptible genotypes could trigger the change of genetic constitution within the fall population, we investigated density-independent population projection trajectories starting from single adult females with characteristics of chromosome-substituted lines resistant and susceptible to the three organophosphates. Results Density-independent population projection trajectories, expressed as the ratios of the number of each chromosome-substituted line to that of line SSS, for which all chromosomes were derived from the susceptible line, showed significant declines in numbers with time for all the resistant chromosome-substituted lines. Conclusion The declining tendency in the density-independent population projection trajectories of the resistant chromosome-substituted lines could explain the simultaneous decline in the levels of resistance to the three organophosphates, observed in the Katsunuma population in the fall.

On design and development of additional End-Effectors for the Cassette Multifunctional Mover

Energy Technology Data Exchange (ETDEWEB)

Valkama, Peetu, E-mail: peetu.valkama@tut.fi [Department of Intelligent Hydraulics and Automation, Tampere University of Technology, P.O. Box 589, FI-33720 Tampere (Finland); Mattila, J.; Amjad, F.; Vaeyrynen, J.; Vilenius, M. [Department of Intelligent Hydraulics and Automation, Tampere University of Technology, P.O. Box 589, FI-33720 Tampere (Finland); Siuko, M. [VTT Technical Research Centre of Finland, P.O. Box 1300, FI-33101 Tampere (Finland); Semeraro, L.; Esque, S. [F4E, Fusion for Energy, Torres Diagonal Litoral B3, Josep Pla 2, 08019 Barcelona (Spain)

2011-10-15

The divertor area of ITER Vacuum Vessel (VV) consists of 54 modular cassettes which must be replaced three times during the estimated 20 years of operation of the ITER. Cassette Multifunctional Mover (CMM) and Cassette Toroidal Mover (CTM) are used in the cassette remote handling (RH). In this paper we discuss the design and development process for the RH equipment to be used in the ITER environment. Design concepts for the Standard Cassette End-Effector and Central Cassette End-Effector are described and the conceptual design phase methodology is presented. The main improvements of the new End-Effector concept designs are more robust and reliable assembly process with reduced CMM mover assembly accuracy requirement. New Central Cassette locking system was developed to address the high forces and contact pressures emerging during the Central Cassette installation. The chosen design concepts are verified with virtual reality simulations and are fulfilling the requirements defined in the concept design phase, including structural, assembly sequence, safety and reliability.

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.

The Effectors and Sensory Sites of Formaldehyde-responsive Regulator FrmR and Metal-sensing Variant *

Science.gov (United States)

Osman, Deenah; Piergentili, Cecilia; Chen, Junjun; Sayer, Lucy N.; Usón, Isabel; Huggins, Thomas G.; Robinson, Nigel J.; Pohl, Ehmke

2016-01-01

The DUF156 family of DNA-binding transcriptional regulators includes metal sensors that respond to cobalt and/or nickel (RcnR, InrS) or copper (CsoR) plus CstR, which responds to persulfide, and formaldehyde-responsive FrmR. Unexpectedly, the allosteric mechanism of FrmR from Salmonella enterica serovar Typhimurium is triggered by metals in vitro, and variant FrmRE64H gains responsiveness to Zn(II) and cobalt in vivo. Here we establish that the allosteric mechanism of FrmR is triggered directly by formaldehyde in vitro. Sensitivity to formaldehyde requires a cysteine (Cys35 in FrmR) conserved in all DUF156 proteins. A crystal structure of metal- and formaldehyde-sensing FrmRE64H reveals that an FrmR-specific amino-terminal Pro2 is proximal to Cys35, and these residues form the deduced formaldehyde-sensing site. Evidence is presented that implies that residues spatially close to the conserved cysteine tune the sensitivities of DUF156 proteins above or below critical thresholds for different effectors, generating the semblance of specificity within cells. Relative to FrmR, RcnR is less responsive to formaldehyde in vitro, and RcnR does not sense formaldehyde in vivo, but reciprocal mutations FrmRP2S and RcnRS2P, respectively, impair and enhance formaldehyde reactivity in vitro. Formaldehyde detoxification by FrmA requires S-(hydroxymethyl)glutathione, yet glutathione inhibits formaldehyde detection by FrmR in vivo and in vitro. Quantifying the number of FrmR molecules per cell and modeling formaldehyde modification as a function of [formaldehyde] demonstrates that FrmR reactivity is optimized such that FrmR is modified and frmRA is derepressed at lower [formaldehyde] than required to generate S-(hydroxymethyl)glutathione. Expression of FrmA is thereby coordinated with the accumulation of its substrate. PMID:27474740

The Orphan G Protein-coupled Receptor GPR17 Negatively Regulates Oligodendrocyte Differentiation via Gαi/o and Its Downstream Effector Molecules.

Science.gov (United States)

Simon, Katharina; Hennen, Stephanie; Merten, Nicole; Blättermann, Stefanie; Gillard, Michel; Kostenis, Evi; Gomeza, Jesus

2016-01-08

Recent studies have recognized G protein-coupled receptors as important regulators of oligodendrocyte development. GPR17, in particular, is an orphan G protein-coupled receptor that has been identified as oligodendroglial maturation inhibitor because its stimulation arrests primary mouse oligodendrocytes at a less differentiated stage. However, the intracellular signaling effectors transducing its activation remain poorly understood. Here, we use Oli-neu cells, an immortalized cell line derived from primary murine oligodendrocytes, and primary rat oligodendrocyte cultures as model systems to identify molecular targets that link cell surface GPR17 to oligodendrocyte maturation blockade. We demonstrate that stimulation of GPR17 by the small molecule agonist MDL29,951 (2-carboxy-4,6-dichloro-1H-indole-3-propionic acid) decreases myelin basic protein expression levels mainly by triggering the Gαi/o signaling pathway, which in turn leads to reduced activity of the downstream cascade adenylyl cyclase-cAMP-PKA-cAMP response element-binding protein (CREB). In addition, we show that GPR17 activation also diminishes myelin basic protein abundance by lessening stimulation of the exchange protein directly activated by cAMP (EPAC), thus uncovering a previously unrecognized role for EPAC to regulate oligodendrocyte differentiation. Together, our data establish PKA and EPAC as key downstream effectors of GPR17 that inhibit oligodendrocyte maturation. We envisage that treatments augmenting PKA and/or EPAC activity represent a beneficial approach for therapeutic enhancement of remyelination in those demyelinating diseases where GPR17 is highly expressed, such as multiple sclerosis. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Evidence for acquisition of virulence effectors in pathogenic chytrids

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Summers Kyle

2011-07-01

Full Text Available Abstract Background The decline in amphibian populations across the world is frequently linked to the infection of the chytrid fungus Batrachochytrium dendrobatidis (Bd. This is particularly perplexing because Bd was only recently discovered in 1999 and no chytrid fungus had previously been identified as a vertebrate pathogen. Results In this study, we show that two large families of known virulence effector genes, crinkler (CRN proteins and serine peptidases, were acquired by Bd from oomycete pathogens and bacteria, respectively. These two families have been duplicated after their acquisition by Bd. Additional selection analyses indicate that both families evolved under strong positive selection, suggesting that they are involved in the adaptation of Bd to its hosts. Conclusions We propose that the acquisition of virulence effectors, in combination with habitat disruption and climate change, may have driven the Bd epidemics and the decline in amphibian populations. This finding provides a starting point for biochemical investigations of chytridiomycosis.

Field performance of the waste retrieval end effectors in the Oak Ridge gunite tanks

International Nuclear Information System (INIS)

Mullen, O.D.

1997-09-01

Waterjet-based tank waste retrieval end effectors have been developed by Retrieval Process Development and Enhancements through several generations of test articles targeted at deployment in Hanford underground storage tanks with a large robotic arm. The basic technology has demonstrated effectiveness for retrieval of simulants bounding a wide range of waste properties and compatibility with foreseen deployment systems. The Oak Ridge National Laboratory (ORNL) selected the waterjet scarifying end effector, the jet pump conveyance system, and the Modified Light Duty Utility Arm and Houdini Remotely Operated Vehicle deployment and manipulator systems for evaluation in the Gunite and Associated Tanks Treatability Study (GAAT-TS). The Retrieval Process Development and Enhancements (RPD ampersand E) team was tasked with developing a version of the retrieval end effector tailored to the Oak Ridge tanks, waste, and deployment platforms. The conceptual design was done by the University of Missouri-Rolla in FY 1995-96. The university researchers conducted separate effects tests of the component concepts, scaled the basic design features, and constructed a full-scale test article incorporating their findings in early FY 1996. The test article was extensively evaluated in the Hanford Hydraulic Testbed and the design features were further refined. Detail design of the prototype item was started at Waterjet Technology, Inc. before the development testing was finished, and two of the three main subassemblies were substantially complete before final design of the waterjet manifold was determined from the Hanford hydraulic testbed (HTB) testing. The manifold on the first prototype was optimized for sludge retrieval; assembled with that manifold, the end effector is termed the Sludge Retrieval End Effector (SREE)

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

Science.gov (United States)

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

2013-10-01

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

Effector protein translocation by the Coxiella burnetii Dot/Icm type IV secretion system requires endocytic maturation of the pathogen-occupied vacuole.

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Hayley J Newton

Full Text Available The human pathogen Coxiella burnetii encodes a type IV secretion system called Dot/Icm that is essential for intracellular replication. The Dot/Icm system delivers bacterial effector proteins into the host cytosol during infection. The effector proteins delivered by C. burnetii are predicted to have important functions during infection, but when these proteins are needed during infection has not been clearly defined. Here, we use a reporter system consisting of fusion proteins that have a β-lactamase enzyme (BlaM fused to C. burnetii effector proteins to study protein translocation by the Dot/Icm system. Translocation of BlaM fused to the effector proteins CBU0077, CBU1823 and CBU1524 was not detected until 8-hours after infection of HeLa cells, which are permissive for C. burnetii replication. Translocation of these effector fusion proteins by the Dot/Icm system required acidification of the Coxiella-containing vacuole. Silencing of the host genes encoding the membrane transport regulators Rab5 or Rab7 interfered with effector translocation, which indicates that effectors are not translocated until bacteria traffic to a late endocytic compartment in the host cell. Similar requirements for effector translocation were discerned in bone marrow macrophages derived from C57BL/6 mice, which are primary cells that restrict the intracellular replication of C. burnetii. In addition to requiring endocytic maturation of the vacuole for Dot/Icm-mediated translocation of effectors, bacterial transcription was required for this process. Thus, translocation of effector proteins by the C. burnetii Dot/Icm system occurs after acidification of the CCV and maturation of this specialized organelle to a late endocytic compartment. This indicates that creation of the specialized vacuole in which C. burnetii replicates represents a two-stage process mediated initially by host factors that regulate endocytic maturation and then by bacterial effectors delivered into

Pathogen-associated molecular pattern-triggered immunity and resistance to the root pathogen Phytophthora parasitica in Arabidopsis.

Science.gov (United States)

Larroque, Mathieu; Belmas, Elodie; Martinez, Thomas; Vergnes, Sophie; Ladouce, Nathalie; Lafitte, Claude; Gaulin, Elodie; Dumas, Bernard

2013-09-01

The cellulose binding elicitor lectin (CBEL) of the genus Phytophthora induces necrosis and immune responses in several plant species, including Arabidopsis thaliana. However, the role of CBEL-induced responses in the outcome of the interaction is still unclear. This study shows that some of CBEL-induced defence responses, but not necrosis, required the receptor-like kinase BAK1, a general regulator of basal immunity in Arabidopsis, and the production of a reactive oxygen burst mediated by respiratory burst oxidases homologues (RBOH). Screening of a core collection of 48 Arabidopsis ecotypes using CBEL uncovered a large variability in CBEL-induced necrotic responses. Analysis of non-responsive CBEL lines Ws-4, Oy-0, and Bla-1 revealed that Ws-4 and Oy-0 were also impaired in the production of the oxidative burst and expression of defence genes, whereas Bla-1 was partially affected in these responses. Infection tests using two Phytophthora parasitica strains, Pp310 and Ppn0, virulent and avirulent, respectively, on the Col-0 line showed that BAK1 and RBOH mutants were susceptible to Ppn0, suggesting that some immune responses controlled by these genes, but not CBEL-induced cell death, are required for Phytophthora parasitica resistance. However, Ws-4, Oy-0, and Bla-1 lines were not affected in Ppn0 resistance, showing that natural variability in CBEL responsiveness is not correlated to Phytophthora susceptibility. Overall, the results uncover a BAK1- and RBOH-dependent CBEL-triggered immunity essential for Phytophthora resistance and suggest that natural quantitative variation of basal immunity triggered by conserved general elicitors such as CBEL does not correlate to Phytophthora susceptibility.

A Legionella Effector Disrupts Host Cytoskeletal Structure by Cleaving Actin.

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Yao Liu

2017-01-01

Full Text Available Legionella pneumophila, the etiological agent of Legionnaires' disease, replicates intracellularly in protozoan and human hosts. Successful colonization and replication of this pathogen in host cells requires the Dot/Icm type IVB secretion system, which translocates approximately 300 effector proteins into the host cell to modulate various cellular processes. In this study, we identified RavK as a Dot/Icm substrate that targets the host cytoskeleton and reduces actin filament abundance in mammalian cells upon ectopic expression. RavK harbors an H95EXXH99 motif associated with diverse metalloproteases, which is essential for the inhibition of yeast growth and for the induction of cell rounding in HEK293T cells. We demonstrate that the actin protein itself is the cellular target of RavK and that this effector cleaves actin at a site between residues Thr351 and Phe352. Importantly, RavK-mediated actin cleavage also occurs during L. pneumophila infection. Cleavage by RavK abolishes the ability of actin to form polymers. Furthermore, an F352A mutation renders actin resistant to RavK-mediated cleavage; expression of the mutant in mammalian cells suppresses the cell rounding phenotype caused by RavK, further establishing that actin is the physiological substrate of RavK. Thus, L. pneumophila exploits components of the host cytoskeleton by multiple effectors with distinct mechanisms, highlighting the importance of modulating cellular processes governed by the actin cytoskeleton in the intracellular life cycle of this pathogen.

Immune effector mechanisms of the nitric oxide pathway in malaria: cytotoxicity versus cytoprotection

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Hossein Nahrevanian

Full Text Available Nitric oxide (NO is thought to be an important mediator and critical signaling molecule for malaria immunopathology; it is also a target for therapy and for vaccine. Inducible nitric oxide synthase (iNOS is synthesized by a number of cell types under inflammatory conditions. The most relevant known triggers for its expression are endotoxins and cytokines. To date, there have been conflicting reports concerning the clinical significance of NO in malaria. Some researchers have proposed that NO contributes to the development of severe and complicated malaria, while others have argued that NO has a protective role. Infection with parasites resistant to the microbicidal action of NO may result in high levels of NO being generated, which could then damage the host, instead of controlling parasitemia. Consequently, the host-parasite interaction is a determining factor for whether the parasite is capable of stimulating NO production; the role of NO in resistance to malaria appears to be strain specific. It is known that NO and/or its related molecules are involved in malaria, but their involvement is not independent of other immune events. NO is an important, but possibly not an essential contributor to the control of acute-phase malaria infection. The protective immune responses against malaria parasite are multifactorial; however, they necessarily involve final effector molecules, including NO, iNOS and RNI.

Schmitt-Trigger-based Recycling Sensor and Robust and High-Quality PUFs for Counterfeit IC Detection

OpenAIRE

Lin, Cheng-Wei; Jang, Jae-Won; Ghosh, Swaroop

2015-01-01

We propose Schmitt-Trigger (ST) based recycling sensor that are tailored to amplify the aging mechanisms and detect fine grained recycling (minutes to seconds). We exploit the susceptibility of ST to process variations to realize high-quality arbiter PUF. Conventional SRAM PUF suffer from environmental fluctuation-induced bit flipping. We propose 8T SRAM PUF with a back-to-back PMOS latch to improve robustness by 4X. We also propose a low-power 7T SRAM with embedded Magnetic Tunnel Junction (...

Reliability model analysis and primary experimental evaluation of laser triggered pulse trigger

International Nuclear Information System (INIS)

Chen Debiao; Yang Xinglin; Li Yuan; Li Jin

2012-01-01

High performance pulse trigger can enhance performance and stability of the PPS. It is necessary to evaluate the reliability of the LTGS pulse trigger, so we establish the reliability analysis model of this pulse trigger based on CARMES software, the reliability evaluation is accord with the statistical results. (authors)

Orbital maneuvering vehicle end effectors

Science.gov (United States)

Myers, W. Neill (Inventor); Forbes, John C. (Inventor); Barnes, Wayne L. (Inventor)

1988-01-01

An end effector device (A) for grasping and holding an article such as a handle (18) of a space telescope is disclosed. The device includes a V-shaped capture window (74) defined as inclined surfaces (76, 78) in parallel face plates (22, 24) which converge toward a retainer recess (54) in which the handle is retained. A pivotal finger (30) meshes with a pair of pivoted fingers (26, 28) which rotate in counterrotation. The fingers rotate to pull a handle within the capture window into recess (54) where latches (50) lock handle (18) in the recess. To align the capture window, plates (22, 24) may be cocked plus or minus five degrees on base (64).

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...... factor. By using the yeast two-hybrid system, the adenosine kinase (ADK) was identified as a host target of PEC6. Virus-induced gene silencing (VIGS) of ADK enhanced wheat susceptibility to stripe rust indicates that ADK is a positive regulator in plant defense. Based on EtHAn-mediated effector delivery......, seventy-two wheat landraces were screened to search for the presence of potential resistance (R) genes. Three landraces showed strong hypersensitive response (HR) when PEC6 was expressed in the cells, suggesting the presence of certain R gene(s) recognizing PEC6. However, these landraces did not show...

Stay away from asthma triggers

Science.gov (United States)

Asthma triggers - stay away from; Asthma triggers - avoiding; Reactive airway disease - triggers; Bronchial asthma - triggers ... clothes. They should leave the coat outside or away from your child. Ask people who work at ...

Tomato Cf resistance proteins mediate recognition of cognate homologous effectors from fungi pathogenic on diots and monocots

NARCIS (Netherlands)

Stergiopoulos, I.; Burg, van den H.A.; Ökmen, B.; Beenen, H.G.; Liere, van S.; Kema, G.H.J.; Wit, de P.J.G.M.

2010-01-01

Most fungal effectors characterized so far are species-specific and facilitate virulence on a particular host plant. During infection of its host tomato, Cladosporium fulvum secretes effectors that function as virulence factors in the absence of cognate Cf resistance proteins and induce

Auto-acetylation on K289 is not essential for HopZ1a-mediated plant defense suppression

Directory of Open Access Journals (Sweden)

Jose Sebastian Rufian

2015-07-01

Full Text Available The Pseudomonas syringae type III-secreted effector HopZ1a is a member of the HopZ / YopJ superfamily of effectors that triggers immunity in Arabidopsis. We have previously shown that HopZ1a suppresses both local (effector-triggered immunity, ETI and systemic immunity (systemic acquired resistance, SAR triggered by the heterologous effector AvrRpt2. HopZ1a has been shown to possess acetyltransferase activity, and this activity is essential to trigger immunity in Arabidopsis. HopZ1a acetyltransferase activity has been reported to require the auto-acetylation of the effector on a specific lysine (K289 residue. In this paper we analyze the relevance of autoacetylation of lysine residue 289 in HopZ1a ability to suppress plant defenses, and on the light of the results obtained, we also revise its relevance for HopZ1a avirulence activity. Our results indicate that, while the HopZ1aK289R mutant is impaired to some degree in its virulence and avirulence activities, is by no means phenotypically equivalent to the catalytically inactive HopZ1aC216A, since it is still able to trigger a defense response that induces detectable macroscopic HR and effectively protects Arabidopsis from infection, reducing growth of P. syringae within the plant. We also present evidence that the HopZ1aK289R mutant still displays virulence activities, partially suppressing both ETI and SAR.

Protecting and rescuing the effectors: roles of differentiation and survival in the control of memory T cell development

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Sema eKurtulus

2013-01-01

Full Text Available Vaccines, arguably the single most important intervention in improving human health, have exploited the phenomenon of immunological memory. The elicitation of memory T cells is often an essential part of successful long-lived protective immunity. Our understanding of T cell memory has been greatly aided by the development of TCR Tg mice and MHC tetrameric staining reagents that have allowed the precise tracking of antigen-specific T cell responses. Indeed, following acute infection or immunization, naïve T cells undergo a massive expansion culminating in the generation of a robust effector T cell population. This peak effector response is relatively short-lived and, while most effector T cells die by apoptosis, some remain and develop into memory cells. Although the molecular mechanisms underlying this cell fate decision remain incompletely defined, substantial progress has been made, particularly with regards to CD8+ T cells. For example, the effector CD8+ T cells generated during a response are heterogeneous, consisting of cells with more or less potential to develop into full-fledged memory cells. Development of CD8+ T cell memory is regulated by the transcriptional programs that control the differentiation and survival of effector T cells. While the type of antigenic stimulation and level of inflammation control effector CD8+ T cell differentiation, availability of cytokines and their ability to control expression and function of Bcl-2 family members governs their survival. These distinct differentiation and survival programs may allow for finer therapeutic intervention to control both the quality and quantity of CD8+ T cell memory. Effector to memory transition of CD4+ T cells is less well characterized than CD8+ T cells, emerging details will be discussed. This review will focus on the recent progress made in our understanding of the mechanisms underlying the development of T cell memory with an emphasis on factors controlling survival of

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

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Soledad R. Ordonez

2017-10-01

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

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

Science.gov (United States)

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

2017-01-01

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

Innovative technology summary report: Confined sluicing end effector

International Nuclear Information System (INIS)

1998-09-01

A Confined Sluicing End-Effector (CSEE) was field tested during the summer of 1997 in Tank W-3, one of the Gunite and Associated Tanks (GAAT) at the Oak Ridge Reservation (ORR). It should be noted that the specific device used at the Oak Ridge Reservation demonstration was the Sludge Retrieval End-Effector (SREE), although in common usage it is referred to as the CSEE. Deployed by the Modified Light-Duty Utility Arm (MLDUA) and the Houdini remotely operated vehicle (ROV), the CSEE was used to mobilize and retrieve waste from the tank. After removing the waste, the CSEE was used to scarify the gunite walls of Tank W-3, removing approximately 0.1 in of material. The CSEE uses three rotating water-jets to direct a short-range pressurized jet of water to effectively mobilize the waste. Simultaneously, the water and dislodged tank waste, or scarified materials, are aspirated using a water-jet pump-driven conveyance system. The material is then pumped outside of the tank, where it can be stored for treatment. The technology, its performance, uses, cost, and regulatory issues are discussed

The potato aphid salivary effector Me47 is a glutathione-S-transferase involved in modifying plant responses to aphid infestation

Directory of Open Access Journals (Sweden)

Graeme James Kettles

2016-08-01

Full Text Available Polyphagous aphid pests cause considerable economic damage to crop plants, primarily through the depletion of photoassimilates and transfer of viruses. The potato aphid (Macrosiphum euphorbiae is a notable pest of solanaceous crops, however the molecular mechanisms that underpin the ability to colonize these hosts are unknown. It has recently been demonstrated that like other aphid species, M. euphorbiae injects a battery of salivary proteins into host plants during feeding. It is speculated that these proteins function in a manner analagous to secreted effectors from phytopathogenic bacteria, fungi and oomycetes. Here we describe a novel aphid effector (Me47 which was identified from the potato aphid salivary secretome as a putative glutathione-S-transferase (GST. Expression of Me47 in Nicotiana benthamiana enhanced reproductive performance of green peach aphid (Myzus persicae. Similarly, delivery of Me47 into leaves of tomato (Solanum lycopersicum by Pseudomonas spp. enhanced potato aphid fecundity. In contrast, delivery of Me47 into Arabidopsis thaliana reduced GPA reproductive performance, indicating that Me47 impacts the outcome of plant-aphid interactions differently depending on the host species. Delivery of Me47 by the non-pathogenic Pseudomonas fluorescens revealed that Me47 protein or activity triggers defense gene transcriptional upregulation in tomato but not Arabidopsis. Recombinant Me47 was purified and demonstrated to have GST activity against two specific isothiocyanates (ITCs, compounds implicated in herbivore defense. Whilst GSTs have previously been associated with development of aphid resistance to synthetic insecticides, the findings described here highlight a novel function as both an elicitor and suppressor of plant defense when delivered into host tissues.

Preliminary soil-slip susceptibility maps, southwestern California

Science.gov (United States)

Morton, Douglas M.; Alvarez, Rachel M.; Campbell, Russell H.; Digital preparation by Bovard, Kelly R.; Brown, D.T.; Corriea, K.M.; Lesser, J.N.

2003-01-01

This group of maps shows relative susceptibility of hill slopes to the initiation sites of rainfall-triggered soil slip-debris flows in southwestern California. As such, the maps offer a partial answer to one part of the three parts necessary to predict the soil-slip/debris-flow process. A complete prediction of the process would include assessments of “where”, “when”, and “how big”. These maps empirically show part of the “where” of prediction (i.e., relative susceptibility to sites of initiation of the soil slips) but do not attempt to show the extent of run out of the resultant debris flows. Some information pertinent to “when” the process might begin is developed. “When” is determined mostly by dynamic factors such as rainfall rate and duration, for which local variations are not amenable to long-term prediction. “When” information is not provided on the maps but is described later in this narrative. The prediction of “how big” is addressed indirectly by restricting the maps to a single type of landslide process—soil slip-debris flows. The susceptibility maps were created through an iterative process from two kinds of information. First, locations of sites of past soil slips were obtained from inventory maps of past events. Aerial photographs, taken during six rainy seasons that produced abundant soil slips, were used as the basis for soil slip-debris flow inventory. Second, digital elevation models (DEM) of the areas that were inventoried were used to analyze the spatial characteristics of soil slip locations. These data were supplemented by observations made on the ground. Certain physical attributes of the locations of the soil-slip debris flows were found to be important and others were not. The most important attribute was the mapped bedrock formation at the site of initiation of the soil slip. However, because the soil slips occur in surficial materials overlying the bedrocks units, the bedrock formation can only serve as

Triggered creep as a possible mechanism for delayed dynamic triggering of tremor and earthquakes

Science.gov (United States)

Shelly, David R.; Peng, Zhigang; Hill, David P.; Aiken, Chastity

2011-01-01

The passage of radiating seismic waves generates transient stresses in the Earth's crust that can trigger slip on faults far away from the original earthquake source. The triggered fault slip is detectable in the form of earthquakes and seismic tremor. However, the significance of these triggered events remains controversial, in part because they often occur with some delay, long after the triggering stress has passed. Here we scrutinize the location and timing of tremor on the San Andreas fault between 2001 and 2010 in relation to distant earthquakes. We observe tremor on the San Andreas fault that is initiated by passing seismic waves, yet migrates along the fault at a much slower velocity than the radiating seismic waves. We suggest that the migrating tremor records triggered slow slip of the San Andreas fault as a propagating creep event. We find that the triggered tremor and fault creep can be initiated by distant earthquakes as small as magnitude 5.4 and can persist for several days after the seismic waves have passed. Our observations of prolonged tremor activity provide a clear example of the delayed dynamic triggering of seismic events. Fault creep has been shown to trigger earthquakes, and we therefore suggest that the dynamic triggering of prolonged fault creep could provide a mechanism for the delayed triggering of earthquakes. ?? 2011 Macmillan Publishers Limited. All rights reserved.

CMS Trigger Performance

CERN Document Server

Donato, Silvio

2017-01-01

During its second run of operation (Run 2) which started in 2015, the LHC will deliver a peak instantaneous luminosity that may reach $2 \\cdot 10^{34}$ cm$^{-2}$s$^{-1}$ with an average pile-up of about 55, far larger than the design value. Under these conditions, the online event selection is a very challenging task. In CMS, it is realized by a two-level trigger system the Level-1 (L1) Trigger, implemented in custom-designed electronics, and the High Level Trigger (HLT), a streamlined version of the offline reconstruction software running on a computer farm. In order to face this challenge, the L1 trigger has been through a major upgrade compared to Run 1, whereby all electronic boards of the system have been replaced, allowing more sophisticated algorithms to be run online. Its last stage, the global trigger, is now able to perform complex selections and to compute high-level quantities, like invariant masses. Likewise, the algorithms that run in the HLT go through big improvements; in particular, new appr...

The NA27 trigger

International Nuclear Information System (INIS)

Bizzarri, R.; Di Capua, E.; Falciano, S.; Iori, M.; Marel, G.; Piredda, G.; Zanello, L.; Haupt, L.; Hellman, S.; Holmgren, S.O.; Johansson, K.E.

1985-05-01

We have designed and implemented a minimum bias trigger together with a fiducial volume trigger for the experiment NA27, performed at the CERN SPS. A total of more than 3 million bubble chamber pictures have been taken with a triggered cross section smaller than 75% of the total inelastic cross section. Events containing charm particles were triggered with an efficiency of 98 +2 sub(-3)%. With the fiducial volume trigger, the probability for a picture to contain an interaction in the visible hydrogen increased from 47.3% to 59.5%, reducing film cost and processing effort with about 20%. The improvement in data taking rate is shown to be negligible. (author)

The Chlamydia type III secretion system C-ring engages a chaperone-effector protein complex.

Directory of Open Access Journals (Sweden)

Kris E Spaeth

2009-09-01

Full Text Available In Gram-negative bacterial pathogens, specialized chaperones bind to secreted effector proteins and maintain them in a partially unfolded form competent for translocation by type III secretion systems/injectisomes. How diverse sets of effector-chaperone complexes are recognized by injectisomes is unclear. Here we describe a new mechanism of effector-chaperone recognition by the Chlamydia injectisome, a unique and ancestral line of these evolutionarily conserved secretion systems. By yeast two-hybrid analysis we identified networks of Chlamydia-specific proteins that interacted with the basal structure of the injectisome, including two hubs of protein-protein interactions that linked known secreted effector proteins to CdsQ, the putative cytoplasmic C-ring component of the secretion apparatus. One of these protein-interaction hubs is defined by Ct260/Mcsc (Multiple cargo secretion chaperone. Mcsc binds to and stabilizes at least two secreted hydrophobic proteins, Cap1 and Ct618, that localize to the membrane of the pathogenic vacuole ("inclusion". The resulting complexes bind to CdsQ, suggesting that in Chlamydia, the C-ring of the injectisome mediates the recognition of a subset of inclusion membrane proteins in complex with their chaperone. The selective recognition of inclusion membrane proteins by chaperones may provide a mechanism to co-ordinate the translocation of subsets of inclusion membrane proteins at different stages in infection.

Tomato immune receptor Ve1 recognizes effector of multiple fungal pathogens uncovered by genome and RNA sequencing

NARCIS (Netherlands)

Jonge, de R.; Esse, van H.P.; Maruthachalam, K.; Bolton, M.D.; Santhanam, P.; Keykha Saber, M.; Zhang, Z.; Usami, T.; Lievens, B.; Subbarao, K.V.; Thomma, B.

2012-01-01

Fungal plant pathogens secrete effector molecules to establish disease on their hosts, and plants in turn use immune receptors to try to intercept these effectors. The tomato immune receptor Ve1 governs resistance to race 1 strains of the soil-borne vascular wilt fungi Verticillium dahliae and

Triggers of oral lichen planus flares and the potential role of trigger avoidance in disease management.

Science.gov (United States)

Chen, Hannah X; Blasiak, Rachel; Kim, Edwin; Padilla, Ricardo; Culton, Donna A

2017-09-01

Many patients with oral lichen planus (OLP) report triggers of flares, some of which overlap with triggers of other oral diseases, including oral allergy syndrome and oral contact dermatitis. The purpose of this study was to evaluate the prevalence of commonly reported triggers of OLP flares, their overlap with triggers of other oral diseases, and the potential role of trigger avoidance as a management strategy. Questionnaire-based survey of 51 patients with biopsy-proven lichen planus with oral involvement seen in an academic dermatology specialty clinic and/or oral pathology clinic between June 2014 and June 2015. Of the participants, 94% identified at least one trigger of their OLP flares. Approximately half of the participants (51%) reported at least one trigger that overlapped with known triggers of oral allergy syndrome, and 63% identified at least one trigger that overlapped with known triggers of oral contact dermatitis. Emotional stress was the most commonly reported trigger (77%). Regarding avoidance, 79% of the study participants reported avoiding their known triggers in daily life. Of those who actively avoided triggers, 89% reported an improvement in symptoms and 70% reported a decrease in the frequency of flares. Trigger identification and avoidance can play a potentially effective role in the management of OLP. Copyright © 2017 Elsevier Inc. All rights reserved.

Preferential susceptibility of Th9 and Th2 CD4+ T cells to X4-tropic HIV-1 infection.

Science.gov (United States)

Orlova-Fink, Nina; Chowdhury, Fatema Z; Sun, Xiaoming; Harrington, Sean; Rosenberg, Eric S; Yu, Xu G; Lichterfeld, Mathias

2017-10-23

The functional polarization of CD4 T cells determines their antimicrobial effector profile, but may also impact the susceptibility to infection with HIV-1. Here, we analyzed the susceptibility of CD4 T cells with different functional polarization to infection with X4 and R5-tropic HIV-1. CD4 T cells with a Th1, Th2, Th17, and Th9 polarization were subjected to in-vitro infection assays with X4, R5, or vesicular stomatitis virus-G protein-pseudotyped HIV-1. In addition, we sorted differentially polarized CD4 T-cell subsets from individuals treated with antiretroviral therapy and analyzed the tropism of viral env sequences. Th9-polarized CD4 T cells and, to a lesser extent, Th2-polarized CD4 T cells expressed higher surface levels of CXCR4, and are more permissive to X4-tropic infection in vitro. In contrast, Th1 and Th17 CD4 T cells exhibited stronger surface expression of CCR5, and were more susceptible to infection with R5-tropic viruses. Correspondingly, the distribution of X4-tropic viral sequences in antiretroviral therapy-treated HIV-1-infected patients was biased toward Th9/Th2 cells, whereas R5-tropic sequences were more frequently observed in Th17 cells. CD4 T-cell polarization is associated with a distinct susceptibility to X4 and R5-tropic HIV-1 infection.

Assessment of Susceptibility to Liquefaction of Saturated Road Embankment Subjected to Dynamic Loads

Science.gov (United States)

Borowiec, Anna; Maciejewski, Krzysztof

2014-03-01

Liquefaction has always been intensely studied in parts of the world where earthquakes occur. However, the seismic activity is not the only possible cause of this phenomenon. It may in fact be triggered by some human activities, such as constructing and mining or by rail and road transport. In the paper a road embankment built across a shallow water reservoir is analyzed in terms of susceptibility to liquefaction. Two types of dynamic loadings are considered: first corresponding to an operation of a vibratory roller and second to an earthquake. In order to evaluate a susceptibility of soil to liquefaction, a factor of safety against triggering of liquefaction is used (FSTriggering). It is defined as a ratio of vertical effective stresses to the shear stresses both varying with time. For the structure considered both stresses are obtained using finite element method program, here Plaxis 2D. The plastic behavior of the cohesionless soils is modeled by means of Hardening Soil (HS) constitutive relationship, implemented in Plaxis software. As the stress tensor varies with time during dynamic excitation, the FSTriggering has to be calculated for some particular moment of time when liquefaction is most likely to occur. For the purposes of this paper it is named a critical time and established for reference point at which the pore pressures were traced in time. As a result a factor of safety distribution throughout embankment is generated. For the modeled structure, cyclic point loads (i.e., vibrating roller) present higher risk than earthquake of magnitude 5.4. Explanation why considered structure is less susceptible to earthquake than typical dam could lay in stabilizing and damping influence of water, acting here on both sides of the slope. Analogical procedure is applied to assess liquefaction susceptibility of the road embankment considered but under earthquake excitation. Only the higher water table is considered as it is the most unfavorable. Additionally the

Development of an optimum end-effector with a nano-scale uneven surface for non-adhesion cell manipulation using a micro-manipulator

International Nuclear Information System (INIS)

Horade, M; Kojima, M; Kamiyama, K; Kurata, T; Mae, Y; Arai, T

2015-01-01

In order to realize effective micro-manipulation using a micro-manipulator system, an optimum end-effector is proposed. Cell-manipulation experiments using mouse fibroblast cells are conducted, and the usability of the proposed end-effector is confirmed. A key advantage of the micro-manipulator is high-accuracy, high-speed 3D micro- and nano-scale positioning. Micro-manipulation has often been used in research involving biological cells. However, there are two important concerns with the micro-manipulator system: gripping efficiency and the release of gripped objects. When it is not possible to grip a micro-object, such as a cell, near its center, the object may be dropped during manipulation. Since the acquisition of exact position information for a micro-object in the vertical direction is difficult using a microscope, the gripping efficiency of the end-effector should be improved. Therefore, technical skill or operational support is required. Since, on the micro-scale, surface forces such as the adsorption force are greater than body forces, such as the gravitational force, the adhesion force between the end-effector and the object is strong. Therefore, manipulation techniques without adhesion are required for placed an object at an arbitrary position. In the present study, we consider direct physical contact between the end-effector and objects. First, the design and materials of the end-effector for micro-scale manipulation were optimized, and an end-effector with an optimum shape to increase the grip force was fabricated. Second, the surface of the end-effector tip was made uneven, and the adhesion force from increasing on the micro-scale was prevented. When an end-effector with an uneven surface was used, release without adhesion was successful 85.0% of the time. On the other hand, when an end-effector without an uneven surface was used, release without adhesion was successful 6.25% of the time. Therefore, the superiority of a structure with an uneven

Consequences of exposure to ionizing radiation for effector T cell function in vivo

International Nuclear Information System (INIS)

Rouse, B.T.; Hartley, D.; Doherty, P.C.

1989-01-01

The adoptive transfer of acutely primed and memory virus-immune CD8+ T cells causes enhanced meningitis in both cyclophosphamide (Cy) suppressed, and unsuppressed, recipients infected with lymphocytic choriomeningitis virus (LCMV). The severity of meningitis is assessed by counting cells in cerebrospinal fluid (CSF) obtained from the cisterna magna, which allows measurement of significant inflammatory process ranging from 3 to more than 300 times the background number of cells found in mice injected with virus alone. Exposure of the donor immune population to ionizing radiation prior to transfer has shown that activated T cells from mice primed 7 or 8 days previously with virus may still promote a low level of meningitis in unsuppressed recipients following as much as 800 rads, while this effect is lost totally in Cy-suppressed mice at 600 rads. Memory T cells are more susceptible and show no evidence of in vivo effector function in either recipient population subsequent to 400 rads, a dose level which also greatly reduces the efficacy of acutely-primed T cells. The results are interpreted as indicating that heavily irradiated cells that are already fully functional show evidence of primary localization to the CNS and a limited capacity to cause pathology. Secondary localization, and events that require further proliferation of the T cells in vivo, are greatly inhibited by irradiation

Consequences of exposure to ionizing radiation for effector T cell function in vivo

Energy Technology Data Exchange (ETDEWEB)

Rouse, B.T.; Hartley, D.; Doherty, P.C. (Univ. of Tennessee, Knoxville (USA))

1989-01-01

The adoptive transfer of acutely primed and memory virus-immune CD8+ T cells causes enhanced meningitis in both cyclophosphamide (Cy) suppressed, and unsuppressed, recipients infected with lymphocytic choriomeningitis virus (LCMV). The severity of meningitis is assessed by counting cells in cerebrospinal fluid (CSF) obtained from the cisterna magna, which allows measurement of significant inflammatory process ranging from 3 to more than 300 times the background number of cells found in mice injected with virus alone. Exposure of the donor immune population to ionizing radiation prior to transfer has shown that activated T cells from mice primed 7 or 8 days previously with virus may still promote a low level of meningitis in unsuppressed recipients following as much as 800 rads, while this effect is lost totally in Cy-suppressed mice at 600 rads. Memory T cells are more susceptible and show no evidence of in vivo effector function in either recipient population subsequent to 400 rads, a dose level which also greatly reduces the efficacy of acutely-primed T cells. The results are interpreted as indicating that heavily irradiated cells that are already fully functional show evidence of primary localization to the CNS and a limited capacity to cause pathology. Secondary localization, and events that require further proliferation of the T cells in vivo, are greatly inhibited by irradiation.

Immune Effector Recovery in Chronic Myeloid Leukemia and Treatment-Free Remission

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Agnes S. M. Yong

2017-04-01

Full Text Available Chronic myeloid leukemia (CML is a hematological cancer, characterized by a reciprocal chromosomal translocation between chromosomes 9 and 22 [t(9;22], producing the Bcr-Abl oncogene. Tyrosine kinase inhibitors (TKIs represent the standard of care for CML patients and exert a dual mode of action: direct oncokinase inhibition and restoration of effector-mediated immune surveillance, which is rendered dysfunctional in CML patients at diagnosis, prior to TKI therapy. TKIs such as imatinib, and more potent second-generation nilotinib and dasatinib induce a high rate of deep molecular response (DMR, BCR-ABL1 ≤ 0.01% in CML patients. As a result, the more recent goal of therapy in CML treatment is to induce a durable DMR as a prelude to successful treatment-free remission (TFR, which occurs in approximately half of all CML patients who cease TKI therapy. The lack of overt relapse in such patients has been attributed to immunological control of CML. In this review, we discuss an immunological timeline to successful TFR, focusing on the immunology of CML during TKI treatment; an initial period of immune suppression, limiting antitumor immune effector responses in newly diagnosed CML patients, linked to an expansion of immature myeloid-derived suppressor cells and regulatory T cells and aberrant expression of immune checkpoint signaling pathways, including programmed death-1/programmed death ligand-1. Commencement of TKI treatment is associated with immune system re-activation and restoration of effector-mediated [natural killer (NK cell and T cell] immune surveillance in CML patients, albeit with differing frequencies in concert with differing levels of molecular response achieved on TKI. DMR is associated with maximal restoration of immune recovery in CML patients on TKI. Current data suggest a net balance between both the effector and suppressor arms of the immune system, at a minimum involving mature, cytotoxic CD56dim NK cells may be important

Stimulation over primary motor cortex during action observation impairs effector recognition.

Science.gov (United States)

Naish, Katherine R; Barnes, Brittany; Obhi, Sukhvinder S

2016-04-01

Recent work suggests that motor cortical processing during action observation plays a role in later recognition of the object involved in the action. Here, we investigated whether recognition of the effector making an action is also impaired when transcranial magnetic stimulation (TMS) - thought to interfere with normal cortical activity - is applied over the primary motor cortex (M1) during action observation. In two experiments, single-pulse TMS was delivered over the hand area of M1 while participants watched short clips of hand actions. Participants were then asked whether an image (experiment 1) or a video (experiment 2) of a hand presented later in the trial was the same or different to the hand in the preceding video. In Experiment 1, we found that participants' ability to recognise static images of hands was significantly impaired when TMS was delivered over M1 during action observation, compared to when no TMS was delivered, or when stimulation was applied over the vertex. Conversely, stimulation over M1 did not affect recognition of dot configurations, or recognition of hands that were previously presented as static images (rather than action movie clips) with no object. In Experiment 2, we found that effector recognition was impaired when stimulation was applied part way through (300ms) and at the end (500ms) of the action observation period, indicating that 200ms of action-viewing following stimulation was not long enough to form a new representation that could be used for later recognition. The findings of both experiments suggest that interfering with cortical motor activity during action observation impairs subsequent recognition of the effector involved in the action, which complements previous findings of motor system involvement in object memory. This work provides some of the first evidence that motor processing during action observation is involved in forming representations of the effector that are useful beyond the action observation period

Immune Effector Recovery in Chronic Myeloid Leukemia and Treatment-Free Remission

Science.gov (United States)

Hughes, Amy; Yong, Agnes S. M.

2017-01-01

Chronic myeloid leukemia (CML) is a hematological cancer, characterized by a reciprocal chromosomal translocation between chromosomes 9 and 22 [t(9;22)], producing the Bcr-Abl oncogene. Tyrosine kinase inhibitors (TKIs) represent the standard of care for CML patients and exert a dual mode of action: direct oncokinase inhibition and restoration of effector-mediated immune surveillance, which is rendered dysfunctional in CML patients at diagnosis, prior to TKI therapy. TKIs such as imatinib, and more potent second-generation nilotinib and dasatinib induce a high rate of deep molecular response (DMR, BCR-ABL1 ≤ 0.01%) in CML patients. As a result, the more recent goal of therapy in CML treatment is to induce a durable DMR as a prelude to successful treatment-free remission (TFR), which occurs in approximately half of all CML patients who cease TKI therapy. The lack of overt relapse in such patients has been attributed to immunological control of CML. In this review, we discuss an immunological timeline to successful TFR, focusing on the immunology of CML during TKI treatment; an initial period of immune suppression, limiting antitumor immune effector responses in newly diagnosed CML patients, linked to an expansion of immature myeloid-derived suppressor cells and regulatory T cells and aberrant expression of immune checkpoint signaling pathways, including programmed death-1/programmed death ligand-1. Commencement of TKI treatment is associated with immune system re-activation and restoration of effector-mediated [natural killer (NK) cell and T cell] immune surveillance in CML patients, albeit with differing frequencies in concert with differing levels of molecular response achieved on TKI. DMR is associated with maximal restoration of immune recovery in CML patients on TKI. Current data suggest a net balance between both the effector and suppressor arms of the immune system, at a minimum involving mature, cytotoxic CD56dim NK cells may be important in mediating

Minimum Bias Trigger in ATLAS

International Nuclear Information System (INIS)

Kwee, Regina

2010-01-01

Since the restart of the LHC in November 2009, ATLAS has collected inelastic pp collisions to perform first measurements on charged particle densities. These measurements will help to constrain various models describing phenomenologically soft parton interactions. Understanding the trigger efficiencies for different event types are therefore crucial to minimize any possible bias in the event selection. ATLAS uses two main minimum bias triggers, featuring complementary detector components and trigger levels. While a hardware based first trigger level situated in the forward regions with 2.2 < |η| < 3.8 has been proven to select pp-collisions very efficiently, the Inner Detector based minimum bias trigger uses a random seed on filled bunches and central tracking detectors for the event selection. Both triggers were essential for the analysis of kinematic spectra of charged particles. Their performance and trigger efficiency measurements as well as studies on possible bias sources will be presented. We also highlight the advantage of these triggers for particle correlation analyses. (author)

Causality and headache triggers

Science.gov (United States)

Turner, Dana P.; Smitherman, Todd A.; Martin, Vincent T.; Penzien, Donald B.; Houle, Timothy T.

2013-01-01

Objective The objective of this study was to explore the conditions necessary to assign causal status to headache triggers. Background The term “headache trigger” is commonly used to label any stimulus that is assumed to cause headaches. However, the assumptions required for determining if a given stimulus in fact has a causal-type relationship in eliciting headaches have not been explicated. Methods A synthesis and application of Rubin’s Causal Model is applied to the context of headache causes. From this application the conditions necessary to infer that one event (trigger) causes another (headache) are outlined using basic assumptions and examples from relevant literature. Results Although many conditions must be satisfied for a causal attribution, three basic assumptions are identified for determining causality in headache triggers: 1) constancy of the sufferer; 2) constancy of the trigger effect; and 3) constancy of the trigger presentation. A valid evaluation of a potential trigger’s effect can only be undertaken once these three basic assumptions are satisfied during formal or informal studies of headache triggers. Conclusions Evaluating these assumptions is extremely difficult or infeasible in clinical practice, and satisfying them during natural experimentation is unlikely. Researchers, practitioners, and headache sufferers are encouraged to avoid natural experimentation to determine the causal effects of headache triggers. Instead, formal experimental designs or retrospective diary studies using advanced statistical modeling techniques provide the best approaches to satisfy the required assumptions and inform causal statements about headache triggers. PMID:23534872

The D0 calorimeter trigger

International Nuclear Information System (INIS)

Guida, J.

1992-12-01

The D0 calorimeter trigger system consists of many levels to make physics motivated trigger decisions. The Level-1 trigger uses hardware techniques to reduce the trigger rate from ∼ 100kHz to 200Hz. It forms sums of electromagnetic and hadronic energy, globally and in towers, along with finding the missing transverse energy. A minimum energy is set on these energy sums to pass the event. The Level-2 trigger is a set of software filters, operating in a parallel-processing microvax farm which further reduces the trigger rate to a few Hertz. These filters will reject events which lack electron candidates, jet candidates, or missing transverse energy in the event. The performance of these triggers during the early running of the D0 detector will also be discussed

Structural basis for sequence-specific recognition of DNA by TAL effectors

KAUST Repository

Deng, Dong; Yan, Chuangye; Pan, Xiaojing; Mahfouz, Magdy M.; Wang, Jiawei; Zhu, Jiankang; Shi, Yi Gong; Yan, Nieng

2012-01-01

TAL (transcription activator-like) effectors, secreted by phytopathogenic bacteria, recognize host DNA sequences through a central domain of tandem repeats. Each repeat comprises 33 to 35 conserved amino acids and targets a specific base pair

A general-purpose trigger processor system and its application to fast vertex trigger

International Nuclear Information System (INIS)

Hazumi, M.; Banas, E.; Natkaniec, Z.; Ostrowicz, W.

1997-12-01

A general-purpose hardware trigger system has been developed. The system comprises programmable trigger processors and pattern generator/samplers. The hardware design of the system is described. An application as a prototype of the very fast vertex trigger in an asymmetric B-factory at KEK is also explained. (author)

BTeV Trigger

International Nuclear Information System (INIS)

Gottschalk, Erik E.

2006-01-01

BTeV was designed to conduct precision studies of CP violation in BB-bar events using a forward-geometry detector in a hadron collider. The detector was optimized for high-rate detection of beauty and charm particles produced in collisions between protons and antiprotons. The trigger was designed to take advantage of the main difference between events with beauty and charm particles and more typical hadronic events-the presence of detached beauty and charm decay vertices. The first stage of the BTeV trigger was to receive data from a pixel vertex detector, reconstruct tracks and vertices for every beam crossing, reject at least 98% of beam crossings in which neither beauty nor charm particles were produced, and trigger on beauty events with high efficiency. An overview of the trigger design and its evolution to include commodity networking and computing components is presented

Methodologies for the assessment of earthquake-triggered landslides hazard. A comparison of Logistic Regression and Artificial Neural Network models.

Science.gov (United States)

García-Rodríguez, M. J.; Malpica, J. A.; Benito, B.

2009-04-01

In recent years, interest in landslide hazard assessment studies has increased substantially. They are appropriate for evaluation and mitigation plan development in landslide-prone areas. There are several techniques available for landslide hazard research at a regional scale. Generally, they can be classified in two groups: qualitative and quantitative methods. Most of qualitative methods tend to be subjective, since they depend on expert opinions and represent hazard levels in descriptive terms. On the other hand, quantitative methods are objective and they are commonly used due to the correlation between the instability factors and the location of the landslides. Within this group, statistical approaches and new heuristic techniques based on artificial intelligence (artificial neural network (ANN), fuzzy logic, etc.) provide rigorous analysis to assess landslide hazard over large regions. However, they depend on qualitative and quantitative data, scale, types of movements and characteristic factors used. We analysed and compared an approach for assessing earthquake-triggered landslides hazard using logistic regression (LR) and artificial neural networks (ANN) with a back-propagation learning algorithm. One application has been developed in El Salvador, a country of Central America where the earthquake-triggered landslides are usual phenomena. In a first phase, we analysed the susceptibility and hazard associated to the seismic scenario of the 2001 January 13th earthquake. We calibrated the models using data from the landslide inventory for this scenario. These analyses require input variables representing physical parameters to contribute to the initiation of slope instability, for example, slope gradient, elevation, aspect, mean annual precipitation, lithology, land use, and terrain roughness, while the occurrence or non-occurrence of landslides is considered as dependent variable. The results of the landslide susceptibility analysis are checked using landslide

Development of position control of end-effector for CS-113 robot based on three degree of freedom motions

International Nuclear Information System (INIS)

Iqbal, Muhammad; Setiawan, Widi; Arif, Agus

2003-01-01

A software development for three degrees of freedom motions of CS-113 robot arm has been done. This software, which was based on inverse kinematic, can be used to control position of D and D (decontamination and Dismantlement) robot. A preliminary construction of robot arm (three degrees of freedom) has been constructed also to study the mechanic aspects. The scope of this research consist of direct kinematic and inverse kinematic implementation. The direct kinematic implementation developed according to following steps: (1) assigning kinematic parameters of CS-113 robot arm using Denavit-Hertenberg methods, (2) formulating kinematic equation for all joint. The inverse kinematic implementation developed by transforming position in Cartesian coordinates into joint angle in angle coordinates. Both direct and inverse kinematic were implemented with computer software which is written in the VISUAL BASIC. This software was tested on CS-113 robot. The theoretically calculation was done on MATLAB. Input of direct kinematic were joint angles (5 o , 10 o , -20 o , 15 o , 25 o , 30 o , -50 o , and 60 o ), whereas the input of inverse kinematic were the position on Cartesian coordinate, with the duration for moving end-effector testing 4 seconds. The test results of direct kinematic implementation on CS-113 robot were the position of end-effector on Cartesian coordinates. The position of end-effector which was measured experimentally on CS-113 robot compared with position of end-effector which was calculated on MATLAB. This comparison showed that static performance of CS-113 robot manipulator, bias (systematic error) that different from the end-effector position change within 8,9%, 12,3% and 27,3% on X, Y, Z axes, respectively, the measurements repeatability (precision) of end-effector position were ± 0,031 cm to ±0,183 cm. The test results of inverse kinematic implementation on CS-113 robot showed that the accuracy of end-effector position varied on all axes, the bias

A Novel Meloidogyne incognita Effector Misp12 Suppresses Plant Defense Response at Latter Stages of Nematode Parasitism

Science.gov (United States)

Xie, Jialian; Li, Shaojun; Mo, Chenmi; Wang, Gaofeng; Xiao, Xueqiong; Xiao, Yannong

2016-01-01

Secreted effectors in plant root-knot nematodes (RKNs, or Meloidogyne spp.) play key roles in their parasite processes. Currently identified effectors mainly focus on the early stage of the nematode parasitism. There are only a few reports describing effectors that function in the latter stage. In this study, we identified a potential RKN effector gene, Misp12, that functioned during the latter stage of parasitism. Misp12 was unique in the Meloidogyne spp., and highly conserved in Meloidogyne incognita. It encoded a secretory protein that specifically expressed in the dorsal esophageal gland, and highly up-regulated during the female stages. Transient expression of Misp12-GUS-GFP in onion epidermal cell showed that Misp12 was localized in cytoplast. In addition, in planta RNA interference targeting Misp12 suppressed the expression of Misp12 in nematodes and attenuated parasitic ability of M. incognita. Furthermore, up-regulation of jasmonic acid (JA) and salicylic acid (SA) pathway defense-related genes in the virus-induced silencing of Misp12 plants, and down-regulation of SA pathway defense-related genes in Misp12-expressing plants indicated the gene might be associated with the suppression of the plant defense response. These results demonstrated that the novel nematode effector Misp12 played a critical role at latter parasitism of M. incognita. PMID:27446188

Remotely Triggered Earthquakes Recorded by EarthScope's Transportable Array and Regional Seismic Networks: A Case Study Of Four Large Earthquakes

Science.gov (United States)

Velasco, A. A.; Cerda, I.; Linville, L.; Kilb, D. L.; Pankow, K. L.

2013-05-01

Changes in field stress required to trigger earthquakes have been classified in two basic ways: static and dynamic triggering. Static triggering occurs when an earthquake that releases accumulated strain along a fault stress loads a nearby fault. Dynamic triggering occurs when an earthquake is induced by the passing of seismic waves from a large mainshock located at least two or more fault lengths from the epicenter of the main shock. We investigate details of dynamic triggering using data collected from EarthScope's USArray and regional seismic networks located in the United States. Triggered events are identified using an optimized automated detector based on the ratio of short term to long term average (Antelope software). Following the automated processing, the flagged waveforms are individually analyzed, in both the time and frequency domains, to determine if the increased detection rates correspond to local earthquakes (i.e., potentially remotely triggered aftershocks). Here, we show results using this automated schema applied to data from four large, but characteristically different, earthquakes -- Chile (Mw 8.8 2010), Tokoku-Oki (Mw 9.0 2011), Baja California (Mw 7.2 2010) and Wells Nevada (Mw 6.0 2008). For each of our four mainshocks, the number of detections within the 10 hour time windows span a large range (1 to over 200) and statistically >20% of the waveforms show evidence of anomalous signals following the mainshock. The results will help provide for a better understanding of the physical mechanisms involved in dynamic earthquake triggering and will help identify zones in the continental U.S. that may be more susceptible to dynamic earthquake triggering.

Persistent Salmonella enterica serovar Typhimurium Infection Increases the Susceptibility of Mice to Develop Intestinal Inflammation

Directory of Open Access Journals (Sweden)

Bárbara M. Schultz

2018-05-01

Full Text Available Chronic intestinal inflammations are triggered by genetic and environmental components. However, it remains unclear how specific changes in the microbiota, host immunity, or pathogen exposure could promote the onset and exacerbation of these diseases. Here, we evaluated whether Salmonella enterica serovar Typhimurium (S. Typhimurium infection increases the susceptibility to develop intestinal inflammation in mice. Two mouse models were used to evaluate the impact of S. Typhimurium infection: the chemical induction of colitis by dextran sulfate sodium (DSS and interleukin (IL-10−/− mice, which develop spontaneous intestinal inflammation. We observed that S. Typhimurium infection makes DSS-treated and IL-10−/− mice more susceptible to develop intestinal inflammation. Importantly, this increased susceptibility is associated to the ability of S. Typhimurium to persist in liver and spleen of infected mice, which depends on the virulence proteins secreted by Salmonella Pathogenicity Island 2-encoded type three secretion system (TTSS-2. Although immunization with a live attenuated vaccine resulted in a moderate reduction of the IL-10−/− mice susceptibility to develop intestinal inflammation due to previous S. Typhimurium infection, it did not prevent bacterial persistence. Our results suggest that persistent S. Typhimurium infection may increase the susceptibility of mice to develop inflammation in the intestine, which could be associated with virulence proteins secreted by TTSS-2.

Different Subsets of T Cells, Memory, Effector Functions, and CAR-T Immunotherapy.

Science.gov (United States)

Golubovskaya, Vita; Wu, Lijun

2016-03-15

This review is focused on different subsets of T cells: CD4 and CD8, memory and effector functions, and their role in CAR-T therapy--a cellular adoptive immunotherapy with T cells expressing chimeric antigen receptor. The CAR-T cells recognize tumor antigens and induce cytotoxic activities against tumor cells. Recently, differences in T cell functions and the role of memory and effector T cells were shown to be important in CAR-T cell immunotherapy. The CD4⁺ subsets (Th1, Th2, Th9, Th17, Th22, Treg, and Tfh) and CD8⁺ memory and effector subsets differ in extra-cellular (CD25, CD45RO, CD45RA, CCR-7, L-Selectin [CD62L], etc.); intracellular markers (FOXP3); epigenetic and genetic programs; and metabolic pathways (catabolic or anabolic); and these differences can be modulated to improve CAR-T therapy. In addition, CD4⁺ Treg cells suppress the efficacy of CAR-T cell therapy, and different approaches to overcome this suppression are discussed in this review. Thus, next-generation CAR-T immunotherapy can be improved, based on our knowledge of T cell subsets functions, differentiation, proliferation, and signaling pathways to generate more active CAR-T cells against tumors.

Different Subsets of T Cells, Memory, Effector Functions, and CAR-T Immunotherapy

Directory of Open Access Journals (Sweden)

Vita Golubovskaya

2016-03-01

Full Text Available This review is focused on different subsets of T cells: CD4 and CD8, memory and effector functions, and their role in CAR-T therapy––a cellular adoptive immunotherapy with T cells expressing chimeric antigen receptor. The CAR-T cells recognize tumor antigens and induce cytotoxic activities against tumor cells. Recently, differences in T cell functions and the role of memory and effector T cells were shown to be important in CAR-T cell immunotherapy. The CD4+ subsets (Th1, Th2, Th9, Th17, Th22, Treg, and Tfh and CD8+ memory and effector subsets differ in extra-cellular (CD25, CD45RO, CD45RA, CCR-7, L-Selectin [CD62L], etc.; intracellular markers (FOXP3; epigenetic and genetic programs; and metabolic pathways (catabolic or anabolic; and these differences can be modulated to improve CAR-T therapy. In addition, CD4+ Treg cells suppress the efficacy of CAR-T cell therapy, and different approaches to overcome this suppression are discussed in this review. Thus, next-generation CAR-T immunotherapy can be improved, based on our knowledge of T cell subsets functions, differentiation, proliferation, and signaling pathways to generate more active CAR-T cells against tumors.

Arabidopsis thaliana resistance to fusarium oxysporum 2 implicates tyrosine-sulfated peptide signaling in susceptibility and resistance to root infection.

Directory of Open Access Journals (Sweden)

Yunping Shen

2013-05-01

Full Text Available In the plant Arabidopsis thaliana, multiple quantitative trait loci (QTLs, including RFO2, account for the strong resistance of accession Columbia-0 (Col-0 and relative susceptibility of Taynuilt-0 (Ty-0 to the vascular wilt fungus Fusarium oxysporum forma specialis matthioli. We find that RFO2 corresponds to diversity in receptor-like protein (RLP genes. In Col-0, there is a tandem pair of RLP genes: RFO2/At1g17250 confers resistance while RLP2 does not. In Ty-0, the highly diverged RFO2 locus has one RLP gene conferring weaker resistance. While the endogenous RFO2 makes a modest contribution to resistance, transgenic RFO2 provides strong pathogen-specific resistance. The extracellular leucine-rich repeats (eLRRs in RFO2 and RLP2 are interchangeable for resistance and remarkably similar to eLRRs in the receptor-like kinase PSY1R, which perceives tyrosine-sulfated peptide PSY1. Reduced infection in psy1r and mutants of related phytosulfokine (PSK receptor genes PSKR1 and PSKR2 shows that tyrosine-sulfated peptide signaling promotes susceptibility. The related eLRRs in RFO2 and PSY1R are not interchangeable; and expression of the RLP nPcR, in which eLRRs in RFO2 are replaced with eLRRs in PSY1R, results in constitutive resistance. Counterintuitively, PSY1 signaling suppresses nPcR because psy1r nPcR is lethal. The fact that PSK signaling does not similarly affect nPcR argues that PSY1 signaling directly downregulates the expression of nPcR. Our results support a speculative but intriguing model to explain RFO2's role in resistance. We propose that F. oxysporum produces an effector that inhibits the normal negative feedback regulation of PSY1R, which stabilizes PSY1 signaling and induces susceptibility. However, RFO2, acting as a decoy receptor for PSY1R, is also stabilized by the effector and instead induces host immunity. Overall, the quantitative resistance of RFO2 is reminiscent of the better-studied monogenic resistance traits.

Triggering trigeminal neuralgia

DEFF Research Database (Denmark)

Di Stefano, Giulia; Maarbjerg, Stine; Nurmikko, Turo

2018-01-01

Introduction Although it is widely accepted that facial pain paroxysms triggered by innocuous stimuli constitute a hallmark sign of trigeminal neuralgia, very few studies to date have systematically investigated the role of the triggers involved. In the recently published diagnostic classification...

LHCb Topological Trigger Reoptimization

CERN Document Server

INSPIRE-00400931; Ilten, Philip; Khairullin, Egor; Rogozhnikov, Alex; Ustyuzhanin, Andrey; Williams, Michael

2015-12-23

The main b-physics trigger algorithm used by the LHCb experiment is the so-called topological trigger. The topological trigger selects vertices which are a) detached from the primary proton-proton collision and b) compatible with coming from the decay of a b-hadron. In the LHC Run 1, this trigger, which utilized a custom boosted decision tree algorithm, selected a nearly 100% pure sample of b-hadrons with a typical efficiency of 60-70%; its output was used in about 60% of LHCb papers. This talk presents studies carried out to optimize the topological trigger for LHC Run 2. In particular, we have carried out a detailed comparison of various machine learning classifier algorithms, e.g., AdaBoost, MatrixNet and neural networks. The topological trigger algorithm is designed to select all "interesting" decays of b-hadrons, but cannot be trained on every such decay. Studies have therefore been performed to determine how to optimize the performance of the classification algorithm on decays not used in the training. ...

How to conquer a tomato plant? Fusarium oxysporum effector targets

NARCIS (Netherlands)

de Sain, M.

2016-01-01

Pathogens secrete small proteins, called effectors, to alter the environment in their host to facilitate infection. The causal agent of Fusarium wilt on tomato, Fusarium oxysporum f. sp. lycopersici (Fol), secretes these proteins in the xylem sap of infected plants and hence they have been called

The TOTEM modular trigger system

Energy Technology Data Exchange (ETDEWEB)

Bagliesi, M.G., E-mail: mg.bagliesi@pi.infn.i [University of Siena and INFN Pisa (Italy); Berretti, M.; Cecchi, R.; Greco, V.; Lami, S.; Latino, G.; Oliveri, E.; Pedreschi, E.; Scribano, A.; Spinella, F.; Turini, N. [University of Siena and INFN Pisa (Italy)

2010-05-21

The TOTEM experiment will measure the total cross-section with the luminosity independent method and study elastic and diffractive scattering at the LHC. We are developing a modular trigger system, based on programmable logic, that will select meaningful events within 2.5{mu}s. The trigger algorithm is based on a tree structure in order to obtain information compression. The trigger primitive is generated directly on the readout chip, VFAT, that has a specific fast output that gives low resolution hits information. In two of the TOTEM detectors, Roman Pots and T2, a coincidence chip will perform track recognition directly on the detector readout boards, while for T1 the hits are transferred from the VFATs to the trigger hardware. Starting from more than 2000 bits delivered by the detector electronics, we extract, in a first step, six trigger patterns of 32 LVDS signals each; we build, then, on a dedicated board, a 1-bit (L1) trigger signal for the TOTEM experiment and 16 trigger bits to the CMS experiment global trigger system for future common data taking.

The TOTEM modular trigger system

International Nuclear Information System (INIS)

Bagliesi, M.G.; Berretti, M.; Cecchi, R.; Greco, V.; Lami, S.; Latino, G.; Oliveri, E.; Pedreschi, E.; Scribano, A.; Spinella, F.; Turini, N.

2010-01-01

The TOTEM experiment will measure the total cross-section with the luminosity independent method and study elastic and diffractive scattering at the LHC. We are developing a modular trigger system, based on programmable logic, that will select meaningful events within 2.5μs. The trigger algorithm is based on a tree structure in order to obtain information compression. The trigger primitive is generated directly on the readout chip, VFAT, that has a specific fast output that gives low resolution hits information. In two of the TOTEM detectors, Roman Pots and T2, a coincidence chip will perform track recognition directly on the detector readout boards, while for T1 the hits are transferred from the VFATs to the trigger hardware. Starting from more than 2000 bits delivered by the detector electronics, we extract, in a first step, six trigger patterns of 32 LVDS signals each; we build, then, on a dedicated board, a 1-bit (L1) trigger signal for the TOTEM experiment and 16 trigger bits to the CMS experiment global trigger system for future common data taking.

Full-scale physical model of landslide triggering

Science.gov (United States)

Lora, M.; Camporese, M.; Salandin, P.

2013-12-01

Landslide triggering induced by high-intensity rainfall infiltration in hillslopes is a complex phenomenon that involves hydrological processes operating at different spatio-temporal scales. Empirical methods give rough information about landslide-prone areas, without investigating the theoretical framework needed to achieve an in-depth understanding of the involved physical processes. In this study, we tackle this issue through physical experiments developed in an artificial hillslope realized in the Department of Civil, Environmental and Architectural Engineering of the University of Padua. The structure consists of a reinforced concrete box containing a soil prism with the following maximum dimensions: 3.5 m high, 6 m long, and 2 m wide. In order to analyze and examine the triggered failure state, the experiments are carried out with intensive monitoring of pore water pressure and moisture content response. Subsurface monitoring instruments are installed at several locations and depths to measure downward infiltration and/or a rising groundwater table. We measure the unsaturated soil water pressure as well as positive pore pressures preceding failure in each experiments with six tensiometers. The volumetric water content is determined through six Time Domain Reflectometry probes. Two pressure transducers are located in observation wells to determine the position of the water table in time. Two stream gauges are positioned at the toeslope, for measuring both runoff and subsurface outflow. All data are collected and recorded by an acquisition data system from Campbell Scientific. The artificial hillslope is characterized by well-known and controlled conditions, which are designed to reproduce an ideal set-up susceptible to heavy rainfall landslide. The hydrologic forcing is generated by a rainfall simulator realized with nozzles from Sprying System and. specifically designed to produce a spatially uniform rainfall of intensity ranging from 50 to 150 mm/h. The aim

Orbital maneuvering end effectors

Science.gov (United States)

Myers, W. Neill (Inventor); Forbes, John C. (Inventor); Barnes, Wayne L. (Inventor)

1986-01-01

This invention relates to an end effector device for grasping and maneuvering objects such as berthing handles of a space telescope. The device includes a V-shaped capture window defined as inclined surfaces in parallel face plates which converge toward a retainer recess in which the handle is retained. A pivotal finger (30) meshes with a pair of pivoted fingers which rotate in counterrotation. The fingers rotate to pull a handle within the capture window into recess where latches lock handle in the recess. To align the capture window, plates may be cocked plus or minus five degrees on base. Drive means is included in the form of a motor coupled with a harmonic drive speed reducer, which provides for slow movement of the fingers at a high torque so that large articles may be handled. Novelty of the invention is believed to reside in the combined intermeshing finger structure, drive means and the harmonic drive speed reducer, which features provide the required maneuverability and strength.

LHCb Topological Trigger Reoptimization

International Nuclear Information System (INIS)

Likhomanenko, Tatiana; Khairullin, Egor; Rogozhnikov, Alex; Ustyuzhanin, Andrey; Ilten, Philip; Williams, Michael

2015-01-01

The main b-physics trigger algorithm used by the LHCb experiment is the so- called topological trigger. The topological trigger selects vertices which are a) detached from the primary proton-proton collision and b) compatible with coming from the decay of a b-hadron. In the LHC Run 1, this trigger, which utilized a custom boosted decision tree algorithm, selected a nearly 100% pure sample of b-hadrons with a typical efficiency of 60-70%; its output was used in about 60% of LHCb papers. This talk presents studies carried out to optimize the topological trigger for LHC Run 2. In particular, we have carried out a detailed comparison of various machine learning classifier algorithms, e.g., AdaBoost, MatrixNet and neural networks. The topological trigger algorithm is designed to select all ’interesting” decays of b-hadrons, but cannot be trained on every such decay. Studies have therefore been performed to determine how to optimize the performance of the classification algorithm on decays not used in the training. Methods studied include cascading, ensembling and blending techniques. Furthermore, novel boosting techniques have been implemented that will help reduce systematic uncertainties in Run 2 measurements. We demonstrate that the reoptimized topological trigger is expected to significantly improve on the Run 1 performance for a wide range of b-hadron decays. (paper)

Transcription Factors Encoded on Core and Accessory Chromosomes of Fusarium oxysporum Induce Expression of Effector Genes

Science.gov (United States)

van der Does, H. Charlotte; Schmidt, Sarah M.; Langereis, Léon; Hughes, Timothy R.

2016-01-01

Proteins secreted by pathogens during host colonization largely determine the outcome of pathogen-host interactions and are commonly called ‘effectors’. In fungal plant pathogens, coordinated transcriptional up-regulation of effector genes is a key feature of pathogenesis and effectors are often encoded in genomic regions with distinct repeat content, histone code and rate of evolution. In the tomato pathogen Fusarium oxysporum f. sp. lycopersici (Fol), effector genes reside on one of four accessory chromosomes, known as the ‘pathogenicity’ chromosome, which can be exchanged between strains through horizontal transfer. The three other accessory chromosomes in the Fol reference strain may also be important for virulence towards tomato. Expression of effector genes in Fol is highly up-regulated upon infection and requires Sge1, a transcription factor encoded on the core genome. Interestingly, the pathogenicity chromosome itself contains 13 predicted transcription factor genes and for all except one, there is a homolog on the core genome. We determined DNA binding specificity for nine transcription factors using oligonucleotide arrays. The binding sites for homologous transcription factors were highly similar, suggesting that extensive neofunctionalization of DNA binding specificity has not occurred. Several DNA binding sites are enriched on accessory chromosomes, and expression of FTF1, its core homolog FTF2 and SGE1 from a constitutive promoter can induce expression of effector genes. The DNA binding sites of only these three transcription factors are enriched among genes up-regulated during infection. We further show that Ftf1, Ftf2 and Sge1 can activate transcription from their binding sites in yeast. RNAseq analysis revealed that in strains with constitutive expression of FTF1, FTF2 or SGE1, expression of a similar set of plant-responsive genes on the pathogenicity chromosome is induced, including most effector genes. We conclude that the Fol

ROBOTIC TANK INSPECTION END EFFECTOR

International Nuclear Information System (INIS)

Rachel Landry

1999-01-01

The objective of this contract between Oceaneering Space Systems (OSS) and the Department of Energy (DOE) was to provide a tool for the DOE to inspect the inside tank walls of underground radioactive waste storage tanks in their tank farms. Some of these tanks are suspected to have leaks, but the harsh nature of the environment within the tanks precludes human inspection of tank walls. As a result of these conditions only a few inspection methods can fulfill this task. Of the methods available, OSS chose to pursue Alternating Current Field Measurement (ACFM), because it does not require clean surfaces for inspection, nor any contact with the Surface being inspected, and introduces no extra by-products in the inspection process (no coupling fluids or residues are left behind). The tool produced by OSS is the Robotic Tank Inspection End Effector (RTIEE), which is initially deployed on the tip of the Light Duty Utility Arm (LDUA). The RTEE combines ACFM with a color video camera for both electromagnetic and visual inspection The complete package consists of an end effector, its corresponding electronics and software, and a user's manual to guide the operator through an inspection. The system has both coarse and fine inspection modes and allows the user to catalog defects and suspected areas of leakage in a database for further examination, which may lead to emptying the tank for repair, decommissioning, etc.. The following is an updated report to OSS document OSS-21100-7002, which was submitted in 1995. During the course of the contract, two related sub-tasks arose, the Wall and Coating Thickness Sensor and the Vacuum Scarifying and Sampling Tool Assembly. The first of these sub-tasks was intended to evaluate the corrosion and wall thinning of 55-gallon steel drums. The second was retrieved and characterized the waste material trapped inside the annulus region of the underground tanks on the DOE's tank farms. While these sub-tasks were derived from the original intent

Generation mechanism of RANKL(+) effector memory B cells: relevance to the pathogenesis of rheumatoid arthritis.

Science.gov (United States)

Ota, Yuri; Niiro, Hiroaki; Ota, Shun-Ichiro; Ueki, Naoko; Tsuzuki, Hirofumi; Nakayama, Tsuyoshi; Mishima, Koji; Higashioka, Kazuhiko; Jabbarzadeh-Tabrizi, Siamak; Mitoma, Hiroki; Akahoshi, Mitsuteru; Arinobu, Yojiro; Kukita, Akiko; Yamada, Hisakata; Tsukamoto, Hiroshi; Akashi, Koichi

2016-03-16

The efficacy of B cell-depleting therapies for rheumatoid arthritis underscores antibody-independent functions of effector B cells such as cognate T-B interactions and production of pro-inflammatory cytokines. Receptor activator of nuclear factor κB ligand (RANKL) is a key cytokine involved in bone destruction and is highly expressed in synovial fluid B cells in patients with rheumatoid arthritis. In this study we sought to clarify the generation mechanism of RANKL(+) effector B cells and their impacts on osteoclast differentiation. Peripheral blood and synovial fluid B cells from healthy controls and patients with rheumatoid arthritis were isolated using cell sorter. mRNA expression of RANKL, osteoprotegerin, tumor necrosis factor (TNF)-α, and Blimp-1 was analyzed by quantitative real-time polymerase chain reaction. Levels of RANKL, CD80, CD86, and CXCR3 were analyzed using flow cytometry. Functional analysis of osteoclastogenesis was carried out in the co-culture system using macrophage RAW264 reporter cells. RANKL expression was accentuated in CD80(+)CD86(+) B cells, a highly activated B-cell subset more abundantly observed in patients with rheumatoid arthritis. Upon activation via B-cell receptor and CD40, switched-memory B cells predominantly expressed RANKL, which was further augmented by interferon-γ (IFN-γ) but suppressed by interleukin-21. Strikingly, IFN-γ also enhanced TNF-α expression, while it strongly suppressed osteoprotegerin expression in B cells. IFN-γ increased the generation of CXCR3(+)RANKL(+) effector B cells, mimicking the synovial B cell phenotype in patients with rheumatoid arthritis. Finally, RANKL(+) effector B cells in concert with TNF-α facilitated osteoclast differentiation in vitro. Our current findings have shed light on the generation mechanism of pathogenic RANKL(+) effector B cells that would be an ideal therapeutic target for rheumatoid arthritis in the future.

Limited preemptive scheduling of mixed time-triggered and event-triggered tasks

NARCIS (Netherlands)

Heuvel, van den M.M.H.P.; Bril, R.J.; Zhang, X.; Abdullah, S.M.J.; Isovic, D.

2013-01-01

Many embedded systems have complex timing constraints and, at the same time, have flexibility requirements which prohibit offline planning of the entire system. To support a mixture of time-triggered and event-triggered tasks, some industrial systems deploy a table-driven dispatcher for

Haplotype-based case-control study between human apurinic/apyrimidinic endonuclease 1/redox effector factor-1 gene and cerebral infarction.

Science.gov (United States)

Naganuma, Takahiro; Nakayama, Tomohiro; Sato, Naoyuki; Fu, Zhenyan; Yamaguchi, Mai; Soma, Masayoshi; Aoi, Noriko; Usami, Ron; Doba, Nobutaka; Hinohara, Shigeaki

2009-10-01

The aim of this study was to investigate the relationship between cerebral infarction (CI) and the human apurinic/apyrimidinic endonuclease 1/redox effector factor-1 (APE1/REF-1) gene using single-nucleotide polymorphisms (SNPs) and a haplotype-based case-control study. We selected 5 SNPs in the human APE1/REF1 gene (rs1760944, rs3136814, rs17111967, rs3136817 and rs1130409), and performed case-control studies in 177 CI patients and 309 control subjects. rs17111967 was found to have no heterogeneity in Japanese. The overall distribution of the haplotype-based case-control study constructed by rs1760944, rs3136814 and rs1130409 showed a significant difference. The frequency of the G-C-T haplotype was significantly higher in the CI group than in the control group (2.5% vs. 0.0%, p>0.001). Based on the results of the haplotype-based case-control-study, the G-C-T haplotype may be a genetic marker of CI, and the APE1/REF-1 gene may be a CI susceptibility gene.

System design description for the LDUA common video end effector system (CVEE)

International Nuclear Information System (INIS)

Pardini, A.F.

1998-01-01

The Common Video End Effector System (CVEE), system 62-60, was designed by the Idaho National Engineering Laboratory (INEL) to provide the control interface of the various video end effectors used on the LDUA. The CVEE system consists of a Support Chassis which contains the input and output Opto-22 modules, relays, and power supplies and the Power Chassis which contains the bipolar supply and other power supplies. The combination of the Support Chassis and the Power Chassis make up the CVEE system. The CVEE system is rack mounted in the At Tank Instrument Enclosure (ATIE). Once connected it is controlled using the LDUA supervisory data acquisition system (SDAS). Video and control status will be displayed on monitors within the LDUA control center

The lupus susceptibility gene Pbx1 regulates the balance between follicular helper T cell and regulatory T cell differentiation

Science.gov (United States)

Choi, Seung-Chul; Hutchinson, Tarun E.; Titov, Anton A.; Seay, Howard R.; Li, Shiwu; Brusko, Todd M.; Croker, Byron P.; Salek-Ardakani, Shahram; Morel, Laurence

2016-01-01

Pbx1 controls chromatin accessibility to a large number of genes and is entirely conserved between mice and humans. The Pbx1-d dominant negative isoform is more frequent in the CD4+ T cells from lupus patients than from healthy controls. Pbx1-d is associated with the production of autoreactive T cells in mice carrying the Sle1a1 lupus susceptibility locus. Transgenic expression of Pbx1-d in CD4+ T cells reproduced the phenotypes of Sle1a1 mice, with increased inflammatory functions of CD4+ T cells and impaired regulatory T cell homeostasis. Pbx1-d Tg also expanded the number of follicular helper T cells in a cell-intrinsic and antigen-specific manner that was enhanced in recall responses, and resulted in TH1-biased antibodies. Moreover, Pbx1-d Tg CD4+ T cells upregulated the expression of miR-10a, miR-21 and miR-155, which have been implicated in Treg and TFH cell homeostasis. Our results suggest that Pbx1-d impacts lupus development by regulating effector T cell differentiation and promoting TFH cells at the expense of Treg cells. In addition, our results identify Pbx1 as a novel regulator of CD4+ T cell effector function. PMID:27296664

Headache triggers in the US military.

Science.gov (United States)

Theeler, Brett J; Kenney, Kimbra; Prokhorenko, Olga A; Fideli, Ulgen S; Campbell, William; Erickson, Jay C

2010-05-01

Headaches can be triggered by a variety of factors. Military service members have a high prevalence of headache but the factors triggering headaches in military troops have not been identified. The objective of this study is to determine headache triggers in soldiers and military beneficiaries seeking specialty care for headaches. A total of 172 consecutive US Army soldiers and military dependents (civilians) evaluated at the headache clinics of 2 US Army Medical Centers completed a standardized questionnaire about their headache triggers. A total of 150 (87%) patients were active-duty military members and 22 (13%) patients were civilians. In total, 77% of subjects had migraine; 89% of patients reported at least one headache trigger with a mean of 8.3 triggers per patient. A wide variety of headache triggers was seen with the most common categories being environmental factors (74%), stress (67%), consumption-related factors (60%), and fatigue-related factors (57%). The types of headache triggers identified in active-duty service members were similar to those seen in civilians. Stress-related triggers were significantly more common in soldiers. There were no significant differences in trigger types between soldiers with and without a history of head trauma. Headaches in military service members are triggered mostly by the same factors as in civilians with stress being the most common trigger. Knowledge of headache triggers may be useful for developing strategies that reduce headache occurrence in the military.

p21-ras effector domain mutants constructed by "cassette" mutagenesis

DEFF Research Database (Denmark)

Stone, J C; Vass, W C; Willumsen, B M

1988-01-01

A series of mutations encoding single-amino-acid substitutions within the v-rasH effector domain were constructed, and the ability of the mutants to induce focal transformation of NIH 3T3 cells was studied. The mutations, which spanned codons 32 to 40, were made by a "cassette" mutagenesis...

Silencing of the PiAvr3a effector-encoding gene from Phytophthora infestans by transcriptional fusion to a short interspersed element.

Science.gov (United States)

Vetukuri, Ramesh R; Tian, Zhendong; Avrova, Anna O; Savenkov, Eugene I; Dixelius, Christina; Whisson, Stephen C

2011-12-01

Phytophthora infestans is the notorious oomycete causing late blight of potato and tomato. A large proportion of the P. infestans genome is composed of transposable elements, the activity of which may be controlled by RNA silencing. Accumulation of small RNAs is one of the hallmarks of RNA silencing. Here we demonstrate the presence of small RNAs corresponding to the sequence of a short interspersed retrotransposable element (SINE) suggesting that small RNAs might be involved in silencing of SINEs in P. infestans. This notion was exploited to develop novel tools for gene silencing in P. infestans by engineering transcriptional fusions of the PiAvr3a gene, encoding an RXLR avirulence effector, to the infSINEm retroelement. Transgenic P. infestans lines expressing either 5'-infSINEm::PiAvr3a-3' or 5'-PiAvr3a::SINEm-3' chimeric transcripts initially exhibited partial silencing of PiAvr3a. Over time, PiAvr3a either recovered wild type transcript levels in some lines, or became fully silenced in others. Introduction of an inverted repeat construct was also successful in yielding P. infestans transgenic lines silenced for PiAvr3a. In contrast, constructs expressing antisense or aberrant RNA transcripts failed to initiate silencing of PiAvr3a. Lines exhibiting the most effective silencing of PiAvr3a were either weakly or non-pathogenic on susceptible potato cv. Bintje. This study expands the repertoire of reverse genetics tools available for P. infestans research, and provides insights into a possible mode of variation in effector expression through spread of silencing from adjacent retroelements. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Aminoacyl-tRNA-charged eukaryotic elongation factor 1A is a bona fide substrate for Legionelle pneumophila effector glucosyltransferases

DEFF Research Database (Denmark)

Tzivelekidis, Tina; Jank, Thomas; Pohl, Corinna

2011-01-01

Legionella pneumophila, which is the causative organism of Legionnaires disease, translocates numerous effector proteins into the host cell cytosol by a type IV secretion system during infection. Among the most potent effector proteins of Legionella are glucosyltransferases (Lgt’s), which...

The LHCb trigger

CERN Document Server

Hernando Morata, Jose Angel

2006-01-01

The LHCb experiment relies on an efficient trigger to select a rate up to 2 kHz of events useful for physics analysis from an initial rate of 10 MHz of visible collisions. In this contribution, we describe the different LHCb trigger algorithms and present their expected performance.

The Verticillium-specific protein VdSCP7 localizes to the plant nucleus and modulates immunity to fungal infections.

Science.gov (United States)

Zhang, Lisha; Ni, Hao; Du, Xuan; Wang, Sheng; Ma, Xiao-Wei; Nürnberger, Thorsten; Guo, Hui-Shan; Hua, Chenlei

2017-07-01

Fungal pathogens secrete effector proteins to suppress plant basal defense for successful colonization. Resistant plants, however, can recognize effectors by cognate R proteins to induce effector-triggered immunity (ETI). By analyzing secretomes of the vascular fungal pathogen Verticillium dahliae, we identified a novel secreted protein VdSCP7 that targets the plant nucleus. The green fluorescent protein (GFP)-tagged VdSCP7 gene with either a mutated nuclear localization signal motif or with additional nuclear export signal was transiently expressed in Nicotiana benthamiana, and investigated for induction of plant immunity. The role of VdSCP7 in V. dahliae pathogenicity was characterized by gene knockout and complementation, and GFP labeling. Expression of the VdSCP7 gene in N. benthamiana activated both salicylic acid and jasmonate signaling, and altered the plant's susceptibility to the pathogens Botrytis cinerea and Phytophthora capsici. The immune response activated by VdSCP7 was highly dependent on its initial extracellular secretion and subsequent nuclear localization in plants. Knockout of the VdSCP7 gene significantly enhanced V. dahliae aggressiveness on cotton. GFP-labeled VdSCP7 is secreted by V. dahliae and accumulates in the plant nucleus. We conclude that VdSCP7 is a novel effector protein that targets the host nucleus to modulate plant immunity, and suggest that plants can recognize VdSCP7 to activate ETI during fungal infection. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

The ATLAS High Level Trigger Steering Framework and the Trigger 
Configuration System.

CERN Document Server

Pérez Cavalcanti, Tiago; The ATLAS collaboration

2011-01-01

The ATLAS High Level Trigger Steering Framework and the Trigger 
Configuration System.
 
The ATLAS detector system installed in the Large Hadron Collider (LHC) 
at CERN is designed to study proton-proton and nucleus-nucleus 
collisions with a maximum center of mass energy of 14 TeV at a bunch 
collision rate of 40MHz.  In March 2010 the four LHC experiments saw 
the first proton-proton collisions at 7 TeV. Still within the year a 
collision rate of nearly 10 MHz is expected. At ATLAS, events of 
potential interest for ATLAS physics are selected by a three-level 
trigger system, with a final recording rate of about 200 Hz. The first 
level (L1) is implemented in custom hardware; the two levels of 
the high level trigger (HLT) are software triggers, running on large 
farms of standard computers and network devices. 

Within the ATLAS physics program more than 500 trigger signatures are 
defined. The HLT tests each signature on each L1-accepted event; the 
test outcome is recor...

Functional differences between PD-1+ and PD-1- CD4+ effector T cells in healthy donors and patients with glioblastoma multiforme.

Directory of Open Access Journals (Sweden)

Brittany A Goods

Full Text Available Immune checkpoint inhibitors targeting programmed cell death protein 1 (PD-1 have been highly successful in the treatment of cancer. While PD-1 expression has been widely investigated, its role in CD4+ effector T cells in the setting of health and cancer remains unclear, particularly in the setting of glioblastoma multiforme (GBM, the most aggressive and common form of brain cancer. We examined the functional and molecular features of PD-1+CD4+CD25-CD127+Foxp3-effector cells in healthy subjects and in patients with GBM. In healthy subjects, we found that PD-1+CD4+ effector cells are dysfunctional: they do not proliferate but can secrete large quantities of IFNγ. Strikingly, blocking antibodies against PD-1 did not rescue proliferation. RNA-sequencing revealed features of exhaustion in PD-1+ CD4 effectors. In the context of GBM, tumors were enriched in PD-1+ CD4+ effectors that were similarly dysfunctional and unable to proliferate. Furthermore, we found enrichment of PD-1+TIM-3+ CD4+ effectors in tumors, suggesting that co-blockade of PD-1 and TIM-3 in GBM may be therapeutically beneficial. RNA-sequencing of blood and tumors from GBM patients revealed distinct differences between CD4+ effectors from both compartments with enrichment in multiple gene sets from tumor infiltrating PD-1-CD4+ effectors cells. Enrichment of these gene sets in tumor suggests a more metabolically active cell state with signaling through other co-receptors. PD-1 expression on CD4 cells identifies a dysfunctional subset refractory to rescue with PD-1 blocking antibodies, suggesting that the influence of immune checkpoint inhibitors may involve recovery of function in the PD-1-CD4+ T cell compartment. Additionally, co-blockade of PD-1 and TIM-3 in GBM may be therapeutically beneficial.

Phosphoinositide 3-kinase/Akt signalling is responsible for the differential susceptibility of myoblasts and myotubes to menadione-induced oxidative stress.

Science.gov (United States)

Lim, Jeong A; Woo, Joo Hong; Kim, Hye Sun

2008-09-01

In this study, it was found that undifferentiated myoblasts were more vulnerable to menadione-induced oxidative stress than differentiated myotubes. Cell death occurred with a relatively low concentration of menadione in myoblasts compared to myotubes. With the same concentration of menadione, the Bcl-2/Bax ratio decreased and nuclei containing condensed chromatin were observed in myoblasts to a greater extent than in myotubes. However, myotubes became increasingly susceptible to menadione when phosphoinositide 3-kinase (PI3-K) was blocked by pre-incubation with LY294002, a PI3-K inhibitor. Actually, PI3-K activity was reduced by menadione in myoblasts but not in myotubes. In addition, the phosphorylation of Akt, a downstream effector of PI3-K, was inhibited in myoblasts by menadione but increased in myotubes. Both LY294002 and API-2, an Akt inhibitor, decreased the Bcl-2/Bax ratio in menadione-exposed myotubes. These results suggest that the differential activity of PI3-K/Akt signalling is responsible for the differential susceptibility of myoblasts and myotubes to menadione-induced oxidative stress.

The ATLAS trigger: high-level trigger commissioning and operation during early data taking

International Nuclear Information System (INIS)

Goncalo, R

2008-01-01

The ATLAS experiment is one of the two general-purpose experiments due to start operation soon at the Large Hadron Collider (LHC). The LHC will collide protons at a centre of mass energy of 14 TeV, with a bunch-crossing rate of 40 MHz. The ATLAS three-level trigger will reduce this input rate to match the foreseen offline storage capability of 100-200 Hz. This paper gives an overview of the ATLAS High Level Trigger focusing on the system design and its innovative features. We then present the ATLAS trigger strategy for the initial phase of LHC exploitation. Finally, we report on the valuable experience acquired through in-situ commissioning of the system where simulated events were used to exercise the trigger chain. In particular we show critical quantities such as event processing times, measured in a large-scale HLT farm using a complex trigger menu

Macrophages are critical effectors of antibody therapies for cancer.

Science.gov (United States)

Weiskopf, Kipp; Weissman, Irving L

2015-01-01

Macrophages are innate immune cells that derive from circulating monocytes, reside in all tissues, and participate in many states of pathology. Macrophages play a dichotomous role in cancer, where they promote tumor growth but also serve as critical immune effectors of therapeutic antibodies. Macrophages express all classes of Fcγ receptors, and they have immense potential to destroy tumors via the process of antibody-dependent phagocytosis. A number of studies have demonstrated that macrophage phagocytosis is a major mechanism of action of many antibodies approved to treat cancer. Consequently, a number of approaches to augment macrophage responses to therapeutic antibodies are under investigation, including the exploration of new targets and development of antibodies with enhanced functions. For example, the interaction of CD47 with signal-regulatory protein α (SIRPα) serves as a myeloid-specific immune checkpoint that limits the response of macrophages to antibody therapies, and CD47-blocking agents overcome this barrier to augment phagocytosis. The response of macrophages to antibody therapies can also be enhanced with engineered Fc variants, bispecific antibodies, or antibody-drug conjugates. Macrophages have demonstrated success as effectors of cancer immunotherapy, and further investigation will unlock their full potential for the benefit of patients.

The trigger supervisor: Managing triggering conditions in a high energy physics experiment

International Nuclear Information System (INIS)

Wadsworth, B.; Lanza, R.; LeVine, M.J.; Scheetz, R.A.; Videbaek, F.

1987-01-01

A trigger supervisor, implemented in VME-bus hardware, is described, which enables the host computer to dynamically control and monitor the trigger configuration for acquiring data from multiple detector partitions in a complex experiment

Cancer resistance of SR/CR mice in the genetic knockout backgrounds of leukocyte effector mechanisms: determinations for functional requirements.

Science.gov (United States)

Sanders, Anne M; Stehle, John R; Blanks, Michael J; Riedlinger, Gregory; Kim-Shapiro, Jung W; Monjazeb, Arta M; Adams, Jonathan M; Willingham, Mark C; Cui, Zheng

2010-03-31

Spontaneous Regression/Complete Resistant (SR/CR) mice are a colony of cancer-resistant mice that can detect and rapidly destroy malignant cells with innate cellular immunity, predominately mediated by granulocytes. Our previous studies suggest that several effector mechanisms, such as perforin, granzymes, or complements, may be involved in the killing of cancer cells. However, none of these effector mechanisms is known as critical for granulocytes. Additionally, it is unclear which effector mechanisms are required for the cancer killing activity of specific leukocyte populations and the survival of SR/CR mice against the challenges of lethal cancer cells. We hypothesized that if any of these effector mechanisms was required for the resistance to cancer cells, its functional knockout in SR/CR mice should render them sensitive to cancer challenges. This was tested by cross breeding SR/CR mice into the individual genetic knockout backgrounds of perforin (Prf-/-), superoxide (Cybb-/), or inducible nitric oxide (Nos2-/). SR/CR mice were bred into individual Prf-/-, Cybb-/-, or Nos2-/- genetic backgrounds and then challenged with sarcoma 180 (S180). Their overall survival was compared to controls. The cancer killing efficiency of purified populations of macrophages and neutrophils from these immunodeficient mice was also examined. When these genetically engineered mice were challenged with cancer cells, the knockout backgrounds of Prf-/-, Cybb-/-, or Nos2-/- did not completely abolish the SR/CR cancer resistant phenotype. However, the Nos2-/- background did appear to weaken the resistance. Incidentally, it was also observed that the male mice in these immunocompromised backgrounds tended to be less cancer-resistant than SR/CR controls. Despite the previously known roles of perforin, superoxide or nitric oxide in the effector mechanisms of innate immune responses, these effector mechanisms were not required for cancer-resistance in SR/CR mice. The resistance was

Susceptibility-Weighted Imaging and Quantitative Susceptibility Mapping in the Brain

Science.gov (United States)

Liu, Chunlei; Li, Wei; Tong, Karen A.; Yeom, Kristen W.; Kuzminski, Samuel

2015-01-01

Susceptibility-weighted imaging (SWI) is a magnetic resonance imaging (MRI) technique that enhances image contrast by using the susceptibility differences between tissues. It is created by combining both magnitude and phase in the gradient echo data. SWI is sensitive to both paramagnetic and diamagnetic substances which generate different phase shift in MRI data. SWI images can be displayed as a minimum intensity projection that provides high resolution delineation of the cerebral venous architecture, a feature that is not available in other MRI techniques. As such, SWI has been widely applied to diagnose various venous abnormalities. SWI is especially sensitive to deoxygenated blood and intracranial mineral deposition and, for that reason, has been applied to image various pathologies including intracranial hemorrhage, traumatic brain injury, stroke, neoplasm, and multiple sclerosis. SWI, however, does not provide quantitative measures of magnetic susceptibility. This limitation is currently being addressed with the development of quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI). While QSM treats susceptibility as isotropic, STI treats susceptibility as generally anisotropic characterized by a tensor quantity. This article reviews the basic principles of SWI, its clinical and research applications, the mechanisms governing brain susceptibility properties, and its practical implementation, with a focus on brain imaging. PMID:25270052

Susceptibility-weighted imaging and quantitative susceptibility mapping in the brain.

Science.gov (United States)

Liu, Chunlei; Li, Wei; Tong, Karen A; Yeom, Kristen W; Kuzminski, Samuel

2015-07-01

Susceptibility-weighted imaging (SWI) is a magnetic resonance imaging (MRI) technique that enhances image contrast by using the susceptibility differences between tissues. It is created by combining both magnitude and phase in the gradient echo data. SWI is sensitive to both paramagnetic and diamagnetic substances which generate different phase shift in MRI data. SWI images can be displayed as a minimum intensity projection that provides high resolution delineation of the cerebral venous architecture, a feature that is not available in other MRI techniques. As such, SWI has been widely applied to diagnose various venous abnormalities. SWI is especially sensitive to deoxygenated blood and intracranial mineral deposition and, for that reason, has been applied to image various pathologies including intracranial hemorrhage, traumatic brain injury, stroke, neoplasm, and multiple sclerosis. SWI, however, does not provide quantitative measures of magnetic susceptibility. This limitation is currently being addressed with the development of quantitative susceptibility mapping (QSM) and susceptibility tensor imaging (STI). While QSM treats susceptibility as isotropic, STI treats susceptibility as generally anisotropic characterized by a tensor quantity. This article reviews the basic principles of SWI, its clinical and research applications, the mechanisms governing brain susceptibility properties, and its practical implementation, with a focus on brain imaging. © 2014 Wiley Periodicals, Inc.

Exocarp Properties and Transcriptomic Analysis of Cucumber (Cucumis sativus) Fruit Expressing Age-Related Resistance to Phytophthora capsici.

Science.gov (United States)

Ando, Kaori; Carr, Kevin M; Colle, Marivi; Mansfeld, Ben N; Grumet, Rebecca

2015-01-01

Very young cucumber (Cucumis sativus) fruit are highly susceptible to infection by the oomycete pathogen, Phytophthora capsici. As the fruit complete exponential growth, at approximately 10-12 days post pollination (dpp), they transition to resistance. The development of age-related resistance (ARR) is increasingly recognized as an important defense against pathogens, however, underlying mechanisms are largely unknown. Peel sections from cucumber fruit harvested at 8 dpp (susceptible) and 16 dpp (resistant) showed equivalent responses to inoculation as did whole fruit, indicating that the fruit surface plays an important role in defense against P. capsici. Exocarp from 16 dpp fruit had thicker cuticles, and methanolic extracts of peel tissue inhibited growth of P. capsici in vitro, suggesting physical or chemical components to the ARR. Transcripts specifically expressed in the peel vs. pericarp showed functional differentiation. Transcripts predominantly expressed in the peel were consistent with fruit surface associated functions including photosynthesis, cuticle production, response to the environment, and defense. Peel-specific transcripts that exhibited increased expression in 16 dpp fruit relative to 8 dpp fruit, were highly enriched (Pfunctions. Specific transcripts included genes associated with potential physical barriers (i.e., cuticle), chemical defenses (flavonoid biosynthesis), oxidative stress, penetration defense, and molecular pattern (MAMP)-triggered or effector-triggered (R-gene mediated) pathways. The developmentally regulated changes in gene expression between peels from susceptible- and resistant- age fruits suggest programming for increased defense as the organ reaches full size.

Landslide susceptibility mapping in the coastal region in the State of São Paulo, Brazil

Science.gov (United States)

Alvala, R. C.; Camarinha, P. I.; Canavesi, V.

2013-05-01

The exposure of populations in risk areas is a matter of global concern, because it is a determining factor for the natural disasters occurrences. Furthermore, it has also been observed an intensification of extreme hydrometeorological events that has triggered disasters in various parts of the globe, further increasing the need for monitoring and alerting for natural disasters, aiming the safeguarding of life and minimize economic losses. Accordingly, different methodologies for risk assessment have been proposed, focusing on the specific natural hazards. Particularly for Brazil, which has economic axis of development in the regions near the coast, it is common to observe the process of urbanization advancing on steep slopes of the mountain regions. This characteristic causes the population exposure to the natural hazards related to the mass movements, which the landslides stood out as the cause of many deaths and economic losses every year. Thus, prior to risk analysis (when human occupation intersect with natural hazard), it is essential to analyze the susceptibility, which reflects the physical and environmental conditions that trigger for such phenomena. However, this task becomes a major challenge due to the difficulty of finding databases with good quality. In this context, this paper presents a methodology based only on spatial information in the public domain, integrated into a Geographic Information System free, in order to analyze the landslides susceptibility. In a first effort, we evaluated four counties of Southeastern Brazil - Santos, Cubatão, Caraguatatuba and Ubatuba - located in a region that includes the rugged reliefs of Serra do Mar and the transition to the coastal region, that have historic of disasters related. It is noteworthy that the methodology takes into account many variables that was weighted and crossed by Fuzzy Gamma technique, such as: topography (horizontal and vertical curvature of the slopes), geology, geomorphology, slope

Regional landslide susceptibility assessment using multi-stage remote sensing data along the coastal range highway in northeastern Taiwan

Science.gov (United States)

Lee, Ching-Fang; Huang, Wei-Kai; Chang, Yu-Lin; Chi, Shu-Yeong; Liao, Wu-Chang

2018-01-01

Typhoons Megi (2010) and Saola (2012) brought torrential rainfall which triggered regional landslides and flooding hazards along Provincial Highway No. 9 in northeastern Taiwan. To reduce property loss and saving lives, this study combines multi-hazard susceptibility assessment with environmental geology map a rock mass rating system (RMR), remote sensing analysis, and micro-topography interpretation to develop an integrated landslide hazard assessment approach and reflect the intrinsic state of slopeland from the past toward the future. First, the degree of hazard as indicated by historical landslides was used to determine many landslide regions in the past. Secondly, geo-mechanical classification of rock outcroppings was performed by in-situ investigation along the vulnerable road sections. Finally, a high-resolution digital elevation model was extracted from airborne LiDAR and multi-temporal remote sensing images which was analyzed to discover possible catastrophic landslide hotspot shortly. The results of the analysis showed that 37% of the road sections in the study area were highly susceptible to landslide hazards. The spatial distribution of the road sections revealed that those characterized by high susceptibility were located near the boundaries of fault zones and in areas of lithologic dissimilarity. Headward erosion of gullies and concave-shaped topographic features had an adverse effect and was the dominant factor triggering landslides. Regional landslide reactivation on this coastal highway are almost related to the past landslide region based on hazard statistics. The final results of field validation demonstrated that an accuracy of 91% could be achieved for forecasting geohazard followed by intense rainfall events and typhoons.

Natural killer cell biology illuminated by primary immunodeficiency syndromes in humans.

Science.gov (United States)

Voss, Matthias; Bryceson, Yenan T

2017-04-01

Natural killer (NK) cells are innate immune cytotoxic effector cells well known for their role in antiviral immunity and tumor immunosurveillance. In parts, this knowledge stems from rare inherited immunodeficiency disorders in humans that abrogate NK cell function leading to immune impairments, most notably associated with a high susceptibility to viral infections. Phenotypically, these disorders range from deficiencies selectively affecting NK cells to complex general immune defects that affect NK cells but also other immune cell subsets. Moreover, deficiencies may be associated with reduced NK cell numbers or rather impair specific NK cell effector functions. In recent years, genetic defects underlying the various NK cell deficiencies have been uncovered and have triggered investigative efforts to decipher the molecular mechanisms underlying these disorders. Here we review the associations between inherited human diseases and NK cell development as well as function, with a particular focus on defects in NK cell exocytosis and cytotoxicity. Furthermore we outline how reports of diverse genetic defects have shaped our understanding of NK cell biology. Copyright © 2015. Published by Elsevier Inc.

The ATLAS Muon and Tau Trigger

CERN Document Server

Dell'Asta, L; The ATLAS collaboration

2013-01-01

[Muon] The ATLAS experiment at CERN's Large Hadron Collider (LHC) deploys a three-levels processing scheme for the trigger system. The level-1 muon trigger system gets its input from fast muon trigger detectors. Fast sector logic boards select muon candidates, which are passed via an interface board to the central trigger processor and then to the High Level Trigger (HLT). The muon HLT is purely software based and encompasses a level-2 (L2) trigger followed by an event filter (EF) for a staged trigger approach. It has access to the data of the precision muon detectors and other detector elements to refine the muon hypothesis. Trigger-specific algorithms were developed and are used for the L2 to increase processing speed for instance by making use of look-up tables and simpler algorithms, while the EF muon triggers mostly benefit from offline reconstruction software to obtain most precise determination of the track parameters. There are two algorithms with different approaches, namely inside-out and outside-in...

Performance of the ATLAS Muon Trigger and Phase-1 Upgrade of Level-1 Endcap Muon Trigger

CERN Document Server

Mizukami, Atsushi; The ATLAS collaboration

2017-01-01

The ATLAS experiment utilises a trigger system to efficiently record interesting events. It consists of first-level and high-level triggers. The first-level trigger is implemented with custom-built hardware to reduce the event rate from 40 MHz to100 kHz. Then the software-based high-level triggers refine the trigger decisions reducing the output rate down to 1 kHz. Events with muons in the final state are an important signature for many physics topics at the LHC. An efficient trigger on muons and a detailed understanding of its performance are required. Trigger efficiencies are, for example, obtained from the muon decay of Z boson, with a Tag&Probe method, using proton-proton collision data collected in 2016 at a centre-of-mass energy of 13 TeV. The LHC is expected to increase its instantaneous luminosity to $3\\times10^{34} \\rm{cm^{-2}s^{-1}}$ after the phase-1 upgrade between 2018-2020. The upgrade of the ATLAS trigger system is mandatory to cope with this high-luminosity. In the phase-1 upgrade, new det...

ULtiMATE system for rapid assembly of customized TAL effectors.

Directory of Open Access Journals (Sweden)

Junjiao Yang

Full Text Available Engineered TAL-effector nucleases (TALENs and TALE-based constructs have become powerful tools for eukaryotic genome editing. Although many methods have been reported, it remains a challenge for the assembly of designer-based TALE repeats in a fast, precise and cost-effective manner. We present an ULtiMATE (USER-based Ligation Mediated Assembly of TAL Effector system for speedy and accurate assembly of customized TALE constructs. This method takes advantage of uracil-specific excision reagent (USER to create multiple distinct sticky ends between any neighboring DNA fragments for specific ligation. With pre-assembled templates, multiple TALE DNA-binding domains could be efficiently assembled in order within hours with minimal manual operation. This system has been demonstrated to produce both functional TALENs for effective gene knockout and TALE-mediated gene-specific transcription activation (TALE-TA. The feature of both ease-of-operation and high efficiency of ULtiMATE system makes it not only an ideal method for biologic labs, but also an approach well suited for large-scale assembly of TALENs and any other TALE-based constructions.

Effect of long-term voluntary exercise wheel running on susceptibility to bacterial pulmonary infections in a mouse model.

Directory of Open Access Journals (Sweden)

Pauline B van de Weert-van Leeuwen

Full Text Available Regular moderate exercise has been suggested to exert anti-inflammatory effects and improve immune effector functions, resulting in reduced disease incidence and viral infection susceptibility. Whether regular exercise also affects bacterial infection susceptibility is unknown. The aim of this study was to investigate whether regular voluntary exercise wheel running prior to a pulmonary infection with bacteria (P. aeruginosa affects lung bacteriology, sickness severity and phagocyte immune function in mice. Balb/c mice were randomly placed in a cage with or without a running wheel. After 28 days, mice were intranasally infected with P. aeruginosa. Our study showed that regular exercise resulted in a higher sickness severity score and bacterial (P. aeruginosa loads in the lungs. The phagocytic capacity of monocytes and neutrophils from spleen and lungs was not affected. Although regular moderate exercise has many health benefits, healthy mice showed increased bacterial (P. aeruginosa load and symptoms, after regular voluntary exercise, with perseverance of the phagocytic capacity of monocytes and neutrophils. Whether patients, suffering from bacterial infectious diseases, should be encouraged to engage in exercise and physical activities with caution requires further research.

DUMAND data acquisition with triggering

International Nuclear Information System (INIS)

Brenner, A.E.; Theriot, D.; March, R.H.

1980-01-01

A data acquisition scheme for the standard DUMAND array that includes a simple triggering scheme as a fundamental part of the system is presented. Although there are a number of not yet fully understood parameters, it is assumed that thresholds can be set in such a manner as to give rise to a triggered signal that is not so dominated by randoms that it gives a substantial decrease in the data acquisition rate over that which would be required by a nontriggered system. It is also assumed that the triggering logic is relatively simple and does not need major computational capabilities for a trigger logic decision. With these assumptions, it is possible to generate the trigger at the array and restrict the data transfer to shore. However, with a not unreasonable delay of 200 microseconds, it is even possible to transmit the information for the trigger to shore and perform all that logic on the shore. The critical point is to send the minimum amount of information necessary to construct the trigger such that one need not send all the possible information in all detectors of the array continuously to shore. 1 figure

A molecular threshold for effector CD8(+) T cell differentiation controlled by transcription factors Blimp-1 and T-bet.

Science.gov (United States)

Xin, Annie; Masson, Frederick; Liao, Yang; Preston, Simon; Guan, Tianxia; Gloury, Renee; Olshansky, Moshe; Lin, Jian-Xin; Li, Peng; Speed, Terence P; Smyth, Gordon K; Ernst, Matthias; Leonard, Warren J; Pellegrini, Marc; Kaech, Susan M; Nutt, Stephen L; Shi, Wei; Belz, Gabrielle T; Kallies, Axel

2016-04-01

T cell responses are guided by cytokines that induce transcriptional regulators, which ultimately control differentiation of effector and memory T cells. However, it is unknown how the activities of these molecular regulators are coordinated and integrated during the differentiation process. Using genetic approaches and transcriptional profiling of antigen-specific CD8(+) T cells, we reveal a common program of effector differentiation that is regulated by IL-2 and IL-12 signaling and the combined activities of the transcriptional regulators Blimp-1 and T-bet. The loss of both T-bet and Blimp-1 leads to abrogated cytotoxic function and ectopic IL-17 production in CD8(+) T cells. Overall, our data reveal two major overlapping pathways of effector differentiation governed by the availability of Blimp-1 and T-bet and suggest a model for cytokine-induced transcriptional changes that combine, quantitatively and qualitatively, to promote robust effector CD8(+) T cell differentiation.

Triggers, Inhibitors, Mechanisms, and Significance of Eryptosis: The Suicidal Erythrocyte Death

Directory of Open Access Journals (Sweden)

Elisabeth Lang

2015-01-01

Full Text Available Suicidal erythrocyte death or eryptosis is characterized by erythrocyte shrinkage, cell membrane blebbing, and cell membrane scrambling with phosphatidylserine translocation to the erythrocyte surface. Triggers of eryptosis include Ca2+ entry, ceramide formation, stimulation of caspases, calpain activation, energy depletion, oxidative stress, and dysregulation of several kinases. Eryptosis is triggered by a wide variety of xenobiotics. It is inhibited by several xenobiotics and endogenous molecules including NO and erythropoietin. The susceptibility of erythrocytes to eryptosis increases with erythrocyte age. Phosphatidylserine exposing erythrocytes adhere to the vascular wall by binding to endothelial CXC-Motiv-Chemokin-16/Scavenger-receptor for phosphatidylserine and oxidized low density lipoprotein (CXCL16. Phosphatidylserine exposing erythrocytes are further engulfed by phagocytosing cells and are thus rapidly cleared from circulating blood. Eryptosis eliminates infected or defective erythrocytes thus counteracting parasitemia in malaria and preventing detrimental hemolysis of defective cells. Excessive eryptosis, however, may lead to anemia and may interfere with microcirculation. Enhanced eryptosis contributes to the pathophysiology of several clinical disorders including metabolic syndrome and diabetes, malignancy, cardiac and renal insufficiency, hemolytic uremic syndrome, sepsis, mycoplasma infection, malaria, iron deficiency, sickle cell anemia, thalassemia, glucose 6-phosphate dehydrogenase deficiency, and Wilson’s disease. Facilitating or inhibiting eryptosis may be a therapeutic option in those disorders.

Bio-effectors from waste materials as growth promoters, an agronomic and metabolomic study

Science.gov (United States)

Alwanney, Deaa; Chami, Ziad Al; Angelica De Pascali, Sandra; Cavoski, Ivana; Fanizzi, Francesco Paolo

2014-05-01

Nowadays, improving plant performance by providing growth promoters is a main concern of the organic agriculture. As a consequence of increased food demands, more efficient and alternatives of the current plant nutrition strategies are becoming urgent. Recently, a novel concept "bio-effectors" raised on to describe a group of products that are able to improve plant performance and do not belong to fertilizers or pesticides. Agro-Food processing residues are promising materials as bio-effector. Three plant-derived materials: brewers' spent grain (BSG), fennel processing residues (FPR) and lemon processing residues (LPR) were chosen as bio-effector candidates. Plant-derived materials were characterized in term of total macro and micronutrients content. Green extraction methodology and solvent choice (aqueous; ethanol; and aqueous: ethanol mixture 1:1) was based on the extraction yield as main factor. Optimum extracts, to be used on the tomato test plant, were determined using phytotoxicity test (seed germination test) as main constraint. Thereafter, selected extracts were characterized and secondary metabolites profiling were detected by NMR technique. Selected extracts were applied on tomato in a growth chamber at different doses in comparison to humic-like substances as positive control (Ctrl+) and to a Hoagland solution as negative control (Ctrl-). At the end of the experiment, agronomical parameters were determined and NMR-metabolomic profiling were conducted on tomato seedlings. Results are summarized as follow: (i) raw showed an interesting content, either at nutritional or biological level; (ii) aqueous extraction resulted higher yield than other used solvent; (iii) at high extraction ratio (1:25 for BSG; 1:100 for FPR; and 1:200 for LPR) aqueous extracts were not phytotoxic on the tomato test plant; (iv) all aqueous extract are differently rich in nutrients, aminoacids, sugars and low molecular weight molecules; (v) all extract exhibited a growth promotion at

The ATLAS hadronic tau trigger

CERN Document Server

Black, C; The ATLAS collaboration

2012-01-01

With the high luminosities of proton-proton collisions achieved at the LHC, the strategies for triggering have become more important than ever for physics analysis. The naive inclusive single tau lepton triggers now suffer from severe rate limitations. To allow for a large program of physics analyses with taus, the development of topological triggers that combine tau signatures with other measured quantities in the event is required. These combined triggers open many opportunities to study new physics beyond the Standard Model and to search for the Standard Model Higgs. We present the status and performance of the hadronic tau trigger in ATLAS. We demonstrate that the ATLAS tau trigger ran remarkably well over 2011, and how the lessons learned from 2011 led to numerous improvements in the preparation of the 2012 run. These improvements include the introduction of tau selection criteria that are robust against varying pileup scenarios, and the implementation of multivariate selection techniques in the tau trig...

The ATLAS hadronic tau trigger

CERN Document Server

Black, C; The ATLAS collaboration

2012-01-01

With the high luminosities of proton-proton collisions achieved at the LHC, the strategies for triggering have become more important than ever for physics analysis. The naïve inclusive single tau lepton triggers now suffer from severe rate limitations. To allow for a large program of physics analyses with taus, the development of topological triggers that combine tau signatures with other measured quantities in the event is required. These combined triggers open many opportunities to study new physics beyond the Standard Model and to search for the Standard Model Higgs. We present the status and performance of the hadronic tau trigger in ATLAS. We demonstrate that the ATLAS tau trigger ran remarkably well over 2011, and how the lessons learned from 2011 led to numerous improvements in the preparation of the 2012 run. These improvements include the introduction of tau selection criteria that are robust against varying pileup scenarios, and the implementation of multivariate selection techniques in the tau tri...

Bacterial Effectors and Their Functions in the Ubiquitin-Proteasome System: Insight from the Modes of Substrate Recognition

Directory of Open Access Journals (Sweden)

Minsoo Kim

2014-08-01

Full Text Available Protein ubiquitination plays indispensable roles in the regulation of cell homeostasis and pathogenesis of neoplastic, infectious, and neurodegenerative diseases. Given the importance of this modification, it is to be expected that several pathogenic bacteria have developed the ability to utilize the host ubiquitin system for their own benefit. Modulation of the host ubiquitin system by bacterial effector proteins inhibits innate immune responses and hijacks central signaling pathways. Bacterial effectors mimic enzymes of the host ubiquitin system, but may or may not be structurally similar to the mammalian enzymes. Other effectors bind and modify components of the host ubiquitin system, and some are themselves subject to ubiquitination. This review will describe recent findings, based on structural analyses, regarding how pathogens use post-translational modifications of proteins to establish an infection.

Bacterial effectors and their functions in the ubiquitin-proteasome system: insight from the modes of substrate recognition.

Science.gov (United States)

Kim, Minsoo; Otsubo, Ryota; Morikawa, Hanako; Nishide, Akira; Takagi, Kenji; Sasakawa, Chihiro; Mizushima, Tsunehiro

2014-08-18

Protein ubiquitination plays indispensable roles in the regulation of cell homeostasis and pathogenesis of neoplastic, infectious, and neurodegenerative diseases. Given the importance of this modification, it is to be expected that several pathogenic bacteria have developed the ability to utilize the host ubiquitin system for their own benefit. Modulation of the host ubiquitin system by bacterial effector proteins inhibits innate immune responses and hijacks central signaling pathways. Bacterial effectors mimic enzymes of the host ubiquitin system, but may or may not be structurally similar to the mammalian enzymes. Other effectors bind and modify components of the host ubiquitin system, and some are themselves subject to ubiquitination. This review will describe recent findings, based on structural analyses, regarding how pathogens use post-translational modifications of proteins to establish an infection.

Developmental control of integrin expression regulates Th2 effector homing

Science.gov (United States)

Integrin CD18, a component of the LFA-1 complex that also includes CD11a, is essential for Th2, but not Th1, cell homing, but the explanation for this phenomenon remains obscure. In this study, we investigate the mechanism by which Th2 effector responses require the LFA-1 complex. CD11a-deficient T ...

Data analysis at the CMS level-1 trigger: migrating complex selection algorithms from offline analysis and high-level trigger to the trigger electronics

CERN Document Server

Wulz, Claudia

2017-01-01

With ever increasing luminosity at the LHC, optimum online data selection is becoming more and more important. While in the case of some experiments (LHCb and ALICE) this task is being completely transferred to computer farms, the others -- ATLAS and CMS -- will not be able to do this in the medium-term future for technological, detector-related reasons. Therefore, these experiments pursue the complementary approach of migrating more and more of the offline and high-level trigger intelligence into the trigger electronics. The presentation illustrates how the level-1 trigger of the CMS experiment and in particular its concluding stage, the so-called ``Global Trigger", take up this challenge.

Nonlinear dynamical triggering of slow slip

Energy Technology Data Exchange (ETDEWEB)

Johnson, Paul A [Los Alamos National Laboratory; Knuth, Matthew W [WISCONSIN; Kaproth, Bryan M [PENN STATE; Carpenter, Brett [PENN STATE; Guyer, Robert A [Los Alamos National Laboratory; Le Bas, Pierre - Yves [Los Alamos National Laboratory; Daub, Eric G [Los Alamos National Laboratory; Marone, Chris [PENN STATE

2010-12-10

Among the most fascinating, recent discoveries in seismology have been the phenomena of triggered slip, including triggered earthquakes and triggered-tremor, as well as triggered slow, silent-slip during which no seismic energy is radiated. Because fault nucleation depths cannot be probed directly, the physical regimes in which these phenomena occur are poorly understood. Thus determining physical properties that control diverse types of triggered fault sliding and what frictional constitutive laws govern triggered faulting variability is challenging. We are characterizing the physical controls of triggered faulting with the goal of developing constitutive relations by conducting laboratory and numerical modeling experiments in sheared granular media at varying load conditions. In order to simulate granular fault zone gouge in the laboratory, glass beads are sheared in a double-direct configuration under constant normal stress, while subject to transient perturbation by acoustic waves. We find that triggered, slow, silent-slip occurs at very small confining loads ({approx}1-3 MPa) that are smaller than those where dynamic earthquake triggering takes place (4-7 MPa), and that triggered slow-slip is associated with bursts of LFE-like acoustic emission. Experimental evidence suggests that the nonlinear dynamical response of the gouge material induced by dynamic waves may be responsible for the triggered slip behavior: the slip-duration, stress-drop and along-strike slip displacement are proportional to the triggering wave amplitude. Further, we observe a shear-modulus decrease corresponding to dynamic-wave triggering relative to the shear modulus of stick-slips. Modulus decrease in response to dynamical wave amplitudes of roughly a microstrain and above is a hallmark of elastic nonlinear behavior. We believe that the dynamical waves increase the material non-affine elastic deformation during shearing, simultaneously leading to instability and slow-slip. The inferred

ATLAS: triggers for B-physics

International Nuclear Information System (INIS)

George, Simon

2000-01-01

The LHC will produce bb-bar events at an unprecedented rate. The number of events recorded by ATLAS will be limited by the rate at which they can be stored offline and subsequently analysed. Despite the huge number of events, the small branching ratios mean that analysis of many of the most interesting channels for CP violation and other measurements will be limited by statistics. The challenge for the Trigger and Data Acquisition (DAQ) system is therefore to maximise the fraction of interesting B decays in the B-physics data stream. The ATLAS Trigger/DAQ system is split into three levels. The initial B-physics selection is made in the first-level trigger by an inclusive low-p T muon trigger (∼6 GeV). The second-level trigger strategy is based on identifying classes of final states by their partial reconstruction. The muon trigger is confirmed before proceeding to a track search. Electron/hadron separation is given by the transition radiation tracking detector and the Electromagnetic calorimeter. Muon identification is possible using the muon detectors and the hadronic calorimeter. From silicon strips, pixels and straw tracking, precise track reconstruction is used to make selections based on invariant mass, momentum and impact parameter. The ATLAS trigger group is currently engaged in algorithm development and performance optimisation for the B-physics trigger. This is closely coupled to the R and D programme for the higher-level triggers. Together the two programmes of work will optimise the hardware, architecture and algorithms to meet the challenging requirements. This paper describes the current status and progress of this work

Designing signal-enriched triggers for boosted jets.

CERN Document Server

Toumazou, Marina

2017-01-01

Triggers designed to favour the selection of hadronically decaying massive particles have been studied. Both triggers using solely ET and mass cuts (similar to new 2017 triggers) and triggers exploiting polarization information have been studied. The mass cut triggers show substantial gains in rate reduction, while the benefits of polarization triggers are less obvious. The final conclusion is that it is more useful to identify and trigger on generic boosted decays, irrespective of the polarization of the decaying particle

Multinucleation during C. trachomatis infections is caused by the contribution of two effector pathways.

Directory of Open Access Journals (Sweden)

Heather M Brown

Full Text Available Chlamydia trachomatis is an obligate intracellular bacterial pathogen and the second leading cause of sexually transmitted infections in the US. Infections cause significant morbidity and can lead to serious reproductive sequelae, including an epidemiological link to increased rates of reproductive cancers. One of the overt changes that infected cells exhibit is the development of genomic instability leading to multinucleation. Here we demonstrate that the induction of multinucleation is not conserved equally across chlamydial species; C. trachomatis L2 caused high levels of multinucleation, C. muridarum intermediate levels, and C. caviae had very modest effects on multinucleation. Our data show that at least two effector pathways together cause genomic instability during infection leading to multinucleation. We find that the highly conserved chlamydial protease CPAF is a key effector for one of these pathways. CPAF secretion is required for the loss of centrosome duplication regulation as well as inducing early mitotic exit. The second effector pathway involves the induction of centrosome position errors. This function is not conserved in three chlamydial species tested. Together these two pathways contribute to the induction of high levels of genomic instability and multinucleation seen in C. trachomatis infections.

Engineering development of waste retrieval end effectors for the Oak Ridge gunite waste tanks

International Nuclear Information System (INIS)

Mullen, O.D.

1997-05-01

The Gunite and Associated Tanks Treatability Study at Oak Ridge National Laboratory selected the waterjet scarifying end effector, the jet pump conveyance system, and the Modified Light Duty Utility Arm and Houdini Remotely Operated Vehicle deployment and manipulator systems for evaluation. The waterjet-based retrieval end effector had been developed through several generations of test articles targeted at deployment in Hanford underground storage tanks with a large robotic arm. The basic technology had demonstrated effectiveness at retrieval of simulants bounding the foreseen range of waste properties and indicated compatibility with the planned deployment systems. The Retrieval Process Development and Enhancements team was tasked with developing a version of the retrieval end effector tailored to the Oak Ridge tanks, waste and deployment platforms. The finished prototype was delivered to PNNL and subjected to a brief round of characterization and performance testing at the Hydraulic Testbed prior to shipment to Oak Ridge. It has undergone extensive operational testing in the Oak Ridge National Laboratory Tanks Technology Cold Test Facility and performed well, as expected. A second unit has been delivered outfitted with the high pressure manifold

An effector of the Irish potato famine pathogen antagonizes a host autophagy cargo receptor

Science.gov (United States)

Dagdas, Yasin F; Belhaj, Khaoula; Maqbool, Abbas; Chaparro-Garcia, Angela; Pandey, Pooja; Petre, Benjamin; Tabassum, Nadra; Cruz-Mireles, Neftaly; Hughes, Richard K; Sklenar, Jan; Win, Joe; Menke, Frank; Findlay, Kim; Banfield, Mark J; Kamoun, Sophien; Bozkurt, Tolga O

2016-01-01

Plants use autophagy to safeguard against infectious diseases. However, how plant pathogens interfere with autophagy-related processes is unknown. Here, we show that PexRD54, an effector from the Irish potato famine pathogen Phytophthora infestans, binds host autophagy protein ATG8CL to stimulate autophagosome formation. PexRD54 depletes the autophagy cargo receptor Joka2 out of ATG8CL complexes and interferes with Joka2's positive effect on pathogen defense. Thus, a plant pathogen effector has evolved to antagonize a host autophagy cargo receptor to counteract host defenses. DOI: http://dx.doi.org/10.7554/eLife.10856.001 PMID:26765567

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

Science.gov (United States)

Annunziato, Francesco; Romagnani, Chiara; Romagnani, Sergio

2015-03-01

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

Attention to body-parts varies with visual preference and verb-effector associations.

Science.gov (United States)

Boyer, Ty W; Maouene, Josita; Sethuraman, Nitya

2017-05-01

Theories of embodied conceptual meaning suggest fundamental relations between others' actions, language, and our own actions and visual attention processes. Prior studies have found that when people view an image of a neutral body in a scene they first look toward, in order, the head, torso, hands, and legs. Other studies show associations between action verbs and the body-effectors used in performing the action (e.g., "jump" with feet/legs; "talk" with face/head). In the present experiment, the visual attention of participants was recorded with a remote eye-tracking system while they viewed an image of an actor pantomiming an action and heard a concrete action verb. Participants manually responded whether or not the action image was a good example of the verb they heard. The eye-tracking results confirmed that participants looked at the head most, followed by the hands, and the feet least of all; however, visual attention to each of the body-parts also varied as a function of the effector associated with the spoken verb on image/verb congruent trials, particularly for verbs associated with the legs. Overall, these results suggest that language influences some perceptual processes; however, hearing auditory verbs did not alter the previously reported fundamental hierarchical sequence of directed attention, and fixations on specific body-effectors may not be essential for verb comprehension as peripheral visual cues may be sufficient to perform the task.

Duplications and losses in gene families of rust pathogens highlight putative effectors.

Science.gov (United States)

Pendleton, Amanda L; Smith, Katherine E; Feau, Nicolas; Martin, Francis M; Grigoriev, Igor V; Hamelin, Richard; Nelson, C Dana; Burleigh, J Gordon; Davis, John M

2014-01-01

Rust fungi are a group of fungal pathogens that cause some of the world's most destructive diseases of trees and crops. A shared characteristic among rust fungi is obligate biotrophy, the inability to complete a lifecycle without a host. This dependence on a host species likely affects patterns of gene expansion, contraction, and innovation within rust pathogen genomes. The establishment of disease by biotrophic pathogens is reliant upon effector proteins that are encoded in the fungal genome and secreted from the pathogen into the host's cell apoplast or within the cells. This study uses a comparative genomic approach to elucidate putative effectors and determine their evolutionary histories. We used OrthoMCL to identify nearly 20,000 gene families in proteomes of 16 diverse fungal species, which include 15 basidiomycetes and one ascomycete. We inferred patterns of duplication and loss for each gene family and identified families with distinctive patterns of expansion/contraction associated with the evolution of rust fungal genomes. To recognize potential contributors for the unique features of rust pathogens, we identified families harboring secreted proteins that: (i) arose or expanded in rust pathogens relative to other fungi, or (ii) contracted or were lost in rust fungal genomes. While the origin of rust fungi appears to be associated with considerable gene loss, there are many gene duplications associated with each sampled rust fungal genome. We also highlight two putative effector gene families that have expanded in Cqf that we hypothesize have roles in pathogenicity.

Functions of Calcium-Dependent Protein Kinases in Plant Innate Immunity

Directory of Open Access Journals (Sweden)

Xiquan Gao

2014-03-01

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

Functions of Calcium-Dependent Protein Kinases in Plant Innate Immunity

Science.gov (United States)

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

2014-01-01

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

Towards RTOS support for mixed time-triggered and event-triggered task sets

NARCIS (Netherlands)

Heuvel, van den M.M.H.P.; Bril, R.J.; Lukkien, J.J.; Isovic, D.; Sankar Ramachandran, G.

2012-01-01

Many embedded systems have complex timing constraints and, at the same time, have flexibility requirements which prohibit offline planning of the entire system. To support a mixture of time-triggered and event-triggered tasks, some industrial systems deploy a real-time operating system (RTOS) with a

DESIGN AND ANALYSIS OF STATIC RANDOM ACCESS MEMORY BY SCHMITT TRIGGER TOPOLOGY FOR LOW VOLTAGE APPLICATIONS

Directory of Open Access Journals (Sweden)

RUKKUMANI V.

2016-12-01

Full Text Available Aggressive scaling of transistor dimensions with each technology generation has resulted an increased integration density and improved device performance at the expense of increased leakage current. The Supply voltage scaling is an effective way of reducing dynamic as well as leakage power consumption. However the sensitivity of the circuit parameters increases with reduction of the supply voltage. SRAM bit- cells utilizing minimum sized transistors are susceptible to various random process variations. The Schmitt Trigger based operation gives better readconstancy as well as superior write-ability compared to the standard bitcell configurations. The proposed Schmitt Trigger based bitcells integrate a built-in feedback mechanism make the process with high tolerance. In this paper an obsolete design of a differential sensing Static Random Access Memory (SRAM bit cells for ultralow-power and ultralow-area Schmitt trigger operation is introduced. The ST bit cells incorporate a built-in feedback mechanism, provided by separate control signal if the feedback is given by the internal nodes, achieving process variation tolerance that must be used for future nano-scaled technology nodes. In this we proposed 32nm technology for designing 10T SRAM cell using Microwind.Total power about 30% is reduced due to 32 nm technology as compared to 65 nm technlology.

The Run-2 ATLAS Trigger System

CERN Document Server

AUTHOR|(INSPIRE)INSPIRE-00222798; The ATLAS collaboration

2016-01-01

The ATLAS trigger successfully collected collision data during the first run of the LHC between 2009-2013 at different centre-of-mass energies between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 and a software-based high level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV and higher luminosity, resulting in roughly five times higher trigger rates. A brief review of the ATLAS trigger system upgrades that were implemented between Run-1 and Run-2, allowing to cope with the increased trigger rates while maintaining or even improving the efficiency to select physics processes of interest, will be given. This includes changes to the Level-1 calorimeter and muon trigger systems, the introduction of a new Level-1 topological trigger module and the merging of the previously two-level HLT system into a single event filter farm. A ...

The LVL2 trigger goes online

CERN Multimedia

David Berge

On Friday, the 9th of February, the ATLAS TDAQ community reached an important milestone. In a successful integration test, cosmic-ray muons were recorded with parts of the muon spectrometer, the central-trigger system and a second-level trigger algorithm. This was actually the first time that a full trigger slice all the way from the first-level trigger muon chambers up to event building after event selection by the second-level trigger ran online with cosmic rays. The ATLAS trigger and data acquisition system has a three-tier structure that is designed to cope with the enormous demands of proton-proton collisions at a bunch-crossing frequency of 40 MHz, with a typical event size of 1-2 MB. The online event selection has to reduce the incoming rate by a factor of roughly 200,000 to 200 Hz, a rate digestible by the archival-storage and offline-processing facilities. ATLAS has a mixed system: the first-level trigger (LVL1) is in hardware, while the other two consecutive levels, the second-level trigger (LVL2)...

The Database Driven ATLAS Trigger Configuration System

CERN Document Server

Martyniuk, Alex; The ATLAS collaboration

2015-01-01

This contribution describes the trigger selection configuration system of the ATLAS low- and high-level trigger (HLT) and the upgrades it received in preparation for LHC Run 2. The ATLAS trigger configuration system is responsible for applying the physics selection parameters for the online data taking at both trigger levels and the proper connection of the trigger lines across those levels. Here the low-level trigger consists of the already existing central trigger (CT) and the new Level-1 Topological trigger (L1Topo), which has been added for Run 2. In detail the tasks of the configuration system during the online data taking are Application of the selection criteria, e.g. energy cuts, minimum multiplicities, trigger object correlation, at the three trigger components L1Topo, CT, and HLT On-the-fly, e.g. rate-dependent, generation and application of prescale factors to the CT and HLT to adjust the trigger rates to the data taking conditions, such as falling luminosity or rate spikes in the detector readout ...

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

NARCIS (Netherlands)

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

2017-01-01

Fungal infections of the lung are life-threatening but rarely occur in healthy, immunocompetent individuals, indicating efficient clearance by pulmonary defense mechanisms. Upon inhalation, fungi will first encounter the airway surface liquid which contains several soluble effector molecules that

A Fungal Effector With Host Nuclear Localization and DNA-Binding Properties Is Required for Maize Anthracnose Development.

Science.gov (United States)

Vargas, Walter A; Sanz-Martín, José M; Rech, Gabriel E; Armijos-Jaramillo, Vinicio D; Rivera, Lina P; Echeverria, María Mercedes; Díaz-Mínguez, José M; Thon, Michael R; Sukno, Serenella A

2016-02-01

Plant pathogens have the capacity to manipulate the host immune system through the secretion of effectors. We identified 27 putative effector proteins encoded in the genome of the maize anthracnose pathogen Colletotrichum graminicola that are likely to target the host's nucleus, as they simultaneously contain sequence signatures for secretion and nuclear localization. We functionally characterized one protein, identified as CgEP1. This protein is synthesized during the early stages of disease development and is necessary for anthracnose development in maize leaves, stems, and roots. Genetic, molecular, and biochemical studies confirmed that this effector targets the host's nucleus and defines a novel class of double-stranded DNA-binding protein. We show that CgEP1 arose from a gene duplication in an ancestor of a lineage of monocot-infecting Colletotrichum spp. and has undergone an intense evolution process, with evidence for episodes of positive selection. We detected CgEP1 homologs in several species of a grass-infecting lineage of Colletotrichum spp., suggesting that its function may be conserved across a large number of anthracnose pathogens. Our results demonstrate that effectors targeted to the host nucleus may be key elements for disease development and aid in the understanding of the genetic basis of anthracnose development in maize plants.

Long-Term Live Cell Imaging Reveals New Roles For Salmonella Effector Proteins SseG and SteA

Science.gov (United States)

McQuate, Sarah E.; Young, Alexandra M.; Silva-Herzog, Eugenia; Bunker, Eric; Hernandez, Mateo; de Chaumont, Fabrice; Liu, Xuedong; Detweiler, Corrella S.; Palmer, Amy E.

2016-01-01

Summary Salmonella Typhimurium is an intracellular bacterial pathogen that infects both epithelial cells and macrophages. Salmonella effector proteins, which are translocated into the host cell and manipulate host cell components, control the ability to replicate and/or survive in host cells. Due to the complexity and heterogeneity of Salmonella infections, there is growing recognition of the need for single cell and live-cell imaging approaches to identify and characterize the diversity of cellular phenotypes and how they evolve over time. Here we establish a pipeline for long-term (16 hours) live-cell imaging of infected cells and subsequent image analysis methods. We apply this pipeline to track bacterial replication within the Salmonella-containing vacuole in epithelial cells, quantify vacuolar replication versus survival in macrophages, and investigate the role of individual effector proteins in mediating these parameters. This approach revealed that dispersed bacteria can coalesce at later stages of infection, that the effector protein SseG influences the propensity for cytosolic hyperreplication in epithelial cells, and that while SteA only has a subtle effect on vacuolar replication in epithelial cells, it has a profound impact on infection parameters in immunocompetent macrophages, suggesting differential roles for effector proteins in different infection models. PMID:27376507

DT Local Trigger performance in 2015

CERN Document Server

CMS Collaboration

2015-01-01

The Local Trigger system of the CMS Drift Tube chambers (DT) was checked applying similar methods as in the LHC Run 1 (2012). The main variables shown in this note are the trigger efficiency, the trigger quality and the fraction of trigger ghosts. The performance was found to be comparable or better than in Run 1.

Type 1 diabetes epidemic in Finland is triggered by zinc-containing amorphous silica nanoparticles.

Science.gov (United States)

Junnila, S K

2015-04-01

Type 1 diabetes (T1D), an autoimmune disease, breaks out in some of the children who has genetic susceptibility to T1D. Besides genetic susceptibility some environmental factor(s) are required to trigger the disease. The incidence of T1D in Finland is highest in the world, so we must seek an environmental factor, that is typical for Finland and can declare many aspects of T1D epidemiology and biology. In the literature most popular trigger has been enterovirus infections. It is difficult however to find why enteroviruses would be in this role in Finland in contrary to neighbouring countries e.g. Sweden. Colloidal amorphous silica (ASi) is typical for Finnish environment in consequency of the geohistory of Finland, great part of Finland is an ancient lake and sea bottom. ASi concentrations in natural waters are high in April-June and in November, only traces can be found in the rest of months. Pure colloidal ASi is not a strong trigger for T1D, but ASi particle which has surface adsorbed tetrahedrally coordinated zinc (ASiZn) is probably the trigger which has kept it's secret up to date. Zn functions as address label which conducts the ASiZn particle to the beta cell, whose content of zinc is highest in the body. ASi particle adheres to membrane proteins distorting their tertiary structure revealing new epitopes. If the fetus has not met these epitopes at proper time during intrauterine development, the consequence is that the negative selection of lymphocytes in the thymus and bone marrow and fetal liver is not perfect. When a child later in postnatal life becomes predisposed to ASiZn particles the immune system reacts to these as to nonself proteins. As a consequence the insulin producing beta cells are destroyed. Many observations from diabetes research support the hypothesis, some to mentioned. 1. Three common autoantigens (ZnT8, ICA512/IA-2, GAD65) are membrane proteins whose function zinc regulates. 2. Geographical variation in Finland is convergent with

Profiling calcium signals of in vitro polarized human effector CD4+ T cells.

Science.gov (United States)

Kircher, Sarah; Merino-Wong, Maylin; Niemeyer, Barbara A; Alansary, Dalia

2018-06-01

Differentiation of naïve CD4 + T cells into effector subtypes with distinct cytokine profiles and physiological roles is a tightly regulated process, the imbalance of which can lead to an inadequate immune response or autoimmune disease. The crucial role of Ca 2+ signals, mainly mediated by the store operated Ca 2+ entry (SOCE) in shaping the immune response is well described. However, it is unclear if human effector CD4 + T cell subsets show differential Ca 2+ signatures in response to different stimulation methods. Herein, we provide optimized in vitro culture conditions for polarization of human CD4 + effector T cells and characterize their SOCE following both pharmacological store depletion and direct T-cell receptor (TCR) activation. Moreover, we measured whole cell Ca 2+ release activated Ca 2+ currents (I CRAC ) and investigated whether the observed differences correlate to the expression of CRAC genes. Our results show that Ca 2+ profiles of helper CD4 + Th1, Th2 and Th17 are distinct and in part shaped by the intensity of stimulation. Regulatory T cells (Treg) are unique being the subtype with the most prominent SOCE response. Analysis of in vivo differentiated Treg unraveled the role of differential expression of ORAI2 in fine-tuning signals in Treg vs. conventional CD4 + T cells. Copyright © 2018 The Author(s). Published by Elsevier B.V. All rights reserved.

Revealing the inventory of type III effectors in Pantoea agglomerans gall-forming pathovars using draft genome sequences and a machine-learning approach.

Science.gov (United States)

Nissan, Gal; Gershovits, Michael; Morozov, Michael; Chalupowicz, Laura; Sessa, Guido; Manulis-Sasson, Shulamit; Barash, Isaac; Pupko, Tal

2018-02-01

Pantoea agglomerans, a widespread epiphytic bacterium, has evolved into a hypersensitive response and pathogenicity (hrp)-dependent and host-specific gall-forming pathogen by the acquisition of a pathogenicity plasmid containing a type III secretion system (T3SS) and its effectors (T3Es). Pantoea agglomerans pv. betae (Pab) elicits galls on beet (Beta vulgaris) and gypsophila (Gypsophila paniculata), whereas P. agglomerans pv. gypsophilae (Pag) incites galls on gypsophila and a hypersensitive response (HR) on beet. Draft genome sequences were generated and employed in combination with a machine-learning approach and a translocation assay into beet roots to identify the pools of T3Es in the two pathovars. The genomes of the sequenced Pab4188 and Pag824-1 strains have a similar size (∼5 MB) and GC content (∼55%). Mutational analysis revealed that, in Pab4188, eight T3Es (HsvB, HsvG, PseB, DspA/E, HopAY1, HopX2, HopAF1 and HrpK) contribute to pathogenicity on beet and gypsophila. In Pag824-1, nine T3Es (HsvG, HsvB, PthG, DspA/E, HopAY1, HopD1, HopX2, HopAF1 and HrpK) contribute to pathogenicity on gypsophila, whereas the PthG effector triggers HR on beet. HsvB, HsvG, PthG and PseB appear to endow pathovar specificities to Pab and Pag, and no homologous T3Es were identified for these proteins in other phytopathogenic bacteria. Conversely, the remaining T3Es contribute to the virulence of both pathovars, and homologous T3Es were found in other phytopathogenic bacteria. Remarkably, HsvG and HsvB, which act as host-specific transcription factors, displayed the largest contribution to disease development. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Expression Profiling during Arabidopsis/Downy Mildew Interaction Reveals a Highly-Expressed Effector That Attenuates Responses to Salicylic Acid

Science.gov (United States)

Asai, Shuta; Caillaud, Marie-Cécile; Furzer, Oliver J.; Ishaque, Naveed; Wirthmueller, Lennart; Fabro, Georgina; Shirasu, Ken; Jones, Jonathan D. G.

2014-01-01

Plants have evolved strong innate immunity mechanisms, but successful pathogens evade or suppress plant immunity via effectors delivered into the plant cell. Hyaloperonospora arabidopsidis (Hpa) causes downy mildew on Arabidopsis thaliana, and a genome sequence is available for isolate Emoy2. Here, we exploit the availability of genome sequences for Hpa and Arabidopsis to measure gene-expression changes in both Hpa and Arabidopsis simultaneously during infection. Using a high-throughput cDNA tag sequencing method, we reveal expression patterns of Hpa predicted effectors and Arabidopsis genes in compatible and incompatible interactions, and promoter elements associated with Hpa genes expressed during infection. By resequencing Hpa isolate Waco9, we found it evades Arabidopsis resistance gene RPP1 through deletion of the cognate recognized effector ATR1. Arabidopsis salicylic acid (SA)-responsive genes including PR1 were activated not only at early time points in the incompatible interaction but also at late time points in the compatible interaction. By histochemical analysis, we found that Hpa suppresses SA-inducible PR1 expression, specifically in the haustoriated cells into which host-translocated effectors are delivered, but not in non-haustoriated adjacent cells. Finally, we found a highly-expressed Hpa effector candidate that suppresses responsiveness to SA. As this approach can be easily applied to host-pathogen interactions for which both host and pathogen genome sequences are available, this work opens the door towards transcriptome studies in infection biology that should help unravel pathogen infection strategies and the mechanisms by which host defense responses are overcome. PMID:25329884

Expression profiling during arabidopsis/downy mildew interaction reveals a highly-expressed effector that attenuates responses to salicylic acid.

Directory of Open Access Journals (Sweden)

Shuta Asai

2014-10-01

Full Text Available Plants have evolved strong innate immunity mechanisms, but successful pathogens evade or suppress plant immunity via effectors delivered into the plant cell. Hyaloperonospora arabidopsidis (Hpa causes downy mildew on Arabidopsis thaliana, and a genome sequence is available for isolate Emoy2. Here, we exploit the availability of genome sequences for Hpa and Arabidopsis to measure gene-expression changes in both Hpa and Arabidopsis simultaneously during infection. Using a high-throughput cDNA tag sequencing method, we reveal expression patterns of Hpa predicted effectors and Arabidopsis genes in compatible and incompatible interactions, and promoter elements associated with Hpa genes expressed during infection. By resequencing Hpa isolate Waco9, we found it evades Arabidopsis resistance gene RPP1 through deletion of the cognate recognized effector ATR1. Arabidopsis salicylic acid (SA-responsive genes including PR1 were activated not only at early time points in the incompatible interaction but also at late time points in the compatible interaction. By histochemical analysis, we found that Hpa suppresses SA-inducible PR1 expression, specifically in the haustoriated cells into which host-translocated effectors are delivered, but not in non-haustoriated adjacent cells. Finally, we found a highly-expressed Hpa effector candidate that suppresses responsiveness to SA. As this approach can be easily applied to host-pathogen interactions for which both host and pathogen genome sequences are available, this work opens the door towards transcriptome studies in infection biology that should help unravel pathogen infection strategies and the mechanisms by which host defense responses are overcome.

The Run-2 ATLAS Trigger System

CERN Document Server

Ruiz-Martinez, Aranzazu; The ATLAS collaboration

2016-01-01

The ATLAS trigger has been successfully collecting collision data during the first run of the LHC between 2009-2013 at a centre-of-mass energy between 900 GeV and 8 TeV. The trigger system consists of a hardware Level-1 (L1) and a software based high-level trigger (HLT) that reduces the event rate from the design bunch-crossing rate of 40 MHz to an average recording rate of a few hundred Hz. In Run-2, the LHC will operate at centre-of-mass energies of 13 and 14 TeV resulting in roughly five times higher trigger rates. We will briefly review the ATLAS trigger system upgrades that were implemented during the shutdown, allowing us to cope with the increased trigger rates while maintaining or even improving our efficiency to select relevant physics processes. This includes changes to the L1 calorimeter and muon trigger systems, the introduction of a new L1 topological trigger module and the merging of the previously two-level HLT system into a single event filter farm. At hand of a few examples, we will show the ...

Triggering soft bombs at the LHC

Science.gov (United States)

Knapen, Simon; Griso, Simone Pagan; Papucci, Michele; Robinson, Dean J.

2017-08-01

Very high multiplicity, spherically-symmetric distributions of soft particles, with p T ˜ few×100 MeV, may be a signature of strongly-coupled hidden valleys that exhibit long, efficient showering windows. With traditional triggers, such `soft bomb' events closely resemble pile-up and are therefore only recorded with minimum bias triggers at a very low efficiency. We demonstrate a proof-of-concept for a high-level triggering strategy that efficiently separates soft bombs from pile-up by searching for a `belt of fire': a high density band of hits on the innermost layer of the tracker. Seeding our proposed high-level trigger with existing jet, missing transverse energy or lepton hardware-level triggers, we show that net trigger efficiencies of order 10% are possible for bombs of mass several × 100 GeV. We also consider the special case that soft bombs are the result of an exotic decay of the 125 GeV Higgs. The fiducial rate for `Higgs bombs' triggered in this manner is marginally higher than the rate achievable by triggering directly on a hard muon from associated Higgs production.

The Toolbox for Uncovering the Functions of Legionella Dot/Icm Type IVb Secretion System Effectors: Current State and Future Directions