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  • 1
    Language: German
    Description: Das Team IFL PiRo des KIT nahm 2017 an der Amazon Robotics Challenge in Nagoya, Japan teil. Bei diesem Wettbewerb müssen Kommissionieraufträge in inhomogenen und chaotischen Lagern durchgeführt werden. Diese Veröffentlichung behandelt die getroffenen Entscheidungen bei der Entwicklung des Robotersystems PiRo und dessen Steuerung. Das Abschneiden bei dem Wettbewerb und die gewonnenen Erfahrungen werden dargestellt.... ; Team IFL PiRo of KIT participated in the Amazon Robotics Challenge in Nagoya, Japan. In this competition, picking orders must be carried out in inhomoge¬¬¬neous and chaotic storages. This paper describes the decisions taken during the development of the robot system PiRo and its control. The performance in the competition and the gained experiences are presented....
    Keywords: Amazon Robotics Challenge ; Automatisierung ; Kommissionierung ; Objekterkennung
    ISSN: 18607977
    Source: DataCite
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  • 2
    Language: English
    In: Chemosphere, 2011, Vol.84(9), pp.1188-1193
    Description: ► Titanium dioxide coated surfaces are appropriate to eliminate different pathogenic bacteria. ► We examined whether these surfaces can inactivate bacterial-derived contaminations like LPS. ► We established highly sensitive immuno-based assays to quantify inactivation of LPS and RNase A. ► Our titanium dioxide coatings degrade RNase A and LPS even with increased concentration levels. TiO coated surfaces are able to generate highly reactive oxidizing species under mild UV-A light exposure in the presence of water and oxygen. We have demonstrated that these radicals are sufficient to eliminate different pathogenic bacteria, by breaking their cell walls. The photocatalytic activity of surfaces coated with titanium dioxide offers therefore an alternative possibility of disinfection. However, restriction of bacterial growth does not protect surfaces from bacterial derived contaminations, such as endotoxins. Lipopolysaccharides (LPS) and Ribonuclease A (RNAse A) represent the two most abundant contaminations, causing severe problems in biomedical and immunological research as well as in the pharmaceutical industry. Due to their high stability, complete removal of these contaminants is technically challenging. Using irradiated TiO coated glass plates, RNAse A and LPS containing contaminations could be completely inactivated. By establishing highly sensitive immuno-based assays, destruction of the contaminants was quantified and shown to be independent of the initial concentrations, following a zero-order reaction. Exposure for 96 h resulted in a reduction of 11 ng of LPS and 7 units of RNase A cm surface. These amounts are comparable to contamination levels found under standard working conditions. Titanium dioxide coatings provide therefore a powerful tool for auto-disinfection and self-cleaning of surfaces.
    Keywords: Titanium Dioxide (Tio 2) ; Photocatalysis ; Endotoxin ; Lipopolysaccharide ; Photocatalytic Oxidation ; Endotoxin Degradation ; Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
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  • 3
    Language: English
    In: 2015, Vol.11(11), p.e1005264
    Description: Sensing viruses by pattern recognition receptors (PRR) triggers the innate immune system of the host cell and activates immune signaling cascades such as the RIG-I/IRF3 pathway. Mitochondrial antiviral-signaling protein (MAVS, also known as IPS-1, Cardif, and VISA) is the crucial adaptor protein of this pathway localized on mitochondria, peroxisomes and mitochondria-associated membranes of the endoplasmic reticulum. Activation of MAVS leads to the production of type I and type III interferons (IFN) as well as IFN stimulated genes (ISGs). To refine the role of MAVS subcellular localization for the induction of type I and III IFN responses in hepatocytes and its counteraction by the hepatitis C virus (HCV), we generated various functional and genetic knock-out cell systems that were reconstituted to express mitochondrial (mito) or peroxisomal (pex) MAVS, exclusively. Upon infection with diverse RNA viruses we found that cells exclusively expressing pexMAVS mounted sustained expression of type I and III IFNs to levels comparable to cells exclusively expressing mitoMAVS. To determine whether viral counteraction of MAVS is affected by its subcellular localization we employed infection of cells with HCV, a major causative agent of chronic liver disease with a high propensity to establish persistence. This virus efficiently cleaves MAVS via a viral protease residing in its nonstructural protein 3 (NS3) and this strategy is thought to contribute to the high persistence of this virus. We found that both mito- and pexMAVS were efficiently cleaved by NS3 and this cleavage was required to suppress activation of the IFN response. Taken together, our findings indicate comparable activation of the IFN response by pex- and mitoMAVS in hepatocytes and efficient counteraction of both MAVS species by the HCV NS3 protease. ; Mammalian cells developed several defense mechanisms against viral infection. One major strategy involves pattern recognition receptors (PRRs) recognizing non-self motifs in viral RNA and triggering the production of type I and III interferon (IFN) that induce an antiviral state. One central signaling molecule in this cascade is MAVS (Mitochondrial Antiviral Signaling protein), residing on mitochondria, mitochondria-associated membranes of the endoplasmic reticulum, and peroxisomes. Here we characterized the role of mitochondrial and peroxisomal MAVS for the activation of the IFN response and their counteraction by the hepatitis C virus (HCV), a major causative agent of chronic liver disease with a high propensity to establish persistence. By using various functional and genetic knock-out cell systems reconstituted to express exclusively mitochondrial or peroxisomal MAVS, we observed comparable activation of type I and III IFN response by either MAVS species. In addition, we found that the HCV protease residing in nonstructural protein 3 (NS3) efficiently cleaves MAVS independent from its subcellular localization. This cleavage is required for suppression of the IFN response and might contribute to HCV persistence. Our results indicate a largely localization-independent activation of the IFN response by MAVS in hepatocytes and its efficient counteraction by the HCV NS3 protease.
    Keywords: Research Article
    ISSN: 1553-7366
    E-ISSN: 1553-7374
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  • 4
    Language: English
    In: Cytokine, November 2015, Vol.76(1), pp.85-85
    Description: Sensing viruses by pattern recognition receptors (PRR) triggers the innate immune system of the host cell and activates immune signaling cascades like the RIG-I/IRF3 pathway. Mitochondrial antiviral-signaling protein (MAVS) is the crucial adaptor protein of this pathway localized on mitochondria, peroxisomes and mitochondria associated membranes (MAMs). Activation of MAVS leads to the production of type I and type III interferon (IFN) as well as interferon stimulated genes (ISGs). To refine the role of MAVS subcellular localization for the induction of type I and III IFN responses in hepatocytes, we generated cell lines with organelle-targeted MAVS and characterized innate immune response after viral infection. We established various functional and genetic knock-out cell systems reconstituted to express exclusively mitochondrial or peroxisomal MAVS. Infection with diverse RNA viruses mounted comparable levels of type I and III IFN expression irrespective of MAVS subcellular localization. To determine whether viral counteraction of MAVS is affected in these systems we employed infection of cells with the hepatitis C virus (HCV), a major causative agent of chronic liver diseases with a high propensity to establish persistence. This virus efficiently cleaves MAVS via a viral protease residing in nonstructural protein 3 (NS3). We found that both mitochondrial and peroxisomal MAVS were efficiently cleaved by NS3 and this cleavage was required to suppress activation of the IFN response. Taken together, our findings indicate comparable activation of the IFN response by peroxisomal and mitochondrial MAVS in hepatocytes and efficient counteraction of both MAVS species by the HCV NS3 protease.
    Keywords: Medicine ; Biology
    ISSN: 1043-4666
    E-ISSN: 1096-0023
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  • 5
    In: PLoS Pathogens, 2015, Vol.11(11)
    Description: Sensing viruses by pattern recognition receptors (PRR) triggers the innate immune system of the host cell and activates immune signaling cascades such as the RIG-I/IRF3 pathway. Mitochondrial antiviral-signaling protein (MAVS, also known as IPS-1, Cardif, and VISA) is the crucial adaptor protein of this pathway localized on mitochondria, peroxisomes and mitochondria-associated membranes of the endoplasmic reticulum. Activation of MAVS leads to the production of type I and type III interferons (IFN) as well as IFN stimulated genes (ISGs). To refine the role of MAVS subcellular localization for the induction of type I and III IFN responses in hepatocytes and its counteraction by the hepatitis C virus (HCV), we generated various functional and genetic knock-out cell systems that were reconstituted to express mitochondrial (mito) or peroxisomal (pex) MAVS, exclusively. Upon infection with diverse RNA viruses we found that cells exclusively expressing pexMAVS mounted sustained expression of type I and III IFNs to levels comparable to cells exclusively expressing mitoMAVS. To determine whether viral counteraction of MAVS is affected by its subcellular localization we employed infection of cells with HCV, a major causative agent of chronic liver disease with a high propensity to establish persistence. This virus efficiently cleaves MAVS via a viral protease residing in its nonstructural protein 3 (NS3) and this strategy is thought to contribute to the high persistence of this virus. We found that both mito- and pexMAVS were efficiently cleaved by NS3 and this cleavage was required to suppress activation of the IFN response. Taken together, our findings indicate comparable activation of the IFN response by pex- and mitoMAVS in hepatocytes and efficient counteraction of both MAVS species by the HCV NS3 protease. Author Summary Mammalian cells developed several defense mechanisms against viral infection. One major strategy involves pattern recognition receptors (PRRs) recognizing non-self motifs in viral RNA and triggering the production of type I and III interferon (IFN) that induce an antiviral state. One central signaling molecule in this cascade is MAVS (Mitochondrial Antiviral Signaling protein), residing on mitochondria, mitochondria-associated membranes of the endoplasmic reticulum, and peroxisomes. Here we characterized the role of mitochondrial and peroxisomal MAVS for the activation of the IFN response and their counteraction by the hepatitis C virus (HCV), a major causative agent of chronic liver disease with a high propensity to establish persistence. By using various functional and genetic knock-out cell systems reconstituted to express exclusively mitochondrial or peroxisomal MAVS, we observed comparable activation of type I and III IFN response by either MAVS species. In addition, we found that the HCV protease residing in nonstructural protein 3 (NS3) efficiently cleaves MAVS independent from its subcellular localization. This cleavage is required for suppression of the IFN response and might contribute to HCV persistence. Our results indicate a largely localization-independent activation of the IFN response by MAVS in hepatocytes and its efficient counteraction by the HCV NS3 protease.
    Keywords: Research Article
    ISSN: 1553-7366
    E-ISSN: 1553-7374
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  • 6
    Language: English
    In: The Journal of biological chemistry, 05 August 2011, Vol.286(31), pp.27278-87
    Description: RIG-I is a major innate immune sensor for viral infection, triggering an interferon (IFN)-mediated antiviral response upon cytosolic detection of viral RNA. Double-strandedness and 5'-terminal triphosphates were identified as motifs required to elicit optimal immunological signaling. However, very little is known about the response dynamics of the RIG-I pathway, which is crucial for the ability of the cell to react to diverse classes of viral RNA while maintaining self-tolerance. In the present study, we addressed the molecular mechanism of RIG-I signal detection and its translation into pathway activation. By employing highly quantitative methods, we could establish the length of the double-stranded RNA (dsRNA) to be the most critical determinant of response strength. Size exclusion chromatography and direct visualization in scanning force microscopy suggested that this was due to cooperative oligomerization of RIG-I along dsRNA. The initiation efficiency of this oligomerization process critically depended on the presence of high affinity motifs, like a 5'-triphosphate. It is noteworthy that for dsRNA longer than 200 bp, internal initiation could effectively compensate for a lack of terminal triphosphates. In summary, our data demonstrate a very flexible response behavior of the RIG-I pathway, in which sensing and integration of at least two distinct signals, initiation efficiency and double strand length, allow the host cell to mount an antiviral response that is tightly adjusted to the type of the detected signal, such as viral genomes, replication intermediates, or small by-products.
    Keywords: Immunity, Innate ; Dead-Box RNA Helicases -- Physiology
    E-ISSN: 1083-351X
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  • 7
    Language: English
    In: Journal of immunology (Baltimore, Md. : 1950), 01 March 2008, Vol.180(5), pp.3229-37
    Description: Synthetic small interfering RNA (siRNA) can suppress the expression of endogenous mRNA through RNA interference. It has been reported that siRNA can induce type I IFN production from plasmacytoid dendritic cells, leading to off-target effects. To separate immunostimulation from the desired gene-specific inhibitory activity, we designed RNA strands with chemical modifications at strategic positions of the ribose or nucleobase residues. Substitution of uridine residues by 2'-deoxyuridine or thymidine residues was found to decrease type I IFN production upon in vitro stimulation of human PBMC. Thymidine residues in both strands of a siRNA duplex further decreased immunostimulation. Fortunately, the thymidine residues did not affect gene-silencing activity. In contrast, 2'-O-methyl groups at adenosine and uridine residues reduced both IFN-alpha secretion and gene-silencing activity. Oligoribonucleotides with 2'-O-methyladenosine residues actively inhibited IFN-alpha secretion induced by other immunostimulatory RNAs, an effect not observed for strands with 2'-deoxynucleosides. Furthermore, neither 5-methylcytidine nor 7-deazaguanosine residues in the stimulatory strands affected IFN-alpha secretion, suggesting that recognition does not involve sites in the major groove of duplex regions. The activity data, together with structure prediction and exploratory UV-melting analyses, suggest that immunostimulatory sequences adopt folded structures. The results show that immunostimulation can be suppressed by suitable chemical modifications without losing siRNA potency by introducing seemingly minor structural changes.
    Keywords: Oligoribonucleotides -- Chemistry ; RNA Interference -- Immunology ; RNA, Small Interfering -- Chemistry ; Thymidine -- Chemistry
    ISSN: 0022-1767
    E-ISSN: 15506606
    Source: MEDLINE/PubMed (U.S. National Library of Medicine)
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  • 8
    Language: English
    In: The Journal of experimental medicine, 13 February 2012, Vol.209(2), pp.225-33
    Description: Naturally occurring nucleotide modifications within RNA have been proposed to be structural determinants for innate immune recognition. We tested this hypothesis in the context of native nonself-RNAs. Isolated, fully modified native bacterial transfer RNAs (tRNAs) induced significant secretion of IFN-α from human peripheral blood mononuclear cells in a manner dependent on TLR7 and plasmacytoid dendritic cells. As a notable exception, tRNA(Tyr) from Escherichia coli was not immunostimulatory, as were all tested eukaryotic tRNAs. However, the unmodified, 5'-unphosphorylated in vitro transcript of tRNA(Tyr) induced IFN-α, thus revealing posttranscriptional modifications as a factor suppressing immunostimulation. Using a molecular surgery approach based on catalytic DNA, a panel of tRNA(Tyr) variants featuring differential modification patterns was examined. Out of seven modifications present in this tRNA, 2'-O-methylated G(m)18 was identified as necessary and sufficient to suppress immunostimulation. Transplantation of this modification into the scaffold of yeast tRNA(Phe) also resulted in blocked immunostimulation. Moreover, an RNA preparation of an E. coli trmH mutant that lacks G(m)18 2'-O-methyltransferase activity was significantly more stimulatory than the wild-type sample. The experiments identify the single methyl group on the 2'-oxygen of G(m)18 as a natural modification in native tRNA that, beyond its primary structural role, has acquired a secondary function as an antagonist of TLR7.
    Keywords: Escherichia Coli -- Immunology ; Immunity, Innate -- Immunology ; Interferon-Alpha -- Metabolism ; RNA Processing, Post-Transcriptional -- Immunology ; RNA, Transfer, Amino Acyl -- Immunology ; Trna Methyltransferases -- Metabolism
    ISSN: 00221007
    E-ISSN: 1540-9538
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  • 9
    Language: English
    In: Nucleic acids research, 2007, Vol.35(18), pp.e124
    Description: Techniques for investigation of exogenous small interfering RNA (siRNA) after penetration of the cell are of substantial interest to the development of efficient transfection methods as well as to potential medical formulations of siRNA. A FRET-based visualization method including the commonplace dye labels fluorescein and tetramethylrhodamin (TMR) on opposing strands of siRNA was found compatible with RNA interference (RNAi). Investigation of spectral properties of three labelled siRNAs with differential FRET efficiencies in the cuvette, including pH dependence and FRET efficiency in lipophilic environments, identified the ratio of red and green fluorescence (R/G-ratio) as a sensitive parameter, which reliably identifies samples containing 〉90% un-degraded siRNA. Spectral imaging of siRNAs microinjected into cells showed emission spectra indistinguishable from those measured in the cuvette. These were used to establish a calibration curve for assessing the degradation state of siRNA in volume elements inside cells. An algorithm, applied to fluorescence images recorded in standard green and red fluorescence channels, produces R/G-ratio images of high spatial resolution, identifying volume elements in the cell with high populations of intact siRNA with high fidelity. To demonstrate the usefulness of this technique, the movement of intact siRNA molecules are observed after introduction into the cytosol by microinjection, standard transfection and lipofection with liposomes.
    Keywords: Fluorescence Resonance Energy Transfer ; Microscopy, Fluorescence ; RNA Interference ; RNA, Small Interfering -- Chemistry
    ISSN: 03051048
    E-ISSN: 1362-4962
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  • 10
    In: Immunology, January 2008, Vol.123(1), pp.118-128
    Description: Synthetic oligodeoxynucleotides containing unmethylated CpG sequences (CpG‐ODNs) stimulate Toll‐like receptor‐9 (TLR‐9), thereby activating innate immunity. Stimulatory CpG‐ODNs have been shown to be valuable in modifying immune responses in allergy, infection and cancer. Recently, it has been reported that the stimulation of TLR‐9 by endogenous DNA might contribute to the pathogenesis of autoimmune diseases. We here report the identification of a suppressive, guanosine‐rich ODN (G‐ODN) that inhibited the activation of TLR‐9 by stimulatory CpG‐ODNs. The G‐ODN was suppressive in murine macrophages and dendritic cells as well as in human plasmacytoid dendritic cells . G‐ODN blocked the secretion of tumour necrosis factor‐α (TNF‐α) and interleukin‐12p40 and interfered with the up‐regulation of major histocompatibility complex (MHC) class II and costimulatory molecules. G‐ODN was inhibitory even at a molar ratio of 1 : 10 (G‐ODN:CpG‐ODN) and when administered up to 7 hr after stimulation with CpG. G‐ODN specifically inhibited TLR‐9 but not other TLRs. Inhibition was dependent on a string of five guanosines. G‐ODN was also inhibitory in an model of CpG/galactosamin (GalN) lethal shock. G‐ODN interfered with upstream TLR‐9 signalling. However, by extensive analysis we can exclude that G‐ODN acts at the stage of cellular uptake. G‐ODN therefore represents a class of suppressive ODNs that could be of therapeutic use in situations with pathologic TLR‐9 activation, as has been proposed for certain autoimmune diseases.
    Keywords: Cpg Oligodeoxynucleotides ; Inhibition ; Innate Immunity ; Suppressive Oligodeoxynucleotides ; Toll‐Like Receptor‐9
    ISSN: 0019-2805
    E-ISSN: 1365-2567
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