76 research outputs found
Nan-O-Style – experiments and arts
In this project, high school students (aged 16-17) tested various protocols of experiments in nanotechnology and evaluated them whether such experiments could also be performed by middle school students (aged 11-15) or even elementary school students (aged 6-10). Protocols pre-selected and provided by the instructing team consisting of Sciencetainment and the Department of Biosciences, University of Salzburg were applied. Laboratory techniques such as thin-layer chromatography, measuring the contact angle by high-resolution 3D microscopy and analyzing and constructing surface layers represented some of the experiments performed. Moreover, students produced short video clips and images and designed photo-collages out of microscopic and electron microscopic pictures. Hence, the school students acquired a number of soft skills during this special science day
(Re)Conceptualizing decision-making tools in a risk governance framework for emerging technologies—the case of nanomaterials
The utility of decision-making tools for the risk governance of nanotechnology is at the core of this paper. Those working in nanotechnology risk management have been prolific in creating such tools, many derived from European FP7 and H2020-funded projects. What is less clear is how such tools might assist the overarching ambition of creating a fair system of risk governance. In this paper, we reflect upon the role that tools might and should play in any system of risk governance. With many tools designed for the risk governance of this emerging technology falling into disuse, this paper provides an overview of extant tools and addresses their potential shortcomings. We also posit the need for a data readiness tool. With the EUs NMP13 family of research consortia about to report to the Commission on ways forward in terms of risk governance of this domain, this is a timely intervention on an important element of any risk governance system
The microRNA-29 family in cartilage homeostasis and osteoarthritis
MicroRNAs have been shown to function in cartilage development and homeostasis, as well as in progression of osteoarthritis. The objective of the current study was to identify microRNAs involved in the onset or early progression of osteoarthritis and characterise their function in chondrocytes. MicroRNA expression in mouse knee joints post-DMM surgery was measured over 7 days. Expression of miR-29b-3p was increased at day 1 and regulated in the opposite direction to its potential targets. In a mouse model of cartilage injury and in end-stage human OA cartilage, the miR-29 family were also regulated. SOX9 repressed expression of miR-29a-3p and miR-29b-3p via the 29a/b1 promoter. TGFβ1 decreased expression of miR-29a, b and c (3p) in primary chondrocytes, whilst IL-1β increased (but LPS decreased) their expression. The miR-29 family negatively regulated Smad, NFκB and canonical WNT signalling pathways. Expression profiles revealed regulation of new WNT-related genes. Amongst these, FZD3, FZD5, DVL3, FRAT2, CK2A2 were validated as direct targets of the miR-29 family. These data identify the miR-29 family as microRNAs acting across development and progression of OA. They are regulated by factors which are important in OA and impact on relevant signalling pathways
Enhanced inhibition of Avian leukosis virus subgroup J replication by multi-target miRNAs
<p>Abstract</p> <p>Background</p> <p>Avian leukosis virus (ALV) is a major infectious disease that impacts the poultry industry worldwide. Despite intensive efforts, no effective vaccine has been developed against ALV because of mutations that lead to resistant forms. Therefore, there is a dire need to develop antiviral agents for the treatment of ALV infections and RNA interference (RNAi) is considered an effective antiviral strategy.</p> <p>Results</p> <p>In this study, the avian leukosis virus subgroup J (ALV-J) proviral genome, including the <it>gag </it>genes, were treated as targets for RNAi. Four pairs of miRNA sequences were designed and synthesized that targeted different regions of the <it>gag </it>gene. The screened target (i.e., the <it>gag </it>genes) was shown to effectively suppress the replication of ALV-J by 19.0-77.3%. To avoid the generation of escape variants during virus infection, expression vectors of multi-target miRNAs were constructed using the multi-target serial strategy (against different regions of the <it>gag</it>, <it>pol</it>, and <it>env </it>genes). Multi-target miRNAs were shown to play a synergistic role in the inhibition of ALV-J replication, with an inhibition efficiency of viral replication ranging from 85.0-91.2%.</p> <p>Conclusion</p> <p>The strategy of multi-target miRNAs might be an effective method for inhibiting ALV replication and the acquisition of resistant mutations.</p
Constitutively elevated levels of SOCS1 suppress innate responses in DF-1 immortalised chicken fibroblast cells.
The spontaneously immortalised DF-1 cell line is rapidly replacing its progenitor primary chicken embryo fibroblasts (CEFs) for studies on avian viruses such as avian influenza but no comprehensive study has as yet been reported comparing their innate immunity phenotypes. We conducted microarray analyses of DF-1 and CEFs, under both normal and stimulated conditions using chicken interferon-α (chIFN-α) and the attenuated infectious bursal disease virus vaccine strain PBG98. We found that DF-1 have an attenuated innate response compared to CEFs. Basal expression levels of Suppressor of Cytokine Signalling 1 (chSOCS1), a negative regulator of cytokine signalling in mammals, are 16-fold higher in DF-1 than in CEFs. The chSOCS1 “SOCS box” domain (which in mammals, interacts with an E3 ubiquitin ligase complex) is not essential for the inhibition of cytokine-induced JAK/STAT signalling activation in DF-1. Overexpression of SOCS1 in chIFN-α-stimulated DF-1 led to a relative decrease in expression of interferon-stimulated genes (ISGs; MX1 and IFIT5) and increased viral yield in response to PBG98 infection. Conversely, knockdown of SOCS1 enhanced induction of ISGs and reduced viral yield in chIFN-α-stimulated DF-1. Consequently, SOCS1 reduces induction of the IFN signalling pathway in chicken cells and can potentiate virus replication
Mechanisms of Allergen-Antibody Interaction of Cockroach Allergen Bla g 2 with Monoclonal Antibodies That Inhibit IgE Antibody Binding
BACKGROUND: Cockroach allergy is strongly associated with asthma, and involves the production of IgE antibodies against inhaled allergens. Reports of conformational epitopes on inhaled allergens are limited. The conformational epitopes for two specific monoclonal antibodies (mAb) that interfere with IgE antibody binding were identified by X-ray crystallography on opposite sites of the quasi-symmetrical cockroach allergen Bla g 2. METHODOLOGY/PRINCIPAL FINDINGS: Mutational analysis of selected residues in both epitopes was performed based on the X-ray crystal structures of the allergen with mAb Fab/Fab' fragments, to investigate the structural basis of allergen-antibody interactions. The epitopes of Bla g 2 for the mAb 7C11 or 4C3 were mutated, and the mutants were analyzed by SDS-PAGE, circular dichroism, and/or mass spectrometry. Mutants were tested for mAb and IgE antibody binding by ELISA and fluorescent multiplex array. Single or multiple mutations of five residues from both epitopes resulted in almost complete loss of mAb binding, without affecting the overall folding of the allergen. Preventing glycosylation by mutation N268Q reduced IgE binding, indicating a role of carbohydrates in the interaction. Cation-π interactions, as well as electrostatic and hydrophobic interactions, were important for mAb and IgE antibody binding. Quantitative differences in the effects of mutations on IgE antibody binding were observed, suggesting heterogeneity in epitope recognition among cockroach allergic patients. CONCLUSIONS/SIGNIFICANCE: Analysis by site-directed mutagenesis of epitopes identified by X-ray crystallography revealed an overlap between monoclonal and IgE antibody binding sites and provided insight into the B cell repertoire to Bla g 2 and the mechanisms of allergen-antibody recognition, including involvement of carbohydrates
A direct comparison of strategies for combinatorial RNA interference
<p>Abstract</p> <p>Background</p> <p>Combinatorial RNA interference (co-RNAi) is a valuable tool for highly effective gene suppression of single and multiple-genes targets, and can be used to prevent the escape of mutation-prone transcripts. There are currently three main approaches used to achieve co-RNAi in animal cells; multiple promoter/shRNA cassettes, long hairpin RNAs (lhRNA) and miRNA-embedded shRNAs, however, the relative effectiveness of each is not known. The current study directly compares the ability of each co-RNAi method to deliver pre-validated siRNA molecules to the same gene targets.</p> <p>Results</p> <p>Double-shRNA expression vectors were generated for each co-RNAi platform and their ability to suppress both single and double-gene reporter targets were compared. The most reliable and effective gene silencing was achieved from the multiple promoter/shRNA approach, as this method induced additive suppression of single-gene targets and equally effective knockdown of double-gene targets. Although both lhRNA and microRNA-embedded strategies provided efficient gene knockdown, suppression levels were inconsistent and activity varied greatly for different siRNAs tested. Furthermore, it appeared that not only the position of siRNAs within these multi-shRNA constructs impacted upon silencing activity, but also local properties of each individual molecule. In addition, it was also found that the insertion of up to five promoter/shRNA cassettes into a single construct did not negatively affect the efficacy of each individual shRNA.</p> <p>Conclusions</p> <p>By directly comparing the ability of shRNAs delivered from different co-RNA platforms to initiate knockdown of the same gene targets, we found that multiple U6/shRNA cassettes offered the most reliable and predictable suppression of both single and multiple-gene targets. These results highlight some important strengths and pitfalls of the currently used methods for multiple shRNA delivery, and provide valuable insights for the design and application of reliable co-RNAi.</p
Vectors Based on Modified Vaccinia Ankara Expressing Influenza H5N1 Hemagglutinin Induce Substantial Cross-Clade Protective Immunity
New highly pathogenic H5N1 influenza viruses are continuing to evolve with a potential threat for an influenza pandemic. So far, the H5N1 influenza viruses have not widely circulated in humans and therefore constitute a high risk for the non immune population. The aim of this study was to evaluate the cross-protective potential of the hemagglutinins of five H5N1 strains of divergent clades using a live attenuated modified vaccinia Ankara (MVA) vector vaccine.The replication-deficient MVA virus was used to express influenza hemagglutinin (HA) proteins. Specifically, recombinant MVA viruses expressing the HA genes of the clade 1 virus A/Vietnam/1203/2004 (VN/1203), the clade 2.1.3 virus A/Indonesia/5/2005 (IN5/05), the clade 2.2 viruses A/turkey/Turkey/1/2005 (TT01/05) and A/chicken/Egypt/3/2006 (CE/06), and the clade 2.3.4 virus A/Anhui/1/2005 (AH1/05) were constructed. These experimental live vaccines were assessed in a lethal mouse model. Mice vaccinated with the VN/1203 hemagglutinin-expressing MVA induced excellent protection against all the above mentioned clades. Also mice vaccinated with the IN5/05 HA expressing MVA induced substantial protection against homologous and heterologous AH1/05 challenge. After vaccination with the CE/06 HA expressing MVA, mice were fully protected against clade 2.2 challenge and partially protected against challenge of other clades. Mice vaccinated with AH1/05 HA expressing MVA vectors were only partially protected against homologous and heterologous challenge. The live vaccines induced substantial amounts of neutralizing antibodies, mainly directed against the homologous challenge virus, and high levels of HA-specific IFN-γ secreting CD4 and CD8 T-cells against epitopes conserved among the H5 clades and subclades.The highest level of cross-protection was induced by the HA derived from the VN/1203 strain, suggesting that pandemic H5 vaccines utilizing MVA vector technology, should be based on the VN/1203 hemagglutinin. Furthermore, the recombinant MVA-HA-VN, as characterized in the present study, would be a promising candidate for such a vaccine
Derivation of chicken induced pluripotent stem cells tolerant to Newcastle disease virus-induced lysis through multiple rounds of infection
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