Adenovirus Strategies For Altering The Cellular Environment In Favor Of Infection

Viruses, as obligate intracellular pathogens, rely on their host cell for successful replication. Viruses have evolved different strategies to hijack and redirect cellular processes to benefit infection and overcome host immune responses. Understanding the mechanisms by which viruses exploit their host cells will reveal new targets for antiviral therapies. In addition, these studies can provide insights into the regulation of fundamental cellular processes. While much progress has been made in this area, many unexpected nuances of virus-host interaction are still being discovered. Here, we employed several strategies to uncover new aspects of viral manipulation of the host environment by adenovirus, a nuclear-replicating DNA virus that commonly infects humans. The first project focused on how viral histone-like proteins impact cellular chromatin. Adenovirus encodes the small, basic protein VII that coats and condenses viral genomes. The effect of this viral DNA-binding protein on host chromatin structure and function had remained unexplored. Here we demonstrated that protein VII interacts with host nucleosomes and is sufficient to alter nuclear morphology. We also identified post-translational modifications of protein VII that regulate chromatin association. Through a proteomics analysis of chromatin composition, we revealed that protein VII causes nuclear retention of HMGB1, a host alarmin, and reduces downstream inflammation. The second project examined roles of viral-mediated ubiquitination during infection. Ubiquitination of host proteins, mediated by adenovirus proteins E1B55K and E4orf6, is important for viral RNA processing. However, previously identified substrates of viral-mediated ubiquitination do not explain this phenotype. Here we used a proteomics approach to define new substrates of the E1B55K/E4orf6 complex. We uncovered viral-mediated ubiquitination of RNA-binding proteins (RBPs) which, unlike ubiquitination of other substrates, does not result in proteasomal degradation. We furthermore demonstrated that ubiquitination of RBPs RALY and hnRNP-C decreases their binding to viral RNA and relieves a restriction these host proteins exert on adenovirus RNA processing. Our study of adenovirus proteins revealed new strategies employed by viruses to alter host functions: manipulating host chromatin through viral histone-like proteins to dampen immune responses and regulating RNA processing by non-degradative ubiquitination of cellular RBPs

Retroviruses use CD169-mediated trans-infection of permissive lymphocytes to establish infection

Dendritic cells can capture and transfer retroviruses in vitro across synaptic cell-cell contacts to uninfected cells, a process called trans-infection. Whether trans-infection contributes to retroviral spread in vivo remains unknown. Here, we visualize how retroviruses disseminate in secondary lymphoid tissues of living mice. We demonstrate that murine leukemia virus (MLV) and human immunodeficiency virus (HIV) are first captured by sinus-lining macrophages. CD169/Siglec-1, an I-type lectin that recognizes gangliosides, captures the virus. MLV-laden macrophages then form long-lived synaptic contacts to trans-infect B-1 cells. Infected B-1 cells subsequently migrate into the lymph node to spread the infection through virological synapses. Robust infection in lymph nodes and spleen requires CD169, suggesting that a combination of fluid-based movement followed by CD169-dependent trans-infection can contribute to viral spread

Optimized utilization of Salix-Perspectives for the genetic improvement toward sustainable biofuel value chains

Bioenergy will be one of the most important renewable energy sources in the conversion from fossil fuels to bio-based products. Short rotation coppice Salix could be a key player in this conversion since Salix has rapid growth, positive energy balance, easy to manage cultivation system with vegetative propagation of plant material and multiple harvests from the same plantation. The aim of the present paper is to provide an overview of the main challenges and key issues in willow genetic improvement toward sustainable biofuel value chains. Primarily based on results from the research project "Optimized Utilization of Salix" (OPTUS), the influence of Salix wood quality on the potential for biofuel use is discussed, followed by issues related to the conversion of Salix biomass into liquid and gaseous transportation fuels. Thereafter, the studies address genotypic influence on soil carbon sequestration in Salix plantations, as well as on soil carbon dynamics and climate change impacts. Finally, the opportunities for plant breeding are discussed using willow as a resource for sustainable biofuel production. Substantial phenotypic and genotypic variation was reported for different wood quality traits important in biological (i.e., enzymatic and anaerobic) and thermochemical conversion processes, which is a prerequisite for plant breeding. Furthermore, different Salix genotypes can affect soil carbon sequestration variably, and life cycle assessment illustrates that these differences can result in different climate mitigation potential depending on genotype. Thus, the potential of Salix plantations for sustainable biomass production and its conversion into biofuels is shown. Large genetic variation in various wood and biomass traits, important for different conversion processes and carbon sequestration, provides opportunities to enhance the sustainability of the production system via plant breeding. This includes new breeding targets in addition to traditional targets for high yield to improve biomass quality and carbon sequestration potential

Citizen science’s transformative impact on science, citizen empowerment and socio-political processes

Citizen science (CS) can foster transformative impact for science, citizen empowerment and socio-political processes. To unleash this impact, a clearer understanding of its current status and challenges for its development is needed. Using quantitative indicators developed in a collaborative stakeholder process, our study provides a comprehensive overview of the current status of CS in Germany, Austria and Switzerland. Our online survey with 340 responses focused on CS impact through (1) scientific practices, (2) participant learning and empowerment, and (3) socio-political processes. With regard to scientific impact, we found that data quality control is an established component of CS practice, while publication of CS data and results has not yet been achieved by all project coordinators (55%). Key benefits for citizen scientists were the experience of collective impact (“making a difference together with others”) as well as gaining new knowledge. For the citizen scientists’ learning outcomes, different forms of social learning, such as systematic feedback or personal mentoring, were essential. While the majority of respondents attributed an important value to CS for decision-making, only few were confident that CS data were indeed utilized as evidence by decision-makers. Based on these results, we recommend (1) that project coordinators and researchers strengthen scientific impact by fostering data management and publications, (2) that project coordinators and citizen scientists enhance participant impact by promoting social learning opportunities and (3) that project initiators and CS networks foster socio-political impact through early engagement with decision-makers and alignment with ongoing policy processes. In this way, CS can evolve its transformative impact

Grundwasser - Altlasten aktuell

Neun Fachbeiträge dokumentieren die Ergebnisse der aktuellen Projekt- und Forschungsarbeit des Landesamtes im Bereich Grundwasser und Altlasten. Themen sind u. a. diffuse Schwermetallbelastungen in 10 Grundwasserkörpern, die nach Wasserrahmenrichtlinie im schlechten chemischen Zustand ausgewiesen wurden, die Umsetzung der EG-Wasserrahmenrichtlinie in von Punktquellen beeinflussten Grundwasserkörpern und die bisherigen Ergebnisse des internationalen Projektes SHARP. Weitere Beiträge befassen sich mit dem Bearbeitungsstand und dem Handlungsbedarf der im Sächsischen Altlastenkataster (SALKA) erfassten Flächen, dem Gefährdungspotenzial von Gärtnereien und den altlastenbezogenen Bewertungs- und Analyseempfehlungen für kurzkettige Alkylphenole

Charge Delocalization in an Organic Mixed Valent Bithiophene Is Greater Than in a Structurally Analogous Biselenophene

A series of selenophenes with redox-active amine end-capping groups was synthesized and investigated. A combination of cyclic voltammetry, optical absorption, EPR spectroscopy, and quantum-chemical calculations based on Kohn–Sham density functional theory was used to explore charge delocalization in the monocationic mixed-valence forms of these selenophenes, and the results were compared to those obtained from analogous studies of structurally identical thiophenes. The striking finding is that the comproportionation constant (Kc) for the experimentally investigated biselenophene is more than 2 orders of magnitude lower than for its bithiophene counterpart (in CH3CN with 0.1 M TBAPF6), and the electronic coupling between the two amine end-capping groups in the mixed-valent biselenophene monocation is only roughly half as strong as in the corresponding bithiophene monocation. These are surprisingly large differences given the structural similarity between the respective biselenophene and bithiophene molecules. However, the computationally determined comproportionation constants for biselenophene and bithiophene are almost identical, and the electronic coupling in the monocationic biselenophene is only slightly smaller than that in the monocationic bithiophene. We assume that the external electric field may be responsible for the differences in monocation stabilities between experiment and computation. Our findings indicate that charge delocalization across individual selenophenes tends to be less pronounced than across individual thiophenes, and this may have important implications for long-range charge transfer across selenophene oligomers or polymers