Biophysical analysis of MarR family transcription factors from Streptomyces coelicolor

Streptomycetes represent a rich source of potentially useful therapeutics. However, in a laboratory environment, a large proportion of their secondary metabolite gene clusters remain silent, and thus their full metabolic potential is not realised. One way to unlock these so-called "cryptic" clusters may be to manipulate specific regulatory proteins. But, the vast majority of these regulators are uncharacterized, making it difficult to do this in a rational way. The MarR family of regulatory proteins (MFRs) represents an important group of transcriptional regulators. Named after the first to be characterized in Escherichia coli, the multiple antibiotic resistance repressor (MarR), the members of this family are involved in a number of biological processes which include antibiotic resistance, virulence, oxidative stress responses and pathogenesis and are therefore of significant clinical interest. There are 42 of these MFRs present in the genome of Streptomyces coelicolor, a prolific producer of secondary metabolites, the majority of which are uncharacterized. In this work, the crystal structures of three of these MFRs from Streptomyces coelicolor, Sco3914, Sco4122 and Sco5413, have been determined using anomalous dispersion methods. The structure of Sco5413 was determined to 1.25 Å resolution, the highest resolution for an MFR at this point. Genetic and biophysical analyses of these transcription factors have also been performed and the DNA footprints of Sco3914 and Sco4122 have been defined. Disruption mutants for each of the genes have been created and phenotypic analysis revealed a distinct phenotype for Sco5413. The structures do not reveal a ligand for any of the structures, but comparisons with other MFR structures provide some evidence towards a conserved ligand binding site amongst MFRs

Accelerating progress in the Replacement, Reduction and Refinement of animal testing through better knowledge sharing

In the context of the European Commission's Communication published in response to the European Citizens' Initiative "Stop Vivisection", Action 1 aimed to conduct an assessment of current technologies, information sources and networks from all relevant sectors with potential impact on the advancement of the refinement, reduction and replacement of animals used for scientific purposes (the "Three Rs"). The main objective of this study is to map knowledge sources relevant to the Three Rs, to examine how knowledge is being shared, and to identify possible gaps and opportunities to enhance knowledge sharing. An inventory of knowledge sources (KS) potentially relevant to the Three Rs used in the area of life sciences has been compiled which should be viewed as a snapshot of the current status of knowledge sources available (the supply), and as a starting point for further analysis of knowledge sharing strategies. A public survey was also conducted to complement this study (supply versus demand), and to inform on how to proceed effectively with any knowledge management strategy. The survey has revealed that many involved in this area consider that whilst access to relevant knowledge sources is adequate, there is a need for better coordination of the sources, as well as for the communication of information. Opportunities for face-to-face exchanges are highly valued and there is a firm call for more developments in education and training at professional, university and secondary school levels.JRC.F.3-Chemicals Safety and Alternative Method

EURL ECVAM Status Report on the Development, Validation and Regulatory Acceptance of Alternative Methods and Approaches (2016)

Replacement, Reduction and Refinement of animal testing is anchored in EU legislation. Alternative non-animal approaches facilitate a shift away from animal testing. Cell-based methods and computational technologies are integrated to translate molecular mechanistic understanding of toxicity into safety testing strategies.JRC.F.3-Chemicals Safety and Alternative Method

NASA Applied Sciences' DEVELOP Program Fosters the Next Generation of Earth Remote Sensing Scientists

Satellite remote sensing technology and the science associated with the evaluation of the resulting data are constantly evolving. To meet the growing needs related to this industry, a team of personnel that understands the fundamental science as well as the scientific applications related to remote sensing is essential. Therefore, the workforce that will excel in this field requires individuals who not only have a strong academic background, but who also have practical hands-on experience with remotely sensed data, and have developed knowledge of its real-world applications. NASA's DEVELOP Program has played an integral role in fulfilling this need. DEVELOP is a NASA Science Mission Directorate Applied Sciences training and development program that extends the benefits of NASA Earth science research and technology to society

Fusion Learning Conference 2021 - Supplement

This is a supplement to the proceedings of the 2021 Fusion Learning Conference held at Bournemouth University in the UK and contains material not previously published

EURL ECVAM status report on the development, validation and regulatory acceptance of alternative methods and approaches (2017)

Every year, EURL ECVAM prepares a Status Report with the primary purpose of which is to inform its stakeholders and all interested parties (the public, press etc.) on updates on the status of alternative methods and approaches. The EURL ECVAM status report provides updates on activities since the last report published in October 2016. It reports on research and development, validation activities as well as on activities which promote the regulatory and international adoption and use of alternative approaches and their dissemination. It describes primarily, but not exclusively, all the activities that EURL ECVAM has undertaken or has been involved in since the publication of the last report.JRC.F.3 - Chemicals Safety and Alternative Method

Fusion Learning Colloquium 2022 - Proceedings

This is the proceedings of the 2022 Fusion Learning Colloquium held at Bournemouth University in the UK

Long-term cellular immunity of vaccines for Zaire Ebola Virus Diseases

Recent Ebola outbreaks underscore the importance of continuous prevention and disease control efforts. Authorized vaccines include Merck’s Ervebo (rVSV-ZEBOV) and Johnson & Johnson’s two-dose combination (Ad26.ZEBOV/MVA-BN-Filo). Here, in a five-year follow-up of the PREVAC randomized trial (NCT02876328), we report the results of the immunology ancillary study of the trial. The primary endpoint is to evaluate long-term memory T-cell responses induced by three vaccine regimens: Ad26–MVA, rVSV, and rVSV–booster. Polyfunctional EBOV-specific CD4+ T-cell responses increase after Ad26 priming and are further boosted by MVA, whereas minimal responses are observed in the rVSV groups, declining after one year. In-vitro expansion for eight days show sustained EBOV-specific T-cell responses for up to 60 months post-prime vaccination with both Ad26-MVA and rVSV, with no decline. Cytokine production analysis identify shared biomarkers between the Ad26-MVA and rVSV groups. In secondary endpoint, we observed an elevation of pro-inflammatory cytokines at Day 7 in the rVSV group. Finally, we establish a correlation between EBOV-specific T-cell responses and anti-EBOV IgG responses. Our findings can guide booster vaccination recommendations and help identify populations likely to benefit from revaccination

Long-term cellular immunity of vaccines for Zaire Ebola Virus Diseases

Recent Ebola outbreaks underscore the importance of continuous prevention and disease control efforts. Authorized vaccines include Merck’s Ervebo (rVSV-ZEBOV) and Johnson & Johnson’s two-dose combination (Ad26.ZEBOV/MVA-BN-Filo). Here, in a five-year follow-up of the PREVAC randomized trial (NCT02876328), we report the results of the immunology ancillary study of the trial. The primary endpoint is to evaluate long-term memory T-cell responses induced by three vaccine regimens: Ad26–MVA, rVSV, and rVSV–booster. Polyfunctional EBOV-specific CD4+ T-cell responses increase after Ad26 priming and are further boosted by MVA, whereas minimal responses are observed in the rVSV groups, declining after one year. In-vitro expansion for eight days show sustained EBOV-specific T-cell responses for up to 60 months post-prime vaccination with both Ad26-MVA and rVSV, with no decline. Cytokine production analysis identify shared biomarkers between the Ad26-MVA and rVSV groups. In secondary endpoint, we observed an elevation of pro-inflammatory cytokines at Day 7 in the rVSV group. Finally, we establish a correlation between EBOV-specific T-cell responses and anti-EBOV IgG responses. Our findings can guide booster vaccination recommendations and help identify populations likely to benefit from revaccination

Evaluation of waning of IgG antibody responses after rVSVΔG-ZEBOV-GP and Ad26.ZEBOV, MVA-BN-Filo Ebola virus disease vaccines: a modelling study from the PREVAC randomized trial.

rVSVΔG-ZEBOV-GP and Ad26.ZEBOV, MVA-BN-Filo are WHO-prequalified vaccination regimens against Ebola virus disease (EVD). Challenges associated with measuring long-term clinical protection warrant the evaluation of immune response kinetics after vaccination. Data from a large phase 2 randomized double-blind clinical trial (PREVAC) were used to evaluate waning of anti-Ebola virus (EBOV) glycoprotein (GP1,2) antibody concentrations after rVSVΔG-ZEBOV-GP or Ad26.ZEBOV, MVA-BN-Filo vaccination with linear mixed-effect regression models. After a post-vaccination peak, each vaccination strategy was associated with a decrease of anti-EBOV GP1,2 antibody concentrations with distinct kinetics, highlighting a less-rapid decline in antibody levels after vaccination by rVSVΔG-ZEBOV-GP. One year after administration of the vaccine, antibody concentrations were higher in children compared to adults for both vaccines, although with different effect sizes: 1.74-fold higher concentrations (95% confidence interval [CI] [1.48; 2.02]) for children 12-17 years old to 3.10-fold higher concentrations (95% CI [2.58; 3.69]) for those 1-4 years old compared to adults for Ad26.ZEBOV, MVA-BN-Filo versus 1.36-fold (95% CI [1.12; 1.61]) to 1.41-fold (95% CI [1.21; 1.62]) higher than these values for adults, with relatively small changes from one age category of children to another, for rVSVΔG-ZEBOV-GP. Antibody concentrations also differed according to geographical location, pre-vaccination antibody concentration, and sex. In combination with knowledge on memory response, characterization of the major determinants of immune response durability of both vaccinations may guide future EVD control protocols.Trial registration: ClinicalTrials.gov identifier: NCT02876328