Structural analysis of Salmonella enterica effector protein SopD

Salmonella outer protein D (SopD) is a type III secreted virulence effector protein from Salmonella enterica. Full-length SopD and SopD lacking 16 amino acids at the N-terminus (SopDDeltaN) have been expressed as fusions with GST in Escherichia coli, purified with a typical yield of 20-30 mg per litre of cell culture and crystallized. Biophysical characterization has been carried out mainly on SopDDeltaN. Analytical size exclusion chromatography shows that SopDDeltaN is monomeric and probably globular in aqueous solution. The secondary structure composition, calculated from the CD spectrum, is mixed (38% alpha-helix and 26% beta-strand). Sequence analysis indicates that SopD contains a coiled coil motif, as found in numerous other type III secretion system-associated proteins. This suggests that SopD has the potential for one or more heterotypic protein-protein interactions. Limited trypsin digestion of SopDDeltaN, monitored by both one-dimensional proton NMR spectroscopy and SDS-PAGE, shows that the protein has a large, protease-resistant core domain of 286 amino acid residues. This single-domain architecture suggests that SopD lacks a cognate chaperone. In crystallization trials, SopDDeltaN produced better crystals than either full-length SopD or trypsin-digested SopDDeltaN. Diffraction to 3.0 Angstrom resolution has so far been obtained from crystals of SopDDeltaN

Интеллектуалы в дискурсе власти постсовременности

Background: It is suggested that allergic immune activation, combined with a genetic predisposition, may contribute to the expression of aberrant social behaviour relevant to autism. We have previously shown that a food allergic response reduced social behaviour in mice, which was associated with altered dopaminergic activity in brain regions relevant for social and emotional behaviour. Dietary fatty acid composition has been shown to affect both the immune system and neurological processes and may therefore contribute to the prevention of food allergy-induced abnormalities in social behaviour. Method: The aim of this study was to assess whether dietary supplementation with fish oil rich in long chain omega-3 polyunsaturated fatty acids (n-3 LCPUFA) prevents food allergy-induced abnormalities in social behaviour and associated deficits of the dopaminergic system in the prefrontal cortex of whey-sensitised mice. Results: The n-3 LCPUFA-enriched fish oil diet decreased the acute allergic skin response and was able to prevent the disturbance in social behaviour of whey-sensitised mice. N-3 LCPUFA supplementation increased docosahexaenoic acid (DHA) incorporation in the brain and restored levels of dopamine and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC), 3-methoxytyramine (3-MT) and homovanillic acid (HVA) in the prefrontal cortex of allergic mice. Moreover, reduced levels of 5-HIAA, metabolite of serotonin, in intestines of allergic mice was also restored by the n-3 LCPUFA-enriched diet. Conclusion: In addition to its effects on the allergic skin response, n-3 LCPUFA restored allergy-induced deficits in social behaviour and in prefrontal dopamine and metabolite levels. Therefore, n-3 LCPUFA may exert its beneficial effect on behaviour via modulation of the dopaminergic system in the prefrontal cortex and may therefore be an interesting target in the use of dietary interventions for immune-mediated psychiatric disorders such as ASD

Soil-Improving Cropping Systems for Sustainable and Profitable Farming in Europe

Soils form the basis for agricultural production and other ecosystem services, and soil management should aim at improving their quality and resilience. Within the SoilCare project, the concept of soil-improving cropping systems (SICS) was developed as a holistic approach to facilitate the adoption of soil management that is sustainable and profitable. SICS selected with stakeholders were monitored and evaluated for environmental, sociocultural, and economic effects to determine profitability and sustainability. Monitoring results were upscaled to European level using modelling and Europe-wide data, and a mapping tool was developed to assist in selection of appropriate SICS across Europe. Furthermore, biophysical, sociocultural, economic, and policy reasons for (non)adoption were studied. Results at the plot/farm scale showed a small positive impact of SICS on environment and soil, no effect on sustainability, and small negative impacts on economic and sociocultural dimensions. Modelling showed that different SICS had different impacts across Europe-indicating the importance of understanding local dynamics in Europe-wide assessments. Work on adoption of SICS confirmed the role economic considerations play in the uptake of SICS, but also highlighted social factors such as trust. The project's results underlined the need for policies that support and enable a transition to more sustainable agricultural practices in a coherent way

Prospective evaluation of improving fluoroquinolone exposure using centralised therapeutic drug monitoring (TDM) in patients with tuberculosis (PERFECT): a study protocol of a prospective multicentre cohort study

Introduction Global multidrug-resistant tuberculosis (MDR-TB) treatment success rates remain suboptimal. Highly active WHO group A drugs moxifloxacin and levofloxacin show intraindividual and interindividual pharmacokinetic variability which can cause low drug exposure. Therefore, therapeutic drug monitoring (TDM) of fluoroquinolones is recommended to personalise the drug dosage, aiming to prevent the development of drug resistance and optimise treatment. However, TDM is considered laborious and expensive, and the clinical benefit in MDR-TB has not been extensively studied. This observational multicentre study aims to determine the feasibility of centralised TDM and to investigate the impact of fluoroquinolone TDM on sputum conversion rates in patients with MDR-TB compared with historical controls. Methods and analysis Patients aged 18 years or older with sputum smear and culture-positive pulmonary MDR-TB will be eligible for inclusion. Patients receiving TDM using a limited sampling strategy (t=0 and t=5 hours) will be matched to historical controls without TDM in a 1:2 ratio. Sample analysis and dosing advice will be performed in a centralised laboratory. Centralised TDM will be considered feasible if >80% of the dosing recommendations are returned within 7 days after sampling and 100% within 14 days. The number of patients who are sputum smear and culture-negative after 2 months of treatment will be determined in the prospective TDM group and will be compared with the control group without TDM to determine the impact of TDM. Ethics and dissemination Ethical clearance was obtained by the ethical review committees of the 10 participating hospitals according to local procedures or is pending (online supplementary file 1). Patients will be included after obtaining written informed consent. We aim to publish the study results in a peer-reviewed journal. Trial registration number ClinicalTrials.gov Registry (NCT03409315)

Trypanosoma brucei Modifies the Tsetse Salivary Composition, Altering the Fly Feeding Behavior That Favors Parasite Transmission

Tsetse flies are the notorious transmitters of African trypanosomiasis, a disease caused by the Trypanosoma parasite that affects humans and livestock on the African continent. Metacyclic infection rates in natural tsetse populations with Trypanosoma brucei, including the two human-pathogenic subspecies, are very low, even in epidemic situations. Therefore, the infected fly/host contact frequency is a key determinant of the transmission dynamics. As an obligate blood feeder, tsetse flies rely on their complex salivary potion to inhibit host haemostatic reactions ensuring an efficient feeding. The results of this experimental study suggest that the parasite might promote its transmission through manipulation of the tsetse feeding behavior by modifying the saliva composition. Indeed, salivary gland Trypanosoma brucei-infected flies display a significantly prolonged feeding time, thereby enhancing the likelihood of infecting multiple hosts during the process of a single blood meal cycle. Comparison of the two major anti-haemostatic activities i.e. anti-platelet aggregation and anti-coagulation activity in these flies versus non-infected tsetse flies demonstrates a significant suppression of these activities as a result of the trypanosome-infection status. This effect was mainly related to the parasite-induced reduction in salivary gland gene transcription, resulting in a strong decrease in protein content and related biological activities. Additionally, the anti-thrombin activity and inhibition of thrombin-induced coagulation was even more severely hampered as a result of the trypanosome infection. Indeed, while naive tsetse saliva strongly inhibited human thrombin activity and thrombin-induced blood coagulation, saliva from T. brucei-infected flies showed a significantly enhanced thrombinase activity resulting in a far less potent anti-coagulation activity. These data clearly provide evidence for a trypanosome-mediated modification of the tsetse salivary composition that results in a drastically reduced anti-haemostatic potential and a hampered feeding performance which could lead to an increase of the vector/host contact and parasite transmission in field conditions