Expression and regulation of antimicrobial peptides in mucosal immunity

Antimicrobial polypeptides (AMPs) are effector molecules of the innate immune defense. AMPs are mainly expressed in epithelial cells and immune cells, providing the first line of defense to infection as direct antimicrobials. In addition, many AMPs display immunomodulatory functions in both the adaptive and innate immune system. Thus, a tight control of AMP-expression is necessary for a functional immune response. In this thesis the antimicrobial polypeptide armament of neutrophils (PMNs) was evaluated for its activity against four human pathogens S. aureus, H. influenzae, M. catarrhalis and C. albicans. We observed a high degree of redundancy in antimicrobial activity for a majority of the AMPs. Still, some polypeptides exhibited a more specific activity against individual pathogens. This suggests that PMNs are equipped with a repertoire of antimicrobial peptides and proteins with broad activities, underscoring the importance of PMNs in the host response. In a clinical study the expressions of cathelicidin LL-37 and α-defensins HNP1-3 were quantified in nasal fluids of patients with primary immunodeficiencies (PIDs). Healthy controls and most PID patients responded to pathogens with increased levels of AMPs in their nasal fluid. Interestingly, in patients with common variable immune deficiency (CVID) and Hyper IgE syndrome (HIES), the levels of AMPs did not increase in response to pathogens. Thus, there is a dysregulation in AMP-release in CVID and HIES patients, which may explain why these patients suffer from frequent respiratory tract infections. Furthermore, we have detected an induced expression of AMPs by human breast milk in colonic epithelial cell lines. We isolated and characterized the inducing compound as lactose and noted that the inducing effect of the gene encoding LL-37 (CAMP) was dependent on intact p38 mitogen-activated protein kinase and c-Jun N-terminal kinase signaling. A strong synergistic effect on CAMP expression in HT-29 cells was observed in stimulations with lactose and phenylbutyrate or butyrate. This synergistic effect was further dissected by a proteomic approach. The subsequent pathway analysis of the proteomic results indicated that eleven pathways were activated. By using the novel CAMP gene reporter system we confirmed that the pathways of thyroid hormone receptor and retinoid X receptor (TR/RXR) activation, eicosanoid signaling and steroid biosynthesis were associated with the regulation of CAMP. In summary, AMPs exhibit both a large redundancy and strict specificity with regards to microbial killing. This may be relevant for certain disease conditions, where AMPs are lacking or dysregulated. Endogenous molecules, such as lactose and thyroid hormones are inducers of AMPs. In light of the wide-spread antibiotic resistance, attempts to strengthen epithelial barriers are highly warranted and the data presented here provide a concrete rationale for such studies

Metabolic and cometabolic degradation of herbicides in the fine material of railway ballast

Microbial degradation of 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron) and mineralization of 4-chloro-2-methylphenoxyacetic acid (MCPA) were studied in soil samples taken from the ballast layers of three Swedish railway embankments. The degradation of diuron followed first-order kinetics and half-lives ranged between 122 and 365 days. The half-lives correlated strongly with microbial biomass estimated by substrate-induced respiration (SIR; R=-0.85; p<0.05) and with the amount of organic matter measured as loss on ignition (R=-0.87; p<0.05). Accumulation of the metabolites 1-(3,4-dichlorophenyl)-3-methyl urea (DCPMU) and 1-(3,4-dichlorophenyl) urea (DCPU) was observed in all samples and these were only detectably degraded in the sample with the highest SIR. Addition of ground lucerne straw to the ballast samples stimulated microbial activity and led to increased formation of metabolites, but further transformation of DCPMU and DCPU was not enhanced. Mineralization of MCPA followed growth-linked kinetics and the time for 50% mineralization was 44.5±7.1 days in samples of previously untreated ballast. In samples of ballast that had been previously treated with the herbicide formulation MCPA 750, the time for 50% mineralization was reduced to 13.7±11.3 days. The number of MCPA degraders, quantified using an MPN technique, was clearly increased but highly variable. An average yield of 0.18 cells pg−1 of MCPA was estimated from the kinetic data. The yield estimates correlated with the amount of nitrogen in the ballast, indicating that mineralization of MCPA was nitrogen-limited in the railway embankments studied. This has practical implications for weed control using herbicides on railways

Viscoelastic properties of human and bovine articular cartilage : a comparison of frequency-dependent trends

Acknowledgments The authors would like to thank Spencer C. Barnes and Hamid Sadeghi for assistance during experimentation. We would also like to thank patients donating tissue and the surgeons collecting these. Funding The equipment used in this study was funded by Arthritis Research UK (Grant number H0671). We are grateful to Arthritis Research UK for the award of a PhD studentship to Anna A. Cederlund (Grant number 19971). Arthritis Research UK had no role in the design of the study and collection, analysis and interpretation of data and in writing the manuscript.Peer reviewedPublisher PD

Causes of non-malarial febrile illness in outpatients in Tanzania.

OBJECTIVE: In sub-Saharan Africa, the use of malaria rapid diagnostic tests (mRDT) has raised awareness of alternative fever causes in children but few studies have included adults. To address this gap, we conducted a study of mRDT-negative fever aetiologies among children and adults in Tanzania. METHODS: A total of 1028 patients aged 3 months to 50 years with a febrile illness and negative mRDT were enrolled from a Tanzanian hospital outpatient department. All had a physical examination and cultures from blood, nasopharynx/throat and urine. Patients were followed on Days 7 and 14 and children meeting WHO criteria for pneumonia were followed on Day 2 with chest radiology. RESULTS: Respiratory symptoms were the most frequent presenting complaint, reported by 20.3% of adults and 64.0% (339/530) of children. Of 38 X-rayed children meeting WHO pneumonia criteria, 47.4% had a normal X-ray. Overall, only 1.3% of 1028 blood cultures were positive. Salmonella typhi was the most prevalent pathogen isolated (7/13, 53.8%) and S. typhi patients reported fever for a median of 7 days (range 2-14). Children with bacteraemia did not present with WHO symptoms requiring antibiotic treatment. Young children and adults had similar prevalences of positive urine cultures (24/428 and 29/498, respectively). CONCLUSION: Few outpatient fevers are caused by blood stream bacterial infection, and most adult bacteraemia would be identified by current clinical guidelines although paediatric bacteraemia may be more difficult to diagnose. While pneumonia may be overdiagnosed, urinary tract infection was relatively common. Our results emphasise the difficulty in identifying African children in need of antibiotics among the majority who do not

Beyond climate envelope projections : roe deer survival and environmental change.

Research on climate change impacts has focused on projecting changes in the geographic ranges of species, with less emphasis on the vital rates giving rise to species distributions. Managing ungulate populations under future climate change will require an understanding of how their vital rates are affected by direct climatic effects and the indirect climatic and non-climatic effects that are often overlooked by climate impact studies. We used generalized linear models and capture–mark–recapture models to assess the influence of a variety of direct climatic, indirect climatic, and non-climatic predictors on the survival of roe deer (Capreolus capreolus) at 2 sites in Sweden. The models indicated that although direct climatic effects (e.g., precipitation) explained some variation in survival, indirect climatic effects (e.g., an index of vegetation production), and non-climatic effects (hunting by lynx [Lynx lynx] and humans) had greater explanatory power. Climate change is likely to increase vegetation productivity in northern Europe, and, coupled with the positive effects of vegetation productivity on roe deer survival, might lead to population increases in the future. Survival was negatively affected by lynx presence where these predators occur and by human harvest in the site that lacked predators. In the future, managers might find that a combination of increased harvest and predation by recovering carnivore populations may be necessary to mitigate climate-induced increases in roe deer survival. Considering vegetation availability and predation effects is likely to improve predictions of ungulate population responses to variation in climate and, therefore, inform management under future climate change

Cellular responses of Candida albicans to phagocytosis and the extracellular activities of neutrophils are critical to counteract carbohydrate starvation, oxidative and nitrosative stress

Acknowledgments We thank Alexander Johnson (yhb1D/D), Karl Kuchler (sodD/D mutants), Janet Quinn (hog1D/D, hog1/cap1D/D, trx1D/D) and Peter Staib (ssu1D/D) for providing mutant strains. We acknowledge helpful discussions with our colleagues from the Microbial Pathogenicity Mechanisms Department, Fungal Septomics and the Microbial Biochemistry and Physiology Research Group at the Hans Kno¨ll Institute (HKI), specially Ilse D. Jacobsen, Duncan Wilson, Sascha Brunke, Lydia Kasper, Franziska Gerwien, Sea´na Duggan, Katrin Haupt, Kerstin Hu¨nniger, and Matthias Brock, as well as from our partners in the FINSysB Network. Author Contributions Conceived and designed the experiments: PM HW IMB AJPB OK BH. Performed the experiments: PM CD HW. Analyzed the data: PM HW IMB AJPB OK BH. Wrote the paper: PM HW OK AJPB BH.Peer reviewedPublisher PD

From Olaus Magnus to Carl Reinhold Berch: on the background of Swedish marine archaeology and ship archaeology in the history of ideas

Der vorliegende Beitrag gibt einen Überblick über die in der frühen schwedischen Geschichtsschreibung seit der ersten Hälfte des 16. Jahrhunderts herrschenden Vorstellungen, deren Blickwinkel verrät, in welcher Weise man sich Schiffen sowie dem Leben auf und in der See zu früheren Zeiten annäherte. Es wird deutlich, dass sich gewisse historische Anschauungen durch die Jahrhunderte hindurchziehen, während andere ihr Erscheinungsbild wandelten, ohne jedoch ihre Kernaussage zu verändern. Wann immer seit Beginn des 19. Jahrhunderts schiffahrtsbezogene archäologische Funde oder Funde an unterseeischen bzw. überfluteten Plätzen als solche erkannt und dokumentiert werden, ist das auf sie bezogene Interesse motiviert durch lange bestehende historische Vorstellungen zur gesellschaftlichen Bedeutung des maritimen Aspekts. In Teilen decken sich diese mit den Vorstellungen, die um die Archäologie im allgemeinen kreisen, in anderen Fällen haben sie eine ganz besondere Ausprägung. Der Beitrag zeigt, dass die Ideen früherer Jahrhunderte auch heute noch sehr lebendig sein können, und blickt auf einige Beispiele archäologischer Funde an überschwemmten Orten bzw. Schiffsfunde des 19. Jahrhunderts zurück und zeichnet frühere Interpretationen meeres- und schiffsarchäologischen Fundmaterials in der um die schwedische und nordische Geschichtsschreibung kreisenden Geistesgeschichte seit dem 16. Jahrhundert nach. Anliegen des Beitrags ist es, daran zu erinnern, dass es für die Interpretationen und Schlüsse der heutigen Meeres- und Schiffsarchäologie wichtig ist, deren schon lange bestehende, zugrundeliegende Anschauungen zu verstehen, denn sie spielen für diese eine weitaus größere Rolle als man zunächst glauben mag

Antimicrobial Nodule-Specific Cysteine-Rich Peptides Induce Membrane Depolarization-Associated Changes in the Transcriptome of Sinorhizobium meliloti.

Leguminous plants establish symbiosis with nitrogen-fixing alpha- and betaproteobacteria, collectively called rhizobia, which provide combined nitrogen to support plant growth. Members of the inverted repeat-lacking clade of legumes impose terminal differentiation on their endosymbiotic bacterium partners with the help of the nodule-specific cysteine-rich (NCR) peptide family composed of close to 600 members. Among the few tested NCR peptides, cationic ones had antirhizobial activity measured by reduction or elimination of the CFU and uptake of the membrane-impermeable dye propidium iodide. Here, the antimicrobial spectrum of two of these peptides, NCR247 and NCR335, was investigated, and their effect on the transcriptome of the natural target Sinorhizobium meliloti was characterized. Both peptides were able to kill quickly a wide range of Gram-negative and Gram-positive bacteria; however, their spectra were only partially overlapping, and differences were found also in their efficacy on given strains, indicating that the actions of NCR247 and NCR335 might be similar though not identical. Treatment of S. meliloti cultures with either peptide resulted in a quick downregulation of genes involved in basic cellular functions, such as transcription-translation and energy production, as well as upregulation of genes involved in stress and oxidative stress responses and membrane transport. Similar changes provoked mainly in Gram-positive bacteria by antimicrobial agents were coupled with the destruction of membrane potential, indicating that it might also be a common step in the bactericidal actions of NCR247 and NCR335

MRI of the lung (3/3)-current applications and future perspectives

BACKGROUND: MRI of the lung is recommended in a number of clinical indications. Having a non-radiation alternative is particularly attractive in children and young subjects, or pregnant women. METHODS: Provided there is sufficient expertise, magnetic resonance imaging (MRI) may be considered as the preferential modality in specific clinical conditions such as cystic fibrosis and acute pulmonary embolism, since additional functional information on respiratory mechanics and regional lung perfusion is provided. In other cases, such as tumours and pneumonia in children, lung MRI may be considered an alternative or adjunct to other modalities with at least similar diagnostic value. RESULTS: In interstitial lung disease, the clinical utility of MRI remains to be proven, but it could provide additional information that will be beneficial in research, or at some stage in clinical practice. Customised protocols for chest imaging combine fast breath-hold acquisitions from a "buffet" of sequences. Having introduced details of imaging protocols in previous articles, the aim of this manuscript is to discuss the advantages and limitations of lung MRI in current clinical practice. CONCLUSION: New developments and future perspectives such as motion-compensated imaging with self-navigated sequences or fast Fourier decomposition MRI for non-contrast enhanced ventilation- and perfusion-weighted imaging of the lung are discussed. Main Messages • MRI evolves as a third lung imaging modality, combining morphological and functional information. • It may be considered first choice in cystic fibrosis and pulmonary embolism of young and pregnant patients. • In other cases (tumours, pneumonia in children), it is an alternative or adjunct to X-ray and CT. • In interstitial lung disease, it serves for research, but the clinical value remains to be proven. • New users are advised to make themselves familiar with the particular advantages and limitations

An investigation of spray drift deposition of glyphosate from an herbicide spraying train and its potential impact on non-target vegetation and railway ditches

Spray drift of glyphosate has the potential to affect non-target vegetation and surface waters close to the application area. To assess the likelihood of such impact along Swedish railways, four field experiments were conducted at three railway sites during 2019 and 2020. An herbicide spraying train applied herbicide Roundup Ultra (glyphosate) at speeds of 33 to 48 km/h. Quantitative filter papers were placed at 0.5, 1, 1.5, 2, 3 and 5 m distances to capture spray droplets. Wind speeds were low (0–2 m/s), but were found to be representative of normal operating conditions. Spray deposition decreased rapidly with distance, declining from 1800 g a.e./ha to an average of 5 g/ha within 1 m. Predicted 90th percentile drift rates suggested potential impact on vegetation within distance