Inhibition of Haemonchus contortus larval development by fungal lectins

BACKGROUND Lectins are carbohydrate-binding proteins that are involved in fundamental intra- and extracellular biological processes. They occur ubiquitously in nature and are especially abundant in plants and fungi. It has been well established that certain higher fungi produce lectins in their fruiting bodies and/or sclerotia as a part of their natural resistance against free-living fungivorous nematodes and other pests. Despite relatively high diversity of the glycan structures in nature, many of the glycans targeted by fungal lectins are conserved among organisms of the same taxon and sometimes even among different taxa. Such conservation of glycans between free-living and parasitic nematodes is providing us with a useful tool for discovery of novel chemotherapeutic and vaccine targets. In our study, a subset of fungal lectins emanating from toxicity screens on Caenorhabditis elegans was tested for their potential to inhibit larval development of Haemonchus contortus. METHODS The effect of Coprinopsis cinerea lectins - CCL2, CGL2, CGL3; Aleuria aurantia lectin - AAL; Marasmius oreades agglutinin - MOA; and Laccaria bicolor lectin - Lb-Tec2, on cultivated Haemonchus contortus larval stages was investigated using a larval development test (LDT). To validate the results of the toxicity assay and determine lectin binding capacity to the nematode digestive tract, biotinylated versions of lectins were fed to pre-infective larval stages of H. contortus and visualized by fluorescent microscopy. Lectin histochemistry on fixed adult worms was performed to investigate the presence and localisation of lectin binding sites in the disease-relevant developmental stage. RESULTS Using an improved larval development test we found that four of the six tested lectins: AAL, CCL2, MOA and CGL2, exhibited a dose-dependent toxicity in LDT, as measured by the number of larvae developing to the L3 stage. In the case of AAL, CGL2 and MOA lectin, doses as low as 5 μg/ml caused >95 % inhibition of larval development while 40 μg/ml were needed to achieve the same inhibition by CCL2 lectin. MOA was the only lectin tested that caused larval death while other toxic lectins had larvistatic effect manifesting as L1 growth arrest. Using lectin histochemistry we demonstrate that of all lectins tested, only the four toxic ones displayed binding to the larvae's gut and likewise were found to interact with glycans localized to the gastrodermal tissue of adults. CONCLUSION The results of our study suggest a correlation between the presence of target glycans of lectins in the digestive tract and the lectin-mediated toxicity in Haemonchus contortus. We demonstrate that binding to the structurally conserved glycan structures found in H. contortus gastrodermal tissue by the set of fungal lectins has detrimental effect on larval development. Some of these glycan structures might represent antigens which are not exposed to the host immune system (hidden antigens) and thus have a potential for vaccine or drug development. Nematotoxic fungal lectins prove to be a useful tool to identify such targets in parasitic nematodes

Rapid Affinity Purification of Tagged Plant Mitochondria (Mito-AP) for Metabolome and Proteome Analyses

The isolation of organelles facilitates the focused analysis of subcellular protein and metabolite pools. Here we present a technique for the affinity purification of plant mitochondria (Mito-AP). The stable ectopic expression of a mitochondrial outer membrane protein fused to a GFP:Strep tag in Arabidopsis (Arabidopsis thaliana) exclusively decorates mitochondria, enabling their selective affinity purification using magnetic beads coated with Strep-Tactin. With Mito-AP, intact mitochondria from 0.5 g plant material were highly enriched in 30–60 min, considerably faster than with conventional gradient centrifugation. Combining gradient centrifugation and Mito-AP techniques resulted in high purity of >90% mitochondrial proteins in the lysate. Mito-AP supports mitochondrial proteome analysis by shotgun proteomics. The relative abundances of proteins from distinct mitochondrial isolation methods were correlated. A cluster of 619 proteins was consistently enriched by all methods. Among these were several proteins that lack subcellular localization data or that are currently assigned to other compartments. Mito-AP is also compatible with mitochondrial metabolome analysis by triple-quadrupole and orbitrap mass spectrometry. Mito-AP preparations showed a strong enrichment with typical mitochondrial lipids like cardiolipins and demonstrated the presence of several ubiquinones in Arabidopsis mitochondria. Affinity purification of organelles is a powerful tool for reaching higher spatial and temporal resolution for the analysis of metabolomic and proteomic dynamics within subcellular compartments. Mito-AP is small scale, rapid, economic, and potentially applicable to any organelle or to organelle subpopulations

Patient and healthcare professional eHealth literacy and needs for systemic sclerosis support: a mixed methods study

OBJECTIVES: We engaged patients with systemic sclerosis (SSc) and healthcare professionals to assess electronic health (eHealth) literacy and needs relating to web-based support using internet-based information and communication technologies (ICT). METHODS: We employed an explanatory sequential mixed methods design. First, we conducted a cross-sectional survey in patients (n=101) and professionals (n=47). Next, we conducted three focus groups with patients, family members and professionals (n=17). RESULTS: Of patients, 89.1% used ICT at least weekly for private communication. Patients reported relatively high comprehension of eHealth information ([Formula: see text] =6.7, 95% CI: 6.2 to 7.3, range 1-10), yet were less confident evaluating information reliability ([Formula: see text] =5.8, 95% CI: 5.1 to 6.4) and finding eHealth apps ([Formula: see text] =4.8, 95% CI: 4.2 to 5.4). Patients and professionals reported little experience with web-based self-management support. Focus groups revealed 'considering non-ICT-accessible groups' and 'fitting patients' and professionals' technology' as crucial for acceptability. In relation to understanding/appraising eHealth, participants highlighted that general SSc information is not tailored to individual's disease course. Recommendations included 'providing timely, understandable and safe information' and 'empowering end-users in ICT and health decision-making skills'. Professionals expressed concerns about lacking resources. Patients were concerned about data security and person-centredness. Key eHealth drivers included 'addressing end-user perceptions' and 'putting people at the centre of technology'. CONCLUSIONS: Patients and professionals need education/training to support uptake of eHealth resources. Key elements include guiding patients to timely/reliable information and using eHealth to optimise patient-provider communication. Design that is responsive to end-users' needs and considers individuals with limited eHealth literacy and/or ICT access appears to be critical for acceptability

Patient Assessment Chronic Illness Care (PACIC) and its associations with quality of life among Swiss patients with systemic sclerosis: a mixed methods study

BACKGROUND: The Chronic Care Model (CCM) is a longstanding and widely adopted model guiding chronic illness management. Little is known about how CCM elements are implemented in rare disease care or how patients' care experiences relate to health-related quality of life (HRQoL). We engaged patients living with systemic sclerosis (SSc) to assess current care according to the CCM from the patient perspective and their HRQoL. METHODS: We employed an explanatory sequential mixed methods design. First, we conducted a cross-sectional quantitative survey (n = 101) using the Patient Assessment of Chronic Illness Care (PACIC) and Systemic Sclerosis Quality of Life (SScQoL) questionnaires. Next, we used data from individual patient interviews (n = 4) and one patient focus group (n = 4) to further explore care experiences of people living with SSc with a focus on the PACIC dimensions. RESULTS: The mean overall PACIC score was 3.0/5.0 (95% CI 2.8-3.2, n = 100), indicating care was 'never' to 'generally not' aligned with the CCM. Lowest PACIC subscale scores related to 'goal setting/tailoring' (mean = 2.5, 95% CI 2.2-2.7) and 'problem solving/contextual counselling' (mean = 2.9, 95% CI 2.7-3.2). No significant correlations were identified between the mean PACIC and SScQoL scores. Interviews revealed patients frequently encounter major shortcomings in care including 'experiencing organized care with limited participation', 'not knowing which strategies are effective or harmful' and 'feeling left alone with disease and psychosocial consequences'. Patients often responded to challenges by 'dealing with the illness in tailored measure', 'taking over complex coordination of care' and 'relying on an accessible and trustworthy team'. CONCLUSIONS: The low PACIC mean overall score is comparable to findings in patients with common chronic diseases. Key elements of the CCM have yet to be systematically implemented in Swiss SSc management. Identified gaps in care related to lack of shared decision-making, goal-setting and individual counselling-aspects that are essential for supporting patient self-management skills. Furthermore, there appears to be a lack of complex care coordination tailored to individual patient needs

A rare disease patient-reported outcome measure: revision and validation of the German version of the Systemic Sclerosis Quality of Life Questionnaire (SScQoL) using the Rasch model

Background: Rare disease patient-reported outcome measures (PROMs) require linguistic adaptation to overcome the challenge of geographically dispersed patient populations. Importantly, PROMs such as health-related quality of life (HRQoL) should accurately capture responses to patient-identified concerns. The Systemic Sclerosis Quality of Life Questionnaire (SScQoL) is a 29-item tool validated in six languages. Previous evaluation of the German version revealed problems with dichotomous responses. This study aimed to revise the German SScQoL, extend the response structure, and evaluate content and construct validity, reliability and unidimensionality. Methods: The instrument validation study involved revising the German SScQoL response structure, cognitive debriefing with patients and validation using Rasch analysis. The revised SScQoL was completed by Swiss-German-speaking patients with SSc within the Swiss MANagement Of Systemic Sclerosis (MANOSS) study. Rasch analysis was employed to test the validity, reliability and unidimensionality of the revised instrument. Results: Based on cognitive debriefing with patients (n = 6) dichotomous items were extended to a polytomous 4-point response structure. A total of 78 patients completed the revised SScQoL. Initial analysis of the 29 items suggested the scale lacked fit to the model (χ2 = 51.224, df = 29, p = 0.007). Grouping items into five domains resulted in an adequate fit to the Rasch model (χ2 = 5.343, df = 5, p = 0.376) and unidimensionality (proportion of significant independent t tests: 0.045, 95% CI 0.016–0.114). Overall, the scale was well targeted, had high internal consistency (Person Separation Index, PSI = 0.931) and worked consistently in patients with different demographic and clinical characteristics. Conclusions: The revised German SScQoL has a 4-point response structure and is a valid, reliable measure. Rasch analysis is useful for validating continuous response structure of quality of life measures. Further evaluation of measurement equivalence with other German-speaking cultures is required for multinational comparisons and data pooling

Caenorhabditis elegans N-glycan Core β-galactoside Confers Sensitivity towards Nematotoxic Fungal Galectin CGL2

The physiological role of fungal galectins has remained elusive. Here, we show that feeding of a mushroom galectin, Coprinopsis cinerea CGL2, to Caenorhabditis elegans inhibited development and reproduction and ultimately resulted in killing of this nematode. The lack of toxicity of a carbohydrate-binding defective CGL2 variant and the resistance of a C. elegans mutant defective in GDP-fucose biosynthesis suggested that CGL2-mediated nematotoxicity depends on the interaction between the galectin and a fucose-containing glycoconjugate. A screen for CGL2-resistant worm mutants identified this glycoconjugate as a Galβ1,4Fucα1,6 modification of C. elegans N-glycan cores. Analysis of N-glycan structures in wild type and CGL2-resistant nematodes confirmed this finding and allowed the identification of a novel putative glycosyltransferase required for the biosynthesis of this glycoepitope. The X-ray crystal structure of a complex between CGL2 and the Galβ1,4Fucα1,6GlcNAc trisaccharide at 1.5 Å resolution revealed the biophysical basis for this interaction. Our results suggest that fungal galectins play a role in the defense of fungi against predators by binding to specific glycoconjugates of these organisms