Search bioRxiv⌕ Search

Biology subjects

Cordwell, S. J.

Publications and source records attributed to Cordwell, S. J..

5 recordsLinked to original sources

Recently emerged Fusarium chemotypes reprogram wheat defence and detoxification networks during Fusarium head blight development

Fusarium head blight (FHB) is a major threat to global wheat production and food safety due to contamination with mycotoxins, such as deoxynivalenol (DON). The emergence of new mycotoxin chemotypes, including 7--hydroxy,15-deacetylcalonectrin (3ANX), presents an evolving challenge for disease management and resistance breeding. Here, we performed a field-based, systems-level proteome analysis of wheat infected with Fusarium graminearum strains belonging to the common 15ADON and recently emerged 15ADON/3ANX chemotypes. Across host and pathogen, we quantified more than 9,200 proteins, providing extensive coverage of infection-associated molecular responses. Infection with 15ADON/3ANX strains suppressed canonical wheat detoxification pathways while promoting structural and oxidative defence responses. Concurrently, the fungal proteome of 15ADON/3ANX-producing strains indicated altered mitochondrial ribosome function and alternative virulence strategies. Further investigation of the host-pathogen interface defined hub protein networks negatively regulating classical detoxification markers, suggesting coordinated regulation of host defence responses regardless of chemotype. Molecular responses were linked to field phenotypes by quantification of DON-3-glucoside/DON ratios and disease severity, defining positive correlations in 15ADON infections, which were abolished upon 15ADON/3ANX infection, indicating chemotype-specific evasion or suppression of host defenses. These findings demonstrate reprogramming of host-pathogen interaction networks and reveal molecular targets that may inform chemotype-aware breeding strategies to enhance crop resilience.

systems biology↗

Uncovering bacterial pseudaminylation with pan-specific antibody tools

Pseudaminic acids (Pse) are a family of carbohydrates found within bacterial lipopolysaccharides, capsular polysaccharides and glycoproteins that are critical for the virulence of human pathogens. However, a dearth of effective tools for detecting and enriching Pse has restricted study to only the most abundant Pse-containing glycoconjugates. Here, we devise a synthesis of - and {beta}-O-pseudaminylated glycopeptides to generate pan-specific monoclonal antibodies (mAbs) that recognise - and {beta}-configured Pse and its C8 epimer (8ePse) presented within glycans or directly linked to polypeptide backbones. Structural characterisation reveals the molecular basis of Pse recognition across a range of diverse chemical contexts. Using these mAbs, we establish a glycoproteomic platform to provide unprecedented depth in mapping the Pse glycome of Helicobacter pylori, Campylobacter jejuni, and Acinetobacter baumannii strains. Finally, we demonstrate that the mAbs recognise diverse capsule types in multidrug-resistant Acinetobacter baumannii and enhance phagocytosis to eliminate infections in mice.

biochemistry↗

Fecal microbial transfer and complex carbohydrates mediate protection against COPD

ObjectiveChronic obstructive pulmonary disease (COPD) is a major cause of global illness and death, most commonly caused by cigarette smoke. The mechanisms of pathogenesis remain poorly understood, limiting the development of effective therapies. The gastrointestinal microbiome has been implicated in chronic lung diseases via the gut-lung axis, but its role is unclear. DesignUsing an in vivo mouse model of cigarette smoke-induced COPD and fecal microbial transfer (FMT), we characterized the fecal microbiota using metagenomics, proteomics and metabolomics. Findings were correlated with airway and systemic inflammation, lung and gut histopathology, and lung function. Complex carbohydrates were assessed in mice using a high resistant starch diet, and in sixteen COPD patients using a randomized, double-blind, placebo-controlled pilot study of inulin supplementation. ResultsFMT alleviated hallmark features of COPD (inflammation, alveolar destruction, impaired lung function), gastrointestinal pathology and systemic immune changes. Protective effects were additive to smoking cessation. Disease features correlated with the relative abundance of Muribaculaceae, Desulfovibrionaceae and Lachnospiraceae family members. Proteomics and metabolomics identified downregulation of glucose and starch metabolism in cigarette smoke-associated microbiota, and supplementation of mice or human patients with complex carbohydrates improved disease outcomes. ConclusionThe gut microbiome contributes to COPD pathogenesis and can be targeted therapeutically. What is already known on this topicO_LIChanges in gut microbiota are associated with COPD but the underlying host and microbial mechanisms are unclear, limiting the therapeutic applications. C_LI What this study addsO_LIMicrobiome composition and metabolism is reproducibly correlated with lung and gastrointestinal pathology in experimental COPD. C_LIO_LIMicrobiome modifying interventions effectively alleviate disease, including protective effects supplementing smoking cessation. C_LIO_LINutritional interventions targeting the microbiome in COPD patients demonstrate efficacy in a small pilot study. C_LI How this study might affect research, practice or policyO_LIMicrobiome-targeting therapeutics and nutritional interventions may be developed for COPD, including as supplements to smoking cessation. C_LI

physiology↗

Standardization and Harmonization of Distributed Multi-National Proteotype Analysis supporting Precision Medicine Studies

Cancer has no borders: Generation and analysis of molecular data across multiple centers worldwide is necessary to gain statistically significant clinical insights for the benefit of patients. Here we conceived and standardized a proteotype data generation and analysis workflow enabling distributed data generation and evaluated the quantitative data generated across laboratories of the international Cancer Moonshot consortium. Using harmonized mass spectrometry (MS) instrument platforms and standardized data acquisition procedures, we demonstrated robust, sensitive, and reproducible data generation across eleven sites in nine countries on seven consecutive days in a 24/7 operation mode. The data presented from the high-resolution MS1-based quantitative data-independent acquisition (HRMS1-DIA) workflow shows that coordinated proteotype data acquisition is feasible from clinical specimens using such standardized strategies. This work paves the way for the distributed multi-omic digitization of large clinical specimen cohorts across multiple sites as a prerequisite for turning molecular precision medicine into reality.

molecular biology↗

Assigning a role for chemosensory signal transduction in Campylobacter jejuni biofilms using a combined omics approach

Biofilms serve as a protective mechanism for bacteria to cope with environmental stress. Whilst ordinarily a fastidious organism, it has been long suggested that C. jejuni is able to utilise this mode of growth as a way to transmit infection from the avian host to humans. Herein, we undertook a combinatorial approach to examine differential expression of C. jejuni genes and protein abundance during biofilm formation. RNA sequencing and proteomics via quantitative liquid chromatography - tandem mass spectrometry (LC-MS/MS) revealed biofilm growth induced a substantial rearrangement of the C. jejuni transcriptome and proteome, with [~]600 genes differentially expressed in biofilms compared to planktonic cells. Biofilm-induced genes / proteins were those involved in iron metabolism and acquisition, cell division, glycan production and attachment, while those repressed were associated with metabolism, amino acid uptake and utilisation, and large tracts of the chemotaxis pathway. We further examined the role of chemotaxis in C. jejuni biofilm formation by assessing the behaviour of isogenic strains with deletions of the cheV and cheW genes. Both {Delta}cheV and {Delta}cheW exhibited a significant decrease in directed motility when compared to wild-type C. jejuni. Both mutants also demonstrated an increase in autoagglutination ability and increased biofilm formation. A subtle difference was also observed between the phenotypes of {Delta}cheV and {Delta}cheW mutants, both in motility and biofilm formation. This suggests roles for the CheV and CheW signal transduction proteins and may present signal transduction as a potential method for modulating C. jejuni biofilm formation. Author summaryCampylobacter jejuni is a gastroenteric bacterium that is responsible for most cases of bacterial food poisoning in the developed world. The organism commonly resides in avian reservoirs and is passed to humans through contaminated poultry and animal products. Ordinarily, C. jejuni requires a strict set of conditions in order to survive and cause infections in humans. Biofilms are a method of bacterial growth that may provide shielding from harsh environments and provide an important link between reservoirs and human hosts. In this study, we have utilised a multi-platform approach to compare gene expression and protein abundance in planktonic C. jejuni cells and those growing as a biofilm. We subsequently focused on the chemosensory system of C. jejuni and demonstrated that signal transduction proteins play a role in biofilm formation. Our work has provided a broad profile of which genes are important to C. jejuni biofilms and that the chemosensory pathway has an influence on biofilm formation.

microbiology↗