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Simon Leedham has been one of this year's recepients of Cancer Research UK's "Future Leaders" prizes.
Pericardial and mediastinal fat-associated lymphoid clusters are rapidly activated in an alkane-induced model of systemic lupus erythematosus.
Systemic lupus erythematosus (SLE) is an autoimmune disease predominated by auto-antibodies that recognise cellular components. Pleural involvement is the most common SLE-related lung disease. Natural antibodies are rapidly secreted by innate-like B cells following perturbation of homeostasis and are important in the early stages of immune activation. The serous cavities are home to large numbers of innate-like B cells present both within serous fluid and resident within fat-associated lymphoid clusters (FALCs). FALCs are important hubs for B-cell activation and local antibody secretion within the body cavities. Patients with SLE can develop anti-phospholipid antibodies and in rare situations develop alveolar haemorrhage. Utilising delivery of the hydrocarbon oil pristane in C57BL/6 mice as a model of SLE we identify a rapid expansion of pleural cavity B cells as early as day 3 after intra-peritoneal pristane delivery. Following pristane delivery, pericardial B1 B cells are proliferative, express the plasma-cell surface marker CD138, and secrete both innate and class-switched antibodies highlighting that this cavity niche may play an unrecognised role in the initiation of lupus pleuritis.
Developing the next-generation of adenoviral vector vaccines.
The COVID-19 pandemic saw the first extensive use of adenoviral vector vaccines, with over 3 billion doses produced during the first year of the pandemic alone and an estimated 6 million lives saved. These vaccines were safe and effective, and could be produced at low cost in several continents allowing widespread use in low- and middle-income countries (LMICs). Despite their successful deployment against SARS-CoV-2, their impact has been overshadowed by relatively lower immunogenicity in contrast to mRNA vaccine technologies and very rare but serious adverse events such as vaccine-induced thrombotic thrombocytopaenia (VITT). The next-generation of adenoviral vector vaccines must address these challenges: here, we explore strategies to improve immunogenicity and safety by novel serotype selection, vector engineering, capsid modification and new delivery technologies, and discuss opportunities for next-generation adenoviral vectors against infectious disease and cancer.
Synovial tissue atlas in juvenile idiopathic arthritis reveals pathogenic niches associated with disease severity
Precision application of targeted therapies is urgently needed to improve long-term clinical outcomes for children affected by inflammatory arthritis, known as juvenile idiopathic arthritis (JIA). Progress has been hampered by our limited understanding of the cellular basis of inflammation in the target tissue of the disease, the synovial membrane. Here, we analyzed biopsies from the inflamed joints of treatment-naïve children with JIA, early in the course of their disease, using single-cell RNA sequencing, multiplexed immunofluorescence, and spatial transcriptomics to establish a cellular atlas of the JIA synovium. We identified distinct spatial tissue niches, composed of specific stromal and immune cell populations. In addition, we localized genes linked to arthritis severity and disease risk to effector cell populations, including tissue resident SPP1 + macrophages and fibrin-associated myeloid cells. Combined analyses of synovial fluid and peripheral blood from matched individuals revealed differences in cellular composition, signaling pathways, and transcriptional programs across these distinct anatomical compartments. Furthermore, our analysis revealed several pathogenic cell populations that are shared with adult-onset inflammatory arthritis, as well as age-associated differences in tissue vascularity, prominence of innate immunity, and enrichment of TGF-β–responsive stromal subsets that up-regulate expression of disease risk–associated genes. Overall, our findings demonstrate the need for age-specific analyses of synovial tissue pathology to guide targeted treatment strategies in JIA.
Evaluation of the Wondfo G6PD/Hb Test for glucose-6-phosphate dehydrogenase deficiency: preliminary performance, matrix equivalence, and usability.
BackgroundCurrent treatment guidelines for radical cure of Plasmodium vivax malaria recommend the use of 8-aminoquinolines, which can result in life-threatening complications in people with glucose-6-phsophate dehydrogenase (G6PD) deficiency. Testing for this condition is recommended prior to administering such drugs. The Wondfo G6PD/Hb Test (Guangzhou Wondfo Biotech Co., Ltd., China) is a novel, quantitative point-of-care (POC) G6PD test that may help decentralize testing, expanding access to safe treatment options.MethodsTwo studies were conducted: a retrospective diagnostic accuracy study on frozen venous whole blood specimens and a prospective matrix equivalency study. First, 300 frozen specimens from Mae Sot, Thailand were tested from July-August 2022 using the Wondfo test in laboratory and simulated field conditions. Reference testing for G6PD and Hb (spectrophotometer [Pointe Scientific, USA] and HemoCue [HemoCue AB, Sweden], respectively) was completed in the laboratory. Usability was evaluated among 10 intended users. Next, 225 participants were enrolled into a prospective matrix equivalency study from March-May 2023 in Memphis, Tennessee, USA. The Wondfo test was conducted at the POC with fingerstick capillary blood, and Wondfo and HemoCue tests were completed on fresh venous (K2EDTA) blood within 12 h. Remaining specimens were shipped to PATH for repeat Wondfo and reference testing.ResultsThe Wondfo G6PD measurement showed strong correlation under both laboratory and field conditions (R2>0.9). The area under the curve was 1.00 for deficient (95% CI: 1.00-1.00) and 0.99 for intermediate individuals (95% CI: 0.99-1.00). Sensitivity was high (1.00) across all conditions and groups (lower bound of the 95% CI ≥0.85). Good correlation was observed in both capillary and fresh venous blood against the reference and each other (R2>0.75). McNemar's test showed no significant differences in classification between venous and capillary specimens. The Wondfo test achieved 98.2% (95%CI: 95.5-99.5%) overall agreement. All usability participants successfully completed quality control and test procedures, rating the test system highly for ease of use.ConclusionsThe Wondfo G6PD/Hb Test demonstrates good diagnostic performance using current manufacturer thresholds across various conditions and both venous and capillary specimens. Comparable performance in both specimen types supports matrix equivalence. Usability is acceptable for end users, though refinements were recommended.
Macrocyclization of backbone <i>N</i>-methylated peptides by a prolyl oligopeptidase with a distinctive substrate recognition mechanism.
Macrocyclization and multiple backbone N-methylations can significantly improve the pharmacological properties of peptides. Since chemical synthesis of such compounds is often challenging, enzyme-based production platforms are an interesting option. Here, we characterized OphP, a serine peptidase involved in the cyclization of omphalotins, a group of ribosomally produced dodecapeptides with multiple backbone N-methylations. OphP displays robust peptidase and macrocyclase activity towards multiply α-N-methylated peptides of various lengths and composition derived from the omphalotin precursor protein OphMA. In addition, OphP processes, with lower efficiency, peptides unrelated to OphMA, containing a MeGly, MeAla or Pro residue at the P1 site. Structural analysis reveals that OphP adopts a canonical prolyl oligopeptidase fold but, unlike other enzymes of this enzyme family, recognizes its substrates by their hydrophobic and multiply backbone N-methylated core rather than by the follower peptide. The activity of OphP could be harnessed for the enzymatic production of therapeutic peptides.
Spatio-Temporal Dynamics of M<sub>1</sub> and M<sub>2</sub> Macrophages in a Multiphase Model of Tumor Growth.
This study investigates the complex dynamics of vascular tumors and their interplay with macrophages, key agents of the innate immune response. We model the tumor microenvironment as a multiphase fluid, with each cellular population treated as a distinct, non-mixing phase. The framework also incorporates diffusible species that are critical for processes such as nutrient transport, angiogenesis, chemotaxis, and macrophage activation. A central contribution of this work is the explicit modeling of macrophage infiltration and polarization within the tumor microenvironment. The model captures the divergent roles of M1 (anti-tumor) and M2 (pro-tumor) macrophages and their influence on tumor aggressiveness and progression. Through numerical simulations, we demonstrate the emergence of both spatial and phenotypic heterogeneity in the macrophage population, including their peripheral localization and limited core infiltration -patterns consistent with experimental observations. Furthermore, this is the first multiphase model to incorporate the effects of TGF- β -targeting immunotherapy using vactosertib. Our simulations demonstrate that treatment initially enhances the presence of anti-tumor macrophages, followed by a relapse period where tumor dynamics returns to pre-treatment trends. Model parameters are grounded in experimental data and clinically relevant dosage protocols.
The Risk-Benefit Balance of Oral Corticosteroid Treatment for Asthma Attacks: A Discrete Choice Experiment of Patients and Healthcare Professionals in the UK and New Zealand.
Background and objectiveOral corticosteroids (OCS) are the guideline recommended treatment for all asthma attacks, but benefits must be considered alongside the potential for cumulative side-effects. There is interest in trialling biomarker-directed management of attacks to rationalise OCS treatment in those with least benefit. Understanding stakeholder perspectives on the risks and benefits associated with OCS treatment can inform trial design and shared decision-making discussions in clinical practice. The aim was to examine patients' and healthcare professionals' preferences for the risks and benefits associated with OCS treatment for asthma attacks.MethodsDiscrete choice experiment (DCE) by patients with asthma and HCPs in the UK and New Zealand. Preferences were analysed using logit models.ResultsEight hundred and twenty-four patients and 171 HCPs completed the DCE. Avoiding the risks of permanent side effects had the greatest impact on treatment preference by patients and HCPs. Avoidance of side effects was weighted higher by patients than HCPs. Patients with uncontrolled asthma were more prepared to trade risk for benefit. Symptom recovery was the most valued clinical benefit to patients and HCPs. Patients preferred 'improving lung function' over 'avoiding additional GP treatment or hospitalisation', whereas HCPs preferred avoidance of further healthcare utilisation. Based on their responses we estimated the minimum clinically important difference for the treatment failure outcome at 20%.ConclusionPatients and HCPs will trade-off treatment benefits to avoid the side-effects associated with OCS. The risk-benefit balance of OCS should feature in shared decision-making discussions with patients experiencing outpatient asthma attacks. The findings support developing trials to personalise acute asthma treatment.
Analysis of airway inflammation demonstrates a mechanism for T2-biologic failure in asthma.
BackgroundTargeted T2 biologics have transformed asthma care, but the clinical response to biologic therapy varies between patients.ObjectiveAssess airways inflammation in T2-high asthma patients treated with anti-IL5 biologics to investigate if differential mechanisms of airway inflammation explains varied response to biologics.MethodsProteomic analysis (Olink®, 1463 protein panel) & high sensitivity cytokine analysis (ELISAs) were performed on induced sputum from T2-high, severe asthma patients in the UK multicentre Mepolizumab EXacerbation (MEX) study. Samples included were pre-mepolizumab (n=28), stable on mepolizumab (n= 43) & at first exacerbation (n=26).ResultsClustering of sputum proteins while stable on mepolizumab identified two clusters. Cluster 1 had increased differentially expressed sputum proteins pre-mepolizumab, stable on mepolizumab & at exacerbation. Cluster 1 were younger at diagnosis, had a longer duration of asthma, lower FEV1% & higher ACQ5 on mepolizumab. Cluster 1 had increased expression of pro-inflammatory cytokines (IL1β, IL6, sIL6R), epithelial alarmins (TSLP, IL 33) and neutrophil activation (MPO, NE & Neutrophil extracellular trap (NET). All patients were T2-high with no difference in FeNO, eosinophil number or activity (EDN) across the two clusters.ConclusionIn a cohort of T2-high severe asthma patients, a subgroup of patients with long duration of disease had worse clinical parameters, increased sputum proteins with increased markers of neutrophil activity, proinflammatory cytokines and epithelial alarmins even when stable on mepolizumab. This suggests the presence of biology not treated by targeted T2-biologics which may contribute to poorer outcomes on biologics and could be a treatable airways trait in severe asthma.
Analysis of IDH1 and IDH2 mutations as causes of the hypermethylator phenotype in colorectal cancer
AbstractThe CpG island methylator phenotype (CIMP) occurs in many colorectal cancers (CRCs). CIMP is closely associated with global hypermethylation and tends to occur in proximal tumours with microsatellite instability (MSI), but its origins have been obscure. A few CRCs carry oncogenic (gain‐of‐function) mutations in isocitrate dehydrogenase IDH1. Whilst IDH1 is an established CRC driver gene, the low frequency of IDH1‐mutant CRCs (about 0.5%) has meant that the effects and molecular covariates of those mutations have not been established. We first showed computationally that IDH2 is also a CRC driver. Using multiple public and in‐house CRC datasets, we then identified IDH mutations at the hotspots (IDH1 codons 132 and IDH2 codons 140 and 172) frequently mutated in other tumour types. Somatic IDH mutations were associated with BRAF mutations and expression of mucinous/goblet cell markers, but not with KRAS mutations or MSI. All IDH‐mutant CRCs were CIMP‐positive, mostly at a high level. Cell and mouse models showed that IDH mutation was plausibly causal for DNA hypermethylation. Whilst the aetiology of hypermethylation generally remains unexplained, IDH‐mutant tumours did not form a discrete methylation subcluster, suggesting that different underlying mechanisms can converge on similar final methylation phenotypes. Although further analysis is required, IDH mutations may be the first cause of hypermethylation to be identified in a common cancer type, providing evidence that CIMP and DNA methylation represent more than aging‐related epiphenomena. Cautious exploration of mutant IDH inhibitors and DNA demethylating agents is suggested in managing IDH‐mutant CRCs. © 2025 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.
Amyloid-β disrupts APP-regulated protein aggregation and dissociation from recycling endosomal membranes.
Secretory proteins aggregate into non-soluble dense-core granules in recycling endosome-like compartments prior to regulated release. By contrast, aberrantly processed, secreted amyloid-β (Aβ) peptides derived from amyloid precursor protein (APP) form pathological extracellular amyloidogenic aggregations in late-stage Alzheimer's disease (AD). By examining living Drosophila prostate-like secondary cells, we show that both APP and Aβ peptides affect normal biogenesis of dense-core granules. These cells generate dense-core granules and secreted nanovesicles called Rab11-exosomes via evolutionarily conserved mechanisms within highly enlarged secretory compartments with recycling endosomal identity. The fly APP homologue, APP-like (APPL), associates with these vesicles and the compartmental limiting membrane, from where its extracellular domain modulates protein aggregation. Proteolytic release of this domain permits mini-aggregates to coalesce into a large central dense-core granule. Mutant Aβ expression disrupts this process and compartment motility, and increases aberrant lysosomal targeting, mirroring previously unexplained early-stage pathological events in AD. It also promotes cell-to-cell propagation of these endolysosomal defects, again phenocopying changes observed in AD. Our data therefore demonstrate physiological roles for APP in membrane-dependent protein aggregation, involving molecular mechanisms, which when disrupted by Aβ peptides, trigger Alzheimer's disease-relevant pathologies.
Genomic surveillance of multidrug-resistant Klebsiella in Wales reveals persistent spread of Klebsiella pneumoniae ST307 and adaptive evolution of pOXA-48-like plasmids
Rising rates of multidrug-resistant Klebsiella infections necessitate a comprehensive understanding of the major strains and plasmids driving spread of resistance elements. Here, we analysed 540 clinical, screen and environmental Klebsiella isolates recovered from across Wales between 2007 and 2020 using combined short- and long-read sequencing approaches. We identified resistant clones that have spread within and between hospitals including the high-risk strain sequence type (ST)307, which acquired the bla OXA-244 carbapenemase gene on a pOXA-48-like plasmid. We found evidence that this strain, which caused an acute outbreak largely centred on a single hospital in 2019, had been circulating undetected across South Wales for several years prior to the outbreak. In addition to clonal transmission, our analyses revealed evidence for substantial plasmid spread, mostly notably involving bla KPC-2 and bla OXA-48-like (including bla OXA-244) carbapenemase genes that were found among many species and strain backgrounds. Two thirds (20/30) of the bla KPC-2 genes were carried on the Tn4401a transposon and associated with IncF plasmids. These were mostly recovered from patients in North Wales, reflecting an outward expansion of the plasmid-driven outbreak of bla KPC-2-producing Enterobacteriaceae in North-West England. A total of 92.1 % (105/114) of isolates with a bla OXA-48-like carbapenemase carried the gene on a pOXA-48-like plasmid. While this plasmid family is highly conserved, our analyses revealed novel accessory variation including integrations of additional resistance genes. We also identified multiple independent deletions involving the tra gene cluster among pOXA-48-like plasmids in the ST307 outbreak lineage. These resulted in loss of conjugative ability and signal adaptation of the plasmids to carriage by the host strain. Altogether, our study provides, to our knowledge, the first high resolution view of the diversity, transmission and evolutionary dynamics of major resistant clones and plasmids of Klebsiella in Wales, and forms an important basis for ongoing surveillance efforts. This article contains data hosted by Microreact.
Oral antiretroviral adherence interventions in the era of U=U.
Antiretroviral therapy (ART) is a keystone of the public health response to HIV, making the support of adherence a point of focus in research and service delivery. Over the past decade, measurements of viral suppression have increasingly been used to evaluate interventions, with more robust study designs gaining traction. Effective approaches include adherence counselling beyond ART education (including mental health and wellbeing approaches), reducing burden of care, tackling structural and societal determinants of health, and using mHealth platforms to deliver interventions. Increasingly, single-strategy interventions are giving way to multicomponent approaches to respond to nuances in adherence behaviour. However, determining which effective strategy to offer and to whom, when, and how remain pressing questions if professionals in the field (eg, researchers, clinicians, and community health workers) are to reach the UNAIDS 95-95-95 goals in the recent context of decreased funding. As new long-acting treatments enter global formularies, interventions showing success with oral ART will probably remain relevant to inform service delivery in most contexts.