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Quantitative, Systems & Engineering Biology Publications

See our "Latest Publications" page for a full list of SLS publications

Quantitative, Systems & Engineering Biology

Phospho-tau serine-262 and serine-356 as biomarkers of pre-tangle soluble tau assemblies in Alzheimer’s disease

Tohidul Islam et al, including Emily Hill & Mark J Wall

Patients with Alzheimer’s disease (AD) with little or no quantifiable insoluble brain tau neurofibrillary tangle (NFT) pathology demonstrate stronger clinical benefits of therapies than those with advanced NFTs. The formation of NFTs can be prevented by targeting the intermediate soluble tau assemblies (STAs). However, biochemical understanding and biomarkers of STAs are lacking. Our findings inform about the status of early-stage tau aggregation, reveal aggregation-relevant phosphorylation epitopes in tau and offer a diagnostic biomarker and targeted therapeutic opportunities for AD.

Nature Medicine. February 2025 

Press Release

Multiple carbamylation events are required for differential modulation of Cx26 hemichannels and gap junctions by CO2

Sarbjit Nijjar, Deborah Brotherton, Jack Butler, Valentin-Mihai Dospinescu, Harry G Gannon, Victoria Linthwaite, Martin Cann, Alexander Cameron, Nicholas Dale 

CO2 directly modifies the gating of connexin26 (Cx26) gap junction channels and hemichannels. This gating depends upon Lys125, and the proposed mechanism involves carbamylation of Lys125 to allow formation of a salt bridge with Arg104 on the neighbouring subunit. We demonstrate via carbamate trapping and tandem mass spectrometry that five Lys residues within the cytoplasmic loop, including Lys125, are indeed carbamylated by CO2 . Our findings directly demonstrate carbamylation in connexins, provide further insight into the differential action of CO2 on Cx26 hemichannels and gap junction channels, and increase support for the role of the N-terminus in gating the Cx26 channel. KEY POINTS: Direct evidence of carbamylation of multiple lysine residues in the cytoplasmic loop of Cx26. Concentration-dependent carbamylation at lysines 108, 122 and 125. Only carbamylation of lysine 125 is essential for hemichannel opening to CO2. Carbamylation of lysine 108 along with lysine 125 is essential for CO2-dependent gap junction channel closure.

Journal of Physiology. February 2025

Antimicrobial triazinedione inhibitors of the translocase MraY–protein E interaction site: synergistic effects with bacitracin imply a new mechanism of action

Julia A. Fairbairn, Rachel V. Kerr, Nika-Kare A. Pierre-White, Anthony Jacovides, Becca W. A. Baileeves, Phillip J. Stansfeld, Gerhard Bringmann, Andrew T. Merritt and Timothy D. H. Bugg

Escherichia coli translocase MraY is the target for bacteriolytic protein E from bacteriophage fX174, interacting at a site close to Phe-288 on helix 9, on the extracellular face of the protein. A peptide motif Arg-Trp-x-x-Trp from protein E was used to design a set of triazinedione peptidomimetics, which inhibit particulate MraY (6d IC50 48 µM), and show antimicrobial activity against Gram-negative and Gram-positive antibiotic-resistant clinical strains (7j MIC Acinetobacter baumannii 16 µg/mL, Staphyloccoccus aureus MRSA 2-4 µg/mL). Docking against a predicted structure for E. coli MraY revealed two possible binding sites close to helix 9, the binding site for protein E. Antimicrobial activity of analogue 6j was found to be synergistic with bacitracin in Micrococcus flavus, consistent with a link between this inhibition site and undecaprenyl phosphate uptake. Alkaloid michellamine B, also predicted to bind in the cleft adjacent to helix 9, was also found to be synergistic with bacitracin. These data provide experimental evidence that the unusual hydrophobic cleft adjacent to helix 9 in MraY is involved in uptake of undecaprenyl phosphate, in addition to recently identified transporters UptA and PopT, and that this process can be targetted by small molecules as a novel antibacterial mechanism.

RSC Medicinal Chemistry. January 2025

A comparative study of ionic pesticide sorption and degradation in contrasting Brazilian soils and the development of a novel 3-Phase Assay to assess sorption reversibility

Baudin, Nastasia, Garrod, Mark, Bramke, Irene, Mckillican, Carol, Schafer, Hendrik, Hand, Laurence, Cione, Ana, Bending, Gary D, Marshall, Samantha

Brazilian soils have distinctive characteristics to European and North American soils which are typically used to investigate pesticide fate. This study aimed to compare soil–water partition coefficient (Kd), reversibility of adsorption and degradation half-life (DT50) of 5 pesticides covering a wide range of physico-chemical properties in contrasting Brazilian soils and a temperate (UK) alfisol soil, and to study their relationship with soil OM, clay and expandable clay content, CEC and pH. The results showed that pesticide behaviour in Brazilian soils was not systematically different from those in European and North American soils. The 3PA was shown to be a reliable and simple method for assessing pesticide desorption in soil and could be adapted to assess pesticide bioavailability. The use of the 3PA allowed a more thorough explanation of the observed differences in degradation behaviour between the compounds.

Environmental Monitoring and Assessment. January 2025

MCC950 Mitigates SIRT3-NLRP3-driven Inflammation and Rescues Post-Stroke Neurogenesis

Prakash R., Waseem A., Siddiqui A.J., Naim M., Khan M.A., Robertson A.A.B., Boltze J., Raza S.S.

after ischemic stroke. The objective of this study was to examine the potential mechanism by which the SIRT3-NLRP3 inflammasome affects neural stem and progenitor cells (NSPCs) after transient middle cerebral artery occlusion (tMCAO) in rats. Overall, our results suggest that protecting NSPCs and neurogenesis in the ischemically damaged brain by mitigating the impact of the SIRT3-NLRP3 inflammasome may be a feasible treatment strategy for ischemic stroke.

Biomedicine and Pharmacotherapy. January 2025

Inference of multiple mergers while dating a pathogen phylogeny

Helekal, David, Koskela, Jere and Didelot, Xavier

Here we consider the problem of detecting the presence of multiple mergers in the context of dating a phylogeny, that is determining the date of each of the nodes. We use the Lambda-coalescent theory as a modelling framework and show how Bayesian inference can be efficiently performed using a Billera-Holmes- Vogtmann space embedding and a customised Markov Chain Monte Carlo sampling scheme. We applied this new analysis methodology to a large number of simulated datasets to show that it is possible to infer if and when multiple merger events occurred, and that the phylogenetic dating is improved as a result of taking this information into account. We also analysed real datasets of Vibrio cholerae and Mycobacterium tuberculosis to demonstrate the relevance of our approach to real pathogen evolutionary epidemiology. We have implemented our new methodology in a R package which is freely available at https://github.com/dhelekal/MMCTime.

Systematic Biology. January 2025

MIBiG 4.0: advancing biosynthetic gene cluster curation through global collaboration

Zdouc, Mitja M. et al inc. Alberti, F

Specialized or secondary metabolites are small molecules of biological origin, often showing potent biological activities with applications in agriculture, engineering and medicine. Usually, the biosynthesis of these natural products is governed by sets of co-regulated and physically clustered genes known as biosynthetic gene clusters (BGCs). To share information about BGCs in a standardized and machine-readable way, the Minimum Information about a Biosynthetic Gene cluster (MIBiG) data standard and repository was initiated in 2015. Here, we describe MIBiG version 4.0, an extensive update to the data repository and the underlying data standard.

Nucleic Acids Research. January 2025

Single-Cell Analysis with Spatiotemporal Control of Local pH

Kelsey Cremin, Gabriel N. Meloni, Orkun S. Soyer, Patrick R. Unwin

This work presents an experimental platform combining scanning ion conductance microscopy (SICM) with confocal laser scanning microscopy (CLSM), using intra- and extracellular pH indicator dyes to study the impact of acid delivery on individual HeLa cells within a population.. We find a strong dependency between the intracellular pH and the extracellular pH gradient imposed by local acid delivery. Postdelivery intracellular pH recovery depends on the extent of the acid challenge, with cells exposed to lower pH not returning to basal intracellular pH values after the extracellular pH recovers. This is a unique method for concentration-gradient challenge studies of cell populations that will have broad applications in cell biology. SICM can be used to deliver different chemicals and enables a wide range of local conditions to be applied across a cell population, for which the effects can be investigated at the single-cell level.

ACS Measurement Science. January 2025

Partitioning of fatty acids between membrane and storage lipids controls ER membrane expansion

Pawel K Lysyganicz, Antonio D Barbosa, Shoily Khondker, Nicolas A Stewart, George M Carman, Phillip J Stansfeld, Marcus K Dymond, Symeon Siniossoglou

Here we demonstrate that a lipid-degradation pathway inhibits expansion of the endoplasmic reticulum (ER) membrane. Phospholipid diacylglycerol acyltransferases (PDATs) use endogenous phospholipids as fatty-acyl donors to generate triglyceride stored in lipid droplets. The significance of this non-canonical triglyceride biosynthesis pathway has remained elusive. We show that active Lro1 mediates retraction of ER membrane expansion driven by phospholipid synthesis. Furthermore, subcellular distribution and membrane turnover activity of Lro1 are controlled by diacylglycerol produced by the activity of Pah1, a conserved member of the lipin family. Collectively, our findings reveal a lipid-metabolic network that regulates endoplasmic reticulum biogenesis by converting phospholipids into storage lipids.

EMBO Journal. January 2025

Modulation of stress-related behaviour by preproglucagon neurons and hypothalamic projections to the nucleus of the solitary tract

Marie K. Holt, Natalia Valderrama, Maria J. Polanco, Imogen Hayter, Ellena G. Badenoch, Stefan Trapp, Linda Rinaman

Stress-induced behaviours are driven by complex neural circuits and some neuronal populations concurrently modulate diverse behavioural and physiological responses to stress. Glucagon-like peptide-1 (GLP-1)-producing preproglucagon (PPG) neurons within the lower brainstem caudal nucleus of the solitary tract (cNTS) are particularly sensitive to stressful stimuli and are implicated in multiple physiological and behavioural responses to interoceptive and psychogenic threats. However, the afferent inputs driving stress-induced activation of PPG neurons are largely unknown, and the role of PPG neurons in anxiety-like behaviour is controversial. Through chemogenetic manipulations we reveal that cNTS PPG neurons have the ability to moderately increase anxiety-like behaviours in mice in a sex-dependent manner. Our findings reveal sex differences in behavioural responses to PPG neural activation and highlight a hypothalamic-brainstem pathway in stress-induced hypophagia.

Molecular Metabolism. January 2025

Jeremy Keown publications

Structure of the Nipah virus polymerase complex

Esra Balıkçı, Franziska Günl, Loïc Carrique, Jeremy R Keown, Ervin Fodor, Jonathan M Grimes

Nipah virus is a highly virulent zoonotic paramyxovirus causing severe respiratory and neurological disease. Despite its lethality, there is no approved treatment for Nipah virus infection. The viral polymerase complex, composed of the polymerase (L) and phos-phoprotein (P), replicates and transcribes the viral RNA genome. Here, we describe structures of the Nipah virus L-P polymerase complex and the L-protein’s Connecting Domain (CD). Our findings offer insights into the structural details of the L-P polymerase complex and the molecular interactions between L-proteinand P-protein, shedding light on the mechanisms of the replicationmachinery. This work will underpin efforts to develop antiviraldrugs that target the polymerase complex of Nipah virus.

EMBO Journal. December 2024.


Structural characterization of the full-length Hantaan virus polymerase

Jeremy R. Keown, Loïc Carrique, Benjamin E. Nilsson-Payant, Ervin Fodor, Jonnathan M. Grimes

Hantaviridae are a family of segmented negative-sense RNA viruses that contain important human and animal pathogens. Hantaviridae contain a viral RNA-dependent RNA polymerase that replicates and transcribes the viral genome. Here we establish the expression and purification of the polymerase from the Old World Hantaan virus and characterise the structure using Cryo-EM. The insights gained here guide future mechanistic studies of both the transcription and replication activities of the hantavirus polymerase and for the development of therapeutic targets.

PLoS Pathogens. December 2024

The influence of farm connectedness on foot-and-mouth disease outbreaks in livestock

Jean B. Contina, Rachel L. Seibel, Bhim Chaulagain, Karasi B. Mills, Michael J. Tildesley, Christopher C. Mundt

We applied a previously published livestock foot-and-mouth disease (FMD) model to estimate host connectivity using a transmission kernel based on contact tracing and measured subsequent to an animal movement ban in the 2001 United Kingdom epidemic. Connectivity within county-level farm landscapes were evaluated by considering the transmission kernel, host species composition, farm-level susceptibility, farm-level transmissibility, and distances between farms.  Connectivity of the initially infected farm and mean connectivity among all farms in a county were strongly associated with effects of cull size, with disease control more effective at lower levels of farm connectivity. Host connectivity provides early information on the host-pathogen landscape and could be used as an assessment tool for predicting epidemic risks, as well as enabling preemptive control strategies to limit the size of disease outbreaks.

Ecosphere. December 2024

Regional scale diversity and distribution of soil inhabiting Tetracladium

Anna Lazar, Robert I. Griffiths, Tim Goodall, Lisa R. Norton, Ryan M. Mushinski & Gary D. Bending

The genus Tetracladium has historically been regarded as an aquatic hyphomycete. However, sequencing of terrestrial ecosystems has shown that Tetracladium species might also be terrestrial soil and plant-inhabiting fungi. The diversity of Tetracladium species, their distribution across ecosystems, and the factors that shape community composition remain largely unknown. Using internal transcribed spacer (ITS) amplicon sequencing, we investigated the spatial distribution of Tetracladium in 970 soil samples representing the major ecosystems found across the British landscape. Overall, this study provides insights into the community composition patterns of Tetracladium in terrestrial ecosystems and highlights the importance of vegetation characteristics in shaping Tetracladium communities.

Environmental Microbiome. December 2024

Balancing selfing and outcrossing : the genetics and cell biology of nematodes with three sexual morphs

Adams, Sally, Tandonnet, Sophie and Pires-da Silva, André Francisco

Trioecy, a rare reproductive system where hermaphrodites, females, and males coexist, is found in certain algae, plants, and animals. Though it has evolved independently multiple times, its rarity suggests it may be an unstable or transitory evolutionary strategy. In the well-studied Caenorhabditis elegans, attempts to engineer a trioecious strain have reverted to the hermaphrodite/male system, reinforcing this view. However, these studies did not consider the sex-determination systems of naturally stable trioecious species. The discovery of free-living nematodes of the Auanema genus, which have naturally stable trioecy, provides an opportunity to study these systems. In Auanema, females produce only oocytes, while hermaphrodites produce both oocytes and sperm for self-fertilization. Crosses between males and females primarily produce daughters (XX hermaphrodites and females), while male-hermaphrodite crosses result in sons only. These skewed sex ratios are due to X-chromosome drive during spermatogenesis, where males produce only X-bearing sperm through asymmetric cell division. The stability of trioecy in Auanema is influenced by maternal control over sex determination and environmental cues. These factors offer insights into the genetic and environmental dynamics that maintain trioecy, potentially explaining its evolutionary stability in certain species.

Genetics 2024

Speeding up Inference of Homologous Recombination in Bacteria

Felipe J Medina-Aguayo, Xavier Didelot, Richard G Everitt

Bacteria reproduce clonally but most species recombine frequently, so that the ancestral process is best captured using an ancestral recombination graph. This graph model is often too complex to be used in an inferential setup, but it can be approximated for example by the ClonalOrigin model. Inference in the ClonalOrigin model is performed via a Reversible-Jump Markov Chain Monte Carlo algorithm, however this often performs poorly due to the complexity of the target distribution since it needs to explore spaces of different dimensions. Recent developments in Bayesian computation methodology have provided ways to improve existing methods and code, but are not well-known outside the statistics community. We show how exploiting one of these new computational methods can lead to faster inference under the ClonalOrigin model.

Bayesian Analysis. December 2024

Metabolic profiling and antibacterial activity of tree wood extracts obtained under variable extraction conditions

Diana Vinchira-Villarraga, Sabrine Dhaouadi, Vanja Milenkovic, Jiaqi Wei, Emily R. Grace, Katherine G. Hinton, Amy J. Webster, Andrea Vadillo-Dieguez, Sophie E. Powell, Naina Korotania, Leonardo Castellanos, Freddy A. Ramos, Richard J. Harrison, Mojgan Rabiey & Robert W. Jackson

This study aimed to develop a methodological approach to obtain extracts from different tree species with the highest reproducibility and chemical diversity possible, to ensure proper coverage of the trees’ metabolome. Each tree species has a unique metabolic profile, which means that no single protocol is universally effective. Extraction at 50 °C for three cycles using 80% methanol or chloroform/methanol/water showed the best results and is suggested for studying wood metabolome. These observations highlight the need to tailor extraction protocols to each tree species to ensure comprehensive metabolome coverage for metabolic profiling.

Metabolomics. December 2024

Delivery determinants of an Acinetobacter baumannii type VI secretion system bifunctional peptidoglycan hydrolase

Valeriya Bezkorovayna, Brooke K. Hayes, Francesca N. Gillett, Amy Wright, David I. Roper, Marina Harper, Sheena McGowan, John D. Boyce

Acinetobacter baumannii is a Gram-negative opportunistic pathogen and is a common cause of nosocomial infections.). Here we define the regions of interaction between Tae17 and its cognate delivery protein VgrG17 and identify that amino acids G1069 and W1075 in VgrG17 are essential for Tae17 delivery via the T6SS, the first time such specific delivery determinants of T6SS cargo effectors have been defined. Furthermore, we determine that the Tae17 effector is a multidomain, bifunctional, peptidoglycan-degrading enzyme that has both amidase activity, which targets the sugar-peptide bonds, and lytic transglycosylase activity, which targets the peptidoglycan sugar backbone. Moreover, we show that the Tae17 transglycosylase activity is more important than amidase activity for the killing of Escherichia coli. This study provides molecular insight into how the T6SS allows A. baumannii strains to gain dominance in polymicrobial communities and thus improve their chances of survival and transmission.

mBio. December 2024

Characterisation of Itersonilia spp. from Parsnip and Other Hosts

Lauren HK Chappell, Guy C Barker, John P Clarkson

Parsnips (Pastinaca sativa) are a speciality UK crop with an economic value of at least 31M GBP annually. Currently, the major constraints to production are losses associated with root canker disease due to a range of fungal pathogens, among which Itersonilia pastinacae is of most concern to growers. With limited research conducted on this species, this work aimed to provide a much-needed characterisation of isolates from across the UK, continental Europe, and New Zealand. Following whole genome sequencing, specific primers were designed for the molecular characterisation of the isolates using six housekeeping genes and three highly variable functional genes. Phylogenetic analysis separated isolates into two and six clades, respectively, but the grouping was not associated with hosts or locations. Based on the results of this research, there was no evidence to support more than a single species of Itersonilia among the isolates studied.

Journal of Fungi. December 2024

Mike Tildesley publications

The impact of natural climate variability on the global distribution of Aedes aegypti : a mathematical modelling study

Kaye, A. R., Obolski, U., Sun, L., Hart, W. S., Hurrell, J. W., Tildesley, M. J. and Thompson, R. N.

Aedes aegypti spread pathogens affecting humans, including dengue, Zika, and yellow fever viruses. Anthropogenic climate change is altering the spatial distribution of Ae aegypti and therefore the locations at risk of vector-borne disease. In addition to climate change, natural climate variability, resulting from internal atmospheric processes and interactions between climate system components (eg, atmosphere–land and atmosphere–ocean interactions), determines climate outcomes. However, the role of natural climate variability in modifying the effects of anthropogenic climate change on future environmental suitability for Ae aegypti has not been assessed fully. In this study, we aim to assess uncertainty arising from natural climate variability in projections of Ae aegypti suitability up to the year 2100. Lancet Planetary Health. December 2024

The time between symptom onset and various clinical outcomes : a statistical analysis of MERS-CoV patients in Saudi Arabia

Althobaity, Yehya, Alkhudaydi, Muhammad, Hill, Edward M., Thompson, Robin N. and Tildesley, Michael J

In this study, we investigate the impact of demographic characteristics on MERS-CoV cases in Saudi Arabia, specifically focusing on the time intervals between symptom onset and key events such as hospitalization, case confirmation, reporting and death. Importantly, we observe age-based differences in the risk of hospitalization and other measures of infection severity, including the probability of death conditional on hospitalization. Careful quantification of epidemiological characteristics, including inference of key epidemiological periods and assessments of differences between cases of different ages, plays a crucial role in understanding the progression of MERS-CoV outbreaks and formulating effective public health strategies to mitigate their impact.

Royal Society Open Society. November 2024

Identification of a terpene synthase arsenal using long-read sequencing and genome assembly of Aspergillus wentii

Richard Olumakaiye, Christophe Corre, Fabrizio Alberti

Fungi are talented producers of secondary metabolites with applications in the pharmaceutical and agrochemical sectors. Aspergillus wentii CBS 141173 has gathered research interest due to its ability to produce high-value norditerpenoid compounds, including anticancer molecules. In this study, we aimed to expand the genomic information available for A. wentii to facilitate the identification of terpenoid biosynthetic genes that may be involved in the production of bioactive molecules.

The results provide a scaffold for the future exploration of terpenoid biosynthetic pathways for bioactive molecules in A. wentii. The terpenoid clusters identified in this study are candidates for heterologous gene expression and/or gene disruption experiments. The description and availability of the long-read genome assembly of A. wentii CBS 141173 further provides the basis for downstream genome analysis and biotechnological exploitation of this species.

BMC Genomics. November 2024

Transcription factor deformed wings is an Atg8a-Interacting protein that regulates autophagy

Kołodziej, Marta, Tsapras, Panagiotis, Cameron, Alexander and Nezis, Ioannis P

LC3 (microtubule-associated protein 1 light chain 3, called Atg8 in yeast and Drosophila) is one of the most well-studied autophagy-related proteins. LC3 controls the selectivity of autophagic degradation by interacting with LIR (LC3-interacting region) motifs also known as AIM (Atg8-interacting motifs) on selective autophagy receptors that carry cargo for degradation. Although the function of Atg8 family proteins is primarily cytoplasmic, they are also enriched in the nucleus. Here, we used yeast two-hybrid screening, and we identified transcription factor Deformed wings (Dwg) as an Atg8a-interacting protein in Drosophila. Dwg-Atg8a interaction is LIR motif-dependent. We have created Dwg Y129A/I132A LIR mutant flies and shown that they exhibit elevated autophagy, improved resistance to oxidative stress, and starvation. Our results provide novel insights into the transcriptional regulation of autophagy in Drosophila.

Cells. November 2024

Understanding the ecological versatility of Tetracladium species in temperate forest soils

Anna Lazar, Richard P Phillips, Stephanie Kivlin, Gary D Bending, Ryan M Mushinski

Although Tetracladium species have traditionally been studied as aquatic saprotrophs, the growing number of metagenomic and metabarcoding reports detecting them in soil environments raises important questions about their ecological adaptability and versatility. We investigated the factors associated with the relative abundance, diversity and ecological dynamics of Tetracladium in temperate forest soils. Collectively, our findings highlight the ecological significance of Tetracladium in temperate forest soils and emphasize the importance of site-specific factors and microbial interactions in shaping their distribution patterns and ecological dynamics.

Environmental Microbiology. November 2024

Gladiolin produced by pathogenic Burkholderia synergizes with amphotericin B through membrane lipid rearrangements

Claudia Simm, Tzong-Hsien Lee, Harshini Weerasinghe, Dean Walsh, Ioanna T Nakou, Madhu Shankar, Wai Chung Tse, Rebecca Inman, Robert J Mulder, Freya Harrison, Marie-Isabel Aguilar, Gregory L Challis, Ana Traven

Amphotericin B (AmpB) is an effective but toxic antifungal drug.. AmpB disrupts fungal membranes by two proposed mechanisms: ergosterol sequestration from the membrane and pore formation. Whether these two mechanisms operate in conjunction and how they could be potentiated remains to be fully understood. Here, we report that gladiolin, a polyketide antibiotic produced by Burkholderia gladioli, is a strong potentiator of AmpB and acts synergistically against Cryptococcus and Candida species, including drug-resistant C. auris. Gladiolin also synergizes with AmpB against drug-resistant fungal biofilms, while exerting no mammalian cytotoxicity.. Collectively, our findings shed light on AmpB’s mechanism of action and characterize gladiolin as an AmpB potentiator, showing an antifungal mechanism distinct from its proposed antibiotic activity. We shed light on the synergistic mechanism at the membrane, and provide insights into potentiation strategies to improve AmpB’s activity/toxicity relationship.

mBio. November 2024

Membrane staining and phospholipid tracking in Pseudomonas aeruginosa PAO1 using the phosphatidylcholine mimic propargyl-choline

Chris L B Graham, Jack Bryant, David I Roper, Manuel Banzhaf 

Here we describe a method for in vivo phospholipid labelling by fluorescent imaging in Pseudomonas aeruginosa using a phosphatidylcholine (PC) mimic, “propargyl-choline”(PCho). This click-chemistry liable headgroup mimic is visible by microscopy and allows the covalent labelling of lipids. Fluorescence of the cell membranes, visible in heterogenous patches, is dependent on PCho concentration and is localised in the membrane fraction of cells, demonstrating that it is suitable for membrane labelling and cell imaging.

Access Microbiology. November 2024

Isolation and Characterisation of Novel Lytic Bacteriophages for Therapeutic Applications in Biofilm-Associated Prosthetic Joint Infections

Nathan J. Burton, Luís D R. Melo, Michaël F D. Tadesse, Bethany Pearce, Evangelos Vryonis, Antonia P. Sagona

In this study, we produced a cocktail of novel bacteriophages and assessed their viability to eradicate nosocomial staphylococcal biofilms. Here, we used clinical isolates from prosthetic joint infections to isolate and identify four new bacteriophages from sewage effluent. These novel phages were characterized through electron microscopy and full genome sequencing. Subsequently, we combined them into a phage cocktail, which effectively re-sensitized biofilms to vancomycin and flucloxacillin. Notably, this phage cocktail demonstrated low cytotoxicity in vitro to human epithelial cells, even when used alongside antibiotic treatments. These findings highlight the potential of the phage cocktail as a tool to increase antibiotic treatment success in prosthetic joint infections.

Sustainable Microbiology. November 2024

Cutaneous leishmaniasis in British troops following jungle training in Belize: Cumulative incidence and potential risk practices

Rawlings, Ngwa Niba, Bailey, Mark, Craig, Peter, Courtenay, Orin

British soldiers undergoing jungle training in Belize typically experience a relatively low risk of developing cutaneous leishmaniasis. However, an uncharacteristically large outbreak of cutaneous leishmaniasis occurred in 2022. This study aimed to determine the cumulative incidence of the disease and highlight potential shortcomings in personal protective measures to mitigate exposure to sand fly vector bites. A retrospective analysis was conducted on medical records of cutaneous leishmaniasis cases between 2005 and 2022, as well as on questionnaire responses regarding personal protective measures administered to cutaneous leishmaniasis cases in 2022. The reasons behind the unusually high numbers of cutaneous leishmaniasis cases and cumulative incidence in 2022 remain unclear, emphasising the need to improve personal protective measures provision and implement a comprehensive health education programme for troops undergoing jungle training in Belize.

Parasite Epidemiology and Control. November 2024

Emergence of synchronised growth oscillations in filamentous fungi

Praneet Prakash, Xue Jiang , Luke Richards, Zoe Schofield, Patrick Schafer Marco Polin, Orkun S. Soyer & Munehiro Asally

Many species of soil fungi grow in the form of branched networks that enable long-range communication and mass flow of nutrient. While there have been investigations on the branching of the fungal networks, their long-term growth dynamics in space and time is still not very well understood. In this study, we monitor the spatio-temporal growth dynamics of the plant-promoting filamentous fungus Serendipita indica for several days in a controlled environment within a microfluidic chamber. We find that S. indica cells display synchronised growth oscillations with the onset of sporulation and at a period of 3 hours. Quantifying this experimental synchronisation of oscillatory dynamics, we show that the synchronisation can be recapitulated by the nearest neighbour Kuramoto model with a millimetre-scale cell-cell coupling.

Royal Society Interface. October 2024

Complement-mediated killing of Escherichia coli by mechanical destabilization of the cell envelope

Georgina Benn, Christian Bortolini, David M Roberts, Alice L B Pyne, Seamus Holden, Bart W Hoogenboom

Complement proteins eliminate Gram-negative bacteria in the blood via the formation of membrane attack complex (MAC) pores in the outer membrane. However, it remains unclear how outer membrane poration leads to inner membrane permeation and cell lysis. Using atomic force microscopy (AFM) on living Escherichia coli (E. coli), we probed MAC-induced changes in the cell envelope and correlated these with subsequent cell death. We conclude that bacterial cell lysis is only an indirect effect of MAC formation; outer membrane poration leads to mechanical destabilization of the cell envelope, reducing its ability to contain the turgor pressure, leading to inner membrane permeation and cell death.

EMBO Journal. October 2024

Comparative genomics and transcriptomics reveal differences in effector complement and expression between races of Fusarium oxysporum f.sp. lactucae

Helen J. Bates, Jamie Pike, R. Jordan Price, Sascha Jenkins, John Connell, Andrew Legg, Andrew Armitage, Richard J. Harrison and John P. Clarkson

This study presents the first genome and transcriptome analyses for Fusarium oxysporum f. sp. lactucae (Fola) which causes Fusarium wilt disease of lettuce. Long-read genome sequencing of three race 1 (Fola1) and three race 4 (Fola4) isolates revealed key differences in putative effector complement between races and with other F. oxysporum ff. spp. following mimp-based bioinformatic analyses.

Frontiers in Plant Science. October 2024

Early Steps of the Biosynthesis of the Anticancer Antibiotic Pleurotin

Jack A. Weaver, Duha Alkhder, Panward Prasongpholchai, Michaël D. Tadesse, Emmanuel L. de los Santos, Lijiang Song, Christophe Corre, Fabrizio Alberti

Pleurotin is a meroterpenoid specialized metabolite made by the fungus Hohenbuehelia grisea, and it is a lead anticancer molecule due to its irreversible inhibition of the thioredoxin-thioredoxin reductase system. Total synthesis of pleurotin has been achieved, including through a stereoselective route; however, its biosynthesis has not been characterized. In this study, we used isotope-labeled precursor feeding to show that the nonterpenoid quinone ring of pleurotin and its congeners is derived from phenylalanine. This work sets the foundation to fully elucidate the biosynthesis of pleurotin and its congeners, with long-term potential to optimize their production for therapeutic use and engineer the pathway toward the biosynthesis of valuable analogues.

ACS Chemical Biology. October 2024

Imaging Glucose Metabolism and Dopaminergic Dysfunction in Sheep (Ovis aries) Brain using PET Imaging Reveals Abnormalities in OVT73 Huntington’s Disease Sheep

Williams G.K., Akkermans J., Lawson M., Syta P., Staelens S., Adhikari M.H., Morton A.J., Nitzsche B., Boltze J., Christou C., Bertoglio D., Ahamed M.

The major goal of our preliminary cross-sectional study is to demonstrate the feasibility and utility of the unique transgenic sheep model of HD (OVT73) in positron emission tomography (PET) imaging. In this first-of-its-kind study, we showed the usefulness and validity of HD sheep model in imaging cerebral glucose metabolism and dopamine uptake using PET imaging. The identification of discrete patterns of metabolic abnormality using [18F]FDG and decline of [18F]FDOPA uptake may provide a useful means of quantifying early HD-related changes in these models, particularly in the transition from presymptomatic to early symptomatic phases of HD.

ACS Chemical Neuroscience. October 2024

A regulatory module mediating temperature control of cell-cell communication facilitates tree bud dormancy release

Shashank K Pandey, Jay Prakash Maurya, Bibek Aryal, Kamil Drynda, Aswin Nair, Pal Miskolczi, Rajesh Kumar Singh, Xiaobin Wang, Yujiao Ma, Tatiana de Souza Moraes, Emmanuelle M Bayer, Etienne Farcot, George W Bassel, Leah R Band, Rishikesh P Bhalerao

The control of cell–cell communication via plasmodesmata (PD) plays a key role in plant development. In tree buds, low-temperature conditions (LT) induce a switch in plasmodesmata from a closed to an open state, which restores cell-to-cell communication in the shoot apex and releases dormancy. Using genetic and cell-biological approaches, we have identified a previously uncharacterized transcription factor, Low-temperature-Induced MADS-box 1 (LIM1), as an LT-induced, direct upstream activator of the gibberellic acid (GA) pathway. Mathematical modeling and experimental validation suggest that negative feedback regulation of LIM1 by gibberellin could play a crucial role in maintaining the robust temporal regulation of bud responses to low temperature. These results reveal genetic factors linking temperature control of cell–cell communication with regulation of seasonally-aligned growth crucial for adaptation of trees.

EMBO Journal. October 2024

Ammonia leakage can underpin nitrogen-sharing among soil microorganisms.

Luke Richards, Kelsey Cremin, Mary Coates, Finley Vigor, Patrick Schäfer, and Orkun S Soyer

Soil microbial communities host a large number of microbial species that support important ecological functions such as biogeochemical cycling and plant nutrition. The extent and stability of these functions are affected by inter-species interactions among soil microorganisms, yet the different mechanisms underpinning microbial interactions in the soil are not fully understood. Here, we study the extent of nutrient-based interactions among two model, plant-supporting soil microorganisms, the fungi Serendipita indica, and the bacteria Bacillus subtilis. Our findings highlight that ammonia based N-sharing can be a previously under-appreciated mechanism underpinning interaction among soil microorganisms and could be influenced by microbial or abiotic alteration of pH in microenvironments.

ISME Journal. September 2024

MSK1 is required for the experience- and ampakine-dependent enhancement of spatial reference memory and reversal learning and for the induction of Arc and BDNF

Lorenzo Morè, Lucia Privitera, Marcia Lopes, J. Simon C. Arthur, Julie C. Lauterborn, Sonia A.L. Corrêa, Bruno G. Frenguelli

One class of cognitive enhancers, the ampakines, has attracted particular attention by virtue of improving cognition associated with animal models of neurodevelopmental, neurodegenerative, and psychiatric conditions, as well as in age-related cognitive impairment. Ampakines elevate CNS levels of BDNF, and it is through this elevation that their beneficial actions are believed to occur. To establish whether MSK1 converts ampakine-induced elevations of BDNF into cognitive enhancement we tested an ampakine (CX929) in male WT mice and in male mice in which the kinase activity of MSK1 was inactivated. We found that MSK1 is required for the ampakine-dependent improvement in spatial reference memory and cognitive flexibility, and for the elevations of BDNF and the plasticity-related protein Arc associated with ampakines and experience. These observations implicate MSK1 as a key enabler of the beneficial effects of ampakines on cognitive function, and furthermore identify MSK1 as a hub for BDNF-elevating nootropic strategies.

Neuropharmacology. 2024

A retrospective assessment of forecasting the peak of the SARS-CoV-2 Omicron BA.1 wave in England

Keeling, Matthew James and Dyson, Louise

We discuss the invasion of the Omicron BA.1 variant into England as a paradigm for real-time model fitting and projection. Here we use a mixture of simple SIR-type models, analysis of the early data and a more complex age-structure model fit to the outbreak to understand the dynamics. In particular, we highlight that early data shows that the invading Omicron variant had a substantial growth advantage over the resident Delta variant. However, early data does not allow us to reliably infer other key epidemiological parameters - such as generation time and severity - which influence the expected peak hospital numbers. With more complete epidemic data from January 2022 are we able to capture the true scale of the epidemic in terms of both infections and hospital admissions, driven by different infection characteristics of Omicron compared to Delta and a substantial shift in estimated precautionary behaviour during December. This work highlights the challenges of real time forecasting, in a rapidly changing environment with limited information on the variant’s epidemiological characteristics.

PLoS Computational Biology. September 2024

Genetic-epigenetic interplay in the determination of plant 3D genome organization

Xiaoning He, Chloé Dias Lopes, Leonardo I Pereyra-Bistrain, Ying Huang, Jing An, Rim Brik Chaouche, Hugo Zalzalé, Qingyi Wang, Xing Ma, Javier Antunez-Sanchez, Catherine Bergounioux, Sophie Piquerez, Sotirios Fragkostefanakis, Yijing Zhang, Shaojian Zheng, Martin Cresp, Magdy M Mahfouz, Olivier Mathieu, Federico Ariel, Jose Gutierrez-Marcos, Xingwang Li, Nicolas Bouché, Cécile Raynaud, David Latrasse, Moussa Benhamed

The 3D chromatin organization plays a major role in the control of gene expression. In this study, employing a combination of genetics and advanced 3D genomics approaches, we demonstrated that a redistribution of facultative heterochromatin marks in regions usually occupied by constitutive heterochromatin marks disrupts the 3D genome compartmentalisation. This disturbance, in turn, triggers novel chromatin interactions between genic and transposable element (TE) regions. Interestingly, our results imply that epigenetic features, constrained by genetic factors, intricately mold the landscape of 3D genome organisation. This study sheds light on the profound genetic-epigenetic interplay that underlies the regulation of gene expression within the intricate framework of the 3D genome. Our findings highlight the complexity of the relationships between genetic determinants and epigenetic features in shaping the dynamic configuration of the 3D genome.

Nucleic Acids Research. September 2024

New fungal primers reveal the diversity of Mucoromycotinian arbuscular mycorrhizal fungi and their response to nitrogen application

Mirjam Seeliger, Sally Hilton, George Muscatt, Christopher Walker, David Bass, Felipe Albornoz, Rachel J Standish, Neil D Gray, Louis Mercy, Leonidas Rempelos, Carolin Schneider, Megan H Ryan, Paul E Bilsborrow, Gary D Bending

Arbuscular mycorrhizas (AM) are the most widespread terrestrial symbiosis and are both a key determinant of plant health and a major contributor to ecosystem processes through their role in biogeochemical cycling. Until recently, it was assumed that the fungi which form AM comprise the subphylum Glomeromycotina (G-AMF), and our understanding of the diversity and ecosystem roles of AM is based almost exclusively on this group. However recent evidence shows that fungi which form the distinctive 'fine root endophyte’ (FRE) AM morphotype are members of the subphylum Mucoromycotina (M-AMF), so that AM symbioses are actually formed by two distinct groups of fungi. We investigated the influence of nitrogen (N) addition and wheat variety on the assembly of AM communities under field conditions. The results demonstrate the need to consider both G-AMF and M-AMF when investigating AM communities, and highlight the importance of primer choice when investigating AMF community dynamics.

Environmental Microbiome. September 2024

Establishment of single-cell transcriptional states during seed germination

Lim Chee Liew, Yue You, Lucas Auroux, Marina Oliva, Marta Peirats-Llobet, Sophia Ng, Muluneh Tamiru-Oli, Oliver Berkowitz, Uyen Vu Thuy Hong, Asha Haslem, Tim Stuart, Matthew E. Ritchie, George W. Bassel, Ryan Lister, James Whelan, Quentin Gouil & Mathew G. Lewsey

Here we describe a temporal analysis of the germinating Arabidopsis thaliana embryo at single-cell resolution. We define the highly dynamic cell type-specific patterns of gene expression and how these relate to changing cellular function as germination progresses. Underlying these are unique gene regulatory networks and transcription factor activity. We unexpectedly discover that most embryo cells transition through the same initial transcriptional state early in germination, even though cell identity has already been established during embryogenesis. Cells later transition to cell type-specific gene expression patterns. Furthermore, our analyses support previous findings that the earliest events leading to the induction of seed germination take place in the vasculature. Overall, our study constitutes a general framework with which to characterize Arabidopsis cell transcriptional states through seed germination, allowing investigation of different genotypes and other plant species whose seed strategies may differ. Nature Plants. September 2024

A Pan Plasmodium lateral flow recombinase polymerase amplification assay for monitoring malaria parasites in vectors and human populations

Matthew Higgins, Mojca Kristan, Emma L. Collins, Louisa A. Messenger, Jamille G. Dombrowski, Leen N. Vanheer, Debbie Nolder, Christopher J. Drakeley, William Stone, Almahamoudou Mahamar, Teun Bousema, Michael Delves, Janvier Bandibabone, Sévérin N’Do, Chimanuka Bantuzeko, Bertin Zawadi, Thomas Walker, Colin J. Sutherland, Claudio R. F. Marinho, Mary M. Cameron, Taane G. Clark & Susana Campino

Malaria caused by neglected Plasmodium parasites is often underestimated due to the lack of rapid diagnostic tools that can accurately detect these species. Here, we present a Pan Plasmodium recombinase polymerase amplification lateral flow (RPA–LF) assay, capable of detecting all six human infecting Plasmodium species in low resource settings.. When combined with crude nucleic acid extraction, the assay can serve as a point-of-need tool for molecular xenomonitoring. This utility was demonstrated by screening laboratory-reared Anopheles stephensi mosquitoes fed with Plasmodium-infected blood, as well as field samples of An. funestus s.l. and An. gambiae s.l. collected from central Africa. Overall, our proof-of-concept Pan Plasmodium diagnostic tool has the potential to be applied for clinical and xenomonitoring field surveillance, and after further evaluation, could become an essential tool to assist malaria control and elimination.

Scientific Reports. August 2024

Hendrik Schafer publications-

Overview of the MOSAiC expedition: Ecosystem

Allison A. Fong, Clara J. M. Hoppe et al. (incl. H Schafer)


The international and interdisciplinary sea-ice drift expedition “The Multidisciplinary drifting Observatory for the Study of Arctic Climate” (MOSAiC) was conducted from October 2019 to September 2020. The aim of MOSAiC was to study the interconnected physical, chemical, and biological characteristics and processes from the atmosphere to the deep sea of the central Arctic system. The ecosystem team addressed current knowledge gaps and explored unknown biological properties over a complete seasonal cycle focusing on three major research areas: biodiversity, biogeochemical cycles, and linkages to the environment. This article provides a detailed overview of the sampling approaches used to address the three main science objectives. It highlights the core sampling program and provides examples of habitat- or process-specific sampling. The initial results presented include high biological activities in wintertime and the discovery of biological hotspots in underexplored habitats. The unique interconnectivity of the coordinated sampling efforts also revealed insights into cross-disciplinary interactions like the impact of biota on Arctic cloud formation. This overview further presents both lessons learned from conducting such a demanding field campaign and an outlook on spin-off projects to be conducted over the next years.

Elementa: Science of the Anthropocene. August 2024  

Microbial assimilatory sulfate reduction-mediated H2S: an overlooked role in Crohn's disease development

Wanrong Luo, Min Zhao, Mohammed Dwidar, Yang Gao, Liyuan Xiang, Xueting Wu , Marnix H Medema, Shu Xu, Xiaozhi Li, Hendrik Schafer, Minhu Chen, Rui Feng, Yijun Zhu


H2S imbalances in the intestinal tract trigger Crohn's disease (CD), a chronic inflammatory gastrointestinal disorder characterized by microbiota dysbiosis and barrier dysfunction. However, a comprehensive understanding of H2S generation in the gut, and the contributions of both microbiota and host to systemic H2S levels in CD, remain to be elucidated. This investigation aimed to enhance comprehension regarding the sulfidogenic potential of both the human host and the gut microbiota. The study significantly advances understanding of microbial sulfur metabolism in the human gut, elucidating the complex interplay between diet, gut microbiota, and host sulfur metabolism. We highlight the microbial ASR pathway as an overlooked endogenous H2S producer and a potential therapeutic target for managing CD. Microbiome. August 2024

Modelling bluetongue and African horse sickness vector (Culicoides spp.) distribution in the Western Cape in South Africa using random forest machine learning

de Klerk, Joanna N., Tildesley, Michael J., Labuschagne, Karien and Gorsich, Erin E

Culicoides biting midges exhibit a global spatial distribution and are the main vectors of several viruses of veterinary importance, including bluetongue (BT) and African horse sickness (AHS). The aim of this study was to model distributions for two primary vectors for BT and AHS (Culicoides imicola and Culicoides bolitinos) using random forest (RF) machine learning and explore the relative importance of environmental and anthropological factors in a region of South Africa with frequent AHS and BT outbreaks. This study yielded novel insight into the spatial abundance and drivers of abundance of competent vectors of BT and AHS. It also provided valuable data to inform mathematical models exploring disease outbreaks so that Culicoides-transmitted diseases in South Africa can be further analysed.

Parasites & Vectors. August 2024

Self-organization of mortal filaments and its role in bacterial division ring formation

Christian Vanhille-Campos, Kevin D. Whitley, Philipp Radler, Martin Loose, Seamus Holden & Anđela Šarić

Filaments in the cell commonly treadmill. Driven by energy consumption, they grow on one end while shrinking on the other, causing filaments to appear motile even though individual proteins remain static. This process is characteristic of cytoskeletal filaments and leads to collective filament self-organization. Here we show that treadmilling drives filament nematic ordering by dissolving misaligned filaments. Taking the bacterial FtsZ protein involved in cell division as an example, we show that this mechanism aligns FtsZ filaments in vitro and drives the organization of the division ring in living Bacillus subtilis cells. We find that ordering via local dissolution also allows the system to quickly respond to chemical and geometrical biases in the cell, enabling us to quantitatively explain the ring formation dynamics in vivo. Beyond FtsZ and other cytoskeletal filaments, our study identifies a mechanism for self-organization via constant birth and death of energy-consuming filaments.

Nature Physics. August 2024

A neuronal circuit driven by GLP-1 in the olfactory bulb regulates insulin secretion

Mireia Montaner, Jessica Denom, Vincent Simon, Wanqing Jiang, Marie K. Holt, Daniel I. Brierley, Claude Rouch, Ewout Foppen, Nadim Kassis, David Jarriault, Dawood Khan, Louise Eygret, Francois Mifsud, David J. Hodson, Johannes Broichhagen, Lukas Van Oudenhove, Xavier Fioramonti, Victor Gault, Daniela Cota, Frank Reimann, Fiona M. Gribble, Stephanie Migrenne-Li, Stefan Trapp, Hirac Gurden & Christophe Magnan

Glucagon-like peptide 1 (GLP-1) stimulates insulin secretion and holds significant pharmacological potential. Nevertheless, the regulation of energy homeostasis by centrally-produced GLP-1 remains partially understood. Preproglucagon cells, known to release GLP-1, are found in the olfactory bulb (OB). We show that activating GLP-1 receptors (GLP-1R) in the OB stimulates insulin secretion in response to oral glucose in lean and diet-induced obese male mice. This is associated with reduced noradrenaline content in the pancreas and blocked by an α2-adrenergic receptor agonist, implicating functional involvement of the sympathetic nervous system (SNS). Inhibiting GABAA receptors in the paraventricular nucleus of the hypothalamus (PVN), the control centre of the SNS, abolishes the enhancing effect on insulin secretion induced by OB GLP-1R. Therefore, OB GLP-1-dependent regulation of insulin secretion relies on a relay within the PVN. This study provides evidence that OB GLP-1 signalling engages a top-down neural mechanism to control insulin secretion via the SNS.

Nature Communications. August 2024

Acidic polymers reversibly deactivate phages due to pH changes

Huba L. Marton, Antonia P. Sagona, Peter Kilbride and Matthew I. Gibson

Poly(carboxylic acids) have been reported to inhibit phages’ ability to infect their bacterial hosts and hence offer an exciting route to discover additives to prevent infection. Here, we report the role of pH in inactivating phages to determine if the polymers are unique or simply acidic. It is shown that lower pH (= 3) triggered by either acidic polymers or similar changes in pH using HCl lead to inhibition. There is no inhibitory activity at higher pHs (in growth media). It is also shown that poly(acrylic acid) leads to reversible deactivation of phage, but when the pH is adjusted using HCl alone the phage is irreversibly deactivated. Further experiments using metal binders ruled out ion depletion as the mode of action.  These results show that polymeric phage inhibitors may work by unique mechanisms of action and that pH alone cannot explain the observed effects whilst also placing constraints on the practical utility of poly(acrylic acid).

RSC Applied Polymers. August 2024

Matt Keeling publications

Prioritising older individuals for COVID-19 booster vaccination leads to optimal public health outcomes in a range of socio-economic settings

Bouros, Ioana, Hill, Edward M., Keeling, Matt J., Moore, Sam and Thompson, Robin N.


The rapid development of vaccines against SARS-CoV-2 altered the course of the COVID-19 pandemic. In most countries, vaccinations were initially targeted at high-risk populations, including older individuals and healthcare workers. Policy makers must now determine how to deploy booster vaccinations, particularly when constraints in vaccine supply, delivery and cost mean that booster vaccines cannot be administered to everyone. A key question is whether older individuals should again be prioritised for vaccination, or whether alternative strategies (e.g. offering booster vaccines to the individuals who have most contacts with others and therefore drive infection) can instead offer indirect protection to older individuals. Here, we use mathematical modelling to address this question, considering SARS-CoV-2 transmission in a range of countries with different socio-economic backgrounds. We show that the population structures of different countries can have a pronounced effect on the impact of booster vaccination, even when identical booster vaccination targeting strategies are adopted. However, under the assumed transmission model, prioritising older individuals for booster vaccination consistently leads to the most favourable public health outcomes in every setting considered. PLoS Computational Biology. August 2024

Modelling timelines to elimination of sleeping sickness in the Democratic Republic of Congo, accounting for possible cryptic human and animal transmission

Crump, Ronald E., Aliee, Maryam, Sutherland, Samuel A., Huang, Ching-I, Crowley, Emily, Spencer, Simon E. F., Keeling, Matt J., Shampa, Chansy, Mwamba Miaka, Erick and Rock, Kat S.


Sleeping sickness (gambiense human African trypanosomiasis, gHAT) is a vector-borne disease targeted for global elimination of transmission (EoT) by 2030. There are, however, unknowns that have the potential to hinder the achievement and measurement of this goal. These include asymptomatic gHAT infections (inclusive of the potential to self-cure or harbour skin-only infections) and whether gHAT infection in animals can contribute to the transmission cycle in humans. Using modelling, we explore how cryptic (undetected) transmission impacts the monitoring of progress towards and the achievement of the EoT goal. This study is the first to simulate an (as-yet-to-be available) screen-and-treat strategy and found that removing a parasitological confirmation step was predicted to have a more noticeable benefit to transmission reduction under the asymptomatic model compared with the others. Our simulations suggest vector control could greatly impact all transmission routes in all models, although this resource-intensive intervention should be carefully prioritised. Parasites & Vectors. August 2024

Nanoscale synchrotron x-ray analysis of intranuclear iron in melanised neurons of Parkinson’s substantia nigra

Jake Brooks, James Everett, Emily Hill, Kharmen Billimoria, Christopher M. Morris, Peter J. Sadler, Neil Telling & Joanna F. Collingwood

Neuromelanin-pigmented neurons of the substantia nigra are selectively lost during the progression of Parkinson’s disease. These neurons accumulate iron in the disease state, and iron-mediated neuron damage is implicated in cell death. Here, scanning transmission x-ray microscopy (STXM) is used to probe iron foci in relation to the surrounding ultrastructure in melanised neurons of human substantia nigra from a confirmed Parkinson’s case. The findings show that STXM is a powerful label-free tool for the in situ, nanoscale chemical characterisation of both organic and inorganic intracellular components. Future applications are likely to shed new light on incompletely understood biochemical mechanisms, such as metal dysregulation and morphological changes to cell nucleoli, that are important in understanding the pathogenesis of Parkinson’s.

Communications Biology. August 2024

Fluorinated trehalose analogues for cell surface engineering and imaging of Mycobacterium tuberculosis

Collette S. Guy, James A. Gott, Jonathan Ramírez-Cárdenas, Christopher de Wolf, Christopher M. Furze, Geoff West, Juan C. Muñoz-García, Jesus Angulo and Elizabeth Fullam 

The sensitive, rapid and accurate diagnosis of Mycobacterium tuberculosis (Mtb) infection is a central challenge in controlling the global tuberculosis (TB) pandemic. Yet the detection of mycobacteria is often made difficult by the low sensitivity of current diagnostic tools, with over 3.6 million TB cases missed each year. To overcome these limitations there is an urgent need for next-generation TB diagnostic technologies. Here we report the use of a discrete panel of native 19F-trehalose (F-Tre) analogues to label and directly visualise Mtb by exploiting the uptake of fluorine-modified trehalose analogues via the mycobacterial trehalose LpqY-SugABC ATP-binding cassette (ABC) importer.. This rapid one-step labelling approach facilitates the direct visualisation of F-Tre-labelled Mtb by Focused Ion Beam (FIB) Secondary Ion Mass Spectrometry (SIMS), enabling detection of the Mtb pathogen. Collectively, our findings highlight that F-Tre analogues have potential as tools to probe and unravel Mtb biology and can be exploited to detect and image TB

Chemical Science.August 2024

Structure of the MlaC-MlaD complex reveals molecular basis of periplasmic phospholipid transport

Peter Wotherspoon, Hannah Johnston, David J. Hardy, Rachel Holyfield, Soi Bui, Giedrė Ratkevičiūtė, Pooja Sridhar, Jonathan Colburn, Charlotte B. Wilson, Adam Colyer, Benjamin F. Cooper, Jack A. Bryant, Gareth W. Hughes, Phillip J. Stansfeld, Julien R. C. Bergeron & Timothy J. Knowles

The Maintenance of Lipid Asymmetry (Mla) pathway is a multicomponent system found in all gram-negative bacteria that contributes to virulence, vesicle blebbing and preservation of the outer membrane barrier function. Here, we report the structure of E. coli MlaC in complex with the MlaD hexamer in two distinct stoichiometries. Utilising in vivo complementation assays, an in vitro fluorescence-based transport assay, and molecular dynamics simulations, we confirm key residues, identifying the MlaD β6-β7 loop as essential for MlaCD function. We also provide evidence that phospholipids pass between the C-terminal helices of the MlaD hexamer to reach the central pore, providing insight into the trajectory of GPL transfer between MlaC and MlaD.

Nature Communications. July 2024

Biophysical cartography of the native and human-engineered antibody landscapes quantifies the plasticity of antibody developability

Habib Bashour, Eva Smorodina, Matteo Pariset, Jahn Zhong, Rahmad Akbar, Maria Chernigovskaya, Khang Lê Quý, Igor Snapkow, Puneet Rawat, Konrad Krawczyk, Geir Kjetil Sandve, Jose Gutierrez-Marcos, Daniel Nakhaee-Zadeh Gutierrez, Jan Terje Andersen & Victor Greiff

Designing effective monoclonal antibody (mAb) therapeutics faces a multi-parameter optimization challenge known as “developability”, which reflects an antibody’s ability to progress through development stages based on its physicochemical properties. To chart natural and engineered DP landscapes, we computed 40 sequence- and 46 structure-based DPs of over two million native and human-engineered single-chain antibody sequences. We show that sequence DPs are more predictable than structure-based ones across different machine-learning tasks and embeddings, indicating a constrained sequence-based design space. Human-engineered antibodies localize within the developability and sequence landscapes of natural antibodies, suggesting that human-engineered antibodies explore mere subspaces of the natural one. Our work quantifies the plasticity of antibody developability, providing a fundamental resource for multi-parameter therapeutic mAb design.

Communications Biology July 2024

Direct water-soluble molecules transfer from transplanted bone marrow mononuclear cell to hippocampal neural stem cells

Okinaka Y, Maeda M, Kataoka Y, Nakagomi T, Doi A, Boltze J, Claussen C, Gul S, Taguchi A

Intravascularly transplanted bone marrow cells, including bone marrow mononuclear cells (BM-MNC) and mesenchymal stem cells, transfer water-soluble molecules to cerebral endothelial cells via gap junctions. Following transplantation of BM-MNC, this fosters hippocampal neurogenesis and enhancement of neuronal function. Herein, we report the impact of transplanted BM-MNC on neural stem cells (NSC) in the brain. Surprisingly, direct transfer of water-soluble molecules from transplanted BM-MNC and peripheral mononuclear cells to NSC in the hippocampus was observed already 10 minutes after cell transplantation, and transfer from BM-MNC to GFAP-positive cortical astrocytes was also observed. In-vitro investigations revealed that BM-MNC abolish the expression of HIF1α in astrocytes. We suggest that the transient and direct transfer of water-soluble molecules between cells in circulation and NSC in the brain may be one of the biological mechanisms underlying repair of brain function.

Stem Cells & Development. July 2024