Biology subjects

Clarke, M.

Publications and source records attributed to Clarke, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Neurite Complexity and Plasticity Markers Track Synaptic Vesicle Density in the Living Human Brain: A Multimodal PET-MRI-EEG Study

Neuroplasticity, the brain's capacity to reorganise its structure and function, is a transdiagnostic feature across psychiatric and neurodegenerative diseases and a putative mechanism of action for pharmacological interventions. [11C]-UCBJ positron emission tomography (PET), which quantifies synaptic vesicle glycoprotein 2A (SV2A) density, offers the most direct in vivo measure of human synaptic density, but its relationship to complementary, more scalable neuroimaging measures of structural and functional plasticity remains uncharacterised. We combined [11C]-UCBJ PET, diffusion weighted imaging (DWI/NODDI), resting-state functional magnetic resonance imaging (rs-fMRI), and electroencephalography (EEG)-based sensory tasks (roving mismatch negativity, MMN; visual long-term potentiation, vLTP) in 18 healthy volunteers to test the relationship between synaptic terminal SV2A density and complementary structural and functional neuroplasticity measures, and whether these relationships were reproducible following pharmacological challenge with ketamine (n = 11) or N,N-dimethyltryptamine (DMT; n = 7). There were no statistically significant differences in PET-derived SV2A binding potential (BPND), DWI-derived neurite orientation dispersion (ODI) and structural weighted degree (SWD), EEG-derived MMN repetition suppression, and late-phase vLTP P2 potentiation, 1 to 8 days following DMT and ketamine exposure compared to baseline. BPND was coupled with ODI across cortical regions before and after pharmacological challenge, and this relationship was tighter within visual, attentional, and frontoparietal control brain networks. SWD showed a weaker, more spatially restricted association with BPND, primarily in regions belonging to the limbic and visual brain networks, but was not replicated post-drug. No consistent association was found between BPND and functional weighted degree (FWD), derived from rs-fMRI, at baseline or after pharmacological challenge. Frontotemporal BPND was positively associated with MMN repetition suppression (r = 0.61), and occipital BPND with late-phase vLTP P2 potentiation (r = 0.54), with the MMN-BPND association replicating after pharmacological challenge (r = 0.49). These findings link synaptic terminal SV2A density in the living human brain to neurite architecture and the capacity for short-term and Hebbian-like long-term synaptic plasticity, while dissociating these relationships from generic functional connectivity and magnitude of sensory-evoked responses. These data provide cross-modal validation for DWI- and EEG-derived measures as biological indices and surrogate measures of human synaptic plasticity.

neuroscience↗

bioRxiv2026

An Integrated Multi-omics Single Cell Atlas of the Human RPE and Choroid

The retinal pigment epithelium and choroid are critical for supporting the function and maintaining the homeostasis of the outer retina, and their dysfunction underlies a range of inherited and complex ocular diseases. To comprehensively characterize the cellular, transcriptomic, and epigenomic heterogeneity and dynamics within these tissues, we assembled an integrated multi-omics reference atlas comprising 719,813 single-cell/single-nucleus transcriptomes and 234,007 snATAC-seq profiles from 102 ancestrally diverse donors spanning 0 to 99 years of age, including cells from both the macula and periphery. This atlas resolves 48 distinct cell types or states and catalogs 448,567 open chromatin regions. Specifically, we resolved five distinct RPE subpopulations organized along a central-to-peripheral spatial axis, alongside two distinct stress/senescence states. We reconstructed the transcriptomic and epigenetic zonation of endothelial cells and expanded choroidal stromal heterogeneity by characterizing 11 fibroblast and two pericyte types. Age-associated compositional analysis revealed a significant fractional depletion of melanocytes, PI16+ fibroblasts, and venule endothelial cells with age, alongside a modest relative loss of central RPE and a corresponding increase in far-peripheral RPE. Cell-type-specific aging transcriptomics uncovered shared pathways related to inflammatory responses alongside distinct cell-type-specific signatures. Notably, significant age-associated epigenetic changes concentrated in the macula during the transition from early-to-middle adulthood and remained stable into old age, with transcription factors from the AP-1/bZIP family emerging as the dominant enriched motifs. Finally, integrating this atlas with AMD GWAS data provides novel variant-to-gene evidence implicating LIPG and COL4A3 in AMD pathogenesis. Together, this multi-omics atlas serves as both an invaluable community reference and a powerful discovery engine that translates genetic risk signals into localized target cells and candidate mechanisms, laying a foundation for understanding RPE/choroid biology in health and disease.

genomics↗

bioRxiv2026

Single-cell multi-omic analyses resolve the cellular diversity of ALK/ROS1/MET/NTRK-fused gliomas in infants and older children

Pediatric cancers are thought to arise from dysregulation of developmental programs, otherwise tightly regulated in time and space. Infant-type hemispheric gliomas (IHGs) arise in early childhood, driven by characteristic ALK/ROS1/MET/NTRK receptor tyrosine kinase (RTK) gene fusions. We dissected the cellular hierarchies of 24 fusion-positive gliomas, spanning infants through adolescents, using single-cell and single-nucleus RNA/ATAC-seq, and spatial transcriptomics. We identified five cancer cell states, with radial glia-like cells at the apex of a neoplastic hierarchy resembling neuronal- and glial-like trajectories. Neuronal-like cells were enriched in most IHGs but diminished in ROS1-fused IHGs and older patients. Integration of chromatin profiling revealed FOS/JUN-driven oncogenic programs and high inferred plasticity across all cancer cell populations. Myeloid cells, the most abundant non-neoplastic population, comprised distinct subgroups, suggesting context-dependent functions. Despite lacking high-order structure, spatial transcriptomics revealed discrete cellular niches within IHGs. Collectively, our findings elucidate the cellular states and developmental programs underlying IHGs and RTK-fused gliomas in older patients, opening new avenues for research and therapy innovation.

cancer biology↗

bioRxiv2026

BCL11B predetermines a persister state in breast cancer that is reversed by TNFα

The frequent development of chemoresistance in cancer presents a significant clinical challenge, yet the underlying causes for heterogeneous drug responses remain largely elusive. Here, we systematically assessed the cellular differentiation status of human breast cancer cells utilizing single-cell atlases and identified a distinct population of immature basal-like cancer cells marked by BCL11B. Notably, higher levels of BCL11B+ cancer cells are significantly associated with early relapse in breast cancer patients who received chemotherapy. Functioning as a central regulator, BCL11B delineates an immature cell state that preferentially transitions to a drug-resistant persister state during treatment through multiple pre-existing and adaptive drug-resistance programs. Importantly, the cytokine tumor necrosis factor alpha (TNF) is revealed as a natural inhibitor of BCL11B and can directly reverse the emergence of chemoresistant persister cells. Therefore, we identify BCL11B as an unappreciated pre-determinant of drug response and a therapeutic target for a subset of breast cancer patients at high risk of developing chemoresistance.

Cancer Biology↗

bioRxiv2026

A Functional Genetic Atlas of Parkin Resolves Variants of Uncertain Significance and Predicts Parkinson's Disease Age at Onset

Autosomal recessive mutations in the Parkin gene (PRKN) cause early-onset Parkinsons disease (PD). Parkin functions as a ubiquitin E3 ligase acting downstream of the PINK1 kinase to promote phosphorylated ubiquitin at sites of mitochondrial damage. Yet the functional effects of most PRKN gene variants remain unknown. Here we use a pooled cellular assay measuring phosphorylated ubiquitin accumulation to quantify the activity of [~]9,200 PRKN missense and nonsense variants. Our screen identifies thousands of loss- and gain-of-function variants, including activating variants mainly residing at autoinhibitory interfaces. Functional scores accurately distinguish known PD pathogenic and benign variants, and enable reclassification of 173/184 variants of uncertain significance (VUS). When combined into biallelic genotype scores, these data predict the age at disease onset in patients, revealing a quantitative link between Parkin activity and clinical manifestation. Our results provide a comprehensive functional genetic map of Parkin and demonstrate the power of multiplexed assays of variant effects (MAVEs) for variant interpretation and precision medicine in PD.

genetics↗

bioRxiv2025

Controlling GRF4-GIF1 Expression for Efficient, Genotype-Independent Transformation Across Wheat Cultivars

Bread wheat (Triticum aestivum L.) plays a vital role in global food security, and its continuous genetic improvement is essential to meet the demands of a rapidly growing world population. Advances in genome sequencing and assembly have positioned wheat as a model crop for functional genomics and have increased the demand for highly efficient, genotype-independent transformation systems. A fusion technology involving a GROWTH-REGULATING FACTOR (GRF) and a GRF-INTERACTING FACTOR (GIF) has emerged as a powerful tool to enhance regeneration efficiency and expand the range of transformable genotypes. In this study, we present an optimized and robust Agrobacterium-mediated wheat transformation protocol incorporating GRF4-GIF1, tested across multiple wheat varieties. Across all tested wheat cultivars, GRF4-GIF1 containing constructs consistently enabled successful transformation, with varied efficiencies depending on the genotype and promotors used to drive the gene fusion. Our method significantly improves transformation efficiency while minimizing GRF4-GIF1 pleiotropic effects, providing a versatile platform for gene function analysis and gene editing. This work represents a critical step toward efficient, genotype-independent transformation in wheat, supporting both research and breeding applications aimed at improving crop resilience, nutritional value, and productivity.

plant biology↗

bioRxiv2025

A GCN1-independent activator of the kinase GCN2

Mutations of EIF2AK4, which encodes the eIF2 kinase GCN2, cause a severe inherited form of pulmonary hypertension called pulmonary veno-occlusive disease (PVOD). Some pathogenic variants of GCN2 are amenable to pharmacological reactivation by low concentrations of ATP-pocket binding inhibitors. Kinase inhibition at modestly elevated concentrations limits the clinical utility of these drugs against PVOD. We therefore performed an in cellulo chemical screen for GCN2 activators and identified three structurally distinct compounds with low micromolar stimulatory activities. Unlike previously described GCN2 activators, one of these molecules activated GCN2 independently of GCN1. Modelling supported by structure activity screens suggested it binds within the ATP-pocket of GCN2, but unlike existing ligands does not protrude inward into the allosteric pocket or outward into the solvent. This overcomes a key requirement of other GCN2 activators.

cell biology↗

bioRxiv2025

Efficacy of DNA Methyltransferase Inhibitor Immune Priming Therapy in Combination with PD-1 Inhibitors to Treat High-Risk Pediatric Brain Tumors

BackgroundDespite intensive therapies, outcomes for high-risk pediatric brain tumors (PBTs) remain dismal, prompting the search for novel treatments. DNA methyltransferase inhibitors (DNMTi) have been shown to prime tumors to improve response to checkpoint inhibition. The aim of this study was to investigate the potential of decitabine (DAC), in combination with a PD-1 inhibitor, to improve survival in pediatric high-risk brain tumor models. MethodsAnalysis of human PBT datasets was performed to determine gene expression levels of immune cell associated markers. Tumor response to DAC, with or without a PD-1 inhibitor, was tested in murine models representing H3-wildtype diffuse intrinsic pontine glioma (DIPG), H3K27-mutant diffuse midline glioma (DMG), atypical teratoid rhabdoid tumor (ATRT), and medulloblastoma (MB). CyTOF analysis of allograft tumors was performed to characterize changes within the tumor microenvironment. ResultsAnalysis of PBT subtypes revealed heterogeneous expression of immune cell markers, checkpoint receptors, and MHC molecules. DAC treatment decreased DNA methylation and increased neoantigen expression in human and mouse tumor cells. DAC alone or in combination with a PD-1 inhibitor resulted in prolonged survival in syngeneic mouse models of DIPG and ATRT but not DMG and MB models. CyTOF analysis of mouse tumors revealed changes in local immune cell infiltration upon combination treatment. ConclusionsDAC in combination with a PD-1 inhibitor can alter the immune microenvironment in mouse tumor models. Changes were observed in H3-wildtype DIPG and ATRT models, suggesting that certain tumor subtypes may respond to checkpoint blockade after immune augmentation with DNMTi. Key PointsO_LIPBTs show heterogenous expression of immune cell infiltrates C_LIO_LIDAC or DAC plus a PD-1 inhibitor shows extension of survival in H3-wildtype DIPG and ATRT mouse models C_LIO_LIMyeloid-derived suppressor cell abundance could be a major contributing factor to treatment response C_LI Importance of the StudyChildren with high-risk PBTs face dismal outcomes. Immune checkpoint inhibitor (ICI) successes have been demonstrated in a variety of adult malignancies; however, such beneficial outcomes have not been realized in PBTs. Here we investigate single and combination treatment of DNMTi and PD-1 checkpoint inhibition in syngeneic mouse models of high-risk PBTs. Our results suggest that some H3-wildtype DIPG and ATRT tumor types may be responsive to checkpoint therapy post immunomodulation and warrant further investigation.

immunology↗

bioRxiv2025

A typology of Australian terrestrial bird communities

AimIncreasing interest in holistic measurement of the response of fauna communities to interventions requires suitable community condition metrics. However, the development of such metrics is hindered by the absence of broad-scale typologies at suitable spatial and ecological resolutions. We aimed to derive a preliminary typology of terrestrial bird communities for Australia, based on bird co-occurrence data, and describe and map the likely distribution of each community type across the continent. LocationMainland Australia, continental islands Time period1973-2022 Major taxa studiedAves MethodsWe used fine-scale co-occurrence data from standard 2-ha surveys in BirdLife Australias citizen-science database. After filtering to reduce bias, we used hierarchical clustering followed by iterative consultation with experts to identify reliably distinct and recognisable terrestrial bird communities across Australia. We used Maxent to model the likely distributions of each community, and developed community descriptions based on each communitys composition and distribution. ResultsThe resultant typology included 29 reliably distinct and recognisable bird communities with major clusters corresponding with seven broad geographical regions. The distributions of bird communities did not correspond tightly to the boundaries of major vegetation groups, with most communities occurring across multiple vegetation types. Main ConclusionsOur preliminary typology of bird communities provides a standard classification at a continental scale. It newly defines distinct bird communities as entities for which condition benchmarks can be established to allow assessment of their conservation status and monitoring of change over time. Refinement will enable cryptic communities in areas with sparse data to be identified. The method could be translated to other regions where adequate coverage of data in the form of standardised surveys of fauna are available. Vast biodiversity datasets delivered through citizen science programs provide the opportunity to develop such typologies for fauna communities, as a precursor to developing targeted and informative community condition metrics.

ecology↗

bioRxiv2023

Septoria tritici blotch resistance gene Stb15 encodes a lectin receptor-like kinase

Septoria tritici blotch (STB), caused by the Dothideomycete fungus Zymoseptoria tritici, is of one of the most damaging diseases of bread wheat (Triticum aestivum)1 and the target of costly fungicide applications2. In line with the fungus apoplastic lifestyle, STB resistance genes isolated to date encode receptor-like kinases (RLKs) including a wall-associated kinase (Stb6) and a cysteine-rich kinase (Stb16q)3,4. Here, we used genome-wide association studies (GWAS) on a panel of 300 whole-genome shotgun-sequenced diverse wheat landraces (WatSeq consortium) to identify a 99 kb region containing six candidates for the Stb15 resistance gene. Mutagenesis and transgenesis confirmed a gene encoding an intronless G-type lectin RLK (LecRK) as Stb15. The characterisation of Stb15 exemplifies the unexpected diversity of RLKs conferring Z. tritici resistance in wheat.

genetics↗

bioRxiv2023

A pro-inflammatory stem cell niche drives myelofibrosis through a targetable galectin 1 axis

Myeloproliferative neoplasms are stem cell-driven cancers associated with a large burden of morbidity and mortality. The majority of patients present with early-stage disease, but a substantial proportion progress to myelofibrosis and/or secondary leukemia, advanced cancers with a poor prognosis and high symptom burden. Currently, it remains difficult to predict progression, and we lack therapies that reliably prevent or reverse fibrosis development. A major bottleneck to the discovery of disease-modifying therapies has been an incomplete understanding of the interplay between perturbed cellular and molecular states. Several cell types have individually been implicated, but a comprehensive analysis of myelofibrotic bone marrow is lacking. We therefore mapped the crosstalk between bone marrow cell types in myelofibrotic bone marrow. We found that inflammation and fibrosis are orchestrated by a quartet of immune and stromal cell lineages - with basophils and mast cells creating a TNF signaling hub, communicating with megakaryocytes, mesenchymal stromal cells and pro-inflammatory fibroblasts. We identified the y-galactoside binding protein galectin 1 as a striking biomarker of progression to myelofibrosis and poor survival in multiple patient cohorts, and as a promising therapeutic target, with reduced myeloproliferation and fibrosis in vitro and in vivo and improved survival following galectin 1 inhibition. In human bone marrow organoids, TNF increased galectin 1 expression, suggesting a feedback loop wherein the pro-inflammatory MPN clone creates a self-reinforcing niche, fueling progression to advanced disease. This study provides a valuable resource for studying hematopoietic cell-niche interactions, with broad relevance for cancer-associated inflammation and disorders of tissue fibrosis.

cancer biology↗

bioRxiv2023

Progressive Senescence Programs Induce Intrinsic Vulnerability to Aging-related Breast Cancer

Cancer incidence escalates exponentially with advancing age; however, the underlying mechanism remains unclear. In this study, we built a chronological molecular clock at the single-cell transcription level with a mammary stem cell-enriched population to depict physiological aging dynamics in mice. We found that the mammary aging process was asynchronous and progressive, initiated by an early senescence program with elevated NF-kB and P53 signaling, succeeded by an entropic late senescence program with reduced NF-kB and P53 signaling and enhanced PI3K-Akt-mTOR, Wnt, Notch and pluripotent activity, vulnerable to cancer predisposition. The transition towards senescence program was governed by the master stem cell factor Bcl11b, loss of which accelerated mammary ageing with enhanced DMBA-induced tumor formation. We identified a drug TPCA-1 that can elevate Bcl11b, rejuvenate mammary cells and significantly reduce aging-related cancer incidence. Our findings established a molecular portrait of progressive mammary cell aging and elucidated the transcriptional regulatory network bridging mammary aging and cancer predisposition, which can be modulated to control cancer initiation; therefore, this study has potential implications for the management of cancer prevalence in the aged.

cancer biology↗

bioRxiv2022

Improved SpCas9 and LbCas12a genome editing systems in Brassica oleracea and Brassica napus

We report highly efficient genome editing in Brassica species. We compare the efficiency of targeted mutagenesis using four Streptococcus pyogenes Cas9 (SpCas9) systems in Brassica oleracea and Brassica napus over 3 target genes and five guides to identify two which show a striking improvement to our first published system (Lawrenson et al., 2015). Targeted mutagenesis occurred in up to 100% of T0 plants with the improved systems, compared to 20% in the original system. This is the only reported comparison of SpCas9 systems we are aware of in Brassica species. Secondly, we report the first successful use of Lachnospiraceae bacterium Cas12a (LbCas12a) in Brassica oleracea. We test three LbCas12a coding sequences and two guide architectures against one target gene using four guides. From this we identify the best performing combination of our novel, multi-intron coding sequence and a ribozyme flanked guide expression cassette. In this case 68% of T0 plants contained targeted mutations. Heritability of LbCas12a mutations is shown. We show that our two useful and novel LbCas12a coding sequences have utility in Brassica species.

genomics↗

bioRxiv2022

Identification of Fusarium Head Blight resistance in Triticum timopheevii accessions and characterisation of wheat-T. timopheevii introgression lines for enhanced resistance.

A diverse panel of wheat wild relative species was screened for resistance to Fusarium head blight (FHB) by spray inoculation. The great majority of species and accessions were susceptible or highly susceptible to FHB. Accessions of Triticum timopheevii (P95-99.1-1), Agropyron desertorum (9439957) and Elymus vaillantianus (531552) were highly resistant to FHB while additional accessions of T. timopheevii were found to be susceptible to FHB. A combination of spray and point inoculation assessments over two consecutive seasons indicated that the resistance in accession P95-99.1-1 was due to enhanced resistance to initial infection of the fungus (type 1 resistance), and not to reduction in spread (type 2 resistance). A panel of wheat-T. timopheevii (accession P95-99.1-1) introgression lines was screened for FHB resistance over two consecutive seasons using spray inoculation. Most introgression lines were similar in susceptibility to FHB as the wheat recipient (Paragon) but substitution of the terminal portion of chromosome 3BS of wheat with a similar-sized portion of 3G of T. timopheevii significantly enhanced FHB resistance in the wheat background.

plant biology↗

bioRxiv2022

A Cdh3-Lam332 signaling axis in a leader cell subpopulation controls protrusion dynamics and tumor organoid collective migration

Carcinoma dissemination can occur when heterogeneous tumor and tumor stromal cells clusters migrate together via collective migration. Cells at the front lead and direct collective migration, yet how these leader cells form and interact with the microenvironment to direct migration are not fully appreciated. From live videos of primary mouse and human breast tumor organoids in a 3D microfluidic system that mimics the native breast tumor microenvironment, we developed 3D computational models which hypothesize that leader cells generate high protrusive forces and overcome extracellular matrix (ECM) resistance. Using single cell sequencing, we reveal leader cells are heterogeneous, and identify and isolate a unique Cadherin-3 (Cdh3) positive leader cell subpopulation that is necessary and sufficient to lead migration. Cdh3 controls leader cell protrusion dynamics through the local production of Laminin-332 which is required for integrin/focal adhesion function. Our findings highlight how a subset of leader cells interact with the microenvironment to direct collective migration. TeaserHigher protrusions of Cdh3+ leader cells polarize tumor organoids that then invade collagen via Lam332 adhesion feedback.

cancer biology↗

bioRxiv2022

Structural and biochemical basis of FANCI-FANCD2 interdependent ubiquitination

The Fanconi Anaemia pathway operates for the repair of interstrand crosslinks and the maintenance of genomic stability upon replication stalling. Di-monoubiquitination of the FANCI-FANCD2 (ID2) complex is a central and crucial step in this pathway. Evidence suggests that FANCD2 ubiquitination precedes FANCI ubiquitination, and that both the FANCD2-ubiquitinated (ID2Ub) and the di- monoubiquitinated (IUbD2Ub) complex clamp on DNA. However, FANCD2 is deubiquitinated at a faster rate than FANCI, which can result in a FANCI-ubiquitinated ID2 complex (IUbD2). Here, we present a 4.1 [A] cryo-EM structure of IUbD2 complex bound to double-stranded DNA. We show that this complex, like ID2Ub and IUbD2Ub, is also in the closed ID2 conformation and clamps on DNA. While the target lysine of FANCD2 (K561) is partially buried in the non-ubiquitinated ID2-DNA complex, it becomes fully exposed in the IUbD2-DNA structure, and thus can be ubiquitinated at a faster rate. The IUbD2-DNA complex cannot easily revert to the non-ubiquitinated ID2 state, due to USP1-UAF1-resistance, conferred by the presence of DNA and FANCD2. ID2Ub-DNA, on the other hand, can be efficiently deubiquitinated by USP1-UAF1, unless further ubiquitination on FANCI occurs. FANCI ubiquitination also progresses at a faster rate in ID2Ub-DNA over ID2-DNA complex, and results in partial DNA-dependent protection from FANCD2 deubiquitination. Taken together, our results suggest that, while FANCD2 ubiquitination promotes FANCI ubiquitination, FANCI ubiquitination in turn maintains FANCD2 ubiquitination by two mechanisms: it prevents excessive FANCD2 deubiquitination within an IUbD2Ub-DNA complex, and it enables re-ubiquitination of FANCD2 within a transient, closed-on-DNA, IUbD2 complex.

biochemistry↗

bioRxiv2022

Temporin B forms hetero-oligomers with Temporin L, modifies its membrane activity and increases the cooperativity of its antibacterial pharmacodynamic profile

The pharmacodynamic profile of antimicrobial peptides (AMPs) and their in vivo synergy are two factors that are thought to restrict resistance evolution and ensure their conservation. The frog Rana temporaria secretes a family of closely related AMPs, temporins A-L, as an effective chemical dermal defence. The antibacterial potency of temporin L has been shown to increase synergistically in combination with both temporins B and A but this is modest. Here we show that the less potent temporin B enhances the cooperativity of the in vitro antibacterial activity of the more potent temporin L against EMRSA-15 and that this may be associated with an altered interaction with the bacterial plasma membrane, a feature critical for the antibacterial activity of most AMPs. Addition of buforin II, a histone H2A fragment, can further increase the cooperativity. Molecular dynamics simulations indicate temporins B and L readily form hetero-oligomers in models of Gram-positive bacterial plasma membranes. Patch-clamp studies show transmembrane ion conductance is triggered with lower amounts of both peptides and more quickly, when used in combination, but conductance is of a lower amplitude and pores are smaller. Temporin B may therefore act by forming temporin L/B hetero-oligomers that are more effective than temporin L homo-oligomers at bacterial killing and/or by reducing the probability of the latter forming until a threshold concentration is reached. Exploration of the mechanism of synergy between AMPs isolated from the same organism may therefore yield antibiotic combinations with advantageous pharmacodynamic properties.

biochemistry↗

bioRxiv2021

Generation of chimeric respiratory viruses with altered tropism by coinfection of influenza A virus and respiratory syncytial virus

Interactions between respiratory viruses impact viral transmission dynamics and clinical outcomes. To identify and characterize virus-virus interactions at the cellular level, we coinfected human lung cells with influenza A virus (IAV) and respiratory syncytial virus (RSV). Super-resolution microscopy, live-cell imaging, scanning electron microscopy, and cryo-electron tomography revealed extracellular and membrane-associated filamentous structures consistent with hybrid viral particles (HVPs). We show that HVPs harbor surface glycoproteins and ribonucleoproteins of IAV and RSV, and use the RSV fusion glycoprotein to evade anti-IAV neutralising antibodies and to infect and spread among cells lacking IAV receptors. Finally, we show evidence of IAV and RSV coinfection within cells of the bronchial epithelium, with viral proteins from both viruses co-localising at the apical surface. Our observations have profound implications for infection biology as they define a previously unknown interaction between respiratory viruses that might affect virus pathogenesis by expanding virus tropism and facilitating immune evasion.

microbiology↗