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Robinson, M. W.

Publications and source records attributed to Robinson, M. W..

5 recordsLinked to original sources

Development and validation of a multilocus sequence typing scheme for Fasciola hepatica using next-generation deep amplicon sequencing

Fasciolosis caused by Fasciola hepatica is an economically important disease in sheep and cattle. Knowledge of the population genetic structure of F. hepatica is important for understanding gene flow and informing disease control. In the present study, we designed, developed, and validated a multilocus sequence typing (MLST) scheme based on six markers. These markers were selected by aligning newly sequenced whole-genome sequence (WGS) data with available reference genomes and selecting variable regions with five or more single-nucleotide polymorphisms SNPs from different scaffolds of the F. hepatica reference genome Fasciola 10x pilon (GCA_900302435.1). Twenty markers were initially identified, of which 12 were multiplexed for deep amplicon sequencing after validation on worm and faecal eggs DNA; six markers were ultimately retained for downstream population genetics analysis. These markers were used to investigate population genetic structure in 15 cattle- and 27 sheep-derived F. hepatica populations in UK. A total of 53 unique alleles from six MLST markers were identified from 30 faecal (cattle = 13, sheep = 17) and 12 adult worm (cattle = 2, sheep = 10) populations. Shared alleles were observed in sheep- and cattle-derived populations. The highest allelic variation was observed in the Scottish Borders, Southern Scotland, and South-West England, and the lowest in North-West England. Minimal genetic differentiation was observed between cattle- and sheep-derived populations, with most genetic structuring within rather than between populations. Five markers showed high allelic polymorphism, whereas one marker showed low levels of allelic polymorphism, highlighting the importance of multilocus approaches. Overall, this six MLST-marker panel provides a tool for population genetic studies, revealing high gene flow and clonal expansion of F. hepatica across hosts and regions in the UK.

genetics↗

A comparative analysis of liver tissue and novel primary organoid cultures from ruminants reveals species-specific immune architecture and metabolic specialization

The liver is widely considered to be one of the most conserved organs amongst vertebrates, with it being involved in blood detoxification, bile production and the metabolism of xenobiotic compounds. Liver organoids have previously been derived from several species and used as models of drug metabolism, toxicity, and fundamental tissue biology. To date, however, these models have not been developed from ruminant species, specifically cattle and sheep. Here we present the first report of the development and comprehensive characterisation of bovine and ovine liver organoids derived from primary liver tissue. When initially established, organoids from both species were comprised of KRT19- and KRT18-positive cholangiocytes. The capacity for organoids to differentiate into hepatocyte-enriched cultures was evaluated and it was noted that there was an increase in hepatocyte markers in bovine cultures. A comparative analysis of the liver tissue and organoids of both species revealed species-specific differences in gene expression, which were conserved within organoid cultures. Most notably, bovine liver tissue and organoids had enriched expression of genes associated with fatty acid uptake and storage whereas ovine samples had higher expression of genes associated with fatty acid conversion, highlighting fundamental differences between these two ruminant species. Differences in expression of cytochrome P450 family genes were identified alongside those associated with an inflammatory response specifically in bovine samples, whereas ovine samples had higher expression of genes associated with a protective immune response. Despite this, transcriptomic analysis of organoids from both species, cultured in both growth and differentiation media, revealed preserved expression of genes associated with key liver functions, including gluconeogenesis and xenobiotic metabolism. Transcripts associated with the flavin-containing monooxygenases (FMO) family were expressed in both organoid growth media and organoid development media (OGM and ODM respectively), and both species could metabolise triclabendazole into its primary metabolite triclabendazole sulfoxide, therefore validating the potential of the organoids to be applied as in vitro models of metabolism and/or toxicity. Overall, this study provides novel insights into differences in liver composition and function between ruminant species, as well as providing novel experimental models of the liver for both cattle and sheep.

cell biology↗

Development of a qPCR assay and tremabiome deep amplicon sequencing method for differentiation of fluke species in livestock

BackgroundTrematode parasites, or flukes, are a significant economic threat to ruminant production worldwide. Traditional diagnostic methods rely on egg sedimentation from faeces, a time-consuming methodology lacking sensitivity and specificity. This study aimed to develop and validate two diagnostic methods: firstly, qPCR for accurate identification of Fasciola spp, and secondly, tremabiome, deep amplicon sequencing technique for identifying fluke species using faecal egg DNA. MethodologyTo detect fluke infection primers targeting mitochondrial DNA were repurposed to develop a SYBR Green qPCR diagnostic. For the identification of fluke species, a tremabiome approach was developed. A reference sequence library and taxonomy file were generated for 21 fluke species, enabling species sequence read separation and extracting amplicon sequence variants (ASVs). To validate the qPCR and tremabiome approach, 402 faecal samples were collected from cattle and sheep across the UK. Fluke eggs were isolated by sedimentation, detected by microscopy and qPCR, and tremabiome used to identify fluke eggs to species level. ResultsqPCR demonstrated high analytical sensitivity, detecting Fasciola hepatica DNA down to 19.2fg and F. gigantica down to 6.4fg, with no cross-amplification of other flukes. Tremabiome was able to detect as few as five F. hepatica and Calicophoron daubneyi eggs and identify mixed infections. High levels of co-infection (14.4%) of F. hepatica and C. daubneyi were observed in faecal samples, followed by single infections with C. daubneyi (12.6%) and F. hepatica (3.2%). Notably, tremabiome detected F. hepatica in 20 samples missed by qPCR. Data analysis identified 55 and 32 ASVs for F. hepatica and C. daubneyi, respectively, with phylogenetic clustering within their respective clades. ConclusionThis study developed qPCR assay for Fasciola detection and validated a tremabiome deep amplicon sequencing for fluke species differentiation. These approaches have improved capacity to identify fluke species compared to microscopy and are valuable tools for enhancing fasciolosis surveillance and control. Author SummaryFlukes are flatworm parasites that cause disease domestic and wild animals and humans. The main species infecting cattle and sheep globally are the liver flukes F. hepatica and F. gigantica, with other species including the rumen fluke Calicophoron daubneyi locally important or emerging. Infections result in serious economic losses. The traditional method of diagnosing fluke infection involves observation of eggs in faecal samples under the microscope, but this can be time-consuming and error prone, since the eggs of different species often look similar. In this study, we developed and validated two methods to improve detection: qPCR, a sensitive DNA-based test to identify Fasciola infections, and tremabiome, a DNA sequencing technique that can accurately differentiate between different fluke species. We tested these methods using faecal samples collected from cattle and sheep across the UK. The qPCR could detect small amounts of Fasciola DNA, while tremabiome was more sensitive, identifying different fluke species from as few as five eggs. Our study found that co-infections of F. hepatica and C. daubneyi are common in the UK. The approaches we have developed could be valuable tools for to improve fluke diagnosis and enable better control of this important parasitic disease.

molecular biology↗

Developmental regulation and functional prediction of microRNAs in an expanded Fasciola hepatica miRNome

1The liver fluke, Fasciola hepatica, is a global burden on the wellbeing and productivity of farmed ruminants, and a zoonotic threat to human health. Despite the clear need for accelerated discovery of new drug and vaccine treatments for this pathogen, we still have a relatively limited understanding of liver fluke biology and host interactions. Noncoding RNAs, including micro (mi)RNAs, are key to transcriptional regulation in all eukaryotes, such that an understanding of miRNA biology can shed light on organismal function at a systems level. Four previous publications have reported up to 89 mature miRNA sequences from F. hepatica, but our data show that this does not represent a full account of this species miRNome. We have expanded on previous studies by sequencing, for the first time, miRNAs from multiple life stages (adult, newly excysted juvenile (NEJ), metacercariae and adult-derived extracellular vesicles (EVs)). These experiments detected an additional 61 high-confidence miRNAs, most of which have not been described in any other species, expanding the F. hepatica miRNome to 150 mature sequences. We used quantitative (q)PCR assays to provide the first developmental profile of miRNA expression across metacercariae, NEJ, adult and adult-derived Evs. The majority of miRNAs were expressed most highly in metacercariae, with at least six distinct expression clusters apparent across life stages. Intracellular miRNAs were functionally analysed to identify target mRNAs with inversely correlated expression in F. hepatica tissue transcriptomes, highlighting regulatory interactions with key virulence transcripts including cathepsin proteases, and neuromuscular genes that control parasite growth, development and motility. We also linked 28 adult-derived EV miRNAs with downregulation of 397 host genes in F. hepatica-infected transcriptomes from ruminant lymph node, peripheral blood mononuclear cell (PBMC) and liver tissue transcriptomes. These included genes involved in signal transduction, immune and metabolic pathways, adding to the evidence for miRNA-based immunosuppression during fasciolosis. These data expand our understanding of the F. hepatica miRNome, provide the first data on developmental miRNA regulation in this species, and provide a set of testable hypotheses for functional genomics interrogations of liver fluke miRNA biology. CONTRIBUTION TO THE FIELDPrevious studies identified 89 micro (mi)RNAs (non-coding RNAs responsible for regulating gene expression) in the trematode parasite, Fasciola hepatica, and attached functional annotations to the miRNAs that are secreted by liver fluke in vitro. This study expands the known miRNA complement of F. hepatica by 40%, adding an additional 61 miRNAs, many of which appear Fasciola-specific. We used this expanded dataset to perform the first analysis of developmental miRNA expression across intra-mammalian parasites, showing clear developmentally regulated expression profiles across infectious metacercariae, juvenile and adult parasites, and extracellular vesicles secreted by adult parasites. We performed rigorous functional annotation of cellular miRNAs, correlating their expression with mRNA transcriptomes to identify potential roles for specific miRNAs in regulating expression of important proteases and nerve/muscle transcripts, all of which are important for parasite virulence. We also functionally analysed miRNAs secreted by adult parasites in terms of interactions with host transcripts; for the first time this analysis was supported by host transcriptome data, linking secreted miRNAs with mRNAs that are downregulated by fluke infection in sheep and cattle. This work contributes new data, insights and analyses to the field, providing a rich source of hypotheses for future experimental validation.

molecular biology↗

Enhanced cytokine responsiveness in natural killer cells from a pilot cohort of uninfected seronegative women exposed to hepatitis C virus contaminated anti-D immunoglobulin

BackgroundSome people exposed to hepatitis C virus (HCV) appear to be capable of preventing infection in the absence of detectable antibody responses. These exposed seronegative (ESN) people appear naturally resistant to HCV infection. Here, we aimed to examine innate immune mechanisms in ESN individuals amongst rhesus negative Irish women exposed to HCV via contaminated anti-D immunoglobulin between 1977-79 and 1991-94.\n\nMethodsA total of 16 ESN individuals were recruited, along with 9 age- and gender-matched healthy controls. All tested negative for HCV-specific antibodies using conventional diagnostic assays. Peripheral blood cells were analysed for presence of adaptive immune response markers, innate immune responsiveness and natural killer cell phenotype and function.\n\nResultsThe innate immune cell profile of ESN women in the present study was characterised by a significant decrease in monocyte frequency and elevated levels of interleukin-8 and -18 compared to age- and gender-matched healthy controls. NK cells from ESN women had normal expression of NK cell receptors but increased IFN{gamma}-production upon cytokine and target cell stimulation as well as enhanced natural killer (NK) cell STAT3 phosphorylation in response to Type I IFN.\n\nConclusionsWe describe for the first time ESN individuals amongst Irish women with past exposure to HCV via contaminated anti-D immunoglobulin. NK cells from these ESN individuals are more responsive to cytokine signalling compared with age- and gender-matched controls. Human ESN cohorts can provide unique insights into the biological mechanisms associated with antigen-independent natural resistance to viral infection.

immunology↗