About
136
Publications
14,536
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
5,202
Citations
Introduction
Mark works at the School of Biological Sciences, Queen’s University, Belfast, UK. His research focusses on understanding the molecular-level interactions between helminths and their mammalian hosts. In particular, his work involves the application of -omics technologies to study trematodes of veterinary and medical importance.
Skills and Expertise
Current institution
Publications
Publications (136)
Helminth parasites have long adapted to survive hostile host environments and can likely adapt against the chemical anthelmintic challenge. One proposed adaptation route is via Phase I and II xenobiotic metabolizing enzymes (XMEs). For successful Helminth pharmacotherapy discovery programs, a working understanding of Helminth-derived chemical detox...
Background
The rumen fluke, Calicophoron daubneyi, is the major paramphistome species infecting ruminants within Europe. Adult flukes reside within the rumen where they are in direct contact with a unique collection of microorganisms. Here, we report a 1.76-Gb draft genome for C. daubneyi, the first for any paramphistome species.
Results
Several g...
Greenhouse gas (GHG) emissions from livestock production must be urgently tackled to substantially reduce their contribution to global warming. Simply reducing livestock numbers to this end risks impacting negatively on food security, rural livelihoods and climate change adaptation. We argue that significant mitigation of livestock emissions can be...
The phylogenetic relationships within Neodermata were examined based on putative orthologous groups of proteins (OGPs) from 11 species of Monogenea, Trematoda, and Cestoda. The dataset included OGPs from BUSCO and OMA. Additionally, peptidases were identified and evaluated as phylogenetic markers. Phylogenies were inferred using the maximum likelih...
Over the last decade, research interest in defining how extracellular vesicles (EVs) shape cross‐species communication has grown rapidly. Parasitic helminths, worm species found in the phyla Nematoda and Platyhelminthes, are well‐recognised manipulators of host immune function and physiology. Emerging evidence supports a role for helminth‐derived E...
Thirty-six ewes aged 18 months were assigned to one of three groups (n = 12) on the basis of faecal egg count (FEC) for rumen fluke; C: control (FEC = 0–5 epg), T: affected (FEC ≥ 6 epg) and treated, NT: affected (FEC ≥ 6 epg) and not treated. T ewes were treated with oxyclozanide 14 days prior to the trial commencing. Ewes were fed grass silage ad...
The incidence of paramphistomosis, caused by the rumen fluke, Calicophoron daubneyi, has greatly increased within Europe in the last 15–20 years. However, the production impacts of this disease are poorly understood. This study firstly aimed to investigate the prevalence of rumen fluke in England and Northern Ireland (NI) by conducting an abattoir...
Foodborne trematodes (FBTs) have a worldwide distribution (with particular prevalence in south-east Asia) and are believed to infect almost 75 million people, with millions more living at risk of infection. Although mortality due to trematodiasis is low, these infections cause considerable morbidity and some species are associated with the developm...
The liver fluke, Fasciola hepatica, is an obligate blood-feeder, and the gastrodermal cells of the parasite form the interface with the host’s blood. Despite their importance in the host–parasite interaction, in-depth proteomic analysis of the gastrodermal cells is lacking. Here, we used laser microdissection of F. hepatica tissue sections to gener...
Sm16 is a 16 KDa protein released by Schistosoma mansoni that modulates inflammatory responses in host cells. Sm16 is expressed by several life cycle stages of S. mansoni, including the egg stage. Schistosome eggs are known to provoke chronic schistosomiasis pathology, which involves the development of liver fibrosis. Hepatic stellate cells (HSCs),...
The 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. Non...
MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression being involved in many different biological processes and play a key role in developmental timing. Additionally, recent studies have shown that miRNAs released from parasites are capable of regulating the expression of host genes. In the present work, we studied the...
This book consists of 14 chapters that deal with modern technologies applied to learn more about the molecular biology of liver flukes, biochemistry, metabolism, immunology, immunopathology and genetics of Fasciola . In addition, this book seeks to have a better understanding of global importance of fascioliasis, its cost to farming communities, an...
This book consists of 14 chapters that deal with modern technologies applied to learn more about the molecular biology of liver flukes, biochemistry, metabolism, immunology, immunopathology and genetics of Fasciola . In addition, this book seeks to have a better understanding of global importance of fascioliasis, its cost to farming communities, an...
Background
Hepatic stellate cells (HSCs) are liver-resident myofibroblast precursors responsible for the production of collagen and maintenance of the hepatic extracellular matrix (ECM). As such, they are generally associated with fibrotic liver diseases. HSCs become “activated” in response to tissue damage or pathogen invasion, a process most comm...
The 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. No...
Type 1 diabetes (T1D) is an autoimmune disease characterised by the destruction of the insulin-producing beta (β)-cells within the pancreatic islets. We have previously identified a novel parasite-derived molecule, termed Fasciola hepatica helminth defence molecule 1 (FhHDM-1), that prevents T1D development in non-obese diabetic (NOD) mice. In this...
Helminth infections in people contribute to the 1 [...]
Hepatic stellate cells (HSCs) are liver-resident myofibroblast precursors. In chronic liver disease, HSC-derived myofibroblasts are responsible for the production of collagen and, as such, are generally associated with diseases characterised by hepatic fibrosis. HSCs undergo a process of "activation" in response to tissue damage or pathogen invasio...
Background
Hepatic stellate cells (HSCs) are liver-resident myofibroblast precursors responsible for the production of collagen and maintenance of the hepatic extracellular matrix (ECM). As such, they are generally associated with fibrotic liver diseases. HSCs become "activated" in response to tissue damage or pathogen invasion, a process most comm...
Trematodes cause disease in millions of people worldwide, but the absence of commercial vaccines has led to an over-reliance on a handful of monotherapies to control infections. Since drug-resistant fluke populations are emerging, a deeper understanding of parasite biology and host interactions is required to identify new drug targets and immunogen...
Background
The major pathogenesis associated with Fasciola hepatica infection results from the extensive tissue damage caused by the tunnelling and feeding activity of immature flukes during their migration, growth and development in the liver. This is compounded by the pathology caused by host innate and adaptive immune responses that struggle to...
Paramphistomosis, caused by the rumen fluke, Calicophoron daubneyi , is a parasitic infection of ruminant livestock which has seen a rapid rise in prevalence throughout Western Europe in recent years. Following ingestion of metacercariae (parasite cysts) by the mammalian host, newly-excysted juveniles (NEJs) emerge and invade the duodenal submucosa...
Morbidity associated with hepatic and urogenital schistosomiasis stems primarily from the host immune response directed against schistosome eggs. When eggs become entrapped in host tissues, the development of fibrotic plaques drives downstream pathology. These events occur due to the antigenic nature of egg excretory/secretory products (ESPs). Both...
Parasite-released extracellular vesicles (EVs) deliver signals to the host immune system that are critical to maintaining the long-term relationship between parasite and host. In the present study, total EVs (FhEVs) released in vitro by adults of the helminth parasite Fasciola hepatica were isolated using a recently described gravity flow method th...
Helminth parasites have a remarkable ability to persist within their mammalian hosts, which is largely due to their secretion of molecules with immunomodulatory properties. Although the soluble components of helminth secretions have been extensively studied, the discovery that helminths release extracellular vesicles (EVs) has added further complex...
Parasitic helminths secrete extracellular vesicles (EVs) which have potent immunomodulatory effects. Whilst the cargo of EVs has been characterised for many species, we know little about the mechanisms that govern their biogenesis and release. Using antibodies raised against a panel of Fasciola hepatica EV (FhEV) marker proteins, we have identified...
A comparative genomics approach was used to determine whether established extracellular vesicle (EV) biogenesis pathways are conserved in helminths. This revealed conservation of membrane and cytoskeletal organising proteins as well as the endosomal sorting complex required for transport (ESCRT) previously described in mammalian cells. Domain level...
Proteins secreted by, or displayed on the surface tegument of, trematodes have key functions in the host–parasite interaction. As such, they are often leading targets for diagnostic tests or vaccine candidates. Here we describe methods for the isolation and analysis of soluble secreted proteins (i.e., the secretome) released during in vitro culture...
Liver flukes include Fasciola hepatica, Fasciola gigantica, Clonorchis sinensis, Opisthorchis spp., Fascioloides magna, Gigantocotyle explanatum and Dicrocoelium spp. The two main species, F. hepatica and F. gigantica, are major parasites of livestock and infections result in huge economic losses. As with C. sinensis, Opisthorchis spp. and Dicrocoe...
Cytochemical staining techniques were carried out en bloc with in vitro excysted and gut-penetrated Fasciola gigantica larvae in order to visualise the glycocalyx of the tegument, a structure which comprises the parasite component of the host-parasite interface, yet is incompletely preserved by conventional fixation and preparation techniques for e...
The gastro-intestinal tract hosts a complex microbial ecosystem that helps regulate the physiological, immunological and nutritional functions of the pig so disturbances within this microbiota can have profound effects on porcine health and disease. The gut microbiota is shaped by the environment, immune pressures and diet. The weaning transition r...
Helminth parasites secrete extracellular vesicles (EVs) that can be internalised by host immune cells resulting in modulation of host immunity. While the molecular cargo of EVs have been characterised in many parasites, little is known about the surface-exposed molecules that participate in ligand-receptor interactions with the host cell surface to...
Bar chart comparing relative lectin microarray responses generated for 15k and 120k EVs and tegument samples.
Data subjected to total intensity mean normalization. Error bars represent +/- one standard deviation.
(TIF)
Effect of exo-glycosidase treatment on lectin-binding at the EV surface.
A. 120k EV mean lectin microarray responses imparted by exo-glycosidase treatment with (A) β-galactosidase (n = 5) and (B) α-mannosidase (n = 5) and their respective pH-matched controls (controls n = 3). Error bars represent one +/- standard deviation.
(TIF)
Enrichment of GO terms (A) and protein domains (B) for the proteins identified on the surface of the 15k and 120k EVs.
(TIF)
Uptake of 120k EVs by macrophages is inhibited by cytochalasin D.
RAW264.7 macrophages were incubated with PKH26-labelled 120k EVs for 3 h at 37°C and the cells were analysed by confocal microscopy. Co-incubation of cells with cytochalasin D (2μg/ml) inhibited uptake of EVs.
(TIF)
Effect of endo-glycosidase treatment on lectin-binding at the EV surface.
120k EV mean lectin microarray responses imparted by treatment with endo-glycosidases A. Endo H (n = 4) and B. Endo Tv (n = 4) and glyco-amidase C. PNGase F (n = 4) and their respective pH-matched controls (all n = 3). Error bars represent +/- one standard deviation.
(TIF)
Uptake of 15k EVs by macrophages.
RAW264.7 macrophages were incubated with PKH26-labelled 15k EVs for 3 h at 37°C and the cells were analysed by confocal microscopy. (A) Pre-treatment of labelled EVs with the glycosidases PNGase F and Endo H considerably reduced their uptake. (B) Pre-treatment of labelled EVs with 21-day rat serum increased the int...
Uptake of 120k EVs by macrophages is not effected by exo-glycosidases.
RAW264.7 macrophages were incubated with PKH26-labelled 120k EVs for 3 h at 37°C and the cells were analysed by confocal microscopy. Pre-treatment of labelled EVs with the exo-glycosidases α1–2,3 mannosidase and β1–4 galactosidase had no effect on the uptake of the EVs.
(TIF)
Proteins identified on the surface of F. hepatica EVs by mass spectrometry.
(XLSX)
Surface biotinylation of F. hepatica EVs and streptavidin pulldown workflow.
F. hepatica 15k and 120k EVs were incubated with a non-permeable biotin reagent. The EVs were solubilised with detergent and the biotinylated surface proteins recovered using a streptavidin affinity column.
Western blot with streptavidin conjugated with alkaline phosphatas...
Bar charts detailing competitive inhibition of lectin binding on the 120k EV surface.
120k EV mean lectin microarray response changes imparted by competitive inhibition with 50 mM final concentrations of A. Lac, B. αManOMe and C. GlcNAc. Error bars represent +/- one standard deviation based on three technical replicates. Significance of inhibition...
Fasciolosis caused by trematode parasites of the genus Fasciola is a global disease of livestock, particularly cattle, sheep, water buffalo and goats. It is also a major human zoonosis with reports suggesting that 2.4–17 million people are infected worldwide, and 91.1 million people currently living at risk of infection. A unique feature of these w...
Using in vitro procedures to prepare newly excysted metacercariae and gut-penetrated juvenile Fasciola gigantica, the ultrastructural features of the tegumental syncytium and perikarya of these ephemeral stages in the host-invasion process were compared. The T0-type tegumental cells in newly excysted metacercariae are packed with stored T0 granules...
Hepatic fibrosis is a common pathology in various liver diseases. Hepatic stellate cells (HSCs) are the main cell type responsible for collagen deposition and fibrosis formation in the liver. Schistosomiasis is characterised by granulomatous fibrosis around parasite eggs trapped within the liver and other host tissues. This response is facilitated...
The parasite Fasciola hepatica infects a broad range of mammals with impunity. Following ingestion of parasites (metacercariae) by the host, newly excysted juveniles (NEJ) emerge from their cysts, rapidly penetrate the duodenal wall and migrate to the liver. Successful infection takes just a few hours and involves negotiating hurdles presented by h...
Paramphistomosis, caused by Calicophoron daubneyi , is an emerging infection of ruminants throughout Western Europe. Despite its prevalence, many questions remain regarding the basic biology of this parasite and how it interacts with its host. Consequently, there is a need to develop methods to study C. daubneyi in vitro to improve our understandin...
Whilst historically regarded as being of minor importance in European livestock, recent evidence suggests that the prevalence of paramphistomosis is greater than that of fasciolosis in parts of the UK. In order to address this emerging threat to ruminant farming systems, and associated risks for food security posed by rumen fluke infection, it is i...
Helminth parasites secrete molecules that potently modulate the immune responses of their hosts and, therefore, have potential for the treatment of immune-mediated human diseases. FhHDM-1, a 68-mer peptide secreted by the helminth parasite Fasciola hepatica, ameliorated disease in two different murine models of autoimmunity, type 1 diabetes and rel...
The recent discovery that parasites release extracellular vesicles (EVs) that can transfer a range of effector molecules to host cells has made us re-think our understanding of the host-parasite interface. In this opinion article we consider how recent proteomics and transcriptomics studies, together with ultrastructural observations, suggest that...
The NLRP3 inflammasome is a multimeric protein complex that controls the production of IL-1β, a cytokine that influences the development of both innate and adaptive immune responses. Helminth parasites secrete molecules that interact with innate immune cells, modulating their activity to ultimately determine the phenotype of differentiated T cells,...
Kunitz-type (KT) protease inhibitors are low molecular weight proteins classically defined as serine protease inhibitors. We identified a novel secreted KT inhibitor associated with the gut and parenchymal tissues of the infective juvenile stage of Fasciola hepatica, a helminth parasite of medical and veterinary importance. Unexpectedly, recombinan...
Extracellular vesicles (EVs) released by parasites have important roles in establishing and maintaining infection. Analysis of the soluble and vesicular secretions of adult Fasciola hepatica has established a definitive characterisation of the total secretome of this zoonotic parasite. Fasciola secretes at least two sub-populations of EVs that diff...
Infections with helminth parasites prevent/attenuate auto-inflammatory disease. Here we show that molecules secreted by a helminth parasite could prevent Type 1 Diabetes (T1D) in nonobese diabetic (NOD) mice. When delivered at 4 weeks of age (coincident with the initiation of autoimmunity), the excretory/secretory products of Fasciola hepatica (FhE...
The third edition of the Handbook of Proteolytic Enzymes aims to be a comprehensive reference work for the enzymes that cleave proteins and peptides, and contains over 800 chapters. Each chapter is organized into sections describing the name and history, activity and specificity, structural chemistry, preparation, biological aspects, and distinguis...
The third edition of the Handbook of Proteolytic Enzymes aims to be a comprehensive reference work for the enzymes that cleave proteins and peptides, and contains over 800 chapters. Each chapter is organized into sections describing the name and history, activity and specificity, structural chemistry, preparation, biological aspects, and distinguis...
Author Summary
In mammals, secreted host defence peptides (HDPs) protect against a wide range of infectious pathogens. They also perform a range of immune modulatory functions which regulate the immune response to pathogens, ensuring that the protective inflammatory response is not exacerbated and that post-infection repair mechanisms are initiated...
The liver fluke, Fasciola hepatica, causes fascioliasis in domestic animals (sheep, cattle), a global disease that is also an important infection of humans. As soon as the parasite invades the gut wall its interaction with various host immune cells (e.g. dendritic cells, macrophages and mast cells) is complex. The parasite secretes a myriad of mole...
Bacterial aminopeptidases play important roles in pathogenesis by providing a source of amino acids from exogenous proteins, destroying host immunological effector peptides and executing posttranslational modification of bacterial and host proteins. We show that MHJ_0125 from the swine respiratory pathogen Mycoplasma hyopneumoniae represents a new...
The success of helminth parasites is partly related to their ability to modulate host immune responses towards an anti-inflammatory/regulatory phenotype. This ability resides with the molecules contained in the secretome of various helminths that have been shown to interact with host immune cells and influence their function. Consequently, there ex...
Host defense peptides (HDPs) are an evolutionarily conserved component of the innate immune response found in all living species. They possess antimicrobial activities against a broad range of organisms including bacteria, fungi, eukaryotic parasites, and viruses. HDPs also have the ability to enhance immune responses by acting as immunomodulators....
The liver fluke Fasciola hepatica can live for long periods in its definitive mammalian host. This longevity is related to the parasite's ability to modulate host immune responses to benefit its survival (i.e., suppression of Th1/Th17 responses and the promotion of strong Th2/Treg-mediated responses). Various reports indicate that this immune regul...
We previously reported the identification of a novel family of immunomodulatory proteins, termed helminth defense molecules (HDMs), that are secreted by medically important trematode parasites. Since HDMs share biochemical, structural, and functional characteristics with mammalian cathelicidin-like host defense peptides (HDPs), we proposed that HDM...
Elastic network analysis of PfA-M1. Per residue fluctuations due to slowmodes 1–3 from the ANM analysis of PfA-M1 (PDB 3EBH). Units of fluctuations are relative only. Mode 1, blue; mode 2, red; mode 3, yellow.
(TIF)
PCA mode 1 from simulation ADPPi-1. (A) to illustrate the mode, the maximum and minimum projections of PC1 along the trajectory, together with 8 interpolated structures, are superimposed by rms fitting using all Cα atom coordinates. Cα atom coordinates only are shown, with core subdomains blue and helical subdomains green. Red arrows indicate P-loo...
Structure of the ADP+Pi-bound active site in the MJ0796 NBD Dimer. Structural figure prepared from PDB entry 3TIF, used as the starting structure in the simulations. Orientation of the monomers is approximately as in Figure 1A; as are the stick forms and colours of the nucleotide and sidechains. Backbone atoms of the C-motif (left) and D-loop (righ...
Per residue changes during the simulations. A. Per residue rms deviation relative to the starting structure after alignment using coordinates of the Cα atoms of domain II (392–649). Ligand-bound complex blue, apo red. B. Per residue rms fluctuations relative to the starting structure after alignment using coordinates of all Cα atoms. Ligand-bound c...
This table shows the mean distances between the Zn apex atoms and the proximal coordinating atoms.
(DOCX)
Malaria caused by several species of Plasmodium is major parasitic disease of humans, causing 1-3 million deaths worldwide annually. The widespread resistance of the human parasite to current drug therapies is of major concern making the identification of new drug targets urgent. While the parasite grows and multiplies inside the host erythrocyte i...
Fasciola hepatica is a food-borne parasite of animals and humans. It secretes a large family of cysteine peptidases, termed cathepsins, that are important virulence factors. Here, we discuss how advances in molecular technologies have helped to probe the function of liver fluke cathepsins, and consider how evolving systems/molecular biology approac...
Hydrodynamic properties of recombinant FhHDM-1 samples.
(DOC)
Sedimentation velocity analysis of recombinant FhHDM-1. Absorbance versus radial position of recombinant FhHDM-1 at pH 4.5 (A) and pH 7.3 (B). The residuals for the resulting c(s) distribution best-fits are shown.
(TIF)
Secondary structure proportions of native and recombinant FhHDM-1.
(DOC)
Functional genomics have not been reported for Opisthorchis viverrini or the related fish-borne fluke, Clonorchis sinensis. Here we describe the introduction by square wave electroporation of Cy3-labeled small RNA into adult O. viverrini worms. Adult flukes were subjected to square wave electroporation employing a single pulse for 20 ms of 125V in...
Over the last decade a significant number of studies have highlighted the central role of host antimicrobial (or defence) peptides in modulating the response of innate immune cells to pathogen-associated ligands. In humans, the most widely studied antimicrobial peptide is LL-37, a 37-residue peptide containing an amphipathic helix that is released...
Residues contacting the ligand. Final trajectory frame from the MD simulation of Ligand A (AALR*NAA) bound to wild type FhCL1, with Leu at P2. The ligand is shown in stick form with carbon atoms magenta, oxygen red and nitrogen blue. The side-chain of P2 residue Leu (cyan) is bound in the S2 subsite. Secondary structural elements of the protease in...
The temporal expression and secretion of distinct members of a family of virulence-associated cathepsin L cysteine peptidases (FhCL) correlates with the entry and migration of the helminth pathogen Fasciola hepatica in the host. Thus, infective larvae traversing the gut wall secrete cathepsin L3 (FhCL3), liver migrating juvenile parasites secrete b...
Cysteine proteases expressed by pathogenic organisms play key roles in virulence including host entry, feeding and suppression of host immune responses. This book gives comprehensive coverage to all aspects of pathogen cysteine proteases and brings together numerous scientific advances which have been made over many years. Thus, the biochemistry, m...
Helminth parasites (nematodes, flatworms and cestodes) infect over 1 billion of the world's population causing high morbidity and mortality. The large tissue-dwelling worms express papain-like cysteine peptidases, termed cathepsins that play important roles in virulence including host entry, tissue migration and the suppression of host immune respo...
In mammals, cysteine proteases are essential for the induction and development of both innate and adaptive immune responses. These proteases play a role in antigen-and pathogen-recognition and elimination, signal processing and cell homeostasis. Many pathogens also secrete cysteine proteases that often act on the same target proteins as the mammali...
Guidelines for submitting commentsPolicy: Comments that contribute to the discussion of the article will be posted within approximately three business days. We do not accept anonymous comments. Please include your email address; the address will not be displayed in the posted comment. Cell Press Editors will screen the comments to ensure that they...
Opisthorchis viverrini is an important helminth pathogen of humans that is endemic in Thailand and Laos. Adult flukes reside within host bile ducts and feed on epithelial tissue and blood cells. Chronic opisthorchiasis is associated with severe hepatobiliary diseases such as cholangiocarcinoma. Here we report that adult O. viverrini secrete two maj...
Peroxiredoxins (Prx) are a family of anti-oxidants that protect cells from metabolically produced reactive oxygen species (ROS). The presence of these enzymes in the secretomes of many parasitic helminths suggests they provide protection against ROS released by host immune effector cells. However, we recently reported that helminth-secreted Prx als...
Novel targets for new drug development are urgently required to combat malaria, a disease that puts half of the world's population at risk. One group of enzymes identified within the genome of the most lethal of the causative agents of malaria, Plasmodium falciparum, that may have the potential to become new targets for antimalarial drug developmen...
Helminth pathogens prepare a Th2 type immunological environment in their hosts to ensure their longevity. They achieve this
by secreting molecules that not only actively drive type 2 responses but also suppress type 1 responses. Here, we show that
the major cysteine proteases secreted from the helminth pathogens Fasciola hepatica (FheCL1) and Schis...
Zoonotic infections are among the most common on earth and are responsible for >60 per cent of all human infectious diseases. Some of the most important and well-known human zoonoses are caused by worm or helminth parasites, including species of nematodes (trichinellosis), cestodes (cysticercosis, echinococcosis) and trematodes (schistosomiasis). H...
