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Host Transcription Factors in the Immediate Pro-Inflammatory Response to the Parasitic Mite Psoroptes ovis
Stewart T. G. Burgess, Tom N. McNeilly, Craig A. Watkins, Alasdair J. Nisbet, John F. Huntley
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0024402
Abstract: Background Sheep scab, caused by infestation with the ectoparasitic mite Psoroptes ovis, results in the rapid development of cutaneous inflammation and leads to the crusted skin lesions characteristic of the disease. We described previously the global host transcriptional response to infestation with P. ovis, elucidating elements of the inflammatory processes which lead to the development of a rapid and profound immune response. However, the mechanisms by which this response is instigated remain unclear. To identify novel methods of intervention a better understanding of the early events involved in triggering the immune response is essential. The objective of this study was to gain a clearer understanding of the mechanisms and signaling pathways involved in the instigation of the immediate pro-inflammatory response. Results Through a combination of transcription factor binding site enrichment and pathway analysis we identified key roles for a number of transcription factors in the instigation of cutaneous inflammation. In particular, defined roles were elucidated for the transcription factors NF-kB and AP-1 in the orchestration of the early pro-inflammatory response, with these factors being implicated in the activation of a suite of inflammatory mediators. Conclusions Interrogation of the host temporal response to P. ovis infestation has enabled the further identification of the mechanisms underlying the development of the immediate host pro-inflammatory response. This response involves key regulatory roles for the transcription factors NF-kB and AP-1. Pathway analysis demonstrated that the activation of these transcription factors may be triggered following a host LPS-type response, potentially involving TLR4-signalling and also lead to the intriguing possibility that this could be triggered by a P. ovis allergen.
Quantitative PCR-based genome size estimation of the astigmatid mites Sarcoptes scabiei, Psoroptes ovis and Dermatophagoides pteronyssinus
Kate E Mounsey, Charlene Willis, Stewart TG Burgess, Deborah C Holt, James McCarthy, Katja Fischer
Parasites & Vectors , 2012, DOI: 10.1186/1756-3305-5-3
Abstract: Quantitative real-time PCR was used to estimate the genome sizes of the burrowing ectoparasitic mite Sarcoptes scabiei, the non-burrowing ectoparasitic mite Psoroptes ovis, and the free-living house dust mite Dermatophagoides pteronyssinus. Additionally, the chromosome number of S. scabiei was determined by chromosomal spreads of embryonic cells derived from single eggs.S. scabiei cells were shown to contain 17 or 18 small (< 2 μM) chromosomes, suggesting an XO sex-determination mechanism. The average estimated genome sizes of S. scabiei and P. ovis were 96 (± 7) Mb and 86 (± 2) Mb respectively, among the smallest arthropod genomes reported to date. The D. pteronyssinus genome was estimated to be larger than its parasitic counterparts, at 151 Mb in female mites and 218 Mb in male mites.This data provides a starting point for understanding the genetic organisation and evolution of these astigmatid mites, informing future sequencing projects. A comparitive genomic approach including these three closely related mites is likely to reveal key insights on mite biology, parasitic adaptations and immune evasion.There is a distinct paucity of genomic data available for the class Acari (mites and ticks), and subsequently our understanding of their biology is limited. More information regarding mite genomics would greatly assist the development of novel control strategies underpinned by molecular approaches. Three astigmatid mites of particular medical and veterinary interest are the itch mite Sarcoptes scabiei (Sarcoptidae), the sheep scab mite Psoroptes ovis (Psoroptidae) and the house dust mite Dermatophagoides pteronyssinus (Pyroglyphidae).Scabies remains a truly neglected disease, caused by the burrowing ectoparasitc "itch mite" S. scabiei. The scarcity of molecular data on S. scabiei has been due in part to very low parasite burden in most patients, and the historical lack of in vitro culture and animal models. A major advance was the creation of S. scabiei var. hominis
Generation, analysis and functional annotation of expressed sequence tags from the ectoparasitic mite Psoroptes ovis
Stewart TG Burgess, Alasdair J Nisbet, Fiona Kenyon, John F Huntley
Parasites & Vectors , 2011, DOI: 10.1186/1756-3305-4-145
Abstract: In order to further expand upon the transcriptomic coverage of P. ovis thus facilitating novel insights into the mite biology we undertook a larger scale EST approach, incorporating newly generated and previously described P. ovis transcript data and representing the largest collection of P. ovis ESTs to date. We sequenced 1,574 ESTs and assembled these along with 484 previously generated P. ovis ESTs, which resulted in the identification of 1,545 unique P. ovis sequences. BLASTX searches identified 961 ESTs with significant hits (E-value < 1E-04) and 584 novel P. ovis ESTs. Gene Ontology (GO) analysis allowed the functional annotation of 880 ESTs and included predictions of signal peptide and transmembrane domains; allowing the identification of potential P. ovis excreted/secreted factors, and mapping of metabolic pathways.This dataset currently represents the largest collection of P. ovis ESTs, all of which are publicly available in the GenBank EST database (dbEST) (accession numbers FR748230 - FR749648). Functional analysis of this dataset identified important homologues, including house dust mite allergens and tick salivary factors. These findings offer new insights into the underlying biology of P. ovis, facilitating further investigations into mite biology and the identification of novel methods of intervention.Sheep scab, caused by the mite Psoroptes ovis is, arguably, the most important ectoparasitic disease of sheep in the UK in terms of both animal welfare and financial impact. In continental Europe and in the USA, psoroptic mange is also a welfare problem in cattle and is becoming increasingly common in cattle in the UK [1]. Psoroptic mange is highly contagious, causing considerable pruritis and irritation [2]. Current disease control strategies are heavily reliant upon chemotherapy; however concerns over residues, eco-toxicity and the development of parasite resistance threaten the sustainability of current control strategies and have highlighted interes
Transcriptomic Analysis of Circulating Leukocytes Reveals Novel Aspects of the Host Systemic Inflammatory Response to Sheep Scab Mites
Stewart T. G. Burgess, Andrew Greer, David Frew, Beth Wells, Edward J. Marr, Alasdair J. Nisbet, John F. Huntley
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0042778
Abstract: Infestation of ovine skin with the ectoparasitic mite Psoroptes ovis results in the development of a rapid cutaneous inflammatory response, leading to the crusted skin lesions characteristic of sheep scab. To facilitate the identification of novel diagnostic and therapeutic targets, a better understanding of the host-parasite relationship in sheep scab is essential. Although our knowledge of the host's local cutaneous inflammatory response to sheep scab has increased in recent years, we still know relatively little about the mechanisms of this response at the systemic level. This study used a combined network and pathway analysis of the in vivo transcriptomic response of circulating leukocytes to infestation with P. ovis, during a 6 week period. Network graph analysis identified six temporally-associated gene clusters, which separated into two distinct sub-networks within the graph, representing those genes either up or down-regulated during the time course. Functional and pathway analysis of these clusters identified novel insights into the host systemic response to P. ovis infestation, including roles for the complement system, clotting cascade and fibrinolysis. These analyses also highlighted potential mechanisms by which the systemic immune response to sheep scab can influence local tissue responses via enhanced leukocyte activation and extravasation. By analysing the transcriptomic responses of circulating leukocytes in sheep following infestation with P. ovis, this study has provided key insights into the inflammatory response to infestation and has also demonstrated the utility of these cells as a proxy of events occurring at local tissue sites, providing insight into the mechanisms by which a local allergen-induced inflammatory response may be controlled.
Ectopic Pregnancy as a Model to Identify Endometrial Genes and Signaling Pathways Important in Decidualization and Regulated by Local Trophoblast
W. Colin Duncan, Julie L. V. Shaw, Stewart Burgess, Sarah E. McDonald, Hilary O. D. Critchley, Andrew W. Horne
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0023595
Abstract: The endometrium in early pregnancy undergoes decidualization and functional changes induced by local trophoblast, which are not fully understood. We hypothesized that endometrium from tubal ectopic pregnancy (EP) could be interrogated to identify novel genes and pathways involved in these processes. Gestation-matched endometrium was collected from women with EP (n = 11) and intrauterine pregnancies (IUP) (n = 13). RNA was extracted from the tissue. In addition, tissues were prepared for histological analysis for degree of decidualization. We compared a) the samples from EP that were decidualized (n = 6) with non-decidualized samples (n = 5), and b) the decidualized EP (n = 6) with decidualization-matched IUP (n = 6) samples using an Affymetrix gene array platform, with Ingenuity Pathway Analysis, combined with quantitative RT-PCR. Expression of PRL and IGFBP1 was used to confirm the degree of decidualization in each group. There were no differences in PRL or IGFBP1 expression in the decidualization-matched samples but a marked reduction (P<0.001) in the non-decidualized samples. Decidualization was associated with increased expression of 428 genes including SCARA5 (181-fold), DKK1 (71-fold) and PROK1 (32-fold), and decreased expression of 230 genes including MMP-7 (35-fold) and SFRP4 (21-fold). The top canonical pathways associated with these differentially expressed genes were Natural Killer Cell and Wnt/b-Catenin signaling. Local trophoblast was associated with much less alteration of endometrial gene expression with an increase in 56 genes, including CSH1 (8-fold), and a reduction in 29 genes including CRISP3 (8-fold). The top associated canonical pathway was Antigen Presentation. The study of endometrium from tubal EP may promote novel insights into genes involved in decidualization and those influenced by factors from neighboring trophoblast. This has afforded unique information not highlighted by previous studies and adds to our understanding of the endometrium in early pregnancy.
Transcriptomic analysis of the temporal host response to skin infestation with the ectoparasitic mite Psoroptes ovis
Stewart TG Burgess, David Frew, Francesca Nunn, Craig A Watkins, Tom N McNeilly, Alasdair J Nisbet, John F Huntley
BMC Genomics , 2010, DOI: 10.1186/1471-2164-11-624
Abstract: Infestation with P. ovis resulted in differential expression of 1,552 genes over a 24 hour time course. Clustering by peak gene expression enabled classification of genes into temporally related groupings. Network and pathway analysis of clusters identified key signalling pathways involved in the host response to infestation. The analysis implicated a number of genes with roles in allergy and inflammation, including pro-inflammatory cytokines (IL1A, IL1B, IL6, IL8 and TNF) and factors involved in immune cell activation and recruitment (SELE, SELL, SELP, ICAM1, CSF2, CSF3, CCL2 and CXCL2). The analysis also highlighted the influence of the transcription factors NF-kB and AP-1 in the early pro-inflammatory response, and demonstrated a bias towards a Th2 type immune response.This study has provided novel insights into the signalling mechanisms leading to the development of a pro-inflammatory response in sheep scab, whilst providing crucial information regarding the nature of mite factors that may trigger this response. It has enabled the elucidation of the temporal patterns by which the immune system is regulated following exposure to P. ovis, providing novel insights into the mechanisms underlying lesion development. This study has improved our existing knowledge of the host response to P. ovis, including the identification of key parallels between sheep scab and other inflammatory skin disorders and the identification of potential targets for disease control.Sheep scab, caused by the mite Psoroptes ovis is, arguably, the most important ectoparasitic disease of sheep in the UK.The disease is highly contagious, causing pruritis and irritation and is a major welfare concern [1]. Current disease control strategies are reliant upon chemotherapy; however concerns over residues, eco-toxicity and parasite resistance have raised concerns regarding current control strategies [2]. Developing alternative control methods requires a deeper understanding of both the parasite and it
The use of a Psoroptes ovis serodiagnostic test for the analysis of a natural outbreak of sheep scab
Stewart TG Burgess, Giles Innocent, Francesca Nunn, David Frew, Fiona Kenyon, Alasdair J Nisbet, John F Huntley
Parasites & Vectors , 2012, DOI: 10.1186/1756-3305-5-7
Abstract: Serum samples were obtained from an outbreak of sheep scab within an experimental flock (n = 480 (3 samples each from 160 sheep)) allowing the assessment, by ELISA of sheep scab specific antibody prior to infestation, mid-outbreak (combined with clinical assessment) and post-treatment.Analysis of pre-infestation samples demonstrated low levels of potential false positives (3.8%). Of the 27 animals with clinical or behavioural signs of disease 25 tested positive at the mid-outbreak sampling period, however, the remaining 2 sheep tested positive at the subsequent sampling period. Clinical assessment revealed the absence of clinical or behavioural signs of disease in 132 sheep, whilst analysis of mid-outbreak samples showed that 105 of these clinically negative animals were serologically positive, representing potential sub-clinical infestations.This study demonstrates that this ELISA test can effectively diagnose sheep scab in a natural outbreak of disease, and more importantly, highlights its ability to detect sub-clinically infested animals. This ELISA, employing a single recombinant antigen, represents a major step forward in the diagnosis of sheep scab and may prove to be critical in any future control program.Sheep scab is caused by the mite Psoroptes ovis and is, arguably, the most important ectoparasitic disease of sheep in the UK. Recent data relating to the financial impact of sheep scab suggest that the disease costs the UK sheep industry in excess of £8 million per annum, including costs associated with lost performance, preventative measures, and treatment of affected animals; with the major costs relating to disease prevention [1]. Since its deregulation as a notifiable disease in 1992, sheep scab has become endemic throughout the UK [2]. The disease is highly contagious, causing considerable pruritis and irritation and is a major welfare concern [3]. Current disease control strategies are reliant upon chemotherapy; however, concerns over residues, eco-to
Genome-Wide Transcriptomic Analysis of Intestinal Tissue to Assess the Impact of Nutrition and a Secondary Nematode Challenge in Lactating Rats
Spiridoula Athanasiadou,Leigh A. Jones,Stewart T. G. Burgess,Ilias Kyriazakis,Alan D. Pemberton,Jos G. M. Houdijk,John F. Huntley
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0020771
Abstract: Gastrointestinal nematode infection is a major challenge to the health and welfare of mammals. Although mammals eventually acquire immunity to nematodes, this breaks down around parturition, which renders periparturient mammals susceptible to re-infection and an infection source for their offspring. Nutrient supplementation reduces the extent of periparturient parasitism, but the underlying mechanisms remain unclear. Here, we use a genome wide approach to assess the effects of protein supplementation on gene expression in the small intestine of periparturient rats following nematode re-infection.
Development of a cDNA microarray for the measurement of gene expression in the sheep scab mite Psoroptes ovis
Stewart TG Burgess, Alison Downing, Craig A Watkins, Edward J Marr, Alasdair J Nisbet, Fiona Kenyon, Carol McNair, John F Huntley
Parasites & Vectors , 2012, DOI: 10.1186/1756-3305-5-30
Abstract: Herein we describe the development and utilisation of an annotated P. ovis cDNA microarray containing 3,456 elements for the measurement of gene expression in this economically important ectoparasite. The array consists of 981 P. ovis EST sequences printed in triplicate along with 513 control elements. Array performance was validated through the analysis of gene expression differences between fed and starved P. ovis mites.Sequences represented on the array include homologues of major house dust mite allergens and tick salivary proteins, along with factors potentially involved in mite reproduction and xenobiotic metabolism. In order to validate the performance of this unique resource under biological conditions we used the array to analyse gene expression differences between fed and starved P. ovis mites. These analyses identified a number of house dust mite allergen homologues up-regulated in fed mites and P. ovis transcripts involved in stress responses, autophagy and chemosensory perception up-regulated in starved mites.The P. ovis cDNA microarray described here has been shown to be both robust and reproducible and will enable future studies to analyse gene expression in this important ectoparasite.Sheep scab, a highly contagious disease caused by the mite Psoroptes ovis, is characterised by pruritis and irritation of host skin and is therefore a major welfare concern in addition to the substantial costs associated with lost performance, preventative measures, and treatment [1,2]. Current disease control strategies are heavily reliant upon injectable endectocides and acaricidal dips but concerns over residues, environmental contamination and the development of acaricide resistance limit the sustainability of this approach and have resulted in growing interest in the development of alternative control methods [3]. The development of such methods requires a more detailed understanding of both the parasite and its interaction with the host.The basic biology of the mi
RESOLVING THE QUESTION OF DOUBT: GEOMETRICAL DEMONSTRATION IN THE MEDITATIONS
Steven BURGESS
Societate ?i Politic? , 2012,
Abstract: The question of what Descartes did and did not doubt in the Meditations has received a significant amount of scholarly attention in recent years. The process of doubt in Meditation I gives one the impression of a rather extreme form of skepticism, while the responses Descartes offers in the Objections and Replies make it clear that there is in fact a whole background of presuppositions that are never doubted, including many that are never even entertained as possible candidates of doubt. This paper resolves the question of this undoubted background of rationality by taking seriously Descartes’ claim that he is carrying out demonstrations modeled after the great geometers. The rational order of geometrical demonstration demands that we first clear away previous demonstrations not proven with the certainty necessary for genuine science. This is accomplished by the method of doubt, which is only applied to the results of possible demonstrations. What cannot be doubted are the very concepts and principles employed in carrying out geometrical demonstration, which enable it to take place. It would be senseless to ask whether we can doubt the essential components of the structure through which questioning, doubting, and demonstration are made possible.
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