Identification and characterization of a novel specific secreted protein family for selected members of the subfamily Ostertagiinae (Nematoda)

Saverwyns, Heidi; Visser, Aline; Nisbet, Alasdair J.; Peelaers, Iris; Gevaert, Kris; Vercruysse, Jozef; Claerebout, Edwin; Geldhof, Peter

doi:10.1017/s0031182007003666

Cited by 10 publications

(6 citation statements)

References 34 publications

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“…More generally, mixed results concerning the efficiency of RNAi have been reported in several clades of parasitic nematodes [45]. Problems encountered using RNAi in parasitic nematodes includes non-target effects of dsRNA, variable efficiencies of RNAi with regard to the target gene silenced and dsRNA preparation, and in vitro cultivation.…”

Section: Resultsmentioning

confidence: 99%

Postembryonic RNAi in Heterorhabditis bacteriophora: a nematode insect parasite and host for insect pathogenic symbionts

Ciche

Sternberg

2007

BMC Dev Biol

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BackgroundHeterorhabditis bacteriophora is applied throughout the world for the biological control of insects and is an animal model to study interspecies interactions, e.g. mutualism, parasitism and vector-borne disease. H. bacteriophora nematodes are mutually associated with the insect pathogen, Photorhabdus luminescens. The developmentally arrested infective juvenile (IJ) stage nematode (vector) specifically transmits Photorhabdus luminescens bacteria (pathogen) in its gut mucosa to the haemocoel of insects (host). The nematode vector and pathogen alone are not known to cause insect disease. RNA interference is an excellent reverse genetic tool to study gene function in C. elegans, and it would be useful in H. bacteriophora to exploit the H. bacteriophora genome project, currently in progress.ResultsSoaking L1 stage H. bacteriophora with seven dsRNAs of genes whose C. elegans orthologs had severe RNAi phenotypes resulted in highly penetrant and obvious developmental and reproductive abnormalities. The efficacy of postembryonic double strand RNA interference (RNAi) was evident by abnormal gonad morphology and sterility of adult H. bacteriophora and C. elegans presumable due to defects in germ cell proliferation and gonad development. The penetrance of RNAi phenotypes in H. bacteriophora was high for five genes (87–100%; Hba-cct-2, Hba-daf-21, Hba-icd-1; Hba-nol-5, and Hba-W01G7.3) and moderate for two genes (usually 30–50%; Hba-rack-1 and Hba-arf-1). RNAi of three additional C. elegans orthologs for which RNAi phenotypes were not previously detected in C. elegans, also did not result in any apparent phenotypes in H. bacteriophora. Specific and severe reduction in transcript levels in RNAi treated L1s was determined by quantitative real-time RT-PCR. These results suggest that postembryonic RNAi by soaking is potent and specific.ConclusionAlthough RNAi is conserved in animals and plants, RNAi using long dsRNA is not. These results demonstrate that RNAi can be used effectively in H. bacteriophora and can be applied for analyses of nematode genes involved in symbiosis and parasitism. It is likely that RNAi will be an important tool for functional genomics utilizing the high quality draft H. bacteriophora genome sequence.

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Section: Resultsmentioning

confidence: 99%

Postembryonic RNAi in Heterorhabditis bacteriophora: a nematode insect parasite and host for insect pathogenic symbionts

Ciche

Sternberg

2007

BMC Dev Biol

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“…Other intestinal nematodes of livestock, very closely related to H. contortus, secrete a similar GAL/VAL-dominated suite of ES proteins including Cooperia spp. [79], Ostertagia ostertagi [80], and Teladorsagia circumcincta [81].…”

Section: Functional and Molecular Analyses Of Helminth Productsmentioning

confidence: 99%

Helminth immunoregulation: The role of parasite secreted proteins in modulating host immunity

Hewitson

Grainger

Maizels

2009

Molecular and Biochemical Parasitology

634

590

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Helminths are masterful immunoregulators. A characteristic feature of helminth infection is a Th2-dominated immune response, but stimulation of immunoregulatory cell populations, such as regulatory T cells and alternatively activated macrophages, is equally common. Typically, Th1/17 immunity is blocked and productive effector responses are muted, allowing survival of the parasite in a “modified Th2” environment. Drug treatment to clear the worms reverses the immunoregulatory effects, indicating that a state of active suppression is maintained by the parasite. Hence, research has focussed on “excretory–secretory” products released by live parasites, which can interfere with every aspect of host immunity from initial recognition to end-stage effector mechanisms. In this review, we survey our knowledge of helminth secreted molecules, and summarise current understanding of the growing number of individual helminth mediators that have been shown to target key receptors or pathways in the mammalian immune system.

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“…The identification of excretory/secretory (ES) antigens of some parasite families; like Trichostrongyloidea and Ancylostomatoidea by multiple identification tools [3,5], and their potential to mediate protective immune responses were studied [6]. H. contortus and its closely related nematode parasites for example; Teladorsagia circumcincta [7], Ostertagia ostertagi [8], and Cooperia species [9] release large number of ES products, which are assumed to have complex functional activity.…”

Section: Introductionmentioning

confidence: 99%

Characterization of Haemonchus contortus Excretory/Secretory Antigen (ES-15) and Its Modulatory Functions on Goat Immune Cells In Vitro

et al. 2020

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Small size excretory/secretory (ES) antigens of the Haemonchus contortus parasite have intense interest among researchers for understanding the molecular basis of helminths immune regulation in term of control strategies. Immunomodulatory roles of H. contortus ES-15 kDa (HcES-15) on host immune cells during host–parasite interactions are unknown. In this study, the HcES-15 gene was cloned and expression of recombinant protein (rHcES-15) was induced by isopropyl-ß-d-thiogalactopyranoside (IPTG). Binding activity of rHcES-15 to goat peripheral blood mononuclear cells (PBMCs) was confirmed by immunofluorescence assay (IFA) and immunohistochemical analysis showed that H. contortus 15 kDa protein localized in the outer and inner structure of the adult worm, clearly indicated as the parasite’s ES antigen. The immunoregulatory role on cytokines production, cell proliferation, cell migration, nitric oxide (NO) production, apoptosis, and phagocytosis were observed by co-incubation of rHcES-15 with goat PBMCs. The results showed that cytokines IL-4, IL-10, IL-17, the production of nitric oxide (NO), PBMCs apoptosis, and monocytes phagocytosis were all elevated after cells incubated with rHcES-15 at differential protein concentrations. We also found that IFN-γ, TGF-β1, cells proliferation and migration were significantly suppressed with the interaction of rHcES-15 protein. Our findings indicated that low molecular ES antigens of H. contortus possessed discrete immunoregulatory roles, which will help to understand the mechanisms involved in immune evasion by the parasite during host–parasite interactions.

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Identification and characterization of a novel specific secreted protein family for selected members of the subfamily Ostertagiinae (Nematoda)

Cited by 10 publications

References 34 publications

Postembryonic RNAi in Heterorhabditis bacteriophora: a nematode insect parasite and host for insect pathogenic symbionts

Postembryonic RNAi in Heterorhabditis bacteriophora: a nematode insect parasite and host for insect pathogenic symbionts

Helminth immunoregulation: The role of parasite secreted proteins in modulating host immunity

Characterization of Haemonchus contortus Excretory/Secretory Antigen (ES-15) and Its Modulatory Functions on Goat Immune Cells In Vitro

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