Haemonchus contortus utilises catalase in defence against exogenous hydrogen peroxide in vitro

Kotze, Andrew C.; McClure, S.J.

doi:10.1016/s0020-7519(01)00303-4

Cited by 59 publications

(38 citation statements)

References 37 publications

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“…The adult worm recovery and culture methods were as described previously (25). Briefly, adult nematodes were removed from sheep abomasa approximately 10 to 15 weeks postinfection and placed into RPMI 1640 medium containing 1% glucose, 0.25 g/ml amphotericin B, 10 U/ml penicillin, 10 g/ml streptomycin, and 10 mM HEPES buffer (pH 6.8) at approximately 37°C.…”

Section: Methodsmentioning

confidence: 99%

Cyclotide Interactions with the Nematode External Surface

Colgrave

Huang

Craik

et al. 2010

Antimicrob Agents Chemother

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Cyclotides are a large family of cyclic cystine knot-containing plant peptides that have anthelminthic activities against Haemonchus contortus and Trichostrongylus colubriformis, two important gastrointestinal nematodes of sheep. In this study, we investigated the interaction of the prototypic cyclotide kalata B1 with the external surface of H. contortus larvae and adult worms. We show that cyclotides do not need to be ingested by the worms to exert their toxic effects but that an interaction with the external surface alone is toxic. Evidence for this was the toxicity toward adult worms in the presence of a chemically induced pharyngeal ligature and toxicity of cyclotides toward nonfeeding larval life stages. Uptake of tritiated inulin in ligated adult worms was increased in the presence of cyclotide, suggesting that cyclotides increase the permeability of the external membranes of adult nematodes. Polyethylene glycols of various sizes showed protective effects on the nonfeeding larval life stage, as well as in hemolytic activity assays, suggesting that discrete pores are formed in the membrane surfaces by cyclotides and that these can be blocked by polyethylene glycols of appropriate size. This increased permeability is consistent with recently reported effects of cyclotides on membranes in which kalata B1 was demonstrated to form pores and cause leakage of vesicle/cellular contents. Our data, together with known size constraints on the movement of permeants across nematode cuticle layers, suggest that one action of the cyclotides involves an interaction with the lipid-rich epicuticle layer at the surface of the worm.Cyclotides are disulfide-rich peptides from plants that are characterized by their cyclic peptide backbone; they are the largest known family of genetically encoded cyclic proteins (11,23,46). More than 140 cyclotides have been reported to exist in the Violaceae and Rubiaceae plant families, and this number is expanding rapidly. Recent investigations suggest that thousands more cyclotides have yet to be discovered (46). Cyclotides exhibit a diverse range of biological activities, including anti-HIV (17, 22), antimicrobial (50), antineurotensin (52), cytotoxic (28, 49), and hemolytic (3, 40) activities. It has been postulated that the natural function of cyclotides is one of defense against plant pests and pathogens (2,23,24). The cyclotides kalata B1 (kB1) and kalata B2 (kB2) have a dramatic effect on growth and development of Helicoverpa punctigera (23) and Helicoverpa armigera larvae (24), two major pests of cotton. Recently, we demonstrated that cyclotides isolated from the plant Oldenlandia affinis display anthelminthic activity toward the gastrointestinal parasitic nematodes Haemonchus contortus and Trichostrongylus colubriformis (8). Subsequent studies found that cycloviolacins (a group of cyclotides isolated from Viola odorata) showed up to an 18-foldincreased potency against these nematodes relative to the prototypic cyclotide, kB1 (9). More recently, selected cyclotides have been shown to ...

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Section: Methodsmentioning

confidence: 99%

Cyclotide Interactions with the Nematode External Surface

Colgrave

Huang

Craik

et al. 2010

Antimicrob Agents Chemother

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“…Catalase also has a low activity in several species of helminths. Its typical amino acid sequence has been found only in few species of nematodes such as Haemonchus contortus (Kotze and McClure 2001), Ascaris suum ) and B. malayi (Ou et al 1995a) where high levels of activity have been recorded.…”

Section: Enzymatic Antioxidant Systems In Helminthic Parasitesmentioning

confidence: 99%

Enzymatic antioxidant systems in helminth parasites

2009

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“…The infections were maintained by weekly administration of the cortico-steroid Trimadexil (0.5 ml per sheep each week). Adult nematodes were recovered in RPMI-1640-based medium [as described by Kotze and McClure (2001)], rinsed several times in this medium, and then snap frozen in liquid nitrogen, before transfer to À70°C for storage. RNA was extracted from L3 and adults using the RNeasy kit (Qiagen) after initial homogenization using a shaped glass rod as a pestle in an Eppendorf tube.…”

Section: Methodsmentioning

confidence: 99%

“…The homogenate was centrifuged at 10,000 g for 10 min, and the supernatant was used as the enzyme solution. Catalase activity was assayed as described previously (Kotze and McClure 2001) by monitoring (at 240 nm) the disappearance of hydrogen peroxide over a 30-s period. Protein was measured by the method of Bradford (1976) using bovine serum albumin (BSA) as standard.…”

Section: Catalase Enzyme Activitymentioning

confidence: 99%

“…There is some evidence that catalase plays a role in defence against hydrogen peroxide in the nematode Haemonchus contortus. Kotze and McClure (2001) showed that inhibition of H. contortus catalase (using aminotriazole) rendered the nematode more susceptible to hydrogen peroxide. A subsequent study (Kotze 2003) demonstrated that both adult and L4 H. contortus showed induced catalase activities after exposure to low levels of hydrogen peroxide, and that this increased catalase activity in adult worms was associated with a greater ability of the parasite to survive subsequent exposure to toxic levels of the peroxide (compared to controls with no pre-exposure).…”

Section: Introductionmentioning

confidence: 99%

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cDNA cloning and expression patterns of a peroxiredoxin, a catalase and a glutathione peroxidase from Haemonchus contortus

Bagnall

Kotze

2004

Parasitol Res

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The range of antioxidant enzyme systems available to Haemonchus contortus for detoxification of hydrogen peroxide was investigated using cDNA cloning of candidate genes. PCR with primers based on conserved amino acid regions and spliced leader sequences was used to obtain full-length sequences for a 2-Cys peroxiredoxin, a catalase, and a selenium-independent glutathione peroxidase, indicating that H. contortus expresses a number of antioxidant systems with the potential to detoxify peroxide (nucleotide sequence data reported in this paper are available in the GenBank, EMBL and DDBJ databases under the accession numbers AY603335, AY603336 and AY603337). Quantitative PCR analysis comparing L3-stage larvae with adult worms showed significantly elevated peroxiredoxin levels in adults, equivalent catalase levels in the two stages, and significantly less glutathione peroxidase in adults, suggesting a significant role for peroxiredoxin in allowing the nematode to detoxify hydrogen peroxide encountered in the parasitic environment. Exposure of L4-stage worms to hydrogen peroxide in vitro (generated using glucose/glucose oxidase) caused no change in mRNA levels for each of the genes, though the exposed worms showed up to eightfold higher catalase activities. The lack of mRNA changes alongside increased catalase enzyme activity indicates that transcript level was not predictive of enzyme activity, suggesting that activity may be regulated in response to oxidative stress by a mechanism other than increased transcription.

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Haemonchus contortus utilises catalase in defence against exogenous hydrogen peroxide in vitro

Cited by 59 publications

References 37 publications

Cyclotide Interactions with the Nematode External Surface

Cyclotide Interactions with the Nematode External Surface

Enzymatic antioxidant systems in helminth parasites

cDNA cloning and expression patterns of a peroxiredoxin, a catalase and a glutathione peroxidase from Haemonchus contortus

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