Echinococcus multilocularisMetacestodes: Immunological and Immunocytochemical Analysis of the Relationships between Alkaline Phosphatase and the Em2 Antigen

Lawton, Philippe; Hemphill, Andrew; Deplazes, Peter; Gottstein, Bruno; Sarciron, Marie‐Elisabeth

doi:10.1006/expr.1997.4190

Cited by 21 publications

(17 citation statements)

References 18 publications

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“…EmAP has been previously found to be a major component of the laminated layer of E. multilocularis metacestodes (20). In control cultures, fixed and processed for immunogold labeling following 14 days of in vitro culture, we could indeed localize this protein almost exclusively within the laminated layer, as evidenced by immunogold labeling employing antiEmAP antibodies (Fig.…”

Section: Vol 45 2001supporting

confidence: 58%

“…The following steps were performed at room temperature. Blocking of unspecific binding sites was done in PBS-1% bovine serum albumin for 2 h, followed by incubation with an affinity-purified anti-EmAP antibody diluted 1:1 in blocking buffer (20). Following washing in PBS, grids were incubated with a goat anti-rabbit immunoglobulin G antibody conjugated to 10-nm gold particles (Amersham, Zürich, Switzerland) for 1 h. Subsequently, they were washed extensively in PBS, were air dried, and were stained with uranyl acetate and lead citrate (11).…”

Section: Methodsmentioning

confidence: 99%

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Echinococcus multilocularis Alkaline Phosphatase as a Marker for Metacestode Damage Induced by In Vitro Drug Treatment with Albendazole Sulfoxide and Albendazole Sulfone

Stettler

Siles-Lucas

Sarciron

et al. 2001

Antimicrob Agents Chemother

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Alveolar echinococcosis (AE) is caused by the metacestode stage of the fox tapeworm Echinococcus multilocularis. The disease affects the human liver and occasionally other organs and is fatal if treatment is unsuccessful. The present chemotherapy of AE is based on the administration of benzimidazole carbamate derivatives, such as mebendazole and albendazole. Albendazole treatment has been found to be ineffective in some cases, parasitostatic rather than parasiticidal, and the recurrence rate is rather high. Therefore, chemotherapy usually involves the lifelong uptake of massive doses of albendazole and new treatment options are urgently needed. In order to avoid costly and time-consuming animal experimentation, a first step in searching for novel parasiticidal compounds could be the in vitro drug screening of novel compounds by employing metacestode cultivation. However, presently used techniques (e.g., transmission electron microscopy) for determination of parasite viability involve costly equipment and time-consuming preparation of rather large amounts of parasite material. We therefore searched for a parasite marker which can be easily traced and the presence or absence of which is indicative of parasite viability. In this study we show that the increase of E. multilocularis alkaline phosphatase activity in culture supernatants during in vitro drug treatment with albendazole derivatives correlates with the progressive degeneration and destruction of the metacestode tissue. The inexpensive and rapid assay presented here will serve as an ideal tool for performing first-round in vitro tests on the efficacy of a large number of antiparasitic compounds.

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Section: Vol 45 2001supporting

confidence: 58%

Section: Methodsmentioning

confidence: 99%

Echinococcus multilocularis Alkaline Phosphatase as a Marker for Metacestode Damage Induced by In Vitro Drug Treatment with Albendazole Sulfoxide and Albendazole Sulfone

Stettler

Siles-Lucas

Sarciron

et al. 2001

Antimicrob Agents Chemother

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“…Second, the E. multilocularis alkaline phosphatase (EmAP), which is highly glycosylated, was shown to be localized on the laminated layer and on the periphery of brood capsules and developing protoscolices. Anti-EmAP antibodies cross-reacted with purified Em2(G11) antigen, and MAb G11 reacted with purified EmAP (33). In any case, the exact relationship between Em492 antigen and Em2(G11) antigen, and between EmP2 and EmAP, needs to be investigated in more detail.…”

Section: Vol 72 2004 Secretory Component Of E Multilocularis Metacmentioning

confidence: 99%

Isolation and Characterization of a Secretory Component ofEchinococcus multilocularisMetacestodes Potentially Involved in Modulating the Host-Parasite Interface

Walker¹,

Baz

Dematteis

et al. 2004

Infect Immun

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Echinococcus multilocularis metacestodes are fluid-filled, vesicle-like organisms, which are characterized by continuous asexual proliferation via external budding of daughter vesicles, predominantly in the livers of infected individuals. Tumor-like growth eventually leads to the disease alveolar echinococcosis (AE). We employed the monoclonal antibody (MAb) E492/G1, previously shown to be directed against a carbohydraterich, immunomodulatory fraction of Echinococcus granulosus, to characterize potentially related components in E. multilocularis. Immunofluorescence studies demonstrated that MAb E492/G1-reactive epitopes were found predominantly on the laminated layer and in the periphery of developing brood capsules. The respective molecules were continuously released into the exterior medium and were also found in the parasite vesicle fluid. The MAb E492/G1-reactive fraction in E. multilocularis, named Em492 antigen, was isolated by immunoaffinity chromatography. Em492 antigen had a protein/carbohydrate ratio of 0.25, reacted with a series of lectins, and is related to the laminated layer-associated Em2(G11) antigen. The epitope recognized by MAb E492/G1 was sensitive to sodium periodate but was not affected by protease treatment. Anti-Em492 immunoglobulin G1 (IgG1) and IgG2 and, at lower levels, IgG3 were found in sera of mice suffering from experimentally induced secondary, but not primary, AE. However, with regard to cellular immunity, a suppressive effect on concanavalin A-or crude parasite extract-induced splenocyte proliferation in these mice was observed upon addition of Em492 antigen, but trypan blue exclusion tests and transmission electron microscopy failed to reveal any cytotoxic effect in Em492 antigen-treated spleen cells. This indicated that Em492 antigen could be modulating the periparasitic cellular environment during E. multilocularis infection through as yet unidentified mechanisms and could be one of the factors contributing to immunosuppressive events that occur at the host-parasite interface.Alveolar echinococcosis (AE) is caused by the metacestode (larval) stage of Echinococcus multilocularis and is a rare but life-threatening disease, which is confined to the northern hemisphere (14, 15). The adult tapeworm exists as an enteric parasite in the fox and in a few other carnivores, such as wolves, cats, and dogs. Through fecal shedding, parasite eggs are released into the environment. The eggs contain oncospheres, which upon ingestion by a suitable intermediate host and subsequent passage through stomach and intestine get activated, penetrate the mucosa, enter blood and lymphatic vessels, and end up in the liver. In the liver parenchyma, oncospheres develop over time to form mature, asexually proliferating metacestodes, which are characterized by tumor-like growth. Metastasis formation in other organs has been reported (38). Mice and other small mammals act as natural intermediate hosts for E. multilocularis, while humans acquire AE by accidentally ingesting viable parasite eggs.As for many o...

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“…The germinal layer secretes the components of the laminated layer towards the metacestode periphery into the laminated layer, and also secretes and/or releases metabolites into the vesicle fluid. One enzyme that represents an intrinsic component of the vesicle fluid, and which is also found on the laminated layer, is alkaline phosphatase (AP ; Sarciron et al 1991 ;Lawton et al 1997). The detection of AP activity in medium supernatants of drug-treated metacestode cultures has been proposed as a method to screen for active drugs (Stettler et al 2001).…”

Section: E T H O D S F O R T H E a S S E S S M E N T O F A N T I-e mentioning

confidence: 99%

Echinococcusmetacestodes as laboratory models for the screening of drugs against cestodes and trematodes

Hemphill¹,

Lundström‐Stadelmann²,

Scholl³

et al. 2009

Parasitology

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Among the cestodes, Echinococcus granulosus, Echinococcus multilocularis and Taenia solium represent the most dangerous parasites. Their larval stages cause the diseases cystic echinococcosis (CE), alveolar echincoccosis (AE) and cysticercosis, respectively, which exhibit considerable medical and veterinary health concerns with a profound economic impact. Others caused by other cestodes, such as species of the genera Mesocestoides and Hymenolepis, are relatively rare in humans. In this review, we will focus on E. granulosus and E. multilocularis metacestode laboratory models and will review the use of these models in the search for novel drugs that could be employed for chemotherapeutic treatment of echinococcosis. Clearly, improved therapeutic drugs are needed for the treatment of AE and CE, and this can only be achieved through the development of medium-to-high throughput screening approaches. The most recent achievements in the in vitro culture and genetic manipulation of E. multilocularis cells and metacestodes, and the accessability of the E. multilocularis genome and EST sequence information, have rendered the E. multilocularis model uniquely suited for studies on drug-efficacy and drug target identification. This could lead to the development of novel compounds for the use in chemotherapy against echinococcosis, and possibly against diseases caused by other cestodes, and potentially also trematodes.

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Echinococcus multilocularisMetacestodes: Immunological and Immunocytochemical Analysis of the Relationships between Alkaline Phosphatase and the Em2 Antigen

Cited by 21 publications

References 18 publications

Echinococcus multilocularis Alkaline Phosphatase as a Marker for Metacestode Damage Induced by In Vitro Drug Treatment with Albendazole Sulfoxide and Albendazole Sulfone

Echinococcus multilocularis Alkaline Phosphatase as a Marker for Metacestode Damage Induced by In Vitro Drug Treatment with Albendazole Sulfoxide and Albendazole Sulfone

Isolation and Characterization of a Secretory Component ofEchinococcus multilocularisMetacestodes Potentially Involved in Modulating the Host-Parasite Interface

Echinococcusmetacestodes as laboratory models for the screening of drugs against cestodes and trematodes

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