Immunochemical localization of major hydatid fluid antigens in protoscoleces and cysts of Echinococcus granulosus from human origin

Sánchez, Federico; March, Francesca; Mercader, Manel Bautista; Coll, Pere; Muñoz, Carme; Prats, Guillem

doi:10.1111/j.1365-3024.1991.tb00554.x

Cited by 28 publications

(21 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…These tests have relatively high sensitivities for hepatic (85-95%) and multiple organ cysts (90-100%), but lower sensitivities for lung cysts (50-60%) [33][34][35]. Additionally, tests based on the partially purified lipoproteins antigen B (AgB) and antigen 5 (both found in the germinal membrane, protoscolex parenchyma and cyst fluid [36]) are used either in ELISA or immunoblot assays. The major drawback of these tests is the lack of species specificity, as cross-reactions between AE and CE and many other helminthic infections are commonly observed (cestodes, 89%; nematodes, 39%; trematodes; 30%) [5,20,[37][38][39][40].…”

Section: Discussionmentioning

confidence: 99%

Serological diagnosis of echinococcosis: the diagnostic potential of native antigens

et al. 2011

View full text Add to dashboard Cite

PURPOSE: Human alveolar (AE) and cystic echinococcosis (CE) caused by the metacestode stages of Echinococcus multilocularis and E. granulosus, respectively, lack pathognomonic clinical signs. Diagnosis therefore relies on the results of imaging and serological studies. The primary goal of this study was to evaluate the efficacy of several easy-to-produce crude or partially purified E. granulosus and E. multilocularis metacestode-derived antigens as tools for the serological diagnosis and differential diagnosis of patients suspicious for AE or CE. METHODS: The sera of 51 treatment-naïve AE and 32 CE patients, 98 Swiss blood donors and 38 patients who were initially suspicious for echinococcosis but suffering from various other liver diseases (e.g., liver neoplasia, etc.) were analysed. RESULTS: According to the results of enzyme-linked immunosorbent assays (ELISA), metacestode-derived antigens of E. granulosus had sensitivities varying from 81 to 97% and >99.9% for the diagnosis of CE and AE, respectively. Antigens derived from E. multilocularis metacestodes had sensitivities ranging from 84 to 91% and >99.9% for the diagnosis of CE and AE, respectively. Specificities ranged from 92 to >99.9%. Post-test probabilities for the differential diagnosis of AE from liver neoplasias, CE from cystic liver lesions, and screening for AE in Switzerland were around 95, 86 and 2.2%, respectively. Cross-reactions with antibodies in sera of patients with other parasitic affections (fasciolosis, schistosomosis, amebosis, cysticercosis, and filarioses) did occur at variable frequencies, but could be eliminated through the use of confirmatory testing. CONCLUSIONS: Different metacestode-derived antigens of E. granulosus and E. multilocularis are valuable, widely accessible, and cost-efficient tools for the serological diagnosis of echinococcosis. However, confirmatory testing is necessary, due to the lack of species specificity and the occurrence of cross-reactions to other helminthic diseases. Abstract Purpose Human alveolar (AE) and cystic echinococcosis (CE) caused by the metacestode stages of Echinococcus multilocularis and E. granulosus, respectively, lack pathognomonic clinical signs. Diagnosis therefore relies on the results of imaging and serological studies. The primary goal of this study was to evaluate the efficacy of several easy-to-produce crude or partially purified E. granulosus and E. multilocularis metacestode-derived antigens as tools for the serological diagnosis and differential diagnosis of patients suspicious for AE or CE. Methods The sera of 51 treatment-naïve AE and 32 CE patients, 98 Swiss blood donors and 38 patients who were initially suspicious for echinococcosis but suffering from various other liver diseases (e.g., liver neoplasia, etc.) were analysed. Results According to the results of enzyme-linked immunosorbent assays (ELISA), metacestode-derived antigens of E. granulosus had sensitivities varying from 81 to 97% and [99.9% for the diagnosis of CE and AE, respectively. Antigens derived from...

show abstract

Section: Discussionmentioning

confidence: 99%

Serological diagnosis of echinococcosis: the diagnostic potential of native antigens

et al. 2011

View full text Add to dashboard Cite

show abstract

“…Antigen B (AgB), which accounts for as much as 10% of the total content of hydatid fluid, is a 160-kDa thermostable lipoprotein that produces three subunits at 8 or 12, 16, and 20 or 24 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing and nonreducing conditions (21,36). Immunohistological studies have shown that this antigen is located in the protoscolex tegument and germinal membrane of the metacestode and therefore secreted into the cyst fluid (29,35). Observing that the 12-kDa subunit of AgB is a protease inhibitor with the ability to inhibit neutrophil recruitment Shepherd et al first suggested the role of this antigen in escape mechanisms from the early natural immunity (37).…”

mentioning

confidence: 99%

Modulation of Human Immune Response byEchinococcus granulosusAntigen B and Its Possible Role in Evading Host Defenses

Riganò

Profumo

Bruschi³

et al. 2001

Infect Immun

142

117

View full text Add to dashboard Cite

). AgB skewed the Th1/Th2 cytokine ratios towards a preferentially immunopathology-associated Th2 polarization, predominantly in patients with progressive disease. AgB-stimulated patients' PBMC also proliferated less than SHF-stimulated PBMC (P ‫؍‬ 9 ؋ 10 ؊3 ). In vitro Th2 cytokine production was reflected in vivo by elevated specific immunoglobulin E (IgE) and IgG4 antibodies binding to AgB. These findings confirm that AgB plays a role in the escape from early immunity by inhibiting PMN chemotaxis. They also add new information on the host-parasite relationship, suggesting that AgB exploits the activation of T helper cells by eliciting a nonprotective Th2 cell response.Cystic echinococcosis (CE) is a widely endemic helminthic disease caused by infection with metacestodes (larval stage) of the tapeworm Echinococcus granulosus. It affects humans and a wide range of livestock species (28). The disease is characterized by the growth in the host internal organs, mostly liver and lungs, of steadily growing fluid-filled, unilocular cysts surrounded by a two-layered hydatid cyst wall. The main feature of the host-parasite relationship is the coexistence of the chronic infection with detectable humoral and cellular responses against the parasite. Parasite survival in vivo depends on efficient evasion mechanisms starting to operate as the parasite develops toward a hydatid cyst. A fibrotic host capsule of variable thickness usually develops, thus forming together with the parasite-derived acellular laminated layer a formidable cystic structure. As a consequence, the actively dividing germinal layer within the cyst along with its associated brood capsule and enclosed protoscoleces are effectively sequestered from the host immune responses. In addition to this physical barrier, the hydatid cyst has probably evolved other strategies for immune evasion. Although older models suggested a more passive role for parasites in immune evasion-for example sequestration, antigenic masking by host proteins, and global immunosuppression-later studies suggest in human parasitoses the active deployment of strategies that manipulate and exploit the host response (12, 30).

show abstract

“…AgB represents a major antigenic component secreted by germinal membrane and PSC (Sanchez et al 1991), which is present in large quantities in the hydatid fluid of fertile cysts (Mamuti et al 2006), but the current knowledge on its biological roles is limited. However, there are some evidences pointing to the involvement of this antigen in mechanisms that would be crucial for parasite survival.…”

Section: Discussionmentioning

confidence: 99%

Effects of protoscoleces and AgB from Echinococcus granulosus on human neutrophils: possible implications on the parasite’s immune evasion mechanisms

et al. 2006

View full text Add to dashboard Cite

The factors affecting the innate susceptibility to Echinococcus granulosus infections are largely unknown. We assessed the interaction of healthy human neutrophils with protoscoleces (PSC) and antigen B (AgB) of E. granulosus by analysis of CD11b upregulation and H(2)O(2) production by flow cytometry. PSC induced neutrophil activation, but their viability was not affected. In contrast, no effects were observed with AgB in both assays. Neutrophil-enriched fractions were also incubated with PSC or AgB, and interleukin 8 (IL-8) production was measured by ELISA. Significant increment in IL-8 production was detected only in supernatants from neutrophil-enriched fractions cultured with PSC. The possible effect of a prior incubation with AgB on the phorbol myristate acetate-induced activation was also evaluated. No changes were observed in CD11b expression, but the H(2)O(2) production was significantly reduced in platelet-activating factor (PAF)-primed neutrophils. These results suggest a possible AgB-mediated mechanism of evasion of the host immune response, which would operate upon events of spillage of the fertile hydatid cyst content.

show abstract

Immunochemical localization of major hydatid fluid antigens in protoscoleces and cysts of Echinococcus granulosus from human origin

Cited by 28 publications

References 16 publications

Serological diagnosis of echinococcosis: the diagnostic potential of native antigens

Serological diagnosis of echinococcosis: the diagnostic potential of native antigens

Modulation of Human Immune Response byEchinococcus granulosusAntigen B and Its Possible Role in Evading Host Defenses

Effects of protoscoleces and AgB from Echinococcus granulosus on human neutrophils: possible implications on the parasite’s immune evasion mechanisms

Contact Info

Product

Resources

About