Schistosoma mansoni in the rat: The adherence of macrophages to schistosomula in vitro after sensitization with immune serum

1977 ◽  
Vol 7 (4) ◽  
pp. 315-320 ◽  
Author(s):  
Hilda A. Perez ◽  
S.R. Smithers
Parasitology ◽  
1975 ◽  
Vol 70 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Diane J. McLaren ◽  
J. A. Clegg ◽  
S. R. Smithers

Young schistosomes collected after penetration through isolated mouse skin (3 h schistosomula) were cultured in medium containing immune rhesus monkey serum with a high titre of antibody known to kill schistosomula in the presence of complement. Morphological signs of damage in electron micrographs were confined to the surface tegument of the schistosomula. Antibodies in immune rhesus serum were shown to bind to the surface membrane of 3 h schistosomula using an antibody-enzyme bridge technique involving labelling with horseradish peroxidase and histochemical localization of the enzyme at the ultrastructural level. Schistosomula recovered from the lungs of mice 4 days after infection did not bind monkey antibodies at the surface and these 4-day schistosomula are not susceptible to damage by immune serum in vitro. Mouse erythrocyte antigens were detected on the surface of 4-day schistosomula using an appropriate antibody-enzyme bridge but these host antigens could not be found on 3 h schistosomula. This correlation between the presence of mouse host antigens on the surface of schistosomula and the inability of immune monkey antibodies to bind to the surface membrane is consistent with the hypothesis that host antigens are acquired by young schistosomes and serve to protect the surface membrane against antibody-mediated damage.


1952 ◽  
Vol 26 (1) ◽  
pp. 25-42 ◽  
Author(s):  
O. D. Standen

The majority of normal sera proved in vitro to be cercaricidal to larvae of S. mansoni. Of 502 normal sera. 21 per cent, were noncercaricidal whereas the remainder exhibited varying degrees of cercaricidal potency.The cercaricidal factor was thermolabile and disappeared during storage. It bore several points of similarity to complement.The cercaricidal factor was present to a varying degree in sera from all species investigated. Apparently normal sera from all cattle and different proportions of other species, caused an enveloping precipitate to form around the cercariae. This bore no obvious relationship to the nematode worm burden or presence of F. hepatica.An enveloping precipitate formed around cercariae of S. mansoni when placed in vitro in immune sera and incubated at 87°C. This occurred in serum immune to S. haematobium as well as to S. mansoni. It is not known-whether age and weight of infection influence the rate and extent of envelope precipitation.


Parasitology ◽  
1982 ◽  
Vol 84 (1) ◽  
pp. 83-91 ◽  
Author(s):  
M. A. Smith ◽  
J. A. Clegg ◽  
D. Snary ◽  
A. J. Trejdosiewicz

SUMMARYTwo hybridomas secreting monoclonal IgM antibody to Schistosoma mansoni have been isolated following fusion of spleen cells from Balb/c mice immunized with living S. mansoni and NS1 myeloma cells. One monoclonal IgM antibody (WP66.4) mediated about the same level of passive protection against a challenge infection as immune serum from mice with a chronic S. mansoni infection. The other monoclonal antibody (WP66.2) did not give a significant level of passive protection. This result indicates that the effective monoclonal antibody recognizes an antigen which may be a valuable candidate for experimental vaccination. In vitro one monoclonal antibody (WP66.4) caused a much higher level of complement-dependent cytotoxicity than the other (WP66.2), suggesting a possible mechanism for the effect observed in vivo. With indirect immunofluorescence both monoclonal antibodies reacted with surface determinants on living S. mansoni schistosomula, adult worms and miracidia but these determinants were not detected on cercariae or lung schistosomula. Neither monoclonal antibody cross-reacted with S. haematobium schistosomula or Fasciola hepatica metacercariae, indicating a possible use for these reagents in differential diagnosis of S. mansoni infections.


Planta Medica ◽  
2012 ◽  
Vol 78 (11) ◽  
Author(s):  
AIO Salloum ◽  
R Lucarini ◽  
MG Tozatti ◽  
J Medeiros ◽  
MLA Silva ◽  
...  

Author(s):  
Daria Monaldi ◽  
Dante Rotili ◽  
Julien Lancelot ◽  
Martin Marek ◽  
Nathalie Wössner ◽  
...  

The only drug for treatment of Schistosomiasis is Praziquantel, and the possible emergence of resistance makes research on novel therapeutic agents necessary. Targeting of Schistosoma mansoni epigenetic enzymes, which regulate the parasitic life cycle, emerged as promising approach. Due to the strong effects of human Sirtuin inhibitors on parasite survival and reproduction, Schistosoma sirtuins were postulated as therapeutic targets. In vitro testing of synthetic substrates of S. mansoni Sirtuin 2 (SmSirt2) and kinetic experiments on a myristoylated peptide demonstrated lysine long chain deacylation as an intrinsic SmSirt2 activity for the first time. Focused in vitro screening of the GSK Kinetobox library and structure-activity relationships (SAR) of identified hits, led to the first SmSirt2 inhibitors with activity in the low micromolar range. Several SmSirt2 inhibitors showed potency against both larval schistosomes (viability) and adult worms (pairing, egg laying) in culture without general toxicity to human cancer cells.<br>


1976 ◽  
Vol 4 (3-4) ◽  
pp. 207-211
Author(s):  
SHUN SHINBO ◽  
TAKATOSHI KOBAYAKAWA ◽  
HIROSHI ISHIYAMA ◽  
KAZUSHIGE MASUDA

2021 ◽  
Vol 14 (7) ◽  
pp. 686
Author(s):  
Raquel Porto ◽  
Ana C. Mengarda ◽  
Rayssa A. Cajas ◽  
Maria C. Salvadori ◽  
Fernanda S. Teixeira ◽  
...  

The intravascular parasitic worm Schistosoma mansoni is a causative agent of schistosomiasis, a disease of great global public health significance. Praziquantel is the only drug available to treat schistosomiasis and there is an urgent demand for new anthelmintic agents. Adopting a phenotypic drug screening strategy, here, we evaluated the antiparasitic properties of 46 commercially available cardiovascular drugs against S. mansoni. From these screenings, we found that amiodarone, telmisartan, propafenone, methyldopa, and doxazosin affected the viability of schistosomes in vitro, with effective concentrations of 50% (EC50) and 90% (EC90) values ranging from 8 to 50 µM. These results were further supported by scanning electron microscopy analysis. Subsequently, the most effective drug (amiodarone) was further tested in a murine model of schistosomiasis for both early and chronic S. mansoni infections using a single oral dose of 400 mg/kg or 100 mg/kg daily for five consecutive days. Amiodarone had a low efficacy in chronic infection, with the worm and egg burden reduction ranging from 10 to 30%. In contrast, amiodarone caused a significant reduction in worm and egg burden in early infection (>50%). Comparatively, treatment with amiodarone is more effective in early infection than praziquantel, demonstrating the potential role of this cardiovascular drug as an antischistosomal agent.


Author(s):  
Annika S. Mokosch ◽  
Stefanie Gerbig ◽  
Christoph G. Grevelding ◽  
Simone Haeberlein ◽  
Bernhard Spengler

AbstractSchistosoma mansoni is a parasitic flatworm causing schistosomiasis, an infectious disease affecting several hundred million people worldwide. Schistosomes live dioeciously, and upon pairing with the male, the female starts massive egg production, which causes pathology. Praziquantel (PZQ) is the only drug used, but it has an inherent risk of resistance development. Therefore, alternatives are needed. In the context of drug repurposing, the cancer drug imatinib was tested, showing high efficacy against S. mansoni in vitro. Besides the gonads, imatinib mainly affected the integrity of the intestine in males and females. In this study, we investigated the potential uptake and distribution of imatinib in adult schistosomes including its distribution kinetics. To this end, we applied for the first time atmospheric-pressure scanning microprobe matrix-assisted laser desorption/ionization mass spectrometry imaging (AP-SMALDI MSI) for drug imaging in paired S. mansoni. Our results indicate that imatinib was present in the esophagus and intestine of the male as early as 20 min after in vitro exposure, suggesting an oral uptake route. After one hour, the drug was also found inside the paired female. The detection of the main metabolite, N-desmethyl imatinib, indicated metabolization of the drug. Additionally, a marker signal for the female ovary was successfully applied to facilitate further conclusions regarding organ tropism of imatinib. Our results demonstrate that AP-SMALDI MSI is a useful method to study the uptake, tissue distribution, and metabolization of imatinib in S. mansoni. The results suggest using AP-SMALDI MSI also for investigating other antiparasitic compounds and their metabolites in schistosomes and other parasites. Graphical abstract


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