Cultivation of Schistosoma mansoni In vitro. I. Establishment of Cultures from Cercariae and Development until Pairing

Basch, Paul F.

doi:10.2307/3280632

Cited by 290 publications

(235 citation statements)

References 8 publications

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“…For the isolation of cercarial bodies from tails, an ice-cold Hank's basal salt solution (HBSS) is added to the cercarial suspension and the tail-rich supernatant is decanted (Manneck et al 2009). Schistosomula are incubated in Basch medium (Basch, 1981) supplemented with serum and antibiotics or other culture media (Smyth and Halton, 1983). Our own studies have shown that schistosomula survive for at least 96 h in different media (Basch,MEM,DMEM or TC 199) reported that schistosomula survive in Basch medium for several weeks (Abdulla et al 2009).…”

Section: S Mansoni In Vitro Assay Based On Schistosomulamentioning

confidence: 99%

In vitroandin vivotrematode models for chemotherapeutic studies

2009

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Schistosomiasis and food-borne trematodiases are chronic parasitic diseases affecting millions of people mostly in the developing world. Additional drugs should be developed as only few drugs are available for treatment and drug resistance might emerge. In vitro and in vivo whole parasite screens represent essential components of the trematodicidal drug discovery cascade. This review describes the current state-of-the-art of in vitro and in vivo screening systems of the blood fluke Schistosoma mansoni, the liver fluke Fasciola hepatica and the intestinal fluke Echinostoma caproni. Examples of in vitro and in vivo evaluation of compounds for activity are presented. To boost the discovery pipeline for these diseases there is a need to develop validated, robust high-throughput in vitro systems with simple readouts.

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Section: S Mansoni In Vitro Assay Based On Schistosomulamentioning

confidence: 99%

In vitroandin vivotrematode models for chemotherapeutic studies

2009

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“…Cercarial tails were sheared off by 20 passes through 22G emulsifying needles after which schistosomule bodies were isolated free from tails by Percoll gradient centrifugation [19]. Schistosomula were washed 3 times in wash medium and cultured at 37°C under 5% CO 2 in air in modified Basch's medium [16] supplemented with small quantities of washed human erythrocytes. In some experiments, parasites were incubated in wash medium at 37° C under 5% CO 2 for 3 hours and recovered directly for electroporation.…”

Section: Parasitesmentioning

confidence: 99%

“…With the aim of establishing a more effective gene silencing, we employed electroporation procedures (as recommended [14]) to introduce dsRNA into cultured schistosomules. This developmental stage is readily maintained in vitro [16] and the life cycle can be subsequently re-established in vivo by needle passage into mice of schistosomules that have been genetically transformed in vitro [17]. This system is attractive and tractable for RNAi based investigation of gene function in S. mansoni [17,18].…”

Section: Introductionmentioning

confidence: 99%

RNA interference of Schistosoma mansoni cathepsin D, the apical enzyme of the hemoglobin proteolysis cascade

Morales

Rinaldi

Gobert

et al. 2008

Molecular and Biochemical Parasitology

119

111

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The aspartic protease cathepsin D (Clan AA, Family A1) is expressed in the schistosome gut where it plays an apical role in the digestion of hemoglobin released from ingested erythrocytes. In this report, RNA interference approaches were employed to investigate the effects of knockdown of schistosome cathepsin D. Cultured schistosomules of Schistosoma mansoni were exposed by square wave electroporation to double stranded RNA (dsRNA) specific for cDNA encoding S. mansoni cathepsin D. RNAi mediated reductions in transcript levels led to phenotypic changes including significant growth retardation in vitro and suppression of aspartic protease enzyme activity. In addition, black-pigmented heme, the end point by-product of normal hemoglobin proteolysis that accumulates in the schistosome gut, was not apparent within the guts of the treated schistosomules. Rather, their guts appeared to be red in color, rather than black, apparently indicating the presence of intact rather than digested host hemoglobin. These phenotypic effects were apparent when either of two forms of dsRNA, a long form spanning the entire target transcript or a short form specific for the 3'-region were employed. Off-target effects were not apparent in transcript levels of the gut-localized cysteine protease cathepsin B1. Finally, cathepsin D may be an essential enzyme in the mammal-parasitic stages of schistosomes because schistosomules treated ex vivo with dsRNA did not survive to maturity after transfer into Balb/c mice. These and earlier findings suggest that, given its essential function in parasite nutrition, schistosome cathepsin D could be developed as a target for novel anti-schistosomal interventions.

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“…Cercariae harvested from infected B. glabrata were used to infect C57BL/6 mice by subcutaneous injection (2,000 cercariae/mouse). Worms were perfused from mice 3 weeks postinfection (20) in Basch Schistosoma culture medium 169 (SCM) 3 with 10% fetal bovine serum instead of human serum (21) and complemented with 100 units/ml penicillin and 100 g/ml streptomycin. Worms were washed thoroughly and cultured in SCM at 37°C in a 5% CO 2 incubator.…”

Section: Methodsmentioning

confidence: 99%

A Multienzyme Network Functions in Intestinal Protein Digestion by a Platyhelminth Parasite

Delcroix

Sajid

Caffrey

et al. 2006

Journal of Biological Chemistry

213

205

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Proteases frequently function not only as individual enzymes but also in cascades or networks. A notable evolutionary switch occurred in one such protease network that is involved in protein digestion in the intestine. In vertebrates, this is largely the work of trypsin family serine proteases, whereas in invertebrates, cysteine proteases of the papain family and aspartic proteases assume the role. Utilizing a combination of protease class-specific inhibitors and RNA interference, we deconvoluted such a network of major endopeptidases functioning in invertebrate intestinal protein digestion, using the parasitic helminth, Schistosoma mansoni as an experimental model. We show that initial degradation of host blood proteins is ordered, occasionally redundant, and substrate-specific. Although inhibition of parasite cathepsin D had a greater effect on primary cleavage of hemoglobin, inhibition of cathepsin B predominated in albumin degradation. Nevertheless, in both cases, inhibitor combinations were synergistic. An asparaginyl endopeptidase (legumain) also synergized with cathepsin B and L in protein digestion, either by zymogen activation or facilitating substrate cleavage. This protease network operates optimally in acidic pH compartments either in the gut lumen or in vacuoles of the intestinal lining cells. Defining the role of each of these major enzymes now provides a clearer understanding of the function of a complex protease network that is conserved throughout invertebrate evolution. It also provides insights into which of these proteases are logical targets for development of chemotherapy for schistosomiasis, a major global health problem.

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Cultivation of Schistosoma mansoni In vitro. I. Establishment of Cultures from Cercariae and Development until Pairing

Cited by 290 publications

References 8 publications

In vitroandin vivotrematode models for chemotherapeutic studies

In vitroandin vivotrematode models for chemotherapeutic studies

RNA interference of Schistosoma mansoni cathepsin D, the apical enzyme of the hemoglobin proteolysis cascade

A Multienzyme Network Functions in Intestinal Protein Digestion by a Platyhelminth Parasite

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