Schistosoma mansoni: a comparative study of artificially transformed schistosomula and schistomula recoverd after cercarial penetration of isolated skin

Parasitology ◽  
1977 ◽  
Vol 74 (1) ◽  
pp. 73-86 ◽  
Author(s):  
Linda H. Brink ◽  
Diane J. McLaren ◽  
S. R. Smithers
Keyword(s):  
Comparative Study ◽  
Schistosoma Mansoni ◽  
Amorphous Material ◽  
Surface Membrane ◽  
Antigenic Determinants ◽  
Agglutination Reaction ◽  
Rat Serum ◽  
Mechanical Separation ◽  
B Blood Group

A comparison was made of the ultrastructure, development and antigenic nature of the surfaces and of the viability of three types of schistosomula of Schistosoma mansoni: schistosomula formed afrer cercariae had penetrated isolated skin (SS), schistosomula produced after mechanical separation of cercarial tails from bodies (MS), and schistosomula transformed from cercariae after incubation in fresh rat serum (RS).Within 2 h of transformation, the surface membrane of all three types of schistosomula had changed from trilaminate to heptalaminate structures and SS and MS had lost their cercarial glycocalyx. Initially a dense amorphous material was demonstrated on the surfaces of RS, which was thought to be the result of an interaction between a factor in rat serum and the glycocalyx: this material was greatly reduced within 2 h of transformation. The pre-acetabular glands of SS were emptied while those of MS and RS retained their contents. Immunofluorescent studies showed that all schistosomula bound serum from mice immune to S. mansoni, but the binding was stronger with MS and RS. The mixed agglutination reaction demonstrated the presence of human A and B blood group-like antigenic determinants on approximately 30% of 3 h old SS; these determinants were not detected on MS or RS. In vitro, the development of MS and RS was similar to SS; the first schistosomula reached the ‘gut-closed’ stage by day 10; 50–70% of SS reached this stage by day 12, in contrast to only 25–50% of MS and RS. Between 28 and 45% of all schistosomula developed to maturity when injected intravenously into mice.It was concluded that the two types of artificially prepared schistosomula fultil the main criteria of transformation from cercaria to schistosomulum. Further, it is suggested that MS are the most appropriate source of material for immunochemical and physiological studies.

Fluorescent lipid uptake and transport in adult Schistosoma mansoni

Parasitology ◽  
1992 ◽  
Vol 105 (1) ◽  
pp. 81-89 ◽  
Author(s):  
D. Moffat ◽  
J. R. Kusel
Keyword(s):  
Schistosoma Mansoni ◽  
External Medium ◽  
Surface Membrane ◽  
Lipid Uptake ◽  
Lipophilic Compounds ◽  
Oesophageal Gland ◽  
Labelled Compound ◽  
Positively Charged ◽  
Uptake And Transport

Fluorescent lipophilic compounds can be used to label the surface membrane of Schistosoma mansoni by adding the compound in small amounts of organic solvents to aqueous medium in vitro. Under these conditions it is difficult to follow routes of distribution of the label. Here we have absorbed nitrobenzoxadiazolamine methylamino–(NBD)–ceramides to positively charged Dowex beads, and incubated the labelled beads with living parasites. The NBD–ceramide transfers to the surface membrane as a patch 50–100 μm in diameter, after which the label can be seen localized in the gut and in a very concentrated form in organelles within the oesophageal gland cells. Subsequently the labelled compound can be found in organelles within other body cells, including subtegumental cells. We show that the labelled ceramide has been transported from the patch in the surface membrane through internal membrane systems to the destination in the gut and oesophageal gland and not transported through the gut via the external medium. A different pattern was observed when NBD–cholesterol was used. The pharynx was rapidly labelled when NBD–cholesterol was added in medium with or without serum or attached to red blood cells only. Diffuse labelling of the surface membrane and oesophageal gland occurred. We have demonstrated a novel route of lipid transport within the parasite. The route requires the surface membrane to have very specialized regions to facilitate such transport.

scholarly journals Epithelioid cell cultures from rat small intestine. Characterization by morphologic and immunologic criteria.

1979 ◽  
Vol 80 (2) ◽  
pp. 248-265 ◽  
Author(s):  
A Quaroni ◽  
J Wands ◽  
R L Trelstad ◽  
K J Isselbacher
Keyword(s):  
Basement Membrane ◽  
Amorphous Material ◽  
Population Doubling ◽  
Antigenic Determinants ◽  
Intestinal Epithelial ◽  
Epithelioid Cells ◽  
Intestinal Crypt ◽  
Ultrastructural Studies ◽  
Small Intestinal

Rat small intestinal epithelial cell lines have been established in vitro and subcultured serially for periods up to 6 mo. These cells have an epithelioid morphology, grow as monolayers of closely opposed polygonal cells, and during the logarithmic phase of growth have a population doubling time of 19--22 h. Ultrastructural studies revealed the presence of microvilli, tight junctions, an extensive Golgi complex, and the presence of extracellular amorphous material similar in appearance to isolated basement membrane. These cells exhibit a number of features characteristic of normal cells in culture; namely, a normal rat diploid karyotype, strong density inhibition of growth, lack of growth in soft agar, and a low plating efficiency when seeded at low density. They did not produce tumors when injected in syngeneic animals. Immunochemical studies were performed to determine their origin using antisera prepared against rat small intestinal crypt cell plasma membrane, brush border membrane of villus cells and isolated sucrase-isomaltase complex. Antigenic determinants specific for small intestinal epithelial (crypt and villus) cells were demonstrated on the surface of the epithelioid cells, but they lacked immunological determinants specific for differentiated villus cells. An antiserum specifically staining extracellular material surrounding the cells cultured in vitro demonstrated cross-reactivity to basement membrane in rat intestinal frozen sections. It is concluded that the cultured epithelioid cells have features of undifferentiated small intestinal crypt cells.

Damage to surface membrane ofSchistosoma mansoniby pristane (2,6,10,14 tetramethyl pentadecane) and other hydrophobic compounds

Parasitology ◽  
1980 ◽  
Vol 80 (1) ◽  
pp. 83-94 ◽  
Author(s):  
J. R. Kusel ◽  
L. Stones ◽  
L. Tetley
Keyword(s):  
Schistosoma Mansoni ◽  
Organic Solvents ◽  
Intraperitoneal Injection ◽  
Trypan Blue ◽  
Surface Membrane ◽  
Hydrophobic Compounds ◽  
Release Studies ◽  
Significant Release

SummaryIntraperitoneal injection of cercariae into pristane (2, 6, 10, 14 tetramethyl pentadecane)-primed Balb/c mice led to greatly diminished numbers of portal and peritoneal worms compared with untreated mice. Schistosomula taken from the peritoneal cavity of pristane-primed mice carried globules of pristane on their surfaces, were contracted and were permeable to Trypan blue. Pristane globules bound also to adult wormsin vitroandin vivocausing rapid damage to the surface membrane. Hydrophobic compounds other than hydrocarbons either bound without causing gross damage, or did not bind to the adult worms.51Cr release studies showed that pristane had no effect on the permeability of human erythrocytes, while causing significant release from both schistosomula and adult worms. The binding of hydrocarbon globules to a variety of other parasites did not occur. The binding ofn-[1-14C]hexadecane to adultSchistosoma mansoniwas significantly decreased by extraction of the parasite with organic solvents or treatment with staphylococcal δ toxin, which interacts with phospholipids in the membrane. Possible mechanisms of damage of the parasite by the hydrocarbons are discussed.

Ultrastructural evidence for complement and antibody-dependent damage to schistosomula of Schistosoma mansoni by rat eosinophils in vitro

Parasitology ◽  
1978 ◽  
Vol 77 (3) ◽  
pp. 313-324 ◽  
Author(s):  
Diane J. McLaren ◽  
F. J. Ramalho-Pinto ◽  
S. R. Smithers
Keyword(s):  
Schistosoma Mansoni ◽  
Surface Damage ◽  
The Body ◽  
Receptor Interaction ◽  
Focal Lesions ◽  
Rat Serum ◽  
Ultrastructural Evidence ◽  
Basal Plasma ◽  
Normal Rat

SummaryRat peritoneal eosinophils adhere to live Schistosoma mansoni schistosomula in vitro in the presence of fresh normal rat serum, or in heat-inactivated serum from rats immune to the parasite. When the eosinophils are present in sufficient numbers the worms show ultrastructural evidence of surface damage and are ultimately killed. It is believed that the appearance of focal lesions in the tegument of the schistosomulum follows the secretion of enzymes by the eosinophils onto the parasite surface. The cells have been observed within these lesions and later between the basal plasma membrane of the tegument and the underlying interstitial material. It is suggested that the cells are responsible for prising the tegument away from the body of the worm. The detached tegument shows evidence of further degradation. Adherent eosinophils which have released their secretions appear to degenerate and are eventually replaced by macrophages. Remnants of both the expended eosinophils and the disrupted tegument have been identified within the macrophages. Adherence of eosinophils through C3–C3 receptor interaction results in earlier and more severe damage to the schistosomula than when adherence occurs through Fe receptors. Rat eosinophils also adhere to C3-coated, glutaraldehyde-flxed schistosomula and C3-coated Sepharose beads. However, evidence of enzyme secretion is only obtained when the target is a schistosomulum.

Acquisition of host antigens by young Schistosoma mansoni in mice: correlation with failure to bind antibody in vitro

Parasitology ◽  
1975 ◽  
Vol 70 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Diane J. McLaren ◽  
J. A. Clegg ◽  
S. R. Smithers
Keyword(s):  
Horseradish Peroxidase ◽  
Rhesus Monkey ◽  
Schistosoma Mansoni ◽  
Surface Membrane ◽  
Mouse Skin ◽  
Ultrastructural Level ◽  
High Titre ◽  
Immune Serum ◽  
Mouse Erythrocyte

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.

Schistosoma mansoni: the occurrence of microvilli on the surface of the tegument during transformation from cercaria to schistosomulum

Parasitology ◽  
1976 ◽  
Vol 73 (2) ◽  
pp. 169-187 ◽  
Author(s):  
Diane J. McLaren ◽  
D. J. Hockley
Keyword(s):  
Schistosoma Mansoni ◽  
Surface Area ◽  
Mouse Skin ◽  
The Body ◽  
Skin Preparation ◽  
Mechanical Separation

Microvilli are developed on the surface of Schistosoma mansoni schistosomula during penetration of the host skin; they form rapidly but are lost approximately 90 min after penetration. Identical microvilli are also formed on schistosomula which have penetrated a mouse skin preparation in vitro, and on schistosomula prepared by mechanical separation of the tail from the body of the cercaria. The microvilli, which are limited by the trilaminate tegumental membrane of the cercaria, eventually degenerate and are cast off from the surface of the tegument. There is little change in the surface area of the schistosomulum at this time, and the formation and loss of microvilli coincides with the replacement of the cercarial tegumental membrane by the new heptalaminate membrane. It is suggested that during the cercaria/schistosomulum transformation, some intramembraneous components of the original cercarial membrane may migrate into the new heptalaminate membrane and thus be retained, while other peripheral components such as the glycocalyx are almost certainly lost.

Eimeria tenella sporozoites: the method of excystation affects the surface membrane proteins

Parasitology ◽  
1987 ◽  
Vol 95 (3) ◽  
pp. 479-489 ◽  
Author(s):  
M. H. Wisher ◽  
M. E. Rose
Keyword(s):  
Bile Salts ◽  
Polyacrylamide Gel Electrophoresis ◽  
Surface Membrane ◽  
Sodium Dodecyl ◽  
Eimeria Tenella ◽  
Immunofluorescent Staining ◽  
Antigenic Determinants ◽  
Western Blots

SUMMARYEimerian sporozoites can be recovered from intestinal washings after oral administration of oocysts to chickens but suspensions of sporozoites are usually prepared in the laboratory by incubation of sporocysts or fractured oocysts in vitro, at body temperatures, with relatively high concentrations of trypsin and bile salts. Since these agents affect membrane structure, the surface membrane of proteins of Eimeria tenella sporozoites excysted in vivo and in vitro have been compared. Surface radio-iodination followed by sodium dodecyl sulphate–polyacrylamide gel electrophoresis (SDS–PAGE) showed that more 125I was incorporated into polypeptides on sporozoites excysted in vivo than on sporozoites excysted in vitro. The 125I-polypeptide profile of sporozoites excysted in vivo was more resistant to subsequent incubation with pure trypsin than that of sporozoites excysted in vitro, but incubation with bile salts resulted in the loss of some iodinated polypeptides from both preparations of iodinated sporozoites. Reaction with combinations of crude trypsin and bile salts led to the lysis of sporozoites. The method of excystation had no effect on the reaction of convalescent chicken serum with Western blots of sporozoites but the results of immunofluorescent staining carried out with mouse monoclonal antibodies indicated that the structure of the cell surface was altered and some antigenic determinants were lost from sporozoites excysted in vitro. In contrast, neither the infectivity of sporozoites determined in vivo, nor their invasion of cultured cells was changed by the method of excystation.

scholarly journals In Vitro and In Vivo Activities of Arachidonic Acid against Schistosoma mansoni and Schistosoma haematobium

2010 ◽  
Vol 54 (8) ◽  
pp. 3383-3389 ◽  
Author(s):  
Rashika El Ridi ◽  
Marwa Aboueldahab ◽  
Hatem Tallima ◽  
Mohamed Salah ◽  
Noha Mahana ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Schistosoma Mansoni ◽  
Schistosoma Haematobium ◽  
Unsaturated Fatty Acids ◽  
Ex Vivo ◽  
Surface Membrane ◽  
Calf Serum ◽  
The United States

ABSTRACT The development of arachidonic acid (ARA) for treatment of schistosomiasis is an entirely novel approach based on a breakthrough discovery in schistosome biology revealing that activation of parasite tegument-bound neutral sphingomyelinase (nSMase) by unsaturated fatty acids, such as ARA, induces exposure of parasite surface membrane antigens to antibody binding and eventual attrition of developing schistosomula and adult worms. Here, we demonstrate that 5 mM ARA leads to irreversible killing of ex vivo 1-, 3-, 4-, 5-, and 6-week-old Schistosoma mansoni and 9-, 10-, and 12-week-old Schistosoma haematobium worms within 3 to 4 h, depending on the parasite age, even when the worms were maintained in up to 50% fetal calf serum. ARA-mediated worm attrition was prevented by nSMase inhibitors, such as CaCl2 and GW4869. Scanning and transmission electron microscopy revealed that ARA-mediated worm killing was associated with spine destruction, membrane blebbing, and disorganization of the apical membrane structure. ARA-mediated S. mansoni and S. haematobium worm attrition was reproduced in vivo in a series of 6 independent experiments using BALB/c or C57BL/6 mice, indicating that ARA in a pure form (Sigma) or included in infant formula (Nestle) consistently led to 40 to 80% decrease in the total worm burden. Arachidonic acid is already marketed for human use in the United States and Canada for proper development of newborns and muscle growth of athletes; thus, ARA has potential as a safe and cost-effective addition to antischistosomal therapy.

scholarly journals Loss of covalently labeled glycoproteins and glycolipids from the surface of newly transformed schistosomula of Schistosoma mansoni.

1982 ◽  
Vol 94 (2) ◽  
pp. 363-369 ◽  
Author(s):  
J C Samuelson ◽  
J P Caulfield
Keyword(s):  
Schistosoma Mansoni ◽  
Trichloroacetic Acid ◽  
Culture Medium ◽  
Surface Membrane ◽  
Apparent Molecular Weight ◽  
Acid Precipitation ◽  
Defined Medium ◽  
Galactose Oxidase ◽  
Newly Transformed Schistosomula

Schistosomula of Schistosoma mansoni were labeled by oxidation with galactose oxidase or with periodate followed by reduction with NaB3H4 to study the loss of the surface membrane of these parasites in vitro. Grain counts of light microscope autoradiographs (LMARG) of radiolabeled schistosomula show that both galactose oxidase and periodate specifically label the surface of the organisms. Galactose oxidase labels 11 glycoproteins on the surface of skin and mechanical schistosomula, ranging in apparent molecular weight from 17,000 to greater than 105,000. These glycoproteins are lost from the surface of schistosomula with a halftime of 10-15 h in culture in defined medium. Most of these glycoproteins appear to be shed intact from the surface of the schistosomula rather than endocytosed and degraded, because greater than 50% of each of the lost proteins can be recovered by trichloroacetic acid precipitation of the culture medium and because there is no internalization of the radiolabels into cultured schistosomula examined by LMARG. In addition to glycoproteins, periodate labels at least seven glycolipids on the surface of mechanical schistosomula. After culture for 15 h, more than half of each of these periodate-labeled proteins and lipids are lost from the schistosomula, and their abundance relative to each other remains similar to that of freshly labeled organisms. Since both proteins and lipids are lost from the surface of the schistosomula at the same rate, we believe that we are observing a general loss of the parasite surface membrane.

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