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: 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.

Recognition and invasion of human skin by Schistosoma mansoni cercariae: the key-role of L-arginine

Parasitology ◽  
2002 ◽  
Vol 124 (2) ◽  
pp. 153-167 ◽  
Author(s):  
W. HAAS ◽  
K. GRABE ◽  
C. GEIS ◽  
T. PÄCH ◽  
K. STOLL ◽  
...  
Keyword(s):  
Schistosoma Mansoni ◽  
Mouse Skin ◽  
Ventral Side ◽  
Body Axis ◽  
Surface Layers ◽  
Mammalian Skin ◽  
Cellular Immune ◽  
Arginine Concentration

The attachment of Schistosoma mansoni cercariae to mammalian skin is specifically stimulated by L-arginine. As L-arginine is an unsuitable signal for a specific identification of mammalian skin we examined the following 5 hypotheses to explain the advantage of the cercarial sensitivity to L-arginine. (1) A Schistosoma infection lowered the arginine concentration in the serum of mice, and this could enable the cercariae to avoid attachments to already infected mice. However, the infection did not reduce the arginine concentration in the skin and the cercarial attachment responses to it. (2) Creeping cercariae showed chemotactic orientation specifically along increasing L-arginine gradients. L-arginine could act as a pheromone which could guide cercariae towards common penetration sites. However, the cercarial acetabular gland contents were not attractive and they did not (in contrast to previous reports) contain much arginine. (3) Schistosomula (transformed cercariae) could use L-arginine to produce nitric oxide (NO) for blood vessel dilation during their migration in the host. However, in vitro the transformed cercariae did not convert L-arginine into citrulline and NO. (4) Schistosomula could bind L-arginine from the surrounding tissues and so escape the cellular immune attack (which needs L-arginine as the precursor of NO). However, transformed cercariae bound no more L-arginine than L-serine and L-lysine. (5) Schistosomula, migrating parallel to the surface in the mammalian epidermis, are dependent on information on their position between the inner and the surface layers of the skin. In the mouse skin, they adjusted their body axis with the ventral side toward the deeper (arginine-residue rich) epidermis layers. When migrating in agar, they showed chemo-orientation toward serum, and D-glucose and L-arginine were the stimulating compounds therein. The burrowing schistosomula adjusted their body axis (as in the epidermis) with the ventral side toward the higher concentration of L-arginine and not of glucose. We argue that the sensitivity for L-arginine has its primary function in orientation within mammalian skin and in location of blood vessels.

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.

Schistosoma mansoni: differential cell death associated with in vitro culture and treatment with Astiban (Roche)

Parasitology ◽  
1977 ◽  
Vol 75 (1) ◽  
pp. 101-109 ◽  
Author(s):  
J. R. Shaw ◽  
D. A. Erasmus
Keyword(s):  
Cell Death ◽  
Schistosoma Mansoni ◽  
Cell Damage ◽  
Ultrastructural Level ◽  
Egg Laying ◽  
Biochemical Status ◽  
Differential Cell ◽  
Vitelline Cells

A simple technique for the maintenance in vitro of mature Schistosoma mansoni is described and critically assessed at the ultrastructural level. Females were cultured for 4–6 days with no apparent ultrastructural change, but after this period changes appeared in the cells of the ovary and vitelline gland. At a later stage (10–12 days) lipid bodies appeared in the parenchyma cells. These changes occurred in worms which were active, paired with males and were egg–laying. Thus the activity, pairing behaviour and egg–laying characteristics are not adequate to reveal the true morphological condition and presumably the physiological and biochemical status of cultured worms.This technique was used to study the effect of Astiban on females and the results were compared with worms treated in vivo. Astiban concentrations greater than 30 µg/ml killed worms within 7–20 h and acted non–selectively. Astiban at low concentrations (10µg/ml) during short–term culture (1–3 h) resulted in a selective action of the drug on maturing vitelline cells. Thus, although the degree of cell damage caused by drug treatment was more severe and occurred earlier than the effects observed in worms cultured in vitro without drugs, both treatments resulted in differential cell death.

Pathways for the influx of molecules into cercariae of Schistosoma mansoni during skin penetration

Parasitology ◽  
2010 ◽  
Vol 137 (7) ◽  
pp. 1089-1098 ◽  
Author(s):  
J. A. THORNHILL ◽  
P. McVEIGH ◽  
A. D. JURBERG ◽  
J. R. KUSEL
Keyword(s):  
Molecular Weight ◽  
Linoleic Acid ◽  
Schistosoma Mansoni ◽  
Propidium Iodide ◽  
Lucifer Yellow ◽  
Surface Membrane ◽  
Mouse Skin ◽  
Skin Penetration ◽  
Excretory Bladder ◽  
Normal Constituent

SUMMARYIt has been observed that fluorescent membrane-impermeant molecules can enter the cercariae as they penetrate mouse skin. The hypothesis to be tested was that such molecules, which included Lucifer Yellow and a variety of fluorescent dextrans, entered the parasite through the nephridiopore and excretory tubules as well as through the surface membrane. FITC-labelled poly-L-lysine (molecular weight 10 kDa), added at 4°C during syringe transformation, was found to enter the nephridiopore and labelled the excretory bladder and sometimes the excretory tubules. This finding indicates that macromolecules (10 kDa) can enter the nephridiopore. It was found that linoleic acid (a normal constituent of skin) greatly stimulated uptake of Lucifer Yellow and dextrans into the excretory/subtegumental region of 2-h-old schistosomula. This correlated with an increased uptake of membrane-impermeant propidium iodide at 37°C. Since increased uptake of propidium iodide occurs when membranes become permeable, the surface membrane could also be a pathway of transport of the membrane-impermeant molecules into the schistosomulum.

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