Changing surface antigen and carbohydrate patterns during the development of Oesophagostomum dentatum

Parasitology ◽  
1999 ◽  
Vol 119 (5) ◽  
pp. 491-501 ◽  
Author(s):  
A. JOACHIM ◽  
B. RUTTKOWSKI ◽  
A. DAUGSCHIES

Living and fixed specimen of Oesophagostomum dentatum were labelled in situ with serum antibodies or a panel of biotin- labelled lectins. Specific binding of antibodies was observed in all parasitic stages – freshly exsheathed 3rd-stage larvae (L3), 3rd- and 4th-stage (L4) larvae cultured in vitro and L3 and L4 and adults isolated from pig intestines. The shedding of the stained layer by motile larvae was inhibited by levamisole-induced paralysis. Larvae cultured in vitro exposed serum-derived proteins on their surface which could be labelled with secondary antibody directed against the respective serum donor species. While freshly exsheathed larvae were recognized by O. dentatum-positive serum only, older larvae and adults cross-reacted with serum from pigs infected with O. quadrispinulatum, a closely related species. Lectin binding varied considerably between stages. While binding was not observed in pre-parasitic stages, Concanavalin A, Soybean Agglutinin, Wheat Germ Agglutinin, Ricinus communis Agglutinin and Peanut Agglutinin bound to developing larvae in varying degrees. Dolichos biflorus Agglutinin only bound to advanced (luminal) larval stages, while adults generally displayed only weak or partial lectin binding (except with Concanavalin A and Wheat Germ Agglutinin). Ulex europaeus Agglutinin only labelled larvae derived from cultures containing 10% pig serum. Cleavage of the carbohydrate residues by sodium periodate treatment resulted in reduction of antibody binding to cultured larvae, but not to freshly exsheathed L3. Concanavalin A, Soybean Agglutinin, and Peanut Agglutinin binding was also reduced by periodate treatment, while binding of Wheat Germ Agglutinin and Ricinus communis Agglutinin was inhibited only in early L3, but not in older stages. The different lectin labelling patterns are related to the different stages of the nematode – infective, invasive, histotropic, and luminal – and may serve as a mode of adaptation for the parasite against the host's immune attack by surface glycoprotein variation, together with antigen shedding (as demonstrated by labelling of motile larvae) and a possible acquisition of host molecules at the parasite's surface. Furthermore, a possible role of this developmental variation in surface carbohydrates in parasite–parasite interactions is discussed.

Parasitology ◽  
1991 ◽  
Vol 103 (1) ◽  
pp. 51-59 ◽  
Author(s):  
M. J. T. Gerhardus ◽  
J. M. C. Baggen ◽  
W. P. W. Van Der Knaap ◽  
T. Sminia

Miracidia and in vitro-derived primary sporocysts of the avian schistosome Trichobilharzia ocellata were studied for the expression and the characteristics of glycoconjugate moieties comprising the surface coat. Using a panel of 9 peroxidase labelled lectins, several different lectin binding sites were demonstrated on the larvae. Fixed miracidia have binding sites for 7 of the lectins; wheat-germ agglutinin binds to both the ciliated plates and the tegumental ridges between them; the other 6 lectins bind to the plates only. Three of the miracidia-binding lectins, wheat-germ agglutinin, concanavalin A and peanut agglutinin, also bind to fixed sporocysts. Since the miracidial ridges are devoid of binding sites for concanavalin A and peanut agglutinin, whereas the sporocyst tegument binds these lectins, it appears that these sites become exposed during or shortly after transformation. In saturation experiments, low concentrations of peanut agglutinin and concanavalin A are bound more avidly by sporocysts than by miracidia, indicating a higher binding affinity of the former. The two larval forms do not differ in affinity for wheat-germ agglutinin but they have different binding capacities; when offered in high concentrations, more of this lectin is bound by sporocysts than by miracidia. Lectin binding was competitively inhibited by adding the appropriate free saccharides. Live larvae showed the same lectin binding pattern as did fixed specimens. Proteinase treatment reduced lectin binding to living and, to a lesser extent, to fixed larvae, suggesting that binding sites are constituents of proteoglycoconjugates. After SDS–PAGE of extracts from miracidia and sporocysts and subsequent Western blotting, some of the lectins failed to bind glycoproteins, others reacted with an array of bands. The patterns differed among the lectins and each lectin gave different patterns for miracidia and sporocysts. The results obtained with these two lectin-binding techniques support the conclusion that stage-specific proteoglycoconjugates occur at the surface of T. ocellata larvae.


Parasitology ◽  
1980 ◽  
Vol 81 (1) ◽  
pp. 1-15 ◽  
Author(s):  
A. J. G. Simpson ◽  
S. R. Smithers

SUMMARYThe surface architecture of adult male Schistosoma mansoni was explored using a range of lectins with differing carbohydrate specificities. Highest specific binding was achieved with concanavalin A and the agglutinin of molecular weight 60000 from Ricinus communis; the binding of wheat germ agglutinin was mostly non-specific. Small amounts of peanut agglutinin and soybean agglutinin binding were observed and the binding of these lectins was increased by pre-treating the parasite with neuraminidase. The fucose binding protein of Lotus tetragonolobus failed to bind. These results indicate that mannose and/or glucose, galactose, N-acetyl-glucosamine, N-acetyl-galactosamine and sialic acid are exposed on the surface of the adult male schistosome.


1984 ◽  
Vol 103 (1) ◽  
pp. 111-116 ◽  
Author(s):  
A. J. Chapman ◽  
J. T. Gallagher ◽  
C. G. Beardwell ◽  
S. M. Shalet

ABSTRACT The lectin-binding properties of serum α subunit were studied by lectin affinity chromatography. Normal individuals and most patients with pituitary tumours produced α subunit which bound specifically to Concanavalin A–Sepharose (Con A). Some patients with pituitary tumours produced both Con A-reactive α subunit and α subunit which did not bind to Con A. Concanavalin A–Sepharose-binding α subunit from all sources bound strongly to Ricinus communis agglutinin–Sepharose after treatment with neuraminidase. Serum α subunit from those patients with pituitary tumours, which did not bind to Con A, bound to wheat germ agglutinin–Sepharose, exhibiting both weakly binding and strongly binding forms. Serum α subunit from both patients and controls, which did bind to Con A, showed only weak affinity for wheat germ agglutinin–Sepharose. Neither the low affinity nor the high affinity of serum α subunit from any source for wheat germ agglutinin–Sepharose was affected by neuraminidase. These findings show that (a) the predominant pattern of glycosylation of serum α subunit from normal controls is a Con A-reactive, biantennate complex oligosaccharide and (b) that the structural alteration which results in serum α subunit which does not bind to Con A in some patients with pituitary tumours is not an absence of carbohydrate, rather the α subunit contains highly branched, either complex or hybrid oligosaccharides. J. Endocr. (1984) 103, 111–116


1987 ◽  
Vol 241 (2) ◽  
pp. 513-520 ◽  
Author(s):  
S M Gokhale ◽  
N G Mehta

Vesicles and cell remnants have been obtained by aging of erythrocytes in vitro. The vesicles lacking the membrane skeletal proteins and the remnants known to possess a rigid skeleton have been used to assess the role of membrane skeletal proteins in the process of Con A (concanavalin A)-mediated agglutination of erythrocytes. Both the vesicles and the remnants were found to bind Con A at the same density as did intact cells. The vesicles, isolated from normal as well as from the Con A-agglutinable trypsin- and Pronase-treated cells, failed to agglutinate with Con A. They were, however, well agglutinated by WGA (wheat-germ agglutinin) and RCA [Ricinus communis (castor bean) agglutinin], indicating that the vesicles are not defective in agglutination. Large, cytoskeleton-free, vesicles prepared by another procedure also gave the same results. The aged remnants from trypsin- and Pronase-treated erythrocytes showed significantly decreased agglutination with Con A, but were agglutinated as well as the fresh cells by WGA and RCA. The agglutination with Con A is thus abolished when the membrane skeleton is absent, and reduced when it is rigid, suggesting that the skeleton may play an important role in the agglutination of erythrocytes by Con A.


1985 ◽  
Vol 33 (5) ◽  
pp. 384-388 ◽  
Author(s):  
A Bacic ◽  
M L Williams ◽  
A E Clarke

The nature of the surface saccharides of zoospores, "partially encysted zoospores" and cysts of the root-rotting fungus Phytophthora cinnamomi, has been examined by quantitative lectin binding studies. Zoospores bound concanavalin A (Con A), but did not bind any of a variety of other lectins tested. In contrast, both cysts and "partially encysted zoospores" bound soybean agglutinin (SBA) as well as Con A. This indicates that accessible alpha-D-glucosyl/alpha-D-mannosyl-containing glycoconjugates predominate at the zoospore surface, whereas both alpha-D-glucosyl/alpha-D-mannosyl and galactosyl and/or N-acetyl-D-galactosaminosyl residues are accessible at the surface of cysts and "partially encysted zoospores." Neither Ulex europeus lectin nor wheat germ agglutinin (WGA) bound to any of the three cell preparations, indicating the absence of accessible alpha-L-fucosyl and N-acetyl-D-glucosaminosyl residues.


1980 ◽  
Vol 29 (2) ◽  
pp. 600-608 ◽  
Author(s):  
Cynthia Kuehn ◽  
Dennis E. Van Epps

Six lectins, including concanavalin A, phytohemagglutinin P, castor bean I, wheat germ agglutinin, peanut agglutinin, and pokeweed mitogen, were studied for their ability to stimulate human neutrophil locomotion and cap formation. Five of these lectins with known monosaccharide specificities, including concanavalin A, phytohemagglutinin, P, castor bean I, wheat germ agglutinin, and peanut agglutinin, were found to stimulate human neutrophil migration in a modified Boyden assay. Pokeweed mitogen showed negligible activity in the locomotion assay as compared with other lectins. Tests were performed to determine if the observed neutrophil migration in response to lectins was directional, and it was found that concanavalin A, phytohemagglutinin P, and peanut agglutinin were both chemokinetic and chemotactic, whereas castor bean I was only chemokinetic. Wheat germ agglutinin could not be declared chemotactic or chemokinetic due to its tendency to agglutinate neutrophils. Studies with fluoresceinated lectins demonstrated that lectins which stimulate neutrophil migration also bind to neutrophil surfaces. Preincubation with specific monosaccharide ligands blocked both stimulated locomotion and fluorescence, suggesting that an available lectin-binding site was required both for lectin binding and the stimulation of migration. Additional experiments indicated that fluoresceinated concanavalin A, phytohemagglutinin P, castor bean I, wheat germ agglutinin, and peanut agglutinin all induce cap formation on the neutrophil.


1991 ◽  
Vol 81 (3) ◽  
pp. 393-399 ◽  
Author(s):  
Masayuki Hosoi ◽  
Shokei Kim ◽  
Kenjiro Yamamoto

1. In this study, the carbohydrate structure of pure human renin was examined by using various lectins. 2. Pure renin could be separated into three forms by concanavalin A chromatography, a concanavalin A-unbound form, a loosely bound form and a tightly bound form, termed renins A, B and C, respectively. Renins A, B and C accounted for 3, 13 and 84%, respectively, of the purified renin. These forms were all present in individual human plasma and the relative proportions in plasma were 27 ± 3, 33 ± 4 and 39 ± 5% (means ± sem) for renins A, B and C, respectively (n = 5). 3. Each form, electroblotted on to the nitrocellulose sheet after gel electrophoresis, was incubated with five peroxidase-labelled lectins, lentil lectin, erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin, Ricinus communis agglutinin and peanut agglutinin. The protein was stained with 4-chloro-l-naphthol. 4. The staining pattern obtained with these lectins was significantly different among the three forms of human renin, confirming that they have different carbohydrate structures. Furthermore, the positive staining of human renin with erythroagglutinating phytohaemagglutinin, wheat-germ agglutinin and Ricinus communis agglutinin was in contrast with the lack of binding of rat renin to these lectins. 5. These results indicate the renal secretion of differently glycosylated multiple forms of human renin. The carbohydrate structure of human renin appears to differ from that of rat renin.


1986 ◽  
Vol 103 (4) ◽  
pp. 1369-1382 ◽  
Author(s):  
L M Greenberger ◽  
K H Pfenninger

A subcellular fraction prepared from fetal rat brain and enriched in growth cone membranes is analyzed for its lectin-binding proteins. Growth-associated glycoproteins are identified by comparing the growth cone glycoproteins with those of synaptosomes. Protein was resolved in one- or two-dimensional gels, electroblotted, and blots probed with radioiodinated concanavalin A, wheat germ agglutinin, and Ricinus communis agglutinins I and II. In one-dimensional gels, each lectin recognizes approximately 20 polypeptides (with substantial overlap) most of which migrate diffusely and have relatively high molecular masses (range 30-200 kD). The seven major Coomassie-staining proteins of the membrane fraction (34-52 kD) are not the major lectin-binding proteins. In two-dimensional gels, the lectin-binding proteins are either streaked across the pH gradient or exist as multiple spots, indicating broad charge heterogeneity. Seven wheat germ agglutinin- and Ricinus communis agglutinin II-binding glycoproteins are present in greater abundance in growth cone fractions compared with synaptosomes. Most notably, an acidic, sialic acid-rich protein (27-30 kD, pI 4.0; termed gp27-30) is most abundant at postnatal day 4, but absent from adult brain. The protein's very acidic isoelectric point is due, at least in part, to its high sialic acid content. Growth regulation of specific protein-linked oligosaccharides suggests that they play a special role in growth cone function. In addition, the great diversity of growth cone glycoproteins from whole brain suggests glycoprotein heterogeneity among growth cones from different neuron types.


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