Despite the existence of an effective medication against schistosomiasis, the disease remains a major health problem in affected areas, especially for those lacking appropriate sanitary facilities. Moreover, treatment cannot prevent re-infection since it is only effective on adult schistosome worms. Previous retrospective studies in the Sudan have discovered unique immuno-epidemiological profiles in uninfected individuals and those positive for via polymerase chain reaction (PCR) but egg-negative and those with eggs in their stool.
View Article and Find Full Text PDFAn amendment to this paper has been published and can be accessed via a link at the top of the paper.
View Article and Find Full Text PDFPrevious studies have shown that rabbit IgG antibodies against Schistosoma mansoni egg antigens (SmSEA) cross-react with allergens in natural rubber latex, peanuts and grass and tree pollens. Here we describe antigenic molecules that cross-react with rabbit anti-S. mansoni IgG antibodies in extracts of the house dust mite (HDM) Dermatophagoides farinae, the Australian cockroach (ACR) Periplaneta australasiae and in the venom of the honey bee Apis mellifera (HBV).
View Article and Find Full Text PDFWhen adult schistosome worm pairs are transferred from experimental hosts to in vitro culture they cease producing viable eggs within a few days. Female worms in unisexual infections fail to mature, and when mature adult females are separated from male partners they regress sexually. Worms cultured from the larval stage are also permanently reproductively defective.
View Article and Find Full Text PDFSchistosomes control inflammation in their hosts highly effective mechanisms such as induction of Tregs, Bregs, and alternatively activated macrophages (AAMs). Notably, IPSE/alpha-1, the major secretory product from eggs, triggers basophils to release interleukin (IL)-4 and IL-13. Both cytokines are essential for AAM induction, suggesting an important role for IPSE/alpha-1 in inflammation control.
View Article and Find Full Text PDFPrevious studies have shown that schistosome infection can protect against allergic symptoms, but the underlying mechanisms are still not fully understood. Here we have shown that rabbit IgG antibodies raised against Schistosoma mansoni soluble egg antigens (SmSEA) are cross-reactive with a wide array of molecules in Timothy grass pollen (TGP) and birch tree pollen (BTP). Five of the cross-reactive pollen molecules (two from TGP and three from BTP) were selected randomly and identified by tandem mass spectrometric (TMS) analysis to be, respectively, the TGP allergens Phl p 1 and Phl p 5b, and BTP glutathione S-transferase (GST), and the BTP allergens Bet v 1 and Bet v 6.
View Article and Find Full Text PDFBackground: Miltefosine, an anti-cancer drug that has been successfully repositioned for treatment of Leishmania infections, has recently also shown promising effects against Schistosoma spp targeting all life cycle stages of the parasite. The current study examined the effect of treating Schistosoma mansoni adult worms with miltefosine on exposure of worm surface antigens in vitro.
Methodology/principal Findings: In an indirect immunofluorescence assay, rabbit anti-S.
The Schistosoma mansoni cercarial elastase (SmCE) has previously been shown to be poorly immunogenic in mice. However, a minority of mice were able to produce antibodies against SmCE after multiple immunizations with crude preparations containing the enzyme. These mice were partially protected against challenge infections of S.
View Article and Find Full Text PDFThe antigenic reactivity of constituents of Schistosoma mansoni and peanut (Arachis hypogaea) was investigated to determine whether identical antigenic epitopes possessed by both organisms provided a possible explanation for the negative correlation between chronic schistosome infection and atopy to allergens. Aqueous extracts of peanuts were probed in Western immunoblots with rabbit IgG antibodies raised against the egg, cercarial and adult worm stages of S. mansoni.
View Article and Find Full Text PDFIgG antibodies produced by rabbits immunized against S. mansoni antigens cross-reacted with aqueous soluble constituents of a variety of allergens. The antibody cross-reactivity was largely sensitive to degradation by treatment of the target antigens with sodium meta-periodate, suggesting the cross-reactivity was due to carbohydrate determinants that were common to both the schistosome and the allergens (CCDs).
View Article and Find Full Text PDFA serine protease-like enzyme found in detergent extracts of Schistosoma mansoni adult worms perfused from infected mice has been purified from mouse blood and further characterized. The enzyme is approximately 85 kDa and hydrolyses N-acetyl-DL-phenylalanine β-naphthyl-ester, a chromogenic substrate for chymotrypsin-like enzymes. The enzyme from S.
View Article and Find Full Text PDFBackground: Parasite-specific IgE is thought to correlate with protection against Schistosoma mansoni infection or re-infection. Only a few molecular targets of the IgE response in S. mansoni infection have been characterised.
View Article and Find Full Text PDFBackground: Rapid diagnostic tests (RDTs) for use at the point-of-care (POC) are likely to become increasingly useful as large-scale control programmes for schistosomiasis get underway. Given the low sensitivity of the reference standard egg count methods in detecting light infections, more sensitive tests will be required to monitor efforts aimed at eliminating schistosomiasis as advocated by the World Health Assembly Resolution 65.21 passed in 2012.
View Article and Find Full Text PDFBackground: A sensitive and reliable rapid diagnostic test (RDT) which should have comparable diagnostic performance against reference host serological methods is urgently needed for use in point-of-care (POC) diagnosis of intestinal schistosomiasis in pre school-aged children.
Methods: The diagnostic accuracy of a RDT incorporating Schistosoma mansoni cercarial transformation fluid (SmCTF) for anti-schistosome antibody detection was evaluated with serum samples from a cohort of children from Uganda: 42 children aged under the age of 3 years and 40 children aged between 3 and 5 years. The infection status of these children had been previously determined by inspection of quadruplicate Kato-Katz faecal smears, a single urine circulating cathodic antigen (CCA) dipstick and antibody titres to S.
Background: Parasitological methods are widely used for the diagnosis of schistosomiasis. However, they are insensitive, particularly in areas of low endemicity, and labour-intensive. Immunoassays based on detection of anti-schistosome antibodies have the merit of high sensitivity and recently a rapid diagnostic test (RDT), incorporating Schistosoma mansoni cercarial transformation fluid (SmCTF) for detection of anti-schistosome antibodies in blood has been developed.
View Article and Find Full Text PDFImmunization with Schistosoma mansoni soluble antigen preparations protects non-obese diabetic (NOD) mice against the development of type 1 diabetes. These preparations have long been known to induce Th2 responses in vitro and in vivo. Recently, two separate groups have reported that ω-1, a well-characterized glycoprotein in S.
View Article and Find Full Text PDFGlycans present on glycoproteins from the eggs of the parasite Schistosoma mansoni are mediators of various immune responses of the human host, including T-cell modulation and granuloma formation, and they are the target of glycan-specific antibodies. Here we have analyzed the glycosylation of kappa-5, a major glycoprotein antigen from S. mansoni eggs using a targeted approach of lectin purification followed by mass spectrometry of glycopeptides as well as released glycans.
View Article and Find Full Text PDFSchistosomiasis is traditionally diagnosed by microscopic detection of ova in stool samples, but this method is labour intensive and its sensitivity is limited by low and variable egg secretion in many patients. An alternative is an ELISA using Schistosoma mansoni soluble egg antigen (SEA) to detect anti-schistosome antibody in patient samples. SEA is a good diagnostic marker in non-endemic regions but is of limited value in endemic regions, mainly because of its high cost and limited specificity.
View Article and Find Full Text PDFComparative analyses of the N-glycosylation pattern of hemolymph glycoproteins from Biomphalaria glabrata strains Puerto Rico (BgPR) and Salvador (BgBS-90), differing in their susceptibility towards Schistosoma mansoni infection, were performed by Western blotting, enzyme-linked immunosorbent assays, two-dimensional high-performance liquid chromatography and mass spectrometry. Obtained data demonstrated an enhanced expression of serologically cross-reacting, fucosylated carbohydrate epitopes by the highly susceptible BgPR-strain in comparison to the resistant BgBS-90-strain. In particular, glycoproteins of BgPR snails exhibited larger amounts of glycans with (β1-2)-linked xylose or terminal Fuc(α1-3)GalNAc(β1-4)[±Fuc(α1-3)]GlcNAc(β1-)-units which are known to mediate cross-reactivity with schistosomal glycoconjugates.
View Article and Find Full Text PDFSoluble egg antigens (SEA) of the human parasite Schistosoma mansoni are among the strongest natural stimuli of Th2 responses. Omega-1, a major glycoprotein in SEA, initiates these characteristic Th2 responses through conditioning of dendritic cells (DCs). In view of the reported immunomodulatory potential of SEA glycans, we have investigated omega-1 glycosylation, using an approach combining mass spectrometric techniques and enzyme treatments at the glycopeptide level.
View Article and Find Full Text PDFImmune effector mechanisms can enhance the activity of antischistosomal drugs. We examined the in vivo effect of single oral doses of the antimalarials artemether (400 mg/kg) and mefloquine (200 mg/kg), recently described to have promising antischistosomal properties, against juvenile and adult Schistosoma mansoni in T cell-deficient and in comparably infected age- and sex-matched immunologically intact control mice. Artemether and mefloquine are equally effective in athymic and immunocompetent mice.
View Article and Find Full Text PDFBackground: Plasmodium and Schistosoma are two of the most common parasites in tropical areas. Deregulation of the immune response to Plasmodium falciparum, characterized by a Th1 response, leads to cerebral malaria (CM), while a Th2 response accompanies chronic schistosomiasis.
Methods: The development of CM was examined in mice with concomitant Schistosoma mansoni and Plasmodium berghei ANKA infections.
Soluble egg antigens of the parasitic helminth Schistosoma mansoni (S. mansoni egg antigen [SEA]) induce strong Th2 responses both in vitro and in vivo. However, the specific molecules that prime the development of Th2 responses have not been identified.
View Article and Find Full Text PDFIt has previously been shown that experimental infections of the parasitic trematode Schistosoma mansoni, the adult worms of which reside in the blood stream of the mammalian host, significantly reduced atherogenesis in apolipoprotein E gene knockout (apoE(-/-)) mice. These effects occurred in tandem with a lowering of serum total cholesterol levels in both apoE(-/-) and random-bred laboratory mice and a beneficial increase in the proportion of HDL to LDL cholesterol. To better understand how the parasitic infections induce these effects we have here investigated the involvement of adult worms and their eggs on lipids in the host.
View Article and Find Full Text PDFA laboratory strain of Schistosoma mansoni subjected to repeated in vivo praziquantel (PZQ) treatments for several generations has been previously found to have lesser sensitivity to the drug than the original unselected strain. In this study we have collected evidence on the mode of inheritance of the partial insensitivity exhibited by the PZQ-selected schistosomes. A single male and a single female worm of the two strains, assorted in the four possible combinations, were introduced into the mesenteric veins of mice and the eggs produced by each pair were used as the source of the F(1) progeny.
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