Identification of exposed components on the surface of adult Schistosoma mansoni by lactoperoxidase-catalysed iodination

Roberts, S.M.; Aitken, Robert; Vojvodic, Maria; Wells, Edward; Wilson, R. A.

doi:10.1016/0166-6851(83)90105-6

Cited by 29 publications

(9 citation statements)

References 19 publications

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“…This tegumental localization of SmNPP-5 has been reported by other research groups using proteomic approaches (7,33) and immunofluorescence localization (26); also, as noted earlier, phosphodiesterese activity in tegument-enriched fractions of on May 7, 2018 by guest http://iai.asm.org/ adult worms was previously reported (10,11,23,25). The localization of SmNPP-5 as determined using immunogold electron microscopy and reported here confirms and extends those data.…”

Section: Discussionsupporting

confidence: 77%

Tegumental Phosphodiesterase SmNPP-5 Is a Virulence Factor for Schistosomes

et al. 2011

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The intravascular trematode Schistosoma mansoni is a causative agent of schistosomiasis, a disease that constitutes a major health problem globally. In this study we cloned and characterized the schistosome tegumental phosphodiesterase SmNPP-5 and evaluated its role in parasite virulence. SmNPP-5 is a 52.5-kDa protein whose gene is rapidly turned on in the intravascular parasitic life stages, following invasion of the definitive host. Highest expression is found in mated adult males. As revealed by immunofluorescence analysis, SmNPP-5 protein is found prominently in the dorsal surface of the tegument of males. Localization by immuno-electron microscopy illustrates a unique pattern of immunogold-labeled SmNPP-5 within the tegument; some immunogold particles are scattered throughout the tissue, but many are clustered in tight arrays. To determine the importance of the protein for the parasites, RNA interference (RNAi) was employed to knock down expression of the SmNPP-5-encoding gene in schistosomula and adult worms. Both quantitative real-time PCR (qRT-PCR) and Western blotting confirmed successful and robust gene suppression. In addition, the suppression and the ectolocalization of this enzyme in live parasites were evident because of a significantly impaired ability of the suppressed parasites to hydrolyze exogenously added phosphodiesterase substrate p-nitrophenyl 5-dTMP (p-Nph-5-TMP). The effects of suppressing expression of the SmNPP-5 gene in vivo were tested by injecting parasites into mice. It was found that, unlike controls, parasites whose SmNPP-5 gene was demonstrably suppressed at the time of host infection were greatly impaired in their ability to establish infection. These results demonstrate that SmNPP-5 is a virulence factor for schistosomes.

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Section: Discussionsupporting

confidence: 77%

Tegumental Phosphodiesterase SmNPP-5 Is a Virulence Factor for Schistosomes

et al. 2011

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“…Localization using immuno-EM shows that a majority of the immunogold particles appear to be distributed at the edge of surface pits which is consistent with a host interactive localization of this enzyme in the tegument. High alkaline phosphatase activity was previously reported in tegument enriched fractions of both male and female worms [26], [27], [28]. More recent tegumental proteomic analysis confirms that the protein is found in the schistosome surface membranes [29], [30] and is available for surface biotinylation [31].…”

Section: Discussionsupporting

confidence: 59%

Characterization of Schistosome Tegumental Alkaline Phosphatase (SmAP)

Bhardwaj

Skelly

2011

PLoS Negl Trop Dis

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Schistosomes are parasitic platyhelminths that currently infect over 200 million people globally. The parasites can live for years in a putatively hostile environment - the blood of vertebrates. We have hypothesized that the unusual schistosome tegument (outer-covering) plays a role in protecting parasites in the blood; by impeding host immunological signaling pathways we suggest that tegumental molecules help create an immunologically privileged environment for schistosomes. In this work, we clone and characterize a schistosome alkaline phosphatase (SmAP), a predicted ∼60 kDa glycoprotein that has high sequence conservation with members of the alkaline phosphatase protein family. The SmAP gene is most highly expressed in intravascular parasite life stages. Using immunofluorescence and immuno-electron microscopy, we confirm that SmAP is expressed at the host/parasite interface and in internal tissues. The ability of living parasites to cleave exogenous adenosine monophosphate (AMP) and generate adenosine is very largely abolished when SmAP gene expression is suppressed following RNAi treatment targeting the gene. These results lend support to the hypothesis that schistosome surface enzymes such as SmAP could dampen host immune responses against the parasites by generating immunosuppressants such as adenosine to promote their survival. This notion does not rule out other potential functions for the adenosine generated e.g. in parasite nutrition.

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“…Tegument preparations were prepared by sucrose-gradient centrifugation of a freeze/thaw extraction method previously described (Roberts et al, 1983; Brouwers et al, 1999). Briefly, adult worms were washed twice with Hanks balanced salt solution (HBBS, Invitrogen) and frozen in liquid nitrogen.…”

Section: Methodsmentioning

confidence: 99%

Schistosoma mansoni host-exposed surface antigens characterized by sera and recombinant antibodies from schistosomiasis-resistant rats

Sepúlveda

Tremblay

DeGnore

et al. 2010

International Journal for Parasitology

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Antibodies from Schistosoma mansoni-infected rats, unlike mice, show a higher titer for schistosome apical tegumental antigens compared with non-apical membrane antigens. These antibodies bind to the surface of living lung stage worms and to formaldehyde-fixed adult worms. We produced a singlechain antibody Fv domain (scFv) phage library displaying the antibody repertoire of rats highly immune to schistosome infection and we selected for scFvs that recognize the host-exposed surface of worms. Five unique rat scFvs (Teg1, Teg4, Teg5, Teg20 and Teg37) were obtained which recognize schistosome surface epitopes. Each of the scFvs recognizes the surface of living schistosomula and lung stage schistosomules and/or the surface of formaldehyde-fixed adult worms. None of these scFvs reproducibly stained living adult worms. This suggests that a change occurs during the transition from lung schistosomules to 4 week adults such that at least some surface antigens, although remaining on the surface in living adult worms, can no longer be immunologically stained. Teg1 and Teg4 scFvs both recognize specific bands on Western blots. No bands were observed for the other three scFvs, suggesting that these scFvs may recognize non-protein or conformationally-dependent epitopes. Teg1 was unambiguously identified as recognizing the S. mansoni tetraspanin antigen, SmTSP-2, within the large extracellular domain. Teg4 recognizes a 35 kD band tentatively identified as Sm29 by proteomic analysis. These scFvs can now be used to characterize schistosome epitopes at the host-parasite interface, to target worms in vivo, and to study the mechanisms by which these worms naturally evade immune damage to the tegument within permissive hosts.

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Identification of exposed components on the surface of adult Schistosoma mansoni by lactoperoxidase-catalysed iodination

Cited by 29 publications

References 19 publications

Tegumental Phosphodiesterase SmNPP-5 Is a Virulence Factor for Schistosomes

Tegumental Phosphodiesterase SmNPP-5 Is a Virulence Factor for Schistosomes

Characterization of Schistosome Tegumental Alkaline Phosphatase (SmAP)

Schistosoma mansoni host-exposed surface antigens characterized by sera and recombinant antibodies from schistosomiasis-resistant rats

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