Limits...
Inconsistent protective efficacy and marked polymorphism limits the value of Schistosoma japonicum tetraspanin-2 as a vaccine target.

Zhang W, Li J, Duke M, Jones MK, Kuang L, Zhang J, Blair D, Li Y, McManus DP - PLoS Negl Trop Dis (2011)

Bottom Line: We determined the protective efficacy of one subclass - Sj-TSP-2e.Following the alignment of 211 cDNAs, we identified 7 clusters encoding S. japonicum TSP-2 (Sj-TSP-2) based on sequence variation in the large extracellular loop (LEL) region with differing frequency of transcription in male and female worms.We expressed in E. coli the LEL region of one of the clusters which exhibited a high frequency of transcription in female worms, and showed the purified recombinant protein (Sj-TSP-2e) was recognised by 43.1% of sera obtained from confirmed schistosomiasis japonica patients.

View Article: PubMed Central - PubMed

Affiliation: Molecular Parasitology Laboratory, Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research, Brisbane, Queensland, Australia.

ABSTRACT

Background: Schistosoma mansoni tetraspanin 2 (Sm-TSP-2) has been shown to be strongly recognized by IgG1 and IgG3 antibodies from individuals putatively resistant to schistosome infection, but not chronically infected people, and to induce high levels of protection against challenge infection in the murine model of schistosomiasis. Amplification by PCR of homologous sequences from male and female S. japonicum worms showed the presence of 7 different clusters or subclasses of S. japonicum TSP-2. We determined the protective efficacy of one subclass - Sj-TSP-2e.

Methodology/principal findings: Following the alignment of 211 cDNAs, we identified 7 clusters encoding S. japonicum TSP-2 (Sj-TSP-2) based on sequence variation in the large extracellular loop (LEL) region with differing frequency of transcription in male and female worms. Quantitative PCR analysis revealed elevated expression of Sj-TSP-2 in adult worms compared with other life cycle stages. We expressed in E. coli the LEL region of one of the clusters which exhibited a high frequency of transcription in female worms, and showed the purified recombinant protein (Sj-TSP-2e) was recognised by 43.1% of sera obtained from confirmed schistosomiasis japonica patients. Vaccination of mice with the recombinant protein induced high levels of IgG1 and IgG2 antibodies, but no consistent protective efficacy against challenge infection was elicited in three independent trials.

Conclusions/significance: The highly polymorphic nature of the Sj-TSP-2 gene at the transcriptional level may limit the value of Sj-TSP-2 as a target for future S. japonicum vaccine development.

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Related in: MedlinePlus

Immunolocalization of S. japonicum Sj-TSP-2e in adult female worms.Parasite sections were reacted with specific antibodies produced in mice against recombinant Sj-TSP-2e. The antibodies that specifically bound to the sections were probed with an anti-mouse IgG labelled with Cy3 conjugate (a, c). Red fluorescence in panel c indicates Sj-TSP-2e is located in the parasite tegument (teg); anti-thioredoxin (fusion protein tagged with 6His) antibodies in panel a did not react. DAPI to label nuclei (nuc in blue) (b, d) was used as a quality control marker for the sections. Tegument, teg.
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pntd-0001166-g006: Immunolocalization of S. japonicum Sj-TSP-2e in adult female worms.Parasite sections were reacted with specific antibodies produced in mice against recombinant Sj-TSP-2e. The antibodies that specifically bound to the sections were probed with an anti-mouse IgG labelled with Cy3 conjugate (a, c). Red fluorescence in panel c indicates Sj-TSP-2e is located in the parasite tegument (teg); anti-thioredoxin (fusion protein tagged with 6His) antibodies in panel a did not react. DAPI to label nuclei (nuc in blue) (b, d) was used as a quality control marker for the sections. Tegument, teg.

Mentions: Thirdly, we used the hyper-immune mouse serum prepared against recombinant Sj-TSP-2e to localize Sj-TSP-2e in female S. japonicum. The results showed that specific antibodies against Sj-TSP-2e bound to the tegument and gut of adult female worms (Fig. 6). Sections of male worms showed minimal staining (data not shown).


Inconsistent protective efficacy and marked polymorphism limits the value of Schistosoma japonicum tetraspanin-2 as a vaccine target.

Zhang W, Li J, Duke M, Jones MK, Kuang L, Zhang J, Blair D, Li Y, McManus DP - PLoS Negl Trop Dis (2011)

Immunolocalization of S. japonicum Sj-TSP-2e in adult female worms.Parasite sections were reacted with specific antibodies produced in mice against recombinant Sj-TSP-2e. The antibodies that specifically bound to the sections were probed with an anti-mouse IgG labelled with Cy3 conjugate (a, c). Red fluorescence in panel c indicates Sj-TSP-2e is located in the parasite tegument (teg); anti-thioredoxin (fusion protein tagged with 6His) antibodies in panel a did not react. DAPI to label nuclei (nuc in blue) (b, d) was used as a quality control marker for the sections. Tegument, teg.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3104969&req=5

pntd-0001166-g006: Immunolocalization of S. japonicum Sj-TSP-2e in adult female worms.Parasite sections were reacted with specific antibodies produced in mice against recombinant Sj-TSP-2e. The antibodies that specifically bound to the sections were probed with an anti-mouse IgG labelled with Cy3 conjugate (a, c). Red fluorescence in panel c indicates Sj-TSP-2e is located in the parasite tegument (teg); anti-thioredoxin (fusion protein tagged with 6His) antibodies in panel a did not react. DAPI to label nuclei (nuc in blue) (b, d) was used as a quality control marker for the sections. Tegument, teg.
Mentions: Thirdly, we used the hyper-immune mouse serum prepared against recombinant Sj-TSP-2e to localize Sj-TSP-2e in female S. japonicum. The results showed that specific antibodies against Sj-TSP-2e bound to the tegument and gut of adult female worms (Fig. 6). Sections of male worms showed minimal staining (data not shown).

Bottom Line: We determined the protective efficacy of one subclass - Sj-TSP-2e.Following the alignment of 211 cDNAs, we identified 7 clusters encoding S. japonicum TSP-2 (Sj-TSP-2) based on sequence variation in the large extracellular loop (LEL) region with differing frequency of transcription in male and female worms.We expressed in E. coli the LEL region of one of the clusters which exhibited a high frequency of transcription in female worms, and showed the purified recombinant protein (Sj-TSP-2e) was recognised by 43.1% of sera obtained from confirmed schistosomiasis japonica patients.

View Article: PubMed Central - PubMed

Affiliation: Molecular Parasitology Laboratory, Australian Centre for International and Tropical Health and Nutrition, Queensland Institute of Medical Research, Brisbane, Queensland, Australia.

ABSTRACT

Background: Schistosoma mansoni tetraspanin 2 (Sm-TSP-2) has been shown to be strongly recognized by IgG1 and IgG3 antibodies from individuals putatively resistant to schistosome infection, but not chronically infected people, and to induce high levels of protection against challenge infection in the murine model of schistosomiasis. Amplification by PCR of homologous sequences from male and female S. japonicum worms showed the presence of 7 different clusters or subclasses of S. japonicum TSP-2. We determined the protective efficacy of one subclass - Sj-TSP-2e.

Methodology/principal findings: Following the alignment of 211 cDNAs, we identified 7 clusters encoding S. japonicum TSP-2 (Sj-TSP-2) based on sequence variation in the large extracellular loop (LEL) region with differing frequency of transcription in male and female worms. Quantitative PCR analysis revealed elevated expression of Sj-TSP-2 in adult worms compared with other life cycle stages. We expressed in E. coli the LEL region of one of the clusters which exhibited a high frequency of transcription in female worms, and showed the purified recombinant protein (Sj-TSP-2e) was recognised by 43.1% of sera obtained from confirmed schistosomiasis japonica patients. Vaccination of mice with the recombinant protein induced high levels of IgG1 and IgG2 antibodies, but no consistent protective efficacy against challenge infection was elicited in three independent trials.

Conclusions/significance: The highly polymorphic nature of the Sj-TSP-2 gene at the transcriptional level may limit the value of Sj-TSP-2 as a target for future S. japonicum vaccine development.

Show MeSH
Related in: MedlinePlus