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

Purification and recognition of recombinant Sj-TSP-2e.Left panel, SDS-PAGE of soluble and insoluble proteins extracted from adult S. japonicum and recombinant proteins. Right panel: Recognition of recombinant Sj-TSP-2e and native proteins by antibodies in hyper immune mouse serum raised against recombinant Sj-TSP-2e. Lane M, protein markers; Lanes 1 and 2, soluble and insoluble proteins of S. japonicum; lane 3, Thi; lane 4, Sj-TSP-2e-Thi; lane 5, Sj-TSP-2e expressed in Pichia yeast; lane 6, Sm-TSP-2e-Thi; lane 7, Sj-23-GST-His as a control protein.
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pntd-0001166-g004: Purification and recognition of recombinant Sj-TSP-2e.Left panel, SDS-PAGE of soluble and insoluble proteins extracted from adult S. japonicum and recombinant proteins. Right panel: Recognition of recombinant Sj-TSP-2e and native proteins by antibodies in hyper immune mouse serum raised against recombinant Sj-TSP-2e. Lane M, protein markers; Lanes 1 and 2, soluble and insoluble proteins of S. japonicum; lane 3, Thi; lane 4, Sj-TSP-2e-Thi; lane 5, Sj-TSP-2e expressed in Pichia yeast; lane 6, Sm-TSP-2e-Thi; lane 7, Sj-23-GST-His as a control protein.

Mentions: As the LEL region of Sm-TSP-2 was used successfully as a vaccine for S. mansoni [5], we expressed the homologous region of Sj-TSP-2e using the pBAD/Thio-TOPO plasmid expression system; this expresses the target protein fused with thioredoxin. As described earlier, we cloned several clusters of Sj-TSP-2 but we expressed the Sj-TSP-2e subclass due to its high frequency of transcription in females (Table 1), indicating its role in female development, which is a target for vaccine development [2]. The purity of Sj-TSP-2e and Sm-TSP-2 are shown in Fig. 4. In an effort to increase antigenicity, we also employed a yeast expression system to express the LEL region of Sj-TSP-2e (Fig. 4).


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)

Purification and recognition of recombinant Sj-TSP-2e.Left panel, SDS-PAGE of soluble and insoluble proteins extracted from adult S. japonicum and recombinant proteins. Right panel: Recognition of recombinant Sj-TSP-2e and native proteins by antibodies in hyper immune mouse serum raised against recombinant Sj-TSP-2e. Lane M, protein markers; Lanes 1 and 2, soluble and insoluble proteins of S. japonicum; lane 3, Thi; lane 4, Sj-TSP-2e-Thi; lane 5, Sj-TSP-2e expressed in Pichia yeast; lane 6, Sm-TSP-2e-Thi; lane 7, Sj-23-GST-His as a control protein.
© Copyright Policy
Related In: Results  -  Collection

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

pntd-0001166-g004: Purification and recognition of recombinant Sj-TSP-2e.Left panel, SDS-PAGE of soluble and insoluble proteins extracted from adult S. japonicum and recombinant proteins. Right panel: Recognition of recombinant Sj-TSP-2e and native proteins by antibodies in hyper immune mouse serum raised against recombinant Sj-TSP-2e. Lane M, protein markers; Lanes 1 and 2, soluble and insoluble proteins of S. japonicum; lane 3, Thi; lane 4, Sj-TSP-2e-Thi; lane 5, Sj-TSP-2e expressed in Pichia yeast; lane 6, Sm-TSP-2e-Thi; lane 7, Sj-23-GST-His as a control protein.
Mentions: As the LEL region of Sm-TSP-2 was used successfully as a vaccine for S. mansoni [5], we expressed the homologous region of Sj-TSP-2e using the pBAD/Thio-TOPO plasmid expression system; this expresses the target protein fused with thioredoxin. As described earlier, we cloned several clusters of Sj-TSP-2 but we expressed the Sj-TSP-2e subclass due to its high frequency of transcription in females (Table 1), indicating its role in female development, which is a target for vaccine development [2]. The purity of Sj-TSP-2e and Sm-TSP-2 are shown in Fig. 4. In an effort to increase antigenicity, we also employed a yeast expression system to express the LEL region of Sj-TSP-2e (Fig. 4).

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