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.

Show MeSH

Related in: MedlinePlus

Recognition of recombinant Sj-TSP-2e by human sera.I: ELISA IgG screen of 72 sera collected from positive schistosomiasis japonica patients and 24 normal human sera (negative controls) probed by protein preparation from S. japonicum adult worms (SWAP), recombinant tag protein thioredoxin (Thio) and Sj-TSP-2e. II. Panel a: SDS-PAGE of soluble and insoluble protein extracted from adult S. japonicum and recombinant Sj-TSP-2e. Panels b and c: Western blot analysis with pooled sera randomly selected from confirmed schistosomiasis japonica patients (n = 15) and pooled sera from negative control subjects (n = 15) from northern China. Lane M, protein markers; lanes 1 and lane 2, soluble and insoluble proteins from adult S. japonicum; lane 3, Sj-TSP-2e (arrowed); lane 4, thioredoxin tag (Thi) (arrowed); lane 5, Sj-TSP-2e expressed in Pichia yeast (arrowed).
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3104969&req=5

pntd-0001166-g005: Recognition of recombinant Sj-TSP-2e by human sera.I: ELISA IgG screen of 72 sera collected from positive schistosomiasis japonica patients and 24 normal human sera (negative controls) probed by protein preparation from S. japonicum adult worms (SWAP), recombinant tag protein thioredoxin (Thio) and Sj-TSP-2e. II. Panel a: SDS-PAGE of soluble and insoluble protein extracted from adult S. japonicum and recombinant Sj-TSP-2e. Panels b and c: Western blot analysis with pooled sera randomly selected from confirmed schistosomiasis japonica patients (n = 15) and pooled sera from negative control subjects (n = 15) from northern China. Lane M, protein markers; lanes 1 and lane 2, soluble and insoluble proteins from adult S. japonicum; lane 3, Sj-TSP-2e (arrowed); lane 4, thioredoxin tag (Thi) (arrowed); lane 5, Sj-TSP-2e expressed in Pichia yeast (arrowed).

Mentions: Secondly, recombinant Sj-TSP-2e LEL was recognized by a serum pool, from 15 randomly selected patients, with confirmed S. japonicum infection, but the pool did not bind the Thi tag protein (Fig. 5I). We coated the recombinant protein and native proteins onto ELISA plates for screening 72 individual sera collected from positive schistosomiasis japonica patients. All the sera recognised the native proteins with different OD values (Fig. 5II). We reacted the sera with Sj-TSP-2e-Thi protein; 43.1% (31/72) of the sera had OD values 2.5-fold higher than the average OD values of negative sera (Fig. 5II) and only one of the 72 sera reacted positively with the Thi tag protein alone.


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)

Recognition of recombinant Sj-TSP-2e by human sera.I: ELISA IgG screen of 72 sera collected from positive schistosomiasis japonica patients and 24 normal human sera (negative controls) probed by protein preparation from S. japonicum adult worms (SWAP), recombinant tag protein thioredoxin (Thio) and Sj-TSP-2e. II. Panel a: SDS-PAGE of soluble and insoluble protein extracted from adult S. japonicum and recombinant Sj-TSP-2e. Panels b and c: Western blot analysis with pooled sera randomly selected from confirmed schistosomiasis japonica patients (n = 15) and pooled sera from negative control subjects (n = 15) from northern China. Lane M, protein markers; lanes 1 and lane 2, soluble and insoluble proteins from adult S. japonicum; lane 3, Sj-TSP-2e (arrowed); lane 4, thioredoxin tag (Thi) (arrowed); lane 5, Sj-TSP-2e expressed in Pichia yeast (arrowed).
© Copyright Policy
Related In: Results  -  Collection

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

pntd-0001166-g005: Recognition of recombinant Sj-TSP-2e by human sera.I: ELISA IgG screen of 72 sera collected from positive schistosomiasis japonica patients and 24 normal human sera (negative controls) probed by protein preparation from S. japonicum adult worms (SWAP), recombinant tag protein thioredoxin (Thio) and Sj-TSP-2e. II. Panel a: SDS-PAGE of soluble and insoluble protein extracted from adult S. japonicum and recombinant Sj-TSP-2e. Panels b and c: Western blot analysis with pooled sera randomly selected from confirmed schistosomiasis japonica patients (n = 15) and pooled sera from negative control subjects (n = 15) from northern China. Lane M, protein markers; lanes 1 and lane 2, soluble and insoluble proteins from adult S. japonicum; lane 3, Sj-TSP-2e (arrowed); lane 4, thioredoxin tag (Thi) (arrowed); lane 5, Sj-TSP-2e expressed in Pichia yeast (arrowed).
Mentions: Secondly, recombinant Sj-TSP-2e LEL was recognized by a serum pool, from 15 randomly selected patients, with confirmed S. japonicum infection, but the pool did not bind the Thi tag protein (Fig. 5I). We coated the recombinant protein and native proteins onto ELISA plates for screening 72 individual sera collected from positive schistosomiasis japonica patients. All the sera recognised the native proteins with different OD values (Fig. 5II). We reacted the sera with Sj-TSP-2e-Thi protein; 43.1% (31/72) of the sera had OD values 2.5-fold higher than the average OD values of negative sera (Fig. 5II) and only one of the 72 sera reacted positively with the Thi tag protein alone.

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