[Screening and identification of egg mimotope of Schistosoma japonicum].

OBJECTIVE

To explore egg mimotope of Schistosoma japonicum that can be used in the development of diagnostic reagents for schistosomiasis.

METHODS

By performing three rounds of biopanning in the affinity selection before picking out single clones for identification, target specific phages were effectively enriched from a random 15-peptides phage library with an immobilized mAb 6B12 which is specific to egg antigen of S. japonicum as a bait. By using ELISA, competitive ELISA with natural egg antigen as competitor, and Western blotting, 13 phage clones with high affinity and specificity to 6B12 were obtained and amplified from 400 single clones.

RESULTS

DNA sequencing revealed that all the 13 selected single clones were identical in displaying gene sequence. Serum samples were tested by ELISA for the presence of IgG antibodies to the phages with mimic epitope, and showed that there was a significant difference between healthy volunteers and schistosomiasis patients.

CONCLUSION

It is possible that the phage display peptide antigen, egg mimotope of S. japonicum may be a replacement of natural egg antigen for the diagnosis of schistosomiasis.