Screening and identification of B cell epitopes of Toxoplasma gondii / 中国血吸虫病防治杂志

ABSTRACT

Objective To screen and identify B cell epitopes in SAG1, SAG2, SAG3, GRA1, GRA6 and P35 antigens of Toxoplasma gondii. Methods The indexes such as hydrophilicity, accessibility, flexibility, secondary structure and polarity of the 6 antigen moleculars above mentioned were analyzed by BioSun system. Two B cell epitopes with high antigenicity from each antigen molecular were selected, and the total twelve pairs of oligonucleotide chains were designed according to the 12 B cell epitopes’ sequence and synthesized, then cloned into plasmid pET-32c. The 12 fragment B cell epitopes were expressed and the expressed fusion proteins were identified with Western blot. Results Twelve B cell epitopes from 6 Toxoplasma antigens (two from each antigen) were predicted and selected. The epitope genes were successfully cloned into pET-32c and expressed. Western blot results showed that 3 of 12 expressed fusion proteins could be recognized by the immunized rabbit sera with soluble antigen of Toxoplasma gondii, but not by the unimmunized rabbit sera Conclusion Three B cell epitopes of Toxoplasma[with potential diagnostic value are obtained.