Wang Y.,State Key Laboratory of Veterinary Etiological Biology |
Wang Y.,Chinese Academy of Agricultural Sciences |
Wang G.,State Key Laboratory of Veterinary Etiological Biology |
Wang G.,Chinese Academy of Agricultural Sciences |
And 7 more authors.
Parasites and Vectors | Year: 2013
Background: The identification of protein epitopes is useful for diagnostic purposes and for the development of peptide vaccines. In this study, the epitopes of Toxoplasma gondii SAG1 were identified using synthetic peptide techniques with the aid of bioinformatics. Findings. Eleven peptides derived from T. gondii SAG1 were assessed by ELISA using pig sera from different time points after infection. Four (PS4, PS6, PS10 and PS11), out of the eleven peptides tested were recognized by all sera. Then, shorter peptides that were derived from PS4, PS6, PS10 and PS11 were predicted using bioinformatics and tested by experimentation. Four out of nine shorter peptides were identified successfully (amino acids 106-120, 166-180, 289-300 and 313-332). Conclusions: We have precisely located the epitopes of T. gondii SAG1 using pig sera collected at different time points after infection. The identified epitopes may be useful for the further study of epitope-based vaccines and diagnostic reagents. © 2013 Wang et al.; licensee BioMed Central Ltd.
Lou Z.-Z.,Chinese Academy of Agricultural Sciences |
Lou Z.-Z.,State Key Laboratory of Veterinary Etiological Biology |
Lou Z.-Z.,Key Laboratory of Veterinary Public Health |
Li Z.-Y.,Chinese Academy of Agricultural Sciences |
And 19 more authors.
Virologica Sinica | Year: 2010
Three pairs of specific primers were designed to amplify the F2-1, F2-2 and XF2-2 truncated sequences of ORF2 which encodes the capsid protein of porcine circovirus type 2 (PCV-2). The F2-1 sequence had most of the NLS region of ORF2, but the F2-2 and XF2-2 genes had the NLS region deleted. Truncated genes were subcloned into pET-32a(+) vectors to construct recombinant fusion expression vectors. The vectors were then transformed into Rosetta(DE3) E. coli and expressed by induction of IPTG. Expressed proteins were detected by western blotting and ELISA. The protein with best immunoreactivity was confirmed and selected, then utilized to inoculate SPF rabbits to prepare polyclonal antibodies. The protein and prepared polyclonal antibody were utilized to detect sera samples against PCV-2 from Shandong province and PCV-2 particles in PK-15 cells. In our study, three recombinant fusion proteins were successfully obtained, and the molecular weights of fusion proteins were 35.9 kDa, 33.6 kDa and 38.6 kDa respectively detected by SDS-PAGE. All of the proteins showed positive reaction with anti-PCV-2 antisera, and His-XF2-2 showed better immunoreactivity than the others. The protein of His-XF2-2 was coated as antigen in ELISA to detect the seroprevalence of PCV-2 in certain districts of Shandong province, the seropositivity rate was 27.7 % (73/264). Specific fluorescence and positive signals for PCV-2 could be detected in PK-15 cells inoculated with PCV-2 with the participation of prepared antibodies against His-XF2-2 in IFA and IPMA. Experimental results indicated that the truncated PCV-2 ORF2 gene containing most of the NLS region was successfully expressed in E. coli, and His-XF2-2 was demonstrated to have better immunoreactivity with anti-PCV-2 antisera than the other two fusion proteins. His-XF2-2 and prepared polyclonal antibodies against it had a satisfactory capability in detecting PCV-2 infection. © 2010 Wuhan Institute of Virology, CAS and Springer-Verlag Berlin Heidelberg.