Prediction and identification of B-cell epitopes of outer membrane protein Tp92 on Treponema pallidum

Abstract:

[Objective] To predict and identify the B-cell epitopes of outer membrane protein Tp92 on Treponema pallidum and provide the basis for further discussion on effects of these epitopes for the epitope-based syphilis vaccine. [Methods] The B-cell epitopes of the protein Tp92 was analyzed with comprehensive meta-analysis Mobyle, ABCpred and IEDB online softwares, and the six peptides containing predicted epitopes were artificially synthesized. The sera from syphilis patients and Tp92-immunized rabbits (normal human and normal rabbits as negative control) were used to determine the immunoreactivity and specificity of six predicted peptides of Tp92 by indirect ELISA. [Results] Comprehensive meta-analysis of online softwares showed that P1 (24-39AA), P2 (332-347AA), P3 (520-536AA), P4 (575-588AA), P5 (103-118AA), and P6 (694-712AA) might be the B-cell epitopes. The result of indirect ELISA indicated that P1、P3、P5 and P6 were active with syphilis patient sera and Tp92-immunized rabbit sera but not with negative control sera. [Conclusion] These results indicate that P1、P3 、P5 and P6 are the potential specific B-cell epitopes, and immunoreactivities of P3 and P6 are the strongest especially.