梅毒螺旋体Tp92蛋白B细胞表位的预测与鉴定

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

【目的】预测和鉴定梅毒螺旋体(Tp)Tp92蛋白的B细胞表位,为深入探讨这些表位在梅毒表位疫苗中的作用奠定基础。【方法】采用Mobyle、ABCpred和IEDB在线软件综合分析预测Tp92蛋白的B细胞表位,人工合成6条表位多肽,以梅毒患者/感染兔血清(同时设健康人/兔血清对照)为标本,用间接ELISA法鉴定预测Tp92蛋白B细胞表位的免疫反应性。【结果】软件预测显示,Tp92蛋白的P1(24-39AA)、P2(332-347AA)、P3(520-536AA)、P4(575-588AA)、P5(103-118AA)、P6(694-712AA)氨基酸序列可能为其B细胞表位。间接ELISA分析表明,预测的P1、P3、P5和P6均与梅毒患者/感染兔血清呈阳性反应,而与健康人/兔血清不反应。【结论】本研究初步得出以下结论:P1、P3、P5和P6均为Tp92蛋白潜在的特异性B细胞表位,尤其是P3和P6免疫反应性最强。

[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 todetermine 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 （575-588A_A）, P5 （103-118AA）, and P6 （694-712AA） might be the B-cell epitopes. The result of indirect ELISA indicated that P 1, 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.