赖型钩体flaB2与VR1012中的CpG基序分析

Analysis of CpG Motifs in Endoflagellar Gene (flaB2) and Expression Vector (VR1012) of Leptospiral DNA Vaccine

目的 对问号赖型钩端螺旋体 (赖型钩体 ) DNA疫苗〔包括内鞭毛蛋白基因 (fla B2 )和质粒 DNA表达载体 (VR10 12 )〕的 Cp G基序 (Cp G motifs)进行分析 ,为 DNA疫苗免疫机制的阐明和提高 DNA疫苗的效能奠定基础。方法 以 fla B2与 VR10 12构建重组 DNA的免疫原 ,对 fla B2及 VR10 12全核苷酸序列进行计算机分析 (分类、计数和定位 )。结果 Cp G的“C”的侧翼为两个嘌呤 ,“G”的侧翼为两个嘧啶 ,在 fla B2中共 3个 ,分别为GACGCT,GACGTC和 GACGCC;在 VR10 12中共 11个 ,分别为 GACGTC1个 ,GACGCT2个 ,GACGCC1个 ,GACGTT1个 ,GGCGTT2个 ,GGCGCT2个 ,GGCGCC1个 ,AACGCT1个 ,其中特别重要的 TGACGTCA4个和 TAACGCCA有 1个 ,位于 5′端 4 5 6～ 4 6 3;5 0 9～ 5 16 ;5 92～ 5 99;778～ 785和 4 86～ 4 93;4个 TGACGTCA和 1个TAACGCCA均位于 5′端且相对集中。结论 赖型钩体 fla B2与 VR10 12构成的 DNA疫苗含有 TGACGTCA等Cp G,这些基序又称免疫刺激序列 ,构成了

Objective To provide basis for the exploring of the mechanism and improvement of the efficacy of DNA vaccines, through the analysis of CpG motifs in endoflagellar gene (flaB2) and expression vector (VR1012) of the Leptospiral DNA vaccine. Methods Directed by Kreig's immunostimulatory nucleic acid molecules, we undertook the computer assisted analysis of the total number and locations of CpG motifs in flaB2 and VR1012 sequences. Results The CpG motifs was flanked by two 5′purines and 3′pyrimidines. There were 3 CpG motifs in flaB2 and 11 in VR1012. Four particularly important TGACGTCA and 1 TAACGCCA were located in the 5′ end of VR1012. Conclusion One of the most important consideration in optimizing a DNA vaccine is the appropriate choice of vectors. The essential feature of a plasmid DNA vector includes a transcriptional unit and an adjuvant unit. The adjuvant properties of a plasmid DNA vector are highly influenced by the number of CpG motifs within the plasmid backbone. Our results showed that both flaB2 and VR1012 contain CpG motifs, which are immunostimulatory sequence and can act as adjuvant of DNA vaccines.