中缅边境地区恶性疟原虫株裂殖子顶端膜抗原1(PfAMA1)Domain Ⅰ的基因多态性分析

Genetic Polymorphism Analysis of Plasmodium falciparum Apical Membrane Antigen Ⅰ(PfAMA1) Domain Ⅰ in China-Myanmar Border Area

明确中国和缅甸边境地区恶性疟原虫疫苗候选抗原Pf AMA1蛋白的基因特点。收集中缅边境地区88例恶性疟原虫感染患者血样,制备血样滤纸片;试剂盒提取恶性疟原虫基因组DNA(g DNA);PCR和测序检测分析恶性疟原虫Pf AMA1基因的Domain I(DI)区域的多态性。成功扩增88例恶性疟原虫分离株Pf AMA1胞外段DI区域基因,与恶性疟原虫标准株3D7比较,检测出31个分离位点,18个单倍型,单倍型多样度为0.794。其中c1特别是c1L区域的基因多样性显著高于其他检测区域。同时,分子进化分析显示,DI区域及其中的c1和c1L区域在进化过程中经历阳性选择。研究发现,中缅边境地区恶性疟原虫疫苗候选抗原Pf AMA1基因DI区和其中c1、c1L区域高度多态,提示上述区域作为红内期疫苗候选抗原研制靶位的可能性。

In order to confirm the genetic features of Plasmodium falciparum vaccine candidates Pf AMA1 protein in China-Myanmar border area,88 blood samples from patients infected by P.falciparum in the border area were collected,and prepared filter paper sheets of blood samples,and extracted genomic DNA of P.falciparum with reagent kid;as well as PCR and sequence determination to analyse the polymorphism of Domain I（DI） of P.falciparum＇s Pf AMA1 gene.The DNA sequence of Pf AMA1 gene of extracellular Domain I（DI） was amplified successfully by PCR and compared with standard 3D7 strain of P.falciparum and isolated 31 segregation sites,18 haploid types,with haploid diversity of 0.794.Among them the diversity in c1 especially c1 L domains significantly higher than the other tested domains.At the same time,molecular evolution analyses showed that during the evolution process DI domain and of its c1 and c1 L domains had experienced positive choice.The study has found that the candidate vaccine antigen Pf AMA1 gene of DI domain and its c1 and c1 L domains of P.falciparum in China-Myanmar border has high polymorphism,suggested that the above mentioned areas have the possibility to develop target of endoerythrocytic stage vaccine candidate antigen.