Evaluation of antibody responses to the early transcribed membrane protein family in Plasmodium vivax
Evaluation of antibody responses to the early transcribed membrane protein family in Plasmodium vivax
复制标题
间日疟原虫早期转录膜蛋白家族的抗体反应评估
DOI：
10.1186/s13071-019-3846-4
复制
发表时间：
2019-12-19
影响因子：
3.2
通讯作者：
Han，Eun-Taek
中科院分区：
文献类型：
--
作者：
Lee，Seong-Kyun;Han，Jin-Hee;Han，Eun-Taek
背景
疟疾寄生虫形成细胞内膜，将寄生虫与红细胞内部空间隔开，寄生虫的膜蛋白通过膜输出到宿主。在我们先前的研究中，间日疟原虫早期转录膜蛋白(PvETRAMP)11.2是一种在血液期寄生虫中高表达的胞内膜蛋白，在间日疟患者中是一种高免疫原性蛋白。然而，其他PvETRAMP家族蛋白尚未被研究。在这项研究中，表达并评估了PvETRAMPs，以确定它们的免疫学特性。
方法
利用生物信息学分析软件进行蛋白质结构和氨基酸序列比对。利用小麦胚细胞无细胞蛋白表达系统成功表达和纯化了6个PvETRAMP家族蛋白，并将纯化的蛋白用于蛋白质芯片和免疫小鼠。用PvETRAMP4抗血清检测该蛋白的定位。对免疫小鼠的免疫球蛋白亚类进行了鉴定。
结果
电子分析显示间日疟原虫有9个基因编码ETRAMP家族。ETRAMP家族蛋白是相对较小的分子，具有保守的结构特征。共成功表达和纯化了6个重组ETRAMP蛋白。用蛋白质芯片技术检测间日疟患者和健康人血清中间日疟原虫的阳性率。在PvETRAMP中，ETRAMP4的阳性率最高，为62%，与作为阳性对照的PvETRAMP11.2相当，在间日疟原虫中观察到典型的PvETRAMP4输出模式。对PvETRAMP4免疫小鼠的免疫球蛋白亚类的检测显示，小鼠体内有较高水平的IgG1和IgG2b。PvETRAMP家族蛋白被鉴定为血清学标志物。
结论
在免疫小鼠中观察到的对PvETRAMP4相对较高的抗体应答和特异性的Ig G亚类表明，ETRAMP家族在病原体中具有免疫原性，可作为蛋白质标志物用于疫苗开发。
Background
Malaria parasites form intracellular membranes that separate the parasite from the internal space of erythrocytes, and membrane proteins from the parasites are exported to the host via the membrane. In our previous study, Plasmodium vivax early transcribed membrane protein (PvETRAMP) 11.2, an intracellular membrane protein that is highly expressed in blood-stage parasites, was characterized as a highly immunogenic protein in P. vivax malaria patients. However, the other PvETRAMP family proteins have not yet been investigated. In this study, PvETRAMPs were expressed and evaluated to determine their immunological profiles.
Methods
The protein structure and amino acid alignment were carried out using bioinformatics analysis software. A total of six PvETRAMP family proteins were successfully expressed and purified using a wheat germ cell free protein expression system and the purified proteins were used for protein microarray and immunization of mice. The localization of the protein was determined with serum against PvETRAMP4. IgG subclasses were assessed from the immunized mice.
Results
In silico analysis showed that P. vivax exhibits nine genes encoding the ETRAMP family. The ETRAMP family proteins are relatively small molecules with conserved structural features. A total of 6 recombinant ETRAMP proteins were successfully expressed and purified. The serum positivity of P. vivax malaria patients and healthy individuals was evaluated using a protein microarray method. Among the PvETRAMPs, ETRAMP4 showed the highest positivity rate of 62%, comparable to that of PvETRAMP11.2, which served as the positive control, and a typical export pattern of PvETRAMP4 was observed in the P. vivax parasite. The assessment of IgG subclasses in mice immunized with PvETRAMP4 showed high levels of IgG1 and IgG2b. PvETRAMP family proteins were identified and characterized as serological markers.
Conclusions
The relatively high antibody responses to PvETRAMP4 as well as the specific IgG subclasses observed in immunized mice suggest that the ETRAMP family is immunogenic in pathogens and can be used as a protein marker and for vaccine development.