From the ‡Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Im Neuenheimer Feld 324, D 69120 Heidelberg, Germany;; §German Center for Infectious Disease Research, Heidelberg (DZIF);; ¶HEiKA - Heidelberg Karlsruhe Research Partnership, Heidelberg University, Karlsruhe Institute of Technology (KIT), Germany;.
From the ‡Center for Infectious Diseases, Parasitology Unit, Heidelberg University Hospital, Im Neuenheimer Feld 324, D 69120 Heidelberg, Germany;; §German Center for Infectious Disease Research, Heidelberg (DZIF).
Mol Cell Proteomics. 2019 Apr;18(4):642-656. doi: 10.1074/mcp.RA118.000992. Epub 2019 Jan 10.
High-density peptide arrays are an excellent means to profile anti-plasmodial antibody responses. Different protein intrinsic epitopes can be distinguished, and additional insights are gained, when compared with assays involving the full-length protein. Distinct reactivities to specific epitopes within one protein may explain differences in published results, regarding immunity or susceptibility to malaria. We pursued three approaches to find specific epitopes within important plasmodial proteins, (1) twelve leading vaccine candidates were mapped as overlapping 15-mer peptides, (2) a bioinformatical approach served to predict immunogenic malaria epitopes which were subsequently validated in the assay, and (3) randomly selected peptides from the malaria proteome were screened as a control. Several peptide array replicas were prepared, employing particle-based laser printing, and were used to screen 27 serum samples from a malaria-endemic area in Burkina Faso, West Africa. The immunological status of the individuals was classified as "protected" or "unprotected" based on clinical symptoms, parasite density, and age. The vaccine candidate screening approach resulted in significant hits in all twelve proteins and allowed us (1) to verify many known immunogenic structures, (2) to map B-cell epitopes across the entire sequence of each antigen and (3) to uncover novel immunogenic epitopes. Predicting immunogenic regions in the proteome of the human malaria parasite , via the bioinformatics approach and subsequent array screening, confirmed known immunogenic sequences, such as in the leading malaria vaccine candidate CSP and discovered immunogenic epitopes derived from hypothetical or unknown proteins.
高密度肽阵列是分析抗疟抗体反应的极好方法。与涉及全长蛋白质的测定相比，可以区分不同的蛋白质固有表位，并获得更多的见解。在一种蛋白质内对特定表位的不同反应性可能解释了有关疟疾免疫或易感性的已发表结果的差异。我们采用了三种方法来寻找重要疟原虫蛋白中的特定表位，（1）将 12 种主要候选疫苗作为重叠的 15 肽进行映射，（2）生物信息学方法用于预测免疫原性疟原虫表位，随后在测定中进行验证，（3）随机选择来自疟原虫蛋白质组的肽作为对照进行筛选。使用基于粒子的激光打印制备了多个肽阵列副本，并用于筛选来自西非布基纳法索疟疾流行地区的 27 份血清样本。根据临床症状、寄生虫密度和年龄，将个体的免疫状况分类为“受保护”或“不受保护”。疫苗候选物筛选方法在所有 12 种蛋白质中均产生了显著的命中，使我们能够（1）验证许多已知的免疫原性结构，（2）在每个抗原的整个序列上绘制 B 细胞表位，（3）发现新的免疫原性表位。通过生物信息学方法预测人类疟原虫蛋白质组中的免疫原性区域，并随后进行阵列筛选，证实了已知的免疫原性序列，例如在领先的疟疾候选疫苗 CSP 中，并发现了源自假设或未知蛋白质的免疫原性表位。
