Longley Rhea J, Bauza Karolis, Ewer Katie J, Hill Adrian V S, Spencer Alexandra J
The Jenner Institute, University of Oxford, Oxford, United Kingdom.
PLoS One. 2015 Mar 30;10(3):e0119880. doi: 10.1371/journal.pone.0119880. eCollection 2015.
The development of an efficacious vaccine against the Plasmodium parasite remains a top priority. Previous research has demonstrated the ability of a prime-boost virally vectored sub-unit vaccination regimen, delivering the liver-stage expressed malaria antigen TRAP, to produce high levels of antigen-specific T cells. The liver-stage of malaria is the main target of T cell-mediated immunity, yet a major challenge in assessing new T cell inducing vaccines has been the lack of a suitable pre-clinical assay. We have developed a flow-cytometry based in vitro T cell killing assay using a mouse hepatoma cell line, Hepa1-6, and Plasmodium berghei GFP expressing sporozoites. Using this assay, P. berghei TRAP-specific CD8+ T cell enriched splenocytes were shown to inhibit liver-stage parasites in an effector-to-target ratio dependent manner. Further development of this assay using human hepatocytes and P. falciparum would provide a new method to pre-clinically screen vaccine candidates and to elucidate mechanisms of protection in vitro.
开发一种有效的抗疟原虫疫苗仍然是首要任务。先前的研究表明，一种初免-加强病毒载体亚单位疫苗接种方案能够产生高水平的抗原特异性T细胞，该方案可递送在肝脏阶段表达的疟疾抗原TRAP。疟疾的肝脏阶段是T细胞介导免疫的主要靶点，但评估新型T细胞诱导疫苗的一个主要挑战是缺乏合适的临床前检测方法。我们利用小鼠肝癌细胞系Hepa1-6和表达绿色荧光蛋白的伯氏疟原虫子孢子，开发了一种基于流式细胞术的体外T细胞杀伤检测方法。利用该检测方法，已证明富含伯氏疟原虫TRAP特异性CD8+ T细胞的脾细胞能够以效应细胞与靶细胞比例依赖性方式抑制肝脏阶段的寄生虫。使用人肝细胞和恶性疟原虫进一步开发该检测方法，将为临床前筛选候选疫苗和阐明体外保护机制提供一种新方法。
