3Rs of murine models of malaria infection: immunology meets experimental genetics

疟疾是一种蚊虫肆虐的传染病，由疟原虫引起。根据世界卫生组织最近的估计，疟疾在全球范围内造成2.5亿临床疾病病例和600-120万人死亡，特别是在非洲和其他发展中国家。因此，疟疾仍然是全球卫生优先事项，研究工作的目标是开发更有效的疫苗和治疗方法。为了实现这一目标，小鼠模型在了解免疫系统及其如何应对疟疾并提供对未来感染的保护方面至关重要。同样，小鼠模型对于确定潜在的干预目标至关重要。最近，我们确定了潜在保护性疟疾特异性免疫白细胞的新蛋白质靶点。这一发现现在使我们能够解决基本的寄生虫学和免疫学问题：这些蛋白质在疟疾寄生虫的生命周期中具有什么功能？它们对宿主的成功感染是必不可少的吗？对这些蛋白质的免疫反应是否有助于个体抵御感染的能力？这些蛋白质是如何呈现给免疫细胞的？是什么使疟疾特有的蛋白质能够被免疫系统有效地识别？对这些和类似问题的回答可以提高我们对所涉及的免疫过程的理解，重要的是，有助于设计新一代疟疾疫苗和治疗剂。我们将通过产生一系列含有某些突变或特征的改良疟疾寄生虫来开始回答这些问题，从而使我们能够表征这些蛋白质靶标或抗原的分子和免疫学特性。在这样做的过程中，我们将结合和应用支持3RS框架的工具，即“以人道的方式使用动物进行科学实验”。目前，标准方案要求在疟疾研究中使用大量动物来获得有意义的数据。在这个项目中，我们将把最近在产生修饰寄生虫方面的进展整合到一个单一的新策略中。我们的目标是大幅减少产生这些寄生虫所需的动物数量(减少)，允许在选择寄生虫期间非侵入性地给药，并使用生物发光寄生虫实时对完整动物体内的寄生虫发展进行非侵入性检测(改进)。此外，使用我们通过优化策略产生的寄生虫，我们的目标是开发体外分析，以了解免疫细胞和蛋白质靶标(替换)之间的相互作用。这项研究的工具和结果将为疟疾寄生虫的基本生物学研究和疫苗开发提供信息，同时在传染病研究的背景下促进3Rs框架。

Malaria is a mosquito-bourne, infectious disease that is caused by Plasmodium parasites. According the the World Health Organization's recent estimates, malaria accounts for 250 million cases of clinical disease and 0.6-1.2 million deaths worldwide, particularly in Africa and other developing nations. As such, malaria remains a global health priority, and research efforts have been aimed at developing more effective vaccines and treatments. Toward this goal, mouse models have been essential in the drive to understand the immune system and how it responds to malaria and confers protection against future infection. Similarly, mouse models are vital to identify potential targets of intervention. Recently, we identified novel protein targets of potentially protective malaria-specific immune white blood cells. This finding now enables us to address fundamental parasitological and immunological questions: What are the functions of these proteins in the life cycle of the malaria parasite? Are they essential for the successful infection of the host? Do immune responses to these proteins contribute to the ability of an individual to be protected against infection? How are these proteins presented to immune cells? What allows a malaria-specific protein to be efficiently recognised by the immune system? The answer to these and similar questions can improve our understanding of the immune processes involved, and importantly, inform the design of new generation vaccines and therapeutic agents for malaria. We will begin to answer these questions by generating a series of modified malaria parasites that harbour certain mutations or features, thereby allowing us to characterise the molecular and immunological properties of these protein targets or antigens. In doing so, we will combine and apply tools that support the 3Rs framework of "conducting scientific experiments using animals humanely." Currently, standard protocols require that large numbers of animals are employed to obtain meaningful data in malaria research. In this project, we will integrate recent advances in the generation of modified parasites into a single novel strategy. Our objective is to drastically reduce the number of animals required to generate these parasites (Reduction), to allow the non-invasive administration of drugs during the selection of parasites and to perform non-invasive detection of parasite development within intact animals in real time using bioluminescent parasites (Refinement). In addition, using the parasites that we have generated with our optimized strategy, we aim to develop in vitro assays to understand the interactions between the immune cells and the protein targets (Replacement). The tools and findings of this research will inform research both into the basic biology of malaria parasites and vaccine development whilst promoting the 3Rs framework in the context of infectious disease research.