Malaria parasite determinants of host cell tropism

项目总结 疟疾仍然是人类的一大祸害，由人感染红细胞引起。 原生动物疟原虫。寄生虫。恶性疟原虫在我国可获得较高的寄生量 导致严重发病和死亡的血液循环。血液期寄生虫对红细胞有严格的细胞嗜性， 与红细胞中的许多分子决定因素相互作用，进行生产性感染和传播。 允许寄生虫在不同类型的红细胞中繁殖和持续存在的寄生虫多态是一种主要的 对疟疾控制和消除的挑战。这包括入侵的裂殖子形式使用 红细胞上的不同受体，称为侵袭途径。我们将利用前向遗传学的力量 确定调节恶性疟原虫细胞嗜性的两个关键特征的分子决定因素：红细胞年龄 和RBC的物种偏好。我们发现不同的恶性疟原虫株在这些方面存在显著差异。 偏好，并假设这种变异背后的寄生虫多态对 恶性疟原虫在人群中的出现和持续，是致病的关键决定因素 和变速箱。我们将使用一种正向遗传学方法来识别多态和相关基因。 与RBC年龄和物种偏好有关的遗传后代的特异体分段分析(BSA) 具有不同入侵偏好的恶性疟原虫亲本杂交。反向遗传学方法将是 用于候选基因中自然发生的多态的功能分析，既有单个的也有 组合。这些研究将提供一个全面的分子基础的理解 恶性疟原虫的细胞嗜性，主要集中在红细胞年龄和物种偏好上。从长远来看，我们 希望我们的研究将阐明持续、致病性和 恶性疟原虫在寄生虫人群中的传播，为公共卫生干预和疫苗提供信息 发展。

PROJECT SUMMARY Malaria continues to be a major scourge of humanity, and is caused by infection of red blood cells (RBCs) by the protozoan Plasmodium spp. parasites. Plasmodium falciparum can achieve high parasite biomasses in the circulation causing severe morbidity and mortality. Blood-stage parasites have a strict cellular tropism for RBCs, interacting with numerous molecular determinants in the RBCs for productive infection and transmission. Parasite polymorphisms that allow parasites to propagate and persist in different types of RBCs present a major challenge to malaria control and elimination. This includes the ability of the invasive merozoite forms to use different receptors on RBCs, known as invasion pathways. We will leverage the power of forward genetics to identify the molecular determinants mediating two key features of the cellular tropism of P. falciparum: RBC age and RBC species preference. We have found that different P. falciparum strains vary significantly in these preferences, and hypothesize that the parasite polymorphisms underlying this variation are critical to the emergence and persistence of P. falciparum in human populations, and are key determinants of pathogenesis and transmission. We will employ a forward genetics approach to identify polymorphisms and genes associated with RBC age and species preference, specifically Bulk Segregant Analysis (BSA) of progeny from genetic crosses of P. falciparum parental lines with varying invasion preferences. Reverse genetics approaches will be used for the functional analysis of naturally occurring polymorphisms in candidate genes, both singly and in combination. Together these studies will provide a comprehensive understanding of the molecular basis of cellular tropism in P. falciparum parasites, focused on RBC age and species preference. In the long-term we hope that our studies will elucidate the critical interactions required for the persistence, pathogenicity and transmission of P. falciparum in parasite populations, to inform public health interventions and inform vaccine development.