Comprehensive characterization of the genetic factors and the host immune response associated to protection from clinical Plasmodium vivax malaria

我们目前对遗传或免疫相关因素的了解非常有限， 保护临床间日疟原虫（Pv）疟疾。解读这种保护背后的机制 将允许为消除PV设计量身定制的干预策略。抗Pv Duffy抗体的制备 结合蛋白（DBP）结合抑制性抗体（BIabs）与功能性和保护性 对Pv疟疾免疫。只有少数人会产生这种抗体， 其生产能力是未知的。不产生BIabs的个人仍然可以免受Pv的侵害 临床疟疾表明额外的免疫和/或遗传因素可以提供保护。 利用我们在柬埔寨流行地区建立的纵向队列，我们确定了 个人表现出显着的临床保护，对Pv和本提案的总体目标的目的 在描述这些保护的因素。第一个具体目标（SA 1）是了解 驱动抗PvDBP BIabs产生的因素，从而进一步预防Pv的临床保护。 通过对自然感染的人中DBP特异性CD 4 + T细胞和B细胞进行表型和功能表征， 参与者具有特征量的BIabs，我们将更好地了解适应性免疫 导致产生天然获得性抗PvDBP BIabs的个体应答。另一方面，在一项研究中， 通过表征PvDBP等位基因多态性和由从 对于具有不同水平BIabs的个体，我们将确定寄生虫遗传因素是否也有助于 收购BIabs。第二个和第三个SA将是破译遗传（SA 2）或免疫（SA 3） 导致不产生抗PvDBP BIabs的个体免受Pv疟疾保护的因素。在SA 2中，我们 将比较从慢性感染者中分离出的寄生虫的基因表达谱和基因型， 无症状个体和有症状的寻求治疗的患者，以确定寄生虫因素 区分这两种截然不同的临床结果。我们还将测定人体红细胞 显示感染的对比临床结果的个体的蛋白质多态性以鉴定宿主 遗传因素提供保护。将在体外对鉴定出的任何宿主多态性进行功能测试， Pv入侵/发展变化。在SA 3中，我们将确定与保护相关的宿主免疫因子， 临床上的Pv疟疾使用与SA 2相同的患者队列，我们将研究离体和体外免疫应答。 PV感染患者的反应。使用抗原特异性B细胞的单细胞培养物，我们旨在鉴定 Pv裂殖子或iRBC上的新的体液靶点，其可能参与赋予对临床 疟原虫侵入阻断或替代抗体效应子功能。

We currently have a very limited understanding of the factors, either genetic or immune-related, conferring protection to clinical Plasmodium vivax (Pv) malaria. Deciphering the mechanisms underlying such protection would allow the design of tailored intervention strategies for the elimination of Pv. Production of anti-Pv Duffy Binding Protein (DBP) binding-inhibitory antibodies (BIabs) is associated to functional and protective immunity against Pv malaria. Only a minority of individuals develops such antibodies and the mechanisms enabling their production are unknown. Individuals not producing BIabs can still be protected against Pv clinical malaria indicating that additional immunological and/or genetic factors can confer protection. Leveraging a longitudinal cohort we have constituted in endemic area of Cambodia, we have identified individuals displaying remarkable clinical protection against Pv and the overall goal of this proposal aims at characterizing the factors enabling such protection. The first specific aim (SA1) will be to understand the factors that drive the production of anti-PvDBP BIabs and therefore further clinical protection against Pv. By phenotyping and functionally characterizing DBP-specific CD4+ T cells and B cells in naturally infected participants with characterized amounts of BIabs, we will have a better understanding of the adaptive immune response of individuals leading to the production of naturally-acquired anti-PvDBP BIabs. On the other hand, by characterizing the PvDBP allelic polymorphism and isoforms produced by isolates collected from individuals with various levels of BIabs, we will determine if parasite genetic factors are also contributing to the acquisition of BIabs. The second and third SA will be to decipher the genetic (SA2) or immune (SA3) factors leading to protection against Pv malaria for individuals not producing anti-PvDBP BIabs. In SA2, we will compare the gene expression profiles and genotypes of parasites isolated from chronically-infected asymptomatic individuals and from symptomatic treatment-seeking patients to identify parasite factors differentiating these two drastically different clinical outcomes. We will also determine the human erythrocyte proteins’ polymorphism of individuals displaying contrasted clinical outcome of infection to identify host genetic factors conferring protection. Any host polymorphism identified will be functionally tested in vitro for Pv invasion/development alterations. In SA3, we will identify host immune factors associated to protection from clinical Pv malaria. Using the same patient cohort as SA2, we will study ex vivo and in vitro the immune responses in Pv-infected patients. Using single cell cultures of antigen-specific B cells, we aim to identify novel humoral targets on the Pv merozoite or iRBC that could be involved in conferring protection from clinical Pv malaria trough blockade of invasion or alternative antibody effector functions.