Cellular GWAS of the host-pathogen interaction in melioidosis

类鼻疽病是一种热带传染病，由接种、吸入或摄入革兰氏阴性土壤引起。 腐植菌和Tier 1选择了假鼻疽伯克霍尔德氏菌。疾病通常是严重的，治疗是 由于其广泛的抗菌素耐药性，难以根除病原体。肺炎和 菌血症是常见的临床表现，常导致败血症和多器官衰竭。整体而言 类鼻疽死亡率在东南亚为40%，在澳大利亚北部为20%。没有疫苗可用，而且 减少环境中接触这种细菌的努力一直具有挑战性。虽然分布在 B.假鼻疽在环境中还没有完全确定，最近的模拟工作表明，它可能是 广泛存在，每年有165,000例人类类鼻炎病例和89,000例死亡 全世界。研究表明，全血天然免疫存在明显的个体间差异。 体外对细菌配体的反应。在个体间也存在显著差异。 假腮腺进入原代人类细胞，如肺泡巨噬细胞和单核细胞并进行复制。 值得注意的是，据报道，观察到的表型的遗传率-或比例解释为 遗传因素--沙门氏菌侵袭细胞超过50%。总而言之，这表明自然地 在体外发生的表型变异可以被用来识别调节寄主防御的基因的变异 抗入侵细菌，如假鼻疽杆菌。EB病毒转化的淋巴母细胞系(LCLS) 从HapMap/100基因组计划中广泛的基因分型和测序的个体是一个有用的工具 用于疾病相关性状的遗传调节的体外筛选。在体外表型可以合并为 易于获得和无与伦比的基因组结构数据来进行细胞基因组全关联研究 (Gwas)高效和廉价。感染假腮腺炎的LCL表现出不同的侵袭性和 复制动力学。这可能反映了宿主对感染反应的显著遗传性，并表明 基于LCL的细胞GWAs可以有效地用于研究类鼻疽病中宿主防御的调节因子。 了解假鼻疽杆菌在细胞内成功入侵和复制的宿主决定因素 对于制定预防感染这种足智多谋的病原体的战略至关重要。这是一个假设 项目是新的宿主基因变异在类鼻疽中调节宿主细胞入侵的动态，并且 这些遗传调节因子可以通过对细胞内LCL表型进行定量检测来识别。这个 本项目的目的是1)确定假鼻疽杆菌入侵和存活的遗传决定因素。 淋巴母细胞系和2)证实观察到的人类原代淋巴细胞和 单核细胞。这一探索性项目提供了令人兴奋的潜力，开辟了了解宿主的新途径 类鼻疽的防御。这些新知识对于应对日益严重的全球公共卫生威胁至关重要。

Melioidosis is a tropical infection caused by inoculation, inhalation, or ingestion of the Gram-negative soil saprophyte and Tier 1 select agent Burkholderia pseudomallei. Disease is often severe and treatment is hampered by difficulty eradicating the pathogen due to its extensive antimicrobial resistance. Pneumonia and bacteremia are common presentations and often result in sepsis and multi-organ failure. The overall melioidosis mortality rate is 40% in southeast Asia and 20% in northern Australia. No vaccine is available and efforts to reduce environmental exposure to the bacterium have been challenging. Although the distribution of B. pseudomallei in the environment is not fully determined, recent modeling work suggests that it may be widespread and that an extraordinary 165,000 cases of human melioidosis and 89,000 deaths occur annually worldwide. Studies show that there is marked inter-individual variation in the whole blood innate immune response to bacterial ligands in vitro. There is also significant inter-individual variation in the ability of B. pseudomallei to enter and replicate in primary human cells such as alveolar macrophages and monocytes. Remarkably, it has been reported that the heritability – or proportion of the observed phenotype explained by genetic factors – of Salmonella invasion of cells exceeds 50%. Combined, this suggests that naturally occurring phenotypic variation in vitro can be exploited to identify variants in genes that regulate host defense against invading bacteria such as B. pseudomallei. EBV-transformed lymphoblastoid cell lines (LCLs) derived from extensively genotyped and sequenced individuals in the HapMap/100 Genomes Projects are a useful tool for in vitro screening of genetic regulators of disease-related traits. In vitro phenotypes can be merged with readily available and unparalleled genomic structure data to perform cellular genome wide association studies (GWAS) efficiently and cheaply. LCLs infected with B. pseudomallei demonstrate differential invasion and replication dynamics. This likely reflects significant heritability in the host response to infection, and indicates that LCL-based cellular GWAS can be effectively used to study modulators of host defense in melioidosis. Understanding the host determinants of successful B. pseudomallei invasion and replication within cells is crucial to developing strategies to prevent infection with this resourceful pathogen. The hypothesis of this project is that novel host genetic variation modulates the dynamics of host cell invasion in melioidosis and that these genetic modulators can be identified by performing cellular GWAS of quantitative LCL phenotypes. The aims of this project are to 1) identify genetic determinants of B. pseudomallei invasion and survival in lymphoblastoid cell lines and 2) validate observed genetic associations in primary human lymphocytes and monocytes. This exploratory project offers exciting potential to open up new avenues of knowledge about host defense in melioidosis. Such new knowledge is essential to tackle this increasingly global public health threat.