Lyme Disease Diagnosis with Host Gene Expression Arrays

描述（由申请人提供）：莱姆病是美国最流行的媒介传播疾病，由螺旋体伯氏疏螺旋体感染引起。早期感染期间的抗生素治疗通常是有效的。如果不治疗，该疾病可能会发展为更慢性的神经系统和风湿病表现，因此，莱姆病的有效治疗取决于早期诊断。目前，诊断基于临床发现和血清学检测。最常用的血清学检测在疾病早期缺乏敏感性、缺乏标准化、实验室内和实验室间差异以及高假阳性率。因此，患者经常接受多次检测，过度检测和过度诊断（或误诊）的倾向很大。该项目的长期目标是开发一种新的诊断方法，该方法基于接触伯氏疏螺旋体引起的宿主基因表达的变化。宿主全局基因表达反映了宿主对特定病原体的反应，可能有可能提供这种感染的证据。我们假设伯氏疏螺旋体感染会诱导宿主基因表达的改变。通过差异基因表达分析，我们建议鉴定其表达因伯氏疏螺旋体感染而改变的宿主基因。然后可以将该基因集用作临床标本中伯氏疏螺旋体感染的指示剂。提出以下具体目标： 1) 将在小鼠模型中评估伯氏疏螺旋体感染时宿主基因表达的变化。小鼠将被伯氏疏螺旋体感染，并通过微阵列分析测量对照动物和感染动物之间 mRNA 表达的差异； 2) 从健康捐献者分离的外周血单核细胞（PBMC）将暴露于伯氏疏螺旋体或其他潜在的血源性病原体，并通过微阵列分析监测整体基因表达的差异； 3)通过微阵列分析鉴定从莱姆病患者分离的PBMC中差异表达的基因。这些研究将包括患有急性非播散性早期疾病、早期播散性感染和莱姆关节炎的患者。这里提出的研究应该能够鉴定出宿主中那些在伯氏疏螺旋体感染期间表达发生改变的基因。这些信息反过来可用于设计基于宿主基因的莱姆病诊断方法，以检测活动性伯氏疏螺旋体感染。

DESCRIPTION (provided by applicant): Lyme disease, the most prevalent vector-borne disease in the United States, is caused by infection with the spirochete, Borrelia burgdorferi. Antibiotic treatment during early infection is generally curative. Untreated, the disease can progress to more chronic neurologic and rheumatologic manifestations and therefore, effective management of Lyme disease is dependent on early diagnosis. Currently, diagnosis is based on both clinical findings and serologic testing. The most commonly employed serologic assays suffer from lack of sensitivity during early disease, lack of standardization, intra- and inter-laboratory variation and a high false-positivity rate. As a result, patients are often tested multiple times and the tendency for overtesting and overdiagnosis (or misdiagnosis) is great. A long-term goal of this project is development of a novel diagnostic approach based on alterations in host gene expression induced by exposure to B. burgdorferi. Host global gene expression, reflecting responses of the host to a specific pathogen, may have the potential to provide evidence of such an infection. We hypothesize that B. burgdorferi infection induces modifications in host gene expression. Using differential gene expression analysis, we propose to identify host genes whose expression is altered by B. burgdorferi infection. This gene set can then be employed as an indicator for B. burgdorferi infection in clinical specimens. The following specific aims are proposed: 1) Variation in host gene expression on infection with B. burgdorferi will be assessed in a murine model. Mice will be infected B. burgdorferi and differences in mRNA expression between control and infected animals will be measured by microarray analysis; 2) Peripheral blood mononuclear cells (PBMCs) isolated from healthy donors will be exposed to B. burgdorferi or other potential blood-borne pathogens and differences in global gene expression will be monitored by microarray analysis; 3) Genes differentially expressed in PBMCs isolated from Lyme disease patients will be identified by microarray analysis. These studies will include patients with acute, non-disseminated early disease, early disseminated infection and Lyme arthritis. The studies proposed here should result in identification of those genes in the host whose expression is modified during B. burgdorferi infection. This information, in turn, can be used to design host gene-based Lyme disease diagnostics for the detection of active B. burgdorferi infection.