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。早期感染的抗生素治疗通常是可以治愈的。未经治疗，该病可发展为更慢性的神经系统和风湿病表现，因此，莱姆病的有效管理依赖于早期诊断。目前，诊断是基于临床表现和血清学检测。最常用的血清学检测在疾病早期缺乏敏感性，缺乏标准化，实验室内部和实验室之间存在差异，假阳性率高。因此，患者往往要接受多次检查，过度检查和过度诊断（或误诊）的趋势很大。该项目的长期目标是开发一种基于暴露于伯氏疏螺旋体诱导的宿主基因表达改变的新型诊断方法。宿主的全局基因表达，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诱导宿主基因表达的改变。通过差异基因表达分析，我们提出鉴定受伯氏疏螺旋体感染后表达改变的宿主基因。该基因集可作为临床标本中伯氏疏螺旋体感染的指标。提出以下具体目标：1)在小鼠模型中评估宿主基因表达对伯氏疏螺旋体感染的影响。将感染伯氏疏螺旋体的小鼠，通过微阵列分析测量对照组和感染动物之间mRNA表达的差异；2)将从健康供体中分离的外周血单个核细胞（PBMCs）暴露于伯氏疏螺旋体或其他潜在的血源性病原体中，并通过微阵列分析监测其整体基因表达的差异；3)莱姆病患者PBMCs中差异表达的基因将通过微阵列分析进行鉴定。这些研究将包括急性、非播散性早期疾病、早期播散性感染和莱姆病关节炎患者。本文提出的研究结果应该是鉴定宿主中在伯氏疏螺旋体感染期间表达被修饰的基因。反过来，这些信息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.