GENE EXPRESSION IN BRUCELLA-INFECTED MACROPHAGES

性状（由申请方提供）：布鲁氏菌是引起动物和人类布鲁氏菌病的细胞内兼性细菌。四种布鲁氏菌属对人类具有致病性，并被归类为NIAID B类优先病原体。然而，没有安全有效的布鲁氏菌疫苗可供人类使用，布鲁氏菌在宿主组织中成功细胞内复制的基本机制仍不清楚。B。melitensis，B. suis和B.流产病毒对人类的毒性最强。脂多糖（LPS）中O-侧链的存在将光滑的强毒株与粗糙的减毒或无毒毒株区分开来。布鲁氏菌O-侧链已显示诱导保护性细胞介导的免疫。光滑布鲁氏菌在宿主巨噬细胞内感染和复制，而粗糙菌株在有限的时间内感染和复制。我们建议使用高通量DNA微阵列技术来研究小鼠巨噬细胞对光滑和粗糙布鲁氏菌菌株感染的反应的时间过程中的差异和协调的基因表达。将分析布鲁氏菌O-侧链在刺激特异性巨噬细胞基因应答中的作用。通过DNA微阵列实验检测的基因表达谱将通过实时RT-PCR进行确认。拟议的研究将极大地帮助理解宿主防御强毒和减毒布鲁氏菌菌株感染的遗传基础，并可能开发治疗和预防感染的新策略。

DESCRIPTION (provided by applicant): Brucella are intracellular facultative bacteria causing brucellosis in animals and humans. Four Brucella species are pathogenic to humans and classified as NIAID category B priority pathogens. However, no safe and effective Brucella vaccine is available for human use and the basic mechanisms by which Brucella successfully replicate intracellularly in host tissues remains unclear. B. melitensis, B. suis, and B. abortus are the most virulent to humans. The presence of the O-side chain in lipopolysaccharide (LPS) distinguishes smooth virulent Brucella strains from rough attenuated or avirulent strains. Brucella O-side chain has been shown to induce protective cell mediated immunity. Smooth Brucella infect and replicate within host macrophages whereas rough strains infect and replicate for a limited time. We propose to use high throughput DNA microarray technology to study differential and coordinated gene expression in the time course of murine macrophage responses to infection with smooth and rough Brucella strains. The role of Brucella O-side chain in stimulation of specific macrophage gene responses will be analyzed. The gene expression profiles detected by DNA microarray experiments will be confirmed by real-time RT-PCR. The proposed research will greatly help in understanding the genetic basis of host defenses against infection by virulent and attenuated Brucella strains and make possible development of novel strategies to treat and prevent infections.