Molec Analys Of Neutrophil Activation By Chemoattractant

该项目的目的是确定血液白细胞迁移到发炎或感染的特定组织部位的分子机制。我们已经集中在介导这一过程的趋化蛋白，并确定了一个大家族的趋化受体，部署在白细胞表面的成员。我们还鉴定了由病毒（包括疱疹病毒、痘病毒和HIV）产生的不同化学引诱物和化学引诱物受体模拟物。我们使用基因组学，分子生物学，细胞生物学和流行病学，以及与病毒学家的合作，作为分析这些分子的主要方法。前几年提出并在2004财政年度继续提出的一个主要问题是确定单个趋化因子和趋化因子受体的特定疾病相关性，以确定潜在的新治疗靶点。在这方面，我们已经研究了SARS冠状病毒肺部感染的小鼠模型，其中病毒定位于一些邦奇和细支气管，但不是肺泡，并短暂复制到高滴度。病毒复制诱导肺中炎性趋化因子子集的强烈但短暂的产生，而没有大量白细胞积聚。该病毒传播到呼吸道以外的多个其他器官，特别是大脑，但在这些器官中几乎没有炎症，除了一个微妙的相对失败之外，没有明显的临床疾病。这项工作的意义在于，它提供了一个亚临床SARS冠状病毒感染的小鼠模型，确定了其他因素在体内增强趋化因子的白细胞迁移活性的作用，并提出了在这个模型中特定的炎症趋化因子在SARS冠状病毒清除中的潜在作用。在一个无关的发现来自这个项目，我们已经报道，猴巨细胞病毒有五个ORF编码不同的趋化因子受体同源物。这代表了该病毒基因组的惊人3%，致力于这些类型的分子，并表明分子盗版/模仿在其生命周期中的重要作用。到目前为止，我们已经确定了这些ORF的进化历史，并已能够将其表达为哺乳动物细胞表面的蛋白质，但我们尚未确定推定的配体和功能。

The aim of this project is to define the molecular mechanisms by which blood leukocytes migrate to specific tissue sites that are inflamed or infected. We have focused on chemoattractant proteins that mediate this process and have identified members of a large family of chemoattractant receptors that are deployed on the leukocyte cell surface. We have also identified members of a diverse group of chemoattractant and chemoattractant receptor mimics made by viruses, including herpesviruses, poxviruses and HIV. We use genomics, molecular biology, cell biology and epidemiology, and collaborations with virologists, as the principle methods for analyzing these molecules. A major question addressed in previous years and continued in FY2004 is to identify specific disease associations of individual chemoattractant and chemoattractant receptors, in order to identify potential new therapeutic targets. In this regard, we have studied a mouse model of SARS-CoV virus pulmonary infection in which the virus localizes to some bonchi and bronchioles, but not alveoli, and replicates transiently to high titers. Viral replication induces intense but transient production of a subset of inflammatory chemokines in the lung, without much leukocyte accumulation. The virus spreads beyond the respiratory tract to multiple other organs, particularly the brain, but again in these organs there is little inflammation, and no obvious clinical disease save a subtle relative failure to thrive. The significance of this work is that it provides a mouse model of subclinical SARS-CoV infection, identifies a role for other factors in potentiating the leukocyte migration activity of chemokines in vivo, and suggests a potential role for specific inflammatory chemokines in SARS-CoV clearance in this model. In an unrelated published finding coming from this project, we have reported that simian cytomegalovirus has five ORFs that encode distinct chemokine receptor homologues. This represents an astounding 3% of the genome of this virus that is devoted to these types of molecules and suggests an important role for molecular piracy/mimicry in its life cycle. To date we have defined the evolutionary history of these ORFs and have been able to express them as proteins on the surface of mammalian cells, but we have not yet defined putative ligands and functions.