Molec Analys Of Neutrophil Activation By Chemoattractant

该项目的目的是确定血液白细胞迁移到炎症或感染的特定组织部位的分子机制。我们关注的是介导这一过程的化学引诱蛋白，并已经确定了部署在白细胞细胞表面的化学引诱受体大家族的成员。我们还发现了由病毒（包括疱疹病毒、痘病毒和艾滋病毒）制造的多种化学引诱剂和化学引诱剂受体模拟物的成员。我们使用基因组学、分子生物学、细胞生物学和流行病学，并与病毒学家合作，作为分析这些分子的主要方法。前几年解决并在2004财政年度继续解决的一个主要问题是确定个别化学引诱剂和化学引诱剂受体与特定疾病的关联，以便确定潜在的新治疗靶点。在这方面，我们研究了SARS-CoV病毒肺部感染的小鼠模型，其中病毒定位于一些支气管和细支气管，而不是肺泡，并短暂复制到高滴度。病毒复制在肺中诱导强烈但短暂的炎性趋化因子亚群的产生，没有太多的白细胞积累。病毒从呼吸道扩散到其他多个器官，尤其是大脑，但在这些器官中，几乎没有炎症，除了轻微的相对失败之外，没有明显的临床疾病。这项工作的意义在于，它提供了一种亚临床SARS-CoV感染的小鼠模型，确定了其他因素在增强体内趋化因子白细胞迁移活性中的作用，并提示在该模型中特异性炎症趋化因子在SARS-CoV清除中的潜在作用。在该项目发表的一项不相关的发现中，我们报道了类人猿巨细胞病毒有五个编码不同趋化因子受体同源物的orf。这表明该病毒基因组中有惊人的3%专门用于这些类型的分子，这表明分子盗版/模仿在其生命周期中起着重要作用。迄今为止，我们已经确定了这些orf的进化史，并能够在哺乳动物细胞表面以蛋白质的形式表达它们，但我们还没有确定假定的配体和功能。

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.