SMALLPOX VIRULENCE AND COMPLEMENT REGULATORY PROTEINS

天花毒力和补体调节蛋白

• 批准号: 7641538
• 负责人: John Atkinson
• 金额: $ 38.97万
• 依托单位: WASHINGTON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-03-01 至 2009-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7641538
• 关键词: Active Sites; American; Amino Acids; Binding; Binding Sites; Biological Assay; CD46 Antigen; CD55 Antigens; Catalytic Domain; Cells; Complement; Complement 3b; Complement 3d Receptors; Complement 4b; Complement Activation; Complement Factor H; Complement Inactivators; Complement Receptor; Data; Data Set; Ectromelia; Eczema; Enzymes; Excision; Family; Gene Deletion; Goals; Grant; Heparin Binding; Homologous Protein; Human; Human Activities; Immune; Immune response; Immunity; Immunologic Deficiency Syndromes; Individual; Infection; Infectious Ectromelia; Label; Laboratories; Maize; Membrane; Membrane Proteins; Modeling; Mouse Pox Virus; Mouse Protein; Mouse Strains; Mus; Mutagenesis; Mutate; Mutation; Pathogenesis; Plasma Proteins; Positioning Attribute; Poxviridae; Poxviridae Infections; Proteins; Public Health; Publishing; Regulation; Relative (related person); Resistance; Role; Russia; Site; Smallpox; Smallpox Vaccine; Structure; Surface; System; Transmembrane Domain; United States; Vaccines; Vaccinia; Vaccinia virus complement-control protein; Viral; Viral Proteins; Virulence; Virulence Factors; Virus; Zea mays; analog; base; cofactor; complement 4b-binding protein; experience; functional mimics; genetic regulatory protein; genome sequencing; human disease; in vivo; inhibitor/antagonist; man; member; microorganism; novel; receptor; research study; toe corn

Public health concems have emerged regarding use of smallpox as a bioterrorist weapon since most Americans are no longer immune. Poxviruses subvert the complement system via the expression of regulatory proteins. In variola, vaccinia and ectromelia, the proteins are called SPICE (for smallpox inhibitor of complement enzymes), VCP (vaccinia virus complement control protein) and EMICE (an uncharactedzed analog in ectromelia that we have labeled "ectromelia inhibitor of complement enzymes"). These secreted virulence factors down-regulate complement activation by mimicking the functional repertoire of a family of host proteins called the Regulators of Complement Activation (RCA). The viral proteins are also structurally related to their host counterparts. Specific Aims: 1. To characterize the complement inhibitory profile of SPICE compared to its human counterparts. We will identify the principal complement-evading activity of SPICE and this will become a target for neutralization. These assessments will take place with the native soluble protein as well as after it attaches to cells via either its heparin-binding site(s) or by addition of an anchor. 2. To determine the complement regulatory sites of SPICE. These experiments will take advantage of the functional profiles (defined in Aim 1) and the sequences of active sites of RCA proteins that are homologous to corresponding regions of SPICE, VCP, and EMICE. These two sets of data provide a logical strategy for a mutational analysis to locate the active sites. 3. To characterize the complement regulatory activity of EMICE. This mousepox protein has not been evaluated for its complement inhibitory (virulence) activity. It is about 90% identical to SPICE and VCP. We will first characterize its regulatory activity for human and mouse complement. Second, we will assess its role in vivo as a virulence factor by infecting sensitive and resistant mouse strains with the ectromelia virus deleted of its complement regulator. The proposed experiments should provide novel information relative to the pathogenesis of poxvirus infections of man and mouse. Additionally, these results will serve as a guide to produce a less toxic small pox vaccine and to identify a viral target for mAb treatment of variola infection.

由于大多数 美国人不再免疫。痘病毒通过表达来颠覆补体系统 调节蛋白。在Variola，Vaccinia和Ectromelia中，蛋白质称为香料（对于天花抑制剂 补体酶），VCP（Vaccinia病毒补体对照蛋白）和EMITE（未塑性 在胚胎中，我们标记了“补体酶的抑制剂”）。这些分泌 毒力因子通过模仿一个家族的功能库来下调补体激活 宿主蛋白称为补体激活调节剂（RCA）。病毒蛋白在结构上也是 与他们的主机同行有关。具体目的：1。表征补体的抑制作用 与人类对应物相比，香料。我们将确定主要的补体撤回活动 香料，这将成为中和的目标。这些评估将与当地人进行 可溶性蛋白以及之后，它通过其肝素结合位点附着在细胞上或通过添加 锚。 2。确定香料的补体调节位置。这些实验将利用 功能轮廓（在AIM 1中定义）和RCA蛋白的活性位点的序列是 与香料，VCP和Emice的相应区域同源。这两组数据提供了逻辑 突变分析的策略来定位活动位点。 3。表征补体调节 Emice的活性。该菌蛋白的补体抑制（毒力）尚未评估 活动。它与香料和VCP相同约90％。我们首先将其调节活动描述 人和老鼠的补充。其次，我们将通过感染来评估其在体内的作用作为毒力因子 敏感和抗性小鼠菌株具有其补体调节剂缺失的胚胎病毒。这 提出的实验应提供与痘病毒感染的发病机理的新信息 男人和鼠标。此外，这些结果将作为产生毒性较小的小痘疫苗的指南 并确定用于MAB治疗Variola感染的病毒靶标。