MODULATION OF IL-5 MEDIATED INFLAMMATION

描述(改编自《调查者摘要》)：白介素5 (IL-5)是螺旋束家族短链亚家族的成员 细胞因子。IL-5通过异二聚体受体传递信号， IL-5R-α/IL-5R-β，诱导多个 白细胞。从生理上讲，IL-5有助于宿主防御寄生虫和 肿瘤虽然其调节失调与哮喘和过敏有关 疾病。因此，IL-5及其受体是明显的调控靶点。 这样的炎症反应。这个应用程序的目标是理解 IL-5与其受体亚基之间的分子相互作用。冲向 为此，我们成功地模拟并表达了第一个IL-5单体 具有生物活性(标记为mon5)，从而表明所有 IL-5功能所需的结构特征包含在 单螺旋束。此外，一组抗IL-5中和单抗， COS-7表达种间IL-5嵌合体，分子模拟已被 用于定位5个中和表位和物种特异性 IL-5在两个区域内的残留量。具体目标提出如下：1) 测试我们的假设，即Mon5可以作为研究的范例 天然IL-5的同源二聚化是生物学上有利的还是 保护一个基本功能基序的新生物机制 在螺旋束中的细胞因子家族中；和2)定义精确的 IL-5及其受体结合的结构要求。我会瞄准的 确定同源二聚体IL-5构型是否赋予功能性 在受体结合方面优于单体螺旋束。天然IL-5 和Monone 5将研究受体配体结合的差异 运动学。此外，单体细胞因子的环3缺失突变体 将产生GM-CSF并对其进行分析以预测AN的形成 具有增强生物活性的交叉型同源二聚体。AIM II将 检验假设：位于环3和环3交界处的残基 IL-5的D螺旋与IL-5R-α链结合。预测的残留物将是 通过定义IL-5的确认表位和生物活性进行评估 通过定点突变产生的突变体。AIM III将测试 假设接近环2的残基和螺旋A的中间 IL-5参与IL-5R-β链，利用 COS-7表达IL-5。IL-5信号转导的结构/功能分析 应该能够开发出能够拮抗IL-5的类似物 IL-5介导的炎症反应。

DESCRIPTION (Adapted from the Investigator's abstract): lnterleukin-5 (IL-5) is a member of the short chain subfamily of the helical bundle family of cytokines. IL-5 signals through a heterodimeric receptor, IL-5R-alpha/IL-5R-beta, inducing pleotrophic effects on a number of leukocytes. Physiologically IL-5 aids in host defense against parasites and tumors while its dysregulation has been associated with asthma and allergic disease. Thus, IL-5 and its receptor are obvious targets for modulation of such inflammatory responses. The goal of this application is to understand the molecular interactions between IL-5 and its receptor subunits. Toward this goal, we have successfully modeled and expressed the first IL-5 monomer with biologic activity (designated mono5), thereby demonstrating that all the structural features necessary for IL-5 function are contained within a single helical bundle. In addition, a panel of anti-IL-5 neutralizing mAb, COS-7 expressed interspecies IL-5 chimeras, and molecular modeling have been used to localize five neutralizing epitopes and the species specificity residues of IL-5 within two domains. The specific aims are proposed to: 1) test our hypothesis that mono5 serves as a paradigm for investigating whether homodimerization of native IL-5 is biologically advantageous or is a novel biologic mechanism for conservation of an essential functional motif within the helical bundle family of cytokines; and 2) define the precise structural requirements for engagement of IL-5 and its receptor. Aim I will determine whether a homodimeric IL-5 configuration imparts a functional advantage over a monomeric helical bundle for receptor binding. Native IL-5 and mono5 will be studied for differences in receptor ligand binding kinetics. In addition, a loop 3 deletion mutant of the monomeric cytokine GM-CSF will be generated and analyzed for the predicted formation of an interdigitating homodimer with enhanced biological activity. Aim II will test the hypothesis that residues proximate to the junction of loop 3 and helix D of IL-5 engage the IL-5R-alpha chain. Predicted residues will be assessed by defining the confirmational epitopes and bioactivity of IL-5 mutants generated by site-directed mutagenesis. Aim III will test the hypothesis that residues proximate to loop 2 and the middle of helix A of IL-5 engage the IL-5R-beta chain, utilizing site-directed mutagenesis of COS-7 expressed IL-5. The structure/function analyses of IL-5 signaling should enable the development of IL-5 analogs capable of antagonizing IL-5-mediated inflammation.