MODULATION OF IL-5 MEDIATED INFLAMMATION

描述（改编自研究者摘要）：白细胞介素-5 （IL-5）是螺旋束家族的短链亚家族成员 细胞因子。 IL-5通过异二聚体受体发出信号， IL-5 R-α/IL-5 R-β，诱导对许多 白细胞 在生理学上，IL-5有助于宿主防御寄生虫， 肿瘤，而它的失调已与哮喘和过敏 疾病 因此，IL-5及其受体是调节IL-10的明显靶标。 这种炎症反应。 本应用程序的目标是了解 IL-5及其受体亚单位之间的分子相互作用。 朝向 为了实现这一目标，我们成功地模拟并表达了第一个IL-5单体， 具有生物活性（指定为mono 5），从而证明所有 IL-5功能所必需的结构特征包含在 单螺旋束。 此外，一组抗IL-5中和mAb， COS-7表达种间IL-5嵌合体，分子建模已经被证实。 用于定位5个中和表位和种属特异性 IL-5在两个结构域内的残基。 具体目标是：1） 测试我们的假设，即mono 5作为一个范式，调查 天然IL-5的同源二聚化是否是生物学上有利的， 一种重要功能基序保守的新生物学机制 在细胞因子的螺旋束家族内;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的IL-5结合。 对于受体结合来说，单体螺旋束具有优势。 天然IL-5 和mono 5将研究受体配体结合的差异 动力学 此外，单体细胞因子的环3缺失突变体 将生成GM-CSF并分析其预测的 具有增强生物活性的指状交叉同源二聚体。 Aim II将 测试接近环3的连接处的残基和 IL-5的螺旋D接合IL-5 R-α链。 预测残留物将为 通过定义IL-5的确认表位和生物活性进行评估 通过定点诱变产生的突变体。 Aim III将测试 假设接近环2和螺旋A中间的残基 IL-5接合IL-5 R-β链，利用IL-5的定点诱变。 COS-7表达IL-5。 IL-5信号通路的结构/功能分析 应该能够开发出能够拮抗 IL-5介导的炎症。

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.