EOSINOPHIL APOPTOSIS IN ASTHMA

哮喘中的嗜酸性粒细胞凋亡

• 批准号: 2005528
• 负责人: GERALD LITWACK
• 金额: $ 20.95万
• 依托单位: THOMAS JEFFERSON UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-03-01 至 2002-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2005528
• 关键词: apoptosis; asthma; cell line; cellular pathology; colony stimulating factor; cytokine; endopeptidases; eosinophil; glucocorticoids; immunogenetics; interleukin 3; interleukin 5; isozymes; laboratory rabbit; leukocyte activation /transformation; molecular cloning; tissue /cell culture

Eosinophils are known to be important effector cells in the pathogenesis of asthma. The cytokines interleukin-3 (IL-3), IL-5, and granulocyte- macrophage colony-stimulating factor (GM-CSF) are important in eosinophil development and activation. Without the influence of these cytokines, eosinophils rapidly undergo apoptosis. We have confirmed previous observations that eosinophils recruited to the airways of humans by segmental antigen challenge (SAC) show a prolonged survival ex vivo, in comparison with peripheral blood eosinophils. Moreover, we have recently determined that the prolonged survival appears to be primarily due to the autocoid secretion of GM-CSF by the airway eosinophils ex vivo. Investigations into the molecular mechanisms involved in apoptosis have exploded in the last several years. The Ced- 3/ICE cysteine protease gene family are important pro-apoptotic mediators, while Bcl-2 and related proteins provide important counter- regulatory effects and inhibit apoptosis. We have recently identified four novel isoforms of ICE (beta, gamma, delta epsilon) as well as the novel Ced-3/ICE homologs, CPP32, Mch2 and Mch3. Significantly, we have also identified several of these proteins in BAL eosinophils from asthmatics. In this investigation we propose to study the role of cysteine proteases in programmed cell death in eosinophils. We will first characterize the known cysteine protease genes and their products in BAL and peripheral blood eosinophils, and the eosinophil inducible cell line AML14. Second, we will determine the effects of glucocorticoids and the eosinophil-active cytokines on cysteine protease gene expression, and also systematically investigate mechanisms by which the eosinophil-active cytokines might antagonize glucocorticoid mediated apoptosis. Third, the effect of crosslinking eosinophil surface APO- 1/FAS-antigen on cysteine protease gene expression will be examined, as well as determining the role of apoptotic inhibitors BcL-2 and p35 on glucocorticoid- and FAS-mediated apoptosis. Finally, we propose a strategy for identifying and cloning novel apoptotic cysteine proteases from eosinophils and the AML cell line. The elucidation of mechanisms by which eosinophil survival is regulated in vivo at sites on inflammation is critical to our understanding of asthma pathogenesis. Furthermore, manipulation of these pathways will be a key area for therapeutic intervention in asthma.

嗜酸性粒细胞是重要的效应细胞在发病机制 哮喘 细胞因子白细胞介素-3（IL-3）、IL-5和粒细胞-白细胞介素-3（IL-3）在体内表达。 巨噬细胞集落刺激因子（GM-CSF）在 嗜酸性粒细胞的发育和活化。 如果没有这些影响， 细胞因子，嗜酸性粒细胞迅速经历凋亡。 我们已经证实 以前的观察表明，嗜酸性粒细胞招募到气道的 通过节段性抗原攻击（SAC），人类显示出延长的生存期， 体内，与外周血嗜酸性粒细胞相比。 而且我们 最近已经确定，延长生存期似乎是 主要是由于GM-CSF通过气道的自体分泌 离体嗜酸性粒细胞。 分子机制研究 参与细胞凋亡的基因在过去几年里激增。 该Ced- 3/ICE半胱氨酸蛋白酶基因家族是重要的促凋亡基因 介质，而Bcl-2和相关蛋白质提供重要的反， 调节作用和抑制凋亡。 我们最近发现 四种新的ICE亚型（β，γ，δ β）以及 新的Ced-3/ICE同源物，CPP 32，Mch 2和Mch 3。 值得注意的是， 我还在来自于H.N.的BAL嗜酸性粒细胞中鉴定了几种这些蛋白质。 哮喘患者 在这项调查中，我们建议研究的作用， 嗜酸性粒细胞程序性细胞死亡中的半胱氨酸蛋白酶。 我们将 首先表征已知的半胱氨酸蛋白酶基因及其产物， 在BAL和外周血嗜酸性粒细胞中， AML 14细胞系。 其次，我们将确定 糖皮质激素和嗜酸性细胞活性细胞因子对半胱氨酸蛋白酶的影响 基因表达，并系统地研究机制， 嗜酸性细胞因子可拮抗糖皮质激素介导的 凋亡 第三，交联嗜酸性粒细胞表面APO- 将检查1/FAS-抗原对半胱氨酸蛋白酶基因表达的影响， 以及确定凋亡抑制剂BcL-2和p35在 糖皮质激素和Fas介导的凋亡。 最后，我们提出了一个 鉴定和克隆新凋亡半胱氨酸蛋白酶的策略 嗜酸性粒细胞和急性髓细胞白血病细胞系。 阐明机制 在体内调节嗜酸性粒细胞的存活， 炎症对我们理解哮喘发病机制至关重要。 此外，操纵这些途径将是一个关键领域， 哮喘的治疗干预。