MODULATION OF THE HUMAN IGE RESPONSE BY XENOBIOTICS

该项目将确定芳香烃， 如在空气污染中，可增强人体过敏性抗体(IgE) 反应，从而导致过敏的显著增加 本世纪发生的呼吸道疾病。流行病学数据 表明环境因素在气候变化中起重要作用 过敏性疾病的表达增加。然而，几乎没有人注意到 致力于直接测试环境影响，举例说明 柴油废气中发现的多环芳烃(PAH- DEP)，特别是在IgE应答之后，也不是通过 这种情况可能会发生。关于免疫球蛋白E调节的知识和考虑 现有的流行病学数据将我们引向开创性的实验 PAH-DEP对人IgE具有直接免疫增强作用的研究 PAH-DEP可协同B细胞产生IgE 以及改变T和B细胞表面分子的表达 IGE制作。本项目将研究PAH-DEP如何调制定义 IgE产生途径中的步骤，从而确定其机制 通过PAH-DEP定量改变IgE应答(总量 Ige蛋白)和定性的(6种异构体的相对含量 交替生成的Epsilon链[4个分泌，2个膜] 拼接[由我们描述])。具体地说，我们将#1确定 PAH-DEP对NB细胞a)表面分子/受体的直接作用 与IgE合成有关，b)epsilon mRNAs转录水平和 剪接变异体和c)膜和分泌的IgE异构体的数量 制作。这包括通过确定的阶段刺激人类B细胞 在IgE产生中(epsilon生殖系转录，epsilon同型 产生的epsilon mRNA的开关和调节)，并定义PAH- 环保部改变了这些过程和结果。我们将#2)评估PAH-DEP 修改T细胞提供的激活/接触信号的能力 (和T细胞亚群)参与IgE的产生。这包括两者 多色流式细胞术的表型研究和功能研究 PAH-DEP治疗T细胞在产生IgE方面的协作能力。#3) PAH-DEP改变关键细胞因子产生的能力 在产生IgE的途径中(如IL-4、TGFbeta、IL-6等)将会是 在蛋白质和信使核糖核酸水平进行检测。我们将延长这些措施 评估柴油机尾气颗粒物(DEP)影响的活体研究 低芳烃和高芳烃体内IgE抗体应答的研究 水解酶活性(ah活性)小鼠。这些研究将证明 PAH-DEP通过共同的ah受体复合体发挥作用，并提供 用于扩展PAH-DEP暴露动力学研究的模型。我们 还将承担#4b)活体人类挑战研究的主题 地塞米松对免疫球蛋白定量和定性表达的影响 上呼吸道的反应。我们的研究将为我们提供关于 可能是影响变态反应变化的关键因素之一 本世纪发生的呼吸道疾病。

This project will determine the mechanisms which aromatic hydrocarbons, such as those in air pollution, enhance human allergic antibody (IgE) responses and thereby contribute to the marked increase in allergic airway disease that has occurred this century. Epidemiologic data suggest that environmental factors play an important role in the increasing expression of allergic disease. Yet almost no attention has been given to directly testing if environmental influences, exemplified by the polycyclic aromatic hydrocarbons found in diesel exhaust (PAH- DEP), specifically after the IgE response nor to the basic mechanism by which this may occur. Knowledge about IgE regulation and consideration of the available epidemiologic data lead us to the seminal experimental discovery that PAH-DEP has direct immuno-enhancing effects on human IgE production; PAH-DEP can synergize in production of IgE from B cells as well as alter expression of T and B cell surface molecules relevant to IgE production. This project will examine how PAH-DEP modulates defined steps in pathways for IgE production and thereby determine the mechanisms by which PAH-DEP alter the IgE response quantitatively (total amount of IgE protein) and qualitatively (relative amount of the 6 isoforms of epsilon chains [4 secreted and 2 membrane] generated by alternative splicing [described by us]). Specifically we will #1 determine the direct effects of PAH-DEP on NB cell a) surface molecules/receptors relevant to IgE synthesis, b) epsilon mRNAs transcript levels and splicing variants and c) the amount of membrane and secreted IgE isoforms produced. This involves stimulating human B cells through defined stages in IgE production (epsilon germ line transcription, epsilon isotype switch and modulation of productive epsilon mRNA) and defining how PAH- DEP alters these processes and outcomes. We will #2) assess PAH-DEP for the ability to modify the activation/contact signals provided by T cells (and T cell subsets) involved in IgE production. This includes both multicolor flow cytometric phenotypic studies and functional studies of PAH-DEP treated T cells' ability to collaborate in IgE production. #3) The ability to PAH-DEP to alter the production of key cytokines involved in pathways for IgE production (e.g. IL-4, TGFbeta, IL-6, etc.) will be examined at both the protein and MRNA levels. We will extend these studies in vivo by #4a) assessing diesel exhaust particle (DEP) effects on the in vivo IgE antibody response in low and high aromatic hydrocarbon hydrolase activity (Ah activity) mice. These studies will prove whether PAH-DEP is working via the common Ah receptor complex as well as provide for a model to extend studies of kinetics of exposure to PAH-DEP. We will also undertake #4b) in vivo human challenge studies of the topical effects of DEP on the expression of the quantitative and qualitative IgE response in the upper airway. Our studies will provide insight into what may be one of the critical factors affecting the change in allergic airway disease that has occurred this century.