CC Chemokines in Allergic Asthma

描述（由申请人提供）：哮喘是一个重大的公共卫生问题，其发病机制复杂。特别是，CC趋化因子在这种疾病中的作用尚不清楚。我们已经成功地开发了一种新的动物模型，其中抗原（Ag）脉冲树突状细胞（DC）能够诱导气道高反应性（AHR）、杯状细胞增生、特异性IgE反应、嗜酸性粒细胞增多和明显的肺部炎症。我们还表明，在CC趋化因子受体2 （CCR2-/-）缺乏的突变小鼠中，在空气过敏原攻击后，肺部出现加速的Th2反应。其他人和我们已经证明，CCR2缺乏会改变单核细胞的迁移，也可能改变其他细胞，如Th淋巴细胞的迁移。本文将探讨MCP-1在诱导各种病理变化中的作用。此外，改变白细胞迁移，作为相关的哮喘发病机制，将进行研究。提出了三个具体目标。目的1：通过中和抗MCP-1抗体2H5或CCR2-/-/MCP-/- 1双突变小鼠，证明MCP-1升高在Ag诱导哮喘模型中观察到的肺部Th2反应增强中起主要作用。目的2：确定过敏原刺激CCR2-/-小鼠中淋巴细胞、单核细胞和嗜酸性粒细胞向肺和气道迁移的动力学。这将通过使用流式细胞术对总肺白细胞或肺组织免疫组织化学染色，在ag攻击开始后增加间隔研究小鼠来完成。针对表征白细胞的抗体将包括F4/80（巨噬细胞）、抗cd4单抗、抗cd8单抗、Thi （IFNghigh, IL-5low）、Th2 （IFNglow, IL-5high）、抗mhc I类单抗（抗原呈递细胞）和抗dec -205 （DC）。Aim 2还将评估来自CCR2-/-或CCR2+/+ DO 11.10小鼠的过继转移Tg+ CD4细胞的肺转运，以解决肺中Th亚群数量的改变是否与转运或原位分化有关的问题。目的3：确定单核细胞和淋巴细胞在过敏原刺激CCR2-/-小鼠中Th2反应增强中的相对作用。这将通过将CCR2+/+或CCR2-/- Tg+ DO 11.10 CD4细胞过继转移到CCR2+/+或CCR2-/-裸小鼠中创建嵌合小鼠来完成。预期的结果将进一步深入了解细胞因子和趋化因子以及细胞迁移在过敏性哮喘中的作用。这种见解可能使我们能够设计针对特定分子或特定细胞群的新疗法。

DESCRIPTION (provided by applicant): Asthma is a major public health issue, and its pathogenesis is complex. In the particular, the role of CC chemokines in this disease is poorly understood. We have successfully developed a new animal model in which antigen (Ag)-pulsed dendritic cells (DC) are able to induce airway hyperreactivity (AHR), goblet cell hyperplasia, specific IgE response, hypereosinophilia, and marked lung inflammation. We have also shown that in mutant mice deficient in CC chemokine receptor 2 (CCR2-/-), an accelerated Th2 response is seen in the lung after aeroallergen challenge. Others and we have shown that CCR2 deficiency alters the migration of monocytes, and possibly other cells, such as Th lymphocytes. In this proposal, the role of MCP-1 in the induction of various pathological changes will be investigated. In addition, altered leukocyte migration, as related to the pathogenesis of asthma, will be studied. Three specific aims are proposed. Aim 1: To demonstrate that elevated MCP- 1 plays a major role in the observed accentuated Th2 response in the lung in the Ag induced asthma model, using either neutralizing anti-MCP-1 antibody 2H5 or CCR2-/-/MCP-/--1 double mutant mice. Aim 2: To determine the kinetics of lymphocyte, monocyte and eosinophil migration to the lungs and airways in allergen-challenged CCR2-/- mice. This will be done by studying mice at increasing intervals after onset of Ag-challenge using flow cytometry on total lung leukocytes, or immunohistochemical staining of lung tissue. Antibodies to characterization leukocytes will include F4/80 (macrophage), anti-CD4 mAb, anti-CD8 mAb, Thi (IFNghigh, IL-5low), Th2 (IFNglow, IL-5high), anti-MHC class I mAb (antigen presenting cells), and anti-DEC-205 (DC). Aim 2 will also evaluate lung trafficking of adoptively transferred Tg+ CD4 cells from CCR2-/- or CCR2+/+ DO 11.10 mice, to address the issue of whether altered numbers of Th subsets in the lung are related to trafficking or in situ differentiation. Aim 3: To determine the relative role of monocytes and lymphocytes in the accentuated Th2 response in the allergen-challenged CCR2-/- mice. This will be done using chimeric mice created by adoptive transfer of CCR2+/+ or CCR2-/- Tg+ DO 11.10 CD4 cells into either CCR2+/+ or CCR2-/- nude mice. The expected results will provide further insight into the role of cytokines and chemokines and cellular migration in allergic asthma. This insight may allow us to devise novel therapeutics targeted at a specific molecule or at a specific cell population.