CC Chemokines in Allergic Asthma

描述(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还知之甚少。我们已经成功地建立了一种新的动物模型，在该模型中，抗原(Ag)冲击的树突状细胞(DC)能够诱导气道高反应性(AHR)、杯状细胞增生、特异性IgE反应、高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-/-)缺陷的突变小鼠中，在空气变应原攻击后，肺中可以看到加速的Th2反应。我们已经证明CCR2缺乏改变了单核细胞的迁移，也可能改变了其他细胞，如Th淋巴细胞的迁移。在这项提案中，将研究MCP-1在诱导各种病理变化中的作用。此外，还将研究与哮喘发病机制相关的改变的白细胞迁移。提出了三个具体目标。目的：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诱导的哮喘模型肺内Th2应答增强中起主要作用。目的：研究CCR2-/-小鼠体内淋巴细胞、单核细胞和嗜酸性粒细胞向肺和呼吸道的迁移动力学。这将通过在抗原攻击开始后增加间隔时间来研究小鼠，方法是对总的肺白细胞进行流式细胞术检测，或对肺组织进行免疫组织化学染色。用于表征白细胞的抗体将包括F4/80(巨噬细胞)、抗CD4mAb、抗CD8mAb、Thi(IFNgHigh，IL-5low)、Th2(IFNglow，IL-5High)、抗MHC-I类mAb(抗原提呈细胞)和抗DEC-205(DC)。目的2还将评估过继转移的CCR2-/-或CCR2+/+DO 11.10小鼠的TG+CD4细胞的肺转运，以解决肺内Th亚群数量变化是否与转运或原位分化有关的问题。目的：探讨单核细胞和淋巴细胞在过敏原诱导的CCR2-/-小鼠Th2应答中的相对作用。这将使用通过过继将CCR2+/+或CCR2-/-TG+DO 11.10 CD4细胞转移到CCR2+/+或CCR2-/-裸鼠而产生的嵌合小鼠来完成。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。这种洞察力可能会让我们设计出针对特定分子或特定细胞群体的新疗法。

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.