Eosinophil Recruitment and Activation in Solid Tumors

描述(申请人提供)：嗜酸性粒细胞在实体瘤中的渗透和聚集已被认为是几种肿瘤类型的相关临床特征，包括结肠癌、胰腺癌和乳腺癌。这种嗜酸性粒细胞募集也出现在许多肿瘤形成的小鼠模型中。尽管有大量的临床研究和可获得的小鼠模型，但嗜酸性粒细胞效应器的功能总体上还知之甚少，实际上，这些白细胞的作用(如果有的话)仍然存在疑问。小鼠肿瘤相关嗜酸性粒细胞的研究仍然不明确，部分原因是缺乏明确定义效应器功能机制的特定试剂和模型。这项建议的目标是通过利用我们使用肺部疾病的过敏原激发模型检查嗜酸性粒细胞活动的丰富经验来弥合这一差距。例如，我们已经创造了几种特定的抗体，可以明确地检测到渗透的嗜酸性粒细胞和颗粒蛋白的释放(即，激活导致脱颗粒)。此外，我们还培育了几只缺乏主要颗粒蛋白的基因敲除小鼠，这将使脱颗粒的评估成为可能。我们还开发了一种先天缺乏嗜酸性粒细胞的转基因小鼠新品系。在这些转基因动物中，嗜酸性粒细胞的消融是通过在嗜酸性粒细胞系细胞中专门表达自杀基因(即白喉毒素A)来完成的，这为确定嗜酸性粒细胞对肿瘤的反应提供了独特的机会。这项建议利用这些新的模型和试剂来检验嗜酸性粒细胞调节肿瘤发生/生长的假设。我们的目标将通过完成以下特定目标来实现：(1)确定实体肿瘤中嗜酸性粒细胞聚集的动力学以及它们被吸引到的肿瘤内的嗜酸性粒细胞激活/脱颗粒的程度；(2)确定嗜酸性粒细胞相关的宿主反应在多大程度上调节乳腺肿瘤的发生、生长动力学或转移率；(3)确定嗜酸性粒细胞脱颗粒(即释放有毒的阳离子次级颗粒蛋白)是否对乳腺肿瘤有直接影响。

DESCRIPTION (provided by applicant): The infiltration and accumulation of eosinophils in solid tumors has been recognized as a correlative clinical feature of several tumor types, including colon, pancreatic, and breast cancers. This eosinophil recruitment also occurs in many mouse models of tumorigenesis. Despite the abundance of clinical studies and the availability of mouse models, eosinophil effector functions in general are poorly understood and, indeed, questions remain as to the role(s), if any, of these leukocytes. Studies of tumor associated eosinophils in the mouse have remained equivocal, in part, due to the lack of specific reagents and models with which to define unequivocally mechanisms of effector function. The goal of this proposal is to bridge this gap by exploiting our extensive experience examining eosinophil activities using allergen provocation models of lung disease. For example, we have created several specific antibodies that allow unambiguous detection of infiltrating eosinophils and the release of granule proteins (i.e., activation leading to degranulation). In addition, we have developed several knockout mice deficient of the predominant granule proteins that will permit assessments of degranulation. We have also developed a novel line of transgenic mice congenitally devoid of eosinophils. The ablation of eosinophils in these transgenic animals was accomplished through the expression of a suicide gene (i.e., Diphtheria Toxin A) exclusively in eosinophil-lineage cells and provides a unique opportunity to define eosinophil responses to tumors. This proposal utilizes these novel models and reagents to test the hypothesis that eosinophils modulate tumor onset/growth. Our objectives will be achieved by completing the following Specific Aims: (1) To define the kinetics of eosinophil recruitment to solid tumors as well as the extent of eosinophil activation/degranulation within tumors to which they have been attracted; (2) To determine the extent to which eosinophil-associated host responses modulate mammary gland tumor onset, growth kinetics, or rate of metastasis; (3) To determine whether eosinophil degranulation (i.e., the release of toxic cationic secondary granule proteins) has direct effects on mammary gland tumors.