Eosinophil Recruitment and Activation in Solid Tumors

描述（由申请人提供）：实体瘤中嗜酸性粒细胞的浸润和积聚已被认为是几种肿瘤类型（包括结肠癌、胰腺癌和乳腺癌）的相关临床特征。这种嗜酸性粒细胞募集也发生在许多肿瘤发生的小鼠模型中。尽管有大量的临床研究和小鼠模型的可用性，但嗜酸性粒细胞效应子功能通常知之甚少，实际上，这些白细胞的作用（如果有的话）仍然存在问题。小鼠肿瘤相关嗜酸性粒细胞的研究仍然模棱两可，部分原因是缺乏明确定义效应子功能机制的特异性试剂和模型。本提案的目的是利用我们在使用肺部疾病的变应原激发模型检查嗜酸性粒细胞活性方面的丰富经验来弥合这一差距。例如，我们已经产生了几种特异性抗体，其允许明确检测浸润性嗜酸性粒细胞和颗粒蛋白的释放（即，活化导致脱粒）。此外，我们已经开发了几个敲除小鼠缺乏的主要颗粒蛋白，将允许评估脱粒。我们还开发了一种新的先天性缺乏嗜酸性粒细胞的转基因小鼠品系。这些转基因动物中嗜酸性粒细胞的消融是通过自杀基因的表达（即，白喉毒素A）专门存在于嗜酸性细胞系细胞中，并为确定嗜酸性细胞对肿瘤的反应提供了独特的机会。该提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作/生长的假设。我们的目标将通过完成以下具体目标来实现：（1）确定嗜酸性粒细胞向实体瘤募集的动力学以及嗜酸性粒细胞在肿瘤内被吸引的活化/脱粒的程度;（2）确定嗜酸性粒细胞相关宿主反应调节乳腺肿瘤发病、生长动力学或转移率的程度;（3）为了确定嗜酸性粒细胞脱粒（即，释放有毒的阳离子次级颗粒蛋白）对乳腺肿瘤有直接作用。

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.