The Role of AID in Contact Sensitivity

描述（由申请人提供）：本申请的长期目标是了解引发过敏性炎症的免疫学机制，并着眼于识别反应本身上游的新治疗靶点。本提案旨在开发新技术和新的研究途径，使研究者能够识别和表征在再次暴露于过敏原后立即发生的事件中起核心作用的罕见白细胞群，并且对后期全面过敏性炎症反应的发展是必要的。近年来，研究清楚地表明，接触敏感性和延迟型超敏性过敏反应依赖于一种涉及许多罕见白细胞亚群的新型免疫回路。其中，非经典B细胞亚群起着特别重要的作用。这些B细胞产生抗体，在再次暴露于过敏原时，启动一系列促炎事件，这些事件是后期和更严重的T细胞介导的超敏反应的发展所必需的。重要的是，干扰这一途径或这些B细胞可以防止严重炎症的发展。虽然负责接触敏感性起始的B细胞已被证明与B-1细胞相似，但它们尚未被完全表征。进一步了解这些类型的过敏反应依赖于这些细胞的鉴定和表征。这些细胞的活性依赖于酶激活诱导的脱氨酶（AID），它参与了B细胞受体基因组装的许多步骤。对AID的依赖性将初始B细胞与一般B-1细胞群区分开来。因此，本提案的具体目标是：1)确定AID在B-1细胞中的表达亚群；2)确定AID促进启动反应的机制。使用多种细胞表面标记的多色流式辅助细胞术分析和在表达AID的细胞中表达荧光标记的新小鼠株将用于鉴定这些细胞。体内过继转移实验将用于表征其生物活性。最后，将对来自单个细胞的B细胞受体基因进行分子遗传学分析，以确定AID在相关初始抗体产生中的作用。过敏性疾病，如接触性过敏和延迟型超敏反应，可使人非常虚弱，是美国公共卫生系统迅速增加和昂贵的负担。该建议将开发新技术，以促进与这些疾病相关的严重延迟炎症的上游免疫事件的表征。这将有可能导致识别新的治疗靶点，从而有效地在反应充分发展之前预防它们。

DESCRIPTION (provided by applicant): The long term objective of this application is to understand the immunological mechanisms responsible for initiating allergic inflammation, with an eye to identifying novel therapeutic targets upstream of the response itself. This proposal aims to develop novel techniques and a new avenue of investigation which will allow the investigator to identify and characterize a rare population of leukocytes that plays a central role in the events that occur immediately following re-exposure to allergen and are necessary for the later development of the full allergic inflammatory response. In recent years, research has clearly demonstrated that contact sensitivity and delayed type hypersensitivity allergic responses are dependent on a novel immune circuit that involves a number of rare leukocyte subsets. Of these, a subpopulation of non-classical B cells plays a particularly central role. These B cells produce antibodies that, upon re-exposure to allergen, initiate a cascade of pro-inflammatory events required for the development of the later and more severe T cell-mediated hypersensitivity response. Importantly, interference with this pathway or these B cells prevents the development of the development of severe inflammation. While the B cells responsible for initiation of contact sensitivity have been shown to be similar to B-1 cells, they have not yet been fully characterized. Further understanding of these types of allergic responses is dependent on the identification and characterization of these cells. The activity of these cells is dependent on the enzyme activation-induced deaminase (AID), which is involved in a number of steps in the assembly of the B cell receptor gene. The dependence on AID distinguishes the initiating B cell from the general B-1 cell population. Therefore, the specific aims of this proposal are to: 1) Identify AID expressing subpopulations of B-1 cells and 2) determine the mechanism by which AID contributes to the initiation response. Multicolor flow assisted cytometery analysis using multiple cell surface markers and a new strain of mice that expresses a fluorescent marker in cells that have expressed AID will be used to identify these cells. In vivo adoptive transfer experiments will be used to characterize their biological activity. Finally, molecular genetic analysis of B cell receptor genes from individual cells will be developed and performed to identify the role of AID in the generation of the relevant initiating antibodies.Allergic diseases such as contact sensitivity and delayed type hypersensitivity can be very debilitating and are a rapidly increasing and costly burden on public health systems in the United States. This proposal will develop new technology to facilitate the characterization of the immune events upstream of the severe, delayed inflammation associated with these disorders. This will potentially lead to the identification of novel therapeutic targets to effectively prevent responses before they develop fully.