Role of ABCA7 in iNKT development and function and its impact on atherosclerosis

描述（由申请人提供）：心血管疾病是北美成年人的最大单一杀手，目前治疗动脉粥样硬化的药物以他汀类药物为代表。不变的自然杀伤T细胞（iNKT），即具有先天和适应性免疫反应特征的T淋巴细胞，已被证明在动脉粥样硬化的进展中起着关键作用。ABCA7是一种三磷酸腺苷结合盒转运蛋白，已被证明在免疫细胞对他汀类药物的反应中上调。研究表明，他汀类药物治疗通过调节ABCA7直接参与宿主防御系统的调节。他汀类药物在动脉粥样硬化中的有益作用部分归因于其免疫调节功能。我们提出，他汀类药物作用于iNKT细胞中ABCA7的表达，而ABCA7的这种改变导致iNKT群体的发育和功能异常，这对动脉粥样硬化的发生/进展有直接影响。我们将首先详细研究ABCA7在iNKT细胞功能和发育中的作用，因为我们有初步数据表明ABCA7的缺失会对iNKT的发育和功能产生负面影响。我们的第一个具体目标是验证ABCA7调节胸腺细胞CD1d功能改变iNKT细胞胸腺发育进程的假设。我们将在体外和体内通过产生混合骨髓嵌合体来检测ABCA7敲除的DP胸腺细胞的功能能力。我们将利用混合骨髓嵌合体来测试ABCA7对iNKT在细胞内在效应中的作用。第二个特定目标将测试ABCA7调节外周抗原呈递细胞中的CD1d功能，影响iNKT激活的假设。这将通过使用共聚焦显微镜来完成，我们将分析ABCA7敲除CD11c+细胞中的CD1d定位和脂质抗原运输。特异性目的3将测试他汀类药物是否引起abca7介导的iNKT细胞功能改变，最终影响动脉粥样硬化的发展。我们将进行ABCA7的过继性转移。ldlr双敲除和ldlr敲除iNKT细胞，在转移前接受或不接受他汀类药物治疗，进入ldlr。Jalpha18双敲除受体用于动脉粥样硬化研究。

DESCRIPTION (provided by applicant): Cardiovascular disease is the single largest killer of adults in North America with current therapeutics against atherosclerosis represented by drugs known as statins. Invariant Natural Killer T (iNKT) cells, T lymphocytes with qualities characterized by both innate and adaptive immune responses, have been demonstrated as key players in the progression of atherosclerosis. ABCA7, an adenosine triphosphate binding cassette transporter, has been shown to be upregulated in immune cells in response to statins. Studies have shown direct involvement of statin treatment in the regulation of the host defense system through the modulation of ABCA7. The beneficial effects of statins in atherosclerosis have been partly attributed to their immunomodulating functions. We propose that statins act on ABCA7 expression in iNKT cells, and that this alteration in ABCA7 brings about developmental and functional aberrancies in the iNKT population, which has a direct effect on the development/progression of atherosclerosis. We will first examine in detail the role ABCA7 plays in iNKT cell function and development as we have preliminary data that suggests the absence of ABCA7 negatively impacts iNKT development and function. Our first specific aim will test the hypothesis that ABCA7 modulates CD1d function in thymocytes altering the thymic developmental progression of iNKT cells. We will examine the functional capabilities of ABCA7 knockout DP thymocytes in vitro, and in vivo through the generation of mixed bone marrow chimeras. We will utilize the mixed bone marrow chimeras to also test the role of ABCA7 on iNKT in a cell intrinsic effect. The second specific aim will test the hypothesis that ABCA7 modulates CD1d function in peripheral antigen presenting cells, impacting iNKT activation. This will be done through the use of confocal microscopy where we will analyze CD1d localization and lipid antigen trafficking in ABCA7 knockout CD11c+ cells. Specific aim three will test whether statin administration causes ABCA7-mediated changes in iNKT cell function ultimately effecting the development of atherosclerosis. We will perform adoptive transfers of ABCA7.ldlr double knockout and ldlr knockout iNKT cells, with or without statin treatment prior to transfer, into ldlr.Jalpha18 double knockout recipients for atherosclerosis studies.