Genetic Regulation of B Lymphocyte Aortic Homing and Atheroprotection

B 淋巴细胞主动脉归巢和动脉粥样硬化的基因调控

• 批准号: 8243525
• 负责人: Coleen A McNamara
• 金额: $ 38.5万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-04-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8243525
• 关键词: Address; Adoptive Transfer; Alleles; Animal Model; Animals; Apolipoprotein E; Arteries; Atherosclerosis; Attenuated; B-Lymphocytes; Biochemical; Biological Markers; CCL20 gene; CCR6 gene; CXCR4 gene; Cell Culture Techniques; Cells; Chemotaxis; Data; Defect; Development; Diet; Dimerization; Disease; Dominant-Negative Mutation; E protein; Early treatment; Gene Targeting; Genes; Genetic; Genetic Polymorphism; Hand; Helix-Turn-Helix Motifs; Homing; Human; Immune; Immunity; Individual; Inflammatory; Intervention; Knockout Mice; Lead; Ligands; Link; Medial; Mediating; Membrane Proteins; Messenger RNA; Minor; Modeling; Molecular; Morbidity - disease rate; Mus; Pathway interactions; Patients; Plasma Cells; Process; Proteins; Public Health; Reagent; Regulation; Repression; Risk; Risk Factors; Risk Marker; Role; Single Nucleotide Polymorphism; T-Lymphocyte; Thick; Tunica Adventitia; atherogenesis; atheroprotective; attenuation; base; burden of illness; chemokine receptor; humoral immunity deficiency; in vivo; inhibitor/antagonist; innovation; mRNA Expression; macrophage; mortality; mouse model; novel; novel marker; promoter; protein expression; public health relevance; receptor expression

DESCRIPTION (provided by applicant): Atherosclerosis is a progressive, inflammatory process leading to plaque formation in large arteries. Much is known about recruitment of macrophages and T cells to the vessel wall and their role in plaque progression. B cells and plasma cells have been identified in plaque and adventitia in humans and animal models of atherosclerosis throughout the course of disease and global B cell deficiency has been shown to promote atherosclerosis in murine models. Yet, the factors that regulate aortic B cell homing and the impact of modulation of these factors on atherogenesis, remain unknown. Using cell culture and animal studies, we have identified the helix-loop-helix factor (HLH), Id3, as a novel atheroprotective factor that regulates expression of chemokine receptors and aortic homing of B lymphocytes and demonstrated that Id3 was essential for B lymphocyte-mediated atheroprotection. In addition, we have recently identified a single nucleotide polymorphism (SNP) in the human ID3 gene that encodes an Id3 protein with attenuated function as a dimerization partner and dominant negative inhibitor of the bHLH E-protein, E12. This SNP is associated with carotid intima medial thickness (cIMT) in humans. Humans with the minor allele encoding an Id3 protein with attenuated Id3:E12 dimerization have an increase in cIMT (marker of subclinical atherosclerosis). Taking the mouse, human and biochemical data together, leads us to hypothesize that loss of E12 activity promotes atheroprotection through increased chemokine receptor expression and increased arterial homing of B lymphocytes in mice and that polymorphism in the human ID3 gene at rs11574 (Id3105T) resulting in reduced antagonism of human E12 activity allows repression of chemokine receptor expression, reducing chemotaxis and arterial homing of human B lymphocytes. Identification of E12 as a critical regulator of aortic B lymphocyte homing and B lymphocyte-mediated atheroprotection is not only important for further studies to broaden the paradigm of our understanding of immune regulation of atherogenesis, but may also lead to identification of novel biomarkers (ID3 gene polymorphism) and innovative strategies to promote atheroprotection in humans. Based on our compelling preliminary data and utilizing novel reagents, we propose the following aims to address our hypothesis: Aim 1: Determine if modulation of E12 expression regulates CCR6 surface protein expression and chemotaxis in B lymphocytes. Aim 2: Determine if B lymphocytes harboring the Id3 polymorphism associated with attenuated antagonism of E12 and increased cIMT in humans have reduced CCR6 expression and reduced B lymphocyte chemotaxis. Aim 3: Determine the role of E12 on aortic B cell homing and atheroprotection in vivo and determine if polymorphism in Id3 at rs11574 alters aortic B cell homing. PUBLIC HEALTH RELEVANCE: Atherosclerosis is a public health issue of considerable importance due to the magnitude of the problem and the associated morbidity and mortality. Traditional atherosclerotic risk factors are not always predictive of disease burden in patients. Identification of novel markers of atherosclerosis risk based on loss of protective immunity has the potential to broaden the paradigm of atherosclerosis development and lead to early, innovative, intervention strategies to reduce atherosclerosis through enhancing immune protection. We have identified a novel atheroprotective pathway in mice mediated by immune cells called B lymphocytes, and discovered molecular (Id3) and cellular (CCR6 and CXCR4) factors in B lymphocytes mediating this effect. In this application, we propose to further dissect out the molecular pathways that regulate B lymphocyte- mediated atheroprotection in mice and determine if polymorphism in the human ID3 gene at rs11574 results in alterations of this important molecular pathway as a link to potential atheroprotective mechanisms in humans. Results may not only identify, original and unconventional risk markers, but may also lay the groundwork for bold and creative approaches to bolster immune protection from atherosclerosis in humans.

描述（由申请人提供）：动脉粥样硬化是一种进行性炎症过程，导致大动脉中形成斑块。关于巨噬细胞和 T 细胞向血管壁的募集及其在斑块进展中的作用，人们已经了解很多。在人类和动物动脉粥样硬化模型的整个疾病过程中，斑块和外膜中都发现了 B 细胞和浆细胞，并且在小鼠模型中，整体 B 细胞缺乏已被证明会促进动脉粥样硬化。然而，调节主动脉 B 细胞归巢的因素以及这些因素的调节对动脉粥样硬化形成的影响仍然未知。通过细胞培养和动物研究，我们发现螺旋-环-螺旋因子（HLH）Id3是一种新型动脉粥样硬化保护因子，可调节趋化因子受体的表达和B淋巴细胞的主动脉归巢，并证明Id3对于B淋巴细胞介导的动脉粥样硬化保护至关重要。此外，我们最近在人类 ID3 基因中发现了一个单核苷酸多态性 (SNP)，它编码一种 Id3 蛋白，其作为 bHLH E 蛋白 E12 的二聚化伙伴和显性失活抑制剂的功能减弱。该 SNP 与人类颈动脉内膜内侧厚度 (cIMT) 相关。具有编码 Id3 蛋白且 Id3:E12 二聚化减弱的次要等位基因的人类 cIMT（亚临床动脉粥样硬化标志物）增加。将小鼠、人类和生化数据结合在一起，使我们推测 E12 活性的丧失通过增加趋化因子受体表达和增加小鼠 B 淋巴细胞的动脉归巢来促进动脉粥样硬化保护，并且人类 ID3 基因 rs11574 (Id3105T) 的多态性导致人类 E12 活性的拮抗作用减少，从而抑制趋化因子受体表达， 减少人类 B 淋巴细胞的趋化性和动脉归巢。 E12作为主动脉B淋巴细胞归巢和B淋巴细胞介导的动脉粥样硬化保护的关键调节因子的鉴定不仅对于进一步研究以拓宽我们对动脉粥样硬化形成的免疫调节的理解范式很重要，而且还可能导致新的生物标志物（ID3基因多态性）的鉴定和促进人类动脉粥样硬化保护的创新策略。基于我们令人信服的初步数据并利用新型试剂，我们提出以下目标来解决我们的假设： 目标 1：确定 E12 表达的调节是否调节 B 淋巴细胞中的 CCR6 表面蛋白表达和趋化性。目标 2：确定携带与 E12 拮抗作用减弱和人类 cIMT 增加相关的 Id3 多态性的 B 淋巴细胞是否会降低 CCR6 表达并降低 B 淋巴细胞趋化性。目标 3：确定 E12 在体内对主动脉 B 细胞归巢和动脉粥样硬化保护的作用，并确定 Id3 rs11574 的多态性是否会改变主动脉 B 细胞归巢。 公共卫生相关性：由于动脉粥样硬化问题的严重性以及相关的发病率和死亡率，它是一个相当重要的公共卫生问题。传统的动脉粥样硬化危险因素并不总是能够预测患者的疾病负担。基于保护性免疫丧失的动脉粥样硬化风险新标志物的鉴定有可能扩大动脉粥样硬化发展的范式，并导致早期、创新的干预策略，通过增强免疫保护来减少动脉粥样硬化。我们在小鼠中发现了一种由称为 B 淋巴细胞的免疫细胞介导的新型动脉粥样硬化通路，并在 B 淋巴细胞中发现了介导这种作用的分子 (Id3) 和细胞 (CCR6 和 CXCR4) 因子。在本申请中，我们建议进一步剖析调节小鼠 B 淋巴细胞介导的动脉粥样硬化保护的分子途径，并确定人类 ID3 基因 rs11574 的多态性是否会导致这一重要分子途径的改变，从而与人类潜在的动脉粥样硬化保护机制相关。结果不仅可以识别原始和非常规的风险标记，还可以为大胆和创造性的方法奠定基础，以增强人类动脉粥样硬化的免疫保护。