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(申请人提供)：动脉粥样硬化是一种进行性炎症过程，导致大动脉斑块形成。关于巨噬细胞和T细胞在血管壁上的募集以及它们在斑块进展中的作用，人们已经知道了很多。在人类的斑块和外膜中已经发现了B细胞和浆细胞，并在整个疾病过程中建立了动脉粥样硬化的动物模型，在小鼠模型中，全球B细胞缺陷被证明促进了动脉粥样硬化。然而，调节主动脉B细胞归巢的因素以及这些因素对动脉粥样硬化形成的影响尚不清楚。通过细胞培养和动物实验，我们发现螺旋-环-螺旋因子ID3是一种新的动脉粥样硬化保护因子，调节B淋巴细胞趋化因子受体的表达和主动脉归巢，证明ID3在B淋巴细胞介导的动脉粥样硬化保护中是必不可少的。此外，我们最近在人类ID3基因中发现了一种单核苷酸多态性(SNP)，它编码一种ID3蛋白，其功能减弱，是bHLHE蛋白E12的二聚化伙伴和显性负抑制因子。这种SNP与人类颈动脉内膜中层厚度(CIMT)相关。具有编码ID3蛋白的微小等位基因且ID3：E12二聚化减弱的人，其cIMT(亚临床动脉粥样硬化的标记物)增加。综合小鼠、人类和生化数据，我们假设E12活性的丧失通过增加趋化因子受体的表达和增加小鼠B淋巴细胞的动脉归巢来促进动脉粥样硬化保护，而人类ID3基因rs11574(Id3105T)的多态导致人E12活性的拮抗作用降低，从而抑制趋化因子受体的表达，减少人B淋巴细胞的趋化和动脉归巢。确定E12是主动脉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，不仅对于进一步研究拓宽我们对动脉粥样硬化形成的免疫调节的范式具有重要意义，而且还可能导致识别新的生物标志物(ID3基因多态性)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和利用新的试剂，我们提出了以下目的来解决我们的假设：目的1：确定E12表达的调节是否调节B淋巴细胞表面CCR6蛋白的表达和趋化作用。目的：研究人类携带与E12拮抗减弱和CIMT增加相关的ID3基因多态性的B淋巴细胞是否降低了CCR6的表达，降低了B淋巴细胞的趋化能力。目的：研究E12基因在体内对主动脉B细胞归巢和动脉粥样硬化保护中的作用，以及rs11574位ID3基因多态性是否改变了主动脉B细胞归巢。 公共卫生相关性：动脉粥样硬化是一个相当重要的公共卫生问题，因为问题的严重性以及相关的发病率和死亡率。传统的动脉粥样硬化危险因素并不总是预测患者的疾病负担。识别基于保护性免疫丧失的动脉粥样硬化风险的新标记物，有可能拓宽动脉粥样硬化发展的范式，并导致早期、创新的干预策略，通过加强免疫保护来减少动脉粥样硬化。我们已经在小鼠中发现了一种新的由免疫细胞介导的动脉粥样硬化保护途径，称为B淋巴细胞，并在B淋巴细胞中发现了介导这一作用的分子(ID3)和细胞(CCR6和CXCR4)因子。在这一应用中，我们建议进一步剖析调节B淋巴细胞介导的小鼠动脉粥样硬化保护的分子途径，并确定人类ID3基因rs11574的多态性是否导致这一重要分子途径的改变，作为人类潜在的动脉粥样硬化保护机制的联系。结果不仅可能识别原始和非传统的风险标记物，还可能为大胆和创造性的方法奠定基础，以加强对人类动脉粥样硬化的免疫保护。