Immunization against Atherosclerosis

项目总结 动脉粥样硬化的部分原因是致病的CD4+效应T细胞对抗原有反应 在病变中上调(“动脉粥样硬化抗原”)。重要的是，CD4+CD25+Foxp3+调节性T细胞(Treg)，a 抑制T细胞反应的T细胞亚群，已被证明在控制中起作用 动脉硬化。在动脉粥样硬化的背景下，致病因子和致病因子之间可能存在不平衡 抑制Treg对动脉粥样硬化抗原的反应，导致促进动脉粥样硬化的形成。这些观念 促使我们设计了一种抗动脉粥样硬化的策略，旨在通过 在体内增加动脉粥样硬化特异性的Treg。以前，与传统佐剂的使用情况类似， 为了提高免疫力，我们探索了耐受性佐剂的概念，并设计了一种新的免疫方案 策略。在迟发性超敏反应(DTH)和自发性I型糖尿病的小鼠模型中，我们发现 当在免疫抑制药的影响下进行多肽抗原免疫时 地塞米松(DEX)作为耐受性佐剂(我们称之为“抑制免疫”的策略)， 分别导致迟发型超敏反应和自身免疫性糖尿病的长期脱敏。我们向大家展示了 这种保护作用与抗原特异性Treg的选择性扩增有关。受这些因素的鼓舞 结果，我们将检验我们的假设，即使用地塞米松和动脉粥样硬化抗原抑制免疫(SI)可能 选择性地扩大动脉粥样硬化的特异性Treg，减少动脉粥样硬化。在具体目标1下，我们将确定 SI是否增加了治疗小鼠皮损部位和外周血中Treg/Tef的比率。到那时候 最后，雄性ApoE-/-/Foxp3-GFP+/+小鼠(我们最近产生)将接受SI联合DEX治疗 与HSP60衍生肽HP1结合。作为对照，小鼠将单独接受PBS或HP1治疗。无名动脉 经过处理的小鼠将被冷冻，并将进行免疫组织化学分析以量化Tef (CD4+Foxp3-)和Treg(CD4+Foxp3-GFP+)。Treg的抗原特异性将通过ELISPOT进行分析 从主动脉弓制备单个细胞。此外，外周血中的Tef和Treg将通过 免疫染色和流式细胞术，以及Treg的抗原特异性将通过其增殖来评估 作为对免疫多肽HP1的反应。在特定目标2下，我们将评估其抗动脉粥样硬化的效果 在接受治疗的动物中为SI。为此，已建立动脉粥样硬化的雄性载脂蛋白E-/-小鼠将被分为3组 组(N E 6)。其中一组将在治疗前进行解剖，以确定病变范围的基线。每一个 两组分别给予HP1单独治疗(对照组)或SI治疗。随后，无名症中的病变 动脉将通过组织化学/形态计量学分析进行量化。此外，无名动脉的节段 将分析巨噬细胞、平滑肌细胞(SMC)和胶原的含量。统计分析将 对所获得的数据进行处理。在具体目标3下，我们将利用收养转移来确定是否 SI诱导的Treg参与了SI的抗动脉粥样硬化作用。为此，ApoE-/-/Foxp3-GFP+小鼠将 用SI治疗；4周后，从脾中分离Treg(Foxp3-GFP+)作为供者Treg (测试Treg)。从未经治疗的小鼠中分离出的Treg将用作对照Treg。人外周血中分离的CD4+/Foxp3-细胞 已经发展为晚期动脉粥样硬化的APOE-/-小鼠将被用作致病因子。后来， 致病性TEFF将单独(对照)过继转移，或与检测(以不同比例)结合转移 Treg或对照Treg，导入受体ApoE-/-/RAG-2-/-小鼠(T细胞和B细胞缺陷)。六周 稍后，将分析受体的动脉粥样硬化病变程度。完成这些具体目标可能会 产生安全、有效、实用的抗动脉粥样硬化疗法。此外，这项研究还将进一步界定 动脉粥样硬化特异性Treg在控制动脉粥样硬化中的作用并提供与靶向有关的有用见解 这些Treg是最好的。

PROJECT SUMMARY Atherosclerosis is driven partially by pathogenic CD4+ effector T cells (Teff) reactive to antigens upregulated in the lesion ("athero-antigens"). Importantly, CD4+CD25+Foxp3+ regulatory T cells (Treg), a subset of T cells that function to suppress the response of Teff, have been shown to play a role in controlling atherosclerosis. Within the context of atherosclerosis an imbalance may exist between pathogenic Teff and suppressive Treg in response to athero-antigens, leading to the promotion of atherogenesis. These notions prompted us to design an anti-atherosclerosis strategy aimed at resetting the balance between Treg and Teff via increasing athero-specific Treg in vivo. Previously, mirroring the use of the conventional adjuvants for enhancing immunity, we explored the concept of "tolerogenic adjuvant" and designed a novel immunization strategy. In mouse models of delayed-type hypersensitivity (DTH) and spontaneous type I diabetes, we showed that immunization with peptide antigen, when performed under the influence of the immunosuppressant dexamethasone (DEX) serving as tolerogenic adjuvant (a strategy we termed "suppressed immunization"), caused long-term desensitization of DTH and blockade of autoimmune diabetes, respectively. We showed that such protective efficacy was associated with selective expansion of antigen-specific Treg. Encouraged by these results, we here will test our hypothesis that suppressed immunization (SI) using DEX and athero-antigens may selectively expand athero-specific Treg and reduce atherosclerosis. Under Specific Aim #1, we will determine whether SI increases the ratio of Treg to Teff at the lesion site and in peripheral blood in treated mice. To that end, male ApoE-/-/Foxp3-GFP+/+ mice (we have recently generated) will be treated with SI combining DEX with HSP60-derived peptide HP1. As controls, mice will be treated with PBS or HP1 alone. Innominate arteries from treated mice will be cryosectioned, and immunohistochemical analysis will be performed to quantify Teff (CD4+Foxp3-) and Treg (CD4+Foxp3-GFP+). Antigen specificity of Treg will be analyzed via ELISPOT with single cells prepared from the aortic arch. In addition, Teff and Treg in peripheral blood will be quantified via immunostaining and flow cytometry, and antigen specificity of the Treg will be assessed by their proliferation in response to the immunizing peptide HP1. Under Specific Aim #2, we will assess anti-atherogenic efficacy of SI in treated animals. To that end, male ApoE-/- mice with established atherosclerosis will be divided into 3 groups (n e 6). One group will be dissected before treatment to establish the baseline for lesion extent. Each of the 2 treatment groups will be treated with HP1 alone (control) or SI. Subsequently, lesions in the innominate artery will be quantified by histochemical/morphometric analysis. In addition, sections of the innominate artery will be analyzed for contents of macrophage, smooth muscle cell (SMC), and collagen. Statistical analyses will be performed on obtained data. Under Specific Aim #3, we will exploit adoptive transfer to determine whether SI-induced Treg contribute to the anti-atherogenic efficacy of SI. To that end, ApoE-/-/Foxp3-GFP+ mice will be treated with SI; 4 weeks later, Treg (Foxp3-GFP+) will be isolated from the spleen and used as donor Treg (test Treg). Treg isolated from non-treated mice will be used as control Treg. CD4+/Foxp3- cells isolated from ApoE-/- mice that have developed advanced atherosclerosis will be used as pathogenic Teff. Subsequently, pathogenic Teff will be adoptively transferred alone (control), or in combination (in various ratios) with test Treg or control Treg, into recipient ApoE-/-/Rag-2-/- mice (which are T cell- and B cell-deficient). Six weeks later, atherosclerosis lesion extent in recipients will be analyzed. Completion of these specific aims is likely to generate a safe, effective, and practical anti-atherosclerosis therapy. In addition, this study will further define the role of athero-specific Treg in controlling atherosclerosis and provide useful insights pertaining to targeting these Treg optimally.