Tunable Assembly of Regulatory Immune Signals to Promote Myelin-specific Tolerance

在自身免疫过程中，身体识别并攻击外来的“自我”分子。目前的治疗方法广泛应用于 免疫抑制，这对患者有益，但可能会使他们的免疫功能受损。这一限制， 随着治疗方法的缺乏，人们对控制自身免疫的策略也产生了浓厚的兴趣 疫苗般的特异性，保持免疫系统的其余部分完好无损。几个临床前报告和临床试验 我研究了这个理论来对抗多发性硬化症(MS)，这是一种影响许多人的神经退行性疾病 退伍军人，当中枢神经系统(CNS)中的髓鞘受到免疫系统的攻击时发生。一个 这些研究的重要发现是髓磷脂多肽和耐受免疫信号的联合给药 可以促进调节性T细胞(Tregs)的发展，从而减轻疾病。有趣的是，有一套 阻碍控制髓鞘驱动的炎症的途径是Toll样受体(Toll Like Receptor，TLR)。在健康的个体中， 这些途径检测病原体相关的模式，以支持先天免疫。然而，最近的研究表明， 这种Toll样受体信号--例如，TLR9--在人类多发性硬化症和实验性自身免疫中升高 脑脊髓炎(EAE)是MS的一种小鼠模型，抑制TLR9功能不仅可以减少炎症，而且 还能促进Tregs，改善疾病。幼稚的髓鞘反应性T细胞分化为炎性T细胞 细胞(如TH17)或Tregs定位于脾和淋巴结(LNS)，这是协调免疫的组织。因此， 当髓鞘出现在LNS中时，帮助编程T细胞如何分化的策略-例如，传递 调控线索--可能产生大量髓鞘特异性树突状细胞，阻止病原免疫细胞 没有广泛的镇压。纳米技术在这一领域拥有巨大的希望，因为它增加了对 靶向、释放动力学和多种信号的传递。然而，许多聚合物颗粒和其他材料 表现出激活炎症途径的内在特征，这可能会加剧自身免疫性疾病。 模仿生物材料的吸引人的特征，同时消除炎性“载体”效应的策略可能是 对多发性硬化症或其他自身免疫性疾病的新疗法具有变革性。为了实现这一目标，拟议的研究 将使用多离子免疫信号来创造完全由调节免疫构建的新型纳米结构胶囊 信号和髓鞘抗原。这些免疫聚电解质多层膜(IPEM)是通过 模板上的静电相互作用，然后将模板移除以留下与髓鞘并列的疫苗胶囊 和TLR9抑制核酸(GPG)。由于没有载波，iPEM中的信号密度非常高 相对于基质中嵌有货物的脂类或聚合物配方。此外，这些粒子凝聚了 高密度信号，这一特征可以通过共定位促进向Treg分化 LNS中髓磷脂和GPG的比例。小鼠体内的生物分布研究表明，即使在贩运到LNS后，iPEMS 保持髓鞘和调节信号的并列。对多发性硬化症小鼠模型的初步研究表明 显著的疗效，与IPEM治疗相比，100%的小鼠停止了疾病-临床评分为0 91%的未经治疗的小鼠出现数次瘫痪。拟议的工作将以这些调查结果为基础 检测自身抗原和调节性免疫信号在小鼠体内产生耐受的假说 多发性硬化症模型和人类多发性硬化症患者的样本，测试这种耐受性是否具有髓鞘特异性，并调查 药效的机理和持久性。具体目标是：1)表征IPEM的属性和在鼠标中的屏幕 来自巴尔的摩退伍军人管理局多发性硬化症患者队列的细胞和样本，2)评估进行性小鼠模型的效力 3)阐明LNS的结构和功能变化， 脾和导致耐受的中枢神经系统，4)测试耐受性是否可推广到其他自身抗原 MS复发缓解模型(RR-EAE)。VA对此项目的支持可以使技术能够创建 对影响许多退伍军人的多发性硬化症或其他自身免疫性疾病进行更具体和有效的治疗。

During autoimmunity, the body identifies and attacks “self” molecules as foreign. Current therapies employ broad immunosuppression, which is beneficial to patients, but can leave them immunocompromised. This limitation, along with the lack of cures, has sparked intense interest in strategies that could control autoimmunity with vaccine-like specificity, leaving the rest of the immune system intact. Several pre-clinical reports and clinical trials have investigated this theory to combat multiple sclerosis (MS), a neurodegenerative disease that impacts many Veterans and occurs when myelin in the central nervous system (CNS) is attacked by the immune system. An important finding from these studies is that co-administration of myelin peptide and tolerizing immune signals can promote the development of regulatory T cells (TREGS) that ameliorate disease. Interestingly, one set of pathways hindering control of myelin-driven inflammation are toll like receptors (TLRs). In healthy individuals, these pathways detect pathogen-associated patterns to support innate immunity. However, recent studies reveal that toll like receptor signaling – TLR9, for example – is elevated in human MS and in experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Suppressing TLR9 function not only reduces inflammation, but also promotes TREGS and improves disease. Polarization of naïve, myelin-reactive T cells into inflammatory T cells (e.g., TH17) or TREGS is localized to spleen and lymph nodes (LNs), tissues that coordinate immunity. Thus, strategies that help program how T cells differentiate when myelin is presented in LNs – for example, delivering regulatory cues – could generate large populations of myelin-specific TREGS that stop pathogenic immune cells without broad suppression. Nanotechnology holds great promise in this area through increased control over targeting, release kinetics, and delivery of multiple signals. However, many polymer particles and other materials exhibit intrinsic features that activate inflammatory pathways, which could exacerbate autoimmune disease. Strategies that mimic attractive features of biomaterials, while eliminating inflammatory “carrier” effects could be transformative for new therapies for MS or other autoimmune diseases. Toward this goal, the proposed research will use polyionic immune signals to create novel nanostructured capsules built entirely from regulatory immune signals and myelin antigens. These immune polyelectrolyte multilayers (“iPEMs”) are assembled through electrostatic interactions on a template, which is then removed to leave vaccines capsules that juxtapose myelin and TLR9-suppressive nucleic acids (GpG). Since there is no carrier, the density of signals in iPEMs is very high relative to lipid or polymer formulations with cargo embedded in a matrix. Further, the particles condense the signals at high densities, a characteristic that could promote differentiation toward TREG through co-localization of myelin with GpG in LNs. Biodistribution studies in mice reveal that even upon trafficking to LNs, iPEMs maintain juxtaposition of myelin and the regulatory signal. Pilot studies in a mouse model of MS demonstrate striking efficacy, with iPEM treatment stopping disease in 100% of mice – clinical score of 0, compared to development of several paralysis in 91% of untreated mice. The proposed work will build on these findings to test the hypotheses that assembly of self-antigen and regulatory immune signals generates tolerance in mouse models of MS and samples from human MS patients, test if this tolerance is myelin-specific, and investigate the mechanism and durability of efficacy. The specific aims are 1) characterize iPEM properties and screen in mouse cells and samples from the Baltimore VA’s MS patient cohort, 2) assess potency in a progressive mouse model of MS (EAE) and test if tolerance is myelin-specific, 3) elucidate the structural and functional changes in LNs, spleen, and the CNS that lead to tolerance, 4) test if tolerance is generalizable to other self-antigens using a relapsing-remitting model of MS (RR-EAE). VA support for this project could enable technology that creates more specific and effective treatments for MS or other autoimmune diseases that impact many Veterans.