Defining the induction and maintenance of myelin-specific tolerance in T cells and B cells using local lymph node depots

项目摘要：在自身免疫过程中，身体错误地将“自身”分子识别为外源分子。在……里面 多发性硬化症(MS)中枢神经系统(CNS)中髓鞘的攻击会导致神经变性。现有 治疗多发性硬化症的方法很多，从免疫抑制剂到新的单抗，但即使是后者也不能 区分显示抗体靶标的健康细胞和自我反应细胞。因此，虽然有益，但存在 治疗方法不能治愈，会引起免疫损害的副作用，并且需要终生依从性。这些 限制促使人们努力以疫苗般的特异性控制自身免疫，让其余的 免疫系统完好无损。一种这样的抗原特异性耐受策略正在临床前和人类身上进行研究 试验是联合传递髓磷脂多肽和耐受免疫信号以促进种群，如调节 对抗多发性硬化的T细胞(Treg)T细胞分化为炎性T细胞(如TH17)或Treg是局部的 到淋巴结(LNS)，即协调免疫的组织。新的研究还表明，Treg可以采用记忆 保持容忍度的功能。此外，在适当的组织利基中，炎性TH17细胞可以 转化为特雷格。同样，B细胞在几个方面与多发性硬化症相关，包括产生致病 髓鞘特异性抗体，并可作为治疗靶点，具有调节功能。LNS在以下方面发挥关键作用 这些过程，引导动态间质组织促进和调节细胞的相互作用和调节 控制T细胞和B细胞在(自动)炎症和耐受功能之间极化的信号。从一个 治疗观点，控制这一利基市场具有挑战性，使用传统的交付技术(例如，系统 注射/输注)，甚至生物材料方法，如靶向纳米颗粒，都面临着建立 注射后耐用的组织环境。然而，理解和控制集成的能力 LN微环境中的信号可以实现有效的髓鞘特异性免疫疗法，从而避免 免疫抑制。我们建议使用结合直接内部LN(I.LN)的平台来实现这一目标。注射法 有控制释放的生物材料库。我们已经展示了扩散受限的聚合物仓库，这些仓库太大了 在注入浓缩物后从LNS中排出，并将仓库装载的货物保留在LNS中。使用装载有 髓磷脂多肽和雷帕霉素-一种免疫调节药物，我们已经展示了一种单一的治疗方法，在 多发性硬化症临床前模型中的疾病可以逆转90多天的瘫痪。静脉注射LN不能达到疗效。 注入可溶货物，或通过传统路线注入仓库。我们将使用这种跨学科 免疫工程方法了解局部控制释放如何促进耐受性间质LN 以及这些效应如何诱导和维持T和T细胞对髓鞘的长期耐受功能 B细胞。其目的是1)确定疗效的稳健性和基础的治疗效果 神经炎症，2)表明耐受性是抗原依赖的，并由Treg维护和驱动 可塑性，3)显示iLN库破坏生发中心，减少自身抗体，并诱导耐受性B细胞。

PROJECT SUMMARY: During autoimmunity, the body incorrectly identifies “self” molecules as foreign. In multiple sclerosis (MS) attack of myelin in the central nervous system (CNS) leads to neurodegeneration. Existing therapies for MS range from immunosuppressants to newer monoclonal antibodies, but even the latter do not distinguish between healthy and self-reactive cells displaying the antibody target. Thus, while beneficial, existing therapies are not curative, cause immunocompromising side effects, and require life-long compliance. These limitations have motivated efforts to control autoimmunity with vaccine-like specificity, leaving the rest of the immune system intact. One such antigen-specific tolerance strategy being studied pre-clinically and in human trials is co-delivery of myelin peptide and tolerizing immune signals to promote populations, such as regulatory T cells (TREG) that combat MS. The polarization of T cells into inflammatory T cells (e.g., TH17) or TREG is localized to lymph nodes (LNs), tissues that coordinate immunity. New studies also reveal TREG can adopt memory functions to maintain tolerance. Further, in appropriate tissue niches, inflammatory TH17 cells can transdifferentiate to TREG. Likewise, B cells are relevant to MS in several ways, including producing pathogenic myelin-specific antibodies, and as therapeutic targets able to adopt regulatory function. LNs play key roles in these processes, directing dynamic stromal organization to promote and regulate cell interaction and modulatory cues that control T and B cell polarization between (auto)inflammatory and tolerance functions. From a therapeutic view, controlling this niche is challenging using conventional delivery technologies (e.g., systemic injections/infusions), and even biomaterial approaches such as targeted nanoparticles face difficulty establishing durable tissue environments after injection. However, the ability to understand and control the integration of signals in the LN microenvironment could enable potent, myelin-specific immunotherapies that avoid immunosuppression. We propose tackling this goal using a platform that combines direct intra-LN (i.LN.) injection with controlled release biomaterial depots. We have shown diffusion-restricted polymer depots that are too large to drain from LNs after injection concentrate and retain depot-loaded cargo in LNs. Using depots loaded with myelin peptide and rapamycin - an immunoregulatory drug, we have shown a single treatment at the peak of disease in a pre-clinical model of MS reverses paralysis for over 90 days. Efficacy is not achieved with i.LN. injection of soluble cargo, or during injection of depots via traditional routes. We will use this interdisciplinary immune engineering approach to understand how local controlled release promotes a tolerogenic stromal LN environment and how these effects induce and maintain long-lasting tolerizing function against myelin in T and B cells. The aims are 1) Define the robustness of efficacy and the underpinning therapeutic effects on neuroinflammation, 2) Show the durability of tolerance is antigen-dependent and driven by TREG maintenance & plasticity, 3) Show i.LN. depots disrupt germinal centers, reduce auto-antibodies, & induce tolerogenic B cells.