Leveraging nanotechnology and skin delivery to drive selective immune tolerance for Multiple Sclerosis

多发性硬化症(MS)是一种自身免疫性疾病，当免疫系统对 髓鞘包裹着中枢神经系统(CNS)的轴突。髓鞘的损伤可能 导致瘫痪、视力障碍和其他神经并发症，这些并发症会显著减少MS 患者的生活质量。目前还没有治愈的方法，许多多发性硬化症疗法也会消除有益的免疫力。一 特异性对抗自身免疫的实验策略是产生调节细胞类型，如 调节性T细胞(Treg)。这种方法的目标是选择性地抑制炎性T和B细胞 它们分别通过细胞毒途径或抗体生成而成为过度活跃的髓鞘和靶向髓鞘。 抗自身免疫的抗原特异性树突状细胞和耐受性的产生可以提供持久的 治疗，同时保持保护性免疫。促进Tregs的一个新想法是抑制Toll样受体 (TLR)信令。TLRs调节一组调节免疫的强大通路，并进化为检测 病原体与启动炎症和消除危险病原体的分子模式相关联。而当 TLRs因其在病原体检测中的作用而广为人知，令人惊讶的新研究表明TLRs也过度活跃 在自体免疫期间。为了利用TLR信号，Jewell实验室开发了一个纳米技术平台，其中 调节TLR配体(GPG)是用髓鞘自身抗原(MOG)合成的，以确保免疫细胞同时接收 促进髓鞘特异性树突状细胞的信号。由于这些被称为免疫聚电解质的纳米材料 多层膜(IPEM)-完全由免疫信号构建，它们以高密度显示信号 调节免疫功能。服用含有GPG和MOG的iPEM可预防疾病相关 MS实验性自身免疫性脑脊髓炎(EAE)小鼠模型的瘫痪。 尽管前景看好，但这些效果是暂时的，需要多次、高剂量的iPEM注射。要克服 这些挑战，我将开发微针阵列(MNAs)来交付由髓鞘自身抗原和 调节性TLR配体直接作用于皮肤。MNAs是小斑块(直径约1厘米)。用聚合物针刺几个 数百微米长，旨在针对皮肤中免疫丰富的层。皮肤是我们最大的免疫力 器官，含有高密度的免疫细胞，具有特殊的表型，不断地研究 皮肤是外来病原体的来源。最近的证据表明，这些免疫细胞中的一些具有独特的能力 在体内促进Tregs，然后能够抑制普通小鼠模型的瘫痪症状 这些令人兴奋的最新结果表明，如果皮肤中的免疫细胞对耐受性有偏见， 通过它们的TLR信号通路，它们可能被导向耐受表型。 这种VA CDA-2方案的中心假设是，通过MNAs传递的耐受性iPEM将推动 迁移到引流淋巴结(LNS)的皮肤驻留抗原提呈细胞的耐受性表型 并指示T细胞向抑制MS小鼠模型中自身免疫的Treg表型转化，以测试这一点。 假设，我设计了三个具体的目标：1)在MNAs上组装IPEM涂层并预测其有效性 在体外，2)使用MNAs将iPEMS传递到皮肤以测试MS小鼠模型的有效性和特异性，以及3)测试 Tregs在提高IPEM包被MNAs疗效和研究皮肤耐受生物标志物中的作用 抽干了国民警局。这种方法将提供两个独特的机会来同时解决疾病和生活质量问题 退伍军人及其家人面临的问题。首先，利用皮肤独特的免疫环境来实现 抗原特异性耐受可提高MS的治疗效果和特异性。其次，MNAs可以 由患有运动障碍的多发性硬化症患者独立应用，将提高独立性和依从性。 总体而言，实现这些目标将提高退伍军人多发性硬化症患者的生活质量。

Multiple sclerosis (MS) is an autoimmune disease that develops when the immune system loses tolerance for myelin in the sheath wrapping axons of the central nervous system (CNS). Damage to the myelin sheath can result in paralysis, vision impairment, and other neurological complications that significantly diminishes MS patient quality of life. There is no cure and many MS therapies also eliminate beneficial immunity. One experimental strategy to specifically counter autoimmunity is the generation of regulatory cell types, such as regulatory T cells (TREGS). The goal of such approaches is to selectively suppress the inflammatory T and B cells that are overactive and target myelin through cytotoxic pathways or antibody generation, respectively. Generation of antigen-specific TREGS and tolerance that counter autoimmunity could provide long-lasting treatments, while preserving protective immunity. A new idea to promote TREGS is suppression of toll-like receptor (TLR) signaling. TLRs regulate a power set of pathways that regulate immunity and evolved to detect the pathogens associated molecular patterns to initiate inflammation and eliminate dangerous pathogens. While TLRs are well known for their role in pathogen detection, surprising new studies show TLRs are also over-active during autoimmunity. To harness TLR signaling, the Jewell lab developed a nanotechnology platform where a regulatory TLR ligand (GpG) is synthesized with myelin self-antigen (MOG) to ensure immune cells receive both the signals to promote myelin-specific TREGS. Since these nanomaterials – termed immune polyelectrolyte multilayers (iPEMs) – are built entirely from the immune signals, they display the cues at a high density to potently modulate immune function. Administration of the iPEMs containing GpG and MOG prevents disease-associated paralysis in the experimental autoimmune encephalomyelitis (EAE) mouse model of MS. While promising, these effects were transient, and required multiple, high doses of iPEM injections. To overcome these challenges, I will develop microneedle arrays (MNAs) to deliver iPEMs built from myelin self- antigen and regulatory TLR ligands directly to the skin. MNAs are small patches (~1 cm dia.) with polymer needles several hundred microns in length, designed to target the immune-rich layers in skin. Skin is our largest immunological organ and contains a high density of immune cells, with specialized phenotypes that are constantly surveying the skin for foreign pathogens. Recent evidence indicates that some of these immune cells have a unique ability to promote TREGS in vivo, which were then able to suppress symptoms of paralysis in a common mouse model of MS. These exciting and recent results suggest that if the tolerance biased immune cells in skin could be harnessed through their TLR signaling pathways, they may be directed towards a tolerogenic phenotype. The central hypothesis of this VA CDA-2 proposal is that tolerogenic iPEMs delivered through MNAs will drive tolerogenic phenotypes in skin-resident antigen-presenting cells that will migrate to draining lymph nodes (LNs) and instruct T cells toward a TREG phenotype that restrains autoimmunity in a mouse model of MS. To test this hypothesis, I have designed three specific aims to: 1) assemble iPEM coatings on MNAs and predict their efficacy in vitro, 2) deliver iPEMs to skin using MNAs to test efficacy and specificity in mouse models of MS, and 3) test the role of TREGS in promoting efficacy of iPEM coated MNAs and investigate tolerance biomarkers in skin- draining LNs. This approach will provide two unique opportunities to address both disease and quality of life issues facing Veterans and their families. First, leveraging the unique immune environment in skin to achieve antigen-specific tolerance for MS could improve therapeutic efficacy and specificity. Second, MNAs can be applied independently by MS patients with motor deficits, which would improve independence and compliance. Collectively, achieving these goals would elevate Veteran MS patient quality of life.