Novel Therapies for Epilepsy Using Biodegradable Immune-Modifying Nanoparticles

 描述(申请人提供)：抗癫痫药是癫痫的标准治疗方法，但只控制症状，不解决疾病的机制。约三分之一的患者出现抗药性癫痫，只有部分患者适合接受切除手术，作为减少癫痫发作的最后尝试。最近，为了寻找可能针对癫痫病因的新疗法，我们的实验室率先在手术切除的新鲜脑组织样本中表征了炎性细胞渗透。我们的数据有力地表明了免疫细胞在癫痫脑中的激活作用，而与癫痫的特定病因无关。我们发现癫痫患者和实验动物的大脑中都有显著的功能性激活淋巴细胞的渗透。此外，以抗炎著称的类固醇在多种类型的耐药癫痫中都显示出了疗效。然而，长期使用类固醇的严重免疫抑制和其他严重副作用阻碍了这些药物对原本可以治疗的患者的广泛处方。这项建议的目标是利用小鼠模型设计新的治疗癫痫的方法，使用不依赖广泛作用的免疫抑制剂的定向免疫调节方法。我们建议测试这一假说，即抑制大脑中持续的炎症可以有效地减少早期癫痫发作的致痫作用，并 最终在没有全身性免疫抑制的情况下预防癫痫。这项提议有两个目的。具体目标1将确定由FDA批准的生物聚合物聚(丙交酯-乙交酯)(PLG)配制的可生物降解纳米颗粒在脾中隔离白细胞和减少脑部炎症以防止早期癫痫发作的启动效应的有效性和潜在机制。具体目的2旨在评估自体自然调节性T细胞(NTreg)输注的疗效以及PLG纳米颗粒治疗与外源性nTregs联合治疗在改善癫痫小鼠模型神经炎症方面的潜在协同作用。我们之前的工作证明了使用可生物降解的纳米颗粒在动物模型中治疗各种炎症性免疫介导性疾病的成功。值得注意的是，我们的初步结果表明，在我们的两次打击癫痫发生模型中，使用PLG纳米颗粒治疗可以改善癫痫发作的结果。我们建议阐明其潜在的治疗机制。此外，我们建议测试患者的nTregs单独或与PLG纳米颗粒联合抑制癫痫脑内免疫反应的能力。我们之前曾报道，在几种多发性硬化症动物模型中，补充nTregs可以通过预防脑部炎症显著降低疾病严重程度。我们的方法针对炎症并在没有类固醇复杂影响的情况下通过炎性白细胞亚群限制脑渗透，这是非常新颖的，可能是朝着癫痫根本原因的新治疗方法的转化迈出的重要一步。

 DESCRIPTION (provided by applicant): Anticonvulsants are the standard treatment for epilepsy, but only control the symptoms without addressing the mechanisms of the disease. About 1/3 of patients develop drug-resistant epilepsies and only some are candidates for resective surgery as a final attempt to reduce seizure occurrence. Recently, our laboratory has pioneered the characterization of inflammatory cell infiltrates in surgically removed fresh brain samples in a search for novel therapies that may target the cause of epilepsy. Our data strongly indicate a role for immune cell activation in the epileptic brain irrespective of the particular etiology of epilepsy. We discovered significant brain infiltration of functionally activated lymphocytes in both epileptic patients and experimental animals. Additionally, steroids that are known for their anti-inflammatory properties have shown efficacy in a number of types of drug-resistant epilepsy. However, the profound immunosuppressive and other severe side effects of chronic steroid use have prevented widespread prescription of these drugs to otherwise treatable patients. The goal of this proposal is to use mouse models to design novel therapies to treat epilepsy using directed immunomodulatory approaches independent of broad-acting immunosuppressive agents. We propose to test the hypothesis that dampening ongoing inflammation in the brain could effectively reduce epileptogenic effects of early-life seizures and ultimately prevent epilepsy in the absence of systemic immunosuppression. This proposal has two aims. Specific Aim 1 will determine the efficacy and underlying mechanisms by which biodegradable nanoparticles formulated from the FDA-approved biopolymer poly(lactide-co- glycolide) (PLG) induce leukocyte sequestration in the spleen and reduction of brain inflammation to prevent the priming effect of early-life seizures. Specific Aim 2 is designed to assess the efficacy of autologous natural regulatory T cell (nTreg) infusion and the potential synergistic effect of PLG nanoparticle treatment in combination with exogenously introduced nTregs in the amelioration of neuroinflammation in murine models of epilepsy. Our previous work documented the success of using biodegradable nanoparticles to treat a variety of inflammatory immune-mediated diseases in animal models. Strikingly, our preliminary results indicate that treatment with PLG nanoparticles can improve seizure outcomes in our two-hit model of epileptogenesis. We propose to elucidate the underlying therapeutic mechanisms. Additionally, we propose to test the ability of a patient's nTregs to dampen immune responses in the epileptic brain alone or in combination with PLG nanoparticles. We have previously reported that supplementation of nTregs could significantly reduce disease severity in several animal models of multiple sclerosis by preventing brain inflammation. Our approaches that target inflammation and restrict brain infiltration by inflammatory leukocyte subsets in the absence of the complicating effects of steroids are highly novel and may be a major step forward for the translation of novel treatments for the root cause of epilepsy.