Inflammatory Cells for Transport of Therapeutic Polypeptides Across the BBB

描述（由申请人提供）：目前，帕金森病（PD）没有治愈或阻断性治疗，只有姑息性治疗，如缺失神经递质的替代策略存在。主要障碍是血脑屏障（BBB），它严重限制了治疗药物的脑渗透，这可以成功地用于PD治疗。特别是，血脑屏障实际上对参与抗炎神经保护的多肽是不可渗透的。然而，有一类炎症反应细胞由于其边缘和外渗增加而具有非凡的穿越血脑屏障的能力。该方案的长期目标是开发一种靶向细胞介导的治疗性多肽输送到大脑，以减轻PD患者的神经炎症并产生神经保护作用。具体来说，我们的目标是在体外将抗炎多肽、过氧化氢酶加载小鼠骨髓源性单核细胞（BMM），并将这些细胞注入血液。为了防止酶在宿主细胞内降解，过氧化氢酶将与一种合成的带相反电荷的聚电解质偶联。载药的BMM将在体内通过血脑屏障向炎症信号移动，并释放纳米颗粒，减轻炎症。我们假设：1)加入过氧化氢酶的纳米颗粒将通过加速内吞作用被BMM吸收；2)负载的BMM会越过血脑屏障向炎症信号移动，3)纳米颗粒会通过胞外作用从脑内的载体细胞排出，在那里过氧化氢酶会产生神经保护作用。将过氧化氢酶掺入纳米颗粒将保持其在BMM内的活性，而使用细胞介导的递送将降低其免疫原性并将治疗多肽靶向到大脑。为了验证这一假设，首先，我们将合成一系列嵌段共聚物，以获得保护细胞内过氧化氢酶酶活性的过氧化氢酶/聚合物纳米颗粒，并优化其组成，以获得最大的负载效率和BMM多肽的持续释放。其次，我们将表征过氧化氢酶纳米颗粒在PD体内模型中的生物分布和治疗效果。预计这些研究将导致基于细胞介导的治疗性多肽主动递送的新技术的发展，从而减轻PD患者的神经炎症并产生神经保护作用。

DESCRIPTION (provided by applicant): Currently, there are no curative or interdictive therapies available for Parkinson's disease (PD), and only palliative therapies such as replacement strategies for missing neurotransmitters exist. The main obstacle is the blood brain barrier (BBB) that severely limits the brain penetration of therapeutics, which can be successfully used for PD therapy. In particular, BBB is practically impermeable for polypeptides involved in anti-inflammatory neuroprotection. Nevertheless, there is a class of inflammatory response cells that have extraordinary ability to cross the BBB due to their increased margination and extravasation. A long-term objective of this proposal is to develop a targeted cell-mediated delivery of therapeutic polypeptides to the brain to attenuate neuroinflammation and produce neuroprotection in patients with PD. Specifically, we aimed to load mouse bone-marrow derived monocytes (BMM) ex vivo with an anti-inflammatory polypeptide, catalase, and administer these cells into the blood stream. To protect the enzyme against degradation inside the host cells, catalase will be coupled with a synthetic polyelectrolyte of opposite charge. The drug-loaded BMM will migrate across the BBB in vivo toward the inflammation signal and release the nanoparticles that attenuate inflammation. We hypothesize that 1) catalase-incorporated nanoparticles will be taken by BMM through the accelerated endocytosis; 2) loaded BMM will migrate across the BBB toward the inflammation signal, and 3) the nanoparticles will be discharged by exocytosis from the carrier cells in the brain, where catalase will produce its neuroprotection effect. Incorporation of catalase into nanoparticles will preserve its activity inside BMM, while using cell-mediated delivery will reduce its immunogenecity and target the therapeutic polypeptide to the brain. To test this hypothesis, first, we will synthesize series of block copolymers to obtain catalase/polymer nanoparticles that protect enzymatic activity of catalase inside the cells, and optimize their composition with maximal loading efficiency and sustained release of the polypeptide from BMM. Second, we will characterize the biodistribution and therapeutic efficacy of catalase nanoparticles delivered by BMM in the PD in vivo model. It is anticipated that these studies will lead to the developing a new technology based on cell- mediated active delivery of therapeutic polypeptides that attenuate neuroinflammation and produce neuroprotection in patients with PD. Public Health Relevance: It is anticipated that these studies will lead to the developing a new technology based on cell-mediated active delivery of therapeutic polypeptides that attenuate neuroinflammation and produce neuroprotection in patients with PD.