Targeted depletion of programmed death-1 positive cells, a method that not only stops autoimmune attack but also preserves adaptive immunity

项目摘要 自身免疫性疾病（AD）影响着5000万美国人和全球12.5%的人， 对于大多数AD患者，目前还没有治愈或有效的预防方法。广告的根本原因是免疫攻击 通过自身反应性效应淋巴细胞和淋巴细胞分泌的抗体作用于自身组织。因此，我们认为， 淋巴细胞抑制已被用作改善AD的策略。这种策略已经产生了药物， 减缓某些AD的进展，但不能预防或治愈AD。此外，这些药物会导致长期免疫 缺乏并使AD患者容易受到致命的机会性感染。一个核心原因是， 目前的淋巴细胞抑制药物未能集中于自身反应性效应细胞。的 药物抑制和消耗不导致AD的天然淋巴细胞，这导致不必要的和 广泛的免疫缺陷同时，目前的药物不能抑制所有的自身反应性效应淋巴细胞： 仅抑制B效应细胞或仅抑制T效应细胞。为了解决这个问题，我们提出了一个新的 淋巴细胞抑制方法包括所有自身反应性效应细胞，但不包括幼稚细胞。的 该方法利用程序性死亡-1受体（PD-1）作为生物标志物，以识别、靶向和消除 自身反应性效应细胞PD-1在B和T效应淋巴细胞上表达。因此，可以针对 使用PD-1标记的所有自身反应性效应淋巴细胞。更重要的是，PD-1阳性（PD-1+）细胞具有 在AD患者的炎症组织中发现有浸润，并且随着AD的进展，浸润加剧。一个 通过阻断PD-1对这些细胞诱导的活性和扩增的增强， 在动物和人类中的严重广告。相反，我们的初步数据表明，PD-1+的消耗 细胞是非常有希望治疗自身免疫性1型糖尿病和慢性实验性自身免疫性 脑脊髓炎（EAE）。另一方面，幼稚淋巴细胞不表达PD-1，因此PD-1+细胞的消耗将导致PD-1+细胞的减少。 让他们保持完整。综上所述，我们假设PD-1阳性细胞的靶向清除不仅 改善AD，但也保持健康的免疫力。为了验证这一假设，我们制造了一种 用于体内PD-1+细胞耗竭的分子，aPD-1-ABD-PE。aPD-1-ABD-PE被设计成具有三种功能性 元件，靶向PD-1+细胞的抗PD-1抗体（aPD-1），增加PD-1+细胞的白蛋白结合结构域（ABD）， aPD-1-ABD-PE的血浆存在，以及假单胞菌外毒素（PE）以杀死aPD-1-ABD-PE 进入。aPD-1-ABD-PE对PD-1+细胞具有选择性毒性。在本项目中，我们将通过以下方式测试该假设 三个具体目标：目标1：表征和制备aPD-1-ABD-PE作为靶向PD-1+细胞耗竭的工具; 目的2：确定PD-1+细胞耗竭可改善T1 D、EAE和SLE（三种代表性AD）;目的3： 确定长期PD-1+细胞耗竭不会导致长期免疫缺陷。该项目响应 直接针对改善AD治疗的突出需求，这是国家研究所的优先研究领域 过敏症和传染病。

Project Summary Autoimmune diseases (ADs) affect 50 million Americans and 12.5% of people worldwide, and for the vast majority of AD patients, there is no cure or effective prevention methods. The root cause of ADs is immune attack on self-tissues by auto-reactive effector lymphocytes and antibodies secreted by the lymphocytes. Therefore, lymphocyte suppression has been utilized as a strategy to ameliorate ADs. This strategy has yielded drugs that slow the progression of some ADs but do not prevent or cure ADs. Further, these drugs cause long-term immune deficiency and render AD patients susceptible to lethal opportunistic infections. One core reason for these deficiencies is the failure of current lymphocyte suppression drugs to focus on autoreactive effector cells. The drugs suppress and deplete native lymphocytes that do not contribute to ADs, which cause unnecessary and broad immune deficiency. Meanwhile, the current drugs fail to suppress all autoreactive effector lymphocytes: only B effector cells or only T effector cells are suppressed. To address this issue, we propose a novel lymphocyte suppression approach that encompasses all autoreactive effector cells but not naive cells. The approach utilizes the programmed death-1 receptor (PD-1) as a biomarker to identify, target and eliminate autoreactive effector cells. PD-1 is expressed on both B and T effector lymphocytes. Thus, it is possible to target all autoreactive effector lymphocytes using the PD-1 marker. More importantly, PD-1-positive (PD-1+) cells have been found to infiltrated inflamed tissues in ADs, and the infiltration is intensified while the ADs progress. An enhancement of the activity and amplification of PD-1+ cells by blocking PD-1 on these cells induced and aggravated ADs in animals and humans. On the contrary, our preliminary data showed that depletion of PD-1+ cells is very promising to treat autoimmune type-1 diabetes and chronic experimental autoimmune encephalomyelitis (EAE). On the hand, naive lymphocytes do not express PD-1, so depletion of PD-1+ cells will keep them intact. Taken together, we hypothesize that targeted depletion of PD-1-positive cells not only ameliorates in ADs but also preserves healthy immunity. To test this hypothesis, we generated an elegant protein molecule for in vivo PD-1+ cell depletion, aPD-1-ABD-PE. aPD-1-ABD-PE was designed to have three functional elements, an anti-PD-1 antibody (aPD-1) to target PD-1+ cells, an albumin-binding domain (ABD) to increase plasma presence of aPD-1-ABD-PE, and a Pseudomonas exotoxin (PE) to kill the cells that aPD-1-ABD-PE enters. aPD-1-ABD-PE has selective toxicity to PD-1+ cells. In this project, we will test the hypothesis through three specific aims: Aim 1: Characterize and prepare aPD-1-ABD-PE as a tool for targeted PD-1+ cell depletion; Aim 2: Establish that PD-1+ cell depletion ameliorates T1D, EAE, and SLE, three representative ADs; Aim 3: Establish that long-term PD-1+ cell depletion does not cause long-term immune deficiency. This project responds directly to the prominent need to improve the treatment for ADs, a priority area of study of the National Institute of Allergy and Infectious Diseases.