Controlling complement to unleash nanomedicine for acute critical illnesses

摘要/摘要 急性危重病会迅速导致严重的器官损伤和生命损失。这些疾病包括 败血症、中风和急性呼吸窘迫综合征(ARDS)。这里我们关注的是急性呼吸窘迫综合征。 肺部气囊发炎，新冠肺炎的死因。对于ARDS和这些其他疾病， 我们已经开发了配体靶向的纳米载体，可以将药物定位于受影响的炎症微血管系统 器官。随着我们走向临床翻译，我们发现关键的一步是获得补体的控制，补体是一组 结合微生物并帮助其清除的血浆蛋白。但我们发现了补体纳米颗粒 交互是一把“双刃剑”，既有需要优化的好处，也有需要解决的有害特性。 首先，我们发现补体蛋白C3迅速调理特定的纳米颗粒，并且这种C3- 然后，调理后的纳米颗粒充当“诱饵”，将ARDS小鼠模型(例如，雾化内毒素)改善约75%。 C3包裹的纳米颗粒聚集在边缘的白细胞中，这是ARDS病理生理的关键， 并使这些细胞离开肺部。然而，C3的调理作用会引起一种类似过敏反应的反应，称为 CARPA(补体激活相关假性变态反应)。因此，在目标1中，我们将设计纳米颗粒 这可以像C3包裹的诱饵一样起到改善ARDS的作用，但没有CARPA。我们还将调查 纳米粒子诱饵疗法的机制。然后我们将测试这些词的翻译潜力 通过在新鲜的、灌流的、体外的人肺中测试诱饵纳米颗粒来优化它们。 其次，我们发现我们一直在开发的用于药物输送的配体靶向纳米颗粒 年份也会诱发CARPA。因此，在目标2中，我们将重新设计我们的配体靶向纳米颗粒，以防止 CARPA。我们将测试一种我们以前用来在肺泡内浓缩药物的药物载体 肺微血管构筑：与结合内皮细胞的抗PECAM抗体结合的脂质体。我们 将在体外和在小鼠体内测试各种工程版本的抗PECAM脂质体是否可以逃避 C3调理和CARPA，从而实现更具体的肺部给药。最后，我们将测试这些 避免CARPA的纳米颗粒与ARDS患者的血浆一起使用，因为这类患者的补体受到干扰。 在完成这两个目标后，我们将开发出两种技术，可能有助于治疗 ARDS：1)诱骗纳米颗粒，安全地使边缘白细胞离开肺，从而 改善ARDS样表型；2)预防补体副作用的技术，如CARPA 当输送配体靶向的纳米颗粒时。因为边缘白细胞在大多数急性危重病中起着关键作用 疾病，以及对CARPA的敏感性对这些人也很常见，这里开发的技术可能不会影响 不仅是急性呼吸窘迫综合征，还有败血症、中风等。

ABSTRACT / SUMMARY Acute critical illnesses rapidly lead to severe organ damage and loss of life. These illnesses include sepsis, stroke, and acute respiratory distress syndrome (ARDS). Here we focus on ARDS, which is acute inflammation of the lungs’ air sacs, and the cause of death in COVID-19. For ARDS and these other diseases, we have developed ligand-targeted nanocarriers that localize drugs to the inflamed microvasculature of affected organs. As we moved towards clinical translation, we found the key step is gaining control of complement, a set of plasma proteins that bind microbes and aid their clearance. But we found complement-nanoparticle interactions are a “double-edged sword”, with both benefits to optimize, and deleterious features to resolve. First, we found that complement protein C3 rapidly opsonizes particular nanoparticles, and that such C3- opsonized nanoparticles then act as “decoys” to ameliorate ARDS mouse models (e.g., nebulized LPS) by ~75%. The C3-coated nanoparticles accumulate in marginated leukocytes, which are key to ARDS pathophysiology, and cause those cells to leave the lungs. However, C3 opsonization induces an anaphylaxis-like reaction called CARPA (complement-activation-related pseudo-allergy). Therefore, in Aim 1, we will engineer nanoparticles that can function like C3-coated decoys to ameliorate ARDS, but without CARPA. We will also investigate the mechanism underlying nanoparticle decoy therapy. Then we will test the translational potential of these optimized decoy nanoparticles by testing them in fresh, perfused, ex vivo human lungs. Second, we found that the ligand-targeted nanoparticles we have been developing for drug delivery for years also induce CARPA. Therefore, in Aim 2, we will re-engineer our ligand-targeted nanoparticles to prevent CARPA. We will test a drug carrier we have previously used to concentrate drugs in the alveolar microvasculature of the lungs: liposomes conjugated to anti-PECAM antibodies that bind endothelial cells. We will test in vitro and in vivo in mice whether various engineered versions of anti-PECAM liposomes can evade C3 opsonization and CARPA, and thereby achieve more specific delivery to the lungs. Lastly, we will test these CARPA-avoiding nanoparticles with plasma from ARDS patients, as such patients have perturbed complement. Upon completion of these two Aims, we will have developed two technologies that may aid therapy of ARDS: 1) Decoy nanoparticles that safely cause marginated leukocytes to leave the lungs, and thereby ameliorate ARDS-like phenotypes; 2) A technology for preventing complement side effects such as CARPA when delivering ligand-targeted nanoparticles. As marginated leukocytes play pivotal roles in most acute critical illnesses, and CARPA sensitivity is common to those as well, the technologies developed here may impact not only ARDS, but also sepsis, stroke, and more.