Submicron ultrasound contrast agents as diagnostic agents and therapeutic vehicles in type 1 diabetes

项目总结 1型糖尿病(T1D)的特征是自身反应性T细胞在胰岛中的渗透，导致 自身免疫破坏产生胰岛素的β细胞和糖尿病。启动自身免疫和实质性 β细胞丢失可能在症状出现前几年就开始了。因此，迫切需要发展 针对T1D这一通常漫长的症状前阶段的诊断和治疗干预。 针对症状前T1D的治疗方法的临床试验取得了有限的成功。 虽然抗CD3抗体显示出了希望，但抗CD3抗体仅在研究队列的一部分中预防了糖尿病的发生 不是针对对胰岛素等β细胞抗原有反应的T细胞。一种具有 在临床前研究中获得了实质性的支持是使用多肽疗法来提供对 自身反应性T细胞靶向的抗原。胰岛素肽疗法在小鼠身上的应用已被证明 通过扩大胰岛素反应调节性T细胞来预防糖尿病的发生，这种T细胞具有抗炎和 对于适当的免疫耐受和调节是必不可少的。尽管胰岛素多肽具有治疗潜力，但它已经 在不同的组中显示出不同的结果，并且只有通过外科手术才能有效地使用 植入输液泵。因此，通过靶向递送和 与诊断学的结合是必要的。这可以使用超声造影剂(UCAS)来完成， 它们是可以使用对比增强超声(CEU)显示的充满气体的小气泡，并且 安全，易于配制，并得到临床批准。一种新型的亚微米“纳米气泡”超声造影剂 已经开发出来，先前的工作表明，在小鼠的胰岛中增加了纳米气泡的积累 症状前T1D是炎症相关的微血管通透性所致。我的总体目标是 开发和应用亚微米UCA用于针对疾病部位的靶向治疗药物和 追踪治疗对T1D进展的影响。我假设亚微米级的UCA可以应用于 两者都预测治疗性诱发疾病的预防，并作为靶向多肽输送的载体。我会检查一下 这是通过两个具体的目标实现的：我的目标1，我将预测使用亚微米UCA进行治疗性疾病预防， 使用CEUS检测治疗干预后亚微米UCAs的胰岛堆积的变化。在……里面 目的2、应用Ucas作为治疗性多肽载体。初步数据表明，多肽可以 被掺入纳米泡泡中，纳米泡泡可以将多肽靶向胰岛。我将描述……的影响 多肽细胞摄取的纳米气泡消融表征了多肽-纳米气泡胰岛外渗的动力学， 并评估多肽-纳米气泡治疗的免疫学和疾病修改效果。开发代理 这使得治疗性多肽在胰岛中积累，增强了治疗效果，并使疾病- 逆转预测诊断学可以作为T1D预防的一个重大进步。

PROJECT SUMMARY Type 1 diabetes (T1D) is characterized by infiltration of autoreactive T cells in pancreatic islets, leading to autoimmune destruction of insulin-producing beta cells and diabetes. Initiation of autoimmunity and substantial beta cell loss may begin years prior to symptomatic onset. Therefore, there is a crucial need to develop diagnostics and therapeutic interventions directed towards this often-lengthy presymptomatic phase of T1D. Limited success has been demonstrated in clinical trials for therapeutics directed towards presymptomatic T1D. While anti-CD3 has shown promise, anti-CD3 only prevented diabetes onset in a subset of the study cohort and is not directed specifically against T cells reactive to beta cell antigens, such as insulin. An approach that has gained substantial traction in preclinical studies is the usage of peptide therapeutics to provide tolerance towards antigens targeted by autoreactive T cells. Administration of insulin peptide therapeutics in mice has been shown to prevent diabetes onset by expanding insulin-reactive regulatory T cells, which are anti-inflammatory and are essential for proper immune tolerance and regulation. Despite their therapeutic potential, insulin peptides have shown mixed results amongst different groups and have only been effectively administered via surgical implantation of an infusion pump. Therefore, optimizing therapeutic efficacy through targeted delivery and incorporation with diagnostics is warranted. This could be accomplished with ultrasound contrast agents (UCAs), which are small gas-filled bubbles that can be visualized using contrast enhanced ultrasound (CEUS) and are safe, easy to formulate, and clinically approved. A novel, submicron, ‘nanobubble’ ultrasound contrast agent has been developed and prior work has demonstrated enhanced accumulation of nanobubbles in islets of mice with presymptomatic T1D as a result of inflammation-associated microvascular permeability. My overall goal is to develop and apply submicron UCAs to both target therapeutic agents specifically to the disease site and track the effect of therapeutics on T1D progression. I hypothesize that submicron UCAs can be applied to both predict therapeutic induced disease prevention and as vehicles for targeted peptide delivery. I will examine this via two specific aims: I aim 1, I will predict therapeutic-induced disease prevention using submicron UCAs, using CEUS to detect changes in islet accumulation of submicron UCAs following therapeutic intervention. In aim 2, I will apply UCAs as therapeutic peptide delivery vehicles. Preliminary data indicates that peptide can be incorporated into nanobubbles and nanobubbles can target peptide to islets. I will characterize effect of nanobubble ablation on peptide cellular uptake characterize dynamics of peptide-nanobubble islet extravasation, and assess immunological and disease-modifying effects of peptide-nanobubble treatment. Developing an agent that allows for accumulation of therapeutic peptides in islets, enhanced therapeutic efficacy, and disease- reversal-predicting diagnostics can serve as a major advancement in T1D prevention.