Optical Imaging of Beta-Cell Function and Engraftment

β 细胞功能和植入的光学成像

• 批准号: 6666714
• 负责人: MASSIMO M. TRUCCO
• 金额: $ 14.31万
• 依托单位: CHILDREN'S HOSP PITTSBURGH/UPMC HLTH SYS
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-09-30 至 2004-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6666714
• 关键词: NOD mouse; T lymphocyte; bioimaging /biomedical imaging; bioluminescence; cell line; gene targeting; genetic recombination; genetically modified animals; green fluorescent proteins; insulin; intracellular transport; laboratory mouse; leukocyte activation /transformation; luciferin monooxygenase; optics; pancreas imaging /visualization; pancreatic islet function; pancreatic islet transplantation; reporter genes; somatostatin; transcription factor

DESCRIPTION (provided by applicant): The clinical practicality of treating type 1 diabetics with islet transplants obviating the need for exogenous insulin replacement became evident once the first seven successful transplants were officially announced by the Edmonton group. This study proved two major points: the technical feasibility of improved islet isolation procedures and transplantation modalities and second, that more than one allogeneic donor is required to obtain an appropriate ¿-cell mass to treat one recipient. Apparently, necrotic and apoptotic processes during the isolation procedure dramatically reduce the number of functional ¿-cell mass obtainable. Even with an appropriate ¿-cell mass, islet transplants are still susceptible to autoimmune and alloimmune rejection. To protect the graft against the negative consequences of these processes, the Edmonton team used a cocktail of potent immunosuppressive drugs. The recipients are required to maintain this regimen of immunosuppression for their entire lifetime. However, this therapy does pose toxicity risks in that prolonged use of this cocktail can impair kidney and liver function. This concern is a major factor that impedes the introduction of this regimen for routine clinical use to prevent immune rejection of islet transplants in young diabetics. In contrast, tolerance induction strategies, rather than immunosuppression, appear to be the favorable approach to treat children with diabetes. In an attempt to study different tolerogenic protocols, it will become extremely important to be able to follow in vivo the activities of activated T cells simultaneously with the damage inflicted to the transplanted islets. The imaging system we are proposing herein will certainly be valuable to more quickly acquire the knowledge needed to progress from intervening in rodents to rational human trials. These methods should allow non-invasive live cell imaging in live animals. We propose the development of an optical fluorescence and luminescence-based system where the fluorescent and luminescent markers are detectable above physiologic self-fluorescent backgrounds, yet sufficiently discriminative (e.g., green versus red) to allow the monitoring of different cell types simultaneously. These constitute the main goals of this application and the basis upon which the feasibility of our tolerogenic approaches will be carefully evaluated.

描述（由申请人提供）：埃德蒙顿小组正式宣布前七次成功移植后，通过胰岛移植治疗 1 型糖尿病而无需外源性胰岛素替代的临床实用性就变得显而易见。这项研究证明了两个要点：技术。改进胰岛分离程序和移植方式的可行性，其次，需要多个同种异体供体才能获得适当的 ¿显然，分离过程中的坏死和凋亡过程大大减少了功能性细胞的数量。 -即使使用适当的 ¿ 也可获得细胞质量。细胞团、胰岛移植物仍然容易受到自身免疫和同种免疫排斥的影响，为了保护移植物免受这些过程的负面影响，埃德蒙顿团队使用了强效免疫抑制药物的混合物，要求受者维持这种免疫抑制方案。然而，这种疗法确实会带来毒性风险，因为长期使用这种混合物会损害肾脏和肝脏功能，这种担忧是阻碍这种疗法常规临床使用以防止免疫排斥反应的主要因素。相比之下，耐受诱导策略而不是免疫抑制似乎是治疗糖尿病儿童的有利方法。在尝试研究不同的耐受性方案时，能够在体内遵循将变得极其重要。我们在此提出的成像系统对于更快地获取从干预啮齿动物到合理的人体试验所需的知识肯定是有价值的。我们建议开发一种基于光学荧光和发光的系统，其中荧光和发光标记在生理自荧光背景之上是可检测的，但具有足够的辨别力（例如，绿色与红色）以允许同时监测不同的细胞类型，这些构成了该应用的主要目标，也是仔细评估我们的耐受性方法的可行性的基础。