CEST/FLEX MRI for the Detection of the Host Immune Response to CNS Grafts

CEST/FLEX MRI 用于检测宿主对中枢神经系统移植物的免疫反应

• 批准号: 8672704
• 负责人: Miroslaw Janowski
• 金额: $ 20.05万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-07-01 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8672704
• 关键词: Address; Adverse effects; Affect; Animals; Behavior assessment; Behavioral; Blood - brain barrier anatomy; Brain; Cell Survival; Cell Therapy; Cell Transplantation; Cell Transplants; Cells; Cellular Infiltration; Cellularity; Cerebrum; Chemicals; Clinic; Clinical; Clinical Trials; Complex; Data; Deposition; Detection; Diagnostic; Edema; Employee Strikes; Encephalitis; Evaluation; Frequencies; Future; Goals; Graft Rejection; Image; Immune; Immune response; Immunocompetent; Immunohistochemistry; Immunosuppression; Individual; Infiltration; Inflammation; Inflammatory; Injection of therapeutic agent; Intention; Label; Life; Luciferases; Magnetic Resonance Imaging; Measurement; Methods; Modality; Molecular; Molecular Profiling; Monitor; Multiple Sclerosis; Mus; Needles; Non-Invasive Cancer Detection; Normal tissue morphology; Oligodendroglia; Outcome; Patients; Pharmaceutical Preparations; Process; Proteins; Protons; Relative (related person); Research Personnel; Resistance; Rodent; Shivering; Signal Transduction; Site; Slice; Techniques; Tissues; Toxic effect; Translating; Translations; Transplant Recipients; Transplantation; Water; Weight; base; behavior test; dysmyelination; experience; implantation; interest; meetings; nervous system disorder; neuroinflammation; novel; protein metabolite; public health relevance; research study; response; tool

DESCRIPTION (provided by applicant): There have been an increased number of clinical trials with the use of intracerebral grafts for the treatment of neurological disorders. However, once the graft is deposited intracerebrally, the patient's immune response and the possible influence of that response on graft functionality is unknown. Imaging of neuroinflammation, such as with MRI in multiple sclerosis, is based on increased relative water content (edema) and/or measurements of a blood brain barrier (BBB) breach. Inflammation within cellular grafts, due to the small size, high cellularity, and the BBB that is affected by the injection needle, cannot be monitored by the same methods. In our extensive experience with cell transplantation in rodents, we have observed a great variability of graft infiltration by immune cells between individual animals, and a similar variability likely occurs in patients. This could explain the striking difference in outcomes between patients, including the unexpected severe side effects observed in a few patients, which frustrates both patients and clinical researchers. Thus, the aim of this proposal is to develop novel, clinically applicable approaches to the non-invasive detection of immune cell infiltration of the cellular graft. We have already established an experimental platform that is ideally suited to address the aims of this proposal. The immune deficient rag2-/- mice, characterized by absolute tolerance to all types of cellular grafts, will b employed as a reference for experimental, immune- competent hosts. Graft viability within the brain will be repeatedly evaluated by non-invasive bioluminescent imaging. The use of dysmyelinating shiverer mice (both rag2-/- and wild-type) as transplant recipients will enable the behavioral assessment of compromised graft functionality due to infiltration of immune cells, and will also enable post mortem assessment of graft differentiation using immunohistochemistry against MBP. Our preliminary studies have demonstrated that the survival of cells grafted into immunocompetent hosts is highly dependent on the implantation site. We will employ both rejection-prone and rejection-resistant target sites, to validate the applicability of the proposed non-invasive rejection monitoring readouts. We hypothesize that immune cell infiltration results in an alteration of the local microenvironment. Thus, we will employ novel MRI techniques, such as CEST, which has been recognized as a powerful tool for the non-invasive acquisition of molecular information in living tissues, and FLEX, which is complementary and adds information about rapidly exchanging protons. We will use these techniques for the detection of the molecular signature of graft rejection and to monitor the effects of immunosuppression on graft infiltration with regard to behavioral outcomes and post mortem analysis of graft differentiation and infiltration by immune cells. Upon the successful completion of this proposal, we anticipate that we will have established an efficient method by which to evaluate the immune response against transplanted cells, with the intention to translate this technique further as a diagnostic tool for patients with intracerebral grafts.

描述(由申请人提供)：使用脑内移植物治疗神经疾病的临床试验数量有所增加。然而，一旦移植物被放置在大脑中，患者的免疫反应以及这种反应对移植物功能的可能影响是未知的。神经炎症的成像，例如多发性硬化症的MRI，是基于相对水分含量(水肿)和/或血脑屏障(BBB)突破的测量。细胞移植物内的炎症，由于体积小，细胞密度高，以及受注射针影响的血脑屏障，不能用同样的方法监测。在我们对啮齿动物细胞移植的广泛经验中，我们观察到不同动物之间免疫细胞对移植物的渗透存在很大的差异，类似的差异可能发生在患者身上。这可以解释患者之间结果的显著差异，包括在少数患者中观察到的意想不到的严重副作用，这让患者和临床研究人员都感到沮丧。因此，这项建议的目的是开发新的、临床适用的方法来非侵入性地检测细胞移植物中的免疫细胞渗透。我们已经建立了一个实验平台，非常适合于实现这一提案的目标。免疫缺陷的RAG2-/-小鼠的特点是对所有类型的细胞移植物都具有绝对的耐受性，将被用作实验的、具有免疫能力的宿主的参考。脑内移植物的存活能力将通过非侵入性生物发光成像进行反复评估。使用髓鞘受损的寒战小鼠(包括RAG2-/-和野生型)作为移植受体，将能够对由于免疫细胞渗透而导致的移植物功能受损进行行为学评估，也将能够使用抗MBP的免疫组织化学对移植物分化进行死后评估。我们的初步研究表明，移植到免疫活性宿主体内的细胞的存活高度依赖于植入部位。我们将使用易被拒绝和抵抗被拒绝的目标地点，以验证建议的适用性。 无创排异监测读数。我们假设免疫细胞的渗透导致了局部微环境的改变。因此，我们将采用新的核磁共振技术，如CEST和FLEX，CEST已被公认为非侵入性获取活组织中分子信息的强大工具，FLEX是互补的，并增加了关于快速交换质子的信息。我们将使用这些技术来检测移植物排斥反应的分子特征，并监测免疫抑制对移植物渗透的影响，包括行为结果和移植物分化和免疫细胞渗透的尸检分析。在这项提议成功完成后，我们预计我们将建立一种有效的方法来评估对移植细胞的免疫反应，目的是进一步将这项技术转化为脑内移植物患者的诊断工具。