Intracellular oxygen sensing using 19F MRI

使用 19F MRI 进行细胞内氧传感

基本信息

批准号：
8720000
负责人：
ERIC T. AHRENS
金额：
$ 32.79万
依托单位：
UNIVERSITY OF CALIFORNIA, SAN DIEGO
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-01 至 2017-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8720000
关键词：
Anti-Inflammatory Agents Anti-inflammatory Antigens Apoptosis Apoptotic Beds Binding Biological Biological Assay CD8B1 gene Cancer Model Cell Communication Cell Count Cell Survival Cell Therapy Cells Central Nervous System Neoplasms Clinical Cytometry Cytotoxic T-Lymphocytes Data Dendritic Cells Development Drug Formulations Employee Strikes Emulsions Event Fluorine Fluorocarbons Foundations Future Glioma Goals HSV-Tk Gene Home environment Human Image Imagery Immunosuppression Immunotherapy Implant In Situ Inflammation Inflammatory Inflammatory Bowel Diseases Infusion procedures Intravenous infusion procedures Label Leukocytes Magnetic Resonance Imaging Magnetic Resonance Spectroscopy Malignant Neoplasms Measurement Measures Metabolism Methods Modeling Monitor Mus Neuraxis Oxygen Oxygen saturation measurement Partial Pressure Patients Pharmaceutical Preparations Process Prodrugs Property Protocols documentation Reagent Relaxation Reporting Research Personnel Rodent Signal Transduction Site Stem cells Suicide Gene Therapy Symptoms T-Lymphocyte Techniques Technology Testing Therapeutic Therapy Clinical Trials Thymidine Kinase Time Tissues Translations Universities Work base cancer cell cancer therapy cell killing cell type chemotherapeutic agent chemotherapy design image processing imaging probe implantation in vivo interest intravenous injection macrophage monocyte nanoparticle neoplastic cell new technology non-drug preclinical evaluation public health relevance receptor research study response suicide gene tissue culture tool tumor uptake

项目摘要

DESCRIPTION (provided by applicant): A widely recognized limitation of MRI cell tracking using nanoparticle probes is that they cannot report on cellular activity or cell viability in vivo Non-invasive cell tracking methods that can monitor changes in cell viability and activation would be a great value in the development of cancer treatments, cell therapies, and anti-inflammatory drugs. Towards these goals, we will explore the utility of real-time monitoring of intracellular oximetry in vivo using perfluorocarbon (PFC) emulsion imaging probes. This proposal builds on our prior work developing MRI cell tracking methods for ex vivo and in situ labeling of cells with PFC imaging reagents. For ex vivo cell labeling, isolated cells of interest (e.g., leukocytes, stem cells, or cancer cells) are labeled in culture with PFC emulsion, and following transfer to the subject, cells are tracked in vivo using fluorine-19 (19F) MRI. The fluorine signal yields cell-specific images, with no background, that can be used to quantify apparent cell numbers at sites of accumulation. For in situ labeling, PFC emulsion is injected intravenously and taken up by macrophages that home to sites of inflammation and can be visualized by 19F MRI. In this proposal, we will exploit the oxygen sensing properties of the intracellular PFC molecules. Oxygen binding to PFC results in a reduction in the 19F spin-lattice relaxation time (T1), where T1 varies linearly with the partial pressure of oxygen (pO2). Hence, we propose combining 19F-based cell tracking with 19F T1 measurements to monitor intracellular pO2 in a cell-specific manner. Results from our lab in cancer models have demonstrated the feasibility of measuring the absolute intracellular pO2 in tumor cells and response to anti-cancer treatments. Overall, the proposal has two Specific Aims. Aim 1: Can intracellular pO2 detect cell viability in vivo? We will test the hypothesis that a measureable increase in pO2 is an indirect consequence of apoptotic processes. In tumor cells, we will characterize the cellular pO2 response following chemotherapy, suicide gene therapy, and effector T cell immunotherapy, all of which drive the cell towards apoptosis, but employ different triggers. The establishment of a relationship between cell viability and intracellular pO2 can be exploited in the preclinical evaluation of emerging cancer therapies. Moreover, as human clinical translation of 19F cell tracking matures, these oximetry techniques may be used in cell therapy clinical trials to determine whether the cellular graft is viable after delivery to the patient. Stdies in tumor models will help set the foundation for future studies in a variety of therapeutic cell types. Aim 2: Can macrophage intracellular pO2 detect immunoactivity? In a further extension, we will test the hypothesis that macrophages localized at sites of inflammation will respond to pharmacological immunosuppression by altering intracellular pO2 levels. A murine model of inflammatory bowel disease will be used, along with in situ PFC labeling of macrophages. We will test whether macrophage intracellular pO2 can be used as a tool to assess anti-inflammatory drugs non-invasively. Overall, the proposed experiments will set the foundation for a broad field of inquiries using intracellular PFC cell tracking agents to garner information about real-time cell metabolism in vivo.

描述（由申请人提供）：使用纳米颗粒探针的 MRI 细胞追踪的一个广泛认可的局限性是它们无法报告体内细胞活性或细胞活力。能够监测细胞活力和激活变化的非侵入性细胞追踪方法将是一个很好的选择。在癌症治疗、细胞疗法和抗炎药物的开发中具有价值。为了实现这些目标，我们将探索使用全氟化碳 (PFC) 乳液成像探针实时监测体内细胞内血氧饱和度的实用性。该提案建立在我们之前开发 MRI 细胞追踪方法的工作基础上，用于使用 PFC 成像试剂对细胞进行离体和原位标记。对于离体细胞标记，使用 PFC 乳剂在培养物中标记分离的感兴趣细胞（例如，白细胞、干细胞或癌细胞），并在转移至受试者后，使用 19F (19F) MRI 进行体内追踪。氟信号产生无背景的细胞特异性图像，可用于量化积累位点的表观细胞数量。对于原位标记，PFC 乳液通过静脉注射并被巨噬细胞吸收，巨噬细胞聚集在炎症部位，并可通过 19F MRI 可视化。在本提案中，我们将利用细胞内 PFC 分子的氧传感特性。氧与 PFC 结合导致 19F 自旋晶格弛豫时间 (T1) 缩短，其中 T1 随氧分压 (pO2) 线性变化。因此，我们建议将基于 19F 的细胞跟踪与 19F T1 测量相结合，以细胞特异性方式监测细胞内 pO2。我们实验室在癌症模型中的结果证明了测量肿瘤细胞中绝对细胞内 pO2 和抗癌治疗反应的可行性。总体而言，该提案有两个具体目标。目标 1：细胞内 pO2 能否检测体内细胞活力？我们将检验以下假设：pO2 可测量的增加是细胞凋亡过程的间接结果。在肿瘤细胞中，我们将描述化疗、自杀基因疗法和效应 T 细胞免疫疗法后细胞 pO2 反应的特征，所有这些疗法都会驱动细胞凋亡，但采用不同的触发因素。细胞活力和细胞内 pO2 之间关系的建立可用于新兴癌症疗法的临床前评估。此外，随着 19F 细胞追踪的人类临床转化的成熟，这些血氧测定技术可用于细胞治疗临床试验，以确定细胞移植物在递送给患者后是否可行。肿瘤模型的研究将有助于为未来研究各种治疗细胞类型奠定基础。目标 2：巨噬细胞胞内 pO2 能否检测免疫活性？在进一步的扩展中，我们将检验这样的假设：位于炎症部位的巨噬细胞将通过改变细胞内 pO2 水平来响应药物免疫抑制。将使用炎症性肠病的小鼠模型以及巨噬细胞的原位 PFC 标记。我们将测试巨噬细胞胞内 pO2 是否可以作为非侵入性评估抗炎药物的工具。总体而言，拟议的实验将为使用细胞内 PFC 细胞跟踪剂来收集有关信息的广泛调查领域奠定基础体内实时细胞代谢。