Diagnostic SPECT & PET Fungal Infection Imaging Using Fungal Specific rRNA Probes

诊断性SPECT

基本信息

批准号：
8011453
负责人：
MARY RUSCKOWSKI
金额：
$ 20.34万
依托单位：
UNIV OF MASSACHUSETTS MED SCH WORCESTER
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-01-01 至 2012-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8011453
关键词：
3-Dimensional Aerosols Affect Angiography Animal Model Animals Antibiotic Therapy Antifungal Therapy Area Aspergillosis Aspergillus Aspergillus fumigatus Autopsy Bacterial Infections Binding Biodistribution Blood Blood Tests Bone Marrow Transplantation Burn injury Candida Candida albicans Candidiasis Cells Chelating Agents Chemicals Chemistry Clinic Clinical Communicable Diseases Complement Controlled Study DNA DNA Probes Detection Development Diabetes Mellitus Diagnosis Diagnostic Diagnostic Imaging Diagnostic Procedure Discipline of Nuclear Medicine Disease Disease model Early treatment Endocarditis Exhibits Figs - dietary Flow Cytometry Fluorescence Fluorescence Microscopy Fluorine Frequencies Functional disorder Fungal Typing Gallium Goals Granulomatous HIV Half-Life Histology Image Imaging technology Immunocompromised Host In Vitro Incubated Indium-111 Indwelling Catheter Infection Intervention Investigation Kidney Label Laboratories Life Literature Location Lung Malignant Neoplasms Measures Methodology Methods Microscopy Modality Modeling Molecular Molecular Probes Mus Mycoses New Zealand Normal tissue morphology Operative Surgical Procedures Optics Organ Transplantation Oryctolagus cuniculus Outcome Patients Peptides Phase Positron Positron-Emission Tomography Process Property RNA Probes RNA, Ribosomal, 18S RNA, Ribosomal, 28S Radioactive Radioactivity Radiolabeled Radionuclide Imaging Reaction Relative (related person)Reporting Research Ribosomal DNA Ribosomal RNA Sampling Science Sensitivity and Specificity Series Serum Site Solid Solutions Source Species Specificity Specificity Sputum Staging Technetium 99m Technology Testing Tissue Sample Tissues Tracer Translating Transplant Recipients Travel Vertebral column Work analog aortic valve base biological systems chemotherapy clinical decision-making cone-beam computed tomography cystic fibrosis patients design dosage experience fluorophore fungus high risk imaging modality improved in vitro testing in vivo interest meetings molecular imaging molecular marker mortality mouse model optical imaging radiochemical radiotracer single photon emission computed tomography success

项目摘要

DESCRIPTION (provided by applicant): Fungal infections have been reported with increased frequency in severe immunosuppressed patients and ranks as one of the top 10 most common causes of infectious disease-related mortality. There is a pressing need for development of an improved means to diagnose fungal infection. Identification of the fungal species is essential for appropriate clinical decision making concerning both the significance of a particular isolate and the dosage and duration of antifungal therapy. The use of short DNA oligomers with specificity to segments of fungal 18S ribosomal RNA (rRNA) is well documented for in vitro fungal identification by PCR. PCR based technologies have identified the value of DNA/RNA methodologies for in vitro detection of invasive fungal infections in blood, sputum and tissue samples. Thus, an oligomer analogue radiolabeled with an imaging radionuclide such as 99mTc may show preferential localization in sites of fungal infection. We concluded that radiolabeled species specific short oligomers should be investigated as potential agents for specific imaging of fungal infection especially since these agents may be useful for a broad range of patients. The objective of this proposed research is to conduct these investigations to identify the oligomer analogues that can be used with fungi to show specific binding, and that is also compatible with in vivo conditions. Then we will evaluate to what degree radiolabeled oligomers may be useful in vivo for fungal infection detection. This laboratory has experience with infection detection using bacterial mouse models and an extensive background in radiolabeled oligomer analogues for in vivo applications. We wish to continue our studies of infection specific agents and expand it to include fungal infections and complement it with our experience with radiolabeled oligomers to expand upon our other studies. Beginning with species specific oligomer sequences already in the literature, we will evaluate their chemical forms in vitro using morpholino oligomer analogues. Using fungal specific oligomer sequence and their respective fungi we will evaluate their specificity using fluorescence and radiolabeling molecular technologies. As controls we will use a conserved universal fungus binding oligomer and a known non-binding oligomer as negative control. Thereafter, we will test in vivo only those oligomers showing specificity in a mouse model of invasive pulmonary aspergillosis. Oligomer probes will be tested first at the genus level for Aspergillus and for Candida for proof of concept. After the first two years, and we have proven our hypothesis, we will focus on the species specific level to further define sensitivity and specificity of this approach. Finally, we will move towards the development of the oligomers for PET imaging using fluorine-18 and gallium-68 as tracers, plus work with larger animal models, such as the rabbit with endocarditis, and study mice with various fungal infections to establish specificity to facilitate the transition from the laboratory to the clinic. In this way, we expect to confirm our hypothesis that radiolabeled oligomers hold considerable promise as diagnostic agents for fungal infection through imaging. Our goal is to extend this science to diagnostic imaging by investigating whether fungal specific oligomers, specific to segments of the rRNA, can be applied to in vivo applications to identify the location of the fungal infection through imaging. In addition, in the process, the causative fungal agent may also be confirmed. The ultimate goal is to develop a noninvasive molecular imaging molecular marker with specificity to fungal rRNA that once radiolabeled can be used to for the diagnostic imaging of invasive fungal infection using SPECT and PET imaging. We expect this technology to be easily and readily translated into the clinic.

描述（由申请人提供）：据报道，严重免疫抑制患者的频率增加，并将其作为与传染病相关的死亡率最常见的十大最常见原因之一。迫切需要开发改进的方法来诊断真菌感染。鉴定真菌物种对于特定分离株的重要性以及抗真菌治疗的剂量和持续时间的适当临床决策至关重要。通过PCR充分记录了对真菌18S核糖体RNA（rRNA）的特异性的短DNA低聚物（RRNA）。基于PCR的技术已经确定了DNA/RNA方法的值，用于体外检测血液，痰液和组织样品中浸润性真菌感染的值。因此，用成像放射性核素（如99mtc）的低聚物类似物标签可能显示出在真菌感染部位的优先定位。我们得出的结论是，应将放射性标记物种特异性的短寡聚物作为对真菌感染的特异性成像的潜在药物进行研究，尤其是因为这些药物可能对广泛的患者有用。这项拟议的研究的目的是进行这些研究，以识别可与真菌一起使用以显示特定结合的低聚物类似物，并且与体内条件也兼容。然后，我们将评估放射性标记的低聚物在多大程度上在体内可用于真菌感染检测。该实验室具有使用细菌小鼠模型的感染检测经验，并且在放射性标记的低聚物类似物中具有广泛的背景，用于体内应用。我们希望继续我们对感染特定剂的研究，并将其扩展到包括真菌感染，并与我们在放射标记的低聚物方面的经验相辅相成，以扩展我们的其他研究。从文献中已经有特定的低聚物序列开始，我们将使用Morpholino低聚物类似物在体外评估它们的化学形式。使用真菌特异性的低聚物序列及其各自的真菌，我们将使用荧光和放射标记的分子技术评估它们的特异性。作为对照，我们将使用保守的通用真菌结合寡聚物和已知的非结合寡聚物作为阴性对照。此后，我们将仅在体内测试那些在浸润性肺曲霉病小鼠模型中显示出特异性的低聚物。低聚物探针将首先在属水平上进行曲霉和念珠菌的概念证明。在头两年之后，我们证明了我们的假设，我们将重点关注特定水平，以进一步定义这种方法的敏感性和特异性。最后，我们将迈向使用氟-18和甲壳68作为示踪剂的低聚物进行POT成像的发展，并与大型动物模型一起工作，例如患有心内膜炎的兔子，并研究具有各种真菌感染的小鼠，以建立特异性，以促进从实验室到诊所的过渡。通过这种方式，我们希望确认我们的假设，即放射性标记的低聚物作为通过成像进行真菌感染的诊断剂具有相当大的希望。我们的目标是通过调查特定于rRNA段的真菌特异性低聚物来扩展该科学诊断成像，以应用于体内应用，以通过成像识别真菌感染的位置。此外，在此过程中，还可以确认致病真菌剂。最终目标是开发具有对真菌rRNA的特异性的非侵入性分子成像分子标记物，曾经将放射性标记可用于使用SPECT和PET成像对侵入性真菌感染的诊断成像。我们希望这项技术很容易被转化为诊所。