A PET Radiotracer for Diagnostic and Theranostics Imaging in Lyme Disease

项目摘要/摘要 莱姆病是由伯氏疏螺旋体(BBSL)引起的一种扁虱传播的感染。 是美国最流行的媒介传播疾病。来自该中心的最新监控 疾病控制中心仅在2017年就报告了4万例新的莱姆病病例。令人担忧的是，这种疾病 从东北部、大西洋中部和中西部的流行区扩展到邻近的州。 与这种疾病相关的迅速增加的公共健康风险和不断上升的医疗费用是 因围绕其诊断和治疗的争议而加剧，特别是在治疗后的情况下 莱姆病综合征“和”慢性莱姆病“。在这些情况下，没有明确的共识。 对感染既敏感又特异的诊断标志物。而莱姆的诊断不足 疾病自然导致治疗不足，对疾病的误诊和误治导致了 发病率也很高。综上所述，这些数据清楚地表明，新诊断和新技术的发展 治疗莱姆病的治疗工具是一种迫切的、尚未得到满足的临床需求。 这份R21提案的重点是设计、合成和体外评价敏感和特异的 放射性示踪剂在莱姆病诊断和治疗正电子发射断层扫描中的应用 疾病。这些放射性药物的靶标将是VlsE，这是一种在 在脊椎动物宿主中，BBSL的整个时间都在其表面。具体目标1(SA1)将重点放在 通过对BBSL基因组的比较分析鉴定基于VlsE的广活性生物标志物，并与 总体目标设计15个候选目标(10个VlsE变体和5个基于VLS的多肽) 一致的和保守的序列。具体目标2(SA2)将集中在表达 VlsE候选蛋白、VLS编码多肽的合成及体外抗原性检测 将这些生物分子与患者抗血清结合，以确定反应最广泛的靶分子。 特异性目标3(SA3)将专注于VlsE特异性单抗和F(Ab)片段的产生 以及相应的正电子标记的放射免疫结合物的放射合成 放射性金属锆-89(89Zr)和镓-68(68Ga)。它们的体外免疫反应性 放射免疫结合物将与几株表达VlsE的BBSL以及对照进行询问 革兰氏阴性和革兰氏阳性细菌。最终，我们相信这项提议可能会有一个 对莱姆病的基础科学和临床治疗都产生了革命性的影响。在实验室里， 莱姆靶向放射性示踪剂可能是一种有价值的研究工具，在小鼠模型的发展过程中 疾病和BBSL靶向治疗的评价。更重要的是，在临床上，针对VlsE的 放射性药物可以被证明是一种有用的诊断工具，可以帮助识别活动期患者 这是一种用于监测患者对治疗反应的宝贵治疗工具。

Project Summary/Abstract Lyme disease is a tick-borne infection caused by the spirochete Borrelia burgdorgeri sensu lato (Bbsl) and is the most prevalent vector-borne disease in the United States. The latest surveillance from the Centers for Disease Control reported 40,000 new cases of Lyme disease in 2017 alone. Alarmingly, the disease is expanding from its endemic areas in the Northeast, mid-Atlantic, and Upper Midwest to neighboring states. The rapidly increasing public health risks and rising healthcare costs associated with the disease are exacerbated by controversies surrounding its diagnosis and treatment, especially in cases of `post-treatment Lyme disease syndrome' and `chronic Lyme disease'. In these cases, there are no definitive consensus diagnostic markers that are both sensitive and specific for the infection. While the under-diagnosis of Lyme disease has naturally lead to under-treatment, the mis-diagnosis and mis-treatment of the condition has led to serious morbidity as well. Taken together, the data make it clear that the development of new diagnostic and theranostic tools for Lyme disease is an urgent, unmet clinical need. This R21 proposal is focused on the design, synthesis, and in vitro evaluation of sensitive and specific radiotracers for the diagnostic and theranostic positron emission tomography (PET) of patients with Lyme disease. The target for these radiopharmaceuticals will be VlsE, a protein that is abundantly expressed on the surface of Bbsl throughout its time in its vertebrate host. Specific Aim 1 (SA1) will be focused on the identification of broadly reactive VlsE-based biomarkers via the comparative analysis of BBsl genomes, with an overall goal designing 15 candidate targets (10 variants of VlsE and 5 vls-based peptides) based on consensus and conserved sequences. Specific Aim 2 (SA2) will be centered on the expression of the candidate VlsE proteins, the synthesis of the vls-encoded peptides, and the in vitro testing of the antigenicity of these biomolecules with patient antisera in order to identify the most broadly reactive target molecules. Specific Aim 3 (SA3) will focus on the generation of a VlsE-specific monoclonal antibody and F(ab) fragment as well as the radiosynthesis of the corresponding radioimmunoconjugates labeled with positron-emitting radiometals zirconium-89 (89Zr) and gallium-68 (68Ga). The in vitro immunoreactivity of these radioimmunoconjugates will be interrogated with several strains of VlsE-expressing BBsl as well as control gram-negative and gram-positive bacteria. Ultimately, we believe that this proposal could have a transformational impact on both the basic science and clinical management of Lyme disease. In the laboratory, a Lyme-targeted radiotracer could be a valuable research tool during the development of murine models of the disease and the evaluation of Bbsl-targeted therapeutics. Even more importantly, in the clinic, a VlsE-targeted radiopharmaceutical could prove to be both a useful diagnostic tool to help identify patients with active infections and a valuable theranostic tool to monitor the response of patients to therapy.