Nanoparticles for In Vivo Labeling of T Cells During Cancer Immunotherapy

项目摘要 尽管经过数十年的研究，恶性脑肿瘤患者的预后仍然很差且新颖 迫切需要治疗策略。恶性神经胶质瘤是特别难治的治疗，统一 致命的，并没有看到超过三十年的结果改善。免疫疗法具有巨大的 通过利用肿瘤抗原的细胞毒性能力， 反应性淋巴细胞阻断程序性死亡1（PD-1）通路的免疫检查点阻断疗法 临床上用于治疗黑色素瘤、非小细胞肺癌、头颈部鳞状细胞癌、肾 细胞癌和霍奇金淋巴瘤。尽管单独的抗PD-1治疗对恶性肿瘤无效， 胶质瘤，最近复发性多形性胶质母细胞瘤（GBM）的临床试验表明新辅助抗肿瘤治疗的益处。 肿瘤切除前的PD-1治疗。免疫活性小鼠模型的初步结果 GBM表明在肿瘤切除前的新辅助抗PD-1治疗期间CD 8 + T细胞募集的作用。 这项探索性/发展性生物工程研究补助金将开发技术，使非侵入性 使用磁粒子成像的CD 8+示踪剂募集到肿瘤切除部位的定量成像 (MPI)这是一种新的成像方式，具有优于免疫PET成像的潜在优势。MPI示踪剂将 由具有靶向基序的超顺磁性氧化铁纳米颗粒（SPION）组成， 标记CD 8 + T细胞，使其生物分布的非侵入性，明确和定量成像成为可能。 初步结果表明，PI已经开发出高灵敏度和长血液循环的MPI示踪剂 时间T细胞的选择性体内标记将通过用以下物质官能化这些优化的MPI示踪剂来实现： 结合T细胞表面标志物的抗体片段，导致内化或持续结合T细胞表面标志物。 细胞膜在体内和实体瘤中原位标记T细胞的一个重要考虑因素是T细胞的渗透。 图像标签。初步结果表明，加速和增强的肿瘤积累， 通过磁靶向系统性给予SPION。PI假设磁性靶向 肿瘤切除部位的T细胞靶向SPION将导致SPION/T细胞相互作用增加， 对肿瘤切除部位T细胞存在的敏感性增加。在Aim 1中，用MPI标记T细胞 将离体优化示踪剂，并且将研究标记对T细胞活力和细胞毒性表型的影响。 评估。然后，在目标2中，将在本发明的实施方案中评价使用全身施用的示踪剂的体内T细胞标记。 在复发性GBM的小鼠模型中，在肿瘤切除之前的新辅助抗PD-1疗法的背景下。的 拟议的工作将利用SPION示踪剂的磁响应性来加速和增强肿瘤 使用磁性靶向进行渗透。在拟议的研究中取得成功将增加MPI作为一种工具， 免疫成像工具箱，帮助加速癌症的发展和机制理解 通过原位和体内标记CD 8 + T细胞生物分布和募集至肿瘤的免疫疗法。

Project Summary Despite decades of research, the prognosis for patients with malignant brain tumors remains poor and novel treatment strategies are urgently needed. Malignant gliomas are particularly refractory to treatment, uniformly fatal, and have not seen improvement in outcomes for over three decades. Immunotherapy has tremendous promise for eradicating cancers with exquisite precision by leveraging the cytotoxic capabilities of tumor antigen- reactive lymphocytes. Immune checkpoint blockade therapy blocking the programmed death 1 (PD-1) pathway is used clinically against melanoma, non-small cell lung cancer, head and neck squamous cell carcinoma, renal cell carcinoma, and Hodgkin's lymphoma. Although anti-PD-1 therapy alone is ineffective against malignant gliomas, recent clinical trials with recurrent glioblastoma multiforme (GBM) suggest benefit of neoadjuvant anti- PD-1 therapy prior to tumor resection. Preliminary results with an immunocompetent mouse model of recurrent GBM suggests a role for CD8+ T cell recruitment during neoadjuvant anti-PD-1 therapy prior to tumor resection. This Exploratory/Developmental Bioengineering Research Grant will develop technology to enable non-invasive quantitative imaging of CD8+ tracer recruitment to the site of tumor resection using magnetic particle imaging (MPI), a new imaging modality with potential advantages over immunoPET imaging. MPI tracers will be formulated consisting of superparamagnetic iron oxide nanoparticles (SPION) with targeting motifs to selectively label CD8+ T cells, enabling non-invasive, unambiguous, and quantitative imaging of their biodistribution. Preliminary results show the PI has already developed MPI tracers with high sensitivity and long blood circulation time. Selective in vivo labeling of T cells will be achieved by functionalizing these optimized MPI tracers with antibody fragments that bind to T cell surface markers, resulting in internalization or persistent binding to the T cell membrane. An important consideration in labeling T cells in vivo and in situ in solid tumors is penetration of the imaging label. Preliminary results demonstrate accelerated and enhanced tumor accumulation of systemically administered SPIONs through magnetic targeting. The PI hypothesizes that magnetic targeting of T cell targeting SPIONs at the site of tumor resection will lead to increased SPION/T cell interactions and increased sensitivity to the presence of T cells at the tumor resection site. In Aim 1 T cell labeling with the MPI tracers will be optimized ex vivo and the effect of labeling on T cell viability and cytotoxic phenotype will be evaluated. Then, in Aim 2 in vivo T cell labeling using systemically administered tracers will be evaluated in the context of neoadjuvant anti-PD-1 therapy prior to tumor resection in a mouse model of recurrent GBM. The proposed work will capitalize on magneto responsiveness of the SPION tracers to accelerate and enhance tumor penetration using magnetic targeting. Success in the proposed research will add MPI as a tool in the growing immunoimaging toolbox, helping accelerate development and mechanistic understanding of cancer immunotherapies through in situ and in vivo labeling of CD8+ T cell biodistribution and recruitment to tumors.