Nanoscale Metal-Organic Frameworks Enable Radiotherapy-Radiodynamic Therapy and Deliver CpG Oligodeoxynucleotides to Generate Tumor Vaccines and Potentiate Immunotherapy of Head and Neck Cancers

靶向PD-1的检查点阻断抗体已证明在转移性头部和颈部肿瘤中改善了存活率。 颈部鳞状细胞癌（HNSCC）患者通过重新激活已经浸润的效应T细胞， 肿瘤微环境然而，PD-1阻断剂的总体缓解率仍然较低，约为18%， 这表明不同的治疗结果是由于患者疾病的内在差异， 作为肿瘤微环境。最近，我们开发了一类新的放射增强剂，纳米金属- 有机框架（nMOFs），可以改变免疫微环境。通过协调构建 在铌氧簇和卟啉样分子之间，nMOF既产生羟基自由基， 在称为放射治疗-放射动力学治疗（RT-RDT）的过程中的单线态氧。在这方面的目标 应用是定义RT-RDT和nMOF激活的免疫疗法改变免疫功能的机制。 免疫微环境，以便使HNSCC对检查点阻断敏感。我们的核心假设是 nMOFs可以递送CpG寡脱氧核苷酸并与RT-RDT诱导的抗原释放协同作用， 和I型IFN表达，其刺激CD 8+和CD 4 + T细胞增殖和浸润到HNSCC中， 使用PD-1/PD-L1阻断剂处理的经辐照和未经辐照的肿瘤均消退。我们的目标是 拟议的研究是确定一种新的疗法，并确定它改变免疫的机制。 在某些实施方案中，本发明的方法可以改善微环境以使HNSCC和可能的其他癌症对当前的临床免疫疗法敏感。这 该项目将使用创新的分子可调nMOFs，通过独特的 RT-RDT机制。这一提议是重要的，因为它解决了治疗抗辐射的未满足的需求。 和转移性HNSCC两者都直接通过RT-RDT和通过作为免疫刺激剂以增强 现有检查点抑制剂的功效。本提案将通过追求四个具体的假设来检验中心假设。 目的：（1）确定RT-RDT后先天免疫激活的细胞机制;（2）确定RT- RDT影响鳞状细胞癌中的肿瘤微环境;（3）评估不同肿瘤微环境的贡献。 免疫组分对RT-RDT和免疫疗法组合的功效的影响;以及（4）确定有效的 用于对PD-1/PD-L1阻断具有抗性的HNSCC的治疗。目的1将处理细胞并离体刺激或 用nMOF和辐射培养免疫组分，以确定RT-RDT如何启动STING和I型 肿瘤微环境中的干扰素信号传导。目标2将确定肿瘤微环境和 细胞外基质受到nMOF介导的RT-RDT的影响。目标3将评估不同组织的贡献 免疫组分对nMOF的抗癌功效的影响。目标4将使用原发性口腔肿瘤模型， 抗PD-1/PD-L1阻断剂作为鉴定协同作用的新型免疫治疗组合的模型 关于RT-RDT最终，该项目将提供新的治疗策略， 纳米药物以增强HNSCCs的放射治疗和免疫排斥。

Checkpoint blockade antibodies targeting PD-1 have demonstrated improved survival in metastatic head and neck squamous cell carcinomas (HNSCC) patients by reactivating effector T cells that have infiltrated the tumor microenvironment. However, PD-1 blockade still has low overall response rates approximating 18%, suggesting that the different treatment outcomes are due to intrinsic differences in the patients' diseases, such as tumor microenvironments. Recently, we have developed a new class of radioenhancers, nanoscale metal- organic frameworks (nMOFs), that can alter the immune microenvironment. Constructed via coordination between hafnium-oxo clusters and porphyrin-like molecules, nMOFs generate both hydroxyl radicals and singlet oxygen in a process termed radiotherapy-radiodynamic therapy (RT-RDT). The objective in this application is to define the mechanisms by which RT-RDT and nMOF-enabled immunotherapy alter the immune microenvironment in order to sensitize HNSCCs to checkpoint blockade. Our central hypothesis is that nMOFs can deliver the CpG oligodeoxynucleotides and synergize with RT-RDT-induced antigen release and Type I IFN expression, which stimulates CD8+ and CD4+ T cell proliferation and infiltration into HNSCCs to regress both irradiated and non-irradiated tumors treated with PD-1/PD-L1 blockade. The goal for this proposed research is to identify a novel therapy and define the mechanisms by which it alters the immune microenvironment to sensitize HNSCCs and possibly other cancers to current clinical immunotherapies. This project will use innovative molecularly tunable nMOFs having unprecedented radioenhancement via the unique RT-RDT mechanism. This proposal is significant because it addresses an unmet need of treating radioresistant and metastatic HNSCCs both directly via RT-RDT and by acting as an immunostimulant to enhance the efficacy of existing checkpoint inhibitors. This proposal will test the central hypothesis by pursuing four specific aims: (1) define the cellular mechanisms of innate immune activation after RT-RDT; (2) determine how RT- RDT affects the tumor microenvironment in squamous cell cancers; (3) evaluate the contributions of different immune components on the efficacy of RT-RDT and immunotherapy combinations; and (4) determine effective therapies for HNSCCs resistant to PD-1/PD-L1 blockade. Aim 1 will treat cells and ex vivo stimulated or cultured immune components with nMOFs and radiation to determine how RT-RDT initiates STING and Type I interferon signaling in the tumor microenvironment. Aim 2 will determine how the tumor microenvironment and extracellular matrix are affected by nMOF-mediated RT-RDT. Aim 3 will evaluate the contribution of different immune components to the anticancer efficacy of nMOFs. Aim 4 will use primary oral tumor models that are resistant to PD-1/PD-L1 blockade as a model to identify novel immunotherapy combinations that synergize with RT-RDT. Ultimately, this project will afford new therapeutic strategies using clinically relevant nanomedicines to enhance both the radiation therapy and immunological rejection of HNSCCs.