Stroma penetrating and immune modulating nanoparticles for image-guided therapy of pancreatic cancer

项目摘要 对治疗的抵抗是胰腺癌治疗的主要挑战。尽管最近取得了成功 在几种人类癌症类型的免疫检查点治疗中，胰腺癌显示出对 免疫疗法越来越多的证据表明，胰腺癌中的致密间质屏障阻断药物 递送和肿瘤内分布。间质的物理屏障和生物屏障 免疫抑制反应进一步限制了浸润效应T细胞的数量和功能。客观 该项目的目的是开发一种新的免疫治疗策略， 免疫调节治疗诊断纳米颗粒和PD-L1抑制剂。我们的创新uPAR靶向和基质 断裂配体由uPA的氨基末端片段（ATF）和基质的催化结构域组成 金属蛋白酶14（ATFmmp 14）。它靶向肿瘤中的多种细胞类型，并促进纳米颗粒/药物 通过基质和细胞外基质屏障迁移到达肿瘤细胞。ATFmmp 14共轭磁性 携带阿霉素或SN 38的氧化铁纳米颗粒（IONP）使能磁共振成像（MRI）引导的 纳米颗粒/药物在肿瘤中靶向递送，以及在胰腺癌患者中的强治疗效果 衍生的异种移植物（PDX）和Kras驱动的转基因小鼠肿瘤模型。值得注意的是， 治疗诊断性IONP进入肿瘤促进免疫效应细胞的浸润，并降低免疫抑制作用。 细胞，将免疫“冷”胰腺肿瘤转化为“热”肿瘤。我们进一步开发了超小型IONP PD-L1抑制剂（Nano-iPD-L1）使用工程PD-L1阻断肽。我们发现纳米iPD-L1 在全身递送后选择性地积聚在胰腺肿瘤中。Nano-iPD-L1与 ATFmmp 14-IONP/药物增强肿瘤内递送并显著抑制小鼠肿瘤生长 胰腺癌模型。因此，我们假设，通过联合给药改善胰腺肿瘤的药物输送， 施用基质穿透性ATFmmp 14-IONP/SN 38和Nano-iPD-L1导致了强治疗效果， 通过直接杀死肿瘤细胞、调节免疫抑制基质和阻断PD-L1功能， 产生强烈的细胞毒性T细胞反应。在拟议的研究中，我们将首先调查和优化 在小鼠胰腺中共递送ATFmmp 14-IONP/SN 38和Nano-iPD-L1的剂量和治疗功效 癌症模型（Aim 1）。随后进行非侵入性MRI，以评估治疗诊断IONP输送和肿瘤反应 在转基因小鼠和胰腺中使用ATFmmp 14-IONP/SN 38和Nano-iPD-L1的联合治疗后， 癌症PDX模型（Aim 2）。最后，ATFmmp 14 - 14的增强的肿瘤内积累的作用被证实。 IONP/SN 38和Nano-iPD-L1对促进效应免疫细胞浸润、调节间质 将在转基因小鼠中研究免疫抑制细胞和因子以及活化细胞毒性T细胞 胰腺肿瘤模型（目的3）。这项研究的结果应该为我们提供新的靶向治疗诊断IONP 和免疫疗法来转化这种治疗晚期胰腺癌的新疗法。

Project Summary Resistance to therapy is the major challenge for the treatment of pancreatic cancer. Despite recent successes in immune checkpoint therapy of several human cancer types, pancreatic cancer showed a poor response to the immunotherapy. Increasing evidence reveals that a dense stromal barrier in pancreatic cancer blocks drug delivery and intratumoral distribution. The physical barrier of stromal and biological barrier from immunosuppressive responses further limit the number and function of infiltrating effector T cells. The objective of this project is to develop a new immunotherapy strategy by co-delivery of tumor penetrating and immunomodulating theranostic nanoparticles and PD-L1 inhibitors. Our innovative uPAR targeted and stroma breaking ligand consists of the amino terminal fragment (ATF) of uPA and the catalytic domain of matrix metalloproteinase-14 (ATFmmp14). It targets multiple cell types in tumors and promotes nanoparticle/drugs migrating through stromal and extracellular matrix barriers to reach tumor cells. ATFmmp14 conjugated magnetic iron oxide nanoparticle (IONP) carrying Doxorubicin or SN38 enabled magnetic resonance imaging (MRI) guided targeted delivery of nanoparticle/drug in tumors, and strong therapeutic effect in pancreatic cancer patient derived xenograft (PDX) and Kras-driven transgenic mouse tumor models. Notably, targeted delivery of the theranostic IONPs into tumors promoted infiltration of immune effector cells and decreased immunosuppressive cells, converting an immune “cold” pancreatic tumor into a “hot” tumor. We further developed an ultrasmall IONP PD-L1 inhibitor (Nano-iPD-L1) using an engineered PD-L1 blocking peptide. We showed that Nano-iPD-L1 selectively accumulated in pancreatic tumors following systemic delivery. Co-delivery of Nano-iPD-L1 with ATFmmp14-IONP/drug enhanced intratumroal delivery and significantly inhibited tumor growth in a mouse pancreatic cancer model. Therefore, we hypothesize that improved drug delivery in pancreatic tumors by co- administrations of stroma penetrating ATFmmp14-IONP/SN38 and Nano-iPD-L1 leads to a strong therapeutic efficacy through direct tumor cell killing, modulating immunosuppressive stroma, and blocking PD-L1 function to generate a strong response from cytotoxic T cells. In the proposed study, we will first investigate and optimize dose and therapeutic efficacy of co-delivery of ATFmmp14-IONP/SN38 and Nano-iPD-L1 in mouse pancreatic cancer models (Aim1). Followed by non-invasive MRI to assess theranostic IONP delivery and tumor response after the combined therapy using ATFmmp14-IONP/SN38 and Nano-iPD-L1 in transgenic mouse and pancreatic cancer PDX models (Aim 2). Finally, the effects of an enhanced intratumoral accumulation of ATFmmp14- IONP/SN38 and Nano-iPD-L1 on promoting infiltration of effector immune cells, modulating stromal immunosuppressive cells and factors, and activating cytotoxic T cells will be investigated in transgenic mouse pancreatic tumor models (Aim 3). Results of this study should provide us with new targeted theranostic IONPs and immunotherapy for translation of this novel therapy for advanced pancreatic cancer.