NMPA Key Laboratory for Technology Research and Evaluation of Drug Products and Key Laboratory of Chemical Biology (Ministry of Education), Department of Pharmaceutics, School of Pharmaceutical Sciences, Cheeloo College of Medicine, Shandong University, 44 Cultural West Road, Jinan, Shandong 250012, China.
College of Pharmacy, Shandong University of Traditional Chinese Medicine, 4655 University Road, Jinan, Shandong 250355, China.
Acta Biomater. 2023 Aug;166:512-523. doi: 10.1016/j.actbio.2023.05.001. Epub 2023 May 5.
Immune evasion caused by the paucity of MHCI is a prominent characteristic of pancreatic adenocarcinoma (PAAD), which is thought to underlie dysfunctional even absent adaptive T cell immunity and is responsible for ineffective immunotherapy. Here, we report a ROS-responsive DNA nano-orchestrator to cascade reverse MHC I-associated immune evasion and boost anti-tumor T cell stimulation, stimulating the activation of tumoricidal immunity against PAAD. Chloroquine phosphate (CQP) as an autophagy inhibitor was first encapsulated with ferritin, and via DNA modular self-assembly technology, the generated ferritin nanocores (FNC) were then caged into ROS-responsive CpG-DNA nanoframe. After systemic injection, the FNC-laden DNA nanoframe (FNC@NF) was passively enriched in tumor tissues in which the DNA nanoframe was cleaved upon the ROS stimulation. Oligodeoxynucleotide (ODN) with CpG motifs was detached and functioned as a TLR9 agonist. The liberated FNC was then endocytosed in an actively targeted manner by binding to transferrin receptor 1. In the lysosome, CQP was burst released from FNC due to acid-triggering. Through CQP-mediated autophagy abrogation, MHC-I molecules were preserved. We demonstrated that cascade inhibiting autophagy and boosting TLR9 stimulation via our proposed DNA-based hybrid nanosystem restored MHC I on the tumor cell surface and reshaped the antigen presentation of DCs, and ultimately reversed immune evasion and synergistically reinforced the activation of cytotoxic T cells against PAAD cells. In sum, our work provides an alternative strategy for cascade reversing immune evasion and boosting anti-tumor T cell stimulation and holds great potential for pancreatic cancer immunotherapy. STATEMENT OF SIGNIFICANCE: A DNA nano-orchestrator was created by sequentially assembling chloroquine phosphate-laden ferritin nanocores with ROS-responsive CpG-DNA nanoframe. Through cascade inhibiting autophagy and boosting TLR9 stimulation, the nano-orchestrator efficiently reversed MHC I-associated immune evasion and augmented anti-tumor T cell stimulation, which ultimately activated tumoricidal immunity against pancreatic adenocarcinoma.
免疫逃避导致 MHC I 的缺乏是胰腺导管腺癌（PAAD）的一个显著特征，这被认为是适应性 T 细胞免疫功能障碍甚至缺失的基础，也是免疫治疗无效的原因。在这里，我们报告了一种 ROS 响应性 DNA 纳米级联物，用于级联逆转 MHC I 相关免疫逃避并增强抗肿瘤 T 细胞刺激，刺激针对 PAAD 的细胞毒性免疫的激活。磷酸氯喹（CQP）作为自噬抑制剂首先被包裹在铁蛋白中，并且通过 DNA 模块化自组装技术，生成的铁蛋白纳米核（FNC）然后被笼入 ROS 响应性 CpG-DNA 纳米框架中。在系统注射后，FNC 负载的 DNA 纳米框架（FNC@NF）在肿瘤组织中被动富集，其中 DNA 纳米框架在 ROS 刺激下被切割。带有 CpG 基序的寡脱氧核苷酸（ODN）被分离并作为 TLR9 激动剂发挥作用。释放的 FNC 然后通过与转铁蛋白受体 1 结合以主动靶向的方式被内吞。在溶酶体中，CQP 由于酸触发而从 FNC 中爆发释放。通过 CQP 介导的自噬阻断，MHC-I 分子得以保留。我们证明，通过我们提出的基于 DNA 的杂交纳米系统级联抑制自噬和增强 TLR9 刺激，恢复了肿瘤细胞表面的 MHC I，并重塑了 DC 的抗原呈递，最终逆转了免疫逃避并协同增强了针对 PAAD 细胞的细胞毒性 T 细胞的激活。总之，我们的工作为级联逆转免疫逃避和增强抗肿瘤 T 细胞刺激提供了一种替代策略，为胰腺癌免疫治疗带来了巨大的潜力。
通过依次将负载 CQP 的铁蛋白纳米核与 ROS 响应性 CpG-DNA 纳米框架组装，创建了 DNA 纳米级联物。通过级联抑制自噬和增强 TLR9 刺激，纳米级联物有效地逆转了 MHC I 相关免疫逃避并增强了抗肿瘤 T 细胞刺激，最终激活了针对胰腺导管腺癌的细胞毒性免疫。
