免疫检查点蛋白 V 域 T 细胞激活免疫球蛋白抑制因子 (VISTA) 控制抗肿瘤免疫，是癌症免疫治疗的重要靶点。先前的机制研究表明，VISTA 会损害 Toll 样受体 (TLR) 介导的髓样抗原呈递细胞的激活，促进髓样源性抑制细胞的扩增，并抑制肿瘤反应性细胞毒性 T 细胞功能。该研究旨在开发一种双作用脂质纳米颗粒 (dual-LNP)，其共同负载 VISTA 特异性 siRNA 和 TLR9 激动剂 CpG 寡核苷酸。我们使用三种小鼠临床前肿瘤模型，黑色素瘤 YUMM1.7、黑色素瘤 B16F10 和结肠癌 MC38 来评估双 LNP 两种货物的功能协同作用和治疗效果。双 LNP 协同增强抗肿瘤免疫反应，并拒绝大量已建立的免疫反应。而单独含有 VISTA siRNA 或 CpG 的 LNP 则无效。与使用可溶性 CpG 和 VISTA 特异性单克隆抗体的疗法相比，双 LNP 表现出卓越的治疗效果，同时减少了全身炎症细胞因子的产生。在三个小鼠模型中，双 LNP 治疗取得了很高的治愈率。肿瘤排斥与免疫细胞涌入肿瘤组织、增强树突状细胞活化、促炎细胞因子的产生以及细胞毒性 T 细胞功能的改善有关。我们的研究表明，双 LNP 确保其协同货物同时递送至肿瘤浸润骨髓细胞，导致 VISTA 同时沉默并刺激 TLR9。因此，双 LNP 驱动了一种高效的抗肿瘤免疫反应，可以排斥大型侵袭性肿瘤，因此可能是治疗免疫冷肿瘤的有前途的治疗平台。© 作者（或其雇主）2024。 CC BY-NC 允许重复使用。禁止商业再利用。请参阅权利和权限。英国医学杂志出版。

Immune checkpoint protein V-domain immunoglobulin suppressor of T cell activation (VISTA) controls antitumor immunity and is a valuable target for cancer immunotherapy. Previous mechanistic studies have indicated that VISTA impairs the toll-like receptor (TLR)-mediated activation of myeloid antigen-presenting cells, promoting the expansion of myeloid-derived suppressor cells, and suppressing tumor-reactive cytotoxic T cell function.The aim of this study was to develop a dual-action lipid nanoparticle (dual-LNP) coloaded with VISTA-specific siRNA and TLR9 agonist CpG oligonucleotide. We used three murine preclinical tumor models, melanoma YUMM1.7, melanoma B16F10, and colon carcinoma MC38 to assess the functional synergy of the two cargoes of the dual LNP and therapeutic efficacy.The dual-LNP synergistically augmented antitumor immune responses and rejected large established tumors whereas LNPs containing VISTA siRNA or CpG alone were ineffective. In comparison with therapies using the soluble CpG and a VISTA-specific monoclonal antibody, the dual-LNP demonstrated superior therapeutic efficacy yet with reduced systemic inflammatory cytokine production. In three murine models, the dual-LNP treatment achieved a high cure rate. Tumor rejection was associated with influx of immune cells to tumor tissues, augmented dendritic cell activation, production of proinflammatory cytokines, and improved function of cytotoxic T cells.Our studies show the dual-LNP ensured codelivery of its synergistic cargoes to tumor-infiltrating myeloid cells, leading to simultaneous silencing of VISTA and stimulation of TLR9. As a result, the dual-LNP drove a highly potent antitumor immune response that rejected large aggressive tumors, thus may be a promising therapeutic platform for treating immune-cold tumors.© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.