Ferreira Daniela, Asín Laura, Idiago-López Javier, Grazú Valeria, de la Fuente Jesús M, Fratila Raluca M, Baptista Pedro V, Fernandes Alexandra R
Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2819-516, Caparica, Portugal.
UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, NOVA University Lisbon, 2819-516, Caparica, Portugal.
Cancer Immunol Immunother. 2025 Aug 23;74(9):292. doi: 10.1007/s00262-025-04148-3.
Dendritic cells (DCs) are well-known antigen-presenting cells which have an important role in cancer immunomodulation due to the effective regulation of immune responses in the tumor microenvironment (TME). Indoleamine 2,3-dioxygenase 1 gene (IDO1) is upregulated in many types of cancers and associated with a poor prognosis, contributing to an immunosuppressive TME. IDO1 silencing in DCs is considered a promising new strategy in gene therapy owing to their capability to regulate T cells function and activation. This study focuses on the use of magnetic hyperthermia (MH) combined with bioorthogonal chemistry to promote siRNA transfection against IDO1 in THP-1-derived DCs. Magnetic nanoparticles (MNPs) functionalized with cyclooctyne moieties were attached by strain-promoted azide-alkyne cycloaddition to DCs membranes engineered to express artificial azide receptors. Upon the application of an alternating magnetic field, the MNPs generate heat and trigger the thermal disruption of the cell membrane. Results show that IDO1 gene expression decreases around 70% in THP-1-derived DCs, and that the MH-promoted transfection presents a silencing effect comparable to that attained with a gold standard Lipofectamine reagent, but with less cytotoxicity. Additionally, IDO1 silencing promotes the upregulation of mRNA levels of pro-inflammatory cytokines IL-6, TNF-α and IL-12A, and the downregulation of anti-inflammatory cytokine IL-10, providing a more immunogenic state which may lead to THP-1-derived DCs activation for future T cells antitumor response. Our findings reveal the potential of MH-mediated transfection to enhance the intracellular delivery of silencing moieties in cells difficult to transfect, such as DCs, as well as demonstrate the possibility of silencing IDO1 gene to overcome the immunosuppressive barrier imposed by the TME for cancer therapy.
树突状细胞（DCs）是众所周知的抗原呈递细胞，由于其对肿瘤微环境（TME）中免疫反应的有效调节，在癌症免疫调节中发挥着重要作用。吲哚胺2,3-双加氧酶1基因（IDO1）在多种癌症中上调，并与预后不良相关，导致免疫抑制性TME。由于DCs能够调节T细胞功能和激活，因此DCs中的IDO1沉默被认为是基因治疗中一种有前景的新策略。本研究重点探讨磁热疗（MH）与生物正交化学相结合，以促进针对THP-1来源的DCs中IDO1的siRNA转染。用环辛炔部分功能化的磁性纳米颗粒（MNPs）通过应变促进的叠氮化物-炔烃环加成连接到经工程改造以表达人工叠氮化物受体的DCs膜上。在施加交变磁场时，MNPs产生热量并引发细胞膜的热破坏。结果表明，THP-1来源的DCs中IDO1基因表达下降约70%，并且MH促进的转染呈现出与金标准脂质体转染试剂相当的沉默效果，但细胞毒性较小。此外，IDO1沉默促进促炎细胞因子IL-6、TNF-α和IL-12A的mRNA水平上调，以及抗炎细胞因子IL-10的下调，提供了一种更具免疫原性的状态，这可能导致THP-1来源的DCs激活，以用于未来的T细胞抗肿瘤反应。我们的研究结果揭示了MH介导的转染在增强难转染细胞（如DCs）中沉默部分的细胞内递送方面的潜力，同时也证明了沉默IDO1基因以克服TME对癌症治疗造成的免疫抑制障碍的可能性。
