Li Na, Wang Minghui, Liu Fen, Wu Peixian, Wu Fan, Xiao Hao, Kang Qiang, Li Zelong, Yang Sha, Wu Guilong, Tan Xiaofeng, Yang Qinglai
Department of Hepatopancreatobiliary Surgery, the First Affiliated Hospital & Center for Molecular Imaging Probe & Hunan Engineering Research Center for Early Diagnosis and Treatment of Liver Cancer, Cancer Research Institute, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, China.
Pathology Research Group & Department of Pathology Institute of Basic Disease Sciences & School of Basic Medical Sciences, Xiangnan University, Chenzhou, Hunan 423000, China.
Anal Chem. 2024 Dec 10;96(49):19585-19596. doi: 10.1021/acs.analchem.4c04449. Epub 2024 Nov 27.
The efficacy of immunotherapy in treating triple-negative breast cancer (TNBC) has been restricted due to its low immunogenicity and suppressive immune microenvironment. Bacterial outer membrane vesicles (OMVs) have emerged as innovative immunotherapeutic agents in antitumor therapy by stimulating the innate immune system, but intricate modifications and undesirable multiple dose administration severely hinder their utility. Herein, a two-step bacterial metabolic labeling technique was utilized for the bioorthogonal engineering of OMVs. At first, d-propargylglycine (DPG, an alkyne-containing d-amino acid) was introduced into the incubation process of probiotic 1917 (Ecn) to produce DPG-functionalized OMVs, which were subsequently conjugated with azide-functionalized new indocyanine green (IR820) to yield OMV-DPG-IR820. The combination of phototherapy and immunostimulation of OMV-DPG-IR820 effectively arouses adaptive immune responses, causing maturation of dendritic cells, infiltration of T cells, repolarization of the M2 macrophage to the M1 macrophage, and upregulation of inflammatory factors. Remarkably, OMV-DPG-IR820 demonstrated tumor-targeting capabilities with guidance provided by near-infrared II (NIR-II) fluorescence imaging, leading to remarkable inhibition on both primary and distant tumors and preventing metastasis without causing noticeable adverse reactions. This study elucidates a sophisticated bioorthogonal engineering strategy for the design and production of functionalized OMVs and provides novel perspectives on the microbiome-mediated reversal of TNBC through a precise and efficient immunotherapy.
免疫疗法在治疗三阴性乳腺癌（TNBC）时，由于其低免疫原性和抑制性免疫微环境，疗效受到限制。细菌外膜囊泡（OMVs）已成为抗肿瘤治疗中的创新免疫治疗剂，可刺激先天免疫系统，但复杂的修饰和不理想的多剂量给药严重阻碍了它们的应用。在此，采用两步细菌代谢标记技术对OMVs进行生物正交工程改造。首先，将d-炔丙基甘氨酸（DPG，一种含炔基的d-氨基酸）引入益生菌1917（Ecn）的培养过程中，以产生DPG功能化的OMVs，随后将其与叠氮功能化的新型吲哚菁绿（IR820）偶联，得到OMV-DPG-IR820。OMV-DPG-IR820的光疗和免疫刺激相结合，有效地激发了适应性免疫反应，导致树突状细胞成熟、T细胞浸润、M2巨噬细胞向M1巨噬细胞的极化以及炎症因子的上调。值得注意的是，OMV-DPG-IR820在近红外II（NIR-II）荧光成像的引导下表现出肿瘤靶向能力，对原发性和远处肿瘤均有显著抑制作用，并能防止转移，且不会引起明显的不良反应。本研究阐明了一种用于设计和生产功能化OMVs的复杂生物正交工程策略，并为通过精确高效的免疫疗法实现微生物群介导的TNBC逆转提供了新的视角。
