Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin 300192, China; Key Laboratory of Functional Polymer Materials, Ministry of Education, Nankai University, Tianjin 300071, China.
Tianjin Key Laboratory of Biomaterial Research, Institute of Biomedical Engineering, Chinese Academy of Medical Science & Peking Union Medical College, Tianjin 300192, China.
J Control Release. 2017 Jun 28;256:170-181. doi: 10.1016/j.jconrel.2017.04.020. Epub 2017 Apr 13.
The purpose of the present study was to identify an "easy-to-adopt" strategy to enhance immune responses using functionalized alginate (ALG) nanoparticles (MAN-ALG/ALG=OVA NPs), which were prepared by CaCl cross-linking of two different types of ALG. The mannose (MAN) modified ALG (MAN-ALG) was used for dendritic cell targeting. The other component, composed of ovalbumin (OVA), a model antigen, is conjugated to ALG (ALG=OVA) via pH sensitive Schiff base bond. Grafting of alginate was demonstrated by FT-IR and H NMR, while the morphological structure, particle size, Zeta potential of MAN-ALG/ALG=OVA NPs were measured using TEM and DLS. The OVA releasing behavior of MAN-ALG/ALG=OVA NPs was determined as a function of pH. Antigen uptake was examined by flow cytometry and confocal laser scanning microscopy in vitro using mouse bone marrow dendritic cells (BMDCs). The results showed that MAN-ALG/ALG=OVA NPs facilitated antigen uptake of BMDCs and cytosolic release of the antigen. Significant up-regulation of cytokine secretion and expression levels of the surface co-stimulatory molecules were also observed in MAN-ALG/ALG=OVA NPs-treated BMDCs, compared to free OVA. In vivo bio-distribution study using Cy7 (a near-infrared fluorescence dye) labeled MAN-ALG/ALG=OVA NPs showed efficient in vivo trafficking of the nanoparticles from the injection site to the draining lymph nodes. Moreover, MAN-ALG/ALG=OVA NPs were found to enhance cross-presentation of OVA to B3Z T cell hybridoma in vitro. Subcutaneous administration of MAN-ALG/ALG=OVA NPs also induced major cytotoxic T lymphocytes (CTL) response and inhibition of E.G7 tumor growth in C57BL/6 mice. In summary, we report here that the MAN-ALG/ALG=OVA NPs have the potential as a potent nanovaccine for cancer immunotherapy.
本研究的目的是确定一种“易于采用”的策略，以通过功能化海藻酸钠（ALG）纳米粒子（MAN-ALG/ALG=OVA NPs）增强免疫反应，该纳米粒子通过 CaCl2 交联两种不同类型的 ALG 制备。甘露糖（MAN）修饰的 ALG（MAN-ALG）用于树突状细胞靶向。另一种成分由卵清蛋白（OVA）组成，是一种模型抗原，通过 pH 敏感的席夫碱键与 ALG 偶联（ALG=OVA）。FT-IR 和 H NMR 证明了海藻酸钠的接枝，而通过 TEM 和 DLS 测量了 MAN-ALG/ALG=OVA NPs 的形态结构、粒径和 Zeta 电位。MAN-ALG/ALG=OVA NPs 的 OVA 释放行为作为 pH 的函数进行了测定。通过流式细胞术和体外共聚焦激光扫描显微镜检查了 MAN-ALG/ALG=OVA NPs 处理的骨髓树突状细胞（BMDCs）中的抗原摄取。结果表明，MAN-ALG/ALG=OVA NPs 促进了 BMDCs 中的抗原摄取和抗原的细胞质释放。与游离 OVA 相比，在 MAN-ALG/ALG=OVA NPs 处理的 BMDCs 中还观察到细胞因子分泌和表面共刺激分子表达水平的显著上调。使用 Cy7（近红外荧光染料）标记的 MAN-ALG/ALG=OVA NPs 的体内生物分布研究表明，纳米粒子从注射部位有效地向引流淋巴结体内转运。此外，MAN-ALG/ALG=OVA NPs 被发现可增强 B3Z T 细胞杂交瘤体外的 OVA 交叉呈递。MAN-ALG/ALG=OVA NPs 的皮下给药还诱导了 C57BL/6 小鼠中的主要细胞毒性 T 淋巴细胞（CTL）反应并抑制了 E.G7 肿瘤的生长。总之，我们在这里报告，MAN-ALG/ALG=OVA NPs 具有作为癌症免疫治疗的有效纳米疫苗的潜力。
