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 CaCl₂ 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 ¹H 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.

中文翻译：

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通过功能化藻酸盐纳米颗粒靶向抗原递送至树突状细胞用于癌症免疫治疗

本研究的目的是确定使用功能化藻酸盐（ALG）纳米颗粒（MAN-ALG / ALG = OVA NPs）增强免疫反应的“易于采用”策略，该纳米颗粒是通过CaCl ₂交联制备的。两种不同类型的ALG。甘露糖（MAN）修饰的ALG（MAN-ALG）用于树突状细胞靶向。由卵白蛋白（OVA）（一种模型抗原）组成的其他成分通过pH敏感的席夫碱键与ALG（ALG = OVA）缀合。FT-IR和¹证明了藻酸盐的接枝1 H NMR，同时使用TEM和DLS测量MAN-ALG / ALG = OVA NP的形态结构，粒径，Zeta电位。确定MAN-ALG / ALG = OVA NPs的OVA释放行为是pH的函数。使用小鼠骨髓树突状细胞（BMDC），通过流式细胞术和共聚焦激光扫描显微镜在体外检查抗原的摄取。结果表明，MAN-ALG / ALG = OVA NPs促进了BMDCs的抗原摄取和抗原的胞质释放。与游离OVA相比，在MAN-ALG / ALG = OVA NPs处理的BMDC中也观察到细胞因子分泌的显着上调和表面共刺激分子的表达水平。使用Cy7（近红外荧光染料）标记的MAN-ALG / ALG = OVA NP进行的体内生物分布研究显示，纳米颗粒从注射部位到引流淋巴结的有效体内转运。此外，发现MAN-ALG / ALG = OVA NPs在体外可增强OVA与B3Z T细胞杂交瘤的交叉表达。皮下给药MAN-ALG / ALG = OVA NPs还诱导了C57BL / 6小鼠的主要细胞毒性T淋巴细胞（CTL）反应和E.G7肿瘤生长的抑制。总而言之，我们在此报告，MAN-ALG / ALG = OVA NPs具有作为癌症免疫疗法的强大纳米疫苗的潜力。皮下给药MAN-ALG / ALG = OVA NPs还诱导了C57BL / 6小鼠的主要细胞毒性T淋巴细胞（CTL）反应和E.G7肿瘤生长的抑制。总而言之，我们在此报告，MAN-ALG / ALG = OVA NPs具有作为癌症免疫疗法的强大纳米疫苗的潜力。皮下给药MAN-ALG / ALG = OVA NPs还诱导了C57BL / 6小鼠的主要细胞毒性T淋巴细胞（CTL）反应和E.G7肿瘤生长的抑制。总而言之，我们在此报告，MAN-ALG / ALG = OVA NPs具有作为癌症免疫疗法的强大纳米疫苗的潜力。