BACKGROUND The greatest challenges in vaccine development include optimization of DNA vaccines for use in humans, creation of effective single-dose vaccines, development of delivery systems that do not involve live viruses, and the identification of effective new adjuvants. Herein, we describe a novel, simple technique for efficiently vaccinating mice against tuberculosis (TB). Our technique consists of a single-dose, genetic vaccine formulation of DNA-hsp65 complexed with cationic liposomes and administered intranasally. RESULTS We developed a novel and non-toxic formulation of cationic liposomes, in which the DNA-hsp65 vaccine was entrapped (ENTR-hsp65) or complexed (COMP-hsp65), and used to immunize mice by intramuscular or intranasal routes. Although both liposome formulations induced a typical Th1 pattern of immune response, the intramuscular route of delivery did not reduce the number of bacilli. However, a single intranasal immunization with COMP-hsp65, carrying as few as 25 microg of plasmid DNA, leads to a remarkable reduction of the amount of bacilli in lungs. These effects were accompanied by increasing levels of IFN-gamma and lung parenchyma preservation, results similar to those found in mice vaccinated intramuscularly four times with naked DNA-hsp65 (total of 400 microg). CONCLUSION Our objective was to overcome the significant obstacles currently facing DNA vaccine development. Our results in the mouse TB model showed that a single intranasal dose of COMP-hsp65 elicited a cellular immune response that was as strong as that induced by four intramuscular doses of naked-DNA. This formulation allowed a 16-fold reduction in the amount of DNA administered. Moreover, we demonstrated that this vaccine is safe, biocompatible, stable, and easily manufactured at a low cost. We believe that this strategy can be applied to human vaccines to TB in a single dose or in prime-boost protocols, leading to a tremendous impact on the control of this infectious disease.

中文翻译：

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通过单次鼻内施用与阳离子脂质体复合的 DNA-hsp65 疫苗来预防结核病。

背景疫苗开发中的最大挑战包括优化用于人类的 DNA 疫苗、创建有效的单剂量疫苗、开发不涉及活病毒的递送系统以及识别有效的新佐剂。在此，我们描述了一种新颖、简单的技术，可有效地为小鼠接种结核病 (TB) 疫苗。我们的技术包括与阳离子脂质体复合并鼻内给药的 DNA-hsp65 的单剂量基因疫苗制剂。结果我们开发了一种新型无毒的阳离子脂质体制剂，其中 DNA-hsp65 疫苗被包裹 (ENTR-hsp65) 或复合 (COMP-hsp65)，并用于通过肌内或鼻内途径对小鼠进行免疫。尽管两种脂质体制剂都诱导了典型的 Th1 免疫反应模式，肌内给药途径并没有减少杆菌的数量。然而，使用 COMP-hsp65 进行单次鼻内免疫，携带少至 25 微克的质粒 DNA，导致肺部细菌数量显着减少。这些影响伴随着 IFN-γ 和肺实质保存水平的增加，结果类似于在肌肉注射四次裸 DNA-hsp65（共 400 微克）的小鼠中发现的结果。结论 我们的目标是克服目前 DNA 疫苗开发面临的重大障碍。我们在小鼠 TB 模型中的结果表明，单次鼻内剂量的 COMP-hsp65 引发的细胞免疫反应与四次肌肉注射裸 DNA 所诱导的免疫反应一样强烈。这种配方使施用的 DNA 量减少了 16 倍。此外，我们证明了这种疫苗安全、生物相容、稳定且易于以低成本制造。我们相信，这种策略可以应用于单剂量或以致敏-加强方案的人类结核病疫苗，从而对控制这种传染病产生巨大影响。