S50 nanocapsules for transcutaneous DNA vaccination

描述(申请人提供)：世界卫生组织估计，全世界有4000万人感染艾滋病，每天有1.6万人新感染，这为疫苗技术的新方法提供了持续的支持。与蛋白质疫苗相比，DNA疫苗通过模拟细胞内病原体的感染来提高细胞毒性T细胞(CTL)的反应。然而，新的证据表明，这种转染必须针对树突状细胞(DC)，并伴随着DC的显著成熟和迁移。在开发艾滋病疫苗的努力中，已经通过DNA基元/病毒增强方案实现了与自然感染相媲美的早期CTL反应，但这些反应在猕猴身上并没有持续足够的时间来提供保护，这表明需要佐剂或重组病毒样颗粒来激发更强的初始T细胞反应。 我们已经开发了一种亚50 nm纳米胶囊递送载体，能够通过被动局部应用，利用体外猪皮肤器官培养模型，诱导大颗粒高效地导入激活的、迁移的朗格汉斯细胞。LCS是皮肤的树突状细胞，可以有效地诱导广泛的全身和粘膜反应，但目前的经皮方法很难在大型动物身上有效地刺激迁移。由于猪与人类在解剖学上的相似性，猪的模型在评价经皮疫苗方面更具优势。在这项初步研究中，使用细菌蛋白13-半乳糖苷作为模型抗原，我们建议在器官培养和断奶仔猪中制备和测试由透明质酸和铝或镍离子组成的疫苗配方。随着剂量的减少，细胞和体液免疫反应得到改善，这将为猕猴提高粘膜免疫和T细胞对SIV的反应的后续研究提供坚实的基础。

DESCRIPTION (provided by applicant): The WHO estimates that 40 million individuals are infected with AIDS worldwide and that 16,000 new infections occur daily, lending continuing support for new approaches in vaccine technology. DNA vaccines offer the advantage over protein vaccines of improved cytotoxic T cells (CTL) responses by simulating infection by intracellular pathogens following effective transfection. Emerging evidence suggests, however, this transfection must be directed at dendritic cells (DC) and be coupled with significant maturation and migration of DCs. In the effort to develop an AIDS vaccine, early CTL responses rivaling natural infection have been achieved with DNA prime / viral boost protocols, but these responses have not persisted sufficiently in macaques to provide protection, suggesting the need for adjuvants or recombinant virus-like particles to provoke stronger initial T-cell responses. We have developed a sub-50 nm nanocapsule delivery vector, capable of caveolar uptake, that induces efficient transfection of large plasmids into activated, migrating Langerhans cells by passive topical application using an ex vivo porcine skin organ culture model. LCs, the dendritic cells of skin, are efficient for inducing a broad range of systemic and mucosal responses, but effective stimulation of migration has proven difficult in large animals by current transcutaneous methods. Due to anatomical similarities with humans, the porcine model is superior for evaluation of transcutaneous vaccines. In this pilot study, using the bacterial protein 13-galactosidse as a model antigen, we propose to prepare and test in organ culture and in weanling pigs, vaccine formulations comprised of hyaluronan and aluminum or nickel ion. Demonstration of improved cellular and humoral immune responses with decreased dosing will provide a strong foundation for follow-on studies in Rhesus macaques to improve mucosal immunity and T-cell responses against SIV.