Development of Efficacious and Stable Nasal Vaccine Formulations

描述(申请人提供)：目前，世界上唯一可供人类使用的佐剂是明矾，这是一种诱导粘膜免疫能力有限的劣佐剂。其他佐剂，如Toll样受体(TLR)配体正在研究中，但这些佐剂在疗效和成本方面受到限制。最近，我们描述了一类新的有效的粘膜佐剂，具有广泛的适用性，可以对抗多种疫苗抗原(《自然医学》，2008年4月20日)。我们报道，无针鼻注射含有小分子肥大细胞(MC)激活化合物的疫苗制剂，可在小鼠血清中诱发高水平的抗原特异性IgG和沿粘膜表面的IgA。这些反应在致命的挑战模型中是保护性的，而且没有引起任何有害的副作用。许多MC激活剂都是由14个氨基酸组成的小分子多肽序列(肥大细胞激活肽，MCAP)，其制备方法简单、经济、纯度高。MCAP与TLR配体MPL或CpG联合使用所提供的佐剂活性优于任何单独使用的佐剂。我们还确定疫苗抗原的干粉制剂在室温储存后保持效力，在鼻腔免疫后高度有效，这表明它们在运输过程中不需要冷藏，同时保持诱导保护性免疫的能力。因此，本项目的目标是开发一种高效、安全的干粉疫苗配方，用于西尼罗河病毒的鼻免疫。因此，本研究的具体目的是：1.利用重复多肽设计，确定MC活化肽(MCAP)的最佳结构，使其对西尼罗河病毒抗原具有最大的佐剂活性。2.确定MC激活肽与TLR配基佐剂联合使用是否具有附加或协同佐剂活性，从而减少诱导保护性西尼罗河病毒免疫所需的抗原剂量。3.研制出与人鼻腔具有相同结构特征的WNV干粉鼻腔疫苗制剂，并在兔体内进行试验。

DESCRIPTION (provided by applicant): Currently, the only adjuvant available for world-wide human use is alum, a poor adjuvant with limited capacity to induce mucosal immunity. Additional adjuvants such as Toll-like receptor (TLR) ligands are being investigated, but these adjuvants are limiting with respect to efficacy and cost. Recently, we described a novel class of potent mucosal adjuvants with broad applicability against a wide range of vaccine antigens (Nature Medicine April 20, 2008). We reported that needle free, nasal administration of vaccine formulations containing small molecule mast cell (MC) activating compounds, evoked high levels of antigen-specific IgG in the serum and IgA along mucosal surfaces in mice. These responses were protective in lethal challenge models, and moreover, did not incur any harmful side effects. Many of these MC activating compounds are small peptide sequences (mast cell activating peptides, MCAP) ~ 14 amino acids in length, which can be readily and economically prepared with high purity. MCAP combined with TLR ligands MPL or CpG provided adjuvant activity that was superior to any adjuvant used alone. We have also determined that dry powder formulations of vaccine antigens maintain potency after room temperature storage and are highly efficacious after nasal immunization, suggesting that they will not require refrigeration during transport while maintaining the ability to induce protective immunity. Therefore the goal of this project is to develop a highly efficacious and safe dry powder vaccine formulation for nasal immunization against West Nile Virus. The Specific Aims are therefore: 1. Utilize reiterative peptide design to determine the optimal structure of MC activating peptides (MCAP) for maximal adjuvant activity with West Nile Virus antigens in mice. 2. Determine if MC activating peptides combined with TLR ligand adjuvants provides additive or synergistic adjuvant activity able to reduce the antigen dose required for induction of protective WNV immunity. 3. Develop and test WNV dry powder nasal vaccine formulations in rabbits, which share structural features with human nasal passages.