Biomimetic nanoparticles to enhance the breadth of influenza vaccines

摘要 目前的流感(流感)疫苗只对接近匹配的流感病毒株有效，必须更新 每年处理猪表面血凝素(HA)和/或神经氨酸酶(NA)的持续抗原转移/漂移 病毒。即使每年更新，流感疫苗也有几年是无效的，因为 用于制备疫苗的菌株和用于制备疫苗的菌株之间HA和/或NA的抗原性有显著差异 传播的病毒，使我们处于大流行的高风险，以防出现新的高度病理性病毒。 毫无疑问，一种既能预防季节性流感，又能预防季节性流感的“通用”流感疫苗 不匹配)和大流行流感病毒是迫切需要的，但到目前为止，它仍然是“炼金术士的梦想”。我们 通过包裹干扰素基因激动剂cGAMP开发新型佐剂 (刺痛)，进入肺表面活性物质(PS)-仿生脂质体(PS-GMNP)。佐剂，与一种 灭活流感疫苗，强烈刺激体液和CD8+T细胞免疫反应，类似于 在病毒感染的早期阶段，无论在规模上还是在动态上都发生了。令人惊讶的是，一剂 PS-GMNP佐剂流感疫苗对多种致命性挑战产生了强大的交叉保护作用 异亚型甲型流感病毒最早在免疫后2天。同时刺激健壮的异亚型 免疫，佐剂未在肺组织学、体重或体温等方面引起任何不良反应。 与流感病毒感染造成的严重肺部炎症和死亡形成鲜明对比。在这项提案中，我们将 研究PS-2诱导的交叉保护所必需的细胞和体液免疫反应 GMNP佐剂的流感疫苗。具体来说，我们将确定PS-GMNP是否可以扩大交叉反应 CD8+T细胞，并诱导广谱中和抗体(BNAbs)，在PS-GMNP诱导的交叉反应中起关键作用。 保护。在目标2中，我们将排除预先存在的免疫对PS-佐剂的任何不利影响。 GMNP，并将交叉保护扩展至大流行前的野生型H5N1和H7N9病毒，以建立其 临床潜力。与主要激活抗原提呈细胞的传统佐剂不同 肺泡巨噬细胞(APC)和肺泡上皮细胞(AMɸ) 细胞(AEC)，这可能是至关重要的，因为在流感期间也观察到这两种类型的细胞类似的激活 病毒感染。目标3将采用两种替代方法，以证实 AEC和/或AMɸ在PS-GMNP介导的异型免疫中的作用，包括阻断细胞缝隙连接 并产生野生型和棘突缺陷骨髓(BM)细胞的嵌合小鼠。如果这项研究 成功，可提供有关PS-GMNP临床潜力的宝贵信息，以拓宽 将现有的流感疫苗转变为“宇宙”疫苗，这将对全球健康产生巨大而直接的影响。

Abstract Current influenza (flu) vaccines are effective only for closely matched flu viral strains and must be updated annually to address constant antigenic shift/drifts of surface hemagglutinin (HA) and/or neuraminidase (NA) of the virus. Even with annual update, there have been years in which flu vaccines were ineffective due to significant differences in antigenicity of HA and/or NA between the strains used for preparing the vaccines and the circulating ones, leaving us at high risk of pandemics in case a new and highly pathological virus emerges. It is without any doubt that a “Universal” flu vaccine that can protect against both seasonal (matched or mismatched) and pandemic flu viruses is urgently needed, but it remains “an alchemist’s dream” so far. We developed a novel adjuvant by encapsulation of cGAMP, an agonist of the stimulator of interferon (IFN) gene (STING), into pulmonary surfactant (PS)-biomimetic liposomes (PS-GMNP). The adjuvant, alongside an inactivated flu vaccine, robustly stimulated humoral and CD8+ T cell immune responses that resemble those ocurring during the early phase of viral infection both in magnitude and in dynamics. Strikingly, a single dose of PS-GMNP-adjuvant flu vaccine elicited strong cross-protection against a lethal challenge of diverse heterosubtypic flu A viruses as early as 2 days after immunization. While stimulating robust heterosubtypic immunity, the adjuvant did not cause any adverse events in lung histology, body weight or temperature, in sharp contrast to the severe lung inflammation and death caused by flu viral infection. In this proposal, we will investigate the cellular and humoral immune responses essential to the cross-protection induced by PS- GMNP-adjuvanted flu vaccines. Specifically, we will determine whether PS-GMNP can expand cross-reactive CD8+ T cells and induce broadly neutralizing antibodies (bnAbs), pivotal to PS-GMNP-induced cross- protection. In Aim 2, we will preclude any adverse effects of pre-existing immunity on the adjuvanticity of PS- GMNP and extend the cross-protection to pre-pandemic wild type H5N1 and H7N9 viruses to establish its clinical potentials. Distinguished from conventional adjuvants that activate primarily antigen-presenting cells (APCs), cGAMP delivered by PS-GMNP activated both alveolar macrophages (aMɸ) and alveolar epithelial cells (AEC), which can be crucial since similar activation of these two types of cells is also observed during flu viral infection. Two alternative approaches will be employed in Aim 3 to corroborate indispensable function of AEC and/or aMɸ in PS-GMNP-mediated heterosubtypic immunity, including a blockade of cell-gap junctions and generation of chimeric mice of wild type and STING-deficient bone marrow (BM) cells. The study, if successful, could provide invaluable information about clinical potentials for PS-GMNP to widen the breadth of existing flu vaccines toward a “Universe” one, which will have a huge and immediate impact on global health.