基于铝离子脂质卷构建的微针疫苗佐剂-传递系统

Cochleates, a novel type of drug and vaccine carriers, are rod-like particulates formed of negatively charged phosphatidylserine (PS) bilayer sheets rolled up in a spiral structure owing to the mediation of divalent cations. In this proposal, trivalent aluminum ions are employed instead of divalent cations to have PS bilayer roll up into a novel type of antigen-carrying aluminum ion-based cochleates (ACOs), which are subsequently embedded in tips of a dissolvable microneedle array (MA), forming the ACO-entrapped MA (ACOM), to develop a vaccine adjuvant-delivery system (VADS). When painlessly administered at mucosa, the ACOM microneedles pierce through the stratified squamous epithelia and implant whole vaccines in mucosal tissues avoiding the active ingredient loss caused by mucus and fluids, while aluminum composition is a traditional adjuvant and can activate the innate immune system to prime an adaptive immune response. The unique structure of cochleates results in vaccine uptake by antigen presenting cells (APCs) via membrane fusion, favoring MHC- antigen presentation. Meanwhile PS is the well-known “eat-me” signal and, thus, can facilitate APCs to engulf ACOs through receptor-mediated endocytosis, rendering ACOs tragically trapped in lysosomes enriched in both protons and enzymes, especially acid phosphatase, which will disassemble ACOs to: 1) release aluminum ions to produce an osmotic pressure high enough to burst the lysosomes encompassing them, allowing Ags to escape easily from degradation; 2) engender the aluminum nanoparticles to form autophagosomes, facilitating antigen (cross) presentation to enhance the final immune responses. Moreover, ACOMs have a high stability and when inoculated via mucosa can induce robust cellular as well as mucosal immunity as a multiple defense against pathogen invasion. Thus, this proposal involves examination of the efficacy of ACOMs through cell and animal in vivo and in vitro experiments and clarify the function mechanisms associated with the novel carrier, laying certain foundation for the development of a safe and effective VADS and thus, bearing a significant research value.

脂质卷为二价阳离子介导磷脂酰丝氨酸（PS）双分子层自发席卷形成的螺杆状微粒，是新兴的药物及疫苗载体。项目以铝离子取代二价阳离子制备运载抗原的新型脂质卷(ACO)，并以其构建微针（ACOM），发展疫苗佐剂-传递系统（VADS）。粘膜接种ACOM，疫苗被完整植入粘膜组织，无成分流失；铝发挥传统佐剂功能，激活固有免疫系统，诱发免疫应答。ACO结构及PS吞噬信号特征，促使抗原提呈细胞以两种方式摄取疫苗：1）膜融合，利于MHC-抗原呈递；2）受体介导内吞，ACO被递入溶酶体，继而在质子及酶作用下解体：i）释放铝离子，产生高渗致溶酶体破裂，抗原逃逸；ii）产生铝纳米粒，形成自嗜体，促进抗原提呈，增强细胞免疫。ACOM性质稳定，粘膜接种诱导产生体液、细胞及粘膜免疫，对病原体入侵形成多重防御。项目通过细胞及动物实验，检测ACOM效力，深入探讨相关机理，为发展安全、有效VADS奠定基础，具有重要研究价值。

脂质卷为二价阳离子介导磷脂双分子层自发席卷形成的螺杆状微粒， 是新型的药物及疫苗载体。本项目以铝离子取代二价阳离子制备运载抗原的新型脂质卷(ACO )，发展疫苗佐剂-传递系统（VADS）。铝离子还能发挥传统佐剂功能，激活固有免疫系统，诱发高强度免疫应答。本研究植被的抗原载体系统性质稳定，粘膜接种可诱导产生体液、细胞及粘膜免疫， 对病原体入侵形成多重防御。本研究通过细胞及动物实验，检测免疫效力，深入探讨相关机理，为发展安全、有效的疫苗载体系统奠定基础，具有重要研究价值和实际意义。小鼠口腔黏膜免疫接种后，血液中检测到高水平且持续时间较长的特异性IgG；相对于传统的铝佐剂和钙离子脂质卷等，血液和脾细胞培养液中检测到较高水平的IgG2a和IFN-γ，表明其诱导了混合型Th1/Th2免疫应答。本项目按照年度计划完成了研究内容，得出了具有一定应用价值的实验研究结果。基于本项目的研究成果，发表了5篇相关论文，出版1部学术专著，参与多次学术会议，并获得1项奖励。