A transfollicular nanovaccine against leishmaniasis

描述（由申请人提供）：世界卫生组织估计，全世界有超过3.5亿人面临患利什曼病的风险，感染流行率为1400万人。每年有200万人感染利什曼原虫，其中27万人死亡。利什曼病是当今影响美国军队的最重要的寄生虫病之一，超过2500名美国军人被诊断患有皮肤利什曼病（CL）。目前的非免疫治疗方法效果不一，毒性高，价格昂贵，而且没有临床使用的疫苗。有重要证据支持免疫系统在控制利什曼原虫感染方面的作用。因此，疫苗接种仍然是一种有吸引力的疾病预防策略。必须解决两个重大的科学知识空白：1)一种能够接触皮肤树突状细胞（dc）的疫苗，以及2)鉴定与人类具有生物学相关性的利什曼原虫抗原。针头疫苗绕过这些具有免疫能力的皮肤细胞。这项提议的长期目标是开发一种纳米级基于聚合物的疫苗，通过经滤泡免疫（TFI）向皮肤树突状细胞提供抗原和佐剂。我们将描述将toll样受体7/8激动剂雷昔莫特（RSQ）整合到聚合体膜中并将利什曼原虫模型抗原（活化C激酶受体（LACK）的利什曼原虫同源物）包封到水核中的可行性。然后，我们将评估其在体内产生th1型细胞因子谱和功能性细胞毒性CD8+ T细胞的功能特性。我们假设将LACK和RSQ共包封到纳米疫苗中可以逐步实现，并且所产生的纳米疫苗将穿透毛囊并激活皮肤dc。我们还假设局部注射这种纳米疫苗会诱导lack特异性T细胞反应。最后，我们假设这种纳米疫苗将在仓鼠模型中保护免受内脏利什曼原虫菌株的攻击。目的1构建包封抗原LACK和TLR7/8激动剂RSQ的纳米疫苗（LACK/RSQ- nps）。目的2：确定LACK/ rsq -纳米疫苗穿透滤泡管、激活皮肤dc并诱导LACK特异性适应性免疫应答的最佳理化性质。目的3：确定LACK/ rsq纳米疫苗是否在体内诱导保护性免疫反应。我们预计从该提案中产生的数据将产生一种商业上可行的局部纳米疫苗，可以通过经滤泡途径进入皮肤dc。NIAID支持免疫介导疾病（如利什曼病）的基础、临床前和临床研究以及有效疫苗的开发。SBIR第一阶段计划提出的目标与NIAID的使命声明是一致的。

DESCRIPTION (provided by applicant): The World Health Organization estimates that over 350 million people are at risk of developing leishmaniasis and infection prevalence is 14 million people in the world. Annually, 2 million people are infected with Leishmania species and 270,000 will die. Leishmaniasis is one of the most important parasitic diseases affecting the U.S. military today, with over 2500 U.S. military personnel diagnosed with cutaneous leishmaniasis (CL). Current non-immunization based treatments are variably effective, highly toxic, expensive, and there are no vaccines in clinical use. Significant evidence has supported the role of the immune system in controlling Leishmania infection. Thus, a vaccination remains an attractive disease prevention strategy. Two significant scientific knowledge gaps must be addressed: 1) a vaccine that can access the skin resident dendritic cells (DCs), and 2) the identification of Leishmania antigens that are biologically relevant in humans. Needle based vaccines bypass these immunopotent skin cells. The long-term objective of this proposal is to develop a nanoscale polymersome-based vaccine that delivers an antigen and adjuvant to skin dendritic cells through transfollicular immunization (TFI). We will characterize the feasibility of integrating the Toll-like receptor 7/8 agonist resiquimod (RSQ) into the polymersome membrane and encapsulating a model Leishmania antigen, Leishmania homolog of receptors for activated C kinase (LACK), into the aqueous core. We will then evaluate its functional properties in generating a TH1-type cytokine profile and functional cytotoxic CD8+ T cells in vivo. We hypothesize that co-encapsulation of LACK and RSQ into the nanovaccine can be achieved in a stepwise manner and that the resulting nanovaccine will penetrate the follicle and activate skin DCs. We also hypothesize that the topical administration of this nanovaccine will induce a LACK-specific T cell response. Finally, we hypothesize that this nanovaccine will protect against challenge with a visceral Leishmania strain in a hamster model. AIM 1 Construct a nanovaccine encapsulating the antigen LACK and TLR7/8 agonist RSQ (LACK/RSQ-NPS). AIM 2 Determine the optimal physicochemical properties of LACK/RSQ-nanovaccine to penetrate the follicular duct, activate skin DCs, and induce a LACK-specific adaptive immune response. AIM 3 Determine if the LACK/RSQ-nanovaccine induces protective immune responses in vivo. We anticipate the data generated from this proposal will result in a commercially viable topical nanovaccine that can access skin DCs via the transfollicular route. The NIAID supports basic, preclinical, and clinical research on immune-mediated diseases such as leishmaniasis and the development of effective vaccines. The aims proposed in this SBIR Phase I program are consistent with the mission statement of the NIAID. PUBLIC HEALTH RELEVANCE: The World Health Organization estimates that over 350 million people are at risk of developing leishmaniasis and infection prevalence is 14 million people in the world. Annually, 2 million people are infected with Leishmania species and 270,000 will die. Leishmaniasis is one of the most important parasitic diseases affecting the U.S. military today. We plan to develop a nanovaccine against Leishmania that delivers the vaccine payload through the hair follicle duct to stimulate skin immune cells, all without a needle. This major advance in Leishmania vaccine design may provide the first effective vaccine against Leishmania and would create biotechnology jobs in the US via US military contracts and international government contracts in countries suffering from leishmaniasis.