A transfollicular nanovaccine against leishmaniasis

描述(申请人提供)：世界卫生组织估计，全球有超过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，27万人死亡。利什曼病是当今影响美军的最重要的寄生虫病之一，超过2500名美军人员被诊断为皮肤利什曼病(CL)。目前基于非免疫的治疗方法效果参差不齐，毒性大，价格昂贵，而且还没有疫苗在临床上使用。大量证据支持免疫系统在控制利什曼原虫感染中的作用。因此，接种疫苗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)可以访问皮肤常驻树突状细胞(DC)的疫苗；2)识别与人类生物学相关的利什曼原虫抗原。针头疫苗绕过了这些具有免疫潜力的皮肤细胞。这项提议的长期目标是开发一种基于纳米多聚体的疫苗，通过跨毛囊免疫(TFI)将抗原和佐剂输送到皮肤树突状细胞(DC)。我们将研究将Toll样受体7/8激动剂resquimod(RSQ)整合到多聚体膜上，并将模型利什曼原虫抗原激活的C激酶受体(LACK)包裹到房水核心的可行性。然后我们将在体内评估其在产生TH1型细胞因子谱和功能性细胞毒性CD8+T细胞方面的功能特性。我们假设，LACK和RSQ共包裹到纳米疫苗中可以循序渐进地实现，所产生的纳米疫苗将穿透毛囊并激活皮肤树突状细胞。我们还假设，局部注射这种纳米疫苗将诱导缺乏特异性的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株的攻击。目的1构建包裹LACK和TLR7/8激动剂RSQ的纳米疫苗(LACK/RSQ-NPS)。目的2确定LACK/RSQ纳米疫苗穿透卵泡管，激活皮肤树突状细胞，诱导LACK特异性获得性免疫应答的最佳理化性质。目的3确定LACK/RSQ纳米疫苗在体内是否诱导保护性免疫反应。我们预计，这项提议产生的数据将导致一种商业上可行的局部纳米疫苗，可以通过跨毛囊途径进入皮肤树突状细胞。NIAID支持对免疫介导性疾病(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第一阶段计划中提出的目标与NIAID的使命声明是一致的。 公共卫生相关性：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，27万人死亡。利什曼病是当今影响美军的最重要的寄生虫病之一。我们计划开发一种针对利什曼原虫的纳米疫苗，这种疫苗通过毛囊导管传递疫苗有效载荷，刺激皮肤免疫细胞，所有这些都不需要针头。利什曼病疫苗设计的这一重大进展可能会提供首个有效的利什曼病疫苗，并将通过美国军事合同和国际政府合同在患有利什曼病的国家创造生物技术就业机会。

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.