Mechanisms of induction of protective anti-malarial CD8+ T Cells

保护性抗疟疾 CD8 T 细胞的诱导机制

• 批准号: 8631476
• 负责人: MORIYA TSUJI
• 金额: $ 35万
• 依托单位: AARON DIAMOND AIDS RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-03-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8631476
• 关键词: Address; Adenoviruses; Albumins; Antibodies; Antigen-Presenting Cells; Antigens; Antimalarials; Attenuated; CD8B1 gene; Cells; Chloroquine; Communicable Diseases; Dendritic Cells; Disease; Epitopes; Erythrocytes; Goals; Hepatocyte; Human; ITGAX gene; Immunity; Immunization; In Vitro; Infection; Intramuscular; Intravenous; Kupffer Cells; Lead; Life; Life Cycle Stages; Liver; Malaria; Malaria Vaccines; Mediating; Monkeys; Mus; Nature; Parasites; Plasmodium yoelii; Radiation; Recombinants; Rodent; Role; Route; Societies; Spleen; Sporozoites; Staging; T cell response; T-Lymphocyte; Testing; Transgenic Mice; Transgenic Organisms; Vaccination; Vaccines; base; circumsporozoite; circumsporozoite protein; design; improved; in vivo; intravenous administration; macrophage; mouse model; promoter; public health relevance; subcutaneous; tool; vector vaccine

PROJECT SUMMARY/ABSTRACT Malaria remains one of the most devastating infectious diseases of the world, underscoring the need to develop effective vaccines. The current candidate malaria vaccines against the liver stages induce CD8+ T- cell-mediated protection. However, what remains unknown is the manner in which the anti-malarial CD8+ T cells are elicited in vivo. This unanswered question is particularly prominent in view of a very recent study showing that only through intravenous administration (and no other routes) do radiation-attenuated sporozoites (IrSpz) induce a potent malaria-specific CD8+ T-cell response in the livers of monkeys and of mice and provide anti-malarial protection in mice. Therefore, it appears that the nature of vaccine vectors, as well as the routes of vaccination, influences the mode of induction of "protective" anti-malarial CD8+ T cells in vivo. The overall aim of this proposal is to determine the mechanisms of in vivo induction of anti-malarial CD8+ T cells. SYVPSAEQI, derived from the P. yoelii circumsporozoite (PyCS) protein, is to date the only known CD8+ epitope that mediates "protection" against P. yoelii infection in mice and is presented by an H-2Kd molecule. Therefore, in addressing our overall goal, we have generated C57BL/6 transgenic (Tg) mice, in which Kd molecule is expressed only on dendritic cell (DC) (CD11c-Kd), macrophage (huCD68-Kd), or hepatocyte (Alb- Kd), by using CD11c promoter, huCD68 promoter, or albumin promoter, respectively. We have also generated MHC-I-Kd Tg mice that express a Kd molecule under the MHC-I promoter, in which we could induce a potent, protective anti-malarial immunity, dependent on both the PyCS protein and CD8+ T cells. These MHC-I-Kd Tg mice will be used as a positive control. In the proposed study, we will immunize the Kd Tg mice with malaria vaccines, including an adenovirus expressing the PyCS antigen, IrPySpz, or live PySpz followed by treatment with chloroquine, by different routes. We will determine the quantity, quality, and durability of PyCS antigen- specific CD8+ T-cell response induced in each group of Kd Tg mice in Aim 1. In Aim 2, we will challenge these immunized Kd Tg mice with live malaria parasites to determine the level and persistence of protective immunity induced in vivo. In Aim 3, we will determine which Kd-expressing cells induce the protective anti-malarial immunity by isolating these Kd+ cells from immunized, various Kd Tg mice, and adoptively transferring them to na¿ve MHC-I-Kd Tg mice, followed by a malaria challenge. Finally, we will isolate PyCS antigen-specific CD8+ T cells from immunized, various Kd Tg mice and adoptively transfer them to na¿ve MHC-I-Kd Tg mice, followed by a malaria challenge, to determine the protective capacity of the CD8+ T cells in Aim 4. Overall, we believe that the identification of the induction mechanisms of anti-malarial "protective" CD8+ T cells could ultimately lead to the vastly improved designs of potent T-cell-based vaccines against human malaria.

项目概要/摘要 疟疾仍然是世界上最具破坏性的传染病之一，强调需要 开发有效的疫苗，针对肝脏阶段的候选疟疾疫苗可诱导 CD8+ T-。 然而，目前尚不清楚抗疟疾 CD8+ T 的作用方式。 鉴于最近的一项研究，这个悬而未决的问题尤为突出。 表明只有通过静脉注射（而不是其他途径）才能使辐射减弱的子孢子 (IrSpz) 在猴子和小鼠的肝脏中诱导有效的疟疾特异性 CD8+ T 细胞反应，并提供 因此，看来疫苗载体的性质以及途径。 疫苗接种的影响，影响体内“保护性”抗疟疾 CD8+ T 细胞的诱导模式。 该提案的目的是确定体内诱导抗疟疾 CD8+ T 细胞的机制。 SYVPSAEQI 源自 P. yoelii 环子孢子 (PyCS) 蛋白，是迄今为止唯一已知的 CD8+ 介导小鼠免受约氏疟原虫感染“保护”的表位，由 H-2Kd 分子呈递。 因此，为了实现我们的总体目标，我们生成了 C57BL/6 转基因 (Tg) 小鼠，其中 Kd 该分子仅在树突状细胞 (DC) (CD11c-Kd)、巨噬细胞 (huCD68-Kd) 或肝细胞 (Alb- Kd)，分别使用CD11c启动子、huCD68启动子或白蛋白启动子。 MHC-I-Kd Tg 小鼠在 MHC-I 启动子下表达 Kd 分子，我们可以在其中诱导有效的、 保护性抗疟疾免疫，依赖于 PyCS 蛋白和 CD8+ T 细胞。 小鼠将用作阳性对照。在拟议的研究中，我们将对 Kd Tg 小鼠进行疟疾免疫。 疫苗，包括表达 PyCS 抗原的腺病毒、IrPySpz 或活 PySpz，然后进行治疗 与氯喹，通过不同的途径，我们将确定 PyCS 抗原的数量、质量和耐久性。 在目标 1 中，每组 Kd Tg 小鼠诱导特异性 CD8+ T 细胞反应。在目标 2 中，我们将挑战这些 用活疟原虫免疫 Kd Tg 小鼠，以确定保护性免疫的水平和持久性 在目标 3 中，我们将确定哪些 Kd 表达细胞诱导保护性抗疟疾。 通过从免疫的各种 Kd Tg 小鼠中分离这些 Kd+ 细胞，并将其过继转移至 呐ve MHC-I-Kd Tg 小鼠，然后进行疟疾攻击最后，我们将分离 PyCS 抗原特异性 CD8+。 来自免疫的各种 Kd Tg 小鼠的 T 细胞，并将其过继转移至 na¿ ve MHC-I-Kd Tg 小鼠，随后 通过疟疾挑战，确定目标 4 中 CD8+ T 细胞的保护能力。总体而言，我们认为 抗疟疾“保护性”CD8+ T 细胞的诱导机制的鉴定最终可以 导致针对人类疟疾的有效 T 细胞疫苗的设计得到极大改进。