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

基本信息

批准号：
9232993
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
项目类别：
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/9232993
关键词：
Address Adenoviruses Adoptive Transfer Albumins Antibodies Antigen-Presenting Cells Antigens Antimalarials Attenuated CD8-Positive T-Lymphocytes CD8B1 gene Cells Chloroquine Communicable Diseases Dendritic Cells Disease Epitopes Erythrocytes Goals Hepatocyte Human ITGAX gene Immunity Immunization Immunize In Vitro Infection Intramuscular Intravenous Kupffer Cells Lead Life Cycle Stages Liver Malaria Malaria Vaccines Mediating Modernization Monkeys Mus Nature Parasites Plasmodium yoelii Radiation Recombinants Rodent Role Route Societies Spleen Sporozoites 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 recombinant adenovirus response subcutaneous tool vector vaccine

项目摘要

DESCRIPTION (provided by applicant): 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.

描述（由申请人提供）：疟疾仍然是世界上最具破坏性的传染病之一，这凸显了开发有效疫苗的必要性。目前针对肝脏阶段的候选疟疾疫苗可诱导 CD8+ T 细胞介导的保护。抗疟疾 CD8+ T 细胞在体内产生的方式尚不清楚，鉴于最近的一项研究表明，只有通过静脉注射（没有其他途径）才能产生抗疟疾 CD8+ T 细胞，这一悬而未决的问题尤为突出。辐射减毒子孢子 (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，并为小鼠提供抗疟疾保护。疫苗接种途径，影响体内“保护性”抗疟疾 CD8+ T 细胞的诱导模式该提案的总体目标是确定抗疟疾体内诱导的机制。 CD8+ T 细胞源自约氏疟原虫环子孢子 (PyCS) 蛋白，是迄今为止唯一已知的介导小鼠免受约氏疟原虫感染的“保护”的 CD8+ 表位，并由 H-2Kd 分子呈递。为了实现我们的总体目标，我们培育了 C57BL/6 转基因 (Tg) 小鼠，其中 Kd 分子仅在树突状细胞上表达(DC) (CD11c-Kd)、巨噬细胞 (huCD68-Kd) 或肝细胞 (Alb-Kd)，分别通过使用 CD11c 启动子、huCD68 启动子或白蛋白启动子，我们还生成了 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、保护性的抗疟疾免疫，这取决于 PyCS 蛋白和 CD8+ T这些 MHC-I-Kd Tg 小鼠将用作阳性对照。在拟议的研究中，我们将用疟疾疫苗（包括表达 PyCS 抗原的腺病毒、IrPySpz 或活 PySpz）对 Kd Tg 小鼠进行免疫，然后进行治疗。我们将通过不同途径确定在 Aim 中每组 Kd Tg 小鼠中诱导的 PyCS 抗原特异性 CD8+ T 细胞反应的数量、质量和持久性。 1. 在目标 2 中，我们将用活疟原虫攻击这些免疫的 Kd Tg 小鼠，以确定体内诱导的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免疫。通过从免疫的各种 Kd Tg 小鼠中分离这些 Kd+ 细胞，并将它们过继转移到幼稚的 MHC-I-Kd Tg 小鼠中，然后进行疟疾攻击，最后，我们将分离。来自免疫的各种 Kd Tg 小鼠的 PyCS 抗原特异性 CD8+ T 细胞，并将其过继转移至幼稚 MHC-I-Kd Tg 小鼠，然后进行疟疾攻击，以确定目标 4 中 CD8+ T 细胞的保护能力。我们相信，抗疟疾“保护性”CD8+ T 细胞诱导机制的识别最终可能导致针对人类疟疾的有效 T 细胞疫苗设计的大幅改进。