Optimizing adenoviral vector to elicit a potent anti-malaria immunity

优化腺病毒载体以引发有效的抗疟疾免疫力

• 批准号: 7674272
• 负责人: MORIYA TSUJI
• 金额: $ 45.63万
• 依托单位: AARON DIAMOND AIDS RESEARCH CENTER
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-02-19 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7674272
• 关键词: Adenovirus Vector; Adenoviruses; Affect; Africa; Antibodies; Antibody Formation; Antigens; Antimalarials; B-Lymphocyte Epitopes; CD4 Positive T Lymphocytes; CD8B1 gene; Capsid; Capsid Proteins; Cell physiology; Cells; Cellular Tropism; Child; Communicable Diseases; Disease; Dose; Epitopes; Erythrocytes; Fiber; Figs - dietary; Humoral Immunities; Immune response; Immunity; Immunization; Immunohistochemistry; Lead; Malaria; Malaria Vaccines; Mediating; Modification; Morbidity - disease rate; Mus; Nature; Parasites; Phagocytes; Plasmodium yoelii; Process; Production; Proteins; Recombinants; Staging; T-Lymphocyte; Testing; Tissues; Transgenes; Treatment Protocols; Upper arm; Vaccinated; Vaccination; Vaccines; Virus; base; circumsporozoite; circumsporozoite protein; fluorophore; immunogenicity; in vivo; mortality; novel; prevent; public health relevance; response; trafficking; Adenovirus Vector; Adenoviruses; Affect; Africa; Antibodies; Antibody Formation; Antigens; Antimalarials; B-Lymphocyte Epitopes; CD4 Positive T Lymphocytes; CD8B1 gene; Capsid; Capsid Proteins; Cell physiology; Cells; Cellular Tropism; Child; Communicable Diseases; Disease; Dose; Epitopes; Erythrocytes; Fiber; Figs - dietary; Humoral Immunities; Immune response; Immunity; Immunization; Immunohistochemistry; Lead; Malaria; Malaria Vaccines; Mediating; Modification; Morbidity - disease rate; Mus; Nature; Parasites; Phagocytes; Plasmodium yoelii; Process; Production; Proteins; Recombinants; Staging; T-Lymphocyte; Testing; Tissues; Transgenes; Treatment Protocols; Upper arm; Vaccinated; Vaccination; Vaccines; Virus; base; circumsporozoite; circumsporozoite protein; fluorophore; immunogenicity; in vivo; mortality; novel; prevent; public health relevance; response; trafficking

DESCRIPTION (provided by applicant): Malaria is still a devastating infectious disease of the world. Approximately 300 - 500 million people become infected yearly, with relatively high rates of morbidity and mortality. In fact, the WHO estimates that 2 - 3 million children die of malaria in Africa alone, every year. The overall aim of this proposal is to optimize adenoviral (Ad) vector in order to elicit a robust anti-malarial immunity as an effective malaria vaccine. Our earlier studies have shown that a recombinant Ad expressing a major malaria antigen, circumsporozoite (CS) antigen of Plasmodium yoelii, AdPyCS, could induce a protective anti-malarial immunity, which is mediated by CD8+ T cells. However, AdPyCS was unable to induce high levels of antibody response against malaria parasites. Because Ad is known to elicit a strong pre-existing anti-Ad immunity that is primarily against its capsid proteins, we hypothesized that the insertion of a foreign epitope into the capsid proteins results in an induction of a robust epitope-specific humoral response. To test this hypothesis, we have inserted an immunodominant B cell epitope of the PyCS protein into two different capsid proteins, i.e. one in the fiber and another in the hexon, of Ad that expresses an entire PyCS protein fused to GFP, as a transgene. After multiple immunization of each capsid-modified, or unmodified Ad(PyCS+GFP), we found that Ad(PyCS+GFP) expressing the B epitope in the fiber, Ad(PyCS+GFP)-F/B, induces a highest level of protective anti-malarial immunity, as well as anti-malarial humoral response. In Aim 1 of this proposal, we plan to seek the reasons why Ad(PyCS+GFP)-F/B can induce a strongest anti-malarial protection than other Ad-based vaccines. We will first confirm the protective capacity of Ad(PyCS+GFP)-F/B and then determine the levels of malaria-specific humoral and cellular responses induced by the different Ad vectors and characterize their responses in detail. Our next hypothesis is that a repeated immunization or a pre-existing immunity still affects capsid-modified Ad, reducing the production of the PyCS protein that includes a CD4+ epitope from the transgene. In Aim 2, therefore, we will construct a novel Ad vector by inserting a malaria-specific CD4+ epitope into various capsids of Ad(PyCS+GFP)-F/B, and determine whether the insertion of a CS-specific CD4+ epitope into the Ad capsid protein could elicit a strong CS-specific CD4+ T cell (helper) response, thereby enhancing further a robust anti-CS antibody response. It is possible that capsid modification of Ad makes the virus escape from anti-capsid antibodies, and that capsid-modified Ad is able to maintain its infectivity in vivo. In the last Aim, therefore, we will determine the tissue/cellular tropism and the intracellular trafficking of capsid-modified Ad and compare to those of unmodified Ad. PUBLIC HEALTH RELEVANCE: Malaria is still a devastating disease. The aim of this project is to develop a new adenovirus- based malaria vaccine that can elicit not only a strong malaria-specific cellular response, but also a robust malaria-specific humoral response. The simultaneous induction of high levels of both arms of the immune responses should lead to a successful induction of a potent protective immunity against malaria, thus ultimately placing Ad-based malaria vaccine, as a promising vaccine.

描述（由申请人提供）：疟疾仍然是世界上毁灭性的传染病。每年大约有300-5亿人被感染，发病率和死亡率相对较高。实际上，世卫组织估计每年有2-300万儿童仅在非洲死于疟疾。该提案的总体目的是优化腺病毒（AD）载体，以便引起强大的抗疟疾免疫作为有效的疟疾疫苗。我们的较早研究表明，表达疟原虫YOELII的主要疟疾抗原，外孢子菌（CS）抗原ADPYCS的重组AD可以诱导保护性的抗疟疾免疫，这是由CD8+ T细胞介导的。但是，ADPYC无法诱导对疟疾寄生虫的高水平抗体反应。由于已知AD会引起强烈的预先存在的抗AD免疫，这主要是针对其衣壳蛋白的，因此我们假设将外来表位插入capsid蛋白中会导致诱导强大的表位特异性体液反应。为了检验该假设，我们已将PYCS蛋白的免疫主导B细胞表位插入了两个不同的衣壳蛋白中，即一种在纤维中，另一个在己酮中，将AD表示为整个PYCS蛋白融合到GFP，作为转基因。 After multiple immunization of each capsid-modified, or unmodified Ad(PyCS+GFP), we found that Ad(PyCS+GFP) expressing the B epitope in the fiber, Ad(PyCS+GFP)-F/B, induces a highest level of protective anti-malarial immunity, as well as anti-malarial humoral response.在本提案的目标1中，我们计划寻求与其他基于AD的疫苗相比，AD（PYCS+GFP）-F/B可以诱导最强大的抗疟疾保护的原因。我们将首先确认AD（PYCS+GFP）-f/b的保护能力，然后确定由不同的AD向量引起的疟疾特异性体液和细胞反应水平，并详细表征其反应。我们的下一个假设是，重复的免疫或预先存在的免疫力仍然会影响Capsid修饰的AD，从而减少了PYCS蛋白的产生，其中包括来自转基因的CD4+表位。因此，在目标2中，我们将通过将疟疾特异性CD4+表位插入AD（PYCS+ GFP）-F/B的各种衣壳中来构建新的AD载体，并确定CS特异性CD4+表位的插入是否可以插入AD AD CAPSID蛋白可以启用强的CSS cd4+ t cd4+ t theper（helter）。 回复。 AD的衣壳修饰可能会使病毒从抗Capsid抗体中逸出，并且Capsid修饰的AD能够在体内保持其感染性。因此，在最后一个目的中，我们将确定组织/细胞的向流和辛苦修饰的AD的细胞内运输，并与未修饰的AD进行比较。公共卫生相关性：疟疾仍然是一种毁灭性疾病。该项目的目的是开发一种新的基于腺病毒的疟疾疫苗，不仅可以引起强烈的疟疾特异性细胞反应，而且还会引起强大的疟疾特异性体液反应。同时诱导高水平的免疫反应的臂，应成功诱导对疟疾的有效保护性免疫，从而最终将基于AD的疟疾疫苗作为一种有希望的疫苗。