Development of a Malaria DNA Vaccine with Enchanced Immunogenicity

开发具有增强免疫原性的疟疾 DNA 疫苗

• 批准号: 7530124
• 负责人: Richard B. Markham
• 金额: $ 24.6万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-06-10 至 2010-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7530124
• 关键词: Adjuvant; Antibodies; Antigen Presentation; Antigen-Presenting Cells; Antigens; Area; B-Lymphocyte Epitopes; Biological Assay; Biological Models; Blood; CD8B1 gene; CRISP Thesaurus; Cells; Cellular Immunity; Cessation of life; Chimeric Proteins; Class; Clinical Trials; DNA; DNA Vaccines; DNA delivery; Dendritic Cells; Development; Electroporation; Ensure; Enzyme-Linked Immunosorbent Assay; Epitopes; Erythrocytes; Evaluation; Flow Cytometry; Gene Expression; Hepatocyte; Human; Humoral Immunities; Immune; Immune response; Immune system; Immunity; Immunization; Immunofluorescence Immunologic; Inbred BALB C Mice; Infection; Interferon Type II; Intramuscular Injections; Ligands; Link; Liver; Macrophage Inflammatory Proteins; Malaria; Malaria Vaccines; Measures; Mediating; Membrane Proteins; Memory; Modeling; Molecular Profiling; Mus; Outcome; Parasitemia; Plasmids; Plasmodium yoelii; Play; Polymerase Chain Reaction; Proteins; Public Health; Recruitment Activity; Research; Ribosomal RNA; Role; Sampling; Site; Sporozoites; Staging; Standards of Weights and Measures; Stem cells; Stimulus; T memory cell; T-Lymphocyte; T-Lymphocyte Epitopes; Techniques; Testing; Time; Tissues; Tumor-Derived; Upper arm; Vaccination; Vaccines; Virus; antigen processing; base; chemokine; cytokine; design; immunogenicity; in vivo; innovation; interest; nonhuman primate; novel; novel strategies; plasmid DNA; protein expression; receptor; response; uptake; vaccination strategy; vaxfectin

DESCRIPTION (provided by applicant): Although DNA vaccines offer many advantages, their inability to elicit sustained protective immune responses in non-human primates and humans has been disappointing. Based on substantial evidence derived from tumor model systems and preliminary studies with a candidate Plasmodium yoelii vaccine, this proposal hypothesizes that an effective DNA-based vaccine against malaria can be developed by expressing malarial protein antigens as fusion proteins linked to chemokine ligands for receptors on immature dendritic cells (iDC). This vaccine model differs from related approaches in that it attracts the appropriate antigen-presenting cell to the inoculation site and by fusing the vaccine epitopes of interest to the chemokine, ensures the efficient uptake of the antigen for processing. This hypothesis will be tested in a murine model of Plasmodium yoelii infection and immunogenicity. Specifically, we will 1. Evaluate ex vivo the responses elicited in BALB/c mice by a candidate multi-epitope DNA vaccine administered by in vivo electroporation that targets the pre-erythrocytic stages of P. yoelii. The candidate vaccine to be evaluated will consist of a plasmid that expresses macrophage inflammatory protein 31 (MIP- 31) fused to (a) The SYVPSAEQI immunodominant P. yoelii Class I-restricted T cell epitope in BALB/c mice (b) The (QGPGAP)4 immunodominant P. yoelii B cell epitope in BALB/c mice and (c) The YNRNIVNRLLGDALNGKPEEKA immunodominant Class II-restricted T cell epitope in BALB/c mice. A similar DNA construct will be created that lacks the MIP-31 component and several additional positive and negative control immunization groups will also be established. Outcomes of immunization will be measured by interferon gamma (IFN-3) Elispot assays, antibody concentrations measured in ELISA and immunofluorescence assays, and by flow cytometry evaluation the development of central memory T cells. 2. Evaluate the protective efficacy of this candidate vaccine in mouse malaria challenge models. Outcomes will be followed using real-time PCR to quantitate malaria gene expression in liver samples from the mice and levels of blood parasitemia attained in immune compared to nonimmune mice. PUBLIC HEALTH RELEVANCE: This project is designed to develop a vaccine for malaria. Should this approach be successful, this vaccine could save the more than 1 million deaths that occur annually as a result of this infection.

描述（由申请人提供）：尽管DNA疫苗提供了许多优点，但它们不能在非人灵长类动物和人类中引发持续的保护性免疫应答，这令人失望。基于来自肿瘤模型系统的大量证据和候选约氏疟原虫疫苗的初步研究，该提议假设可以通过表达疟疾蛋白抗原作为与未成熟树突状细胞（iDC）上受体的趋化因子配体连接的融合蛋白来开发有效的基于DNA的疟疾疫苗。这种疫苗模型与相关方法的不同之处在于，它将适当的抗原呈递细胞吸引到接种部位，并通过将感兴趣的疫苗表位融合到趋化因子，确保抗原的有效摄取以进行处理。将在约氏疟原虫感染和免疫原性的鼠模型中检验这一假设。具体来说，我们将1。离体评价通过靶向约氏疟原虫红细胞前期的体内电穿孔施用的候选多表位DNA疫苗在BALB/c小鼠中引发的应答。待评价的候选疫苗将由表达巨噬细胞炎性蛋白31（MIP- 31）的质粒组成，该质粒与（a）BALB/c小鼠中SYVPSAEQI免疫显性约氏疟原虫I类限制性T细胞表位（B）BALB/c小鼠中（QGPGAP）4免疫显性约氏疟原虫B细胞表位和（c）BALB/c小鼠中YNRNIVNRLLGDALNGKPEEKA免疫显性II类限制性T细胞表位融合。将创建缺乏MIP-31组分的类似DNA构建体，还将建立几个额外的阳性和阴性对照免疫组。免疫结果将通过干扰素γ（IFN-3）Elispot测定、ELISA和免疫荧光测定中测量的抗体浓度以及通过流式细胞术评价中央记忆T细胞的发育来测量。2.评价该候选疫苗在小鼠疟疾攻毒模型中的保护效力。结果将使用实时PCR来定量小鼠肝脏样本中的疟疾基因表达，以及免疫小鼠与非免疫小鼠相比获得的血液寄生虫血症水平。公共卫生相关性：该项目旨在开发疟疾疫苗。如果这种方法成功，这种疫苗可以挽救每年因这种感染而死亡的100多万人。