Human immune responses to vaccine candidate antigens in chagasic patients

恰加斯病患者对疫苗候选抗原的人体免疫反应

• 批准号: 6352632
• 负责人: Rick L Tarleton
• 金额: $ 14.56万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6352632
• 关键词: South America; T lymphocyte; Trypanosoma cruzi; antibody titering; antigen antibody reaction; antigen presentation; biomarker; clinical research; expression cloning; genetic library; human subject; human therapy evaluation; immunity; immunoglobulins; immunologic assay /test; immunoregulation; phlebotomy; protozoal antigen; protozoal vaccine; transfection /expression vector; vaccine development

Projects 1 and 2 of this program project will use expression library immunization (ELI) and DNA microarraying respectively to identify T. cruzi genes which are capable of eliciting protection from lethal infection when delivered as DNA in a mammalian expression plasmid. Project 3 will more fully access the vaccine potential of combinations of genes delivered with and without genetic cytokine adjuvants. The goal of this project is to determine if any of the vaccine candidates identified and characterized in Projects 1-3 are the target of immune responses in humans and if these responses correlated with clinical status of the infected individuals. To allow for the efficient and economic analysis of immune responses of human patients to multiple genes and gene products, we will develop systems for protein expression and targeting, and immunoassays for quantitative determination of antibody, CD4+ and CD8+ T cell responses. Inserts from the genomic library used in projects 1 and 2 will be recloned into bacterial expression vectors with and without membrane translocating sequences (MTS) to facilitate antigen presentation via class I MHC. ELISA and ELISPOT assay systems will be refined and optimized for measurement responses of a large group of donors to at least 20 candidate vaccine molecules. Quantitative humoral and cell mediated immune responses, including titers for antigen-specific immunoglobulin levels and frequencies of antigen-specific CD4+ and CD8+ cytokine-producing cells will be obtained. The presence and potency of these antigen specific responses will be correlated with the disease status of a selected group of human patients. The ultimate goal will be to determine if the quality or quantity of the immune response to any particular candidate vaccine molecules correlates with the disease status of the patients. These experiments will begin to allow us to address the concern that heightened immune responses to particular parasite antigens (as might occur naturally or induced through vaccination) will exacerbate rather than ameliorate disease.

该计划的项目1和2将分别使用表达文库免疫（ELI）和DNA微阵列技术来鉴定克氏锥虫基因，这些基因在以哺乳动物表达质粒中的DNA形式递送时能够引发免受致命感染的保护。项目 3 将更充分地发挥使用和不使用遗传细胞因子佐剂的基因组合的疫苗潜力。该项目的目标是确定项目 1-3 中确定和表征的候选疫苗是否是人类免疫反应的目标，以及这些反应是否与感染个体的临床状态相关。为了能够有效、经济地分析人类患者对多个基因和基因产物的免疫反应，我们将开发蛋白质表达和靶向系统，以及定量测定抗体、CD4+和CD8+T细胞反应的免疫测定。项目 1 和 2 中使用的基因组文库中的插入片段将被重新克隆到带有或不带有膜转位序列 (MTS) 的细菌表达载体中，以促进通过 I 类 MHC 的抗原呈递。 ELISA 和 ELISPOT 测定系统将得到完善和优化，以测量大量捐赠者对至少 20 种候选疫苗分子的反应。将获得定量的体液和细胞介导的免疫反应，包括抗原特异性免疫球蛋白水平的滴度以及抗原特异性CD4+和CD8+细胞因子产生细胞的频率。这些抗原特异性反应的存在和效力将与选定的人类患者组的疾病状态相关。最终目标是确定对任何特定候选疫苗分子的免疫反应的质量或数量是否与患者的疾病状态相关。这些实验将开始让我们解决这样的担忧：对特定寄生虫抗原的增强的免疫反应（可能自然发生或通过疫苗接种诱导）将加剧而不是改善疾病。