DNA Vaccines

DNA疫苗

• 批准号: 9343688
• 负责人: George N. Pavlakis
• 金额: $ 156.09万
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/9343688
• 关键词: Acquired Immunodeficiency Syndrome; Address; Adjuvant; Affect; Animal Model; Animals; Antigens; Biological Models; CD4 Positive T Lymphocytes; CD8-Positive T-Lymphocytes; Cancer Model; Cancer Vaccines; Cellular Immunity; Clinic; Clinical; Clinical Trials; Codon Nucleotides; Collaborations; Communicable Diseases; Comparative Study; Consensus; Cooperative Research and Development Agreement; DNA; DNA Vaccines; Data; Development; Disease; Dose; Electroporation; Elements; Epitopes; Formulation; Gene Expression Regulation; Generations; Genetic Engineering; Goals; HIV; Human; Hybrids; Immune response; Immune system; Immunity; Immunization; Immunomodulators; Immunotherapy; Infection prevention; Knowledge; Lead; Legal patent; Liposomes; Longevity; Macaca; Macaca mulatta; Malignant Neoplasms; Methodology; Methods; Modality; Modeling; Molecular; Molecular Biology; Natural Killer Cells; Pathology; Pathway interactions; Plasmids; Procedures; Property; Proteins; Protocols documentation; RNA; SIV; Safety; Technology; Testing; Therapeutic; Tissues; Translations; Vaccination; Vaccines; Viral; Viral Vaccines; Viremia; Virus; Virus Replication; Work; base; cell killing; clinical application; cytokine; cytotoxic; expression vector; gag Gene Products; gene therapy; human DNA; immunogenicity; improved; in vivo; mRNA Stability; member; method development; nanoparticle; neutralizing antibody; new technology; novel; pathogen; prevent; prophylactic; protective effect; research and development; response; simian human immunodeficiency virus; vaccine delivery; vector

An important goal of this project continues to be the generation and testing of maximally efficient expression vectors for specific antigens. Our hypothesis is that the DNA vaccine dose is suboptimal for many human applications; therefore, increased efficiency is necessary for practical human DNA vaccines. We have generated a set of optimized expression vectors for HIV and SIV. HIV vectors are developed for eventual human clinical trials. These vectors are studied in macaques for immunogenicity and ability to protect against challenge with Simian/Human Immunodeficiency Virus hybrid viruses (SHIV). Several of our vectors were used in clinical trials sponsored by our previous CRADA collaborator (Wyeth). In parallel, SIV expression vectors are developed and studied in the most faithful model system for human AIDS, i.e., challenge of Rhesus macaques by SIV, a virus closely related to HIV, which causes very similar pathology to human AIDS. Our results have shown that optimized DNA expression vectors in the absence of any other form of vaccine boosting are able to protect rhesus macaques from high viremia after challenge with a highly pathogenic SIVmac251 challenge. In addition, we have developed powerful new DNA and protein co-immunization protocols that increase the magnitude, rapidity and longevity of immune responses. To further improve vaccine efficiency we study the intrinsic properties of the different candidate antigens. We take advantage of the ability to manipulate the form of expressed antigen by recombinant DNA technology. We have shown that modulating the form, stability and cellular fate of the DNA-produced antigens has profound effects on their immunogenicity and the type of response generated. We perform comparative studies to develop optimal forms of several antigens. Results in rhesus macaques verified that the form of expressed antigen affects the type and magnitude of immune response. We study several different antigen forms to achieve optimal immune response and to address the variability of HIV strains circulating worldwide. We compare the immune response generated by either mixes of native antigens, mosaics, centralized and consensus candidates, and also antigens containing only conserved elements of HIV proteins. Such comparisons may lead to further optimization of a protective immune response. We have recently shown that vaccination with conserved elements vaccine constructs have the ability to alter the hierarchy of immune response and to direct it towards conserved elements, which are found in all HIV clades. On the basis of these data, we have proposed a clinical trial to test the ability of Conserved Element vectors to provide broader immune response in humans. The methodology and vectors used for DNA vaccination of macaques have shown that we produce a strong, broad and long-lasting immunity, which is able to contain virus replication and prevent disease development. More recently, we showed that DNA in combination with an adjuvanted protein is able to delay or prevent infection after repeated low dose virus challenge. DNA vaccination is emerging as the strongest and most effective vaccination procedure for the development of cellular immunity in humans, based on clinical trials using the same methods and vectors we co-developed for macaques. These results strongly suggest that DNA vaccination will have many practical clinical applications. We have used our understanding of gene regulation to develop non-pathogenic strains of SIV, which are maintained in macaques for more than 10 years, yet they do not cause any disease. These animals develop a strong protective immune response and are able to resist high viremia and disease development even after challenge with wild-type SIV. We showed that these animals develop neutralizing antibodies against difficult-to-neutralize SIVmac239, and that CD8 cells contribute to the protective effect. We have also shown that these animals develop high levels of cytotoxic CD4 cells, which contribute to viral control. This macaque model is important for the further understanding of the pathogenic mechanisms leading to AIDS, the virus interactions in different tissues and the components of the immune system contributing to protection from disease development. In addition to prophylactic vaccination against AIDS, the same methodologies were used in therapeutic vaccination protocols. A strong boost of cellular immune responses and subsequent control of viremia was observed in macaque studies, suggesting that therapeutic vaccination may contribute to long-term virus control. These results have also implications for the development of methods to apply DNA vaccine methodology to therapeutic cancer vaccines. We wish to combine therapeutic vaccination with additional methods to boost immune response and specific cell killing by cytotoxic cells. We therefore will use hetIL-15 to further boost cytotoxic cells responses based on our completion of studies demonstrating the safety of hetIL-15 in infected macaques. We have shown that inclusion of hetIL-15 in therapeutic vaccination results in high levels of cytotoxic cells.

该项目的一个重要目标继续是对特定抗原的最大有效表达向量的产生和测试。我们的假设是，对于许多人类应用，DNA疫苗剂量是次优的。因此，实用的人DNA疫苗是必需的效率。我们为HIV和SIV生成了一组优化的表达向量。 HIV载体是针对人类临床试验开发的。这些载体在猕猴中进行了免疫原性和防止抗simian/人类免疫缺陷病毒杂种病毒（SHIV）的挑战的能力。我们的几个向量用于我们以前的Crada合作者（Wyeth）赞助的临床试验。同时，在最忠实的人类援助模型系统中开发和研究了SIV表达载体，即SIV对恒河猕猴的挑战，SIV是一种与HIV密切相关的病毒，该病毒与人类艾滋病非常相似。我们的结果表明，在没有任何其他形式的疫苗促进的情况下，优化的DNA表达载体能够在挑战后能够保护恒河猕猴免受高病毒血症的影响，并具有高度致病的SIVMAC251挑战。此外，我们开发了强大的新DNA和蛋白质共免疫协议，以增加免疫反应的幅度，速度和寿命。为了进一步提高疫苗效率，我们研究了不同候选抗原的内在特性。我们利用通过重组DNA技术来操纵表达抗原形式的能力。我们已经表明，调节DNA生产抗原的形式，稳定性和细胞命运对其免疫原性和产生的反应类型具有深远的影响。我们进行比较研究以开发几种抗原的最佳形式。结果猕猴的结果证实了表达抗原的形式会影响免疫反应的类型和幅度。我们研究几种不同的抗原形式，以实现最佳的免疫反应并解决全球循环的HIV菌株的变异性。我们比较了由天然抗原，马赛克，集中式和共识的混合物以及仅包含HIV蛋白保守元素的抗原产生的免疫反应。这种比较可能会导致保护性免疫反应的进一步优化。我们最近表明，具有保守元件疫苗构建体的疫苗接种能够改变免疫反应的层次结构并将其引导到所有HIV进化枝中发现的保守元素。在这些数据的基础上，我们提出了一项临床试验，以测试保守元素向量在人类中提供更广泛免疫反应的能力。猕猴的DNA疫苗接种的方法和矢量表明，我们产生了强大，宽阔和长期的免疫力，能够包含病毒复制并防止疾病的发展。最近，我们表明DNA与辅助蛋白结合使用后能够在重复的低剂量病毒挑战后延迟或预防感染。基于我们使用相同的方法和矢量，我们共同开发了猕猴的临床试验，DNA疫苗接种已成为人类细胞免疫开发的最强，最有效的疫苗接种程序。这些结果强烈表明DNA疫苗接种将具有许多实际的临床应用。我们已经利用对基因调节的理解来发展非致病性SIV菌株，SIV的猕猴中维持了10年以上，但不会引起任何疾病。这些动物会产生强烈的保护性免疫反应，即使在使用野生型SIV挑战之后，也能够抵抗高病毒血症和疾病的发育。我们表明，这些动物会产生对难以中和SIVMAC239的中和抗体，并且CD8细胞有助于保护作用。我们还表明，这些动物会形成高水平的细胞毒性CD4细胞，从而有助于病毒控制。这种猕猴模型对于进一步理解导致艾滋病的致病机制，不同组织中的病毒相互作用以及免疫系统的成分有助于保护疾病发育。除了针对艾滋病的预防性疫苗接种外，在治疗疫苗接种方案中也使用了相同的方法。在猕猴研究中观察到了细胞免疫反应的强大增强和随后控制病毒血症的后续控制，这表明治疗性疫苗接种可能有助于长期的病毒控制。这些结果也对开发将DNA疫苗方法的方法的开发带入了治疗性癌症疫苗。我们希望将治疗疫苗与其他方法相结合，以增强免疫反应和细胞毒性细胞的特异性细胞杀伤。因此，我们将使用HETIL-15根据我们完成的研究，进一步增强细胞毒性细胞反应，以证明Hetil-15在感染猕猴中的安全性。我们已经表明，将HETIL-15纳入治疗性疫苗接种会导致高水平的细胞毒性细胞。