Prevention of AIDS

预防艾滋病

• 批准号: 10014358
• 负责人: BARBARA K FELBER
• 金额: $ 225.17万
• 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/10014358
• 关键词: AIDS prevention; Acquired Immunodeficiency Syndrome; Adjuvant; Adverse effects; Anatomy; Antibodies; Antibody Formation; Antigens; Biology; Canis familiaris; Chronic; Clinical Trials; Codon Nucleotides; DNA; DNA Vaccines; DNA delivery; Data; Development; Disease; Electroporation; Epitopes; Formulation; Gene Expression; HIV; HIV Infections; HIV vaccine; Human; Immune response; Immunity; Immunization; Individual; Interleukin-12; Intramuscular; Intramuscular Injections; Liposomes; Longevity; Macaca; Malignant Neoplasms; Methods; Modality; Modeling; Molecular; Mucous Membrane; Mus; Muscle; Mutation; Pathogenicity; Play; Prevention; Preventive; Proteins; QS21; RNA; Regimen; Relative Risks; Reporting; Resistance; Role; SIV; Site; T cell response; TLR4 gene; Testing; Time; Vaccinated; Vaccination; Vaccines; Viremia; Virus; base; cytokine; efficacy testing; expression vector; immunogenicity; improved; in vivo; interest; lymph nodes; mRNA Expression; melanoma; mucosal site; neutralizing antibody; novel; pathogen; prevent; protective efficacy; rectal; response; simian human immunodeficiency virus; vaccine delivery; vaccine efficacy; vaccine-induced immunity; vaginal mucosa; vector; vector vaccine; virology

Our recognition of the fundamental mechanisms mRNA expression, exemplified by the regulated expression of HIV, provided the basics for our interest in developing preventive HIV DNA based vaccine strategies. Attractive features of the DNA platform lie in its simplicity, versatility, stability, with repeated administration without vector immunity, being a non-replicating vaccine and not association with adverse effects. Several DNA vaccines are currently in clinical trials against HIV and cancer, and there is a licensed DNA vaccine against dog melanoma. We are testing immunogenicity of SIV and HIV DNA vaccines in mice and selected DNA candidates advance to the macaque model. Some of our successful candidates have been moved to clinical trials. Because intramuscular injection of DNA induces relatively low immune responses in macaques and humans, we are testing additional delivery methods, including in vivo electroporation and liposomes. We reported that electroporation dramatically increased the efficiency of DNA delivery in naive macaques, leading to greatly augmented antigen expression and resulting in the induction of highest levels of T cell responses. Our DNA vaccine includes the cytokine IL-12 DNA (expressed from optimized DNA) as adjuvant and we reported increased magnitude and quality of the responses. Importantly, we reported the dissemination of the DNA vaccine induced T cell responses to mucosal sites including rectal and vaginal mucosa, the portal of entry of HIV. We also found that DNA induced immune responses show extraordinary longevity in vaccinated macaques detectable for several years after the last vaccination. DNA vaccination elicits moderate humoral immune responses in macaques. Using DNA-only vaccination, we found that our optimized DNA vaccine vectors are able to induce potent immune responses able to protect from high viremia. We showed that a protein boost can induce higher levels of Ab. We found that co-delivery of DNA+protein, using either unadjuvanted or adjuvanted protein, in the same muscle at the same time increased antibody production and mucosal dissemination. DNA+Protein co-immunization is superior to vaccination with either of the two individual components in eliciting humoral immune responses. Combination of DNA+Protein induces potent humoral responses able to significantly delay or prevent virus acquisition and improve virological control of the highly pathogenic SIV challenge. To optimize vaccine-induced immunity and efficacy of the DNA+protein co-immunization vaccine regimen, a SIVmac251 based vaccine was compared using two TLR-4-based liposomal formulations as adjuvants (TLR-4+TLR-7 or TLR-4+QS21) in macaques, which resulted in induction of robust humoral immune responses with qualitative differences. Vaccinees were preferentially infected by SIVsmE660 transmitted founder T/F virus carrying the neutralization resistant A/K mutation, demonstrating a strong vaccine-induced sieve effect. SIVsmE660-specific systemic neutralizing antibody and mucosal antibodies targeting V2 region of Env correlated with delay in acquisition of the neutralization-sensitive virus and. V2-specific antibodies and cellular SIV-specific T cell responses contributed to control of viremia. Although both DNA+protein vaccine groups show delay of virus acquisition, the TLR4+7 adjuvanted vaccine induced stronger protective responses resulting in lower peak and chronic viremia. We are further exploring approaches to improve immunogenicity targeting the V2 epitopes to induce more effective responses. We also compared immunogenicity and protective efficacy of a DNA+Protein vaccine delivered following two different strategies: co-administration in the same site or separate delivery of DNA and protein in opposite anatomical sites. We found that the co-immunization induces higher vaccine-induced Env Ab and T cell responses. Importantly, only the co-immunization group showed significant delay in SHIV acquisition with a 67% reduction in per exposure acquisition risk relative to the controls after 15 weekly intravaginal challenges. These data indicate that simultaneous recognition of the two vaccine components (DNA and protein) by the draining lymph node plays a critical role in the development of protective immunity. We are identifying correlates of protection from disease development, which will provide critical information to further improve our vaccine approaches. The advantage of co-immunization vaccine regimens targeting immunogens to the same draining lymph node could be applicable to other vaccine modalities and other pathogens.

我们对 mRNA 表达基本机制的认识（以 HIV 的调节表达为例）为我们开发基于 HIV DNA 的预防性疫苗策略的兴趣提供了基础。 DNA平台的吸引人的特点在于其简单性、多功能性、稳定性、可重复施用、无载体免疫、是非复制疫苗且不产生不良反应。目前有几种 DNA 疫苗正在进行针对 HIV 和癌症的临床试验，并且有一种获得许可的针对狗黑色素瘤的 DNA 疫苗。我们正在小鼠中测试 SIV 和 HIV DNA 疫苗的免疫原性，并将选定的 DNA 候选物推进到猕猴模型中。我们的一些成功的候选人已进入临床试验。由于肌内注射 DNA 在猕猴和人类中诱导的免疫反应相对较低，因此我们正在测试其他递送方法，包括体内电穿孔和脂质体。我们报道，电穿孔显着提高了幼猴中 DNA 传递的效率，导致抗原表达大大增强，并诱导最高水平的 T 细胞反应。我们的 DNA 疫苗包含细胞因子 IL-12 DNA（由优化的 DNA 表达）作为佐剂，我们报告了反应强度和质量的提高。重要的是，我们报告了 DNA 疫苗的传播诱导了 T 细胞对粘膜部位的反应，包括直肠和阴道粘膜，即 HIV 的进入门户。我们还发现，在接种疫苗的猕猴中，DNA 诱导的免疫反应显示出非凡的寿命，在最后一次接种疫苗后的几年内均可检测到。 DNA 疫苗接种可在猕猴中引发适度的体液免疫反应。使用纯 DNA 疫苗接种，我们发现我们优化的 DNA 疫苗载体能够诱导有效的免疫反应，从而预防高病毒血症。我们证明蛋白质增强可以诱导更高水平的抗体。我们发现，使用未佐剂或佐剂蛋白质在同一肌肉中同时递送DNA+蛋白质可增加抗体产生和粘膜传播。 DNA+蛋白质联合免疫在引发体液免疫反应方面优于使用两种单独成分中的任何一种的疫苗接种。 DNA+蛋白质的组合诱导有效的体液反应，能够显着延迟或阻止病毒获得并改善对高致病性 SIV 攻击的病毒学控制。为了优化疫苗诱导的免疫力和 DNA+蛋白质联合免疫疫苗方案的功效，使用两种基于 TLR-4 的脂质体制剂作为佐剂（TLR-4+TLR-7 或 TLR-4+QS21）对基于 SIVmac251 的疫苗进行了比较。 ）在猕猴中，这导致了强烈的体液免疫反应的诱导，但存在质的差异。疫苗优先感染携带中和抗性 A/K 突变的 SIVsmE660 传播的创始人 T/F 病毒，表现出强烈的疫苗诱导筛效应。 SIVsmE660特异性全身中和抗体和针对Env V2区的粘膜抗体与中和敏感病毒的获得延迟相关。 V2 特异性抗体和细胞 SIV 特异性 T 细胞反应有助于控制病毒血症。尽管DNA+蛋白质疫苗组均显示病毒获得延迟，但TLR4+7佐剂疫苗诱导了更强的保护性反应，从而导致较低的峰值和慢性病毒血症。我们正在进一步探索提高针对 V2 表位的免疫原性的方法，以诱导更有效的反应。我们还比较了按照两种不同策略递送的 DNA+蛋白质疫苗的免疫原性和保护功效：在同一位点共同施用或在相反的解剖位点分别递送 DNA 和蛋白质。我们发现联合免疫可诱导更高的疫苗诱导的 Env Ab 和 T 细胞反应。重要的是，在 15 周阴道内激发后，只有联合免疫组表现出 SHIV 获得的显着延迟，相对于对照组，每次暴露的获得风险降低了 67%。这些数据表明，引流淋巴结同时识别两种疫苗成分（DNA 和蛋白质）在保护性免疫的发展中发挥着关键作用。我们正在确定预防疾病发展的相关因素，这将为进一步改进我们的疫苗方法提供关键信息。将免疫原靶向同一引流淋巴结的联合免疫疫苗方案的优点可适用于其他疫苗方式和其他病原体。