New Approaches To Passive And Active Immunoprophylaxis

被动和主动免疫预防的新方法

• 批准号: 6808974
• 负责人: Robert H. Purcell
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF ALLERGY AND INFECTIOUS DISEASES
• 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/6808974
• 关键词: Callithricidae; Hepatovirus; Macaca mulatta; Pan; active immunization; attenuated microorganism; biotechnology; enzyme linked immunosorbent assay; hepatitis A; hepatitis B; hepatitis B virus group; hepatitis C virus; hepatitis vaccine; hepatitis virus; immunomodulators; infectious hepatitis; live vaccine; nonhuman therapy evaluation; passive immunization; polymerase chain reaction; tissue /cell culture; vaccine development; vector vaccine; virus protein; virus replication

The HVS in collaboration with GlaxoSmithKline, Rixensart, Belgium, has developed several candidate live attenuated HAV vaccines. In addition, the HVS has developed a candidate recombinant hepatitis E vaccine that is highly promising and that is currently in clinical trials. In studies to further characterize this candidate hepatitis E vaccine, we have performed extensive pre-clinical trials to determine the potency of the vaccine, the duration of protection, the optimum regimen for administration, its protective efficacy against homologous versus heterologous virus strains, its ability to prevent infection as well as hepatitis and the minimum antibody titer that was effective in preventing infection and hepatitis, respectively. The HVS is studying the technology of DNA vaccines with a model system based upon hepatitis B virus (HBV) vaccine, a vaccine with which the HVS has had extensive experience. We have tested the efficacy of an immunostimulant (CpG) as an adjuvant for DNA vaccines, as well as for protein vaccines. In addition, the utility of DNA vaccines for the control of hepatitis C virus (HCV) has been explored. A DNA vaccine based on the E2 envelope protein of HCV proved to be highly immunogenic in mice and rhesus monkeys and moderately immunogenic in chimpanzees, but the chimpanzees were not fully protected when they were challenged with live HCV. A similar approach has been utilized in the study of a DNA vaccine based on the E1 envelope protein of HCV: various constructs of the E1 gene were prepared as DNA vaccines (expression vector plasmids) and as vectored vaccines (recombinant vaccinia) and tested in mice. The mice had excellent immune responses to the DNA vaccine as well as to the vaccinia boost. In other studies, recombinant HCV E1 envelope glycoprotein is being tested in chimpanzees as an immunoprophylactic and immunotherapeutic vaccine. Passive immunoprophylaxis has also been an important public health tool. For example, normal immunoglobulin has been important in the prevention of hepatitis A. However, monoclonal preparations could be more potent, tailored to specific neutralization epitopes and highly consistent in potency. We have prepared combinatorial libraries from the bone marrow of chimpanzees that had been experimentally infected in sequence with each of the five human hepatitis viruses. Chimpanzee globulins are virtually identical to human immunoglobulins, making them attractive choices for immunoprophylactic and immunotherapeutic agents. To date, we have isolated monoclonal immunoglobulins that react with HAV, HBV, HDV and HEV. In other studies, we have recovered human monoclonal antibodies that react with HCV. Many of the monoclonal antibodies described above are neutralizing and their production is being scaled up for tests of passive immunoprophylaxis in chimpanzees. Similar construction of combinatorial libraries from bone marrow is being carried out for chimpanzees that have been experimentally infected with dengue viruses 1 through 4 and the Norwalk virus. We have now extended these studies to other viruses and bacteria of interest that can be experimentally administered to chimpanzees. For example, in response to new concerns about bioterrorism, we are preparing neutralizing monoclonal antibodies to vaccinia virus for use as an immunoprophylactic/immunotherapeutic agent in those who require immunization with vaccinia but who are susceptible to the side-effects of such immunization. Similarly, we are immunizing chimpanzees with the three components of anthrax toxin, in an attempt to make monoclonal antibodies that could immediately neutralize anthrax in vivo. We are also preparing chimpanzee monoclonal antibodies to the three serotypes of poliovirus, to rabies virus, Japanese encephalitis virus, to West Nile virus and to the tick-borne encephalitis virus complex. Most recently we have added the seven toxins of Clostridium botulinum and the SARS virus.Some of these will have potential utility in efforts to counteract bioterrorism and all will have immunoprophylactic and immunotherapeutic potential in the battle against emerging and re-emerging pathogens.

HVS 与比利时 Rixensart 的 GlaxoSmithKline 合作开发了几种候选 HAV 减毒活疫苗。此外，HVS还开发了一种候选重组戊型肝炎疫苗，前景广阔，目前正在进行临床试验。在进一步表征该候选戊型肝炎疫苗的研究中，我们进行了广泛的临床前试验，以确定疫苗的效力、保护持续时间、最佳给药方案、其对同源病毒株与异源病毒株的保护功效、其预防感染和肝炎的能力以及分别有效预防感染和肝炎的最低抗体滴度。 HVS 正在研究基于乙型肝炎病毒 (HBV) 疫苗的模型系统的 DNA 疫苗技术，HVS 在该疫苗方面拥有丰富的经验。我们测试了免疫刺激剂 (CpG) 作为 DNA 疫苗和蛋白质疫苗佐剂的功效。此外，还探索了 DNA 疫苗用于控制丙型肝炎病毒 (HCV) 的效用。基于HCV E2包膜蛋白的DNA疫苗被证明在小鼠和恒河猴中具有高免疫原性，在黑猩猩中具有中等免疫原性，但黑猩猩在受到活HCV攻击时并没有得到充分的保护。类似的方法已用于基于 HCV E1 包膜蛋白的 DNA 疫苗的研究：E1 基因的各种构建体被制备为 DNA 疫苗（表达载体质粒）和载体疫苗（重组痘苗）并在小鼠中进行测试。这些小鼠对 DNA 疫苗和牛痘加强疫苗都有极好的免疫反应。在其他研究中，重组 HCV E1 包膜糖蛋白正在黑猩猩中作为免疫预防和免疫治疗疫苗进行测试。被动免疫预防也是一种重要的公共卫生工具。例如，正常的免疫球蛋白对于预防甲型肝炎很重要。然而，单克隆制剂可能更有效，针对特定的中和表位进行定制，并且效力高度一致。我们从黑猩猩的骨髓中制备了组合文库，这些黑猩猩已通过实验依次感染了五种人类肝炎病毒中的每一种。黑猩猩球蛋白实际上与人类免疫球蛋白相同，这使得它们成为免疫预防和免疫治疗药物的有吸引力的选择。迄今为止，我们已经分离出与 HAV、HBV、HDV 和 HEV 发生反应的单克隆免疫球蛋白。在其他研究中，我们已经回收了与 HCV 发生反应的人单克隆抗体。上述许多单克隆抗体都具有中和作用，并且它们的生产规模正在扩大，用于黑猩猩被动免疫预防的测试。目前正在对实验性感染登革热病毒 1 至 4 号和诺瓦克病毒的黑猩猩进行类似的骨髓组合文库构建。我们现在已将这些研究扩展到其他感兴趣的病毒和细菌，可以对黑猩猩进行实验性施用。例如，为了应对生物恐怖主义的新担忧，我们正在制备针对痘苗病毒的中和单克隆抗体，作为免疫预防/免疫治疗剂，用于那些需要痘苗免疫但易受此类免疫副作用影响的人。同样，我们正在用炭疽毒素的三种成分对黑猩猩进行免疫，试图制造出可以立即中和体内炭疽的单克隆抗体。我们还正在制备针对三种血清型脊髓灰质炎病毒、狂犬病病毒、日本脑炎病毒、西尼罗河病毒和蜱传脑炎病毒复合体的黑猩猩单克隆抗体。最近，我们添加了肉毒杆菌和 SARS 病毒的七种毒素。其中一些毒素将在对抗生物恐怖主义方面具有潜在效用，而所有毒素都将在对抗新出现和重新出现的病原体的战斗中具有免疫预防和免疫治疗潜力。