New Approaches To Passive Immunoprophylaxis

被动免疫预防的新方法

• 批准号: 7964628
• 负责人: Robert H. Purcell
• 金额: $ 106.45万
• 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/7964628
• 关键词: Adverse effects; Animal Model; Animals; Anthrax disease; Antibodies; Antibody Therapy; Bacteria; Belgium; Binding; Biological Assay; Bioterrorism; Bone Marrow; Botulinum Toxins; Cell Culture Techniques; Centers for Disease Control and Prevention (U.S.); Characteristics; Chronic Hepatitis C; Clinical; Collaborations; Complex; Cooperative Research and Development Agreement; Dengue; Dengue Hemorrhagic Fever; Dengue Shock Syndrome; Dengue Virus; Disease; Ebola virus; Epitopes; Frankfurt-Marburg Syndrome Virus; Genotype; Globulins; Glycoproteins; Goals; HCV Vaccine; Hepatitis; Hepatitis A; Hepatitis B Virus; Hepatitis C; Hepatitis C virus; Hepatitis Viruses; Human; Human poliovirus; Immune response; Immunization; Immunoglobulins; Immunotherapeutic agent; Immunotherapy; Infection prevention; Interferons; Lassa fever virus; Lead; Libraries; Measures; Mediating; Monoclonal Antibodies; Pan Genus; Patients; Polioviruses; Population; Preparation; Prevention; Prevention therapy; Production; Prophylactic treatment; Public Health; Rabies virus; Recombinants; Retroviridae; Serotyping; Serum; Smallpox; Smallpox Viruses; Testing; Tick-Borne Encephalitis Virus; Tick-Borne Encephalitis Viruses; Time; Vaccinated; Vaccination; Vaccines; Vaccinia; Vaccinia virus; Vesicular stomatitis Indiana virus; Viral; Virulent; Virus; Virus Diseases; West Nile virus; anthrax protective factor; anthrax toxin; base; biodefense; capsule; combinatorial; human monoclonal antibodies; immunoprophylaxis; in vitro Assay; in vivo; interest; neutralizing antibody; neutralizing monoclonal antibodies; novel strategies; passive immunoprophylaxis; pathogen; programs; response; scale up; tool; vaccine candidate; virus envelope

Antibodies. Passive immunoprophylaxis has 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 a variety of animals and, eventually, in humans. These and the following studies have been extended through 2009. Construction of combinatorial libraries from bone marrow has also been carried out for chimpanzees that have been experimentally infected with dengue viruses 1 through 4: these have yielded important neutralizing monoclonal antibodies to dengue virus types 1, 2 and 4. More importantly, we have reestablished an animal model for antibody-mediated enhancement of dengue virus infections, which can lead to the more severe forms of dengue virus infection: dengue hemorrhagic fever and dengue shock syndrome. Furthermore, we have identified a deletion in the antibody molecule that abrogates enhancement, possibly making antibody therapy practical for the first time. We have extended our antibody 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 have prepared neutralizing monoclonal antibodies to vaccinia virus for use as immunoprophylactic/ immunotherapeutic agents in those who require immunization with vaccinia but who are susceptible to the side-effects of such immunization. More importantly, in collaboration with the CDC, we have demonstrated that monoclonal antibodies that neutralize vaccinia can also neutralize variola (the smallpox virus). Thus, these neutralizing monoclonal antibodies should be useful not only for prophylaxis and therapy of the side effects of vaccination but also for the prevention and therapy of smallpox, should it ever be released into populations. Similarly, we have immunized chimpanzees with anthrax toxin in an attempt to make monoclonal antibodies that could immediately neutralize anthrax in vivo and have isolated highly potent monoclonal antibodies that can neutralize all three anthrax toxins (PA, LF and EF), as well as bind to the capsule of B.anthracis and opsonize the bacterium. These and monoclonal antibodies that neutralize vaccinia and smallpox are the subjects of a CRADA with MacroGenics. We are also preparing chimpanzee monoclonal antibodies to the three serotypes of poliovirus, to rabies virus, to West Nile virus and to the tick-borne encephalitis virus complex. We have also added the seven toxins of Clostridium botulinum. 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. An impediment to understanding the immune response to hepatitis C virus (HCV) has been the inability to measure neutralizing antibodies because most HCV strains do not replicate in cell culture. We previously demonstrated neutralizing antibodies in an in vivo neutralization assay utilizing chimpanzees. This has been the only accepted neutralization assay until recently, when an in vitro assay based on the neutralization of recombinant retroviruses bearing the envelope glycoproteins of HCV was developed. We demonstrated that this assay generally correlated with the in vivo assay and that the neutralizing antibodies were more broadly reactive than previously thought. We have applied the pseudo-typed virus neutralization assay to sera from chimpanzees experimentally vaccinated with two candidate antibody-based HCV vaccines and have shown that one vaccine, which was effective in preventing infection, hepatitis and chronicity in most animals following challenge with virulent HCV stimulated high levels of broadly neutralizing antibody, whereas the other vaccine, which was completely ineffective in preventing infection, hepatitis or chronicity, completely failed to stimulate neutralizing antibodies as measured by the pseudo-typed virus assay. Broadly neutralizing monoclonal antibodies have been identified for HCV through a CRADA with Innogenetics, Ghent, Belgium. These monoclonal antibodies, directed against the E1 envelope glycoprotein of HCV, were recovered from a patient who had been successfully treated for chronic hepatitis C with interferon. The monoclonal antibodies were highly neutralizing and broadly reactive in the pseudo-typed virus assay. The results obtained with them (and with other polyclonal sera) suggest that hepatitis C viruses, which consist of six genotypes, may comprise two or three serotypes. It is hoped that these monoclonal neutralizing antibodies will find clinical utility in the prevention and therapy of HCV infections. Also in FY 2009, we have initiated a program whereby chimpanzees are being immunized with candidate vaccines against Ebola virus, Marburg virus and Lassa fever virus. Briefly, we are utilizing vesicular stomatitis virus (VSV) that has been modified by replacing the VSV envelope with glycoproteins of the BSL4 viruses. These chimeric viruses, developed by Heinz Feldmann, have been shown to be highly protective as vaccines in animal studies. Our goal is to recover potent neutralizing monoclonal antibodies that can be tested for immunoprophylaxis and immunotherapy. Previous attempts to generate such antibodies have yielded mixed results for reasons that are not completely clear but may be related to enhancing activity of certain antibodies. We plan to evaluate both the neutralizing and the enhancing activity of recovered antibodies and, if necessary, modify their FC portions to abolish enhancement but not neutralization, similar to what we have done with anti-dengue monoclonal antibodies.

抗体。被动免疫预防是一种重要的公共卫生工具。例如，正常的免疫球蛋白在预防甲型肝炎中很重要。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准备了组合文库，这些黑猩猩在实验中按顺序感染了五种人类肝炎病毒中的每一种。黑猩猩的免疫球蛋白与人类的免疫球蛋白几乎相同，这使它们成为免疫预防和免疫治疗药物的有吸引力的选择。到目前为止，我们已经分离出与甲型肝炎、乙型肝炎、甲型肝炎和乙型肝炎反应的单克隆免疫球蛋白。在其他研究中，我们已经恢复了与HCV反应的人单克隆抗体。上述许多单克隆抗体正在中和，它们的生产正在扩大，用于各种动物的被动免疫预防试验，并最终用于人类。这些研究和以下研究已延长至2009年。从骨髓中构建组合文库也被用于实验感染登革热病毒1到4的黑猩猩：这些已经产生了针对登革热病毒1、2和4型的重要中和单克隆抗体。更重要的是，我们重新建立了一种动物模型，用于抗体介导的登革热病毒感染增强，这可能导致更严重的登革热病毒感染形式：登革出血热和登革休克综合征。此外，我们已经在抗体分子中发现了一个消除增强的缺失，这可能使抗体治疗首次成为现实。我们已经将抗体研究扩展到其他感兴趣的病毒和细菌，这些病毒和细菌可以在黑猩猩身上进行实验。例如，为了应对对生物恐怖主义的新关注，我们制备了牛痘病毒的中和单克隆抗体，用于需要牛痘免疫但易受这种免疫副作用影响的人的免疫预防/免疫治疗剂。更重要的是，在与美国疾病控制与预防中心的合作中，我们已经证明，中和牛痘的单克隆抗体也可以中和天花病毒。因此，这些中和性单克隆抗体不仅可用于预防和治疗疫苗接种的副作用，而且如果天花被释放到人群中，也可用于预防和治疗天花。同样，我们用炭疽毒素免疫黑猩猩，试图制造能在体内立即中和炭疽的单克隆抗体，并分离出能中和所有三种炭疽毒素（PA、LF和EF）的高效单克隆抗体，并与炭疽杆菌的荚膜结合，使细菌活化。这些和单克隆抗体，中和牛痘和天花是一个CRADA与MacroGenics的主题。我们还在准备针对脊髓灰质炎病毒、狂犬病毒、西尼罗河病毒和蜱传脑炎病毒复合物三种血清型的黑猩猩单克隆抗体。我们还添加了肉毒杆菌的七种毒素。其中一些将在对抗生物恐怖主义的努力中具有潜在的效用，所有这些都将在对抗新出现和再出现的病原体的战斗中具有免疫预防和免疫治疗潜力。了解丙型肝炎病毒（HCV）免疫反应的一个障碍是无法测量中和抗体，因为大多数丙型肝炎病毒株在细胞培养中不能复制。我们之前在黑猩猩体内中和试验中证明了中和抗体。这一直是唯一被接受的中和实验，直到最近，当一种基于携带HCV包膜糖蛋白的重组逆转录病毒的中和的体外实验被开发出来。我们证明了这种检测通常与体内检测相关，并且中和抗体的反应性比以前认为的更广泛。我们将伪型病毒中和试验应用于实验接种了两种基于抗体的候选HCV疫苗的黑猩猩血清，结果表明，一种疫苗在大多数动物受到强毒性HCV攻击后，能有效预防感染、肝炎和慢性疾病，从而刺激了高水平的广泛中和抗体，而另一种疫苗在预防感染、肝炎或慢性疾病方面完全无效。假型病毒试验完全不能刺激中和抗体。广泛中和的单克隆抗体已通过比利时根特Innogenetics公司的CRADA鉴定出HCV。这些针对丙型肝炎病毒E1包膜糖蛋白的单克隆抗体是从一位用干扰素成功治疗慢性丙型肝炎的患者身上回收的。该单克隆抗体在伪型病毒试验中具有高度中和性和广泛的反应性。用它们（和其他多克隆血清）获得的结果表明，由六种基因型组成的丙型肝炎病毒可能包括两种或三种血清型。希望这些单克隆中和抗体在预防和治疗HCV感染方面具有临床应用价值。