New Approaches To Passive Immunoprophylaxis

被动免疫预防的新方法

• 批准号: 8336238
• 负责人: Robert H. Purcell
• 金额: $ 133.45万
• 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/8336238
• 关键词: Acidosis; Adverse effects; Animal Model; Animals; Anthrax disease; Antibodies; Antibody Therapy; Antigens; Bacillus anthracis; Bacillus anthracis spore; Bacteria; Belgium; Binding; Biological Assay; Bioterrorism; Bone Marrow; Botulinum Toxins; Cell Culture Techniques; Centers for Disease Control and Prevention (U.S.); Cessation of life; Characteristics; Chronic Hepatitis C; Clinical; Collaborations; Complex; Cooperative Research and Development Agreement; Dengue Hemorrhagic Fever; Dengue Shock Syndrome; Dengue Virus; Disease; Dose; Edema; Environment; Epitopes; Exposure to; Genotype; Globulins; Glycoproteins; Goals; HCV Vaccine; Hepatitis; Hepatitis A; Hepatitis B Virus; Hepatitis C; Hepatitis C virus; Hepatitis Viruses; Hour; Human; Human poliovirus; Hypotension; Immune response; Immunization; Immunoglobulins; Immunotherapeutic agent; Individual; Infection; Infection prevention; Interferons; Intoxication; Kidney; Lead; Libraries; Liver Dysfunction; Measures; Mediating; Monitor; Monoclonal Antibodies; Morbidity - disease rate; Mus; Pan Genus; Paralysed; Patients; Poliomyelitis; Polioviruses; Population; Preparation; Prevention; Prevention therapy; Production; Prophylactic treatment; Proteins; Public Health; Rabies virus; Rattus; Recombinants; Reproduction spores; Retroviridae; Serotyping; Serum; Shock; Smallpox; Smallpox Viruses; TMEV; Testing; Tick-Borne Encephalitis Virus; Tick-Borne Encephalitis Viruses; Time; Toxin; Vaccinated; Vaccination; Vaccines; Vaccinia; Vaccinia virus; Vaccinium; Viral; Virulent; Virus; Virus Diseases; Virus Shedding; West Nile virus; anthrax lethal factor; anthrax toxin; base; biodefense; capsule; combinatorial; human monoclonal antibodies; human poliovirus receptor; humanized monoclonal antibodies; in vitro Assay; in vivo; interest; metabolic abnormality assessment; neutralizing antibody; neutralizing monoclonal antibodies; novel strategies; passive immunoprophylaxis; pathogen; prevent; research clinical testing; response; scale up; tool

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. Chimpanzee globulins are virtually identical to human immunoglobulins, making them attractive choices for immunoprophylactic and immunotherapeutic agents. 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. We isolated monoclonal immunoglobulins that react with HAV, HBV, HDV and HEV. In other studies, we recovered human monoclonal antibodies that react with HCV. Many of the monoclonal antibodies described above were neutralizing and their production was scaled up for tests of passive immunoprophylaxis in a variety of animals and, eventually, in humans. These studies were extended through 2010. 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 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 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 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 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 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.) In 2010 we extended the study of monoclonal antibody to protective antigen (PA) to include a metabolic study of protection in rats administered either edema toxin (EF plus PA) or lethal toxin (LF plus PA) or both toxins. Rats were administered the antibody, followed by the toxin and monitored for hypotension, acidosis and renal and liver dysfunction. The antibody increased survival and reduced hypotension, in some cases even when administered up to 12 hours after intoxication. Similarly, rats administered Bacillus anthracis spores subcutaneously had increased survival when the antibody was administered up to 48 hours after intoxication. Thus, the monoclonal antibody had the potential to reduce morbidity due to ET or LT even after toxin release and shock had developed. Also in 2010, we generated monoclonal antibodies to the capsule of B. anthracis by immunizing chimpanzees with synthetic capsular protein. These antibodies can bind to the capsule of the bacterium and opsonize it. We demonstrated that a single 30 mcg dose of monoclonal antibody administered to mice 18 hours before challenge conferred approximately 50% protection against a lethal intra-tracheall spore challenge by the virulent B. anthracis Ames strain. More importantly, monoclonal antibody given eight hours or 20 hours after challenge provided significant protection also. These and monoclonal antibodies that neutralize vaccinia and smallpox were the subjects of a CRADA with MacroGenics. We have also prepared 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 were 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. In 2011 we demonstrated in collaborative studies with the FDA that monoclonal antibodies derived from chimpanzees were highly potent for the neutralization of all three poliovirus serotypes and that at least one of these antibodies could neutralize two different serotypes. Furthermore, they could protect mice from paralysis and death whether administered before or after exposure to virulent poliovirus (the mice used in this study are genetically modified to express the human receptor for polioviruses). One of the antibodies is being prepared for clinical testing. A major impediment to the eradication of poliomyelitis worldwide is the presence of immunologically compromised individuals who chronically shed the virus into the environment; these would be subjects for antibody therapy. In 2011 we have also demonstrated pre-and post-exposure protection against virulent anthrax infection in mice by humanized monoclonal antibodies to Bacillus anthracis capsule. These antibodies have potential, in concert with antibodies against B. anthracis toxins, to prevent and treat anthrax .

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。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。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。我们分离出能与甲型肝炎、乙型肝炎、乙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，我们恢复了与HCV反应的人单克隆抗体。上述许多单克隆抗体已被中和，其生产规模已扩大，可用于各种动物的被动免疫预防试验，并最终用于人类试验。这些研究一直延续到2010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，我们重新建立了抗体介导的登革热病毒感染增强的动物模型，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，我们在抗体分子中发现了一个缺失，该缺失消除了增强，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CDC的合作中，我们证明了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，试图制造能够立即在体内中和炭疽的单克隆抗体，并分离出能够中和所有三种炭疽毒素（PA， LF和EF）的高效单克隆抗体。2010年，我们扩展了对保护抗原（PA）单克隆抗体的研究，包括对给予水肿毒素（EF + PA）或致死毒素（LF + PA）或两种毒素的大鼠的保护代谢研究。给大鼠注射抗体，然后注射毒素，监测低血压、酸中毒、肾功能和肝功能障碍。这种抗体增加了生存率，降低了低血压，在某些情况下，甚至在中毒12小时后给药。同样，在中毒48小时后皮下注射炭疽芽胞杆菌抗体的大鼠存活率也有所提高。因此，即使在毒素释放和休克发生后，单克隆抗体也有可能降低因ET或LT引起的发病率。同样在2010年，我们用合成的荚膜蛋白免疫黑猩猩，产生了针对炭疽杆菌荚膜的单克隆抗体。这些抗体可以与细菌的囊结合并使其调理。我们证明，在攻毒前18小时给小鼠单次30微克剂量的单克隆抗体，对强毒炭疽芽孢杆菌Ames菌株的致死性气管内孢子攻毒具有约50%的保护作用。更重要的是，在攻毒后8小时或20小时给予单克隆抗体也具有显著的保护作用。这些和单克隆抗体，中和牛痘和天花是一个CRADA与MacroGenics的对象。我们还制备了三种血清型脊髓灰质炎病毒、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。