Mechanisms of Neutralizing Antibody Resistance in Chronic HCV and HIV Infection

描述(申请人提供)：这项K08职业发展奖的研究目标是确定丙型肝炎病毒(丙型肝炎病毒)包膜突变的共同模式，这些突变介导逃避自体中和抗体(NAB)，衡量这些突变的适合性成本，并确定编码丙型肝炎病毒感染期间诱导的广泛中和抗体的人类B细胞谱系。通过指导、结构化教学和实验室经验，K08职业发展奖是允许Justin Bailey博士成为一名独立研究员的理想机制，该研究员对丙型肝炎病毒感染中广泛的中和抗体反应进行翻译研究。候选人：贝利博士是约翰·霍普金斯医院传染病研究员培训的最后一年的内科医生。他于2007年通过医学科学家培训计划在约翰霍普金斯大学医学院获得免疫学医学博士和博士学位，并于2009年通过ABIM研究途径在马萨诸塞州综合医院完成了内科住院医师培训。在他的传染病奖学金研究期间，他与他的主要导师斯图尔特·雷博士一起研究丙型肝炎病毒(HCV)包膜的进化。他的短期目标是识别和表征丙型肝炎病毒NAB逃逸突变，确定广泛NAB反应的遗传特征，在杂交瘤生成和深度测序方面获得实践经验，并在生物信息学方法和B细胞免疫学方面进行指导性培训。他的长期目标是成为一名独立的研究人员，研究病毒进化和B细胞谱系的进化可以导致广泛的NAB反应的机制。环境：本建议中描述的调查将在约翰霍普金斯医院感染科教授、国际公认的丙型肝炎病毒病毒学、体液免疫和计算生物学专家Stuart Ray博士和范德比尔特大学医学中心儿科、微生物学和免疫学教授JJames E.Crowe，Jr.的实验室进行。这两位导师都是各自领域的领导者，资金充足，在指导年轻调查人员走向独立方面有着良好的记录。两位导师的实验室都有完成拟议研究所需的设备，相关的患者样本、抗体和其他试剂也很容易获得。研究：丙型肝炎病毒(丙型肝炎病毒)疫苗是迫切需要的，诱导有效的中和抗体反应可能是任何成功疫苗策略的关键。困难在于丙型肝炎病毒复制到高水平 使用容易出错的聚合酶，导致病毒在世界范围内具有广泛的遗传多样性，并在受感染的个人中快速进化。大多数抗体是在自然感染期间诱导的 没有足够广泛的特异性来中和不同的丙型肝炎病毒分离株，病毒的进化可能导致感染个体逃避NAB反应。然而，罕见的感染者会产生广泛的NAB反应，一些表位上的NAB逃逸突变可能会给病毒带来很大的适应成本。这项研究的目的是确定丙型肝炎病毒(HCV)包膜突变的共同模式，这些突变介导对自体中和抗体(NAB)的逃逸，衡量这些突变的适合性成本，并确定编码丙型肝炎病毒感染期间诱导的广泛中和抗体的人类B细胞谱系。对这些问题的更好理解将有助于丙型肝炎病毒疫苗的开发，方法是识别可能用作疫苗抗原的免疫原性但适合性受限的表位，并定义应由丙型肝炎病毒疫苗诱导的广泛的NAB的基因特征。这项建议中描述的研究是新颖的，可以在获奖期内实现，并且具有很高的潜在意义。通过完成这项工作获得的研究经验、密集的指导和结构化的教学，K08职业发展奖将允许首席研究员贾斯汀·贝利博士成为一名独立研究员，对丙型肝炎病毒感染中广泛的中和抗体反应进行翻译研究。世界卫生组织估计，全世界有1.7亿人感染丙型肝炎病毒，在大多数国家，丙型肝炎病毒感染在总人口中占1-2%。迫切需要一种预防或减轻丙型肝炎病毒感染的疫苗，而刺激有效的中和抗体(NAB)反应可能是任何成功的疫苗策略的关键。因此，更好地了解病毒逃避NAB和发展广泛的NAB反应应该有助于丙型肝炎疫苗的开发。

DESCRIPTION (provided by applicant): The research objectives of this K08 career development award are to to define shared patterns of hepatitis C virus (HCV) envelope mutation that mediate escape from autologous neutralizing antibody (nAb), to measure the fitness costs of those mutations, and to define the human B cell repertoire encoding broadly neutralizing antibodies induced during HCV infection. Through mentoring, structured didactics and laboratory experience, this K08 career development award is the ideal mechanism to allow Dr. Justin Bailey to become an independent investigator conducting translational research on broadly neutralizing antibody responses in HCV infection. Candidate: Dr. Bailey is a physician in his final year of fellowship training in Infectious Diseases at the Johns Hopkins Hospital. He earned an M.D. and Ph.D. in Immunology at the Johns Hopkins University School of Medicine through the Medical Scientist Training Program in 2007 and completed residency training in Internal Medicine at the Massachusetts General Hospital through the ABIM research pathway in 2009. He has spent the research years of his Infectious Diseases fellowship studying hepatitis C virus (HCV) envelope evolution with his primary mentor, Dr. Stuart Ray. His short term goals are to identify and characterize HCV nAb escape mutations, to define genetic characteristics of a broad nAb response, to gain practical experience in hybridoma generation and deep sequencing, and to pursue didactic training in bioinformatic methods and B cell immunology. His long term goal is to become an independent investigator studying the mechanisms by which viral evolution and evolution of the B cell repertoire can lead to a broad nAb response. Environment: The investigations described in this proposal will be performed in the laboratories of Dr Stuart Ray, a Professor in the Infectious Diseases Division at Johns Hopkins Hospital and an internationally- recognized expert in HCV virology, humoral immunity, and computational biology and Dr. James E. Crowe, Jr., a Professor of Pediatrics, Microbiology and Immunology at Vanderbilt University Medical Center and an expert in B cell biology and the molecular basis for the development of effective B cell responses to viruses in humans. Both mentors are leaders in their respective fields, are well-funded, and have a strong track record of mentoring young investigators to independence. Necessary equipment is available in the labs of both mentors for the completion of the proposed studies, and relevant patient samples, antibodies, and other reagents are readily available. Research: A vaccine against hepatitis C virus (HCV) is urgently needed, and induction of an effective neutralizing antibody response will likely be a keystone of any successful vaccine strategy. The difficulty lies in the fact that HCV replicates to high levels using an error-prone polymerase, leading to extensive world-wide genetic diversity of the virus and rapid viral evolution in infected individuals. Most antibodies induced during natural infection do not have broad enough specificity to neutralize diverse HCV isolates, and viral evolution can lead to escape from nAb responses in individuals who become infected. However, rare infected individuals develop broad nAb responses, and nAb escape mutations in some epitopes may convey significant fitness cost to the virus. The goal of this investigation is to define shared patterns of hepatitis C virus (HCV) envelope mutation that mediate escape from autologous neutralizing antibody (nAb), to measure the fitness costs of those mutations, and to define the human B cell repertoire encoding broadly neutralizing antibodies induced during HCV infection. A better understanding of these questions will facilitate HCV vaccine development by identifying immunogenic but fitness-constrained epitopes that might serve as vaccine antigens and also by defining genetic features of broadly nAb that should be induced by a vaccine against HCV. The research described in this proposal is novel, achievable within the award period, and of high potential significance. Through the research experience acquired through completion of this work, intensive mentoring, and structured didactics, this K08 career development award will allow the primary investigator, Dr. Justin Bailey, to become an independent investigator conducting translational research on broadly neutralizing antibody responses in HCV infection. Relevance The World Health Organization estimates there are 170 million persons with hepatitis C virus (HCV) infection worldwide, and in most countries, HCV infection is found in 1-2% of the general population. A vaccine to prevent or attenuate HCV infection is urgently needed, and stimulation of effective neutralizing antibody (nAb) responses will likely be a keystone of any successful vaccine strategy. Therefore, a better understanding of viral escape from nAb and development of broadly nAb responses should facilitate HCV vaccine development.