Profiling the protective B cell response to HCV

描述（由申请人提供）：斯坦福大学丙型肝炎合作研究中心将支持一项综合研究计划，重点是定义在自发清除重复感染的高危受试者中保护HCV的免疫相关性。累积的证据表明，针对HCV的保护性免疫包括病毒中和（Vn）抗体和细胞免疫。从高风险个体纵向采集的样本集的可用性，随后从感染前到暴露，然后自然清除或进展为慢性感染，为表征自然发生的免疫保护提供了前所未有的机会。该中心将重点关注B细胞反应。项目1将通过单细胞克隆和酵母展示高通量分离Vn人单克隆抗体（HMAb），分析B细胞应答的特异性，重点分析对E1糖蛋白的应答。单个单克隆抗体的功能和生物化学表征将提供对Vn和非Vn抗体应答的特异性的广度、非Vn抗体是否干扰Vn抗体、以及在具有慢性感染的受试者中引发的Vn抗体是否在其反应性的广度方面更具限制性的见解。项目2将首先探索病毒相关脂蛋白、HCV-受体相互作用、细胞间传递和非Vn抗病毒活性在调节抗体介导的功能中的作用;并将通过研究特异性Vn或非Vn HMAb通过其与Fc受体的相互作用和/或细胞内病毒中和作用促进抗病毒作用的能力来评估它们是否通过其Fc部分表现出抗病毒作用。第二，该项目将在急性HCV感染的人肝嵌合小鼠模型中确定Vn和非Vn HCV HMAb的体内功能。将在这种急性HCV感染的小动物模型中评估所选Vn HMAb（单独和组合）的保护效力和广度以及非Vn HMAb干扰这种保护的能力。总的来说，从这些研究中获得的信息将为合理的疫苗设计提供基础，并提供急需的对免疫接种应引起的抗体分子特异性的了解。

DESCRIPTION (provided by applicant): The Stanford Hepatitis C Cooperative Research Center will support an integrated research program focused on defining the immune correlates of protection against HCV in at-risk subjects that spontaneously clear their repeated infections. Cumulative evidence suggests that protective immunity against HCV includes both virus neutralizing (Vn) antibodies and cellular immunity. The availability of a specimen set of longitudinally collected samples from high-risk individuals followed from pre-infection to exposure followed by natural clearance or progression to chronic infection provides an unprecedented opportunity to characterize naturally-occurring immune protection. This Center will focus on the B cell response. Project 1 will analyze the specificity of the B cell responses employing high throughput isolation of Vn human monoclonal antibodies (HMAbs) by single cell cloning and by yeast display, with an emphasis on analyzing the response to the E1 glycoprotein. Functional and biochemical characterization of individual monoclonal antibodies will provide insights into the breadth of specificities of the Vn and non-Vn antibody responses, whether non-Vn antibodies interfere with Vn antibodies, and whether Vn antibodies elicited in subjects with chronic infections are more restrictive in their breadth of reactivity. Project 2 wil first explore the roles of virus-associated lipoproteins, HCV-receptor interactions, cell- to-cell transmission and non-Vn antiviral activity in modulating antibody-mediated functions; and will assess whether specific Vn or non-Vn HMAbs exhibit an antiviral effect through their Fc part by studying their ability to contribute to an antiviral effect through their interaction with Fc recepors and/or intracellular viral neutralization. Second, the project will determine the in vivo function f Vn and non-Vn HCV HMAbs in a human liver chimeric mouse model for acute HCV infection. The potency and breadth of protection of selected Vn HMAbs, single and in combination, and the ability of non-Vn HMAbs to interfere with this protection will be assessed in this small animal model of acute HCV infection. Collectively, the information gained from these studies will provide the basis for rational vaccine design, and provide much needed insights into the molecular specificities of antibodies that should be elicited by immunization.