Protective B-cell responses in chikungunya virus infection

 描述（由申请人提供）：基孔肯雅病毒（CHIKV）有可能造成重大的公共卫生影响，如果它被引入美国，似乎有可能在大规模持续爆发后，首先在加勒比地区，然后进入美洲大陆。CHIKV引起广泛的人类和经济损害，部分是由于急性发热和关节痛，但主要是因为病毒后慢性关节疼痛/关节炎。目前，没有针对CHIKV的许可的治疗性治疗或疫苗。我们将通过鉴定主要候选单克隆抗体（mAb）来解决CHIKV造成的重要公共卫生威胁，以开发出能够用于预防和治疗的治疗方法。重要的是，我们已经证明了针对CHIKV的mAb阻断病毒组装/出芽的能力-可能是通过阻止形成颗粒所需的包膜糖蛋白驱动的膜曲率。我们将描述针对这种机制的新抗体，以及描述对感染的全部B细胞库-无论是在急性感染患者还是康复者中。最后，我们将描述CHIKV的遗传多样性和进化，重点是检测B细胞表位的变异和选择特征。为了实现这些目标，我们将执行三个具体目标：目标1。能够抑制出芽的有效人类单克隆抗体的鉴定和表征。我们将从恢复的CHIKV患者中衍生和筛选B细胞克隆，特异性地抑制CHIKV病毒释放/出芽。将对所得mAb进行体外和体内效价表征，并使用逃逸突变体和诱变对其表位进行作图。目标2.表征对CHIKV感染的急性和记忆性B细胞应答。使用免疫库捕获（IRCTM）技术，我们将在CHIKV感染期间完全绘制B细胞库。共同表位将通过寻找多个个体中B细胞互补位的趋同进化来鉴定，并且进入中和和出芽抑制之间的关系将被确定。 以急性感染和康复个体为特征。目标3。CHIKV包膜糖蛋白多样性和进化的表征。为了评估目的1和2中衍生的抗体具有广泛交叉反应性的可能性，我们将表征来自入组研究的个体的病毒分离株（超过3年）中CHIKV包膜序列变异的性质和程度，以及来自更广泛全球人群的CHIKV序列。将对数据集进行筛选，以确定选择性压力的特征，特别是体液反应。 总之，我们希望开发新的mAb，靶向病毒生命周期的特定阶段。感染期间的体液反应将被映射并与病毒多样性和进化相关。

 DESCRIPTION (provided by applicant): Chikungunya virus (CHIKV) has the potential to create a major public health impact should it be introduced into the United States, as seems likely following a large and sustained outbreak, first in the Caribbean and then into the mainland Americas. CHIKV causes extensive human and economic damage, partially due to acute fever and arthralgia, but primarily because of post-viral chronic joint pain/arthritis. Currently no licensed therapeutic treatments or vaccines exist for CHIKV. We will address the important public health threat posed by CHIKV by identifying lead candidate monoclonal antibodies (mAbs) for development into treatments capable of being used both prophylactically and therapeutically. Importantly, we have demonstrated the ability of mAbs directed against CHIKV to block viral assembly/budding - probably by preventing the envelope glycoprotein-driven membrane curvature required to form particles. We will characterize new antibodies targeting this mechanism, as well as describe the full B-cell repertoire in response to infection - both in acutely infected patients and recovered individuals. Finally, we will characterize CHIKV genetic diversity and evolution with emphasis on detecting variation and signatures of selection at B-cell epitopes. In order to achieve these goals we will perform three Specific Aims: Aim 1. Identification and characterization of potent human monoclonals capable of budding inhibition. We will derive and screen B-cell clones from recovered CHIKV patients specifically for inhibition of CHIKV virus release/budding. Resulting mAbs will be characterized for in vitro and in vivo potency, and their epitopes will be mapped using escape mutants and mutagenesis. Aim 2. Characterize acute and memory B-cell responses to CHIKV infection. Using Immune Repertoire Capture (IRCTM) technology, we will fully map B-cell repertoires during CHIKV infection. Common epitopes will be identified by looking for convergent evolution of B-cell paratopes in multiple individuals, and the relationship between entry neutralization and budding inhibition will be characterized in acutely infected and recovered individuals. Aim 3. Characterization of CHIKV envelope glycoprotein diversity and evolution. In order to assess the potential for the antibodies derived in Aims 1 and 2 to be broadly cross reactive, we will characterize the nature and extent of CHIKV envelope sequence variation in viral isolates derived from individuals enrolled in the study (over three years) together with CHIKV sequences from the wider global population. Data sets will be screened for signatures of selective pressure, particularly from the humoral response. In summary, we hope to develop novel mAbs, targeting specific stages of the viral lifecycle. The humoral responses during infection will be mapped and related to viral diversity and evolution.