Discovery & characterization of human monoclonal antibodies targeting multiple arthritogenic alphaviruses

项目摘要 甲型病毒是有包膜的、阳性的单链RNA病毒，它包括几种 重要的人类病原体。致炎甲型病毒是全球分布的蚊子传播病毒。 导致人类风湿病的病毒包括基孔肯雅病毒(CHIKV)和马亚罗病毒(MAYV)。 症状性感染的特征是发烧、皮疹、肌肉痛以及急性和慢性多关节痛。 在感染后，这种情况可以持续几个月到几年。甲型病毒性疾病更严重的表现- 包括出血、脑病和死亡--已有报道。这些病毒导致地方性疾病 疾病以及世界范围内大规模的零星流行。目前，还没有批准的疫苗或抗病毒药物 预防或治疗甲型病毒感染的疗法；因此，新疗法的发展 针对一种或多种致关节炎的甲型病毒的策略是非常有意义的。 已经描述了一些有效中和CHIKV单抗(MAbs)，但 目前，已报道的唯一广泛中和甲型病毒单抗是小鼠。因此，达到的程度 在甲型病毒感染后，人类抗体反应引起广泛中和的单抗，并且 表位(S)这类单抗可能的靶点，目前尚不清楚。为了解决这个问题，这项提议寻求扩大 我们通过系统研究交叉病毒对甲型病毒的中和抗体反应的知识 CHIKV感染患者的反应性抗体。为此，我们使用单个B细胞分类来 从恢复期CHIKV患者中分离出大量MAYV反应性单抗。我们会研究 这些单抗对相关致关节炎甲型病毒的反应性和中和特性(目标1)。我们 然后将通过生化方法确定中和的要求(目标2)并阐明 单抗抑制(目标3)。这些研究将有助于我们从根本上理解 免疫系统对抗致关节炎甲型病毒的感染，并可能有助于开发新的单抗- 以治疗和疫苗为基础。

Project Summary Alphaviruses are enveloped, positive sense single-stranded RNA viruses, which include several important human pathogens. Arthritogenic alphaviruses are globally distributed, mosquito-transmitted viruses that cause human rheumatic disease and include chikungunya virus (CHIKV) and Mayaro virus (MAYV). Symptomatic infection is characterized by fever, rash, myalgia, as well as both acute and chronic polyarthralgia that can persist for months to years after infection. More severe manifestations of alphaviral disease – including hemorrhage, encephalopathy and mortality – have been reported. These viruses cause endemic disease as well as large, sporadic epidemics worldwide. Currently, there are no approved vaccines or anti-viral therapies for the prevention or treatment of alphavirus infection; therefore, the development of new therapeutic strategies targeting one or multiple arthritogenic alphaviruses is of substantial interest. A number of potently neutralizing CHIKV monoclonal antibodies (mAbs) have been described, but currently the only broadly neutralizing alphavirus mAbs that have been reported are murine. Thus, the extent to which the human antibody response elicits broadly-neutralizing mAbs following alphavirus infection, and which epitope(s) such mAbs may target, remains unknown. To address this question, this proposal seeks to expand our knowledge of the neutralizing antibody response to alphaviruses by systematically investigating cross- reactive antibodies from CHIKV-infected patients. Towards this end, we have used single B cell sorting to isolate a large panel of MAYV-reactive mAbs from CHIKV patients in the convalescent phase. We will study the reactivity and neutralization profiles of these mAbs against related arthitogenic alphaviruses (Aim 1). We will then biochemically determine the requirements of neutralization (Aim 2) and elucidate the mechanism of mAb inhibition (Aim 3). These studies will contribute to our fundamental understanding of how the adaptive immune system combats infection by arthritogenic alphaviruses and may aid the development of novel mAb- based treatments and vaccines.