Dengue virus (DENV) infection causes dengue fever, dengue hemorrhagic fever and dengue shock syndrome. It is estimated that a third of the world’s population is at risk for infection, with an estimated 390 million infections annually. Dengue virus serotype 2 (DENV2) causes severe epidemics, and the leading tetravalent dengue vaccine has lower efficacy against DENV2 compared to the other 3 serotypes. In natural DENV2 infections, strongly neutralizing type-specific antibodies provide protection against subsequent DENV2 infection. While the epitopes of some human DENV2 type-specific antibodies have been mapped, it is not known if these are representative of the polyclonal antibody response. Using structure-guided immunogen design and reverse genetics, we generated a panel of recombinant viruses containing amino acid alterations and epitope transplants between different serotypes. Using this panel of recombinant viruses in binding, competition, and neutralization assays, we have finely mapped the epitopes of three human DENV2 type-specific monoclonal antibodies, finding shared and distinct epitope regions. Additionally, we used these recombinant viruses and polyclonal sera to dissect the epitope-specific responses following primary DENV2 natural infection and monovalent vaccination. Our results demonstrate that antibodies raised following DENV2 infection or vaccination circulate as separate populations that neutralize by occupying domain III and domain I quaternary epitopes. The fraction of neutralizing antibodies directed to different epitopes differs between individuals. The identification of these epitopes could potentially be harnessed to evaluate epitope-specific antibody responses as correlates of protective immunity, potentially improving vaccine design.

登革热病毒 (DENV) 感染会导致登革热、登革出血热和登革休克综合征。据估计，世界上三分之一的人口面临感染风险，估计每年有 3.9 亿人感染。登革病毒血清型 2 (DENV2) 引起严重流行，与其他 3 种血清型相比，领先的四价登革热疫苗对 DENV2 的效力较低。在自然 DENV2 感染中，强中和类型特异性抗体可防止随后的 DENV2 感染。虽然已经绘制了一些人类 DENV2 类型特异性抗体的表位，但尚不清楚这些表位是否代表多克隆抗体反应。使用结构引导的免疫原设计和反向遗传学，我们生成了一组重组病毒，其中包含不同血清型之间的氨基酸改变和表位移植。在结合、竞争和中和分析中使用这组重组病毒，我们精细地绘制了三种人类 DENV2 类型特异性单克隆抗体的表位，发现了共享和不同的表位区域。此外，我们使用这些重组病毒和多克隆血清来剖析原发性 DENV2 自然感染和单价疫苗接种后的表位特异性反应。我们的结果表明，在 DENV2 感染或疫苗接种后产生的抗体作为单独的群体循环，这些群体通过占据域 III 和域 I 四元表位来中和。针对不同表位的中和抗体的比例因人而异。