Department of Biomedical Sciences, Unit of Virology, Institute of Tropical Medicine, Antwerp, Belgium.
Virology Unit, Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru.
Front Immunol. 2021 Jul 5;12:686691. doi: 10.3389/fimmu.2021.686691. eCollection 2021.
Dengue is a major public health problem in tropical and sub-tropical regions worldwide. Since the Zika epidemic and the increased co-circulation of other arboviruses, the serology-based diagnosis of dengue has become more problematic due to the high antigenic resemblance, especially among the flavivirus family. Therefore, a more comprehensive understanding of the diversity, specificity and temporal evolution of the antibody response following dengue infection is needed. In order to close this knowledge gap, we used a high-density peptide microarray of 9,072 linear peptides covering the entire proteome diversity of dengue, Zika, yellow fever and chikungunya viruses. The IgM and IgG antibody responses were measured against the designed microarray in symptomatic dengue infected individuals from an arbovirus endemic area in Peru and in overseas travelers returning to Belgium, as representatives of multiple-exposed and primary infections, respectively. Serum samples were collected longitudinally across four time points over the period of six months in Peru and over two time points in travelers. We show that epitopes eliciting the strongest flavivirus cross-reactive antibodies, in both primary and secondary infections were concentrated in the capsid, E, NS1, NS3 and NS5 proteins. The IgG antibody responses against NS1 and NS3 followed a rise-and-fall pattern, with peak titers between two to four weeks after onset of illness. The response to the E and NS5 proteins increased rapidly in the acute phase and was maintained at stable levels until at least 6 months after illness. A more scattered IgM antibody reactivity across the viral proteome was observed in the acute phase of the disease and that persisted through the 6-month window. The magnitude, breadth (i.e. number of unique epitopes targeted) and depth (i.e. number of epitope variants recognized) of the IgG response was higher in secondary infections compared to primary infections. For IgM antibodies, the magnitude of the response was higher in primary infected individuals whereas the breadth and depth of the response was lower in this group compared with the endemic subjects. Finally, through this arboviral proteome-wide epitope mapping, we were able to identify IgM and IgG dengue-specific epitopes which can be useful serological markers for dengue diagnosis and serostatus determination.
登革热是全球热带和亚热带地区的一个主要公共卫生问题。自寨卡疫情和其他虫媒病毒的共同传播增加以来，由于抗原相似性高，特别是在黄病毒家族中，基于血清学的登革热诊断变得更加成问题。因此，需要更全面地了解登革热感染后抗体反应的多样性、特异性和时间演变。为了弥补这一知识空白，我们使用了一个包含 9072 个线性肽的高密度肽微阵列，这些肽覆盖了登革热、寨卡、黄热病和基孔肯雅热病毒的整个蛋白质组多样性。针对在秘鲁虫媒病毒流行地区感染的有症状登革热患者和返回比利时的海外旅行者（分别代表多次暴露和初次感染），我们在设计的微阵列上测量了 IgM 和 IgG 抗体反应。在秘鲁，血清样本在六个月的时间内分四个时间点采集，在旅行者中分两个时间点采集。我们表明，在初次和再次感染中引起最强的黄病毒交叉反应性抗体的表位集中在衣壳、E、NS1、NS3 和 NS5 蛋白中。针对 NS1 和 NS3 的 IgG 抗体反应呈上升-下降模式，在发病后两到四周达到峰值滴度。E 和 NS5 蛋白的抗体反应在急性期迅速增加，并在至少 6 个月的疾病后保持稳定水平。在疾病急性期观察到更分散的针对病毒蛋白质组的 IgM 抗体反应，并持续到 6 个月的窗口期。与初次感染相比，二次感染的 IgG 反应的幅度、广度（即靶向的独特表位数量）和深度（即识别的表位变体数量）更高。对于 IgM 抗体，初次感染个体的反应幅度更高，而该组的反应广度和深度低于流行地区的个体。最后，通过这种虫媒病毒蛋白质组全范围表位作图，我们能够识别出 IgM 和 IgG 登革热特异性表位，这些表位可作为登革热诊断和血清学状态确定的有用血清学标志物。
