Amrun Siti Naqiah, Yee Wearn-Xin, Abu Bakar Farhana, Lee Bernett, Kam Yiu-Wing, Lum Fok-Moon, Tan Jeslin Jl, Lim Vanessa Wx, Watthanaworawit Wanitda, Ling Clare, Nosten Francois, Renia Laurent, Leo Yee-Sin, Ng Lisa Fp
Singapore Immunology Network Agency for Science, Technology and Research (ASTAR) Singapore City Singapore.
Communicable Diseases Centre Institute of Infectious Diseases and Epidemiology Tan Tock Seng Hospital Singapore City Singapore.
Clin Transl Immunology. 2019 Jul 26;8(7):e1066. doi: 10.1002/cti2.1066. eCollection 2019.
Recent Zika virus (ZIKV) outbreaks challenged existing laboratory diagnostic standards, especially for serology-based methods. Because of the genetic and structural similarity of ZIKV with other flaviviruses, this results in cross-reactive antibodies, which confounds serological interpretations.
Plasma from Singapore ZIKV patients was screened longitudinally for antibody responses and neutralising capacities against ZIKV. Samples from healthy controls, ZIKV patients and DENV patients were further assessed using ZIKV and DENV peptides of precursor membrane (prM), envelope (E) or non-structural 1 (NS1) viral proteins in a peptide-based ELISA for epitope identification. Identified epitopes were re-validated and diagnostically evaluated using sera of patients with DENV, bacteria or unknown infections from Thailand.
Long-lasting ZIKV-neutralising antibodies were elicited during ZIKV infection. Thirteen potential linear B-cell epitopes were identified, and of these, four common flavivirus, three ZIKV-specific and one DENV-specific differential epitopes had more than 50% sensitivity and specificity. Notably, ZIKV-specific peptide 26 on domain I/II of E protein (amino acid residues 271-288) presented 80% sensitivity and 85.7% specificity. Importantly, the differential epitopes also showed significance in differentiating non-flavivirus patient samples.
Linear B-cell epitope candidates to differentiate between ZIKV and DENV infections were identified, providing the first step towards the design of a much-needed serology-based assay.
近期寨卡病毒（ZIKV）的爆发对现有的实验室诊断标准提出了挑战，尤其是基于血清学的方法。由于ZIKV与其他黄病毒在基因和结构上的相似性，这导致了交叉反应抗体的产生，从而混淆了血清学解释。
对来自新加坡ZIKV患者的血浆进行纵向筛查，以检测其对ZIKV的抗体反应和中和能力。使用基于肽的ELISA法，利用包膜前体（prM）、包膜（E）或非结构1（NS1）病毒蛋白的ZIKV和登革病毒（DENV）肽，对来自健康对照、ZIKV患者和DENV患者的样本进行进一步评估，以鉴定表位。使用来自泰国的DENV、细菌感染或不明感染患者的血清，对鉴定出的表位进行重新验证和诊断评估。
ZIKV感染期间会产生持久的ZIKV中和抗体。鉴定出13个潜在的线性B细胞表位，其中4个常见黄病毒表位、3个ZIKV特异性表位和1个DENV特异性差异表位的敏感性和特异性超过50%。值得注意的是，E蛋白结构域I/II上的ZIKV特异性肽26（氨基酸残基271-288）的敏感性为80%，特异性为85.7%。重要的是，这些差异表位在区分非黄病毒患者样本方面也具有显著意义。
鉴定出了可区分ZIKV和DENV感染的线性B细胞表位候选物，这为设计急需的基于血清学的检测方法迈出了第一步。
