Casey Joanne L, Coley Andrew M, Street Graham, Parisi Kathy, Devine Peter L, Foley Michael
Cooperative Research Centre for Diagnostics, La Trobe University, Melbourne, Victoria 3086, Australia.
J Clin Microbiol. 2006 Mar;44(3):764-71. doi: 10.1128/JCM.44.3.764-771.2006.
Epstein-Barr virus (EBV) is a ubiquitous, worldwide infectious agent that causes infectious mononucleosis, affecting >90% of the world's population. Currently, enzyme-linked immunosorbent assay, mostly with purified preparations of EBV cell extracts to capture immunoglobulin M (IgM) antibodies in patients' serum, is used for primary diagnosis. Our objective was to determine whether a small set of peptides could contain sufficient immunogenic information to replace solid-phase antigens in EBV diagnostics. Using monoclonal antibodies, we selected four peptides that mimic different epitopes of EBV from a phage-displayed random peptide library. To assess their diagnostic value, we screened a panel of 62 individual EBV IgM sera for their reactivities with the peptides alone. For all peptides, there was a clear distinction between the EBV-positive and the EBV-negative samples, resulting in 100% specificity. The sensitivities were 88%, 85%, 71%, and 54% for peptides F1, A3, gp125, and A2, respectively. Any combination of peptides increased the sensitivity, indicating that individual peptides react with different subsets of antibodies. Furthermore, when the F1 and the gp125 peptides were coupled to bovine serum albumin and screened against 216 serum samples, there were dramatic improvements in sensitivities (95% and 92%, respectively) and little cross-reactivity with the other peptides encountered during acute viral infections, including rheumatoid factor. This study shows the potential for the use of peptide mimotopes as alternatives to the complex antigens used in current serodiagnostics for EBV infection.
爱泼斯坦-巴尔病毒（EBV）是一种普遍存在于全球的传染性病原体，可引起传染性单核细胞增多症，全球超过90%的人口受其影响。目前，酶联免疫吸附测定主要使用EBV细胞提取物的纯化制剂来捕获患者血清中的免疫球蛋白M（IgM）抗体，用于初步诊断。我们的目标是确定一小部分肽是否包含足够的免疫原性信息，以替代EBV诊断中的固相抗原。我们使用单克隆抗体从噬菌体展示随机肽库中筛选出四种模拟EBV不同表位的肽。为了评估它们的诊断价值，我们单独检测了62份EBV IgM血清样本与这些肽的反应性。对于所有肽，EBV阳性和阴性样本之间有明显区别，特异性达100%。肽F1、A3、gp125和A2的灵敏度分别为88%、85%、71%和54%。任何肽的组合都能提高灵敏度，表明单个肽与不同的抗体亚群发生反应。此外，当F1和gp125肽与牛血清白蛋白偶联并针对216份血清样本进行检测时，灵敏度有显著提高（分别为95%和92%），并且与急性病毒感染（包括类风湿因子）期间遇到的其他肽几乎没有交叉反应。这项研究表明，肽模拟表位有可能替代目前用于EBV感染血清诊断的复杂抗原。
