Development of a serotyping-capable dengue detection test is hampered by the absence of an identified unique marker that can detect specific dengue virus (DENV) serotype. In the current commercially available antibody-capture diagnostic methods, immobilized nonstructural 1 (NS1) antigen indiscriminately binds and detects immunoglobulin M or immunoglobulin G against any serotype, thus limiting its capability to distinguish existing serotypes of dengue. Identification of dengue serotype is important because certain serotypes are associated with severe forms of dengue as well as dengue hemorrhagic fever. In this study, we aimed to identify an immunogenic epitope unique to DENV2 NS1 antigen and determine the binding specificity of its synthetic peptide mimotope to antibodies raised in animal models. Selection of a putative B-cell epitope from the reported DENV2 NS1 antigen was done using Kolaskar and Tongaonkar Antigenicity prediction, Emini surface accessibility prediction, and Parker hydrophilicity prediction available at the immune epitope database and analysis resource. Uniqueness of the B-cell epitope to DENV2 was analyzed by BLASTp. Immunogenicity of the synthetic peptide analog of the predicted immunogenic epitope was tested in rabbits. The binding specificity of the antibodies raised in animals and the synthetic peptide mimotope was tested by indirect ELISA. A synthetic peptide analog comprising the unique epitope of DENV2 located at the 170th-183rd position of DENV2 NS1 was found to be immunogenic in animal models. The antipeptide antibody produced in rabbits showed specific binding to the synthetic peptide mimotope of the predicted unique DENV2 NS1 immunogenic epitope.

中文翻译：

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登革热病毒血清型2 NS1抗原独有的计算机预测的免疫原性表位的合成肽类似物，可特异性结合兔体内产生的免疫球蛋白G抗体。

具有血清分型能力的登革热检测测试的发展因缺少可检测特定登革热病毒（DENV）血清型的已鉴定独特标记而受阻。在当前市售的抗体捕获诊断方法中，固定的非结构性1（NS1）抗原可针对任何血清型无差别地结合并检测免疫球蛋白M或免疫球蛋白G，从而限制了其区分登革热现有血清型的能力。登革热血清型的鉴定很重要，因为某些血清型与登革热的严重形式以及登革出血热有关。在这项研究中，我们旨在鉴定DENV2 NS1抗原特有的免疫原性表位，并确定其合成肽模拟表位与动物模型中产生的抗体的结合特异性。使用Kolaskar和Tongaonkar抗原性预测，Emini表面可及性预测和Parker亲水性预测可从已报告的DENV2 NS1抗原中选择假定的B细胞表位，可从免疫表位数据库和分析资源获得。通过BLASTp分析B细胞表位对DENV2的唯一性。在兔中测试了预测的免疫原性表位的合成肽类似物的免疫原性。通过间接ELISA测试在动物和合成肽模拟表位中产生的抗体的结合特异性。发现在动物模型中，包含位于DENV2 NS1第170-183位的DENV2独特表位的合成肽类似物具有免疫原性。