Centro de Tecnologia em Vacinas (CT-Vacinas), Parque Tecnológico da UFMG (BH-Tec), Universidade Federal de Minas Gerais (UFMG), Belo Horizonte-MG 31320-000, Brazil.
Laboratório de Virologia Molecular e Aplicada, Departamento de Microbiologia, Instituto de Ciências Biológicas (ICB/UFMG), Belo Horizonte-MG 31270-901, Brazil.
Viruses. 2020 Aug 26;12(9):939. doi: 10.3390/v12090939.
Chikungunya virus (CHIKV) is a mosquito-borne pathogen that causes a disease characterized by the acute onset of fever accompanied by arthralgia and intense joint pain. Clinical similarities and cocirculation of this and other arboviruses in many tropical countries highlight the necessity for efficient and accessible diagnostic tools. CHIKV envelope proteins are highly conserved among alphaviruses and, particularly, the envelope 2 glycoprotein (CHIKV-E2) appears to be immunodominant and has a considerable serodiagnosis potential. Here, we investigate how glycosylation of CHIKV-E2 affects antigen/antibody interaction and how this affects the performance of CHIKV-E2-based Indirect ELISA tests. We compare two CHIKV-E2 recombinant antigens produced in different expression systems: prokaryotic-versus eukaryotic-made recombinant proteins. CHIKV-E2 antigens are expressed either in BL21(DE3)-a prokaryotic system unable to produce post-translational modifications-or in HEK-293T mammalian cells-a eukaryotic system able to add post-translational modifications, including glycosylation sites. Both prokaryotic and eukaryotic recombinant CHIKV-E2 react strongly to anti-CHIKV IgG antibodies, showing accuracy levels that are higher than 90%. However, the glycan-added viral antigen presents better sensitivity and specificity (85 and 98%) than the non-glycosylated antigen (81 and 71%, respectively) in anti-CHIKV IgM ELISA assays.
基孔肯雅热病毒（CHIKV）是一种经蚊子传播的病原体，可引起以急性发热伴有关节炎和剧烈关节痛为特征的疾病。许多热带国家中此类病毒和其他虫媒病毒的临床相似性和共同流行，突出了对高效且易于获得的诊断工具的需求。甲病毒属中的包膜蛋白高度保守，特别是包膜 2 糖蛋白（CHIKV-E2）似乎具有免疫优势，并且具有相当大的血清学诊断潜力。在这里，我们研究了 CHIKV-E2 的糖基化如何影响抗原/抗体相互作用，以及这如何影响基于 CHIKV-E2 的间接 ELISA 测试的性能。我们比较了在两种不同表达系统中产生的两种 CHIKV-E2 重组抗原：原核与真核系统。CHIKV-E2 抗原分别在 BL21(DE3)-一种不能产生翻译后修饰的原核系统-或在 HEK-293T 哺乳动物细胞-一种能够添加翻译后修饰物，包括糖基化位点的真核系统中表达。原核和真核重组 CHIKV-E2 均与抗 CHIKV IgG 抗体强烈反应，准确率均高于 90%。然而，与未糖基化抗原（分别为 81%和 71%）相比，糖基化病毒抗原在抗 CHIKV IgM ELISA 检测中表现出更好的灵敏度和特异性（85%和 98%）。
