False-positive results in a recombinant severe acute respiratory syndrome-associated coronavirus (SARS-CoV) nucleocapsid-based Western blot assay were rectified by the use of two subunits (S1 and S2) of spike for detection of antibody to SARS-CoV
False-positive results in a recombinant severe acute respiratory syndrome-associated coronavirus (SARS-CoV) nucleocapsid-based Western blot assay were rectified by the use of two subunits (S1 and S2) of spike for detection of antibody to SARS-CoV
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DOI：
10.1128/cvi.13.3.409-414.2006
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发表时间：
2006-03-01
影响因子：
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通讯作者：
Paranhos-Baccalà, G
中科院分区：
文献类型：
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作者：
Maache, M;Komurian-Pradel, F;Paranhos-Baccalà, G
为了评价在大肠杆菌菌株BL 21（DE 3）中表达的重组蛋白的反应性，通过使用分别从感染严重急性呼吸综合征相关冠状病毒（SARS-Cov）的恢复期患者（30个样品）和从健康供体（48个样品）获得的一组78个血清样品进行Western印迹分析。作为检测SARS-CoV的抗原，核衣壳蛋白（N）与来自SARS-CoV患者的所有样品均显示出高灵敏度和强反应性，并与来自健康受试者的所有血清样品（来自中国的10个样品或来自法国的38个血清样品）发生交叉反应，从而产生显著的假阳性率。具体地说，我们的数据表明，两个亚基，S1（残基14至760）和S2（残基761至1190），从分开的尖峰与所有样本的SARS-CoV患者，没有任何交叉反应与任何健康血清样品。因此，这些数据揭示了N蛋白在SARS-CoV血清学诊断中的非特异性性质，而S1和S2的特异性为100%。此外，报道的结果表明，使用单一蛋白作为SARS-CoV感染的检测抗原可能导致假阳性诊断。这些可以通过使用一种以上的蛋白质用于SARS-CoV的血清学诊断来纠正。
To evaluate the reactivity of the recombinant proteins expressed in Escherichia coli strain BL21(DE3), a Western blot assay was performed by using a panel of 78 serum samples obtained, respectively, from convalescent-phase patients infected with severe acute respiratory syndrome-associated coronavirus (SARS-Cov) (30 samples) and from healthy donors (48 samples). As antigen for detection of SARS-CoV, the nucleocapsid protein (N) showed high sensitivity and strong reactivity with all samples from SARS-CoV patients and cross-reacted with all serum samples from healthy subjects, with either those obtained from China (10 samples) or those obtained from France (38 serum samples), giving then a significant rate of false positives. Specifically, our data indicated that the two subunits, S1 (residues 14 to 760) and S2 (residues 761 to 1190), resulted from the divided spike reacted with all samples from SARS-CoV patients and without any cross-reactivity with any of the healthy serum samples. Consequently, these data revealed the nonspecific nature of N protein in serodiagnosis of SARS-CoV compared with the S1 and S2, where the specificity is of 100%. Moreover, the reported results indicated that the use of one single protein as a detection antigen of SARS-CoV infection may lead to false-positive diagnosis. These may be rectified by using more than one protein for the serodiagnosis of SARS-CoV.