Chen Hongying, Coote Bruce, Attree Simon, Hiscox Julian A
School of Animal and Microbial Sciences, University of Reading, UK.
Avian Pathol. 2003 Oct;32(5):519-26. doi: 10.1080/0307945031000154125.
As an immunogen of the coronavirus, the nucleoprotein (N) is a potential antigen for the serological monitoring of infectious bronchitis virus (IBV). In this report, recombinant N protein from the Beaudette strain of IBV was produced and purified from Escherichia coli as well as Sf9 (insect) cells, and used for the coating of enzyme-linked immunosorbent assay (ELISA) plates. The N protein produced in Sf9 cells was phosphorylated whereas N protein from E. coli was not. Our data indicated that N protein purified from E. coli was more sensitive to anti-IBV serum than the protein from Sf9 cells. The recombinant N protein did not react with the antisera to other avian pathogens, implying that it was specific in the recognition of IBV antibodies. In addition, the data from the detection of field samples and IBV strains indicated that using the recombinant protein as coating antigen could achieve an equivalent performance to an ELISA kit based on infected material extracts as a source of antigen(s). ELISAs based on recombinant proteins are safe (no live virus), clean (only virus antigens are present), specific (single proteins can be used) and rapid (to respond to new viral strains and strains that cannot necessarily be easily cultured).
作为冠状病毒的免疫原，核蛋白（N）是传染性支气管炎病毒（IBV）血清学监测的潜在抗原。在本报告中，从IBV的Beaudette株产生的重组N蛋白在大肠杆菌以及Sf9（昆虫）细胞中生产和纯化，并用于酶联免疫吸附测定（ELISA）板的包被。在Sf9细胞中产生的N蛋白被磷酸化，而来自大肠杆菌的N蛋白则没有。我们的数据表明，从大肠杆菌纯化的N蛋白比来自Sf9细胞的蛋白对抗IBV血清更敏感。重组N蛋白不与针对其他禽病原体的抗血清反应，这意味着它在识别IBV抗体方面具有特异性。此外，来自现场样本和IBV毒株检测的数据表明，使用重组蛋白作为包被抗原可以达到与基于感染材料提取物作为抗原来源的ELISA试剂盒相当的性能。基于重组蛋白的ELISA是安全的（无活病毒）、清洁的（仅存在病毒抗原）、特异的（可使用单一蛋白）且快速的（可应对新的病毒毒株以及不一定易于培养的毒株）。
