Arbour N, Côté G, Lachance C, Tardieu M, Cashman N R, Talbot P J
Laboratory of Neuroimmunovirology, Human Health Research Center, Armand-Frappier Institute, INRS, University of Quebec, Laval, Québec, Canada H7V 1B7.
J Virol. 1999 Apr;73(4):3338-50. doi: 10.1128/JVI.73.4.3338-3350.1999.
Human coronaviruses (HuCV) are recognized respiratory pathogens. Data accumulated by different laboratories suggest their neurotropic potential. For example, primary cultures of human astrocytes and microglia were shown to be susceptible to an infection by the OC43 strain of HuCV (A. Bonavia, N. Arbour, V. W. Yong, and P. J. Talbot, J. Virol. 71:800-806, 1997). We speculate that the neurotropism of HuCV will lead to persistence within the central nervous system, as was observed for murine coronaviruses. As a first step in the verification of our hypothesis, we have characterized the susceptibility of various human neural cell lines to infection by HuCV-OC43. Viral antigen, infectious virus progeny, and viral RNA were monitored during both acute and persistent infections. The astrocytoma cell lines U-87 MG, U-373 MG, and GL-15, as well as neuroblastoma SK-N-SH, neuroglioma H4, oligodendrocytic MO3.13, and the CHME-5 immortalized fetal microglial cell lines, were all susceptible to an acute infection by HuCV-OC43. Viral antigen and RNA and release of infectious virions were observed during persistent HuCV-OC43 infections ( approximately 130 days of culture) of U-87 MG, U-373 MG, MO3.13, and H4 cell lines. Nucleotide sequences of RNA encoding the putatively hypervariable viral S1 gene fragment obtained after 130 days of culture were compared to that of initial virus input. Point mutations leading to amino acid changes were observed in all persistently infected cell lines. Moreover, an in-frame deletion was also observed in persistently infected H4 cells. Some point mutations were observed in some molecular clones but not all, suggesting evolution of the viral population and the emergence of viral quasispecies during persistent infection of H4, U-87 MG, and MO3.13 cell lines. These results are consistent with the potential persistence of HuCV-OC43 in cells of the human nervous system, accompanied by the production of infectious virions and molecular variation of viral genomic RNA.
人类冠状病毒（HuCV）是公认的呼吸道病原体。不同实验室积累的数据表明它们具有嗜神经性。例如，人类星形胶质细胞和小胶质细胞的原代培养物显示对HuCV的OC43株感染敏感（A.博纳维亚、N.阿尔布尔、V.W. Yong和P.J.塔尔博特，《病毒学杂志》71:800 - 806，1997年）。我们推测，HuCV的嗜神经性将导致其在中枢神经系统内持续存在，正如在鼠冠状病毒中所观察到的那样。作为验证我们假设的第一步，我们已对各种人类神经细胞系对HuCV - OC43感染的敏感性进行了表征。在急性和持续性感染期间监测病毒抗原、感染性病毒子代和病毒RNA。星形细胞瘤细胞系U - 87 MG、U - 373 MG和GL - 15，以及神经母细胞瘤SK - N - SH、神经胶质瘤H4、少突胶质细胞MO3.13和CHME - 5永生化胎儿小胶质细胞系，均对HuCV - OC43的急性感染敏感。在U - 87 MG、U - 373 MG、MO3.13和H4细胞系的持续性HuCV - OC43感染（大约130天培养）期间观察到病毒抗原、RNA以及感染性病毒粒子的释放。将培养130天后获得的编码推测的高变病毒S1基因片段的RNA核苷酸序列与初始病毒接种物的序列进行比较。在所有持续感染的细胞系中均观察到导致氨基酸变化的点突变。此外，在持续感染的H4细胞中还观察到一个框内缺失。在一些分子克隆中观察到了一些点突变，但并非全部，这表明在H4、U - 87 MG和MO3.13细胞系的持续感染期间病毒群体发生了进化以及病毒准种的出现。这些结果与HuCV - OC43在人类神经系统细胞中潜在的持续存在一致，同时伴有感染性病毒粒子的产生和病毒基因组RNA的分子变异。
