鸡传染性支气管炎病毒纤突蛋白裂解与致病性的研究

冠状病毒的致病机理一直不清楚。对副粘病毒和正粘病毒的研究结果表明病毒的致病力与病毒纤突蛋白裂解程度有关,反过来纤突蛋白裂解程度是由纤突蛋白的连结多肽的氨基酸顺序决定的。本文试图从IBV致细胞病变作用,纤突蛋白裂解状态和连结多肽氨基酸顺序三个方面探讨IBV的致病机理。结果表明,IBV毒株在不同细胞培养(CK.CEF和Vero)中,从宿主细胞范围、致细胞病变作用和引起细胞融合几项指标表现了不同的致病力,但不同毒株从同一种细胞释放后其纤突蛋白的裂解程度无差异。连结多肽的氮基酸序列表明23株IBV的连结多肽均由5个氨基酸组成即二对碱性氨基酸Arg—Arg和Arg—Arg,中间由苯丙氨酸或丝氨酸联接。这些结果说明在致病机理方面,冠状病毒可能不同于副粘病毒和正粘病毒。

Cleavage of the Spike Protein and Cytopathogenesis of Avian Infectious Bronchitis Virus

Studies on paramyxoviruses and myxoviruses have shown that the viral pathogenesis is related to the cleavibility of the viral spike protein, in turn, cleavibility of the spike protein is determined by the amino acid sequence of the connecting peptide of the spike protein This paper intended to investigate the pathogenesis of avian coronavirus, infectious bronchitis virus(IBV) by looking into three aspects, i. e. cytopathogenesis of the virus, cleavage status of the viral spike protein and amino acid sequence of the connecting peptide The results revealed that IBV strains showed distinct cytopathogenesis in term of spectrum of host cell% cytopathic effect and capacity to induce cell-cell fusion in different cell types However, cleavage of the spike protein had no significant difference between different strains when they are derived from the same cell types. RNA Sequencing data showed that the connecting peptide of all 23 IBV strains consist of 5 amino acids, i.e. Arg-Arg and Arg-Arg intervened by a phenylalanine or serineo The results herein showed that the pathogenic mechanism of eoronavilus may differ from that of paramyxoviruses or myxoviruses.