Mori Yoshio, Borgan Mohammed Ali, Takayama Mutsuyo, Ito Naoto, Sugiyama Makoto, Minamoto Nobuyuki
Laboratory of Zoonotic Diseases, Division of Veterinary Medicine, Faculty of Agriculture, Gifu University, 1-1 Yanagido, 501-1193, Gifu, Japan.
Virology. 2003 Nov 10;316(1):126-34. doi: 10.1016/j.virol.2003.08.006.
We previously demonstrated that a pigeon rotavirus, PO-13, but not turkey strains Ty-3 and Ty-1 and a chicken strain, Ch-1, induced diarrhea in heterologous suckling mice. In this study, it was suggested that these avirulent strains, but not PO-13, were inactivated immediately in gastrointestinal tracts of suckling mice when they were orally inoculated. To determine which viral proteins contribute to the differences between the pathogenicitiy and the inactivation of PO-13 and Ty-3 in suckling mice, six PO-13 x Ty-3 reassortant strains that had the genes of the outer capsid proteins, VP4 and VP7, derived from the opposite strain were prepared and were orally inoculated to suckling mice. A single strain that had both PO-13 VP4 and VP7 with the genetic background of Ty-3 had an intermediate virulence for suckling mice. Three strains with Ty-3 VP7, regardless of the origin of VP4, rapidly disappeared from gastrointestinal tracts of suckling mice. These results indicated that the difference between the pathogenicity of PO-13 and that of Ty-3 was mainly dependent on both their VP4 and VP7. In particular, VP7 was found to be related to the inactivation of Ty-3 in gastrointestinal tracts of suckling mice.
我们之前证明，鸽轮状病毒PO-13可使异源乳鼠发生腹泻，而火鸡轮状病毒株Ty-3和Ty-1以及鸡轮状病毒株Ch-1则不会。在本研究中，结果表明，这些无毒力毒株在经口接种乳鼠后，会在其胃肠道中迅速失活，而PO-13不会。为了确定哪些病毒蛋白导致了PO-13和Ty-3在乳鼠中的致病性和失活情况存在差异，制备了六个PO-13×Ty-3重配毒株，这些毒株的外衣壳蛋白VP4和VP7基因来自相反的毒株，并将其经口接种给乳鼠。一个同时具有PO-13的VP4和VP7以及Ty-3遗传背景的毒株对乳鼠具有中等毒力。三个具有Ty-3 VP7的毒株，无论VP4的来源如何，均迅速从乳鼠的胃肠道中消失。这些结果表明，PO-13和Ty-3致病性的差异主要取决于它们的VP4和VP7。特别是，发现VP7与Ty-3在乳鼠胃肠道中的失活有关。
