Characterization of temperature-sensitive Akabane virus mutants and their roles in attenuation
Characterization of temperature-sensitive Akabane virus mutants and their roles in attenuation
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DOI：
10.1007/s00705-007-0991-4
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发表时间：
2007-09-01
影响因子：
2.7
通讯作者：
Akashi, H.
中科院分区：
文献类型：
--
作者：
Ogawa, Y.;Kato, K.;Akashi, H.
赤羽病毒（Akabane virus，AKAV）是布尼亚病毒科正布尼亚病毒属（Orthobunyavirus）的一种重要动物病原体，但其生物学特性研究较少。因此，我们产生了AKAV的温度敏感（ts）突变体，以研究其发病机制。通过将毒性OBE-1菌株与化学诱变剂5-氟尿嘧啶一起孵育来产生ts AKAV突变体。将每种ts突变体脑内接种到小鼠体内以评估其毒力，并测定减毒突变体的基因组序列。研究的12个ts突变体中有3个的死亡率低于10%。虽然在这三个突变体的S RNA片段中没有检测到突变，但在M和L RNA片段中都观察到氨基酸取代。三个突变体和野生型病毒表现出类似的模式，在ELISA与抗Gc单克隆抗体的免疫反应性。另一方面，使用微复制子系统，每个ts突变体的L蛋白活性水平随着温度的升高而降低。这些结果表明，L RNA片段可能参与了AKAV的毒力，这增加了我们对病毒基因产物如何参与致病的理解。
Akabane virus (AKAV) of the genus Orthobunyavirus in the family Bunyaviridae is an important animal pathogen; however, studies on AKAV biology are scarce. Therefore, we generated temperature-sensitive (ts) mutants of AKAV in order to study its pathogenesis. The ts AKAV mutants were generated by incubating the virulent OBE-1 strain with the chemical mutagen 5-fluorouracil. Each ts mutant was inoculated intracerebrally into mice to assess its virulence, and the genomic sequences of the attenuated mutants were also determined. Three of the twelve ts mutants studied showed a mortality rate of less than 10%. Although no mutation was detected in the S RNA segment of these three mutants, amino acid substitutions were observed in both the M and L RNA segments. Three of the mutants and the wild-type virus demonstrated a similar pattern of immunoreactivity in an ELISA with anti-Gc monoclonal antibodies. On the other hand, using a minireplicon system, the level of L protein activity of each ts mutant decreased as the temperature increased. These results suggest that the L RNA segment could be involved in the virulence of AKAV, which increases our understanding of how the viral gene products contribute to pathogenesis.