Cloning,expression, and antiviral activity of interferon β from the Chinese microbat,Myotis davidii

Bats are natural reservoir hosts for many viruses that produce no clinical symptoms in bats.Therefore, bats may have evolved effective mechanisms to control viral replication. However, little information is available on bat immune responses to viral infection. Type I interferon(IFN) plays a key role in controlling viral infections. In this study, we report the cloning, expression, and biological activity of interferon β(IFNβ) from the Chinese microbat species, Myotis davidii. We demonstrated the upregulation of IFNB and IFN-stimulated genes in a kidney cell line derived from M. davidii after treatment with poly I:C or infection with Sendai virus. Furthermore, the recombinant IFNβ inhibited vesicular stomatitis virus and bat adenovirus replication in cell lines from two bat species, M. davidii and Rhinolophus sinicus. We provide the first in vitro evidence of IFNβ antiviral activity in microbats, which has important implications for virus interactions with these hosts.     

孤儿核受体hB1F／hLRH-1铰链区一个保守结构域对其转录功能的抑制作用

孤儿核受体hB1F(NR5A2 ,也称之为LRH 1、CPF或FTF)在胆汁酸合成代谢、乙肝病毒基因和部分肝特异性基因表达的调控中起着重要的作用。为理解hB1F激活转录的分子机制 ,对其铰链区潜在的功能结构域进行了分析。利用GAL4 DBD融合的hB1F缺失片段所进行的报告基因分析 ,发现了一个位于铰链区的强烈抑制hB1F反式激活能力的结构域。该结构域核心残基的定点突变导致了hB1F反式激活能力的显著上升 ,而且明显地增强hB1F对乙肝病毒增强子II 核心启动子的转录激活能力。生物信息学分析显示该结构域不存在明显的二级结构 ,但有意思的是 ,其氨基酸序列在核受体FTZ F1亚家族的成员中高度保守 ,且不见于其他蛋白质中。转染分析发现 ,该结构域的抑制活性存在于测试的五个不同细胞株中 ,但抑制的强度表现出明显差异。半定量RT PCR分析表明 ,与SF 1不同 ,该结构域抑制转录活性的强度与潜在的结合因子DP10 3的表达水平之间没有相关性。共转染实验还表明 ,参与hB1F转录活性调控的辅激活子SRC 1和辅抑制子SMRT与该抑制作用不直接相关。实验结果提示 ,孤儿核受体hB1F转录活性可能存在一种新的调控机制。