宿主tRNA调控鸭甲肝病毒在鸡胚细胞中翻译的分子机制

鸭甲肝病毒(DHAV)鸡胚传代减毒苗免疫是预防DHAV感染的重要手段。前期研究表明多株鸡胚传代的DHAV弱毒均产生了大量的同义密码改变。由于病毒密码依赖宿主tRNA的解码，因此DHAV弱毒密码的改变理应需要宿主tRNA的响应，以促进弱毒的翻译。然而宿主鸡的哪些tRNA会响应，及其调控鸡胚弱毒翻译的分子机制仍不清楚。基于此，本项目将利用DHAV及其鸡胚弱毒、鸡胚细胞系和tRNA检测方法，明确DHAV和鸡胚弱毒影响宿主的哪些tRNA，分析tRNA响应数据和弱毒密码改变的关联，最后筛选出鸡胚弱毒特异调节的关键tRNA。进一步，通过抑制或过表达关键tRNA在氨酰化过程中的重要分子，如tRNA、偶联氨基酸及tRNA氨酰化合成酶，探究其对弱毒翻译的影响，进而阐明关键tRNA调控DHAV弱毒翻译的分子机制。本研究对宿主tRNA调控鸭源病毒在鸡胚中或其它病毒在异源宿主中翻译的机制解析具有重要的科学价值。

Immunization of Duck hepatitis A virus (DHAV) live attenuated vaccine is a key approach to prevent DHAV infection. This type of vaccine has been developed by a series of passaging of the virulent strain in chicken embryos. The previous researches have analysed the key causative mutations by comparing the genomes of virulent strains and the vaccine strains, which caused the codon usage bias of the DHAV attenuated strains. Because the decoding of the viral genetic codon relies on host tRNAs, biased codons of the DHAV attenuated strain theoretically require biased tRNAome to promote the viral RNA translation. While which tRNA species will be specifically induced by the DHAV attenuated strain and with what’s mechanism to promote its translation in the host chicken embryos cells are largely obscure. Hereby, we aim to use a tRNAome detection method to explore the impacts of the virus (Virulent and vaccine strains) on the tRNAome dynamics of the chicken embryo cell. By analysing the correlation between the tRNAome dynamics and viral codon bias, we will identify the specifically regulated tRNAs. Furthermore, by inhibiting or overexpressing key targets within tRNA-amino acid coupling biological process, such as tRNA per se, coupled amino acids and tRNA aminoacylation synthetase, the molecular mechanism of key tRNAs to promote translation of DHAV in chicken embryo will be clarified. This project has important scientific value in understanding the mechanisms of tRNA to regulate the translation of duck origin viruses in chicken embryos, as well as the role of tRNA in promoting translation of a virus in a heterologous host.