Determination of the role of the intergenic region (IGR) of arenavirus in translation and rational design of the IGR sequence to develop a novel LCMV vector

2021 Fiscal Year Final Research Report

• Project/Area Number: 19H03477
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 49060:Virology-related
• Research Institution: Osaka University
• Principal Investigator: IWASAKI Masaharu 大阪大学, 微生物病研究所, 特任准教授(常勤) (90820788)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 翻訳制御 / アレナウイルス / 遺伝子発現 / 非翻訳領域 / ウイルスベクター / マイナス鎖RNAウイルス

Outline of Final Research Achievements

Mammarenavirus mRNA is characterized by 5′-capped and 3′-non-polyadenylated untranslated regions (UTRs). We previously reported that the non-polyadenylated 3′-UTR of viral mRNA, which is derived from the non-coding intergenic region (IGR), regulates viral protein levels at the post-transcriptional level. In this study, using in vitro-transcribed RNA mimics encoding a reporter gene, we showed that the 3′-UTR of lymphocytic choriomeningitis virus (LCMV) nucleoprotein mRNA without a poly(A) tail promoted translation in a poly(A)-binding protein-independent manner. We compared the 3′-UTR of this mRNA with the 3′-UTR of LCMV glycoprotein precursor mRNA, which is translated less efficiently. We found that a 10-nucleotide sequence proximal to the nucleoprotein open reading frame and its predicted secondary structure were critical for promoting translation. Modification of the 10-nucleotide sequence also affected reporter gene expression in cells infected with recombinant LCMV.

Free Research Field

ウイルス学

Academic Significance and Societal Importance of the Research Achievements

ラッサ熱を引き起こすラッサウイルスの様に、アレナウイルス科にはヒトに重篤なウイルス性出血熱症を引き起こす、公衆衛生上重要な病原体が複数含まれる。本研究ではアレナウイルスのmRNAに特徴的な、ポリA付加を受けない3′-UTR配列の翻訳制御おける役割を明らかにした。今後さらに詳細に解析を進めることで、翻訳効率の調節により、弱毒化の程度を制御可能なラッサウイルス弱毒生ワクチンの開発や、外来遺伝子の発現量を自由自在に制御できる新規ウイルスベクター開発への応用が期待される。