Molecular Cloning, Characterization and Expression Analysis of Woodchuck Retinoic Acid-Inducible Gene

• Published in: 华中科技大学学报（医学英德文版） Vol. 36; no. 3; pp. 335 - 343
• Main Author: 严琦 刘钦 李蒙蒙 李芳慧 朱彬 Jun-zhong WANG 王俊忠 卢银平 刘嘉 吴珺 郑昕 陆蒙吉 王宝菊 杨东亮
• Format: Journal Article
• Language: English
• Published: Department of Infectious Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology,Wuhan 430022, China 2016
• Subjects: caspase; 乙型肝炎病毒; 分子克隆; 土拨鼠; 小干扰RNA; 表达分析; 视黄酸; 诱导基因; retinoic acid-inducible gene; woodchuck; woodchuck hepatitis virus
• ISSN: 1672-0733; 1993-1352
• DOI: 10.1007/s11596-016-1588-5

Cytosolic retinoic acid-inducible gene I（RIG-I） is an important innate immune RNA sensor and can induce antiviral cytokines, e.g., interferon-β（IFN-β）. Innate immune response to hepatitis B virus（HBV） plays a pivotal role in viral clearance and persistence. However, knowledge of the role that RIG-I plays in HBV infection is limited. The woodchuck is a valuable model for studying HBV infection. To characterize the molecular basis of woodchuck RIG-I（w RIG-I）, we analyzed the complete coding sequences（CDSs） of w RIG-I, containing 2778 base pairs that encode 925 amino acids. The deduced w RIG-I protein was 106.847 k D with a theoretical isoelectric point（p I） of 6.07, and contained three important functional structures [caspase activation and recruitment domains（CARDs）, DEx D/H-box helicases, and a repressor domain（RD）]. In woodchuck fibroblastoma cell line（WH12/6）, w RIG-I-targeted small interfering RNA（si RNA） down-regulated RIG-I and its downstrean effector–IFN-β transcripts under RIG-I＇ ligand, 5＇-ppp double stranded RNA（ds RNA） stimulation. We also measured m RNA levels of w RIG-I in different tissues from healthy woodchucks and in the livers from woodchuck hepatitis virus（WHV）-infected woodchucks. The basal expression levels of w RIG-I were abundant in the kidney and liver. Importantly, w RIG-I was significantly up-regulated in acutely infected woodchuck livers, suggesting that RIG-I might be involved in WHV infection. These results may characterize RIG-I in the woodchuck model, providing a strong basis for further study on RIG-I-mediated innate immunity in HBV infection.