Host Targets Interacting with Influenza Virus NP and Mechanism of Gardenia Jasminoides Iridoid Glycoside Against Influenza Virus / 中国实验方剂学杂志

ABSTRACT

ObjectiveTo explore host factors interacting with influenza virus nucleoprotein （NP） and study their effects on influenza virus replication， as well as the mechanism of gardenia jasminoides iridoid glycoside （IGE） in inhibiting influenza virus. MethodA yeast two-hybrid system was utilized to screen host factors that interacted with influenza virus NP. Heterogeneous nuclear ribonucleoprotein D0 （HNRNPD）， glucosamine-6-phosphate deaminase 1 （GNPDA1）， poly（rC）-binding protein 1 （PCBP1）， and protein inhibitor of activated signal transducer and activator of transcription （STAT） protein 1 （PIAS1） were validated by immunoprecipitation assay. The effects of PIAS1 and HNRNPD on influenza virus replication were compared by a dual luciferase assay， and the effects of IGE on influenza virus replication were examined in the presence of transfected ribonucleoprotein （RNP） and knockdown of PIAS1. ICR mice were randomly divided into a normal group， model group， oseltamivir phosphate group， and high， medium， and low dose IGE groups， with 10 mice in each group. In addition to the normal group， each group was infected with the influenza A virus FM1 strain by nasal drip to establish a viral pneumonia model. The high， medium， and low dose IGE groups were given drugs of 50， 25， and 12.5 mg∙kg-1 by gavage， and the oseltamivir phosphate group was given the drug of 27.5 mg∙kg-1 by gavage. Equal amounts of distilled water were instilled in the normal and model groups for four consecutive days. Later， protein expression of PIAS1， NP， phosphorylated （p）-STAT3， STAT3， p-STAT1， and STAT1 were detected in the lung tissue by Western blot. ResultIn yeast two-hybrid assays， 16 potential host targets interacting with influenza virus NP were identified. Immunoprecipitation experiments revealed that HNRNPD and PIAS1 could interact with influenza virus NP. The dual luciferase reporter assays found that both PIAS1 knockdown and overexpression significantly affected IAV RNP activity （P<0.05， P<0.01）， and the effect of HNRNPD on IAV RNP was not significant. Both high and low dose IGE groups reduced influenza virus replication （P<0.05） and reversed the increase in influenza virus replication caused by the knockdown of PIAS1（P<0.05， P<0.01）. The expressions of PIAS1， NP， p-STAT3， p-STAT1， and STAT1 in the lung tissue of infected mice were reduced to different degrees in each IGE group （P<0.05， P<0.01）. ConclusionPIAS1 interacts with influenza virus NP and is able to inhibit influenza virus replication. IGE may exert antiviral effects by inhibiting the activity of IAV RNP through the PIAS1/STAT1 pathway.