Duck hepatitis A virus type 1 (DHAV-1) is a mortal virus to ducklings under three weeks old. Bush sophora root polysaccharide (BSRPS) and its sulfate, sulfated BSRPS (sBSRPS), inhibited the replication of DHAV-1. However the detailed mechanisms were still unknown. The protein translation and RNA synthesis are two most important steps of the replication. Additionally, DHAV-1 3D protein, cellular Hsp70 protein, and DHAV-1 IRES were the important regulatory factors. Therefore, the influence of BSRPS and sBSRPS on DHAV-1 protein translation and RNA synthesis were studied. RT-qPCR, western blot, and dual-luciferase reporter system were used to study the inhibition mechanisms of BSRPS and sBSRPS on DHAV-1. The results showed both BSRPS and sBSRPS significantly inhibited the DHAV-1 protein translation and RNA synthesis, and the effect of sBSRPS was stronger. Furthermore, they dropped the protein translation via suppressing DHAV-1 IRES activity and dropped the DHAV-1 synthesis via suppressing cellular Hsp70 expression.

鸭A型肝炎病毒1型（DHAV-1）是三周龄以下雏鸭的致命病毒。布什槐槐根多糖（BSRPS）及其硫酸盐，硫酸化BSRPS（sBSRPS）抑制DHAV-1的复制。但是，详细的机制仍是未知的。蛋白质翻译和RNA合成是复制的两个最重要步骤。此外，DHAV-1 3D蛋白，细胞Hsp70蛋白和DHAV-1 IRES是重要的调节因子。因此，研究了BSRPS和sBSRPS对DHAV-1蛋白翻译和RNA合成的影响。采用RT-qPCR，western blot和双荧光素酶报告系统研究BSRPS和sBSRPS对DHAV-1的抑制机制。结果表明BSRPS和sBSRPS均显着抑制DHAV-1蛋白质翻译和RNA合成，sBSRPS的效果更强。此外，他们通过抑制DHAV-1 IRES活性来降低蛋白质翻译，并通过抑制细胞Hsp70的表达来降低DHAV-1的合成。