latent infection pathogenicity phylogenetic analysis pig pseudorabies virus vaccination variation Aujeszky’s disease Bartha-K61 Enterococcus faecium Glycyrrhiza polysaccharide Huaier polysaccharide ICP0 protein ISG15 knockout mice Liver X receptors MDA5 NF-κB NF-κB signaling pathway P65 PK-15 cells PRV PRV variant RIG-I TMT-based proteomic analysis UHPLC-QE-MS UL54 Vero cell antiviral antiviral activity antiviral breeding