Porcine pseudorabies (PR) is an important infectious disease caused by pseudorabies virus (PRV), which poses a major threat to food safety and security. Vaccine immunization has become the main means to prevent and control the disease. However, since 2011, a new PRV variant has caused huge economic losses to the Chinese pig industry. Panax notoginseng polysaccharides have immunomodulatory activity and other functions, but the antiviral effect has not been reported. We studied the anti-PRV activity of Panax notoginseng polysaccharides in vitro. A less cytopathic effect was observed by increasing the concentration of Panax notoginseng polysaccharides. Western blot, TCID₅₀, plaque assay, and IFA revealed that Panax notoginseng polysaccharides could significantly inhibit the infectivity of PRV XJ5 on PK15 cells. In addition, we also found that Panax notoginseng polysaccharides blocked the adsorption and replication of PRV to PK15 cells in a dose-dependent manner. These results show that Panax notoginseng polysaccharides play an antiviral effect mainly by inhibiting virus adsorption and replication in vitro. Therefore, Panax notoginseng polysaccharides may be a potential anti-PRV agent.

Pseudorabies virus (PRV) is one of the most important pathogens causing serious diseases and leads to huge economic losses in the global swine industry. With the continuous emergence of PRV variants and the increasing number of cases of human infection, there is an urgent need to develop antiviral drugs. In this study, we discover that Glycyrrhiza polysaccharide (GCP) has anti-PRV infection activity in vitro, and 600 μg/mL GCP can completely block viral infection. The addition of GCP simultaneously with or after PRV infection had a significant inhibitory effect on PRV. Addition of GCP at different times of the virus life cycle mainly led to the inhibition of the attachment and internalization of PRV but does not affect viral replication and release. Our findings suggest that GCP has potential as a drug against PRV infection.

Senecavirus A (SVA) is an emerging picornavirus. Its genome is one positive-sense, single-stranded RNA. The viral protein (VPg) is covalently linked to the extreme 5′ end of the SVA genome. A complex hairpin-pseudoknot-hairpin (HPH) RNA structure was computationally predicted to form at the 5′ end of the SVA genome. A total of three extra “U” residues (UUU) served as a linker between the HPH structure and the VPg, causing putative UUU–HPH formation at the extreme 5′ end of the SVA genome. It is unclear how the UUU–HPH structure functions. One SVA cDNA clone (N0) was constructed previously in our laboratory. Here, the N0 was genetically tailored for reconstructing a set of 36 modified cDNA clones (N1 to N36) in an attempt to rescue replication-competent SVAs using reverse genetics. The results showed that a total of nine viruses were successfully recovered. Out of them, five were independently rescued from the N1 to N5, reconstructed by deleting the first five nucleotides (TTTGA) one by one from the extreme 5′ end of N0. Interestingly, these five viral progenies reverted to the wild-type or/and wild-type-like genotype, suggesting that SVA with an ability to repair nucleotide defects in its extreme 5′ end. The other four were independently rescued from the N26 to N29, containing different loop-modifying motifs in the first hairpin of the HPH structure. These four loop-modifying motifs were genetically stable after serial passages, implying the wild-type loop motif was not a high-fidelity element in the first hairpin during SVA replication. The other genetically modified sequences were demonstrated to be lethal elements in the HPH structure for SVA recovery, suggesting that the putative HPH formation was a crucial cis-acting replication element for SVA propagation.

• Fourteen 3′-end poly(A)s are sufficient for rescuing Senecavirus A (SVA). • Fourteen 3′-end poly(A)s are inadequate to meet requirement of SVA replication. • Length of poly(A) tail is unstable during SVA replication.

Pseudorabies (PR) is an acute infectious disease of various domestic animals and wild animals caused by pseudorabies virus (PRV). It is mainly characterized by fever, itching, encephalomyelitis, and respiratory and neurological disorders. Plantago asiatica polysaccharide (PLP), extracted from the whole plant of Plantago asiatica L., showed immunomodulatory and antioxidation effects, but the antiviral activity had not been reported. In this study, the inhibitory effect of PLP on PRV infection was studied. Our study first revealed that PLP could inhibit PRV infection in a dose‐dependent manner. By adding PLP at different stages of the virus’s life cycle, we revealed that PLP could reduce the attachment and penetration of PRV into PK15 cells. The inhibition of PRV attachment was better than inhibition of PRV penetration. However, PLP did not affect PRV replication and inactivation. In addition, PLP decreased the intracellular ROS levels in infected cells significantly, and ROS scavenger NAC decreased PRV infection. Therefore, our study provided preliminary data of anti‐PRV activity of PLP, which was established to be a novel anti‐PRV infection agent.

Senecavirus A (SVA), also known as Seneca Valley virus, belongs to the genus Senecavirus in the family Picornaviridae. SVA can cause vesicular disease and epidemic transient neonatal losses in pigs. This virus efficiently propagates in some non-pig-derived cells, like the baby hamster kidney (BHK) cell line and its derivate (BSR-T7/5). Conventionally, a few proteins or only one protein is selected for exploiting a given mechanism concerning cellular regulation after SVA infection in vitro. Proteomics plays a vital role in the analysis of protein profiling, protein-protein interactions, and protein-directed metabolisms, among others. Tandem mass tag-labeled liquid chromatography-tandem mass spectrometry combined with the parallel reaction monitoring technique is increasingly used for proteomic research. In this study, this combined method was used to uncover separately proteomic profiles of SVA- and non-infected BSR-T7/5 cells. Furthermore, both proteomic profiles were compared with each other. The proteomic profiling showed that a total of 361 differentially expressed proteins were identified, out of which, 305 and 56 were upregulated and downregulated in SVA-infected cells at 12 h post-inoculation, respectively. GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) enrichment analyses showed that cellular metabolisms were affected mainly in SVA-inoculated cells at an early stage of infection. Therefore, an integrated metabolic atlas remains to be explored via metabolomic methods.