Functional analysis of prv-miR-LLT11a encoded by pseudorabies virus

Viral-encoded microRNAs (miRNAs) have vital roles in the regulation of virus replications and host immune responses. The results of previous studies have indicated that miRNA clusters are involved in the replication and virulence of the pseudorabies virus (PRV), which may potentially lead to immune escape or facilitation of PRV replication. This study's previous research revealed that prv-miR-LLT11a was differentially expressed during PRV infection. The present study's results have demonstrated that prv-miR-LLT11a could significantly inhibit PRV replication. It was further determined that SLA-1 was the target gene of prv-miR-LLT11a, and simultaneously, that overexpression of prv-miR-LLT11a could downregulate the mRNA and protein levels of SLA-1 in a dose-independent manner. Furthermore, the present study also observed that prv-miR-LLT11a can downregulate TAP1 expression. Our findings provide a better understanding of the molecular mechanism involved in the effects of prv-miR-LLT11a on SLA-1 and TAP1 as well as its involvement in immune system evasion of PRV.

Effect of porcine epidemic diarrhea virus nsp1 on type Ⅰ interferon response / 生物工程学报

Porcine epidemic diarrhea virus (PEDV) inhibits the host typeⅠinterferon and cellular antiviral response, but its inhibition mechanism is unclear, and the roles of PEDV nonstructural proteins in regulating typeⅠinterferon responses have been seldom studied. To study the effect of nsp1 on typeⅠinterferon response, nsp1 gene was cloned into a eukaryotic expression vector pCAGGS. The expression of nsp1 in transfected cells was determined by Western blot and indirect immunofluorescence assay. The effects of nsp1 on the induction of typeⅠinterferon were evaluated by dual luciferase reporter gene assay, ELISA and VSV bioassay. Western blot and indirect immunofluorescence assay showed that nsp1 was highly expressed in transfected cells and PEDV-infected cells. Dual luciferase reporter gene assay results indicated that nsp1 strongly inhibited the IFN-β promoter activity, and the inhibitory effect was nsp1 dose-dependent. ELISA results showed that nsp1 significantly inhibited the expression of IFN-β in protein level. And VSV replication-inhibition bioassay revealed that nsp1 significantly inhibited typeⅠIFN antiviral activities induced by poly(I:C). Our results implied that nsp1 was a highly conserved protein of PEDV and exhibited antagonistic function on interferon promoter activity. The results have laid a foundation for further understanding the immune evasion mechanism of PEDV and for developing new effective vaccine against PEDV.

Research Progress in the Function of SUMOylation during Infection by the Influenza Virus / 病毒学报

The influenza virus has evolved numerous mechanisms to overcome host defenses for its benefit. It can also manipulate the immune system to stop it monitoring and clearing the virus. Small ubiquitin-like modifier (SUMO)ylation is emerging as a key post-translational modification that plays an important part in virus replication. This brief review focuses on recent findings on the roles of SUMOylation during infection by the influenza virus. As such, it will aid understanding of the mechanism of action of infection by the influenza virus, and help to provide new strategies for anti-viral treatment.

Isolation,identification and full-length genome sequence of EMCV f rom domesticated boar / 中国人兽共患病学报

Encephalomyocarditis virus (EMCV) ,named JZ1202 ,was isolated from domesticated boar in Henan ,China . We performed the full-length genome sequencing and molecular characteristic analysis of the isolated strain .Results showed that the full-genome sequence of EMCV JZ1202 generated a sequence of 7 735 bp in length ,and had 81 .2%-99 .9% nucleotide identity with other reference strains from different animals ,but 99 .4% with Chinese reference from pig .The phylogenetic tree was constructed based on the full-length genome;ORF and VP1 gene sequences identified EMCV was divided into G1 ,G2 and G3 groups ;the strain JZ1202 belongs to G1 with other Chinese reference strains .Results identified that the EMCV infection could cause severe clinical symptoms in domesticated boar .Big regional differences exist in EMCV and the transmission is limit-ed in a range of area .However ,cross infection and prevalence of EMCV disease between domesticated boar and mice might ex-ist .Mutation of some amino acid may occurred in EMCV infected domesticated boar .