Regulation Of Cold-inducible Rna-binding Protein(CIRBP)in PRRSV-induced Inflammatory Response

Porcine reproductive and respiratory syndrome virus(PRRSV)infection causes severe systemic inflammation,which leads to imbalance in inflammation regulation and release of inflammatory factors.Some studies have showed that RNA binding proteins are closely related to the disease occurrence and cell immune.Cold-inducible RNA-binding protein(CIRBP),as one of the RNA binding proteins,participates in many biological and disease processes.Although extracellular CIRBP has been reported as a new pro-inflammatory mediator,its regulatory role in PRRSV-induced inflammatory responses remains unclear.This study found that CIRBP was up-regulated in PRRSV-infected porcine alveolar macrophages cell lines 3D4/21.In order to systematically explore the effect of CIRBP on PRRSV-induced inflammatory response and reveal the mechanism of CIRBP regulating the inflammatory response,the main research contents and results are as follows:(1)CIRBP showed up-regulation in both transcriptional and protein levels after PRRSV infection by transcriptome sequencing data,RT-q PCR and flow cytometry,indicating that it has the function of participating in the response to PRRSV infection.(2)PRRSV infection promoted the aggregation of CIRBP from the nucleus to the cytoplasmic stress granules,which had a positive effect on the formation of stress granules to a certain extent,providing a basis for the subsequent research on the pro-inflammatory function of CIRBP.(3)CIRBP promoted the m RNA and protein expression level of inflammatory cytokines in PRRSV infection.In addition,CIRBP increased i NOS activity and ROS content.While the expression level of CAT,GPX1,SOD1 in antioxidant enzyme system were decreased,so that it could not resist excessive ROS,thus mediating oxidative stress and promoting inflammation.(4)CIRBP activated PRRSV-induced NF-?B promoter and increased I?B? and p65 phosphorylation,mediating NF-?B pathway to promote the expression of inflammatory factors,which establishes a new relationship among CIRBP,NF-?B pathway and inflammation.In addition,CIRBP,as an RNA binding protein,enhanced the stability of inflammatory cytokine m RNA and inhibited the target m RNA degradation to promote its translation,thus inducing inflammatory response.In conclusion,the study elaborated the relevant mechanism of CIRBP involved in regulating PRRSV-induced inflammatory response and proposed a new idea of CIRBP involved in immune regulation of PRRSV infection,which enriches the pathogenesis of PRRSV and provides a potential direction for PRRSV biotherapy strategies.