适应肠道细胞的猪德尔塔冠状病毒对仔猪的致病性分析OA北大核心CSTPCD

To analyze the pathogenicity of the Porcine deltacoronavirus(PDCoV)adapted to intestinal cells in piglets,the IPEC-J2 cells were infected with PDCoV which was isolated from ST cells for adaptability testing.The PDCoV antigen was detected by indirect immunofluorescent assay(IFA),and then the virus growth curve was plotted.Finally,the pathogenicity of PDCoV adapted to IPEC-J2 cells in piglets was analyzed.The results showed that:1)PDCoV isolated from ST cells could infect IPEC-J2 cells with CPEs and PDCoV antigen could be detected within the cells.PDCoV reached its proliferation peak at 48 hours after infecting IPEC-J2 cells.2)PDCoV adapted to IPEC-J2 had intestinal pathogenicity in piglets,causing significant diarrhea symptoms and even death.Obvious intestinal histopathologic lesions were observed,and histopathological examination revealed lesions in intestinal epithelial cells and villi,and the antigen was localized in the intestinal epithelial cells by immunohistochemistry.3)Gut immune cytokine analysis revealed that the type Ⅰ interferon expression was upregulated after PDCoV infection in piglets.Both Th1 and Th2 type intestinal cell immune responses were activated simultaneously,inducing the production of immune cytokines in infected piglets to exert antiviral effects.Taken together,PDCoV isolated from ST cells,has strong adaptability to IPEC-J2 cells,and exhibits strong intestinal pathogenicity in piglets.The study lays the foundation for further research on the pathogenic mechanism and antiviral immunity of PDCoV.