title: In Vitro Coinfection and Replication of Classical Swine Fever Virus and Porcine Circovirus Type 2 in PK15 Cells.
abstract: Increasing clinical lines of evidence have shown the coinfection/superinfection of porcine circovirus type 2 (PCV2) and classical swine fever virus (CSFV). Here, we investigated whether PCV2 and CSFV could infect the same cell productively by constructing an in vitro coinfection model. Our results indicated that PCV2-free PK15 cells but not ST cells were more sensitive to PCV2, and the PK15 cell line could stably harbor replicating CSFV (PK15-CSFV cells) with a high infection rate. Confocal and super-resolution microscopic analysis showed that PCV2 and CSFV colocalized in the same PK15-CSFV cell, and the CSFV E2 protein translocated from the cytoplasm to the nucleus in PK15-CSFV cells infected with PCV2. Moreover, PCV2-CSFV dual-positive cells increased gradually in PK15-CSFV cells in a PCV2 dose-dependent manner. In PK15-CSFV cells, PCV2 replicated well, and the production of PCV2 progeny was not influenced by CSFV infection. However, CSFV reproduction decreased in a PCV2 dose-dependent manner. In addition, cellular apoptosis was not strengthened in PK15-CSFV cells infected with PCV2 in comparison with PCV2-infected PK15 cells. Moreover, using this coinfection model we further demonstrated PCV2-induced apoptosis might contribute to the impairment of CSFV HCLV strain replication in coinfected cells. Taken together, our results demonstrate for the first time the coinfection/superinfection of PCV2 and CSFV within the same cell, providing an in vitro model to facilitate further investigation of the underlying mechanism of CSFV and PCV2 coinfection.
authors.affiliation: Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, PR China.
authors.forename: Niu
authors.initials: N
authors.lastname: Zhou
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China.
authors.forename: Gang
authors.initials: G
authors.lastname: Xing
authors.affiliation: Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, PR China.
authors.forename: Jianwei
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, PR China.
authors.forename: Yulan
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, PR China.
authors.forename: Cuiqin
authors.initials: C
authors.lastname: Liang
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China.
authors.forename: Jinyan
authors.initials: J
authors.lastname: Gu
authors.affiliation: College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China.
authors.forename: Boli
authors.initials: B
authors.lastname: Hu
authors.affiliation: Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Liao
authors.affiliation: China Institute of Veterinary Drug and Control, Beijing, PR China.
authors.forename: Qin
authors.initials: Q
authors.lastname: Wang
authors.affiliation: Key Laboratory of Animal Virology of Ministry of Agriculture, Zhejiang University, Hangzhou, PR China; College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, PR China; State Key Laboratory and Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, Zhejiang University, Hangzhou, PR China.
authors.forename: Jiyong
authors.initials: J
authors.lastname: Zhou
mesh_terms: D000818:Animals; D017209:Apoptosis; D002455:Cell Division; D002460:Cell Line; D002467:Cell Nucleus / Q000821:virology; D017925:Circovirus / Q000502:physiology*; D006692:Classical Swine Fever Virus / Q000502:physiology*; D060085:Coinfection; D003588:Cytopathogenic Effect, Viral; D003593:Cytoplasm / Q000821:virology; D004847:Epithelial Cells / Q000821:virology*; D007668:Kidney / Q000166:cytology / Q000821:virology*; D016676:Macrophages, Alveolar / Q000821:virology; D008297:Male; D015163:Superinfection; D034421:Sus scrofa; D013552:Swine; D013737:Testis / Q000166:cytology / Q000821:virology; D014762:Viral Interference; D019562:Viral Load; D014779:Virus Replication