Porcine circovirus type 2 induces the activation of nuclear factor kappa B by IkappaBalpha degradation.
The transcription factor NF-kappaB is commonly activated upon virus infection and a key player in the induction and regulation of the host immune response. The present study demonstrated for the first time that porcine circovirus type 2 (PCV2), which is the primary causative agent of an emerging swine disease, postweaning multisystemic wasting syndrome, can activate NF-kappaB in PCV2-infected PK15 cells. In PCV2-infected cells, NF-kappaB was activated concomitantly with viral replication, which was characterized by increased DNA binding activity, translocation of NF-kappaB p65 from the cytoplasm to the nucleus, as well as degradation and phosphorylation of IkappaBalpha protein. We further demonstrated PCV2-induced activation of NF-kappaB and colocalization of p65 nuclear translocation with virus replication in cultured cells. Treatment of cells with CAPE, a selective inhibitor of NF-kappaB activation, reduced virus protein expression and progeny production followed by decreasing PCV2-induced apoptotic caspase activity, indicating the involvement of this transcription factor in induction of cell death. Taken together, these data suggest that NF-kappaB activation is important for PCV2 replication and contributes to virus-mediated changes in host cells. The results presented here provide a basis for understanding molecular mechanism of PCV2 infection.
Institute of Animal Husbandry and Veterinary Medicine, Beijing Municipal Academy of Agriculture and Forestry Sciences, No.9 Shuguang Garden Central Road, Haidian District, Beijing 100097, People's Republic of China.
Li
L
Wei
Jimmy
J
Kwang
Jin
J
Wang
Lei
L
Shi
Bing
B
Yang
Yongqing
Y
Li
Jue
J
Liu
D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D017925:Circovirus / Q000472:pathogenicity*; D005786:Gene Expression Regulation; D020672:I-kappa B Proteins / Q000378:metabolism*; D007668:Kidney / Q000166:cytology* / Q000821:virology*; D016328:NF-kappa B / Q000378:metabolism*; D010766:Phosphorylation; D013552:Swine; D014779:Virus Replication
D020672:I-kappa B Proteins; D016328:NF-kappa B