Porcine adenovirus type 3 E1B(large )protein downregulates the induction of IL-8

Replication-defective (E1-E3 deleted) adenovirus vector based gene delivery results in the induction of cytokines including IL-8, which may contribute to the development of inflammatory immune responses. Like other adenoviruses, E1 + E3 deleted porcine adenovirus (PAdV) 3 induces the production of IL-8 in infected cells. In contrast, no IL-8 production could be detected in cells infected with wild-type or mutant PAdV-3s containing deletion in E1A + E3 (PAV211) or E1B(small )+ E3 (PAV212). Expression of PAdV-3 E1B(large )inhibited the NF-κB dependent transcription of luciferase from IL-8 promoter. Imunofluorescence and electrophoretic mobility shift assays suggested that constitutive expression of PAdV-3 E1B(large )inhibited the nuclear translocation of NF-κB and its subsequent binding to DNA. These results suggest that E1B(large )interacts with NF-κB to prevent transcription and down regulate proinflammatory cytokine IL-8 production.