title: Baculovirus transduction of chondrocytes elicits interferon-alpha/beta and suppresses transgene expression.
abstract: BACKGROUND
  Baculovirus is an effective vector for gene delivery into primary chondrocytes and repeated baculovirus transduction (i.e. supertransduction) appears to be promising for prolonging transgene expression, but how supertransduction may influence baculovirus-mediated gene delivery is unknown.
  
  
  METHODS
  We first investigated whether prior baculovirus transduction suppressed the ensuing transgene expression mediated by the supertransduced baculovirus, and then examined whether baculovirus triggered the expression of various cytokines. Whether interferon-alpha and -beta (IFN-alpha/beta) suppressed the transgene expression as well as the pivotal step responsible for the attenuated transgene expression were examined.
  
  
  RESULTS
  Baculovirus transduction of chondrocytes elicited an immediate yet transient expression of IFN-alpha/beta, which repressed the transgene expression in a dose-dependent manner. The attenuation was observed for transgene expression driven by different promoters and resulted neither from internalization or nuclear import of baculovirus. Moreover, the attenuation was alleviated if supertransduction was performed when IFN-alpha/beta responses diminished. Baculovirus transduction also triggered the expression of tumor necrosis factor-alpha and interleukin (IL)-6, but not IL-1beta. Despite the induction of these responses, supertransduction of chondrocytes with a baculovirus expressing bone morphogenetic protein-2 successfully enhanced the chondrogenic differentiation and matrix synthesis.
  
  
  CONCLUSIONS
  Baculovirus transduction of primary chondrocytes elicits antiviral effects that suppress transgene expression. Nonetheless, baculovirus supertransduction comprises a feasible approach to extend transgene expression for cartilage engineering.
authors.affiliation: Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan.
authors.forename: Hsiao-Ping
authors.initials: HP
authors.lastname: Lee
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Matsuura
authors.forename: Huang-Chi
authors.initials: HC
authors.lastname: Chen
authors.forename: Yen-Lin
authors.initials: YL
authors.lastname: Chen
authors.forename: Ching-Kuang
authors.initials: CK
authors.lastname: Chuang
authors.forename: Takayuki
authors.initials: T
authors.lastname: Abe
authors.forename: Shiaw-Min
authors.initials: SM
authors.lastname: Hwang
authors.forename: Hsiao-Chiao
authors.initials: HC
authors.lastname: Shiah
authors.forename: Yu-Chen
authors.initials: YC
authors.lastname: Hu
mesh_terms: D000818:Animals; D016367:Baculoviridae / Q000235:genetics* / Q000276:immunology; D002478:Cells, Cultured; D019902:Chondrocytes / Q000378:metabolism*; D016207:Cytokines / Q000235:genetics; D005822:Genetic Vectors / Q000276:immunology; D016898:Interferon-alpha / Q000235:genetics*; D016899:Interferon-beta / Q000235:genetics*; D011401:Promoter Regions, Genetic; D011817:Rabbits; D051381:Rats; D023822:Tissue Engineering; D015533:Transcriptional Activation; D014161:Transduction, Genetic / Q000379:methods*; D019076:Transgenes / Q000235:genetics*
chemical_list: D016207:Cytokines; D016898:Interferon-alpha; D016899:Interferon-beta