Baculovirus transduction of chondrocytes elicits interferon-alpha/beta and suppresses transgene expression.
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.
Lee
Hsiao-Ping
HP
Department of Chemical Engineering, National Tsing Hua University, Hsinchu, Taiwan.
Matsuura
Yoshiharu
Y
Chen
Huang-Chi
HC
Chen
Yen-Lin
YL
Chuang
Ching-Kuang
CK
Abe
Takayuki
T
Hwang
Shiaw-Min
SM
Shiah
Hsiao-Chiao
HC
Hu
Yu-Chen
YC
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*
D016207:Cytokines; D016898:Interferon-alpha; D016899:Interferon-beta