Sequestration of adenoviral vector by Kupffer cells leads to a nonlinear dose response of transduction in liver.
Systemic administration of a recombinant adenovirus encoding the human interferon-beta gene (H5.110CMVhIFN-beta) results in transduction of hepatocytes and detectable circulating levels of IFN-beta protein. In preclinical studies in mice, we noticed a distinctly nonlinear dose response, with low levels of virus (1-3 x 10(10) viral particles) yielding barely detectable levels of IFN-beta but with a higher viral dose (1 x 10(11) particles) resulting in disproportionately high IFN-beta levels. Further studies showed that transgene expression levels from low viral doses could be dramatically enhanced by coadministering an unrelated recombinant adenovirus (H5.110CMVlacZ), suggesting that there was a viral dose threshold effect for efficient viral transduction and/or IFN-beta expression. This enhancement of reporter expression by a nonreporter adenovirus, effective upon coadministration, was further enhanced by preadministration of H5.110CMVlacZ (up to 8 h), but was ineffective if the helper virus was administered as little as 5 min after the H5.110CMVhIFN-beta reporter virus. Our data suggest that the reticuloendothelial system plays a role in this threshold effect, such that low doses of virus are efficiently taken up by the RES/Kupffer cells without leading to appreciable transgene expression, whereas high doses saturate these cells and are able to productively transduce hepatocytes. A better understanding of this phenomenon could have an impact on gene therapy clinical trial safety and efficacy.
Tao
N
N
Biogen, Inc., 12 Cambridge Center, Cambridge, Massachusetts 02142, USA.
Gao
G P
GP
Parr
M
M
Johnston
J
J
Baradet
T
T
Wilson
J M
JM
Barsoum
J
J
Fawell
S E
SE
D000256:Adenoviridae / Q000235:genetics*; D000818:Animals; D002232:Carbocyanines / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004727:Endothelium / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005456:Fluorescent Dyes / Q000494:pharmacology; D017930:Genes, Reporter; D005822:Genetic Vectors; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D016899:Interferon-beta / Q000235:genetics / Q000378:metabolism; D007728:Kupffer Cells / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008819:Mice, Nude; D013045:Species Specificity; D014018:Tissue Distribution; D014161:Transduction, Genetic; D019076:Transgenes / Q000235:genetics; D014407:Tumor Cells, Cultured; D000515:alpha 1-Antitrypsin / Q000235:genetics / Q000378:metabolism; D001616:beta-Galactosidase / Q000378:metabolism
D002232:Carbocyanines; D005456:Fluorescent Dyes; D000515:alpha 1-Antitrypsin; C089187:cyanine dye 3; D016899:Interferon-beta; D001616:beta-Galactosidase