Transgene expression and local tissue distribution of naked and polymer-condensed plasmid DNA after intradermal administration in mice.
DNA vaccination using cationic polymers as carriers has the potential to be a very powerful method of immunotherapy, but typical immune responses generated have been less than robust. To better understand the details of DNA vaccine delivery in vivo, we prepared polymer/DNA complexes using three structurally distinct cationic polymers and fluorescently labeled plasmid DNA and injected them intradermally into mice. We analyzed transgene expression (luciferase) and the local tissue distribution of the labeled plasmid at the injection site at various time points (from hours to days). Comparable numbers of luciferase expressing cells were observed in the skin of mice receiving naked plasmid or polyplexes one day after transfection. At day 4, however, the polyplexes appeared to result in more transfected skin cells than naked plasmid. Live animal imaging revealed that naked plasmid dispersed quickly in the skin of mice after injection and had a wider distribution than any of the three types of polyplexes. However, naked plasmid level dropped to below detection limit after 24h, whereas polyplexes persisted for up to 2 weeks. The PEGylated polyplexes had a significantly wider distribution in the tissue than the nonPEGylated polyplexes. PEGylated polyplexes also distributed more broadly among dermal fibroblasts and allowed greater interaction with antigen-presenting cells (APCs) (dendritic cells and macrophages) starting at around 24h post-injection. By day 4, co-localization of polyplexes with APCs was observed at the injection site regardless of polymer structure, whereas small amounts of polyplexes were found in the draining lymph nodes. These in vivo findings demonstrate the superior stability of PEGylated polyplexes in physiological milieu and provide important insight on how cationic polymers could be optimized for DNA vaccine delivery.
Department of Biomedical Engineering, University of Minnesota, 7-105 Hasselmo Hall, 312 Church Street S. E., Minneapolis, MN 55455, USA.
R Noelle
RN
Palumbo
Xiao
X
Zhong
David
D
Panus
Wenqing
W
Han
Weihang
W
Ji
Chun
C
Wang
D000180:Acrylic Resins / Q000737:chemistry; D000818:Animals; D002412:Cations; D004247:DNA / Q000008:administration & dosage* / Q000235:genetics / Q000493:pharmacokinetics; D004337:Drug Carriers / Q000737:chemistry*; D004355:Drug Stability; D015870:Gene Expression; D007271:Injections, Intradermal; D008156:Luciferases / Q000235:genetics; D008297:Male; D008689:Methacrylates / Q000737:chemistry; D051379:Mice; D008810:Mice, Inbred C57BL; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D015394:Molecular Structure; D010957:Plasmids / Q000008:administration & dosage* / Q000235:genetics / Q000493:pharmacokinetics; D011092:Polyethylene Glycols / Q000737:chemistry; D011094:Polyethyleneimine / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D012867:Skin / Q000378:metabolism; D014018:Tissue Distribution; D019076:Transgenes / Q000235:genetics; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000235:genetics / Q000493:pharmacokinetics
D000180:Acrylic Resins; D002412:Cations; D004337:Drug Carriers; D008689:Methacrylates; D011108:Polymers; D019444:Vaccines, DNA; C550180:polyethylene glycol-block-poly(aminoethyl methacrylate); D011092:Polyethylene Glycols; C072703:2-aminoethylmethacrylate; D011094:Polyethyleneimine; D004247:DNA; D008156:Luciferases