Gene Therapy

Lipofection of nondividing cells is inefficient because much of the transfected DNA is retained in endosomes, and that which escapes to the cytoplasm enters the nucleus at low rates. To improve the final ratelimiting step of nuclear import, we have used the nonclassical nuclear localization signal (NLS) containing the M9 sequence of heterogeneous nuclear ribonucleoprotein (hnRNP) A1. This approach has been validated in endothelial cells, neurons, and mouse embryonic stem cells.

During the delivery of plasmid DNA for gene therapy often provokes an inflammatory response that reduces transgene expression. Cationic lipids for lipofection lack pharmacological activity despite the hydrophobicity of many drug candidates that could be exploited. We have developed a one-step synthesis of a water-soluble, dexamethasone–spermine (DS) cationic lipid that has potent gene transfer capability in confluent endothelial cells when used with the neutral lipid, dioleoylphosphatidylethanolamine (DOPE). DS retains partial corticosteroid character as quantified by the rapid translocation of glucocorticoid receptor to the nucleus and by dosedependent transactivation from a glucocorticoid response element. DS has anti-inflammatory activity in vivo in the mouse thioglycollate model of inflammation. In a mouse lung model, DS:DOPE resulted in significantly less interferon-g production at Day 1 and elevated transgene expression at Days 1 and 7 postintranasal instillation compared to DCChol: DOPE.

We formulated adenovirus (AdV) vectors with cationic steroid liposomes containing dexamethasone–spermine (DS)/dioleoylphosphatidylethanolamine (DOPE) in an effort to overcome the lack of apically expressed AdV vector receptors on airway epithelial cells and to reduce the inflammation associated with AdV vector exposure. An AdV vector (1 to 2.5 x10^11 genome copies) expressing human placental alkaline phosphatase or B-galactosidase (LacZ) was delivered alone or complexed with DS/DOPE, DC-Chol/DOPE, or dexamethasone to C57Bl/6 mice via intranasal instillation. Formulation of the AdV vector with DS/DOPE and DC-Chol/DOPE resulted in transgene expression targeted only to the airway epithelial cells with minimal expression in alveolar cells, while AdV alone caused high alveolar transduction. The DS/DOPE and dexamethasone formulations greatly reduced cellular infiltrates compared to AdV vector alone, while formulation with DC-Chol/DOPE did not. Viral vectors can be formulated with DS/DOPE to improve targeting to the airway epithelium in vivo and to attenuate vector-induced inflammation through the pharmacological activity of DS.

Publications

A. Subramanian, S.L. Diamond. "Enhancement of nonviral gene transfer to endothelial cells using lipofection of histone complexed DNA," Tissue Engineering 3, 39 (1997).

A. Subramanian, P. Ranganathan, S. L. Diamond. "Nuclear targeting peptide scaffold for lipofection of nondividing mammalian cells." Nature Biotechnology. 17, 873 (1999).

A. Subramanian, H. Ma, K.N. Dahl, J. Zhu, and S.L. Diamond. Adenovirus or HA-2 peptide assisted lipofection increases cytoplasmic plasmid in nondividing endothelium with little enhancement of transgene expression. J. Gene Med. 4:75 (2002).

H. Ma, S.L. Diamond. Non-viral gene therapy and its delivery systems. Curr. Pharmaceut. Biot. 2, 1 (2001).

C.K. Byrnes, P. H. Nass, M. D. Duncan, S.L. Diamond, J. W. Harmon. Assessment of a nuclear targeting peptide scaffold (M9) to improve plasmid DNA transfection efficiency. Surg. Forum. 102, 538 (2001).

H. Ma, J. Zhu, M. Maronski, V.M.Y. Lee, M. Dichter, S.L. Diamond. Nonclassical nuclear localization signal peptides for high efficiency lipofection of primary neurons and neuronal cell lines. Neuroscience 111, 1 (2002).

E. A. Pierce, Q. Liu, O. Igoucheva, H.Ma, R. Omarrudin, S. L. Diamond, K. Yoon. Oligonucleotide-directed single base DNA alterations in mouse embryonic stem cells. Gene Therapy. 10:24 (2003).

J. Gruneich, A. R. Price, H. Jing, S. L. Diamond. Cationic corticosteroid for nonviral gene delivery. Gene Therapy 11:668 (2004).

A. Price, M. Limberis, J. Gruneich, J. M. Wilson, S. L. Diamond. Targeting viral-mediated transduction to the lung airway epithelium with the anti-inflammatory cationic lipid dexamethasone-spermine. Molecular Therapy. 12:502 (2005).

Kim MS, Diamond SL: Controlled release of DNA/polyamine complex by photoirradiation of a solid phase presenting o-nitrobenzyl ether tethered spermine or polyethyleneimine. Bioorg Med Chem Lett. 2006 Nov 1;16(21):5572-5.

Murphy BR, Moayedpardazi HS, Gewirtz AM, Diamond SL, Pierce EA: Delivery and mechanistic considerations for the production of knock-in mice by single-stranded oligonucleotide gene targeting. Gene Ther. 2007 Feb;14(4):304-15.

Gruneich JA, Diamond SL. Synthesis and structure-activity relationships of a series of increasingly hydrophobic cationic steroid lipofection reagents. J Gene Med. 2007 May;9(5):381-91.

Handwerger RG, Diamond SL. Biotinylated photocleavable polyethylenimine: capture and triggered release of nucleic acids from solid supports. Bioconjug Chem. 2007 May-Jun;18(3):717-23. Epub 2007 Apr 14.

Price AR, Limberis MP, Wilson JM, Diamond SL. Pulmonary delivery of adenovirus vector formulated with dexamethasone-spermine facilitates homologous vector re-administration. Gene Ther. 2007 Nov;14(22):1594-604. Epub 2007 Sep 27.

Barker GA, Diamond SL. RNA interference screen to identify pathways that enhance or reduce nonviral gene transfer during lipofection. Mol Ther. 2008 Sep;16(9):1602-8.

Fein DE, Limberis MP, Maloney SF, Heath JM, Wilson JM, Diamond SL. Cationic lipid formulations alter the in vivo tropism of AAV2/9 vector in lung. Mol Ther. 2009 Dec;17(12):2078-87. Epub 2009 Jul 28.