Nonviral Transfection of Intact Pancreatic Islets
Abstract:Ex vivo gene transfer offers a potential means to introduce genes into cells, which may play an important role in preventing graft rejection and inducing graft tolerance. This study examined the efficiency and toxicity of several lipid-based transfection reagents (LipofectAMINE, DOTAP, and DOSPER) in intact pancreatic islets. Isolated islets were transfected with a pCMV-β-galactosidase plasmid using several DNA/liposome ratios (1:12) of liposomes (3–72 μl) and DNA (3 and 6 μg). Transfection efficiency was quantified by microscopic evaluation of β-galactosidase gene expression in whole intact islets. Functionality of the transfected islets was measured by insulin response to glucose solutions. All transfection reagents evaluated in this study transfected cells within the islets. As expected, untransfected controls and transfected islets with DNA alone did not express β-gal. The highest transfection efficiency and functional viability were obtained following a 48-h incubation after exposure to the transfection mixtures as follows: 3 μl DNA and 18 μl DOTAP/ml (1:6 ratio), 6 μg DNA and 12 μl DOSPER/ml (1:2 ratio), or 6 μg DNA and 12 μl LipofectAMINE/ml (1:2 ratio). The highest rate of transfected cells per islet was obtained using DOTAP. In vitro functionality was not significantly different between DOTAP and nontreated controls. However, optimal transfection efficiency doses of LipofectAMINE and DOSPER significantly reduced the stimulated insulin response of the transfected islets (p < 0.05, ANOVA). The calculated stimulation index (SI) was 7.8 ± 0.6 (mean ± SEM) for DOTAP-transfected islets compared with 8.4 ± 0.5 for nontransfected control islets (p = ns). The SI of DOSPER- and LipofectAMINE-transfected islets was significantly lower (6.1 ± 0.5 and 3.4 ± 0.5, respectively, p < 0.05). Lipid-based transfection using DOTAP at a DNA/lipid ratio of 1:6 provides an effective means of ex vivo gene delivery without compromising in vitro functionality of the transfected islets.
Document Type: Research Article
Publication date: January 1, 2001
More about this publication?
- Cell Transplantation publishes original, peer-reviewed research and review articles on the subject of cell transplantation and its application to human diseases. To ensure high-quality contributions from all areas of transplantation, separate section editors and editorial boards have been established. Articles deal with a wide range of topics including physiological, medical, preclinical, tissue engineering, and device-oriented aspects of transplantation of nervous system, endocrine, growth factor-secreting, bone marrow, epithelial, endothelial, and genetically engineered cells, among others. Basic clinical studies and immunological research papers are also featured. To provide complete coverage of this revolutionary field, Cell Transplantation will report on relevant technological advances, and ethical and regulatory considerations of cell transplants. Cell Transplantation is now an Open Access journal starting with volume 18 in 2009, and therefore there will be an inexpensive publication charge, which is dependent on the number of pages, in addition to the charge for color figures. This will allow work to be disseminated to a wider audience and also entitle the corresponding author to a free PDF, as well as prepublication of an unedited version of the manuscript.