Assessment of delivery parameters with the multi-electrode array for development of a DNA vaccine against Bacillus anthracis
Old Dominion University, Center for Bioelectrics, 4211 Monarch Way, Suite 300, Norfolk, VA 23508, USA. Electronic address: . Bioelectrochemistry (Amsterdam, Netherlands)
(Impact Factor: 4.17).
04/2013; 94C:1-6. DOI: 10.1016/j.bioelechem.2013.04.004
Gene electrotransfer (GET) enhances delivery of DNA vaccines by increasing both gene expression and immune responses. Our lab has developed the multi-electrode array (MEA) for DNA delivery to skin. The MEA was used at constant pulse duration (150ms) and frequency (6.67Hz). In this study, delivery parameters including applied voltage (5-45V), amount of plasmid (100-300μg), and number of treatments (2-3) were evaluated for delivery of a DNA vaccine. Mice were intradermally injected with plasmid expressing Bacillus anthracis protective antigen with or without GET and αPA serum titers measured. Within this experiment no significant differences were noted in antibody levels from varying dose or treatment number. However, significant differences were measured from applied voltages of 25 and 35V. These voltages generated antibody levels between 20,000 and 25,000. Serum from animals vaccinated with these conditions also resulted in toxin neutralization in 40-60% of animals. Visual damage was noted at MEA conditions of 40V. No damage was noted either visually or histologically from conditions of 35V or below. These results reflect the importance of establishing appropriate electrical parameters and the potential for the MEA in non-invasive DNA vaccination against B. anthracis.
Available from: Augusto Amici
- "The vaccination course consisted of two intradermal injections into the skin of the back near the base of the tail. Immediately after the plasmid or FITC-dextran administration, a conducting gel and an electrode were placed over the injection site and voltage was set up according to previously described protocols (2 pulses, 1125 V/cm 50 í µí¼s, and 8 pulses, 275 V/cm 10 msec) . Electrodes conslehisted of two parallel lamellae at 6–8 mm distance. "
[Show abstract] [Hide abstract]
ABSTRACT: Skin represents an attractive target for DNA vaccine delivery because of its natural richness in APCs, whose targeting may
potentiate the effect of vaccination. Nevertheless, intramuscular electroporation is the most common delivery method for ECTM
vaccination. In this study we assessed whether intradermal administration could deliver the vaccine into different cell types and
we analyzed the evolution of tissue infiltrate elicited by the vaccination protocol. Intradermal electroporation (EP) vaccination
resulted in transfection of different skin layers, as well as mononuclear cells. Additionally, we observed a marked recruitment of
reactive infiltrates mainly 6–24 hours after treatment and inflammatory cells included CD11c+. Moreover, we tested the efficacy
of intradermal vaccination against Her2/neu antigen in cellular and humoral response induction and consequent protection from
a Her2/neu tumor challenge in Her2/neu nontolerant and tolerant mice. A significant delay in transplantable tumor onset was
observed in both BALB/c (𝑝 ≤ 0,0003) and BALB-neuT mice (𝑝 = 0,003). Moreover, BALB-neuT mice displayed slow tumor
growth as compared to control group (𝑝 < 0,0016). In addition, while in vivo cytotoxic response was observed only in BALB/c
mice, a significant antibody response was achieved in both mouse models. Our results identify intradermal EP vaccination as a
promising method for delivering Her2/neu DNA vaccine.
Journal of Immunology Research 06/2015; 2015(10):10. DOI:10.1155/2015/159145 · 2.93 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: The presence of increased temperature for gene electrotransfer has largely been considered negative. Many reports have published on the lack of heat from electrotransfer conditions to demonstrate that their effects are from the electrical pulses and not from a rise in temperature. Our hypothesis was to use low levels of maintained heat to aid in gene electrotransfer. The goal was to increase gene expression and/or reduce electric field. In our study we evaluated high and low electric field conditions from 90 V to 45 V which had been preheated to 40 °C, 43 °C, or 45 °C. Control groups of non-heated as well as DNA only were included for comparison in all experiments. Luciferase gene expression, viability, and percent cell distribution were measured. Our results indicated a 2–4 fold increase in gene expression that is temperature and field dependent. In addition levels of gene expression can be increased without significant decreases in cell death and in the case of high electric fields no additional cell death. Finally, in all conditions percent cell distribution was increased from the application of heat. From these results, we conclude that various methods may be employed depending on the end users desired goals. Electric field can be reduced 20-30% while maintaining or slightly increasing gene expression and increasing viability or overall gene expression and percent cell distribution can be increased with low viability.
Bioelectrochemistry 08/2014; 103. DOI:10.1016/j.bioelechem.2014.08.007 · 4.17 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: DNA vaccines are a rapidly deployed next generation vaccination platform for treatment of human and animal disease. DNA delivery devices, such as electroporation and needle free jet injectors, are used to increase gene transfer. This results in higher antigen expression which correlates with improved humoral and cellular immunity in humans and animals. This review highlights recent vector and transgene design innovations that improve DNA vaccine performance. These new vectors improve antigen expression, increase plasmid manufacturing yield and quality in bioreactors, and eliminate antibiotic selection and other potential safety issues. A flowchart for designing synthetic antigen transgenes, combining antigen targeting, codon-optimization and bioinformatics, is presented. Application of improved vectors, of antibiotic free plasmid production, and cost effective manufacturing technologies will be critical to ensure safety, efficacy, and economically viable manufacturing of DNA vaccines currently under development for infectious disease, cancer, autoimmunity, immunotolerance and allergy indications.
Current Gene Therapy 08/2014; 14(3):170-89. DOI:10.2174/156652321403140819122538 · 2.54 Impact Factor
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.