Electroporation at low voltages enables DNA vaccine to provide protection against a lethal H5N1 avian influenza virus challenge in mice.
OBJECTIVE
Electroporation has been proved to enhance the efficacy of intramuscular delivery of DNA. However, the process of electroporation causes pain and discomfort to the patient receiving the treatment. Higher the electroporation voltages inflict greater pain, and this limits the circumstances in which the technique can be used clinically. The voltages generally used for electroporation in animals range from 100 to 1,200 V/cm. We studied the effect of DNA vaccination when electroporation was performed at lower voltages.


METHODS
BALB/c mice were immunized twice by electroporation, at a 3-week interval, with H5N1 virus hemagglutinin (HA) DNA. One week after the booster had been given, the mice were challenged with a lethal dose of mouse-adapted H5N1 virus. The immune effects of HA DNA were evaluated by the survival rate, lung virus titer, bodyweight change and antibody titer of the mice.


RESULTS
The higher the voltage used, the more able were the mice to survive the challenge. However, a significant degree of protection could also be achieved with a voltage as low as 5 V. When electroporation was performed at a voltage of 10 V, an immunization amount of 5 microg is enough for HA DNA to provide effective protection.


CONCLUSIONS
Low-voltage electroporation can induce immunity and protect mice effectively. There is, therefore, the potential to reduce the voltages currently used for DNA electroporation.
Zhou
Yu
Y
College of Life Sciences, Hunan Normal University, Changsha, China.
Fang
Fang
F
Chen
Jianjun
J
Wang
Huadong
H
Chang
Haiyan
H
Yang
Zhongdong
Z
Chen
Ze
Z
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D001835:Body Weight; D018274:Electroporation / Q000379:methods*; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics / Q000276:immunology; D007117:Immunization, Secondary; D053124:Influenza A Virus, H5N1 Subtype / Q000235:genetics* / Q000276:immunology*; D007252:Influenza Vaccines / Q000276:immunology*; D008168:Lung / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D009976:Orthomyxoviridae Infections / Q000517:prevention & control*; D016019:Survival Analysis; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000276:immunology*
D000914:Antibodies, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D007252:Influenza Vaccines; D019444:Vaccines, DNA