Persistent immune responses induced by a human immunodeficiency virus DNA vaccine delivered in association with electroporation in the skin of nonhuman primates.
Strategies to improve vaccine efficacy are still required, especially in the case of chronic infections, including human immunodeficiency virus (HIV). DNA vaccines have potential advantages over conventional vaccines; however, low immunological efficacy has been demonstrated in many experiments involving large animals and in clinical trials. To improve the immunogenicity of DNA vaccines, we have designed a plasmid vector exploiting the binding capacity of the bovine papillomavirus E2 protein and we have used electroporation (EP) to increase DNA uptake after intradermal inoculation. We demonstrated, in nonhuman primates (NHPs), efficient induction of anti-HIV immunity with an improved DNA vaccine vector encoding an artificial fusion protein, consisting of several proteins and selected epitopes from HIV-1. We show that a DNA vaccine delivery method combining intradermal injection and noninvasive EP dramatically increased expression of the vaccine antigen selectively in the epidermis, and our observations strongly suggest the involvement of Langerhans cells in the strength and quality of the anti-HIV immune response. Although the humoral responses to the vaccine were transient, the cellular responses were exceptionally robust and persisted, at high levels, more than 2 years after the last vaccine boost. The immune responses were characterized by the induction of significant proportions of T cells producing both interferon-gamma and interleukin-2 cytokines, in both subpopulations, CD4(+) and CD8(+). This strategy is an attractive approach for vaccination in humans because of its high efficacy and the possible use of newly developed devices for EP.
Martinon
Frédéric
F
Division of Immunovirology, Life Sciences Program (DSV), Institute for Emerging Diseases and Innovative Therapies, Atomic Energy Commission (CEA), Fontenay aux Roses, France. frederic.martinon@cea.fr
Kaldma
Katrin
K
Sikut
Rein
R
Culina
Slobodan
S
Romain
Gabrielle
G
Tuomela
Mari
M
Adojaan
Maarja
M
Männik
Andres
A
Toots
Urve
U
Kivisild
Toomas
T
Morin
Julie
J
Brochard
Patricia
P
Delache
Benoît
B
Tripiciano
Antonella
A
Ensoli
Fabrizio
F
Stanescu
Ioana
I
Le Grand
Roger
R
Ustav
Mart
M
D016915:AIDS Vaccines / Q000009:adverse effects*; D000818:Animals; D016207:Cytokines / Q000276:immunology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018274:Electroporation; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000235:genetics; D005822:Genetic Vectors / Q000235:genetics / Q000276:immunology*; D015658:HIV Infections / Q000517:prevention & control*; D015497:HIV-1 / Q000276:immunology*; D007150:Immunohistochemistry; D007801:Langerhans Cells / Q000276:immunology; D008252:Macaca fascicularis; D012867:Skin / Q000276:immunology*; D018709:Statistics, Nonparametric; D013601:T-Lymphocytes / Q000276:immunology; D016896:Treatment Outcome; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism
D016915:AIDS Vaccines; D016207:Cytokines; D004268:DNA-Binding Proteins; C051550:E2 protein, Bovine papillomavirus; D018984:Epitopes, T-Lymphocyte; D014764:Viral Proteins