title: Vaccination with a piggyBac plasmid with transgene integration potential leads to sustained antigen expression and CD8(+) T cell responses.
abstract: DNA vaccination with plasmid has conventionally involved vectors designed for transient expression of antigens in injected tissues. Next generation plasmids are being developed for site-directed integration of transgenes into safe sites in host genomes and may provide an innovative approach for stable and sustained expression of antigens for vaccination. The goal of this study was to evaluate in vivo antigen expression and the generation of cell mediated immunity in mice injected with a non-integrating plasmid compared to a plasmid with integrating potential. Hyperactive piggyBac transposase-based integrating vectors (pmhyGENIE-3) contained a transgene encoding either eGFP (pmhyGENIE-3-eGFP) or luciferase (pmhyGENIE-3-GL3), and were compared to transposase-deficient plasmids with the same transgene and DNA backbone. Both non-integrating and integrating plasmids were equivalent at day 1 for protein expression at the site of injection. While protein expression from the non-integrating plasmid was lost by day 14, the pmhyGENIE-3 was found to exhibit sustained protein expression up to 28 days post-injection. Vaccination with pmhyGENIE-3-eGFP resulted in a robust CD8(+) T cell response that was three-fold higher than that of non-integrating plasmid vaccinations. Additionally we observed in splenocyte restimulation experiments that only the vaccination with pmhyGENIE-3-eGFP was characterized by IFNγ producing CD8(+) T cells. Overall, these findings suggest that plasmids designed to direct integration of transgenes into the host genome are a promising approach for designing DNA vaccines. Robust cell mediated CD8(+) T cell responses generated using integrating plasmids may provide effective, sustained protection against intracellular pathogens or tumor antigens.
authors: Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA. Electronic address: pbertino@hawaii.edu.
authors: Pietro
authors: P
authors: Bertino
authors: Department of Anatomy, Biochemistry and Physiology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA.
authors: Johann
authors: J
authors: Urschitz
authors: Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA.
authors: Fukun W
authors: FW
authors: Hoffmann
authors: Department of Physiology, Medical School, Chonbuk National University, Jeonju, South Korea.
authors: Bo Ra
authors: BR
authors: You
authors: Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA.
authors: Aaron H
authors: AH
authors: Rose
authors: Department of Physiology, Medical School, Chonbuk National University, Jeonju, South Korea.
authors: Woo Hyun
authors: WH
authors: Park
authors: Department of Anatomy, Biochemistry and Physiology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA; Manoa BioSciences, Honolulu, HI 96822, USA.
authors: Stefan
authors: S
authors: Moisyadi
authors: Department of Cell and Molecular Biology, John A. Burns School of Medicine, University of Hawaii, Honolulu, HI, USA.
authors: Peter R
authors: PR
authors: Hoffmann
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D005260:Female; D017930:Genes, Reporter; D005822:Genetic Vectors; D057809:HEK293 Cells; D006801:Humans; D007111:Immunity, Cellular; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids; D014162:Transfection; D019076:Transgenes; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
chemical_list: D019444:Vaccines, DNA
keywords: Cancer; Cell mediated immunity; DNA vaccine; Transposase; Tumor; piggyBac