R. Schirmbeck et al., Priming of immune responses to hepatitis B surface antigen with minimal DNA expression constructs modified with a nuclear localization signal peptide, J MOL MED-J, 79(5-6), 2001, pp. 343-350
Citations number
19
Categorie Soggetti
Research/Laboratory Medicine & Medical Tecnology","Medical Research General Topics
Nuclear localization signal (NLS) peptides conjugated to DNA increase trans
fection efficiency in vitro. We tested in mice whether conjugation of NLS p
eptides to DNA vaccines enhances their immunogenicity after intramuscular i
njection or gene gun mediated intradermal delivery. We constructed the plas
mid pMOK-HBsAY that contains a transcription unit encoding hepatitis B surf
ace antigen (HBsAg) and bacterial sequences for amplification of plasmid DN
A. From this plasmid we derived the minimal expression construct pMOK-HBsAY
-MIDGE, a covalently closed linear DNA that contains only the HBsAg transcr
iption unit. Both constructs stimulated similar (predominantly IgG1) antibo
dy response to HBsAg after gene gun immunization. In contrast, pMOK-HBsAY p
lasmid DNA was more efficient than pMOK-HBsAY-MIDGE DNA in priming predomin
antly IgG2a antibody responses to HBsAg after intramuscular injection. Both
constructs efficiently primed cytotoxic T lymphocyte responses after intra
muscular immunization. When a NLS peptide was coupled to the pMOK-HBsAY-MID
GE DNA, HBsAg transfection efficiency in vitro and priming of antibody resp
onses to HBsAg after intramuscular (but not gene gun mediated) injection wa
s enhanced 10- to 15-fold. These data show: (a) MIDGE constructs can be use
d as DNA vaccines indicating that bacterial sequences are not essential cof
actors; and (b) in intramuscular (but not gene gun mediated) delivery the i
mmunogenicity of a MIDGE-based vaccine is enhanced by coupling NLS peptides
to the vector DNA.