title: Virus-specific cytotoxic T-lymphocyte activity elicited by coimmunization with human immunodeficiency virus type 1 genes regulated by the bacteriophage T7 promoter and T7 RNA polymerase protein.
abstract: Cytotoxic T lymphocyte (CTL) activity was assessed in mice immunized with DNA plasmids containing the human immunodeficiency virus type 1 (HIV-1) gp120 envelope (pTMIgp120) or p55gag (pTMIgag) gene regulated by the bacteriophage T7 promoter. Immunization with either plasmid resulted in CTL activity against class I major histocompatibility complex-restricted viral epitopes when coadministered with a recombinant vaccinia virus expressing the T7 RNA polymerase protein (T7 RNAP) but not a control vaccinia virus. Recombinant vaccinia-T7 RNAP virus (VTF7-3) could be replaced with a noninfectious source of T7 RNAP. A three-component vaccine consisting of pTMIgag, a recombinant subunit T7 RNAP protein, and a plasmid (pT7T7) encoding T7 RNAP under the control of its own promoter induced gag-specific CTL activity. Intramuscular immunization with the pTMIgag plasmid delivered with either the T7 RNAP protein or pT7T7 plasmid alone also induced HIV-1-specific CTL. Thus, there is adventitious expression of the pT7T7 plasmid in vivo, and enough T7 RNAP is produced to result in production of p24gag protein from the pTMIgag plasmid. The results demonstrate that regulated expression of genes in vivo is possible with this T7-based expression system, and may be useful in vaccine settings where short-term cytoplasmic expression of protein in antigen presenting cells is desired.
authors.affiliation: Chiron Corporation, Emeryville, California 94608, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Selby
authors.forename: B
authors.initials: B
authors.lastname: Doe
authors.forename: C M
authors.initials: CM
authors.lastname: Walker
mesh_terms: D016915:AIDS Vaccines; D000818:Animals; D017123:Bacteriophage T7 / Q000235:genetics*; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D015967:Gene Expression Regulation, Viral; D015683:Gene Products, gag / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D051379:Mice; D008807:Mice, Inbred BALB C; D010446:Peptide Fragments / Q000276:immunology; D011401:Promoter Regions, Genetic; D011498:Protein Precursors / Q000276:immunology*; D011994:Recombinant Proteins / Q000276:immunology; D013154:Spleen / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000821:virology; D014614:Vaccines, Synthetic; D014616:Vaccinia virus / Q000276:immunology; D014764:Viral Proteins
chemical_list: D016915:AIDS Vaccines; D015683:Gene Products, gag; D015699:HIV Envelope Protein gp120; D010446:Peptide Fragments; D011498:Protein Precursors; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic; D014764:Viral Proteins; C059767:p55 gag precursor protein, Human immunodeficiency virus 1; C062210:bacteriophage T7 RNA polymerase; D012321:DNA-Directed RNA Polymerases