title: Deoxyribonucleic acid vaccines encoding antigens with rapid proteasome-dependent degradation are highly efficient inducers of cytolytic T lymphocytes.
abstract: We generated plasmid expression vectors encoding ubiquitin and beta-galactosidase (beta-gal) with different intervening amino acids, allowing for the production of processed protein products that have either stabilizing or destabilizing residues at their N-termini. P815 cells transfected with plasmids encoding beta-gal with a destabilizing N-terminus did not have detectable expression beta-gal unless they were treated with inhibitors specific for the proteasome. Inhibitors of other proteolysis pathways had no such effect. Nevertheless, transfectants expressing beta-gal with different amino acid residues were equally sensitive to cytolysis by a CTL clone specific for a beta-gal peptide presented in the context of H-2Ld. In contrast to vectors encoding native beta-gal, plasmid vectors encoding beta-gal with a destabilizing residue did not induce detectable anti-beta-gal Abs when injected into skeletal muscle of BALB/c mice. However, such vectors were significantly more effective than vectors encoding native beta-gal or beta-gal with a stabilizing residue in stimulating CTL specific for P13.2, a lacZ transfectant of P815. We conclude that incorporation of strategies that enhance proteasome-dependent degradation may generate DNA vaccines that are more effective in inducing cellular immunity against targeted Ags.
authors.affiliation: University of California-San Diego Human Gene Therapy Program, Department of Medicine, La Jolla 92093-0663, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Wu
authors.forename: T J
authors.initials: TJ
authors.lastname: Kipps
mesh_terms: D000818:Animals; D017951:Antigen Presentation; D000941:Antigens / Q000235:genetics* / Q000276:immunology / Q000378:metabolism; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D003602:Cytotoxicity, Immunologic / Q000235:genetics*; D005822:Genetic Vectors / Q000096:biosynthesis / Q000378:metabolism; D007111:Immunity, Cellular; D007763:Lac Operon; D008213:Lymphocyte Activation / Q000235:genetics; D012515:Mast-Cell Sarcoma; D051379:Mice; D008807:Mice, Inbred BALB C; D009097:Multienzyme Complexes / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D014162:Transfection; D014407:Tumor Cells, Cultured; D014452:Ubiquitins / Q000235:genetics / Q000378:metabolism; D019444:Vaccines, DNA / Q000276:immunology*; D001616:beta-Galactosidase / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism
chemical_list: D000941:Antigens; D015853:Cysteine Proteinase Inhibitors; D009097:Multienzyme Complexes; D011993:Recombinant Fusion Proteins; D014452:Ubiquitins; D019444:Vaccines, DNA; D001616:beta-Galactosidase; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex