title: Priming polyvalent immunity by DNA vaccines expressing chimeric antigens with a stress protein-capturing, viral J-domain.
abstract: The N-terminal domain of large tumor antigens (T-Ag) of polyomaviruses forms a DnaJ-like structure with a conserved J domain that associates with constitutively expressed stress protein heat shock protein (hsp)73. Mutant (but not wild-type) SV40 T-Ag show stable, ATP-dependent binding to the stress protein hsp73 when expressed in cells from different vertebrate tissues. Intracellular T/hsp73 complexes accumulate to high steady-state levels. From this observation, we designed a vector system that supports stable expression of a large variety of hsp73-capturing, chimeric antigens containing an N-terminal, T-Ag-derived domain, and different C-terminal antigenic domains from unrelated antigens. Most antigenic domains tested could be stably expressed only in eukaryotic cells as fusion protein/hsp73 complexes. The N-terminal 77 residues representing the J domain of T-Ag were required for stable hsp73 binding and efficient expression of chimeric antigens. Hsp73-bound chimeric antigens expressed by DNA vaccines showed strikingly enhanced immunogenicity evident in humoral (antibody) and cellular cytolytic T lymphocytes (CTL) responses. The described system supports efficient expression of chimeric, polyvalent antigens and their codelivery with hsp73 as a "natural adjuvant" for enhanced immunogenicity for T and B cells.
authors.affiliation: Institute of Medical Microbiology and Immunology, University of Ulm, Ulm, Germany. reinhold.schirmbeck@medizin.uni-ulm.de
authors.forename: Reinhold
authors.initials: R
authors.lastname: Schirmbeck
authors.forename: Marcin
authors.initials: M
authors.lastname: Kwissa
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fissolo
authors.forename: Shereen
authors.initials: S
authors.lastname: Elkholy
authors.forename: Petra
authors.initials: P
authors.lastname: Riedl
authors.forename: Jörg
authors.initials: J
authors.lastname: Reimann
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology; D001665:Binding Sites; D001709:Biotechnology / Q000379:methods; D002352:Carrier Proteins / Q000378:metabolism*; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D009154:Mutation; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014407:Tumor Cells, Cultured; D019444:Vaccines, DNA / Q000276:immunology; D014765:Viral Vaccines / Q000235:genetics* / Q000276:immunology*
chemical_list: D000952:Antigens, Polyomavirus Transforming; D002352:Carrier Proteins; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; C494372:Hspa8 protein, mouse; D011993:Recombinant Fusion Proteins; D019444:Vaccines, DNA; D014765:Viral Vaccines