title: A stress protein-facilitated antigen expression system for plasmid DNA vaccines.
abstract: In DNA vaccination, an exciting new immunization technique with potential applications in clinical medicine, expression plasmid DNA containing antigen-encoding sequences cloned under heterologous promoter control are delivered by techniques that lead in vivo to antigen expression in transfected cells. DNA vaccination efficiently primes both humoral and cellular immune responses. We developed a novel expression system for DNA vaccines in which a fusion protein with a small, N-terminal, viral DnaJ-like sequence (J domain) is translated in frame with C-terminal antigen-encoding sequences. The J domain stable bind to constitutively expressed, cytosolic stress protein hsp73 and triggers intracellular accumulation of antigen/hsp73 complexes. The system supports enhanced expression of chimeric antigens of >800 residues in length in immunogenic form. A unique advantage of the system is that even unstable or toxic proteins (or protein domains) can be expressed. We describe the design of DNA vaccines expressing antigens with a stress protein-capturing domain and characterize the immunogenicity of the antigens produced by this expression system.
authors.affiliation: Institute for Medical Microbiology and Immunology, University of Ulm, Ulm, Germany.
authors.forename: Petra
authors.initials: P
authors.lastname: Riedl
authors.forename: Nicolas
authors.initials: N
authors.lastname: Fissolo
authors.forename: Jörg
authors.initials: J
authors.lastname: Reimann
authors.forename: Reinhold
authors.initials: R
authors.lastname: Schirmbeck
mesh_terms: D000818:Animals; D000957:Antigens, Viral, Tumor / Q000235:genetics* / Q000276:immunology; D045744:Cell Line, Tumor; D002645:Chickens; D015870:Gene Expression; D050883:HSC70 Heat-Shock Proteins / Q000235:genetics* / Q000276:immunology; D006801:Humans; D046912:Multiprotein Complexes / Q000235:genetics / Q000276:immunology; D010957:Plasmids / Q000235:genetics* / Q000276:immunology; D017434:Protein Structure, Tertiary / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D014611:Vaccination; D019444:Vaccines, DNA / Q000235:genetics* / Q000276:immunology
chemical_list: D000957:Antigens, Viral, Tumor; D050883:HSC70 Heat-Shock Proteins; C494371:HSPA8 protein, human; D046912:Multiprotein Complexes; D011993:Recombinant Fusion Proteins; D019444:Vaccines, DNA