title: Development of a novel Hsp70-based DNA vaccine as a multifunctional antigen delivery system.
abstract: DNA vaccination is a simple and effective method to induce immune responses against a variety of tumors as well as infectious diseases. Vaccination with major histocompatibility complex (MHC) class I tumor peptide has been carried out to induce an antigen-specific and tumor-reactive cytotoxic T lymphocytes (CTLs) response in vivo. In this study, we describe a novel DNA vaccine based on heat shock protein 70 (Hsp70), which can chaperon antigenic peptides and initiate innate and adaptive immune responses, to induce a more effective immune response. Ovalbumin (OVA) MHC class I epitope peptide (OVA(257-264): SIINFEKL) was selected as a model antigen and polyhistidine was used to facilitate the cytosolic delivery of the antigen-Hsp70 after endocytic uptake. A novel plasmid DNA vector encoding polyhistidine, Hsp70 and OVA(257-264) (pHis-Hsp70-pep) was designed. When mice were immunized with pHis-Hsp70-pep by intradermal injection in combination with electroporation, strong antigen-specific CTL responses were generated. pHis-Hsp70-pep also showed a significant protective effect against tumor challenge with an OVA-expression EL4 tumor line. These results indicate that the Hsp70-based DNA vaccine is useful as a multifunctional antigen delivery system to induce the antigen-specific immune response.
authors.affiliation: Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Yamaoka
authors.forename: Xin
authors.initials: X
authors.lastname: Guan
authors.forename: Seiji
authors.initials: S
authors.lastname: Takemoto
authors.forename: Makiya
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takakura
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000187:drug effects / Q000276:immunology; D019556:COS Cells; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D003600:Cytosol / Q000187:drug effects / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology; D016503:Drug Delivery Systems / Q000379:methods*; D018274:Electroporation; D005260:Female; D018840:HSP70 Heat-Shock Proteins / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology; D006639:Histidine / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D007271:Injections, Intradermal; D051379:Mice; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D009374:Neoplasms, Experimental / Q000276:immunology / Q000517:prevention & control; D010047:Ovalbumin / Q000276:immunology; D010446:Peptide Fragments / Q000276:immunology; D010957:Plasmids; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000187:drug effects / Q000276:immunology*; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000235:genetics / Q000276:immunology
chemical_list: D018840:HSP70 Heat-Shock Proteins; D015395:Histocompatibility Antigens Class I; C110366:OVA-8; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D019444:Vaccines, DNA; C033223:polyhistidine; D006639:Histidine; D010047:Ovalbumin