title: Induction of tumor-specific immune response by gene transfer of Hsp70-cell-penetrating peptide fusion protein to tumors in mice.
abstract: To induce a tumor-specific immune response by delivering tumor-associated antigens in tumor cells to antigen-presenting cells (APCs), we designed a fusion protein which consists of heat-shock protein 70 (Hsp70) and the C-terminal 34 amino acids of herpes simplex virus VP22 protein (VP22(268-301)), the former having a peptide binding domain and an ability to be recognized by APCs, and the latter able to achieve cell penetration. Hsp70-VP22(268-301), the fusion protein, was efficiently taken up by mouse dendritic cell (DC) line DC2.4. Major histocompatibility complex (MHC) class I-restricted presentation of an epitope peptide of ovalbumin (OVA) was examined in DC2.4, and Hsp70-VP22(268-301) significantly increased the presentation of the peptide compared with Hsp70. Electroporation-assisted injection of naked plasmid vector expressing Hsp70-VP22(268-301) (pHsp70-VP22(268-301)) into subcutaneous tumors of EG7-OVA, a mouse lymphoma-expressing OVA, significantly increased the survival of mice compared with the same treatment with pHSp70, a plasmid expressing Hsp70. Splenocytes from the pHsp70-VP22(268-301)-treated mice exhibited cytolytic activity against both EG7-OVA and the parent EL4, but not against mouse melanoma B16-F10, suggesting that not only OVA-derived antigens but those common to EG7-OVA and EL4 are delivered to APCs. These results provide a new therapeutic method to induce tumor-specific antitumor immunity without identifying nor isolating tumor-associated antigens.
authors.affiliation: Department of Biopharmaceutics and Drug Metabolism, Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Japan. makiya@pharm.kyoto-u.ac.jp
authors.forename: Makiya
authors.initials: M
authors.lastname: Nishikawa
authors.forename: Takayuki
authors.initials: T
authors.lastname: Otsuki
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ota
authors.forename: Xin
authors.initials: X
authors.lastname: Guan
authors.forename: Seiji
authors.initials: S
authors.lastname: Takemoto
authors.forename: Yuki
authors.initials: Y
authors.lastname: Takahashi
authors.forename: Yoshinobu
authors.initials: Y
authors.lastname: Takakura
mesh_terms: D000818:Animals; D015153:Blotting, Western; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000378:metabolism; D005260:Female; D005455:Fluorescent Antibody Technique; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D008223:Lymphoma / Q000276:immunology* / Q000628:therapy*; D008285:Major Histocompatibility Complex / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism*; D018139:Simplexvirus / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D018840:HSP70 Heat-Shock Proteins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins