title: Enhancement of Sindbis virus self-replicating RNA vaccine potency by linkage of Mycobacterium tuberculosis heat shock protein 70 gene to an antigen gene.
abstract: Recently, self-replicating RNA vaccines (RNA replicons) have emerged as an effective strategy for nucleic acid vaccine development. Unlike naked DNA vaccines, RNA replicons eventually cause lysis of transfected cells and therefore do not raise the concern of integration into the host genome. We evaluated the effect of linking human papillomavirus type 16 E7 as a model Ag to Mycobacterium tuberculosis heat shock protein 70 (HSP70) on the potency of Ag-specific immunity generated by a Sindbis virus self-replicating RNA vector, SINrep5. Our results indicated that this RNA replicon vaccine containing an E7/HSP70 fusion gene generated significantly higher E7-specific T cell-mediated immune responses in vaccinated mice than did vaccines containing the wild-type E7 gene. Furthermore, our in vitro studies demonstrated that E7 Ag from E7/HSP70 RNA replicon-transfected cells can be processed by bone marrow-derived dendritic cells and presented more efficiently through the MHC class I pathway than can wild-type E7 RNA replicon-transfected cells. More importantly, the fusion of HSP70 to E7 converted a less effective vaccine into one with significant potency against E7-expressing tumors. This antitumor effect was dependent on NK cells and CD8(+) T cells. These results indicated that fusion of HSP70 to an Ag gene may greatly enhance the potency of self-replicating RNA vaccines.
authors.affiliation: Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD 21205, USA.
authors.forename: W F
authors.initials: WF
authors.lastname: Cheng
authors.forename: C F
authors.initials: CF
authors.lastname: Hung
authors.forename: C Y
authors.initials: CY
authors.lastname: Chai
authors.forename: K F
authors.initials: KF
authors.lastname: Hsu
authors.forename: L
authors.initials: L
authors.lastname: He
authors.forename: C M
authors.initials: CM
authors.lastname: Rice
authors.forename: M
authors.initials: M
authors.lastname: Ling
authors.forename: T C
authors.initials: TC
authors.lastname: Wu
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D017951:Antigen Presentation / Q000235:genetics; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000276:immunology; D017209:Apoptosis / Q000235:genetics / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000821:virology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000821:virology; D002460:Cell Line; D006224:Cricetinae; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D018984:Epitopes, T-Lymphocyte / Q000276:immunology; D005260:Female; D005822:Genetic Vectors / Q000138:chemical synthesis / Q000235:genetics; D006131:Growth Inhibitors / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D018840:HSP70 Heat-Shock Proteins / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009169:Mycobacterium tuberculosis / Q000235:genetics* / Q000276:immunology; D009856:Oncogene Proteins, Viral / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology; D050725:Papillomavirus E7 Proteins; D012367:RNA, Viral / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D012845:Sindbis Virus / Q000235:genetics* / Q000276:immunology; D014162:Transfection; D014407:Tumor Cells, Cultured; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*; D014779:Virus Replication / Q000235:genetics* / Q000276:immunology
chemical_list: D000276:Adjuvants, Immunologic; D000914:Antibodies, Viral; D000970:Antineoplastic Agents; D018984:Epitopes, T-Lymphocyte; D006131:Growth Inhibitors; D018840:HSP70 Heat-Shock Proteins; D015395:Histocompatibility Antigens Class I; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012367:RNA, Viral; D014614:Vaccines, Synthetic; D014765:Viral Vaccines; C059731:oncogene protein E7, Human papillomavirus type 16; D007371:Interferon-gamma