title: Enhancement of dendritic cell-based vaccine potency by anti-apoptotic siRNAs targeting key pro-apoptotic proteins in cytotoxic CD8(+) T cell-mediated cell death.
abstract: Dendritic cells (DCs) have become an important measure for the treatment of malignancies. Current DC preparations, however, generate short-lived DCs because they are subject to cell death from various apoptotic pressures. Antigen-specific CD8(+) cytotoxic T lymphocytes (CTLs) is one of the main obstacles to limit the DC-mediated immune priming since CTLs can recognize the target antigen expressing DCs as target cells and kill the DCs. CTLs secret perforin and serine protease granzymes during CTL killing. Perforin and serine protease granzymes induce the release of a number of mitochondrial pro-apoptotic factors, which are controlled by members of the BCL-2 family, such as BAK, BAX and BIM. FasL linking to Fas on DCs triggers the activation of caspase-8, which eventually leads to mitochondria-mediated apoptosis via truncation of BID. In this study, we tried to enhance the DC priming capacity by prolonging DC survival using anti-apoptotic siRNA targeting these key pro-apoptotic molecules in CTL killing. Human papillomavirus (HPV)-16 E7 antigen presenting DCs that were transfected with these anti-apoptotic siRNAs showed increased resistance to T cell-mediated death, leading to enhanced E7-specific CD8(+) T cell activation in vitro and in vivo. Among them, siRNA targeting BIM (siBIM) generated strongest E7-specific E7-specific CD8(+) T cell immunity. More importantly, vaccination with E7 presenting DCs transfected with siBIM was capable of generating a marked therapeutic effect in vaccinated mice. Our data indicate that ex vivo manipulation of DCs with siBIM may represent a plausible strategy for enhancing dendritic cell-based vaccine potency.
authors.affiliation: Laboratory Of Infection and Immunology, Graduate School of Medicine, Korea University, Seoul, Republic of Korea.
authors.forename: Jin Hee
authors.initials: JH
authors.lastname: Kim
authors.forename: Tae Heung
authors.initials: TH
authors.lastname: Kang
authors.forename: Kyung Hee
authors.initials: KH
authors.lastname: Noh
authors.forename: Hyun Cheol
authors.initials: HC
authors.lastname: Bae
authors.forename: Seok-Ho
authors.initials: SH
authors.lastname: Kim
authors.forename: Young Do
authors.initials: YD
authors.lastname: Yoo
authors.forename: Seung-Yong
authors.initials: SY
authors.lastname: Seong
authors.forename: Tae Woo
authors.initials: TW
authors.lastname: Kim
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000235:genetics / Q000276:immunology; D017209:Apoptosis / Q000235:genetics / Q000276:immunology; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D002461:Cell Line, Transformed; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D005260:Female; D052162:Human papillomavirus 16 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D008213:Lymphocyte Activation / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D009856:Oncogene Proteins, Viral / Q000235:genetics / Q000276:immunology; D050725:Papillomavirus E7 Proteins; D034622:RNA Interference / Q000276:immunology; D034741:RNA, Small Interfering; D014161:Transduction, Genetic; D014612:Vaccines / Q000008:administration & dosage / Q000276:immunology*
chemical_list: D051017:Apoptosis Regulatory Proteins; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D034741:RNA, Small Interfering; D014612:Vaccines; C059731:oncogene protein E7, Human papillomavirus type 16