title: Immunostimulatory CpG-DNA and PSA-peptide vaccination elicits profound cytotoxic T cell responses.
abstract: OBJECTIVE
  Novel strategies for the treatment of advanced prostate cancer (CaP), including immunotherapy or gene therapy, are currently under evaluation with Sipuleucel-T as first FDA-approved immunotherapeutic. Here, we examine cytosine-phosphorothioate-guanine (CpG)-DNA oligonucleotides (ODN) to boost cytokine responses and costimulatory molecule expression on murine bone marrow-derived dendritic cells (mBMDC). Furthermore, we evaluate the potency of a PSA-peptide based vaccine in combination with CpG-DNA to elicit specific cytotoxic T cell (CTL) responses.
  
  
  METHODS
  mBMDC were stimulated with CpG-DNA (1668: 5'-TCCATGACGTTCCTGATGCT-3') or non-stimulatory control-ODN (1720: 5'-TCCATGAGCTTCCTGATGCT-3'). Subsequently, expression of the costimulatory molecules CD40 and CD86 and induction of proinflammatory cytokines (interleukin (IL)-6 and IL-12) were analyzed. For induction of PSA-peptide specific CTL, female C57BL/6 mice were immunized with PSA-peptide 65-73 (HCIRNKSVI) alone or in combination with 1668 or 1720-ODN. In vivo cytotoxicity assay determined PSA-peptide specific cytotoxicity 1 week after vaccination.
  
  
  RESULTS
  Treatment of mBMDC with stimulatory CpG-DNA ODN resulted in pronounced up-regulation of costimulatory molecule expression on mBMDC in a dose-dependent manner. CpG-ODN significantly increased production of IL-6 and IL-12 in mBMDC (P < 0.001). Induction of PSA-peptide specific CTL responses in mice immunized with PSA-peptide and CpG-DNA were significantly greater than those of PSA-peptide and control-ODN immunized mice or PSA-peptide only vaccination.
  
  
  CONCLUSIONS
  CpG-DNA acts as potent adjuvant for vaccination therapies and elicits profound PSA-peptide specific CTL responses in combination with an immunodominant PSA-peptide. CpG-ODN mediated immunotherapy represents a potentially inexpensive, safe, easy-to-produce, and easy-to-handle treatment alternative. Therefore, further evaluation of CpG-DNA in immunization therapies against CaP is warranted.
authors: Department of Urology, Munich, Germany. Electronic address: t.maurer@lrz.tum.de.
authors: Tobias
authors: T
authors: Maurer
authors: Christos
authors: C
authors: Pournaras
authors: Juan A
authors: JA
authors: Aguilar-Pimentel
authors: Mark
authors: M
authors: Thalgott
authors: Thomas
authors: T
authors: Horn
authors: Matthias
authors: M
authors: Heck
authors: Antje
authors: A
authors: Heit
authors: Hubert
authors: H
authors: Kuebler
authors: Jürgen E
authors: JE
authors: Gschwend
authors: Roman
authors: R
authors: Nawroth
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D051940:B7-2 Antigen / Q000276:immunology / Q000378:metabolism; D001854:Bone Marrow Cells / Q000276:immunology / Q000378:metabolism; D019013:CD40 Antigens / Q000276:immunology / Q000378:metabolism; D019496:Cancer Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D018664:Interleukin-12 / Q000276:immunology / Q000378:metabolism; D015850:Interleukin-6 / Q000276:immunology / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009838:Oligodeoxyribonucleotides / Q000276:immunology*; D010446:Peptide Fragments / Q000276:immunology*; D017430:Prostate-Specific Antigen / Q000737:chemistry / Q000276:immunology*; D011471:Prostatic Neoplasms / Q000276:immunology / Q000517:prevention & control; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism; D014611:Vaccination / Q000379:methods
chemical_list: D051940:B7-2 Antigen; D019013:CD40 Antigens; C408982:CPG-oligonucleotide; D019496:Cancer Vaccines; D015850:Interleukin-6; D009838:Oligodeoxyribonucleotides; D010446:Peptide Fragments; D018664:Interleukin-12; D017430:Prostate-Specific Antigen