title: Dendritic cell-induced activation of adaptive and innate antitumor immunity.
abstract: While studying Ag-pulsed syngeneic dendritic cell (DC) immunization, we discovered that surprisingly, unpulsed DCs induced protection against tumor lung metastases resulting from i.v. injection of a syngeneic BALB/c colon carcinoma CT26 or a syngeneic C57BL/6 lung carcinoma LL/2. Splenocytes or immature splenic DCs did not protect. The protection was mediated by NK cells, in that it was abrogated by treatment with anti-asialo-GM1 but not anti-CD8, and was induced by CD1(-/-) DCs unable to stimulate NKT cells, but did not occur in beige mice lacking NK cells. Protection correlated with increased NK activity, and increased infiltration of NK but not CD8(+) cells in lungs of tumor-bearing mice. Protection depended on the presence of costimulatory molecules CD80, CD86, and CD40 on the DCs, but surprisingly did not require DCs that could make IL-12 or IL-15. Unexpectedly, protection sensitive to anti-asialo-GM1 and increased NK activity were still present 14 mo after DC injection. As NK cells lack memory, we found by depletion that CD4(+) not CD8(+) T cells were required for induction of the NK antitumor response. The role of DCs and CD4(+) T cells provides a novel mechanism for NK cell induction and innate immunity against cancer that may have potential in preventing clinical metastases.
authors.affiliation: Molecular Immunogenetics and Vaccine Research Section, Metabolism Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Leon T
authors.initials: LT
authors.lastname: van den Broeke
authors.forename: Emily
authors.initials: E
authors.lastname: Daschbach
authors.forename: Elaine K
authors.initials: EK
authors.lastname: Thomas
authors.forename: Gerda
authors.initials: G
authors.lastname: Andringa
authors.forename: Jay A
authors.initials: JA
authors.lastname: Berzofsky
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D018122:B7-1 Antigen / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D051940:B7-2 Antigen; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000276:immunology; D002450:Cell Communication / Q000276:immunology; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000235:genetics / Q000276:immunology* / Q000628:therapy*; D003602:Cytotoxicity, Immunologic / Q000235:genetics; D003713:Dendritic Cells / Q000276:immunology* / Q000637:transplantation*; D005260:Female; D007113:Immunity, Innate; D016219:Immunotherapy, Adoptive / Q000379:methods; D007275:Injections, Intravenous; D007694:Killer Cells, Natural / Q000276:immunology*; D008175:Lung Neoplasms / Q000235:genetics / Q000276:immunology* / Q000556:secondary / Q000628:therapy*; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008819:Mice, Nude; D016513:Mice, SCID; D009368:Neoplasm Transplantation
chemical_list: D015703:Antigens, CD; D018122:B7-1 Antigen; D051940:B7-2 Antigen; C497965:Cd86 protein, mouse; D008562:Membrane Glycoproteins