title: Inefficient presentation of tumor-derived antigen by tumor-infiltrating dendritic cells.
abstract: BACKGROUND
  Transplantable B16 melanoma is widely used as a tumor model to investigate tumor immunity. We wished to characterize the leukocyte populations infiltrating B16 melanoma tumors, and the functional properties of tumor-infiltrating dendritic cells (TIDC).
  
  
  METHODS
  We used the B16 melanoma cell line expressing ovalbumin protein (OVA) to investigate the phenotype and T cell stimulatory capacity of TIDC.
  
  
  RESULTS
  The majority of leukocytes in B16 melanoma were macrophages, which colocalized with TIDCs, B and T cells to the peripheral area of the tumor. Both myeloid and plasmacytoid DC populations were present within tumors. Most of these DCs appeared immature, but about a third expressed a mature phenotype. TIDCs did not present tumor-derived antigen, as they were unable to induce the proliferation of tumor-specific CD4+ and CD8+ T cells in vitro unless in the presence of specific peptides. Some presentation of tumor-derived antigen could be demonstrated in the tumor-draining lymph node using in vivo proliferation assays. However, while proliferation of CD8+ T cells was reproducibly demonstrated, no proliferation of CD4+ T cells was observed.
  
  
  CONCLUSIONS
  In summary, our data suggest that DCs in tumors have limited antigen-presenting function. Inefficient antigen presentation extends to the tumor-draining lymph node, and may affect the generation of antitumor immune responses.
authors.affiliation: Malaghan Institute of Medical Research, Wellington, New Zealand. Patrizia.Stoitzner@i-med.ac.at
authors.forename: Patrizia
authors.initials: P
authors.lastname: Stoitzner
authors.forename: Laura K
authors.initials: LK
authors.lastname: Green
authors.forename: Jae Y
authors.initials: JY
authors.lastname: Jung
authors.forename: Kylie M
authors.initials: KM
authors.lastname: Price
authors.forename: Haley
authors.initials: H
authors.lastname: Atarea
authors.forename: Bronwyn
authors.initials: B
authors.lastname: Kivell
authors.forename: Franca
authors.initials: F
authors.lastname: Ronchese
mesh_terms: D000818:Animals; D017951:Antigen Presentation / Q000276:immunology*; D000938:Antigen-Presenting Cells / Q000276:immunology / Q000473:pathology; D000951:Antigens, Neoplasm / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000473:pathology; D049109:Cell Proliferation; D003713:Dendritic Cells / Q000276:immunology* / Q000473:pathology; D005260:Female; D007962:Leukocytes / Q000276:immunology / Q000473:pathology; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D016246:Lymphocytes, Tumor-Infiltrating / Q000276:immunology*; D008297:Male; D008546:Melanoma, Experimental / Q000276:immunology* / Q000473:pathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D010047:Ovalbumin / Q000276:immunology*; D010641:Phenotype; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology / Q000473:pathology
chemical_list: D000951:Antigens, Neoplasm; D010047:Ovalbumin