title: Influence of drug-induced apoptotic death on processing and presentation of tumor antigens by dendritic cells.
abstract: Here we have studied the effects of apoptotic cell death induced by chemotherapic agents on tumor phagocytosis by dendritic cells (DC) and presentation of the relevant antigen to T lymphocytes. Annexin-V-FITC (Ann-V) and propidium iodide (PI) staining was used to assess early apoptotic (Ann-V(+)/PI(-)) vs. late apoptotic/secondary necrotic (Ann-V(+)/PI(+)) death after a 24 hr observation of untreated and drug-treated gastric carcinoma cells. After treatments, the HLA-A*0201(+) tumor cell line KATO III was exposed for 24 hr to allogeneic, HLA-related GM-CSF, IL-4-driven immature (i) DC. Tumor-loaded iDC were tested for IL-12 release in an ELISA assay, incubated with the DC-maturating factor TNF-alpha and used as stimulators for autologous T lymphocytes. Generation of antitumor T response against KATO cells was evaluated in an anti-MHC class I MAb-blocked Interferon-gamma ELISPOT assay. After treatment with Cis-platin (cis), all dying cells were in early apoptosis, whereas secondary necrosis was the prevalent death pattern observed after epirubicin (epi) and doxorubicin (doxo). Doxo and epi increased tumor expression of heat shock protein (hsp) 70 and uptake of tumor cell components by DC, whereas cis treatment had no effect on hsp70 and was associated with poor tumor uptake by DC. Significant upmodulation of IL-12 was observed by DC that had taken up the doxo- and epi-treated tumors (p< 0.005 and p< 0.01, respectively). Increased IFN-gamma release was also observed after stimulation of T lymphocytes with DC loaded with doxo- and epi-treated (p< 0.02 and p< 0.005, respectively) but not with cis-treated DC. These data show that the products of early apoptosis cannot efficiently cross-activate MHC class I-restricted anti-tumor lymphocytes even in the presence of DC maturating factors, whereas secondary necrosis is associated with robust T cell response.
authors.affiliation: Department of Oncology, Centro OncoEmatologicoSubalpino (COES), Turin, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Buttiglieri
authors.affiliation: Department of Oncology, Centro OncoEmatologicoSubalpino (COES), Turin, Italy.
authors.forename: Alessandra
authors.initials: A
authors.lastname: Galetto
authors.affiliation: Department of Internal Medicine, University of Turin, Turin, Italy.
authors.forename: Sarah
authors.initials: S
authors.lastname: Forno
authors.affiliation: Department of Microbiology and Public Health, Turin, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: De Andrea
authors.affiliation: Department of Internal Medicine, University of Turin, Turin, Italy.
authors.forename: Lina
authors.initials: L
authors.lastname: Matera
mesh_terms: D017304:Annexin A5 / Q000378:metabolism; D017951:Antigen Presentation / Q000502:physiology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D000970:Antineoplastic Agents / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D002945:Cisplatin / Q000494:pharmacology; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology*; D004317:Doxorubicin / Q000494:pharmacology; D015251:Epirubicin / Q000494:pharmacology; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D015395:Histocompatibility Antigens Class I / Q000276:immunology; D006801:Humans; D009336:Necrosis; D010587:Phagocytosis / Q000187:drug effects; D011419:Propidium / Q000378:metabolism; D013274:Stomach Neoplasms / Q000473:pathology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014407:Tumor Cells, Cultured
chemical_list: D017304:Annexin A5; D000951:Antigens, Neoplasm; D000970:Antineoplastic Agents; D016207:Cytokines; D018840:HSP70 Heat-Shock Proteins; D015395:Histocompatibility Antigens Class I; D011419:Propidium; D015251:Epirubicin; D004317:Doxorubicin; D002945:Cisplatin