title: Dendritic cells generated from acute myeloid leukemia (AML) blasts maintain the expression of immunogenic leukemia associated antigens.
abstract: Recently, the focus is on new specific immunotherapies for AML such as cellular therapies employing dendritic cells (DCs) generated from AML blasts. AML-DCs express constitutionally leukemia-associated antigens (LAAs) present in AML blasts they are generated from. Here we investigated whether the generation of AML-DCs would alter the expression level of LAAs. Moreover, we evaluated the presence of HLA and costimulatory molecules on AML blasts versus AML-DCs. Quantitative real-time polymerase chain reaction (PCR) was performed for the following LAAs: preferentially expressed antigen in melanoma (PRAME), the receptor for hyaluronic acid mediated motility (RHAMM/CD168), Wilms' tumor gene 1 (WT-1) and proteinase 3. The expression of HLA-ABC, HLA-DR, CD40, CD80, CD83 and CD86 was evaluated by flow cytometry. RHAMM protein expression was evaluated by immunocytochemistry, recognition of AML-DCs by PRAME epitope-specific T cells was evaluated in a chromium-release assay. Quantitative real-time PCR for AML-DCs versus AML blasts showed an alteration in mRNA expression of LAAs. An elevated PCR signal for PRAME was detected in 7/12 AML-DC preparations. 6/12 AML-DC preparations showed a significant upregulation of the PCR signal for RHAMM. A stronger WT-1 and proteinase-3 signal was observed in PCR for only 2/12 and 1/12 AML-DCs , respectively. All preparations showed a strong expression of at least one of the LAAs examined. As demonstrated by flow cytometry, AML-DCs strongly upregulated costimulatory molecules like CD40 and CD80 in comparison with AML blasts. AML-DCs tested positive for RHAMM protein. PRAME positive AML-DCs were recognized by specific T cells. AML-DCs might constitute a powerful tool in immunotherapy for AML. Real-time PCR allows a quick and quantitative assessment of immunologically relevant LAA expression with only 10(5) DCs and might be helpful for the decision whether the AML-DC vaccination strategy is favourable or not.
authors.affiliation: Third Department of Internal Medicine, University of Ulm, Robert-Koch-Street 8, 89081 Ulm, Germany.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.forename: Peter
authors.initials: P
authors.lastname: Reinhardt
authors.forename: Anita
authors.initials: A
authors.lastname: Schmitt
authors.forename: Thomas F E
authors.initials: TF
authors.lastname: Barth
authors.forename: Jochen
authors.initials: J
authors.lastname: Greiner
authors.forename: Mark
authors.initials: M
authors.lastname: Ringhoffer
authors.forename: Hartmut
authors.initials: H
authors.lastname: Döhner
authors.forename: Markus
authors.initials: M
authors.lastname: Wiesneth
authors.forename: Michael
authors.initials: M
authors.lastname: Schmitt
mesh_terms: D000208:Acute Disease; D015703:Antigens, CD / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000276:immunology* / Q000378:metabolism; D001752:Blast Crisis; D002470:Cell Survival / Q000276:immunology; D003713:Dendritic Cells / Q000276:immunology*; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D006684:HLA-DR Antigens / Q000378:metabolism; D006801:Humans; D018960:Hyaluronan Receptors / Q000378:metabolism; D007951:Leukemia, Myeloid / Q000276:immunology* / Q000473:pathology; D053146:Myeloblastin; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012697:Serine Endopeptidases / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014407:Tumor Cells, Cultured; D025721:WT1 Proteins / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; D016326:Extracellular Matrix Proteins; D006684:HLA-DR Antigens; D018960:Hyaluronan Receptors; C404944:PRAME protein, human; D012334:RNA, Neoplasm; D025721:WT1 Proteins; C098946:hyaluronan-mediated motility receptor; D012697:Serine Endopeptidases; D053146:Myeloblastin