title: Lack of T-cell-mediated recognition of the fusion region of the pml/RAR-alpha hybrid protein by lymphocytes of acute promyelocytic leukemia patients.
abstract: In previous studies, it was shown that the fusion region of the pml/RAR-alpha protein, expressed by acute promyelocytic leukemia (APL) cells, can be specifically recognized in vitro by donor (D. E. ) CD4 T cells in a HLA class II DR11-restricted fashion. We present here the results on the recognition of several pml/RAR-alpha peptides by APL patients expressing HLA DR11. The in vitro immunization of peripheral blood lymphocytes from four patients in remission (S. R., F. R., M. M., P. G.) with BCR1/25, a 25-mer pml/RAR-alpha, did not elicit either a polyclonal or a clonal immune response specific to the peptide. We then generated new donor anti-pml/RAR-alpha CD4(+) T-cell clones. These clones were tested for their recognition of BCR1/25. One clone (C3/5, CD3(+), CD4(+), CD8(-)) was selected for further analysis. Clone C3/5 showed specific proliferation, cytotoxicity, and cytokine (tumor necrosis factor alpha, granulocyte-macrophage colony-stimulating factor) production when challenged with autologous lymphoblastic cell lines pulsed with peptide BCR1/25. C3/5 cells developed specific proliferation and cytotoxicity when challenged with peptide-pulsed lymphoblastic cell lines and peripheral blood lymphocytes from the four DR11(+) APL patients. APL blasts, available only from patients F. R. and P. G., were not lysed by C3/5 and were unable to present peptide BCR1/25. Incubation of APL cells with IFN-gamma failed to induce HLA class II molecules and recognition by the C3/5 clone. Since APL cells do not express HLA class II molecules, we tested in two donors (D. E. and C. H. R.) and in patients S. R. and P. G. whether the use of 9-mer peptides (BCR1/9) would generate a CD8/HLA class I-restricted response. No peptide-specific T-cell line or clone could be generated from both donors and patients. These findings are discussed in relation to possible therapeutic approaches to the immunotherapy of APL.
authors.affiliation: Division of Experimental Oncology D and Blood Bank, Istituto Nazionale Tumori, Via Venezian 1, 20133 Milan, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Dermime
authors.forename: C
authors.initials: C
authors.lastname: Bertazzoli
authors.forename: E
authors.initials: E
authors.lastname: Marchesi
authors.forename: F
authors.initials: F
authors.lastname: Ravagnani
authors.forename: K
authors.initials: K
authors.lastname: Blaser
authors.forename: G M
authors.initials: GM
authors.lastname: Corneo
authors.forename: E
authors.initials: E
authors.lastname: Pogliani
authors.forename: G
authors.initials: G
authors.lastname: Parmiani
authors.forename: C
authors.initials: C
authors.lastname: Gambacorti-Passerini
mesh_terms: D001665:Binding Sites; D002460:Cell Line; D016207:Cytokines / Q000096:biosynthesis; D006684:HLA-DR Antigens / Q000276:immunology; D059810:HLA-DR Serological Subtypes; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute / Q000276:immunology*; D008213:Lymphocyte Activation; D009363:Neoplasm Proteins / Q000276:immunology*; D009687:Nuclear Proteins; D010835:Phytohemagglutinins / Q000494:pharmacology; D000071156:Promyelocytic Leukemia Protein; D018168:Receptors, Retinoic Acid / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000276:immunology*; D000072482:Retinoic Acid Receptor alpha; D013601:T-Lymphocytes / Q000276:immunology*; D013745:Tetanus Toxoid / Q000494:pharmacology; D014157:Transcription Factors / Q000276:immunology*; D025521:Tumor Suppressor Proteins
chemical_list: D016207:Cytokines; D006684:HLA-DR Antigens; D059810:HLA-DR Serological Subtypes; C080766:HLA-DR11 antigen; D015395:Histocompatibility Antigens Class I; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D010835:Phytohemagglutinins; D000071156:Promyelocytic Leukemia Protein; C000607071:RARA protein, human; D018168:Receptors, Retinoic Acid; D011993:Recombinant Fusion Proteins; D000072482:Retinoic Acid Receptor alpha; D013745:Tetanus Toxoid; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; C070576:PML protein, human