title: Leukemia-associated antigen-specific T-cell responses following combined PR1 and WT1 peptide vaccination in patients with myeloid malignancies.
abstract: We describe the safety and immunogenicity of a combined vaccine of 2 leukemia-associated antigenic peptides, PR1 and WT1. Eight patients with myeloid malignancies received one subcutaneous dose each of PR1 and WT1 vaccines in Montanide adjuvant, with granulocyte-macrophage colony-stimulating factor. Patients were reviewed weekly for 4 weeks to monitor toxicity and immunologic responses. Toxicity was limited to grades 1 to 2. Using peptide/HLA-A 0201 tetramers and intracellular interferon-gamma staining, CD8(+) T cells against PR1 or WT1 were detected in 8 of 8 patients after a single vaccination. To monitor the kinetics of vaccine-induced CD8(+) T-cell responses and disease regression after vaccination, absolute PR1 and WT1(+)CD8(+) T-cell numbers and WT1 expression were studied weekly after vaccination. Responses occurred as early as 1 week after vaccination. After vaccination, the emergence of PR1 or WT1(+)CD8(+) T cells was associated with a decrease in WT1 mRNA expression as a marker of minimal residual disease, suggesting a vaccine-driven antileukemia effect. Conversely, loss of response was associated with reappearance of WT1 transcripts (P < .01). This is the first demonstration that a combined PR1 and WT1 vaccine is immunogenic. These results support further studies of combination immunization strategies in leukemia patients.
authors: Stem Cell Allotransplantation Section, Hematology Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1201, USA. rezvanik@nhlbi.nih.gov
authors: Katayoun
authors: K
authors: Rezvani
authors: Agnes S M
authors: AS
authors: Yong
authors: Stephan
authors: S
authors: Mielke
authors: Bipin N
authors: BN
authors: Savani
authors: Laura
authors: L
authors: Musse
authors: Jeanine
authors: J
authors: Superata
authors: Behnam
authors: B
authors: Jafarpour
authors: Carol
authors: C
authors: Boss
authors: A John
authors: AJ
authors: Barrett
mesh_terms: D000328:Adult; D000368:Aged; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D019496:Cancer Vaccines / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D015234:HLA-A Antigens / Q000276:immunology*; D015789:HLA-A2 Antigen; D006801:Humans; D007167:Immunotherapy / Q000379:methods; D007700:Kinetics; D015470:Leukemia, Myeloid, Acute / Q000276:immunology* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000276:immunology / Q000628:therapy; D009842:Oligopeptides / Q000008:administration & dosage / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism; D025721:WT1 Proteins / Q000235:genetics / Q000276:immunology*
chemical_list: D019496:Cancer Vaccines; D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D009842:Oligopeptides; C521843:RMFPNAPYL; D012333:RNA, Messenger; D025721:WT1 Proteins