Immunogenicity of a p210(BCR-ABL) fusion domain candidate DNA vaccine targeted to dendritic cells by a recombinant adeno-associated virus vector in vitro.
Chronic myelogenous leukemia (CML) is characterized by a t(9;22) translocation, which results in the expression of chimeric BCR-ABL fusion oncoproteins that are necessary for oncogenesis, unique to the leukemic clones, and represent enticing targets for immunotherapy. As a strategy for the immunotherapy of CML, we constructed a recombinant adeno-associated virus vector encoding the p210(BCR-ABL) b3a2 variant fusion region with flanking sequences (CWRBA) and used it to express the BCR-ABL fusion region within primary human dendritic cells (DCs), the most potent antigen-presenting cells currently known. Peripheral blood mononuclear cells from healthy donors were primed and restimulated in vitro with autologous DCs transduced with purified CWRBA, CWRAP (negative control), or pulsed with a peptide corresponding to the fusion domain (positive control). No specific responses were generated using DCs transduced with CWRAP. In contrast, CWRBA-transduced DCs primed autologous T cells in an antigen-specific, MHC-restricted fashion to levels comparable with the positive control. CWRBA-transduced DCs elicited both cytotoxic CD4+/Th1 and CD8+ responses, although the former were more readily detected in this system. Cytotoxicity against a tumor cell line endogenously expressing the p210(BCR-ABL) b3a2 variant fusion region was also demonstrable. In addition, HLA-DRB5(*)0101+DRA (DR2a) was identified as a new restriction element capable of presenting the b3a2 BCR-ABL fusion region epitope. Thus, the construct developed herein may serve as a candidate vaccine for gene-based antigen-specific immunotherapy of CML and may serve as a paradigm for the use of DCs transduced with recombinant adeno-associated virus vectors encoding multiepitope immunogens for vaccine development.
Sun
Ji-Yao
JY
Division of Hematology and Stem Cell Transplantation, City of Hope National Medical Center, 1500 East Duarte Road, Duarte, CA 91010, USA.
Krouse
Robert S
RS
Forman
Stephen J
SJ
Senitzer
David
D
Sniecinski
Irena
I
Chatterjee
Saswati
S
Wong
K K
KK
D000595:Amino Acid Sequence; D002460:Cell Line; D003713:Dendritic Cells / Q000276:immunology*; D000229:Dependovirus / Q000235:genetics; D018984:Epitopes, T-Lymphocyte; D016044:Fusion Proteins, bcr-abl / Q000235:genetics / Q000276:immunology*; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D020014:K562 Cells; D015464:Leukemia, Myelogenous, Chronic, BCR-ABL Positive / Q000235:genetics / Q000276:immunology; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014161:Transduction, Genetic; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*
D018984:Epitopes, T-Lymphocyte; D019444:Vaccines, DNA; D016044:Fusion Proteins, bcr-abl