title: Induction of BCR-ABL-specific immunity following vaccination with chaperone-rich cell lysates derived from BCR-ABL+ tumor cells.
abstract: We have previously reported that chaperonerich cell lysates (CRCL) derived from the BCR-ABL+ 12B1 leukemia activate dendritic cells (DCs) and stimulate leukemia-specific immune responses. Because CRCL contain a variety of heat shock/chaperone proteins, we theorized that CRCL obtained from BCR-ABL+ leukemias are likely to chaperone BCR-ABL-derived fusion peptides and that DCs pulsed with 12B1 CRCL could cross-present BCR-ABL fusion peptides to T cells. We found that splenocytes from mice vaccinated with BCR-ABL+ leukemia-derived CRCL secreted interferon-gamma (IFN-gamma) when restimulated with a BCR-ABL peptide, GFKQSSKAL, indicating that BCR-ABL peptides are chaperoned by leukemia-derived CRCL. We next eluted peptides from 12B1 leukemia-derived CRCL and used high-pressure liquid chromatography (HPLC) fractions to restimulate splenocytes harvested from mice vaccinated with DC/GFKQSSKAL or DC/12B1 CRCL. We found that the same peptide fractions derived from 12B1 CRCL and from "refractionated" GFKQSSKAL stimulated IFN-gamma production, suggesting the presence of BCR-ABL peptides in the peptide repertoire of 12B1 CRCL. We also demonstrated that immunization with DCs loaded with leukemia-derived CRCL induced BCR-ABL-specific cytotoxic T lymphocytes (CTLs) in vivo. Moreover, mice immunized with DCs pulsed with 12B1-derived CRCL had superior survival (60%) when compared with those immunized with DCs pulsed with BCR-ABL peptide (20%), indicating that CRCL vaccines provide additional immune stimulus over and above individual peptide vaccination.
authors.affiliation: University of Arizona, Department of Pediatrics, Steele Memorial Children's Center, 1501 N Campbell Ave, PO Box 245073, Tucson, AZ 85724-5073, USA.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zeng
authors.forename: Michael W
authors.initials: MW
authors.lastname: Graner
authors.forename: Sylvia
authors.initials: S
authors.lastname: Thompson
authors.forename: Marilyn
authors.initials: M
authors.lastname: Marron
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Katsanis
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019496:Cancer Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002457:Cell Extracts / Q000008:administration & dosage* / Q000276:immunology; D045744:Cell Line, Tumor; D003713:Dendritic Cells / Q000276:immunology / Q000637:transplantation; D016044:Fusion Proteins, bcr-abl / Q000276:immunology* / Q000627:therapeutic use; D007109:Immunity; D016219:Immunotherapy, Adoptive; D007371:Interferon-gamma / Q000378:metabolism; D007938:Leukemia / Q000276:immunology* / Q000473:pathology / Q000628:therapy*; D051379:Mice; D008807:Mice, Inbred BALB C; D018832:Molecular Chaperones / Q000502:physiology*; D009368:Neoplasm Transplantation; D010446:Peptide Fragments / Q000008:administration & dosage / Q000276:immunology / Q000627:therapeutic use; D013154:Spleen / Q000166:cytology; D037182:T-Cell Antigen Receptor Specificity; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
chemical_list: D019496:Cancer Vaccines; D002457:Cell Extracts; D018832:Molecular Chaperones; D010446:Peptide Fragments; D007371:Interferon-gamma; D016044:Fusion Proteins, bcr-abl