Differential capacity of chaperone-rich lysates in cross-presenting human endogenous and exogenous melanoma differentiation antigens.
The goal of immune-based tumor therapies is the activation of immune cells reactive against a broad spectrum of tumor-expressed antigens. Vaccines based on chaperone proteins appear promising as these proteins naturally exist as complexes with various protein fragments including those derived from tumor-associated antigens. Multi-chaperone systems are expected to have highest polyvalency as different chaperones can carry distinct sets of antigenic fragments. A free-solution isoelectric focusing (FS-IEF) technique was established to generate chaperone-rich cell lysates (CRCL). Results from murine systems support the contention that CRCL induce superior anti-tumor responses than single chaperone vaccines. We established an in vitro model for human melanoma to evaluate the capacity of CRCL to transfer endogenously expressed tumor antigens to the cross-presentation pathway of dendritic cells (DC) for antigen-specific T cell stimulation. CRCL prepared from human melanoma lines contained the four major chaperone proteins Hsp/Hsc70, Hsp90, Grp94/gp96 and calreticulin. The chaperones within the melanoma cell-derived CRCL were functionally active in that they enhanced cross-presentation of exogenous peptides mixed into the CRCL preparation. Superior activity was observed for Hsp70-rich CRCL obtained from heat-stressed melanoma cells. Despite the presence of active chaperones, melanoma cell-derived CRCL failed to transfer endogenously expressed melanoma-associated antigens to DC for cross-presentation and cytotoxic T cell (CTL) recognition, even after increasing intracellular protein levels of tumor antigen or chaperones. These findings reveal limitations of the CRCL approach regarding cross-presentation of endogenously expressed melanoma-associated antigens. Yet, CRCL may be utilized as vehicles to enhance the delivery of exogenous antigens for DC-mediated cross-presentation and T cell stimulation.
Bleifuss
Elke
E
Clinical Cooperation Group Hyperthermia, Helmholtz Zentrum München-German Research Center for Environmental Health, 81377 Munich, Germany. elke.bleifuss@gmx.de
Bendz
Henriette
H
Sirch
Birgit
B
Thompson
Sylvia
S
Brandl
Anna
A
Milani
Valeria
V
Graner
Michael W
MW
Drexler
Ingo
I
Kuppner
Maria
M
Katsanis
Emmanuel
E
Noessner
Elfriede
E
Issels
Rolf-Dieter
RD
D000818:Animals; D017951:Antigen Presentation / Q000276:immunology; D000943:Antigens, Differentiation / Q000276:immunology*; D000951:Antigens, Neoplasm / Q000276:immunology*; D015415:Biomarkers / Q000378:metabolism; D019496:Cancer Vaccines / Q000276:immunology; D045744:Cell Line, Tumor; D045142:Cross-Priming / Q000276:immunology*; D003713:Dendritic Cells / Q000276:immunology; D006358:Hot Temperature; D006801:Humans; D018664:Interleukin-12 / Q000276:immunology; D008545:Melanoma / Q000276:immunology* / Q000473:pathology; D018832:Molecular Chaperones / Q000276:immunology*; D014442:Monophenol Monooxygenase / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
D000943:Antigens, Differentiation; D000951:Antigens, Neoplasm; D015415:Biomarkers; D019496:Cancer Vaccines; D018832:Molecular Chaperones; D018664:Interleukin-12; D014442:Monophenol Monooxygenase