title: Melanoma-associated antigen tyrosinase but not Melan-A/MART-1 expression and presentation dissociate during the heat shock response.
abstract: Heat shock has been shown to have pleiotropic effects on tumor physiology besides a direct cytotoxic effect. In the present study, we address the question whether heat shock treatment has an impact on the antigenicity of human melanoma cells and their specific recognition by cytotoxic lymphocytes. The heat shock response was induced by treating the cells with two different thermal isoeffect doses, which resulted in equivalent clonogenic survival, mimicking doses achieved during clinical hyperthermia treatment of tumors. Antigen expression and immune recognition by cytotoxic T cells was studied using the human melanoma cell lines 624.38-MEL, SK-MEL23, WM115 and WM266-4, which naturally express, process and present tyrosinase and Melan-A/melanoma antigen recognized by T cells (MART)-1-derived peptides in the context of HLA-A2 molecules. We demonstrate that during the heat shock response following the two thermal doses, heat shock protein 70 (Mr 72 kDa) (HSP70) was induced with differential kinetics; tyrosinase protein and mRNA levels dissociated with a significant increase in tyrosinase protein and a decrease in transcript levels. A similar dissociation was not observed for Melan-A/MART-1. Furthermore, tyrosinase-specific T-cell recognition did not correlate with changes in HSP70 and antigen protein levels. These results suggest that caution has to be taken when considering protein levels as a marker for the antigenic status of a tumor. Moreover, these results document the maintenance of immunological homeostasis during recovery from heat treatment, thus challenging the view that tumor cells subjected to heat shock become resistant to CTL recognition.
authors.affiliation: Clinical Cooperation Group of Hyperthermia, Internal Medicine Department III, Klinikum Grosshadern, Ludwig-Maximilians-University, Marchioninistrasse 15, 81377 Munich, Germany.
authors.forename: Valeria
authors.initials: V
authors.lastname: Milani
authors.forename: Bernhard
authors.initials: B
authors.lastname: Frankenberger
authors.forename: Oksana
authors.initials: O
authors.lastname: Heinz
authors.forename: Anna
authors.initials: A
authors.lastname: Brandl
authors.forename: Sibylle
authors.initials: S
authors.lastname: Ruhland
authors.forename: Rolf Dieter
authors.initials: RD
authors.lastname: Issels
authors.forename: Elfriede
authors.initials: E
authors.lastname: Noessner
mesh_terms: D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000276:immunology; D000951:Antigens, Neoplasm; D045744:Cell Line, Tumor; D015789:HLA-A2 Antigen / Q000378:metabolism; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D018869:Heat-Shock Response; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D058965:MART-1 Antigen; D008545:Melanoma / Q000276:immunology* / Q000378:metabolism; D014442:Monophenol Monooxygenase / Q000276:immunology* / Q000378:metabolism; D009363:Neoplasm Proteins / Q000276:immunology* / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; D015789:HLA-A2 Antigen; D018840:HSP70 Heat-Shock Proteins; D015395:Histocompatibility Antigens Class I; D058965:MART-1 Antigen; C548667:MLANA protein, human; D009363:Neoplasm Proteins; D014442:Monophenol Monooxygenase