Cross-presentation of NY-ESO-1 cytotoxic T lymphocyte epitope fused to human heat shock cognate protein 70 by dendritic cells.
The cancer-testis antigen NY-ESO-1 has been implicated as one of the most attractive candidates for a cancer vaccine. However, a protein vaccine generally meets inefficient antigen presentation to CD8(+) T cells, which could be overcome by combination with an appropriate adjuvant. Heat shock protein is a natural adjuvant and activates the antigen-presenting cells to channel exogenous antigens into the classical major histocompatibility complex class I antigen-processing pathway (cross-presentation). Therefore, we genetically fused a minigene encompassing the NY-ESO-1 cytotoxic T lymphocyte (CTL) epitope 157-165 (ESO p157-165) to the human heat shock cognate protein 70 (hsc70) and expressed the resulting fusion proteins in Escherichia coli. By using a human leukocyte antigen-A*0201-restricted NY-ESO-1-specific CTL clone, the cross-presentation of ESO p157-165 by monocyte-derived dendritic cells (mo-DC) pulsed with the fusion protein was evaluated. The fusion protein-pulsed mo-DC activates the CTL clone much more efficiently than the free NY-ESO-1 protein-pulsed mo-DC. Moreover, the magnitude of the CTL activity was comparable between ESO p157-165 and the fusion protein of hsc70 and ESO p157-165 (hsc70-ESO p157-165 fusion protein). In addition, the CTL activation induced by the fusion protein, but not by the epitope, was inhibited by paraformaldehyde fixation of the mo-DC and by treatment with lactacystin, a specific inhibitor for the proteasome. Finally, the hsc70-ESO p157-165 fusion protein-pulsed DC was able to induce an antigen-specific T-cell response. These results suggest that the hsc70-ESO p157-165 fusion protein is therefore considered to be a promising candidate as a cancer vaccine.
Susumu
Seiya
S
Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. susumu_gi@mac.com
Nagata
Yasuhiro
Y
Ito
Shinichiro
S
Matsuo
Mitsutoshi
M
Valmori
Danila
D
Yui
Katsuyuki
K
Udono
Heiichiro
H
Kanematsu
Takashi
T
D017951:Antigen Presentation; D000951:Antigens, Neoplasm / Q000235:genetics / Q000276:immunology*; D003429:Cross Reactions; D003713:Dendritic Cells / Q000276:immunology*; D018984:Epitopes, T-Lymphocyte / Q000235:genetics / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000276:immunology; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000276:immunology*; D006801:Humans; D008213:Lymphocyte Activation; D008565:Membrane Proteins / Q000235:genetics / Q000276:immunology*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000951:Antigens, Neoplasm; C104948:CTAG1B protein, human; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen; D018840:HSP70 Heat-Shock Proteins; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins