Targeting heat shock proteins for immunotherapy in multiple myeloma: generation of myeloma-specific CTLs using dendritic cells pulsed with tumor-derived gp96.
OBJECTIVE
To develop effective immunotherapies for patients with multiple myeloma, it is important to use novel tumor antigens. Recent studies in solid tumors show that tumor-derived heat shock proteins (Hsp) can be used as immunogen; however, no such study has yet been reported in multiple myeloma.


METHODS
We examined whether myeloma-derived Hsp gp96 can be used as a myeloma antigen. Specific CTL lines were obtained after repeatedly stimulating T cells with autologous, HLA-A*0201+ dendritic cells pulsed with gp96 derived from HLA-A*0201+ human myeloma cell line (HMCL) U266 or primary myeloma cells.


RESULTS
These T cells lysed not only gp96-pulsed dendritic cells, U266, and other HLA-A*0201+ HMCLs IM-9 and XG1 but also effectively killed HLA-A*0201+ primary myeloma cells from patients. No killing was observed against unpulsed dendritic cells, dendritic cells pulsed with control gp96, HLA-A*0201- HMCLs, and primary myeloma cells, or HLA-A*0201+ nonmyeloma cells. Cytotoxicity was mainly MHC class I/HLA-A*0201 restricted, suggesting that the CTLs recognized gp96-chaperoned peptides on HLA-A*0201 that were derived from shared myeloma antigens and that myeloma cells naturally present these peptides in the context of their surface MHC molecules. Upon antigen stimulation, these T cells secreted IFN-gamma and tumor necrosis factor-alpha, indicating that they belong to type 1 T-cell subsets.


CONCLUSIONS
These results show that these T cells are potent CTLs that are able to effectively lyse myeloma cells but not normal blood cells and also suggest that Hsps from allogeneic tumor cells may be used as vaccines to immunize patients.
Qian
Jianfei
J
Myeloma Institute for Research and Therapy, Arkansas Cancer Research Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
Wang
Siqing
S
Yang
Jing
J
Xie
Jin
J
Lin
Pei
P
Freeman
Muta E
ME
Yi
Qing
Q
D000951:Antigens, Neoplasm / Q000032:analysis / Q000276:immunology* / Q000302:isolation & purification; D018920:Coculture Techniques; D016207:Cytokines / Q000378:metabolism; D003713:Dendritic Cells / Q000276:immunology*; D005089:Exocytosis / Q000276:immunology; D006360:Heat-Shock Proteins / Q000032:analysis / Q000276:immunology* / Q000302:isolation & purification; D006801:Humans; D016219:Immunotherapy, Adoptive; D008562:Membrane Glycoproteins / Q000276:immunology; D009101:Multiple Myeloma / Q000737:chemistry / Q000276:immunology* / Q000628:therapy; D010455:Peptides / Q000494:pharmacology; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology* / Q000378:metabolism; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm; D016207:Cytokines; D006360:Heat-Shock Proteins; D008562:Membrane Glycoproteins; D010455:Peptides; D052899:Pore Forming Cytotoxic Proteins; C052646:sarcoma glycoprotein gp96 rejection antigens; D054353:Perforin