Identification of a cyclin B1-derived CTL epitope eliciting spontaneous responses in both cancer patients and healthy donors.
With the aim to identify cyclin B1-derived peptides with high affinity for HLA-A2, we used three in silico prediction algorithms to screen the protein sequence for possible HLA-A2 binders. One peptide scored highest in all three algorithms, and the high HLA-A2-binding affinity of this peptide was verified in an HLA stabilization assay. By stimulation with peptide-loaded dendritic cells a CTL clone was established, which was able to kill two breast cancer cell lines in an HLA-A2-dependent and peptide-specific manner, demonstrating presentation of the peptide on the surface of cancer cells. Furthermore, blood from cancer patients and healthy donors was screened for spontaneous T-cell reactivity against the peptide in IFN-γ ELISPOT assays. Patients with breast cancer, malignant melanoma, or renal cell carcinoma hosted powerful and high-frequency T-cell responses against the peptide. In addition, when blood from healthy donors was tested, similar responses were observed. Ultimately, serum from cancer patients and healthy donors was analyzed for anti-cyclin B1 antibodies. Humoral responses against cyclin B1 were frequently detected in both cancer patients and healthy donors. In conclusion, a high-affinity cyclin B1-derived HLA-A2-restricted CTL epitope was identified, which was presented on the cell surface of cancer cells, and elicited spontaneous T-cell responses in cancer patients and healthy donors.
Andersen
Rikke Sick
RS
Department of Hematology, 54P4, Center for Cancer Immune Therapy, University Hospital Herlev, Herlev Ringvej 75, Herlev, Denmark. risian01@heh.regionh.dk
Sørensen
Rikke Bæk
RB
Ritter
Cathrin
C
Svane
Inge Marie
IM
Becker
Jürgen C
JC
thor Straten
Per
P
Andersen
Mads Hald
MH
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D000906:Antibodies / Q000097:blood* / Q000276:immunology*; D002478:Cells, Cultured; D056744:Cyclin B1 / Q000737:chemistry / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000276:immunology*; D015789:HLA-A2 Antigen / Q000276:immunology; D006262:Health; D006801:Humans; D008875:Middle Aged; D009369:Neoplasms / Q000097:blood / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D000906:Antibodies; C534699:CCNB1 protein, human; D056744:Cyclin B1; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen