TY - JOUR
T1 - Identification of a new hTERT-derived HLA-A*0201 restricted, naturally processed CTL epitope
AU - Thorn, Mette
AU - Wang, Mingjun
AU - Kløverpris, Henrik
AU - Schmidt, Esben G W
AU - Fomsgaard, Anders
AU - Wenandy, Lynn
AU - Berntsen, Annika
AU - Brunak, Søren
AU - Buus, Soren
AU - Claesson, Mogens H
N1 - Keywords: Amino Acid Sequence; Amino Acid Substitution; Animals; Antigen Presentation; Blotting, Western; CD8-Positive T-Lymphocytes; Cell Line, Tumor; Epitopes, T-Lymphocyte; HLA-A Antigens; Humans; Mice; Mice, Transgenic; Molecular Sequence Data; Peptide Fragments; Protein Binding; T-Lymphocytes, Cytotoxic; Telomerase
PY - 2007
Y1 - 2007
N2 - By the use of a neural network capable of performing quantitative predictions of peptides binding to HLA-A*0201 molecules, we identified a number of nonamer peptides derived from the catalytic subunit of telomerase, human telomerase reverse transcriptase (hTERT). Five nonimmunogenic peptides with measured binding affinities for HLA-A*0201 ranging from 155 to 1,298 nM were modified at the P1, P2 and P9 positions, respectively, to achieve stronger HLA-A*0201 binding. One peptide, mp30-38 (mp30), with an L to V substitution at position 9 was subsequently found to be immunogenic in mp30 immunized HLA-A*0201/H2K(b) or HHD transgenic mice. The T cell reactivity obtained was directed against both the mp30 and against the unmodified p30. Anti-mp30 specific T cells generated in HLA-A*0201 transgenic mice were dependent on TCR-CD8/MHC-I alpha3 binding and therefore not capable of recognizing mp30-pulsed human HLA-A*0201(+) cells or murine HLA-A*0201 transfectants. In order to show reactivity against naturally processed peptide in human tumor cells, an hTERT positive HLA-A*0201 negative colon carcinoma cell line (CCL220) was transfected with an HLA-A*0201/H2K(b) cDNA construct and used as target in ELISPOT and cytotoxicity assays. The data show that T cells from mp30 immunized HHD transgenic mice react specifically against the CCL220 transfectant indicating that p30 is naturally processed. In conclusion, we have identified a new CTL HLA-A*0201 restricted hTERT epitope, which is now, included in an ongoing phase 2 vaccine trial of patients with disseminated cancer.
AB - By the use of a neural network capable of performing quantitative predictions of peptides binding to HLA-A*0201 molecules, we identified a number of nonamer peptides derived from the catalytic subunit of telomerase, human telomerase reverse transcriptase (hTERT). Five nonimmunogenic peptides with measured binding affinities for HLA-A*0201 ranging from 155 to 1,298 nM were modified at the P1, P2 and P9 positions, respectively, to achieve stronger HLA-A*0201 binding. One peptide, mp30-38 (mp30), with an L to V substitution at position 9 was subsequently found to be immunogenic in mp30 immunized HLA-A*0201/H2K(b) or HHD transgenic mice. The T cell reactivity obtained was directed against both the mp30 and against the unmodified p30. Anti-mp30 specific T cells generated in HLA-A*0201 transgenic mice were dependent on TCR-CD8/MHC-I alpha3 binding and therefore not capable of recognizing mp30-pulsed human HLA-A*0201(+) cells or murine HLA-A*0201 transfectants. In order to show reactivity against naturally processed peptide in human tumor cells, an hTERT positive HLA-A*0201 negative colon carcinoma cell line (CCL220) was transfected with an HLA-A*0201/H2K(b) cDNA construct and used as target in ELISPOT and cytotoxicity assays. The data show that T cells from mp30 immunized HHD transgenic mice react specifically against the CCL220 transfectant indicating that p30 is naturally processed. In conclusion, we have identified a new CTL HLA-A*0201 restricted hTERT epitope, which is now, included in an ongoing phase 2 vaccine trial of patients with disseminated cancer.
U2 - 10.1007/s00262-007-0319-y
DO - 10.1007/s00262-007-0319-y
M3 - Journal article
C2 - 17464507
SN - 0340-7004
VL - 56
SP - 1755
EP - 1763
JO - Cancer Immunology, Immunotherapy
JF - Cancer Immunology, Immunotherapy
IS - 11
ER -
