In vitro generation of cytotoxic T lymphocytes against HLA-A2.1-restricted peptides derived from human thymidylate synthase.
5-Fluorouracil (5-FU) is a pyrimidine antimetabolite active against colorectal carcinoma and other malignancies of the digestive tract. Over-expression or mutation of thymidylate synthase (TS), the target enzyme of the 5-FU metabolite, 5-fluorodeoxyuridine monophosphate, is strictly correlated with cancer cell resistance to 5-FU. On this basis we investigated whether TS is a potential target for active specific immunotherapy of human colon carcinoma, which acquires resistance to 5-FU. Three TS-derived epitope peptides which fit defined amino acid consensus motifs for HLA-A2.1 binding were synthesized and investigated for their ability to induce human TS-specific cytotoxic T cell (CTL) responses in vitro. CTL lines specific for each peptide were established by stimulating peripheral blood mononuclear cells (PBMC) from an HLA-A2.1+ healthy donor with autologous dendritic cells loaded with TS peptide. Specific CTL lines showed HLA-A2.1-restricted cytotoxicity in vitro to HLA-A2.1+ target cells pulsed with the specific TS peptide and to HLA-class I matching colon carcinoma target cells over-expressing TS enzyme after exposure to 5-FU. Recognition by CTL lines suggests that these TS peptides may be potential candidates for use in a peptide-based vaccine against 5-FU resistant colon carcinoma.
Correale
P
P
Oncopharmacology Center, School of Medicine, University of Siena, Italy.
Sabatino
M
M
Cusi
M G
MG
Micheli
L
L
Nencini
C
C
Pozzessere
D
D
Petrioli
R
R
Aquino
A
A
De Vecchis
L
L
Turriziani
M
M
Prete
S P
SP
Sanguedolce
R
R
Rausa
L
L
Giorgi
G
G
Francini
G
G
D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology*; D019496:Cancer Vaccines; D002277:Carcinoma / Q000276:immunology* / Q000473:pathology; D002460:Cell Line; D003110:Colonic Neoplasms / Q000276:immunology* / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D018984:Epitopes, T-Lymphocyte; D005434:Flow Cytometry; D005472:Fluorouracil / Q000494:pharmacology*; D015789:HLA-A2 Antigen / Q000276:immunology*; D006801:Humans; D010455:Peptides; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D013940:Thymidylate Synthase / Q000096:biosynthesis* / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000964:Antimetabolites, Antineoplastic; D019496:Cancer Vaccines; D018984:Epitopes, T-Lymphocyte; D015789:HLA-A2 Antigen; D010455:Peptides; D013940:Thymidylate Synthase; D005472:Fluorouracil