Chemotherapeutic drugs may be used to enhance the killing efficacy of human tumor antigen peptide-specific CTLs.
The effects of anticancer chemotherapy on antigen-specific cytotoxic T lymphocytes (CTLs) are mostly unknown. We tested the effects of cytotoxic drugs such as 5-fluorouracil, gemcitabine, and oxaliplatin on the functional activity of antigen-specific CTL cultures derived from the peripheral blood mononuclear cells of human donors. We found that a biweekly drug-exposure of human HLA-A(*)02.01+ CTLs derived from bulk cultures led to completely different effects if occurring early (day second) or late (day thirteenth) after the in vitro stimulations with the cognate peptides. In the first case, there was a significant CTL inhibition, whereas in the second, there was a marked enhancement of the antigen-specific cytolytic activity. Results of immunocytofluorimetric studies and CTL/natural killer inhibition assays suggested that the latter effect could be related to a more selective drug-mediated inhibition of cohabitant T regulatory (reg) cells. These results were translated in an in vivo therapeutic mouse model where humanized HLA-A(*)02.01 transgenic mice inoculated with EL-4/humanized HLA-A(*)02.01 transgenic mice showed a prolonged survival and the greatest rate of cure when receiving a combined treatment with a thymidylate synthase-specific peptide vaccine and a multidrug chemotherapy regimen administered late after immunization. Tumor samples derived from this group of mice showed a reduced expression of the target thymidylate synthase antigen, a marked reduction of T(reg)s, and a noteworthy infiltration of C8+ T cells. These results may have clinical implications for the design of new translational anticancer regimens aimed at combining chemotherapy and immunotherapy.
Correale
Pierpaolo
P
Medical Oncology Section, Department of Human Pathology and Oncology, Siena University School of Medicine, Italy. correale@unisi.it
Del Vecchio
Maria Teresa
MT
La Placa
Marco
M
Montagnani
Francesco
F
Di Genova
Giuseppa
G
Savellini
Gianni Gori
GG
Terrosi
Chiara
C
Mannucci
Susanna
S
Giorgi
Giorgio
G
Francini
Guido
G
Cusi
Maria Grazia
MG
D000818:Animals; D000951:Antigens, Neoplasm / Q000276:immunology*; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D019496:Cancer Vaccines / Q000276:immunology / Q000627:therapeutic use; D002272:Carcinoembryonic Antigen / Q000276:immunology; D002460:Cell Line; D045744:Cell Line, Tumor; D003110:Colonic Neoplasms / Q000276:immunology / Q000473:pathology; D003602:Cytotoxicity, Immunologic / Q000187:drug effects* / Q000276:immunology; D003841:Deoxycytidine / Q000627:therapeutic use; D004305:Dose-Response Relationship, Drug; D005472:Fluorouracil / Q000627:therapeutic use; D015234:HLA-A Antigens / Q000235:genetics / Q000276:immunology; D015789:HLA-A2 Antigen; D006801:Humans; D053645:Interleukin-2 Receptor alpha Subunit / Q000032:analysis; D002955:Leucovorin / Q000627:therapeutic use; D016399:Lymphoma, T-Cell / Q000276:immunology / Q000473:pathology / Q000628:therapy; D051379:Mice; D008815:Mice, Inbred Strains; D008822:Mice, Transgenic; D009944:Organoplatinum Compounds / Q000627:therapeutic use; D010455:Peptides / Q000276:immunology / Q000494:pharmacology / Q000627:therapeutic use; D052736:Rous sarcoma virus / Q000276:immunology; D029301:Sandfly fever Naples virus / Q000276:immunology; D016019:Survival Analysis; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000737:chemistry / Q000187:drug effects / Q000276:immunology; D013940:Thymidylate Synthase / Q000378:metabolism
D000951:Antigens, Neoplasm; D000970:Antineoplastic Agents; D019496:Cancer Vaccines; D002272:Carcinoembryonic Antigen; D015234:HLA-A Antigens; C435939:HLA-A*02:01 antigen; D015789:HLA-A2 Antigen; D053645:Interleukin-2 Receptor alpha Subunit; D009944:Organoplatinum Compounds; D010455:Peptides; D003841:Deoxycytidine; D013940:Thymidylate Synthase; D002955:Leucovorin; D005472:Fluorouracil