title: Induction of gamma delta T cells using zoledronate plus interleukin-2 in patients with metastatic cancer.
abstract: A loss of human leukocyte antigen (HLA) expression in clinical tumors is one of their escape mechanisms from immune attack by HLA-restricted effector cells. In this study, the induction of HLA-unrestricted effector cells, gamma delta T cells, using zoledronate (ZOL) and interleukin (IL)-2 in vitro was investigated in patients with metastatic cancer. Peripheral blood mononuclear cells (PBMCs) from 10 cancer patients (8 colorectal and 2 esophageal) with multiple metastases and ascites lymphocytes from 3 cancer patients (1 gastric and 2 colorectal) were stimulated with varied concentrations of ZOL plus 100 U/ml IL-2 for 48 hr followed by culturing with IL-2 alone for 12 days. Lymphocyte proliferative responses were determined using 3H-TdR uptakes and interferon (IFN)-gamma production was evaluated using enzyme-linked immunosorbent assay. Surface phenotyping was performed using flow cytometry. Cytotoxic activity of effector cells was determined using 51Cr-releasing assay. It was found that proliferative responses of PBMCs were significantly stimulated with ZOL plus IL-2 when compared with IL-2 alone, showing 200 to 500-fold expansions for 2 weeks, although ZOL alone induced no response. The optimal concentration of ZOL was 1-5 microM. Ascites lymphocytes could also be stimulated with ZOL plus IL-2. The proliferative responses were remarkable in patients whose PBMCs could produce high levels of IFN-gamma during an initial 48-hr stimulation using ZOL plus IL-2. Removal of an adherent cell fraction before the induction augmented the proliferative responses in patients who otherwise had low-grade proliferative responses. Generated cells comprising approximately 90 or 20% in PBMCs from healthy donors or cancer patients, respectively, expressed gamma delta-type T-cell receptor. Gamma delta T cells showed high cytotoxic activity against CD166-positive TE12 and TE13 cancer cells but not against CD166-negative MKN45 cells. The cytotoxic activity against TE13 cells was augmented when target cells were pre-treated overnight with ZOL. These results suggest that ZOL in the presence of IL-2 can efficiently stimulate the proliferation of gamma delta T cells, which have cytotoxic properties against cancer cells. The use of zoledronate-activated killer (ZAK) cells should be encouraged in possible adoptive immunotherapy trials for patients with incurable cancer.
authors.affiliation: Department of Surgical Oncology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minami-ku, Hiroshima 734-8553, Japan.
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nagamine
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ohara
authors.forename: Takuhiro
authors.initials: T
authors.lastname: Ikeda
authors.forename: Morihito
authors.initials: M
authors.lastname: Okada
mesh_terms: D000970:Antineoplastic Agents / Q000008:administration & dosage; D016022:Case-Control Studies; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000276:immunology* / Q000378:metabolism; D004164:Diphosphonates / Q000008:administration & dosage*; D004938:Esophageal Neoplasms / Q000188:drug therapy* / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage*; D016219:Immunotherapy, Adoptive / Q000379:methods; D007376:Interleukin-2 / Q000008:administration & dosage*; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008213:Lymphocyte Activation; D009362:Neoplasm Metastasis; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D013601:T-Lymphocytes / Q000187:drug effects* / Q000378:metabolism*; D000077211:Zoledronic Acid
chemical_list: D000970:Antineoplastic Agents; D004164:Diphosphonates; D007093:Imidazoles; D007376:Interleukin-2; D016692:Receptors, Antigen, T-Cell, gamma-delta; D000077211:Zoledronic Acid