title: Antitumor activity of interleukin-18 against the murine T-cell leukemia/lymphoma EL-4 in syngeneic mice.
abstract: Interleukin (IL)-18 induces interferon (IFN)-gamma production by T cells and natural killer (NK) cells, and augments NK cell activity in mouse spleen cell cultures. It has recently been demonstrated that in vivo administration of IL-18 to mice results in considerable antitumor effects against syngeneic Meth A sarcoma. In this study, the antitumor effects of IL-18 against murine T-cell leukemia (EL-4) were evaluated. EL-4 proliferation was resistant in vitro to IL-18 and IFN-gamma. When 4 x 10(6) EL-4 cells were transplanted intravenously, the antitumor effects of IL-18 were not pronounced, and only a slight prolongation of the mean survival times was observed. The antitumor effects of IFN-gamma were even less apparent than those of IL-18. However, when mice were transplanted intravenously with 5 x 10(5) EL-4 cells, the extent of experimental visceral dissemination of EL-4 was markedly reduced in mice treated subcutaneously with IL-18, resulting in an increase in survival time with some mice even cured. Although IL-18 was highly effective at inhibiting the development of EL-4 lymphoma dissemination in C57BL/6 mice, it could not inhibit the development of dissemination in mutant C57BL/6 beige (bg/bg) mice lacking NK cell activity. The efficacy of IL-18 was also significantly reduced in nude mice lacking T cells. These results suggest that antitumor efficacy of IL-18 is mediated primarily by NK cells, but that T cells are also required for the complete antitumor efficacy of IL-18.
authors.affiliation: Fujisaki Institute, Hayashibara Biochemical Laboratories, Inc., Okayama, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Akamatsu
authors.forename: Norie
authors.initials: N
authors.lastname: Arai
authors.forename: Toshiharu
authors.initials: T
authors.lastname: Hanaya
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Arai
authors.forename: Tadao
authors.initials: T
authors.lastname: Tanimoto
authors.forename: Mitsukiyo
authors.initials: M
authors.lastname: Fujii
authors.forename: Keizo
authors.initials: K
authors.lastname: Kohno
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Micallef
authors.forename: Masao
authors.initials: M
authors.lastname: Ikeda
authors.forename: Masashi
authors.initials: M
authors.lastname: Kurimoto
mesh_terms: D000818:Animals; D016207:Cytokines / Q000187:drug effects / Q000378:metabolism; D004195:Disease Models, Animal; D005260:Female; D007371:Interferon-gamma / Q000187:drug effects* / Q000276:immunology; D020382:Interleukin-18 / Q000494:pharmacology*; D015458:Leukemia, T-Cell / Q000188:drug therapy*; D016399:Lymphoma, T-Cell / Q000188:drug therapy*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009368:Neoplasm Transplantation; D012016:Reference Values; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
chemical_list: D016207:Cytokines; D020382:Interleukin-18; D007371:Interferon-gamma