title: Critical role of the Th1/Tc1 circuit for the generation of tumor-specific CTL during tumor eradication in vivo by Th1-cell therapy.
abstract: Th1 and Th2 cells obtained from OVA-specific T cell receptor transgenic mice completely eradicated the tumor mass when transferred into mice bearing A20-OVA tumor cells expressing OVA as a model tumor antigen. To elucidate the role of Tc1 or Tc2 cells during tumor eradication by Th1- or Th2-cell therapy, spleen cells obtained from mice cured of tumor by the therapy were re-stimulated with the model tumor antigen (OVA) for 4 days. Spleen cells obtained from mice cured by Th1-cell therapy produced high levels of IFN-gamma, while spleen cells from mice cured by Th2-cell therapy produced high levels of IL-4. Intracellular staining analysis demonstrated that a high frequency of IFN-gamma-producing Tc1 cells was induced in mice given Th1-cell therapy. In contrast, IL-4-producing Tc2 cells were mainly induced in mice after Th2-cell therapy. Moreover, Tc1, but not Tc2, exhibited a tumor-specific cytotoxicity against A20-OVA but not against CMS-7 fibrosarcoma. Thus, immunological memory essential for CTL generation was induced by the Th1/Tc1 circuit, but not by the Th2/Tc2 circuit. We also demonstrated that Th1-cell therapy is greatly augmented by combination therapy with cyclophosphamide treatment. This finding indicated that adoptive chemoimmunotherapy using Th1 cells should be applicable as a novel tool to enhance the Th1/Tc1 circuit, which is beneficial for inducing tumor eradication in vivo.
authors.affiliation: Division of Immunoregulation, Section of Disease Control, Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Chamoto
authors.forename: Akemi
authors.initials: A
authors.lastname: Kosaka
authors.forename: Takemasa
authors.initials: T
authors.lastname: Tsuji
authors.forename: Junko
authors.initials: J
authors.lastname: Matsuzaki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sato
authors.forename: Tsuguhide
authors.initials: T
authors.lastname: Takeshima
authors.forename: Kenji
authors.initials: K
authors.lastname: Iwakabe
authors.forename: Yuji
authors.initials: Y
authors.lastname: Togashi
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Koda
authors.forename: Takashi
authors.initials: T
authors.lastname: Nishimura
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000166:cytology* / Q000276:immunology*; D064987:Cell- and Tissue-Based Therapy / Q000379:methods*; D002478:Cells, Cultured; D005434:Flow Cytometry; D016219:Immunotherapy, Adoptive / Q000379:methods*; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000276:immunology* / Q000473:pathology; D013154:Spleen / Q000166:cytology; D015996:Survival Rate; D018417:Th1 Cells / Q000276:immunology* / Q000637:transplantation*; D018418:Th2 Cells / Q000276:immunology / Q000637:transplantation
chemical_list: D015847:Interleukin-4; D007371:Interferon-gamma