title: Sequential involvement of two distinct CD4+ regulatory T cells during the course of transplantable tumor growth and protection from 3-methylcholanthrene-induced tumorigenesis by CD25-depletion.
abstract: The involvement of two phenotypically different regulatory T cells in different stages of tumor growth was investigated. Treatment of BALB/c mice with anti-CD25 monoclonal antibody (mAb) (PC61), but not anti-CD4 mAb (GK1.5) before RL male 1 or Meth A inoculation caused tumor rejection. On the other hand, treatment of BALB/c mice with anti-CD4 mAb (GK1.5) but not anti-CD25 mAb (PC61) on day 6 after inoculation of the same tumors caused rejection. The findings suggest that CD4+CD25+ T cells downregulated the rejection response in the early stage of tumor growth. On the other hand, putative CD4+CD25- T cells downregulated the tumor rejection response in the late stage. Both CD4+CD25+ and putative CD4+CD25- T cells appeared to inhibit the efficient generation of cytotoxic T lymphocytes (CTL). The present study also demonstrated that the treatment of BALB/c mice with anti-CD25 mAb (PC61) at 4 or 6 weeks after 3-methylcholanthrene (3-MC) inoculation retarded tumor occurrence and prolonged survival.
authors.affiliation: Department of Immunology, Okayama University Graduate School of Medicine and Dentistry, Okayama 700-8558, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Tawara
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Take
authors.forename: Akiko
authors.initials: A
authors.lastname: Uenaka
authors.forename: Yuji
authors.initials: Y
authors.lastname: Noguchi
authors.forename: Eiichi
authors.initials: E
authors.lastname: Nakayama
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism* / Q000473:pathology; D002273:Carcinogens; D002455:Cell Division; D015536:Down-Regulation; D005434:Flow Cytometry; D008297:Male; D008748:Methylcholanthrene; D051379:Mice; D008807:Mice, Inbred BALB C; D009368:Neoplasm Transplantation; D009369:Neoplasms / Q000139:chemically induced; D009381:Neoplasms, Radiation-Induced / Q000473:pathology; D015375:Receptors, Interleukin-2 / Q000502:physiology*; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism; D013997:Time Factors; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D002273:Carcinogens; D015375:Receptors, Interleukin-2; D008748:Methylcholanthrene