title: Role of interleukin 6 for differential responsiveness of naive and memory CD4+ T cells in CD2-mediated activation.
abstract: The present study was undertaken to elucidate different requirements for CD2-mediated activation of naive (CD45RO-) and memory (CD45RO+) CD4+ T cells. A mitogenic combination of anti-CD2 (anti-T11(2) and anti-T11(3] mAbs could effectively induce the proliferation of memory CD4+ T cells even in the absence of monocytes. In marked contrast, naive CD4+ T cells did not disclose any proliferative responses to anti-CD2 mAbs, when monocytes were absent in culture. This differential responsiveness of naive and memory CD4+ T cells appeared to be related largely to a difference in IL-6-producing ability between both populations. IL-6 among monocyte-derived cytokines could correct unresponsiveness of naive CD4+ T cells to anti-CD2 stimulation. Unlike naive CD4+ T cells, memory CD4+ T cells produced IL-6 by themselves, with its mRNA being expressed on anti-CD2 stimulation. Anti-IL-6R mAb significantly inhibited proliferation of memory CD4+ T cells seen in the anti-CD2-stimulated cultures without monocytes, indicating the involvement of their own production of IL-6 in CD2-mediated activation. The results suggest an essential role of IL-6 for triggering of CD4+ T cells via the CD2 molecule.
authors.affiliation: Department of Pediatrics, School of Medicine, Kanazawa University, Ishikawa, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Kasahara
authors.forename: T
authors.initials: T
authors.lastname: Miyawaki
authors.forename: K
authors.initials: K
authors.lastname: Kato
authors.forename: H
authors.initials: H
authors.lastname: Kanegane
authors.forename: A
authors.initials: A
authors.lastname: Yachie
authors.forename: T
authors.initials: T
authors.lastname: Yokoi
authors.forename: N
authors.initials: N
authors.lastname: Taniguchi
mesh_terms: D000328:Adult; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000502:physiology; D000945:Antigens, Differentiation, T-Lymphocyte / Q000276:immunology / Q000502:physiology*; D018801:CD2 Antigens; D015704:CD4 Antigens / Q000276:immunology*; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007376:Interleukin-2 / Q000378:metabolism; D015850:Interleukin-6 / Q000502:physiology*; D008213:Lymphocyte Activation / Q000187:drug effects*; D011971:Receptors, Immunologic / Q000276:immunology / Q000502:physiology*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology / Q000378:metabolism / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D015704:CD4 Antigens; D007376:Interleukin-2; D015850:Interleukin-6; D011971:Receptors, Immunologic