title: HTLV-I Tax trans-activation and cell growth signaling.
abstract: We have cloned two genes for cell surface molecules, capable of delivering the intracellular signals, which are modulated for their expression by Tax. One is the gamma chain of the interleukin-2 (IL-2) receptor which is suggested to be critical for IL-2-dependent growth of human T-cell leukemia virus type I (HTLV-I) infected cells. The gamma chain is upregulated by Tax, like the IL-2 receptor alpha chain. This upregulation may compensate the gamma chain downregulation after IL-2 binding, presumably resulting in more frequent growth of HTLV-I infected T cells. The other is gp34 that was initially identified as a molecule specifically expressed on HTLV-I-infected T cells. gp34 has been demonstrated to bind OX40 which belongs to the tumor necrosis factor (TNF) receptor family. We found that HTLV-I Tax induces expression of gp34 and OX40, and that normal T cell transiently express both gp34 and OX40 upon antigenic stimulation. Collectively, it may be possible that HTLV-I-infected T cells are in a predisposition to growth due to modulated expression by HTLV-I Tax of gp34/OX40 and the gamma chain.
authors.affiliation: Human Gene Sciences Center, Tokyo Medical and Dental University, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: N
authors.initials: N
authors.lastname: Takasawa
authors.forename: K
authors.initials: K
authors.lastname: Ohbo
authors.forename: N
authors.initials: N
authors.lastname: Higashimura
authors.forename: K
authors.initials: K
authors.lastname: Ohtani
authors.forename: Y
authors.initials: Y
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Sugamura
mesh_terms: D002455:Cell Division; D002460:Cell Line; D003001:Cloning, Molecular; D015536:Down-Regulation; D016356:Gene Products, tax / Q000096:biosynthesis / Q000378:metabolism*; D017930:Genes, Reporter; D015368:Human T-lymphotropic virus 1 / Q000502:physiology*; D006801:Humans; D008156:Luciferases / Q000096:biosynthesis; D012333:RNA, Messenger / Q000096:biosynthesis; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000502:physiology*; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis / Q000502:physiology*; D053262:Receptors, OX40; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology / Q000821:virology*; D014158:Transcription, Genetic; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D016356:Gene Products, tax; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D053262:Receptors, OX40; D018124:Receptors, Tumor Necrosis Factor; D011993:Recombinant Fusion Proteins; C505716:TNFRSF4 protein, human; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D008156:Luciferases