Transient induction of IL-2 receptor in cultured T cell lines by HTLV-1 LTR-linked tax-1 gene.
Human lymphotropic virus, HTLV-1, encodes in its proviral genome a transcriptional activator protein, tax-1, that may be responsible for the development of virus-induced adult T cell leukemia (ATL), possibly through the aberrant activation of the genes for interleukin-2 (IL-2) and one of its receptor (IL-2R) components, the IL-2 receptor alpha-chain (IL-2R alpha). In the present study, an expression plasmid containing tax-1 cDNA under the control of HTLV-1 LTR was introduced into mouse and human CD4-positive T cell lines. Analysis of the established cell clones revealed a number of interesting features: (i) a limited fraction of the total cell population (less than 25% in each clone) was positive for IL-2R alpha; (ii) the IL-2R alpha expression was not permanent, as the IL-2R alpha positive and negative cells could convert either way. The experimental data suggest that the observed heterogeneity in IL-2R alpha expression in the transformants is due to a cell-cycle-regulated expression and function of tax-1. Furthermore, a proportion of the induced IL-2R in EL-4 was in high-affinity form, suggesting the association of the IL-2R alpha and the IL-2R beta chain (p70-75) components.
Doi
T
T
Institute for Molecular and Cellular Biology, Osaka University, Japan.
Hatakeyama
M
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Itoh
S
S
Taniguchi
T
T
D000818:Animals; D001483:Base Sequence; D002453:Cell Cycle; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D005434:Flow Cytometry; D005814:Genes, Viral; D005822:Genetic Vectors; D015368:Human T-lymphotropic virus 1 / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D015375:Receptors, Interleukin-2 / Q000096:biosynthesis* / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*; D015534:Trans-Activators / Q000235:genetics*; D014162:Transfection
D004279:DNA, Viral; D015345:Oligonucleotide Probes; D015375:Receptors, Interleukin-2; D015534:Trans-Activators