title: Induction of interleukin 2 receptor gene expression by p40x encoded by human T-cell leukemia virus type 1.
abstract: Human T-cell leukemia virus type 1 (HTLV-1) is an etiologic agent of adult T-cell leukemia (ATL). A viral product, p40x, encoded by the pX sequence of HTLV-1 is a trans-acting transcriptional activator of the long terminal repeat (LTR) and has been suspected of involvement in leukemogenesis, activating the cellular genes. The cellular interleukin-2 (IL-2) and its receptor (IL-2R), the latter of which is expressed on ATL leukemic cells, were shown to be transiently induced by transfection of plasmid pMTPX expressing pX in two T-cell lines, Jurkat and HSB-2, but not in other human T- or B-cell lines. The cell type specificity of IL-2R induction by pX expression was the same as that by phytohaemagglutinin/phorbol ester activation, indicating the requirement for some specific cellular factors or a certain state of cellular differentiation. Induction of IL-2 and IL-2R at mRNA level was also demonstrated in transfected cells. Transfections with mutants of pMTPX in which the open reading frames for p40x, p27x-III and p21x-III were inactivated indicated that p40x alone was sufficient for induction of the IL-2R in inducible cells. This induction of the IL-2R by p40x of HTLV-1 may contribute to preferential proliferation of HTLV-1 infected cells at an early stage of ATL development and eventually increase the number of putative target cells for malignant transformation.
mesh_terms: D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D017977:Deltaretrovirus / Q000235:genetics*; D005455:Fluorescent Antibody Technique; D005796:Genes; D005814:Genes, Viral; D006801:Humans; D011971:Receptors, Immunologic / Q000096:biosynthesis / Q000235:genetics*; D015375:Receptors, Interleukin-2; D012191:Retroviridae Proteins / Q000235:genetics*; D015534:Trans-Activators; D014158:Transcription, Genetic; D014162:Transfection
chemical_list: D011971:Receptors, Immunologic; D015375:Receptors, Interleukin-2; D012191:Retroviridae Proteins; D015534:Trans-Activators