Skip Navigation


International Immunology Advance Access originally published online on January 3, 2005
International Immunology 2005 17(2):207-215; doi:10.1093/intimm/dxh201
This Article
Right arrow Full Text Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
17/2/207    most recent
dxh201v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrow Search for citing articles in:
ISI Web of Science (3)
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Matsumura-Arioka, Y.
Right arrow Articles by Nakamura, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Matsumura-Arioka, Y.
Right arrow Articles by Nakamura, M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?


© 2005 The Japanese Society for Immunology

Identification of two distinct elements mediating activation of telomerase (hTERT) gene expression in association with cell growth in human T cells

Yuuki Matsumura-Arioka, Kiyoshi Ohtani, Toshifumi Hara, Ritsuko Iwanaga and Masataka Nakamura

Human Gene Sciences Center, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan

Correspondence to: M. Nakamura; E-mail: naka.gene{at}cmn.tmd.ac.jp

Lymphocytes are exceptional among normal somatic cells in that they express high telomerase activity like germline and malignant cells. We investigated the induction of telomerase in human T cells in association with cell growth. IL-2 significantly augmented the expression of mRNA for human telomerase reverse transcriptase (hTERT), a rate-limiting component of telomerase, in PHA-activated human peripheral blood leukocytes. An isolated 5'-flanking sequence (–3927–+51) of the hTERT gene was examined for its promoter activity in an IL-2-dependent human T cell line Kit 225. Addition of IL-2 into quiescent Kit 225 cells induced activation of the hTERT promoter. Reporter assays with mutant fragments of the hTERT promoter further revealed that IL-2-dependent activation was independently mediated by two elements within the +9–+51 regions. The two elements showed similar kinetics of activation in response to IL-2, which coincided with the G1 to S phase transition of the cell cycle. Interestingly, introduction of mutation in the elements increased background promoter activities in resting T cells in the absence of IL-2. Our results demonstrate that the hTERT promoter may be suppressed by the elements and IL-2 may signal for de-suppression in association with promotion of cell growth. IL-2-dependent activation of the hTERT promoter may be necessary for prevention from senescence induced by extraordinary cell division during immune reactions.

Keywords: gene regulation, hTERT, IL-2, T lymphocytes

Transmitting editor: K. Sugamura


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.