| Project/Area Number |
08671265
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Hematology
|
|---|
| Research Institution | University of Occupational and Environmental Health |
|---|
Principal Investigator |
TSUKADA Junichi University of Occupational and Environmental Health, School of Medicine, assistant professor, 医学部, 助手 (20227367)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MISAGO Masahiro University of Occupational and Environmental Health, School of Health Sciences,, 産業保健学部, 助教授 (30157474)
ETO Sumiya University of Occupational and Environmental Health, School of Medicine, assista, 医学部, 教授 (90010347)
|
|---|
| Project Period (FY) |
1996 – 1997
|
| Project Status |
Completed (Fiscal Year 1997)
|
| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
|
|---|
| Keywords | Tax / HTLV-I / transcription / Interleukin 1 / インターロイキン 1 |
|---|
| Research Abstract |
The human T-cell leukemia virus type I (HTLV-I) , which infects a wide variety of mammalian cells including monocytes and macrophages, encodes a transactivating protein designated as Tax. We now report that Tax induces the human proIL-1beta (IL1B) gene promoter in monocytic cells. In our transient transfection assays using human THP-1 monocytic cells, a chloramphenicol acetyltransferase (CAT) construct containing the IL1B promoter sequence between positions-131 and+12 showed an approximately 90-fold increase in activity following cotransfection of a Tax expression vector. Moreover, Tax synergized with LPS to induce the IL1B promoter activity. Analyzes of specific nucleotide substitutions further indicated that the Tax-induced transcriptional activation requires two transcription factor binding motifs within the IL1B promoter ; One is a binding site for NF-IL6 (CCAAT/enhancer binding protein beta C/EBPbeta) , which belongs to the basic region-leucine zipper (bZIP) family and the other f
… More
or Spi-1 (PU.1) , which is an Ets family protein found principally in monocytes, macrophages and B lymphocytes. In electrophoretic mobility shift assays (EMSA) using in vivo THP-1 nuclear extracts, Tax expression in THP-1 monocytic cells significantly increased binding of the two factors to their target IL1B promoter sequences. However, in contrast to NF-IL6 and Spi-1, DNA binding activity of Oct-1, a ubiquitously expressed octamer-binding protein was not affected by Tax. Additional EMSA using in vitro translated proteins also showed that recombinant Tax enhances DNA binding of both of recombinant NF-IL6 and Spi-1 proteins. These data were supported by our glutathione S-transferase (GST) -pulldown data, which indicated that Tax physically interacts with the two proteins. Based upon the results obtained from the present study, we conclude that the IL1B promoter is a Tax-responsive sequence as a result of ability of Tax to induce binding of NF-IL6 and Spi-1 to IL1B promoter sequence through protein-protein interaction. Less
|
