| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Centro de Biología Molecular "Severo Ochoa" Consejo Superior de Investigaciones Cientificas-Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain
Dysregulation of cytokine secretion plays an important role in AIDS
pathogenesis. Here, we demonstrate that expression of HIV-1 Tat protein
in Jurkat cells induces a severe impairment of IL-2 but not TNF gene
transcription. Interestingly, this inhibition correlates with the
effect of the viral protein on the transactivation of the CD28RE/AP1
composite element (-164/-154), but not with that observed on the
NFAT/AP1 site of the IL-2 gene promoter, neither with the effect on
NF-
B- nor AP1-independent binding sites. Endogenous expression of
Tat induced a decrease in the amount of the specific protein complex
bound to the CD28RE/AP1 probe after PMA plus calcium ionophore
stimulation. This effect was accompanied by qualitative alterations of
the AP1 complex. Thus, in wild-type Jurkat cells, c-jun was absent from
the complex, whereas in Tat-expressing cells, c-jun was increasingly
recruited overtime. By contrast, similar amounts of
c-rel and a small amount of NFAT1 were detected
both in wild type and in Jurkat Tat+ cells. Furthermore,
Tat not only induced the participation of c-jun in the cooperative
complex but also a decrease in its transactivation activity alone or in
combination with c-rel. Thus, the interaction of Tat
with the components of this rel/AP1 cooperative complex seems to induce
quantitative and qualitative alterations of this complex as activation
progresses, resulting in a decrease of IL-2 gene transcription.
Altogether our results suggest the existence of tuned mechanisms that
allow the viral protein to specifically affect cooperative interactions
between transcription factors.
This article has been cited by other articles:
|
|
 |
|
  K. Gee, J. B. Angel, W. Ma, S. Mishra, N. Gajanayaka, K. Parato, and A. Kumar Intracellular HIV-Tat Expression Induces IL-10 Synthesis by the CREB-1 Transcription Factor through Ser133 Phosphorylation and Its Regulation by the ERK1/2 MAPK in Human Monocytic Cells J. Biol. Chem., October 20, 2006; 281(42): 31647 - 31658. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. M. Hidalgo-Estevez, E. Gonzalez, C. Punzon, and M. Fresno Human immunodeficiency virus type 1 Tat increases cooperation between AP-1 and NFAT transcription factors in T cells J. Gen. Virol., June 1, 2006; 87(6): 1603 - 1612. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Rizzi, M. P. Crippa, R. E. Jeeninga, B. Berkhout, F. Blasi, G. Poli, and M. Alfano Pertussis Toxin B-Oligomer Suppresses IL-6 Induced HIV-1 and Chemokine Expression in Chronically Infected U1 Cells via Inhibition of Activator Protein 1 J. Immunol., January 15, 2006; 176(2): 999 - 1006. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J.-F. Fortin, C. Barat, Y. Beausejour, B. Barbeau, and M. J. Tremblay Hyper-responsiveness to Stimulation of Human Immunodeficiency Virus-infected CD4+ T Cells Requires Nef and Tat Virus Gene Products and Results from Higher NFAT, NF-{kappa}B, and AP-1 Induction J. Biol. Chem., September 17, 2004; 279(38): 39520 - 39531. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. A. Calzado, R. Sancho, and E. Munoz Human Immunodeficiency Virus Type 1 Tat Increases the Expression of Cleavage and Polyadenylation Specificity Factor 73-Kilodalton Subunit Modulating Cellular and Viral Expression J. Virol., July 1, 2004; 78(13): 6846 - 6854. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. W. Chung, B. Y. Kang, and T. S. Kim Inhibition of Interleukin-4 Production in CD4+ T Cells by Peroxisome Proliferator-Activated Receptor-{gamma} (PPAR-{gamma}) Ligands: Involvement of Physical Association between PPAR-{gamma} and the Nuclear Factor of Activated T Cells Transcription Factor Mol. Pharmacol., November 1, 2003; 64(5): 1169 - 1179. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. P. Kohm, A. Mozaffarian, and V. M. Sanders B Cell Receptor- and {beta}2-Adrenergic Receptor-Induced Regulation of B7-2 (CD86) Expression in B Cells J. Immunol., June 15, 2002; 168(12): 6314 - 6322. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
