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Atypical Signaling Defects Prevent IL-2 Gene Expression in lpr/lpr CD4–CD8– Cells.
- Source :
- Journal of Biomedical Science; 1998, Vol. 5 Issue 4, p297-304, 8p
- Publication Year :
- 1998
-
Abstract
- T cells with CD4–CD8– (double negative, DN) phenotype in MRL-lpr/lpr mouse serve as a model to establish the correlation between the extremely low IL-2 gene expression and the specific signaling inactivation. The extent of nonresponsiveness in lpr DN cells was distinctive in several unusual defects. First, the poor IL-2 production in lpr DN cells could not be restored by supplement of signals known to augment IL-2 response in normal T cells. Second, the activations of both mitogen-activated protein (MAP) kinase and c-Jun N-terminal kinase (JNK) were attenuated in lpr DN cells upon direct activation by TPA/A23187. Third, IL-2 mRNA was degraded much faster in lpr DN cells than that in normal T cells. Fourth, of the four major transcriptional elements on IL-2 promoter, only AP-1 and nuclear factor of activated T cells (NFAT)-binding activities were suppressed in lpr DN T cells. Altogether, these results suggest that an extremely low level of IL-2 production in lpr DN T cells was due to both the increased instability of mRNA and the reduced activation of IL-2 gene promoter, the latter defect could be attributed to the inactivation of AP-1 and NF-AT as well as the poor activation of the upstream MAP kinase and JNK. [ABSTRACT FROM AUTHOR]
- Subjects :
- GENE expression
CELLS
INTERLEUKIN-2
INTERLEUKINS
T cells
Subjects
Details
- Language :
- English
- ISSN :
- 10217770
- Volume :
- 5
- Issue :
- 4
- Database :
- Complementary Index
- Journal :
- Journal of Biomedical Science
- Publication Type :
- Academic Journal
- Accession number :
- 11378124
- Full Text :
- https://doi.org/10.1159/000025343