- 作者: Hong-Erh Liang; Yi-Ping Hsueh; Chia-Cheng Wu; Shu-Ching Hsu; Shou-Hwa Han; Ming-Zong Lai
- 作者服務機構: a Institute of Molecular Biology, Academia Sinica;; b Graduate Institute of Microbiology and Immunology, National Yang-Ming University;; c Graduate Institute of Microbiology, and; d Graduate Institute of Immunology, National Taiwan University, School of Medicine, Taipei, Taiwan/ROC
- 中文摘要: --
- 英文摘要: 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 non-responsiveness 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 Ipr 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.
- 中文關鍵字: --
- 英文關鍵字: Fas; lpr/lpr; SLE; IL-2 gene expression ; JNK; MAP kinase ; Signaling defect