Expression of the Epstein ± Barr virus (EBV) transforming LMP1 in B cells activates the transcription factor NF-kB and induces phenotypic changes through two distinct domains in the cytoplasmic C-terminus of the protein. The aa 187 ± 231 domain of LMP1, which is important for growth transformation, binds tumour necrosis factor (TNF) receptor associated factor (TRAF) 1 and TRAF3 and this interaction mediates subsequent signalling events. The TRAFs also associate with CD40, a member of the TNFR family, which upon ligation activates NF-kB and induces phenotypic changes similar to those mediated by LMP1. This study demonstrates that LMP1 expression in carcinoma cell lines and SV40-transformed keratinocytes results in induction of the pleiotropic cytokine interleukin 6 (IL6), an e ect which is also observed upon CD40 ligation. The mechanism by which either LMP1 expression or CD40 ligation induces IL6 production was found to be NF-kB-dependent. Mutational analysis identi®ed domains in the C-terminus of LMP1 which are important for NF-kB activation and IL6 secretion. LMP1 and CD40 share a common PxQxT core TRAF binding motif and mutations in or adjacent to this sequence impaired the ability of LMP1 or CD40 to induce NF-kB activation and IL6 secretion. The importance of TRAF interactions in mediating these e ects was con®rmed using dominant negative TRAF2 and TRAF3 mutants which also identi®ed di erences in the signalling events mediated by the two NF-kB activating domains of LMP1. A20, an anti-apoptotic protein which interacts with TRAF2 and blocks CD40-mediated NF-kB activity, also blocked NF-kB and IL6 secretion in LMP1-transfected epithelial cells. These results suggest that LMP1 regulates IL6 production in epithelial cells in a manner similar to CD40 ligation and implicate TRAFs as common mediators in the transduction of signals generated via the CD40 and LMP1 pathways. As a role for IL6 in regulating epithelial cell growth has previously been suggested, the control of IL6 secretion via the CD40 and LMP1 pathways may have implications for the growth of both normal and transformed epithelial cells.
In a neonatal and pediatric intensive care unit population, ventilation in neurally adjusted ventilatory assist mode was associated with improved patient-ventilator synchrony and lower peak airway pressure when compared with pressure-support ventilation with a pneumatic trigger. Ventilating patients in this new mode seem to be safe and well tolerated.
In this study, we find that CD45RO+ memory populations of CD4+ T lymphocytes express the vascular endothelial growth factor (VEGF) receptors KDR and Flt-1 at both the mRNA and protein levels. Furthermore, by Western blot analysis, we find that VEGF increases the phosphorylation and activation of ERK and Akt within CD4+CD45RO+ T cells. These VEGF-mediated signaling responses were inhibited by a KDR-specific small interfering RNA in a VEGF receptor-expressing Jurkat T cell line and by SU5416, a pharmacological KDR inhibitor, in CD4+CD45RO+ T cells. We also find that VEGF augments mitogen-induced production of IFN-γ in a dose-dependent manner (p < 0.001) and significantly (p < 0.05) increases directed chemotaxis of this T cell subset. Collectively, our results for the first time define a novel function for VEGF and KDR in CD45RO+ memory T cell responses that are likely of great pathophysiological importance in immunity.
The chromosome region 17p13.3 is thought to encode a tumour suppressor gene involved in sporadic breast cancer and other malignancies. Physical ordering of markers has been carried out by a series of multicolour fluorescent in situ hybridisation (FISH) experiments, using isolated yeast artificial chromosomes (YACs) and cosmids. Eight polymorphic markers ordered within this new physical map and one external marker were used to investigate the pattern of loss of heterozygosity in a panel of 40 sporadic breast tumour patients. The data revealed a region of high loss (60%) within distal 17p13.3, defined by markers D17S926, D17S695 and D17S849 which mapped close together. A contig of YACs was constructed physically linking these three markers.
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