Signal transduction triggered by lipid A-like molecules in 70Z/3 pre-B lymphocyte tumor cells.
Signal transduction triggered by lipid A-like molecules in 70Z/3 pre-B lymphocyte tumor cells.
复制标题
70Z/3 前 B 淋巴细胞肿瘤细胞中脂质 A 样分子触发的信号转导。
DOI：
10.1016/s1388-1981(99)00014-1
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Raetz,CR
中科院分区：
文献类型：
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作者：
Garrett,TA;Rosser,MF;Raetz,CR
脂多糖的脂A(内毒素)部分可引起包括巨噬细胞、淋巴细胞和单核细胞在内的多种细胞的快速反应。在CD1470z/3前B淋巴细胞肿瘤细胞中，这些反应包括激活MAPK同源物p38，激活NF-κB，转录κ轻链，导致表面Ig M的组装。在这项工作中，我们探索了与脂类结构相关的反应的特异性，以及在对照和κ转染70z/3(CD14-70z/3)细胞中，在NF-CD14B激活之前对p38激酶活性的要求。P38特异性抑制剂SB203580被用来阻断细胞内p38激酶的活性。CD14-70z/3细胞与1-50μM SB203580孵育，然后用脂多糖刺激。制备核提取液，用凝胶迁移率改变分析法检测核转录因子κB的活性。SB203580不能抑制脂多糖诱导的NF-κB活化。此外，在缺乏CD14的70z/3细胞中，内毒素未能激活p38酪氨酸磷酸化，尽管适当较高剂量的内毒素能迅速激活NF-κB并产生强劲的表面免疫球蛋白M。无论是否存在κ，脂类内毒素拮抗剂都能完全阻断脂蛋白对p38磷酸化、核因子-CD14B活化和表面表达的刺激作用。酸性甘油磷脂和神经酰胺在该系统中既不作为激动剂也不作为拮抗剂来模拟类脂A分子。我们的数据支持这一假设，即脂质A介导的细胞激活需要刺激假定的脂A传感器，该传感器位于CD14下游，但在p38和NF-κB的上游。
The lipid A (endotoxin) moiety of lipopolysaccharide (LPS) elicits rapid cellular responses from many cell types, including macrophages, lymphocytes, and monocytes. In CD14 transfected 70Z/3 pre-B lymphocyte tumor cells, these responses include activation of the MAP kinase homolog, p38, activation of NF-κB, and transcription of κ light chains, leading to the assembly of surface IgM. In this work, we explored the specificity of the response with regard to lipid structure, and the requirement for p38 kinase activity prior to NF-κB activation in control and CD14 transfected 70Z/3 (CD14-70Z/3) cells. A p38-specific inhibitor, SB203580, was used to block p38 kinase activity in cells. CD14-70Z/3 cells were incubated with 1–50 μM SB203580, and then stimulated with LPS. Nuclear extracts were prepared, and NF-κB activation was measured using an electrophoretic mobility shift assay. SB203580 did not inhibit LPS induced NF-κB activation. In addition, LPS failed to activate p38 tyrosine phosphorylation in 70Z/3 cells lacking CD14, in spite of rapid NF-κB activation and robust surface IgM production with appropriate higher doses of LPS. LPS stimulation of p38 phosphorylation, NF-κB activation, and surface IgM expression were all blocked completely by lipid A-like endotoxin antagonists whether or not CD14 was present. Acidic glycerophospholipids and ceramides did not mimic lipid A-like molecules either as agonists or antagonists in this system. Our data support the hypothesis that lipid A-mediated activation of cells requires stimulation of a putative lipid A sensor that is downstream of CD14, but upstream of p38 and NF-κB.