Bacterial lipopolysaccharide stimulates protein tyrosine phosphorylation in macrophages.
Bacterial lipopolysaccharide stimulates protein tyrosine phosphorylation in macrophages.
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DOI：
10.1073/pnas.88.10.4148
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发表时间：
1991-05
影响因子：
11.1
通讯作者：
S. L. Weinstein;M. Gold;A. DeFranco
中科院分区：
文献类型：
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作者：
S. L. Weinstein;M. Gold;A. DeFranco
脂多糖（LPS）是革兰氏阴性菌的膜组分，通过激活巨噬细胞、B淋巴细胞和免疫系统的其它细胞来刺激免疫应答。LPS激活这些细胞的机制还不清楚。由于蛋白质酪氨酸磷酸化似乎是介导细胞反应的主要细胞内信号传导事件，我们研究了LPS是否改变巨噬细胞中的酪氨酸磷酸化。我们发现大肠杆菌K235 LPS增加了RAW 264.7小鼠巨噬细胞系和C3 H/HeSNJ小鼠腹腔巨噬细胞中几种蛋白质的酪氨酸磷酸化。酪氨酸磷酸化的变化可检测到4-5分钟，15分钟达到最大值，并在30-60分钟后下降。蛋白酪氨酸磷酸化增加与LPS刺激后，在100 pg/ml和10 ng/ml是最大的。类似的变化，酪氨酸磷酸化诱导沙门氏菌R595 LPS和LPS的生物活性结构域，脂质A，但不是由非活性的脂质A衍生物N2-单酰基葡糖胺1-磷酸。佛波醇12-肉豆蔻酸酯13-乙酸酯也刺激蛋白质酪氨酸磷酸化，但一些调制的蛋白质与LPS磷酸化的蛋白质不同。用酪氨酸激酶抑制剂除莠霉素A处理RAW 264.7细胞，抑制LPS刺激的酪氨酸磷酸化和LPS刺激的花生四烯酸代谢产物的释放。因此，增加的蛋白酪氨酸磷酸化是一种快速的LPS激活的信号传导事件，其可以介导RAW 264.7细胞中花生四烯酸代谢物的释放。
Lipopolysaccharide (LPS), a membrane component of Gram-negative bacteria, stimulates immune responses by activating macrophages, B lymphocytes, and other cells of the immune system. The mechanisms by which LPS activates these cells are poorly characterized. Since protein tyrosine phosphorylation appears to be a major intracellular signaling event that mediates cellular responses, we examined whether LPS alters tyrosine phosphorylation in macrophages. We found that Escherichia coli K235 LPS increased tyrosine phosphorylation of several proteins in the RAW 264.7 murine macrophage cell line and in resident peritoneal macrophages from C3H/HeSNJ mice. Changes in tyrosine phosphorylation were detectable by 4-5 min, reached a maximum by 15 min, and declined after 30-60 min. Protein tyrosine phosphorylation increased following stimulation with LPS at 100 pg/ml and was maximal with 10 ng/ml. Similar changes in tyrosine phosphorylation were induced by Salmonella minnesota R595 LPS and by the biologically active domain of LPS, lipid A, but not by the inactive lipid A derivative N2-monoacylglucosamine 1-phosphate. Phorbol 12-myristate 13-acetate also stimulated protein tyrosine phosphorylation, but some of the modulated proteins were different than those phosphorylated by LPS. Treatment of RAW 264.7 cells with a tyrosine kinase inhibitor, herbimycin A, inhibited both LPS-stimulated tyrosine phosphorylation and LPS-stimulated release of arachidonic acid metabolites. Thus, increased protein tyrosine phosphorylation is a rapid LPS-activated signaling event that may mediate release of arachidonic acid metabolites in RAW 264.7 cells.