Use of a photoactivatable taxol analogue to identify unique cellular targets in murine macrophages: identification of murine CD18 as a major taxol-binding protein and a role for Mac-1 in taxol-induced gene expression.
Use of a photoactivatable taxol analogue to identify unique cellular targets in murine macrophages: identification of murine CD18 as a major taxol-binding protein and a role for Mac-1 in taxol-induced gene expression.
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DOI：
10.4049/jimmunol.162.12.7335
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发表时间：
1999-06
影响因子：
4.4
通讯作者：
N. Bhat;P. Perera;J. Carboni;J. Blanco;D. Golenbock;T. Mayadas;S. Vogel
中科院分区：
文献类型：
--
作者：
N. Bhat;P. Perera;J. Carboni;J. Blanco;D. Golenbock;T. Mayadas;S. Vogel
紫杉醇是一种有效的抗肿瘤药物，可以结合β -微管蛋白并促进微管组装，导致细胞周期G2/M期的有丝分裂停滞。最近，紫杉醇在小鼠中被证明是一种有效的LPS模拟物，但在人巨噬细胞中没有，刺激信号通路和基因表达，与LPS没有区别。虽然在结构上与LPS无关，但紫杉醇的LPS模拟活性被LPS的无活性结构类似物阻断，这表明尽管紫杉醇具有物种限制性作用，但LPS和紫杉醇具有共同的受体/信号复合物，这可能在LPS诱导的人类疾病中起重要作用。为了鉴定推定共享的紫杉醇/LPS受体的成分，一种新的、光激活的紫杉醇类似物被用来鉴定小鼠巨噬细胞膜中独特的紫杉醇结合蛋白。检测到7种主要的紫杉醇结合蛋白，范围约为50至200 kDa。虽然光激活的紫杉醇类似物不能与CD14结合，但主要的紫杉醇结合蛋白被鉴定为CD18，这是β 2整合素家族中大约96 kda的共同成分。这一发现得到了Mac-1敲除小鼠巨噬细胞膜表达免疫反应性CD18和主要紫杉醇结合蛋白的失败的支持。此外，Taxol诱导的il - 12p40 mRNA在Mac-1敲除的巨噬细胞中显著降低，抗Mac-1 Ab阻断了Taxol和lps刺激的巨噬细胞中il - 12p70的分泌。由于CD18被描述为lps诱导的结合和信号转导的参与者，这些数据支持了小鼠CD18与紫杉醇的相互作用参与其促炎活性的假设。
Taxol, a potent antitumor agent that binds beta-tubulin and promotes microtubule assembly, results in mitotic arrest at the G2/M phase of the cell cycle. More recently, Taxol was shown to be a potent LPS mimetic in murine, but not in human macrophages, stimulating signaling pathways and gene expression indistinguishably from LPS. Although structurally unrelated to LPS, Taxol's LPS-mimetic activities are blocked by inactive structural analogues of LPS, indicating that despite the species-restricted effects of Taxol, LPS and Taxol share a common receptor/signaling complex that might be important in LPS-induced human diseases. To identify components of the putatively shared Taxol/LPS receptor, a novel, photoactivatable Taxol analogue was employed to identify unique Taxol-binding proteins in murine macrophage membranes. Seven major Taxol-binding proteins, ranging from approximately 50 to 200 kDa, were detected. Although photoactivatable Taxol analogue failed to bind to CD14, the prominent Taxol-binding protein was identified as CD18, the approximately 96-kDa common component of the beta2 integrin family. This finding was supported by the concomitant failure of macrophage membranes from Mac-1 knockout mice to express immunoreactive CD18 and the major Taxol-binding protein. In addition, Taxol-induced IL-12 p40 mRNA was markedly reduced in Mac-1 knockout macrophages and anti-Mac-1 Ab blocked secretion of IL-12 p70 in Taxol- and LPS-stimulated macrophages. Since CD18 has been described as a participant in LPS-induced binding and signal transduction, these data support the hypothesis that the interaction of murine CD18 with Taxol is involved in its proinflammatory activity.