High-affinity interaction between gram-negative flagellin and a cell surface polypeptide results in human monocyte activation
High-affinity interaction between gram-negative flagellin and a cell surface polypeptide results in human monocyte activation
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DOI：
10.1128/iai.68.10.5525-5529.2000
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发表时间：
2000-10-01
影响因子：
3.1
通讯作者：
Mizel, SB
中科院分区：
文献类型：
--
作者：
McDermott, PF;Ciacci-Woolwine, F;Mizel, SB
来自不同革兰氏阴性菌的鞭毛诱导人单核细胞的肿瘤坏死因子α（TNF-α）和白细胞介素-β（IL-1 β）合成（F，Ciacci-Woolwine，P. F，McDermott和S. B。米泽尔感染Immun，67：5176-5185，1999）。在这项研究中，我们确定了纯化的鞭毛蛋白（FliC或FljB），即来自沙门氏菌肠道血清型，沙门氏菌肠道血清型的主要丝状蛋白。肠血清型鼠伤寒沙门氏菌和铜绿假单胞菌是人单核细胞和THP-1骨髓单核细胞产生TNF-α的极有效诱导剂，用1.5 × 10-（11）M鞭毛蛋白可获得最大TNF-α产量（EC，，诱变研究表明，鞭毛蛋白的中央高变区对于该蛋白的TNF-α诱导活性是必需的。尽管活性低于野生型蛋白，但仅由中央高变区组成的沙门氏菌鞭毛蛋白突变体在纳摩尔浓度下保留了大量TNF-α诱导活性。相反，保守的氨基和羧基末端区域无活性。高变区的突变分析显示，它包含两个同等活性的TNF-α诱导结构域。THP-1细胞对纯化的鞭毛蛋白的反应能力通过温和的胰蛋白酶处理细胞而显著降低。两者合计，我们的研究结果表明，从革兰氏阴性菌的鞭毛蛋白的精氨酸诱导活性的结果从这些蛋白质与单核细胞上的高亲和力细胞表面多肽受体的相互作用。
Flagella from diverse gram-negative bacteria induce tumor necrosis factor alpha (TNF-alpha) and interleukin-lp (IL-1 beta) synthesis by human monocytes (F, Ciacci-Woolwine, P. F, McDermott, and S. B. Mizel, Infect. Immun, 67:5176-5185, 1999), In this study, we establish that purified flagellin (FliC or FljB), the major filament protein from Salmonella enterica serovar Enteritidis, S. enterica serovar Typhimurium, and Pseudomonas aeruginosa, is an extremely potent inducer of TNP-alpha production by human monocytes and THP-1 myelomonocytic cells, Fifty percent of maximal TNF-alpha production (EC,,) was obtained with 1.5 x 10-(11) M flagellin (0.75 ng/ml), Mutagenesis studies revealed that the central hypervariable region of flagellin is essential for the TNF-alpha-inducing activity of the protein. Although less active than the wild-type protein, a Salmonella flagellin mutant composed of only the central hypervariable region retained substantial TNF-alpha-inducing activity at nanomolar concentrations, In contrast, the conserved amino- and carboxy-terminal regions are inactive. Mutational analysis of the hypervariable region revealed that it contains two equally active TNF-alpha-inducing domains. The ability of THP-1 cells to respond to purified flagellins is dramatically reduced by mild trypsin treatment of the cells. Taken together, our results demonstrate that the cytokine-inducing activity of flagellins from gram-negative bacteria results from the interaction of these proteins with high-affinity cell surface polypeptide receptors on monocytes.