• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Infection and immunity >Human phagocytes have multiple lipid A-binding sites.
【24h】

Human phagocytes have multiple lipid A-binding sites.

机译：人吞噬细胞具有多个脂质A结合位点。

获取原文
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Bacterial lipopolysaccharide (LPS) is a potent stimulus of cells, yet a target protein for LPS has not been defined. We used two approaches to define LPS-binding sites on cell surfaces: one assay measured binding of LPS-coated erythrocytes (ELPS) to cultured human cells, and a second measured binding of a radiolabeled probe, [32P]lipid IVA, to intact leukocytes. The first approach identified the CD11-CD18 family of integrins as lipid A-binding sites in human phagocytes, and the latter approach demonstrated saturable lipid A binding to intact murine macrophages, as well as to an approximately 95-kDa binding protein in purified membrane preparations. Because CD18 has a known molecular mass of 95 kDa, we sought to determine whether the [32P]lipid IVA-binding site was CD18. Binding of ELPS and [32P]lipid IVA to human macrophages was found to differ with respect to temperature, divalent cation dependence, cellular specificity, and susceptibility to competition by polyanions. To determine whether the previously described 95-kDa lipid A-binding protein was CD18, nitrocellulose-immobilized RAW264.7 membrane proteins were probed with [32P]lipid IVA and subsequently immunoblotted with a monoclonal antibody to murine CD18. The lipid A-binding protein has an electrophoretic mobility slightly different from that of CD18. Moreover, monoclonal antibodies and polyclonal antiserum to the CD11-CD18 family of proteins did not inhibit lipid IVA binding to intact human macrophages. Finally, mononuclear cells from two patients with CD18 deficiency failed to form rosettes with ELPS but bound [32P]lipid IVA normally. Thus, different LPS preparations may bind to cells in a CD18-dependent or -independent manner. Since ELPS is particulate and lipid IVA is a fine dispersion, the identity of the binding site may depend on the physical state of the LPS.
机译：细菌脂多糖（LPS）是细胞的强大刺激物，但尚未定义LPS的靶蛋白。我们使用了两种方法来定义细胞表面上的LPS结合位点：一种测定方法是测定LPS包被的红细胞（ELPS）与培养的人细胞的结合，另一种方法是测定放射性标记的探针[32P]脂质IVA与完整白细胞的结合。第一种方法将整联蛋白的CD11-CD18家族鉴定为人吞噬细胞中的脂质A结合位点，后一种方法证明了饱和的脂质A与完整的鼠巨噬细胞以及纯化的膜制品中约95 kDa的结合蛋白结合。 。因为CD18的已知分子量为95 kDa，所以我们试图确定[32P]脂质IVA结合位点是否为CD18。发现ELPS和[32P]脂质IVA与人巨噬细胞的结合在温度，二价阳离子依赖性，细胞特异性和对聚阴离子竞争的敏感性方面不同。为了确定先前描述的95 kDa脂质A结合蛋白是否为CD18，将硝化纤维固定的RAW264.7膜蛋白用[32P]脂质IVA探测，然后用鼠CD18单克隆抗体免疫印迹。脂质A结合蛋白的电泳迁移率与CD18略有不同。此外，针对CD11-CD18蛋白质家族的单克隆抗体和多克隆抗血清并未抑制脂质IVA与完整人类巨噬细胞的结合。最后，两名患有CD18缺乏症的患者的单核细胞未能与ELPS形成玫瑰花结，但正常结合[32P]脂质IVA。因此，不同的LPS制品可以以CD18依赖性或非依赖性方式结合细胞。由于ELPS是微粒，脂质IVA是精细分散体，因此结合位点的身份可能取决于LPS的物理状态。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号