Augmentation of human monocyte opsonin-independent phagocytosis by fragments of human plasma fibronectin.
Augmentation of human monocyte opsonin-independent phagocytosis by fragments of human plasma fibronectin.
复制标题
人血浆纤连蛋白片段增强人单核细胞不依赖于调理素的吞噬作用。
DOI：
10.1073/pnas.78.6.3649
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发表时间：
1981
影响因子：
11.1
通讯作者：
Austen,KF
中科院分区：
文献类型：
--
作者：
Czop,JK;Kadish,JL;Austen,KF
通过明胶亲和层析分离的人血浆纤维连接蛋白以剂量依赖性的方式增加了在完全合成的培养基中摄取人替代补体途径颗粒激活剂的人单核细胞的数量。纤维连接蛋白的作用对这些颗粒激活剂是选择性的，并不扩展到那些摄取依赖于IgG的颗粒，并且在单核细胞预处理时没有观察到。44万道尔顿血浆纤维连接蛋白单克隆抗体亲和层析显示，在具有吞噬活性的明胶亲和纯化的纤维连接蛋白制剂中，只有12-53%的蛋白质与抗体结合。活性制剂单克隆抗体亲和层析后洗脱的蛋白，占所用蛋白的10-43%，每微克蛋白的活性比起始明胶亲和纯化的材料高2- 10倍。因此，增加人类单核细胞摄取替代途径颗粒激活剂百分比的活性被抗原定义为血浆纤维连接蛋白。仅含有完整的44万道尔顿纤维连接蛋白的制剂也与单克隆抗体结合并从单克隆抗体中洗脱出来，但它们不能增强吞噬作用。当失活的44万道尔顿血浆纤维连接蛋白受到有限的胰蛋白酶裂解时，产生增强吞噬活性，该活性与单克隆抗体制备的亲和柱结合并被洗脱，从而表明血浆纤维连接蛋白的增强活性存在于裂解片段中。
Human plasma fibronectin isolated by gelatin-affinity chromatography increases in a dose-dependent fashion the number of human monocytes that ingest particulate activators of the human alternative complement pathway in a fully synthetic medium. The fibronectin effect is selective for these particulate activators, does not extend to particles whose ingestion is dependent upon opsonization with IgG, and is not observed with pretreatment of the monocytes. Affinity chromatography with monoclonal antibody to plasma fibronectin of 440,000 daltons reveals that only 12-53% of the protein in a phagocytically active gelatin-affinity-purified fibronectin preparations is bound to the antibody. The protein eluted after affinity chromatography with monoclonal antibody of active preparations, which represented 10-43% of the protein applied, exhibits a 2- to 10-fold increment of activity per microgram of protein above the starting gelatin-affinity-purified material. Thus, the activity that augments the percent of human monocytes ingesting particulate activators of the alternative pathway is antigenically defined as plasma fibronectin. Preparations containing only intact 440,000-dalton fibronectin are also bound to and eluted from the monoclonal antibody, but they fail to augment phagocytosis. When inactive 440,000-dalton plasma fibronectin is subjected to limited trypsin cleavage, phagocytosis-enhancing activity develops that is bound to and elutes from the affinity column prepared with monoclonal antibody, thereby indicating that the enhancing activity of plasma fibronectin resides in cleavage fragments.