Complement (C3b) interaction with the human granulocyte receptor: correlation of binding of fluid-phase radiolabeled ligand with histaminase release.
Complement (C3b) interaction with the human granulocyte receptor: correlation of binding of fluid-phase radiolabeled ligand with histaminase release.
复制标题
补体 (C3b) 与人粒细胞受体的相互作用：液相放射性标记配体的结合与组胺酶释放的相关性。
DOI：
10.4049/jimmunol.128.5.2313
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发表时间：
1982
影响因子：
4.4
通讯作者：
H. Colten
中科院分区：
文献类型：
--
作者：
J. Melamed;M. Arnaout;H. Colten
C3的主要裂解产物C3 b与其在人粒细胞上的受体的相互作用导致重要的生物学功能，包括吞噬作用、超氧化物生成和多种酶（包括组胺酶）的释放。我们已经确定了结合动力学和等温线的胰蛋白酶产生的液相二聚体C3 b在0摄氏度和37摄氏度使用人类多形核白细胞（PMN）。在37 ℃时，每个细胞的受体表观数量是0 ℃时的三倍（66，000对21，000），亲和力（Ka）略低（3.5 × 10（7）M-1对6 × 10（7）M-1）。C3 b二聚体结合被F（ab，）2抗C3 b受体抗体特异性抑制。C3 b二聚体在1 - 4 × 10（7）分子/细胞的浓度下以剂量依赖性方式诱导组胺酶释放，而在较低浓度下，注意到调理素化酵母聚糖诱导的释放的剂量依赖性抑制。这些作用与IgG无关。相反，C3 b单体未能表现出可测量的直接结合或诱导组胺酶释放。然而，在PMN与亲和连接的单体（抗C3 F（ab '）2-C3 b复合物）孵育后，确实发生了组胺酶释放。单价复合物不影响释放。单体C3、C3 c和C3 d没有影响;然而，亲和连接的C3和C3 c确实引起释放。
The interaction of C3b, the major cleavage product of C3, with its receptor on human granulocytes results in important biological functions, including phagocytosis, superoxide generation, and release of a variety of enzymes, including histaminase. We have determined the binding kinetics and isotherm of trypsin-generated fluid-phase dimeric C3b at both 0 degrees C and 37 degrees C using human polymorphonuclear leukocytes (PMN). At 37 degrees C the apparent number of receptors per cell was threefold greater than number at 0 degrees C (66,000 vs 21,000), and the affinity (Ka) was slightly less (3.5 X 10(7) M-1 vs 6 x 10(7) M-1). C3b dimer binding was specifically inhibited by a F(ab,)2 anti-C3b receptor antibody. C3b dimer induced histaminase release in a dose-dependent fashion at a concentration of 1 to 4 X 10(7) molecules/cell, whereas at lower concentrations a dose-dependent inhibition of opsonized zymosan-induced release was noted. These effects were independent of IgG. In contrast, C3b monomer failed to demonstrate measurable direct binding or to induce histaminase release. Histaminase release, however, did occur after incubation of PMN with affinity-linked monomer (anti-C3 F(ab')2-C3b complexes). Monovalent complexes did not affect release. Monomeric C3, C3c, and C3d were without effect; however, affinity-linked C3 and C3c did cause release.