Benichou G, Voisin G A
Cell Immunol. 1987 May;106(2):304-17. doi: 10.1016/0008-8749(87)90174-2.
Antibody bipolar bridging of a cell membrane is the phenomenon by which an antibody specifically binds to the corresponding membrane antigen through its Fab and concomitantly to a membrane Fc receptor, through its Fc, thus forming a molecular bridge at the cell surface. This phenomenon, already described on mouse mast cells with anti-H-2 IgG1 antibodies and on guinea pig polymorphonuclear leukocytes with anti-GPLA IgG2 antibodies, presently is extended to and studied on guinea pig alveolar macrophages. These cell membranes present class I and class II MHC (GPLA) antigens as demonstrated by protein-A-sheep red blood cell rosetting and ELISA techniques. They also present Fc receptors for IgG2 and IgG1 as shown by an ELISA technique. IgG2 antibodies (but not their F(Ab')2) directed against corresponding class I or class II antigens induce a positive signal on alveolar macrophages, leading them to release H2O2 and superoxide anions as detected by a burst of chemiluminescence. This respiratory burst begins almost immediately, peaks at 4 to 11 min (depending on antibody concentrations), and decreases thereafter. There is a striking dose-effect curve. By contrast, IgG1 antibodies (but not there F(ab')2) induce a negative signal leading to a decrease of the background chemiluminescence. This type of mechanism appears potentially to be of importance in immune regulation.
抗体对细胞膜的双极桥接是一种现象，即抗体通过其Fab段特异性结合相应的膜抗原，并通过其Fc段同时结合膜Fc受体，从而在细胞表面形成分子桥。这种现象已在小鼠肥大细胞上用抗H-2 IgG1抗体以及在豚鼠多形核白细胞上用抗GPLA IgG2抗体进行了描述，目前已扩展到豚鼠肺泡巨噬细胞并对其进行研究。如蛋白A-绵羊红细胞花环试验和酶联免疫吸附测定技术所示，这些细胞膜呈现I类和II类主要组织相容性复合体（GPLA）抗原。如酶联免疫吸附测定技术所示，它们还呈现IgG2和IgG1的Fc受体。针对相应I类或II类抗原的IgG2抗体（但不是其F(Ab')2）在肺泡巨噬细胞上诱导阳性信号，导致它们释放过氧化氢和超氧阴离子，这可通过化学发光爆发检测到。这种呼吸爆发几乎立即开始，在4至11分钟达到峰值（取决于抗体浓度），此后下降。有一条明显的剂量效应曲线。相比之下，IgG1抗体（但不是其F(ab')2）诱导阴性信号，导致背景化学发光降低。这种机制类型在免疫调节中似乎可能具有重要意义。
