Mohri H, Tanabe J, Fujita H, Kanamori H, Ohkubo T
First Department of Internal Medicine, Yokohama City University School of Medicine, Japan.
Br J Haematol. 1993 Oct;85(2):341-7. doi: 10.1111/j.1365-2141.1993.tb03176.x.
The binding of fibrinogen to platelets requires the agonist activation of platelet membrane glycoprotein IIb/IIIa. We have now found an anti-fibrinogen polyclonal antibody (YCU-R3) that increases the fibrinogen affinity of GPIIb/IIIa-binding function (activation) and subsequent platelet aggregation. The addition of intact IgG, F(ab)2 fragments or Fab fragments induced platelet aggregation. The antibody-mediated fibrinogen binding was specific and saturable. This binding was inhibited by native fibrinogen, the RGDS peptide, the peptide of the C-terminus gamma chain of fibrinogen (gamma 397-411), and the anti-GPIIb/IIIa monoclonal antibody (LJ-CP8). The antibody-dependent fibrinogen binding was similar to that induced by ADP. Moreover, after pretreatment with the anti-fibrinogen antibody and fibrinogen, formalin-fixed platelets bound to fibrinogen saturably. These results suggest that this anti-fibrinogen antibody may function as partial agonist.
纤维蛋白原与血小板的结合需要血小板膜糖蛋白IIb/IIIa的激动剂激活。我们现已发现一种抗纤维蛋白原多克隆抗体（YCU-R3），它可增加GPIIb/IIIa结合功能（激活）的纤维蛋白原亲和力以及随后的血小板聚集。完整IgG、F(ab)2片段或Fab片段的添加均可诱导血小板聚集。抗体介导的纤维蛋白原结合具有特异性且可饱和。这种结合可被天然纤维蛋白原、RGDS肽、纤维蛋白原C末端γ链肽（γ397-411）以及抗GPIIb/IIIa单克隆抗体（LJ-CP8）抑制。抗体依赖性纤维蛋白原结合类似于ADP诱导的结合。此外，在用抗纤维蛋白原抗体和纤维蛋白原预处理后，甲醛固定的血小板可与纤维蛋白原饱和结合。这些结果表明，这种抗纤维蛋白原抗体可能起部分激动剂的作用。
