APS IgG通过非Fc受体途径诱导血液单核细胞表达TF活性

APS IgG stimulates monocytes to express TF activity,not via Fc receptor pathway

目的 :探讨抗磷脂综合征 (AntiphospholipidSyndrome ,APS)患者血清IgG体外诱导血液单核细胞表达组织因子(TissueFactor,TF)活性的作用及其作用途径。方法 :利用纯化的APS血清IgG及其F(ab’) 2 片段 ,以及抗磷脂结合蛋白 (如 β2glucoproteinⅠ ,β2 GPI)单克隆抗体RP 1分别刺激新鲜分离的外周血单核细胞 ,通过因子Xa的生成量 ,判断单核细胞TF活性的表达。结果 :与健康人血清IgG比较 ,APS患者血清IgG以及RP 1显著增强单核细胞的TF活性 ;外源性 β2 GPI可加强APSIgG的这一诱导作用 ;从APSIgG中纯化出的F(ab)’2 片段具有与完整IgG分子相同的刺激效应。结论 :抗磷脂抗体 ,主要为抗β2 GPI,以与抗原特异结合方式 ,通过非Fc受体途径诱导血液单核细胞表达TF活性 ,成为APS患者血栓形成的机理之一。

Objective:To investigate whether the IgG from patients with antiphospholipid syndrome(APS) is capable of stimulating blood monocytes to express tissue factor(TF) activity and to explore the mechanisms possibly concerned.Methods:Freshly isolated peripheral blood monocytes were cultured in media containing purified APS IgG or normal IgG or RP-1 [a monoclonal anti-β_2 glucoprotein I(α-β_2GPI)antibody] and/or other agonists and the TF activity on monocytes was investigated by measuring factor Ⅶa-dependent generation of factor Xa.Results:APS IgG as well as RP-1 significantly increased monocytes TF activity,comparing to normal IgG;exogenous β_2GPI enhanced the effects as the intact IgG molecule.Conclusion:That certain antiphospholipid antibodies,mainly anti-β_2GPI antibodies,induce monocytes TF activity in an antigen-specific manner,not via Fc receptor pathway,is contributed to the thrombotic diathesis in APS.