Gharavi A E, Pierangeli S S, Colden-Stanfield M, Liu X W, Espinola R G, Harris E N
Department of Medicine, Morehouse School of Medicine, Atlanta, GA 30310, USA.
J Immunol. 1999 Sep 1;163(5):2922-7.
Antiphospholipid (aPL) Abs are associated with thrombosis, pregnancy loss, and thrombocytopenia in patients with systemic lupus erythematosus or primary antiphospholipid syndrome (APS). beta2-Glycoprotein I (beta2GPI), a phospholipid-binding serum protein, is involved in aPL binding to phospholipids. aPL can be generated in mice by immunization with beta2GPI, and these Abs are thrombogenic and cause pregnancy loss in mice. The objective of this study is to determine whether aPL induced by immunization with the phospholipid-binding site of beta2GPI are thrombogenic and whether they activate endothelial cells (EC) in vivo and in vitro. Murine monoclonal aPL were generated from spleen cells of a mouse immunized with GDKV, a synthetic 15-aa peptide spanning Gly274-Cys288 in the fifth domain of human beta2GPI, which represents the phospholipid-binding site of beta2GPI. The Abs generated had aPL and anti-beta2GPI activities. The effect of these Abs on thrombus formation and on EC activation in vivo was determined using a mouse model of thrombosis and microcirculation that enables examination of the adhesion of leukocyte to EC as an indication of EC activation as well as adhesion molecule expression using in vitro ELISA analysis. Mice injected with this monoclonal aPL showed a significant increase in leukocyte sticking and also produced larger thrombi that persisted longer. Exposure to GDKV-induced aPL for 4 h significantly increased surface Ag expression of E-selectin, ICAM-1, and VCAM-1. These data indicate that aPL induced by immunization with the phospholipid binding site of beta2GPI are thrombogenic and activate endothelial cells.
抗磷脂（aPL）抗体与系统性红斑狼疮或原发性抗磷脂综合征（APS）患者的血栓形成、流产和血小板减少有关。β2-糖蛋白I（β2GPI）是一种磷脂结合血清蛋白，参与aPL与磷脂的结合。通过用β2GPI免疫可在小鼠中产生aPL，这些抗体具有血栓形成性，并导致小鼠流产。本研究的目的是确定用β2GPI的磷脂结合位点免疫诱导的aPL是否具有血栓形成性，以及它们在体内和体外是否激活内皮细胞（EC）。从小鼠脾脏细胞中产生鼠单克隆aPL，该小鼠用GDKV免疫，GDKV是一种合成的15个氨基酸的肽，跨越人β2GPI第五结构域中的Gly274-Cys288，代表β2GPI的磷脂结合位点。产生的抗体具有aPL和抗β2GPI活性。使用血栓形成和微循环小鼠模型确定这些抗体对体内血栓形成和EC激活的影响，该模型能够检查白细胞与EC的粘附作为EC激活的指标，以及使用体外ELISA分析检测粘附分子表达。注射这种单克隆aPL的小鼠白细胞黏附显著增加，并且还产生了更大且持续时间更长的血栓。暴露于GDKV诱导的aPL 4小时后，E-选择素、细胞间黏附分子-1（ICAM-1）和血管细胞黏附分子-1（VCAM-1）的表面抗原表达显著增加。这些数据表明，用β2GPI的磷脂结合位点免疫诱导的aPL具有血栓形成性并激活内皮细胞。
