Freedman D O, Ottesen E A
Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, Bethesda, Maryland 20892.
J Infect Dis. 1988 Sep;158(3):556-62. doi: 10.1093/infdis/158.3.556.
In humans chronically infected with Schistosoma mansoni, total hepatic blood flow and normal hepatic function appear to be maintained by neovascularization of the periportal fibrotic tissue. To identify possible stimuli for this neovascularization, we evaluated parasite-derived products for their ability to activate endothelial cells in vitro. Soluble egg antigen (SEA) of S. mansoni at concentrations as low as 30 ng/mL induced a marked proliferation of human umbilical vein endothelial cells (HUVE) that increased in a dose-dependent fashion; equivalent effects were seen with bovine adrenal and murine lung endothelial cells. Live, intact S. mansoni eggs secreted a soluble factor that stimulated HUVE in a manner similar to crude SEA. In contrast, adult worm extracts of S. mansoni had no significant effect on endothelial cell proliferation in any of the three cell lines tested. Preliminary biochemical characterization showed the activity to be protease sensitive and heat stable. S. mansoni SEA, in the absence of inflammatory cells, can stimulate endothelial cell proliferation in vitro.
在慢性感染曼氏血吸虫的人体中，肝门周围纤维化组织的新生血管形成似乎维持了肝脏的总血流量和正常肝功能。为了确定这种新生血管形成的可能刺激因素，我们评估了寄生虫衍生产物在体外激活内皮细胞的能力。曼氏血吸虫的可溶性虫卵抗原（SEA）浓度低至30 ng/mL时就能诱导人脐静脉内皮细胞（HUVE）显著增殖，且呈剂量依赖性增加；牛肾上腺内皮细胞和鼠肺内皮细胞也有类似效果。活的完整曼氏血吸虫虫卵分泌一种可溶性因子，其刺激HUVE的方式与粗制SEA相似。相比之下，曼氏血吸虫成虫提取物对所测试的三种细胞系中的任何一种内皮细胞增殖均无显著影响。初步生化特性表明，该活性对蛋白酶敏感但热稳定。在没有炎性细胞的情况下，曼氏血吸虫SEA可在体外刺激内皮细胞增殖。
