Connors V A, Lodes M J, Yoshino T P
Department of Pathobiological Sciences, University of Wisconsin-Madison 53706.
J Invertebr Pathol. 1991 Nov;58(3):387-95. doi: 10.1016/0022-2011(91)90185-s.
Excretory-secretory (E-S) products obtained during in vitro Schistosoma mansoni miracidium-to-sporocyst transformation were found to contain a 108-kDa polypeptide capable of scavenging both exogenously produced and M-line Biomphalaria glabrata hemocyte-derived superoxide (O2-) anions. Separation of crude transformation E-S products using HPLC and ion exchange chromatography resulted in the separation of two isoforms of the 108-kDa molecule. Using an in vitro phagocytosis assay, both isoforms were found to be capable of reducing O2- production by phagocytically stimulated M-line B. glabrata hemocytes without cell loss and without a concomitant reduction in phagocytosis. Although parasite antioxidant molecules appear to play a role in the evasion of host oxidative defense systems in several parasite-vertebrate systems, no previous reports of a parasite antioxidant capability against the potential of oxidative killing by invertebrate defense systems has been reported. In conjunction with the previously confirmed production of O2- by B. glabrata hemocytes and reports of reactive oxygen metabolite production by hemocytes from several molluscan species, these results indicate that reactive forms of oxygen and parasite antioxidant systems may play an important role in the determination of compatibility in the trematode-mollusc relationship.
在体外曼氏血吸虫毛蚴向胞蚴转化过程中获得的排泄-分泌（E-S）产物，被发现含有一种108 kDa的多肽，它能够清除外源产生的以及光滑双脐螺M系血细胞衍生的超氧阴离子（O₂⁻）。使用高效液相色谱（HPLC）和离子交换色谱对粗制的转化E-S产物进行分离，得到了108 kDa分子的两种同工型。通过体外吞噬试验发现，这两种同工型都能够在不导致细胞损失且不伴随吞噬作用降低的情况下，减少吞噬刺激的光滑双脐螺M系血细胞产生O₂⁻。尽管在几种寄生虫-脊椎动物系统中，寄生虫抗氧化分子似乎在逃避宿主氧化防御系统中发挥作用，但此前尚无关于寄生虫抗氧化能力抵抗无脊椎动物防御系统氧化杀伤潜力的报道。结合此前已证实的光滑双脐螺血细胞产生O₂⁻以及几种软体动物血细胞产生活性氧代谢产物的报道，这些结果表明，活性氧形式和寄生虫抗氧化系统可能在吸虫-软体动物关系的相容性决定中发挥重要作用。
