棘口吸虫雷蚴中的疟色素形成

Hemozoin formation in Echinostoma trivolvis rediae.

作者信息

Pisciotta John M, Ponder Elizabeth L, Fried Bernard, Sullivan David

机构信息

The Malaria Research Institute, Bloomberg School of Public Health, Johns Hopkins University, 615 North Wolfe Street, Baltimore, MD 21205, USA.

出版信息

Int J Parasitol. 2005 Sep;35(10):1037-42. doi: 10.1016/j.ijpara.2005.03.020.

DOI:10.1016/j.ijpara.2005.03.020

PMID:16019007

Abstract

Rediae of the trematode Echinostoma trivolvis, from naturally infected Helisoma trivolvis snails, form a black pigment while inside the snail host. Here we examine the black pigment to show that the insolubility characteristics in detergent and weak base solution are identical to Plasmodium falciparum hemozoin. Laser desorption mass spectrometry of the purified pigment demonstrates the presence of heme. Examination of purified pigment under polarized light microscopy illuminates ordered birefringent crystals. Field emission in lens scanning electron microscopy reveals irregular ovoid crystals of 200-300 nm in diameter. The purified pigment crystals seeded extension of monomeric heme onto the crystal which by Fourier Transform Infrared analysis is beta-hematin. Rediae of a second echinostome parasite, Echinostoma caproni, from experimentally infected Biomphalaria glabrata, do not produce measurable or recoverable heme crystals. These observations are consistent with heme crystal formation by a hematophagous parasite within a non-vertebrate intermediate host.

摘要

来自自然感染的静水椎实螺（Helisoma trivolvis）的三带棘口吸虫（Echinostoma trivolvis）雷蚴，在螺宿主内会形成黑色色素。在此，我们对该黑色色素进行研究，结果表明其在去污剂和弱碱溶液中的不溶性特征与恶性疟原虫的疟色素相同。对纯化色素进行激光解吸质谱分析显示存在血红素。在偏光显微镜下检查纯化色素可观察到有序的双折射晶体。透镜场发射扫描电子显微镜显示直径为200 - 300纳米的不规则卵形晶体。纯化的色素晶体促使单体血红素在晶体上延伸，通过傅里叶变换红外分析可知其为β - 血红素。来自实验感染的光滑双脐螺（Biomphalaria glabrata）的第二种棘口吸虫寄生虫——卡氏棘口吸虫（Echinostoma caproni）的雷蚴，不会产生可测量或可回收的血红素晶体。这些观察结果与吸血寄生虫在非脊椎动物中间宿主体内形成血红素晶体的情况一致。