Kavoosi Gholamreza, Ardestani Sussan K, Kariminia Amina, Tavakoli Zahra
Institute of Biochemistry and Biophysics, University of Tehran, Iran.
Korean J Parasitol. 2006 Mar;44(1):35-41. doi: 10.3347/kjp.2006.44.1.35.
Protozoan parasites of the genus Leishmania cause a number of important human diseases. One of the key determinants of parasite infectivity and survival is the surface glycoconjugate lipophosphoglycan (LPG). In addition, LPG is shown to be useful as a transmission blocking vaccine. Since culture supernatant of parasite promastigotes is a good source of LPG, we made attempts to characterize functions of the culture supernatant, and membrane LPG isolated from metacyclic promastigotes of Leishmania major. The purification scheme included anion-exchange chromatography, hydrophobic interaction chromatography and cold methanol precipitation. The purity of supernatant LPG (sLPG) and membrane LPG (mLPG) was determined by SDS-PAGE and thin layer chromatography. The effect of mLPG and sLPG on nitric oxide (NO) production by murine macrophages cell line (J774.1A) was studied. Both sLPG and mLPG induced NO production in a dose dependent manner but sLPG induced significantly higher amount of NO than mLPG. Our results show that sLPG is able to promote NO production by murine macrophages.
利什曼原虫属的原生动物寄生虫会引发多种重要的人类疾病。寄生虫感染性和生存的关键决定因素之一是表面糖缀合物脂磷壁酸（LPG）。此外，LPG被证明可作为一种传播阻断疫苗。由于寄生虫前鞭毛体的培养上清液是LPG的良好来源，我们尝试对培养上清液以及从硕大利什曼原虫循环后期前鞭毛体中分离出的膜LPG的功能进行表征。纯化方案包括阴离子交换色谱、疏水相互作用色谱和冷甲醇沉淀。通过SDS-PAGE和薄层色谱法测定上清液LPG（sLPG）和膜LPG（mLPG）的纯度。研究了mLPG和sLPG对小鼠巨噬细胞系（J774.1A）产生一氧化氮（NO）的影响。sLPG和mLPG均以剂量依赖性方式诱导NO产生，但sLPG诱导产生的NO量明显高于mLPG。我们的结果表明，sLPG能够促进小鼠巨噬细胞产生NO。
