Savoia Dianella, Scutera Sara, Raimondo Stefania, Conti Stefania, Magliani Walter, Polonelli Luciano
Department of Clinical and Biological Sciences, University of Torino, at S. Luigi Gonzaga Hospital, Regione Gonzole 10, 10143 Orbassano (To), Italy.
Exp Parasitol. 2006 Jul;113(3):186-92. doi: 10.1016/j.exppara.2006.01.002. Epub 2006 Feb 17.
This study was undertaken to analyze the effect of an engineered, killer decapeptide (KP) on Leishmania major and Leishmania infantum promastigotes. The KP was synthesized on the basis of the sequence of a recombinant, single-chain anti-idiotypic antibody acting as a functional internal image of a yeast killer toxin. The evaluation of in vitro inhibitory activity of KP on L. major and L. infantum, release of intracellular green fluorescent protein (GFP) molecules by L. major, DNA fragmentation, and ultrastructural analysis (TEM) of L. infantum upon KP treatment were performed. KP presented antiproliferative and leishmanicidal activity with LC(50)/1 day of 58 and 72 microM for L. major and L. infantum, respectively. A dose-dependent decrease in proliferation and increase of killing of promastigotes was seen after KP treatment. No DNA fragmentation in L. infantum promastigotes or release of intracellular GFP molecules on peptide treatment of a GFP expressing L. major clone was demonstrated. Moreover the plasma-membrane was not disrupted, but, by TEM analysis, intracellular damage was observed.
本研究旨在分析一种工程化的杀伤十肽（KP）对硕大利什曼原虫和婴儿利什曼原虫前鞭毛体的作用。KP是根据作为酵母杀伤毒素功能内影像的重组单链抗独特型抗体的序列合成的。对KP对硕大利什曼原虫和婴儿利什曼原虫的体外抑制活性、硕大利什曼原虫释放细胞内绿色荧光蛋白（GFP）分子、DNA片段化以及KP处理后婴儿利什曼原虫的超微结构分析（透射电子显微镜）进行了评估。KP表现出抗增殖和杀利什曼原虫活性，对硕大利什曼原虫和婴儿利什曼原虫的LC(50)/1天分别为58和72微摩尔。KP处理后，前鞭毛体的增殖呈剂量依赖性降低，杀伤作用增强。在婴儿利什曼原虫前鞭毛体中未显示DNA片段化，在用表达GFP的硕大利什曼原虫克隆进行肽处理时也未显示细胞内GFP分子的释放。此外，质膜未被破坏，但通过透射电子显微镜分析观察到细胞内损伤。
