The cytosolic tryparedoxin of Leishmania infantum is essential for parasite survival
The cytosolic tryparedoxin of Leishmania infantum is essential for parasite survival
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DOI：
10.1016/j.ijpara.2008.11.009
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发表时间：
2009-05-01
影响因子：
4
通讯作者：
Tomas, Ana M.
中科院分区：
文献类型：
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作者：
Romao, Susana;Castro, Helena;Tomas, Ana M.
婴儿利什曼原虫胞质Tryparedosin(LiTXN1)可被视为潜在的药物靶向候选药物。这个氧化还原活性分子属于硫氧还蛋白超家族，是L幼虫过氧化氢清除级联反应的成员之一，也可能参与其他细胞过程，如DNA合成或宿主与寄生虫的相互作用。为了验证LiTXN1作为药物靶点的有效性，我们采用了基因替换策略。我们观察到，两个染色体LiTXN1等位基因的替换只有在寄生虫与该基因的外体副本互补时才可能。此外，与携带空载体的对照寄生虫相反，在没有药物压力的情况下，昆虫和哺乳动物阶段的L婴儿都保留了LiTXN1的异体拷贝。这些结果证实了LiTXN1在寄生虫整个生命周期中的重要性，即在致病的无鞭毛体阶段。此外，获得的数据显示，该基因的一个等位基因的中断只会导致LiTXN1的表达减少25%。尽管这不会影响前鞭毛体的生长和对过氧化氢的敏感性，但体外感染分析表明，野生型LiTXN1是L婴儿最佳毒力所必需的。(C)2008澳大利亚寄生虫学会有限公司出版。保留所有权利。
Leishmania infantum cytosolic tryparedoxin (LiTXN1) can be regarded as a potential candidate for drug targeting. This redox active molecule, which belongs to the thioredoxin superfamily, is one constituent of the hydroperoxide elimination cascade in L infantum and may also be involved in other cellular processes such as DNA synthesis or host-parasite interaction. In order to validate LiTXN1 as a drug target we have employed a gene replacement strategy. We observed that substitution of both chromosomal LiTXN1 alleles was only possible upon parasite complementation with an episomal copy of the gene. Furthermore, contrary to control parasites carrying the empty vector, both the insect and the mammalian stages of L infantum retained the episomal copy of LiTXN1 in the absence of drug pressure. These results confirm the essentiality of LiTXN1 throughout the life cycle of the parasite, namely in the disease-causing amastigote stage. In addition, the data obtained showed that disruption of one allele of this gene leads only to a 25% reduction in the expression of LiTXN1. Even though this does not affect promastigote growth and susceptibility to hydrogen peroxide, ex vivo infection assays suggest that wild-type levels of LiTXN1 are required for optimal L infantum virulence. (C) 2008 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.