Fatty Alcohol Synthesis and Virulence in Leishmania

 描述（由申请方提供）：利什曼原虫属是一种原生动物寄生虫，在全球热带和亚热带地区引起重要的人类疾病，因此是一个主要的公共卫生问题。醚脂质是利什曼原虫膜的重要组成部分，更重要的是，是各种毒力因子的结构组分，如非常丰富的细胞表面脂磷酸聚糖和糖基磷脂酰肌醇（GPI）锚定蛋白酶GP63。两者在寄生虫的整个生命周期中都起着至关重要的作用。目前用于临床试验的醚脂类药物如米替福新，在体外和体内均能抑制寄生虫生长，并可能干扰醚脂生物合成途径。这支持了这种代谢途径可以作为进一步药物设计的目标的想法。我们的前期研究已经证实，L.主要的二羟基丙酮磷酸酰基转移酶LmDAT和烷基二羟基丙酮磷酸合酶LmADS参与毒力因子脂磷酸聚糖和细胞醚脂质的合成，其在寄生虫发病机制中起关键作用。我们的初步结果表明，i）LmFAR参与脂肪醇的生产，这是合成醚脂质所必需的，和ii）LmFAR是重要的寄生虫的生长。这项建议将测试的中心假设，利什曼原虫过氧化物酶体脂肪酰辅酶A还原酶LmFAR是必不可少的醚脂代谢和毒力因子脂磷酸聚糖的产生，因此，发病机制。为了验证这一假设，我们建议使用两个特定目标，结合联合收割机的多学科方法，涉及分子生物学，遗传学，生物化学和细胞生物学技术。在具体目标1中，我们将研究LmFAR的酶性质及其亚细胞定位。在具体目标2中，我们将评估LmFAR在醚脂生物合成、毒力和对醚脂药物的敏感性中的重要性。了解LmFAR的功能对于开发预防和治疗利什曼原虫感染的新策略非常重要。此外，该项目将通过为贫困学生提供学习生物医学研究基础知识的众多机会，改善圣约翰大学的研究环境。

 DESCRIPTION (provided by applicant): Leishmania species are protozoan parasites that cause important human diseases in the tropics and subtropics worldwide and, thus, represent a major public health problem. Ether lipids are important constituents of Leishmania membranes, and more importantly, are structural components of various virulence factors, such as the very abundant cell surface lipophosphoglycan and the glycosylphosphatidylinositol(GPI)-anchored protease GP63. Both play crucial roles during the entire life cycle of the parasite. Ether lipid-based drugs such as miltefosine, currently used in clinical trials, inhibit parasite growth in vitr and in vivo, and are likely to interfere with the ether lipid biosynthetic pathway. This supports te idea that this metabolic route can be targeted for further drug design. Our previous studies have established that the first two enzymes of the ether lipid biosynthetic pathway in L. major, dihydroxyacetonephosphate acyltransferase LmDAT and alkyl dihydroxyacetonephosphate synthase LmADS, are implicated in the synthesis of the virulence factor lipophosphoglycan and cellular ether lipids, which play a crucial role in parasite pathogenesis. Our preliminary results have suggested that i) LmFAR is involved in the production of fatty alcohols which are essential for the synthesis of ether lipids, and ii) LmFAR is important for growth of the parasite. This proposal will test the central hypothesis that Leishmania peroxisomal fatty acyl-CoA reductase LmFAR is essential for ether lipid metabolism and generation of the virulence factor lipophosphoglycan, and consequently, for pathogenesis. To test this hypothesis, we propose to use two Specific Aims that combine a multidisciplinary approach that involves molecular biology, genetics, biochemistry, and cell biology techniques. In Specific Aim 1, we will investigate the enzymatic properties of LmFAR and its subcellular localization. In Specific Aim 2, we will assess the importance of LmFAR in ether lipid biosynthesis, virulence, and sensitivity to ether lipid-based drugs. Understanding the function of LmFAR is important for the development of novel strategies to prevent and treat Leishmania infections. In addition, this project will enhance the research environment at St. John's University by providing underprivileged students with numerous opportunities to learn the fundamentals of biomedical research.