Leishmaniasis treatment: Macrophage scavenger receptor

利什曼病治疗：巨噬细胞清道夫受体

• 批准号: 7146804
• 负责人: ROBERT O'Mara RYAN
• 金额: $ 40.13万
• 依托单位: CHILDREN'S HOSPITAL & RES CTR AT OAKLAND
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-01 至 2011-05-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7146804
• 关键词: antibiotics; apolipoproteins; clinical research; human; leishmaniasis; lipids; macrophage; particle; scavenger receptor; tissues

DESCRIPTION (provided by applicant): The long-term goal of our research is to apply the unique structural features and lipid interaction properties of apolipoproteins to the treatment of leishmaniasis. Apolipoproteins possess the capacity to transform phospholipid vesicles into discrete, nanometer scale, disc-shaped, complexes termed nanodisks (ND). Studies to date have shown that incorporation of specific hydrophobic drug molecules into ND is feasible. ND loaded with the polyene antibiotic amphotericin B (ampB) effectively inhibits fungal growth in vitro. Furthermore, in vivo experiments in Leishmania major infected mice have revealed that ampB-ND show efficacy at non-toxic doses. To investigate the molecular basis of this effect, pharmacokinetic studies will be performed to determine plasma decay kinetics and tissue distribution of ampB administered as ND. The apolipoprotein component of ND will be subject to chemical and/or genetic alteration to create a molecule that is recognized by the class A scavenger receptor (SR-A) on macrophages. Site-directed mutagenesis of the apolipoprotein component of ND will be performed to remove specific positively charged residues and position negatively charged amino acid residues such that they create a recognition site for SR-A. Chinese hamster ovary cells transfected with SR-A will be employed in binding experiments designed to measure the SR-A binding activity of engineered apolipoproteins. The efficacy of ampB-ND harboring apolipoprotein components targeted to SR-A will be evaluated in a mouse model of leishmaniasis. Studies will be performed to examine the potential enhancement achieved by incorporating ampB with a second hydrophobic anti-leishmanial drug, hexadecylphosphocholine, into ND. The extent to which ampB-ND induce parasite destruction in cells that harbor L. major will be assessed and the effect of ampB-ND exposure on the T cell/cytokine response of human peripheral blood mononuclear cells determined. The results of these experiments should offer new opportunity for the treatment of leishmaniasis, provide further insight into the ligand recognition characteristics of SR-A, and document the utility of ND as vehicles for targeted delivery of hydrophobic drugs.

描述（由申请人提供）：我们研究的长期目标是将载脂蛋白独特的结构特征和脂质相互作用特性应用于利什曼病的治疗。载脂蛋白具有将磷脂囊泡转化为离散的、纳米级的、盘状的复合物（称为纳米盘（ND））的能力。迄今为止的研究表明，将特定的疏水性药物分子掺入ND中是可行的。 ND 负载多烯抗生素两性霉素 B (ampB) 可有效抑制体外真菌生长。此外，在利什曼原虫主要感染小鼠中进行的体内实验表明，ampB-ND 在无毒剂量下显示出功效。为了研究这种效应的分子基础，将进行药代动力学研究以确定作为 ND 施用的 ampB 的血浆衰变动力学和组织分布。 ND 的载脂蛋白成分将经过化学和/或遗传改变，产生一种可被巨噬细胞上的 A 类清道夫受体 (SR-A) 识别的分子。将进行 ND 载脂蛋白成分的定点诱变，以去除特定的带正电荷的残基并定位带负电荷的氨基酸残基，以便它们创建 SR-A 的识别位点。转染 SR-A 的中国仓鼠卵巢细胞将用于结合实验，旨在测量工程化载脂蛋白的 SR-A 结合活性。携带针对 SR-A 的载脂蛋白成分的 ampB-ND 的功效将在利什曼病小鼠模型中进行评估。将进行研究以检验将 ampB 与另一种疏水性抗利什曼原虫药物十六烷基磷酸胆碱合并到 ND 中所实现的潜在增强作用。将评估 ampB-ND 在携带 L. Major 的细胞中诱导寄生虫破坏的程度，并确定 ampB-ND 暴露对人外周血单核细胞 T 细胞/细胞因子反应的影响。这些实验的结果应该为利什曼病的治疗提供新的机会，进一步深入了解 SR-A 的配体识别特征，并记录 ND 作为疏水性药物靶向递送载体的效用。