LEISHMANIA-MACROPHAGE CELLULAR INTERACTIONS IN VITRO

我们的长期目标是阐明以下问题： 利什曼原虫感染巨噬细胞，以及这些寄生虫如何 然后在这些地方分化、生存和繁衍 吞噬细胞。了解生物化学和分子生物学 这种宿主-寄生虫细胞相互作用的机制将 为开发更有效的化疗和/或免疫疗法提供线索 利什曼病的治疗和预防。 利什曼原虫主要表面糖蛋白(Gp63)的纯化 前鞭毛体，发现是一种在酸性时活跃的金属蛋白酶 PH值。它似乎调停了利什曼原虫与 巨噬细胞和保护寄生虫免受降解 吞噬酶体。利什曼原虫毒力表型与 DNA标记的gp63丰度与衣霉素抗性 衣霉素敏感N-基因的扩增和水平增加 二醇中的乙酰氨基葡萄糖-1-磷酸转移酶(NAGT) 路径。 这是上述研究细胞的工作的继续 Gp63毒力株的生物学、生化和分子生物学研究 决定簇及其N-糖基化功能的调节 在墨西哥利什曼原虫Miciana spp.具体如下：(1)进一步 开发用金属蛋白酶gp63的特性研究 特异性抑制剂；(2)无鞭毛体gp63的纯化 用于研究其蛋白酶活性；(3)了解 通过研究gp63在吞噬酶体内的保护作用 巨噬细胞与gp63包被脂质体的相互作用 Gp63的胞内路径分析及其结构 多聚糖和利什曼原虫NAGT了解其调节作用 N-糖基化在gp63毒力作用中的作用 行列式；(5)NAGT和其他势的特征 衣霉素耐药细胞扩增DNA中的毒力基因 表达载体的分子克隆。 这些研究的结果不仅有助于我们理解 巨噬细胞胞内寄生中的利什曼毒力 而且还有金属蛋白酶、糖蛋白和二羟基乙醇途径。 将军。

Our long term objectives are to elucidate the questions of how Leishmania infect macrophages, and how these parasites subsequently differentiate, survive and multiply in these phagocytes. Understanding the biochemical and molecular mechanisms of such host-parasite cellular interactions will provide leads for developing more effective chemo and/or immuno- therapy and -prophylaxis for leishmaniasis. A Leishmania major surface glycoprotein (gp63) was purified from promastigotes and found to be a metallo-protease active at acidic pH. It appears to mediate the binding of Leishmania to macrophages and to protect parasites from degradation in phagolysosomes. Leishmania virulent phenotype is associated with the abundance of gp63 and tunicamycin-resistance, marked by DNA amplification and an increased level of tunicamycin-sensitive N- acetylglucosamine-1-phosphate transferase (NAGT) in the dolichol pathway. This is a continuation of above-mentioned work to study cell biology, biochemistry and molecular biology of gp63 as a virulent determinant and the regulation of its function by N-glycosylation in Leishmania mexicana spp. as follows: (1) Further characterization of gp63 as a metallo-protease for developing specific inhibitors; (2) Purification of gp63 from amastigotes for studying its protease activity; (3) Understanding the protective functions of gp63 in phagolysosomes by studying interactions of macrophages with gp63-coated liposomes; (4) Analyses of intracellular routing of gp63, the structure of its glycans and Leishmania NAGT to understand the regulatory role of N-glycosylation in the function of gp63 as a virulent determinant; (5) Characterization of NAGT and other potential virulent genes in amplified DNA of tunicamycin-resistant cells by molecular cloning in expression vectors. The results of these studies will help not only our understanding leishmanial virulence in intracellular parasitism of macrophages but also metallo-protease, glycoprotein and dolichol pathway in general.