Studies of Trypanosoma cruzi trans-sialidase using transfection method

转染法研究克氏锥虫唾液酸转移酶

• 批准号: 10670232
• 负责人: UEMURA Haruki
• 金额: $ 2.3万
• 依托单位: Nagasaki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10670232/
• 关键词: Trypanosoma; Trans-sialidase; Transfection; Sialic acid; Signal peptide; Chagas' disease; Gene family; IL-6; 局在; 分泌; シャガス病

Trypanosoma cruzi trans-sialidase catalyzes the transfer of a(2-3) linked sialic acid from host derived glycoconjugates to the parasite surface mucin-like acceptor molecules and vice versa. Several lines of evidence suggest that trans-sialidase and sialylated molecules on the parasite and host cell surface are important for cell invasion and parasite escape from host defense systems. The enzyme expressed in infective trtpomastigote stage (T-TS) is located on the parasite surface through a glycosyl phosphatididylinositol (GPI) anchor, and readily shed into culture supernatant in vitro and into the bloodstream of animals in, vivo. On the other hands, trans-sialidase is also detectable in noninfective epimastigote stage, however this is not released into the medium nor recognized by antibodies against the carboxyl terminal repeats of T-TS. Actually, there are two types of trans-sialidase gene families, which are localized at different chromosomes and controlled under different regulation. … More We have studied functions, molecular mechanisms of expression and localization of these two different types of trans-sialidases.We have obtained several genes of these two families and prepared some derivatives, hybrid trans-sialidase molecules based on comparison. Both N-terminal sequences of these two types, in which there are no similarities, are highly hydrophobic and functioned as signal peptides of secretary and membrane proteins. C-terminal hydrophobic region of T-TS which is replaced by GPI-anchor structure seems to be not important for secretion. The structural feature of N- and C-terminal regions of trans-sialidase expressed in epimastigote (E-TS) are similar to those of T-TS. Molecular studies of different localization of two TS even structural similarity are ongoing using hybrid molecules and molecular tag epitope.The collaboration research with Dr. Pereira, Tafts University could have shown that T-TS C-terminal repeats induce IL-6 secretion from human endothelial cells and peripheral blood mononuclear cells. Less

克氏锥虫反式唾液酸酶催化（2-3）连接的唾液酸从宿主糖缀合物转移到寄生虫表面黏液样受体分子，反之亦然。一些证据表明，寄生虫和宿主细胞表面的反式唾液酸酶和唾液酸化分子对细胞入侵和寄生虫逃离宿主防御系统很重要。该酶通过糖基磷脂酰肌醇（GPI）锚定位点位于寄生虫表面，在体外很容易进入培养上清，在体内很容易进入动物血液。另一方面，反式唾液酸酶也可在非感染性表皮马鞭毛体阶段检测到，但它不会被释放到培养基中，也不会被针对T-TS羧基末端重复序列的抗体识别。反式唾液酸酶基因家族实际上有两种类型，它们位于不同的染色体上，受到不同的调控。我们对这两种不同类型的反式唾液酸酶的功能、表达和定位的分子机制进行了研究。我们得到了这两个家族的几个基因，并在比较的基础上制备了一些衍生物、杂交反式唾液酸酶分子。这两种类型的n端序列没有相似性，都是高度疏水性的，是秘书蛋白和膜蛋白的信号肽。被gpi锚定结构取代的T-TS c端疏水区似乎对分泌不重要。反式唾液酸酶的N端和c端结构特征与T-TS相似。利用杂交分子和分子标签表位对两种TS的不同定位甚至结构相似性进行分子研究。与塔夫茨大学Pereira博士的合作研究表明，T-TS c末端重复序列可诱导人内皮细胞和外周血单核细胞分泌IL-6。少