营养元素硒对儿童EV71感染免疫应答影响的研究

Selenium (Se), an essential trace element for humans and other mammals, has been suggested to play a role in a wide range of physiological processes, including infection diseases prevention and antiviral fuction. Hand foot mouth disease（HFMD）has been a serious public health problem in China and other Asia countries. More than 12 thousands cases were reported among children under five each year in China, which mainly caused by enterovirus 71(EV71). And many cases lead to serious conditions and death..It was found that there was a higher morbidity of HFMD in Se-deficient area. Meanwhile, our earlier research reported that the blood selenium concentration in HFMD patients were significantly lower than that in health children. These findings suggest that Se associate with infection of EV71. In this study, we'll try to evaluate potential associations between Se and development of HFMD, and to explore the immunologic mechanism by conducting serological study, animal experiment, and human cytology experiment. This research will facilitate the development of novel preventions or effective treatments of this serious infectious disease.

研究证明微量营养元素硒（Se）在人类个体及其他哺乳动物的日常饮食中十分重要，实验证实Se通过硒酶与硒蛋白，对预防感染性疾病和抑制病毒都具有作用。手足口病（ HFMD）已成为中国乃至亚洲地区主要公共卫生问题。在我国HFMD的主要病原体为肠病毒EV71,我国5岁以下儿童年发病在12万例左右，并有重症及死亡病例。流行病学研究发现缺硒地区手足口病发病率高；我们前期的研究证实HFMD儿童血硒含量显著低于健康儿童；这些初步的调查和研究暗示Se关系到儿童EV71感染和HFMD发生，本研究将通过血清流行病学分析和动物实验阐明儿童缺硒是导致HFMD发生和病程重度发展的主要因素之一的科学问题，同时应用人类体外细胞学实验来解析营养元素硒通过非特异性的调节T淋巴细胞、巨噬细胞的免疫应答影响儿童防御EV71感染和HFMD发病机制，以期通过对儿童膳食补硒的措施来预防EV71感染和HFMD的发展。

证明微量营养元素硒（Se）在人类个体及其他哺乳动物的日常饮食中十分重要，实验证实Se通过硒酶与硒蛋白对预防感染性疾病和抑制病毒都具有作用,阐明硒蛋白在酵母中的转化规律，从无机硒转化为硒代蛋氨酸及其相关硒蛋白成分，证实硒蛋白提高人体非特异性免疫应答，提高人体预防手足口病及其流感等病毒性疾病感染的能力；根据SelK基因编码序列及载体相关信息设计SelK相关引物，分别引入同一酶切位点，并将编码区内编码Sec的TGA突变为半胱氨酸（Cys）的TGC。用相关引物扩增突变体SelK并插入载体，经过鉴定和基因测序获得重组质粒，转化到感受态酵母细胞，筛选出阳性克隆并诱导表达后进行分离纯化及产物的鉴，通过小鼠三种淋巴器官：淋巴结，脾脏和胸腺检测SelK硒蛋白mRNA在三种器官中都存在高表达，并证实与小鼠的T细胞免疫应答相关，用移动吞噬作用证实Selk在巨噬细胞中表达和巨噬细胞的趋化及炎症反应对硒蛋白的依赖性，选择两个老年病医院作为酵母硒多糖干预的前瞻性研究对象，观察酵母硒多糖服用人群与对照人群呼吸道疾病的感染率与感染的病原谱差异。.存在于内质网上的Se1K蛋白能够促进巨噬细胞增殖,体外细胞实验阐述免疫功能SelK蛋白在T细胞中的表达和T细胞的发育增殖对SelK的依赖性,SelK的mRNA在它们的表达模式及表达调控方式中表现为组织特异性。并在体外培养人类T细胞，分析人类T细胞中硒摄取与硒蛋白表达、T细胞发育增殖、分化关系,人群干预实验证实硒蛋白能够有效提高人体非特异性免疫能力，预防病毒性疾病的感染。