人轮状病毒NSP4蛋白的表达及其致小鼠腹泻作用的初步研究

研究人轮状病毒非结构蛋白NSP4在轮状病毒致病性中的作用。分离得到我国人轮状病毒97SZ8株，以谷胱甘肽S-转移酶融合蛋白的形式在大肠杆菌BL-21中表达NSN蛋白C端86-175氨基酸并用G1utathione SepharoseTM 4B亲和纯化。将纯化蛋白分别以0．4nmol和1．5nmol的剂量腹腔注射新生Balb／C乳鼠，记录腹泻发生和体重变化情况。当注射0．4nmol GST-NSP4重组蛋白时，有1只小鼠发生-过性腹泻(1／6)，给予1．5nmol重组蛋白时，实验组所有乳鼠都先后出现了腹泻，存在一定的剂量依赖性。本研究初步在新生小鼠建立了一种人轮状病毒腹泻动物模型，该模型有望在人轮状病毒的致腹泻机理、治疗和预防研究中发挥重要作用。

Expression of Human Rotavirus Nonstructural Protein NSP4 and Its Activity of Diarrhea Induction in New Borne Mouse

To investigate the function of human rotavirus nonstructrual protein NSP4 in the pathogenesis of rotavirus, the cDNA of NSP4 gene of a human rotavirus strain 97SZ8 was cloned and its 86-175 amino acid at the C terminal fused with GST was expressed in E.coli BL-21, the recombinant protein was then purified with Glutathione Sepharose~(TM) 4B affinity chromatography. Purified NSP4 protein was administered to young (6d) inbred Balb/C mice by the intraperitoneal (IP) route (0.4nmol or 1.5nmol). IP administration of 0.4nmol recombinant protein induced diarrhea in just 1 of the 6 pups, while diarrhea was observed in all of the 12 pups when inoculated with 1.5nmol GST-NSP4_T and resulted in reduced weight gain (P<0.05). In this study, a mouse model of diarrhea induced by human rotavirus NSP4 was successfully developed, and can be used widely in the highlights on mechanisms of diarrhea, treatment and prevention of human rotaviruses.