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 (P0.05). 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.