The Prokaryotic Expression Of E,NS1 Protein Of SA14-14-2 Strain And Their Immunology Study

Japanese encephalitis virus(JEV) is the cause of the most prevalent viral encephalitis of humans and animals (especially in children) in terms of morbidity and mortality. There is no drug treatment for JE. JE vaccination is the most important control measure. Japanese encephalitis virus belongs to the family Flaviridae. China is one of the major epidemic area,. In the past decades, the morbidity rate of JEV in China has decreased dramatically. The major reason is the vaccination of JEV vaccine. Many countries use the inactivated vaccine from purified mouse brain . In China an attenuated live vcaccine was developed in 1989 and widely used since then. Till now , more than 200 million people in China are administered with the live vaccine SA14-14-2. The recent reduction of JE cases in China indicates that vaccination has contributed to the control of JE.In order to understand non-structural antibodies induced by immunization with the live vaccine, We choose the first translated non-structural gene ns1 for study. The ns1 gene and the envelope gene (E) were amplified by PCR and cloned onto the prokaryotic expression vector pET syetem, and induced for expression. The E and NS1 protein were purified by affinity of chromatography and their purity were over 96%. Mice immunized with E and NS1 proteins were protected against i.p. lethal challenge with 10-100 LD₅₀ of P3 JE strain. E' s protection rate is about...