The Immunal Potentiaton Of M.T Hsp70 In Development Of JEV Engineering Vaccine

Japanese encephalitis (JE) virus, which belongs to the family Flaviviridae, causes infection of the central nervous system in humans and equines and stillbirths in swine. Japanese encephalitis virus (JEV) is transmitted to humans by persistently-infected mosquitoes and is maintained in infected vertebrate reservoirs, especially in viremia-amplifying hosts such as swine and avian. In humans, JEV causes acute encephalitis with fatality rates ranging from 20% to as high as 50% and most of the survivors display persistent neurological or psychological sequelae. In domestic animals such as swine and horses, JEV infection causes stillbirth, encephalitis and even death. Similar to other flaviviruses, JEV contains a single-stranded, positive-sense RNA of approximately 11 kilobases (kb) in length, which has a single open reading frame (ORF) encoding a polyprotein. This polyprotein is proteolytically cleaved into at least 11 proteins. The virus structural proteins, including capsid (C), membrane (M; precursor M, prM) and envelope (E), are encoded by the 5' one-third of the ORF and nonstructural (NS) proteins, designated NS1 through NS5, are encoded in the remainder.Current JE vaccines for use in swine consist of attenuated or inactivated virus, and there are concerns about the safety and cost of producing and using these products. The World Health Organization has been calling for the development of improved and/or new vaccines for JEV. The envelope (E) protein of JEV is associated with viral binding to cellular receptor(s) and membrane fusion. It is also the major antigen that elicits neutralizing antibodies and protection in hosts. Mycobacterium tuberculosis hsp70 has the effect of molecular adjuvant and carrier which was one of major antigenic elements in mycobacterium tuberculosis and can induce or potentiate humoral and cellular immunity. So the fusion expression of hsp70 and some antigenic peptides can improve the immunogenicity and the effect of vaccine. In the study, the fusion protein of the major antigenic segment of E protein and hsp70 expressed in Pichia Pastories was immunized mice in order to determine the influence of hsp70 on specific immune response and the way of hsp70 and the major antigenic segment was studied to function as molecular adjuvant properly. It was reported that the general structure of hsp70 include a N-terminal ATPase domain and a C-...