Abstract
A fragment from the N-terminal part (EA) and a fragment from the C-terminal part (EB) of the envelope (E) protein of Japanese encephalitis virus (JEV) was synthesized in Escherichia coli. These two fragments were overlapping with each other by nine amino acids, however, they were not cross-reacting with each other at the antisera level. Both EA and EB are antigenic by themselves when injected into mice, but when tested against sera from mice, rabbit, swine and human that had been immunized or naturally infected with JEV, EB acted as a better antigen than EA by ELISA assays. EB also proved to be a better immunogen in protection against lethal JEV infection than EA. The protection appears to be correlated with the neutralizing titres of the anti-JEV sera. The response elicited by EB is a Th1 response and the antibody produced contained higher neutralizing titre than EA fragment. The major difference between EA and EB fragments is the solubility during expression in E. coli, while EB fragment is soluble, EA was isolated from the insoluble inclusion bodies. Therefore the antigenicity and immunogenicity expressed by the EB fragment may probably be due to its proper folding to assume a correctly assembled form during expression in E. coli, a quality that is important for a protein to qualify as a good vaccine candidate.
Original language | English (US) |
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Pages (from-to) | 9-19 |
Number of pages | 11 |
Journal | Microbial Pathogenesis |
Volume | 31 |
Issue number | 1 |
DOIs | |
State | Published - 2001 |
Keywords
- Envelope protein
- Immune protection
- JEV
- T helper cells
- Vaccine
ASJC Scopus subject areas
- Microbiology
- Infectious Diseases