Japanese encephalitis virus (JEV) is the agent to cause the disorder of central nervous system (CNS) or even death. Neutralizing antibodies is believed to play a major role to prevent JEV entry to CNS. The importance of T-cell responses in the control of JEV infection is not clear. In addition, the presence of heterologous suboptimal neutralizing antibodies among between JEV and other flaviviuses may enhance viral infection. A peptide vaccine constituted with both CD4 and CD8 T cell epitopes to elicit a Th1-type response can provide an alternative solution to reduce the impact of heterologous suboptimal neutralizing antibodies. Total 40 and 31 of MHC-I and II peptides were predicted and used in these study. Spleen cells harvested from NS3 DNA vaccinated or JEV-infected BALB/c mice were stimulated and the IFN-gamma production was detected by ELISPOT assay. The mixture of Kd and Ld-restricted peptides showed the stronger ability to stimulate IFN-gamma production than Dd. Four individual MHC-I restricted peptides were identified. To prove the peptide is CD4 or CD8-dependent, different cell populations were depleted by magnetic beads before performing ELISPOT assay, and all 4 peptides showed a CD8-dependent pattern. For MHC-II, a similar strategy was used and three IFN-gamma stimulating Ad-restricted peptides were mapped. A peptide based JEV vaccine based on this study will be used to test the immunogenicity and protection in a mouse model.
Date:
2011-04
Relation:
Journal of Immunology. 2011 Apr;186(Suppl. 1):Meeting Abstract 105.25.
