A common conserved peptide harboring predicted T and B cell epitopes in domain III of envelope protein of Japanese Encephalitis Virus and West Nile Virus for potential use in epitope based vaccines

Japanese encephalitis virus (JEV) and West Nile virus (WNV) are two major mosquito borne flaviviruses belonging to same serocomplex. JEV is transmitted by Culex mosquitoes and the reservoir host for the virus is pigs and/or water birds. WNV is also transmitted by Culex mosquitoes and reservoir host in this case is birds. It can also be transmitted through contact with other infected animals, their blood, or other tissues. The envelope protein of these viruses is the major source of epitopes and provides protective immunity. Bioinformatics tools were used to identify conserved epitopes in the envelope protein of these viruses. A conserved peptide "TPVGRLVTVNPFV" present in both the viruses containing predicted T and B cell epitopes was found. The model of one of the predicted epitope was generated and upon docking it bound in the groove of HLA-A0201 Class I MHC molecule. Further, it was amenable to proteasomal cleavage enhancing its chances of processing by cytosolic pathway. The peptide was found to be non toxic, non allergenic and stable in mammalian cells based on database search. The population coverage was pan world and nearly 70% identity of the peptide was found in the Zika virus envelope protein. The peptide was located in the domain III of envelope protein which is the exposed domain therefore B cell receptors may recognize this peptide easily. The conserved peptide containing T and B cell epitopes can have future application for designing epitope based vaccines for both JEV and WNV.

Conserved epitopes in variants of amastin protein of Trypanosoma cruzi for vaccine design: A bioinformatics approach

Chagas disease caused by protozoan parasite Trypanosoma cruzi is endemic disease in South and Central American countries but due to migrating human populations it has shown emergence in Europe, North America and Australia. With only two drugs, benznidazole and nifurtimox for its treatment there is need for newer therapies. In the current study, we have tried to analyse the potential of amastin, a major surface protein as a vaccine target using bioinformatics tools. Using 282 variants of this protein available in NCBI protein database we have found out five conserved potential T_c cell and two T_H cell epitopes. These epitopes are conserved in more than 90% of the cohort of sequences used in the study. The epitopes showed binding to the peptide binding cleft of HLA-A02 and HLA-DR molecules. With coverage of pan world populations and being non-toxic and non-allergic these epitopes could be used for future vaccine applications.