Flaviviruses were reported to induce CD8+ cytotoxic T cells in infected individuals, indicating that nonapeptides, proteolytic cleavage products of the viral precursor
protein, enter the endoplasmic reticulum in infected cells and interact with HLA class I molecules. The assembled HLA class I molecules are transported to the plasma membrane and prime CD8+ T cells. Current knowledge of the interaction of viral
peptides with HLA molecules is reviewed. Based on this review, an idea is presented to use synthetic flavivirus
peptides with an amino acid motif to fit with the HLA class I
peptide binding group of HLA haplotypes prevalent in a given population in an endemic area. These synthetic viral
peptides may be introduced into the human skin using a lotion containing the
peptides ("Peplotion") together with substances capable of enhancing the penetration of these
peptides into the skin to reach Langerhans cells. The
peptide-treated Langerhans cells, professional antigen-presenting cells, may bind the synthetic viral
peptides by their HLA class I
peptide-binding grooves.
Antigens carrying Langerhans cells are able to migrate and induce the cellular immune response in the lymph nodes. This approach to the priming of
antiviral CD8+ cytotoxic T cells may provide cellular immune protection from
flavivirus infection without inducing the humoral immune response, which can lead to the
shock syndrome in
Dengue fever patients. To be able to develop anti-Dengue virus synthetic
peptides for populations with different HLA class I haplotypes, it is necessary to develop computational studies to design HLA class I Dengue virus synthetic
peptides with motifs to fit the HLA haplotypes of the population living in an endemic region for
Dengue fever. Experiments to study Dengue virus and
Japanese encephalitis peptides vaccines and their effectiveness in protection against
Dengue fever and
Japanese encephalitis are needed. The development of human
antiviral vaccines for application of viral
peptides in a lotion to human skin ("Peplotion") may be useful and affordable for populations of developing countries.