DISCOVERY OF CD8 T CELL EPITOPES IN VIRAL DISEASES EMPLOYING CONDITIONAL LIGANDS FOR MURINE MHC AND ASIAN HLA VARIANTS

Abstract

Conditional ligands have enabled high-throughput production of Major Histocompatibility Complex (MHC) tetramer libraries for CD8 T cell epitope discovery. We first employed this strategy in AG129 mice infected with dengue-2 viruses (D2Y98P). Secondly, immunomonitoring platforms typically concentrate on Human Leukocyte Antigen (HLA) restriction elements associated with European ancestry and such tools are scarce for Asian HLA variants. We therefore designed thirty novel UV irradiation-sensitive ligands targeted towards the South East Asian population. Synthesized ligands provided sufficient yield of soluble HLA products for sixteen HLA-A, -B and -C types and peptide exchange was validated by an ELISA-based MHC stability assay. HLA tetramers with redirected specificity could detect known T cell responses against various viral infections, and were utilized to characterize seven novel T cell epitopes from severe acute respiratory syndrome coronavirus, hepatitis B virus and dengue virus. This immunotechnology therefore holds promise for monitoring antigen-specific CD8 T cell responses in populations of distinct ethnicity.