ABSTRACT
While SARS-CoV-2-specific T cells have been characterized to play essential roles in host immune protection in COVID-19 patients, few researches focus on the functional validation of T cell epitopes and development of vaccines inducing specific T cell responses. In this study, 120 CD8 T cell epitopes from E, M, N, S and RdRp proteins of SARS-CoV-2 were validated by on-silicon prediction, DC-peptide-PBL costimulation with PBMCs of healthy donors and HLA-A molecule competitive binding experiments. Among them, 110, 15, 6, 14 and 12 epitopes were highly homologous with SARS-CoV, OC43, NL63, HKU1, and 229E, respectively. Thirty-one epitopes restricted by HLA-A2 molecule were used to generate peptide cocktail vaccines in combination with Poly(I:C), R848 or polylactic-co-glycolic acid nanoparticles, which elicited robust specific CD8 T cell responses in wild-type and HLA-A2/DR1 transgenic mice. Seven of the 31 epitopes were found to be cross-presented by HLA-A2 and H-2K/Db molecules. These data have provided a library of SARS-CoV-2 CD8 T cell epitopes which restricted by a series of high-frequency HLA-A allotypes and covered broad population in Asia, and initially confirmed the feasibility of human MHC class I molecule-restricted SARS-CoV2 epitope peptide cocktail vaccines, thus will facilitate the development of T cell epitope vaccines and specific cellular function detection kits.