| Description |
Long-term T cell responses are crucial for efficient protection against SARS-CoV-2 variants. Although T cell epitopes were identified, the exact sequences of the cross-reactive TCRs are unknown. Here, we predicted relatively conserved T cell epitopes among SARS-CoV-2, SARS-COV and other five coronaviruses. Then, to evaluate the long-term T cell immunity, we collected peripheral blood mononuclear cells (PBMCs) from 18 recovered donors 7-8 months after the infection of COVID-19. Predicted epitopes were constructed into tandem minigenes (TMGs) and transfected into engineered K562 cells expressing a single HLA allele. After the co-culture of PBMCs and K562 cells, T cells were analyzed and sorted for single-cell transcriptome profiling coupled with TCR sequencing. With single-cell information, we constructed 34 TCR-engineered T cells as candidates for recognizing SARS-CoV-2 antigens and 19 of them turned out to be responsive to a specific epitope. Furthermore, many of the TCRs hold cross-reactivity to mutant antigens with comparable levels of activation, providing potential protection to SARS-CoV-2 variants. |
