Fig 1. Schematic representation of donor selection and generation of SARS-CoV-2-specific T cells for T-cell therapy.

Donors for T-cell expansion were selected from a cohort of 60 SARS-CoV-2-convalescent individuals whose cells had been screened for reactivity to SARS-CoV-2 antigens using an intracellular cytokine assay. Venn diagrams represent the number of donors generating a combination of antigen-specific responses by CD4⁺ or CD8⁺ T cells. Donors selected for T-cell expansion showed a minimum of three antigen-specific responses in CD4⁺ and/or CD8⁺ T cells. PBMC from each donor were stimulated with a single mixture of N, S, M and ORF3a overlapping peptide pools then cultured in G-Rex culture vessels for 2 weeks in the presence of IL-2. Cultured T cells were then assessed for a range of standard T-cell attributes.