Figure 5.

SARS‐CoV‐2 epitope‐specific CD8⁺ T cells display a clear memory phenotype. (a) Representative FACS panels indicate the gating strategy used to characterise the phenotype profile of SARS‐CoV‐2 epitope‐specific CD8⁺ T cells. CD27 and CD45RA were used to identify T_cm (CD27⁺CD45RA⁻), T_em (CD27⁻CD45RA⁻), T_emra (CD27⁻CD45RA⁺) and T_naive‐like (CD27⁺CD45RA⁺) cells. Gates were set based on the total CD8⁺ T cell population (left panel). The right panel displays a combination of total CD8⁺ T cells (grey dots) with dual‐tetramer‐positive cells (red dots) (b) Mean phenotypic frequencies of SARS‐CoV‐2 epitope‐specific CD8⁺ T cells pooled donors per epitope. (c) T_cm and T_naive frequencies of tetramer⁺CD8⁺ T cells, populations of multiple donors and epitopes with the respective HLA‐I restriction were pooled. (d) Mean phenotypic frequency of tetramer⁺CD8⁺ T cells per severity group. Mean (c) and SD (b, d) are shown and statistical significance was determined using the Wilcoxon (c) or the Mann–Whitney U‐test, considering P‐values < 0.05 as significant (d).