Figure 2.

T cell response in coronavirus disease (COVID)-19 patients and healthy donors. (A) Gating strategy for identification of T cell subsets is shown. After exclusion of doublets, T cells were gated from lymphocytes (CD45^hiSSc^low) region as CD3⁺CD56^- cells, followed by CD4 and CD8 phenotyping. (B) The percentages of naïve (CD62L⁺CD45⁺), effector (CD62L^-CD45RA⁺), central memory (CD62L⁺CD45RA^-) and effector memory (CD62L^-CD45RA^-) T cells, gated from CD4⁺ T cell (red) or CD8⁺ T cell (blue) region as in (A), are shown as the proportion of total CD4⁺ or CD8⁺ T cells. (C) The percentages of HLA-DR⁺, ICOS-1⁺, and CD38⁺, and (D) IL-4⁺, IL-17⁺, IFN-γ⁺ and PD1⁺ CD4⁺ T, and CD8⁺ T cells are shown as the proportions of total CD4⁺T or CD8⁺T cells as indicated. (E) Relative mRNA expression of T-bet in PBMC is shown. (B–E) The results for each donor in the groups of healthy donors (H, n=16), mild (M, n=19) and severe (S, n=19) patients, and the corresponding medians are shown. *p < 0.05, **p < 0.01, ***p < 0.005, ****p < 0.001 as indicated (Kruskal-Wallis test with Dunn’s post-test).