Extended Data Figure 1. CD8₊ T cell responses in COVID-19 illness.

a, Gating strategy to sort: lymphocytes size-scatter gate, single cells (Height vs Area forward scatter (FSC)), live, CD3₊CD8₊ memory (CD45RA₊CCR7₊ naive cells excluded) activated CD137₊ CD69₊ cells. Surface expression of activation markers was analyzed on CD8₊ memory T cells. b, Representative FACS plots (left) showing surface expression of CD38 and HLA-DR in CD8₊ memory T cells ex vivo and in CD137₊CD69₊ CD8₊ memory T cells following 24 hours of stimulation, post-enrichment (CD137-based), and summary of proportions of cells expressing CD38 (N=39, P=0.24 by Mann-Whitney test)) and HLA-DR (N=34, P=0.11 by Mann-Whitney test) in CD137₊CD69₊ CD8₊ memory T cells following stimulation and post-enrichment (CD137-based) in COVID-19 patients with mild and severe disease (right); Data are mean +/− S.E.M. c, Number of genes recovered for each 10X library sequenced. d, Distribution of cells in each cluster for the 6 batches of SARS-CoV2-reactive CD8₊ T cells from COVID-19 patients (right panel).