Figure 4.

SARS‐CoV‐2‐reactive T‐cell clones may be persistent. PBMCs from two SARS‐CoV‐2 convalescent donors (SCD‐03 and SCD‐06) isolated 5 months after initial blood donation were stimulated in vitro for 12 days with the target peptides A02_P03 and A24_P03 and then stained with tetramers specific for these targets. The experiment was conducted once (n = 2). (A) FACS plots showing the 2D tetramer staining for SARS‐CoV‐2 epitopes A02_P03 and A24_P03. Upper row shows donor SCD‐03, lower row shows donor SCD‐06. For comparison, the plots on the right show the respective tetramer staining from the initial donation of the same donors. The depicted numbers in the gates indicate the respective frequency of parent. Axis are scaled logarithmically. The respective target antigen is indicated on the axis in brackets. Note that the plots shown on the right are also part of Supporting information Fig. S1. (B) The tetramer‐positive cells (shown above) were FACS‐sorted and subjected to single‐cell TCR sequencing using the 10× Chromium system. The diagram shows a V(D)J loop browser visualization of the initial TCR identification data set (x‐axis) compared to the second TCR identification (y‐axis). The blue dot indicates a shared clonotype, which was identified as SCV‐012.