Fig 1.

Flow cytometry gating strategy for identification and quantification of severe acute respiratory syndrome coronavirus 2 S-peptide. After 2 hours, Brefeldin A was added to the culture to block secretion of cytokines and effector molecules. Living single lymphocytes were analyzed for expression of CD3, CD4, and CD8. CD4+ T cells (oranges boxes) were analyzed for the expression of CD154 and CD137. CD8+ T cells (green boxes) were analyzed for expression of CD137. Both CD4+ and CD8+ T cells were further analyzed for production of cytokines IFNγ, TNFα, IL-2 and GrB. The gray box includes untreated samples. Furthermore, CD4+CD154+CD137+ and CD8+CD137+ cells were analyzed for the expression of CXCR5. Representative example of 26 unexposed and 14 convalescent patients. Plots of an unexposed study subject are being presented.