FIG 9.

T cell proliferation responses induced by peptide master pools in convalescent COVID-19 subjects over 1 year PSO. (A) Representative flow cytometry gating strategy for CFSE_Low CD3⁺ T cells, CD4⁺/CD8⁺ T cells, and IFN-γ/granzyme B/IL-2-producing CD4⁺/CD8⁺ T cells. Fluorescence minus one (FMO) controls for cytokines producing CD4⁺/CD8⁺ T cells were included in the dashed box. (B) Representative net master pool peptides induced T cell proliferative in subject OM8083 at different PSO. (C) Total proliferation from full-set peptide master pool stimulations (N, E, M, S-RBD, and S-TM) in subjects OM8083, OM8086, and OM8087. (D) Total proliferation from full peptide master pools stimulations (N and S-RBD and S-TM) in subjects OM8119 and OM8126. (E) Single-time-point total proliferation response using full set peptide master pools stimulations (N, E, M, S-RBD, and S-TM) in two healthy COVID-19 negative donors, OM1 and OM922. Total proliferation was calculated by adding the total of net peptide master pool-induced CFSE_Low responses from all-peptide-master-pool stimulation. The compositions of CD4⁺ and CD8⁺ T cell responses in the total proliferation were calculated by averaging CD4⁺ and CD8⁺ master pool-induced CFSE_Low generated at different time points. (F) Percentages of IFN-γ-, GzmB-, IFN-γ/GzmB-, IL-2-, and IFN-γ/IL-2-secreting CFSE_Low-responding CD4⁺ T cells in subjects OM8083 and OM8086 against days PSO. (G) Percentages of IFN-γ-, GzmB-, and IFN-γ/GzmB-secreting CFSE_Low-responding CD8⁺ T cell in subjects OM8083 and OM8086 against days PSO.