SARS-CoV-2-specific T-cell Detection in Whole Blood
IL-2 is a key growth factor for activated T-cells, while TNF-α and IFN-γ
are considered canonical inflammatory cytokines mediating
effector/memory T-cell functions. Analysis of cytokine production in
stimulated T-cells confirmed that IL-2 and TNF-α were consistent markers
for activated CD4+ T-cells, while activated CD8+ T-cells mainly produced
TNF-α and IFN-γ. After incubating whole blood with SARS-CoV-2 Spike
peptide pool, we were able to discern Spike-reactive T-cells by dual
cytokine gating (Figure 1). Here, healthy individuals without history of
SARS-CoV-2 infection demonstrated no significant T-cell responses to
SARS-CoV-2 spike peptide. However, T-cells from SARS-CoV-2-infected or
vaccinated individuals showed substantial spike-specific CD4+ and CD8+
T-cells.