Dexamethasone suppresses tumor-specific T cell proliferation and differentiation but not activity in antigen-experienced mice.

Healthy mice were administered activated pmel-1 T cells labeled with the congenic marker Thy1.1 on day -21 and vaccinated for the first time with a gp100 vaccine on day -19. From day -2 until day 6, the mice were administered 3 mg/kg dexamethasone daily. On day 0, they were administered the vaccine a second time. Spleens were harvested for flow cytometry on day 7. The cells were stained with Zombie Yellow to eliminate dead cells. The cells were then pretreated with Fc Block, stained with FITC-conjugated anti-Thy1.1, PerCP/Cyanine5.5-conjugated anti-CD4, APC-conjugated anti-CD3, APC/Cyanine7-conjugated anti-CD8, PE/Dazzle594-conjugated anti-B220, anti-F4/80, anti-NK1.1 and anti-Ly6G, followed by fixation, permeabilization and staining with PE-conjugated anti-Foxp3 and PE/Cyanine7-conjugated anti-Ki67 (Thermo Fisher Scientific) using Foxp3/Transcription Factor Staining Buffer Set (Thermo Fisher Scientific) according to the manufacturer's protocols.