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. Splenocytes were stained with Zombie Yellow (BioLegend, San Diego, CA) to eliminate dead cells. The cells were then pretreated with Fc Block (anti-CD16/32 clone 2.4G2; BioXcell), stained with following mAbs: Pacific Blue-conjugated anti-CD3, APC/Cyanine7-conjugated anti-CD8, APC-conjugated anti-Thy1.1, FITC-conjugated anti-CD62L, PE/Cyanine7-conjugated anti-CD44, PE/Dazzle594-conjugated anti-B220, anti-F4/80, anti-NK1.1 and anti-Ly6G, (BioLegend). Stained cell data were acquired on a Gallios flow cytometer (Beckman Coulter, Brea, CA) and analyzed with FlowJo (version 7.6.5, TreeStar, Ashland, OR).