Figure 3. The anti-proliferative properties of AzaC upon allogeneic T cells are, in part, mediated by FOXP3+ Tregs.

(a) B6.Foxp3^DTR/GFP pan T cells (CD45.2) were labeled with CFSE at a final concentration of 300 nM as previously described ⁽¹⁾. Allo-HSCT was performed as described previously. Transplanted mice were injected (i.p.) with either PBS or AzaC (2 mg/kg) on days +15 and +17 followed by injection (i.p.) of DT (10 ug/kg) or PBS on days +16 and +18. Splenocytes were harvested on day 19 and analyzed using flow cytometry. (b and c) CFSE labeled allogeneic donor T cells proliferate significantly less in mice treated with AzaC compared to PBS treated mice (p<0.001) (b) Splenocytes on day 19 post allo-HSCT, gated on H2Kb⁺ CD45.2⁺ CD4⁺_. Suppression of proliferation calculated as a percentage of CFSE⁺ cells as a percentage of total FOXP3^- CD4⁺ donor T cells. In addition, AzaC treated mice had significantly less donor T cell proliferation when compared to mice treated with both AzaC+DT (p=0.04). Data shown is combined from three independent experiments. (c) One representative plot from each group.