MAPCs dampen T-cell proliferation and activation within the local environment. In vivo MLR was performed by administering lethally irradiated BALB/c mice with 5 × 10⁵ B6 MAPCs IS (day 0), followed by 15 × 10⁶ B6 CFSE-labeled CD25-depleted T cells (intravenously; day 1). Control mice were given labeled T cells alone plus sham surgeries. Spleens and LNs were harvested on day 4 and analyzed via FACS for CD4 and CD8 expression and percentage of CFSE dilution (A). The proliferative capacity for CD4⁺ and CD8⁺ T cells in the spleen (B) and LNs (C) of transplanted mice was calculated, as previously published.¹⁸  (D-E) Activation markers for CD4⁺ and CD8⁺ T cells in the spleen and LNs were analyzed using FACS and graphed.