Effect of MSCs on DNA protein synthesis and on the cell cycle. (A) C57BL/6 splenocytes (2.5 × 10⁶) were stimulated with 10 μg/mL ConA in the absence (left) or the presence (right) of MSCs (1 × 10⁵). After 48 hours, cells were harvested, and protein and DNA content were quantified using FITC and PI staining. FACS profiles show T-cell G₁-phase protein content (FITC) and S-phase DNA synthesis (PI). (B) C57BL/6 splenocytes (2.5 × 10⁶) were stimulated with 10 μg/mL ConA for 24 and 48 hours in the presence or absence of MSCs (1 × 10⁵). Intracellular protein and DNA content were assessed using FITC and PI staining and were analyzed using cytofluorometry. FACS plots are representative of 1 of 3 experiments of identical design.