Figure 2. BMSC Treatment Decreased Human Th1 cell Engraftment, Effector Cytokine Production With A Concomitant Reduction In FoxP3⁺ Tregs.

Female NSG mice were reconstituted with human Th1 cells (5 million) and Monocytes (3 million). Within 24 hrs of GVHD onset (between day 20 to day 35), the BMSC cohort was treated 3 times, each injection separated by four days. Post-treatment, the mice were euthanized and the lymphoid organs such as spleen were evaluated for human Th1 cell engraftment. Representative flow plot showing human CD45⁺ cells versus mouse CD45⁺ cells (A). Absolute numbers of human CD45⁺ Th1 cells were calculated from total splenocyte number (B). Representative flow cytometry plots of IFNγ and TNF-α expression determined in the recovered human Th1 cells by intracellular cytokine staining (C). Cumulative absolute numbers of IFNγ producing human Th1 cells (D) and TNF-α producing human Th1 cells in the spleen (E). Absolute number of FoxP3⁺ human Tregs determined by intracellular staining (F). Absolute numbers of human CD39+ Th1 cells in the spleen (G). Absolute numbers of cytokine producing cells, T-regs and CD39⁺ Th1 cells were obtained from the absolute numbers of hCD45⁺ Th1 cells in the spleen. Each experiment had n=5 animals per cohort, experiments were performed in triplicates with 3 different BMSC clinical products. The data shown are cumulative of all three experiments. *=P<0.05, **=P<0.01 and ***=P<0.001.