Figure 6. OX40 costimulation promotes CD28-mediated T regulatory expansion in the presence of rapamycin but often results in loss of suppressive activity.
A. 2×105 enriched Tregs were stimulated with cell-based aAPCs that delivered the indicated costimulatory signals in the presence of rapamycin and the population doubling rate was measured by cell counting. Each data point represents the average of three independent experiments (error bars represent standard deviation). B and C. Scatter plots of percent of Foxp3 expressing cells (B) and in vitro suppressive activity (C) measured after two weeks of culture after stimulation with the indicated cell-based aAPC. Each dot represents a separate experiment and cell donor. Mean values and standard deviation are also indicated.