Treatment with CI A23187 enhances T-cell allosensitizing capacity of cultured CD34^pos bone marrow cells. The latter were treated and harvested as in Fig 6, then cocultured at various APC:T lymphocyte ratios with fixed numbers of freshly prepared allogeneic human T lymphocytes as in Fig 4. Ordinate displays CPM/10⁵ input T cells during the last 18 hours in culture. Groups are “Untreated” (continued culture in rhGM-CSF and rhTNF-), “CD40L” (10 μg/mL rhCD40L) and “A23187” (375 ng/mL). Abscissa displays ratio of APC: T cells. Not shown: CD34^pos cells alone, regardless of treatment, generated < 250 cpm when seeded at 20,000 cells per well; T cells alone generated < 250 cpm. Bars indicate SEM from triplicate wells.