FIG. 5.

Proliferation of allogeneic PBMC cocultured with B cells as APC. Activation of B cells by an increased level of intracellular cAMP enhances their ability to present alloantigen in the allogeneic T-cell response. B cells were stimulated with polyclonal stimuli, including 2.5 μg/ml of CpG ODN 2006, 50 U/ml of IL-2, and 2 μg/ml of anti-Ig MAb, and simultaneously treated with the compounds indicated or left untreated (NT) for 3 days and irradiated. B cells were cocultured with allogeneic PBMC labeled with CFSE at different B cell/PBMC ratios. After 3 days of coculture, cells were collected and stained with anti-human CD4 or anti-human CD8 MAb. The level of PBMC, CD4⁺, and CD8⁺ T-cell proliferation was evaluated by FACS analysis. The error bars indicate standard deviations for duplicates. Data from three independent experiments are shown. PBMC TOT, total PBMC.