Monocyte-derived dendritic cells and T cells transmigrate in a three-cell blood–brain barrier model. Monocyte-derived dendritic cells and T cells transmigrate in response to chemokine ligand 2 (CCL2) in a three-cell blood–brain barrier (BBB) model. (A) One million immune cells were added to the upper chamber of the three-cell BBB model and collected at 24 and 48 hours from the lower chamber. Data shown are the median of three replicate samples from three different donors ± standard deviation. (B) Nonactivated and activated monocyte-derived dendritic cells (MDDCs) and T cells were added to the upper chamber of the three-cell model containing CCL2 in the lower chamber. Cells were collected at 48 hours post migration and counted. These data are representative of at least two independent experiments each performed in duplicate. Statistical significance (*P ≤0.05) between the control (no CCL2) and each CCL2-treated sample was determined by Student’s t test.