CCL2 stimulates activated and nonactivated monocyte-derived dendritic cells and T cells to transmigrate. Chemokine ligand 2 (CCL2) stimulates activated and nonactivated monocyte-derived dendritic cells (MDDCs) and T cells to transmigrate through the blood–brain barrier (BBB) monolayer. (A) One million immune cells were added to the upper chamber of the one-cell BBB model and collected after 24 and 48 hours from the lower chamber and counted. Data shown are the median of three replicate samples from three different donors ± standard deviation. (B) Nonactivated and activated MDDCs and T cells were added to the upper chamber of the one-cell model containing CCL2 in the lower chamber. Cells were collected 48 hours post migration and counted. 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.