Macrophages support CLL cells in culture. (A) Viable (annexin V/propidium iodide-negative) cells in coculture of murine TCL1^+/wtMIF^wt/wt and TCL1^+/wtMIF^−/− CLL cells with thioglycollate-elicited peritoneal macrophages from TCL1^+/wtMIF^wt/wt or TCL1^+/wtMIF^−/− mice. The figure shows 1 representative example of n = 5 independent experiments. (B) Viable (annexin V/propidium iodide-negative) cells in coculture of murine TCL1^+/wtMIF^wt/wt and TCL1^+/wtMIF^−/− CLL cells with thioglycollate-elicited peritoneal macrophages from TCL1^+/wtMIF^wt/wt or TCL1^+/wtMIF^−/− mice. Addition of neutralizing anti-MIF antibody (IIID9, 100 μg/mL) leads to reduced viability. Representative experiment from a total of 2 independent experiments. (C) Migratory activity of peritoneal macrophages in trans-well experiments toward TCL1^+/wtMIF^wt/wt or TCL1^+/wtMIF^−/− B cells depends on MIF status of the macrophages. RFU indicates relative fluorescence units. P = .0077. Figure shows representative results of n = 5 experiments. (D) Gradient-triggered migratory activity of murine TCL1^+/wtMIF^wt/wt and TCL1^+/wtMIF^−/− peritoneal macrophages in the presence of MIF (100 ng/mL), CCL2 (100 ng/mL), CCL3 (10 ng/mL), CCL4 (100 ng/mL), and SDF-1 (100 ng/mL). Only TCL1^+/wtMIF^wt/wt macrophages are reactive to the action of chemokines (n = 3).