Femurs and tibia of wild-type C57BL/6 mice (Jackson) were soaked in 70% ethanol, washed with RPMI (Invitrogen), and epiphyses were cut to expose the bone marrow. The bones were flushed with RPMI supplemented with 10% fetal bovine serum (FBS) to extract the bone marrow. Cells were pelleted by centrifugation, washed once with RPMI and resuspended in ammonium chloride red blood cell lysis buffer. RBC lysis was performed for 1 minute at room temperature, stopped with RPMI-FBS and cells were collected by centrifugation. Bone marrow cells were seeded in 6-well dishes in RPMI containing 10% FBS, 50 U/ml Penicillin (Invitrogen), 50 mg/ml Streptomycin (Invitrogen), 20 ng/ml GM-CSF (Peprotech), 10 ng/ml IL-4 (eBioscience), and 40 mM beta-mercaptoethanol (BIO-RAD). Cells were cultured for 5 days at 37 degrees C, 5% CO2 and fresh media was added every 2-3 days.