Resident macrophages were isolated from 6 to 8 week-old C57BL/6J and genetically-matched tlr2 2/2 , trif 2/2 mice by washing the peritoneum twice with 10 mL DMEM (PAA) supplemented with 10% FBS, 10% LCM and 1% penicillinstreptomycin. Harvested cells were centrifuged at 300 g for 5 minutes and resuspended in complete medium. The percentage of macrophages was determined by flow cytometry analysis as above. Cells were seeded onto 6-well plates (Nunc) at a concentration of 2610 6 cells per well.