Human acute monocytic leukemia THP-1 cells (ATCC TIB202) were maintained in RPMI-1640 supplemented with 10% FBS and 1% penicillin-streptomycin. Cells were seeded onto a 24-well plate at a concentration of 4610 5 cells per well in antibiotic-free media supplemented with 12.5 ng/mL phorbol myristate acetate and incubated for 24 h at 37uC with 5% CO 2 . Differentiation was determined to be successful upon formation of a confluent adherent monolayer. HEK-blue type I IFN cells (Invivogen) were grown in DMEM supplemented with 10% FBS and 1% penicillin-streptomycin. Cells were seeded at a concentration of 5.6610 4 cells per well onto a 96-well plate.