Type I IFNs in combination with LPS or LTA induce apoptosis.

Different combinations of 1000 U/mL IFN-α, 1000 U/mL IFN-β, 1 ng/mL LPS, and 1 μg/mL LTA were added on day 0 to cultures supplemented with IL-4 and GM-CSF. The percentage of Annexin-positive cells was determined by FACS analysis on day 6 as detailed in Figure 1. The data were obtained from 4 different donors, each represented by an individual symbol. Two donors (■, ▵) were tested twice in independent experiments.