Quantification of IL-6 secretion induced by APLAs. TLR2^−/−EFs, TLR2^−/−EFs transduced with control vector or vector for hTLR2, EFs deficient in TLR1, TLR4, or TLR6, or WT-EFs were treated for 8 hours with 500 μg/mL APLA5 or control IgG, or with 25 μg/mL β2GP1-IgG. IL-6 concentrations in the culture medium of the cells were quantified by ELISA. Data are expressed as fold increase of IL-6 quantified in the supernatant of stimulated cells versus IL-6 quantified in the supernatant of unstimulated cells. Data are mean ± SE of at least 5 independent experiments.