FIGURE 3.

Membrane-bound CD14 contributes to IL-6 and nitrite production by BMDMs. BMDMs from C57BL/6, TLR2-deficient (TLR2^−/−), and CD14-deficient (CD14^−/− mice) were stimulated with 50 ng of Pam₃CSK₄ (A), 7 μg of purified curli fibers (B), or GST or GST-CsgA fusion peptide (C) for 6 h. Supernatants were collected at 6 h, and ELISA was conducted to measure IL-6 production. D, BMDMs were also stimulated with 10 μg of purified curli fibers for 24 h, and nitrite levels in the supernatant were measured. Bars represent mean ± S.E. from three independent experiments.