FIG 6.

TLR2 response to whole bacteria. (A) HEK-Blue-TLR2/1/6 cells were exposed to 5-fold dilutions of heat-inactivated whole bacterial cells of L. monocytogenes CFSAN023459 (wild type [WT]) grown with or without 1 mM copper, as well as the derivative Δlit2 cells grown with or without 1 mM CuCl₂. (B) HEK-Blue-TLR2/1/6 cells were pretreated with 10 μg/ml of TLR-neutralizing antibodies and then exposed to the same bacterial cell preparations as in panel A. The “WT + 1 mM Cu” sample was added to 8.0 × 10⁵ CFU/ml, while the others were added to 3.2 × 10⁴ CFU/ml. The percent activity normalized to the water control is indicated. (C and D) HEK-Blue-TLR2/1/6 cells were exposed to 5-fold dilutions of heat-inactivated, whole bacterial cells of strains L. monocytogenes CFSAN023459 (C) and E. faecalis ATCC 19433 (D). The data are shown as the means ± standard deviations of the results of three biological replicates.