Peptidoglycan–polysaccharide (PG-PS)-induced activation of nuclear factor-κB (NF-κB) is inhibited in CD14 knockout spleen macrophages. Spleen macrophages were stimulated for 30 min with PG-PS at a concentration of 20 μg/ml. The left column shows immunostaining of the p65 (RelA) subunit of NF-κB, and the right column shows counterstaining of nuclei with Hoechst 33342. The rows show the following: top – unstimulated cells from wild-type mice; middle – PG-PS stimulated cells from wild-type mice; and bottom row – PG-PS-stimulated cells from CD14 knockout mice. Representative data from three independent experiments are shown.