CD14 participates in regulating microglial chemokine expression following stimulation with either PGN or LPS. Primary microglia from CD14 KO and WT mice were seeded at 2 × 105 cells per well in 96-well plates and incubated overnight. The following day, cells were exposed to various concentrations of heat-inactivated S. aureus (A), PGN (B), or LPS (C) for 24 h, whereupon conditioned supernatants were collected and analyzed for MIP-2 protein expression by ELISA. Results are presented as the amount of MIP-2 (ng) per ml of culture supernatant (mean ± S.D. of three biological replicate wells). Significant differences between CD14 KO versus WT microglia are denoted with asterisks (*p <0.05; **p <0.001), whereas significant differences in MIP-2 expression between unstimulated versus LPS-stimulated CD14 KO microglia are indicated by a hatched sign (*p <0.05; **p <0.001). Results are presented from one of four independent experiments.