Phosphorylation of Ras/Raf/MEK/ERK pathway, but not activation of NF-κB, is responsible for Fas-induced chemokines production in DCs. (A-B) DCs were pretreated with different doses of PD98059 (A) or PDTC (B) for 30 minutes, then stimulated with Jo-2, isotype Ab (Iso), or LPS for 18 hours. Levels of MIP-1α and MIP-2 in supernatants were determined by ELISA. (C) Western blotting analysis of activation of Ras, Raf, and MEK1/2 in DCs in medium alone as a control (Ctrl) or stimulated with Jo-2 (Jo-2), isotype Ab(Iso), or LPS (LPS) for the indicated times. (D) DCs were pretreated with different doses of FTI-277 or Raf-1 inhibitor for 30 minutes, then stimulated with Jo-2, isotype Ab, or LPS for 18 hours. The levels of MIP-1α or MIP-2 in the supernatants were determined by ELISA.