Fig. 6.

Contribution of Naip5 to Ipaf-dependent IL-1β secretion in response to cytosolic flagellin. BMMs were prestimulated with LPS to induce proIL-1β expression and stimulated with purified GST-flagellin or GST-hook protein delivered to the cytosol using the Profect P1 protein transfection reagent. IL-1β secretion was determined 1 h later by ELISA. (A) The BMMs derived from C57BL/6, isogenic TLR5-null, or isogenic Ipaf-null mice were compared. (B–D) Naip-sufficient (C57BL/6 and BALB/c) or Naip5-deficient (A/J) macrophages were analyzed.