FIGURE 6.

Mutation of a caspase-8 recognition motif leads to impaired cleavage and degradation of IRF-3. P2.1 cells expressing Wt or the D121E (DE) mutant of IRF-3 were used in these experiments (A–C). A, cells were transfected with poly(I:C); cell lysates were analyzed for IRF-3 by Western blot (FL, full-length, CL, cleaved); B, cells were treated with poly(I:C) to activate TLR3-dependent signaling, the full-length (FL) and the cleaved (CL) forms of IRF-3 are shown; C, cell lysates from TLR3 activation (T) or RLH activation (R) reactions were analyzed for cleaved Bid by Western blot; D, IRF-3 degradation was analyzed by Western blot following transfection of poly(I:C) (RLH activation); E, IRF-3 degradation was analyzed by Western blot following treatment with poly(I:C) (TLR3 activation).