Fig. 4.

CFTR function is not required for escape of Listeria expressing a gain-of-function LLO allele. (A) RAW macrophages were infected with Listeria expressing wild-type LLO or LLO L461T. Cells were fixed at the times indicated pi, stained with rhodamine-phalloidin and anti-Listeria antibody, and analyzed by fluorescence microscopy. Percentages represent number of bacteria per 100 colocalized with actin (n = 3; **P < 0.001 for comparison between strains). (B) RAW cells were untreated or treated for 1 h with CFTR(inh)-172 or DPC, infected with wild-type or the L461T mutant Listeria, fixed at 2 h pi, and analyzed as in A (n = 3; *P < 0.05 and **P < 0.001, comparing treated with untreated cells or as indicated by the bracket).