Figure 8. Interfering with Bax and Bak function does not enhance L. pneumophila replication in macrophages.

(A) B6, Bak^−/− and Bax^−/−Bak^−/− BMMs or (B) B6 and Tg (bcl2) 535rm BMMs were infected with either L. pneumophila WT (white bars) or ΔflaA (black bars) for 72 hours. Intracellular replication is determined by dividing the L. pneumophila CFUs recovered at 72 h by the CFUs recovered 1 h after infection. Data are the average of values obtained from three independent wells. N.D. = not detectable. (C) Fluorescence micrographs of B6 and Tg (bcl2) 535rm BMMs that were infected with L. pneumophila ΔflaA and fixed either at 2 h or 10 h post infection. BMMs were stained with DAPI (blue) and an anti-L. pneumophila antibody (green). On the right are graphical representations of the percentage of B6 or Tg (bcl2) 535rm BMMs infected at 2 h and the percentage of infected BMMs with vacuoles containing replicating L. pneumophila at 10 h post infection. Data represent the mean±SD of 500 cells counted per coverslip in triplicate. All cells had a dominant Lgn1 allele producing a functional Naip5 protein. R.V. = vacuoles containing replicating bacteria. Bar = 10 µm.