FIG. 3.

Inhibition of Chlamydia-induced apoptosis in cells overexpressing Bax inhibitor-1 (BI-1) or Bcl-2. (A) HeLa cells were transfected transiently with constructs encoding BI-1 or Bcl-2 for 1 day and then infected with C. psittaci for 48 h. Apoptosis was measured by immunofluorescence, as described in Materials and Methods, and the level of apoptosis was normalized to 100 for untransfected cells. (B) The stable U937 or HeLa clones overexpressing Bcl-2 and the corresponding clones transfected with control expression vector were infected with C. psittaci for 48 h. Apoptosis was measured by cytofluorimetry, and the level of apoptosis was normalized to 100 for untransfected cells. Each series of experiments was performed at least three times.