TABLE 2.

Pilus-deficient P. aeruginosa PAK mutants fail to induce significant apoptosis of human Chang conjunctiva epithelial cells^a

P. aeruginosa strain	% Annexin-positive cellsb	% Cells with low Δψmc	% Cells with high ROSd
Without infection	6.0 ± 3.0	2.5 ± 1.5	6.6 ± 3.3
PAO-I	35.1 ± 7.9e	35.3 ± 8.4e	41.5 ± 8.6e
PAK	39.1 ± 11.0e	37.0 ± 11.4e	25.6 ± 5.6e
PAKΔpilA	7.4 ± 4.7	4.1 ± 2.0	10.4 ± 5.1
PAK ΔpilAΔall	6.6 ± 3.5	4.4 ± 3.3	6.8 ± 2.2

^aChang conjunctiva epithelial cells were infected with for 3 h with the P. aeruginosa strains as indicated. Data are means ± standard deviations of 3 experiments.

^bApoptotic cell death was then determined by FACS analysis of FITC-annexin V-stained cells. Values represent percentages of FITC-annexin-positive cells.

^cMitochondrial membrane potential was determined by FACS analysis of JC1-stained cells. Values represent percentages of cells with low Δψm.

^dSynthesis of ROS was determined by FACS analysis of DHE-stained cells. Values indicate percentages of ethidium-positive cells with high ROS production.

^eSignificantly different from value for uninfected control cells (P < 0.05) as calculated by Student's t test.