Figure 1
ROS induced by strain Ra is dose dependent and correlates with apoptosis. (A) PMN were pretreated with DHR and incubated with different relations of Mtb:PMN (1:2, 2:1 and 5:1). Thereafter, the emission of oxidized DHR was evaluated by flow cytometry as a measure of oxidative burst. The results are expressed as mean ± SE (n = 16); control (−−) vs. all Mtb:PMN ratios ***p < 0.001; 1:2 vs. 2:1; 1:2: vs. 5:1 and 2:1 vs. 5:1 Mtb:PMN ratio: #p < 0.05 (B) Apoptosis was measured in 18-hr cultured PMN with or without the presence of clinical strains as described in (A). Results are expressed as the percentage of AV-FITC positive cells (% PMN AV + ± SE) (n = 16); control (−−) vs. all Mtb:PMN ratios: **p < 0.001; 1:2 vs. 2:1; 1:2: vs. 5:1 and 2:1 vs. 5:1 Mtb:PMN ratio: #p < 0.05; C) correlation between ROS generation and apoptosis of PMN (p < 0.0001, r2: 0.9826).