Mycobacterium tuberculosis Multidrug-Resistant Strain M Induces Low IL-8 and Inhibits TNF-α Secretion by Bronchial Epithelial Cells Altering Neutrophil Effector Functions

Figure 3

CM alter PMN activation and ROS production by irradiated H37Rv (i-H37Rv). Freshly, PMN () were incubated for 1.5 h with (a) RPMI 1640 plus (N-T) or with conditioned media (CM) from Calu-6 cells infected with H37Rv or M (H37Rv-CM and M-CM) or noninfected (control-CM) or (b) additionally with H37Rv-CM-depleted TNF-α (depl-H37Rv-CM), M-CM plus TNF-α (M-CM-TNF-α), or TNF-α (20 ng/ml). Thereafter, PMN were stimulated for further 3 h with or without i-H37Rv or PMA (5 nM) as a second stimulus. PMA (50 nM) was employed as positive control for the last 30 min. PMN were tested for CD11b expression (a) and ROS production (b) by labeling with DHR for 30 min (c, d, and e) by FACS. Results are expressed as median fluorescence intensity (MFI) ± SEM. (a) Statistical differences: for PMA versus nontreated (N-T) or CM-treated PMN. (b) Statistical differences: for CM-treated PMN versus N-T PMN; ^# for PMN treated with depl-H37Rv-CM versus H37Rv-CM or PMN treated with M-CM plus TNF-α versus M-CM; for M-CM versus control-CM or H37Rv-CM. (c) Statistical differences: for PMA versus N-T or CM-treated PMN. (d and e) Statistical differences for PMA and i-H37Rv, respectively: for treated PMN versus nontreated PMN; ^# for PMN treated with depleted-H37Rv-CM versus H37Rv-CM or PMN treated with M-CM plus TNF-α versus M-CM; for M-CM versus control-CM or H37Rv-CM.

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