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

Figure 6

Impact of CM on PMN cell death, NO production, and IL-8 secretion. (a) PMN treated or not with CM and infected with H37Rv (MOI = 3) tested the expression of Annexin V and FVD eFluor 780 by flow cytometry. The percentage of early apoptotic (Annexin V pos/FVD eFluor 780neg), late apoptotic (Annexin Vpos/FVD eFluor 780pos), and necrotic (Annexin Vneg/FVD eFluor 780pos) cells was determined. Dot plots from a representative experiment out of 5 done and a bar graph showing the percentage of late apoptotic cells (mean ± SEM) are displayed (b–d). Supernatants derived from H37Rv-infected PMN were recovered at 18 h postinfection and tested for (b) LDH release, expressed as percentage (median ± SEM). Statistical differences: for control-CM-treated PMN versus N-T PMN; ^# H37Rv-CM versus control-CM-treated PMN (), (c) reactive nitrogen species (NO), expressed as μM (median ± SEM) () and (d) IL-8 secretion expressed as pg/ml (mean ± SEM). Statistical differences: for H37Rv-infected versus noninfected PMN; for CM-treated PMN versus N-T PMN ().

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