DNA Is an Antimicrobial Component of Neutrophil Extracellular Traps (original) (raw)
Figure 5
Neutralizing the cation chelating activity of the DNA backbone of NETs protects bacteria.
(A) Percent survival of P. aeruginosa PAO1 and E. coli DH5α as determined by direct plate counts (CFU/ml) before and after 4 hour incubation with PMA-activated neutrophils or combined treatment of NETS with DNase, PTase or Mg2+. Error bars are SEM from 6 replicates. ** or *** denotes a statistically significant difference (P<0.05 or P<0.01, respectively) between NET-alone versus NET and enzymatic or excess cation treatments, as determined by one-way ANOVA with Bonferroni post tests. (B) Luminescence-based viability as a real-time measure of P. aeruginosa PAO1::p16S_lux_ survival in the presence of NETs alone, or combined treatment of NETS with DNase I, PTase or Mg2+. ### denotes a statistically significant difference of P<0.001 between NET-challenged PAO1 versus PAO1 alone (white). ***P<0.001 versus NET killed samples (black). (C) Flow cytometry of P. aeruginosa PAO1 (2 × 107 CFU) coincubated for four hours with PMA-stimulated neutrophils alone (1 × 106; MOI: 10) or with the addition of DNase I, PTase and 5 mM Mg2+. N = 50 000 for each plot. Numbers in each corner represent the % of 50 000 events that fall into each quadrant gate.