Fig. 7. Histones and AMPs form a positive feedback loop that facilitates the uptake of antimicrobials into the cell.

a The interactions between histones and AMPs constitute a positive feedback loop in which AMP-induced pore formation increases the uptake of histones, which in turn, stabilizes the pore to facilitate uptake of additional AMPs. b Simulations indicating the total intracellular histone and AMP concentration for positive feedback and non-interacting relationships for a range of histone and AMP concentrations outside of the cell. Details of the simulations are described in the Methods section. c Growth profiles of E. coli treated with 10 μg/mL H2A, 1 μg/mL PMB, or both in medium containing 1 mM magnesium (n = 3 for each condition). Points are the average of biologically-independent experiments. Error bars indicate SEM.