δ-toxin is deposited in the skin by <i>S. epidermidis</i> and binds neutrophil extracellular traps.

<p>a, normal healthy human skin stained for δ-toxin, showed deposition in the epidermis and dermis. Inset is 40× magnification of δ-toxin in dermis. Bar represents 50 µm. This is a single specimen representative of two. Nuclei are labeled with DAPI (blue) and δ-toxin is labeled with Alexa fluor 488 (green). The far left panel depicts the IgG control for the anti δ-toxin staining. b, δ-toxin was added to neutrophil extracellular traps (NETs), which were subsequently stained for LL-37 and δ-toxin. Staining shows colocalization of antimicrobial peptides along DNA strands. Bar represents 20 µm. Nuclei are labeled with DAPI (blue), δ-toxin is labeled with Alexa fluor 488 (green), and LL-37 is labeled with Alexa fluor 568 (red). The far left panel depicts the IgG control for the anti δ-toxin and anti LL-37 staining. c, primary keratinocytes incubated with (+ δ-toxin) and without (-δ-toxin) δ-toxin then anti δ-toxin staining evaluated. Nuclei are stained with DAPI (blue) and δ-toxin is labeled with Alexa fluor 568 (red). d, tryptophan spectroscopy of δ-toxin in the presence and absence of neutrophil DNA.