Figure 7.

PA-dPEG24 inhibition of immune complex-activated serum-initiated neutrophil extracellular trap (NET) formation with human neutrophils (PMN) assayed by fluorescence microscopy and PicoGreen quantitation of free DNA. Ovalbumin–antiovalbumin immune complexes (IC) were utilized. (A) NET formation induced by PMNs incubated alone (untreated), with normal human sera (NHS), IC alone (IC), or immune-complex-activated human sera (ICsera). Data are means of (n = 5) independent experiments ± SEM. (B) PA-dPEG24 inhibition of NET generation by human neutrophils stimulated with ICsera assayed by PicoGreen. Data are means of (n = 4) independent experiments ± SEM. (C) The first row shows unstimulated neutrophils, the second row shows neutrophils stimulated with ICsera and hydrogen peroxide (H₂O₂), and the third row shows neutrophils stimulated with ICsera + H₂O₂ in the presence of PA-dPEG24 (peptide inhibitor of complement C1). The first column is slides probed with DAPI to visualize DNA and the second column is slides probed with anti-MPO antibody.