Pro-inflammatory and cytolytic capacities of PSM-mec and derivatives.

<p>(A) Chemotaxis of human neutrophils. Peptides were applied at 0.5 µg/ml (PSMα3), 2 µg/ml (δ-toxin), 5 µg/ml (PSM-mec), and 10 µg/ml (PSMβ1). (B) Calcium flux in human neutrophils. Peptides were applied at 0.1 µg/ml (PSMα3), 1 µg/ml (δ-toxin, PSM-mec), and 2.5 µg/ml (PSMβ1). In (A) and (B), values were corrected for the different concentrations applied. (C,D) Surface expression of CD11b and gp91<i>phox</i> on human neutrophils. #, lysis of neutrophils occurred. For PSMs, bars represent values obtained from increasing concentrations of peptide: 10, 100, 200, 400, 1000, 10000 ng/ml, from left to right in each group. (E) Secretion of the cytokine IL-8 at 10 µg/ml of PSM. (F) Neutrophil lysis at 50 µg/ml of PSM, comparison of PSM-mec with C17A and C17S replacement peptides. (G) Hemolytic activity. (H) Secretion of IL-8, comparison of PSM-mec with with C17A and C17S replacement peptides. (G,H) PSM peptides were applied at 10 µg/ml. (F,H) Statistical comparisons are vs. PSM-mec. *, p<0.05; **,p<0.01; N.S., not significant. In (A,B,C,D,E, and G) values for PSMs other than PSM-mec and controls that are shown for comparison are from Wang et al. <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1000533#ppat.1000533-Wang1" target="_blank">[7]</a>. Values for all samples including PSM-mec were obtained in parallel.