Inactivation of Staphylococcal Phenol Soluble Modulins by Serum Lipoprotein Particles
Figure 5
Serum lipoproteins inhibit PSM-mediated neutrophil lysis and activation.
(A) Dose-dependent neutrophil lysis by synthetic PSMα3 preincubated with 1% and 10% human serum or human lipid-free (LF) serum or preincubated with (B) 5 and 50 µg/ml HDL or 10 and 100 µg/ml LDL (concentrations are based on protein content). PBS was used as buffer control. Neutrophil lysis was measured via LDH release. (C) Calcium mobilization of human neutrophils. Neutrophils were stimulated with 10−6 M PSMα1, 10−7 M PSMα2, 10−7 M PSMα3, 10−6 M PSMα4, 3×10−6 M δ-toxin, 10−5 M PSMβ1, 10−5 M PSMβ2, 10−9 M fMLP, 10−10 M C5a and 10−10 M IL-8, all preincubated with or without 5 µg/ml HDL or LDL, before calcium mobilization was measured by flow cytometry. *, p<0.001; N.S., not significant.