Figure 3

The neutrophil chemotactic and activating effects of Listeria products.

(a) Chemotactic activity of Listeria-derived peptide fMIVIL for mouse neutrophils. * significantly increased cell migration in response to the peptide as compared with medium control (0) (p = 0.0007). (b) Chemotactic activity of Listeria lysate for HEK293 cells transfected with Fprs. * significantly increased cell chemotaxis in response to Listeria lysate as compared with medium control (0) (p = 0.004). (c) Migration of mouse neutrophils to Listeria lysate. * significantly increased chemotaxis response of neutrophils to lysates as compared with medium control (0) (p = 0.003). (d) Listeria lysate-induced phosphorylation of Erk1/2 in WT mouse neutrophils in the presence or absence of Fpr antagonists and a TLR2 neutralizing antibody. (e) Semiquantitative analysis of phosphorylated Erk1/2. * significantly decreased Erk1/2 phosphorylation compared with cells stimulated with Listeria lysate at 1: 10 dilution in the absence of Fpr antagonists or TLR2 antibody. Results are from 1 experiment out of 3 performed. (f) Induction of Erk1/2 phosphorylation in WT and Fpr1/2^−/− mouse neutrophils by Listeria lysate (at 1:10 dilution) in the presence or absence of an Fpr antagonist Boc-2. (g) Semiquantitative analysis of phosphorylated Erk1/2. # significantly reduced Erk1/2 phosphorylation in Fpr1/2^−/− mouse neutrophils as compared with WT mouse neutrophils. * significantly decreased Erk1/2 phosphorylation in WT mouse neutrophils stimulated with Listeria lysate in the presence of Fpr antagonist Boc-2 as compared with cells stimulated with Listeria lysate alone (p = 0.001).