FIG 4.
Effect of TLR blocking on IL-6 stimulation by GMMA from STmG ΔmsbB ΔpagP or SEnG ΔmsbB ΔpagP. Human PBMC either were incubated with anti-TLR5, anti-TLR4, or anti-TLR2 or were left untreated (not treated [nt]) and were subsequently stimulated with 1 ng/ml or 10 ng/ml of GMMA. Results in each TLR-blocking experiment were normalized according to the results for untreated PMBC in the same experiment. To illustrate the different levels of stimulation by the different GMMA and concentrations, the normalized results were then back calculated to the average IL-6 production in the untreated samples. Error bars show standard deviations with 6 independent replicates using PBMC from 3 different donors. The results for untreated PBMC and for TLR2-, TLR4-, and TLR5-blocked PBMC using the same type and concentration of GMMA were compared using the Kruskal-Wallis test with Dunn's post hoc multiple comparisons. Asterisks indicate treatments that gave results statistically different from those for the untreated samples (*, P ≤ 0.05; ***, P ≤ 0.001; ****, P ≤ 0.0001).