Direct Visualization by Cryo-EM of the Mycobacterial Capsular Layer: A Labile Structure Containing ESX-1-Secreted Proteins (original) (raw)
Figure 5
Capsular layer promotes binding to macrophages and inhibits the pro-inflammatory cytokine response.
The results represent the mean relative binding ± standard error of the mean (SEM) of the pooled data from three independent donors. (A) The percentage of macrophages associated with Tween. M. bovis BCG expressing dsRed bacteria was determined using flow cytometry. Binding of Tween-treated M. bovis BCG at MOI 0.5 (1.13% +/− 0.24 (SD)) is set at 1. (B and C) Macrophages were stimulated with/without Tween treatment M. bovis BCG (B) or M. smegmatis (C) at MOIs 2 and 8. Cells stimulated with PBS served as a control. After 24 h, the supernatants were harvested and the amount of IL-12p40, IL-6, and TNF-α was determined using ELISA. The results represent the mean relative cytokine production (± SEM) of the pooled data from at least three independent donors. Cytokine production following stimulation with Tween-treated bacteria at MOI 8 is set at 100 [for M. bovis BCG, IL-6: 12087±3056, IL-12p40: 2928±618, TNFα: 38490±6446; for M. smegmatis, IL-6: 61629±17411, IL-12p40: 22693±2100, TNFα: 122663±17350 (all in pg mL−1 ± SEM)]. An asterisk indicates significant differences (p<0.05).