Journal: Cell Communication and Signaling : CCS
Article Title: Extracellular vesicles derived from Enterococcus faecalis : inflammatory activation does not require internalization
doi: 10.1186/s12964-026-02926-9
Figure Lengend Snippet: Ef -EVs activate the NF-κB/AP-1 pathways in human reporter macrophages via TLR2 signaling. A dTHP1-XBlue cells were treated with Ef -EVs (100 − 50,000 EVs/cell). LPS (100 ng/mL) was used as a positive control. B dTHP1-XBlue cells were treated with EVs derived from clinical E. faecalis bloodstream isolates (1000-10,000 EVs/cell). LPS (100 ng/mL) and Pam 3 CSK 4 (100 ng/mL) were used as positive controls. C-E) dTHP1-XBlue cells were pretreated with increasing concentrations (from 0.1 to 5 µg/mL) of anti-hTLR2-IgA mAb (dark pink) or human IgA2 control mAb (light pink) for 1 h. Subsequently, cells were treated with either (C) EVs (7000 EVs/cell), (D) Pam 3 CSK 4 (TLR2 ligand, 1 ng/mL), or (E) LPS (TLR4 ligand, 1 ng/mL) in the presence of antibodies for 24 h. Cells treated with cell culture medium supplemented only with Ef -EVs (7000 EVs/cell) in (C, blue), Pam 3 CSK 4 (1 ng/mL) in (D, dark blue), or LPS (1 ng/mL) in (E, red) were used as positive activating controls while cells treated with cell culture medium supplemented alone ( C - E , light green) were used as negative controls. NF-κB/AP-1 activation was measured as the activity of secreted SEAP and expressed as a normalized value relative to the positive controls. Data are shown as means ± SD of three independent experiments ( N = 3, n ≥ 3) and analyzed either by Kruskal-Wallis test followed by Dunn’s multiple comparison post hoc test in (A and B) or by two-way analysis of variance (ANOVA) followed by Šídák multiple comparison post hoc test in ( C - E )
Article Snippet: To elucidate whether Ef -EVs induce NF-κB/AP-1 activation by TLR2 engagement, dTHP1-XBlue were pre-incubated for 1 h with fresh medium containing 1 μg/mL of neutralizing monoclonal antibodies (anti-hTLR2-IgA mAb, cat. no. maba2-htlr2-2, Invivogen) or human IgA2 control (cat. no. maba2-ctrl, Invivogen) before adding either Ef -EVs (7000 EVs/cell), ultrapure LPS from E. coli K12 (LPS, 1 ng/mL, cat.no. tlrl-peklps, Invivogen), or Pam 3 CSK 4 (1 ng/mL) in antibody-containing medium.
Techniques: Positive Control, Derivative Assay, Control, Cell Culture, Activation Assay, Activity Assay, Comparison