Fig. 8: BLP prevents Lm-induced NF-κB activation and modulates cytokine production and immune cells to maintain intestinal immune homeostasis.
From: Receptor-targeted engineered probiotics mitigate lethal Listeria infection
a Immunofluorescence micrographs showing decreased nuclear localization of p65 (a, green) in Caco-2 cells treated with BLP strains (MOE 10, 24 h) before Lm exposure (MOI 50, 1 h). Arrows indicate the nuclear localization of p65. Separated channels; bottom panels. Bars, 10 μm. Images represent five different fields from three independent experiments. b–e Immunofluorescence micrographs of the ileal tissues showing decreased nuclear localization of p65 (b, green) and P-p65 (d, green) in BLP-treated mice (10 days) at 48 hpi. Nuclei; DAPI, blue. Arrows indicate the nuclear localization of p65 (b) and P-p65 (d) in IEC of naive or LbcWT-treated (10 days) mice at 48 hpi. Right panels (c, e) show the quantified results (mean ± SEM) of p65 (c) and P-p65 (d) nuclear-positive IEC. Each point represents an average of 15 villi from a single mouse, four mice per group, n = 60 villi. Bars, 10 μm. f, g, h ELISA showing decreased TNFα (f, n = 6 mice for all groups, except LbcWT and LbcLAPLin + Lm group; n = 5 and 4 mice, respectively), and IL-6 (g, n = 5 mice for all groups except LbcWT, LbcLAPLm and naive +Lm groups; n = 6 mice) levels (mean ± SEM) in the ileal tissues of BLP-treated (10 days) mice, relative to naive or LbcWT-treated (10 days) at 48 hpi and increased IFNγ (h, n = 4) levels (mean ± SEM) pre- or post-Lm challenge at 48 hpi. Each point; individual mouse. i, j Graphs showing increased IL-10+ (i) and TGFβ+ (j) cells quantified (mean ± SEM) from immunostained ileal tissues (Supplementary Fig. 8h, i, respectively) of BLP-treated (10 days) mice pre- or post-Lm challenge at 48 hpi. Each point represents an average of 25 villi from a single mouse, four mice per group, n = 100 villi. Statistical significance (c, e, f–j) was determined by using the one-way ANOVA followed by a Tukey’s multiple comparisons. For all analysis, ****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05; ns no significance. Source data are provided as a Source Data file.
