Fig. 2: BLP prevents lethal L. monocytogenes infection in mice.
From: Receptor-targeted engineered probiotics mitigate lethal Listeria infection
a Schematics showing mouse experiment protocol. b Increased BLP counts in the intestinal content of mice (n = 5) on days 10, 11, and 12. c Normalized mouse body weight (mean ± SD, n = 5) on days 0, 5, 10, and 12. d–h Reduced Lm burdens in the intestine (d, mucosa-associated, n = 5 at 24 hpi; and n = 10, 8, 8, 8, at 48 hpi for each group, respectively), shed in the feces (e, n = 5) and intracellular location in the ileum (f, n = 6), cecum (g, n = 6), and colon (h, n = 6). i, j Micrographs of ileal (i) and colonic villi (j) immunostained for ZO-1 (brown) and Lm (red, arrows) and counterstained for the nucleus (blue) at 48 hpi. Bars, 10 µm. The boxed areas were enlarged. Bars, 1 µm. Lm counts (mean ± SEM) in ileal or colonic lamina propria (LP; right panels). Dots represent an average of 25 villi from a single mouse, four mice/group, n = 100 villi. Lm is observed in the LP (arrows) in naive or LbcWT-treated mice, but confined in the lumen (arrows) in BLP-treated mice. k–o Reduced Lm burdens in the liver (k), spleen (l), (k and l, n = 5 at 24 hpi; and n = 17, 14, 13, 14, at 48 hpi), MLN (m, n = 11, 9, 8, 9, for each group, respectively), blood (n, n = 5 at 24 hpi; and n = 11, 8, 8, 8, at 48 hpi for each group, respectively) and kidney (o, n = 6, 3, 3, 3, for each group, respectively). p Increased survival of BLP-treated mice at LD50 dose. *P < 0.05 Kaplan–Meier log-rank test. For plots b, d–h, and k–o each point represents an individual mouse (n) from three to six independent experiments (median and interquartile range). Dashed horizontal lines indicate the limit of detection for each organ/tissue. Mann–Whitney nonparametric (two-tailed) test (b, d–h, k–o) was used and comparisons were made between each treatment group individually or by using the one-way (c, i, and j) ANOVA test followed by a Tukey’s multiple comparisons. For all analyses, ****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05; ns no significance. Source data are provided as a Source Data file.
