Figure 4
From: A host-directed macrocyclic peptide therapeutic for MDR gram negative bacterial infections
MTD12813 promotes phagocytosis of Kp-1705. (a-b) Phagocytosis by RAW 264.7 macrophages incubated with MTD12813 in the presence of Kp-1705 (50:1 MOI). (a) Cytospins were stained with H&E and phagocytic index (bacteria per cell) was determined manually. Scatter plots depict means ± 95% CI, P values determined by ANOVA with Uncorrected Fisher’s LSD post test, *P ≤ 0.05, **P < 0.01, ***P < 0.0001. (b) Images comparing effects of 0 and 0.313 µg/ml MTD12813 on phagocytic activity. (c) Mice were challenged i.p. with Kp BAA-1705 cells preincubated for 1 h prior to infection with saline (●, n = 26) or 1.25 µg/ml MTD12813 (■, n = 26). A control cohort received saline preincubated bacteria followed immediately by i.p. treatment with 500 µl of MTD12813 at 1.25 µg/ml (▲, n = 12). Survival of each cohort is shown. Experiment was repeated 4 times, P values determined by Fisher’s exact test. (d) PLF was collected from 5 mice challenged with saline (C) or MTD12813-pretreated Kp-1705 (as in panel c) that were euthanized 4 h p.i., and bacteria in each sample were quantified by plating (means ± SD; P values by Student’s t-test). H & E stained cytospin preparations from saline (e) and MTD12813-pretreated samples (f).
