Figure 5.

Anti-CD3 mAb-induced injury is reduced in streptomycin-treated formula feeding (FF) pups. Neonatal mice from multiple litters were gavaged with formula milk with/without streptomycin [STM; postnatal day (P)0–P3: 30–60 µg/pup/feeding] every 3 h for 72 h. On P2, the pups were treated with anti-CD3 mAb (10 mg/kg) or isotype IgG subcutaneously. Pups were monitored for 24 h after treatment (P3). A: intestinal permeability expressed as fluorescence readings in serum 4 h after gavage with FITC-dextran. Intestinal permeability assay was run in duplicate for each sample. Data are presented as means ± SD; n = 6 in each group. B: analysis of body weight (BW) changes after indicated treatment. Data are presented as means ± SD; n = 8 in each group. C: representative microscopic images of hematoxylin-eosin (H&E) staining of ileum tissue samples from pups with or without antibiotics treated with anti-CD3 mAb. Scale bars, 100 μm. D: histological scores using a necrotizing enterocolitis (NEC) scoring system, with NEC-like injury defined as histological grade ≥ 2. Histological score was analyzed by χ² test, and data are presented as means ± SD; n = 8 in each group. A–D: data represent 2 independent experiments and were analyzed by 2-way ANOVA with Tukey posttest. ns, No significance. **P < 0.01, ***P < 0.001, ****P < 0.0001. Changes are considered statistically significant if P < 0.05.