Figure 2.

The ILC-compartment controls intestinal bacterial dissemination to systemic organs

(A–D) Specific pathogen-free (SPF) wild-type, Rag1^−/−, or Rag2^−/−Il2rg^−/− mice underwent major surgery modeled by two-third partial hepatectomy (PH). (A) Schematic representation of two-third PH in mice. (B) Bacterial titers (colony-forming units [CFUs]) in the liver and the spleen in SPF wild-type, Rag1^−/−, and Rag2^−/−Il2rg^−/− mice 24 h after PH. (C and D) Microbial composition within the feces and liver were determined by 16S rRNA amplicon analysis. (C) Principal-component analysis was done using Bray-Curtis distances on all operational taxonomic units (OTUs). (D) Microbial composition at class level.

(E–G) SPF Rag1^−/− and Rag2^−/−Il2rg^−/− mice were co-housed at weaning for 3 weeks. Microbial composition determined by 16S rRNA amplicon sequencing in feces before or after co-housing. The liver tissue was analyzed 24 h after PH. (E) Principal-component analysis was done using Bray-Curtis distances on all OTUs. (F) Relative abundance of Clostridiaceae and Paraprevotellaceae in feces. (G) Bacterial titers in the liver were assessed 24 h post PH.

(H and I) Germ-free wild-type, Rag1^−/−, and Rag2^−/−Il2rg^−/− mice were short-term colonized with 10¹⁰ CFU of E. coli JM83 12 h prior to PH. (H) Scheme of experimental setup. (I) E. coli titers (CFU) in the liver and spleen 24 h after PH. Geometric means for log scales and arithmetic means for linear scales are shown. Normalized values were analyzed by Student’s t test to compare two experimental groups or by ANOVA to compare more than two groups in parallel. Data in (C)–(G) are representative of at least n = 3 mice per group in two independent experiments, and data in (B) and (I) are pooled based on n = 5–9 mice from two or more independent experiments. The p values are indicated as follows: ^∗p ≤ 0.05, ^∗∗p ≤ 0.01, ^∗∗∗p ≤ 0.001, and ^∗∗∗∗p ≤ 0.0001. See also Figure S1.