Germ-Free IL-10 Knockout Colitis

Description

The IL-10 knockout mouse model is among the most utilized models for studying IBD and colitis. Colitis severity and onset can be variable in conventional animals and the colitis phenotype is extremely microbiome-dependent. Administration of a fecal microbial transplant (FMT) to germ-free IL-10 knockout animals (GF IL-10 KO) induces colitis characterized by inflammatory cell infiltration in the lamina propria and epithelial hyperplasia. Elevated fecal LCN2 and calprotectin are also observed. Test article responses can be compared to the effects of Anti-IL-12-p40 mAb.

  • Advantages: relevant model for the role of the microbiome in human IBD.
  • Disadvantages: longer duration, isolator housing/handling doesn’t support all in-life study endpoints.
Model Systems
  • C57Bl/6NTac-il10em8Tac Mice
Standard Readouts
  • Percent weight change
  • Disease Activity Index: diarrhea and blood in stool scoring
  • Fecal LCN2 and calprotectin
  • Terminal colon weight and length measurement
  • Terminal histopathology and/or IHC analyses
Additional Readouts
  • Endoscopy: colitis severity and stool consistency scoring
  • Colon cytokines
  • Colon myeloperoxidase (MPO)
  • Fecal MPO
  • Peripheral lymphoid organ immunophenotyping
  • Intestinal lamina propria immunophenotyping
  • Custom assays
Representative DataClick Image to Enlarge
Percent Weight Change in the Germ-Free IL-10 Knockout Colitis Model

GF IL-10 knockout mice administered a mouse FMT are weighed daily, and body weight change as compared to Day 0 is calculated. The AUC is calculated to compare treatment arms and is shown in the inset.

Colon Weight:Length Ratio in the Germ-Free IL-10 Knockout Colitis Model

Following euthanasia, the colon is excised, measured, rinsed, and weighed; the colon weight:length ratio is calculated. (*p<0.05 compared to the vehicle-control).

Fecal Lipocalin and Calprotectin in the Germ-Free IL-10 Knockout Colitis Model

Lipocalin (left) and calprotectin (right) are measured in fecal samples by commercially available ELISA. (*p<0.05 compared to the vehicle-control).

Colon Histopathology in the Germ-Free IL-10 Knockout Colitis Model

H&E stained mouse colon slides are evaluated with light microscopy. Features of inflammation, necrosis/gland loss, erosions, submucosal edema, and epithelial hyperplasia are given an individual score and scores are added together to obtain a sum score. Naïve is shown in upper right, vehicle is shown in middle right, and reference compound is shown in lower right. (*p<0.05; **p<0.001 as compared to vehicle control). Histopathology performed by Dallas Tissue Research.

Colon Cytokines in the Germ-Free IL-10 Knockout Colitis Model

Colon samples are homogenized and assessed via multiplex cytokine analysis for IL-1β, IL-17, IP-10, MIP-1α, RANTES, and TNFα. Additional cytokines are available. (*p<0.05; **p<0.01 as compared to vehicle control).

Daniel Lichtman

Managing Partner