Crohn's disease (CD) derived intestinal organoids as a model to study inflammation emanating from the intestinal epithelium

Background:

Crohn's disease (CD) represents a chronic inflammatory disorder that may affect the entire gastrointestinal tract with frequent involvement of the Ileum and well-known extraintestinal manifestations. Progress in understanding the pathophysiology of this disease identified a complex interplay between genetic risk, immune cell dysregulation, microbial composition and environmental factors. So far studies relied on descriptive evidence derived from human samples with limited possibilities for mechanistic experiments or elegant but reductionistic animal models. Recently, the development of intestinal epithelial stem-cell derived 3D organoid cultures from human intestinal biopsies has vastly expanded the possibilities to study patient derived biopsies.

Aims:

Establishment of human CD organoids as a reliable model for studying pro-inflammatory signaling emanating from the intestinal epithelium.

Methods:

Ileal organoids from CD patients and healthy individuals were established and growth efficiency and budding rate was quantified. Organoids were stimulated with proinflammatory cytokines and expression of pro- and anti-inflammatory target genes was measured.

Results:

Establishment of organoids from ileal biopsies occurred at a high efficiency rate. CD organoids exhibited a tendency towards delayed budding but otherwise developed indistinguishable compared to healthy control organoids. Upon stimulation of CD organoids with typical pro-inflammatory cytokines associated with CD, such as IL-1β, TNFα or IL-6 the intestinal epithelium showed either a significantly increased expression or a tendency towards increased expression of pro-inflammatory target genes, such as IL-8, TNFα or Iκbα compared to healthy controls.

Conclusions:

CD derived intestinal organoids exhibit signs of a hyper-reactive inflammatory response of the intestinal epithelium upon stimulation with prototypical inflammatory cytokines. Notably, this occurs in the absence of overt inflammation or exposure towards the microbiota or immune cells, highlighting the potential of the intestinal epithelium to fuel intestinal inflammation. As such, organoids may represent a useful model to perform future studies to dissect mechanisms of intestinal inflammation.