Macrophage Immune-Competent Colon Assembloids for Functional Interrogation of Neuroinflammation-Induced Colonic...

Background and Aims: Functional gastrointestinal disorders affect ∼40% of the global population and are frequently characterized by colonic dysmotility. Symptomatic manifestations of colonic dysmotility significantly reduce quality of life in inflammatory bowel disease, diabetes, and Gulf War Illness. Current in vitro models lack the integration of functional physiology with immune and neuronal complexity required to establish causal links between neuroinflammation and dysmotility. Here, an immune-competent bioengineered colon assembloid is introduced that integrates multiple cell types of the external colonic wall, along with functional readouts of motility.

Bioengineered colon assembloids were fabricated using immortalized smooth muscle cells, enteric neuronal progenitor cells, and macrophage immune cells embedded within collagen hydrogels. Assembloids were allowed to compact and mature, prior to inflammatory insult with pyridostigmine bromide or tumor necrosis factor-alpha.

Within bioengineered colon assembloids, various inflammatory insults resulted in enteric neuroinflammation, cascading to changes in colonic motility. Key mechanisms of dysmotility following inflammatory insult within the bioengineered colon assembloids included impaired neuronal regeneration and aberrant smooth muscle remodeling. The bioengineered colon assembloid model mimicked diverse aspects of enteric neuroinflammation.

Ultimately, the platform offers a physiologically relevant avenue to interrogate neuroimmune crosstalk and dissect mechanisms of colonic dysmotility, paving the way to new therapeutic strategies to improve colonic motility.