Suspended Collagen Hydrogels to Replicate Human Colonic Epithelial Cell Interactions with Immune Cells

The human colon plays a critical role in fluid and salt absorption and harbors the largest immune compartment. There is a widespread need for in vitro models of human colon physiology with its innate immune system. A method is described to produce a cassette with a network of struts supporting a suspended, non-chemically cross-linked collagen hydrogel scaffold compatible with the co-culture of primary gastrointestinal epithelium and migratory inflammatory cells. The epithelial monolayer cultured on the suspended collagen possesses a population of polarized and differentiated cells similar to that present in vivo. This epithelial layer displays proper barrier function with a transepithelial electrical resistance (TEER) >= 1,500 omega cm(2) and an apparent permeability <= 10(-5) cm(2) s(-1). Immune cells plated on the basal face of the scaffold transmigrated over a period of 24 h to the epithelial layer in response to epithelial production of IL-8 induced by luminal stimulation of Clostridium difficile Toxin A. These studies demonstrate that this in vitro platform possesses a functional primary colonic epithelial layer with an immune cell compartment capable of recruitment in response to pro-inflammatory cues coming from the epithelium.

Automated summary

This study describes a method to create an in vitro model of human colon physiology with a collagen hydrogel scaffold, allowing co-culture of primary gastrointestinal epithelium and immune cells. The model demonstrates that it possesses a functional primary colonic epithelial layer with a recruitable immune cell compartment in response to pro-inflammatory cues.