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

Abstract

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 Ω cm2 and an apparent permeability ≤10−5 cm2 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.

Lab-on-chip technologies for exploring the gut–immune axis in metabolic disease

“…Gjorevski et al (2020) observed neutrophil movement and infiltration - for which ECM composition and mechanical properties required optimisation – as well as crosstalk between resident and circulating immune cells. 145 Numerous static models have also been developed using collagen hydrogels to support immune-epithelial co-culture including Hinman et al (2022) and Moysidou et al (2022) using neutrophil-like cells 187 and macrophages or monocytes 188 respectively. Studies have additionally found that the presence of macrophages in in vitro models improved enteroid-derived barrier maturity and function.…”