Human mini-guts: new insights into intestinal physiology and host–pathogen interactions

Abstract

The development of indefinitely propagating human ‘mini-guts’ has led to a rapid advance in gastrointestinal research related to transport physiology, developmental biology, pharmacology, and pathophysiology. These mini-guts, also called enteroids or colonoids, are derived from LGR5+ intestinal stem cells isolated from the small intestine or colon. Addition of WNT3A and other growth factors promotes stemness and results in viable, physiologically functional human intestinal or colonic cultures that develop a crypt–villus axis and can be differentiated into all intestinal epithelial cell types. The success of research using human enteroids has highlighted the limitations of using animals or in vitro, cancer-derived cell lines to model transport physiology and pathophysiology. For example, curative or preventive therapies for acute enteric infections have been limited, mostly due to the lack of a physiological human intestinal model. However, the human enteroid model enables specific functional studies of secretion and absorption in each intestinal segment as well as observations of the earliest molecular events that occur during enteric infections. This Review describes studies characterizing these human mini-guts as a physiological model to investigate intestinal transport and host pathogen interactions.

A Primary Human Macrophage-Enteroid Co-Culture Model to Investigate Mucosal Gut Physiology and Host-Pathogen Interactions

“…Confocal microscopy of fluorescently labeled actin and wheat germ agglutinin (WGA; indicating glycocalyx-rich cell membrane) showed that both conditions resulted in an organized and polarized epithelium (Fig. 1c) consistent with previously published data 13,14 . Enteroid differentiation (five days in DFM) was associated with defined brush border formation demonstrated by apical actin labeling (Fig.…”

“…Enteroids and colonoids are reliable human models for the study of viral and bacterial pathogenesis 14,20,21,41,42 . In the present study, we increased the cellular complexity by integrating macrophages to enteroid monolayers with the purpose of interrogating host-pathogen interactions and innate immune response.…”

“…Hence, the development of an epithelial-immune co-culture model derived entirely from primary human tissue that does not require fresh patient samples for each study and exhibits normal intestinal features is a necessary advancement for studying coordinated epithelial immune response under normal or pathogenic conditions 12 . Human enteroids provide an attractive framework for developing in vitro models of gut architecture and function using primary human tissue [13][14][15][16] . Enteroids and colonoids derived from LGR5 + stem cells or LGR5 + -containing crypts from the small intestine and colon 17 , respectively, contain the four major human intestinal epithelial cell lineages with distinct roles in gut homeostasis and immune modulation (i.e.…”

A Fast and Simple Fluorometric Method to Detect Cell Death in 3D Intestinal Organoids

“…Moreover, intestinal organoids have been used to study host–pathogen interactions, for example, during Zika virus infection [9]. Importantly, intestinal organoids may also represent an unlimited source of transplantable tissue suitable for regenerative medicine.…”

Enteroviruses infect human enteroids and induce antiviral signaling in a cell lineage-specific manner

“…Despite serving as the primary portal for enterovirus entry into the human host, it remains unknown whether enteroviruses target select cell types within the intestine for their initial replication. An ex vivo model of the human intestinal epithelium has been developed, whereby primary intestinal crypts are isolated and cultured into epithelial structures that have been described as "mini-guts," often termed enteroids (7)(8)(9). Primary intestinal crypts are plated onto Matrigel, mimicking the enriched levels of laminin α1 and α2 present at crypt bases in vivo (10), and are cultured in the presence of growth factors that induce crucial developmental signaling through the Wnt and Notch pathways.…”