An Intestinal Organ Culture System Uncovers a Role for the Nervous System in Microbe-Immune Crosstalk

Abstract

SUMMARY Investigation of host-environment interactions in the gut would benefit from a culture system that maintained tissue architecture yet allowed tight experimental control. We devised a microfabricated organ culture system that viably preserves the normal multicellular composition of the mouse intestine, with luminal flow to control perturbations (e.g. microbes, drugs). It enables studying short-term responses of diverse gut components (immune, neuronal…). We focused on the early response to bacteria that induce either Th17 or RORg+ T-regulatory (Treg) cells in vivo. Transcriptional responses partially reproduced in vivo signatures, but these microbes elicited diametrically opposite changes in expression of a neuronal-specific geneset, notably nociceptive neuropeptides. We demonstrated activation of sensory neurons by microbes, correlating with RORg+ Treg induction. Colonic RORg+ Treg frequencies increased in mice lacking TAC1 neuropeptide precursor, and decreased in capsaicin-diet fed mice. Thus, differential engagement of the enteric nervous system may partake in bifurcating pro- or anti-inflammatory responses to microbes.

Understanding the Holobiont: How Microbial Metabolites Affect Human Health and Shape the Immune System

“…recently reported the development of a highly functional, microfluidics-based intestinal organ culture system. They found that previous observations made in vivo could be robustly reproduced, while being able to extract compelling new insights due to the tightly controlled nature of their system (Yissachar et al, 2017). Novel systems like this will undoubtedly be crucial in the elucidation of more complex connections between host and microbiome, and ultimately allow the development of new therapeutic approaches to treat ailments ranging from IBD to depression.…”

Gut Microbiota: What We Could Do, Not Just Use ‘Young Healthy Poo’ for Drugs?

“…Most of these primary cells or cell lines could be isolated and cultured in monolayers, and it would be a simplified bacteria-host system if supplied with bacterias. However it is far from enough, Yissachar et al recently built an organ culture system using the mouse intestine, which might try the best to keep hosts' components complete and alive, and also make some essential factors controllable [14]. Of note, mouse intestines from different disease models could also be used as the culture systems, which much broadens this system's applications.…”

Mucosal Bioengineering: Gut in a Dish

“…Therefore, primary IECs are especially prone to cell death when taken outside the body. In a new study in Cell , Yissachar et al., reasoned that maintaining the environmental differential, including intestinal flow, is crucial for maintaining epithelial cell viability, and could improve tissue viability ex vivo [5]. They designed a sealed silicon tissue culture system unit that generates two independent flow environments outside and inside an extracted intestinal segment.…”

“…Intestinal tissue microarchitecture is preserved and this includes tissue histology, epithelial cell barrier function, immune cell subsets, intestinal smooth muscles and the enteric nervous system (ENS). The intestinal segments even exhibit spontaneous peristalsis [5]. …”

“…Moreover, this was a property of multiple RORγ + Treg inducing microbes and suggested that these microbes may engage ENS. The authors further explored this by showing that RORγ + Treg inducing microbes activate neurons, including nociceptor neurons, in primary cultures [5]. Neuronal activation required live bacteria and was mediated by filtered bacterial supernatants, suggesting that gut neurons detect secreted products from metabolically active bacteria.…”