Organ Model: Digestive System

Organ Model: Lung (Alveolus) & Intestine (Colon)

Application: Immunology

Abstract: Traditional drug safety assessments often fail to predict complications in humans, especially when the drug targets the immune system. Rodent-based preclinical animal models are often ill-suited for predicting immunotherapy-mediated adverse events in humans, in part because of the fundamental differences in immunological responses between species and the human relevant expression profile of the target antigen, if it is expected to be present in normal, healthy tissue. While human-relevant cell-based models of tissues and organs promise to bridge this gap, conventional in vitro two-dimensional models fail to provide the complexity required to model the biological mechanisms of immunotherapeutic effects. Also, like animal models, they fail to recapitulate physiologically relevant levels and patterns of organ-specific proteins, crucial for capturing pharmacology and safety liabilities. Organ-on-Chip models aim to overcome these limitations by combining micro-engineering with cultured primary human cells to recreate the complex multifactorial microenvironment and functions of native tissues and organs. In this protocol, we show the unprecedented capability of two human Organs-on-Chip models to evaluate the safety profile of T cell-bispecific antibodies (TCBs) targeting tumor antigens. These novel tools broaden the research options available for a mechanistic understanding of engineered therapeutic antibodies and for assessing safety in tissues susceptible to adverse events. Graphical abstract Figure 1. Graphical representation of the major steps in target-dependent T cell-bispecific antibodies engagement and immunomodulation, as performed in the Colon Intestine-Chip.

Article Type: Review

Organ Models: Small Intestine, Large Intestine, Lung (Airway), Cervix, Vagina

Abstract: The surfaces of human internal organs are lined by a mucus layer that ensures symbiotic relationships with commensal microbiome while protecting against potentially injurious environmental chemicals, toxins, and pathogens, and disruption of this layer can contribute to disease development. Studying mucus biology has been challenging due to the lack of physiologically relevant human in vitro models. Here we review recent progress that has been made in the development of human organ-on-a-chip microfluidic culture models that reconstitute epithelial tissue barriers and physiologically relevant mucus layers with a focus on lung, colon, small intestine, cervix and vagina. These organ-on-a-chip models that incorporate dynamic fluid flow, air–liquid interfaces, and physiologically relevant mechanical cues can be used to study mucus composition, mechanics, and structure, as well as investigate its contributions to human health and disease with a level of biomimicry not possible in the past.

Organ Model: Intestine (Caco2)

Application: Infectious Disease

Abstract: Physical forces are essential to biological function, but their impact at the tissue level is not fully understood. The gut is under continuous mechanical stress because of peristalsis. To assess the influence of mechanical cues on enteropathogen invasion, we combine computational imaging with a mechanically active gut-on-a-chip. After infecting the device with either of two microbes, we image their behavior in real time while mapping the mechanical stress within the tissue. This is achieved by reconstructing three-dimensional videos of the ongoing invasion and leveraging on-manifold inverse problems together with viscoelastic rheology. Our results show that peristalsis accelerates the destruction and invasion of intestinal tissue by Entamoeba histolytica and colonization by Shigella flexneri. Local tension facilitates parasite penetration and activates virulence genes in the bacteria. Overall, our work highlights the fundamental role of physical cues during host-pathogen interactions and introduces a framework that opens the door to study mechanobiology on deformable tissues.

Webinar Abstract

Immune cell recruitment is a key driver of complex human diseases such as inflammatory bowel disease (IBD) but has remained challenging to model due to the biological complexity and species-specific nature of immune response.

In this webinar, we show data on how researchers can use Emulate Organ-on-a-Chip technology to model colon-specific immune cell recruitment, including immune cell vascular attachment, migration, activation, and downstream effector functions.

The Colon Intestine-Chip is a physiologically relevant barrier model incorporating primary human colonic organoids and intestinal microvascular endothelial cells in a dynamic microenvironment with tissue-relevant mechanical forces.

By perfusing peripheral blood mononuclear cells (PBMCs) through the vascular channel in the presence of priming cytokines/chemokines, researchers can model the selective migration of ‘gut-specific’ PBMCs into the epithelial channel, where they secrete IBD-associated cytokines, kick off organ-specific inflammatory cascades, and induce the hallmark ‘leaky gut’ phenotype. In addition, the model has been demonstrated to recapitulate the efficacy and mechanism of clinically relevant, anti-inflammatory IBD therapeutics.

Watch this on-demand webinar to learn how you can use the Colon Intestine-Chip to develop more effective, targeted therapeutic strategies for IBD across an expanded pool of inflammatory pathways in a single model.

In this webinar, you will learn:

• Key challenges in modeling gut inflammation-specific immune cell recruitment
• How to use Organ-on-a-Chip technology to create a more human-relevant model of the colon
• How the Colon Intestine-Chip can be used model immune recruitment and assess the efficacy and mechanism of action of anti-inflammatory drugs

Overview

Inflammatory bowel disease (IBD) is a complex pathology with a large, rapidly growing, unmet medical need. The two methods typically used to study IBD, animals and conventional in vitro models, suffer from poor translatability to humans, the ability to only model a narrow range of disease features, and many more issues that prevent the creation of effective IBD therapeutics.

Emulate’s Colon Intestine-Chip was previously developed as a primary human vascularized model of the intestinal barrier capable of recapitulating physiologic cell composition, morphology, and barrier function. This application uses the Colon Intestine-Chip to model the progression of IBD driven by immune cells more completely than previous models.

Key Highlights

• Applicable in studies of inflammation-specific immune recruitment from vasculature into epithelial tissue and subsequent downstream effects.
• Treatable with clinically relevant IBD therapeutics to reduce PBMC recruitment and protect the epithelium from downstream cytokine response.
• The most complete picture of human IBD pathogenesis and a more human-relevant platform for drug candidate efficacy and mechanism-of-action studies.

Organ Model: Intestine (Duodenum)

Application: Model Development

Abstract: Environmental enteric dysfunction (EED)-a chronic inflammatory condition of the intestine-is characterized by villus blunting, compromised intestinal barrier function and reduced nutrient absorption. Here we show that essential genotypic and phenotypic features of EED-associated intestinal injury can be reconstituted in a human intestine-on-a-chip lined by organoid-derived intestinal epithelial cells from patients with EED and cultured in nutrient-deficient medium lacking niacinamide and tryptophan. Exposure of the organ chip to such nutritional deficiencies resulted in congruent changes in six of the top ten upregulated genes that were comparable to changes seen in samples from patients with EED. Chips lined with healthy epithelium or with EED epithelium exposed to nutritional deficiencies resulted in severe villus blunting and barrier dysfunction, and in the impairment of fatty acid uptake and amino acid transport; and the chips with EED epithelium exhibited heightened secretion of inflammatory cytokines. The organ-chip model of EED-associated intestinal injury may facilitate the analysis of the molecular, genetic and nutritional bases of the disease and the testing of candidate therapeutics for it.

Abstract

Immune cell recruitment into tissues is an essential step in inflammatory responses. This occurs in a highly tissue- and stimulus-specific manner, which presents a significant challenge to modeling disease and testing therapeutics ex vivo. We previously developed an advanced primary human vascularized Colon Intestine-Chip model and showed that it recapitulates physiologic cell composition, morphology and barrier integrity. The goal of this work was to test the ability of this system to model inflammatory bowel disease (IBD)-like immune cell responses.

The described model is advantageous in recapitulating in vivo inflammatory effector functions in that it supports immune cell trafficking under fluid flow conditions, uses primary cell co-culture, and provides a physiologically relevant peristaltic-like stretch.

Organ Model: Intestine (Colon and Duodenum)

Application: Model Development

Abstract: The intestinal mucosa is a complex physical and biochemical barrier that fulfills a myriad of important functions. It enables the transport, absorption, and metabolism of nutrients and xenobiotics while facilitating a symbiotic relationship with microbiota and restricting the invasion of microorganisms. Functional interaction between various cell types and their physical and biochemical environment is vital to establish and maintain intestinal tissue homeostasis. Modeling these complex interactions and integrated intestinal physiology in vitro is a formidable goal with the potential to transform the way new therapeutic targets and drug candidates are discovered and developed. Organoids and Organ-on-a-Chip technologies have recently been combined to generate human-relevant intestine chips suitable for studying the functional aspects of intestinal physiology and pathophysiology in vitro. Organoids derived from the biopsies of the small (duodenum) and large intestine are seeded into the top compartment of an organ chip and then successfully expand as monolayers while preserving the distinct cellular, molecular, and functional features of each intestinal region. Human intestine tissue-specific microvascular endothelial cells are incorporated in the bottom compartment of the organ chip to recreate the epithelial-endothelial interface. This novel platform facilitates luminal exposure to nutrients, drugs, and microorganisms, enabling studies of intestinal transport, permeability, and host-microbe interactions. Here, a detailed protocol is provided for the establishment of intestine chips representing the human duodenum (duodenum chip) and colon (colon chip), and their subsequent culture under continuous flow and peristalsis-like deformations. We demonstrate methods for assessing drug metabolism and CYP3A4 induction in duodenum chip using prototypical inducers and substrates. Lastly, we provide a step-by-step procedure for the in vitro modeling of interferon gamma (IFN?)-mediated barrier disruption (leaky gut syndrome) in a colon chip, including methods for evaluating the alteration of paracellular permeability, changes in cytokine secretion, and transcriptomic profiling of the cells within the chip.

Webinar Abstract

Colorectal cancer (CRC) is one of the deadliest cancers worldwide with over 900,000 people dying from the disease each year (Siegel et al., 2021). In the United States, the 5-year survival rate for patients with metastatic CRC is less than 15% (Siegel et al., 2020). To address this dismal outcome, there is an urgent need to better understand and ultimately control aspects of cancer progression.  

In a recent paper published in iScience, researchers from the Lawrence J Ellison Institute for Transformative Medicine describe an in vitro Organ-Chip model that emulates in vivo tissue structure and the tumor microenvironment (TME) to better understand intravasation, an early step in metastasis.  

In this on-demand webinar, Dr. Mumenthaler discusses recent advancements made through combining Organ-Chip models with high content imaging and mass spectrometry-based metabolomics to improve our understanding of ​microenvironmental contributions to colorectal cancer progression. 

 Study results that will be discussed:  

• Development and characterization of CRC-on-chip 
• Metabolic comparison of Intestine Chips versus CRC chips 
• Examination of tumor cell intravasation 
• CRC cells exhibit phenotypic heterogeneity during intravasation 
• Mechanical and biochemical cues from the TME impact CRC invasion 

Organ Model: Intestine (Duodenum)

Application: Model Development

Abstract: In vitro models of human organs must accurately reconstitute oxygen concentrations and gradients that are observed in vivo to mimic gene expression, metabolism, and host-microbiome interactions. Here we describe a simple strategy to achieve physiologically relevant oxygen tension in a two-channel human small intestine-on-a-chip (Intestine Chip) lined with primary human duodenal epithelium and intestinal microvascular endothelium in parallel channels separated by a porous membrane while both channels are perfused with oxygenated medium. This strategy was developed using computer simulations that predicted lowering the oxygen permeability of poly-dimethylsiloxane (PDMS) chips in specified locations using a gas impermeable film will allow the cells to naturally decrease the oxygen concentration through aerobic respiration and reach steady-state oxygen levels <36 mm Hg (<5%) within the epithelial lumen. The approach was experimentally confirmed using chips with embedded oxygen sensors that maintained this stable oxygen gradient. Furthermore, Intestine Chips cultured with this approach supported formation of a villus epithelium interfaced with a continuous endothelium and maintained intestinal barrier integrity for 72 h. This strategy recapitulates in vivo functionality in an efficient, inexpensive, and scalable format that improves the robustness and translatability of Organ Chip technology for studies on microbiome as well as oxygen sensitivity.