Emulating Immune Dysregulation by Trisomy 21 in a Multi-Organ-on-a-Chip System

Trisomy 21 (T21) is the molecular cause of Oown syndrome (OS), the most common chromosomal abnormality in humans worldwide. Lung disorders represent an important cause of morbidity and mortality in people with OS. Recurrent respiratory infections are particularly common in these individuals and are often life-threatening. However, despite recent studies reporting immune dysregulation and interferon hyperactivity in individuals with OS, there is a critical gap in our understanding on how extra genetic material from chromosome 21 influences homeostatic immune activity of the lung, and innate immune activation and mobilization of myeloid leukocytes, which are key mediators of acute immune response, to respiratory pathogens. Organs-on-chips are biomimetic, microfluidic, cell culture devices created with microchip manufacturing methods that contain continuously perfused hollow microchannels inhabited by living tissue cells arranged to simulate organ-level physiology. By recapitulating the multicellular architectures, tissue-tissue interfaces, chemical gradients, mechanical cues, and vascular perfusion of the body, these devices produce levels of tissue and organ functionality not possible with conventional two- dimensional or three-dimensional culture systems. They also enable high-resolution, real-time imaging and in vitro analysis of biochemical, genetic and metabolic activities of living cells in a functional tissue and organ context. The overarching goal of this project is to apply microengineering principles of organ-on-chip technology and develop a highly innovative and advanced, physiologically relevant model of organ-organ crosstalk to delineate impact of OS on homeostatic physiology of the lung and emulate clinically observed immune dysregulation due to T21. For this, we will create a microfluidically integrated murine multi-organ system that reproduces bone marrow (BM)-lung axis, using primary cells isolated from wild-type (WT) and Op(16)1/Yey mice (a murine model of OS). In parallel, to enable eventual translation of findings to humans, we will focus part of our efforts in generating human lung airway epithelia, vascular endothelium and hematopoietic stem cells from induced pluripotent stem cells of healthy subjects and individuals with OS to recreate Lung and BM tissue in the integrated multi-organ chip system. We will utilize these murine and stem cell-based platforms to study how T21 affects normal functioning and biological responses of the lung airway epithelium and endothelium. Moreover, we will in real-time analyze inflammation development and innate immune cells mobilization in response to challenge with inhaled airborne influenza virus particles. Our central hypothesis is that this dynamic living microsystem can recapitulate innate immune dysregulation in OS, reveal a pulmonary exaggerated immune response to challenge with inhaled infective agents, and enable discovery of previously unknown pathologies in airway function in the context of a multi-organ physiologically linked system.