Human Airway Biomimetics for RSV and Other Respiratory Viruses

PROJECT SUMMARY - Project 2 Respiratory syncytial virus (RSV) is a major global respiratory pathogen. The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has resulted in an unprecedented crisis. Respiratory virus infections are often accompanied by gastrointestinal (GI) symptoms, but how respiratory pathogens cause GI disease is not understood. Moreover, a number of vaccines and therapeutics are being developed against these important pathogens, however, the existing models do not recapitulate the human experience. Small animal and non-human primate models fall short of mimicking human disease, and the human RSV challenge model is expensive and raises safety concerns. The requirement for BSL-3 facilities to study SARS-CoV-2 hampers data generation and increases cost. The human endemic CoV-NL63 can serve as a proxy for SARS-CoV-2 because it uses the same host receptor, angiotensin-converting enzyme 2. This project will develop an ex-vivo Human Challenge Airway Model by advancing our current 3-dimensional (3D) nose/lung model for studies on RSV and CoV-NL63 (proxy for SARS-CoV-2) to address the urgent need for a preclinical model that recapitulates the human disease. In collaboration with the Human Biomimetic Scientific Core, we have developed the expertise for isolating stems cells and generating 3D nose and lung organoid lines from nasal wash and bronchoalveolar fluids, respectively. Our internationally recognized expertise in RSV and other respiratory viruses uniquely positions us to develop advanced 3D nose/lung models for dissecting the pathogenesis of RSV (Aim 1), and develop airway and GI platforms with the Engineering Micro-Environment Core (EMEC) to evaluate molecular mechanisms driving the lung-gut axis of respiratory virus disease (Aim 2). We will select donors based on sex and age so that we can comprehensively study the complex interactions of host (age, sex, distinct airway sites, and immune cells) and virus, and the contribution of humoral and cellular immune responses in an HLA-restricted system. We will also evaluate the lung-gut axis by studying the downstream effects of RSV and CoV-NL63 airway infection on the GI tract by either direct (infection) or indirect (inflammation) pathways using lung-gut flow systems. This project is responsive to the RFA by the development of an advanced nose/lung model with increased complexity that includes humoral and cellular immunity, as well as defining novel mechanistic pathways in the lung-gut axis of respiratory virus disease. The global scientific community will benefit immensely from a 3-D nose/lung airway-virus model that recapitulates human virus infection and serves as a platform to evaluate therapeutics and vaccines.