RAPID: CLEARED: Culture of Living-biopsies for Emerging Airway-pathogens and REspiratory Disease

The ongoing COVID-19 pandemic has highlighted the lack of human cell culture models available for studying this virus, and the devastating consequences of this shortcoming as it relates to human health and disease. The proposed project, known as ?CLEARED? for Culture of Living-biopsies for Emerging Airway-pathogens and REspiratory Disease, combines cutting-edge technologies in 3D-printing, soft tissue engineering, artificial-intelligence-enhanced imaging, human lung biology, and virology to understand the spread of COVID-19 in lungs. This will increase the knowledge of SARS-CoV-2 biology and transmission. The researchers have developed the technology to grow portions of lung into living 3D-printed tissue structures that resembles the architecture found in the lung in a liquid-like-solid matrix. Thus, this system more closely resemble the environment in living humans versus standard cell culture. After infecting these samples with SARS-CoV-2 virus, advanced imaging of these ?living biopsies? will be used to study virus spread from cell to cell, and the efficacy of therapeutic treatments. Outcomes of the proposed research include: (i) Validating a standard model system using human lung biopsies and known diagnostics in response to SARS-CoV-OC43 infection; (ii) Determining how the disease develops and spreads in biopsies infected with different human and bat coronavirus strains. It is expected that this system will allow scientists to better understand virus transmission and prevention. This project also supports the training of three graduate students, leading to an increase in future workers to drive the bioeconomy.

The proposing team hypothesizes that controlled perfusion of SARS-CoV-2 in 3D culture models of human respiratory microtissue explants can recapitulate early stages of SARS-CoV-2 infection and COVID-19 disease. To test this hypothesis, PIs will establish a 3D model of viral infection using living microtissue explants of human bronchus and peripheral lung, quantify the early responses to viral infection using a novel 3D tissue culture platform, and determine the spatiotemporal pathogenesis of different human and bat coronaviruses strains. Preliminary data show that SARS-CoV-2 indeed infects the micro-tissues of bronchus and peripheral lung. This is a transdisciplinary team of investigators from Astronomy, Chemistry, Medicine, Engineering, Virology and lung biology. The proposed work is organized by two tasks. Task 1 will validate a standard model system using human lung biopsies and known host-response to SARS-CoV-2 infection. Readouts will include viral titer, cytokine production and spatiotemporal imaging of viral replication in response to coronavirus infection. Task 2 will determine the spatiotemporal pathogenesis of human lung biopsies infected with different human coronavirus strains (HCoV-OC43, HCoV-NL63, SARS-CoV-2) and one bat strain (btCoV-HKU3). The heterogenous nature of biopsies will alter the viral titer and cytokine production of biopsies compared to measurements in cell lines, and will provide superior information about progression and virus spread through tissues than standard cell culture technology. This RAPID award is made by the Physiological and Structural Systems Cluster in the BIO Division of Integrative Organismal Systems, using funds from the Coronavirus Aid, Relief, and Economic Security (CARES) Act.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.