Kidney Microphysiological Analysis Platforms (MAP) to Explore SARS-CoV-2 Receptors and Inhibitors. A supplement to Parent Grant: Kidney Microphysiological Analysis Platforms (MAP) to Optimize Function

AbstractCoronavirus disease 2019 (COVID-19) has reached pandemic proportions. Pulmonary andkidney disease are highly prevalent serious consequences of infection with SARS-CoV-2. KidneyInjury Molecule-1 (KIM-1) was identified by Drs Bonventre and Ichimura as the most upregulatedprotein in the injured kidney proximal tubule. KIM-1, also called TIM-1, is a receptor for hepatitisA, Ebola, Dengue and possibly SARS-CoV1 viruses. We hypothesize that KIM-1 is a receptorfor SARS-CoV-2 both in renal tubule epithelial cells and in airway epithelial cells and thatJB1, our newly discovered small molecule inhibitor of KIM-1, and/or nanodisc-incorporated KIM-1 ectodomain can be prophylactic and therapeutic agents for COVID-19.We also hypothesize that we can use the high-affinity binding of KIM-1 and ACE2 to thevirus to create novel diagnostic devices for the virus. In Specific Aim 1 we will characterizethe role of KIM-1 in promoting SARS-CoV-2 entry into kidney and lung epithelia using kidneymicrophysiological analysis platforms (MAPs) on chip and develop an ultrasensitive chip for thehigh-throughput evaluation of potential SARS-CoV-2 binding inhibitors. KIM-1 and ACE2mediated endocytosis of SARS-CoV-2 biomimetic viruses (virosomes) will be compared in kidneyand lung epithelial cells. We will evaluate the effects of KIM-1-mediated spike proteins orbiomimetic virus cellular adhesion and uptake on production of paracrine factors which activateendothelial cells using a kidney-lung MAP. In order to understand binding and/or uptake kineticsof SARS-CoV-2 and characterize potential inhibitors we will develop an ultrasensitivenanoplasmonic triplets-based rapid lateral flow diagnostic chip for a rapid and sensitive inhibitionassay using the kidney-lung MAP. This approach can also be used for point of care diagnostictesting for the virus. In Specific Aim 2 we will evaluate the efficacy of JB1, soluble KIM-1ectodomain and nanodisc-incorporated KIM-1 or ACE2 to inhibit binding and internalization ofSARS-CoV-2 biomimetic viruses by kidney and lung cells using an integrated lung-kidney MAPon chip. Potential inhibitors will be tested to evaluate whether they compete with S-protein and/orbiomimetic virus binding and reduce IL-6 production. Binding affinity and kinetics between KIM-1variants or ACE2 either as free ectodomains or incorporated into nanodiscs and the Spike proteinwill be measured using MicroScale Thermophoresis (MST) and Biolayer Interferometry.