Vascular, Cardiac, and Lung Alveolar Human Microphysiological Systems for SARS COV2 Drug Screening

Abstract: The appearance of SARS CVO2 in early 2020 has spurred efforts to limit the disease spread and developeffective treatments. The most promising long-term approach is a vaccine. While some vaccines are enteringaccelerated clinical trials, it may take 12 or more months before an effective vaccine is available. Even ifsuccessful, it may not be possible to treat everyone with a vaccine or the effectiveness of the vaccine may belimited. Given the severity of the disease among a number of those patients, alternative approaches to limitinfection should be developed. The goal of this proposal is to use human cardiac, vascular, and lung alveolarmicrophysiological systems (MPS) to identify possible compounds that block SARS COV2 entry into cells andtissues. While cell binding assays can be used to screen drug candidates, human MPS offer the advantage oftesting promising drug candidates under conditions encountered in the body. We propose a tiered approach inwhich primary cells and cells overexpressing angiotensin converting enzyme (ACE2) are used to identifypromising candidates that block SARS COV2 virus entry into cells, and vascular, cardiac, and lung alveolarMPS are used to provide a robust evaluation of drugs that block SARS COV2 binding. The first tier withindividual cell types enables a rapid screen and the screen with the microphysiological systems enables testingof the most promising candidates with the tissues most likely to be infected. We will develop the screeningassays using a pseudovirus with the SARS COV2 spike protein. In Aim 1, we will develop an assay forpseudovirus binding to ACE2 expressing cells by verifying binding and fusion to cells that express ACE2. Wewill whether the binding specifically involves the spike protein and determine the levels of binding sites on thecell types used in subsequent aims. In Aim 2, we will screen individual cells types for molecules that blockentry into the cell of pseudovirus expressing the spike proteins. Potential drug candidates include those thatpotentially block spike protein binding (e.g. spike proteins, Captopril, Lisinopril, human recombinant solubleACE2, and antibodies to the spike protein or ACE2) and those inhibiting Transmembrane Serine Protease 2(TMPRSS2), activity (e.g. camostat mesylate, nafamostat mesylate). In Aim 3, we will test most promisingcompounds in vascular, cardiac and lung microphysiological systems and compare against results from 2Dstudies. We will also examine the relationship between drug blocking and factors that affect ACE2 expression.