Project-004

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Respiratory infection with COVID-19 (the SARS-CoV-2 virus) has become pandemic. It has significant mortality and high morbidity, particularly among older patients. Death typically results from severe respiratory infection leading to ARDS. To bind to cell membranes, SARS-CoV-2 requires S protein cleavage either by the transmembrane serine protease, serine 2 (TMPRSS2), or by the cathepsin B and L (CatB/L) endosomal complex. TMPRSS2 can be inhibited by camostat methylate (CM), but CM is an irritant and may not be ideal for airway administration in patients with evolving ARDS. Of note, CatB/L is inhibited by endosomal alkalinization using ammonium chloride. As part of P01 project HL128192, we are studying the beneficial effects of airway alkalinization in patients with asthma and cystic fibrosis. We have a drug, alkaline glycine buffer (AGB), that is being produced for inhalation in our P01 project. This drug has an active IND and has excellent safety data. We therefore tested to determine whether AGB would cause intracellular alkalinization in cultured primary human airway epithelial cells obtained from our P01 subjects. It did; and the drug was well-tolerated by the cells in vitro (as it is in vivo). The next step is to determine whether AGB inhibits viral replication (plaque formation as a function of multiplicity of infection [MOI]) and viral entry (PCR) in our primary human airway epithelial cultures. To do this, we are partnering with our Indiana University BSL3 virology lab (Dr.’s Gilk and Robinson) who anticipate delivery of SARS-CoV-2 next week. Their lab has completed preparation, particularly in anticipation of this project. If in fact AGB inhibits viral replication, we would propose to discuss with the FDA the possibility that we could expand our IND, allowing a trial in patients at risk for respiratory distress associated with known COVID-2 respiratory disease. Ultimately, outcomes of this trial would be proposed to include: mortality (primary); as well as ICU length of stay and oxygen saturation index area under the curve (secondary). In the study proposed here, we plan to accomplish three Aims. First we will test the hypothesis that SARS-CoV-2 S-protein cleavage is inhibited by human primary airway epithelial cell alkalinization using AGB. Second, we will test the hypothesis that AGB exposure prevents SARS-CoV-2 replication and cell entry in primary human airway epithelial cells in vitro. Third, we will perform dose-response and time course experiments to determine whether the inhibition of SARS-CoV-2 replication and cell entry using AGB could be a realistic therapy.