A safe inhalational treatment prevents SARS–CoV-2 viral replication in human airway epithelial cells.

Because epithelial surface pH affects airway inflammation and host defense, we study the benefit of an inhaled buffer in patients with asthma. Inhaled Optate is designed safely to raise airway surface pH and is well-tolerated in humans. Epithelial infection with SARS-CoV2 is attenuated by raising intracellular pH. Here, we show that Optate raises intracellular pH in primary normal human airway epithelial (NHAE) cells without affecting cell viability. Moreover, doses of Optate used in our human trials inhibit SARS-CoV-2 replication in NHAE cells. Specifically, Optate almost completely ablates viral plaque formation and nucleocapsid protein expression, decreasing expression of critical processing proteins. Optate could be a candidate to evaluate for treating COVID-19 patients. Six samples of extracted and purified RNA from one line of primary human airway epithelial cells were processed for RNAseq analysis. This included three samples that were exposed to Optate for 48 hours and three control samples.