Evaluation of SARS-CoV-2 Spike S1 Protein Response on PI3K-Mediated IL-8 Release

Borchers, Christina; Thyagarajan, Anita; Rapp, Christine M.; Travers, Jeffrey B.; Sahu, Ravi P.

A novel coronavirus related to a condition known as a severe acute respiratory syndrome (SARS) was termed as SARS Coronavirus-19 (SARS-CoV-2 or COVID-19), which has caused an unprecedented global pandemic. Extensive efforts have been dedicated worldwide towards determining the mechanisms of COVID-19 associated pathogenesis with the goals of devising potential therapeutic approaches to mitigate or overcome comorbidities and mortalities. While the mode of SARS-CoV-2 infection, its structural configuration, and mechanisms of action, including the critical roles of the Spike protein have been substantially explored, elucidation of signaling pathways regulating its cellular responses is yet to be fully determined. Notably, phosphoinositide 3-kinases (PI3K) and its downstream pathway have been exploited among potential therapeutic targets for SARS-CoV-2, and its activation modulates the release of cytokines such as IL-8. To that end, the current studies were sought to determine the response of the SARS-CoV-2 Spike S1 protein on PI3K-mediated IL-8 release using relevant and widely used cellular models. Overall, these studies indicate that PI3K signaling does not directly mediate Spike S1 protein-induced IL-8 release in these cellular models.