Pharmacological inhibition of bromodomain and extra-terminal proteins induces NRF-2-mediated inhibition of SARS-CoV-2 replication and is subject to viral antagonism [RNA-Seq]
Inhibitors of bromodomain and extra-terminal proteins (iBETs), including JQ-1, have been suggested as potential therapeutics against SARS-CoV-2 infection. However, molecular mechanisms underlying JQ-1-induced antiviral activity and its susceptibility to viral antagonism remain incompletely understood. iBET treatment transiently inhibited infection by SARS-CoV-2 variants and SARS-CoV, but not MERS-CoV. Our functional assays confirmed JQ-1-mediated downregulation of angiotensin-converting enzyme 2 (ACE2) expression and multi-omics analysis uncovered induction of an antiviral NRF-2-mediated cytoprotective response as an additional antiviral component of JQ-1 treatment. Serial passaging of SARS-CoV-2 in the presence of JQ-1 resulted in predominance of ORF6-deficient variants. JQ-1 antiviral activity was transient in human bronchial airway epithelial cells (hBAECs) treated prior to infection and absent when administered therapeutically. We propose that JQ-1 exerts pleiotropic effects that collectively induce a transient antiviral state that is ultimately nullified by an established SARS-CoV-2 infection, raising questions about the clinical suitability of iBETs in the context of COVID-19. Overall design: We performed parallel RNAseq and ATACseq on Calu-3 cells that were either naive (untreated, uninfected), treated with DMSO and uninfected, treated with DMSO and infected, treated with JQ-1 and uninfected or treated with JQ-1 and infected.