Abstract
Coronaviruses constitute a global threat to human population since three highly pathogenic coronaviruses (SARS-CoV, MERS-CoV and SARS-CoV-2) have crossed species to cause severe human respiratory disease. Considering the worldwide emergency status due to the current COVID-19 pandemic, effective pan-coronavirus antiviral drugs are required to tackle the ongoing as well as future (re)emerging virus outbreaks. Protein kinase CK2 has been deemed a promising therapeutic target in COVID-19 supported by its in vitro pharmacologic inhibition and molecular studies on SARS-CoV-2 infected cells. CIGB-325 is a first-in-class synthetic peptide impairing the CK2-mediated signaling whose safety and clinical benefit have been evidenced in Covid-19 and cancer patients after intravenous administration. Here, we explored the putative antiviral effect of CIGB-325 over MDBK cells infected by bovine coronavirus (BCoV) Mebus. Importantly, CIGB-325 inhibited both the cytopathic effect and the number of plaques forming units with a half-inhibitory concentrations IC50 = 3.5 μM and 17.7 μM, respectively. Accordingly, viral protein accumulation at the cytoplasm was clearly reduced by treating BCoV-infected cells with CIGB-325 over time, as determined by immunocytochemistry. Of note, data from pull-down assay followed by western blot and/or mass spectrometry identification revealed physical interaction of CIGB-325 with nucleocapsid (N) protein and a bona fide cellular CK2 substrates. Functional enrichment and network analysis from the CIGB-325 interacting proteins indicated cytoskeleton reorganization and protein folding as the most represented biological processes disturbed by this anti-CK2 peptide. Altogether, our findings not only unveil the direct antiviral activity of CIGB-325 on coronavirus infection but also provide molecular clues underlying such effect. Also, our data reinforce the scientific rationality behind the pharmacologic inhibition of CK2 to treat coronavirus infections.
Competing Interest Statement
The authors have declared no competing interest.
