A NOVEL ANTIVIRAL THERAPEUTIC PLATFORM: ANCHORING IFN-β TO THE SURFACE OF INFECTIOUS VIRIONS EQUIPS INTERFERON-EVASIVE VIRIONS WITH POTENT ANTIVIRAL ACTIVITY

Abstract

Emerging viruses with the potential to cause epidemics and pandemics pose a severe threat to human health. Herein, we introduce a novel fusion protein platform that enables therapeutic targeting of distinct viral species based on host receptor specificity. Proof-of-concept studies focused on the human coronavirus NL63, which shares specificity for the ACE2 host receptor with the pandemic SARS-CoV and SARS-CoV-2 species. This antiviral fusion protein combines IFN-β with the soluble extracellular domain of ACE2 (IFNβ-ACE2). The physical linkage allows ACE2 to target IFN-β to the surface of NL63. The fusion protein is thereby designed to decorate virions with a surface array of IFN-β such that robust IFN-β signaling and upregulation of antiviral innate defenses invariably precede subsequent cellular infection. Both domains retained the predicted bioactivities in that the IFN-β domain exhibited potent anti-proliferative activity and the ACE2 domain exhibited full binding to the transmembrane SARS-CoV-2 spike protein. In virus-washed (virus-targeted) and non-washed in vitro infection systems, we showed that the pool of IFNβ-ACE2 targeted to the virion surface had potent and superior antiviral activity against NL63 infection compared to soluble ACE2, IFN-β, or the unlinked combination of ACE2 and IFN-β. The pool of IFNβ-ACE2 on the virion surface exhibited robust antiviral efficacy based on the preemptive targeting of antiviral IFN-β activity to the proximal site of viral infection. In conclusion, virus-targeted IFN-β places interferon optimally and antecedent to viral infection to constitute a new antiviral therapeutic strategy. The COVID-19 pandemic highlighted the need for new antiviral strategies to counter emerging pathogenic viruses. According to a recent study, there is a 38% probability of experiencing a similar pandemic in an individual’s lifetime, and this number may double in the next few decades. Our best chance of combating new outbreaks and pandemics is by being proactive rather than reactive. With continuous antiviral development, we can quickly eliminate and potentially obviate emerging problematic viruses. This platform can be re-engineered to target various viral species by altering the receptor domain. Additionally, the IFN-β domain can be modified to a different effector protein (e.g. IFN-α) with superior activity against the targeted virus